Association of Genetically Related Escherichia coli Strains with Ulcerative Colitis - A Preliminary Study

Abstract

Objective: To explore the genetic relatedness among the Escherichia coli isolates recovered from rectal mucosa of patients with Ulcerative Colitis(UC) as well as from non specific diarrhoea patients by using ERIC PCR (whole genome analysis). Material & Methods:A total of 44 strains of E coli, each from patients suffering from UC with exacerbation while on maintenance therapy, were isolated to see if there is any association with specific genotype of E coli with the clinical condition. For comparison, 20 strains of E coli were also isolated from patients suffering from non specific diarrhoea. These isolates were subjected to ERIC PCR for analysing similarity/ dissimilarity with each other based on the distribution of ERIC sequences in the whole genome of the bacterial species. Results:The dendrogram prepared on the basis of banding pattern showed that majority of UC patients (39/44, 88.6%) grouped in to one major cluster while second major cluster comprised mostly strains isolated from patients with non specific diarrhoea i.e. controls (17/18, 94.4%). Moreover, in the cluster representing UC patients, a total of 11 strains were observed to be genotypically similar followed by 8 strains by ERIC PCR. Conclusion:Our results strongly indicate that specific Escherichia coli strains may be involved/ associated with UC and its relapse.