Exam C Flashcards
Diff between neisseria and moraxella:
Which is DNAase pos?
Moraxella
True or false:
Neisseria gonorrhoeae and meningitidis are ALWAYS pathogenic, but other Neisseria species are normal flora of the upper respiratory tract
True
Streptococcus agalactiae
Characteristics / Morphology
GPC arranged in pairs and chain
Streptococcus agalactiae:
facultative _________.
anaerobe
Streptococcus agalactiae is catalase __________.
neg
Streptococcus agalactiae:
spores?
motile?
Non-motile & non-spore forming
Streptococcus agalactiae:
______ - hemolytic streptococci.
Beta
Streptococcus agalactiae:
Possess ___ carbohydrate antigen (Lance - field antigen) on cell wall making it Group ___ streptococci.
B, B
Where does Streptococcus agalactiae colonize in the body?***
gastrointestinal and genitourinary tract
Is Streptococcus agalactiae a concern for infection?
Able to cause severe invasive infection in newborn, immuno-compromised, and elderly people
Streptococcus agalactiae:
Can cause __________ and __________ in newborn. Acquired during delivery through maternal genital tract.
septicemia, meningitis
What type of infections can Streptococcus agalactiae cause in adults?
Septicemia, endocarditis, osteomyelitis, pneumonia, skin and soft tissue infection
What are the virulence factors of Streptococcus agalactiae?
-Capsular polysaccharide - resistance to phagocytosis
-Hyaluronidase - Destroys connective tissues between host tissue
-Beta - hemolysis
-Peptidase - breaks peptides
-CAMP factor - protein that enhances hemolysis
Colony Morphology
of Streptococcus agalactiae?
Grows on blood agar plate as gray - white colonies that have soft outer margin and narrower zone of beta - hemolysis
Streptococcus agalactiae appearance on Granada medium? (a type of medium selective and differential towards GBS) that allows its straight identification
an produce orange brick - red non-isoprenoid polyene pigment
Selective & differential to selectively isolate streptococcus agalactiae. The medium relies on detection of granadaene which is a red polyenic pigment specific to GBS.
Granada Medium
Granada Medium uses ________ and _________ as pigment enhancer.
starch, methotrexate
Granada Medium:
Crystal violet used to inhibit gram __________ bacteria.
positive
Granada Medium:
_________ used to inhibit growth of gram negative bacteria
Colistin sulfate
Granada Medium:
______________ is used to inhibit anaerobic bacteria.
Metronidazole
S. agalactiae produces a _________ result with CAMP factor test.
pos
S. agalactiae is hippurate test _______.
pos
Bile esculin hydrolysis test - S. agalactiae produces a _________ result where other enterococcus produces a ________ test result.
neg
pos
Important test that differentiates Streptococcus agalactiae (positive test) from other streptococcus species (negative test, no arrow head).
CAMP test
CAMP test:
S. agalactiae has a synergistic effect with ____________ enhancing hemolysis on BAP creating an arrow head.
Staphylococcus aureus
CLO test =
urea, H.pylori
How does the Rapid Urease Test work?
by placing the specimen in an agar or onto a paper strip containing urea and a pH indicator (phenol red) and it will turn pink/red (alkaline)* in the presence of urea
Urea Breath Test for H. pylori:
Detects ___ and ____ isotopes (carbon dioxide levels are measured)
C13 and C14
E Coli O19241024829 = ____ growth on SMAC
no
EHEC has a serotype E. coli _______ and a differentiating factor for this serotype is that it can grow on ___________ unlike other serotypes that cannot.
O157:H7***
Sorbitol MacConkey (SMAC)***
E. coli O____:H__ is nonmotile
157, 7
What is the cause of hemorrhagic colitis and hemolytic uremic syndrome (HUS)?
EHEC (aka STEC – Shiga Toxin producing E. coli)
Which org is biochemically inactive?
Eikenella
CAMPY = microaerophile @ _____ C
42
Campylobacter are
motile or non-motile?
motile
Campylobacter is…
Catalase ____________
Oxidase ____________
pos, pos
Campylobacter is nit __________.
pos
Campylobacter is urease ________
negative
Campylobacter is _____________ which is why it can grow at 42C
thermophilic
Morphology for Campylobacter?
Gull (bird) wing morphology
Campylobacter media for ID
if you run out of this media, what could you use instead?
CAMPY blood agar
(HE)
what is in MAC?
bile salt and crystal violet
MAC:
_________ red is the indicator that turns red at a pH below ____
Neutral
6.8
Shigella TSI/KIA =
K/A
Salmonella TSI/KIA =
K/AG H2S+
Shigella color on HE agar?
XLD?
green
colorless
Salmonella color on HE agar?
XLD agar?
-Green with or without black centers***
Red with black centers
Where is salmonella isolated from in the body?
intestines
What does salmonella look like on HE agar?
blue/green with or without black center
Does sputum require refrigeration?
does NOT require refrigeration unless it is going to be more than a 1-2 hour delay
An accepted sputum sample has ___ or fewer epithelial cells per LPF and ____ or more leukocytes***
10
25
-Samples that contain predominantly upper respiratory tract material should be rejected.
Endotracheal aspirates (ETAs) from mechanically ventilated adult patients can be screened by…
gram stain
Presence of ciliated columnar bronchial epithelial cells, goblet cells, or pulmonary macrophages in specimens by bronchoscopy or BAL indicates specimen is from…
lower respiratory tract
100 colonies = _________ cfu
100,000
where does Trep comes from in the body (darkfield of trep)
vagina
Corynebacterium:
gram-________
What shape?
positive
V-shaped
bacteria with a pseudomembrane?
Corynebacterium
True or false:
Corynebacterium diphtheria is acid fast bacilli
False.
non acid fast bacilli
What is the toxin-virulent gene produced by Corynebacterium diphtheria?
bacteriophage-tox gene)
Aerobic/elek test-positive for virulent stains (precipitation test)
Corynebacterium diphtheria:
Arrangement of Corynebacterium diphtheria?
Curved or Chinese letter arrangement
Corynebacterium diphtheria motility, capsule, and spore ___________.
negative
Corynebacterium diphtheria ____________ granules.
Metachromatic
Is Corynebacterium diphtheria indigenous bacteria?
no!
Corynebacterium diphtheria catalase __________.
positive
Corynebacterium diphtheria Cystine tellurite BA/modified tin scale medium-______ colonies (because it has potassium chloride).
black
What is the vaccine for Corynebacterium diphtheria?
DTaP
What illnesses does Corynebacterium diphtheria cause?
Primarily upper respiratory tract illness, pharyngitis, dysphagia, membrane can form in throat, cutaneous diphtheria, polyneuritis
How can C. diphtheria be treated?
Treat w/ horse serum antitoxin, BUT serum sickness can occur (allergic to horse serum protein
Bacterial infection associated with the placenta
Listeria. monocytogenes
What can Listeria. monocytogenes infection cause?
can cause influenza like symptoms, followed by placentitis, amnionitis, infection of the fetus, abortion, stillbirth, or premature birth
Early diagnosis of listeriosis in neonates:
Gram _________ bacilli in CSF, blood, amniotic fluid, respiratory secretions, placenta, or cutaneous swabs, gastric aspirate, or meconium
positive
Enterobacteriacea:
almost all are…
Catalase _________
Nitrate __________
oxidase _________
pos
pos
neg
MacConkey agar isolates gram __________ bacteria
negative
What does MacConkey agar contain?
bile salts, crystal violet, and neutral red pH indicator
Lac (+) = pink
Lac(-) = yellow
Hektoen - isolates ___________ and ___________.
Salmonella and Shigella
What does Hektoen agar contain?
contains bile salts and the dyes bromothymol blue and acid fuchsin. Ferric ammonium citrate allows H2S production.
On Hektoen agar
Lac(+)= Lac(-)= H2S(+)=
Lac(+)= Orange
Lac(-)= Blue-Green
H2S(+)= Black center
Xylose Lysine Deoxycholate (XLD) - isolates gram ____________ organisms, contains phenol _____ indicator
negative
red
Xylose Lysine Deoxycholate (XLD):
Lac (+) =
Lac (-) =
H2S (+) =
yellow
red
black center
SS agar:
Gram-__________ enteric organisms.
negative
SS agar contains…
neutral red indicator, sodium thiosulfate and ferric citrate enable the detection of H2S
What is CNA agar used for?
isolating and differentiating pathogenic gram positive cocci from clinical and non-clinical samples
How does CNA agar inhibit gram-negative bacteria?
Antimicrobials colistin (C) and nalidixic acid (NA)
Thioglycollate broth:
Gram positive cocci frequently grow as…
discrete “puffballs”
which broth for enrichment of stool specimens?*
-Selenite Enrichment broth is an enrichment broth for stool samples (Salmonella and Shigella)
-Cary-blair transport medium
What is the media for vibrio?
TCBS
Which bacteria is associated with seafood?
V. parahaemolyticus
Which media helps diff for org that shows swarming?
?
P. vulgaris is indole ________
P. mirabilis is indole ________
pos
neg
which orgs are orange/salmon on HE?
-E. coli and K. pneumonia are both orange/salmon on HE because they are lactose fermenters
-Y. ENTEROCOLITICA also produces salmon color colonies on HE
Organism that….
No growth on mac
Gram neg
Oxi pos
Nonmotile
Pasteurella
What agar for Corynebacterium diphtheriae?
Loeffler agar
what org Martin lewis look for?
Neisseria gonorrhoeae
Martin-Lewis Agar is the formulation made after modification that contains an increased level of _____________ for greater inhibition of gram-positive organisms.
vancomycin
Martin-Lewis Agar:
Vancomycin inhibits gram-_______ bacteria.
positive
Martin-Lewis Agar:
colistin inhibits gram-__________ bacteria including the commensal Neisseria spp.
negative
Martin-Lewis Agar:
__________ inhibits swarming of Proteus spp.
trimethoprim
Martin-Lewis Agar:
_________ is an antifungal agent
nystatin
Staining used for fungi that binds chitin and cellulose.
calcofluor stain
Gardnerella is associated with what type of infection?
bacterial vaginosis
What bacteria?
Pseudomembranous when toxin produced
Corynebacterium diphtheriae
The bacteria that causes Whooping cough.
Bordetella pertussis
How is Whooping cough (from Bordetella pertussis) confirmed?
with fluorescent antibody test
Causes acute epiglottitis in children (Do not attempt throat culture; blood culture is best)
Hemophilus influenzae
“Normal” flora of the throat, oropharynx?
Alpha strep, staph sp., Neisseria sp., Gram pos Rods anaerobes
What two organisms can cause infection the eyes of newborns?
-Chlamydia
-Neisseria gonorrhoeae
Bacteria associated with simmer’s ear
Pseudomonas aeruginoosa
Two bacteria associated with otitis media infection?
-H. influenzae
-Streptococcus pneumoniae
Criteria for a suitable sputum sample for testing?
Early morning sputum specimen is best; should have less than 10-15 squamous epith. cells per LPF
Expected infection source for H. influenzae?
lower respiratory tract (sputum)
Expected infection source for S. aureus
lower respiratory tract (sputum) (???)
Expected infection source for Streptococcus pneumoniae?
lower respiratory tract (sputum)
Expected infection source for Klebsiella pneumoniae?
lower respiratory tract (sputum)
Expected infection source for Mycoplasma pneumoniae?
lower respiratory tract (sputum)
Expected infection source for Mycobacterium tuberculosis?
lower respiratory tract (sputum)
Expected infection source for Legionella?
lower respiratory tract (sputum)
Expected infection source for Fungi?
lower respiratory tract (sputum) (others too)
What type of bacterial infections are associated with transtracheal aspirate, and lung tissue?
anaerobes (normally should be sterile)
AFB and mycology set-up should be used for __________ washings.
bronchial
What is the test for H. pylori?
Where is the organicism found?
rapid urase test
stomach
EIA is best for….
Clostridium difficile
Genital tract infection that is significant in pregnant women?
Strep Group B
What is used to culture BYCE (Buffered Charcoal Yeast Extract)?
Legionella
fastidious slow growing obligate aerobe, use BYCE media
Legionella spp.
What is in BYCE (Buffered Charcoal Yeast Extract) media?
-yeast extract
-L-cystine
-charcoal activate
-ferric pyrophosphate
-ACES (buffer for pH)
-alpha-ketoglutarate
Quad plate interpretation:
Quad 1: growth
Quad 2: growth
Quad 3: growth
Quad 4:growth, no hemolysis
H. aphrophilus
Quad plate interpretation:
Quad 1: no growth
Quad 2: no growth
Quad 3: growth
Quad 4: growth, no hemolysis
H. influenzae
Quad plate interpretation:
Quad 1: no growth
Quad 2: growth
Quad 3: growth
Quad 4: growth, beta-hemolysis
H. parahaemolyticus
Quad plate interpretation:
Quad 1: no growth
Quad 2: growth
Quad 3: growth
Quad 4: growth, no hemolysis
H. parainfluenzae
H. influenzea:
requires X factor (hemin)?
V factor (NAD)?
yes, yes
H. parainfluenzae:
requires X factor (hemin)?
V factor (NAD)?
no, yes
H. aegyptius:
requires X factor (hemin)?
V factor (NAD)?
yes, yes
H. haemolyticus:
requires X factor (hemin)?
V factor (NAD)?
yes, yes
H. parahaemolyticus:
requires X factor (hemin)?
V factor (NAD)?
no, yes
H. ducreyi:
requires X factor (hemin)?
V factor (NAD)?
yes, no
Quad 1 contains…
Factor X (hemin)
Quad 2 contains…
Factor V (NAD)
Quad 3 contains…
Factor X and V
Quad 4 contains….
horse blood agar (determines hemolysis pattern), contains both X and V factor.
Which has growth in 3 out of the 4 on the quad plate?
H. para (quad 2, 3, and 4)
between s.epi and s.aureus which has red growth on MSA (Mannitol Salt Agar)?
S. epidermidis (no fermentation)
S. aureus (yellow for fermentation)
What type of media is Mannitol Salt Agar?
differential and selective
MSA agar:
__________→ inhibitor
___________→ indicator
7.5% NaCl
Phenol Red
Which organism has red slant for LIA?
Proteus
LIA slant is used to identify __________ and ____________.
Salmonella and Shigella
What is the indicator used for LIA slant?
Bromocresol purple***
LIA slant:
__________ → Source of reduced sulfur
Sodium Thiosulfate
LIA slant:
purple color throughout indicates…
Lysine Decarboxylation***
Lysine Decarboxylation (on LIA slant):
If the organism produces lysine decarboxylase, it removes CO2 from L-lysine and forms __________ (alkaline)
cadaverine***
LIA slant, Lysine Deamination:
ysine deamination will only be seen in the slant because…
It requires oxygen
LIA slant, Lysine Deamination:
If the organism produces lysine deaminase, ferric ammonium citrate & Flavin mononucleotide, forming a ______________ color on the slant
burgundy (dark red)
LIA slant:
Red slant/yellow butt =
Lysine deamination
What are the sugars in HE agar?
***lactose and sucrose
HE
(Hektoen Enteric):
What are the indicators?
Bromothymol blue and
Acid fuchsin
HE
(Hektoen Enteric):
lactose positive is _______ in color.
Salmon
lactose neg = Green to Blue
(H2S+ = Black)
HE
(Hektoen Enteric):
What is the selective agent?
bile salts
HE
(Hektoen Enteric):
Wht is the H2S indicator?
Sodium Thiosulfate
HE
(Hektoen Enteric):
Differentiating agent?
Lactose
Sucrose
Salicin