Persistence of Escherichia coli clones and resistance genes in recurrent urinary tract infections in children
Abstract number: P2217
Truusalu K., Kõljalg S., Stsepetova J., Drell T., Vainumäe I., Sepp E., Mikelsaar M.
Objectives: We compared the molecular clonality of E. coli (Ec) from recurrent urinary tract infection (rUTI) episodes with stability of phenotypic antibiotic resistance and presence of gene cassettes. The association between the presence of sul genes and previous trimethoprim-sulfamethoxazole TS treatment was assessed.
Methods: Altogether 78 urinary Ec isolates were obtained during one year follow-up from 27 patients (pt) (aged 2m-180m, mean 44.8m) with 15 episodes after initial UTI. Strain clonality was detected by PFGE. MIC values to TS, sulfamethoxazole SX, ampicillin AM, cefuroxime XM, cefotaxime CT, gentamicin GM, ciprofloxacin CI were measured by E-test. Int1, sul13 genes were detected by PCR and compared with TS treatment data.
Results: In 21/27 pt (78%) the unrelated clonality of Ec strains was detected: in 11 persistent clonal strains (Cs) (n = 24), in 10 both Cs and individual strains (Is) (n = 24; 16, resp) and in 6 only Is (n = 14) were found. The pt with only Is were younger than others (med 7.5 vs 48m; p = 0.03). Ec resistance to TS, SX, AM, XM, CT, GM, CI was 33%, 78%, 40%, 17%, 3%, 2%, 0% resp. The phenotypic antibiotic susceptibility in Cs was more stabile compared to Is (OR, 8.7; 95% CI, 1.840.8) during different infection episodes.
The integrons were found from 55/78 strains. Int pos strains had higher MIC values to XM, CT and GM than int neg ones (p < 0.01; 0.03; 0.01). The presence of integrons was similar in Cs and Is. In half of the pt (n = 14) it did not change, in another 13 the loss of integrons was more frequent than capture (9/13 vs 2/13, p = 0.01).
Sul genes were found in 42/78 Ec strains, it was in accordance with phenotypic resistance to SX compared to gene neg ones (p = 0.03). The Is harboured more sul 1 genes than Cs (p = 0.01). Occurrence of sul genes was more stabile in pt with Cs compared to Is (OR, 4.4; 95% CI, 1.117.7). The Ec strains obtained after previous TS treatment had more frequently any sul genes than TS non treated (p = 0.01).
Conclusion: In children the majority of Ec rUTI episodes are due to individual persisting clones. The stability of antibiograms and persistence of SX resistance encoding sul genes may indicate putative relapses. Previous TS treatment is associated with corresponding resistance.
|Session name:||18th European Congress of Clinical Microbiology and Infectious Diseases|
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