Multilocus Variable-Number Tandem-Repeat Analysis for Geno-typing of Escherichia coli Strains Isolated from Hospital Wastewater, Tehran, Iran

Background: escherichia coli is one of the most frequent causes of many common bacterial infections. as a potential reservoir, hospital wastewater is considered for the dissemination of bacterial pathogens such as e. coli. therefore, research on hospital waste’s bacteria by low-cost, rapid and easy molecular typing methods such as multilocus variable-number tandem-repeat analysis (mlva) can be helpful for the study of epidemics. methods: e. coli strains were isolated from hospital wastewater sources in tehran, iran, over a 24-month sampling period (jun 2014- jun 2016) and identified by standard bacteriological methods. the diversity of repeated sequences of seven variable-number tandem-repeat (vntr) loci was studied by mlva method base on polymerase chain reaction (pcr). results: overall, 80 e. coli isolates were discriminated into 51 different genotypes. analysis of the mlva profiles using a minimum spanning tree (mst) algorithm showed two clonal complexes with 71 isolates and only nine isolates were stayed out of clonal complexes in the form of a singleton. high genotypic diversity was seen among e. coli strains isolated from hospital wastewaters; however, a large number of isolates showed a close genetic relationship. conclusion: mlva showed to be a rapid, inexpensive and useful tool for the analysis of the phylogenetic relationships between e. coli strains under the study.