Arcobacter butzleri isolates exhibit pathogenic potential in intestinal epithelial cell models

Aims: The pathogenic potential of Arcobacter butzleri isolates on human (HT-29/B6) and porcine epithelial (IPEC-J2) cells was investigated by in vitro assays. Methods and Results: Five of six A. butzleri isolates were able to adhere and invade HT-29/B6 cells while only four isolates adhered and two invaded IPEC-J2 cells. Two non-or poorly invasive A. butzleri isolates were highly cytotoxic to differentiated HT-29/B6 cells but none to IPEC-J2 cells as determined by WST-assays. Epithelial integrity of cell monolayers, monitored by measurement of the transepithelial electrical resistance (TER), was decreased by all A. butzleri isolates in HT-29/B6 and IPEC-J2 cells to 30-15% and 90-50% respectively. Conclusion: The A. butzleri strain-specific pathomechanisms observed with the human colon cell line HT-29/B6, like adhesion, invasion and cytotoxicity might all contribute to epithelial barrier dysfunction, which could explain a leak-flux type of diarrhoea in humans. In contrast, porcine cells seem to be less susceptible to A. butzleri. Significance and Impact of the Study: Arcobacter butzleri has enteric pathogenic potential, characterized by defined interactions with human epithelial cells and strain-specific pathomechanisms.