Conventional and molecular detection of Vibrio cholerae isolated from environmental water with the prevalence of antibiotic resistance mechanisms

Abstract

Environmental water is an important source for Vibrio cholerae, which is autochthonous to the aquatic environment, monitoring this bacterium in water is important for control of cholera. Vibrio cholerae represents an enormous public health problem around the world, especially in developing countries. One hundred samples were collected and selected. All presumptive isolates were confirmed by using a series of biochemical tests including Oxidase test, Simmon Citrate test, DNase test, Indole test, Klingler Iron Agar (KIA) test, MacConkey agar test and motility. Confirmed Vibrio cholera strains were then screening for slide agglutination test by using commercially antisera polyvalent and monovalent O1 and O139 for determining strain serotype. The resistance to antibiotics by Vibrio cholerae was determining by using thirteen standardized disc diffusion including Amikacin, Ceftriaxone, Ceftazidime, Gentamycin, Tetracycline, Streptomycin, Tobramycin, Cephotaxime, Nalidixic Acid, Norfloxacin, Cephalothin, Rifampicin, Cefixime. From one hundred water samples were detected, fifty-six samples were motile and positive for biochemical tests. Fifteen isolates confirmed as Vibrio cholera by Polymerase Chain Reaction (PCR) assay with primers de­signed for ctxA and 241bp band was observed. They showed sensitive to all antibiotics except Amikacin, Streptomycin, Cefixime, Norfloxacin, Cephalothin. the aim of this study was determined the accurate method for detection of Vibrio cholerae in environmental water. In the current study, we found that the molecular method using Polymerase Chain Reaction performance using the ctxA gene-specific primers for detection of Vibrio cholerae was faster and accurate and specific.