caecal microbiota
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Enterococcus cecorum (EC) is one of the most relevant bacterial pathogens in modern broiler chicken production from an economic and animal welfare perspective. Although EC pathogenesis is generally well described, predisposing factors are still unknown. This study aimed to understand the effect of heat stress on the caecal microbiota, intestinal integrity, and EC pathogenesis. A total of 373 1-day-old commercial broiler chicks were randomly assigned to four groups: (1) noninoculated, thermoneutral conditions (TN); (2) noninoculated, heat stress conditions (HS); (3) EC-inoculated, thermoneutral conditions (TN + EC); and (4) EC-inoculated, heat stress conditions (HS + EC). Birds were monitored daily for clinical signs. Necropsy of 20 broilers per group was performed at 7, 14, 21, and 42 days post-hatch (dph). A trend towards enhanced and more pronounced clinical disease was observed in the EC-inoculated, heat-stressed group. EC detection rates in extraintestinal tissues via culture were higher in the HS + EC group (~19%) than in the TN + EC group (~11%). Significantly more birds were colonized by EC at 7 dph in the HS + EC group (100%) than in the TN + EC group (65%, p < 0.05). The caecal microbiota in the two EC-inoculated groups was significantly more diverse than that in the TN group (p < 0.05) at 14 dph, which may indicate an effect of EC infection. An influence of heat stress on mRNA expression of tight junction proteins in the caecum was detected at 7 dph, where all six investigated tight junction proteins were expressed at significantly lower levels in the heat stressed groups compared to the thermoneutral groups. These observations suggest that heat stress may predispose broilers to EC-associated disease and increase the severity thereof. Furthermore, heat stress may impair intestinal integrity and promote EC translocation.
- Klíčová slova
- Enterococcus cecorum, broiler, caecal microbiota, heat stress, intestinal integrity,
- MeSH
- cékum mikrobiologie MeSH
- Enterococcus MeSH
- kur domácí * mikrobiologie MeSH
- mikrobiota * MeSH
- proteiny těsného spoje MeSH
- reakce na tepelný šok MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- randomizované kontrolované studie veterinární MeSH
- Názvy látek
- proteiny těsného spoje MeSH
The chicken caecum is colonised by hundreds of different bacterial species. Which of these are targeted by immunoglobulins and how immunoglobulin expression shapes chicken caecal microbiota has been addressed in this study. Using cell sorting followed by sequencing of V3/V4 variable region of 16S rRNA, bacterial species with increased or decreased immunoglobulin coating were determined. Next, we determined also caecal microbiota composition in immunoglobulin knockout chickens. We found that immunoglobulin coating was common and major taxa were coated with immunoglobulins. Similarly, more taxa required immunoglobulin production for caecum colonisation compared to those which became abundant in immunoglobulin-deficient chickens. Taxa with low immunoglobulin coating such as Lactobacillus, Blautia, [Eubacterium] hallii, Megamonas, Fusobacterium and Desulfovibrio all encode S-layer proteins which may reduce interactions with immunoglobulins. Although there were taxa which overgrew in Ig-deficient chickens (e.g. Akkermansia) indicating immunoglobulin production acted to exclude them from the chicken caecum, in most of the cases, immunoglobulin production more likely contributed to fixing the desired microbiota in the chicken caecum.
- MeSH
- Bacteria klasifikace genetika MeSH
- cékum * mikrobiologie MeSH
- imunoglobuliny * MeSH
- kur domácí * mikrobiologie imunologie MeSH
- RNA ribozomální 16S * genetika MeSH
- střevní mikroflóra * MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- Názvy látek
- imunoglobuliny * MeSH
- RNA ribozomální 16S * MeSH
In the present study, we examined the influence of the dietary inclusion of black soldier fly (BSF) larvae meal on the diversity and composition of the bacterial community in the caecum of Barbary partridges (Alectoris barbara). A total of 54 partridges were divided equally into three treatment groups. The control group (C) received a diet containing corn-soybean meals and the two experimental groups received diets in which soybean meal protein was partially substituted with BSF larvae meal at proportions of 25% (H25) and 50% (H50). The bacterial community of the caecal samples was analysed in 30 slaughtered animals (10 per group) at 64 days of age. High-throughput sequencing targeting the V4-V5 region of the 16 S rRNA gene was used. Firmicutes were the most abundant phylum in all studied categories. This phylum was dominated by the families Ruminococcaceae and Lachnospiraceae. The caecal microbiota was significantly altered at the genus level. The linear discriminant analysis effect size (LefSe) analysis for the differential taxa abundance revealed several significant dissimilarities between the control group (C) and the groups with 25% and 50% insect meal replacement, with 13 and 20 taxa with significantly different abundances, respectively. Several of these taxa are associated with gut health, fiber fermentation, and metabolic functions, indicating a biological importance of the observed microbial shifts. Compared with the control group, the partridges fed 25% BSF larvae meal had a significantly higher bacterial phylogenetic abundance and richness, which may contribute to improved gut health and a more stable microbial environment. The beta diversity measures revealed that all three groups of animals were significantly spatially separated. The results demonstrated the significant impact of black soldier fly larvae meal on the caecal microbiota of Barbary partridges. The positive influence of the insect meal used was indicated by increased bacterial diversity in the H25 group and increased relative abundance of several potentially beneficial genera in both experimental groups.
- Klíčová slova
- Barbary partridges, Black soldier fly, Gut microbiota, Insect,
- MeSH
- Bacteria genetika klasifikace MeSH
- biodiverzita MeSH
- cékum * mikrobiologie MeSH
- dieta * MeSH
- Diptera * MeSH
- Galliformes * mikrobiologie MeSH
- krmivo pro zvířata * MeSH
- larva MeSH
- RNA ribozomální 16S genetika MeSH
- střevní mikroflóra * MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- Názvy látek
- RNA ribozomální 16S MeSH
Chickens in commercial production are hatched in a clean hatchery environment in the absence of any contact with adult hens. However, Gallus gallus evolved to be hatched in a nest in contact with an adult hen which may act as a donor of gut microbiota. In this study, we therefore addressed the issue of microbiota development in newly hatched chickens with or without contact with an adult hen. We found that a mere 24-hour-long contact between a hen and newly hatched chickens was long enough for transfer of hen gut microbiota to chickens. Hens were efficient donors of Bacteroidetes and Actinobacteria. However, except for genus Faecalibacterium and bacterial species belonging to class Negativicutes, hens did not act as an important source of Gram-positive Firmicutes. Though common to the chicken intestinal tract, Lactobacilli and isolates from families Erysipelotrichaceae, Lachnospiraceae and Ruminococcaceae therefore originated from environmental sources instead of from the hens. These observation may have considerable consequences for the evidence-based design of the new generation of probiotics for poultry.
In this study, we investigated the influence of the inclusion of Tenebrio molitor (TM) larvae meal in the diet on the diversity and structure of the bacterial community in the caecal content of Barbary partridges. A total of 36 partridges, selected randomly for slaughter from 54 animals, were divided equally into three treatment groups, including the control group (C) with a diet containing corn-soybean meal and two experimental groups, in which 25% (TM25) and 50% (TM50) of the soybean meal protein was replaced by the meal from TM larvae. After slaughtering, the bacterial community of the 30 caecal samples (10 samples per each experimental group) was analysed by high-throughput sequencing using the V4-V5 region of the 16 S rRNA gene. Alpha diversity showed a higher diversity richness in the TM50 group. Beta diversity showed statistical dissimilarities among the three groups. Firmicutes was the dominant phylum regardless of the diet, with the predominant families Ruminococcaceae and Lachnospiraceae. Clostridia and Faecalibacterium were decreased in both TM groups, Lachnospiraceae was suppressed in the TM50 group, but still this class, genus and family were abundantly present in all samples. Several potentially beneficial genera, such as Bacillus, Ruminococcaceae UCG-009, Oscillibacter and UC1-2E3 (Lachnospiraceae) were increased in the TM50 group. The results showed a beneficial effect of the T. molitor larvae meal on the caecal microbiota of Barbary partridges, particularly in the TM50 group, which showed an increase in bacterial diversity.
- Klíčová slova
- Tenebrio molitor larvae meal, Caecal microbiota, Partridges,
- MeSH
- Bacteria klasifikace genetika izolace a purifikace MeSH
- biodiverzita MeSH
- cékum * mikrobiologie MeSH
- dieta MeSH
- Galliformes mikrobiologie MeSH
- krmivo pro zvířata * MeSH
- larva * mikrobiologie MeSH
- RNA ribozomální 16S genetika MeSH
- střevní mikroflóra * MeSH
- Tenebrio * mikrobiologie MeSH
- vysoce účinné nukleotidové sekvenování MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- Názvy látek
- RNA ribozomální 16S MeSH
Epidemiological data show that the composition of gut microbiota influences host health, disease status, and even behaviour. However, to confirm these epidemiological observations in controlled experiments, pure cultures of gut anaerobes must be obtained. Since the culture of gut anaerobes is not a simple task due to the large number of bacterial species colonising the intestinal tract, in this study we inoculated 174 different culture media with caecal content from adult hens, and compared the microbiota composition in the original caecal samples and in bacterial masses growing in vitro by 16S rRNA sequencing. In total, 42% of gut microbiota members could be grown in vitro and since there were some species which were not cultured but for which the culture conditions are known, it is likely that more than half of chicken gut microbiota can be grown in vitro. However, there were two lineages of Clostridiales and a single lineage of Bacteroidetes which were common in chicken caecal microbiota but resistant to culture. Of the most selective culture conditions, nutrient broths supplemented with mono- or di-saccharides, including those present in fruits, positively selected for Lactobacillaceae. The addition of bile salts selected for Veillonellaceae and YCFA (yeast casitone fatty acid agar) enriched for Desulfovibrionaceae. In addition, Erysipelotrichaceae were positively selected by colistin, trimethoprim, streptomycin and nalidixic acid. Culture conditions tested in this study can be used for the selective enrichment of desired bacterial species but also point towards the specific functions of individual gut microbiota members.
- Klíčová slova
- anaerobic culture, caecum, chicken microbiota, culturomics, microbiome, selective culture,
- Publikační typ
- časopisecké články MeSH
Data on the gut microbiota (GM) of wild animals are key to studies on evolutionary biology (host-GM interactions under natural selection), ecology and conservation biology (GM as a fitness component closely connected to the environment). Wildlife GM sampling often requires non-invasive techniques or sampling from dead animals. In a controlled experiment profiling microbial 16S rRNA in 52 house mice (Mus musculus) from eight families and four genetic backgrounds, we studied the effects of live- and snap-trapping on small mammal GM and evaluated the suitability of microbiota from non-fresh faeces as a proxy for caecal GM. We compared CM from individuals sampled 16-18 h after death with those in live traps and caged controls, and caecal and faecal GM collected from mice in live-traps. Sampling delay did not affect GM composition, validating data from fresh cadavers or snap-trapped animals. Animals trapped overnight displayed a slight but significant difference in GM composition to the caged controls, though the change only had negligible effect on GM diversity, composition and inter-individual divergence. Hence, the trapping process appears not to bias GM profiling. Despite their significant difference, caecal and faecal microbiota were correlated in composition and, to a lesser extent, diversity. Both showed congruent patterns of inter-individual divergence following the natural structure of the dataset. Thus, the faecal microbiome represents a good non-invasive proxy of the caecal microbiome, making it suitable for detecting biologically relevant patterns. However, care should be taken when analysing mixed datasets containing both faecal and caecal samples.
- MeSH
- cékum MeSH
- feces MeSH
- myši MeSH
- RNA ribozomální 16S genetika MeSH
- savci MeSH
- střevní mikroflóra * MeSH
- zvířata MeSH
- Check Tag
- myši MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- RNA ribozomální 16S MeSH
In this study, we addressed the origin of chicken gut microbiota in commercial production by a comparison of eggshell and feed microbiota with caecal microbiota of 7-day-old chickens, using microbiota analysis by 16S rRNA sequencing. In addition, we tested at which timepoint during prenatal or neonatal development it is possible to successfully administer probiotics. We found that eggshell microbiota was a combination of environmental and adult hen gut microbiota but was completely different from caecal microbiota of 7-day-old chicks. Similarly, we observed that the composition of feed microbiota was different from caecal microbiota. Neither eggshell nor feed acted as an important source of gut microbiota for the chickens in commercial production. Following the experimental administration of potential probiotics, we found that chickens can be colonised only when already hatched and active. Spraying of eggs with gut anaerobes during egg incubation or hatching itself did not result in effective chicken colonisation. Such conclusions should be considered when selecting and administering probiotics to chickens in hatcheries. Eggshells, feed or drinking water do not act as major sources of gut microbiota. Newly hatched chickens must be colonised from additional sources, such as air dust with spores of Clostridiales. The natural colonisation starts only when chickens are already hatched, as spraying of eggs or even chickens at the very beginning of the hatching process did not result in efficient colonisation.
- Klíčová slova
- caecum, chicken, eggshell, feed, hatchery, microbiota,
- Publikační typ
- časopisecké články MeSH
In this study, we compared the caecal microbiota composition of egg-laying hens from commercial production that are kept indoors throughout their whole life with microbiota of hens kept outdoors. The microbiota of outdoor hens consisted of lower numbers of bacterial species than the microbiota of indoor hens. At the phylum level, microbiota of outdoor hens was enriched for Bacteroidetes (62.41 ± 4.47% of total microbiota in outdoor hens and 52.01 ± 6.27% in indoor hens) and Proteobacteria (9.33 ± 4.99% in outdoor and 5.47 ± 2.24% in indoor hens). On the other hand, Firmicutes were more abundant in the microbiota of indoor hens (33.28 ± 5.11% in indoor and 20.66 ± 4.41% in outdoor hens). Horizontally transferrable antibiotic resistance genes tetO, tet(32), tet(44), and tetW were also less abundant in the microbiota of outdoor hens than indoor hens. A comparison of the microbiota composition at the genus and species levels pointed toward isolates specifically adapted to the two extreme environments. However, genera and species recorded as being similarly abundant in the microbiota of indoor and outdoor hens are equally as noteworthy because these represent microbiota members that are highly adapted to chickens, irrespective of their genetics, feed composition, and living environment.
- Klíčová slova
- backyard chicken, caecum, chicken microbiota, environment, microbiome,
- Publikační typ
- časopisecké články MeSH
The effect of the dietary inclusion of Hermetia illucens larvae meal on the diversity of the methanogenic archaea in the caecum of laying hens (Hy-line Brown) was investigated using molecular methods. A total of 27 hens, selected equally for slaughter from 162 birds which were divided equally into 3 treatment groups including control group C with a diet containing corn-soybean meal and 2 experimental groups, HI25 and HI50, in which 25% and 50% of the soybean meal protein was replaced by the protein from a Hermetia illucens larvae meal, respectively. At 40 weeks of age, the methanogenic community of caecal content of 9 hens per group was analyzed using a 16S rRNA gene clone library. A total of 108 positive clones, 35 from the control group, 44 from the HI25 group and 29 from the HI50 group, were analyzed by Sanger sequencing. Methanomicrobiales, Methanobacteriales and Methanomassiliicoccales were the main orders found in groups C and HI25. Methanomassiliicoccales was absent in the HI50 group, which was dominated by the order Methanobacteriales. At the species level, Methanobrevibacter woesei was the most prevalent species in all three groups regardless of diet. Some species were found exclusively either in the control group (Methanogenic archaeon CH1270) or in the HI25 group (Methanorbis furvi strain Ag1). Methanogenic diversity was significantly lower in the HI50 group compared to the control and HI25 groups and Methanomassiliicoccaceae archaeon DOK was completely suppressed in HI50 group. Our preliminary results indicate that ingestion of Hermetia illucens larvae meal has considerable effect on the methanogenic community, promoting the abundance of Methanobrevibacter woesei and suppressing Methanomassiliicoccaceae archaeon DOK in the caeca of laying hens.
- Klíčová slova
- Egg layers, Insects, Methane,
- MeSH
- Archaea * klasifikace genetika MeSH
- cékum * mikrobiologie MeSH
- dieta veterinární MeSH
- krmivo pro zvířata analýza MeSH
- kur domácí * mikrobiologie MeSH
- larva chemie MeSH
- methan metabolismus MeSH
- náhodné rozdělení MeSH
- RNA ribozomální 16S analýza genetika MeSH
- střevní mikroflóra * účinky léků MeSH
- zvířata MeSH
- Check Tag
- ženské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- Názvy látek
- methan MeSH
- RNA ribozomální 16S MeSH
