E4 sp15 Study Guide (1) - Microbiology Exam 4 Study Guide...

Microbiology Exam 4 Study Guide Spring 2015
Chapter 14 (20 Questions)
-Normal microbiota (permanently colonize host) and transient microbiota (weeks days or months)
-Antagonism (competition between microbes) and benefits of normal microbiota (protect the
host by occupying niches that pathogens might, producing acids, producing bacteriocins (proteins that
interfere with growth of competing organisms), probiotics, live microbes applied or ingested into the
body)
-Koch’s postulates used to determine cause of disease, as it links the etiological agent to disease
1. Same pathogen must be present in every case of the disease
2. Pathogen must be isolated from diseased host and grown in pure culture
3. Pathogen from pure culture must cause disease when inoculated into a healthy lab animal
4. Pathogen must be isolated from inoculated animal and shown to be original organism
-Classifying infectious diseases- sign (change in the body that can be measured or observed), symptom
(felt change in the body), syndrome (specific group of signs and symptoms that accompany disease),
communicable (spread form one host to another)/non communicable( not transmitted from one host to
another)
-Severity or duration of disease – acute (symptoms develop rapidly), chronic (disease develops slowly) ,
primary(acute infection that causes initial illness), secondary (opportunistic infection after a primary
infection), inapparent or subclinical disease (no noticeable signs or symptoms)
-Extent of host involvement- bacteremia (bacteria in the blood), septicemia (growth of bacteria in the
blood), local (pathogens limited to small area of the body) and focal infection (systemic infection that
began as local infection), toxemia (presence of toxins in the blood), viremia (viruses in the blood)
-Reservoirs of infection, continual sources of infection
 Human (AIDS, gonorrhea, Shigella,) Carriers (unapparent infections, latent diseases)]
 Animals – Rabies, lyme disease. Some zoonoses transmitted to humans
 Nonliving, botulism, tetanus. (Soil, fertilizer animal feces), Water
-Transmission of disease (recognize examples of each type)
1. Contact (Direct, person to person), (Indirect, spread by fomites – inanimate objects), (droplet,
airborne within one meter, sneeze, coughing, talking)
2. Vehicle (by an inanimate reservoid, food, water, air body fluids) (Airborne (droplet in dust that
travels more than 1 meter)
3. Vectors fleas, ticks, mosquitoes (mechanical, carries pathogen on feet – passive), (biological,
pathogen reproduces in vector)
-Nosocomial infections, acquired by hospital stay – what contributes to a nosocomial infection?
Microorganisms in hospital environment, compromised host, chain of transmission