Detection of Panton-valentine Leukocidin Gene Isoforms of Isolates in Al-Zahra Hospital, Isfahan-Iran.

BACKGROUND

Panton-Valentine leukocidin (PVL) is a gamma-toxin produced by encoded by genes with several single-nucleotide polymorphisms. A mutation at nucleotide position 527 results in substitution of histidine (H) to arginine (R) at amino acid 176. The groups defined based on the amino acid change, the "R isoform" group and the "H isoform" group. The purpose of this study was to determine the frequency of PVL gene isoforms in strains isolated from patients at Al-Zahra Hospital Isfahan and molecular characterization of PVL-positive methicillin-resistant (MRSA) strains including the detection of mecA gene and staphylococcal chromosomal cassette mec (SCCmec) typing.

MATERIALS AND METHODS

In this study, 130 isolates of were collected from Al-Zahra Hospital. The PVL gene identified using polymerase chain reaction (PCR); PCR products were sequenced to identify the type of isoform. The molecular characterization of isolates of PVL-positive MRSA including detection of mecA gene by PCR and also SCCmec typing was performed by multiplex PCR.

RESULTS

Out of 130 isolates, 23% were positive for the presence of PVL genes. The PVL positive isolates were comprised 37% (11/30) of methicillin-resistant isolates and 63% (19/30) of methicillin-susceptible (MSSA) isolates. The results showed that 17 isolated carrying isoform H and 13 isolated carrying the R isoform.

CONCLUSION

The PVL gene was predominantly found in MSSA isolates. There was no relation between PVL isoforms and the presence of mecA and SCCmec types.