Isolation and characterization of vibrio spp. from surface water in Dhaka city

Abstract

Vibrio spp. is an estuarine bacterium prevalent in water bodies throughout the world. Twelve species of the Vibrioceae family are known to cause diseases in human. The aim of this study was to investigate the occurrence, biochemical characteristics, antibiotic resistance and haemolytic abilities of Vibrio spp. in water of Hatirjheel and the Buriganga River in the capital of Bangladesh. A total of 6 Vibrio isolates could be identified from Hatirjheel which were all confirmed using biochemical characterization. Water samples from the Buriganga river did not yield any Vibrio. Among the isolates collected during the entire study period, 3 of the isolates were found to be resistant to the antibiotic Ampicillin, 5 were resistant to Nalidixic Acid, 1 was resistant to Erythromycin and all 6 were resistant to Trimethoprim-sulfamethoxazole. However, all the isolates were susceptible to Impinem, Chloramphenicol, Amikacin, Gentamycin, Ciprofloxacin, Doxycycline and Tetracycline. The overall Multiple Antibiotic Resistance (MAR) index value varied from 0.02 and 0.04. Among the tested isolates, 2 of the isolates were found to be non-haemolytic and the remaining 4 showed complete haemolysis. These results are significant because of the role of these water bodies in the spread and transmission of Vibrio infections. This study highlights the presence of potential microbial hazard in the surface water bodies of Dhaka city.