Diversity among 2481 Escherichia coli from women with community-acquired lower urinary tract infections in 17 countries

Objectives: In the recently published ECO-SENS survey, the antimicrobial susceptibility of Escherichia coli from urinary tract infections in women in 16 European countries and Canada was investigated. This study reports the diversity among these E. coli. Methods: The 2481 E. coli, typed with the PhenePlate (TM) (PhP) System utilizing the dynamics and end result of 11 biochemical reactions in a microplate system, were clustered and the Simpson's index of diversity calculated. Results: Seventy-four Common PhP Types (CT) comprising 2067 isolates and 414 Single Types (Si) were identified. Of these, 916 isolates (37%) belonged to one of the four most frequent CT (arbitrarily numbered CT48, 10, 26 and 20). CT48 with 400 isolates and 11 different susceptibility patterns, was widely disseminated across Europe and Canada and was the most frequent type in 13 countries and the second most frequent in the remaining four countries. Sixty-four per cent of the E. coli were susceptible to all eight investigated antimicrobials (CT48: 73%, CT10: 77%, CT26: 62% and CT20: 37%). Forty-six different susceptibility patterns were seen, the three most common being isolated resistance to ampicillin, resistance to ampicillin and trimethoprim, and isolated resistance to trimethoprim. Multiresistance, here defined as resistance to four or more of the investigated antibiotics, was distributed among E. coli belonging to several PhP types. Conclusions: There was no obvious correlation between the phenotypes identified with the PhP System and the susceptibility pattern. The data did not indicate clonal dissemination within or between countries as a major reason for differences in antimicrobial resistance rates.