In this article. Methicillin-resistant Staphylococcus aureus (MRSA) is a bacterium that causes infections in different parts of the body. It's tougher to treat than most strains of staphylococcus aureus -- or staph -- because it's resistant to some commonly used antibiotics.n this article. Methicillin-resistant Staphylococcus aureus (MRSA) is a bacterium that causes infections in different parts of the body. It's tougher to treat than most strains of staphylococcus aureus -- or staph -- because it's resistant to some commonly used antibiotics.
Although enterococci have been known to be intrinsically resistant to cephalosporins for decades, the mechanism of cephalosporin resistance remains incompletely understood. Three determinants for cephalosporin resistance in E. faecalis have been described.
Beta-lactam antibiotics include penicillins, cephalosporins and related compounds. As a group, these drugs are active against many gram-positive, gram-negative and anaerobic organisms.acterial resistance against beta-lactam antibiotics is increasing at a significant rate and has become a common problem in primary care medicine. There are several mechanisms of antimicrobial resistance to beta-lactam antibiotics.