[Quantitative and qualitative studies of Campylobacter in a sewage treatment plant]

The occurrence and distribution of campylobacter spp. in the wastewater of a sewage treatment plant was examined from July 1985 to July 1986. The number of campylobacter was determined in a double set-up by the MPN-method. Preston broth and -agar containing FBP supplement were used as nutrient media. The samples were incubated at 37 degrees C and 42 degrees C, respectively. Subsequently 1345 isolated campylobacter strains were biotyped. The number of fecal and total coliforms, pH-value and temperature in the sewage were determined as auxiliary parameters. In addition to that data concerning air temperature and amount of sewage flow were available. The median-value of campylobacters in the inflow of the sewage treatment plant amounted to 3,7 X 10(3) cfu/100 ml. The following passage through the wastewater plant resulted in a campylobacter reduction of 99,5%. Distinctly more Campylobacter coli than Campylobacter jejuni could be isolated; Campylobacter laridis, fetus and Cephalothin-susceptible Campylobacter coli were to be found only occasionally. Probably due to toxic effects by the sewage the percentage of not totally biotypable, coccoid campylobacter increased during the clarification process. The number of campylobacters and their distribution was neither influenced by the auxiliary parameters nor by seasonal variations.