final exam guide Flashcards
Bacterial capsules are associated with what property?
primary virulence factor
what phase of the bacterial growth curve is best for biochemical testing?
exponential growth phase
what type of environment (aerobic, anaerobic, or microaerophilic) is provided by the candle jar?
microaerophilic
what is the purpose of the Albert’s stain?
used to stain metachromatic granules of corynebacterium diptheriae
give an example of a differential, enriched, and selective media
enriched = blood agar differential = McConkey selective = MacConkey OR thayer martin
what are the standard conditions for the autoclave?
15 lbs/square inch
121 degrees
for 15 minutes
what is the most abundant organism found in the human intestinal tract?
bacteroides
what is the most important single test that differentiates staphylococcus aureus from non-pathogenic staphylococci ?
coagulase
alpha streptococcus viridians are the most important cause of what serious illness?
SBE
what is the only significant pathogen in the throat?
group a beta strep
Enterococcus ( which is BEA + and 6.5% NaCl+) belongs to which lancefield group?
D
foul smelling pus from an abcess which yields gram positive cocci in chains on gram stain would be indicative of what organism?
anaerobic strep
how do you identify Neisseria Gonorrhoeae?
dextrose and oxidase +
gram =
how do you identify Neisseria Meningitidis ?
gram = oxidase + dextrose and maltose + grows on thayer martin can be normal in throat
what three antibiotics are added to Thayer-Martin to make it a selective medium for pathogenic Neisseria?
Vancomysin
colistin
nystatin
what are the general characteristics of the family Enterobacteriaceae?
glucose fermenters
oxidase =
peritrichous flagella
what is the appearance of a positive test for citrate?
blue color on slant and/or growth
what is the appearance of a positive test for indole?
red color
what is the appearance of a positive test for H2S?
black
what is the appearance of a positive test for phenylalanine
dark green color
what is the appearance of a positive test for VP?
pink-red color
what is the reagent used for the indole test?
kova’s reagent
what are the reagents used for the nitrate test?
sulfanilic acid and alpha-naphthylamine
what are the reagents used for the phenylalanine test?
10% ferric chloride
what are the reagents used for the VP test?
alpha-naphthol
potassium hydroxide
what is the best means to differentiate the genus enterobacter from the genus klebsiella?
motility
which genera are urea positive?
proteus
LDC differentiates what organism from non-pathogenic H2S producers, such as citrobacter and proteus?
salmonella
what is the causative agent of hemorrhagic colitis and hemolytic uremic syndrome due to its production of Verotoxin ( also known as shigella-like toxin)?
e. coli 0157
what are the characteristics of serratia marcesens ?
chromogenic antibiotic resistant associated with UTI hospital acquired infections people with wounds who are outside a lot
what test differentiates proteus mirabilis from proteus vulgaris? (both of which who can swarm on SBA or chocolate agar)
indole
M is =
V is +
which genera are phenylalanine positive?
proteus
providencia
morganella
which organisms causes an infection of the mesentery suggestive of actue appendicitis?
yersinea
K/A with gas and H2S in TSI is suggestive of what intestinal pathogen?
salmonella
what non-pathogenic organism is biochemically so similar to shigella that isolates that are biochemically identified as shigella must be typed?
alkalecense dispar
what is the difference between a food poisoning and a food infection?
food poisoning - staph aureus , preformed toxins, early on set of symptoms
food infection- salmonella , viable organisms, later onset of symptoms
what organism could be described as an oxidase positive glucose-fermenting rod commonly found in water and soil?
aeromonac hydrophilus
a gram negative coccobacillus isolated from a cat bike is most likely to be
pasturella multocida
a salt-loving organism responsible for gastroenteritis due to contaminated sea food is most likely to be ?
vibrio
what media is used to differentiate between oxidation and fermentation?
hugh-leifson
a gram negative coccobacillus isolated from a patient with endocarditis that is oxidase + catalase = indole + non-motile and weakly fermentative would most likely be?
cardio bacterium
what are the three most commonly isolated non-fermentative bacteria?
pseudomonas aerogenosa, acetobacter, stinotrophomonas
a non-fermentor with a blue-green pigment and a grape-like odor is?
pseudomonas aerogonosa
a non-fermenter that is a strong maltose oxidizer and a weak glucose oxidizer is?
stinotrophomonas montophilia
the causative agent of glanders is?
burholderia (pseudomonas mallie)
a gram negative, oxidase negative coccobacillus
bordetella pertussis
what genus of bacteria can be confused with neisseria beceause they are oxidase + and sometimes grow on Thayer-Martin and can be differentiated by gram stain since those organisms are gram negative rods rather than cocci?
morexella
a yellow pigemented, oxidase + gram negative rod which can cause meningitis (especially in infants) is?
flavobacterium meningosepticum
when is it the best time to try to isolate brucella from the bloodstream?
first three weeks
Listeria and corynebacterium are best differentiated by what test?
motility
what organism is described as a gram + aerobic partially acid-fast rod which usually appears on gram stain as a delicate branching rod?
nocardia
why are routine sterile swabs (culturettes) NOT acceptable for anaerobic cultures?
not anaerobic
the causative agent of pseudomembranous colitis (PMC) associated with over-treatment with antibiotics is?
clostridium difficile
what anaerobic organism usually produces a black colony on laked blood agar?
prevetella melininegenica
gram negative, pleomorphic rods which are non-spore forming and are strict anaerobes could be ___________?they are normal inhabitants of the mouth so can be isolated from infections of the nasopharynx, the sinuses, etc.
fusobacterium
a gram positive branching rod isolated from “sulfur granules” obtained from a patient’s jaw is?
actinomiyces
lactobacillus is most frequently isolated from vaginal swabs or?
adult female urines
what anaerobic organism is a normal inhabitant of the skin most frequently isolated from 5-7 day old blood cultures where it is a contaminant?
propioni bacterium acnes
acid-fast bacillus are usually catalase?
+
what substance is the most commonly used agent for concentrating sputums in AFB culture becuase it decontaminates the sputum (removes normal flora organisms) is a mucolytic ( mucuous destroying) agent, and it does not damage the AFB?
N-acetyl-L-cystine
an acid fast bacillus (AFB) producing a buff colored, dry heaped up colony that is niacin and nitrate positive is most likely to be ?
mycobacterium tuberculosis
which species of organism causes a form of rat bite fever known as Haverhill fever and characteristically produces L-forms?
streptobacillus moniliformis
in a sputum culture which reveals large numbers of WBC’s on gram stain but no organisms, one would suspect what organism?
legionella pneumophilia
what respiratory pathogen is associated with primary atypical pneumonia (Eaton’s agent pneumonia) increased cold agglutination titre, and streptococcus MG?
mycoplasma pneumoniae
the results of kirby-bauer susceptibility tests are reported as
sensitive, intermediate , or resistant
the __________ is defined as the smallest concentration of a drug that completely inhibits growth
MIC
for which diseases are blood cultures are the best means of identification?
sepsis, SBE, typhoid fever
_______ is often added to blood culture media because it acts as an anticoagulant inactivates teh aminoglycosides and will neutralize the bactericidal effects of human serum
sudium polyanithol sulfonate
which serological typing of Hemophilus influenza is the most pathogenic?
type B
what organism is enhanced by cold temperatures?
Listeria
the toxicity test for crynebacterium diptheriae is called the
elek test
what is the test used to identify the alpha toxin of clostridium?
nagler
what agar is used in kirby bauer sensitivity test?
mueller hinton
what is a castaneda bottle?
blood culture bottler with slant off media, broth
isolates brucella
the bacterial infection which is characterized by donovan bodies is caused by what organism ?
klebsiella granulomatis
sulfa drugs
broad spectrum
compete with folic acid
aplastic anemia, granulocytopenia, thrombocytopenia
toxic to kidneys
penicillin
gram + organisms
interferes with cell wall synthesis
may produce allergies
nonphotochromgens
unpigmented (except light yellow color which is not intensified by light)
photochromgens
unpigmented in the dark, but pigmented in the light
rapid growers
colonies appear in 3-5 days
scotochromogens
pigmented even in the dark
mycobacterium kansaii
group 1
nontuberculous mycobacterial pulmonary
photochromogen
mycobacterium marinum
group 1
photochromogen
“swimming pool granuloma” a cutaneous infection when traumatized skin comes in contact inadequately chlorinated fresh/salt water
M. szulgai
group II
scotochromogens
pulmonary disease similar to TB
M. Tuberculosis
group III
causative agent of tuberculosis
a slightly curved gram negative rod
oxidase +
sensitive to naladixic acid
campylobacter fetus s.s. jejni
gram + CAMP +
Group B
gram + lancet “p”disc
optochin sensitive
strep pneumoniae
gram = rod
oxidase +
blue-green pigment
42 degree tube
pseudomonas aereogenosa
gram + pleomorphic rods
hematin NAD “XV”
hemophilus influenza
what agar does bordatella use?
potato-blood-glycerol
what agar does C. diptheriae use?
potassium tellurite
what agar does francisella use?
cystine-blood-glucose
what agar does vibrio use?
thiosulfate-citrate-bile salt- sucrose TCBS
what diseases dos bordetella pertusis cause?
whooping cough
what disease does brucella cause?
undlent fever
what diseases does hemophilus influenza cause?
meningitis
what disease does hemophilius bucrydi cause?
chancroid
what disease does chlostridium cause?
tetanus (tetani/ lock jaw)
what disease does chlostridium perfringence cause?
gang green
what disease does corynebacterium cause?
diptheria
what disease does listeria cause?
still births
what disease does leptospira cause
hemorrhagic jaundice
what disease does treponema cardium cause?
penta
what disease does Treponema palladium cause?
syphilis
what disease does Treponema partenoe cause?
yaws
what organism is this nickname used for: friedlanders bacillus
klebsiella pneumoniae
what ogniams is this nickname used for: kochweeks bacillus
hemophilus aegypticus
what is the nickname for this organism: hemophilus influenzae
pheiffer bacillus
what is the nickname for this organism: mycobacteria leprea
(leprosy)
hansons bacillus
