MRSA is able to generate a modified variety of penicillin binding protein named as PBP2a instead of PBP which makes it resistant against penicillin and methicillin. Production of PBP2a is due to the presence of a gene...MRSA is able to generate a modified variety of penicillin binding protein named as PBP2a instead of PBP which makes it resistant against penicillin and methicillin. Production of PBP2a is due to the presence of a gene on Staphylococcal cassette chromosome or SCC termed as “mec-A gene”. SCC is a mobile genetic element carrying many resistance genes. It is because of current antibiotic selection pressure that by now there are eight types (I - VIII) of SCCmec. This research has been designed to determine frequency of SCCmec type IV and V in clinical isolates of MRSA. A total of 70 presumptive MRSA isolates collected from a tertiary care hospital of Lahore were cultured on blood agar, incubated overnight at 37°C aerobically. Next day, they were examined for cultural characteristics, colonial morphology, gram stain, and biochemical profile. Confirmation of MRSA was done by phenotypic disk diffusion method according to (CLSI) 2013 guidelines. mecA gene was also detected at molecular level. Molecular identification of SCCmec type IV and V was done by Nested PCR strategy. A total of 50 isolates were confirmed to be MRSA Molecular detection of SCCmec type IV and V revealed that 11 isolates (22%) possess SCCmec type IV and only 2 isolate (4%) carries SCCmec type V. It is obvious from results that SCCmec type IV and V are present in our population too. Larger study (with larger sample size) might be undertaken to find out actual emergence of SCCmec type IV and V in our population.展开更多
文摘MRSA is able to generate a modified variety of penicillin binding protein named as PBP2a instead of PBP which makes it resistant against penicillin and methicillin. Production of PBP2a is due to the presence of a gene on Staphylococcal cassette chromosome or SCC termed as “mec-A gene”. SCC is a mobile genetic element carrying many resistance genes. It is because of current antibiotic selection pressure that by now there are eight types (I - VIII) of SCCmec. This research has been designed to determine frequency of SCCmec type IV and V in clinical isolates of MRSA. A total of 70 presumptive MRSA isolates collected from a tertiary care hospital of Lahore were cultured on blood agar, incubated overnight at 37°C aerobically. Next day, they were examined for cultural characteristics, colonial morphology, gram stain, and biochemical profile. Confirmation of MRSA was done by phenotypic disk diffusion method according to (CLSI) 2013 guidelines. mecA gene was also detected at molecular level. Molecular identification of SCCmec type IV and V was done by Nested PCR strategy. A total of 50 isolates were confirmed to be MRSA Molecular detection of SCCmec type IV and V revealed that 11 isolates (22%) possess SCCmec type IV and only 2 isolate (4%) carries SCCmec type V. It is obvious from results that SCCmec type IV and V are present in our population too. Larger study (with larger sample size) might be undertaken to find out actual emergence of SCCmec type IV and V in our population.
