Bacteriological study of Karatoa river and their antimicrobial resistance

Abstract

The Karatoa River in Bangladesh is extensively contaminated with various contaminants. Water is one of the major cases of infectious illness. The current study concentrates on the bacterial identification by biochemical test and susceptibility to some antibiotics of the isolated organisms. Four samples were collected from the four different sites of the Karatoa River. The water samples were spread on Xylose Lysine Deoxycholate (XLD), Mannitol salt agar (MSA), Thiosulfate-citrate-bile salts-sucrose (TCBS), Nutrient Agar (NA), Cetrimide, MacConkey (MAC), HiCrome UTI following serial dilution within 24 hours of the collection. Also, the filtration method was used for MFC media. After those different types of Biochemical tests like the Triple Sugar Iron (TSI), Motility Indole Urea (MIU), Methyl Red -Voges-Proskauer (MR-VP), Catalase, Oxidase, Gram staining, Nitrate, Indole were used to determine the characteristics. Lastly, antibiotic susceptibility test was conducted using Amoxicillin, Amoxiclav, Ceftriaxone, Cefepime, Impenem, Azithromycin, Tetracycline, Nalidixic Acid, and Tobramycin disc. Around 62 different microorganisms were isolated from the water samples. Among these, Planococcus was the most predominant (15.87%), followed by Staphylococcus spp. (14.29%), and Marinococcus (11.11%). Some other organisms were also isolated in a very small amount. Moreover, the highest resistance was recorded for the antibiotic Amoxicillin (72.6%). On the other hand, 85.5% of the isolates were mostly susceptible to Impenam and Nalidixic acid. From our study, based on biochemical identification we found some highly pathogenic bacteria like Vibrio spp, Klebsiella spp, Enterobacter spp and Staphylococcus spp. Moreover, the presence of fecal coliform was present.