Methicillin Resistance - Causes, Symptoms and Treatment

Methicillin resistant (MR) staphylococci are a paramount cause of nosocomial infections. Staphylococcus aureus is an ominous prognosis associated with a high prevalence of embolic episodes and neurological involvement. Staphylococcus aureus is one of the most common causes of skin infection in North America, causing pimples, boils and carbuncles and impetigo Whether methicillin resistance decreases the risk of embolism in infective endocarditis is unclear. We sought to assess the association between methicillin resistance and risk factors for embolism in S. aureus infective endocarditis. A distinctive feature of methicillin resistance is its heterogeneous expression. Borderline resistance, a low-level type of resistance to methicillin exhibited by strains lacking mecA, is associated with modifications in native PBPs, beta-lactamase hyperproduction, or possibly a methicillinase. The resistance phenotype is influenced by numerous factors, including mec and beta-lactamase (bla) regulatory elements, fem factors, and yet to be identified chromosomal loci. The heterogeneous nature of methicillin resistance confounds susceptibility testing. Methodologies based on the detection of mecA are the most accurate. The independent risk factors for an embolism were injection drug use, presence of a cardiac vegetation with a size of 10 mm or greater, and absence of nosocomial infection.

S. aureus has a number of virulence factors (ability to cause disease) including is Proteins on the organism's surface promote adherence to damaged tissues, increasing its ability to cause skin and invasive infections. Mechanisms to bind proteins in the bloodstream allow it to escape detection and attack by antibodies produced by our immune system. Methicillin-resistant S. aureus is one of these organisms, although there are other antibiotic-resistant organisms that threaten hospitalized patients. Resistance to beta-lactamase unstable penicillins (all those except the methicillin, oxacillin, cloxacillin group) is due to the production of beta-lactamases which destroy the beta-lactam group. Two types of methicillin resistance are differentiated in staphylococci: intrinsic (high-level) resistance; and intermediate resistance (borderline resistance, borderline susceptibility, diminished susceptibility). This classification is based on the results obtained using methods detecting resistance phenotype - e.g., disk diffusion, Vitek, E test, etc. Intrinsic resistance is due to a single mechanism - the production of a unique PBP 2a, encoded by the mecA gene. However, many mecA positive isolates also exhibit borderline susceptibility. These show intrinsic heterogeneous resistance.

Causes of Methicillin Resistance

Common Causes and Risk factors of Methicillin Resistance

Staphylococcus aureus.
High prevalence of embolic episodes.
Neurological involvement.

Sign and Symptoms of Methicillin Resistance

Common Sign and Symptoms of Methicillin Resistance

Pain.
Swelling.
Furuncles (boils) and carbuncles.
Blistering and peeling skin.
Swollen lymph nodes in the neck, armpits or groin.

Treatment for Methicillin Resistance

Common Treatment for Methicillin Resistance

Treatment with stabilised hypochlorite or povidone iodine appears the most effective means of dealing with skin and wound infections by these organisms.
Vancomycin remaining the drug of choice in serious situations.
Fusidic acid and rifampicin can be effective in some situations but resistance quickly develops and they should never be used alone.
New class of antibiotics, the oxazolidinones, which is progressing through Stage III trials.
Mupirocin cream has also use for Methicillin Resistance treatment and no more effective, than more traditional hexachlorophene or povidone iodine cream.

Acne - Acne information, picture, symptom, cause of Acne