Brock BIOL 2P98 - FINAL EXAM

Typhoid fever is caused by what bacteria?

Salmonella typhi

how is Typhoid fever spread?

through water or food supplies contaminated with feces

What are the two main disease causing Salmonella?

Salmonella typhimurium and S. Typhi

the human body contains more microbial cells than human cells

true

when does colonization of the human body by microbes begin?

during birth

in some individuals, this stomach microbe can cause ulcers

helicobacter pylori

which of the following does NOT normally contain microflora in healthy individuals?

urethra

bacteria make up about ___ the weight of fecal matter

1/3

____ is the growth of microorganisms NOT normally present within the host

infection

which of the following does NOT occur during the development of dental carries?

salivary enzymes degrade tooth enamel enabling adherence

exotoxins that affect the small intestines are also known as:

enterotoxins

Botulinum toxin is one of the most potent biological toxins known. the toxin causes:

flaccid paralysis

which is the following is false about age and susceptibility of infection?

young babies are not susceptible to infection as long as they are breast feeding

which of the following is a primary lymphoid tissue?

thymus

the antigen-reactive proteins of T cells are immunoglobulins (antibodies)

false

adaptive immunity requires previous exposure to a pathogen or its products

true

T cells recognize peptide antigens ONLY in the context of:

MHC

antigen stimulation causes B cells to multiply and differentiate into ___ and ___

plasma cells and memory cells

vaccines; good or bad

good

activated neutrophils migrate along a ___ gradient

chemokine

opsonization is the enhancement of ___ due to the depositions of or ____ on the surface of a pathogen or other antigen

phagocytosis/antibody/complement

cholera enterotoxin causes ___, which is the primary way infected individuals dies from the disease

diarrhea ans dehydration

the protective immunity conferred by antibodies and T cells due to exposure to antigens through infection is known as:

natural active immunity

which of the following is not a constitute of LPS subunits?

lipids B

healthcare-associated infections are also called:

nosocomial infections

decalcification of the tooth enamel is caused by:

lactic acid

exotoxins are ____, but endotoxins are ____

proteins/lipopolysacchardies-lipoprotien complxes

the collective term for the organisms living on or in the human body, as opposed to a general term for organisms in an environmental habitat is:

the human microbiome

cells that can engulf foreign particles, and can ingest, kill, and digest most bacterial pathogens are called:

phagocytes

characteristics of Clostridium difficile or C. difficile

are that it is a gram-positive, endospore spore-forming bacterium often associated with antibiotic-related diarrhea and colitis.

what is one of the main characteristics of C. difficile associated colitis?

severe inflammation in the colonic tissue (mucosa) associated with destruction of cells of the colon (colonocytes)

How do you get C. difficile?

almost exclusively picked up in the hospital. when a hospitalized patients who has been unwittingly colonized by the bug is given antibiotics for another condition

Who is at risk of contracting the bacteria C. difficile?

those undergoing chemotherapy, have abdominal surgery or have other stomach or intestine problems

what are AB toxins?

they have a host cell receptor (B Subunit) and a damaging agent (A subunit)

which of the following can be inferred from the presence of coliform in water?

A and B - fecal contamination and poor water quality

which of the following is NOT true about gonorrhoea?

it is caused by an infection

a serious complication associated with enterohemorrhagic E. coli infection is:

kidney damage

which of the following pathogens does not cause diarrhea?

streptococcus pyogenes

which is true about super antigens?

they are a type of exotoxin and the indiscriminately bind to MHC class II receptors on T cells

consider Staphylococcus aureus, clostridium perfingens, escherichia coli and vitro cholera. what do these bacteria have in common?

all produce an enterotoxin

a bacterium can live inside a phagocyte by preventing (e.g., salmonella)

the fusion of the phagosome with lysosomes

reticulate and elementary bodies are two forms of :

chlamydia bacteria.

which of the following produces a biological insecticide?

Bacillus thuringiensis

legionnaires’ disease is so named because:

it was first identified in 1976 during a convention of the American Legion in Philadelphia, where many attendees fell ill.

intracellular Gram-negative diplococci found in a urethra sample of a male is indicative of:

Neisseria gonorrhoea

toxins with ADP ribosyltransferase activity can cause which of the following results?

inhibition of elongation factor 2

which of the following is a nonprotienayceous, yet toxic, compound found in all gram-negative bacteria?

endotoxin

normal microbiota helps to ___ colonization of pathogenic organisms

prevent

the dose of an pathogen that kills 50% of animals in a test group and is used to estimate the virulence of a pathogen is known as:

LD50 (lethal dose 50)

the four characteristics of the immune system are:

specificity, diversity, distinguishing self from non-self, immunological memory

which of the following match?

escherichia/O157:H7/Shiga toxins