lab practical exam

Question 1

staph aureus

Answer 1

SBA- hemolytic
CNA- growth for gram +
gram + cocci slide
coag: clotted
causes: wound infection, throat pneumonia, boils

Question 2

hemophilus influenza

Answer 2

sputum no growth on SBA
gray mucoid on chocolate
plate with 4 streaks, grows best on XV disc
slide with tiny pleomorphic rods gram =
causes meningitis

Question 3

E. Coli

Answer 3

urine sample with dry pink colonies on mac. 
>100 colonies = UTI
TSI: A/A
LIA P/P
indole +
CIT =
UREA =

Question 4

neisseria gonorrhea

Answer 4

slide gram = diplococci “coffee bean” shaped bacteria inside neutrophils
choco. and thayer martin grow gray colonies
dextrose (glucose) +
oxidase +

Question 5

strep pneumoniae

Answer 5

slide from sputum is gram + (purple) lancet shaped with two segments, flattened, and pointed ends
SBA plate with “P” disc alpha hemolytic colonies

Question 6

CAMp test

Answer 6

sheep plate containing a staph streak growing up to an arrow - identifies Group B Beta Strep

Question 7

Group D Enterococcus

Answer 7

SBA will be gray moist nonhemolytic colonies
MAC plate with no growth
bile esculin + (black)
salt broth + (cloudy)

Question 8

how to report out culture on sputum plate?

Answer 8

deciding if this is normal flora, if there are no accompanying test then it is saying it is indeed normal flora

Question 9

how to report out a stool plate?

Answer 9

CNA - any hemolytic colonies are pathogenic
MAC- will be pink for normal flora
HE- orange
XLD- yellow

Question 10

proteus

Answer 10

SBA & CHOC will have swarming colonies
CNA & MAC no growth
morphology for swarming is swarming motility

Question 11

how to differentiate between Mirabilis and Vulgaris

Answer 11

M is indole = and ornithin + (purple)

V is indole + (red) ornithin = (yellow)

Question 12

klebsiella

Answer 12

very mucoid plate
TSI A/A 
citrate +
motility =
ornithin =
LIA +

Question 13

how to differentiate between K. pneumoniae and K. oxytoca

Answer 13

indole
P is =
O is +

Question 14

corynebacterium

Answer 14

blood culture on a chocolate plate > have bright orange colonies
slide will have gram + plemorphic rod with “picket fence” or “chinese letter” shapes
explanation for why its in blood: dipthroid disease or staph epi contamination

Question 15

pseudomonas

Answer 15

urine culture 
green metallic colonies on SBA
clear on MAC
oxidase + 
GNF tube is red (non fermentor)
42 degree tube has growth

Question 16

pathogenic salmonella

Answer 16

TSI tube with K/A H2S (red on slant yellow but)

Question 17

pseudomonas aerogenosa

Answer 17

most commonly isolated non fermentor

Question 18

acetobacter

Answer 18

second most commonly isolated nonfermentor
TSI K/K
blood and mac plate
glucose +
maltose +
motility = 
oxidase =

Question 19

listeria

Answer 19

whitish - gray beta hemolytic SBA
TSI A/A 
bile esculin +
motility at 37 =
motility at 25 umbrella +
slide gram + rods

Question 20

Group A Beta Strep

Answer 20

sub plate from throat with zone around “A” disc
can tell on MIO with kovac’s
“A” disc contains bacitracin

Question 21

bacillus

Answer 21

slide with gram + with spores

SBA flat and hemolytic

Question 22

phenylalanine

Answer 22

+ = blue on slant and/or growth on slant\

three genera providencia, proteus, morganella

Question 23

nitrate broth

Answer 23

red after use of reagents A and B = + result
however, if clear use zinc dust
stays clear =

Question 24

if there is a gram = rod in blood culture, when given a sample of the culture what would you need to do?

Answer 24

the wound has growth on sheep and choc. and they’re pink colonies on MAC
answer question as “ID growth on MAC” etc wth XLD and HE

Question 25

what’s the first test to do on gram +?

Answer 25

catalase

Question 26

what does it mean when a mannitol salt agar turns yellow?

Answer 26

staph aureus confirm with coagulase

Question 27

when looking at LIA agar how would you read P/P with black

Answer 27

H2S +

LIA +

Question 28

HE medium is green

Answer 28

nonfermentor

Question 29

orannge HE medium

Answer 29

lactose fermentor

Question 30

black HE medium

Answer 30

H2S +

Question 31

yellow XLD medium

Answer 31

lactose fermentor

Question 32

NLF on XLD medium

Answer 32

reddish

Question 33

EMB with green metallic sheen

Answer 33

E. Coli

Question 34

a SBA plate with staph streak will have colonies growing around the staph streak what does this demonstrate and what organism is present?

Answer 34

satellite phenomenon

hemophilus influenza

Question 35

what does it mean if GNF tube is yellow?

Answer 35

glucose fermentor