Rıza DURMAZ, Erman ORYAŞIN, Bülent BOZDOĞAN, Selma ŞEN, Banu BAYRAKTAR, Alper GÜNDÜZ, Duygu ERDEMİR, Elif AKTAŞ, Nuray UZUN

Early Detection and Control of Methicillin resistant Staphylococcus aureus Outbreak in an Intensive Care Unit

Background: Although Methicillin resistant Staphylococcus aureus (MRSA) is one of the major pathogens of healthcare associated infec-tions, we had only sporadic cases in our intensive care unit (ICU) for years.Aims: To investigate the sudden increase in the number of MRSA cases in ICU.Study design: Descriptive study.Methods: From the 5th December 2016 to 26th January 2017, we detected 11 new MRSA cases in ICU. Screening of 73 ICU healthcare workers (HCWs) and screening of 13 patients was performed for outbreak in-vestigation. Nine clinical isolates available in stocks and eight screening MRSA isolates were included in molecular studies. PFGE, spa-mecA-mecC-PVL in-house multiplex PCR assay and spa typing, SCCmec typing were performed for all isolates. Sequence type of the representative strain was determined by Multi-Locus Sequence typing (MLST). Results: All strains were mecA positive, PVL negative, and have the same antimicrobial susceptibility pattern except for two strains. All clinical, two patient screening and three nasal isolates of HCWs showed the same pulsotype, named clone A. The spa type of outbreak isolates is t030 and the SCCmec type is SCCmecIII; the MLST type of representative strain is ST239 (PFGE pulsotype A, ST239-SCC-mecIII-t030). Unrelated three isolates had PFGE pulsotype B-SC-CmecI-t030, PFGE pulsotype C-SCCmecIII-t459, PFGE pulsotype D-SCCmecIII. Conclusion: Molecular typing techniques are the cornerstones for the in-vestigation of outbreaks. Infection control measures, such as enhancing cleaning procedures, promoting hand hygiene, should be enforced in the ICU unit. All patients, including those who have already been discharged to other departments, must be put on contact isolation. HCWs carrying the MRSA strains could be offered decolonization.

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1. Liu J, Chen D, Peters BM, Li L, Li B, Xu Z. et al. Staphylococcal chromosomal cassettes mec (SCCmec): A mobile genetic element in methicillin-resistant Staphylococcus aureus. Microb Pathog 2016;101:56-67. [Crossref]
2. Simor AE, Ofner-Agostini M, Bryce E, McGeer A, Paton S, Mulvey MR, et al. Laboratory characterization of methicillin-resistant Staphylococcus aureus in Canadian hospitals: Results of 5 years of National Surveillance, 1995-1999. J Infect Dis 2002;186:652-60. [Crossref]
3. te Witt R, van Belkum A, van Leeuwen WB. Molecular diagnostics and genotyping of MRSA: An update. Expert Rev Mol Diagn 2010;10:375-80. [Crossref]
4. Khan A, Lampitoc M, Slaripour M, McKernan P, Devli R, Muller MP. Rapid control of amethicillin reistant Staphylococcus aureus (MRSA) outbreak in a medical surgical intensive care unit (ICU). Can J Infect Control 2009;24:12-6.
5. Stegger M, Andersen PS, Kearns A, Pichon B, Holmes MA, Edwards G, et al. Rapid detection, differentiation and typing of methicillin-resistant Staphylococcus aureus harbouring either mecA or the new mecA homologue mecA (LGA251). Clin Microbiol Infect 2012;18:395-400. [Crossref]
6. Yetkin GKÇ, Durmaz B, Durmaz R, Çizmeci Z, İşeri L. Molecular typing of methicillin-resistant Staphylococcus aureus isolated from bloodstream infections in a university hospital. Turk J Med Sci 2009;39:959-68.
7. Tenover FC, Arbeit RD, Goering RV. How to select and interpret molecular strain typing methods for epidemiological studies of bacterial infections: A review for healthcare epidemiologists. Molecular Typing Working Group of the Society for Healthcare Epidemiology of America. Infect Control Hosp Epidemiol 1997;18:426-39. [Crossref]
8. McClure-Warnier JA, Conly JM, Zhang K. Multiplex PCR assay for typing of staphylococcal cassette chromosome mec types I to V in methicillin resistant Staphylococcus aureus. J Vis Exp 2013; (79):50779. doi: 10.3791/50779. [Crossref]
9. Enright MC, Day NP, Davies CE, Peacock SJ, Spratt BG. Multilocus sequence typing for characterization of methicillin-resistant and methicillin-susceptible clones of Staphylococcus aureus. J Clin Microbiol 2000;38:1008-15. [Crossref]
10. Stock NK, Petráš P, Melter O, Kapounová G, Vopalková P, Kubele J, et al. Importance of multifaceted approaches in infection control: A practical experience from an outbreak investigation. PLoS One 2016;11:e0157981. [Crossref]
11. Chipolombwe J, Török ME, Mbelle N, Nyasulu P. Methicillin resistant Staphylococcus aureus multiple sites surveillance: A systemic review of the literature. Infect Drug Resist 2016;9:35-42. [Crossref]
12. Song X, Cheung S, Klontz K, Short B, Campos J, Singh N. A stepwise approach to control an outbreak and ongoing transmission of methicillin-resistant Staphylococcus aureus in a neonatal intensive care unit. Am J Infect Control 2010;38:607-11. [Crossref]
13. Jernigan JA, Titus MG, Groschel DH, Getchell-White S, Farr BM. Effectiveness of contact isolation during a hospital outbreak of methicillin-resistant Staphylococcus aureus. Am J Epidemiol 1996;143:496-504. [Crossref]
14. Mutters NT, Heeg K, Späth I, Henny N, Gunther F. Improvement of infection control management by routine molecular evaluation of pathogen clusters. Diagn Microbiol Infect Dis 2017;88:82-7. [Crossref]
15. O'Hara FP, Suaya JA, Ray GT, Baxter R, Brown ML, Mera RM, et al. spa typing and multilocus sequence typing show comparable performance in a macroepidemiologic study of staphylococcus aureus in the United States. Microb Drug Resist 2016;22:88-96. [Crossref]
16. Strommenger B, Kettlitz C, Weniger T, Harmsen D, Friedrich AW, Witte W. Assignment of Staphylococcus isolates to groups by spa typing, SmaI macrorestriction analysis, and multilocus sequence typing. J Clin Microbiol 2006;44:2533-40. [Crossref]
17. Deurenberg RH, Vink C, Kalenic S, Friedrich AW, Bruggeman CA, Stobberingh EE. The molecular evolution of methicillin-resistant Staphylococcus aureus. Clin Microbiol Infect 2007;13:222-35. [Crossref]
18. Bozdoğan B, Yıldız O, Oryasin E, Kırdar S, Gülcü B, Aktepe O, et al. [t030 is the most common spa type among methicillin-resistant Staphylococcus aureus strains isolated from Turkish hospitals]. Mikrobiyol Bul 2013;47:571-81. [Crossref]
19. Alp E, Klaassen CHW, Doganay M, Altoparlak U, Aydın K, Engin A, et al. MRSA genotypes in Turkey: Persistence over 10 years of a single clone of ST239. J Infect 2009;58:433-8. [Crossref]
20. Kırca Yulmaz S, Acuner IC, Strommenger B, Bek Y, Witte W. [Infectivity-resistotype-genotype clustering of methicillin-resistant Staphylococcus aureus strains in the Central Blacksea Region of Turkey]. Mikrobiyol Bul 2014;48:14-27.
21. Oksuz L, Dupieux C, Tristan A, Bes M, Etienne J, Gurler N. The high diversity of MRSA clones detected in a university hospital in İstanbul. Int J Med Sci 2013;10:1740-5. [Crossref]
22. Deurenberg RH, Stobberingh EE. The molecular evolution of hospital- and community-associated methicillin-resistant Staphylococcus aureus. Curr Mol Med 2009;9:100-15. [Crossref]
23. Yamamoto T, Takano T, Higuchi W, Iwao Y, Singur O, Reva I, et al. Comparative genomics and drug resistance of a geographic variant of ST239 methicillin-resistant Staphylococcus aureus emerged in Russia. PLoS One 2012;7:e29187. doi:10.1371/journal.pone.0029187 [Crossref]
24. Hong X, Qin J, Li T, Dai Y, Wang Y, Liu Q, et al. Staphylococcal protein a promotes colonization and immune evasion of the epidemic healthcare-associated MRSA ST239. Front Microbiol 2016;7:951. doi:10.3389/fmicb.2016.00951 [Crossref]
25. Otto M. How colonization factors are linked to outbreaks of methicillin-resistant Staphylococcus aureus: The roles of SasX and ACME. Biomol Concepts 2013;4:533-7. [Crossref]
26. Sabat AJ, Köck R, Akkerboom V, Hendrix R, Skov RL, Becker K, et al. Novel organization of the arginine catabolic mobile element and staphylococcal cassette chromosome mec composite island and its horizontal transfer between distinct Staphylococcus aureus genotypes. Antimicrob Agents Chemother 2013;57:5774-7. [Crossref]
27. Senn L, Clerc O, Zanetti G, Basset P, Prod'hom G, Gordon NC, et al. The stealthy superbug: The role of asymptomatic enteric carriage in maintaining a long-term hospital outbreak of ST228 methicillin-resistant Staphylococcus aureus. mBio 2016;7:e02039-02015. [Crossref]
28. Teo J, Tan TY, Hon PY, Lee W, Koh TH, Krishnan P, et al. ST22 and ST239 MRSA duopoly in Singaporean hospitals: 2006-2010. Epidemiol Infect 2013;141:153-7. [Crossref]