Long-term Escherichia coli asymptomatic bacteriuria among women with diabetes mellitus.
BACKGROUND
Persistent Escherichia coli asymptomatic bacteriuria (ASB) is common among persons with diabetes mellitus, but the duration of colonization and the rates of recolonization are unknown. We estimated the duration of colonization and the rate of recolonization among successively isolated E. coli from diabetic women with ASB and compared the virulence profiles with uropathogenic and commensal E. coli.


METHODS
A total of 105 women with diabetes were enrolled in a randomized, controlled clinical trial for treatment of ASB in Manitoba, Canada, and were observed at least every 3 months for up to 3 years. We analyzed 517 isolates from 70 women with repeated E. coli ASB for genetic similarity using enterobacterial repetitive intergenic consensus polymerase chain reaction. Unique strains were screened for uropathogenic virulence characteristics using dot blot hybridization and compared with different collections of E. coli isolates.


RESULTS
On average, differences were found among women assigned to treatment for ASB, those treated only for symptomatic infections, and untreated women in (1) follow-up time with bacteriuria (29%, 31%, and 66%, respectively; P<.001), (2) duration of bacteriuria (2.2, 2.5, and 3.7 months, respectively; P=.04), and (3) carriage of unique isolates (2.4, 2.8, and 4 months, respectively; P=.03). Women assigned to antibiotic treatment usually had recurrent infection (76%), 64% of the time with a genetically new E. coli strain. Virulence characteristics of these isolates were comparable to those of fecal isolates from healthy women.


CONCLUSIONS
Treatment may reduce the overall proportion of time infected in the long term and carriage of a unique strain, but most treatment regimens were followed by subsequent recolonization. Infecting strains did not have virulence factors characteristic of uropathogenic E. coli.
Dalal
Shona
S
Department of Epidemiology, School of Public Health, University of Michigan, Ann Arbor, MI 48109, USA.
Nicolle
Lindsay
L
Marrs
Carl F
CF
Zhang
Lixin
L
Harding
Godfrey
G
Foxman
Betsy
B
D000328:Adult; D000900:Anti-Bacterial Agents / Q000627:therapeutic use; D015373:Bacterial Typing Techniques / Q000379:methods; D001437:Bacteriuria / Q000188:drug therapy / Q000453:epidemiology* / Q000382:microbiology*; D016000:Cluster Analysis; D016172:DNA Fingerprinting / Q000379:methods; D048909:Diabetes Complications; D004926:Escherichia coli / Q000145:classification / Q000235:genetics / Q000302:isolation & purification* / Q000472:pathogenicity; D004927:Escherichia coli Infections / Q000188:drug therapy / Q000453:epidemiology* / Q000382:microbiology*; D029968:Escherichia coli Proteins / Q000235:genetics; D005260:Female; D005838:Genotype; D006801:Humans; D008137:Longitudinal Studies; D008350:Manitoba / Q000453:epidemiology; D008875:Middle Aged; D009693:Nucleic Acid Hybridization; D019105:Random Amplified Polymorphic DNA Technique; D013997:Time Factors; D016896:Treatment Outcome; D037521:Virulence Factors / Q000235:genetics
D000900:Anti-Bacterial Agents; D029968:Escherichia coli Proteins; D037521:Virulence Factors