staphylococcus identification
IgG binds ______________
Protein A
what are the three types of hemolysis
1. alpha - hemolysis 2. beta- hemolysis 3. gamma- hemolysis
staphylococcus aureus is biosaftey level
2
Shape of staphylococcus
Cocci
what does the DNase agar contain
DNA and the pH indicator Methyl Green
what occurs for a positive result in the DNase agar
DNA hydrolysis releases negatively charged phosphates which causes a drop in the pH. A decrease in pH causes the indicator to change from blue-green to clear. NOTE: Only coagulase positive organisms hydrolyze DNA.
what are the three main groups of pathogens within staph species
S. aureus, S. epidermidis, and S. saprophyticus
What does DNase test for?
Staphylococcus has the ability to hydrolyze DNA
describe results of the bacterial agglutination test
There should not be clumping in the control latex since the beads do not have the antibodies to cause the agglutination reaction. A positive result (clumping of the latex beads) is indicative of S. aureus.
coagulase plasma test tests for
blood clotting by activating prothrombin in the coagulation pathway. Coagulase plasma in a tube will clot in the presence of coagulase. Valid for Gram positive organisms only because Pseudomonas can give a false positive.
fibrinogen binds ______________
coagulase
S. aureus has 2 proteins_________________ The latex beads have 2 antibodies_____________________
coagulase and Protein A fibrinogen and IgG
beta hemolysis
complete lysis of the RBCs results in a clear zone around the growth
what does the SM110 media contain
contains mannitol, 7.5% NaCl
what does the MSA plate contain
contains mannitol, 7.5% NaCl, and the pH indicator Phenol red
phenol red shows yellow when there is a ___________ in ph
decrease pH
alpha-hemolysis
due to partial lysis of red blood cells (RBCs) results in a discoloration of the RBCs to a green color
where are staphylococcus species found
found everywhere tolerate drying and high salt fairly well; normal inhabitants of the skin and nose opportunistic pathogens so hospitals
If the organism is nonpathogenic, then it will
grow well on MSA, but will not ferment mannitol
what does the blood agar show
hemolysis
what is the Bacterial Agglutination Test
it tests for staphylococcus aureus identification and they are based on antibody/antigen reactions
gamma hemolysis
no lysis of the RBCs
The SM110 media favors colony __________________________
pigmentation since S. aureus produces a yellow carotenoid pigment
what gram are staphylococcus
positive
staph are pus forming what is this term
pyogenic
Staphylococcus Medium 110 (SM110) is a _______________media
selective
what type of media is MSA
selective and differential
what types of infections are caused by staph
skin infections, osteomyelitis, and septicemia
____________________ is the most pathogenic of the three.
staphylococcus aureus
the MSA media is selective for
staphylococcus species
how does staph deal with salt
they are halotolerant because they can grow on salt but do not require it
the MSA media differentiates
those that ferment mannitol and are therefore pathogenic
What does Staphylococcus aureus cause?
toxic shock syndrome produces a toxin that can cause fever, rash, and possible death - Rely tampons were found to cause TSS - they were made of material that was super-absorbent so they could be used overnight - they would pick up Staph which would grow to concentrated levels in the tampon - this resulted in colonization of Staph in the vagina and release of the toxin that causes toxic shock syndrome
MSA test Staphyloccocus aureus and staphylococcus saprophytes have a positive result because they ferment mannitol and turn yellow. They are pathogenic
which test is this? Describe the results
Staphylococcus aureus is the only organism a positive result that is indicated with the yellow carotenoid pigment
which test is this? Describe the results
This is the coagulase plasma test. it tests for coagulase plasma and the only organism that has coagulated is staphylococcus aureus because it does not spread out when the tube is slanted
which test is this? Describe the results
this is a blood agar. The staphylococcus aureus is the only one that is positive for alpha hemolysin because it has the alpha hemolysis that does partial lysis of RBC and discolors the RBC to green
which test is this? Describe the results
this is the DNase Test and the only positive organism is staphylococcus aureus because it has a zone of hydrolysis around the line of inoculation
which test is this? Describe the results