Galliscardovia ingluviei gen. nov., sp. nov., a thermophilic bacterium of the family Bifidobacteriaceae isolated from the crop of a laying hen (Gallus gallus f. domestica).

Bacteria with potential probiotic applications are not yet sufficiently explored, even for animals with economic importance. Therefore, we decided to isolate and identify representatives of the family Bifidobacteriaceae, which inhabit the crop of laying hens. During the study, a fructose-6-phosphate phosphoketolase-positive strain, RP51T, with a regular/slightly irregular and sometimes an S-shaped slightly curved rod-like shape, was isolated from the crop of a 13 -month-old Hisex Brown hybrid laying hen. The best growth of the Gram-stain-positive bacterium, which was isolated using Bifidobacterium-selective mTPY agar, was found out to be under strictly anaerobic conditions, however an ability to grow under microaerophilic and aerobic conditions was also observed. Sequencing of the almost complete 16S rRNA gene (1444 bp) showed Alloscardovia omnicolens CCUG 31649T and Bombiscardovia coagulans BLAPIII/AGVT to be the most closely related species with similarities of 93.4 and 93.1 %, respectively. Lower sequence similarities were determined with other scardovial genera and other representatives of the genus Bifidobacterium. Taxonomic relationships with A. omnicolens and other members of the family Bifidobacteriaceaewere also demonstrated, based on the sequences of dnaK, fusA, hsp60 and rplB gene fragments. Low sequence similarities of phylogenetic markers to related scardovial genera and bifidobacteria along with unique features of the bacterial strain investigated within the family Bifidobacteriaceae(including the lowest DNA G+C value (44.3 mol%), a unique spectrum of cellular fatty acids and polar lipids, cellular morphology, the wide temperature range for growth (15-49 °C) and habitat) clearly indicate that strain RP51T is a representative of a novel genus within the family Bifidobacteriaceae for which the name Galliscardovia ingluviei gen. nov., sp. nov. (RP51T=DSM 100235T=LMG 28778T=CCM 8606T) is proposed.

High-throughput sequencing technology to reveal the composition and function of cecal microbiota in Dagu chicken.

BACKGROUND: The chicken gut microbiota is an important and complicated ecosystem for the host. They play an important role in converting food into nutrient and energy. The coding capacity of microbiome vastly surpasses that of the host's genome, encoding biochemical pathways that the host has not developed. An optimal gut microbiota can increase agricultural productivity. This study aims to explore the composition and function of cecal microbiota in Dagu chicken under two feeding modes, free-range (outdoor, OD) and cage (indoor, ID) raising. RESULTS: Cecal samples were collected from 24 chickens across 4 groups (12-w OD, 12-w ID, 18-w OD, and 18-w ID). We performed high-throughput sequencing of the 16S rRNA genes V4 hypervariable regions to characterize the cecal microbiota of Dagu chicken and compare the difference of cecal microbiota between free-range and cage raising chickens. It was found that 34 special operational taxonomic units (OTUs) in OD groups and 4 special OTUs in ID groups. 24 phyla were shared by the 24 samples. Bacteroidetes was the most abundant phylum with the largest proportion, followed by Firmicutes and Proteobacteria. The OD groups showed a higher proportion of Bacteroidetes (>50 %) in cecum, but a lower Firmicutes/Bacteroidetes ratio in both 12-w old (0.42, 0.62) and 18-w old groups (0.37, 0.49) compared with the ID groups. Cecal microbiota in the OD groups have higher abundance of functions involved in amino acids and glycan metabolic pathway. CONCLUSION: The composition and function of cecal microbiota in Dagu chicken under two feeding modes, free-range and cage raising are different. The cage raising mode showed a lower proportion of Bacteroidetes in cecum, but a higher Firmicutes/Bacteroidetes ratio compared with free-range mode. Cecal microbiota in free-range mode have higher abundance of functions involved in amino acids and glycan metabolic pathway.

Characterisation of caecum and crop microbiota of Indian indigenous chicken targeting multiple hypervariable regions within 16S rRNA gene.

A comparative analysis of caecum and crop microbiota of chick, grower and adult stages of Indian indigenous chickens was conducted to investigate the role of the microbiota of the gastrointestinal tract, which play an important role in host performance, health and immunity. High-throughput Illumina sequencing was performed for V3, V4 and V4-V6 hypervariable regions of the 16S rRNA gene. M5RNA and M5NR databases under MG-RAST were used for metagenomic datasets annotation. In the crop, Firmicutes (~78%) and Proteobacteria (~16%) were the predominant phyla whereas in the caecum, Firmicutes (~50%), Bacteroidetes (~29%) and Actinobacteria (~10%) were predominant. The Shannon-Wiener diversity index suggested that sample richness and diversity increased as the chicken aged. For the first time, the presence of Lactobacillus species such as L. frumenti, L. antri, L. mucosae in the chicken crop along with Kineococcus radiotolerans, Desulfohalobium retbaense and L. jensenii in the caecum are reported. Many of these bacterial species have been found to be involved in immune response modulation and disease prevention in pigs and humans. The gut microbiome of the indigenous chicken was enriched with microbes having probiotic potential which might be essential for their adaptability.

Potential use of caprylic acid in broiler chickens: effect on Salmonella enteritidis.

The effect of dietary caprylic acid (CA) on Salmonella Enteritidis, as well as the surface treatment of chicken skin contaminated with Salmonella Enteritidis was evaluated. To evaluate the dietary effect of CA on Salmonella Enteritidis, the individually housed broiler chickens (n=48) were divided into 4 groups (positive control, negative control, 2.5 g/kg of CA in the feed, and 5 g/kg of CA in the feed). The feed of all groups, except the negative control, was artificially contaminated with Salmonella Enteritidis ATCC 13076 (10(7) colony-forming units/100 g of feed). Both concentrations of dietary CA significantly decreased counts of Salmonella Enteritidis in the crop and cecum of experimental chickens (p<0.05). The effect of CA in the crop contents was more pronounced than in the cecum. Surface treatment of chilled chicken halves with CA at 1.25 and 2.5 mg/mL significantly decreased Salmonella Enteritidis contamination of chicken skin (p<0.05). The sensory evaluation of the skin and meat showed that treatment of the skin with 1.25 mg/mL of CA worsened odor and appearance of the chicken skin, while sensory traits of chicken meat were not significantly affected. Taste and overall acceptability was not influenced by CA in both meat and skin. Treatment of the skin with 2.5 mg/mL of CA resulted in more pronounced changes of the skin odor and appearance. In conclusion, dietary CA reduced carriage of Salmonella Enteritidis in chickens, whereas surface-treatment reduced or eliminated Salmonella Enteritidis contamination in the processed bird.

Evaluation of feed grade sodium bisulfate impact on gastrointestinal tract microbiota ecology in broilers via a pyrosequencing platform.

The gastrointestinal microbial community in broiler chickens consists of many different species of bacteria, and the overall microbiota can vary from bird to bird. To control pathogenic bacteria in broilers and improve gut health, numerous potential dietary amendments have been used. In this study, we used a pyrosequencing platform to evaluate the effect of sodium bisulfate on microbiota of the crop, cecum, and ileum of broiler chickens grown over several weeks. The diversity information in each digestive organ sample exhibited considerable variation and was clearly separable, suggesting distinct bacterial populations. Although no apparent microbial clustering occurred between the control and the dietary treatments, we did observe shifts in overall microbiota populations in the crop, ileum, and ceca as well as changes in specific microorganisms such as Bacteroides, Clostridium, and Lactobacillus species that were identified as birds became older.

Correlations between changes in intestinal microbiota composition and performance parameters in broiler chickens.

Growing male Cobb broiler chickens were fed on diets supplemented with additives reported as able to influence intestinal microbiota composition. The diets used were a balanced commercial diet (no additive), inulin (20 g/kg), fructose caramel (FC, 20 g/kg) and the garlic derivative PTS-O (propyl propane thiosulfonate, 45 and 90 mg/kg diet). The composition of the intestinal microbiota was analysed by qPCR at different points of the intestinal tract, and a number of nutritional parameters were also determined. The relative amounts of bacteroides (bacteroides/total bacteria) in the ileal contents correlated (p < 0.05) positively with faecal NDF, ADF, hemicellulose and cellulose digestibility. The relative amounts of Escherichia-Shigella (Escherichia-Shigella/total bacteria) in the crop contents correlated (p = 0.05) negatively with weight gain of broilers. Faecal N digestibility correlated (p < 0.05) negatively with total bacteria in the ileal contents of chickens. The relative amounts of Escherichia-Shigella (Escherichia-Shigella/total bacteria) in the caecal contents correlated (p = 0.05) negatively with faecal fat digestibility of broilers. Total bacteria in ileal or caecal contents of growing chickens correlated (p < 0.05) negatively with ileal N digestibility. The results here reported suggest that positive or negative correlations can be found between performance parameters and changes in intestinal microbiota composition of growing broiler chickens.

Control of Salmonella Enteritidis in turkeys using organic acids and competitive exclusion product.

AIM: To evaluate the use of organic acids (OAs) and competitive exclusion (CE) product administered continuously in the feed and transiently in drinking water on the control of Salmonella enterica subspecie enterica serotype Enteritidis (SE) prior to slaughter. METHODS AND RESULTS: The influence of treatments were evaluated on pH, population of the lactic acid bacteria (LAB) and bacteria of the family Enterobacteriaceae, concentration of volatile fatty acids and SE colonization in the crop and caecum. The birds were challenged with SE 24 h before being slaughtered, and then, the caeca and crop were removed and subjected to SE counts. Continuous administration of OAs reduced the population of bacteria from the Enterobacteriaceae family in both crop and caecum, positively influenced the butyric acid concentration and reduced SE colonization in the caecum. The diet supplemented with CE product positively influenced the quantity of LAB in the crop and caecum, elevated the butyric acid concentration and reduced both Enterobacteriaceae quantity and SE colonization in the caecum. There was no effect from administering the treatments via drinking water on the variables measured. CONCLUSIONS: Continuous supplementation in feed with OAs and CE product reduced SE colonization of the caeca. SIGNIFICANCE AND IMPACT OF THE STUDY: Supplementation of OAs and CE product in diet to turkeys can reduce the SE load, potentially leading to a lower contamination risk of meat during slaughter.

Bacteriophage-induced reduction in Salmonella Enteritidis counts in the crop of broiler chickens undergoing preslaughter feed withdrawal.

Salmonella food poisoning is a public health problem. Feed withdrawal from broiler chickens before slaughter can favor the multiplication of Salmonella in the cecum and crop of contaminated animals and subsequently lead to contamination of carcasses in the processing plant. In the present study, a cocktail of lytic bacteriophages isolated from sewage water was orally administered to 45-d-old broiler chickens 1 h after they received an oral dose of 10(7) cfu/mL Salmonella enterica subspecies enterica serotype Enteritidis. Immediately after phage administration and 30 min, 1, 3, 6, and 12 h thereafter, groups of chicken were killed. Ceca and crops were analyzed for the presence of Salmonella. At 3 h posttreatment, there were 10(3) cfu/g and 10(1) cfu/g of cecal and crop suspension, respectively. At 6 h after treatment, the number of Salmonella was 10(3) cfu/g in the cecal suspension, but below the detection limit in the crops. Our results suggest that bacteriophage therapy may be able to reduce the contamination of chicken carcasses by reducing the preslaughter load of Salmonella in the birds.

Lactobacillus gigeriorum sp. nov., isolated from chicken crop.

In the early 1980s, a facultatively anaerobic, non-motile, short rod, designated 202(T), was isolated from a chicken crop and identified as a homofermentative lactic acid bacterium. Phylogenetic analysis based on the 16S rRNA gene sequence revealed that the strain was affiliated with the genus Lactobacillus, clustering within the Lactobacillus acidophilus-delbrueckii group. In this analysis, strain 202(T) appeared to be most closely related to the type strains of Lactobacillus intestinalis and Lactobacillus amylolyticus, with gene sequence similarities of 96.1 and 96.2 %, respectively. Strain 202(T) was found to differ from these two species, however, when investigated by multilocus sequence analysis, and it also differed in terms of some of its metabolic properties. On the basis of these observations, strain 202(T) is considered to represent a novel species in the genus Lactobacillus, for which the name Lactobacillus gigeriorum sp. nov. is proposed; the type strain is 202(T) ( = CRBIP 24.85(T) = DSM 23908(T)).

FISH analysis of Lactobacillus biofilms in the gastrointestinal tract of different hosts.

AIMS: To investigate the spatial organization of endogenous and exogenously applied Lactobacillus communities at specific locations in the adult gastrointestinal tract of different hosts. METHODS AND RESULTS: Samples of the human, murine and avian gastrointestinal tract of subjects that received or not received a Lactobacillus probiotic were analysed by fluorescence in situ hybridization (FISH) with rRNA-targeted probes. High levels of endogenous lactobacilli were observed on the nonsecretory, stratified squamous epithelia present in the forestomach of mice and crop of chickens, respectively. These epithelial associations showed characteristics of bacterial biofilms, i.e. bacteria attached to a surface and embedded in a matrix of extracellular polymeric substances. In other regions of the analysed intestines, lactobacilli seemed to occur mainly as dispersed bacterial cells or as microcolonies. Exogenous administration of a Lactobacillus probiotic did increase the levels of loosely adherent Lactobacillus cells detected. However, the probiotic strains were unable to establish themselves inside the gastrointestinal biofilms. CONCLUSIONS: Gastrointestinal biofilms of lactobacilli occur only in specific niches in certain hosts, such as the murine forestomach and avian crop. SIGNIFICANCE AND IMPACT OF THE STUDY: Biofilm formation by lactobacilli in specific parts of animal gastrointestinal tracts was documented for the first time by FISH.

Validation of a real-time polymerase chain reaction assay for the detection of Salmonella in crops of broiler chickens.

Salmonella is one of the frequent causes of bacterial foodborne diseases with major public health impact in industrialized countries. Food-producing animals, in particular poultry, are major sources of human salmonellosis. Salmonella is normally found in the gastrointestinal tract of animals and can contaminate the carcass during the slaughtering process. In poultry, crops are also colonized by this pathogen. Crops are more likely to get ruptured during evisceration and contaminate the carcass and therefore present a health risk to consumers. Reducing Salmonella colonization in crops could decrease carcass contamination and is considered a potential preharvest critical control point in poultry production. Furthermore, rapid and reliable diagnostic methods to detect Salmonella are needed to monitor crop colonization to help ensure food safety. However, detection of Salmonella by bacteriological methods is time consuming and labor intensive and is not suitable for routine screening of a large number of samples. Therefore, this study was undertaken to validate a real-time PCR (RPCR) assay for the detection of Salmonella spp. in crop samples of broiler chickens. In total, 997 crop samples (35 spiked, 962 field) were processed by both RPCR and culture. The RPCR correctly identified all spiked crop samples. Out of 962 field crop samples, 100 tested positive by RPCR and 88 tested positive by culture for Salmonella, giving a sample level prevalence of 10.4 % (95% CI: 8.54 to 12.50%) and 9.1% (95% CI: 7.40 to 11.15%), respectively. The agreement beyond chance between RPCR and culture was 92% (P < 0.001) and 100% (P < 0.001) for field and spiked samples, respectively. Compared with culture, the sensitivity and specificity of RPCR were 98.86 and 98.51% for field samples and 100 and 100% for spiked samples, respectively. Where bacterial speciation is required, only the positive samples would be cultured. Therefore, RPCR can be used as a good screening tool for Salmonella spp. in crops by eliminating the time-consuming and labor-intensive culture of negative samples.

Comparison of Campylobacter levels in crops and ceca of broilers at slaughter.

A considerable fraction of the poultry carcasses becomes contaminated with Campylobacter by cross-contamination from the digestive tract of colonized broilers at slaughter. Campylobacter in the crop may serve as a possible source of cross-contamination, because the crop may contain high numbers of Campylobacter and is more likely to rupture during the slaughtering process than intestines. In this study, the correlation between Campylobacter colonization levels in crop and cecum was assessed in 48 broilers of 31 days of age. In addition, the effect of drinking water supplemented with 0.2% volatile fatty acid (VFA) on these Campylobacter colonization levels was studied. No correlation between crop and cecal colonization levels was found (p = 0.09; P = 0.71), indicating that future studies on cross-contamination should include an examination of not only cecal colonization levels but also crop colonization levels. Supplementation of drinking water with VFA did not result in a significant reduction of colonization levels in either the crop (P = 0.50) or the ceca (P = 0.92), indicating that this is not an effective measure to reduce cross-contamination at slaughter.

Effect of Lactobacillus acidophilus D2/CSL (CECT 4529) supplementation in drinking water on chicken crop and caeca microbiome.

In this study we gained insights into the effects of the supplementation with Lactobacillus acidophilus D2/CSL (CECT 4529) in the chicken drinking water on crop and caeca microbiomes. The probiotic was supplemented at the concentrations of 0.2 g Lactobacillus acidophilus/day/bird and 0.02 g Lactobacillus acidophilus/day/bird and its effect on the crop and caeca microbiomes was assessed at 14 and 35 days of rearing. The results showed that mean relative abundance of Lactobacillus acidophilus in the caeca did not show significative differences in the treated and control birds, although Lactobacillus acidophilus as well as Faecalibacterium prausnitzii, Lactobacillus crispatus and Lactobacillus reuteri significantly increased over time. Moreover, the treatment with the high dose of probiotic significantly increased the abundance of Clostridium asparagiforme, Clostridium hathewayi and Clostridium saccharolyticum producing butyrate and other organic acids supporting the chicken health. Finally, at 35 days, the Cell division protein FtsH (EC 3.4.24.-) and the Site-specific recombinase genes were significantly increased in the caeca of birds treated with the high dose of probiotic in comparison to the control group. The results of this study showed that Lactobacillus acidophilus D2/CSL (CECT 4529) supplementation in the drinking water at the concentrations of 0.2 and 0.02 g Lactobacillus acidophilus/day/bird improved beneficial microbes and functional genes in broiler crops and caeca. Nevertheless, the main site of action of the probiotic is the crop, at least in the early stage of the chicken life. Indeed, at 14 days Lactobacillus acidophilus was significantly higher in the crops of chickens treated with the high dose of LA in comparison to the control (14.094 vs 1.741%, p = 0.036).

Evaluation of associations between feed withdrawal and other management factors with Salmonella contamination of broiler chickens at slaughter in Alberta.

Salmonellosis is one of the most common bacterial foodborne diseases of public health concern in industrialized countries. Poultry products are considered an important source of Salmonella-related foodborne disease in humans. This study was undertaken to evaluate the relationship between various management factors including feed withdrawal and transportation time with Salmonella contamination in crops, ceca, and carcasses of broiler chickens at slaughter in Alberta. Using a two-stage sampling procedure, 30 matched crop and cecal samples before evisceration and an additional 30 neck skin samples after final wash of broiler chickens were collected at slaughter. A questionnaire was administered at the time of sampling to collect information on flock management risk factors. Cecal contents were individually screened with Salmonella-specific real-time PCR to detect positive flocks, and all cecal, crop, and neck skin samples from positive flocks were processed further for Salmonella isolation and characterization. The flock prevalence of Salmonella was 57.1% and within-flock prevalence of Salmonella for positive flocks was 17.2, 8.1, and 53.9% for ceca, crops, and neck skins, respectively. Salmonella Hadar was the most common serovar identified from crops, ceca, and neck skins of broiler chickens tested. Longer transport (P = 0.04 for neck skins) and waiting time in-plant (P = 0.04 for crops, P = 0.03 for ceca) were identified as important risk factors for Salmonella contamination of broiler chickens at slaughter. Salmonella contamination of broiler chickens could potentially be minimized by reducing waiting time in-plant for flocks with longer transport time.

Prevalence of Campylobacter jejuni and Campylobacter coli in market-weight turkeys on-farm and at slaughter.

To monitor the effects of feed withdrawal on the prevalence of Campylobacter, market-weight turkeys from six farms were examined before and after perimarketing events (feed withdrawal, transport, and holding at the slaughterhouse). Prior to transport, birds (n = 30 per farm) were slaughtered on-farm, and viscera (crops, duodenum, jejunum, ileum, colon, ceca, gallbladder, and spleen) were removed on the premises. Within ca. 48 h, cohorts (n = 30 per farm) from the same flock were transported to a commercial abattoir, maintained in holding sheds, slaughtered, and the viscera were removed. No differences in the prevalence of Campylobacter spp. were evident when individual flocks were compared pre- and posttransport. However, when data for the six farms were combined, Campylobacter spp. were recovered (pre- versus posttransport) at comparable rates from the duodenum (74.7 versus 74.7%), ileum (87.3 versus 92.7%), ceca (64 versus 57%), colon (86.7 versus 80%), and spleen (0 versus 0%). After feed withdrawal, transport, and holding at the abattoir, there was an overall increase in Campylobacter spp. isolated from the gallbladder at the abattoir (14.7%) when compared with on-farm levels (0%, P < 0.05). When compared with on-farm levels (3%), the overall increase in Campylobacter spp. recovered from the crops of birds at the abattoir (24%) was significant (P < 0.05), which may be associated with a detectable decline in lactic acid in the emptied crop.

Examination of the source and extended virulence genotypes of Escherichia coli contaminating retail poultry meat.

Extraintestinal pathogenic Escherichia coli (ExPEC) are major players in human urinary tract infections, neonatal bacterial meningitis, and sepsis. Recently, it has been suggested that there might be a zoonotic component to these infections. To determine whether the E. coli contaminating retail poultry are possible extraintestinal pathogens, and to ascertain the source of these contaminants, they were assessed for their genetic similarities to E. coli incriminated in colibacillosis (avian pathogenic E. coli [APEC]), E. coli isolated from multiple locations of apparently healthy birds at slaughter, and human ExPEC. It was anticipated that the retail poultry isolates would most closely resemble avian fecal E. coli since only apparently healthy birds are slaughtered, and fecal contamination of carcasses is the presumed source of meat contamination. Surprisingly, this supposition proved incorrect, as the retail poultry isolates exhibited gene profiles more similar to APEC than to fecal isolates. These isolates contained a number of ExPEC-associated genes, including those associated with ColV virulence plasmids, and many belonged to the B2 phylogenetic group, known to be virulent in human hosts. Additionally, E. coli isolated from the crops and gizzards of apparently healthy birds at slaughter also contained a higher proportion of ExPEC-associated genes than did the avian fecal isolates examined. Such similarities suggest that the widely held beliefs about the sources of poultry contamination may need to be reassessed. Also, the presence of ExPEC-like clones on retail poultry meat means that we cannot yet rule out poultry as a source of ExPEC human disease.

Microbial community composition of the crop and ceca contents of laying hens fed diets supplemented with Chlorella vulgaris.

It is generally accepted that the intestinal microbiota plays an important role in sustaining health and productivity of animals. Chlorella vulgaris, a naturally occurring green microalga, is believed to influence performance and health, including bird reproduction and egg quality. The nutritive value of open or indoor cultured C. vulgaris depends upon the technological process used to treat the algal mass. In the present paper, it is presented and discussed how 2 differentially processed C. vulgaris powders (spray-dried: SD-CV; bullet-milled and spray-dried: BMSD-CV) affected crop and cecal microbiota in laying hens. Polymerase chain reaction-denaturing gradient gel electrophoresis (DGGE) of bacterial 16S rRNA gene fragments was applied. The diversity of the crop universal bacterial DGGE fingerprints was not affected (6.4 +/- 1.65, 5.4 +/- 1.19, and 5.5 +/- 1.35 in the control, SD-CV, and BMSD-CV, respectively). Most of the bands from the corresponding positions in the gels were closely related to Lactobacillus sp. The DGGE fingerprints of V2-V3 fragments of 16S rRNA of crop lactobacilli had lower diversity in the control hens (8.7 +/- 1.22) than in the SD-CV (9.2 +/- 1.77) and BMSD-CV (9.9 +/- 1.88); thus, feeding C. vulgaris resulted in increased lactobacilli diversity in crop. A band closely related to Lactobacillus ingluviei was present in 9 out of 12 hens in the control group but in only 1 bird in the SD-CV and in 5 out of 11 birds in the BMSD-CV, suggesting a negative effect of C. vulgaris on this lactobacillus. Feeding C. vulgaris to laying hens also resulted in increased bacterial community diversity in the ceca. No effect of the technological processing of the microalgae on the microbial diversity could be observed. The diversity of the ceca universal bacterial DGGE fingerprints was lower in the control group than in the SD-CV and BMSD-CV (5.6 +/- 1.72 vs. 9.16 +/- 2.64 and 9.31 +/- 2.41, respectively). Most of the sequences retrieved from the DGGE bands formed ceca that were closely related to Ruminococcaceae, Lachnospiraceae, and lactobacilli, giving further insight into still poorly discovered intestinal microbiota of laying hens.

Bacterial community in the crop of the hoatzin, a neotropical folivorous flying bird.

The hoatzin is unique among known avian species because of the fermentative function of its enlarged crop. A small-bodied flying foregut fermenter is a paradox, and this bird provides an interesting model to examine how diet selection and the gut microbiota contribute to maximizing digestive efficiency. Therefore, we characterized the bacterial population in the crop of six adult hoatzins captured from the wild. A total of 1,235 16S rRNA gene sequences were grouped into 580 phylotypes (67% of the pooled species richness sampled, based on Good's coverage estimator, with C(ACE) and Chao1 estimates of 1,709 and 1,795 species-level [99% identity] operational taxonomic units, respectively). Members of 9 of the approximately 75 known phyla in Bacteria were identified in this gut habitat; the Firmicutes were dominant (67% of sequences, belonging to the classes Clostridia, Mollicutes, and Bacilli), followed by the Bacteroidetes (30%, mostly in the order Bacteroidales), Proteobacteria (1.8%), and Lentisphaerae, Verrucomicrobia, TM7, Spirochaetes, Actinobacteria, and Aminanaerobia (all <0.1%). The novelty in this ecosystem is great; 94% of the phylotypes were unclassified at the "species" level and thus likely include novel cellulolytic lineages.

Crop immune response post-Salmonella enteritidis challenge in eight commercial egg-layer strains and specific-pathogen-free White Leghorn chickens.

The crop immune response against Salmonella Enteritidis (SE) challenge in eight commercial egg-layer strains (five white-egg layer and three brown-egg layer) and specific-pathogen-free (SPF) White Leghorn (WL) hens was investigated. Pre- and post-SE challenge mucosal immune responses within the crops were evaluated. Commercial layers and SPF WL hens were orally challenged with 10(8) CFU/ml SE PT13a and SE nalR PT13, respectively. Crop lavage samples were collected at weekly intervals from day 0 (pre-challenge) to day 25-27 postinfection (PI), and bacteriological examination was performed to monitor progression of SE infection. Crop lavage samples were analyzed for SE-lipopolysaccharide (LPS)-specific IgA using enzyme-linked immunosorbent assay (ELISA). H&E-stained slides of crop sections from day 34 PI and uninfected controls were assessed for lymphoid tissue via light microscopy. Lymphoid areas were graded based on morphology, size, and cellularity using a score 0 to 5 scale. The 0 to 5 (low to high) numerical values represented progressive increases in size and cellular density of lymphoid tissue. Bacterial culture results showed the highest percentage of SE-positive crop lavage samples from all hen groups at day 5-6 PI and day 11-12 PI. A progressive decline in percentage of SE-positive crop lavage samples did occur as time PI lengthened; however, at day 25-27 PI SE persisted in crop lavage samples from SPF WL hens and three commercial white-egg layer strains. A marked increase in SE-LPS-specific IgA was measured in crop lavage samples between day 0 and day 11-12 PI for all hen groups. Crop SE-LPS-specific IgA response remained elevated above day 0 baseline for the duration of the experiment. Well-defined score 3 to 5 lymphoid tissue aggregates were observed in crop tissue sections harvested at day 34 PI. Comparison of crop sections determined a 1.2-4.0 times increase in ratio of lymphoid tissue in day 34 PI SE-challenged hens vs. uninfected control hens.

Evaluation of an experimental chlorate product as a preslaughter feed supplement to reduce salmonella in meat-producing birds.

A study was conducted to evaluate the effect of experimental chlorate product (ECP) feed supplementation on Salmonella Typhimurium (ST) in the crop and ceca of market-age broilers. In trial 1, 160 market-age broilers were randomly assigned to 8 treatment groups and replicated twice, with 20 broilers per pen for 1 wk. Trial 2 used the same design, but used 80 market-age broilers with 10 broilers per pen. Treatments were as follows: 1) control feed + double-distilled drinking water (dd H(2)O); 2) control + 18.5% experimental zeolite carrier with dd H(2)O; 3 to 7) control feed supplemented with 0.5, 1.0, 5.0, 10.0, or 18.5% of a feed grade ECP + dd H(2)O; 8) control feed + 1x ECP (0.16% w/v; containing 15 mM chlorate ion equivalent) added to dd H(2)O. Seven-week-old broilers were provided experimental treatments for 7 d, killed, and then ceca and crops were removed and evaluated for ST. Broilers fed 5 to 18.5% ECP or water ECP had a significantly lower (P < 0.05) incidence of ST in the crop (36 to 38% and 14%, respectively) when compared with the control (60%). Broilers fed 10% ECP or water ECP had significantly lower ST crop concentrations (1.03 log(10) and 0.38 log(10) ST/g, respectively) when compared with broilers fed a control diet (1.54 log(10) ST/g). Crop and ceca ST incidence (32 to 48%) and concentration (1.00 to 1.82 log(10) ST/g) were significantly lower in broilers fed 5 to 18.5% ECP as compared with the control (78%; 2.84 log(10) ST/g). Broilers fed 5% or greater ECP had significantly higher water consumption (380 to 580 mL water/d) and litter moisture (31 to 56%) when compared with the control (370 mL water/d; 23% moisture). Only broilers fed 18.5% ECP had significantly lower 7-wk BW (2.77 kg of BW) when compared with the controls (3.09 kg of BW). Average daily gains were significantly depressed in broilers fed 10 or 18.5% ECP compared with the controls. These results indicate broilers supplemented with feed