Correlation among fecal indicator bacteria and physicochemical parameters with the presence of Helicobacter pylori DNA in raw and drinking water from Bogotá, Colombia

Abstract

The quality of raw and drinking water is a matter of considerable concern due to the possibility of fecal contamination. To assess the quality and public health risk of different types of water, the fecal indicator bacteria (FIB) are used. However, some pathogens, such as Helicobacter pylori, may be present in water when FIB cannot be found. Hpylori is recognized as the causative agent of chronic gastritis, peptic and duodenal ulcers, and gastric cancer. The aim of this study was to evaluate the relationships among physicochemical parameters, FIB concentrations, and the presence of Hpylori DNA in raw and drinking water from Bogotá, Colombia. A total of 310 water samples were collected 1day per week from July 2015 to August 2016, and physicochemical parameters (pH, turbidity, conductivity, and residual free chlorine) were measured. Presence of Hpylori DNA was determined and quantified by quantitative polymerase chain reaction (qPCR). Fecal indicator bacteria (total coliforms, Escherichia coli, and spores of sulfite-reducing Clostridia) were enumerated by using standard culture techniques. Thirty of 155 (31%) raw water samples and forty-eight of 155 (38.7%) drinking water samples were positive for the presence of Hpylori. No statistically significant relationships were found between physicochemical parameters or FIB with the presence or absence of Hpylori in any sample (P<0.05). This study provides evidence of the presence of Hpylori DNA in raw and drinking water in Bogotá, and shows that the detection and enumeration of FIB and physicochemical parameters in water do not correlate with the risk of contamination with Hpylori.