Microbiology Chapter 14,15,16,17,19

Classes of Immunoglobulins are as Follows

IgG- (main class of antibody found in blood) can cross placenta and confer immunity to fetus; IgA- found in mucus, saliva, tears, and milk; IgD- found on B-cell membranes; IgM- has strong agglutinating ability, first antibody formed in life; IgE- found in skin, tonsils and mucus

Stages of an Infectious Disease

Incubation Period, Prodromal Phase, Invasive Period, Decline Phase, Convalescence Period

Notifiable Diseases

Infectious diseases that are potentially harmful to the public's health

Acne

Propionibacterium acnes is the causative bacteria

Burns

Pseudomonas aeruginosa is prime cause of life-threatening burn infections: are extremely resistant to antibiotics; produces greenish discoloration at burn site and grapelike odor

Epidemic

Refers to a disease that has a higher than normal incidence in a population

Pandemic

Refers to a disease which spreads world wide

Virulence

Refers to the intensity of the disease produced. Virulence may be increased or decreased by animal passage from one species to another

Colonization

Term referring to the growth of microorganisms on epithelial tissues or surfaces such as skin and mucous membranes after adhering to these surfaces.

Epidemiology

The study of factors and mechanisms involved in the frequency and spread of disease and other health related problems within populations of humans, other animals and plants

Prevalence of Disease

The total number of infected people within the population at any time; both old and newly diagnosed cases

Streptokinase

This enzyme dissolves blood clots and frees bacteria bound in the clots to spread to other areas. This enzyme is produced by some Streptococcus species

Direct Contact Transmission

requires body contact between individuals. Horizontal Transmission, Vertical Transmission, Indirect Contact Transmission and Droplet Transmission

Antigen

substance that the body identifies as foreign (non-self) causing the body to mount an immune response

Toxins

substances poisonous to other organisms

Decline Phase

symptoms begin to subside. the pathogen is being overcome by the body defenses or prescribed treatment

Immunity

the ability of an organism to recognize and defend itself and defend itself against infectious agents

Invasive Period

the individual experiences the typical signs and symptoms of the disease

WHO World Health Organization

Works closely with the UN

Sty

a Staphylococcus infection at the base of an eyelash

syndrome

a combination of signs and symptoms that occur together and are indicative of a particular disease process or condition

Abscess

a deeper pus-filled site

Exterior Abscess

a furuncle or boil

Antibodies (Immunoglobulins)

a protein produced in response to an antigen that is capable of binding specifically to the antigens. Antibodies are produced by B-cells (B-lymphocytes)

Vaccine

a substance that contains an antigen to which the immune system responds

Normal Microflora of the Skin

the majority of microbial organisms commonly found on the skin are Gram positive. These include Staphylococcus sp., Micrococcus sp., Corynebacterium sp., and Proprionibacterium sp..

Susceptibility

the opposite of immunity-the vulnerability of a host to harm by infectious agents

Herd Immunity

the proportion of individuals in a community or a population who are immune to a particular disease. Immunizations are a significant factor in increasing herd immunity. Loss of herd immunity may allow a disasterous reemergence of a disease.

Immunology

the study of specific immunity and how the immune system responds to specific infectious agents

Incubation Phase

the time between infection and the appearance of signs and symptoms

Acme

the time during the invasive phase when the disease reaches its greatest intensity

Lymphocytes

these contribute to immunity

Highly Communicable disease

these diseases are said to be contagious diseases

Gamma-Hemolysins

these do not lyse red blood cells at all

Chemical Barriers

these include anti-microbial substances in the body fluids such as saliva, mucous, gastric juices, and the iron limitation mechanisms

Leukocidins

these toxins destroy or damage leucocytes (neutrophils and macrophages) and alter the body's ability to fight off disease. White blood cells

Animal Reservoirs

about 150 pathogenic microorganisms may infect both humans and some other animals

Toxiod

altered or weakened toxin that has lost the ability to cause harm but can stimulate the immune response and provide protection from the disease itself.

Pyrogen

an agent that causes the body's temperature to rise

Hyaluronidase

an enzyme spreading factor produced by some Streptococci. This enzyme allows the Streptococcus organisms to invade deeper tissues

Toxoid

an inactivated toxin that is no longer harmful, but still retains its antigenic properties

Nosocomial Infection

an infection acquired in a hospital or other medical facility

Gas Gangrene

anaerobic bacteria Clostridium; it can be acquired in deep wounds, surgery, diabetes, or illegal abortions; microbe produce hydrogen gas which destroys tissue; the foul odor produced is a diagnostic tool, hyperbaric chamber may be used in treatment

Vancomycin

antibiotic of choice to treat resistant infections caused by S. aureus

Antitoxins

antibodies against specific diseases (tetanus, botulism)

Bacteria

antibodies produced by plasma cells are the cheif immune defense- most tend to promote phagocytosis

Host

any organism that harbors another organism

Nosocomial Diseases

are acquired during medical treatment. About 10% of every 2,000,000 patients admitted to the hospital in the US acquire an infection that increases the risk of death during the hospital stay as well as the cost of treatment

Folliculitis

bacteria invade a hair follicle. Staphylococcus aureus called pimples or pustules

Nonspecific (innate) Defenses

body defenses that act against any type of invading agent. Nonspecific defenses are the body's first line of defense

Rubella or German Measles

can cross the placenta in pregnant women causing severe organ abnormalities in fetus during first 8 weeks of gestation (vision problems and mental retardation)

Hemolysins

cause the rupture and disintergration of red blood cells

Cat Scratch Fever

caused by Afipia felis or Bartonella henselae; transmitted by lick, scratch or bite of infected cat

Trachoma

caused by Chlamydia trachomatis; is leading cause of preventable blindness worldwide; 500 million people have it and over 20 million are already blind from it; scarring of eyelids causes eyelashes to point inward which damages cornea and leads to blindness

Ophthalmia Neonatorum (Conjunctivitis)

caused by Neisseri gonorrhoeae or Chlamydia trachomatis; treated with erythomycin or 1% silver nitrate drops which are administered immediately after birth

Scarlet Fever

caused by Streptococcus pyogenes (causes classical Strep throat); skin rash

Epidemic Keratoconjunctivitis "Shipyard Eye"

caused by adenovirus; can cause clouding of cornea; can be acquired at eye clinics

Non Infectious disease

caused by any other factor than infectious agents

Acute Hemorrhagic Conjunctivitis

caused by enterovirus; very rapid onset and recovery usually in 10 days

Scaled Skin Syndrome

caused by exotoxin producing stains of Staphylococcus aureus. These exotoxins are exfoliatins which cause the upper skin layers to separate and peel off.

Onchocerciasis (River Blindness)

caused by larvae of roundworm; black fly (vector) bites person and worm migrates to eyes; always causes blindness

Endogenous Infection

caused by opportunists among the patients own normal microflora

Exogenous Infection

caused by organisms that enter the patient from the environment

Leukocytes

cells that are defensive cells which are important to both specific and nonspecific host defenses these are two groups Granulocytes and Agranulocytes

Cellular Defenses

cells that engulf or phagocytize invading microorganisms

Monocytes

cells which function as phagocytes

symptoms

characteristics of a disease that can only be observed or felt by the patient

signs

characteristics of a disease that may be observed by examining the patient

Inflammation

characterized by localized increased temperature, redness, swelling and pain. Is the body's response to tissue damage

Viruses

combated by nonspecific defenses, interferon, and antibodies T-cells and NK cells are also important to defending against viruses

Immune Serum Globulin (Gamma Globulin)

contains serum from many individuals- tends to confer immunity well

Passive Immunity

created when ready made antibodies are introduced into the body

Active Immunity

created when the person's immune system produces antibodies or other defenses against the infectious agent

Disease cycles

cycles are difficult to predict some cycles are seasonal

Infectious disease

diseases caused by infectious agents such as bacteria, viruses, protozoans, fungi and helminths

Intoxications

diseases resulting from the ingestion of toxins or toxic substances

Zoonoses

diseases that can be transmitted under natural conditions to human from other vertebrate animals

Communicable Infectious disease

diseases which can spread from one host to another

Fever

elevation of body temperature to kill invading agents, reduce their ability to grow(reproduce), and/or inactivate their toxic products

Vector Control

eradication of vectors has been very successful

Immune System

especially lymphocytes and organs. Characteristics that distinguish immunity from innate host defense are recognition of self versus nonself, specificity, diversity(heterogeneity), and memory

Innate Immunity (Genetic Immunity)

exists because of genetically determined characteristics

Necrotizing Fascitis

flesh-eating strains of Streptococcus

Modes of Disease Transmission

for a disease to occur the causative agent must be transmitted from a reservoir of infection: Three Modes: Contact Transmission, Vehicle Transmission, Vector Transmission

Direct Person to Person Transmission

from infected patient to staff, visitor or uninfected patient

Eyes

have no known microflora

Susceptibility ans Transmission

having a compromised immune system they are called Compromised Hosts

St. Anthony's Fire (Erysipelas)

hemolytic streptococci

Alpha-Hemolysins

hemolyze blood cells and partially break down hemoglobin

Beta-Hemolysins

hemolyze red blood cells and completely break down hemoglobin

Acquired (Adaptive) Immunity

immunity obtained in some manner other than heredity

Horizontal Transmission

infection may be spread by touching, kissing, or sexual contact. Pathogens may be spread by poor hygiene, especially in the bathroom. Typically this would be by DIRECT ORAL-FECAL TRANSMISSION

Molecular Defenses

interferon and complement which destroy or impede invading microorganisms

Keratin

is a protein that prevents water and water soluble products from entering the body

Pediculosis

is lice infestation; lice lay eggs (nits); Pediculus humanus (body louse) lives on body or hair; Phthirus pubis (crab louse) causes itching in pubic area

Artificially Acquired Adaptive Immunity

is obtained by receiving an antigen by the injection of a vaccine or immune serum that produces

Etiology

is the study of the cause of disease

Ringworms

it is a disease and not an organism; it is difficult to treat and highly contagious; (Tinea corporis or body ringworm; Tinea cruris or groin ringworm), nails (Tinea unguium), scalp (Tinea capitis), beard (Tinea barbae), or foot (Tinea pedis)

Warts

it is caused by human papillomaviruses; may affect skin, mouth, respiratory tract and genitalia; genital warts are associated with cervical cancer; virus can be acquired by newborns from infected mothers (vaginal delivery)

Bacterial Conjunctivitis (Pinkeye)

it is extremely contagious; it is often transferred by hands or insect vectors (gnats)

Immunization

large scale programs work very well

Skin

largest single organ of the human body

Mucous Membranes

line tissue and organs that open to the exterior of the body

Symbiosis

living together of two different kinds of organisms

Chronic Inflammation

long term, may develop rapidly or progress at a slower rate

Hazard of Immunization

may produce fever, malaise, soreness, and allergic reactions. Live vaccines may pose a threat to the fetus of pregnant women-birth defects

Carriers

may transmit disease in a variety of ways-direct, indirect, may even serve as a reservoir host

Protozoa and Helminthes

most are cell mediated- T-cells activate macrophages and other lymphocytes

Fungi

most defenses are cell-mediated: T-cells activate B-cells (lymphocytes) or attack themselves

Vehicle Transmission

nonliving carrier of an infectious agent from its reservoir to a susceptible host. Water, Air, Food

Biological Vector

organisms transmit pathogens actively. The pathogen must complete part of its life cycle on or in the vector

Mechanical Vectors

organisms which transmit pathogens passively usually on feet or other body parts

Pathogen

parasite capable of causing a disease in a host

Food Transmission

pathogens are most likely to be transmitted in foods that are inspected, processed insanitarily, cooked incompletely, or refrigerated poorly. Blood, IV fluids, and other body fluids

Endotoxins

poisons contained in cell walls of Gram negative bacteria. These may be released into host tissues when the bacteria die or multiply. Treatment of these bacteria by using antibiotics may cause large numbers to die, releasing the endotoxins and causing Endotoxic Shock

Eosinophils

present in large numbers during allergic reactions and parasite infestations

Naturally Acquired Active Immunity

produced when a person is exposed to an infectious agent

Artificially Acquired Active Immunity

produced when a person is exposed to vaccine containing live, weakened, or dead organisms, or their toxins

Artificially Acquired Passive Immunity

produced when antibodies made by another host are introduced into a new host

Naturally Acquired Passive Immunity

produced when antibodies made by the mother's immune system are transferred into her offspring

Aspergillosis

produces black fuzzy growth found in wounds, burns and ear wax

Interferon

protein which interferes with viral replication

Antibodies

proteins produced by the body's immune system in response to an antigen that is capable of binding specifically to that antigen and neutralizing it

Endemic

refers to a disease that is constantly present in a specific population

Mast cells

release histamine and are associated with allergies

Basophils

release histamine to help initiate the inflammatory response

Indirect Transmission

through equipment, supplies and hospital procedures

Enterotoxins

toxins that act on the tissues of the gut

Neurotoxins

toxins which act on nerve tissue. Typically these poisons prevent muscle relaxation

Pneumotoxins

toxins which act on the respiratory system

Naturally Acquired Adaptive Immunity

usually obtained by having a disease

Chickenpox and Shingles

varicella-zoster virus (herpesvirus); causes chickenpox in children; once you have had it, the virus remains latent and can cause shingles in the elderly and in AIDS patients

Waterborne Transmission

waterborne pathogens usually thrive in and are transmitted in water contaminated with untreated or inadequately treated sewage

Carbuncle

"multi-headed" and very in nature

Transmission through Air

Airborne

Functions of Complement

1. Enhance phagocytosis 2. Lyse microorganisms directly 3. Generate peptide fragments that regulate inflammation and immune responses 4. Initiates opsonins which coat infectious agents and stimulates their recognition by phagocytes. This process is called opsonization.

7 Categories of Isolation

1. Strict 2. contact 3. respiratory 4. tuberculosis 5. enteric precautions 6. drainage/secretions precautions 7. blood and body fluids precautions

Koch's Postulates

1. The specific causative agent must be present in every case of the disease 2. The agent must be isolated into a pure culture 3. When the agent is inoculated into a healthy, susceptible host, the agent must produce the same disease. 4. The same agent must be re-isolated from the inoculated, diseased experimental host and identified as being identical to the original causative agent

Benefits of fever

1. increased temperature is usually above the optimum temperature for pathogens. This slows their rate of growth thereby reducing the number of microbes. 2. Higher temperature may inactivate microbial enzymes or toxins. 3. Increased temperature may heighten the level of immune response by increasing the rate of chemical reactions. 4. Fever makes a patient feel ill causing the patient to rest thus preventing further damage to the body and allowing energy to be used to fight the disease.

Sites of Nosocomial Infections

1. urinary tract 2. surgical wounds 3. respiratory tract 4. skin (esp. burns) 5. blood 6. GI tract 7. central nervous system

Candidiasis

Candida albicans which is present in normal flora of skin and vagina; it is opportunist pathogen; appears as Vaginitis (pregnancy, diabetes, or antibiotic therapy) or Thrush (milky patches of inflammation on oral mucous membranes)

Disease

An infective agent is altering the host's state of health wherein the host's body cannot carryout normal function

Pathogenicity

An organism's capacity to produce disease

Characteristics of the Immune System

Antigen, Antibodies, Titer

Immunity to Various Kinds of Pathogens

Bacteria, Viruses, Fungi, Protozoa and Helminthes

Coagulase

Bacterial enzyme that accelerates clotting of hosts blood. This allows some Staphylococcus species to avoid human body defenses

Blastomycosis

Blastomyces dermatitidis enters through lungs or wounds; causes pus-producing lesions

Mutualism

Both members of the relationship benefit

Loaiasis

Caused by an eye worm Loa loa; worm is transmitted by deer flies; worm over an inch long in one's eye

Sequence of Microbial Affects on Host

Contamination, Infection, Disease

Recommended Immunizations

Diptheria-Tetanus-Pertussis (DTaP) Measles-Mumps-Rubella (MMR) Poli0; controversy still exists on whether to use the Sabin(3 different live viruses) or The Salk(dead) Hepatitis B(HepB)

Pathogens

Disease causing organisms; Parasite capable of causing disease in a host

Non Communicable Infectious disease

Diseases which are not spread from one host to another. Would include Tetanus, Legionnaire's Disease and Food Poison Toxins

Sources of Infection

Exogenous and Endogenous. Pseudomonas are responsible for about half of the infections

Preventing and Controlling Nosocomial Infections

Hand washing still #1, Maintaining sterility, use of gloves, eradication of pests, monitor antibiotic use

Controlling Disease Transmission

Isolation, Quarantine, Immunization, Vector Control

Measles (Rubeola)

It is highly contagious and caused by rubeola virus: susceptible person has 99% chance of infection if directly exposes to someone releasing the virus

Transmission by Vectors

Living organisms that transmit a disease causing organism from one host to another. Most vectors are arthropods- Ticks, Flies, Fleas, Lice, Mosquitos

STD Transmission

May be transmitted by all types of sex including oral and anal

Droplet Transmission

Occurs when a person sneezes, coughs, speaks, laughs, etc. near others

Indirect Fecal-Oral Transmission

Occurs when pathogens from the feces of one organism, infect another organism

MRSA

Methcillin Resistant Staphylococcus aureus

Resident Microflora

Microorganisms that are always present in or on the body

Airborne Transmission

Most are transients from soil, water, plants or animals. Pathogens are said to be airborne if they travel for more then one meter through the air. Airborne pathogens may combine with dust or become suspended in aerosols. Dust particles may harbor many pathogens such as Staphylococci, Streptococci, naked viruses, as well as bacterial and fungal spores

Infection

Multiplication of an infective agent in or on the host

Types of Symbiotic Relationships

Mutualism, Commensalism, Parasitism

Indirect Contact Transmission

Normally occurs through contact with fomites, nonliving object that harbor and transmit infectious agents.

Morbidity Rate

Number of INDIVIDUALS affected by a disease during a set period in relation to the total population

Parasitism

One member benefits (parasite), while the other member is harmed (host)

Commensalism

One member of the relationship benefits while the other is neither helped nor harmed

Transient Microflora

Organisms that are present when special conditions exist

Normal Microflora

Organisms that live in or on the body but do not cause disease; may also be call Normal Microbiota

Vertical Transmission

Pathogens are passed from parent to offspring in the egg, sperm, across the placenta or in mother's milk

Isolation

Patient with a communicable disease is prevented from having contact with the general population.

Prodromal Phase

Period in which an individual experiences nonspecific mild symptoms such as malaise or headache

Opportunists

Resident or Transient microflora that cause disease when particular conditions arise

Epidemiologist

Scientist that studies epidemiology.

Convalescence Period

Stage where tissues are being repaired and healing is taking place

Contamination

Some microorganism or infective agent is present

The United States

The most important to the public the CDC- Center for Disease Control and Prevention

Incidence of Disease

The number of NEW cases contracted within a set population during a specific period of time

Toxemia

The spreading of toxins by blood

VRSA

Vancomycin Resistant Staphylococcus aureus. Linezolid (Zymox) or Daptomycin (Cubicin) are the antibiotics of choice

Neutrophils

respond quickly to site of infection and may function as phagocytes

Specific (Adaptive) Defenses

respond to particular agents called antigens

Quarantine

separation of "healthy" human or animal carriers from the general population

HyperImmune Sera

serum with antibodies of specific types

Complement or Complement System

set of twenty large regulatory proteins produced by the liver, that circulate in inactive form

Acute Inflammation

short term, develops rapidly

Portals of Entry

site where a microorganism can enter the body. The skin and mucous membranes of the Digestive system, Respiratory system, Urogenital system

Reservoirs of Infection

sites in which organisms can persist and maintain their ability to infect. Human Reservoirs, Animal Reservoirs, Nonliving Reservoirs

Portals of Exit

sites where microorganisms leave the body. Generally with body fluids or feces.

Physical Barriers

skin, mucous membranes and the chemicals they secrete

Exotoxins

soluble poisons secreted into host tissue. are produced by the following genera: Clostridium, Streptococcus, Staphylococcus, and a few other species