Genetic diversity of methicillin resistant Staphylococcus aureus strains isolated from burn patients in Iran: ST239-SCCmec III/t037 emerges as the major clone.
Methicillin-resistant Staphylococcus aureus (MRSA) as a major cause of infection in health care, hospital and community settings is a global health concern. The purpose of this study was to determine the antibiotic susceptibility pattern and distribution of circulating molecular types of MRSA in a burn hospital in Tehran, the capital of Iran. During a 10-month study period, 106 Staphylococcus aureus isolates were assessed. Isolates were subjected to susceptibility testing using the disk diffusion method and Polymerase Chain Reaction (PCR) for detection of mecA, fem and nuc genes. The presence of PVL and tst encoding genes were determined by PCR method. All the MRSA isolates were genotyped by multilocus sequence typing (MLST), spa typing, SCCmec typing and agr typing. The presence of mecA gene was confirmed in all the Staphylococcus aureus isolates. Antimicrobial susceptibility testing revealed a high resistance rate (90.6%) to ampicillin, tetracycline, and erythromycin. The rates of resistance to remaining antibiotics tested varied between 18.9% and 84.9%. The high- level of resistance to mupirocin was confirmed in 19.8% of MRSA strains isolated from burn patients. Multi-drug resistance was observed in 90.6% of isolates. Sixteen of the 106 MRSA isolates (15.1%) harbored PVL-encoding genes. The majority of our MRSA strains carried SCCmec III (71.7%). ST239-SCCmec III/t037 (34%) was the most common genotype followed by ST239-SCCmec III/t030 (24.5%), ST15-SCCmec IV/t084 (15.1%), ST22-SCCmec IV/t790 (13.2%), and ST239-SCCmec III/t631 (13.2%). Mupirocin resistant MRSA isolates belonged to ST15-SCCmec IV/t084 (40%), ST22-SCCmec IV/t790 (23.3%), ST239-SCCmec III/t631 (20%), and ST239-SCCmec III/t030 (16.7%) clones. The results showed that genetically diverse strains of MRSA are circulating in our burn hospitals with relatively high prevalence of ST239-SCCmec III/t037 clone. The findings support the need for regular surveillance of MRSA to determine the distribution of existing MRSA clones and to detect the emergence of new MRSA clones.
Department of Microbiology, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
Mehdi
M
Goudarzi
Clinical Diagnostic Laboratory, Shahid Motahari Burn Hospital, Iran University of Medical Sciences, Tehran, Iran.
Mahnaz
M
Bahramian
Clinical Diagnostic Laboratory, Shahid Motahari Burn Hospital, Iran University of Medical Sciences, Tehran, Iran.
Mahboobeh
M
Satarzadeh Tabrizi
Department of Microbiology, Faculty of Medicine, Kuwait University, Safat 13110, Kuwait.
Edet E
EE
Udo
Departamento de Microbiologia Medica, Instituto de Microbiologia Paulo de Goes, Centro de Ciencias da Saude, Universidade Federal do Rio de Janeiro, Brazil.
Agnes Marie Sá
AM
Figueiredo
WHO Collaborating Center for Reference and Research on Rabies, Pasteur Institute of Iran, Tehran, Iran.
Maryam
M
Fazeli
Department of Microbiology, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran. Electronic address: novelty@sbmu.ac.ir.
Hossein
H
Goudarzi
D000293:Adolescent; D000328:Adult; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D002056:Burns / Q000150:complications*; D002648:Child; D002675:Child, Preschool; D052978:Disk Diffusion Antimicrobial Tests; D005260:Female; D014644:Genetic Variation; D005838:Genotype; D006761:Hospitals; D006801:Humans; D007492:Iran / Q000453:epidemiology; D008297:Male; D055624:Methicillin-Resistant Staphylococcus aureus / Q000145:classification* / Q000187:drug effects / Q000235:genetics* / Q000302:isolation & purification; D008875:Middle Aged; D017720:Molecular Epidemiology; D058889:Molecular Typing; D016133:Polymerase Chain Reaction; D013207:Staphylococcal Skin Infections / Q000453:epidemiology / Q000382:microbiology*; D037521:Virulence Factors / Q000235:genetics; D055815:Young Adult
D000900:Anti-Bacterial Agents; D037521:Virulence Factors
Burn patient; MLST; MRSA; SCCmec type; Spa type