Rate of occurrence and pathogenic effect of enteroaggregative Escherichia coli virulence factors in international travelers.
One or more putative enteroaggregative Escherichia coli (EAEC) virulence factors (aggA, aggR, aspU, or aafA) were identified in 60 (70%) of 86 EAEC isolates from travelers with diarrhea compared with a rate of 7 (8%) of 90 in patients with diarrhea who were infected with nonadherent E. coli (odds ratio, 27.36; 95% confidence interval, 11.30 to 65.91). The presence of aggR or one or more virulence factors in EAEC from patients with diarrhea was associated with a statistically increased concentration of interleukin-8 (IL-8) in feces compared with that in EAEC negative for these factors: for aggR positive (9 of 12 [75%]; median, 800 pg/ml) versus aggR negative (5 of 18 [28%]; median, 0), P < 0.05; and for isolates positive for > or =1 virulence factor (13 of 21 [62%]; median, 360 pg/ml) versus those negative for > or =1 virulence factor (1 of 9 [11%]; median, 0), P < 0.05. Other fecal cytokines (IL-1beta and IL-1ra) were found in increased concentrations (P < 0.05 when at least one EAEC virulence factor was present compared with the concentrations when EAEC negative for multiple virulence factors was found in patients with diarrhea. Putative virulence factors were commonly found in EAEC from patients with diarrhea, and the pathogenicity of many strains was suggested by showing an association between the presence of plasmid-borne virulence factors and the presence of fecal cytokines. The different patterns of virulence factors of EAEC revealed several clusters demonstrating diversity among the isolates from the various regions.
Jiang
Zhi-Dong
ZD
The University of Texas Health Science Center School of Public Health, Houston, Texas 77030, USA. zjiang@sph.uth.tmc.edu
Greenberg
David
D
Nataro
James P
JP
Steffen
Robert
R
DuPont
Herbert L
HL
D001422:Bacterial Adhesion; D016207:Cytokines / Q000032:analysis; D003967:Diarrhea / Q000382:microbiology*; D004926:Escherichia coli / Q000145:classification / Q000235:genetics / Q000472:pathogenicity*; D004927:Escherichia coli Infections / Q000382:microbiology; D029968:Escherichia coli Proteins / Q000235:genetics / Q000378:metabolism*; D005243:Feces / Q000382:microbiology; D006801:Humans; D007194:India; D007563:Jamaica; D008800:Mexico; D015534:Trans-Activators / Q000235:genetics / Q000378:metabolism; D014195:Travel; D037521:Virulence Factors / Q000235:genetics / Q000378:metabolism*
C088603:AggR protein, E coli; D016207:Cytokines; D029968:Escherichia coli Proteins; D015534:Trans-Activators; D037521:Virulence Factors