Duration of the Flaxseed Supplementation Affects Antioxidant Defence Mechanisms and the Oxidative Stress of Fattening Pigs.

This study was conducted to investigate the effect of the duration of a flaxseed diet on fattening pigs' antioxidant defence mechanism in blood and tissues. Eighteen 20-week-old Landrace breed fattening pigs (BW 76.61 ± 2.30 kg) were divided into three groups of six animals. The control group was fed a basal diet. The FS3 group was fed the basal diet supplemented with 10% flaxseed for 3 weeks. The FS6 group received the same basal diet with flaxseed for 6 weeks. The total antioxidant capacity of the blood, measured as the total antioxidant status (TAS), total plasma antioxidant capacity (FRAP), reactive oxygen metabolites (dROMs) and total antioxidant capacity (PAT), was not affected by the flaxseed diet. The superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx) and glutathione reductase (GR) activities were significantly decreased in the FS3 pigs in the heart (p < 0.05). However, in the FS3 group, the glutathione-S-transferase (GST) activity significantly increased compared to the control, but in the FS6 group, the activity was inhibited (p < 0.05). In the muscle, the CAT and GST activity was significantly decreased in the FS3 group (p < 0.05). The thiobarbituric acid reactive substance (TBARS) content was significantly reduced in the brain, muscle and heart in the FS3 group(p < 0.05). In FS6, the TBARS content significantly increased in the heart and brain (p < 0.05). Our results showed that the health effect of a flaxseed diet is significantly conditioned by the length of the flaxseed addition.

The Effect of Enterococcus faecium AL41 on the Acute Phase Proteins and Selected Mucosal Immune Molecules in Broiler Chickens.

Probiotic bacteria, including the Enterococcus faecium strain, can improve intestinal mucosal health by several mechanisms, including modulation of the immune response, as well as by improving the protective function of the epithelial barrier. In this study, we tested the effect of Enterococcus faecium AL41 on the acute phase proteins response (blood), gene expression of selected molecules of mucosal immunity (immunoglobulin A, mucin-2, insulin-like growth factor 2) and mucus production (all parts of the small intestine) in broilers. Eighty broiler chicks were divided into two groups: a control and E. faecium AL41 (birds were inoculated with AL41 for 7 days) group. The whole experiment lasted 11 days. Our results revealed that the administration of E. faecium AL41 had no substantial effect on the concentrations of acute phase proteins, but we recorded a significant increase in ß- and γ-globulin fractions at the end of the experiment, which may indicate an improvement in the immune status. A significant prolonged stimulatory effect of E. faecium AL41 on the relative expression of molecules (immunoglobulin A, mucin-2) as well as on the dynamic of mucus production in the chicken intestine was observed. In addition, AL41 significantly reduced the total number of enterococci in the cecum and faeces.

Bacteriocin-Producing Strain Lactiplantibacillus plantarum LP17L/1 Isolated from Traditional Stored Ewe's Milk Cheese and Its Beneficial Potential.

Stored ewe's milk lump cheese is a local product that can be a source of autochthonous beneficial microbiota, especially lactic acid bacteria. The aim of this study was to show the antimicrobial potential of Lactiplantibacillus plantarum LP17L/1 isolated from stored ewe's milk lump cheese. Lpb. plantarum LP17L/1 is a non-hemolytic, non-biofilm-forming strain, susceptible to antibiotics. It contains genes for 10 bacteriocins-plantaricins and exerted active bacteriocin with in vitro anti-staphylococcal and anti-listerial effect. It does not produce damaging enzymes, but it produces ß-galactosidase. It also sufficiently survives in Balb/c mice without side effects which indicate its safety. Moreover, a reduction in coliforms in mice jejunum was noted. LP17L/1 is supposed to be a promising additive for Slovak local dairy products.

Decarboxylase-positive Enterococcus faecium strains isolated from rabbit meat and their sensitivity to enterocins.

BACKGROUND: The objective of the study was to determine sensitivity of Enterococcus faecium strains from rabbit meat to enterocins. RESULTS: Twenty-five decarboxylase-positive strains (from rabbit meat) allotted to the species E. faecium by genotypization and by MALDI TOF MS spectrometry identification (evaluation score value range 2.104-2.359; in the range for highly probable species identification-score value 2.300-3.000 and secure probable species identification/probable species identification-2.000-2.299) were studied. Seventeen strains were gelatinase positive. Although they did not produce histamine (HIS), spermidine, and spermine, they produce at least one among seven tested biogenic amines (BAs) in small amounts (2-10 mg/L) or up to very high amounts (>1000 mg/L). Putrescine was produced by two strains. These decarboxylase-positive strains were sensitive to enterocins (Ents). All strains were sensitive to Ent 2019 and Ent 55 (inhibitory activity from 200 to 819 200 AU/mL). Twenty-two strains were inhibited by Ent A(P) and Ent 4231; 20 strains were sensitive to Ent M. CONCLUSION: Our results have spread the basic knowledge related to inhibitory spectrum of enterocins showing sensitivity of decarboxylase-positive strains to enterocins. Protective possibilities of enterocins in meat processing were also indicated.

Beneficial effect of lantibiotic nisin in rabbit husbandry.

Nisin is a bacteriocin marketed as Nisaplin. The aim of our work was to test its in vivo effect in a rabbit model; its effect on phagocytic activity (PA) and morphometry has not so far been studied. Post-weaning rabbits (48), 5 weeks old (both sexes, Hycole breed), were divided into the experimental (E) and the control groups (C), 24 animals in each. They were fed a commercial diet with access to water ad libitum. Rabbits in E had nisin additionally administered to their drinking water (500 IU-20 µg per animal/day) for 28 days. The experiment lasted 42 days. On day 28, significant decrease in coagulase-positive (CoPS) staphylococci and coliforms was noted (p < 0.01) in faeces of group E compared with C. Pseudomonads and clostridiae were also significantly reduced (p < 0.001; p < 0.05) and slight decrease was also in CoNS and enterococci. On day 42, coliforms were still significantly reduced (p < 0.001) in faeces; slight decrease in CoPS and pseudomonads was noted. In the caecum, significant decrease in pseudomonads (p < 0.05) was noted on day 28; slight decrease in coliforms. In the appendix slight decrease in coliforms, pseudomonads was obtained on both days. PA was increased significantly in E on days 28, 42 (p < 0.001). Biochemical parameters were not influenced; nor were volatile fatty acids or lactic acid in the chymus. Nisin application did not evoke oxidative stress. In group E, an increase in average body weight gain (about 9.4 %) was noted. The villus height/crypt depth ratio was not influenced; that is, resorption surface and functionality of mucosa were not influenced.

Antimicrobial activity of Enterococcus faecium ef 55 against Salmonella enteritidis in chicks.

The protective effect of Enterococcus faecium EF 55 against Salmonella enterica serovar Enteritidis phage type 4 (SE PT4) was studied in 1-day-old chicks. The EF 55 strain (isolated and characterised by the authors earlier) was applied daily (1.10(9) CFU/0.2 ml PBS) for 7 days. Oral inoculation of the SE PT4 strain was performed on day 8 in a single dose of 5.10(8) CFU/0.2 ml PBS. The experiment lasted for 21 days. Samples were collected on day 1 of the experiment to verify the absence of Salmonella, on day 8 to check colonisation of EF 55 and immunological status in experimental birds, and on days 2, 4, 6, 8 and 14 after SE PT4 infection of chicks. Strain EF 55 sufficiently colonised the digestive tract of chicks after 7 days of application. The highest numbers of EF 55 in the faeces of chicks were observed before SE infection and persisted to day 6 post infection (p.i.) in both the EF and EF+SE groups. PCR confirmed the identity of the EF 55 strain. The counts of SE PT4 strain in faeces of the EF+SE group were significantly reduced in comparison to those in the SE group on days 2 and 14 p.i. (P < 0.01). The significant reduction of salmonellae in the caecum was recorded at the end of the experiment (day 14 p.i.) in the EF+SE group in comparison to the SE group (P < 0.01). At day 4 p.i., colonies of S. Enteritidis PT4 were found in the liver of chicks of the SE group in a higher concentration than in chicks of the EF+SE group (P < 0.001). Salmonellae were isolated from the liver until days 8 and 6 p.i. in the SE and EF+SE groups, respectively. The mean values of actual lymphocyte subpopulations in the blood and the relative percentage of caecal intraepithelial lymphocyte subpopulations (CD4, CD8, CD44, TCR, MHC II and IgM) were not influenced at a statistically significant level by the application of the EF 55 and/or the SE PT4 strain. The results demonstrate the antimicrobial effect of E. faecium EF 55 against S. Enteritidis PT4.