Antimicrobial effect of different peroxyacetic acid and hydrogen peroxide formats against spores of Clostridium estertheticum.

"Blown pack" spoilage is primarily caused by Clostridium estertheticum. The primary source of contamination is probably pelts, faeces and soil during opening cuts and de-hiding. Peroxyacetic acid (POAA) based fogs are commonly included in an abattoir's routine cleaning process. Hydrogen peroxide (H2O2) is a powerful oxidizing agent that penetrates microbe cell walls causing cell death. In this study, we compared the ability of H2O2 and OXYSAN ZS (POAA containing 1-hydroxyethylidine-1,1-diphosphonic acid as a stabilizer) in different formats to inactivate C. estertheticum spores. Hydrogen peroxide treatment using Phytagel™ gel as carrier was effective on fleece against both naturally contaminating microflora and C. estertheticum spores. This is the first time an antimicrobial treatment has been shown to inactivate C. estertheticum spores on such a complex and highly contaminated matrix. Both H2O2 and OXYSAN ZS treatments inactivated C. estertheticum spores on stainless steel indicating their potential use as an in-plant decontamination procedure or inclusion in routine in-process cleaning.

Molecular discrimination of New Zealand sourced meat spoilage associated psychrotolerant Clostridium species by ARDRA and its comparison with 16s RNA gene sequencing.

ARDRA analysis was carried out on 90 New Zealand psychrotolerant Clostridium isolates derived from three meat production animal types and their environments. The isolates included species associated with spoilage: C. gasigenes, C. algidicarnis, C. tagluense, C. frigidicarnis and C. estertheticum. The isolates fell into 14 distinct ARDRA Groups, with 13 previously characterised meat spoilage-associated isolates shared between 6 of the 14 groups. The accuracy of ARDRA profiling analysis was supported by sequencing the 16s rRNA gene from isolates, including the representative spoilage associated Clostridium species and was consistent with previous phylogenetic relationships and classical cultural characterisation. The ARDRA methodology described in this study successfully discriminated between the different spoilage-associated species of clostridia as well as other pyschrotolerant Clostridium species associated with meat production. This discriminatory molecular screen will aid future source attribution studies as well as enable meat processors to identify and validate control measures for clostridia contamination, thus gaining greater efficacy in controlling meat spoilage caused by psychrotolerant clostridia.