Perfil epidemiológico e caracterização molecular de Staphylococcus spp da unidade de terapia intensiva neonatal em um hospital público da cidade de Dourados/MS

Abstract

Staphylococcus are bacteria Gram-positive of great importance in hospital infections and they are responsible for causing folliculitis, endocarditis, pneumonia, bacteremia, among others. These bacteria have become resistant pathogens to several antimicrobials, such as methicillin-resistant Staphylococcus aureus (MRSA) and Coagulase-negative Staphylococcus (CoNS), which have been identified as the third most common agent in nosocomial infections. Thus, the aim of this study was to understand the molecular epidemiology of Staphylococcus spp. isolates from a teaching hospital in the neonatal intensive care unit sector, determining their molecular characteristics and antimicrobial resistance profile and, therefore, to measure the prevalence of hospital infections. The Staphylococcus spp. samples were collected from a public hospital in Dourados/MS between August 2016 and August 2017 and analyzed by the automated systems Vitek® (BioMérieux) and PhoenixTM. The collected isolates were cultured in glycerinated Brain Heart Infusion (2x) broth and submitted to DNA extraction, PCR technique for amplification of mecA gene and electrophoresis with agarose gel. The isolates of the same patient, from patients with indigenous ethnicity, patients older than 29 days, and positive cultures with admission time of less than 48 hours were exclusion criteria for this study. From the 69 samples analyzed, 49 (71%) were identified containing the mecA gene and 20 (29%) samples did not contain the gene in question. S. epidermidis was the most prevalent bacterium (58%), followed by S. haemolyticus (27.53%) and S. aureus with only 1 sample (1.45%). The main culture sites were blood culture with 54 (78.26%) samples and catheter tip with 15 (21.73%) samples. Regarding the antimicrobial resistance profile, 27 (39.13%), 20 (28.99%) and 15 (21.74%) isolates were resistant to 4, 5-7 and 3 classes of antibiotics, respectively, which classify them as multiresistant isolates. Thus, considering the frequency and increase of infections caused by Staphylococcus spp. resistant in hospitalized patients, the study traced the bacterial profile and epidemiological resistance. This may contribute to preventive actions in the control of hospital infections caused by multiresistant microorganisms, giving better care to patients and promoting the adequate antimicrobial therapy.