Lab 45-48 Flashcards
What is beta Hemolysis
Complete hemolysis, giving a clear zone with a clean edge around the colony
What is alpha hemolysis
Green, Claudia zone around the colony. Partial destruction of red blood cells due to bacteria produce hydrogen peroxide
What is gamma hemolysis
No hemolysis, and no change in the blood agar around the colony
Which bacteria is bile soluable
Streptococcus pneumoniae
What is special about MacConkey plates
They only grow (are selective for) gram-negative organisms.
How are MacConkey plates differential
Lactose fermenting organisms give read colonies and non-lactose fermenters give translucent colonies.
What ingredients are in triple sugar ironed agar
.1% glucose, 1% lactose, 1% sucrose. .02% sulfate, phenyl red, nutrient agar
What change happens in a positive citrate test
Turns from green to blue
What change happens in a positive glucose lactose or sucrose fermentation test
The solution turns from red to yellow
What happens in a positive coagulase test
The solution is clumpy not starry
What happens in a positive oxidase test
The smear turns purple
What happens in a positive TSI test and how do you know if sulfur is produced
If it ferments it stays yellow. If sulfurs produced the tube turns black
What tests are necessary to do in order to identify gram-positive bacteria
Blood agar plate, catalase test, thioglycolate. If positive catalase test then inoculate MSA plate and do a coagulase test.
What tests are necessary in order to identify gram-negative bacteria
Oxidase test, MacConkey plate, citrate test, glucose sucrose and lactose fermentation test
List all gram-positive bacteria
Staphylococcus aureus,
micrococcus Luteus,
staphylococcus epidermidis, Streptococcus pneumonia, streptococcus pyogenes
List all gram-negative bacteria
E. coli, Serratia marcescens, Proteus vulgaris, pseudomonas aeruginosa, E aerogenes.
List all test results for Staphylococcus aureus
Gram-positive,
catalase positive,
coagulase positive
List all test results for E. coli
Gram-negative, citrate negative, oxidase negative, MacConkey agar positive, TSI +/(+), GLS: ferment glucose lactose and sucrose + produces gas with glucose and lactose.
List all test results for Serratia marcescens
Gram-negative, citrate positive, oxidase negative, MacConkey agar negative, TSI +/+, GLS: ferment glucose and sucrose.
List all test results for micrococcus Luteus
Gram-positive, coagulase negative, catalase positive, MSA negative, BAP negative, bile soluble
List all test results for staphylococcus epidermidis
Gram-positive, catalase positive, MSA negative, coagulase negative, BAP negative
List all test results for Proteus Vulgaris
Gram-negative, oxidase negative, site trait negative, MacConkey agar negative, TSI +/+ H2S, GLS: +,-,+
List all test results for pseudomonas aeruginosa
Gram-negative, Citrate positive, oxidase positive, MacConkey negative, TSI: -/- GLS: -,-,-
List all test results for streptococcus pneumonia
Gram-positive,
catalase negative,
alpha hemolytic BAP
List all test results for E. Aerogenes
Gram-negative, oxidase negative, Citrate positive, Macconkey positive, GLS: +g, +g, + TSI: +/(+)
List the test results for streptococcus pyogenes
Gram-positive,
catalase negative
beta hemolytic BAP
