Isolation and antibiotic profile of Vibrio spp. in final effluents of two wastewater treatment plants in the Eastern Cape of South Africa

Abstract

BackgroundPoorly or partially treated wastewater disposed of can contaminate water and even properly treated sewage can have its problems. The highlight of this danger is wastewater treatment plants serving as reservoir for proliferation of antibiotic resistant organisms. We have reported the state of two wastewater treatment in the Eastern Cape of South Africa which discharge poorly and partially treated effluents. Our aims to identify Vibrio spp. and their antibiotic profiles in treated final effluent discharge from wastewater treatment plant.\n\nMethodsCulture based approach using the TCBS agar for isolation Vibrio spp., presumptive isolates were purified and confirmed using PCR. The confirmed isolated were also genotyped to identify the species present. The antibiotic profiling of the confirmed isolates was using the CLSI recommended first line antibiotics for Vibrio.\n\nResultsOut of the 786 presumptive isolates, 374 were confirmed as Vibrio spp. None of the Vibrio spp. pathotypes were present in the confirmed isolates. Randomized isolates of 100 Vibrio spp. were selected, > 90 % of the isolates were susceptible to Ciprofloxacin, and > 50 - 80 % for Ampicillin, Chloramphenicol, Tetracycline, Cefotaxime, and Trimethoprim-sulfamethoxazole respectively.\n\nConclusionsWe are able to isolate Vibrio spp. from treated effluents but none of their pathotypes were present. The antibiotic agents considered for primary testing which are ciprofloxacin was the most effective of the antibiotic drugs, followed by cefotaxime, tetracycline with less susceptibility. Contamination from discharged effluents from wastewater treatment can lead to spread of spread of disease in this environment. The WWTPs studied are sources of pollution to surface water with environmental and public health.