Antibiotic susceptibility profiles of some Vibrio strains isolated from wastewater final effluents in a rural community of the Eastern Cape Province of South Africa

The Vibrio strains showed the typical multidrug-resistance phenotype of an SXT element. They were resistant to sulfamethoxazole (Sul), trimethoprim (Tmp), cotrimoxazole (Cot), chloramphenicol (Chl), streptomycin (Str), ampicillin (Amp), tetracycline (Tet) nalidixic acid (Nal), and gentamicin (Gen). The antibiotic resistance genes detected includes dfr18 and dfrA1 for trimethoprim; floR, tetA, strB, sul2 for chloramphenicol, tetracycline, streptomycin and sulfamethoxazole respectively. Some of these genes were only recently described from clinical isolates, demonstrating genetic exchange between clinical and environmental Vibrio species.These results demonstrate that final effluents from wastewater treatment plants are potential reservoirs of various antibiotics resistance genes. Moreover, detection of resistance genes in Vibrio strains obtained from the wastewater final effluents suggests that these resistance determinants might be further disseminated in habitats downstream of the sewage plant, thus constituting a serious health risk to the communities reliant on the receiving waterbodies.Antibiotic-resistant bacteria have been found in a surprisingly diverse range of environments, including human clinics, animal husbandry, orchards, aquaculture, food, sewage, chlorinated, and unchlorinated water supplies [1]. Antimicrobial resistance has become a major medical and public health problem as it has direct links with disease management [2]; and while antibiotics such as tetracycline, doxycycline, norfloxacin, ciprofloxacin and streptomycin may be used as an adjunct in rehydration therapy and are critical in the treatment of septicemia patient [3-5], resistance to many of these drugs in many pathogens including Vibrio pathogens such as V. vulnificus, V. cholerae, V. fluvialis and V. parahaemolyticus [6-8] have been documented.Report of drug-resistant V. cholerae strains are appearing with increasing frequency [9]. Emergence of microbial resistance to multiple drugs is