title: High prevalence of Panton-Valentine leukocidin (PVL) genes in nosocomial-acquired Staphylococcus aureus isolated from tertiary care hospitals in Nepal.
abstract: Methicillin-resistant Staphylococcus aureus (MRSA) carrying the important virulence determinant, Panton-Valentine leukocidin (PVL), is an emerging infectious pathogen associated with skin and soft tissue infections as well as life-threatening invasive diseases. In carrying out the first PVL prevalence study in Nepal, we screened 73 nosocomial isolates of S. aureus from 2 tertiary care Nepali hospitals and obtained an overall PVL-positivity rate of 35.6% among the hospital isolates: 26.1% of MRSA and 51.9% of methicillin sensitive S. aureus (MSSA) isolates were found to be positive for the PVL genes. PVL prevalence was not associated with a specific (i) infection site, (ii) age group, or (iii) hospital of origin. It was found to be positively associated with heterogeneous MRSA (73.3%) compared to homogeneous MRSA (3.2%) and MSSA (51.9%); negatively associated with multiresistant MRSA (22%) compared to nonmultiresistant MRSA (60%) and MSSA (51.9%); and positively associated with macrolide-streptogramin B resistance (93.8%) compared to macrolide-lincosamide-streptogramin B resistance (0%) and no-resistance (45.8%) types. Macrolide-streptogramin B resistance was confirmed by the presence of msr(A) gene. Restriction pattern analyses provided evidence to support the circulation of a limited number of clones of PVL-positive MRSA, arguing for the adaptability of these isolates to a hospital setting.
authors.affiliation: Tri-Chandra Campus, Tribhuvan University, G.P.O. Box 3285, Kathmandu, Nepal.
authors.forename: Bidya
authors.initials: B
authors.lastname: Shrestha
authors.affiliation: New Drug Discovery Research, Ranbaxy Research Laboratories, R & D III, Sector-18, Gurgaon, India.
authors.forename: Winny
authors.initials: W
authors.lastname: Singh
authors.affiliation: New Drug Discovery Research, Ranbaxy Research Laboratories, R & D III, Sector-18, Gurgaon, India.
authors.forename: V Samuel
authors.initials: VS
authors.lastname: Raj
authors.affiliation: Institute of Medicine, Tribhuvan University, Kathmandu, Nepal.
authors.forename: Bharat Mani
authors.initials: BM
authors.lastname: Pokhrel
authors.affiliation: Institute of Medical Sciences, Banaras Hindu University, Varanasi, India.
authors.forename: Tribhuban Mohan
authors.initials: TM
authors.lastname: Mohapatra
mesh_terms: D001427:Bacterial Toxins / Q000235:genetics*; D003428:Cross Infection / Q000235:genetics* / Q000382:microbiology / Q000473:pathology; D005098:Exotoxins / Q000235:genetics*; D006801:Humans; D007956:Leukocidins / Q000235:genetics*; D008712:Methicillin / Q000627:therapeutic use; D055624:Methicillin-Resistant Staphylococcus aureus / Q000187:drug effects / Q000235:genetics* / Q000472:pathogenicity; D008826:Microbial Sensitivity Tests; D009390:Nepal; D013203:Staphylococcal Infections / Q000188:drug therapy / Q000235:genetics*; D025381:Streptogramin B / Q000627:therapeutic use; D062606:Tertiary Care Centers
chemical_list: D001427:Bacterial Toxins; D005098:Exotoxins; D007956:Leukocidins; C078284:Panton-Valentine leukocidin; D025381:Streptogramin B; D008712:Methicillin