Antibiotic resistant sulphite-reducing clostridia in soil and groundwater as indicator of manuring practices

The use of tetracycline- or oleandomycin-resistant sulphite-reducing clostridia as indicators for the application of piggery manure or cow dung was investigated. Sulphite-reducing clostridia resistant to either tetracycline or oleandomycin were detected in all the investigated cattle and piggery manure samples. They were present at high concentrations in the soil of manured fields and virtually absent in the soil of unmanured fields. Antibiotic resistant sulphite-reducing clostridia were also detected in the soil at a depth of 100 cm and in the groundwater of manured fields while they were present at a much lower degree in the groundwater of unmanured fields. The numbers of faecal coliforms and faecal streptococci in groundwater samples were not clearly related to the application of piggery manure.