Analysis of diarrheagenic potential of uropathogenic Escherichia coli isolates in Dhaka, Bangladesh

Introduction: Urinary tract infection is the most frequently diagnosed kidney and urologic disease.

Methodology: Whether the Escherichia coli strains responsible for urinary tract infection (UPEC) carry virulence properties of diarrheagenic E. coli (DEC), 56 UPEC strains were examined for the presence of DEC and UPEC characteristics (e.g. biofilm formation, hemolysis activity, virulence genes).

Results: Among 56 UPEC strains, 21 showed capable of biofilm formation and only 5 showed hemolysis activity on sheep blood agar. In Multiplex PCR on assessment of virulence genes related to uropathogenesis; 42% was found positive for papC gene, 27% was fim1 positive, 11% was afa positive and none was found positive for sfa. Most of the isolates were found carrying none of eight diarrhea associated genes (e.g. estA, eltB, vt1, vt2, eaeA, ea, ial and bfpA) as expected. Only seven isolates were found to harbor these genes: five genes i.e., vt2, ial, eltB, bfpA and ea were found in five different isolates and two isolates were positive for estA, among these two, one was found positive for fim1, papC along with estA, a UPEC strain containing virulent gene of ETEC strain. One isolate was found carrying fim1 and vt2 showing the property of EHEC and another isolate was found positive for fim1 and ial, the characteristic of EIEC. One isolate harboring bfpA gene characterized as EPEC and the another one was found to harbor ea gene, characterized as EAEC.

Conclusions: This study observed that most UPEC strains are unique to uropathogenesis, still very few may carry the diarrheagenic property.