Prevalence and Antibiotic susceptibility pattern of Panton-Valentine Leucocidin( PVL) positive Staphylococcus aureus Strains from clinical specimens in Northeastern Nigeria

Abstract

Panton-Valentine leucocidin (PVL), a synergohymentropic toxins encoded on S.aureus genes are associated with soft tissue infection and  community-acquired staphylococcal infection. The purpose of the study was to determine the prevalence and antibiotic susceptibility of PVL-postive S.aureus isolates from clinical specimens.A total of 96 consecutive S.aureus isolates were examined. 12(12.5%) methicillin-resistant S.aureus
strains(MRSA) and 84(87.5%)methicillin-sentive S.aureus(MSSA) identified by disc-diffusion and PCR assay methods. Screening of S.aureus isolates for PVL locus by PCR assay, 50(52.1%) amplified the PVL genes, 35(70.0%) were recovered from outpatient, 15(30.0) from inpatient. PVL positive S.aureus were isolated from wound specimens, 20 (40.0%); 9(18.0%) urine, 6(12.0%) and least 1(2.0%) each from blood culture and
endocervical swab. Staphylococcal cassette chromosome mec typing by two standard multiplex PCR assay, revealed an uncharacterized resistance element. Overall antibiotic susceptibility pattern showed relatively high
degree of susceptibility,however 1 isolate demostrated multidrug resistant pattern, 37(74.0%)resistant to only penicillin, 5 to one additional drug with penicillin, and 3 to two-additional drugs. The high prevalence of S.aureus PVL-positive strains posed dire clinical conquences, because co-existence of MRSA strains with MSSA PVL –positive strains could result in the emergence of MRSA PVL-positive strains, with propensity of rapid dissemination within the hospital environment in the study area.

Keywords: Panton-Valentine leucocidin, S.aureus , epidemiology, Northeastern Nigeria