title: Nasal colonization of and clonal transmission of methicillin-susceptible Staphylococcus aureus among Chinese military volunteers.
abstract: Military facilities provide unique opportunities for studying Staphylococcus aureus nasal colonization and transmission patterns. In this cross-sectional observational study, we assessed the prevalence of S. aureus nasal colonization among Chinese military volunteers in two camps in the Beijing area. Antimicrobial resistance patterns, risk factors for colonization, and transmission patterns using pulsed-field gel electrophoresis were also evaluated. From May to July 2007, 1,044 nasal swabs were collected from military volunteers from suburban (560) and urban (484) camps. A total of 209 S. aureus isolates were recovered, of which all were methicillin susceptible. Independent factors associated with methicillin-susceptible S. aureus (MSSA) nasal colonization included younger age (odds ratio [OR] = 1.51, 95% confidence interval [95% CI] = 1.03 to 2.21, P = 0.0347), higher education (OR = 1.38, 95% CI = 1.10 to 1.73, P = 0.0056), shorter length of service (OR = 1.74, 95% CI = 1.28 to 2.36, P = 0.0004), nonsmoking (OR = 1.61, 95% CI = 1.14 to 2.28, P = 0.0069), and inactive participation in social events (OR = 2.40, 95% CI = 1.25 to 5.49, P = 0.0082). Among 209 MSSA isolates, 126 (60.3%) were determined to be epidemic and a total of 12 genotypes were identified, of which four (90 isolates [71.4%]) represented the majority of strains. Length of service and camp location were statistically related to the four major MSSA genotype clonal transmissions. Our data indicated that MSSA, not methicillin-resistant S. aureus (MRSA), nasal colonization and clonal transmission occur in healthy military volunteers in Beijing. Younger, female, nonsmoking volunteers with higher education, little or no participation in social events, and less time in service are at higher risk for nasal MSSA carriage.
authors.affiliation: Clinical Diagnostic Center, 302nd Hospital of the People's Liberation Army, Beijing 100039, China.
authors.forename: Fen
authors.initials: F
authors.lastname: Qu
authors.forename: Enbo
authors.initials: E
authors.lastname: Cui
authors.forename: Tongsheng
authors.initials: T
authors.lastname: Guo
authors.forename: Haijing
authors.initials: H
authors.lastname: Li
authors.forename: Suming
authors.initials: S
authors.lastname: Chen
authors.forename: Liming
authors.initials: L
authors.lastname: Liu
authors.forename: Wang
authors.initials: W
authors.lastname: Han
authors.forename: Chunmei
authors.initials: C
authors.lastname: Bao
authors.forename: Yuanli
authors.initials: Y
authors.lastname: Mao
authors.forename: Yi-Wei
authors.initials: YW
authors.lastname: Tang
mesh_terms: D000328:Adult; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D015373:Bacterial Typing Techniques; D002353:Carrier State / Q000453:epidemiology* / Q000382:microbiology / Q000635:transmission*; D002681:China / Q000453:epidemiology; D016000:Cluster Analysis; D003430:Cross-Sectional Studies; D016172:DNA Fingerprinting; D016521:Electrophoresis, Gel, Pulsed-Field; D005260:Female; D005838:Genotype; D006801:Humans; D008297:Male; D008712:Methicillin / Q000494:pharmacology; D008826:Microbial Sensitivity Tests; D008889:Military Personnel; D009297:Nasal Mucosa / Q000382:microbiology*; D015995:Prevalence; D012307:Risk Factors; D013203:Staphylococcal Infections / Q000453:epidemiology* / Q000382:microbiology / Q000635:transmission*; D013211:Staphylococcus aureus / Q000145:classification* / Q000302:isolation & purification*; D055815:Young Adult
chemical_list: D000900:Anti-Bacterial Agents; D008712:Methicillin