Association of PVL Gene with SCCmec Typing in MRSA (both community associated and hospital-acquired) from a Tertiary Care Hospital, Lahore

Abstract

ABSTRACT

Introduction: Antibiotic resistance is a major problem in staphylococcal infections. Resistance against Methicillin in S. aureus is due to the transfer of mobile cassettes of specific genes in S. aureus called Staphylococcal Cassette Chromosome mec (SCCmec). 13 types of SCCmec have been identified till now. Various clinical syndromes are associated with the presence of the PVL gene. Therefore, the present study was designed to check the prevalence of PVL gene and SCCmec types in CA-MRSA and HA-MRSA.
Materials and methods: This cross-sectional descriptive study was done in LGH/PGMI, Lahore. MRSA isolates were phenotypically confirmed by Cefoxitin (30) disc on Mueller-Hinton agar. DNA extraction was done by using a Genomic DNA purification kit. Detection of PVL gene and SCCmec types was done with PCR using specific primers.
Results: Out of 89 isolates, the maximum isolates were from pus swabs (45%), followed by wound swabs (15.5%). It was found that 55 (61.8%) were HA-MRSA isolates, while 34 (38.2%) were CA-MRSA isolates. PVL gene was found in 37% of isolates. Among PVL-positive samples, 36.4% were HA-MRSA, while 63.6% were CA-MRSA. The most common SCCmec in HA-MRSA was type III (69%), while in CA-MRSA, SCCmec type IVa was predominant (35.4%).
Conclusion:The present study provides insight into the prevalence of the PVL gene and different SCCmec types in CA-MRSA and HA-MRSA. The most common SCCmec type is linked with HA-MRSA.