Survival of Clostridium difficile spores at low water activity

Abstract

Clostridium difficile is frequently found in meat and meat products. Germination efficiency, defined as colony formation, was previously investigated at temperatures found in meat handling and processing for spores of strain M120 (animal isolate), R20291 (human isolate), and DK1 (beef isolate). In this study, germination efficiency of these spore strains was assessed in phosphate buffered saline (PBS, a ∼1.00), commercial beef jerky (a ∼0.82/0.72), and a-adjusted PBS (a ∼0.82/0.72). Surface hydrophobicity was followed for spores stored in PBS. After three months and for all PBS a levels tested, M120 and DK1 spores showed a ∼1 decimal reduction in colony formation but this was not the case when kept in beef jerky suggesting a protective food matrix effect. During storage, and with no significant a effect, an increase in colony formation was observed for R20291 spores kept in PBS (∼2 decimal log increase) and beef jerky (∼1 decimal log increase) suggesting a loss of spore superdormancy. For all strains, no significant changes in spore surface hydrophobicity were observed after storage. Collectively, these results indicate that depending on the germination properties of C. difficile spores and the media properties, their germination efficiency may increase or decrease during long term food storage.

Superdormant Spores as a Hurdle for Gentle Germination-Inactivation Based Spore Control Strategies

“…Spores of Clostridium species exhibit a similar germination heterogeneity like Bacillus species and Clostridium SD spores also occur (Webb et al, 2007; Rodriguez-Palacios and LeJeune, 2011; Stringer et al, 2011; Wang et al, 2011, 2012; Nerandzic and Donskey, 2013; Deng et al, 2015, 2017; Olguin-Araneda et al, 2015; Doona et al, 2016a). Similar to Bacillus species, the amount of Clostridium SD spores also depends on the factors that influence the germination efficiency.…”

“…They may stay dormant and remain undetectable during recovery, but germinate later and proliferate, causing spoilage or even foodborne diseases (Deng et al, 2015; Silvestri et al, 2015). For example, spores formed by some Clostridium species could recover from superdormancy during long-term storage and become viable afterward, posing a potential risk (Esty and Meyer, 1922; Deng et al, 2015, 2017).…”

“…Second, more attention should be paid to SD spores of Clostridium species, which have been far less studied than the SD spores of Bacillus species (Rodriguez-Palacios and LeJeune, 2011; Wang et al, 2011; Crowther et al, 2014; Deng et al, 2017). Since germination behavior varies among bacterial genera, further research is needed to clarify the properties of Clostridium SD spores and the underlying mechanisms of their superdormancy (Rodriguez-Palacios and LeJeune, 2011; Xiao et al, 2011; Deng et al, 2015).…”

Prospects of bioinformatics approach for exploring and mapping potential bioactive peptide of Rusip (The traditional Indonesian fermented anchovy): A Review

“…In their study, Chen et al (2018) perform that peptides predicted by the QSAR method are proven to have good antioxidant activity after in vitro validation. Similar study has discovered that several hydrophobic, steric, and amino acid positions near the C terminus of a peptide contribute to its ACE inhibitor efficacy (Deng et al, 2017).…”