Typing of Methicillin-Resistant Staphylococcus aureus Isolate from Healthcare Workers in Larestan, Iran

Objective: The aim of this study was to determine the antimicrobial susceptibility and cassette chromosome typing in Methicillin-Resistant Staphylococcus aureus (MRSA) isolated from healthcare workers. Methods: 230 nasal swabs were collected from healthcare workers of three hospitals in Larestan, Iran. Antibiotic susceptibility was determined by disk diffusion method according to CLSI guideline. The minimum Inhibitory concentration (MIC) of vancomycin and screening test with methicillin were measured by E-test and agar screen plate procedures. Cefoxitin disc diffusion test was performed. MRSA isolates were selected and investigated for mecA gene and SCCmec typing by multiplex-PCR, then five methods were compared. Results: In total, 37 S. aureus were isolated, 28 were defined as MRSA. Frequency of SCCmec types 9 SCCmec I, 8 SCCmec IV, 5 SCCmec II 4 SCCmec V 2 SCCmec III. In this study, 75% of isolates were CA-MRSA, 25% were HA-MRSA. Evaluation of antibiotic resistance showed the greatest resistance to penicillin and the lowest resistance was observed to vancomycin and by E-test method 28.5% of isolates were intermediate resistance to vancomycin. However, screening test detected 92.8% resistance with oxacillin and 28 of isolates were resistant with Cefoxitin disc diffusion. For these 28 isolates mecA was positive. Conclusion: As a result, in our S. aureus isolates methicillin resistance was75.7%. The most frequent type was SCCmec I. Our result showed high rates of antibiotic resistance specially to methicillin in the S. aureus isolated hospitals that is a serious warning to the treatment of infection caused by this bacterium. J Microbiol Infect Dis 2018; 8(1):1-7 Keywords: Methicillin-resistant Staphylococcus aureus, SCCmec, mecA

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  • 1. Changchien CH, Chen SW, Chen YY, Chu C. Antibiotic susceptibility and genomic variations in Staphylococcus aureus associated with Skin and Soft Tissue Infection (SSTI) disease groups. BMC Infect Dis 2016; 10: 276-280. 2. Davoodabadi F, Mobasherizadeh S, Mostafavizadeh K, et al. Nasal colonization in children with community acquired methicillin-resistant Staphylococcus aureus. Adv Biomed Res 2016; 11: 86-90. 3. Iliyasu G, Daiyab FM, Tiamiyu AB, et al. Nosocomial infections and resistance pattern of common bacterial isolates in an intensive care unit of a tertiary hospital in Nigeria: A 4-year review. J Crit Care 2016; 34: 116-120. 4. Gunawardena ND, Thevanesam V, Kanakaratne N, et al. Molecular identification of methicillin resistance and virulence marker in Staphylococcus aureus J infect Dis 2012; 2: 18-29. 5. Hou BP, Zhou S, Hua DH, et al. Staphylococcal cassette chromosome mec (SCCmec) analysis and antimicrobial susceptibility profiles of methicillin resistant Staphylococcus aureus (MRSA) isolates in a teaching hospital, Shantou, China. Afr J Microbiol Res 2010; 4: 844–848. 6. Grundmann H, Aires-de-Sousa M, Boyce J, et al. Emergence and resurgence of methicillin resistant Staphylococcus aureus as a public-health threat. Lancet. 2006; 368: 874–885. 7. Baba-Moussa L, Sina H, Scheftel JM, et al. Staphylococcal Panton-Valentine Leukocidin as a major virulence factor associated to furuncles. Clin infect Dis 2011; 6: 257-260. 8. Japoni A, Jamalidoust M, Farshad, S, et al. Characterization of SCCmec, types and antibacterial susceptibility patterns of methicillin resistant Staphylococcus aureus in Southern Iran. J Infect Dis 2011; 64: 28-33. 9. Tsubakishita S, Kuwahara-Arai K, Sasaki et al. Origin and molecular evolution of the determinant of methicillin resistance in Staphylococci. Antimicrob Agents and Chemother 2010; 54: 352-359. 10. Azimian A, Najar-Pirayesh S, Mirab-Samiees S. Occurrence of methicillin resistant Staphylococcus aureus (MRSA) among clinical samples in Tehran-Iran and its correlation with polymorphism of specific accessory gene regulator (agr) groups. Braz J Microbiol 2012; 43: 779-785. 11. Teruyo I, Katayamay, H, Hiramatsu K. Classification of staphylococcal cassette chromosome mec (SCCmec): Guidelines for reporting novel SCCmec mec elements. Antimicrob Agents Chemother 2009; 53: 4961–4967. 12. Brown DFJ, Edwards DI, Hawkey PM, et al. Guidelines for the laboratory diagnosis and susceptibility testing of Methicillin-Resistant Staphylococcus aureus (MRSA). Antimicrob Agents Chemther 2005; 56: 1000-1018. 13. Performance Standards for Antimicrobial Susceptibility Testing; 21st informational supplement. Clinical and laboratory standards institute (CLSI), 2012. 14. Klein E, Smith DL, Laxminarayan R. Hospitalizations and deaths caused by methicillin resistant Staphylococcus aureus, United States, 1999–2005 Emerg Infect Dis 2007; 12: 1840-1846. 15. Klevens RM, Morrison MA, Nadle J, et al. Invasive methicillin resistant Staphylococcus aureus infections in the United States. JAMA 2007; 15: 1763-1765. 16. Zhang K, Mcclure JA, Elsayed S, et al. Novel multiplex PCR for characterization and concomitant subtyping of Staphylococcal cassette chromosome mec typing I to V in Methicillin Resistant Staphylococcus aureuse. J Antimicrob Agents Chemother 2005; 43: 5026-5033. 17. Shokoohi Sh, Aminzadeh Z, Sharafi K, et al. Prevalence of meticillin resistant in HA-MRSA in Tehran. Iran J Microbiol 2009; 2: 87-89. 18. Najarpeerayeh, S.H., Azimian, A., Mostafaee, M., et al, Identification of methicillin resistant Staphylococcus aureus by disk diffusion method, determination of MIC and PCR for mecA gene. J Sci Med Pathobiol 2009; 12: 61–69. 19. Havaei SA, Karbalaeizadeh Babaki M, Pishva E. Comparison of the results of polymerase chain reaction and oxacillin agar dilution methods in determining resistance to methicillin in isolated staphyloccus aureus at Alzahra Hospital, Isfahan, Iran. J Isfahan Med Sch 2011; 29: 1175-82. [In Persian]. 20. Perez LR, Dias C, Azevedo PA. Agar dilution and agar screen with oxacillin: what is known and what is unknown in detection of MRSA. J Microbiol 2008; 57: 954-956. 21. Venkatakrishna RL, Kishore BG, Manohar KS, et al. Detection of methicillin resistance in Staphylococcus aureus: Comparison of Disc diffusion and MIC with mecA gene detection by PCR. J Pharm Biol Sci 2011, 1: 518-521. 22. Hota B, Lyles R, Rim J, Popovich KJ, et al. Predictors of clinical virulence in community-onset methicillin-resistant Staphylococcus aureus infections. Clin Inf Dis 2011; 53: 757-765.