Microbiology Exam Three

Systemic Anaphylaxis Allergic Response

Systemic, often explosive reaction that involves airway obstruction and circulatory collapse. Chemical mediators cause system-wide vasodilation and bronchiole constriction. Blood pressure drops (shock) and can be fatal. Most common: insect stings, antibiotics, or serum injection. Inhaled and injected allergens trigger this more.

Rickettsia Rickettsii & RMSF

First symptoms are fever, chills, and headache. R Rickettsia infects the endothelium of the vasculature causing a spotted rash which result from leaking of RBCs from dilated blood vessels. Rash starts on palms and soles and then moves throughout the body. Rash accompanied by fever. Necrotic lesions occur and pinpoint hemorrhages may result in major organs leading to permanent central nervous system death, pneumonitis, cardiac problems, and death.

Septicemia Most Common Causes

Any bacteria can cause septicemia but the most common causes come from nosocomial infections. Bacteria from the skin and/or digestive tract making their way into the bloodstream because of an invasive medical procedure (like kidney dialysis for example.) Staphylococcus and Streptococcus genera are most common because they are prolific on humans and they release various toxins that can result in sepsis.

Sanitization

Any cleaning technique that mechanically removes microbes from inanimate objects. Soaps and detergents are commonly employed sanitizers.

Antigen

Anything that stimulates an immune response. Microbial cells or foreign cells.

Plasmodium Symptoms

As long as malaria is caught early on and treated properly, it is curable. The range of symptoms is highly varied, from mild or no symptoms to severe disease and even death. In general, common malaria symptoms are fever, chills, sweats, headaches, nausea and vomiting, body aches, and discomfort.

Zika Virus Transmission

As of May 2017, over 5000 cases of Zika have been reported in the United States, mostly from travelers returning from affected areas. There have however, been about 200 cases that are believed to have been caused by local mosquito-borne transmission (mostly Florida and Texas).

Binary Fission

Asexual reproduction where the mother cell increases in size and copies the genome. Both genomic copies are attached to the cell membrane and pulled toward opposite ends of the mother cell while new cell wall material is made down the center of the mother cell splitting it into 2 identical daughter cells.

Clostridium Botulinum Causes

Associated with eating canned or preserved foods, though it can occur as a result of infection with the bacterium itself.

Multiple Sclerosis (MS)

Attacks myelin sheath wrapped around nerve cells. Causes detachment and destruction, creating a lesion that may cause numbness, pain, or tingling in parts of the body. EBV raises risk of MS. Colder climates raise odds of getting MS.

Type 1 Diabetes Mellitus

Autoantibodies to insulin secreting islet cells of the pancreas recruit T cells. Islet cells are destroyed and insulin is not produced. Insulin is essential to cellular uptake of glucose.

Clonal Deletion

B cells are made in the bone marrow they go through a maturation process called clonal deletion. This process also happens in the bone marrow and screens the newly created B cells for any B cell that has a B cell receptor that might respond to self tissue. If somehow, a B cell with a bad receptor got by, it would result in antibodies that bind to self tissue and this would be catastrophic to the body! Imagine making antibodies that bind to the heart or liver or some other tissue... Those antibodies would trigger a full scale immune attack on the self tissue... Yikes!

Rickettsia Prowazekii & Epidemic Typhus

Bacteria enter endothelial cells and cause necrosis of vascular lining. Results in high fever, macular rash, joint and muscular pain. Can be complicated by personality changes, hypotension and gangrene. Historically present in areas of war, poverty, and famine.

Septicemia

Bacteria or toxins in the bloodstream.

Opsonization

Because the antibody is coating the antigen, phagocytosis of the antigen increases. Coating in antibody cell makes it easier for digestion.

Spastic Paralysis

Begins in jaw, truisms and facial muscles, risus sardonicus. If untreated, descends, causing paralysis of large muscle group (back spasm). Death often due to paralysis of throat and respiratory muscles.

Haemophilus Influenza

Believed to be causative agent of the flue, until the influenza virus was discovered. Responsible for many cases of acute bacterial meningitis, primarily by the b serotype. Transmission via direct contact, but not associated with epidemics. Can also cause epiglottitis, otitis media, sinusitis, pneumonia, and bronchitis.

Prophylaxis

Form of chemotherapy in which drugs are administered to prevent an infection from happening; used in cases of known or possible exposure.

Cascade Benefits

Found in many places in biology because it gives lots of sites for control. Several proteins get activated which means you can turn it on/off at multiple points. Other benefit is amplification of response. When first protein is activated, it goes on to activate several copies of the second protein each of which activates several copies of the third and so on. That means from one stimulus you can get a huge response!

Clostridium Botulinum Presence

Found worldwide and commonly inhabits soil and water, wand the intestinal tract of animals.

Cytokines

General class of messenger molecules that include interleukins and others, and help the immune system response.

Zika Virus Symptoms

Generally a mild infection in adults, often causing few or no symptoms, but can be passed from an infected woman to her developing fetus, leading to microcephaly and other severe fetal brain defects.

Genetically-Engineered (or Recombinant) Vaccines

Genes for a particular pathogen's antigen is inserted into a plasmid vector. The plasmid is then cloned into an appropriate host. In the example above, the gene for the Hepatitis B surface antigen is inserted into a plasmid and cloned into yeast cells. The yeast cells are then stimulated to synthesize and secrete the protein product (the hepatitis B surface antigen), which is then harvested and purified to be used as a recombinant vaccine.

Some Factors that may be related to Autoimmunity

Genetics Infection Being Female Environmental Factors

Yersinia Pestis

Gram - bacillus that is harbors by rodents. Fleas can also pass the bacteria to humans or products. Bubonic plague. Symptoms are feverish with body chills, headaches, and a swollen tender lump (lymph node). Endemic.

Francisella Tularensis

Gram - bacillus. Once the bacteria get into the human, they are ingested by local macrophages, but instead of being killed off by the microphage, the bacteria actually survive inside of it and spread inside the body by movement of macrophages. Endemic.

Borrelia Burgdorferi

Gram - spirochete that causes Lyme disease when transmitted by black-legged ticks into humans. Life cycle is complex and relies on at least two hosts, mouse and deer, but can occasionally accidentally pass it to a human. Endemic, but not evenly spread in the USA because it is seasonal/geographical and relies on certain species of ticks, mice, and deer.

Neisseria

Gram -, bean shaped diplocci. None develop flagella or spores. Residents of mucous membranes of warm-blooded animals. Strict parasites, do not survive long outside of the host. 2 primary human pathogens: Neisseria gonorrhoeae, neisseria meningitidis.

Streptococcus Pneumoniae Cultivation and Diagnosis

Gram stain of specimen-presumptive identification. Quellung test for serotype identification. Culture on blood agar plate: alpha hemolytic, optochin sensitive.

Nonionizing Radiation

Best exemplified by Ultraviolet (UV) rays, which have much less penetrating power but can still mutate DNA by forming abnormal linkages among adjacent bases known as pyrimidine dimers. These pyrimidine dimers interfere with DNA replication and transcription, leading to the inhibition of growth and cellular DNA. UV radiation is usually directed at disinfection rather than sterilization.

Clonal Selection

Binding of antigen to the b cell with the correct receptor. Afterwards, they digest the antigen into little pieces and place it on the MHC2; cell that interacts with MHC2 is T helper cell (TH).

Brucella Causes

Brucellosis or undulant fever, a flu-like disease with a fluctuating pattern of fever lasting weeks to a year. Temperature undulations also cause drenching sweats in late afternoon/evening.

Direct Fluorescence Antibody Test

Buy antibodies connected to fluorescence sample and put it over sample. If fluorescence, patient had substance.

Imunoglobulin Classification

By constant region.

Viral Meningitis aka Aseptic Meningitis Tests

CSF appeared clear, with normal glucose levels but elevated protein levels. A CSF gram stain did not reveal any bacteria and all cultures for microorganisms were negative.

Acanthamoeba

Can wreck havoc on our brain tissue, causing encephalitis. Encephalitis caused by an amoeba is categorized as amebic encephalitis.

Neisseria Meningitidis Virulence Factors

Capsule Adhesive fimbriae IgA protease Endotoxin 12 strains: serotypes A, B, and C cause most cases.

Examples of Subunit or Acellular Vaccines

Capsules - pneumococcus, meningococcus Surface protein - anthrax, hepatitis B Exotoxins - tetanus, pertussis (these acellular vaccines are known as toxoid vaccines since they use inactivated toxins in the vaccine preparation)

West Nile Encephalitis

Caused by the West Nile Virus (enveloped, RNA virus) which can also cause viral meningitis.

Rickettsia Typhi

Causes endemic typhus (or murine typhus). Reservoir is infected mice and rats and it is transferred to humans via fleas. In the USA, most reported cases arise sporadically among workers in rat-infested industrial sites. Causes a milder disease than epidemic typhus (R. prowazekii) with symptoms also including fever, rash, headache, muscle aches, and malaise.

Epstein-Barr Virus (EBV)

Causes mononucleosis. Over 90% of people have this virus by middle age, though usually it is asymptomatic. Part of a large family of viruses called Herpesviruses that include pathogens like Herpes Semplex Viruses 1 and 2 (which cause cold sores and genital herpes), the Varicella Zoster Virus (causing chickenpox and shingles), and Cytomegalovirus (causing mononucleosis) and others.

Antisepsis

Chemical agents that are applied to the body to destroy or inhibit vegetative pathogens.

Clonal Expansion

Clonally selected b cell rapidly reproduces; some of those created cells are memory b cells, other are plasma cells (antibody secretors).

Tetanus Presence

Common resident of soil and GI tracts of animals.

Cascade

Complement acts as a cascade which means the first protein activates the second and the second activates the third and the third activates the fourth and down the line until all of the proteins become activated.

Reaction to Foreign RBC Antigens

Complement, agglutination, hemolysis. Leads to lyses of not only foreign RBCs but the other RBCs, often leading to death.

Nonpolio Enteroviruses

Coxsackie viruses and echovirus are the most common cause of viral meningitis. Similar to poliovirus in infectious characteristics but less virulent. In addition to symptoms of viral meningitis, rash, diarrhea, or upper respiratory symptoms may be present.

DNA Vaccines Available for Pathogens

Currently, DNA vaccine trials are being performed for pathogens that have proven difficult to create whole cell or acellular/subunit vaccines for. These include Lyme disease, Hepatitis C, Herpes Simplex, Influenza, Tuberculosis, and Malaria.

Tetanus Prevention

DTap vaccine containing tetanus toxoid. Toxoid vaccine has been rendered nontoxic but is still capable of eliciting the formation of protective antitoxin antibodies. Childhood immunization provides protection for 10 years, tetanus booster shot needed every 10 years.

Activation of T Helper 1 Cells

Dendritic cell or macrophage acting as an APC ingest and digest an antigen. APC presents the antigen on MHC2. T helper binds to the antigen on MHC2 with it's T cell receptor and CD4. APC releases Interleukin 1 (IL1) to cause the T helper to differentiate into a T helper 1. The T helper 1 releases IL2. The IL2 activates lots of different immune cells including Cytotoxic T cells, Natural Killer cells, Macrophages and other T helpers.

Spread of Dengue Fever

Dengue is endemic to Southeast Asia and India where mosquitoes transmit this enveloped RNA virus. There have also been epidemics in South America, the Caribbean and even into Mexico (which is pretty far from the equator where this mosquito usually lives).

Killed or Inactivated Whole Cell Vaccines

Desired pathogen is cultivated and then treated with heat, chemicals (like formalin), or some agent that kills the microbe but does not destroy its antigenicity. These killed cells or inactivated viruses will stimulate immunity. Whole cell vaccines often require a larger dose and more boosters to be effective.

Enzyme-Linked Immunosorbent Assay (ELISA)

Direct ELISA detects antigen in patient's serum using a specific antibody. Positive result is visualized when a colored product is released by an enzyme-substrate reaction. Indirect ELISA detects antibodies in patient's serum against a specific antigen. Positive result is visualized when a colored product is released by an enzyme-substrate reaction.

Alexander Fleming

Discovered antibiotics; which are mostly natural chemical products made by soil, bacteria, and viruses. Antibiotics are used to kill bacteria inside of our patients just like they are naturally used to kill bacteria in the soil. Lots of research and development goes into investigating soil samples to find new antibiotics or synthesizing new compounds that act similarly.

Bacteriostatic

Drugs inhibit the growth of the microbe as long as they are present but when you remove the drug, the bacteria can start growing again.

Bacteriocidal

Drugs permanently kill the bacteria and when the drug is removed the bacteria will still remain dead.

Desiccation

Drying vegetative cells. Various microbes that are exposed to normal room air gradually become dehydrated, or desiccated, which leads to metabolic inhibition. Can be a valuable way to preserve food because it reduces the amount of water available to support microbial growth. It is, however, not an effective means of microbial control since many cells will grow when water is returned.

Amoeba Encephalitis Diagnosis

Due to the rarity of amebic encephalitis, the speed of the infection and it's severity, the majority of cases (~75%) are diagnosed at autopsy, when amoeba cysts are found in the patient's brain tissue.

EBV Links to Cancer and Autoimmunity

EBV has been linked to the development of several types of cancer particularly in high risk groups. Virus infects the B lymphocytes located in lymph nodes and if the patient has a compromised immune system (often by co-infection), virus can cause cancerous changes to the B cell resulting in Burkitt's lymphoma. There is also a link between EBV and the development of Multiple Sclerosis which is an autoimmune disease.

Poliovirus

Etiological agent of poliomyelitis; an acute viral infection of the spinal cord that can cause neurons-muscular paralysis. Spread via feces and contaminated water. Virus is ingested and can survive in stomach acids. Most infections are short term and mild, causing non-specific symptoms, meningitis, and/or diarrhea. Virus can spread to spinal cord and brain causing flaccid paralysis and withered limbs.

T Cell Receptor

Feels the antigen and MHC2 because T cell receptors need to see both. Helper molecule is CD4, which acts as a docking protein assisting the T cell receptor in binding. First step in B cell activation; causes B cell to release interleukin 4 (IL4) causing T helper to differentiate into T Helper 2 cell.

Viral Meningitis Symptoms

Fever Headache Photophobia Stiff Neck

Haemophilus Influenza Prevention

Haemophilus Influenzae type b was previously a major cause of meningitis in young children. Subunit vaccine Hib dramatically declined the rates over the past years.

Localized or Atopic Allergies

Hay fever/allergic rhinitis. Asthma. Eczema. Food or drug allergies. Genetically, more likely to be allergic to an allergen by same portal or entry, but not so much the same allergy itself. Hormonal link; allergies change as you age.

Bacterial Meningitis Symptoms

Headache, fever, nausea, vomiting, and stiff neck.

Acute Bacterial Endocarditis Symptoms

Fever, anemia, abnormal heartbeat and it can look like heart attack symptoms with side pain and petechiae (purplish red discolorations indicating vascular hemorrhage.) With the rise of IV drug use in Southern California over the past couple of years, this condition has increased in our area.

B Cell Maturation

Helps avoid dangerous B cells. Clonal deletion process where any b cells responding to self tissue are destroyed, before clonal selection occurs after maturation.

EBV Mononucleosis Symptoms

High fever, swollen lymph nodes, sore throat, extreme fatigue, head and body aches, swollen liver, and/or spleen and a rash. Most are asymptomatic and fully recover without ever knowing they were infected.

Streptococcus Pneumoniae Epidemiology and Pathology

Humans are the principal reservoir carrying the pneumococcus in their nasopharynx. From 5-50% of all people carry it as normal flora in the nasopharynx; infections are usually endogenous. Very delicate, does not survive long outside of its habitat.

Colorado Tick Fever (CTF)

Most common tick-borne viral fever in the U.S., primarily in the Rocky Mountain states. This infection is caused by the Coltivirus which is a non-enveloped RNA virus spread by the Wood Tick.

Lymph Fluid

Once they get into the bloodstream and the heart pumps them into a capillary bed, the capillaries are leaky enough that the cell/fluid/protein/pathogen can move through the capillary wall and out into tissues. The nearby lymph vessels then collect/drain the fluids from the tissues and eventually move the fluid back to the circulatory system and around and around the fluids move. Therefore, anything that gets into the body (whether inhaled, ingested or entered through a cut) eventually winds up in the lymph fluid, making lymph fluid an excellent place for the immune system to monitor for pathogens.

Genetics & Autoimmunity

It appears that many autoimmune conditions may have some genetic component. This doesn't seem to be a direct cause but a predisposition that increases the likely hood of developing autoimmunity at some time in the future.

Narrow Spectrum Antibiotics

Kill a specific type or group of bacteria (like only Gram positives for example).

Broad Spectrum Antibiotics

Kill a wide range of microbes (like both Gram positive and Gram negative, or aerobes and anaerobes).

Streptococcus Pneumoniae

Leading cause of bacterial meningitis in all age groups and causes 60-70% of all bacterial pneumonias. Small Gram+ lancet shaped cells arranged in pairs (diplococcus) or short chains.

Treating Viral Meningitis

Less severe than bacterial meningitis with most patients getting better on their own (even without treatment, self-limited). Often acetomenaphine.

Infant Botulism

Occurs most frequently in infants less than 1 year old. Is the most common form of botulism in the USA. The infant ingests spores in dust or honey. Immature GI tract flora permits spore germination and growth of vegetative cells. Symptoms include constipation, generalized weakness, weak crying, poor feeding, lethargy, loss of head control (floppy baby syndrome), and possible respiratory arrest.

Why do warmer temperatures increase growth rate?

On a molecular scale, heat is molecular movement and the warmer the temperature is, the faster the molecules are moving around. As molecules move faster in the cell, it becomes more and more likely that an enzyme will find it's substrate and complete it's reaction. This is why enzymes tend to work faster as the temperature increases, they are more likely to find their substrates! Eventually, however, the temperature will get hot enough to denature enzymes and then growth rates drop quickly.

T Helper 2 Cell

Release more IL4 along with another cytokine called B cell growth factor. The combination causes B cell to start dividing and go through clonal expansion, producing memory B cells and plasma cells.

Disadvantages of Live Vaccines

Require special storage. Can be transmitted to other people and potentially cause infection in immunocompromised individuals. Can conceivably mutate back to virulent strain.

Acute Bacterial Endocarditis

Result of septicemia where bacteria from the bloodstream begin to grow on the heart valves producing vegetations that inhibit proper valve function which can lead to cardiac malfunction, stroke and even death. Any septic bacteria is capable of growing on the valves, most commonly caused by Staphylococcus aureus finding it's way to the heart.

Antibiotic Resistance

Rise of "superbugs" in response constant antibiotic exposure is a public health crisis. Random mutations and natural selection have lead to antibiotic resistance and resistance spreads through transformation and conjugation between bacteria.

MHC1

Self tag found in all body cells except RBCs. Molecule that the cytotoxic T cell attaches to while it looks for cancerous and virally infected cells.

Immune Serum Globulin (ISG)

Sometimes called gamma globulin. Antiserum that contains antibodies extracted from pooled blood of at least 1000 human donors. Since many donors have been immunized for many diseases, they contain antibodies that can be concentrated to increase potency and eliminate potential pathogens to patients who receive the ISG concentrates. A treatment of choice in preventing measles and Hep A and in replacing antibodies in patients who are immunodeficient. Most forms of ISG are injected intramuscularly and the protection they provide lasts 2-3 months.

Alternative Pathway

Some pathogens have components that trigger complement activation on their own. This is not a benefit to the pathogen because it will lead to their destruction but our immune system can recognize some pathogens this way.

Antigenic Determinant

Specific part of the antigen that the antibody binds to.

Antibiotic Terminology

Spectrum, bacteria (bacteriocidal vs bacteriostatic), viruses (viriocidal and virostatic), fungus (fungicidal and fungiostatic) and even more generally you sometimes see these terms used globally for microbes (microbiocidal and microbiostatic).

Bacterial Meningitis Tests

Spinal tap shows cerebrospinal fluid (CSF) with a cloudy white appearance, a high WBC count (especially neutrophils), low glucose levels, and elevated protein levels. Gram Stain of CSF revealed gram-negative diplococci, with culture that grow on both chocolate agar and thayer-martin agar. Rapid tests for capsular polysaccharide.

Wound Botulism

Spores enter a wound or puncture much as in tetanus, but the symptoms are similar to those of food-borne botulism. Increased cases are reported in injection drug users.

Botulinum Food Poisoning

Spores present on food when gathered and processed for canning. If reliable temperature and pressure are not achieved, air will be evacuated but spores will remain. Improper canning of food, especially home-made canned vegetables, smoked meats and cheese spreads, does not kill spores and anaerobic conditions favor spore germination and vegetative growth. Potent toxin, botulinum, is released.

Apicomplexan Life Cycles

Sporozoite - motile, infectious stage. Once inside the host cell, sporozoites asexually reproduce to form merozoites. Merozoite - result of sporozoite asexual reproduction inside a host cell. Non-motile, asexually reproduce within host cells to produce more merozoites. Gametocytes - cells capable of sexual reproduction, produce gametes. Develop from merozoites.

Pandemic

Spread of an epidemic across multiple continents. I.e. ebola or HIV.

Rickettsia Prowazekii

Spread via human louse with humans serving as the only host and reservoir. Louse defecates bite wound or feces scratched in. Etiological agent of Epidemic Typhus (or Louse-Borne Typhus). Transfer of lice is increased by overcrowding, infrequent changing clothes, sharing clothes, and poor hygiene. Low incidence in USA but still present in regions fo Africa, Central America, and South America.

Pathology of Tetanus

Spres enter through deep implantation and germinate in anaerobic tissue, where they grow and release toxin. Vegetative cells release tetanus toxin (tetanospasmin) which blocks muscle relaxation.

Ebola Origin

Started in Guinea Although the natural reservoir has not been identified, scientists believe humans first become infected through contact with an infected animal such as a fruit bat or primate (this is known as a spillover event). It appears that Ebola is carried in wild animals and can cross into humans when they handle or eat "bushmeat" (wild animals hunted for food). No evidence to show casual contact transmission, only way to contract Ebola is through contact with body fluids of infected or diseased humans/animals. Means that animal lab workers, health care workers, and other first responders are the most likely to acquire these infections if an epidemic does develop.

Yellow Fever Symptoms

Starts with flu-like symptoms (fever, weakness, aches, nausea, etc.) and most patients recover in a few days but about 15% of patients develop the hemorrhagic fever and half of the more serious cases lead to death.

Botox Cosmetic Treatment

Super-diluted botulinum toxin is injected into wrinkly areas to create controlled muscle weakening. Toxin wears off so repeat injections are given every 4-6 months.

Ebola Virus Explained How Your Body Fights for Survival Video

Survives by infection. Dendritic cells activate killer t's, b cells, and helper ts. Ebola attacks dendritic cells by binding to receptors for cell transport. Takes over infected cell and disables protective mechanisms. Eliminates alarm signals while rapidly multiply. Natural killer cells kill infected cells, but are also infected so they die too. Also infects guard cells; macrophages and monocytes, manipulates them to signal to cells making blood vessels to release fluids into the body. Neutrophils are activated but cannot help fight, only signal to release more fluids, causing internal bleeding. Attacks liver causing organ failure and more internal bleeding. Last effort cytokine storm hurts virus but leaves lots of collateral damage in blood vessels. Not enough blood left to save the rest of the body, not enough oxygen to organs, so the organs die.

Bubo

Swollen lymph node.

Examples of Autoimmune Diseases

Systemic Lupus Erythematosus Type 1 Diabetes Rheumatoid Arthritis Multiple Sclerosis Celiac Disease

Infection & Autoimmunity

There are several infections that seem to raise someone's risk of developing an autoimmune condition. Infection with the Epstein Barr Virus seems to increase someone's risk of developing a number of different autoimmune conditions. This is also not a direct link since this is a very common human infection so again we are talking about something multifactorial and EBV may be a contributor but definitely not a direct cause.

Burkett's Lymphoma

This B cell cancer is mostly found in young children in central Africa and is thought to happen after a co-infection of EBV and Malaria. EBV has also been associated with other cancers including a nasopharyngeal carcinoma in older Chinese and African men but how that happens isn't understood yet.

Neisseria Meningitidis Vaccines and Antibiotics

Two antibiotic vaccines that contain specific purified capsular antigens. Antibiotic prophylactic treatment of family members, medical personnel, or children in close contact with patient.

Lymphatic System

Two especially important functions: 1. Collection and circulation of lymph fluid and 2. Defense. The lymphatic system removes excess fluid that has left the blood capillaries and entered the spaces surrounding body tissues. This fluid is transported through lymphatic vessels (that run parallel to the blood vessels) and eventually is returned back to the cardiovascular system by emptying the lymph fluid back into the bloodstream (once it reaches subclavian/jugular veins). That is how cells, fluids, proteins and pathogens can all be transported around the body.

Immunotherapy Preparations

Two forms; immune serum globulin (ISG) and specific immune globulin (SIG).

Allergies

Type 1 hypersensitivity reactions and they involve the production of IgE and the stimulation of mast cells. Localized or systemic. Allergen is an antigen that does not affect non-allergic people. Requires 2 exposure to the allergen: Sensitizing/IgE dose (first exposure to allergen) IgE is produced that binds to Mast Cells. Provocative dose (subsequent exposure to the allergen) Mast cells release chemical mediators.

Overreaction Hypersensitivity Reactions

Type 1; immediate (hay fever, anaphylaxis). Type 2; antibody-mediated (blood type incompatibilities). Type 3; immune complex (rheumatoid arthritis, serum sickness). Type 4; cell-mediated, cytotoxic (contact dermatitis, graft rejection).

ABO Blood Type and Transfusion Reactions

Type 2 hypersensitivity reactions involve IgG and IgM (antibodies normally made in the humoral responses) and these reactions are directed at foreign blood cells resulting in transfusion reactions and Hemolytic Disease of the Newborn. Type O lacks both the A and B antigens.

T Helper Cells

Type of T lymphocyte which are white blood cells. Made in bone marrow and mature in thymus. Found in lymphoid tissue including lymph nodes. Have a T cell receptor that will bind to MHC2 on an antigen presenting cell like a B cell. Have an additional receptor called a cluster of differentiation 4 (CD4). Influence other immune cells by releasing cytokines. Differentiate into either a T helper 1 cell or a T helper 2 cell.

Dengue Fever

Unfortunately there is no vaccine for this hemorrhagic fever virus which has seen a steady increase in infection rate over the past several decades.

Botulism Prevention

Use proper canning food techniques, sterilization. Bulging cans or bottles that look or smelled spoiled should be discarded. Botulinum toxin is rapidly inactivated at 100C (10min).

Moist Heat Autoclaving

Uses hot temperature and steam under pressure. Mode of Action: denaturation of proteins. Autoclaving achieves sterilization (121C/15psi/15min)

Yellow Fever Epidemics

have occurred outside of the areas we currently see it. There were some 17th, 18th and 19th century epidemics in North America including several around New Orleans and one in Philadelphia in 1793 which shut down the new federal government as politicians (including George Washington) fled the area that was the capital to avoid contracting yellow fever.

Positive and Negative Selection

T cells also go through a maturation process that helps them to differentiate between self and non-self tissues and those processes are called positive selection and negative selection. T cells are made in the bone marrow (like all blood cells) and then go through positive and negative selection in the thymus. If these processes aren't working properly, you might get T cells that attack some part of the body... Again, Yikes!

Moist Heat Pasteurization

Technique in which heat is applied to liquids to kill potential agents of infection and spoilage. Pasteurization achieves disinfection not sterilization. Goal is to kill vegetative pathogens while retaining the liquid's favor and nutrients. Widely used pasteurization technique is the flash method (15 seconds at 71.6C)

MHC1

The MHC1 self tag on self cells identifies the cells as "self" and prevents them from being attacked by phagocytes and other immune cells.

Subacute Bacterial Endocarditis

The causative agent here is usually a species from the Streptococcus genus. Several Streptococcal species in the Streptococcus viridans group are common inhabitants of the healthy human mouth. Dental surgery can provide a route for the bacteria to get into the bloodstream and then migrate to the heart to set up SBE. People with a history of heart murmur, endocarditis, Rheumatic fever or various other conditions should take an antibiotic before dental work to prevent this condition.

Dry Heat Hot Air and Incineration

The use of dry heat requires higher temperatures than moist heat but can also sterilize. Dry ovens - produce hot air that circulates in an enclosed environment: 150-180C denature proteins. Incineration - using a flame (i.e. bunsen burner) or electric heating coil to reach extremely high temperatures: 800-6500C complete oxidation and combustion of cells.

Environmental Factors & Autoimmunity

There are a number of environmental factors that seem to affect your risk of developing autoimmunity. Again, none of these things are causing it on their own, they may be one of the multifactorial bits that together increase someone's risk. Some environmental factors that seem to affect risk are UV light exposure, use of certain medications, smoking, etc.

Plasmodium

There are multiple species in this genera that are capable of causing malaria infections, and with varying degrees of severity. The Plasmodium genus is a part of the Apicomplexans.

How Does Complement Get Activated

1) Classical Pathway 2) Alternative Pathway 3) Lectin Pathway Regardless of how complement got activated, the result of complement activation is always the same. You always wind up with opsonization, inflammation and the membrane attack complex leading to the death of the pathogen.

Antibiotic Common Targets

1) Inhibition of Cell Wall Synthesis 2) Inhbition of Nucleic Acid Synthesis 3) Inhibition of Metabolic Processes 4) Inhibition of Protein Synthesis 5) Inhibition of Cell Membrane Disruption.

Immune Benefit to Complement

1) Opsonization 2) Inflammation 3) Membrane Attack Complex When the complement cascade gets activated, all of these benefits are happening at the same time allowing the immune system to target and destroy the pathogen.

Treatment for Allergies

1. Avoid allergen. 2. Corticosteroids keeping plasma cell from synthesizing IgE and inhibiting T cells. Inhibit B cells and T cells. 3. Cromolyn acts on surface of mast cell; no degranulation. 4. Antihistamines, aspirin, epinephrine, theophylline counteract effects of cytokines on targets. Block histamine on target tissues.

How The Immune System Recognizes Self vs Non-Self

1. MHC1 2. Clonal Deletion 3. Positive and Negative Selection

Western Blot Test

1. Separate known antigen into bands using electrophoresis. 2. Proteins are transferred to a membrane. 3. Membrane is incubated with patient serum antibodies. 4. Antibodies are labeled with a dye or radioactive label.

Most Common Causes of Bacterial Meningitis

1. Streptococcus pneumoniae (Gram +) 2. Neisseria meningitidis (Gram -) 3. Haemophilus influenzae (Gram -)

Mechanical Vectors

Where the animal simply moves the pathogen from one location to another without participating in the lifecycle of the pathogen.

Biological Vectors

Where the animal that transmits the disease somehow participates in the lifecycle like the mosquitos will in encephalitis.

Rabies Transmission

Wild animals are reservoirs. Spread to humans via saliva during a bite or aerosol from bats. Enters through a bite and multiples at the trauma site for a week. Enters through nerve endings and advances toward the ganglia, up the spinal cord and to the brain. Virus migrates and replicates in salivary gland where it is shed in saliva.

Francisella Tularensis Transmission

Zoonotic pathogen found in wild mammals in the northern hemisphere. Can be passed to humans through cuts in the skin, conjunctive of the eye, or bits of a vector like ticks, flies, mites, and mosquitos. Has been used in bioterrorism.

Complement

2nd line defense. Classical pathway of antibody attaching to antigen and starting complement, forming a membrane attack complex to punch a hole and kill.

Endemic

A disease that is at a relatively steady frequency over a long time period in a particular geographic locale.

Bacterial Pathogens of the Cardiovascular and Lymph Systems

A few pathogens that do result in fever but without the capillary fragility leading to hemorrhagic symptoms: - Rickettsia rickettsii and Rocky Mountain Spotted Fever - Rickettsia prowazekii and Epidemic Typhus - Rickettsia typhi and Endemic Typhus - Bartonella henselae and Cat-Scratch Disease - Brucella and Undulant Fever (Brucellosis)

Vector

A live animal that transmits an infectious agent from one host to another.

Viral Infection of Encephalitis

Most common cause of encephalitis. Primarily from a wthup of viruses referred to as arboviruses.

Viral Meningitis

Most common meningitis.

Sterilization

A process that destroys or removes all viable microbes, including viruses and endospores. Any material that has been subjected to this process is said to be sterile.

Disinfection

A process that destroys vegetative pathogens but not bacterial endospores. Disinfectants are normally used only on inanimate objects.

Antigen Presenting Cell (APC)

A type of cell that makes MHC2. Remember that MHC2 is what T helpers bind to so these APCs are also the cells that can activate a T helper cell. Present foreign antigens on MHC2. 3 Types of Cells: 1) B Cells, 2) Macrophages, 3) Dendritic Cells.

Filtration Example

A vacuum assembly achieves filtration of liquids through suction. The pores are so tiny that complete sterilization can be achieved by only allowing liquids to pass and not microbial cells. Hospital rooms use High-efficiency particulate air (HEPA) filters to provide a flow of sterile air and sterilize rooms.

African Sleeping Sickness

A vector-borne disease found in sub-Saharan Africa caused by Trypanosoma brucei. The vector of T. brucei is the tsetse fly. There have been several major human epidemics of African sleeping sickness, the last epidemic lasting over 20 years! It began in 1970 and was not declared over until the late 1990s. T. brucei has also been shown to pass from mother to fetus, and to be transmitted through sexual contact. Symptoms include fever, headaches, joint pain, changes in behavior, confusion, sensory disturbances, poor coordination, and disturbance of sleep cycle.

Amoebic Encephalitis

Acanthamoeba species, Balamuthia mandrillaris, and Naegleria fowleri. Differences in the three types of amebic encephalitis are in the sources of exposure but generally these amoeba are found in the soil and/or in still, warm, freshwater sources like still lakes, hotsprings, drainage ditches, etc.

Malaria Spread

According to the World Health Organization, there were approximately 198 million clinical cases of malaria in 2013 alone and it was responsible for approximately 500,000 deaths. The countries in which malaria is known to occur are highlighted in the above map in red. With so many people and countries impacted, one would think that we would have eliminated it long ago.

Interleukin 1

Activate T helper cells to become T helper 1 when produced by bound APC.

Interleukin 4

Activates T helper cells to become T helper 2 when produced by the bound APC. Also produced by T helper 2 cells to help activate B cells.

Antibiotic Targets

Aim is to kill the bacterial cell without hurting the human cell, "selective toxicity".

Tetanus Treatment

Aimed at reducing level of toxemia. Patients given antitoxin in therapy with human tetanus immune globin (TIG). Control infection with penicillin or tetracycline. Patient may require a respirator, or tracheostomy is sometimes performed to prevent lung collapse.

CDC Response to Ebola Video

Airport officials screened people traveling from Ebola countries and monitored them for 24 days. Early care can help save people.

Apicomplexans

All members are parasitic to animals. They possess a specialized structure on one end of their cells, an apical complex, that is designed to penetrate host cells. They have complex life cycles, with both asexual and sexual phases.

pH and Growth

All organisms have a minimum pH for growth, a maximum pH for growth and an optimum pH for growth. Neutrophiles: These are organisms with an optimum pH in a neutral range, somewhere between a pH of 6-8. The vast majority of microbes are Neutrophiles. Acidophiles: They grow fastest at a pH below 6, in an acidic environment. Alkalinophiles: They grow fastest at a pH above 8, in a basic environment. There are very few of these alkalinophiles in nature. Acidotolerant organisms are a type of neutrophiles that grow fastest in a neutral environment but can grow in more acid than most microbes. So acidotolerant organisms have a broad pH curve but the peak is still in a neutral environment, i.e. staph aureus.

Sensitizing/IgE Dose to Subsequent Exposure to Allergen

Allergen enters into body by inhalation, ingestion, injection, etc. Enters lymph fluid then lymph node and binds to B cell (clonal selection). Is presented on MHC2 after ingestion and digestion to T Helper. B cell releases IL4 to make T helper 2, which releases IL4 and B cell growth factor for B cell to go through clonal expansion where it creates plasma cells and memory B cells. Typically causes plasma cells to make IgM, but in hypersensitivity reactions, leads to secretion of IgE antibodies which bind to the surface of mast cells. At second exposure, allergen attaches to mast cells, which then go crazy and release all chemical mediators, i.e. histamine, which flood the body and cause typically allergy symptoms (itching, hives, wheezing, red eyes).

Hypersensitivity Reactions

Allergies ABO Blood Type and Transfusion Reactions Autoimmunity

Immune System Problems

Allergy, hypersensitivity; exaggerated misdirected immune responses that damage self tissues, autoimmunity - abnormal responses to self Ag. Immunodeficiency - deficiency or loss of immunity.

Lymphocytes Nodes

Along the lymph vessels are small defense organs called lymph nodes, that filter the lymph fluid and house millions of B and T lymphocytes. As the fluid passes through the lymph nodes the B cells and T cells are ready to defend you and are looking for possible pathogens.

Doubling Time

Amount of time it takes for 1 round of binary fission. Can also be described as the amount of time it takes for the cell population to double in size. Dependent on species and conditions that the cell is in.

B Cell Receptor

An IgD antibody stuck to the B cell surface.

Epidemic

An endemic or sporadic disease that begins to grow and the number of new cases increase beyond the expectations for that population. I.e. influenza or measles.

Zika Virus

An enveloped RNA virus is the cause of Zika fever, and is spread by the bite of an Aedes mosquito.

Hypersensitivity

An exaggerated, misdirected immune response that can damage self tissues.

Growth

An increase in cell number or population size.

Sporadic Outbreak

An outbreak that cropped up suddenly and unpredictably. I.e. salmonella contamination in peanut butter a few years ago.

Dengue Fever Vector Control

Another infection where vector control is of prime importance to limit the spread of this disease. Researchers in Vietnam (where dengue fever is a leading cause of child mortality) have developed a low-tech approach to vector control. Local health officials urged local citizens to round up tiny crustaceans that are common in natural water sources and put them into water tanks and wells where they eat the mosquitoes and mosquito larva. Officials reported a complete elimination of dengue fever cases in communities where this strategy was used!

Agglutination Tests

Antibodies form cross-links across the whole cell, forming complexes that settle out and form visible clumps.

Systemic Lupus Erythematosus (SLE)

Antibodies made against own DNA (antinuclear antibodies). Most common symptom is butterfly rash on face. More common in Hispanics and blacks.

Precipitation Tests

Antibody cross-links particulate antibody, forming complexes that settle out and form precipitates.

IgM

Antibody secreted by plasma cells. A pentamer. Attach to antigen to stimulate destruction by obstinization, agglutination, neutralization, and complement fixation.

Specific Immune Globulin (SIG)

Antiserum derived from a more defined group of donors. Serum from patients who are recovering from an infection is collected. These patients are considered hyperimmune since they have produced a high number of antibodies against the disease they are recovering from. These defined donors have recovered from such infections as tetanus, chickenpox, and hepatitis B and thus their serum has a high concentration of antibodies against those pathogens or any exotoxins produced by bacterial infections. These globulins are preferable to ISG because they contain higher amounts of specific antibodies but their availability is often limited.

Specific Immune Globulin (SIG) Without Human Immune Globulin

Antiserum of animal origin can be used. Antisera has been produced in horses against botulism, rabies, and spider and snake bites. The drawback for some people is that horse antigens in animal antisera can stimulate an allergic reaction such as anaphylaxis. Like human immune globulins, these donated immunities can act instantly and protect patients.

Botulism Treatment

Antitoxin available that must be administered early for greatest effectiveness.

Complement

Part of our 2nd line immune defenses (just like inflammation and fever) and consists about 30 blood proteins that work together to destroy a wide variety of microbial invaders.

Rabies Treatment

Passive and active post exposure immunization; infuse the wound with human rabies immune globulin (HRIG) and globulin; vaccination with human diploid cell vaccine (HDCV), an inactivated vaccine given in 6 doses with 2 boosters. Control; vaccination of domestic animals, elimination of strays, and strict quarantine practices, live oral vaccine incorporated into bait for wild animals. Vaccine and immune globulin.

Complement Deficiencies

Patients with these are at higher risk of infections by multiple capsulated pathogens, particularly N. meningitidis.

Class IGM of Antibodies

Present as pentamer. Made as first-responder.

Neisseria Meningitidis Epidemiology and Pathogenesis

Prevalent cause of meningitis; sporadic or epidemic. Human reservoir, nasopharynx; from 3-30% of adult population, higher in institutional settings. Transmission by aerosolized respiratory droplets (esp in families or crowded situations such as military barracks or dormitories). Very rapid onset; neurological symptoms; endotoxin causes hemorrhage and shock, can be fatal.

Cardiovascular System

Primary function is to transport blood (carrying gases, nutrients, immune cells, etc..) throughout the body. Arteries carry blood away from the heart and into capillaries that surround all tissues. Capillaries allow for oxygen and nutrient exchange between the blood and tissues. Oxygen diffuses out of blood and into the tissues and carbon dioxide leaves tissues and is picked up by blood. Veins return the deoxygenated blood leaving the capillaries, back to the heart.

Cold Temperatures

Principal benefit of cold temperatures is that it is microbistatic, meaning it slows the growth of microbes in food and other perishable materials. Cold temperature are deadly for a few microbes but for the most part the cold merely retards the activities of most microbes. Refrigeration: 0-15C Freezing < 0C Used to preserve food, media, and cultures.

Oxygen and Growth

Reducing Medium: Thick liquid growth, contains a substance that absorbs ozygen or slows pentration of oxygen into medium; used for growing anaerobic bacteria. Aerobes have top growth, anaerobs have bottom growth, and facultative anarobes have growth throughout. Oxygen is technically toxic to all organisms since it causes free radicals, but aerobes have enzymes to get rid of those. Growth in a canister, on a petri dish with a gas pack pulling oxygen, making an anerobic environment, if it grows, the culture is anaerobic. In hospitals, using a hood to vacuum oxygen.

Zika Virus Vector Control

Related to dengue and yellow fever, so not surprising that vector control also plays an important part in limiting the spread of this disease.

Ionizing Radiation

Includes gamma rays, x-rays, and high-speed electrons to sterilize medical equipment and food products. This type of radiation has deep penetrating power that can break DNA and cause massive mutations and microbial death.

Clostridium Botulinum Symptoms

Incubation is 1-2 days. Causes dry moth, difficulty chewing and swallowing, flaccid paralysis, and would put you on a mechanical ventilator. Characteristically affects the muscles supplied by the cranial nerves first, causing eyelid drooping, double vision, and loss of facial expression. Descending muscular paralysis can lead to respiratory failure and death from stoppage of respiration.

Zoonosis

Indigenous to animals but naturally transmissible to humans. Can be bacterial in origin, viral, parasitic, or acellular pathogens.

Endocarditis

Infection of the inner heart lining and/or valves,

Encephalitis

Inflammation of the brain. Can cause flu-like symptoms, such as fever or severe headache. Can also cause confused thinking, seizures, or problems with senses or movement. Many causes can result in only mild flu-like symptoms or even no symptoms. Severe cases, though rare, can be life-threatening.

Bacterial Meningitis

Inflammation of the meninges (3 layers of membrane surrounding and protecting the brain). Begins when bacteria enter bloodstream, cross the blood-brain barrier, permeate the meninges, and grow in the cerebrospinal fluid.

Botulism

Ingested or secreted botulinum toxin travels to the neuromuscular junctions of the skeletal muscles. In normal state, neurons release acetylcholine, which cross the synapse and stimulate muscle contraction. In botulism, the toxin blocks the release of acetylcholine and keeps the muscle from contracting. Results in flaccid paralysis.

Rh Factor & Hemolytic Disease of the Newborn

85% of humans are Rh+. Anti-Rh antibody formed after exposure to Rh. Rh- mothers with Rh+ babies are given anti-Rh antibodies at birth to destroy fetal RBCs and prevent mom's development of anti-Rh antibodies. Hemolytic Disease of the Newborn if the baby survives attack of anti-Rh antibodies, leads to difficulty carrying oxygen.

Degermation

A cleansing technique that reduces the number of microbes on the skin. Examples include surgical handscrub and alcohol wipes.

Antigen Presenting Cell Process

Either way, ingests and digests an antigen and puts in on MHC2; either way, you get memory cells. T helper binds to MHC2; if antigen presenting cell is B cell, releases IL4 to cause T helper cell to become T helper 2, which release more IL4 and growth factor to encourage clonal expansion. T helper 2s can also secrete inhibitory cytokines to inhibit T helper 1s, which can become important because if the body has long term immune responses, it can damage self tissue. T helper binds to MHC2; if antigen presenting cell is macrophage or dendritic cell, releases IL1 to cause T helper cell to become T helper 1, which release IL2 and activate many cells in the immune system.

Clostridium Botulinum

Endospore forming, anaerobic, gram positive bacillus. In anaerobic environments, vegetative cells release the most potent microbial toxin, botulinum toxin.

Causes of Viral Meningitis

Enterovirus Poliovirus Coxsackie viruses Echoviruses West Nile Virus Measles and Mumps Viruses Herpes Simplex Viruses HIV

Tetanospasmin

Enters in local tissue and is absorbed by peripheral nerves and carried to target neurons in spinal column. Neurotoxin inhibits muscle relaxation by blocking the release of neurotransmitter for muscular contraction inhibition, causing muscular contraction inhibition, causing muscles to contract uncontrollably; spastic paralysis.

Yellow Fever

Enveloped RNA virus that can cause hemorrhagic fever. This virus is transmitted by certain species of mosquitoesand is, therefore, only found in parts of the world that currently harbor this mosquito including parts of Africa and South America along the the equator where the mosquito lives.

Ebola

Enveloped RNA virus that is one of the scariest due to its death rates, unclear origins, and horrific symptoms. Starts infection in immune cells including macrophages and T helper cells. This eventually leads to a huge "cytokine storm" which means lots of cytokines are released at once. All of this immune activity causes vascular leakiness which means blood and fluids leak out of capillaries all over the body and this causes the hemorrhagic fever to develop.

West Nile Virus

Enveloped RNA virus. Transmitted by mosquitoes and circulates in birds (particularly lethal to crows). Humans, horses, and other mammals are "dead end" hosts. Infections can range from asymptomatic, mild fever (West Nile Fever) to fever with neurological symptoms. Meningitis more common in children. More severe symptoms in elderly ranging from poliomyelitis-like syndrome, encephalitis, flaccid paralysis, coma, and death.

Other Bacterial Causes of Bacterial Meningitis

Escherichia coli (Gram -) Streptococcus agalactiae (GBS) (Gram +) Listeria monocytogenes (Gram +) Mycobacterium tuberculosis (AFB)

Doubling Time Example

Escherichia coli has a doubling time of around 20 minutes in a warm and nutrient rich environment. So, if E. coli finds itself in a good environment, the entire population size will double every 20 minutes! That's incredible growth and, with the entire population size doubling every 20 minutes, that is a logarithmic growth pattern.

Membrane Attack Complex

Some of the complement proteins will form the membrane attack complex which is a hole that is punched in the pathogen's cell wall and, of course, kills the cell.

Yellow Fever Transmission

Eventually the mosquito was identified as the transmission vector for this disease and mosquito control efforts helped limit yellow fever in this country. There is now a vaccine that shows great efficacy in stopping this infection but is only given to those living in or traveling to areas where yellow fever is considered a risk.

Agglutination

Every antibody has at least 2 antigen binding sites, clumps antigens together making it easier for phagocytosis.

Roles of Chemical Mediators Released by Mast Cells

Ex histamine. Cause vasodilation, rashes, itchy skin, redness in tissues, bronchial constriction, triggering of nerves causing headaches.

Making B Cell Repertoire

Exons from immunoglobulin genes are randomly selected during the development of each B cell. This forms the B cell's receptor and determines the antibodies that will be made by future plasma and memory B cells. Therefore, each B cell is unique in its antigen specificity.

DNA Vaccines

Experimental types of recombinant vaccines where microbial DNA is inserted into a plasmid vector and the vector is directly introduced into a person. The principle intent is that human cells will pick up the plasmid and express the microbial DNA as proteins on the cell surface. These proteins will serve as antigens, causing B and T cells to respond, be sensitized, and form memory cells. The person will then be immunized against future exposure from the actual pathogen.

EBV Mononucleosis Transmission

Extremely contagious and passes easily through small amounts of saliva through kissing, sharing utensils or cups, coughing in close proximity, etc.

Secondary Response

If the pathogen returns, the Memory B cells are ready to react immediately. They do not have to wait for all of those checks and balances of the primary response, they immediately start to release HUGE quantities of their memory antibody, IgG. The entire primary response repeats itself here so you will get plasma cells eventually releasing the same amount of IgM as always but the really exciting thing is the IgG from the Memory Bs. This immediate and overwhelming amount IgG prevents reinfection by the same pathogen.

Vaccination Benefits

Immunized people have the benefit of an immune response to a future exposure that will be immediate, powerful, and sustained.

Serology

In Vitro diagnosis test to find antibodies in patient serum. Useful for its specificity and sensitivity.

Growth Curve

In a closed environment, bacteria exhibit a predictable pattern of growth called the growth curve. The steps of the growth curve are : Lag Phase, Logarithmic Phase, Stationary Phase and Death Phase.

Prophylaxis Examples

In dental procedures, patients are often pretreated with antibiotics prior to their dental work as a precaution against any saliva leaking into the bloodstream. Since the oral cavity is teeming with microbial life, this prophylaxis ensures that any bacteria that does enter the blood is immediately killed before it can lead to an infection. In the event of a growing epidemic (for instance an outbreak of meningitis from Neisseria meningitidis in a boarding school or military camp), mass prophylaxis is given to everyone exposed to the epidemic. The at-risk people are given antibiotics to prevent them from possibly developing meningitis. Immunotherapy is when a patient at risk of a particular infection is given a preparation that contains specific antibodies against that infectious agent.

Celiac Disease

In healthy intestine, tiny hairlike projections called villi absorb nutrients from food. When people with celiacs eat foods with wheat, barley, or rye, the body's immune system attacks gluten proteins in the small intestine. This immune response destroys villi, leading to nutritional deficiencies.

Live, Attenuated Whole Cell Vaccines

In these vaccines, the pathogens are cultivated but they go through a process that substantially lessens or negates the virulence of viruses or bacteria. These live and "weakened" pathogens are then injected into patients where they multiply to some extent, stimulating immunity, but because they have had their virulence factors removed they do not cause disease.

Plasmodium Life Cycle

Lifestyle with the sporozoites being transferred to the human host via a bite from a female Anopheles mosquito (#1). The sporozoites travel to the liver, where they infect the liver cells (#2). Inside the liver cells, the sporozoites divide asexually to produce the merozoites. After being packed full of merozoites, the liver cells burst, releasing the merozoites into the blood stream (#3). In the blood stream, the merozoites infect the red blood cells and asexually reproduce inside those red blood cells. A few of the merozoites turn into male and female gametocytes (#4). When a female Anopheles mosquito bites our host, the gametocytes are picked up along with the host's blood (#5). Inside the mosquito gut, the gametocytes mature and release gametes which fuse forming a zygote by sexual reproduction. Sporozoites are then produced which migrate to the mosquito's salivary glands, ready to be passed to the next human host when the mosquito has it's next meal.

Diagnosing Viral Meningitis

Looking for antibodies instead of looking for the pathogen itself. Antibodies are made in response to a pathogen, finding them in the patient indicates that the immune system is fighting that pathogen. Antibodies are specific so you can search a sample for antibodies to a specific pathogen like the Polio Virus compared to finding high levels of white blood cells which tells you there is an infection but doesn't identify the pathogen.

MHC2 Binding

MHC2 with foreign antigen binds to a T-cell receptor and CD4 on a TH cell. TCR specific for a particular antigen and self-MHC2. 1st step of T helper cell activation. After binding, the APC releases Interleukin-1 or Interleukin-4 to provide the 2nd step of TH activation.

Rickettsia Rickettsii

Most common rickettsial infection in NA. Tick-borne disease with small mammals serving as reservoir (squirrels, chipmunks, raccoons). Etiological agent of Rocky Mountain Spotted Fever (RMSF).

Interleukin 2

Made by T helper 1 cells to activate various immune cells like macrophages, natural killer cells, and cytotoxic T cells.

B Cell Growth Factor

Made by T helper 2 to activate B cells.

MHC2

Made by cells called antigen presenting cells. The B cell is one of these few antigen presenting cells that make MHC2. T helpers will bind to MHC2 via T cell receptor and CD4 when they activate the B cell. Present bits of digested foreign antigens.

B Lymphocyte Maturation

Made in bone marrow, in the bone marrow they then go through a maturation process called clonal deletion that happens in bone marrow too. Once mature, B cells go to lymph nodes and wait for their particular antigen, watching lymp go by. Group is called a repertoire. Each cell has a very specific b cell receptor binding to one antigen.

Rheumatoid Arthritis (RA)

Making antibodies against joint tissue. can cause pain, swelling, and deformity. As the tissue that liens your joints (synovial membrane) becomes inflamed and thickened, fluid builds up and joints erode and degrade. Treatment blocks inflammation.

Neisseria Meningitidis Meningococcus Infection

Meningococcemia; serious complication fo meningococcal infection caused by shedding of endotoxin into systemic circulation. Causes subcutaneous hemorrhages, called petechiae, on trunk and appendages. Can lead to necrosis of tissue in extremities and loss of limbs. Even treated meningococcal disease has a mortality rate of up to 15%.

Physical Means to control Microbes

Moist Heat - Autoclaving Moist Heat - Pasteurization Dry Heat - Hot Air and Incineration Cold Temperatures Desiccation Filtration Radiation - Ionizing or Nonionizing

St Louis Encephalitis

Mosquito-borne and the most common of all viral encephalitis cases in America with epidemics in midwestern and southern states; inapparent infections are very common. Also mosquito-borne and the SLE virus is an enveloped RNA virus.

Western, Eastern, & Venezuelan Eastern Equine Encephalitis (WEE, EEE, VEE)

Mosquito-borne enveloped, RNA viruses and cause more serious CNS involvement and encephalitis. Equine encephalitis viruses are all enveloped RNA viruses. The transmission cycle is identical to West Nile virus, with humans and horses being dead-end hosts. The EEE virus in particular is one of the most severe mosquito-borne diseases in the U.S. with ~30% mortality and significant brain damage in survivors. Mortality rates among horses with the eastern strain range from 70 to 90%.

Endotoxic Shock

Nasty form of septicemia caused by gram - organism in the bloodstream (an example would be sepsis from a perforated bowel that allowed gastrointestinal flora like Escherichia coli into to the blood.) Gram negatives have lipopolysacharrides in their outer membrane which acts as endotoxin when the cells die and release the LPS into the patient's blood. The endotoxin results in a severe drop in blood pressure that can be deadly.

Tetanus aka Lockjaw

Neuromuscular disease caused by clostridium tetanus, a gram +, anaerobic, endospore forming bacillus. Disease is deemed tragic because an infection produces very severe symptoms and yet it is completely preventable by immunization. Bacterial cells resemble a tennis racket or drumstick when round, terminal endospores are present. Neurotoxin causes episodes of spastic paralysis.

Internal Hemorrhage

Number of viruses can cause multi-system infection stat include destruction to the vascular system leading to this bleeding that can range between being relatively mild to life threatening. These viruses come from different viral groups but the common link is that they result in hemorrhage usually accompanied by a fever and sometimes a rash. Most of these infections are geographically limited by the mode of infection since they are spread by contact with infected animals or through the bite of particular vectors that are found in these environments.

Antibody Functions

Opsonization, agglutination, complement fixation and neutralization.

Advantages of Live Vaccines

Organisms can multiply and produce infection (but not disease) like the natural organism. Confer long-lasting protection. Usually require fewer doses and boosters.

Osmotic Pressure and Growth

Osmophiles: Live in high osmotic pressure environments. Halophiles: Live in high salt environments. Most microbes live in slightly hypotonic environments; hypertonic environments are usually very dangerous for microbes. All halophiles are osmophiles but not all osmophiles are halophiles; i.e. organisms living in high sugar concentrations like honey.

Stationary Phase

Overall cell number stays the same. Death rate = growth rate. Nutrient ran out, searching for what to grow on and possibly enter another logarithmic phase, or death phase if they don't.

Measles and Mumps

Paramyxovirus family; enveloped RNA with helical capsid. Spread via respiratory droplets. Measles can lead to complications involving brain damage from encephalitis. Mumps is known for causing parotitis, infection of parotid glands. Mumps meningitis affects ~50% of mumps patients and can occur before, during, or after the parotitis. Both are vaccine preventable with MMR vaccine.

Filtration

Physical removal of microbes by passing a gas or liquid through a filter with openings too small for microbes to pass through. Sterilizes heat sensitive liquids and air in hospital isolation units.

Meninges Layers

Pia mater touches brain. Arachnoid mater in middle. Dura mater on top. Cerebrospinal fluid between meninges. Enteroviruses affect these layers; (mumps, measles, herpes, viruses by blood feeding animals).

Polio Vaccination and Eradication

Post-polio syndrome; progressive muscle deterioration, occurs in 25-50% of patients infected with polioviruses in childhood. Two Vaccines: Salk Vaccines - injected inactivated (killed) poliovirus vaccine (PV) Sabin Vaccines - Attenuated (live) oral poliovirus vaccine (OPV) Vaccination in USA has stopped and global incidence of Polio has been significantly reduced to near eradication levels. Polio infections are now confined to a few pockets in Nigeria, India, Pakistan, and Afghanistan.

Antigenic Determinant

Precise part of antigen that the antibody binds to.

Class IGA of Antibodies

Present as dimers. Secretory component. Found in secretions from the body.

Class IgD of Antibodies

Present as monomers. B-cell receptor.

Class IgE of Antibodies

Present as monomers. Involved in allergy responses.

Class IGG of Antibodies

Present as monomers. Act as memory antibodies.

Rabies Symptoms

Prodromal phase: Fever, nausea, vomiting, headache, fatigue; some experience pain, burning, tingling sensations at site of wound. Furious phase: agitation, disorientation, seizures, twitching, hydrophobia. Dumb phase: paralyzed, disoriented, stuporous, progress to coma phase, resulting in death. Often diagnosed at autopsy where Negri bodies are seen in nervous tissue (brain).

Streptococcus Pneumoniae Virulence Factors

Pronounced capsule. 90 different capsular types have been identified using the Quellung Test (capsular swelling test using antiserum specific for a particular capsule type).

Antibodies AKA Immunoglobulins

Protein made by immune system in response to antigen. 4 different protein chains (2 heavy and 2 light).

Ecological Groups and Temperatures

Psychrophiles: Their optimum temperature for growth is under 10 degrees Celsius. These are organisms that thrive in the refrigerator or naturally grow in the permafrost for example. Mesophiles: Their optimum temperature for growth is in a moderate range, between 20 to 40 degrees C. The majority of microbes are mesophiles including all human pathogens. Thermophiles: Their optimum temperature for growth is hot, above 40 degrees C. These are organisms that live naturally in dessert soils or hot springs for example.

Measuring Growth

Quantify growth by spectraphotometer. Detects how much light passes through tube. Or measure cell growth by cell counter, slide with grid counter.

Radiation as a Microbial Control Agent

Radiation can be used to focus energy emitted from atomic activities to damage microbes. Two types of radiation to achieve sterility are ionizing radiation and non ionizing radiation.

Tetanus Fatality

Ranges from 10-70%, higher in cases involving delayed medical attention or head wounds. Low incidence in North America, mainly geriatric patients or intravenous drug users. In developing countries, accounts for several hundred thousand infant deaths yearly.

Ebola Outbreaks

Several epidemics of Ebola over the last 30 years when the virus crosses into humans and the lethality of the virus varies from one outbreak to the next. Most recent outbreak in humans was around 60% which is low for Ebola but incredibly high compared to most infections. This was more contagious than we have seen before and this allowed the epidemic to spread alarmingly. Not the last Ebola epidemic we will face. Only a matter of time before the virus spreads again and forms a new epidemic. This is why the CDC and WHO must be vigilant in their watch for emerging outbreaks and have updated, successful protocols developed and ready to implement. This most recent outbreak was the most widespread we have ever seen for Ebola and with the interconnected world we live in, it will surely have the ability to spread again in the future. Reminder of why stopping epidemics around the world is so vitally important regardless of where they occur. In addition to humanitarian reasons, if we don't work to limit the epidemic on the other side of the planet, it may wind up in our own backyard.

Logarithmic/Exponential Phase

Sharp increase in cell number. Entire population size doubles until they start running out of nutrients.

Amoeba Encephalitis Symptoms

Similar to other forms of encephalitis, can arise up to 9 days following exposure. Almost always fatal, death can happen after 18 days of infection.

Dengue Fever Symptoms

Similar to yellow fever, dengue infections start with severe flu-like symptoms that progress in severity to extreme headaches, muscle and joint pains. Symptoms are often more severe in children where the extreme pain has earned dengue the nickname "break bone fever" because patients literally describe the pain as though their bones are breaking. Most patients recover at this point but some progress to the hemorrhagic fever form of the infection where death rates increase dramatically.

Lag Phase

Slow increase in population size. Cells are adjusting to environment.

Rabies

Slow, progressive zoonotic disease caused by rabies virus. Rhabdovirus - helical capsid, ssRNA. Distinct, bullet-shaped envelope. Infection is characterized by a fatal meningoencephalitis with symptoms appearing dramatic and frightening.

Subacute Bacterial Endocarditis Symptoms

Slower progressing form of endocarditis where the patient experiences fever, weakness, dizziness and perhaps a heart murmur.

Bartonella Henselae

Small gram-negative bacilli related to Rickettsia family. Most common agent of Cat-Scratch disease. Carried by 40% of cats, especially kittens, and transmitted via cat scratches. Local papule appear at site of inoculation and the regional lymph nodes can become infected. Prevention by thorough determine of a cat scratch.

Rickettsia Genus

Small obligate intracellular parasites Gram-negative cell wall Nonmotile pleomorphic rods or coccobacilli Ticks, fleas, and lice are involved in their life cycle Bacteria enter endothelial cells and cause necrosis of the vascular lining- vasculitis, vascular leakage and thrombosis (blood clot within blood vessels).

Enteroviruses

Small, RNA viruses. Naked capsid. Resistant to acid, bile, and detergents. Transmitted by fecal-oral route. Can survive stomach acids when ingested.

Inflammation

Some of the complement proteins bind to the mast cells which starts the inflammatory process. The inflammation response will bring in more neutrophils and macrophages to phagocytize the pathogen.

Opsonization

Some of the complement proteins bind to the surface of the pathogen and stimulate it's phagocytosis and destruction by the white blood cells. Activated complement and antibodies are both capable of opsonization.

Being Female & Autoimmunity

The data is very clear that women, especially women between 15-50, are at a much higher risk for autoimmunity than men. Why is that? Generally speaking, the "extra X" chromosome in women does offer some extra immune protection and there are several diseases that seem to present more intensely in men than in women possibly because of the "extra X" benefit. (Interestingly, Covid-19 might be another example where the "extra X" is causing women to have less intense infection overall.) Is it possible that this "extra x" is actually a risk that increases autoimmunity because of this overactive immune state in some women? Maybe... There are many other different hypotheses but we just don't know yet.

Subunit or Acellular Vaccines

The exact antigenic determinants of pathogens that stimulate the immune system are known, thus instead of vaccinating with the entire organism, the exact antigen molecules are isolated and used in the vaccine. The antigen can be taken from cultures, produced by genetic engineering, or synthesized.

Activation of Proteins in Cascade

The inactive version that is floating in the blood gets cleaved (cut in half) in order to activate it. So the active forms are actually the cut up versions of the inactive forms. So the first protein gets activated and it cuts several copies of the next protein in half to activate them and each of them cut several copies of the next protein in half and so on...

Incubation Period for Plasmodium

The incubation period following a mosquito bite ranges from 7 to 30 days, and the length is primarily determined by the species of Plasmodium involved.

Why aren't we swimming in E Coli considering its doubling time?

The logarithmic growth is possible only in perfect conditions. When there are plenty of nutrients and waste products are being removed and temperature/pH/etc are all optimal, the bacteria can grow in that logarithmic way. While we can simulate those perfect conditions in the lab, they don't exist very often in the real world. In the real world most organisms live in a closed environment where there is limited access to nutrients and the removal of wastes. That closed environment could be a test tube or it could be a lake or your patient's body or even the planet but it should have some limit in access to nutrients and the removal of wastes.

Amoebic Encephalitis Infecting the Body

The pathogenic amoeba get into the body through a cut in the skin or by being inhaled through the nose. Once in the body they travel to the brain resulting in encephalitis. New route of exposure by Neti Pot, when water is taken from a lake or tap.

Lectin Pathway

The protein lectin is made by the liver and can bind to some pathogens. When lectin binds, it can activate complement as well.

Primary Response

This is the first time your immune system sees the antigen. During the primary response you would have clonal selection, the B cell interacting with the T helper, clonal expansion, and the release of IgM from the plasma cells. All of this activity takes time so there is a lag time before you actually see antibodies in the bloodstream and those first antibodies would be IgM coming from the plasma cells. Its possible that there might also be a little bit of memory antibody if the infection is around for awhile. The plasma cells will die in this fight but the memory B cells will hang out in the lymph nodes to watch for reinfection.

Memory B Cells and the Antibody Response

This memory response is the whole idea behind vaccination. In vaccination we introduce the antigen but not the pathogen. In that vaccination we want to stimulate clonal expansion so your body will have memory B cells against the pathogen.

Haemophilus

Tiny gram - pleomorphic rods. Very fastidious and are cultured in chocolate agar. Normal colonists in the nasopharynx. Others are virulent species responsible for childhood meningitis, pneumonia, and chancroid.

Brucella

Tiny gram negative coccobacilli. Intracellular zoonotic pathogen transmitted to humans from infected animals. Spread from infected animals by direct mucosal contact, traumatic skin implantation, or infection. Occupational hazard of veterinarians, slaughterhouse workers, farmers, and anyone who ingests unpasteurized dairy products (milk and soft cheese). 3 species are B. abortus (cattle), B. melitensis (sheep), and B. suis (pig).

Vaccination Purpose

To deliberately expose a person to material that is antigenic but not pathogenic. Principle intent is to stimulate a primary and secondary anamnestic response to prepare the immune system for future expose to a virulent pathogen.

Francisella Tularensis Symptoms

Tough to diagnose due to non-specific symptoms like headaches, backaches, fever, chills, and regular bad feelings. Also, possibly ulcerative skin lesions, swollen lymph glands, conjunctiva inflammation, sore throat and even involvement of the intestinal and pulmonary systems in severe cases. The case history and ruling out other possible pathogens would lead to testing for this pathogen and eventual diagnosis, often by blood test.

Death Phase

Toxic waste products build up and kill them.

Chagas Disease

Vector-borne disease found primarily in Central and South America caused by Trypanosoma cruzi. The vector for T. cruzi is the triatomine bug, also known as the "kissing" bug as it commonly bites mucous membranes such as the corner of the mouth (or eye). Infection occurs when T. cruzi is inoculated into our body from the bug's feces. This occurs after the kissing bug feeds on human blood and then defecates near the bite. Scratching or rubbing of the bite, causes T. cruzi within the feces, to enter the body. Early symptoms include fever, headache, enlarged lymph nodes, muscle pain, and difficulty breathing. As the disease progresses, the parasites can make it to the heart and muscles of the digestive system. Death can occur from heart failure due to the increasing destruction of the heart muscle.

Malaria

Vector-borne virus caused by a eukaryotic pathogen called Plasmodium spp.

Worldwide Distribution of Major Arboviral Diseases

Vectors and viruses tend to be clustered in the tropics and subtropics; many temperate zones have periodic epidemics. Infections show a peak incidence when the arthropod is actively feeding and reproducing. Humans can serve as dead-end, accidental hosts or they can be a maintenance reservoir. Controlling the vector controls the disease.

Arboviruses

Viruses spread by arthropod vectors, such as mosquitos and ticks. Include 400 viruses belonging to a diverse group of RNA virus families including the toga viruses, flaviviruses, some bunyaviruses and reoviruses. May result in fever with rash and headache, myalgia (muscle pain), and joint stiffness.

Memory B Cells

Wait patiently in the lymph nodes in case the same antigen returns. If the antigen does return, the Memory B cells will respond very quickly and in an enormous way by immediately releasing huge quantities of the memory antibody, IgG. By flooding the body with this IgG, the memory cells protect us against reinfection by the same antigen.

Temperature and Growth

Warmer temperatures increase growth, colder temperature decrease growth. Every organism has a minimum temp for growth, an optimum temperature for growth, and a maximum temperature for growth. Some microbes (like staph aureus) have broad ranges and some microbes (like Rhinoviruses) have a very narrow curve where the minimum and maximum temperatures for Rhinovirus growth are only 4 degrees apart.

Three Reasons We Still Have Malaria

We have a cure and know how to prevent malaria but 500,000 still die yearly. 1. Scientific challenge; parasite is complex, half in cold mosquito, half in warm human. 7 shape shifts in life cycle. 2. Economic challenge; occurs in poorest places in the world. Less likely to be inside more with screen doors, more likely to be outside with crops. Poor people predisposed because they farm outside where it is common. 1.3% economic depression caused by malaria in poor countries. Grows in rural poverty in dirt roads. 3. Cultural challenge; belief that malaria is a normal problem of life in poor areas. The more you get malaria, the less likely you are to die from it. Malaria comes and goes constantly. Those who are affected the most care the least. All add to the fourth problem, which is political. How do you get a political leader to do anything? Historically you don't. Attacks come from outside. 1940s used DDT and ignored speaking to those in the communities, underestimated scientific part and malaria resurged after they found it stopped working and they didn't know why. Most recent use is with bug repellant bed nets. Problem is cultural, they don't care to put up a round net every night and block the breeze because they don't believe they are fighting a killer disease and that it is all necessary. Max 20% actually said they used the bed-nets.

Autoimmunity

When a person's own immune system attacks his/her own self tissue as if it were a foreign antigen. The particular tissue that is being attacked differs depending on the autoimmune disease.

Classical Pathway

When an antibody is bound to a pathogen it triggers the activation of the complement cascade. This is one of the many benefits of antibodies to our immune system.

Neutralization

When antibodies bind to surface of antigen, stopping binding to target tissue.

Pregnancy Compensation Hypothesis

When pregnant, had to detect more non-self cells, but now with less pregnancy, immune system is overactive for detection so this can explain why women have autoimmune diseases more.

Trypanosoma

When viewing trypanosomes under the microscope, notice two dark spots within the protistan cells, one dark region in the center will be the nucleus and the other, slightly smaller region towards one end of the cell is called a kinetoplast (single large mitochondrion containing DNA). Causes two important diseases - African sleeping sickness, and Chagas disease (aka American trypanosomiasis).

Zika Outbreak 2016 Video

Zika found in Uganda, flavivirus. Circulating with only 20% symptomatic with mild symptoms. Aetitis mosquito. Outbreak on Yak islands, 1/3rd had it. Found that many babies were found with extremely small heads (microcephaly) in Brazil, at the same time Zika came around. No Zika vaccine. Main worry is about virus mutation.