Production ofClostridium perfringensspores and their recovery from artificially spiked spices and herbs

In vitro competition with Bifidobacterium strains impairs potentially pathogenic growth of Clostridium perfringens on 2'-fucosyllactose

Fortifying infant formula with human milk oligosaccharides, such as 2'-fucosyllactose (2'-FL), is a global trend. Previous studies have shown the inability of pathogenic gut microbes to utilize 2'-FL. However, the present study demonstrates that the type strain (JCM 1290T) of Clostridium perfringens, a pathobiont species often more prevalent and abundant in the feces of C-section-delivered infants, exhibits potentially pathogenic growth on 2'-FL. The expression of genes for α-toxin, an activator of NLRP3 inflammasome, and ethanolamine ammonia-lyase, a factor responsible for the progression of gas gangrene, was significantly upregulated during 2'-FL assimilation compared to growth on lactose. However, colony-forming unit of C. perfringens JCM 1290T markedly decreased when co-cultivated with selected strains of Bifidobacterium, a taxon frequently detected in the breastfed infant gut. Moreover, during co-cultivation, the expression of virulence-related genes, including the gene for perfringolysin O - another activator of NLRP3 inflammasome - were significantly downregulated, while the lactate oxidation genes were upregulated. This can occur through two different mechanisms: direct competition for 2'-FL between the two organisms, or cross-feeding of lactose, released from 2'-FL by C. perfringens JCM 1290T, to Bifidobacterium. Attenuation of α-toxin production by the selected Bifidobacterium strains was observed to varying extents in 2'-FL-utilizing C. perfringens strains clinically isolated from healthy infants. Our results warrant detailed in vivo studies using animal models with dysbiotic microbiota dominated by various types of C. perfringens strains to further validate the safety of 2'-FL for clinical interventions, particularly on vulnerable preterm infants.

Radiation processing for public health: Croatia's contribution to food safety and sterilisation practices

Radiation processing has become an established and widely used technology in many countries. It is used for decontamination and sterilisation of various products, such as medical devices and accessories, pharmaceutical raw materials, packaging, food components and ingredients, with the aim to eliminate unwanted microorganisms. In Croatia, radiation technologies have been used for more than 40 years at the irradiation facility of the Ruđer Bošković Institute. Its Radiation Chemistry and Dosimetry Laboratory operates and maintains a 60Co panoramic gamma irradiator used for research, development, and industrial services in various aspects of irradiation technologies. This article explains radiation decontamination and sterilisation methods to inform a wider audience of their advantages and challenges in light of food safety and public health and provides a brief overview of related activities in Croatia.

Combined Effect of High-Pressure Processing with Spice Extracts on Quality of Low-Salt Sausage during Refrigerated Storage

The study evaluated the combined effect of high-pressure processing (HPP) and spice extracts on low-salt sausages during refrigerated storage. Physicochemical and microbiological characteristics of the sausages were determined. HPP treatment increased the thiobarbituric acid reactive substances (TBARS) value and the carbonyl content of the samples (p < 0.05), which meant lipid and protein oxidation was accelerated. Adding clove and cinnamon extracts can retard the oxidation caused by HPP (p < 0.05). The pH of the sausages treated with both the spice extracts and HPP maintained a higher pH value during the storage (p > 0.05). Compared with the samples treated with HPP or with the spice extracts alone, the combined treatment observably inhibited the growth of spoilage bacteria (p < 0.05) and improved the microbial community. The results demonstrated that the use of clove and cinnamon extracts in conjunction with HPP improved the storage quality and prolonged the shelf-life of the low-salt sausages. Thus, the combined use of spice extracts and HPP can be developed as a promising way to preserve low-salt meat products.