Tetracycline Resistance Genes of Diarrhogenic E. coli in Pediatric Patients

Escherichia coli is an important group of pathogens associated with diarrhea among children fewer than 5 years old. The aim of this study was to determine the tetracycline resistance genes from diarrhogenic E. coli, as well as frequency and susceptibilities antimicrobial agents in children less than 5 years of age. In this descriptive study from April to December 2010, 450 fecal specimens were collected from children at 3 hospitals in southwest Iran. Isolates were tested for susceptibility to antimicrobial drugs by disc diffusion methods as described by the CLSI. PCR amplification was used to detect genes conferring resistance to tetracycline (tetA, tetB and tetC). From the total number of specimens examined, 77(26/20%) Diarrheagenic E. coli was detected. Antibiogram analysis revealed that the highest rate of antibiotic resistance was against tetracycline (55/8%) and the lowest was amikacin (0%). From tetracycline resistant isolates, 38 cases (88.4%) were positive by PCR for tet genes, as follow: tetA found in 33(76/6%), tetB 27 (62/7%) and tetC 6 (13/9%). Our results showed that the prevalence of antibiotic resistance and the percentage of tetracyclin resistance genes are high in diarrheagenic E.coli isolated from the children under the study, which is probably due to lack of diagnosis in appropriate usage of antibiotics regiments. Therefore, there is the need for updating the treatment protocol.