title: Risk factors assessment for nasal colonization of Staphylococcus aureus and its methicillin resistant strains among pre-clinical medical students of Nepal.
abstract: BACKGROUND
  Staphylococcus aureus (S. aureus), a normal flora of nasal cavity, can cause minor to life threatening invasive diseases and nosocomial infections. Methicillin resistant strains of S. aureus are causing a great challenge for treatment options. Therefore, the purpose of this study was to assess the nasal carriage rate of S. aureus, its methicillin resistant strains and risk factors in medical students prior to clinical exposure.
  
  
  METHODS
  The bacterial growth of S. aureus from nasal swab culture was identified by using standard microbiological methods recommended by American Society for Microbiology. Modified Kirby-Bauer disk diffusion method was used for antibiotic susceptibility testing and methicillin resistance was confirmed using cefoxitin and oxacillin disks. D-zone test method was used to determine the inducible clindamycin resistance.
  
  
  RESULTS
  Among 200 participants, nasal carriage of S. aureus was detected from 30 (15%) subjects. Upper respiratory tract infections significantly (P < 0.05) contributed the carriage of S. aureus and their methicillin resistant strains. All of the isolates were reported to be susceptible to vancomycin and teicoplanin. S. aureus strains detected from 8 (4%) students were confirmed to be methicillin resistant.
  
  
  CONCLUSIONS
  The result of our study demands for strict policy to screen all the students for nasal carriage of S. aureus and its MRSA strains to minimize the transmission of this organism from community to hospital settings.
authors.affiliation: Department of Microbiology, Chitwan Medical College, Bharatpur, Chitwan, Nepal. shamshulansari483@yahoo.com.
authors.forename: Shamshul
authors.initials: S
authors.lastname: Ansari
authors.affiliation: Department of Microbiology, Chitwan Medical College, Bharatpur, Chitwan, Nepal.
authors.forename: Rajendra
authors.initials: R
authors.lastname: Gautam
authors.affiliation: Department of Microbiology, Chitwan Medical College, Bharatpur, Chitwan, Nepal.
authors.forename: Sony
authors.initials: S
authors.lastname: Shrestha
authors.affiliation: Asian College for Advanced Studies, Satdobato, Kathmandu, Nepal.
authors.forename: Safiur Rahman
authors.initials: SR
authors.lastname: Ansari
authors.affiliation: Department of Community Medicine and Public Health, Chitwan Medical College, Bharatpur, Chitwan, Nepal.
authors.forename: Shankar Nanda
authors.initials: SN
authors.lastname: Subedi
authors.affiliation: Department of Community Medicine and Public Health, Chitwan Medical College, Bharatpur, Chitwan, Nepal.
authors.forename: Muni Raj
authors.initials: MR
authors.lastname: Chhetri
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology; D001431:Bacteriological Techniques; D016009:Chi-Square Distribution; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D008297:Male; D055624:Methicillin-Resistant Staphylococcus aureus / Q000187:drug effects / Q000302:isolation & purification*; D008826:Microbial Sensitivity Tests; D009296:Nasal Cavity / Q000382:microbiology*; D009390:Nepal; D018570:Risk Assessment / Q000379:methods / Q000706:statistics & numerical data; D012307:Risk Factors; D013203:Staphylococcal Infections / Q000382:microbiology* / Q000517:prevention & control / Q000635:transmission; D013211:Staphylococcus aureus / Q000187:drug effects / Q000302:isolation & purification*; D013337:Students, Medical / Q000706:statistics & numerical data*; D017334:Teicoplanin / Q000494:pharmacology; D014640:Vancomycin / Q000494:pharmacology; D055815:Young Adult
chemical_list: D000900:Anti-Bacterial Agents; D017334:Teicoplanin; D014640:Vancomycin
keywords: MRSA; Medical students; Nasal colonization; Risk factors; Staphylococcus aureus