New Phylogenetic Groups of Escherichia coli in Iran Based on the New Clermont PhylotypingMethod

In 2013, Clermont and colleagues classified E. coli strains into eight phylogenetic groups using a new quadruplex PCR method. The aims of this study were to identify the phylogenetic groups of E. coli based on this new method and to assess their antibiotic resistance patterns. Methods. In this cross-sectional study, 6406 urine specimens were collected from patients admitted to two hospitals and five clinics in Bushehr, Iran in 2013. Antimicrobial susceptibility testing was performed by the Kirby-Bauer disk diffusion method. All 140 E. coli isolates with a count of 105 CFU/ ml were subjected to phylogenetic typing by a quadruplex PCR method. Results. Phylogenetic group B2 was most predominant (39.3%), followed by unknown (27.1%), E (9.3%), C and Clade I (each 6.4%), B1 (5%), F and D (each 2.9%) and A (0.7%). Also, 82.14% (115 cases) of isolates were detected as multiple drug resistant (MDR). The most common antibiotic resistance was related to amoxicillin (82.1%), and the least to meropenem (0.7%). Antibiotic resistance was mainly detected in phylogenetic group B2 (50%). Conclusions. Our findings showed the high prevalence of MDR E. coli isolates with a dominance of phylogenetic group B2. About 25% of E. coli isolates belong to the newly described phylo-groups C, E, F and clade I. Such studies need to be done also in other regions to provide greater understanding of the antibiotic resistance pattern the prevalences of different phylogenetic groups.

Escherichia coli, Phylogenetic groups, Antibiotic resistance, UTI