Effect of disinfectants on stability and transmissibility of R-plasmid in <i>E</i>. <i>coli</i> isolated from drinking water

Abstract

<span style="font-size:14.0pt;line-height: 115%;font-family:" times="" new="" roman";mso-fareast-font-family:"times="" roman";="" mso-ansi-language:en-in;mso-fareast-language:en-in;mso-bidi-language:hi"="" lang="EN-IN">Drug resistant enteropathogenic <i>E. coli</i> (EPEC, 086 scrotype) isolated from contaminated piped drinking water supply (Fecal coliform 160/100ml) was studied for effect of disinfctants (chlorine and UVB) on stability and transmissibility of R plasmid. The strain was resistant streptomycin and bacitracin and tolerant to multiple metal ions of Cd, Cr, Co, As, Ni, Zn and Hg. A plasmid of molecular size of 3.7 Kb was detected in the organism. After exposure to sublethal doses of disinfectants, complete elimination of resistances to streptomycin and Cr was observed. Partial loss of resistance to Hg due to chlorine was detected. Although UVB did not effected the pattern of transmissibility effect on frequency of transfer was observed. Surprisingly, in UVB irradiated cells, significantly enhanced rate of transfer was noted.</span>