Phenotypic and genomic analysis of Arcobacter cryaerophilus in response to different stress conditions

Arcobacter cryaerophilus is considered an emerging foodborne pathogen frequently detected in various food products and food-associated surfaces. However, the ability to withstand stressful environmental conditions occurring during food processing, preservation, and storage remains poorly investigated. This study therefore aims to investigate the impact of aerobic, thermal, acidic, and osmotic stress conditions on the cell count of eleven Arcobacter cryaerophilus strains. In addition, whole genome sequencing was performed to identify genes potentially involved in stress tolerance. All strains were able to grow under aerobic conditions and in cold temperature (10 °C). Susceptibility to acidic (4 mM citric acid) and osmotic stress (2.5% sodium chloride) revealed a pronounced strain-dependence. In contrast, all strains were susceptible to elevated temperature (42 °C). Genomic analysis revealed many stress-associated genes to be conserved within the strains, though their presence correlated with phenotypic differences only to a limited extent. In conclusion, Arcobacter cryaerophilus was observed to tolerate various stress factors with strain-dependent differences in susceptibility. These findings highlight the ability of this bacterial pathogen to persist under stress factors occurring throughout the food chain and underscores its relevance regarding food safety.