Clinical and bacteriologic correlates of the papG alleles among Escherichia coli strains from children with acute cystitis

Background, papG is the Gal(alpha 1-4)Gal-specific adhesin gene of Escheric hia coli P fimbriae. The three alleles of papG are associated with differen t receptor-binding preferences, occur in different lineages of E. coli and appear differentially associated with specific clinical syndromes, e.g. all ele II with pyelonephritis and allele III with cystitis. However, no data a re available regarding associations of the papG alleles with clinical outco mes. Methods. Alleles I, II and III of papG were sought among 38 E. coli urine i solates from children with acute cystitis by a polymerase chain reaction-ba sed assay. The papG genotype was compared with other bacterial characterist ics and with response to therapy. Results. papG was detected in 13 (34%) strains. It was associated positivel y with sfa and hly (which encode S fimbriae and hemolysin) and negatively w ith afa (which encodes Dr-binding adhesins), Allele II predominated over al lele III (29% of strains, vs. 5%; P < 0.01). Allele II was significantly as sociated with serogroups O1 and O16 and with agglutination of both human an d sheep erythrocytes, whereas allele III was associated with sfa, hly, sero group O6 and preferential agglutination of sheep erythrocytes. The presence of papG predicted recurrent bacteriuria among children receiving 3-day tre atment and Allele III predicted same-strain recurrence. Conclusions. These findings conflict with existing data associating allele III with cystitis, confirm and extend previous associations of papG alleles II and III with other bacterial properties and suggest that papG genotype may predict clinical outcomes.