Staphylococcal cassette chromosome (SCCmec) typing of methicillin-resistant Staphylococcus aureus strains isolated from healthy workers nasal swabs in Larestan hospitals

Subject Areas : Bacteriology

Mehdi Ebadi ¹ , Tahereh Khaliliazad ²

1 - Assistant Professor, Department of Microbiology, Larestan branch, Islamic Azad University, Larestan, Iran.
2 - M.Sc., Department of Laboratory Larestan University of Medical Science, Larestan, Iran.

Received: 2017-08-18 Accepted : 2017-08-31 Published : 2018-05-22

Keywords: Antibiotic resistance, Methicillin-resistant Staphylococcus aureus, Cassette chromosome,

Abstract :

Background & Objectives: Methicillin-resistant Staphylococcus aureus (MRSA) is one of the most important causes of opportunistic infections in the community as well as hospitals. Nowadays, an increase in the antibiotic resistance has caused concern to the medical community. Meanwhile, resistance to methicillin is important because of limiting treatment. This study was conducted to track methicillin resistance gene and to type staphylococcal cassette chromosome (SCCmec) in S. aureus strains isolated from nasal swabs of healthy hospital workers and to determine the antibiotic sensitivity pattern of the strains. Materials & Methods: In this descriptive cross-sectional study, 230 specimens were collected from healthy workers nasal swabs of Larestan hospital during 2015. S. aureus strains were identified using laboratory standard methods. The antibiotic susceptibility pattern was characterized using disk diffusion test, minimum inhibitory concentration (MIC) was determined by E-test and sensitivity to methicillin was assessed by agar screening test. Furthermore, the presence of antibiotic-resistant mecA gene and SCCmec genotyping were investigated using the multiplex-PCR method. Results: Among all nasal swab samples, 37 (14.8%)  S. aureus isolates were recovered. 28 (75.7%) out of 37 S. aureus isolates were confirmed as MRSA. 21 (75%) of 28 MRSA isolates were community-associated MRSA (CA-MRSA), and the remaining 7 (25%) were hospital-acquired MRSA (HA-MRSA). SCCmec genotyping showed the most frequent isolates as follows: 9 (32.1%) isolates as SCCmec type I, 8 (28.6%) isolates as SCCmec type IV, 5 (17.9%) isolates as SCCmec type II, 4 (14.3%) isolates as SCCmec type V and 2 (7.1%) isolates as SCCmec type III. Evaluation of antibiotic resistance pattern showed the highest resistance to penicillin (100%) and oxacillin (60%) respectively, and the lowest resistance to vancomycin (0%). E-test results confirmed 28.5% of the isolates as intermediate vancomycin-resistant. Using agar screening test, oxacillin resistance was shown as 92.8%. Conclusion: Our result showed that 70% methicillin resistance in the S. aureus which is mostly CA-MRSA strains. This could be a serious warning about the need to treat infections caused by this bacterium and control the carriers in the hospital environment. 

References:

1. Davoodabadi F, Mobasherizadeh S, Mostafavizadeh K, Shojaei H, Havaei SA, Koushki AM,
   Moghadasizadeh Z, Meidani M, Shirani K. Nasal colonization in children with community
   acquired methicillin-resistant Staphylococcus aureus. Adv Biomed Res. 2016; 5: 86.
   
   2. 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; 16(1): 276.
   3. Mustapha M, Bukar-Kolo YM, Geidam YA, Gulani IA. Phenotypic and genotypic detection of
   methicillin-resistant Staphylococcus aureus in hunting dogs in Maiduguri metropolitan, Borno
   State, Nigeria. Vet World. 2016; 9(5): 501-506.
   4. Iliyasu G, Daiyab FM, Tiamiyu AB, Abubakar S, Habib ZG, Sarki AM, Habib AG. 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.
   5. Gunawardena ND, Thevanesam V, Kanakaratne N, Abeysekera D, Ekanayake A, Perera N.
   Molecular identification of methicillin resistance and virulence marker in Staphylococcus
   aureus. Sri Lankan J infect Dis. 2012; 2(2): 18-29.
   6. Shittu AO, Okon K, Adesida S, Oyedara O, Witte W, Strommenger B, Layer F, Nubel V.
   Antibiotic resistance and molecular epidemiology of Staphylococcus aureus in Nigera. BMC
   Microbial. 2011; 5(11): 92.
   7. Baba-Moussa L, Sina H, Scheftel JM, Moreau B, Sainte-Marie D. Staphylococcal
   panton-valentine leucocidin as a major virulence factor associated to furuncles. Plos One. 2011;
   6(10): 25716.
   8. Tsubakishita S, Kuwahara-Arai K, Sasaki T, Hiramatsu K. Origin and molecular evolution of the
   determinant of methicillin resistance in staphylococci. Antimicrob Agents Chemother. 2010;
   54(10): 4352-4359.
   9. Zamani A, Sadeghian S, Najafi Mosleh M, Goodarzi M T, Yousefi Mashouf R, Ghaderkhani J.
   Detection of methicillin-resistance gene (mec-A) in Staphylococcus aureus strains by PCR and
   determination of antibiotic sensitivity. Avicenna J Clin Med. 2007; 14(3): 54-58. [In Persian]
   10. Brown DFJ, Edwards DI, Hawkey PM, Morrison D, Ridgway GL, Towner KJ, Wren MW.
   Guidelinesfor the laboratory diagnosis and susceptibility testing of Methicillin-Resistant
   Staphylococcus aureus (MRSA). J Antimicrob Chemther. 2005; 56: 1000-1018.
   11. Performance Standards for Antimicrobial Susceptibility Testing, 21st Informational
   Supplement, M100-S21, Wayne, PA: Clinical and Laboratory Standards Institute. 2016.
   12. 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
   (151): 1175-1182. [In Persian]
   13. Zhang K, Mcclure JA, Elsayed S, Louie T, Conly JM. Novel multiplex PCR for
   characterization and concomitant subtyping of Staphylococcal cassette chromosome mec typing
   I to V in Methicillin Resistant Staphylococcus aureuse. J Antimicrob Chemother. 2005; 43(10):
   5026-5033.
   14. Shokoohi Sh, Aminzadeh Z, Sharafi K, Askari E, Soleimani F. Prevalence of meticillin
   
   resistant in HA-MRSA in Tehran. Iran J Microbiol. 2009; 2(1): 87.
   15. Moise PA, Smyth DS, Robinson DA, El-Fawal N, McCalla C, Sakoulas G. Genotypic and
   phenotypic relationships among methicillin-resistant Staphylococcus aureus from three
   multicenter bacteremia studies. J Antimicrob Chemother. 2009; 63: 873-876.
   16. Hota B, Lyles R, Rim J, Popovich KJ, Rice T, Aroutcheva A, Wenstein R. Predictors of
   clinical virulence in community-onset methicillin-resistant Staphylococcus aureus infections:
   the importance of USA300 and pneumonia. Clin Infect Dis. 2011; 53(8): 757-765.
   17. Adaleti R, Nakipoglu Y, Karahan ZC, Tasdemir C, Kaya F. Comparison of polymerase chain
   reaction and conventional methods in detecting methicillin-resistant Staphylococcus aureus. J
   Infect Dev Ctries. 2008; 2(1): 46-50.
   18. Otter JA, French GL. Molecular epidemiology of community-associated meticillin-resistant
   Staphylococcus aureus in Europe. Lancet Infect Dis. 2010; 10(4): 227-239.
   19. Ghaznavi-Rad E, Nor Shamsudin M, Sekawi Z, van Belkum A, Neela V. A simplified
   multiplex PCR assay for fast and easy discrimination of globally distributed staphylococcal
   cassette chromosome mec types in methicillin-resistant Staphylococcus aureus. J Med
   Microbiol. 2010; 59: 1135-1139.
   20. Zohorinia M, Soleymani E, Nobari H, Ahmadi k, Jafarian S, Bahmani N, Asadi A. Frequency
   of nasal and hand carriage of staphylococcus aureus among the medical and non medical staffs
   i I a ia ai o ce e’saat edical ce te . ilita y ealth Sci Res. 6; 4( ): -907.
   21. Novick RP, Christie GE, Penades JR. The phage-related chromosomal islands of
   Gram-positive bacteria. Nat Rev Microbial. 2010; 8(8): 541-551.
   22. Turlej A, Hryniewicz W, Empel J. Staphylococcal cassette chromosome mec (Sccmec)
   classification and typing methods: an overview. Pol J Microbiol. 2011; 60(2): 95-103.
   23. 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 Med Microbiol. 2008; 57(8): 954-956.