title: Association of Panton Valentine Leukocidin (PVL) genes with methicillin resistant Staphylococcus aureus (MRSA) in Western Nepal: a matter of concern for community infections (a hospital based prospective study).
abstract: BACKGROUND
  Methicillin resistant Staphylococcus aureus (MRSA) is a major human pathogen associated with nosocomial and community infections. Panton Valentine leukocidin (PVL) is considered one of the important virulence factors of S. aureus responsible for destruction of white blood cells, necrosis and apoptosis and as a marker of community acquired MRSA. This study was aimed to determine the prevalence of PVL genes among MRSA isolates and to check the reliability of PVL as marker of community acquired MRSA isolates from Western Nepal.
  
  
  METHODS
  A total of 400 strains of S. aureus were collected from clinical specimens and various units (Operation Theater, Intensive Care Units) of the hospital and 139 of these had been confirmed as MRSA by previous study. Multiplex PCR was used to detect mecA and PVL genes. Clinical data as well as antimicrobial susceptibility data was analyzed and compared among PVL positive and negative MRSA isolates.
  
  
  RESULTS
  Out of 139 MRSA isolates, 79 (56.8 %) were PVL positive. The majority of the community acquired MRSA (90.4 %) were PVL positive (Positive predictive value: 94.9 % and negative predictive value: 86.6 %), while PVL was detected only in 4 (7.1 %) hospital associated MRSA strains. None of the MRSA isolates from hospital environment was found positive for the PVL genes. The majority of the PVL positive strains (75.5 %) were isolated from pus samples. Antibiotic resistance among PVL negative MRSA isolates was found higher as compared to PVL positive MRSA.
  
  
  CONCLUSIONS
  Our study showed high prevalence of PVL among community acquired MRSA isolates. Absence of PVL among MRSA isolates from hospital environment indicates its poor association with hospital acquired MRSA and therefore, PVL may be used a marker for community acquired MRSA. This is first study from Nepal, to test PVL among MRSA isolates from hospital environment.
authors.affiliation: Central Department of Microbiology, Tribhuvan University, Kathmandu, Nepal. ddharma2039@gmail.com.
authors.forename: Dharm R
authors.initials: DR
authors.lastname: Bhatta
authors.affiliation: Research Group for Genomic Epidemiology, National Food Institute, Technical University of Denmark, Kgs Lyngby, Denmark.
authors.forename: Lina M
authors.initials: LM
authors.lastname: Cavaco
authors.affiliation: Department of Microbiology, Institute of Medical Sciences, Banaras Hindu University (BHU), Varanasi, India.
authors.forename: Gopal
authors.initials: G
authors.lastname: Nath
authors.affiliation: Department of Microbiology, Institute of Medical Sciences, Banaras Hindu University (BHU), Varanasi, India.
authors.forename: Kush
authors.initials: K
authors.lastname: Kumar
authors.affiliation: Department of Microbiology, Manipal College of Medical Sciences, Pokhara, Nepal.
authors.forename: Abhishek
authors.initials: A
authors.lastname: Gaur
authors.affiliation: Department of Microbiology, Manipal College of Medical Sciences, Pokhara, Nepal.
authors.forename: Shishir
authors.initials: S
authors.lastname: Gokhale
authors.affiliation: Central Department of Microbiology, Tribhuvan University, Kathmandu, Nepal.
authors.forename: Dwij R
authors.initials: DR
authors.lastname: Bhatta
mesh_terms: D001426:Bacterial Proteins / Q000235:genetics; D001427:Bacterial Toxins / Q000235:genetics*; D003428:Cross Infection / Q000453:epidemiology / Q000382:microbiology; D024901:Drug Resistance, Multiple, Bacterial / Q000235:genetics; D005098:Exotoxins / Q000235:genetics*; D006761:Hospitals; D006801:Humans; D007956:Leukocidins / Q000235:genetics*; D055624:Methicillin-Resistant Staphylococcus aureus / Q000235:genetics* / Q000302:isolation & purification / Q000472:pathogenicity; D008826:Microbial Sensitivity Tests; D009390:Nepal / Q000453:epidemiology; D046915:Penicillin-Binding Proteins / Q000235:genetics; D011446:Prospective Studies; D015203:Reproducibility of Results; D013203:Staphylococcal Infections / Q000453:epidemiology; D037521:Virulence Factors / Q000235:genetics
chemical_list: D001426:Bacterial Proteins; D001427:Bacterial Toxins; D005098:Exotoxins; D007956:Leukocidins; C078284:Panton-Valentine leukocidin; D046915:Penicillin-Binding Proteins; D037521:Virulence Factors; C487789:mecA protein, Staphylococcus aureus
keywords: MRSA; PCR; PVL; Staphylococcus aureus