Abstract
STUDY OF THE DRUG RESISTANT GENE (mec A) IN METHICILLIN RESISTANT STAPHYLOCOCCI IN PATIENTS ATTENDING SILCHAR MEDICAL COLLEGE & HOSPITAL, SILCHAR

Methicillin Resistant Staphylococcus (Both Methicillin Resistant Staphylococcus aureus or MRSA and Methicillin Resistant Coagulase Negative Staphylococci or MR-CONS) is posing healthcare problems all over the world. It is seen that mecA gene is responsible for Methicillin resistance in Staphylococcus Species. PCR based study can give confirmed genomic diagnosis at the earliest. The objective of the study is detection of MRSA& MRCONS by conventional methods ,detection of mecA gene in Staphylococcus species and to compare the results between conventional detection of MRSA & MRCONS and PCR test to detect mecA gene.All isolates of Staphylococcus aureusfrom clinical samples were screened by both Conventional method & PCR to detect mecA gene. For conventional method, samples were cultured in, Blood Agar, Mac Conkey Agar, CLED agar, Mannitol Salt Agar (MSA) etc& Sensitivity tests were being done by Kirby Bauer Disc diffusion method using 1µgm oxacillin disc & 30 µgm Cefoxitin discs in Muller Hinton agar to detect Methicillin resistance. For identification by PCR, colonies were enriched in Brain Heart Infusion broth and then PCR was performed using consensus primers for detection of mecA gene. 200 samples of Staphylococcus aureus & CONS from blood, urine , throat swab, nasal swab, aural swab etc were processed. We conducted conventional study of Oxacillin disc diffusion (ODD) in 90 samples and found 24 MRSA & 03 MRCONS. On performing Cefoxitin disc diffusion test in same 90 samples 21 MRSA & 03 MRCONS were found. In the same 90 samples, PCR tests found 20 MRSA & 03 MRCONS which had mecA gene. The sensitivity of PCR test to detect MRSA and MR-CONS by mecA gene analysis seems to be superior. It will supplement conventional diagnosis by Culture-Sensitivity Methods & also deliver investigative reports early with confirmation.