Study of Methicillin-resistant Staphylococcus Aureus (MRSA) Isolated From Infected Patients in Brazil

Overview

This project has as general objective to determine if there is any Methicillin-resistant Staphylococcus aureus (MRSA) strain disseminating in the hospital of Belo Horizonte. If this is the case, the investigators will determine if this is an international known strain by typing it by PFGE and MLST. The detection of mecA gene will be performed by PCR. Their susceptibility profile to several drugs will also be accessed and it will be possible to compare the response to those drugs commonly in use to that of Daptomycin, a new drug available in Brazil. It will be screened for reduced susceptibility to vancomycin by Macromethod Etest (MET) in order to search for VISA or hetero-VISA. Also, due to the discussions at the literature about mutations in genes that are said to be responsible for reduced susceptibility to vancomycin, the investigators will sequence these genes in all PFGE type strain of this study looking for mutations already described to compare to the screening results.

Multidrug resistant and virulent MRSA strains have been disseminating worldwide and few alternatives of treatment for diseases caused by this pathogen are available. In this study, 36 isolates from colonization or different clinical specimens from infected patients of the Hospital Rizoleta Tolentino Neves will be analyzed. These results will provide important data for doctors and nurses, such as whether there is any strain dissemination or not in the hospital what could suggest an outbreak. It will be performed molecular typing by pulsed field gel electrophoresis (PFGE) and multilocus sequence typing (MLST). The investigators will evaluate the efficiency of several antimicrobials and the frequency of h-VISA and VISA among the Brazilian MRSA. Besides, the investigators will verify the presence of mutation in genes that are involved in resistance mechanisms of VISA. According to the strains profile present in the hospital, if this is suggested that there is a dissemination of some strain, the health professionals can start a more rigid infection control measures in order to decrease the number of cases of nosocomial infection, decreasing the time of hospitalization of patients and, consequently the cost for the hospital.

Conditions