Molecular characterization of methicillin-resistant Staphylococcus aureus nasal isolates from Turkey

Abstract

Methicillin-resistant Staphylococcus aureus (MRSA) colonize most frequently in the anterior nares of the nose and cause serious infections all over the world. The aim of this study was to determine the nasal carriage rate of S. aureus and MRSA strains in Turkish elementary school children. We also analyzed molecular characterizations of MRSA strains by using pulse field gel electrophoresis (PFGE), multi locus sequence typing (MLST), staphylococcal chromosomal cassette mec (SCCmec) typing, and detection of the Panton-valentine leucocidin (PVL) gene. The nasal swabs were obtained from 4,050 children during a 4 month period in Ankara. In vitro antimicrobial susceptibility testing to 1 mug oxacillin and 30 mug cefoxitin was determined by a disk diffusion method. We found that the 1,001 of 4,050 (24.7%) children were colonized with S. aureus. Three S. aureus strains were resistant to oxacillin and cefoxitin. The rate of MRSA among all children was 0.07%. The MRSA strains revealed three different PFGE pattern. All MRSA isolates by harbored the SCCmec type IV element, but not the PVL gene. The two MRSA isolate belonged to sequence type (ST) 30, whereas the other one was a unique type. The results of this study demonstrated that S. aureus nasal carriage rate was consistent with previous studies. However, MRSA carriage rate was low. This study also indicated that the ST30-type IV without PVL gene MRSA clone may be expected to spread in Turkish community.

Nasal Colonization of and Clonal Transmission of Methicillin-Susceptible Staphylococcus aureus among Chinese Military Volunteers

“…The S. aureus nasal carriage rate varies, depending on the specialized populations studied. Our study indicated that there is a 16.1% to 24.6% S. aureus nasal carriage rate in military camps in the Beijing area, which is similar to rates found in general community-based nasal carriage studies in the United States, Turkey, Australia, and Malaysia (2,5,7,21,28), indicating that S. aureus nasal colonization is common in healthy communities all over the world. In contrast, MRSA colonization had significantly geographic distribution variations.…”

“…Our results show that younger age, higher education, newness to military service, nonsmoking, and inactive participation in social events were more likely to be found with S. aureus nasal colonization, a profile which is the exact opposite, except for the educational level, from that for MRSA nasal colonization (1,11,13,21,29,52). The facts, together, suggest an ideal setting for S. aureus, including insufficient immunity, crowds or close contacts, and inactivity.…”

“…MRSA nasal carriage rates are higher in developed countries, such as the United States (2,5,7,9,11,15,19,29,34), where soldiers who were nasal carriers of MRSA strains had a 10-fold-greater risk of clinical infection than nasal MSSA carriers in a longitudinal study (11). Other countries, such as Australia and Turkey, have had relatively rare MRSA colonization reported (21,28). In our study, of the total 209 S. aureus isolates recovered from 1,044 specimens, MRSA was not identified, indicating a discrepancy between the carriage rate and clinical prevalence of MRSA in the Beijing area.…”

“…Nosocomial S. aureus bacteremia was three times more frequent in S. aureus carriers than in noncarriers (48). Numerous studies of S. aureus nasal carriage have been carried out in various geographic regions in the United States and the Netherlands (2,5,7,21,23,27,28,41). Cross-section surveys of nasal carriage prevalence and transmission mechanisms in special healthy populations are beneficial in assessing risk factors associated with S. aureus infections (2,8,13,26,(32)(33)(34)(35).…”

Community-Associated Methicillin-ResistantStaphylococcus aureus: Epidemiology and Clinical Consequences of an Emerging Epidemic

“…In England, colonization with MRSA in the community is rare, despite an estimated 3-fold increase in the rate of hospitalizations for abscesses, carbuncles, furuncles, and cellulitis between 1989 to 1990 and 2003 to 2004 and a greater-than-5-fold increase in the rate staphylococcal pneumonia (374). Similarly, in Ankara, Turkey, 4,050 schoolchildren were assayed for nasal colonization with MRSA in 2007: 24.7% carried S. aureus, but only 0.07% (3 children) carried MRSA (472).…”