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