The non-association of Panton-Valentine leukocidin and mecA genes in the genome of Staphylococcus aureus from hospitals in South Western Nigeria.
OBJECTIVE
Virulence genes play important roles in pathogenesis of infections caused by S. aureus. The aim of this study was to determine the prevalence of PVL, eta and mecA genes in S. aureus isolated from patients in South-Western Nigeria.


METHODS
In this study, a total of 116 S. aureus isolates from the clinical specimens submitted to laboratories in tertiary hospitals in the South Western Nigeria were used. Antibiotic susceptibility test was carried out to determine the susceptibility pattern of the isolates using multiple antibiotics disc. Minimum inhibitory concentration (MIC) was also carried out to determine the degree of resistant of the isolates to methicillin. PCR was used to screen for the presence of PVL, eta, and mecAgenes.


RESULTS
mecA gene was detected in 48 (41.4%) of 116 strains of S. aureus. The MIC 50 and MIC 90 for mecA negative strains were 1 and 8 μg/ml, respectively while the MIC 50 and MIC 90 for mecA positive were >256 μg/ml. Twenty eight (24.1%) of 116 isolates were PVL gene positive with none of them mecA+. The prevalence of community acquired MRSA (CA-MRSA) was estimated to be 6.9% using molecular techniques. No localization of mecA gene and PVL gene on the genome of the entire S. aureus strains studied. Site of isolation of organism /specimen type was found to be associated with the prevalence of PVL+ and mecA+ S. aureus (P< 0.01).


CONCLUSIONS
This study concludes that the PVL+ MRSA is rare and the prevalence of CA-MRSA is low in South-Western, Nigeria.
Department of Biomedical Sciences, College of Health Sciences, Ladoke Akintola University of Technology, Osogbo Campus, Nigeria.
O A
OA
Terry Alli
D O
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Ogbolu
J O
JO
Mustapha
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R
Akinbami
A O
AO
Ajayi
D000328:Adult; D000368:Aged; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D001426:Bacterial Proteins / Q000235:genetics*; D001427:Bacterial Toxins / Q000235:genetics*; D002648:Child; D002675:Child, Preschool; D004269:DNA, Bacterial / Q000235:genetics; D005098:Exotoxins / Q000235:genetics*; D005260:Female; D006761:Hospitals; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D007956:Leukocidins / Q000235:genetics*; D008297:Male; D008826:Microbial Sensitivity Tests; D008875:Middle Aged; D009549:Nigeria; D046915:Penicillin-Binding Proteins; D016133:Polymerase Chain Reaction; D013203:Staphylococcal Infections / Q000382:microbiology*; D013211:Staphylococcus aureus / Q000235:genetics / Q000302:isolation & purification* / Q000472:pathogenicity*; D037521:Virulence Factors / Q000235:genetics*; D055815:Young Adult
D000900:Anti-Bacterial Agents; D001426:Bacterial Proteins; D001427:Bacterial Toxins; D004269:DNA, Bacterial; D005098:Exotoxins; D007956:Leukocidins; C078284:Panton-Valentine leukocidin; D046915:Penicillin-Binding Proteins; D037521:Virulence Factors; C487789:mecA protein, Staphylococcus aureus