title: Molecular heterogeneity of Acinetobacter baumanii isolates during seasonal increase in prevalence.
abstract: OBJECTIVE
  To study the epidemiology of Acinetobacter baumanii during a period of increased seasonal prevalence.
  
  
  METHODS
  Descriptive molecular and clinical epidemiologic study of A baumanii isolates from 1990 through 1992.
  
  
  METHODS
  A 770-bed urban, acute, tertiary-care university hospital.
  
  
  RESULTS
  During 1990 through 1992, the rate of A baumanii isolations was 30.4 per 1,000 culture isolations during the summer, compared to 12.6 per 1,000 culture isolations during the fall, winter, and spring (P < .000001). There were 320 isolates identified among 260 patients during this time. Eighty-one patients with isolates available were identified for evaluation; they ranged in age from 2 months to 95 years. Pulsed-field gel electrophoresis (PFGE) typing showed that 59 (83%) of 71 typed isolates had distinct PFGE patterns. There were three small clusters of isolates with the same PFGE patterns, suggesting cross-transmission in those instances.
  
  
  CONCLUSIONS
  A seasonally increased prevalence of A baumanii largely associated with device-related nosocomial infections in severely ill patients was noted over a 3-year period. Although there were isolated instances of cross-transmission, most isolates had distinct PFGE patterns. Clonal dissemination of a single strain was not responsible for the seasonal increased prevalence of A baumanii. PFGE typing was useful in directing control efforts.
authors.affiliation: Division of Infectious Diseases, Children's Hospital Medical Center, Cincinnati, OH 45229, USA.
authors.forename: C
authors.initials: C
authors.lastname: Christie
authors.forename: D
authors.initials: D
authors.lastname: Mazon
authors.forename: W
authors.initials: W
authors.lastname: Hierholzer
authors.forename: J E
authors.initials: JE
authors.lastname: Patterson
mesh_terms: D000150:Acinetobacter / Q000145:classification / Q000235:genetics / Q000302:isolation & purification*; D000151:Acinetobacter Infections / Q000453:epidemiology* / Q000382:microbiology; D000293:Adolescent; D000328:Adult; D000368:Aged; D002648:Child; D002675:Child, Preschool; D003237:Connecticut / Q000453:epidemiology; D003428:Cross Infection / Q000453:epidemiology* / Q000382:microbiology; D004269:DNA, Bacterial / Q000235:genetics; D016521:Electrophoresis, Gel, Pulsed-Field; D018740:Genetic Heterogeneity; D006785:Hospitals, University; D006801:Humans; D007223:Infant; D008826:Microbial Sensitivity Tests; D008875:Middle Aged; D009820:Ohio / Q000453:epidemiology; D015995:Prevalence; D012621:Seasons
chemical_list: D004269:DNA, Bacterial