SciELO - Scientific Electronic Library Online

 
vol.9 issue5Evaluation of concentrated milk whey as a supplement for SF9 Spodoptera frugiperda cells in cultureGenome analysis of thirteen Colombian clostridial strains by pulsed field gel electrophoresis author indexsubject indexarticles search
Home Pagealphabetic serial listing  

Services on Demand

Journal

Article

Indicators

Related links

Share


Electronic Journal of Biotechnology

On-line version ISSN 0717-3458

Abstract

SILVA, Juan et al. Frequency of transferable multiple antibiotic resistance amongst coliform bacteria isolated from a treated sewage effluent in Antofagasta, Chile. Electron. J. Biotechnol. [online]. 2006, vol.9, n.5. ISSN 0717-3458.  http://dx.doi.org/10.4067/S0717-34582006000500008.

Antibiotic-resistant coliform bacteria from raw and treated water from activated sludge of a sewage treatment plant were isolated on eosin methylene blue agar (EMB) plates in the separate presence of ampicillin, tetracycline, chloramphenicol and streptomycin. Antibiotic resistant coliforms obtained from inflow and effluent waters were studied to determine influences of treatment on the species composition, resistance patterns and transferable resistance in these bacteria. The bacterial counts obtained showed a high proportion of antibiotic resistant coliforms in the treated effluent. The resistant coliform species were eliminated at different rates by the treatment. Escherichia coli decreased, whereas the proportion of Klebsiella sp increased. The percentage of multiple-resistant isolates increased at the end of the treatment process. The high frequency of resistance was to ampicillin, followed by tetracycline and sulpha-trimethoprim. Moderate incidence of resistance was to streptomycin, chloramphenicol and cephradine. The lowest rate of resistance was to kanamicin and nalidixic acid. Mating experiments of multiple-resistant coliforms with an E. coli K-12 donor confirmed the capability of transferring its resistance. The results of this study suggested that wastewater treatment could reduce the total number of enteric bacteria in sewage, but may increase the proportion of antibiotic resistant coliforms in effluent water. Environmental release and agricultural use of treated sewage effluent containing bacteria having elevated antibiotic resistance levels presents a potential public health risk, as well as the risk of transferring the antibiotic resistance to bacterial populations in the environment.

Keywords : antibiotic resistance; coliforms; plasmid; sewage treatment; water pollution.

        · text in English     · English ( pdf )

 

Creative Commons License All the contents of this journal, except where otherwise noted, is licensed under a Creative Commons Attribution License