Molecular heterogeneity of Acinetobacter baumanii isolates during seasonal increase in prevalence.
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.
Christie
C
C
Division of Infectious Diseases, Children's Hospital Medical Center, Cincinnati, OH 45229, USA.
Mazon
D
D
Hierholzer
W
W
Patterson
J E
JE
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
D004269:DNA, Bacterial