Evaluation of Lactobacillus spp. and yeast based probiotic (Lavipan) supplementation for the reduction of Salmonella Enteritidis after infection of broiler chickens.

The number of human cases of salmonellosis in the EU was 94,625 in 2015. Considering the source of these infections, Salmonella spp. was most frequently detected in broiler chicken meat and Salmonella Enteritidis (SE) was the most commonly reported serovar. The efficacy of probiotics in limiting Salmonella spp. infection in poultry has been demonstrated in numerous papers. The administration of probiotics at the level of primary production reduces the risk of contamination of poultry food products with Salmonella spp. A study was carried out in order to determine the potential for reducing the Salmonella spp. population in broiler chickens with the use of the Lavipan (JHJ, Poland) probiotic that comprised selected stains of lactic acid bacteria and Saccharomyces cervisae. Salmonella spp.-free broiler chickens were divided into two groups and received the same feed with (group L) or without (group C) the probiotic throughout the experiment. All day-old chickens were infected per os with SE. Samples of cecum content were collected 2, 4, and 6 weeks after SE infection and pectoral muscles were collected 6 weeks following SE infection for the evaluation of the SE population number. Serum samples for serological examinations were collected 6 weeks after infection. Six weeks after infection, the number of SE-positive cecal samples was lower in the L group (12.5% positive) in comparison to the C group (87.5%). Similar results were demonstrated for the muscle samples (25% in contrast to 87.5%). At the same time, in both cases, the SE CFU/g was significantly lower in the L group. The results of our study indicate that Lavipan was capable of reducing the population of SE in the gastrointestinal tract, which eventually improved the hygienic parameters of the pectoral muscles. Four weeks after infection, SE was not detected in any of the experimental groups. In both groups, no specific anti-SE antibodies were detected.

Modulation of beta-galactosidase activity in peritoneal macrophages from C57B1 mice after exposure to Proprionibacterium acnes.

Peritoneal macrophages (PM luminal diameter) from untreated C57B1 mice contain high levels of beta-galactosidase (beta-gal) and these PM luminal diameter are heterogeneous in their expression of this enzyme. Intraperitoneal (i.p.) injection of saline caused a transient depression in the level of enzyme activity in the PM luminal diameter whereas i.p. injection of Proprionibacterium acnes (P. acnes) gave rise to a marked decrease of beta-gal activity in these cells. This reduction in enzymatic activity persisted for as long as the PM luminal diameter were activated for cytotoxicity towards the L929 tumor cell line, up to 35 days after injection. beta-gal activity was present in the lavage fluid from day 2-21 after injection of P. acnes but none was detected in the lavage fluid after injection of saline. It is proposed that the enzymatic activity in the lavage fluid is derived from monocytes which migrate from the blood into the peritoneal cavity. There was an influx of granulocytes in the P. acnes group which persisted up to 35 days after injection. In contrast none were observed in the saline group after 2 days. PM luminal diameter harvested after 1-35 days were large, highly vacuolized and many contained bacteria; these PM luminal diameter had the typical morphology of activated cells. It is suggested that the processing of P. acnes by granulocytes may play a role in the activation of macrophages in the early inflammatory response, with concurrent loss in beta-gal activity. However, in the later stages, interferon-gamma and other induced lymphokines may be instrumental in causing a decrease in beta-gal activity.