Short Communication: Antibiotic resistance among faecal coliform bacteria isolated from wastewater before and after treatment by an experimental sand filter

During the functioning period of a sand filter, 254 and 234 faecal-coliform strains were isolated from raw wastewater and reclaimed effluent, respectively. When tested for their susceptibility to ampicillin, kanamycin, chloramphenicol, streptomycin and tetracycline, 53% of the strains from the raw sewage and 84% of those isolated from the effluent were resistant to at least one antibiotic. The high incidence of drug resistance in the effluent was connected with a high proportion of Klebsiella pneumoniae, Enterobacter cloacae and Citrobacter freundii.