Detection of some Biological Parameters and Heavy Metals Presence in Tigris River Water by Novel Designed Bacterial Efflux Pump Genes

Abstract

Enterobacteriaceae are Gram-negative bacteria that have many mechanisms to survive in contaminated environments. Klebsiella pneumoniae is one of them that express efflux pump genes in the presence of heavy metals, like AcrAb and OqxA genes. The purpose of this study is to investigate the relationship between the existence of efflux pump genes in K. pneumoniae, and heavy metal contamination in the Tigris River. By comparing important indicators to World Health Organization (WHO) criteria, this study aims to analyze the river's water quality. It focuses on detection of cadmium (Cd), lead (Pb), nickel (Ni), arsenic (As), mercury (Hg), iron (Fe), and cobalt (Co). Fifteen samples of the Tigris River near the Al-Dura project of water remediation were obtained and cultured on selective media, and the water quality parameters, like TSS, TDS, TH, pH, turbidity, EC, BOD, COD, OD, TOC, and heavy metals, were estimated. Bacterial DNA was extracted, then efflux genes were detected with the presence of heavy metals in the tested samples. Results illustrated that K. pneumoniae gave positive results in nine of the total fifteen samples, and the water quality parameters were within the normal ranges, except for elevated levels of DO and TOC, and decreased levels of BOD and COD, with a significant relationship among heavy metal levels with both AcrAB and OqxA genes at a significance level of p ≤ 0.05.