Ca-Mrsa Case Studies

1.) Methicillin Resistant Staphylococcus Aureus (MRSA) is a gram-positive bacterium that is resistant to beta-lactam antibiotics such as Penicillin and Methicillin. CA-MRSA or Community Acquired Methicillin Resistant Staphylococcus is found in the community and not associated with hospitals. This strain can potentially cause disease in healthy individuals by its infamous toxin, Panton-Valentine Leukocidin which causes necrosis of alveoli. CA-MRSA is commonly found among military recruits, athletic teams, correctional facilities, nurseries, and among men who have sex with men.

HA-MRSA or Hospital Acquired Methicillin Resistant Staphylococcus Aureus is primarily found in healthcare facilities and affects most people with weakened immune systems,

Aureus is by analyzing the damaged tissue. Skin infections associated with S. Aureus usually result in Furuncles and Carbuncles, which are boils/lesions filled with abscess. Another skin infection caused by S. Aureus is Staphylococcal scalded skin syndrome (SSSS) which peels the skin’s stratum granulosum layer off causing desquamation. This is due to the toxins ability to hydrolyze desmoglein 1 which holds the keratinocytes together and the absence of desmoglein 3 in granulosum layer. The effects are red bright skin.

In lab, we learned to distinguish two types of bacteria using the gram stain, gram positive and gram negative. Since S. Aureus has a thick peptidoglycan cell wall with teichoic acid, it stains gram positive. Further tests will indicate the bacteria, including the presence of catalase, sheep blood hemolysis, mannitol fermentation, halotolerance, and coagulase, which S. Aureus is positive for all.

3.) MRSA is resistant to beta-lactam antibiotics (penicillin, methicillin, etc.) and can be more virulent and invasive than Staphylococcus Aureus. MRSA carries the mecA gene, which allows the bacterium to fully construct a cell wall by coding for the penicillin binding