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1.
In vitro competitive adhesion and production of antagonistic compounds by lactic acid bacteria against fish pathogens 总被引：2，自引：0，他引：2
Balcázar JL Vendrell D de Blas I Ruiz-Zarzuela I Gironés O Múzquiz JL 《Veterinary microbiology》2007,122(3-4):373-380
The present study describes the screening of five lactic acid bacteria (LAB) for use as probiotics based on their competitive adhesion and production of antagonistic substances against some fish pathogens. A reduction of adhesion of all pathogenic strains tested was obtained with three of the LAB strains (Lactococcus lactis subsp. lactis CLFP100, Lactococcus lactis subsp. cremoris CLFP102 and Lactobacillus curvatus CLFP150). With the exception of fish pathogens Flavobacterium psychrophilum and Renibacterium salmoninarum that were not inhibited by LAB strains, production of antagonistic compounds by all tested LAB was observed against at least one of the indicator strains. Based on mucus adhesion, competitive exclusion, and suppression of fish pathogen growth, the selected LAB strains can be considered for future challenge experiments in fish as a very promising alternative to the use of chemotherapeutic agents. 相似文献
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山竹岩黄芪青贮中优质乳酸菌的分离和鉴定 总被引：1，自引：1，他引：0
从山竹岩黄芪(Hedysarum fruticosum Pall.)青贮饲料中分离到3株乳酸菌(HF84,HF69,HF49)。经传统鉴定方法及16SrRNA序列分析,菌株HF84为蒙氏肠球菌(Enterococcus mundtii),菌株HF69为乳酸乳球菌乳酸亚种(Lactococcus lactis subsp.Lactis),菌株HF49为植物乳杆菌(Lactobacillus plantarum)。3株乳酸菌均为同型发酵乳酸菌,蒙氏肠球菌在pH 3.0条件下不能生长,乳酸乳球菌乳酸亚种在pH 3.0、温度5℃时及6.5%NaCl溶液中不能生长,植物乳杆菌均可在试验设定条件下生长。通过测定3株乳酸菌的生长曲线和产酸速率,菌株HF49生长速度快、产酸性能好,可作为制备乳酸菌青贮饲料添加剂的优良菌株。 相似文献
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The 16S rRNA gene of 39 S. equi subsp. zooepidemicus strains and two S. equi subsp. equi strains was amplified by polymerase chain reaction and subsequently digested with the restriction enzyme Hinc II. A restriction profile with two fragments with sizes of 1250 bp and 200 bp could be observed for both S. equi subsp. equi strains and for 30 of the 39 S. equi subsp. zooepidemicus strains indicating a sequence variation within the V2 region of the 16S rRNA gene of the remaining nine S. equi subsp. zooepidemicus isolates. A segment of the 16S rRNA gene including the hypervariable V2 region of 11 S. equi subsp. zooepidemicus and two S. equi subsp. equi could be amplified by PCR and sequenced. The sequence of the V2 region of eight S. equi subsp. zooepidemicus strains appeared to be identical or almost identical to the sequence of the two S. equi subsp. equi strains. The sequence of the remaining three S equi subsp. zooepidemicus strains differed significantly from the sequence of S. equi subsp. equi. These differences allowed a division of S. equi subsp. zooepidemicus strains into two 16S rRNA types and might possibly have consequences for the taxonomic position of these phenotypically indistinguishable strains of one subspecies. A molecular typing could additionally be performed by amplification of the gene encoding the 16S-23S rRNA spacer region. A single amplicon of the spacer gene of 1100 bp could be observed for one S. equi subsp. zooepidemicus, an amplicon of 950 bp for two S. equi subsp. equi strains and 10 S. equi subsp. zooepidemicus strains, a amplicon of 780 bp for 27 S. equi subsp. zooepidemicus strains and a single amplicon of 600 bp for one S. equi subsp. zooepidemicus strain. The variations of the V2 region of the 16S rRNA gene and the size variations of the 16S-23S rRNA spacer gene were not related to each other. Both variations could be used for molecular typing of this species, possibly useful in epidemiological aspects. 相似文献
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内蒙古发酵酸乳制品中乳酸菌的分离鉴定 《畜牧与饲料科学》2020,41(3):51-55
以采集自内蒙古锡林郭勒盟正蓝旗的2份发酵酸乳样品为研究对象,采用传统纯化培养技术、16S rDNA基因序列测定并构建系统发育树的方法,对样品中的乳酸菌进行了分离鉴定,以期解析发酵乳中乳酸菌的多样性,积累食品微生物资源。研究结果显示,共分离15株乳酸菌,被鉴定为3个属9个种,3个属分别为乳酸乳球菌属、明串珠菌属和乳杆菌属,9个种分别为乳酸乳球菌叶蝉亚种（Lactococcus lactis subsp. hordniae,3株）、乳酸乳球菌（Lactococcus lactis,1株）、乳酸乳球菌乳脂亚种（Lactococcus lactis subsp. cremoris,1株）、乳明串珠菌（Leuconostoc lactis,3株）、肠膜明串珠菌肠膜亚种（Leuconostoc mesenteroides subsp. mesenteroides,1株）、肠膜明串珠菌右旋葡聚糖亚种（Leuconostoc mesenteroides subsp. dextranicum,1株）、植物乳杆菌（Lactobacillus plantarum,1株）、副干酪乳杆菌（Lactobacillus paracasei,3株）和干酪乳杆菌（Lactobacillus casei,1株）。综上表明,该研究采集的酸乳样品中乳酸菌资源丰富,是内蒙古传统乳制品优良发酵剂的研发和产业化生产的潜在微生物资源。 相似文献
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Streptococcus equi subsp. zooepidemicus (SEZ) is an opportunistic and zoonotic pathogen of horses. In this study, genetic intraspecies variability of SEZ obtained mainly from respiratory and genital samples of horses was investigated by analysis of the 16S–23S rRNA intergenic spacer region (ISR) and of the 16S rRNA gene. 16S–23S ISR rRNA type A1 was predominant, although a high rate of multiple products (30.5%) was obtained. Phylogenetic analysis of the 16S rRNA gene detected three genogroups (I, II and III). 16S rRNA variable regions V1 and V2 are the most important regions for evaluating SEZ intraspecies variability, but at least V1-V5 regions should be considered to avoid mistakes. Analysis of all 16S rRNA sequences available in databases assigned human SEZ to groups I and III but not to group II. These results show a high genetic variability in SEZ collected from different specimens of horses from various regions of Italy. 相似文献
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Jin J Xu D Narongwanichgarn W Goto Y Haga T Shinjo T 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2002,64(3):273-276
The 16S-23S rRNA intergenic spacer regions (ISRs) of Fusobacterium necrophorum subsp. necrophorum and F. necrophorum subsp. funduliforme were characterized. Products of two sizes, about 360 bp (small) and 530 bp (large), were generated by PCR amplification from the 16S-23S rRNA ISR of all the strains tested. The large and small 16S-23S rRNA ISRs of F. necrophorum exhibited a level of sequence similarity of 93.9% to 99.7% and 94.2% to 98.6% homologies within the species, respectively. Only the large spacer regions in these bacteria contained one or two tRNA genes. F. necrophorum subsp. necrophorum contains the isoleucine and alanine tRNA gene, whereas F. necrophorum subsp. funduliforme contains the isoleucine tRNA gene. 相似文献
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Hugh Cai Marie Archambault John F Prescott 《Journal of veterinary diagnostic investigation》2003,15(5):465-469
This study evaluated 16S rRNA gene sequence analysis methods as tools for identification of 22 phenotypically difficult to identify veterinary clinical bacterial isolates in a veterinary diagnostic laboratory. The study compared 16S rRNA gene sequencing and conventional phenotypic identification methods. Using 16S rRNA full-gene sequencing, 95% (21/22) of the isolates were identified to the genus level and 86% (19/22) to the species level. The conventional or commercially available manual identification phenotypic characterization methods presumptively identified 91% (20/22) of the isolates to the genus level and 1 isolate to the species level. However, only 55% (12/22) or 4.5% (1/22) of the phenotypic identifications were correct at the genus or species level when they were compared with the 16S rRNA full-gene sequencing. This study also compared 16S rRNA full-gene and partial-gene sequencing. The results demonstrated that the best 16S rRNA gene-sequencing approach is full-gene sequencing because it gives the most precise species identification. Sequencing of the variable regions 1, 2, and 3 of the 16S rRNA gene could be used for tentative identification because the ability of this sequencing to identify bacteria to the genus level is similar to that of the 16S rRNA full-gene sequencing. This method identified only 14% (3/22) isolates differently to the species level compared with the 16S rRNA full gene sequence. Sequencing of the variable regions 7, 8, and 9 is not recommended because it gives more ambiguous identifications. The cost of a 16S RNA full-gene-sequencing analysis was Can 160 dollars and Can 60 dollars for a partial 16S rRNA gene sequence, i.e., sequencing of variable regions 1, 2, and 3 or variable regions 7, 8 and 9. 相似文献
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为获得抑制奶牛乳房炎源金黄色葡萄球菌(S. aureus)的乳酸菌(LAB),本研究从新疆巴音布鲁克牧区鲜牛乳和哈萨克族乳制品奶疙瘩样品中分离培养LAB,通过传统的分离鉴定与16S rDNA基因序列测序相结合的方法鉴定LAB种类,同时以临床奶牛乳房炎源金黄色葡萄球菌S. aureus N2为指示菌,采用双层琼脂扩散法检测分离株的抑菌能力。通过测定生长曲线确定分离株的生长稳定期,进而利用硫酸铵沉淀法透析提取稳定期内分离株的细菌素,并检测其细菌素抑菌效价。结果显示:从样品中筛选获得5株能够抑制指示菌生长的LAB,分别为希氏乳杆菌、干酪乳杆菌、粪肠球菌、戊糖片球菌和乳酸乳球菌亚种。生长规律曲线表明20 h^30 h为5株LAB的稳定期,此期培养液pH值维持在3.8~4.5。从培养20 h的5株LAB上清液中提取到了细菌素,经检测其具有抑菌活性,抑菌效价分别为457 IU/mL、1 023 IU/mL、676 IU/mL、1 862 IU/mL和1 023 IU/mL。本研究结果表明5株LAB通过在生长稳定期内维持较低酸性环境(pH<4.5),代谢产生细菌素对乳房炎源S. aureus发挥抑制生长作用。本研究为S. aureus性奶牛乳房炎的生物防治提供了实验依据。 相似文献
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从河北某养鸡场80日龄左右鸡群所发生的禽霍乱病死鸡中，分离到了相应病原菌多杀巴斯德氏菌（pasteurella multocida）。对分离获得的16株菌（HPs-1至HPs-16）进行了形态特征、培养特性、理化特性等方面的鉴定，同时选取代表菌株（HPs-1）进行了16SrRNA基因的分子鉴定，测定了16SrRNA序列，构建了系统发育树。结果表明分离鉴定的16株细菌均为多杀巴斯德氏菌败血亚种（P．multocida subsp．septica），所测代表菌株的16SrRNA基因长度142bp，在GenBank登录号为AY999017，该菌株与检索出的22株巴斯德氏菌属（Pasteurella Trevisan，1887）细菌16SrRNA基因序列同源性均在98％～100％。另外，药敏试验结果显示分离株对供试的青霉素G等33种抗菌药物高敏、对克林霉素敏感、对苯唑青霉素等3种耐药。 相似文献
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本研究对呼伦贝尔草原牧草青贮饲料中的乳酸菌进行了分离、鉴定,旨为筛选出优良乳酸菌菌株。以4个地区不同群落牧草的青贮饲料为试验材料,并采用传统微生物学鉴定方法及16S rRNA序列分析对分离得到的乳酸菌菌株进行了鉴定。菌株DME53为草乳杆菌,DMG108为干酪乳杆菌,DMC80为植物乳杆菌,DMG138为短乳杆菌,DMG139为戊糖片球菌;其中菌株DMG138为异型发酵乳酸菌,其余4株菌均为同型发酵乳酸菌。除DMG139在40和45 ℃下生长微弱外,其余菌株均在5~45 ℃不同温度条件下, 3.0%和6.5% NaCl培养液中良好生长。除菌株DME53在pH 3.0下不能生长外,其余菌株均在pH 3.0~8.0条件下良好生长或微弱生长。菌株DMC80具有产酸能力较强、发酵速率较快、耐酸、耐低温等特性,可作为制备适用于呼伦贝尔地区青贮饲料菌制剂的优良菌株。 相似文献
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采用实时荧光定量聚合酶链反应(real-time quantitive polymerase chain reaction,q-PCR)技术对从内蒙古鄂尔多斯地区采集的28份传统发酵乳制品(7份酸绵羊乳、8份酸山羊乳以及13份酸牛乳)样品中分离到的乳酸菌优势菌群L.helveticus、Leu.mesenteroides及ac.lactis subsp.lactis的数量进行比较分析.结果表明:酸山羊乳和酸牛乳中,3种优势菌属的数量关系为Leu.mesenteroides＞L.helveticus＞ Lac.lactis subsp.lactis;酸绵羊乳中,3种优势菌属数量关系为L.helveticus＞ Leu.mesenteroides＞ Lac.lactis subsp.lactis. 相似文献
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Hughes MS James G Taylor MJ McCarroll J Neill SD Chen SC Mitchell DH Love DN Malik R 《Journal of Feline Medicine and Surgery》2004,6(4):235-243
16S rRNA gene sequence analysis provided evidence for two different mycobacterial species, Mycobacterium lepraemurium and a potentially novel species, as causative agents of 'feline leprosy'. Comparison of 16S rRNA gene sequence data obtained for M. lepraemurium and the potentially novel species indicated 12 nucleotide differences over a 446 bp region encompassing the V2 and V3 hypervariable regions. From available 16S rRNA gene sequence data, M. lepraemurium shared greatest nucleotide identity with M. avium subsp paratuberculosis and M. avium. The novel species had a long helix 18 in the V3 region and shared greatest nucleotide identity with M. leprae, M. haemophilum and M. malmoense. The novel species had an additional 'A' nucleotide at position 105 of the aligned 16S rRNA gene sequence, the only other mycobacterial database sequence having this same extra nucleotide being M. leprae. This nucleotide variation was exploited to develop specific PCR assays for the two species. These were found to be effective and specific when tested against a panel of mycobacteria including species found in feline leprosy lesions and closely related mycobacteria and also when applied directly to formalin-fixed, paraffin-embedded tissues from feline leprosy cases. 相似文献
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R A Tapp A F Roy R E Corstvet V L Wilson 《Journal of veterinary diagnostic investigation》2001,13(3):219-229
Cat scratch disease (CSD) has been difficult to diagnose in animals because of the protracted clinical course of infection and the quiescent phases when the microbial culprit lies dormant. The causative agent in CSD appears to be multiple species and strains of Bartonella. Using polymerase chain reaction (PCR) techniques for amplification of highly variable regions of the 16S ribosomal RNA (rRNA) gene sequence, a very sensitive species- and strain-specific assay for CSD-causing Bartonella species was developed. PCR primers were designed to specifically amplify the 16S rRNA gene of Bartonella species but not of other microbial pathogens. This initial PCR was multiplexed with a universal primer set, based on conserved sequence regions in the 16S rRNA gene, that provides a 162-bp fragment in all species tested. Subsequently, 3 distinct nested PCR primer sets enabled the individual amplification and specific detection of Bartonella henselae type 1, B. henselae type II, and B. clarridgeae. Thus, this 2-step PCR procedure enabled the sensitive detection and identification of these species and the B. henselae genotype by exploiting minor sequences differences. Verification of these results were demonstrated with both sequencing and ligase chain reaction techniques. The diagnostic usefulness of this CSD test has been demonstrated by the analysis of specimens from control and infected cats. The diagnosis was confirmed and the specific B. henselae strain was correctly identified in peripheral blood specimens obtained from control and strain-specific CSD-infected cats. Such an accurate and sensitive diagnostic tool for the detection and identification of CSD causative agents should be a useful for the medical, veterinary, and scientific communities. 相似文献
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通过形态特征、生理生化特性及16S rRNA序列分析方法对玉米(Zea mays)秸秆和白菜(Brassica pekinensis)尾菜混贮料中的乳酸菌多样性进行分析,并以温度和p H为限制因素筛选优良乳酸菌菌株。结果表明,分离得到的12株乳酸菌分属于乳杆菌属(Lactobacillus)和片球菌属(Pediococcus)。其中,1株(LB-1)为植物乳杆菌(Lactobacillus plantarum),6株(LB-2、LB-4、LB-7、LB-8、LB-9和LB-11)为戊糖片球菌(Pediococcus pentosaceus),3株(LB-5、LB-6和LB-12)为短乳杆菌(Lactobacillus brevis),2株(LB-3和LB-10)为类干酪乳杆菌(Lactobacillus paracasei)。菌株LB-3和LB-8表现出优良的耐高温、耐酸碱特性,且具有较强的产乳酸能力,二者可作为青贮饲料的乳酸菌添加剂。 相似文献
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Masanori TOHNO Hisami KOBAYASHI Masaru NOMURA Maki KITAHARA Moriya OHKUMA Ryuichi UEGAKI Yimin CAI 《Animal Science Journal》2012,83(2):111-120
Twenty-three lactic acid bacteria (LAB) isolated from three cultivars (Akiaoba, Nagahahikari and Tachiwase) of Italian ryegrass (Lolium multiflorum Lam.) silage were precisely characterized by a combination of phenotypic tests, genotypic 16S ribosomal DNA sequencing and rapid PCR-based analyses, focusing on their useful phenotypes for silage preparation as inoculants. We successfully identified both at the species and subspecies levels: phenotypically novel Lactococcus lactis subsp. lactis, Lactobacillus brevis, Lactobacillus coryniformis subsp. torquens, Lactobacillus curvatus, Lactobacillus plantarum subsp. plantarum, Lactobacillus sakei subsp. carnosus, Leuconostoc mesenteroides subsp. dextranicum and Pediococcus parvulus. This is the first report to elucidate the presence of Lactobacillus coryniformis ssp. torquens and Leuconostoc mesenteroides subsp. dextranicum in Italian ryegrass silages. Physiological and biochemical tests revealed that phenotypic characteristics are different among the different strains of the same species and subspecies, and that the isolates show unique and diverse phenotypes related to fermentation factors, such as available carbohydrates, optimal growth pH and temperature. These results suggest that, for various well-preserved silage preparations, the isolates may be useful in producing novel inoculants corresponding to their optimally climatic and ecological niches. 相似文献