Microbiology study guide 4

Adjuvants and preservatives

Materials added to make vaccines more immunogenic (aluminium salts, organic or oil-based) Preservatives - for multi use vials -thimerosal -used since 1930s. Degrades to ethylmerxury (not methylmercury)

Treatment: HIV drug target - HAART

nucleoside reverse transcriptase inhibitors (NRTI) NNRTI Protease inhibitors Fusion inhibitors HAART - combinations of 3 or more drugs (cocktail)

Influenza virus

spherical 80-120nm Enveloped with glycoproteins spikes Natural hosts are wild birds Also infect horses / pigs H - hemmagglutinin N - neuraminidase

Hypersensitivies

"Allergy" - antigenic response that is beyond what is normal Individuals are sensitized to an allergen 1. Anaphylactic 2. Cytotoxic 3. Immune complex 4. Cell-mediated (delayed type)

Food poisoning

(Intoxication) - ingestion of foods containing preformed microbial toxins

Drug resistant N. Gonorrhoeae

CDC superbug - threat level: Urgent This is one of the top 3 bugs the CDC is tracking along with C. difficile and Carbapenem resistant enterobacteriaceae

Complications

1 in 4 (23%) get pneumonia (lung infection) 1 or 2 in 100 (1.6%) will have convulsions ( violent, uncontrolled shaking ) Two thirds (67%) will have apnea (slow or stopped breathing) 1 in 300 (0.4%) will have encephalopathy (disease of the brain) 1 or 2 in 100 (1.6%) will die

signs and symptoms

1-4 day incubation period Starts in the upper respiratory tract, but may also affect lower respiratory tract Signs / symptoms Headache , chills, dry cough, body aches, fever, stuffy nose and sore throat Extreme knock you off your feet fatigue

How cooked food can make you sick

1. Food containing protein is cooked (bacteria is usually killed) 2. Then food is contaminated by workee w/ staphylococci on hands. (competing bacteria have been eliminated). 3. Food is left at room temp. Organisms incubate in food (temp abuse) long enough to form and release toxins. (Reheating will eliminate staphylococci but not the toxins) 4. Food containing toxins is eaten 5. 1-6 hrs, staphlococcal intoxication occurs

Clostridium botulinum

Toxin is very poisonous. If spores contaminate food, they germinate and produce this neurotoxin

Basic principles

1.micro-organism is covered with proteins. These proteins (antigens) are what antibodies can bind to. 2. A dead or inactive form of the pathogen is used to prepare the vaccine. The vaccine contains the antigens from the pathogen. 3. Antibodies are produced by white blood cells 4. Antibodies bind to the antigens in the vaccine

Small pox - infects only humans

1967- world health organization began an intensive vaccination program 1977- the last naturally occuring smallpox case was identified in somalia 1980- world health organization declared smallpox eradicated

Polio

1988 - world health organization tries again, this time with a vaccination program for polio 1988-2001 - the number of polio cases dropped from 300,000 to a low of 483

Pakistan

2007- eradication was in sight 2009- taliban refused to let health workers adminster vaccines 2010- devastating floods hindered vaccination initiatives 2010- on...murders of vaccine workers 2018- more vaccine workers murdered

Latency and Tertiary Syphilis

30% of infections enter latent period that can last 20 years or longer Pathological complications of final stage - cardiovascular damage - gummas - neurosyphilis (blood vessels in the brain cranial nerves, atrophy of optic nerve, dementia) Congenital syphilis - varied consequences from mild to stillbirth

Demographic

44% of those infected are African American (4x their proportion in the population) 26% are Hispanic (18% of the population) HIV rates among black women are 17 percent higher than among white women

Type A viruses

6 subtypes are known to have infected humans H1, H2, H3 - adapted to humans and caused three major 20th century pandemics H5, H7, H9 - caused smaller outbreaks when virus transmitted directly from birds to humans-no sustained human to human transmission yet

GI tract - commensals

600 species just in the mouth Stomach contains transients, but also some risidents Large intestine has 10^11 bacteria per gram of contents IEC = intestinal epithelial cell

What is a conjugated vaccine and what age group in particular is protected? How does this protection work?

A conjugated vaccine is when some antigens are linked to other proteins to stimulate a T dependent response which protects children age 2 and under. This protection works because some antigens are not good enough on their own to provoke an immune response to they are coupled with something to get better immunity.

What is the advantage of a live, attenuated virus over a subunit vaccine?

A live attenuated vaccine gives cellular and humoral immunity while a subunit vaccine only stimulates a humoral response. The viruses in the live attenuated vaccine also replicate in the host acting as boosters

DNA vaccines

A newer type of vaccine based on plasmids Protein antigens are made from the plasmid, which stimulate an immune response Stimulates both cellular and humoral immunity Not good for polysaccharide antigens Not approved for humans yet

Natural History of HIV infection

A normal CD4 count in a healthy, HIV negative adult can vary but is usually between 500 and 1500 CD4 cell/mm^3 (uL)

Condoms are a key component of public health strategies combating STIs. For which pathogens might a condom not provide sufficient protection? What alternatives are available?

A pathogen which a condom does not provide sufficient protection would be herpes, as it might not cover all the herpes lesions. To prevent transmission of herpes one should avoid having sex while experiencing symptoms. Another pathogen would be HPV which is one of the most common STI. Since HPV can be transmitted through skin to skin contact the condom won't necessarily cover the entire area and can also be spread through oral sex. An alternative way to prevent HPV besides condoms would be getting the vaccine.

A patient come into the clinic and after testing you discover that she has a normal T cell count in combination with a high HIV viral load. What part of the natural history of HIV infection is she in? How do you know?

A patient with a normal T cell count with a high HIV viral load is most likely in the acute HIV syndrome part of the natural history of HIV infection. I know this because she has a normal T cell count which is around 500 and 1500 but the high HIV viral load suggests that she has been exposed to HIV. Viral loads increase as the presence of CD4 cells die.

What is a prion made of, and what seems to cause it to become a pathogenic agent?

A prion are made of proteins and it becomes pathogenic when a normal prion gets misfolded and becomes a pathogenic form which then begins to convert normal prions into pathogenic prions.

Prevention/treatment

No vaccine Abstinence Barrier protection Annual screening of young women or older women with new sexual partner Assume co infection with gonorrhea Doxycycline/azithromycin

A patient comes in complaining they have the flu. List three things you are looking for to differentiate between a legitimate case of the flu, and the common cold.

A way differentiate between a legitimate case of the flu and the common cold would be in the flu they will feel severe aches and pains while in a cold is mild. Another way would be that someone that has a flu would have an obvious headache which is rare if they have a cold. Lastly if they had the flu they would have a high fever that would last 3-4 days compare to a cold which is low in adults and up to 102 in infants

2012-2016 regional data

Eight of 10 states and all of 10 metro areas with the highest rates of HIV infection are in the south 20,000 new cases in the south, 6,000 cases in the northeast In SF there were only 221 new cases in 2017

Pertussis (whooping cough)

Acute, highly infectious respiratory diseases An infected person will usually infect everyone in the household who is not vaccinated Greatest risk: infants less than 6 mo 250,000 deaths per year world wide Re-emerged : -inadequate vaccination -safer, but less effective vaccine

What is the difference between adjuvant and preservative? When would a preservative be added to a vaccine?

Adjuvants use aluminum salts which would be added to a vaccine when they would want it to stimulate a inflammatory response which recruits immune cells to develop a stronger immune response. Preservative use thimerosals which maintains sterility which would be added for multi use vials.

An infection with pertussis causes coughing that typically lasts how long? What is the best way to prevent pertussis? How are the very young protected?

An infection with pertussis can cause coughing for up to 12 weeks. The best way to prevent pertussis is to get vaccinated against it and do not carelessly spit, cough, or sneeze. The young can be protected through herd immunity.

Describe an organism that causes food poisoning (intoxication) and explain how that poisoning can be prevented

An organism that causes food poisoning would Staphylococcal Aureus. Even though s. aureus is a skin bacteria it can still get onto our food if the food is being handled by bare hands and prepared in advance with no intentions of it being reheated. If the food was properly cooked all the bacteria have already been killed which gives s. aureus the chance to grow. Ways we can prevent this would be by washing hands before handling food, wearing gloves, and cool or freeze food immediately after a meal.

HPV - msm

Anal infection is much more common in MSM than HM; prevalence ranges from only 15% in HM to 60% in HIV-seronegative MSM and almost 100% in HIV-seropositive MSM HPV infection is highest in HIV positive MSM, followed by HIV negative MSM Cigarette smoking has been positively correlated to HPV infection.

Systemic anaphylaxis

Anaphylactic shock - sensitized individual is exposed again (often injected - bee sting) Peripheral blood vessels enlarge and result in drop in blood pressure Can be fatal Self administer epinephrine (constrict blood vessels)

B. Pertussis

Attach to host cells of upper respiratory tract Excrete pertussis exotoxin -induces cAMP synthesis (cell damage, excess mucus) -tracheal cytoxij (cell damage) -also endotoxin (release of cytokines, cause of cough)

Prevention

Avoid unprotected sexual contact Gardasil: vaccine Protect against 4 of the most carcinogenic HPV (6,11,16,18) Three dose regimen Continue to have Pap smears by age 21 or within 3 years of first sexual contact Anogenital warts can be treated and are an important part of prevention efforts

TB vaccine

BCG - bacillus calmette guerin Prepared from attenuated M. Bovis bacillus 0-80% effective Given to children in endemic countries to protect against miliary TB Not routinelly used in US as it eliminates utilitt of skin teating Can cause disease in immune suppressed

Urine test?

Based on sugars present in TB As sensitive as PCR

Hemagglutinin (H)

Binds to host cell receptor of the respiratory mucosa facilitating viral penetration (breaks "in")- 16 subtypes

The Berlin patient

Bone marrow transplant Functional cure Leukemia - Donated marrow had mutation in CCR5..HIV can't bind to his immune cells Not practical for most people

Neuraminidase (N)

Breaks down the protective mucous coating of the respiratory tract, assists in viral budding and release. (breaks "out") - 9 subtypes

Chlamydia

CDC: 6.8% of sexually active 14-19 year old girls are infected 12% of MSM are infected Vast majority of cases are asymptomatic 1 mill cases are reported each year, actually infection rate is 5-7 times higher C. trachomatis - small, gram negative bacteria Obligate intracellular parasite (phagosome) -prevents formation of phagolysosome -multiples insides of the host cell

1982 - disease renamed AIDS

Case reported in IV drug users Infants Hemophiliacs & blood product recipients Heterosexuals (men and women) Mother to child transmission Delivery, breastfeeding, in-utero

Detecting disease

Chest x ray Stain sputum smear Culture bacteria PCR test (detects TB and sensitivity to rifampicin in 100 min)

Viruses that cause rashes

Chicken pox Shingles Measles Herpes Smallpox Roseola Fifth disease Rubella

HIV infection is the biggest risk factor

Children younger than 5 Persons who are receiving immunosuppressive therapy Person with silicosis, diabetes, chronic renal failure, leukemia, lymphoma, or cancer of the head, neck, or lung Persons who have had a gastrectomy or jejunoileal bypass Persons who weigh less than 90% of their ideal body weight Persons who abuse drugs and alcohol

Food/water infection organisms

Cholera (vibrio chloerae) Typhoid fever (salmonella typhi) Shigella E.coli O157:H7 Norovirus illness (single stranded RNA) Hepatitis A Polio virus

S. pneumoniae

Commonly found in the nasopharynx of healthy carriers Mucoid appearance due to capsule Virulence factors - pneumolysin - anti-phagocyctic capsule - adhesins

Subunit vaccines

Contain only antigenic fragment that best stimulates an immune response Safer than live or killed vaccines Often produced by genetic recombination (called recombinant vaccines)

Variolation - origins of vaccination

Deliberate infection with smallpox - dried smallpox scabs blown into the nose - injection via puncture in skin Produced mild disease 1-2% of people died vs 30% who died when they contracted the disease normally

Toxoid vaccine

Directed at the toxin produced by the parhogen

miliary or disseminated TB

Disseminated tb "millet seeds" 1700 TB in extrapulmonary organs (liver, spleen, kidneys)

Latent disease

Do not feel sick Do not have symptoms Cant spread May develop + skin test Normal chest x-ray Sputum/culture - No symptoms Not infectious Not a case of TB

Pneumococcal disease

Each year S. pneumoniae causes - 135,000 hospitalizations for pneumonia, 6 mill cases otitis media, 3300 cases menungitis (1/2 in children under 5) - up to 40% infections due to S. pneumonia are resistant to at least one drug. 15% cases are resistant to 3 drugs Risk groups - children under 2 and those attending day care - native americans and alaskans, and african americans - immunosuppresion, HIV

Transmission and Epidemiology

Easily transmitted via sexual contact Most common non-viral sexually transmitted infection No vaccine Anti-protozoan drug: metronidazole (some isolates are resistant)

GI tract - protective mechanisms

Exposed to heavy loads of microbes Surfaces are coated with mucus (mechanical protection) IgA antibody (secreted) is on most intestinal surfaces Peristaltic movement continously moves things out Secretions - saliva -lysozyme and lactoferrin - stomach -HCl is highly acidic - bile is antimicrobial

The odds a child will

Have a severe allergic reactioj after the MMR and Hep B are 1 in 1 mill

General symptoms of TB

Fever Chills Night sweats Weight loss Appetite loss Fatigue Malaise

Cold symptoms

Fever : low in adults and youth up to 102 in infants Headache: rare Aches / pains: mild Fatigue: mild Exhaustion: very unusual Stuffy nose: common Sneezing: common Sore throat: common Chest pain/cough: mild/mod hacking Complication: sinusitis / earache

Flu symptoms

Fever: High (102-104 F) lasts 3-4 days Headache: prominent Aches/pains: severe Fatigue: up to 2-3 weeks Exhaustion: sudden Stuffy nose: sometimes Sneezing: sometimes Sore throat: sometimes Chest pain/cough: severe Complication: pneumonia

1981

First US reports of pneumocystis pneumonia in young MSM from LA Year end ~300 reports in MSM Official start of epidemic; CDC MMWR publishes reports of Kaposi's sarcoma and PCP in my previously healthy men

Syphilis

First recognized in the 15th century in Europe Caused by spirochete treponema pallidum Gram negative Strict parasite, complex growth requirements - must be cultivated in living host cells

Food infection

Food contains sufficient numbers of viable pathogens to cause colonization and growth of the pathogen in the host

Foodborne diseases

Food infection Food poisoning Some bacteria do both Four microbes account for 90% of all foodborne illness : salmonella, clostridum perfrigens, campylobacter jejuni, and norovirus (60%)

Food as a disease vehicle

Food is rarely sterile Microbes are used to prepare some foods Pathogens or their toxins are occasionally in our food as well Perishable food - function of water content - preservation of food is a way to store perishable food "preserves"

Inactivated (killed) viruses

For viruses considered too hazardous to administer live verisons Inactivated by formalin or phenol Usually considered safer Often requires boosters Mostly humoral response

1983 - infectious agent identified

Franchise barre sunoussi Luc montagnier French virologists Share 2008 Nobel prize for medicine

GI tract - lymphoid tissue

GALT ( gut associated lymphoid tissue) Tonsils/adenoids, and small areas of tissue in the esophagus Peyers patches - small intestine GALT has B and T cells as well as cells of the innate immune system Commensal bacteria may coat themselves with host sugar molecules to avoid immune destruction

gastroenteritis

General term for inflammation of stomach and intestinal mucosa Can be caused by infection or intoxication (poisoning) Diarrhea and vomiting are defensive One in five children die of diarrhea in some parts of the world due to dehydration

Type I (Anaphylactic Reactions)

General term for when IgE antibodies combine with certain antigens Systemic -circulatory system collapse, airway obstruction (shock) Localized rxn Hay fever, asthma, hives

Gonococcus

Gram negative diplococci Chemicals on the tips of fimbriae to anchor themselves to mucosal epithelial cells (urethra,cervix) Invaded cells and multiplied within the basement membranes Phase variation - can turn fimbrial proteins on and off, and rearrange fimbriae to confuse immune system

How does ground beef become infected with pathogenic strains of E. coli? How can this kind of contamination be prevented?

Ground beef can become infected with pathogenic strains of E. coli because when cattle are killed and processed the bacteria in their intestines can get on the meat and since ground beef combines meat from different cattle it increases the risk of contaimination. This kind of contamination would be hard to prevent unless slaughter houses have better preventative measures but to prevent infection consumers can wash their hands and cooking the ground beef until its well done and avoid keeping cooked beef with raw beef.

Pathogenesis

HIV enters mucous membrane or skin via parenteral route Infects dendritic cells which are CD4+, grows and is shed Is amplified by macrophages (also CD4+) Infects CD4+ T-lymphocyte (helper T cells) Ironic- HIV infects the very cells needed to combat it

HIV structure

HIV is a spherical enveloped virus with central cylindrical nucleocapsid. The core holds 2 identical ssRNA pieces with protease, reverse transcriptase, and integrase. The envelope holds glycoprotein spikes of gp120 and gp41 within a p24 capsid protein. The genome is 2 positive RNA strands.

Global resurgence in TB

HIV/AIDS Drug resistance (difficult and complicated to treat) - MDR-TB - XDR-TB Health systems -Requires political commitment and strong public health infrastructure -many countries have limited resources.

Herpes

HSV 1 and HSV 2 Viruses - icosahedr capsuds Envelopes with glycoproteins spikes Transmitted by direct exposure to secretions containing the virus Estimated that 20% of American adults have genitalia herpes (50-90% don't realize it). By middle age half of adults are infected Increases risk of HIV by 3 fold

Explain what herd immunity is and who it protects

Herd immunity is a form of protection from infectious disease that occurs when a large percentage of a population has become immune to an infection therefore providing protection for individuals who are not immune, such as babies, the immunocompromised, and the elderly.

Herd immunity

Herd immunity protects vulnerable members of the population -too young -immunocompromised +cancer-aids -eldery Vaccination is different. If you are not vaccinated it affects the rest of us.

Degranulation

Histamine (stored in granules) Leukotrienes and prostaglandins (synthesized by antigen triggered cell)

I am your patient, and I'm declining a yearly influenza vaccine because I believe the warnings about pandemics are greatly exaggerated and I'm afraid I'll get the flu from the vaccine. How do you respond to my concerns? Provide me with three unique evidence based sentences that you might use with a patient.

I would explain to my patient that the warnings are not exaggerated. I would tell them how over 80,000 Americans actually died of the flu during the winter of 2017-2018. Next I would tell them that they need to get the vaccine each year because the flu virus has a lot of genetic variability which means that it mutates and becomes a little different each year. I would also tell them that the flu virus in the vaccines are killed and inactivated so that they are less likely to make you sick but I would also let them know that getting slightly sick from the vaccine will be less painful than catching the flu without any protection at all.

The PTA president at your child's school explains that she is intending to decline the HPV vaccines for her son, as he is not as risk for cervical cancer. Give her two scientifically valid reasons why vaccination will still benefit her son.

I would tell her that HPV is the one of top sexually transmitted disease and how HPV can cause cancer that is not in the cervix for example mouth and throat cancer. I would also let her know that HPV is a virus infection that stays forever so it would be more beneficial to have him vaccinated than not.

You are a scientist developing a vaccine against a newly discovered animal virus. What part of the virus would you target your vaccine against and why?

If i was a scientist developing a vaccine against a newly discovered animal virus i would like my vaccine to target the viral spikes on an enveloped virus because the virus does not uncoat until it is in the host cell. So if they can not get into the host cell then they cannot replicate.

Polio in Nigeria

In 2003 mullahs in northern nigeria became suspicious of polio vaccination program there There was fear that is was a plot to spread AIDS and sterility. As a result the local vaccination effort broke down, and polio cases in nigeria tripled over the next three years.

Flu vaccine

In February of each year, who consults with experts from who collaborating centers, essential regulatory laboratories, and other partners to review data Afterward who makes recommendations for the composition of the seasonal flu vaccine for the northern hemisphere

In influenza, what is the difference between antigenic drift and shift?

In antigenic drift there are minor point mutations in H&N which creates new but antigenically related viruses In antigenic shift there are major changes due to the assortment of more than one virus in a cell

Influenza

In the winter of 2017-2018, 80,000 Americans died from the flu. Only diseases caused by the influenza virus are actually the flu. Influenza viruses that circulate every year are called seasonal flu Occasionally a new strain appears and can cause worldwide pandemics Existing or new strains can cause serious illness

Types of flu vaccines

Inactivated virus (trivalent and quadrivalent, fluzone, flulaval, fluarix, etc) High-dose inactivated (trivalent, fluzone) Recombinant (FluBlok) Live attenuated (FluMist - Quadrivalent)

Histamines

Increase permeability and distension of capillaries, edema, redness, increased mucus secretion (runny nose), smooth muscle contraction (breathing difficulty)

infant botulism

Infants up to 2 months old lack competing intestinal microbes. Spores germinate in childs intestine

Food infection

Infection occurs when pathogen enters digestive tract Microbes penetrate intestinal mucosa - m cells - peyers patches Delay in appearance of symptoms Often fever

Food/water infection

Infection occurs when you ingest food containing a pathogen, which then grows and causes diseases in the host. Food infection outnumbers food poisoning 10:1

Flu surveillance

Influenza activity is collected year round to produce "FluView" - weekly report - find out when and where flu activity is occurring - track flu related illness - determine what flu viruses are circulating - detect changes in flu viruses - measure the impact flu is having on hospitalizations and deaths in the US

Genetic variability

Influenza virus is famous for genetic variability "master of disguises" -minor point mutations in H&N create new but antigenically related viruses contribute to epidemics - antigenic drift -hence the need for vaccines every year

Type IV (delayed) hypersensitivity

Involves T cells usually occur in days (not hrs) Poison ivy / oak Latex allergies Contact dermatitis

Jenner - cowpox

Jenner discovered that milkmaids who contracted cowpox were immune to smallpox Deliberately infected people with cowpox - they because immune to smallpox Experimented with his vaccine on kids including his own son Vacca - "cow"

Stage 3 convalescent stage

Last 2-3 weeks, susceptible to other respiratory infections for many Recovery is gradual. Coughing lessens but fits of coughing may return

Stage 2 Paroxysmal stage

Lasts 1-6 weeks may extend to 10 weeks Symptoms: fits of numerous, rapid coughs followed ny whoop sound, vomiting and exhaustion after coughing fits

How is latency in syphilis different than latency in herpes (HSV-2)? Provide a one sentence description of each

Latency in herpes is different than latency in syphilis because it hides in the neurons and does not replicate at all while in syphilis you don't notice the signs and symptoms but it is still replicating in the body

Types of vaccines

Live attenuated vaccines - inactivated, killed vaccines Subunit vaccines Conjugated vaccines Nucleic scid (DNA) vaccines

Live, attenuated vaccines

Live, weakened pathogen, mimics real infection, generates cellular and humoral immunity Often confers lifelong immunity Viruses replicate in the host, increasing dose and acting as boosters

What is the difference between garden variety S. Aureus, MRSA, VISA, and VRSA? What has caused the emergence of strains such as MRSA and VRSA? Use the words lateral gene transfer, selective pressure, and evolution in your answer

MRSA is methicillin resistant staph aureus. VISA is vancomycin intermediate staph aureus. VRSA is vancomycin resistant staph aureus. Antibiotics exert selective pressure on organisms. Organism that are able to survive transfer those genes to other bacteria through lateral gene transfer. Evolution of bacteria occurs as a result of organisms adapting to the antibiotics in the environment.

What types of cells can be infected with HIV? Why does HIV wreak havoc with the immune system?

Macrophages, dendritic cells, and lymphocytes can all be infected with HIV. HIV wreaks havoc on the immune system because the types of cells that are infected is what is needed to fight against this type of infection.

Antigenic shift

Major changes due to reassortment of more than one virus in a cell Give rise to totally unrelated viruses to which we have no prior immunity Pandemics

Stage 1 catarrhal stage

May last 1 to 2 weeks Symptoms: runny nose, low grade fever, mild, occasional cough - highly contagious

Pathogenesis and virulence factors

Men seldom symptomatic Women symptomatic 50% of the time, green frothy discharge Transgender men (who have not undergone phalloplasty) will also potentially be symptomatic if engaging in receptive sex Chronic infections may lead to infertility m

Symptoms - often asymptomatic

Men: inflammation of urethra (discharge, painful urination) Proctitis: recital pain, discharge, bleeding in MSM, and women Women: discharge, PID, salpingitis May be painful or go unnoticed Babies can become infected during birth Conjunctivitis- treated with antibiotic drops, which also treats gonorrhea

STI

Microbes are transmitted from warm, moist mucous membranes of one person to the warm, moist mucous membranes of another Vaginal and anal intercourse, oral sex Semen and vaginal discharge are major sources of the microbes

Clostridium perfringens

Mostly soil, proteolytic bacteria, grows well in high protein foods. Usually a problem when food is not cooked thoroughly. Onset 7-10 hrs, resolves in 24

Pertussis (Tdap)

Movement to safer acellular form of vaccine provides less protection Lower vaccination rates Fewer adults with immunity Evolution of the bacterium?

Staphylococcal Food Poisoning

Multiple staphylococcal enterotoxins (superantigen) Many other tools or virulence factors that assist s. Aureus in pathogenicity 1 mill bacteria per gram produces sufficient toxin to cause illness

Gonorrhea

Neisseria gonorrhoeae (gonococcus) The clap Most infectious when transferred to mucus membranes - doesn't survive long on fomites Strictly human infection, worldwide, common 350,000 cases are reported in the USA each year 50% females, 10% males are symptomatic and spread disease without knowing Prevalence 16.4% in MSM population

Prevention/ treatment

No vaccine Infection greatly enhances risk of HIV infection Dramatic increase in antibiotics resistant infections Penicillin was the drug of choice - many are resistance also to tetracycline and quinolone. Ceftriaxone and azithromycin is now recommended by the CDC

Prevention/Treatment

No vaccine, but ones are being tested Condoms are good if they cover the lesion but some lesions occur outside the covered area Persons experiencing active lesions should abstain Virus is shed prior to lesions forming Condoms should always be used Herpes is forever Acyclovir and derivatives reduce shedding of virus and frequency of lesion occurrence

Prevention/treatment

No vaccines currently Condoms effective for primary syphilis Penicillin G is still a wonder drug Injected in large doses maintain lethal drug level for 7 days

How does a protein cause disease

Normal prion protein exists on the surface or neurons Two forms - normal cellular form (PrPc) -pathogenic form (prpsc) -molecules of prpsc can convert prpc to prpsc

TB transmission and development

Not everyone who inhales droplets get sicks -infected but not sick - latent TB infection -infected and sick - active disease If ur immune system is healthy, and you inhale a droplet you have a 5-10% chance of developing active disease (risk is highest first two years)

TB in the USA

Once the leading cause of death -in 1950s antibiotics resulted in dramatic drip in deaths Today: 9-14 M ppl are infected -over 9,272 ppl developed TB in 2016 -affects racial and ethnic minorities -drug resistant TB is common -more than half of infected individuals are foreign born residents

Pathogenesis and virulence factors

Oncogenes - code for proteins that interfere with normal cell growth Young women have the highest rate of infection (24-46% of women under 25 infected with genital HPV) CDC estimates that 50% of sexually active adults will become infected in their lifetime

The world has experienced a resurgence in TB in the past 20-30 years. Give two reasons why we have experienced such major setbacks in the battle against TB

One reason we have experienced such major setbacks in the battle against TB is because of drug resistance. TB is compicated to treat so those who do not finish their long course of antibiotics can help create antibiotic resistant TB. Another reason is because of health systems. Low and middle income countries have limited resources and may not have political commitment and a strong health public infrastructure.

Name one way that cooking food prevents bacterial illness, and one way that cooking food increases the risk for bacterial illness.

One way cooking food prevents bacterial illness is by killing the bacteria that could have been on the food prior. But cooking food can also increase the risk for bacterial illness because it gives a chance for other types of bacteria to grow on the due to contamination now that theres no competion.

Polio 2017

Only 11 cases so far in 2017 What will it take? Keep vaccinating Build trust Get local Focus on the vaccinators Reach people who are migrating or displaced Stay vigilant

Where do the organisms that cause staph and strep infections typically come from? What causes them to be pathogenic?

Organisms that cause staph and strep infections typically come from damp dank spots such as belly buttons and armpits. They can be pathogenic if they enter the blood stream or internal issues and which can cause serious infections.

What does PID stand for? Which two common STI's are the most likely to result in PID in women? List two serious consequences of PID.

PID stands for pelvic inflammatory disease and two common STIs that are most likely to result in PID would be chlamydia and gonorrhea. Two serious consequences of PID would be infertility and ectopic pregnancies.

Why are people affected by food poisoning (intoxication) more quickly than food infection?

People are affected by food poisoning more quickly than food infection because the food that is being consumed already contains the toxins made by microbes, while in food infection it contains actual microbes that will then colonize in your gut and releases toxins

Pneumococcal infections

Pneumonia Ear infections Sinus infections Meningitis Bacteremia ( bloodstream infections )

Pneumococcus treatment

Pneumovax- multivalent vaccine against 23 most common capsular types Pneumococcal - conjugate vaccine -conjugated to diptheria toxiod -for children under 2 ( 3 doses, 1 boostee ) -penicillin (traditional drug of choice) -erythromycin and other alternatives if resistant

Why has it been so difficult to eradicate polio using vaccination

Polio has been difficult to eradicate due to social issues. Places like nigeria and pakistan became suspicious with the vaccination programs thinking it was a plot to spread AIDS which the local vaccination efforts then broke down.

Pathogenesis and virulence factors

Presence of bacteria causes release of cytokines Provoke severe inflammation Last step of inflammation is repair - severe scarring (tissue damage) Scarring / blockage of Fallopian tube PID- often causes by chlamydia or gonorrhea

Sign / symptoms

Primary syphilis: appearance of hard chancre at the site of entry (small, red, hard bump that enlarged and breaks down, leaving a shallow crater with firm margins) -internal / external genitalia -lips, oral activity, nipples, fingers or anus -tends to be painless -heals spontaneously in 3-6 weeks, but the Bacterium has escaped into the circulation

Leukotrienes

Prolonged contractions of smooth muscle

Prions

Proteinaceous infectious particles No DNA or RNA, but can replicate in a host Stanley prusinee ucsf Nobel prize discoery 1997

Trichomoniasis

Protozoan infection 4 anterior flagella Undulating membrane Asymptomatic infection - long term negative effects

What is the difference between pulmonary TB and miliary or disseminated TB?

Pulmonary TB is TB that is in the lungs while miliary TB is when one or several organs in the body are affected with TB.

Skin and soft tissue bacterial pathogens

S. aureus , epidermis S. pyogenes , pneumoniae Impetigo Soft tissue infections Staphyloccocal scalded skin syndrome Cellulitis Necrotizing fasciitis

Flu types

Seasonal (common) -respiratory illness, transmitted person to person. Most ppl have some immunity. Vaccines are available Pandemic Flu -virulent, severe flu, transmitted person to person. Little natural immunity Avian Bird Flu -caused by viruses among wild birds -no sustained person to person transmission

Tuberculosis

Second only to HIV/AIDS as the greatest killer worldwide due to a single infectious agent -update the worlds deadliest infectious disease More than 2 B ppl are infected. 1.8 M ppl die each year 95% of deaths are in low / middle income countries TB responsible for 1/5 of all deaths in HIV infected people

Signs/symptoms

Single or multiple vesicles on the genitalia, perineum, thigh, buttocks Small - filled with clear fluid Intensely painful Sometimes accompanied by malaise, fever, bilateral swelling/tenderness in the groin Occasionally CNS symptoms (meningitis, encephalitis)

disease eradication

Smallpox plagued humanity for thousands of years In the 18th century, smallpox killed 1/10 children In the 20th century, the virus caused between 300 and 500 million deaths worldwide No effective treatment was ever developed.

Prostaglandins

Smokth muscle and mucous secretion

Secondary infection

Some groups are susceptible to secondary infections that are very serious, often bacterial such as pneumonia ( in USA > 200,000 hospitalizations ) - very young and very old - immunocompromised - pregnant - people with weakened lungs (emphysema, COPD) Estimated 30-50K people die each year in the USA Worldwide 250,000-500,000

What might cause someone with TB to test negative on the TB skin test?

Someone that is immunosuppressed may cause a negative TB skin test.

What might cause someone with a normal chest x ray to have a large induration when given a TB skin test?

Someone with the latent disease of TB can cause them to have a positive skin test but a normal chest x ray.

Normal skin biota

Sparse on dryer areas Love those damp dank spots (belly buttons, armpits, groin) Hair follicles, glandular ducts are protected and thus popular hangouts

Types of foods

Staphylococcus will take over if other organisms have been killed by heating -poultry thats been cooked, cured pork -custards, cream pies -any foods prepared in advanced and not kept chilled Staphylococcus will outcompete other organisms in higher salt

Cure?

Sterilizing cure -requires total eradication of HIV from the body Functional cure -prevent disease progression -have long periods (yrs) that are treatment free (remission)

Hep C

Symptoms: fever, dark urine, abdominal pain, jaundice Causative organism: virus Type: rna, enveloped Transmission: blood borne- sharing needles,sexual transmission, tattoos, pregnancies Type: Ep: ID: Treatment: drugs

Hepatitis A

Symptoms: nausea, vomiting, anorexia, fever, malaise, abdominal pain, jaundice, joint pain Causative organism: virus Type: non-enveloped, single stranded RNA Transmission: fecal - oral highly contagious, contaminated food and water, men and men sex, countries with high infection rates, contaminated needles Type: secondary EP: ID: Treatment: vaccine, rest and hydration

Hep B

Symptoms: nausea/vomiting, fever, fatigue, abdominal pain, jaundice, joint pain, dark urine Causative organism: virus Type: double stranded dna Transmission: body fluids, acute or chronic illness, hepB can lead to liver cancer Type: Ep: 2.2 mill, 240 mill globally ID: Treatment: vaccinations

Specific symptoms

Synptoms of pulmonary TB; coughing, chest pain, coughing up blood or sputum Symptoms of extrapulmonary TB (depends on body part); TB in spine may cause back pain TB in kidneys may cause blood in urine TB in lymph nodes cause swelling in the neck

TB transmission

TB is spread through the air from person to person via tiny water particles when a person with infectious TB -coughs -sneezes -speaks -sings Droplet nuclei - can remain in the air for several hrs

Differentiate between TB, MDR-TB, and XDR-TB using one sentence for each

TB results from an infection with mycobacterium tuberculosis which can usually be cured with a combination of first line drugs that is taken for several months. MDR-TB occurs when a mycobacterium tuberculosis is resistant to isoniazid and rifampin which are the two most powerful first line drugs. XDR-TB occurs when a mycobacterium tuberculosis strain is resistant to isoniazid, rifampin and the key second line drugs.

Secondary syphilis

The Bacterium has invaded many systems in the body ( 3 weeks - 6 months ) Fever, headache, sore throat, swollen, lymph nodes, red/brown rash on all skin surfaces Hair falls out Resolves spontaneously in a few weeks

What part of the immune system is stimulated when someone gets a rash from exposure to position oak, or develops a latex allergy?

The cell-mediated branch of the adaptive immune system is stimulated when someone gets a rash from the exposure of poison oak or develops a latex allergy. When the allergens are first absorbed by the skin the dendritic cells recognize and sensitizes the T helper cells and T memory cells. If the body comes into contact with the allergens a second time the T memory cells are already in place to tell cytotoxic T cells to attack causing dermatitis.

Vaccines provide strong protection

The concentration of antibodies in blood is higher in the secondary response to the same antigen

Describe three protective mechanisms built into the gastrointestinal system. Include in your description how they are protective.

The first protective mechanism that is built into the gastrointestinal system would be how the surfaces of our GI tract is covered in mucus which prevent bacteria from coming into contact with our cells to cause infection The second protective mechanism would be the peristaltic movement which continously moves things out of the GI tract The last protective mechanism would be secretions such as hydrochloric acid in our stomach which makes our stomach highly acidic killing a lot of the bacteria.

What are the 4 stages of Syphilis? Name one characteristic sign or symptom in each stage

The first stage of syphilis is the primary stage. A characteristic of the primary stage of syphilis would a hard chancre at the site of entry. The next stage of syphilis is the secondary stage. A characteristic of this stage would be a red or brown rash on all skin surfaces. The third stage of syphilis is the latency stage. The latency stage does not have visible signs or symptoms but one can still be infected if they don't receive treatment. The last stage of syphilis is the tertiary stage. Characteristics of this stage would be gummas.

List three differences between the structure of HIV and the virus that causes influenza. For one of these differences explain how the structure is key to the function of the virus

The first structural difference between HIV and influenza would be that influenza has 8 RNA strands while HIV has one. The next structural difference would be HIV is a retrovirus contains reverse transcriptase that it needs to convert the hosts DNA into their RNA and into the host while influenza doesn't do this. Lastly, influenza has two different types of surface proteins, while HIV has one. Influenza has H surface proteins that helps binds to host cells and N which help with budding. HIV has gp120 which binds CD4 on target cells.

Name three different infections caused by pneumococcus and write a one sentence description of each

The first type of infection caused by pneumococcus would be pneumonia which is an infection that inflames the air sacs in one or both lungs. The second type of infection cause by pneumococcus would be meningitis which is the swelling of the protective membranes that cover the brain and spinal cord. Lastly another infection caused by pneumococcus would be bacteremia where bacteria in the bloodstream can cause infections.

Conjugated vaccines

The immune system of children under 2 doesnt respond well to T-independent antigens Some antigens are conjugated or linked to other proteins ( such as diphtheria lf tetanus toxoid ) to stimulate T-dependent response Hib vaccine provides good immunity at 2 months

After drinking raw milk a woman developed a fever, abdominal pain and diarrhea. Instead of recovering this episode was followed by severe or temporary paralysis. What organism causes this infection? What is the name of the syndrome the woman experienced?

The organism that caused this infection is campylobacter jejuni. The name of the syndrome the woman experienced is guillain-barre syndrome.

What types of things influence the level of herd immunity that one gets from a vaccinated population

The percentage of people vaccinated, the effectiveness of the vaccine, and how contagious is the disease are things that infuence the level of herd immunity.

Consider the structure of influenza A. Explain how the structure of H and N are key to the function of the virus.

The structure of hemagglutinin helps the virus bind to the host cell receptors facilitating viral penetration. While the structure of neuraminidase breaks down the protective coating assisting in viral budding and release.

Immediately after birth, babies receive antibiotic ointment that is placed in their eyes. Which two pathogens are the primary target for this antibiotic treatment?

The two pathogens that are the primary target for this antibiotic treatment would be gonorrhea and chlamydia.

Priority group

Those at highest risk for serious illness & complications-should receive vaccine between sept-dec -adults >=65 -nursing home residents -infants 6-23 mo's -children and adults (2-64) w/ chronic conditions -pregnant women -household contact & caregivers of infants < 6 mo's -health care workers (mandated in some areas)

What are three major categories of drugs used to treat HIV infection? What is the justification for utilizing a cocktail of drug?

Three major categories of drugs used to treat HIV infection would nucleoside reverse transcriptase inhibitors, protease inhibitors, and fusion inhibitors. HAART which is a cocktail of drugs is used by someone who is HIV negative and wants to delay the symptoms or to help prevent from acquiring HIV from their partner.

You will wish you were dead

Toxins triggers the brains vomiting reflex center Abdominal cramps and diarrhea follow Mortality is essentially zero but misery is high Variability in susceptibility (some ppl may develop some immunity from exposure) Diagnosis is based on symptoms

Prion diseases - TSE

Transmissible spongiform encephalopathies (Creates sponge-like holes in the brain) Scrapie (sheep) BSE (cattle) Kuru (humans - cannibalism) Creutzfeldt-jakob (humans inherited)

Transmissions

Transmitted by direct sexual contact HIV Co-infection increases risk of developing warts Pap smear - look for abnormal cervical cells or anal cells on a microscope slide (resulted in a 74% decrease in the incidence of cervical cancer since 1955 PCR based screening: use PCR to test samples for the most dangerous HPV types

food allergies

True food allergies - usually hives, sometimes systemic anaphylaxsis Eggs, peanuts, tree grown nuts, milk, fish, shellfish, wheat, soy Most children develop tolerance as they age

Detecting latent TB infection

Tuberculin skin test (ppd) Read induration at 48-72 hr (>10 mm or >5 mm if HIV +) Memory T cell response Immunosuppressed may test neg Quantiferon blood test - can distinguish between real TB and vaccinated individuals

A student shows up at the health center with a red swollen and warm area of redness on the back of his leg. Name two organisms that might cause this problem.

Two organism that might cause this problem would be staph or strep.

List two potentially life threatening consequences of a type I hypersensitivity reaction and explain what molecules are involved and how they work

Two potentially life threatening consequences of a type I hypersensitivity reaction would be a localized and systemic anaphylatic reaction. In a systemic reaction one could go into anaphylactic shock which causes peripheral blood vessels enlarge and result in drop in blood pressure which can be fatal. In a localized reaction which is usually caused by something someone ingested or inhaled. In a localized reaction the mast cells in mucous membrane of the upper respiratory tract could cause hay fever and itchy eyes.

Campylobacter Gastroenteritis

Ubiqutious microbes - essentially all retail chicken is contaminated, 60% of cattle excrete organism in feces and milk One of the reasons we pasteruize milk 1/1000 cases linked to neurological disease Guillain - Barre syndrome - molecular mimicry - ganglioside like epitopes in the LPS later oc the bacterium (C. Jejuni - most common cause of GBS)

DOTS

Whos long term strategy Directly observed treatment, short course Detection by sputum smear Health care worker oversees treatment for 2 months (access,support) Uninterrupted drug supply for 6-8 months $10 per day

Active disease

Usually feel sick One or more symptoms May spread TB to others + skin test Abnormal chest x ray Sputum/culturw + Symptomatic Infectious Case of TB

localized anaphylaxis (atopy)

Usually ingested food or inhaled pollen Upper respiratory system: mast cells in mucous membranes of the upper respiratory tract are involved (hay fever, itchy eyes, coughing, and sneezing) Lower respiratory tract (asthma) - wheezing and shortness of breath

Latency

Virus is maintained within the cells of the nervous system between episodes

Human Papillomavirus (HPV)

Virus that causes cancer Not just in the cervix Mouth & throat, penile, anal, vulvar, vaginal, cervical

Transmission of flu

Virus-laden aerosols / droplets Fomites (secondary role) Dry winter air (moist particles become dry quickly and can stay airborne longer) Dry air makes respiratory tract membranes more brittle - facilitates viral invasion Highly contagious

Skin defenses

Waterproof keratin later of the epidermis -replaced every 25-45 days -microbes slough off with the cells Sebaceous glands (sebum) low pH Antimicrobial peptides in epithelial cells keep the microbe count low Sweat - lysozyme and high salt

If 1/3 of the worlds population is infected with TB why don't we see it all around us? Give two reasons why this is the case.

We dont see it all around us because it is latent. A lot of people may be infected with TB but their immune system keeps it under control. Another reason we dont see it all around us is because of the demographics of where it happens. TB is usually within low and middle income countries.

Scientists would really like to develop an influenza vaccine that could be given only a few times in life, rather than annually. What will have to change about our current vaccine to make this a reality?

We would have to create a more effective vaccine to make this a reality. For example, we could target the hemagglutinin which helps the virus bind to the host cell. If we can make a vaccine that prevents the virus from attaching and infecting the host it could stop the virus all together. But since hemagglutinin mutates rapidly scientists would have to develop a way to make antibodies work against multiple different heads

Signs/symptoms

Women: both urinary and genetically tract affected, salpingitis, PID (resulting in scar tissue, infertility) Men: urinary tract, sometimes prostate and epididymis (can cause infertility) Rare complications - meningitis, endocarditis Children - infected during birth Older Children - indicative of sexual abuse Rectal infections - discharge, itching, soreness, bleeding, painful bowel movements

Mycobacterium tuberculosis

acid-fast bacilli Usually affects lungs, but can affect any organ Infection doesnt mean disease Infection rates much higher if HiV + Infection rates are higher in makes Infection most common in afults in economically productive age grps