共查询到20条相似文献，搜索用时 15 毫秒
1.
本试验分析了一株肠源枯草芽孢杆菌生长特性,耐酸、胆盐、高温和重金属性能以及产蛋白酶、淀粉酶的能力。结果表明:菌株最大生长浓度出现在22 h左右。菌株在pH 3.0营养肉汤培养基中培养3 h,存活率为58.6%,培养时间延长至6 h,存活率仍能达到47.5%。在胆盐浓度为0.3%,培养4 h后枯草芽孢杆菌存活率为65.5%,8 h后的存活率仍能达到40.4%。在90℃下,处理10 min成活率为61.8%,处理20 min后仍能达到33.3%。当Cu离子和Zn离子浓度为500 mg/L时,菌株生长量相当于对照的107.6%和86.7%。菌株培养48 h后上清液的淀粉酶活性为1.89 U,蛋白酶活性达到655.2 U。结果表明,本枯草芽孢杆菌具备较好的生长与抗逆特性和较高的酶活力,具备作为益生菌的潜在特质。 相似文献
2.
Competitive exclusion by Bacillus subtilis spores of Salmonella enterica serotype Enteritidis and Clostridium perfringens in young chickens 总被引：3，自引：0，他引：3
Cost effective control of avian diseases and food borne pathogens remains a high priority for all sectors of the poultry industry with cleansing and disinfection, vaccination and competitive exclusion approaches being used widely. Previous studies showed that Bacillus subtilis PY79(hr) was an effective competitive exclusion agent for use in poultry to control avian pathogenic Escherichia coli serotype O78:K80. Here we report experiments that were undertaken to test the efficacy of B. subtilis PY79(hr) in the control of Salmonella enterica serotype Enteritidis and Clostridium perfringens in young chickens. To do this, 1-day-old and 20-day-old specific pathogen free (SPF) chicks were dosed with a suspension of B. subtilis spores prior to challenge with S. Enteritidis (S1400) and C. perfringens, respectively. For both challenge models, a single oral inoculum of 1x10(9) spores given 24h prior to challenge was sufficient to suppress colonisation and persistence of both S. Enteritidis and C. perfringens. In particular, the faecal shedding of S. Enteritidis, as measured by a semi-quantitative cloacal swabbing technique, was reduced significantly for the 36 days duration of the experiment. B. subtilis persisted in the intestine although with decreasing numbers over the same period. These data add further evidence that B. subtilis spores may be effective agents in the control of avian diseases and food borne pathogens. 相似文献
3.
4.
Setta A Barrow PA Kaiser P Jones MA 《Veterinary immunology and immunopathology》2012,146(3-4):212-224
Poultry-derived food is a common source of infection of human with the non-host-adapted salmonellae while fowl typhoid and pullorum disease are serious diseases in poultry. Development of novel immune-based control strategies against Salmonella infection necessitates a better understanding of the host-pathogen interactions at the cellular level. Intestinal epithelial cells are the first line of defence against enteric infections and the role of macrophages is crucial in Salmonella infection and pathogenesis. While gene expression following Salmonella infection has been investigated, a comparison between different serovars has not been, as yet, extensively studied in poultry. In this study, chicken macrophage-like cells (HD11) and chick kidney epithelial cells (CKC) were used to study and compare the immune responses and mechanisms that develop after infection with different Salmonella serotypes. Salmonella serovars Typhimurium, Enteritidis, Hadar and Infantis showed a greater level of invasion and/or uptake characters when compared with S. Pullorum or S. Gallinarum. Nitrate and reactive oxygen species were greater in Salmonella-infected HD11 cells with the expression of iNOS and nuclear factor-κB by chicken macrophages infected with both systemic and broad host range serovars. HD11 cells revealed higher mRNA gene expression for CXCLi2, IL-6 and iNOS genes in response to S. Enteritidis infection when compared to S. Pullorum-infected cells. S. Typhimurium- and S. Hadar-infected HD11 showed higher gene expression for CXCLi2 versus S. Pullorum-infected cells. Higher mRNA gene expression levels of pro-inflammatory cytokine IL-6, chemokines CXCLi1 and CXCLi2 and iNOS genes were detected in S. Typhimurium- and S. Enteritidis-infected CKC followed by S. Hadar and S. Infantis while no significant changes were observed in S. Pullorum or S. Gallinarum-infected CKC. 相似文献
5.
6.
枯草芽孢杆菌属于革兰氏阳性菌,非致病菌,其芽孢是其一种休眠体,能抵御外界恶劣的环境条件。该菌细胞壁不含内毒素,具有单层细胞外膜,动物肠道中枯草芽孢能直接分泌蛋白质到胞外。枯草芽孢杆菌是一种存在于动物的肠道中的有益菌,参与维持肠道内环境的平衡与稳定,且可刺激机体释放分泌型免疫球蛋白,有利于肠道黏膜的局部免疫,进而增强机体免疫力。因其对体液免疫和细胞免疫的特性,其菌体成为当今制备黏膜免疫疫苗的一种理想的疫苗载体。枯草芽孢杆菌具有独特的优势,使其能作为便于推广的疫苗载体进行研究。文章主要对枯草芽孢杆菌的黏膜免疫机制及其作为疫苗载体研究和应用前景进行阐述。 相似文献
7.
Selection and characterization of broad‐spectrum antibacterial substance‐producing Lactobacillus curvatus PA40 as a potential probiotic for feed additives 
下载免费PDF全文
下载免费PDF全文 Sung Wook Hong Jong‐Hui Kim Hyo Ju Bae Jun‐Sang Ham Jae Gyu Yoo Kun Sub Chung Mi‐Hwa Oh 《Animal Science Journal》2018,89(10):1459-1467
Lactic acid bacteria were screened for potential probiotics for use as feed additives. We obtained 3,000 isolates from feces of: cattle, dogs, goats, and infants; milk; yogurt; cheese; fermented sausages; Kimchi; and Cheonggukjang and tested their antibacterial activity toward indicator pathogens, including Bacillus cereus, Listeria monocytogenes, Escherichia coli O157:H7, and Salmonella enterica Enteritidis. We further tested their tolerance to artificial gastric juice (1% [w/v] pepsin, pH 2.5) and bile acid (0.1% [w/v] oxgall, pH 6.8). Six isolates exhibited strong antibacterial activity against indicator pathogens. The PA40 isolate from Kimchi exhibited marked resistance to artificial gastric juice and bile acid. The antibacterial substances produced by PA40 were stable to heat, pH, and enzymes. Strain PA40 was identified as a Lactobacillus curvatus strain using chemical tests and 16S rDNA sequencing and produced 248.4 mmol/L lactic acid after 48 hr of fermentative growth. The L. curvatus PA40 strain was also highly tolerant of the artificial gastrointestinal model system. Our results indicate that L. curvatus PA40 could be used as a potential probiotic feed additive. 相似文献
8.
Salmonella continues to be a significant human health threat, and the objective of this study was to identify microorganisms with the potential to improve porcine food-safety through their antagonism of Salmonella. Anaerobic culture supernatants of 973 bacterial isolates from the gastrointestinal tract and feces of swine were screened for their capacity to inhibit the growth of Salmonella enterica serovar Typhimurium. Growth inhibition of 1000-fold or greater was observed from 16 isolates, and 16S rRNA sequencing identified the isolates as members of the genera Mitsuokella, Escherichia/Shigella, Anaerovibrio, Selenomonas, and Streptococcus. Four isolates were identified as Mitsuokella jalaludinii, and the mechanism of Salmonella Typhimurium growth inhibition by M. jalaludinii was further investigated. M. jalaludinii stationary phase culture supernatants were observed to significantly inhibit growth, and featured the production of lactic, succinic, and acetic acids. Aerobic and anaerobic S. Typhimurium growth was restored when the pH of the culture supernatants (pH 4.6) was increased to pH 6.8. However, S. Typhimurium growth in fermentation acid-free media was the same at pH 4.6 and pH 6.8 - indicating a synergistic effect between fermentation acid production and low pH as the cause of S. Typhimurium growth inhibition. Furthermore, exposure of S. Typhimurium to M. jalaludinii culture supernatants inhibited Salmonella invasion of HEp-2 cells by 10-fold. The results identify M. jalaludinii as a possible inhibitor of Salmonella growth and invasion in swine, and thus a potential probiotic capable of improving food safety. 相似文献
9.
《畜牧与生物技术杂志(英文版)》2017,(2)
Background: The chicken gastrointestinal tract contains a diverse microbiota whose composition and structure play important roles in gut functionality. In this study, microbial shifts resulting from feed supplementation with Bacillus subtilis CSL2 were evaluated in broilers challenged and unchallenged with Salmonella Gallinarum. To analyse bacterial community composition and functionality, 454 GS-FLX pyrosequencing of 16 S r RNA gene amplicons was performed.Results: The Quantitative Insights into Microbial Ecology(QIIME) pipeline was used to analyse changes in the faecal microbiota over a 24-h period. A total of 718,204 sequences from broiler chickens were recorded and analysed. At the phylum level, Firmicutes, Bacteroidetes, and Proteobacteria were the predominant bacterial taxa. In Salmonellainfected chickens(SC), Bacteroidetes were more highly abundant compared to control(NC) and Bacillus-treated(BT)chickens. At the genus level, in the NC and BT groups, Lactobacil us was present at high abundance, and the abundance of Turicibacter, unclassified Enterobacteriaceae, and Bacteroides increased in SC broilers. Furthermore, taxon-independent analysis showed that the SC and BT groups were compositional y distinct at the end of the 24-h period. Further analysis of functional properties showed that B. subtilis CSL2 administration increased gut-associated energy supply mechanisms(i.e. carbohydrate transport and metabolism) to maintain a stable microbiota and protect gut integrity.Conclusions: This study demonstrated that S. Gallinarum infection and B. subtilis CSL2 supplementation in the diet of broiler chickens influenced the diversity, composition, and functional diversity of the faecal microbiota. Moreover, the findings offer significant insights to understand potential mechanisms of Salmonel a infection and the mode of action of probiotics in broiler chickens. 相似文献
10.
Brackelsberg, C.A., Nolan, L.K. and Brown, J., 1997. Characterization of Salmonella dublin and Salmonella typhimurium (Copenhagen) isolates from cattle. Veterinary Research Communications, 21 (6), 409-420Eight Salmonella typhimurium (Copenhagen) and eight Salmonella dublin isolates from cattle were compared by their antibiotic resistance patterns, by their production of colicin, aerobactin, haemolysin and capsule, by their possession of transmissible R plasmids and the spvC gene, and by their ability to invade and replicate within cultured epithelial cells. The two groups differed in their antibiotic resistance profiles, with more of the host-adapted S. dublin isolates resistant to tetracycline than were the non-host-adapted S. typhimurium (Copenhagen) group, but more of the S. typhimurium (Copenhagen) isolates resistant to the other antibiotics tested. None of the isolates produced colicin, but all produced aerobactin. One isolate in each group was encapsulated. All of the S. typhimurium (Copenhagen) and S. dublin isolates contained plasmids, and all of them contained the spvC-homologous sequences. Four of the S. typhimurium (Copenhagen) isolates were able to transfer an R plasmid to a recipient organism by conjugation. One of the five S. dublin isolates, which showed resistance to some of the antibiotics tested, was able to transfer an R plasmid by conjugation. Both groups of isolates invaded cultured epithelial cells to a similar degree after 1 h, but the S. dublin isolates reached significantly higher levels within the cells than did S. typhimurium (Copenhagen) after 9 h. This ability may, in part, explain the association of S. dublin with more severe forms of salmonellosis and prolonged carrier states. Further study of the intracellular growth of these isolates seems warranted. 相似文献
11.
Kwag SI Bae DH Cho JK Lee HS Ku BG Kim BH Cho GJ Lee YJ 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2008,70(10):1031-1035
The objectives of the study were to investigate the phenotypic and genotypic characterization of the persistent Salmonella Enteritidis (S. Enteritidis) isolates in two integrated broiler chicken operations, with attention focused mainly on the epidemiological approach. In the distribution of virulence genes, Salmonella enterotoxin (stn), invading host cell (invA), and Salmonella plasmid virulence (spvC) genes were widely distributed among the S. Enteritidis irrespective of their source of isolation, and Salmonella fimbrial (sefC) and plasmid encoded fimbrial (pef) genes were present in 28 and 20 S. Enteritidis strains, respectively. A total of 5 different XbaI-PFGE types were obtained from 31 S. Enteritidis isolates. Twenty-one types were divided on the basis their PFGE pattern, phage type and antimicrobial resistance pattern determined. There was a significant difference in phenotypic and genotypic characterization by two integrated broiler operations. Also, 8 isolates shown susceptible to all antimicrobials and 11 isolates with resistance to nalidixic acid were partly classified by XbaI PFGE pattern and by the phage type. 相似文献
12.
Screening of the enterocin genes and antimicrobial activity against pathogenic bacteria in Enterococcus strains obtained from different origins 总被引：1，自引：0，他引：1
Theppangna W Murase T Tokumaru N Chikumi H Shimizu E Otsuki K 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2007,69(12):1235-1239
Antimicrobial activities of 139 Enterococcus isolates (48 E. faecium and 91 E. faecalis) obtained from canine feces, boiler meat samples, swine feces, wild waterfowl feces, and human feces were examined against respective bacteria, including Streptococcus pyogenes, Staphylococcus aureus, Bacillus subtilis, Listeria monocytogenes, Salmonella Enteritidis, and Escherichia coli. Bacteriocin (BAC) production assay revealed that the antimicrobial activity against at least one of 6 indicator strains (BAC+ phenotype) was found in 51 (37%) isolates (29 E. faecium and 22 E. faecalis). Twenty-four of 46 isolates positive for at least one of the enterocin structural genes (entA, entB, entL50AB, and cylL) showed a BAC+ phenotype. The existence of other enterocins or nonenterocin factors was implied because the BAC+ phenotype was detected in a total of 27 Enterococcus isolates that had none of the enterocin genes tested. The antimicrobial activity against Gram-negative strains (Salmonella Enteritidis and E. coli) was detected in the 6 Enterococcus isolates that had either the entA, entB, entL50AB or cylL genes. Moreover, the proportion of the antimicrobial activity against L. monocytogenes among the cylL-positive E. faecalis isolates showing beta-hemolysis (10/16) was significantly (p<0.01) higher than among those lacking beta-hemolysis (2/15). The results suggested that certain characteristics are likely to be associated with the antimicrobial activity against specific organisms. 相似文献
13.
A total of 22 Salmonella enterica serotype Enteritidis (S. Enteritidis) strains isolated from human and chicken were subjected to DNA fingerprinting by repetitive sequence PCR using ERIC and BOX primers, antibiotic resistance and plasmid patterns. Both ERIC and BOX PCR amplification data revealed a highly genetic homogeneity between isolates from human and chicken except one isolate, which originated from chicken and showed a different DNA band pattern from others. Eleven of 22 S. Enteritidis isolates (50%) were resistant to more than one antibiotics and characterized by 5 resistance patterns. The most common pattern was penicillin resistant (63.6%). Only one isolate from chicken showed a multiple drug resistance patterns to 4 antibiotics. All 22 S. Enteritidis isolates harbored more than two plasmids with eight different plasmid profiles including two to six plasmids with approximate molecular size ranging from 1.9 to 21 kb. A band of 15 kb size was detected in all isolates tested, however, the band sizes smaller than 15 kb were found only in isolates from chicken. 相似文献
14.
本文旨在探明一株具有益生潜质的枯草芽孢杆菌N2-10对肠道菌的抗菌作用及其活性成分,为深入评价该菌株的益生功能和益生机理奠定基础。以常见的肠道致病菌和有益菌为指示菌,采用抑菌圈法对该菌株发酵液成分的抑菌活性进行测定,并通过高效液相色谱-电喷雾串联质谱(HPLC-ESI-MS/MS)对其中的活性成分进行分析。结果表明:枯草芽孢杆菌N2-10发酵液的氯仿和正丁醇提取液对供试菌无明显的抑制作用;脂肽类对大肠杆菌、痢疾杆菌和沙门氏菌等肠道致病菌表现出明显的抑菌作用,而对肠道有益菌保加利亚乳杆菌抑制作用很弱,对嗜热链球菌则无抑制作用。脂肽粗提物的HPLC-ESI-MS/MS分析结果显示,脂肽粗提物中的脂肽类抗生素为伊枯草素家族中的C14~C17抗霉枯草菌素(Mycosubtilin)的同系物。因此推断,枯草芽孢杆菌N_2-10对肠道致病菌产生抑制作用依赖于其产生的脂肽抗生素Mycosubtilin。 相似文献
15.
Differential regulation of porcine beta-defensins 1 and 2 upon Salmonella infection in the intestinal epithelial cell line IPI-2I 总被引：3，自引：0，他引：3
Veldhuizen EJ Hendriks HG Hogenkamp A van Dijk A Gaastra W Tooten PC Haagsman HP 《Veterinary immunology and immunopathology》2006,114(1-2):94-102
Intestinal epithelial cells represent the first line of defence against pathogenic bacteria in the lumen of the gut. Besides acting as a physical barrier, epithelial cells orchestrate the immune response through the production of several innate immune mediator molecules including beta-defensins. Here, we establish the porcine intestinal cell line IPI-2I as a new model system to test the regulation of porcine beta-defensins 1 and 2. Gene expression of both defensins was highly upregulated by foetal calf serum components in normal growth medium. In serum-free medium, baseline expression remained low, but pBD-2 gene expression was increased 10-fold upon infection with Salmonella Typhimurium. Arcobacter cryaerophilus and Salmonella Enteritidis, pathogenic bacteria with comparable adhesion and invasion characteristics, failed to increase pBD-2 mRNA levels. Heat killed or colistin-treated Salmonella Typhimurium had no effect, showing that the upregulation of pBD-2 was dependent on the viability of the Salmonella Typhimurium. Gene expression of pBD-1 was regulated differently since an increase in pBD-1 mRNA was observed by Salmonella Enteritidis infection. We conclude that the IPI-2I cells can serve as a new model to study porcine beta-defensin regulation and that pBD-1 and pBD-2 are differentially regulated in this cell line. 相似文献
16.
The growth behaviour of the probiotic strain Bacillus cereus var. toyoi in the gastrointestinal tract of broiler chicken and suckling piglets was evaluated. The strain germinated rapidly in intestinal samples from both animal species. Less than 10% of spores were recovered from the chicken crop and piglet stomach, respectively. Lumen samples and mucosal tissues from the hind gut of piglets displayed increasing colonization of the probiotic strain throughout the trial period. After oral administration of vegetative cells to broiler chicken and weaned piglets, sporulation was detected in all intestinal samples. The distribution of spore CFU indicated repeated germination and sporulation during the intestinal passage in piglets. B. cereus var. toyoi was not able to colonize the intestinal tract of both animal species. However, the probiotic strain was detected in suckling piglets before uptake of B. cereus var. toyoi supplemented feed. It is concluded that B. cereus var. toyoi germinates rapidly in broiler chicken and piglets, which is a necessary prerequisite for its possible probiotic effects. Germination and in vivo sporulation of vegetative cells indicated that the probiotic strain was metabolically active in the intestine of both animal species. 相似文献
17.
Cortez AL Carvalho AC Ikuno AA Bürger KP Vidal-Martins AM 《Research in veterinary science》2006,81(3):340-344
The present study was carried out to report the occurrence Salmonella spp., Salmonella Enteritidis, and Salmonella Typhimurium in chicken abattoirs. Samples of feces; feathers; scald, evisceration, and chiller water; and rinse water of non-eviscerated, eviscerated, and chilled carcass were collected from six chicken abattoirs. Salmonella isolates were identified by a multiplex-PCR using three sets of primers targeting the invA, pefA, and sefA gene sequences from Salmonella spp., S. Typhimurium and S. Enteritidis, respectively. Salmonella spp. was detected in 10% (29/288) of the samples, whereas serovars Enteritidis and Typhimurium were identified in 62% (7/288), respectively. The results indicate the need to improve hygiene and sanitary standards in poultry slaughter lines, besides the education of food handlers and information to consumers. 相似文献
18.
鼠李糖乳酸杆菌LG_A对鸡小肠上皮细胞β-防御素-9基因表达的影响 总被引：1，自引：1，他引：0
本研究旨在研究益生性鼠李糖乳酸杆菌LGA对体外培养的鸡小肠上皮细胞β-防御素-9 (AvBD9)表达的调节作用.选用鼠李糖乳酸杆菌LGA对体外培养的鸡小肠上皮细胞进行剂量依赖性及时间依赖性刺激实验,利用实时荧光定量PCR(fluorescence quantitative PCR,FQ-PCR)从mRNA水平研究刺激后上皮细胞AvBD9基因表达水平的差异.结果表明,不同浓度(2×105、2×106、2×107 cfu· mL-1)鼠李糖乳酸杆菌LGA均能上调AvBD9mRNA的表达,且在不同细菌浓度之间AvBD9 mRNA的表达存在差异.热灭活鼠李糖乳杆菌LGA亦能上调AvBD9基因表达,且上调值显著高于活菌(P＜0.05).鼠李糖乳杆菌LGA刺激上皮细胞后AvBD9表达存在时间依赖关系,12 h时AvBD9的表达达到峰值.Western blot检测结果显示,鼠李糖乳杆菌LGA刺激后的上皮细胞培养上清中存在AvBD9蛋白表达,表明AvBD9蛋白可以分泌到细胞外而发挥其生物学功能.益生性鼠李糖乳酸杆菌LGA与鸡肠道上皮细胞的相互作用过程中,鼠李糖乳酸杆菌LGA能够促进上皮细胞抗菌肽β-防御素-9的表达.本研究结果提示益生性乳杆菌可能通过促进肠道上皮抗菌肽的表达而发挥其益生作用. 相似文献
19.
芽孢杆菌B13的分离鉴定及其抑菌作用研究 总被引：1，自引：0，他引：1
试验旨在发掘有效的抗性菌以替代部分抗生素,并研究其抑菌作用,以大肠杆菌K88、鼠伤寒沙门氏菌和金黄色葡萄球菌为指示菌,采用凝胶打孔法从猪肠道内容物中筛选出一株对3种病原菌均具有抑菌活性的菌株,利用形态特征观察、革兰氏染色、16SrDNA序列同源性比对鉴定菌株,并对其抑菌条件和生长条件进行优化。结果显示,试验筛选到1株对大肠杆菌K88、鼠伤寒沙门氏菌和金黄色葡萄球菌均具有较强抑制作用的菌株,经鉴定确定其为芽孢杆菌(Bacillus sp.),并命名为芽孢杆菌B13。此分离菌为革兰氏阳性菌,单生或成对生长。生长试验结果表明,该分离菌在pH为6.0,温度为34℃,以蔗糖为碳源、蛋白胨为氮源时,生长速度最快;在pH为7.0,温度为35℃,以麦芽糖为碳源、蛋白胨为氮源时,抗鼠伤寒沙门氏菌、黄色葡萄球菌和大肠杆菌K88活性最高。本试验通过对芽孢杆菌B13的特性进行研究发现,此菌株具有较好的抑菌效果,在抑菌方面具有良好的开发应用前景。 相似文献
20.
Martin Levkut Viera Revajová Andrea Lauková Zuzana Ševčíková Viera Spišáková Zita Faixová Mária Levkutová Viola Strompfová Juraj Pistl Mikuláš Levkut 《Research in veterinary science》2012,93(1):195-201
The protective effect of Enterococcus faecium EF55 in chickens challenged with Salmonella enterica serovar Enteritidis phage type 4 (SE PT4) was assessed. The antibacterial effect on the bacterial microflora in the small intestine in relation to white blood cell count, phenotyping of peripheral blood and intestinal lymphocytes, functional activity of lymphocytes and phagocytes and mucin quantitation were investigated. Day-old chicks (85) were randomly divided into four groups. The probiotic group (EF) and Salmonella + probiotic group (EFSE) received E. faecium EF55 (109 CFU – 3 g/group/day) for 21 days. The Salmonella group (SE) and EFSE group were infected with Salmonella Enteritidis (108 CFU in 0.2 ml PBS) in a single dose per os on day four of the experiment. The control group chicks (C) were fed a commercial diet without added bacteria. Supplementation of EF55 in the diet of the chickens in the EFSE group, challenged with S. Enteritidis, caused the density of the intestinal mucin layer to increase significantly in non-specific regions (duodenum and jejunum), but decrease significantly in target regions (caeca) for S. Enteritidis. Probiotic treatment also appeared to result in a significantly higher number of lymphocytes in peripheral blood and a tendency to increase CD3, CD4, CD8, and IgM positive cells 3 days post-infection with S. Enteritidis. The results demonstrated an antibacterial effect and suggested that EF55 had a moderating effect on intestinal mucin production and leukocytic response in the early phase of S. Enteritidis infection. 相似文献