The Challenge of Clostridium perfringens Spores
Clostridium perfringens is a gram-positive, spore-forming, anaerobic bacterium that causes both gastrointestinal (GI) and histotoxic diseases in humans and animals. C.perfringens human GI disease is caused mainly by enterotoxigenic type A isolates producing spores that are highly resistant to heat and other environmental stress factors. These resistant spores can survive against traditional cooking methods used for meat and poultry products as well as other processing treatments in the food industry. The surviving spores germinate, outgrow and multiply to hazardous levels in foods during improper cooling and then cause disease after consuming the contaminated foods. The food industry needs to develop alternatives to conventional processing technologies in response to the growing consumer demand for high quality, minimally processed, and additive-free foods. To achieve this goal, several projects have been conducted in my laboratory and following are the findings: 1) high hydrostatic pressure is effective against C. perfringens vegetative cells but not spores; 2) C. perfringens spores can be inactivated in meat products formulated with germinants specific for C. perfringens; 3) although nisin, sorbate and benzoate showed inhibitory effect against spore outgrowth and vegetative cells of C. perfringens isolates in laboratory conditions, no such effect was observed against C. perfringens spores inoculated into a meat model system; 4) inducing spore germination on stainless steel surfaces followed by iodophore treatment represented a promising strategy to inactivate C. perfringens spores; and finally 5) C.perfringens spores can be inactivated in meat products formulated with chitosan and essential oils. Collectively, these findings in conjunction with the findings from our ongoing research should help in developing an effective strategy to inactivate C. perfringens spores.
Professor Mahfuzur Sarker is a professor in the Microbiology department at Oregon State University, USA. His research interests include Bacterial pathogenesis; Molecular pathogenesis of Clostridium perfringens isolates associated with food poisoning and non-food borne gastrointestinal (GI) diseases in humans, and GI diseases in domestic animals; Mechanisms of C. perfringens sporulation, spore germination, and spore resistance.