Mathicillin Resistant Staphylococcus Aureus - Research Paper Example

Methicillin resistant S. aureus is an antibiotic resistant form of S. aureus that has emerged as a significant strain of this bacterium. The first outbreak was reported in 1980 in the region of Detroit and since then MRSA has established itself as a clinically dominant community pathogen. In 2004, a study of adult patients who presented with purulent staphylococcal infections in the emergency, MRSA constituted a 78% of S. aureus infections (Crossley et al 272, 275). The community associated MRSA has been defined on the basis of the criteria provided by the Center for Disease Control and Prevention.

According to the criteria, infections are classified as MRSA if (a) MRSA is isolated within 48 hours from a hospitalized patient, (b) the patient presents with a history of hospital admission, dialysis, surgery or long term care facility residence, (c) patient has an indwelling device during the time of culture isolation, (d) previous history of MRSA infection (Crossley et al 272). It is important to differentiate the microbiological characteristics of the MRSA strains from the S. aureus, the disease spectrum and manifestations so that a correct diagnosis and treatment plan can be devised.

Fig 1 :Prevalence of MRSA shown in relation to the age of the patients performed by the National Health and Nutrition Examination Survey 2001-2004 (Crossley et al 281). The microbiological characteristics of the staphylococcus aureus are significant in understanding the clinical course of the disease. Staphylococci are included in the Gram positive bacteria which are signified by their catalase-positive and facultative anaerobic properties. Staphylococci measure 0.2-1.5 micro-meters in diameter and produce golden yellow colonies on agar or broth cultures within 12-24 hours at 37 C.

The colonies are formed in grape like cluster formation or in the form of pairs, chains or even single bacterium (Weston 128). MRSA is a type of S. aureus that is resistant to a group of antibiotics called beta-lactams. This group includes Methicillin and others such as oxacillin, amoxicillin and penicillin (Centers for disease control and prevention n.p.). Fig 2: Representation of the MRSA colonies on the cultures agar observed through microscopic examination (Centers for Disease Control and Prevention n.p.).

The epidemiology of MRSA is mostly significant in health-care facilities. MRSA is typically introduced through patients who are transferred from other health care settings. Doctors are also considered as important sources of inter-hospital spread of MRSA infections. Spouses of patients can also act as reservoirs of infections at several times. Colonization occurs rapidly once MRSA is introduced into a hospital. Open wound diseases such as skin diseases including chronic dermatitis, ulcers, burns, surgical wounds and decubitus ulcers predispose the patients to the MRSA colonization.

Aged and debilitated patients, patients on poor anti-microbial therapy, intensive-care patients, patients of chronic hemodialysis or long-term hospitalized patients are at higher risks for MRSA infection development (Gantz et al 264,265). Apart from patients in health care facilities, visitors of infected patients are also at high risk. Disease is transmitted through casual contact such as hugging, touching or kissing. Close skin to skin contact or contact of open wounds with contaminated items and surfaces also predisposes to MRSA infections.

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