Induced Lysogen Bacteriophage of E. coli has Lytic Activity on Multiple-Drug Resistant Pseudomonas

Abstract

Escherichia coli is an endemic pathogen causing a variety of human disease. It is one of the common etiologies of Urinary Tract Infections (UTI), which may lead to kidney failure. A twenty-four year athlete lady had the history of frequent UTI. Last episode of recurrence was happened in September 2004. Microbiological examination of urine revealed the presence of E. coli as etiologic agent. This bug was found to be highly resistant to β-lactam antibiotics. Plaque assay of this filter sterilized urine sample on the lawn of two strains of Pseudomonas aeruginosa Ps5 and Ps6 exhibited enormous clear plaques referred to lytic activity. The ecological role of this phage had not been established due to the absence of detectable Pseudomonas in this urine sample. A sample was collected after 50 days of active infection from recovered patient revealed no detectable phage particles. Lysates were prepared in Ps5 and Ps6 from initial filter sterilized urine sample. Electron Micrograph from these lysates indicated the population of mix phages which seems to have characteristics of Myoviridea and Siphoviridea. In addition to these phages small empty headed tailed particles were abundantly of present. Protein profile, DNA profile and morphological details of the phage raised in Ps5 and Ps6 were found to be identical. However, small empty headed tailed particles were abundantly present in Ps5 lysate.

Absence of Pseudomonas in urine sample collected during active disease and absences of phages in convalescent patient’s urine sample was a significant feature and allow us to hypothesize the relation of these phages with E. coli. This warrant us to explore the possible inducing agents which may cause the in vivo induction of lysogen.

Serum, Tetracycline, Urea and Uric acid were used as inducing agent, in attempt of induction. E. coli lysates prepared by induction were plaque assayed on the lawn of Ps5 and Ps6 revealed uncountable small sized clear plaques. However lysate of E. coli induced by urea contained phage particles similar to Myoviridea. Furthermore it is documented that Siphoviridea comprises phages that specifically targeted enterobacteria. The finding of present studies the lytic phages of Pseudomonas evolve from E. coli has similar feature of Siphoviridea.