Diversity of Campylobacter isolates from three activated sludge systems

Thermophilic campylobacters were isolated from three sewage plants in Rio de Janeiro, RJ, Brazil, and identified. Laboratory analysis of 390 sewage samples showed the presence of 169 thermophilic strains. The results demonstrated that human and animal pathogenic biotypes could be isolated from activated sludge during the initial processing steps. The aeration tank could be considered a barrier to Campylobacter survival. C. jejuni was the prevalent species isolated (40.8 per cent). The most common biotypes were C. jejuni biotype I (21.3 per cent), C. coli biotype I (16 per cent) and C. jejuni biotype II (14.8 per cent).