Meticillin-resistant Staphylococcus in Bahrain: evidence of MRS transmission and co-carriage of vancomycin-resistant enterococci
Abstract number: P1447
Senok A., Sharaf E., Al-Mahmeed A., Udo E., Botta G.
Objectives: To determine the transmission of meticillin resistant Staphylococci (MRS) between the hospital and community and evaluate the levels of co-colonisation of MRS positive patients with vancomycin resistant Enterococci (VRE) in our institution
Materials and Methods: From November 2005-April 2006, meticillin resistant Staphylococcus aureus (MRSA) and meticillin resistant coagulase negative Staphylococcus (MRCoNS) positive patients at the Salmaniya Medical Complex, Kingdom of Bahrain were studied. Patients stool specimens were investigated for Enterococci on bile-esculin-azide agar. Enterococci were identified to species level using API 20 STREP, BD PHOENIX system and PCR. Vancomycin resistance in enterococci isolates was confirmed by PCR. Nasal and axillary swabs obtained from family members of patients were screened for MRS. The relatedness of the MRS strains from matching pairs of patients and family members was determined using pulsed-field gel electrophoresis (PFGE).
Results: In total, 182 MRS positive patients (93 MRSA, 89 MRCoNS) and 356 family members were studied. Thirteen MRS patients also carried VRE (12 MRSA & 1 MRCoNS). These were predominantly E. gallinarum with vanC1 genotype and one strain was E. faecium (vanB genotype). Two E. gallinarum isolates haboured an additional vanB gene. Seven MRSA and 41 MRCoNS strains were isolated from the family members. PFGE analysis revealed the presence of variants of a single MRSA clone among patients and their relatives. Twelve MRSA isolates were identical or closely related with six of these showing one to three band differences indicating a clonal origin.
Conclusion: There is evidence of co-carriage of VRE strains in MRSA patients thus setting the stage for possible emergence of vancomycin resistant Staphylococcus aureus. The presence of a single MRSA clone in patients and relatives indicates its transmission between the hospital and the community which poses a significant threat to public health.
|Session name:||18th European Congress of Clinical Microbiology and Infectious Diseases|
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