Lack of a cytolethal distending toxin among Arcobacter isolates from various-sources

Arcobacter has been shown to be present in numerous different sources, including poultry, water, and humans exhibiting gastroenteritis. The production of a cytolethal distending toxin (CDT) has been documented in Campylobacter, Helicobacter, and other species. The polymerase chain reaction was used to screen Arcobacter isolates from poultry, cattle, irrigation water, and human diarrhea for the presence of CDT genes. Cell filtrates and sonic extracts were also tested for CDT-like activity on Chinese Hamster Ovary, HeLa, and Intestinal 407 (INT407) cells in culture. No CDT amplimers were observed in any of the Arcobacter isolates investigated, However, toxicity to HeLa and INT407 cells was observed and was subsequently analyzed for cell cycle arrest in the presence of the Arcobacter extracts with flow cytometry. Cells treated with Arcobacter sonic extracts and filtrates exhibited normal cell cycles, suggesting that CDT is not expressed by Arcobacter. Thus, Arcobacter was shown to produce an entity that was toxic to some cells in culture, but this entity was toxic in a manner different from that of Campylobacter CDT.