Methicillin resistant Staphylococcus aureus
Methicillin-resistant Staphylococcus aureus refers to a group of Gram-positive bacteria that are genetically distinct from other strains of Staphylococcus aureus. MRSA is responsible for several difficult-to-treat infections in humans.
It refers to a group of Gram-positive bacteria that are genetically distinct from other strains of Staphylococcus aureus. MRSA is responsible for several difficult-to-treat infections in humans. MRSA is any strain of S. aureus that has developed, through horizontal gene transfer and natural selection, multiple drug resistance to beta-lactam antibiotics. β-lactam antibiotics are a broad-spectrum group that include some penams (penicillin derivatives such as methicillin and oxacillin) and cephems such as the cephalosporins. Strains unable to resist these antibiotics are classified as methicillin-susceptible S. aureus, or MSSA.
MRSA is common in hospitals, prisons, and nursing homes, where people with open wounds, invasive devices such as catheters, and weakened immune systems are at greater risk of hospital-acquired infection. MRSA began as a hospital-acquired infection but has become community-acquired, as well as livestock-acquired. The terms HA-MRSA (healthcare-associated or hospital-acquired MRSA), CA-MRSA (community-associated MRSA), and LA-MRSA (livestock-associated MRSA) reflect this.
Ongoing infections with CA-MRSA in deprived and overcrowded areas of London was described. There was continued arrival of this strains to the hospital setting. Disparities in CA-MRSA was not explained by racial causes but was associated with overcrowding. We diagnose sporadic cases of wound infection caused by CA-MRSA post cesarean interventions and frequent cases of SSTI (skin and soft tissue infections). We studied familial SSTI at community level and found association of it with overcrowding and location of the home at the poorer neighborhoods. We found 41.3% of the homes had history of SSTI. 22,3% of households had extreme overcrowding. In the poorer neighborhoods 66 of 129 households (51.2%) had a history of SSTI. In the richer neighborhoods the history of SSTI appeared in 37 of 119 (31.1%) (p=0.0019). Presence of CA-MRSA should always be suspected in infections associated with overcrowding and living in poor neighborhoods. A history of SSTI can be easily correlated with the presence of CA-MRSA. We suggest: SSTI should be treated with non beta-lactamic antibiotics, investigate and treat familial dissemination of the infection, explain measures of hygiene and control to block the reentry of the organism. Community sepsis should be treated with antibiotics that cover CA-MRSA, especially in front of personal or family history of SSTI or an overcrowded home or placed in disadvantaged socioeconomic zones. Restrict caesarean births. In the event of a family history of SSTI, extreme overcrowding or living in an area of disadvantaged socioeconomic zone, contemplate adding vancomycin to antibiotic prophylaxis. This recommendation should be evaluated in depth in each programmatic area.
Microbiology: Current Research