Biofilm-forming lactic acid bacteria of honey bee origin intended for potential probiotic use.

Scientists around the world are focusing their interest on the use of probiotics in honey bees as an alternative method of prophylaxis against causative agents of both American and European foulbrood. In our study we tested inhibitory activity against Paenibacillus larvae and the biofilm formation activity by various lactic acid bacteria isolated from honey bee guts or fresh pollen samples in the presence of different sugars added to the cultivation media. In addition, we tested the probiotic effect of a newly selected Apilactobacillus kunkeei V18 in an in situ experiment in bee colonies. We found antibacterial activity against P. larvae in four isolates. Biofilm formation activity of varying intensity was noted in six of the seven isolates in the presence of different sugars. The strongest biofilm formation (OD570 ≥ 1) was noted in A. kunkeei V18 in the presence of fructose; moreover, this isolate strongly inhibited the growth of P. larvae under laboratory conditions. Inhibition of P. larvae and Melissococcus plutonius by A. kunkeei V18 in situ was confirmed in a pilot study.

Effect of Application of Probiotic Pollen Suspension on Immune Response and Gut Microbiota of Honey Bees (Apis mellifera).

Although the use of probiotic bacteria in invertebrates is still rare, scientists have begun to look into their usage in honey bees. The probiotic preparation, based on the autochthonous strain Lactobacillus brevis B50 Biocenol™ (CCM 8618), which was isolated from the digestive tracts of healthy bees, was applied to the bee colonies in the form of a pollen suspension. Its influence on the immune response was determined by monitoring the expression of genes encoding immunologically important molecules in the honey bee intestines. Changes in the intestinal microbiota composition were also studied. The results showed that the probiotic Lact. brevis B50, on a pollen carrier, significantly increased the expression of genes encoding antimicrobial peptides (abaecin, defensin-1) as well as pattern recognition receptors (toll-like receptor, peptidoglycan recognition proteins). Gene expression for the other tested molecules included in Toll and Imd signaling pathways (dorsal, cactus, kenny, relish) significantly changed during the experiment. The positive effect on intestinal microbiota was manifested mainly by a significant increase in the ratio of lactic acid bacteria to enterobacteria. These findings confirm the potential of the tested probiotic preparation to enhance immunity in bee colonies and thus increase their resistance to infectious diseases and stress conditions.

Changes of total protein and protein fractions in broiler chickens during the fattening period.

BACKGROUND AND AIM: Blood proteins in birds serve as an important indicator in the evaluation of health status and represent a basis in general biochemistry allowing the identification of metabolic alterations. The objective of this study was to evaluate the protein profile in broiler chickens extended by the concentrations of serum protein fractions at different periods of fattening. MATERIALS AND METHODS: Into the evaluation, we included 24 clinically healthy Ross 308 line meat-type chickens at the age of 2 days. Blood samples were taken on day 4, 18, 32, and 46 of fattening always from six randomly selected chickens. Chickens were fed with a commercial starter, grower, and finisher feeds. The concentrations of total serum protein and protein fractions were evaluated. RESULTS: Various significant changes in the proportion of the individual protein fractions were found during the observed period except for the beta-globulins in all protein fractions and the albumin/globulin (A/G) ratio. At the beginning of the fattening period, the relative concentrations of albumin, α1-globulins, and A/G ratio were significantly lower and the values of α2- and γ-globulins significantly higher (p<0.05). The values of pre-albumin fraction were found as a small band preceding the albumin fraction differed significantly between the different age groups of chickens (p<0.05). The total serum protein concentrations showed higher values in older broilers; the significantly highest mean value was recorded on day 32 of fattening. CONCLUSION: The results suggest that fattening and age of broilers influences not only the production patterns, metabolic processes, and lipid and mineral profile but also the parameters of protein profile. However, seeing that some contradictory data exist regarding the number and size of globulin fractions in chickens, further analyses are needed.