Sharing of virulent Escherichia coli clones among household members of a woman with acute cystitis.
BACKGROUND
Within-household transmission of extraintestinal pathogenic Escherichia coli (ExPEC) may contribute to the pathogenesis of urinary tract infection (UTI), but this is poorly understood.


METHODS
A woman with acute UTI, 4 human household members who cohabited with her, and the family's pet dog underwent prospective longitudinal surveillance for colonizing E. coli for 7-9 weeks after the woman's UTI episode. Unique clones were resolved by random amplified polymorphic DNA and pulsed-field gel electrophoresis analysis. Virulence genes, phylogenetic group, and O types were defined by PCR. Comparisons with reference strains were made using random amplified polymorphic DNA profiling.


RESULTS
Serial fecal and urine samples from the 6 household members yielded 7 unique E. coli clones (4 of which were ExPEC and 3 of which were non-ExPEC). For 3 clones, extensive among-host sharing was evident in patterns suggesting host-to-host transmission. The mother's UTI clone, which represented E. coli O1:K1:H7, was the clone that was most extensively shared (in 5 hosts, including the dog) and most frequently recovered (in 45% of samples and at all 3 time points). The other 3 ExPEC clones corresponded with E. coli O6:K2:H1, O1:K1:H7, and O2:F10,F48.


CONCLUSIONS
E. coli clones, including ExPEC, can be extensively shared among human and animal household members in the absence of sexual contact and in patterns suggesting host-to-host transmission.
Johnson
James R
JR
Mucosal and Vaccine Research Center, Veterans Affairs Medical Center, Minneapolis, MN 55417, USA. johns007@umn.edu
Clabots
Connie
C
D000208:Acute Disease; D000818:Animals; D003556:Cystitis / Q000382:microbiology*; D004285:Dogs; D004926:Escherichia coli / Q000145:classification* / Q000235:genetics / Q000472:pathogenicity; D004927:Escherichia coli Infections / Q000635:transmission / Q000662:veterinary*; D005191:Family Characteristics; D005260:Female; D006801:Humans; D008137:Longitudinal Studies; D011446:Prospective Studies; D014552:Urinary Tract Infections / Q000382:microbiology* / Q000635:transmission; D014774:Virulence / Q000235:genetics