Campylobacter is the leading cause of food-borne gastrointestinal disease worldwide due to its high prevalence and main reservoir in chicken. Antimicrobial agents have been used during chicken processing in Australia, including chlorine and citric acid. Interaction between chlorine and organic matter during immersion chilling produces by-products that are implicated as human carcinogens. Peracetic acid (PAA) has been considered as an alternative to chlorine in the poultry industry. However, the time-dependent effectiveness of PAA in the Australian poultry industry is uncertain and little is known how Campylobacter survives and tolerates PAA treatment. In this study a C. jejuni poultry strain was investigated to identify the stress response, adaptive changes and survival mechanisms upon the sub-lethal PAA treatment (80 ppm) across four treatment time points (0, 15, 30, 45 min) utilising sequential window acquisition of all theoretical fragment-ion spectra-mass spectrometry (SWATH-MS) with a SCIEX TripleTOF 6600 MS.
A total of 2,146 peptides mapping to 591 proteins were quantified at a <1% false discovery rate. Pairwise comparisons between the 0- and the 15-, 30- and 45-min timepoints revealed proteome-wide alterations in the order of ~11%, ~16% and ~17% proteins, respectively. Between 0 and the 45 min treatment yielded 41 up-regulated proteins (~7%), while 63 (~11%) proteins were down-regulated after 45 min. Gene Ontology (molecular function) revealed that ATP-binding and oxidoreductase activities were up-regulated, whilst hydrolase and transferase activities were down-regulated. The 30- and 45-min treatment showed ~28% overlap in proteins, whilst 2, 5 and 8% of proteins were uniquely produced during 15-, 30- and 45-min treatments, respectively.
Overall time-dependent PAA treatment on C. jejuni delivers an informative portrait of its survival mechanism and presents opportunities to develop better PAA-based poultry processing strategies for commercial application in the future.