Genotyping of Staphylococcus epidermidis strains isolated from nosocomial infections by Multilocus Sequence Typing (MLST)

Subject Areas : Molecular Microbiology

Sara Rafiee ¹ , Elahe Tajbakhsh ² , Hassan Momtaz ³

1 - MS.c., Department of Microbiology, Shahrekord branch, Islamic Azad University, Shahrekord, Iran.
2 - Associated Professor, Department of Microbiology, Shahrekord branch, Islamic Azad University, Shahrekord, Iran.
3 - Professor, Department of Microbiology, Shahrekord branch, Islamic Azad University, Shahrekord, Iran.

Received: 2016-09-22 Accepted : 2016-11-28 Published : 2017-01-01

Keywords: Staphylococcus epidermidis, Genetic clones, Multilocus Sequence Typing (MLST), Housekeeping genes,

Abstract :

Background & Objectives: Staphylococcus epidermidis is one of the main causes of urinary tract infections and second cause of respiratory infections in human. The aim of this study was genotyping S. epidermidis strains isolated from nosocomial infections and detection of genetic clones using Multilocus Sequence Typing (MLST) method. Materials & Methods: In this cross-sectional study, 16 S. epidermidis isolates were selected and PCR products from amplification of seven housekeeping genes were sequenced. The nucleotide sequences of each gene in each isolate were analyzed in the MLST database and, besides identifying different clones, gene - specific alleles in each sequence types (ST) were determined. Results: A total of 3 clones including ST22, ST88 and ST153 were identified from 16 isolates, which was classified into two gene clusters of A and B. ST22 clone with a frequency of 50%, ST88 with 31.25% and ST153 with 18.75% were identified. The most dominant S. epidermidis clone isolated in 16 isolates is ST22. Conclusion: Dendrogram analysis of the isolates showed the homology of all isolates to alleles previously reported. Furthermore, our results suggest the genetic diversity of the isolates.

References:

1. Najar Peerayeh Sh, Jazayeri M , Behmanesh M. Prevalence of virulence related determinants in clinical Isolates of Staphylococcus epidermidis. Jundishapur J Microbiol. 2016; 9(8): e30593.

2. Pinheiro L, Brito CI, Pereira VC, Oliveira A, Camargo CH, Cunha Mde L. Reduced susceptibility to vancomycin and biofilm forma­tion in methicillin-resistant Staphylococcus epidermidis isolated from blood cultures. Mem Inst Oswaldo Cruz. 2014; 109 (7): 871-878.

3. Vuong Liduma I, Tracevska T, Bers U, Zilevica A. Phenotypic and genetic analysis of biofilm formation by Staphylococcus epidermidis. Medicina (Kaunas). 2012; 48(6): 305-309.

4. Halverson S, Malani P, Newton  DW, Habicht  A, Younger G. Impact of hourly emergency department patient volume on blood culture contamination and diagnostic yield. J Clin Microbiol. 2013; 51 (17): 1721-1726.

5. Zimmerli A, Trampuz E, Ochsner F. Prosthetic-joint infections. New Eng J Med. 2004; 351 (16): 1645-1654.

6. Ebrahimzadeh Namvar A, Bastarahang S, Abbasi N, Sheikhi Gh, Farhadbakhtiarian S, Arezi P, Hosseini M, Zaeemi S, Jokar Z, Ganji Chermahin S. Clinical characteristics of Staphylococcus epidermidis: a systematic review. GMS Hygiene Infect Control. 2014; 9(3): 1-10.

7. Wang XM, Noble L, Kreiswirth BN, Eisner W, McClements W, Jansen KU, Anderson AS. Evaluation of a multilocus sequence typing system for Staphylococcus epidermidis. J Med Microbiol. 2003; 52(11): 989-98.

8. Sharma P, Satorius AE, Raff MR, Rivera A, Newton D.W, Younger JG. Multilocus sequence typing for interpreting blood isolates of Staphylococcus epidermidis. Interdiscip Perspect Infect Dis. 2014; 20(14): 787- 458.

9. Mason WJ, Blevins JS, Beenken K, Wibowo N. Oiha N, Smeltzer MS. Multiplex PCR protocol for the diagnosis of Staphylococcal infection. J Clin Microbiol. 2001; 39 (9): 3332-3338.

10. Urwin R, Maiden MC. Multi-locus sequence typing: a tool for global epidemiology. Trends Microbiol. 2003; 11(10): 479-87.

11. Mark C, Enright and Brian, G. Spratt. Multilocus sequence typing. Trends Microbiol. 1999; 7(12): 482-487.

12. Larsen V, Cosentino S, Rasmussen S, Friis C, Hasman H. Multilocus sequence typing of total genome-sequenced bacteria. J Clin Microbiol. 2012; 50(4): 1355-1361.

13. Miragaia  M, Carriço JA, Thomas  JC, Couto I, Enright  MC, Lencastre H. Comparison of molecular typing methods for characterization of Staphylococcus epidermidis: proposal for clone definition. J Clin Microbiol. 2008; 46(1): 118-129.

14. Cunha Mde L, Sinzato YK ,Silveira LV .Comparison of methods for the identification of coagulase negative Staphylococci.  Memórias do Instituto Oswaldo Cruz. 2004; 99(8): 855-860.

15. Cherifi S, Byl. B, Deplano A, Nagant C, Nonhoff C, Denis O, Hallin M. Genetic characteristics and antimicrobial resistance of Staphylococcus epidermidis isolates from patients with catheter related bloodstream infections and from colonized healthcare workers in a Belgian hospital. Ann Clin Microbiol Antimicrob. 2014; 25(4): 13-20.

16. Paulo JM, Hofling lima A, Pigntari CC. Characterization of ocular methicillin resistant Staphylococcus epidermidis isolates belonging predominantly to clonal complex subcluster II. J  Clin Microbiol. 2013; 52(5): 1412-1417.

17. Mendes RE, Deshpande LM, Costello AJ, Farrell DJ. Molecular epidemiology of Staphylococcus epidermidisclinical isolates from U.S. Hospitals. Antimicrob Agent Chemother. 2012; 56(9): 4651-4661.

18. Li M, Wang X, Gao Q, Lu Y. Molecular characterization of Staphylococcus epidermidis strains isolated from a teaching hospital in Shanghai, China. J Med Microbiol. 2009; 58(4): 456-461.