Ceca Of Broiler Chickens Research Articles

Quantification of Faecalibacterium prausnitzii- and Subdoligranulum variabile-like bacteria in the cecum of chickens by real-time PCR

The intestinal microbial community is playing an important role in health and production performance of chickens. To understand the effect on the intestinal microflora induced by various feeding strategies, feed additives, infections, and intestinal disorders, it is important to have methods for quantifying potentially important bacteria in the intestine. We describe a real-time quantitative assay for detection and quantification of a whole group of Faecalibacterium prausnitzii and Subdoligranulum variabile-like bacteria, which has recently been found to dominate in the cecum of broiler chickens. The F. prausnitzii-S. variabile-like bacteria were quantified using a multiprobe assay in which one primer set was used to amplify DNA from all bacteria, whereas 2 probes detected all bacteria and the group of F. prausnitzii-S. variabile-like bacteria, respectively. The multiprobe assay accurately quantified the percentage of this group in a sample if it constituted more than approximately 5% of the total bacterial community. If the fraction of F. prausnitzii-S. variabile-like bacteria was lower than 5%, a duplex assay was applied in which the total bacteria were amplified in one tube and the F. prausnitzii-S. variabile-like group of bacteria was amplified in another tube using a specific forward primer. The F. prausnitzii-S. variabile-like group of bacteria was quantified in the cecum and ileum of conventional and organic raised chickens, in chickens kept in an isolator from 1 d of age, and in hatcher material. Quantification of this group of F. prausnitzii-S. variabile-like bacteria has not been performed before by real-time PCR, but results confirm previous results obtained by cloning and sequencing showing that the F. prausnitzii-S. variabile-like group of bacteria constitutes a major fraction of the cecal bacterial community in chickens. Furthermore, results indicate that the poultry farm environment plays a role in recruitment and development of these bacteria in the intestinal microflora.

Detection of Clostridium sp. and its Relation to Different Ages and Gastrointestinal Segments as Measured by Molecular Analysis of 16S rRNA Genes

The objective of this study was to establish a specific, sensitive and rapid PCR approach for the detection of Clostridium sp. at the genus level. Clostridium sp. in the duodenum, jejunum, ileum and cecum of broiler chickens were analyzed by 16S rRNA genes. The PCR detected the presence of Clostridium spp. in naturally contaminated intestinal samples. For the total gastrointestinal segments, 53.125, 65.625 and 59.375% samples were positive for naturally occurring Clostridium spp. at the ages 4, 14 and 30d, respectively. Analysis of the microbial contents indicated that Clostridium sp. was not consistently detected in all intestinal segments. These results can put in evidence the hypothesis that Clostridium spp. may be interfering in health and performance of chickens.

Broyler Piliçlerin Gastrointestinal Sistemindeki Salmonella spp’nin Polimeraz Zincir Reaksiyonu ile Belirlenmesi

Summary Salmonella spp. cause a number of diseases in broiler, ultimately leading to death or to a decrease in production or condemning of carcasses. Thus, there are needed to rapid, sensitive, and reliable methods for detection of Salmonella to reduce the occurrence of salmonellosis. The objective of the present study was to establish a specific, sensitive and rapid PCR protocol for the detection of Salmonella at the genus level in Iran poultry industries. Salmonella spp. in the duodenum, jejunum, ileum and cecum of broiler chickens were compared by molecular analysis of 16S rRNA genes. Among 96 samples of gastrointestinal segments, a total of 56.25, 12.5 and 6.25% samples were positive for naturally occurring Salmonella spp. by PCR method at 4, 14 and 30d of ages respectively. For cecum, a total of 87.5, 12.5 and 12.5% samples were positive for naturally occurring Salmonella spp. by PCR method at 4, 14 and 30d of ages respectively. Analysis of the microbial contents of the different small intestine segments examined indicated that Salmonella spp. was not consistently detected in all intestinal segments. The results indicated that at 14 and 30 d of ages, Salmonella spp. was not detectable in the most of studied segments. In fact, posterior segments exhibited higher levels of Salmonella spp. compared with the anterior segments especially cecum. As demonstrated here, the development of new tools for high-throughput analyses will be of key importance for these studies. This technique is simple and rapid and can be used on different chicken samples for routine detection of a large number of samples on a daily basis..

이눌로프리바이오틱스의 브로일러에 대한 비피더스균 활성 효과

브로일러에서 항균성장촉진을 위한 프리바이오틱스로서 이눌린의 활용가능성이 제시되었지만, 맹장에서 비피더스균의 활성효과를 개선할 필요가 있다. 이눌린은 공기 중 유통에 의한 변성 및 소화관 상부에서 맹장으로의 이동 시 낮은 통과율과 관련한 몇 가지 문제점이 있다. 이러한 문제를 해결하기 위해서 미세캡슐화, 이눌로프리바이오틱스가 브로일러의 맹장에서 비피도박테리아 균총을 증식시키고 살모넬라균의 집락을 낮출 수 있을 것이라는 가설을 세웠다. 국산 돼지감자로부터 추출한 이눌린을 미생물 배양한 후 대조구와 비교하였을 때, B. longum, B. bifidum, L. acidophilus, L. casei 균주의 성장률은 이눌린 첨가구가 높았으나, S. aureus, Cl. perfringens 균주의 증식은 처리구 간 차이가 없었다. 브로일러는 이눌로프리바이오틱스를 함유하지 않은 대조구 사료, 이눌로프리바이오틱스 0.5%, 이눌로프리바이오틱스 0.7%, 이눌로프리바이오틱스 1.0% 혼합사료를 섭취하였다. 이눌로프리바이오틱스를 섭취한 브로일러의 맹장에서 유익한 Bifidobacterium species는 대조구에 비해서 유의적으로 높았고, 유해한 미생물로 알려진 E. coli 와 Salmonella는 감소하였으나, 이눌로프리바이오틱스 처리구 사이에 있어서 Bifidobacterium species, E. coli 와 Salmonella 균수의 유의차는 없었다. 혈청 면역물질 IgG 함량은 이눌로프리바이오틱스 처리구가 대조구에 비해서 유의적으로 증가하였으나, 흉선지수는 이눌로프리바이오틱스 0.5% 첨가구를 제외한 이눌로프리바이오틱스 0.7%, 1.0% 처리구에서 유의적으로 증가하였다. 본 연구 결과는 돼지감자로부터 추출한 DP 26을 지닌 이눌린을 함유하는 이눌로프리바이오틱스를 브로일러 사료에 첨가, 급여하였을 때, 맹장에서 비피도 박테리아의 선택적인 증식 및 면역능력을 강화해 줌으로서, 유기축산을 위한 사료첨가용 항균성장촉진제로서 활용가능성을 시사해 준다. Recent studies have suggested that inulin might be utilized as a prebiotics for the promotion of antimicrobial growth, but a major obstacle to the use of inulin has been its low bifidogenic effects, which were initially observed in the ceca of broiler chickens. Inulin has some problems with related to denaturation in air and lowering passage rate from upper digestive tract to caecum. To solve this problems, a newly developed compound derived by microencapsulation, inuloprebiotics, was hypothesized to enrich cecal bifidobacterial populations and reduce the colonization levels of Salmonella in the ceca of broiler chickens. The in vitro growth of intestinal beneficial bacteria including Bifidobacterium longum, Bifidobacterium bifidum, Lactobacillus acidophilus, and Lactobacillus casei grew effectively on the medium containing inulin, whereas the growth of Streptococcus aureus and Clostridium perfringens was not differences among the treatment groups. Broiler chickens consumed chow diets containing 0.5%, 0.7% or 1.0% inuloprebiotics, or a control diet without inuloprebiotics supplementation. The chickens on the inuloprebioticssupplemented diets evidenced significantly higher cecal levels of Bifidobacterium and Lactobacillus species as compared with the chickens on the control diet. The population of cecal E. coli and Salmonella was specifically reduced as the result of treatment with inuloprebiotics. However, we noted no significant differences in Bifidobacterium species, E. coli and Salmonella counts among the inuloprebiotics treatment groups. The inuloprebiotics-supplemented diets induced an increase in the serum IgG concentration. The thymus index was significantly increased in the broiler chickens that consumed diets containing 0.7% or 1.0% inuloprebiotics, with the exception of the chickens consuming the diet supplemented with 0.5% inuloprebiotics. These results indicate that the inuloprebiotic preparations exerted an immune system-promoting effect or selectively enriched the cecal Bifidobacterium species populations in the broiler chickens, and also suggest that inuloprebiotics may prove useful as a stable natural antimicrobial agent.

Microbial community composition of the ileum and cecum of broiler chickens as revealed by molecular and culture-based techniques

The microbial communities of the ileum and cecum of broiler chickens from a conventional and an organic farm were investigated using conventional culture techniques as well as cloning and sequencing of 16S rRNA genes. Eighty-five percent of the 557 cloned sequences were <97% related to known cultured species. The chicken ileum was dominated by lactobacilli, whereas the cecum harbored a more diverse microbial community. The cecum was dominated by a large group of bacteria with hitherto no close cultured relatives but most closely related to Faecalibacterium prausnitzii. Approximately 49 and 20% of the cecal clones belonged to this cluster in conventional and organic broiler chickens, respectively. We were, however, able to recover a number of these phylotypes by cultivation, and the isolates were shown to be butyric acid producers. The investigation was a descriptive rather than a comparative study of 2 different rearing systems; however, several differences were observed. For instance, Clostridium perfringens was found in significantly higher numbers in the birds from the organic farm compared with the conventional broilers, probably due to the addition of salinomycin to the conventional feed. In the ileum, the abundance of the different Lactobacillus species differed between the 2 broiler types. The culture-based and culture-independent techniques complemented each other well. Strengths and limitations of the different methods are discussed.

Isomaltooligosaccharide increases cecal Bifidobacterium population in young broiler chickens

A newly developed compound derived by fermentation, isomaltooligosaccharide (IMO), was hypothesized to enrich cecal bifidobacterial populations and reduce colonization levels of Salmonella in the ceca of broiler chickens. Broiler starter diets were prepared with final IMO concentrations of 1% (wt/wt), 2% (wt/wt), and 4% (wt/wt) and a control diet without IMO supplementation. Chickens were divided into 4 groups and challenged with 108 cell of Salmonella enterica ser. Typhimurium with 200μg/mL nalidixic acid resistant (S. Typhimurium Nalr) after 7 d of placement. The experiment was done in 3 replications. IMO-supplemented diets resulted in significantly higher cecal bifidobacteria compared with the control diet (P < 0.05). However, there was no significant difference in bifidobacteria counts among the treatment groups. Chickens fed diets with 1% IMO had a significant 2-log reduction in the level of inoculated S. Typhimurium Nalr (P < 0.05) present in, the ceca compared with the control group, but no differences were found between the control group and the groups fed 2 or 4% IMO for S. Typhimurium Nalr. No differences in feed consumption, feed conversion, or feed efficiency compared with the control group were observed; however, the result showed a significant reduction in weight for birds fed 1% IMO diet compared with those fed the control diet.

16S rRNA-based analysis of microbiota from the cecum of broiler chickens.

The microbiota of the intestinal tract of chickens plays an important role in inhibiting the establishment of intestinal pathogens. Earlier culturing and microscopic examinations indicated that only a fraction of the bacteria in the cecum of chickens could be grown in the laboratory. Therefore, a survey of cecal bacteria was done by retrieval of 16S rRNA gene sequences from DNA isolated from the cecal content and the cecal mucosa. The ribosomal gene sequences were amplified with universal primers and cloned or subjected to temporal temperature gradient gel electrophoresis (TTGE). Partial 16S rRNA gene sequences were determined from the clones and from the major bands in TTGE gels. A total of 1,656 partial 16S rRNA gene sequences were obtained and compared to sequences in the GenBank. The comparison indicated that 243 different sequences were present in the samples. Overall, sequences representing 50 phylogenetic groups or subgroups of bacteria were found, but approximately 89% of the sequences represented just four phylogenetic groups (Clostridium leptum, Sporomusa sp., Clostridium coccoides, and enterics). Sequences of members of the Bacteroides group, the Bifidobacterium infantis subgroup, and of Pseudomonas sp. each accounted for less than 2% of the total. Sequences related to those from the Escherichia sp. subgroup and from Lactobacillus, Pseudomonas, and Bifidobacterium spp. were generally between 98 and 100% identical to sequences already deposited in the GenBank. Sequences most closely related to those of the other bacteria were generally 97% or less identical to those in the databases and therefore might be from currently unknown species. TTGE and random cloning indicated that certain phylogenetic subgroups were common to all birds analyzed, but sequence data from random cloning also provided evidence for qualitative and quantitative differences among the cecal microbiota of individual birds reared under very similar conditions.

Colonization of the Intestinal Tract by Clostridium Perfringens and Fecal Shedding in Diet-Stressed and Unstressed Broiler Chickens

Commercial broiler chicks were given a three-strain composite of bacitracin-resistant Clostridium perfringens by oral gavage and were sampled periodically to determine the dynamics of C. perfringens colonization of the intestinal tract of broiler chickens and fecal shedding. After gavage, the chicks were divided into two groups and placed in isolators, one group received a traditional corn-based diet, and the other group received the same diet supplemented with 50% rye to place the birds under dietary stress. The numbers of bacitracin-resistant C. perfringens in various parts of the intestinal tract, liver, and feces were determined using a selective plating medium containing bacitracin.In chickens on the corn-based or 50% rye diet, C. perfringens was isolated infrequently from the various parts of the intestinal tract, liver, or fecal droppings during the first 36 h following the last gavage. For the 24 chickens on each of the two diets that were sampled from 2 to 21 d after gavage, C. perfringens was recovered more frequently from the crop, proventriculus, duodenum, jejunum, ileum, ceca, and feces, but not the gizzard, of birds on the 50% rye diet as compared to those on the corn-based diet. From 2 to 21 d, the intestinal numbers of C. perfringens in contaminated birds on the corn-based diet were ≤log10 6.2 and did not increase in any portion of the intestinal tract. Numbers of C. perfringens during this time period increased 3.3 to 4.9 log factors in the ileum, ceca, and feces of birds on the 50% rye diet to as high as log10 7.1 to 7.9 at 21 d. This study confirms that addition of rye to the diet of chickens can increase the numbers of C. perfringens in the ceca of broiler chickens and extends these findings to demonstrate increases in the numbers and frequency of recovery of C. perfringens in other parts of the intestinal tract.

Physical, chemical, and microbiological changes in the ceca of broiler chickens subjected to incremental feed withdrawal

Trials were conducted to determine the effect of feed withdrawal on the weight, pH, native bacterial flora, and the persistence of Salmonella typhimurium in the ceca of market-age broilers. Broilers were provided medicated or unmedicated feed and then were subjected to feed withdrawal for 0 to 24 h in transportation crates or on litter. After feed withdrawal, broilers were stunned, bled, scalded, and picked. One cecum from each bird was aseptically removed and weighed. The cecum was then blended in 20 mL of distilled water, and the pH of the blended suspension was measured. The number of total aerobes, Enterobacteriaceae, S. typhimurium, and lactic acid bacteria in the suspension were enumerated on the appropriate bacteriological media. Results indicated that up to 24 h of feed withdrawal produced no significant change in cecal weight and that cecal pH varied by up to 0.3 units during feed withdrawal. There were significant increases in the population of Enterobacteriaceae during feed withdrawal in Trials 2 and 3, and there was a significant increase in the population of cecal aerobes in Trial 3. Feed withdrawal produced significant decreases in the population of lactic acid bacteria in all trials, but no significant change in the population of S. typhimurium occurred during feed withdrawal. There were no significant differences in cecal weight, pH, native bacteria populations, or S. typhimurium populations between broilers that were subjected to feed withdrawal on litter or in crates. Findings indicate that feed withdrawal does not always effectively evacuate the contents of the ceca and that the ceca of broilers subjected to feed withdrawal can remain a source of foodborne bacterial pathogens.

Presence of Salmonella in the crop and ceca of broiler chickens before and after preslaughter feed withdrawal

Recent studies have suggested that crop contents may serve as an important source of Salmonella carcass contamination within processing plants. During the present study, we evaluated the effect of preslaughter feed withdrawal on the presence of Salmonella in the crops of broilers from nine commercial broiler flocks reared in individual growout houses. Crops were collected aseptically from 40 randomly selected broilers in each flock before feed removal and at the end of the feed withdrawal period, immediately before capture and transport to the processing plant. Similarly, the ceca were collected before and after feed withdrawal in six of the nine broiler flocks. The presence of Salmonella in the crops and ceca was determined by enrichment culture in tetrathionate broth followed by culture on brilliant green agar. The incidence of Salmonella in crop contents increased significantly (P < 0.05) in five of the nine flocks during feed withdrawal. The total number of Salmonella contaminated crops from all nine flocks increased significantly (P < 0.005) from 7/360 (1.9%) before feed removal to 36/359 (10.0%) at the end of feed withdrawal. The increased incidence of Salmonella in the crop contents was associated with an increased tendency of the broilers to consume contaminated rearing house litter during feed withdrawal. The incidence of Salmonella in the ceca increased nonsignificantly from 14/240 (5.8%) before feed removal to 19/240 (7.9%) at the end of feed withdrawal. The results indicate that the incidence of Salmonella crop contamination may increase as much as fivefold during preslaughter feed withdrawal and represent a critical preharvest control point in reducing Salmonella entry into the processing plant.

Effect of Butyric or Lactic Acid on the In vivo Colonization of Salmonella typhimurium

Two groups of newly hatched chicks received standard broiler rations supplemented with 0.6% acid (either butyric or lactic) continuously starting at one day of age, while a control group received unsupplemented feed. At two days of age, chicks were inoculated by oral gavage with 1 mL of 106 CFU Salmonella typhimurium. Ceca were obtained from six chicks of each group at day 7, 14, and 21. After seven days there were no differences in level of Salmonella colonization among the supplemented and control groups. After fourteen days, lactic acid decreased colonization by 1.6 logs (P < .05), while no significant decrease was observed with butyric acid. After twenty-one days, both acids had significantly reduced intestinal colonization; butyric and lactic acid produced 1.67 and 1.95 log reductions, respectively. There were no significant differences in body weights among the groups at day 21. It is important to demonstrate that the level of Salmonella in the digestive tract and ceca of broiler chickens can be significantly reduced by the addition of selected carbohydrates to the water or feed. Reduced levels in the intestines means less salmonellae to be spread around in the grow house and during processing, and therefore less contaminated final product.