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Listeria monocytogenes is an important foodborne pathogen implicated in outbreaks related to soft cheese, indicating the importance of its control. In the current study, the antimicrobial efficacy of octanoic acid (OA) and lauric arginate ester (LAE), individually or in combination, against L. monocytogenes in Domiati cheese was evaluated during storage at 4°C for 35 days. Data revealed that the population of L. monocytogenes in untreated Domiati cheese gradually increased during refrigerated storage. The application of 400ppm OA, 200ppm LAE, and 200ppm LAE+200ppm OA reduced the inoculated L. monocytogenes in Domiati cheese with 1.72±0.11, 2.14±0.01, and 2.63±0.08 log CFU/g reduction respectively, after 35 days of refrigerated storage. Moreover, the combination of 200ppm LAE+400ppm OA was the most effective treatment, leading to a 3.31±0.03 log CFU/g reduction of L. monocytogenes by the end of the refrigerated storage period. This study is a guide for the practical application of octanoic acid and lauric arginate during the manufacturing of Domiati cheese to control L. monocytogenes during the refrigerated storage. [ABSTRACT FROM AUTHOR]

Male workers in copper smelting are exposed to copper, lead, and arsenic. This study aimed to assess the effects of combined exposure to these metals on male reproductive hormone levels and assesses malondialdehyde (MDA) as an oxidative stress parameter. The study was conducted on 40 copper smelter workers compared with 40 non-exposed workers. Laboratory investigations included levels of serum copper, blood lead, serum arsenic, follicle-stimulating hormone (FSH), luteinizing hormone (LH), testosterone, and MDA. Levels of copper, arsenic, lead, FSH, and LH were significantly increased compared to controls. However, a statistically significant decrease in the mean value of testosterone was found among exposed workers. Positive correlations between serum copper and both serum FSH and MDA levels were statistically significant as were correlations between serum arsenic and MDA levels. Testosterone levels showed significant negative correlations with both copper and arsenic among exposed workers. A linear regression model of copper, arsenic, and lead levels as independent variables with FSH, LH, and testosterone as dependent variables revealed a significant negative association between serum copper and testosterone levels. The current study concluded that combined exposure to copper, arsenic, and lead in secondary copper smelters had a negative impact on male reproductive hormone levels that may be mediated by oxidative stress. [ABSTRACT FROM AUTHOR]

Probiotics are widely used in livestock animals to improve their health and performance. Feeding behavior is an important sign of health and has an influence on animal productivity. Hence, this study was conducted to compare the efficacy of two commonly used probiotics (Saccharomyces cerevisiae; SAC and Lactobacillus acidophilus; LA) in dairy livestock on the feeding behavior and milk yield of cows. Thirty Holstein-Friesian cows were equally subdivided into three groups. The control group received no feed supplement, the second group received 25 gm SAC/head daily for six weeks and the third group was supplied with 25gm LA/head daily for successive six weeks. Then, the feeding behavior was videotaped every two weeks and the milk yield and composition were measured. Ruminal mobility and score, body condition score, and fecal total colony count were calculated. As a result, SAC increased the feeding frequency of cows in the sixth week of supplementation. SAC increased the milk yield in the fourth and sixth weeks, while LA increased the milk yield in the fourth week of supplementation. In the sixth week of supplementation, LA decreased the total colony count. Both probiotics did not affect the milk composition, rumen mobility, and score as well as body condition score. The obtained data suggested that the use of SAC improved the feeding and milk yield while LA increased the milk yield in addition to a reduction of the gut pathogens that enhances the mucosal immunity. [ABSTRACT FROM AUTHOR]

A novel antimicrobial chitosan-gelatin based edible coating fortified with papaya leaves and thyme extract was prepared for improving the quality and shelf-life of chicken breast fillet and Kareish cheese during chilled storage at 4 ± 1 °C. The samples were dipped for 10 min in distilled water (control), chitosan-gelatin (CG), chitosan-gelatin +2% papaya leaves extract (CG + P) and chitosan-gelatin +2% thyme extract (CG + Th). The coated and uncoated samples were examined periodically for sensory attributes, pH, TBARs, total aerobic mesophilic (TAM), total Enterobacteriaceae (TE), and total yeasts and molds counts (TYM). Sensory evaluation revealed that chicken breast fillet and Kareish cheese samples coated with CG + P were the best in terms of tenderness, juiciness, body & texture and flavor. CG + Th exhibited the highest antimicrobial and antioxidant effect, followed by CG + P. The results of microbiological, physicochemical and sensory analysis of this study demonstrated that the application of CG + P or CG + Th could be a promising method for increasing the shelf life and improving the quality of chicken breast fillet and Kareish cheese. • Preparation of chitosan-gelatin edible coating with papaya leaves or thyme extract. • Thyme and papaya leaves extract improved edible coating antimicrobial activity. • Edible coating fortified with thyme extract had the highest antioxidant activity. • Edible coating with papaya leaves or thyme extract improved the sensory attributes. • The prepared coating improved the quality and extended shelf life of chicken breast fillet and Kareish cheese. [ABSTRACT FROM AUTHOR]

Abstract: Bacterial aggregation phenotype and cell surface hydrophobicity of dairy Lactobacillus plantarum strains were screened in order to assess a correlation with their adhesion and pathogen competitive exclusion abilities. Lactobacilli strains showing an aggregation phenotype, L. plantarum IFPL33, IFPL81, IFPL150, IFPL156 and IFPL162, also exhibited the highest percentages of autoaggregation (>50%) at 24h. In addition, autoaggregation abilities of the lactobacilli were highly correlated with their percentages of co-aggregation with all the pathogens tested, although co-aggregation properties were pathogen specific. Nevertheless, none of the autoaggregation and co-aggregation abilities correlated with the affinity to xylene (hydrophobicity) and the ability of adhesion to Caco-2 cells. Furthermore, these properties are not fully correlated with the ability of the lactobacilli strains for inhibiting pathogen adhesion. Aggregation abilities and cell surface hydrophobicity may not be the only components responsible for adhesion but some of the criteria to bear in mind of a complex mechanism that enables microorganisms to interact with the host and exert its beneficial effect. Further research is needed to identify remaining attributes related to adhesion and pathogen exclusion properties of potential probiotic strains. [Copyright &y& Elsevier]