Methicillin-resistant

Staphylococcus (MRSA) = methicillin-resistant Staphylococcus aureus. 

As recently as 1970, only about 30 naturally occurring organohalogen compounds were known. It was simply assumed that chloroform, halogenated phenols, chlorinated aromatic compounds called PCBs, and other such substances found in the environment were industrial pollutants. Now, only a third of a century later, the situation js quite different. More than 5000 organohalogen compounds have been found to occur naturally, and tens of thousands more surely exist. From a simple compound like chloromethane to an extremely complex one like vancomycin, a remarkably diverse range of organohalogen compounds exists in plants, bacteria, and animals. Many even have valuable physiological activity. Vancomycin, for instance, is a powerful antibiotic produced by the bacterium Amycolatopsis orientalis and used clinically to treat methicillin-resistant Staphylococcus aureus (MRSA). 

Methicillin-resistent staphylococci are strains of staphylococci, which show resistance to a wide variety of antibiotics. They are named for their resistance to methicillin, a (3 -lactamase-resistant penicillin. Methicil-lin-resistante Staphylococcus aureus (MRSA) has become a serious problem particularly in hospitals. 

Oxazolidinones are a new class of synthetic antimicrobial agents, which have activity against many important pathogens, including methicillin-resistant Staphylococcus aureus and others. Oxazolidinones (e.g. linezolid or eperezolid) inhibit bacterial protein synthesis by inhibiting the formation of the 70S initiation complex by binding to the 50S ribosomal subunit close to the interface with the 3OS subunit. 

Mesolimbic System/Reward System Metabolic Syndrome Metabotropic Glutamate Receptors Metabotropic Receptor Metalloprote(in)ases Methicillin-resistant Staphylococci iV-Methyl D-aspartate Receptors Methylating Agents... 

Problems of recent years involving listeriosis, salmonellosis, giardiasis and Legionnaire s disease have received attention, as have the re-emergence of tuberculosis and the importance of methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant enterococci (VRE). 

Early cephalosporins were spelt with ph, more recently with T. t Methicillin-resistant Staph, aureus (MRSA) strains are resistant to cephalosporins. t Enterococci are resistant to cephalosporins. 

HAMILTON-MILLER J M T aud SHAH s (1999) Disorganization of cell division of methicillin-resistant Staphylococcus aureus by a component of tea Camellia sinensis) a study by electron microscopy , FEMS Microbiology Letters, 176, 463-9. 

YAM T s, HAMILTON-MILLER J M T and SHAH s (1998) The effect of a component of tea Camellia sinensis) on methicillin resistance, PBP2 synthesis, and (J-lactamase production in Staphylococcus aureus, J Antimicrobial Chemtherapy, 42, 211-16. 

Inpatient treatment of methicillin-resistant S. aureus can consist of IV vancomycin or oral agents as described above, depending on the severity of infection and concomitant organisms. IV vancomycin may also be converted to oral step-down therapy upon discharge. 

Infections acquired from an external source are referred to as exogenous infections. These infections may occur as a result of human-to-human transmission, contact with exogenous bacterial populations in the environment, and animal contact. Resistant pathogens such as methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant Enterococcus spp. 

Community-acquired methicillin-resistant S. aureus (CA-MRSA) is becoming an increasingly common pathogen in cellulitis. CA-MRSA can be distinguished from health care-associated MRSA (HA-MRSA) by its genetic dissimilarity, host population, drug susceptibility patterns, and toxin production. 

Rybak JM, LaPlante KL. Community-associated methicillin-resistant Staphylococcus aureus A review. Pharmacotherapy 2005 25(1) 74-85. 

It is important to determine (1) whether the isolate is methicillin-susceptible or methicillin-resistant and (2) whether the patient has a prosthetic valve. For patients with no prosthetic material, methicillin-susceptible staphylococci treatment should consist of a penicillinase-resistant penicillin (e.g., nafcillin or oxacillin) with or without gentamicin, and for methicillin-resistant strains, therapy should consist of vancomycin (see Table 71-4). Combination therapy with aminoglycosides, when used in these patients, typically is given only during the first 3 to 5 days of therapy. In the absence of prosthetic material, some treatment guidelines do not recommend combination therapy against MRSA. However, many clinicians may combine either gentamicin or rifampin with vancomycin if the patient is unresponsive to monotherapy. 

MSSA methicillin-sensitive S. aureus MRSA methicillin-resistant S. aureus NBTE nonbacterial thrombotic endocarditis... 

MRSA, methicillin-resistant S. aureus PVD, peripheral vascular disease IJTI, urinary tract infection. 

Fluoroquinolones Not approved by the United States Food and Drug Administration for use in children except for anthrax (ciprofloxacin). MRSA, methicillin-resistant 5. aureus MSSA, methicillin-sensitive 5. aureus. 

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