Circulation of multi drug resistant phage group iii /type 47 hospital acquired methicilin resistant staphylococcus aureus (ha-mrsa) in Tamilnadu

Background: The epidemiology of MRSA is constantly changing, which re¬sults in variation in its drug-resistance patterns throughout regions and countries. Therefore, to support clinicians in preventing and treating infection, epidemiologic surveil¬lance is essential. Phage typing had been reported to be valuable in the identification of known epidemic strains among endemic strains and is preferred as a first line approach in epidemiological investigation of MRSA strains. Aim: To identify the epidemiology of S. aureus strains with reference to phage types, its prevalence and antimicrobial resistance in relation to phage groups. Materials and methods: Study was undertaken on 136 S aureus strains isolated from clinical samples. Strains were phage typed and their resistance to antibiotics was determined by standard microbiological procedures. Molecular detection of MRSA was done using Triplex PCR. Results: Among phage typed S aureus, phage group III 53(39%) was found to be predominant and percentage typeability among the MRSA and MSSA strains was found to be 71(63%) and 17(71%) respectively. Out of 88 phage typed S. aureus isolates, 33 phage type patterns were identified with respect to each phage groups. Conclusion: Our study strongly suggests that a multi drug resistant phage group III with predominant phage type pattern 47 of HA-MRSA strains carrying pvl gene was found to be established hospital pathogen in our study area.