Behavior of some Escherichia coli isolated from Water after exposure to UV-C 254-Study of their main biological and kinetic inactivation characteristics

Abstract

Abstract Wastewater treatment plants show an essential role in regulating the transmission of antibiotic resistance genes/antibiotic-resistant bacteria and antibiotics from wastewater into the natural environment. In our stud, polymerase chain reaction assays were used to characterize some Escherichia coli strains isolated from different sites of secondary wastewater. The virulence genotyping was released by multiplex PCR. Also, the genes encoding antibiotic resistance and biofilm development was monitored. In addition, an experiment in a batch laboratory UV-C irradiation device was released for selected strain. The obtained result of Congo red agar method revealed only four isolates as producing biofilm, and on the contrary, tetrazolium salt assay showed all E. coliisolates as highly strong biofilm producing. All these varied molecular and virulence selected E coli isolate characteristics have shown that the sensitivity to UV-C was variable from one strain to another, and the inactivation rates with a certain limit increased with the increase in UV-C dose. The kinetic parameters K and A calculated confirmed the variability of sensitivity to UV-C of the 4 strains of E. coli selected. Also, the study of the bacterial abatement showed that at a relatively high UV-C dose, the elimination reached over 99 % of E. coli, and corresponded to over 2 U-log10.