Chickens represent one of the most important sources of animal protein for the human population. However, chickens also represent one of the most important reservoirs of Salmonella for humans. Measures to decrease the Salmonella incidence in chickens are therefore continuously sought. In this study, we tested feed supplementation with a mixture of C1 to C12 monoacylglycerides. At 0.7 and 1.5 kg per ton of feed, such supplementation significantly decreased Salmonella counts in the caecum but not in the liver. The chickens were infected on day 4 and the protective effect in the caecum was recorded on day 22 and 23 of life. Supplementation also decreased the inflammatory response of chickens to Salmonella infection determined by avidin, SAA, ExFABP, MMP7, IL1β, IL4I and MRP126 gene expression but did not affect immunoglobulin expression in the caecum. C1 to C12 monoacylglycerides can be used as a feed supplement which, if continuously provided in feed, decrease Salmonella counts in chickens just prior slaughter.

• Keywords
• Caecum, Chicken, Monoacylglyceride, Salmonella,
• MeSH
• Cecum microbiology   MeSH
• Diet veterinary   MeSH
• Animal Feed analysis   MeSH
• Chickens * MeSH
• Monoglycerides * administration & dosage   metabolism   MeSH
• Random Allocation MeSH
• Poultry Diseases * immunology   microbiology   prevention & control   MeSH
• Disease Resistance * drug effects   MeSH
• Dietary Supplements analysis   MeSH
• Salmonella enteritidis * physiology   MeSH
• Salmonella Infections, Animal * immunology   microbiology   prevention & control   MeSH
• Dose-Response Relationship, Drug MeSH
• Animals MeSH
• Check Tag
• Male MeSH
• Animals MeSH
• Publication type
• Journal Article MeSH
• Names of Substances
• Monoglycerides * MeSH

There are extensive differences in the caecal microbiota of chicks from hatcheries and those inoculated with faecal material from adult hens. Besides differences in microbial composition, the latter chickens are highly resistant to Salmonella Enteritidis challenges, while the former are susceptible. In this study, we tested whether strains from genera Bacteroides, Megamonas, or Megasphaera can increase chicken resistance to Salmonella and Campylobacter jejuni when defined microbial mixtures consisting of these bacterial genera are administered. Mixtures consisting of different species and strains from the above-mentioned genera efficiently colonised the chicken caecum and increased chicken resistance to Salmonella by a factor of 50. The tested mixtures were even more effective in protecting chickens from Salmonella in a seeder model of infection (3-5 log reduction). The tested mixtures partially protected chickens from C. jejuni infection, though the effect was lower than that against Salmonella. The obtained data represent a first step for the development of a new type of probiotics for poultry.

• Keywords
• Bacteroides, Megamonas, Megasphaera, caecum, chicken, microbiota, probiotics,
• Publication type
• Journal Article MeSH

Chickens in commercial production are hatched in hatcheries without any contact with their parents and colonization of their skin and respiratory tract is therefore dependent on environmental sources only. However, since chickens evolved to be hatched in nests, in this study we evaluated the importance of contact between hens and chicks for the development of chicken skin and tracheal microbiota. Sequencing of PCR amplified V3/V4 variable regions of the 16S rRNA gene showed that contact with adult hens decreased the abundance of E. coli, Proteus mirabilis and Clostridium perfringens both in skin and the trachea, and Acinetobacter johnsonii and Cutibacterium acnes in skin microbiota only. These species were replaced by Lactobacillus gallinarum, Lactobacillus aviarius, Limosilactobacillus reuteri, and Streptococcus pasterianus in the skin and tracheal microbiota of contact chicks. Lactobacilli can be therefore investigated for their probiotic effect in respiratory tract in the future. Skin and respiratory microbiota of contact chickens was also enriched for Phascolarctobacterium, Succinatimonas, Flavonifractor, Blautia, and [Ruminococcus] torque though, since these are strict anaerobes from the intestinal tract, it is likely that only DNA from nonviable cells was detected for these taxa.

• Keywords
• caecum, chicken, respiratory tract microbiota, skin, trachea,
• MeSH
• Respiratory System MeSH
• Escherichia coli genetics   MeSH
• Chickens * MeSH
• Microbiota * MeSH
• RNA, Ribosomal, 16S analysis   MeSH
• Animals MeSH
• Check Tag
• Female MeSH
• Animals MeSH
• Publication type
• Journal Article MeSH
• Names of Substances
• RNA, Ribosomal, 16S MeSH

The concept of competitive exclusion is well established in poultry and different products are used to suppress the multiplication of enteric pathogens in the chicken intestinal tract. While the effect has been repeatedly confirmed, the specific principles of competitive exclusion are less clear. The aim of the study was to compare metabolites in the cecal digesta of differently colonized chickens. Metabolites in the cecal contents of chickens treated with a commercial competitive exclusion product or with an experimental product consisting of 23 gut anaerobes or in control untreated chickens were determined by mass spectrometry. Extensive differences in metabolite composition among the digesta of all 3 groups of chickens were recorded. Out of 1,706 detected compounds, 495 and 279 were differently abundant in the chicks treated with a commercial or experimental competitive exclusion product in comparison to the control group, respectively. Soyasaponins, betaine, carnitine, glutamate, tyramine, phenylacetaldehyde, or 3-methyladenine were more abundant in the digesta of control chicks while 4-oxododecanedioic acid, nucleotides, dipeptides, amino acids (except for glutamate), and vitamins were enriched in the digesta of chickens colonized by competitive exclusion products. Metabolites enriched in the digesta of control chicks can be classified as of plant feed origin released in the digesta by degradative activities of the chicken. Some of these molecules disappeared from the digesta of chicks colonized by complex microbiota due to them being metabolized. Instead, nucleotides, amino acids, and vitamins increased in the digesta of colonized chicks as a consequence of the additional digestive potential brought to the cecum by microbiota from competitive exclusion products. It is therefore possible to affect metabolite profiles in the chicken cecum by its colonization with selected bacterial species.

• Keywords
• cecum, chicken, competitive exclusion, metabolome, microbiota,
• MeSH
• Cecum microbiology   MeSH
• Chickens * microbiology   MeSH
• Glutamic Acid MeSH
• Poultry Diseases * microbiology   MeSH
• Nucleotides MeSH
• Vitamin K MeSH
• Vitamins MeSH
• Animals MeSH
• Check Tag
• Animals MeSH
• Publication type
• Journal Article MeSH
• Names of Substances
• Glutamic Acid MeSH
• Nucleotides MeSH
• Vitamin K MeSH
• Vitamins MeSH

A large variety of cheeses can be produced using different manufacturing processes and various starter or adjunct cultures. In this study, we have described the succession of the microbial population during the commercial production and subsequent ripening of smear-ripened cheese using 16S rRNA gene sequencing. The composition of the microbiota during the first 6 days of production was constant and consisted mainly of LAB (lactic acid bacteria) originating from the starter culture. From day 7, the proportion of LAB decreased as other bacteria from the production environment appeared. From the 14th day of production, the relative proportion of LAB decreased further, and at the end of ripening, bacteria from the environment wholly dominated. These adventitious microbiota included Psychrobacter, Pseudoalteromonas haloplanktis/hodoensis, Vibrio toranzoniae, and Vibrio litoralis (Proteobacteria phylum), as well as Vagococcus and Marinilactibacillus (Firmicutes phylum), Psychrilyobacter (Fusobacteria phylum), and Malaciobacter marinus (Campylobacterota phylum), all of which appeared to be characteristic taxa associated with the cheese rind. Subsequent analysis showed that the production and ripening of smear-ripened cheese could be divided into three stages, and that the microbiota compositions of samples from the first week of production, the second week of production, and supermarket shelf life all differed.

• Keywords
• 16S rRNA gene sequencing, cheese microbiota, smear-ripened cheese, starter cultures,
• Publication type
• Journal Article MeSH