Variability in lag-duration of Campylobacter spp. during enrichment after cold and oxidative stress and its impact on growth kinetics and reliable detection.

摘要: Abstract Campylobacter jejuni and coli continue to be the leading cause of zoonotic gastroenteritis in European Union, making reliable detection food important. Low storage temperatures atmospheric oxygen concentrations during production can sub-lethal damage or transient non-culturability which is why ISO 10272-1:2017 includes an enrichment step repair cell increase concentrations, thereby supporting campylobacters from foods. The aim this study was assess variability lag-duration C. after different food-relevant stress treatments evaluate its impact on growth kinetics reliability outcomes. Therefore, 13 10 strains were subjected cold refrigerated frozen storage. Refrigerated did not significantly reduce culturability, but reduced by 1.6 ± 0.1 log10cfu/ml for both species. Subsequently, cells enriched following 10272-1:2017-A determined over time rate fitting Baranyi-model. Without prior treatment, mean 2.5 ± 0.2 h 2.2 ± 0.3 h, respectively. increased 4.6 ± 0.4 h 5.0 ± 0.4 h 5.0 ± 0.3 h 6.1 ± 0.4 h coli, Comparison strain- biological showed that differences recovery attributed mainly strain since refrigeration freeze respectively 3-fold 4-fold while remained constant. A subset also oxidative 0.7 ± 0.2 log10 cfu/ml comparison patterns indicated behaviour dependent applied. scenario analysis conducted heterogeneity outgrowth single outcomes protocol 10272-1:2017. This revealed a ‘worst-case’-scenario successful combination longest 7.6 h lowest 0.47 h−1 still resulted positive limit reached within 32.5 h. suggests other factors such as competitive microbiota act causative factor false-negative tested samples.