Escherichia coli clonal group A (CGA) was first reported in 2001 as an
emerging multidrug-resistant extraintestinal pathogen. Because CGA has
considerable implications for public health, we examined the trends of
its global distribution, clinical associations, and temporal prevalence
for the years 1998-2007. We characterized 2,210 E. coli extraintestinal
clinical isolates from 32 centers on 6 continents by CGA status for
comparison with trimethoprim/sulfamethoxazole (TMP/SMZ) phenotype,
specimen type, inpatient/outpatient source, and adult/child host; we
adjusted for clustering by center. CGA prevalence varied greatly by
center and continent, was strongly associated with TMP/SMZ resistance
but not with other epidemiologic variables, and exhibited no temporal
prevalence trend. Our findings indicate that CGA is a prominent,
primarily TMP/SMZ-resistant extraintestinal pathogen concentrated within
the Western world, with considerable pathogenic versatility. The stable
prevalence of CGA over time suggests full emergence by the late 1990s,
followed by variable endemicity worldwide as an antimicrobial drug
resistant public health threat