Bacteriology Flashcards
1
Q
Gram-negative coccobacillus
non-motile
A
Acinetobacter spp.
2
Q
Describe growth of Actinomadura madurae on quad plate containing casein, xanthine, tyrosine, and starch.
A
Growth on casein and starch, maybe tyrosine
3
Q
Swelling of the neck beneath the left jaw with enlargement of cervical lymph nodes
GS of purulent material revealed non-acid fast branching GPR
A
Actinomyces israelii
Classic “Lumpy jaw” case
4
Q
Beaded, branching anaerobic GPR, non-acid fast
Slow growing
Associated with head and neck abscesses
A
Actinomyces spp
5
Q
In a urine culture, a small/pinpoint alpha-hemolytic, weakly pyrase pos GPCL
Sometimes see tetrads
A
Aerococcus urinae
6
Q
Gastroenteritis
Oxidase positive GNR
Hydolyzes esculin
A
Aeromonas spp.
(or plesiomonas)
7
Q
Anaerobic GNC
A
Acidaminococcus
Megasphaera
Veillonella
8
Q
Anaerobic GPC
A
Peptostreptococcus
Finegoldia
Peptococcus (former peptostrep)
Peptoniphilus
Parvimonas
Anaerococcus
9
Q
Pharyngitis in 10-30 year old with a rash
Slow growing, small, indistinct zone of β-hemolysis
GPR that may show rudimentary branching
Catalase-negative, urease negative
Shows CAMP-inhibition
A
Arcanobacterium haemolyticum
Penicillin-resistant (why you need to distinguish from Strep)
10
Q
Non-hemolytic medusa head colony of the consistency of beaten egg whites
boxcar GPR
non-motile
A
FUCKING ANTHRAX. BAG THAT SHIT
Demonstrating either hemolysis or motility will rule it out
11
Q
What are the forms of anthrax possible
A
Cutaneous, Inhalational (die), Gastrointestinal, Injection
12
Q
Patient presents with acute food poisoning
Beta-hemolytic GPR in chains, some spores, catalase pos
A
Bacillus cereus
Can also cause serious eye infections after traumatic inoculation
13
Q
Small anaerobic GNR resistant to vancomycin, colistin, kanamycin and bile
A
Bacterioides fragilis group
14
Q
Only bacillus spp that cannot hydrolize lecithinase
A
B. subtilis
15
Q
Grows on KV agar but no fluorescence
Produces black colonies on BBE
Resistant to penicillin
A
B. fragilis
16
Q
GS with dog bone appearance
A
Bifidobacterium
Normal mouth and GI bug. Rarely causes disease.
17
Q
Light pink colonies on chocolate
Motile, oxidase pos, non-fermenter
Oxidative utilization of maltose only
Rapid urease production and nitrate reduction
A
Bordatella bronchiseptica
18
Q
GNCB produces small grey colonies surrounded by a zone of hemolysis on potato-blood-glycerol agar. Will grow on CA, not on BA.
A
Bordatella pertussis
19
Q
Causative agent of Lyme Disease
- Radiating rash (Erythema migrans)
- Flu-like symptoms
- Arthritis symptoms following bite
Diagnosed by rash and history of tick bite or serology
- ELISA followed by Western to confirm
A
Borrelia burgdorferi
20
Q
Diurnal fever in midwest patient + fatigue
Pos blood @ 9 days on choc
A
Brucella abortis
21
Q
Brucella spp. GS
A
Small GNCB that appear gram positive due to retention of CV
22
Q
Respiratory disease in CF patients
GNR, NLF grown on media with polymixin B and ticarcillin
drastically alters patient care and affects ability to receive lung transplant
A
Burkholderia cepacia
23
Q
Cause of glanders- aggressive pulmonary disease is most common presentation, inhalation or ingestion. Overwhelming septicemia, draining abscesses.
A
Burkholderia mallei
24
Q
Cause of meliodosis
A
Burkholderia pseudomallei
25
The presence of clue cells with gram variable coccobacilli is diagnostic of...
Bacterial vaginosis
Overgrowth of vaginal flora, including Mobiluncus, Prevotella, genital mycoplasmas, and Gardnerella vaginalis
26
C-rective protein is elevated in what circumstances?
Pediatric bacterial infections
27
Test to distinguish C. jejuni from C. coli
Hippurate hydrolysis
| (C. jejuni is positive)
28
Gram stain: curved, S-shaped, or “gull-wing” gram negative rods
Media + Colony Morph
* Selective media, elevated incubation temperature (42oC), and proper atmospheric conditions required for isolation
* Colonies are flat, gray, irregular, and may be either dry or moist with glistening edges
Metabolism
* Microaerophilic (require decreased O2)
* Capnophilic (require increased CO2)
* Nonfermentative and nonoxidative in metabolism
* Oxidase positive
Campylobacter spp
29
Colony recovered after growth at 42oC was indoxyl acetate pos, as evidenced by a green spot on the indoxyl acetate disk.
Campylobacter upsaliensis
30
Capnophilic
Colony morphology --\> gliding motility
Gram stain --\> thin and fusiform (pointed ends)
Normal inhabitants of oral cavities of mammals
Capnocytophaga
31
GS of pictured colonies produce "rosette-like clusters"
Cardiobacterium hominis
32
50% males symptomatic -\> thin discharge, dysuria, epididymitis
25 - 45% infected females have urethritis
* Mucopurulent discharge containing PMNs
* Cervix: friable, red, edematous
* Ectopy increases risk of endocervicitis
Chlamydia trachomatis
33
Non-fermenter that can produce indole
Chryseobacterium
34
Aerotolerant Clostridium include...
C. tertium, C. histolyticum
35
Flaccid paralysis after consuming improperly canned food
Anaerobic GPR
Clostridium botulinum
36
Severe watery diarrhea
Anaerobic GPR
Smells like elephant dung
C difficile
Just PCR it, for god's sake
37
Lecithinase-producing Clostridia
C. perfringens, C. baratii, C. sordelli, C. novyi
38
Lipase producing Clostridium species
C. botulinum, C. sporogenes, C. novyi A
39
Anaerobic GPR, no spores seen in culture
Double zone of B-hemolysis on BA
Lecithinase pos
Clostridium perfringens
Can have sub-terminal spores
Causes gas gangrene or food poisoning
40
The enxyme producing the outer zone of the double-zone hemolysis of C perfingens is...
Lecethinase
41
Describe GS appearance and fermentation patterns of Clostridium septicum.
Produces "drum stick" shaped spores
Ferments maltose and lactose, but rarely sucrose
42
Respiratory sample from patient with pseudomembrane
Black colonies on Cyteine-Tellurite
Palisading GPR, Catalase pos, non-motile
Corynebacterium diphtheriae
Confirm toxin production with Guinea pig lethality or Elek test
43
Small dry colonies
Pallisading club shaped GPR
Catalase pos, non-motile
Corynebacterium spp.
"Diptheroid"
44
UTI patient
Tiny colonies, pallisading GPR
Catalase pos, urease pos
Corynebacterium urealyticum
45
If CSF samples CANNOT be plated within an hour, where should they be stored
Room temp
Freezing or refrigerating will kill meningococcus
46
Urine culture LF that is Beta-hemolytic
What do we think and what's left to prove it?
Show indole positive and call it E. coli. Done
47
Urine culture LF that is not beta-hemolytic
Indole positive and pyrase negative(it'll actually be blue) -\> E coli (NFW)
Indole pos but pyrase pos -\> probably Kleb oxytoca (confirm with MS)
48
Most common causes of bacterial ear infections
Strep pneumoniae = 40-50%
Non-encapsulated H. influenzae = 25-30%
Moraxella catarrhalis = 10-15%
S. pyogenes = 2%
49
H2S producing Enterobacteriacea
S.P.A.C.E.
Salmonella
Proteus
Arizonieae (or something)
Citrobacter
Edwardsiella
50
Strong lactose fermenting Enterobacteriacea
Citrobacter, E. coli, Enterobacter, Klebsiella (CEEK)
51
Enteric organisms that possess the enzyme urease (can hydrolyze urea, releasing ammonia)
Klebsiella and Proteus
52
Species of Enterococcus with stronger alpha hemolysis at 24 hours and is MUCH more likely to be VRE
E. faecium
53
Species of enterococcus with vanC, low level vancR
Enterococcus galinarum
54
Motile enterococcus spp.
Galinarum and casseliflavus
55
Med grey colony with slight alpha underneath the colony
Catalase neg, PYR pos
Growth in 6.5% NaCl and bile-esculin pos
Enterococcus spp.
56
Pyrase reaction of VRE is often stronger or weaker than vancS Enterococcus
Weaker
57
Appearance of VRE on surveillance culture plates
Dark pink-purple or blue
58
Motility deep looks like a pipe cleaner or test tube brush
Erysipelothrix rhusiopathiae
59
wound infection
## Footnote
Thin GPR on GS, may branch or form long filaments
non-hemolytic to slightly alpha-hemolytic
H2S positive in TSI
Catalase negative
Non-motile
Facultative anaerobe
Erysipelothrix rhusopathiae
## Footnote
Generally vancomycin-resistant
60
LF on Mac, A/A + gas, indole pos, motiliy pos, pyrase neg
Escherichia coli
10% can be NLF
61
large anaerobic GPC
Finegoldia magnus
62
Extraction of the inoculated and incubated tryptophan broth with xylene, THEN using Ehrlich's reagent is necessary for detection of indole from...
Flavobacterium indologenes
Production of low amts of indole require extraction first
63
cutaneous or inhalational routes. RABBITS.
BSL 3 required. CDC Category A Select Biological Agent
Francisella tularensis
64
Francisella tularensis gs
Very tiny, pale-staining GNCB, often difficult to see individual cells
65
Long anaerobic GNR
Resistant to vancomycin and colistin
Sensitive to Kanamycin
Variable bile resistance
Chartreuse Fluorescence under UV
Fusobacterium
Bile sensitivity can help distinguish species
66
Causative agent of Lemierre's syndrome in young adults
Presents as pharyngitis --\> abscess --\> sepsis --\> death
Fusobacterium necrophorum
67
Fried egg colony of thin GNR
Fusobacterium necrophorum
68
Species of GNR that has the classic pointy ends
Fusobacterium nucleatum
MS will not distinguish F naviform and F nucleatum but only nucleatum is pointy
69
Bacterial vaginosis
GS: gram variable coccobacilli on "Clue Cells"
Catalase neg, non-motile
Gardnerella vaginalis
Beta hemolytic on human or rabbit blood. But NOT on sheep blood agar
70
Associated infection of Cardiobacterium hominis
Culture negative endocarditis
71
Associated infection of Eikenella corrodens
Clenched fist infection
Skin popping cellulitis
72
HACEK Group
Haemophilus spp.
Aggregatibacter actinomycetomcomitans, formerly Actinobacillus actinomycetemcomitans
Cardiobacterium hominis (more rare)
Eikenella corrodens (normal mouth with agar pits --\> big in human bites)
Kingella spp
73
HACEK Group Characteristics
Capnophilic – prefer increased CO2
Slow or poor growers (day two appearance)
Predilection for damaged heart valves
Normal biota of the oral cavity
74
Associated infection of Kingella kingae
Juvenile osteomyelitis
75
Associated infection of Actinobacillus actinomycetemcomitans
Localized juvenile periodontitis
76
tan flat colonies that grow only on CHOC
Haemophilus
77
Causative agent of Brazilian purpuric fever, an acute febrile disease accompanied by abdominal pain and vomiting and the evolution of a petechial or purpuric rash
Haemophilus aegyptius
\*also causes pink eye
78
Haemophilus spp. that causes genital ulcers
Haemophilus ducreyi
79
Growth on CA only
Pleomorphic – very small gram-negative coccobacilli to long filamentous rods
Non-motile
Facultative anaerobe
Ferment carbohydrates, generally oxidase positive, catalase positive, and reduce nitrates
Haemophilus spp.
## Footnote
Test for beta-lactamase activity to assess ampicillin and amoxicillin efficacy.
80
Differentiate H. influenzae and H. parainfluenzae
XV requirements.
If there is only growth around XV disc or between X and V strips, H. influenzae
If there is growth around V, H. parainfluenzae
81
Gram stain: small, curved, plump bacilli
Microaerophilic (10% CO2, 5% O2, 85% N2)
Temp: 35-37oC
High humidity also favors growth
Most isolates grow within 3 to 5 days
Non-selective blood agar as translucent, gray colonies
Identification: Catalase, urease, and oxidase positive
Helicobacter pylori
82
LF on Mac, A/A, indole pos, non-motile, pyrase pos
Klebsiella oxytoca
83
MS cannot distinguish Klebsiella oxytoca and...
Routella
84
LF on Mac, A/A, indole neg, non-motile, pyrase pos
Klebsiella pneumoniae
85
teeny tiny alpha colonies seen often in female genital or urine cultures chaining GPR, catalase negative and pyrase positive
Lactobacillus spp
86
Lactobacillus is intrinsically resistant to...
Vancomycin
87
Often seen in female urine culture or vaginal swab
Long thin GPR with parallel sides
Tiny, alpha hemolytic on BA and choc
Generally vancomycin resistant
Lactobacillus spp.
88
Legionella R/O Procedure
Cultures on BCYE w/ PAV or PAC (different selective agents to favor different Legionella species)
Gram stain everything on third, fifth, and seventh day
* If GS is GNR, sub to BCYE and BA. Growth on BCYE only would indicate Legionella
* If GS is non-GNR, NFW
89
A human spirochetal disease associated with contact with rats is...
Leptospirosis
90
small GPR, soft beta, catalase positive, tumbling motility
Listeria
91
GPR that produces a rectangular CAMP reaction, as shown by the blue arrow is most likely...
Listeria monocytogenes
92
Abortion or Food-borne gastroenteritis
## Footnote
Short GPR or cocco-bacillus
WILL grow in fridge
Narrow zone of beta hemolysis
CAMP positive (block)
Catalase positive (most strains)
Tumbling motility
Bile-esculin positive
Listeria monocytogenes
93
Common cause of meningitis in 5-40 yrs
N. meningitidis (45%)
S. pneumoniae (20%)
94
Key indicator that meningitis is causes by virus and not bacteria
Normal glucose
95
Common causes of meningitis 6mo - 5 years
Neisseria meningitidis
S. pneumoniae
Haemophilus influenzae type b (less w/ vaccine)
96
Common causes of meningitis \>40 years
S. pneumoniae (50%)
S. aureus (13%)
N. meningitidis
plus Gram-negatives & L. monocytogenes in the elderly
97
Common causes of neonatal meningitis
Streptococcus agalactiae (GBS) – 50%
E. coli – 25%
other Gram-negatives
Listeria monocytogenes
98
Normal flora
## Footnote
yellow colonies, catalase+, Coag-, bacitracin sensitive
Micrococcus
All staph are resistant to bacitracin
Can also do microdase to distinguish from Staph
99
Otitis media and sinusitis in children
GNDC, ox pos
Asacchyrolytic
Moraxella catarrhalis
100
What organism is associated with chronic obstructive pulmonary disease in the elderly?
Moraxella catarrhalis
101
Purulent conjunctivitis
Colonies produce pits in the agar
GS- G neg coccobacilli
Moraxella lacunata
102
Upon exposure to penicillin, this G-neg genera will undergo pleomorphic elongation
Moraxella
| (Differentiates from Neisseria)
103
Non-pigmented Mycobacteria
Mycobacterium avium
Mycobacterium intracellulare
Mycobacterium ulcerans
slow-growing and never produce pigment, regardless of culture conditions
104
Photochromogenic Mycobacteria
Mycobacterium kansasii
Mycobacterium marinum
Mycobacterium asiaticum
Mycobacterium simiae
slow growing, and produce a yellow-orange pigment when exposed to light
105
Rapidly growing mycobacteria
**Mycobacterium fortuitum**
**Mycobacterium chelonae**
**Mycobacterium smegmatis**
**Mycobacterium abscessus**
Mycobacterium mucogenicum
Mycobacterium peregrinum
106
Scotochromogenic mycobacteria
Mycobacterium gordonae
Mycobacterium scrofulaceum
Mycobacterium flavescens
slow-growing and produce a yellow-orange pigment regardless of whether they are grown in the dark or the light
107
A rare Mycobacterium spp. that also accumulates niacin is...
M. simiae
108
Inflammatory bowel disease in cattle sheep and goats with an etiologic agent isolated in patients with Crohn's disease
Johne's Disease
Mycobacterium paratuberculosis (MAC)
109
Invasion of the colon with AFB. Tissue sections show engorged submucous macrophages.
What is the most likely Mycobacterium species?
Mycobacterium avium intracellulare complex
110
Members of slow growing non-photochromogens that reduce tellurite
Mycobacterium avium
| (All rapid growers reduce tellurite)
111
Disease associated with Mycobacterium bovis
Urinary bladder carcinoma
112
Non-chromogenic mycobacteria that grew in 3 days
Characteristic resistance to Ciprofloxacin
Mycobacterium chelonae
113
Mycobacterium culture requirements
Primary nutrient required is LIPID (for cell wall)
Often an ingredient to repress non-acid fast bugs (ig malachite green in LJ media)
Temperature: 35 - 37°C is typical, but some species prefer 30°C or 42°C
Atmosphere: 5 - 10 % CO2
Time: 6 - 8 weeks
Read cultures twice a week first 2 weeks, then once a week
114
Acid fast bacillus with smooth, waxy, light grey colonies within 3-5 days of incubation (rapid grower)
Nitrate positive
Mycobacterium fortuitum
115
Maconkey agar without crystal violet is a culture medium useful in the presumptive identification of...
Mycobacterium fortuitum/chelonai complex
116
Mycobacterium that assimilates iron
Mycobacterium fortuitum
117
Non-cultivatable mycobacterium spp. + what disease does it cause
Mycobacterium leprae
Leprosy (aka Hansen's disease)
118
Disease associated with mycobacterium marinum
Swimming pool granuloma
119
Slender rods, may be straight or slightly curved, short or long
Acid fast
Nonmotile, Non-spore forming
Aerobic, stimulated by CO2
Slow growing
Mycobacterium spp.
120
Members of the TB complex beyone M. tuberculosis
M. bovis, M. microti, M. canetti, M. caprae, M. pinnipedii, and M. africanum
121
A key laboratory characteristic by which M bovis can be separated from M tuberculosis is...
Growth inhibition by T2H
122
Buff-colored, slow growing mycobacteria that reduces nitrates and produces niacin
TB
123
Disease associated with mycobacterium ulcerans
Regional ileitis (Chron's Disease)
124
Disease associated with Mycobacterium ulcerans
Bairnsdale ulcer (cutaneous lesions)
125
Agar for isolation of mycoplasma
PPLO
126
GNDC within PMNs is considered diagnostic for gonnorhea in what case?
Male patient
Females can have normal microbiota that can be mistaken
127
Culture: Will grow on chocolate, but selective media such as Thayer-Martin commonly used
Incubation: Enriched CO2 can be achieved by use of a candle extinction jar
Colonies: Small, tan, translucent, and raised
Oxidase positive, gram negative diplococci
Utilize glucose only in CTA slants
Neisseria gonorrhoeae
128
Young adult presents with signs of meningitis
GNDC in CSF, oxidase pos
CTA slants pos for glucose and maltose
Neisseria meningitidis
129
Waterhouse-Friderichson syndrome is most often the result of...
Fatal, disseminated form of meningococcemia
Microthrombi --\> hemorrhage into the adrenal glands
130
Most common serogroups of N meningitidis to cause meningitis
A, B, C, & W135
Vaccine available for B
Serogroup A causes epidemics in sub-Saharan Africa
131
Describe growth of Nocardia asteroides on quad plate containing casein, xanthine, tyrosine, and starch.
All negative
132
Describe growth of Nocardia brasiliensis on quad plate containing casein, xanthine, tyrosine, and starch.
Growth on casein only
133
Describe growth of Nocardia otitidiscaviarum on quad plate containing casein, xanthine, tyrosine, and starch.
Growth on xanthine only
134
Describe growth patterns for
* Nocardia otitidiscaviarum
* Nocardia asteroides
* Nocardia brasiliensis
on quad-plates containing casein, xanthine, hypoxanthine, and tyrosine
135
Pulmonary infection or brain abscess
## Footnote
beaded, branching, thin, filamentous
Colony morphology often chalky, dry or velvety colonies after 3 days to 2 weeks (usually visible in 3-5 days)
Sometimes pigmented tan, gray, pinkish, or orange
Characteristic freshly-turned soil odor
Nocardia spp
136
Describe growth of Nocardia transvalensis on quad plate containing casein, xanthine, tyrosine, and starch.
Growth on starch only
137
Clues that an organism is a non-fermenter
Pigment
Oxidase pos
Thinner and longer GNR
Failure to grow on MAC
Antimicrobial resistance
Reduces nitrate
138
Oxidase neg non-fermenting GNR
Pseudomonas (Chryseomonas) luteola
Stenotrophomonas maltophilia
Acinetobacter spp.,
some Bordetella spp.,
Pseudomonas (Flavimonas) oryzihabitans
139
Genera of nutritionally variant strep
Abiotrophia or Granulicatella ID by MS then sub to choc slant and send out for sensis
140
Nutritionally variant strep require...
vitamin B6 supplementation (Pyridoxyl)
Will satellite round organisms that release B6 (Staph, E coli, Kleb, Enterobacter, Strep pneumo, yeast)
141
Yellow pigmented nocardioform recovered from blood cultures
Non-acid fast, motile
Filamentous mycelium broke up into fragments as the culture matured
Oerskovia turbata
142
Small light yellow colonies
GS- short GPR in loose clusters
Positive lecithinase, catalase and oxidase pos
Oerskovia xanthenolytica
143
often occur as a result of feline bites.
* ox+ GNR
* no growth on MAC
* indole +
Pasturella multocida
144
Procedure for PBP2a test
1. 2 drops blue reagent
2. Add colonies with BLUE DISPOSABLE LOOP
3. 2 drops clear reagent (solution should turn clear)
4. Drop in chromatography strip and wait 5 minutes -write time on stand
DO CONTROL DOCUMENTATION DAILY
145
Plesiomonas biochemical results for...
* oxidase
* ornithine
* DNase
Oxidase pos
Ornithine pos
DNase neg
Ornithine and DNase differentiate from Aeromonas
146
Child with gastroenteritis
GNR, oxidase pos, DNAse neg, ornithine pos, esculin neg
Plesiomonas shigelloides
147
Anaerobic GNR
Resistant to colistin and kanamycin
Sensitive to vancomycin and bile
Porphyromonas
148
Anaerobic GNR
Resistant to vancomycin and kanamycin
Sensitive to bile
+/- Black Pigment (delayed)
Brick Red Fluorescence
Oral origin
Prevotella
149
The saccharolytic anaerobe that produces red fluorescing colonies when illuminated with a woods lamp is...
Prevotella bivia
150
Propionibacterium appearance in anaerobic cultures
Will appear after ~4 days and be MUCH smaller than Staph Smooth creamy med colony. May or may not be beta-hemolytic May appear as a slightly larger colony in a sea of pinpoints
151
Squashed spider irregular GPR
Blood culture pos within five days
Normal skin flora can be introduced via surgery to cause bone problems
Propionibacterium/Cutibacterium acnes
152
A positive lysine deamination reaction is a reddish/purple and acid butt- which Enterobacteriaceae has this reaction?
Proteus
153
Indole negative proteus (Smells like brownie mix)
Also AmpS
P. mirabilis
154
Indole positive proteus
Also AmpR
P. vulgaris
155
Name the color of each pigment produced by some species of Pseudomonas
* pyoverdin (fluorescein)
* Pyocyanin
* Pyorubrin
* Pyomelanin
pyoverdin (fluorescein) – yellow-green
Pyocyanin – blue
Pyorubrin – red
Pyomelanin – brown/black
156
Pseudomonas protocol for sensitivities
ALWAYS get a sensi
157
Pseudo F agar after inoculation. The righthand tube is...
Pseudomonas putida, aeruginosa, or fluorescens
158
Asaccharolytic Pseudomonas species
P. acidovorans
P. alcaligenes
(Appear blue in OF tube)
159
R/O Beta-Strep Procedure
1. Isolate any B-hemolytic colony, sub if needed
2. If butterscotch smell, tiny beta, ignore after isolation
3. PathoDx to confirm or R/O Grp A, C, G
160
Bite wound or immunocompromised
## Footnote
No hyphae, smooth, glistening salmon-pink to red-orange colonies
Traces of branching in early stages of growth
Rhodococcus equi
161
Bacterial isolate from dental abscess of 14 yo boy
Dry pink-white colonies after 72 hours growth
GS- GPR in diptheroidal arrangement. No spores
Rothia dentocariosa
162
Very sticky small white colonies in respiratory site
Rothia mucilaginosa
163
Which antibody class indicates a primary exposure and which reflects prior exposure to the disease \>6 months.
IgM is formed within 20 days of infection. Also cannot cross the placenta so is an indication of an in utero infection in a newborn.
IgG predominates in a secondary response to a pathogen to which the host has been previously exposed.
164
What lactose reaction is seen with Serratia marcescens?
Late lactose fermenter
165
Only non-fermenter to produce H2S
Shewanella putrifaciens
166
Among the non-fermenters, the only bacterial species to produce H2S is...
Shewanella putrifaciens
167
Ornithine positive and indole negative Shigella spp.
Shigella sonnei
| (Group D)
168
Sputum specimens are acceptible for culture IF...
show few squamous epithelial cells (SEC) (\< 10/lpf) and many PMNs (\> 25/lpf) are acceptable
May see columnar epithelial cells (look like sea anemonies) and that's good but not required.
169
If S aureus and GAS are in the same culture, rule out what organism
Corynebacterium diptheriae
170
Procedure for MRSA surveillance cultures
* MRSA is dark denim blue on chromagar
* S/U slide coagulase, then PBP2a if positive to confirm
* If an isolate needs to be subbed, add a cefoxitin disk to the 1o streak area
171
2+ GPCL 2+ WBC
Creamy yellow colonies on BA with large zones of Beta-hemolysis
Ferments mannitol, catalase pos, coag pos
Staph aureus
172
Commensal organism (usually)
non-hemolytic grey GPC
Catalase pos, coag neg, novobiocin sensitive
S epi (CNS)
173
The bacteria illustrated in this image from a positive blood culture is most likely to be...
Staphylococcus hominis
Forms tetrads
174
How to differentiate Staph lugdunensis and aureus
Lugdunensis is pyrase positive and ornithine positive
175
How to differentiate S lugdunensis and saprophyticus Both are bright white
Lugdunensis is slightly beta-hemolytic
176
What test is always set up on a MRSA
Vanc E-test
177
MRSA resistance mechanism
mecA gene -\> PBP2a (altered binding site for penicillins)
178
25 yo female urine
Bright white non-hemolytic GPC
Catalase pos, coag neg, novobiocin resistant (\<17mm)
S saprophyticus
179
grey-green on BA, non-fermenter, oxidase neg
Stenotrophomonas
180
Species in S. milleri
anginosus, constellatus, intermedius
181
30 yo lab worker bit by mouse
Developed fever, chills, headache, muscle ache
GS from blood cultures show pleomorphic GNR
Streptobacillus moniliformis
"Rat bite fever"
182
Soft beta-hemolytic grey to orange GPPC
PYR neg, Hippurate hydrolysis pos, CAMP pos
GBS
Normal flora of vagina, sometimes UTI, neonatal meningitis
183
Group B streptococci are resistant to what compound?
SXT
184
Screening test for GBS in pregnant women
Swab into carrot broth
Orange color after a day = pos
185
Bacitracin sensitive Streptococci
Groups A, C, and G
186
Non-hemolytic GPC, catalase neg
No growth in 6.5% NaCl but hydrolyzes esculin
Strep bovis
"Group D Streptococcus, not enterococcus"
187
Species of strep associated with colon cancer
Streptococcus gallolyticus (Formerly Strep bovis)
188
Strep milleri will sometimes cross-react with...
C or G
189
Tiny colonies, butterscotch smell, enhanced growth in CO2
Strep milleri group
Group F, but can group with A, C, G or none
190
Test to distinguish large colony groups C and G from small colony (milleri) group
MUG test
## Footnote
Beta-D- Glucuronidase found in large colony groups C and G, but not small colony forming anginosus (milleri ) group
Disk will fluoresce under UV after incubation
191
Flat, alpha-hemolytic colony with indent in center
Lancet shaped diplococci
OptochinS and bile soluble
Streptococcus pneumoniae
192
The test used for the identification of specific capsular serotypes of S pneumo is...
Quellung test
Mix a light suspension with antiserum and observe for swollen appearance of the capsule to detect serogroup matches
193
Reason for S pneumo resistance to penicillins
Altered PBP, but not the same mechanism as MRSA
Definitely becoming more common
194
Species of Strep that be confused with GBS and will cross-agglutinate, but it is not GBS and looks much smaller
Streptococcus pseudoporcinus
195
PYRase positive Beta-hemolytic Strep
GAS
## Footnote
Detects L- pyrroglutamyl- aminopeptidase
Hydrolyzes PYR to β- naphthylamine
β-naphthylamine + cinnamaldehyde reagent = red
196
Treatment for GAS
Still universally susceptible to penicillin, so AST testing unnecessary for pharyngitis
Macrolide resistance still low in US, so Erythromycin if allergic to penicillin
197
Serologic Lancefield grouping based upon...
Type C carbohydrate in the cell wall
198
Describe growth of Streptomyces species on quad plate containing caseine, xanthine, tyrosine, and starch.
Growth on casein and tyrosine, maybe xanthine and starch
199
“sulfur granules” in drainage from wound: clusters of mycelia
May be branching, beaded GPR, but also may appear as cocci, short filaments, rods
NOT acid fast
Streptomyces, Actinomadura, Nocardiopsis
200
Causative agent of syphilis
Can be seen on dark field microscopy but better serology
Treponema pallidum
201
Presentations of infection by Treponema pallidum
* 1o syphilis- chancre (painless ulcer) in the genital area
* 2o syphilis- rash 6-8 weeks after primary infection in 25% of cases. Also systemic disease
* Condyloma lata- generalized raised lesions loaded with spirochetes
* 3o gummas or neurosyphilis (not infectious)
* gummas (15%)- indolent granulomatous lesion w/ central mucoid degeneration
* Arterial destruction (10%)
* Neurosyphilis (8%)- *Tabes dorsalis*; degeneration of the lower spinal cord à chronic progressive dementia
202
Testing sequence to diagnose syphilis
screen treponemal
* Treponemal tests are easier to automate
* Fluorescent antibody test
* ELISA or PCR
confirm with non-treponemal
* RPR- looks for reagin (cholesterol, lecithin, cardiolipin), markers of cell damage
* VRDL- similar test to RPR but need a microscope
203
Severe diarrhea leading to rapid fluid and electrolyte loss
Curved GNR, oxidase pos, NLF
Vibrio cholerae
204
Yellow colonies on TCBS indicate...
Vibrio cholerae
205
Cause of self-limiting gastroenteritis
Curved GNR, oxidase pos, NLF
Vibrio parahaemolyticus
206
Gastroenteritis
Curved GNR, oxidase pos, nitrate reducer, halophilic
Vibrio spp
207
Causative agent of severe septicemia from wound infections
Curved GNR, oxidase pos, lactose fermenter
Vibrio vulnificus
208
Gastroenteritis
Non-motile, grows in cold temps
Yersinia enterocolitica
209
Differentiation between Burkholderia mallei and pseudomallei
Mallei is non-motile and oxidase variable
Pseudomallei is motile and oxidase POS
210
How to separate leuconostoc from other streptococcus-like species..
Gas from glucose in MRS broth
211
What additive is used to restrict growth of Pseudomonads in a mycobacterium culture?
Oxalic acid
