Final Exam Flashcards
1
Q
Bacterial capsules are associated with what property?
A
virulence
2
Q
What phase of the bacterial growth curve is best for biochemical testing?
A
log phase
3
Q
What type of environment is provided by the candle jar?
A
microaerophilic
4
Q
What is the purpose of Albert’s stain?
A
simple stain to stain the metachromatic granules of Corynebacterium diptheriae; used to identify the cause of diphtheria
5
Q
What is an example of differential media?
A
MacConkey
6
Q
What is an example of enriched media?
A
chocolate agar, blood
7
Q
What is an example of selective media?
A
MacConkey, Thayer Martin, and CNA
8
Q
What are the standard conditions for the autoclave?
A
121ºC at 15 psi for 15 minutes
9
Q
What is the most abundant organism found in the human intestinal tract?
A
Bacteroides
10
Q
What is the most important single test that differentiates Staphylococcus aureus from non-pathogenic staphylococci?
A
coag
11
Q
α Streptococcus viridans are the most important cause of what serious illness?
A
subacute bacterial endocarditis
12
Q
What is the ONLY significant pathogen in a throat culture?
A
Group A β Strep
13
Q
Enterococcus belongs to what Lancefield group?
A
Group D
14
Q
Enterococcus results on BEA and 6.5% NaCl
A
+ +
15
Q
Foul smelling pus from an abscess which yields gram positive cocci in chains on gram stain would be indicative of what organism?
A
Anaerobic strep
16
Q
How do you identify Neisseria gonorrhaeae?
A
Oxidase + Gram = diplococci growing on Thayer Martin agar, only dextrose +
17
Q
What are the identifying characteristics of Neisseria meningitidis?
A
Gram = coffe bean shaped diplococci, dextrose +, maltose +, oxidase +
18
Q
What three antibiotics are added to Thayer-Martin to make it a selective medium for pathogenic Neisseria?
A
Vancomycin, colistin, nystatin
19
Q
What are the general characteristics of the family Enterobacteriaceae?
A
all glucose fermenters, oxidase =, nitrate +, peritrichous if motile +
20
Q
What is the appearance of a positive test for citrate?
A
growth and/or blue
21
Q
What is the appearance of a positive test for indole?
A
red layer with addition of Kovac’s reagent
22
Q
What is the appearance of a positive test for H2S?
A
black growth on medium
23
Q
What is the appearance of a positive test for phenylalanine?
A
green to blue color with addition of ferric chloride
24
Q
What is the appearance of a positive test for VP?
A
red
25
What are the reagents used for the indole test?
Kovac's reagent
26
What are the reagents used for the nitrate test?
sulfanilic acid
27
What are the reagents used for the phenylalanine test?
ferric chloride
28
What are the reagents used for the VP test?
alpha napthal/potassium hydroxide
29
What are the characteristics of E. coli?
Gram =, TSI A/A, Indole +, Citrate =, Lysine +, Ornithine +, Urea =, Motile +
30
What is the best means to differentiate the genus Enterobacter from the genus Klebsiella?
motility, Klebsiella is nonmotile
31
Which genera are urea positive?
Klebsiella, Proteus
32
LDC differentiates what organism from non-pathogenic H2S producers such as Citrobacter and Proteus?
Salmonella
33
What is the causative agent of hemorrhagic colitis and hemolytic uremic syndrome due to is production of Verotoxin?
E. coli 0157
34
What is Verotoxin also known as?
Shiga-like toxin
35
What are the characteristics of Serratia marcesens?
chromogenic, resistant to antibiotics, associated with UTI, hospital-acquired infections, and wound infections in people who s pend a lot of time outdoors in the woods
36
What test differentiates Proteus mirabilis from Proteus vulgaris?
Indole, mirabilis is indole =
37
Which genera are phenylalanine positive?
Proteus, Providencia, and Morganella
38
Which organisms causes an infection of the mesentery suggestive of acute appendicitis?
Yersinia pseudotuberculosis
39
K/A with gas and H2S in TSI is suggestive of what intestinal pathogen?
Salmonella
40
What non-pathogenic organism is biochemically so similar to Shigella that isolates that are biochemically identified as Shigella must be typed?
Alkalescens dispar
41
What is the difference between a food poisoning and a food infection?
Food poisoning is rapid from an enterotoxin; food infection is from ingesting large amounts of viable organisms and takes 18-24 hours
42
What organism could be described as an oxidase positive, glucose-fermenting rod commonly found in water and soil?
Aeromonas hydrophilia
43
A Gram negative coccobacillus isolated from a cat bite is most likely to be?
Pasteurella multocida
44
A salt-loving organism responsible for gastroenteritis due to contaminated sea food is most likely to be?
Vibrio parahemolyticus
45
What media is used to differentiate between oxidation and fermentation?
Hugh and Leifson green semisolid
46
A Gram negative coccobacillus isolated from a patient with endocarditis that is oxidase +, catalase -, indole +, non-motile and weakly fermentative would most likely be?
Cardiobacterium hominus
47
What are the three most commonly isolated non-fermentative bacteria?
Pseudomonas aeruginosa, Acinetobacter, Stenotrophomonas maltophilia
48
A non-fermenter with a blue-green pigment and a grape-like odor is what?
Pseudomonas aeruginosa
49
A non-fermentor that is a strong maltose oxidizer and a weak glucose oxidizer is?
Stenotrophomonas (Xanthomonas) maltophilia
50
What is the causative agent of glanders?
Burholederia mallei (Pseudomonas)
51
A Gram negative, oxidase negative coccobacillus is?
Acinetobacter
52
What genus of bacteria can be confused with Neisseria because 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
53
A yellow pigmented, oxidase +, Gram negative rod which can cause meningitis (especially in infants) would be?
Flavobacterium meningisepticum
54
When is it the best time to try to isolate Brucella from the bloodstream?
Within the first three weeks after infection
55
Listeria and Corynebacterium are best differentiated by what test?
motility
56
What organism is described as a Gram +, aerobic partially acid-fast rod which usually appears on gram stain as delicate, branching rods?
Nocardia sp.
57
Why are routine sterile swabs (clutters) NOT acceptable for anaerobic cultures?
because they are not kept from oxygen
58
The causative agent of pseudomembranous colitis (PMC) associated with over-treatment with antibiotics is?
Clostridium dificile
59
What anaerobic organism usually produces a black colony on lake blood agar?
Prevotella melaninogenica
60
Gram negative pleomorphic rods which are non-spore forming, strict anaerobes could be?
Fusobacterium
61
Normal inhabitants of the mouth and isolated from infections of the nasopharynx and sinuses are?
Fusobacterium
62
A Gram positive, branching rod isolated from "sulfur granules" obtained from a patient's jaw is?
Actinomyces
63
Lactobacillus is most frequently isolated from?
urine from adult females
64
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?
Propionibacterium acnes
65
Acid-fast bacilli are usually catalase?
catalase positve
66
What substance is the most commonly used agent for concentrating sputum for AFB culture because it decontaminates the sputum, is a mucolytic agent, and it does not damage the AFB?
N-acetyl-L-cysteine (NALC)
67
Characteristics of nonphotochromogens Runyon groups
unpigmented except for slight yellow color which is not intensified by light
68
Characteristics of photochromogens Runyon groups
unpigmented in the dark, but pigmented in the light
69
Characteristics of rapid growers Runyon groups
colonies appear in 3-5 days
70
Characteristics of scotochromogens Runyon groups
pigmented even in the dark
71
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
72
Which species of organism causes a form of rat bite fever known as Haverhill fever and characteristically produces L-forms?
Streptobacillus moniliformis
73
In a sputum culture which reveals large numbers of WBCs on gram stain but NO organisms, what would be suspected?
Legionella pneumophilia
74
What respiratory pathogen is associated with primary atypical pneumonia, increased cold agglutinin titer, and Streptococcus MG?
Mycoplasma pneumoniae
75
What is the other name of the atypical pneumonia that Mycoplasma pneumoniae causes?
Eaton's agent pneumonia
76
The results of Kirby-Bauer susceptibility tests are reported as?
Sensitivity (susceptible), intermediate, or resistant
77
What is the smallest concentration of a drug that completely inhibits growth?
minimum inhibitory concentration
78
For which diseases are blood cultures the best means of identification?
sepsis, subacute bacterial endocarditis, typhoid fever
79
What is often added to blood culture media because it acts as an anticoagulant, inactivates the ahminoglycosides, and will neutralize the bactericidal effect of human serum?
Sodium polyanethol sulfonate
80
Which serological type of Hemophilus influenza is the most pathogenic?
Hemophilus influenzae Type B
81
What organism is enhanced by cold temperatures?
Listeria
82
The toxicity test for Corynebacterium diptheriae is called?
Elek test
83
What is the test used to identify the alpha toxin of Clostridium?
Nagler test
84
What agar is used in Kirby-Bauer sensitivity testing?
Mueller Hinton agar
85
Name one medium that can be used for the isolation of AFB
L-J or Middlebrook
86
Name one medium that can be used for the isolation of anaerobes
KV or anaerobic sheep blood
87
Name one medium that can be used for the isolation of Legionella
CYE (charcoal yeast extract)
88
What is a Castaneda bottle?
Blood culture bottle with a slant for isolation of Brucella
89
The bacterial infection that is characterized by Donovan bodies is caused by what organisms?
Calymmatobacterium granulomatis
90
What is an important pathogen of Runyon group 1?
Mycobacterium marinum and Kansasii
91
What is an important pathogen of Runyon group 2?
Szulgai
92
What is an important pathogen of Runyon group 3?
Mycobacterium tuberculosis
93
What is an important pathogen of Runyon group 4?
Fortuitum
94
What is the mode of action of penicillin?
interferes with the cell wall synthesis, affects mainly Gram + organisms, and may produce allergies
95
What is the mode of action of sulfonamides?
compete with folic acid, are broad spectrum, and can be toxic to the kidney
96
CAMP+, Gram+, Beta hemolytic
Group B Beta Strep
97
Gram+, lancet shaped, alpha hemolytic, optichin sensitive
Streptococcus pneumoniae
98
Slightly curved rod, Gram=, Oxidase+, naladixic acid sensitive
Campylobacter fetus s.s.jejni
99
Gram= rod, oxidase+, pyocyanin pigment, grows at 42F
Pseudomonas aeruginosa
100
Pleomorphic rods, requires hemotin (X) and NAD (V)
Hemophilus influenzae
101
Bismuth-sulfite agar used to isolate
Salmonella typhi
102
potato-blood-glycerol agar used to isolate
Bordetella pertussis
103
Potassium (K) tellurite agar used to isolate
Clostridium diphtheria
104
cystine-blood-glucose agar used to isolate
Franciscella
105
thiosulfate-citrate-bile salt-sucrose (TCBS) agar used to isolate
Vibrio
106
Causative agent of pink eye
Hemophilus aegypticus
107
Causative agent of whooping cough
Bordetella pertussis
108
Causative agent of undulant fever
Brucella
109
Causative agent of meningitis
Hemophilus influenzae
110
Causative agent of chancroid
Hemophilus ducreyi
111
Causative agent of Woolsorter's disease?
Bacillus anthracis
112
Causative agent of lock jaw?
Clostridium tetani
113
Causative agent of gangrene?
Clostridium perfringens
114
Causative agent of pseudomembrane?
Corynebacterium diptheriae
115
Causative agent of still birth?
Listeria
116
Causative agent of relapsing fever
Borrelia recurrentis
117
Causative agent of hemorrhagic jaundice
Leptospira
118
Causative agent of pinta
Treponema carateum
119
Causative agent of syphilis
Treponema palladum
120
Causative agent of yaws
Treponema partenue
121
Common name for Klebsiella pneumoniae
Friedlander's bacillus
122
Common name for Hemophilus aegypticus
Koch's week's bacillus
123
Common name for Hemophilus influenzae
Pheiffer's bacillus
124
Common name for Mycobacterium leprae
Hanson's bacillus
125
Causative agent of food poisoning
Staphylococcus aureus
126
Causative agent of lobar pneumonia
Streptococus pneumoniae
127
Causative agent of neonatal meningitis
Group B Beta Strep
128
Causative agent of rheumatic or scarlet fever
Group A Beta Strep
129
Causative agent of UTIs and wound infections
Group D
130
Common name for Corynebacterium diptheriae
Klebs-Loeffler bacillus
