Caracterização molecular de cepas de Staphylococcus aureus resistentes à meticilina isolados de pacientes em tratamento de hemodiálise

Abstract

Chronic kidney disease is a kidney injury with progressive and irreversible loss of kidney function. The loss of renal function is gradual and may progress to chronic renal failure. Hemodialysis is indicated when other treatments are no longer sufficient. Infections are the second leading cause of death for dialysis patients in Brazil, preceded only by cardiovascular diseases. Staphylococcus aureus is the main pathogen responsible for nasal colonization of patients undergoing hemodialysis, and in episodes of systemic infections it is the most isolated bacterial species. This study characterized four strains of Methicillin-Resistant Staphylococcus aureus (MRSA) isolated from 375 patients undergoing hemodialysis, at a referral clinic in the city of Natal, RN. MRSA were identified by the agar diffusion method using the cefoxitin disc (30ug) and by the search for the mecA gene through the polymerase chain reaction. The same technique was used to search for the lukF gene and to discriminate against islands of resistance. The MRSA clonal profile was determined using the pulsed field gel electrophoresis (PFGE) technique. All MRSAs had the mecA and lukF gene. Of the 4 strains of MRSA, 3 were related to clone USA800 and carriers of the chromosomal cassettes mec II and IV. The presence of MRSA related to the USA 800 clone represents a major risk factor for this population, as it is a strain involved in many serious infections, especially in populations with compromised immunity, as evaluated in this study.