共查询到20条相似文献，搜索用时 15 毫秒
1.
Hiroto Miura Takuya Hashimoto Yukiko Kawanishi Hiroki Kawauchi Ryo Inoue Noriaki Shoji Kunihiko Saito Mario Sekiya Yosuke Saito Jumpei Yasuda Chiemi Yonezawa Tetsushiro Endo Hirotaka Kasuya Yutaka Suzuki Yasuo Kobayashi Satoshi Koike 《Animal Science Journal》2021,92(1):e13601
The rumen microbiota comprises a vast range of bacterial taxa, which may affect the production of high-quality meat in Japanese Black cattle. The aim of this study was to identify core rumen microbiota in rumen fluid samples collected from 74 Japanese Black cattle raised under different dietary conditions using 16S rRNA gene amplicon sequencing. In the rumen of fattening Japanese Black cattle, 10 bacterial taxa, showing >1% average relative abundance and >95% prevalence, irrespective of the dietary conditions and the fattening periods, were identified as the core rumen bacterial taxa, which accounted for approximately 80% of the rumen microbiota in Japanese Black cattle. Additionally, population dynamics of the core rumen bacterial taxa revealed two distinct patterns: Prevotella spp. and unclassified Bacteroidales decreased in the mid-fattening period, whereas unclassified Clostridiales, unclassified Ruminococcaceae, Ruminococcus spp., and unclassified Christensenellaceae increased during the same period. Therefore, the present study reports the wide distribution of the core rumen bacterial taxa in Japanese Black cattle, and the complementary nature of the population dynamics of these core taxa, which may ensure stable rumen fermentation during the fattening period. 相似文献
2.
Detection and identification of Mycoplasma conjunctivae in infectious keratoconjunctivitis by PCR based on the 16S rRNA gene. 总被引：2，自引：0，他引：2
M Giacometti J Nicolet K E Johansson T Naglic M P Degiorgis J Frey 《Zentralblatt für Veterin?rmedizin. Reihe B. Journal of veterinary medicine. Series B》1999,46(3):173-180
A specific PCR assay based on unique sequences of the rrs genes (16S rRNA) of Mycoplasma conjunctivae was developed for direct detection and identification of this pathogen from clinical material. DNA from eye swabs was amplified after a simple lysis step by either a single PCR with the M. conjunctivae specific primer pair McoR1 and McoF1, or by a nested PCR with the Mycoplasma genus specific primer pair MOLIGEN1-L and 16UNI-R in the first step and McoR1 and McoF1 in the second step. The specificity of the primer pair McoR1 and McoF1 was verified with purified DNA from the type strain, from 17 field isolates of M. conjunctivae and from several Mollicutes which are phylogenetically related to M. conjunctivae or which can be isolated from the same host animals. This method identified mycoplasma isolates from goat, sheep, ibex and chamois originating from different countries as M. conjunctivae. No cross amplifications with other mycoplasmas which are related to M. conjunctivae were observed. Eye swab samples containing known numbers of M. conjunctivae cells were analysed after direct lysis of the material. The detection level was estimated to be 20 cells per swab when the nested PCR procedure was used and 2 x 10(5) by the single PCR method. In an experimental infection model of sheep, the nested PCR method for detection of M. conjunctivae gave results which were comparable to mycoplasmal culture. These are the implications for diagnostic purposes: M. conjunctivae isolates can be identified by the one-step PCR method, whereas for detection and identification of M. conjunctivae in clinical material the two-step method should be used (higher sensitivity). 相似文献
3.
Moraxella ovis was historically the only coccoid Moraxella identified in cultures of ocular fluid from cattle with infectious bovine keratoconjunctivitis (IBK) and could be morphologically and biochemically differentiated from Moraxella bovis. Moraxella bovoculi sp. nov. is a recently characterized Moraxella isolated from ulcerated eyes of calves with IBK in northern California in 2002. Like Moraxella ovis, M. bovoculi sp. nov. is a gram-negative coccus/diplococcus. All 18 original isolates of M. bovoculi sp. nov. possessed phenylalanine deaminase (PADase) activity and could therefore be differentiated from M. ovis and M. bovis. During the characterization of 44 additional isolates of hemolytic gram-negative cocci that were cultured from ulcerated eyes of IBK-affected calves, 2 PADase-negative isolates were identified that could not be differentiated biochemically from M. ovis; however, the DNA sequence of the 16S-23S intergenic spacer region (ISR) of the isolates matched the 16S-23S ISR DNA sequence of M. bovoculi sp. nov. To facilitate the identification of PADase-negative moraxellae, a polymerase chain reaction (PCR) coupled with restriction enzyme digestion analysis of amplified DNA was developed. Amplification of the 16S-23S ISR followed by AfaI digestion of amplified DNA could differentiate M. bovoculi sp. nov. from M. ovis and other moraxellae. The DNA sequence analysis of the amplified 16S-23S ISR from the 42 PADase-positive isolates of hemolytic gram-negative cocci indicated that all were M. bovoculi sp. nov. and all possessed an AfaI site. A PCR coupled with restriction analysis of amplified DNA can aid in identifying M. bovoculi sp. nov. 相似文献
4.
Pille F Martens A Schouls LM Peelman L Gasthuys F Schot CS De Baere C Desmet P Vandenberghe F 《Research in veterinary science》2004,77(3):189-195
Standard culturing techniques are often unrewarding in confirming diagnosis of synovial infection in the equine patient. Several human studies report the use of sensitive polymerase chain reaction (PCR) techniques for the detection of bacterial involvement in acute synovitis. However, successful extraction of bacterial DNA directly from clinical samples from horses without prior culture has not been reported yet. The goal of this study was to develop a sensitive and reliable method for molecular detection and identification of bacterial species in synovial fluid from horses with infectious synovitis. Synovial fluid samples from 6 horses with culture confirmed synovial infection were used for broad range 16S rRNA gene PCR. Synovial aspirates of 2 healthy horses were used as negative controls. Following extraction and purification of synovial fluid DNA, all samples were processed by touchdown PCR. Amplicons were detected by reverse line blot hybridisation and visualised with chemiluminescence. Pathogen-specific detection of 16S rRNA gene sequences was successful in all 6 synovial fluid samples. No bacterial DNA was detected in the aspirates from the negative control horses using touchdown PCR followed by 25 additional cycles of amplification. The identity of the pathogens was confirmed by DNA sequencing of the amplicons. It can be concluded that broad range 16S rRNA gene PCR followed by reverse line blot hybridisation is a promising technique for detection of bacterial DNA in synovial fluid samples. Further research should aim at the detection of bacterial DNA in synovial fluid samples suspected of infection but having negative culture results. When the 16S PCR proves to be reliable and more sensitive than standard culturing techniques, it may become a powerful tool in the diagnosis of synovial infection. 相似文献
5.
Hemotropic mycoplasmas (hemoplasmas) are Gram-negative bacteria that parasitize the erythrocyte surface of a wide variety of mammals. The present study aimed at investigating the occurrence of hemoplasmas in beef cattle in the Brazilian Pantanal, an area endemic for bovine trypanosomiasis in South America. Additionally, the objective of this study was to characterize molecularly the genotypes of the found hemoplasmas. For this purpose, blood and serum samples of 400 beef cattle were collected from five properties in Corumbá, Nhecolândia sub-region, Mato Grosso do Sul, in Midwest Brazil. Blood samples underwent DNA extraction and standard 16S rRNA gene-based PCR assays for hemoplasmas. The sequences obtained were submitted to phylogenetic inferences, distance analysis, and genotype diversity. The Indirect Enzyme-Linked Immunoabsorbent Assay (iELISA) indicated the presence of anti-Trypanosoma vivax IgG antibodies in 89.75% of the animals sampled, confirming the endemicity of said agent in the studied region. Among the 400 bovine blood samples tested, 2.25% (9/400) were positive for hemoplasmas in cPCR. The phylogenetic analysis of the obtained sequences confirmed the presence of 'Candidatus Mycoplasma haemobos' and Mycoplasma wenyonii DNA in 0.5% (2/400) and 1.75% (7/400) animals, respectively. Five genotypes of M. wenyonii and one of 'Candidatus M. haemobos' were detected among the sequenced amplicons. The present study showed low molecular occurrence of haemoplasmas in beef cattle sampled in the Brazilian Pantanal, an area endemic for bovine trypanosomiasis. Despite of the conservation of the 16S rRNA gene, there was considerable diversity of hemoplasma genotypes infecting the sampled beef cattle. 相似文献
6.
Alexander TW Cook SR Yanke LJ Booker CW Morley PS Read RR Gow SP McAllister TA 《Veterinary microbiology》2008,130(1-2):165-175
The objective of this study was to design a multiplex PCR assay to identify Mannheimia haemolytica, Mannheimia glucosida and Mannheimia ruminalis. The multiplex PCR included primer sets HP, amplifying a DNA region from an unknown hypothetical protein, Lkt and Lkt2, amplifying different regions of the leukotoxinD gene, and 16S to amplify universal bacterial sequences of the 16S rRNA gene. Based on positive amplification, isolates were delineated as M. haemolytica (HP, Lkt, 16S), M. glucosida (HP, Lkt, Lkt2, 16S), or M. ruminalis (HP, 16S). The validity of the assay was examined against 22 reference strains within the family Pasteurellaceae and 17 field isolates (nasal) that had been collected previously from feedlot cattle and tentatively identified as M. haemolytica based on morphology and substrate utilization. Additionally, 200 feedlot cattle were screened for M. haemolytica using multiplex PCR. Forty-four isolates from 25 animals were identified as M. haemolytica. The PCR assay positively identified all M. haemolytica, as confirmed by phenotypic tests and clustering based upon cellular fatty acid methyl ester (FAME) profiles. Selected nasal isolates that exhibited evidence of haemolysis, but were M. haemolytica-negative based on PCR, were also confirmed negative by phenotypic and FAME analyses. The multiplex PCR assay required no additional phenotypic tests for confirmation of M. haemolytica, within the group of bacteria tested. 相似文献
7.
Contagious keratoconjunctivitis is a rather common disease in Norwegian sheep. Since the knowledge of its aetiology is limited, the present study was performed to determine the microorganisms involved. Local veterinarians throughout the country collected conjunctival swabs from both sick (n = 43) and healthy (n = 42) sheep on 15 farms with outbreaks of ovine keratoconjunctivitis, and further from healthy sheep (n = 50) on 17 farms not showing any signs of conjunctival disease. All samples were cultivated for bacteria and mycoplasma. Listeria monocytogenes was isolated from 3 cases (1%) in one single herd. Staphylococcus aureus (5%), Corynebacterium spp. (2%) and Escherichia coli (4%) were isolated only in herds with keratoconjunctivitis, but from both sick and healthy animals. Moraxella (Branhamella) ovis was isolated from 28% of sampled animals in affected herds and from 10% of sampled animals in healthy herds. The corresponding numbers for Moraxella spp. were 9%/12%, for Pseudomonas spp. 7%/8%, for Staphylococcus spp. 22//22%, for Bacillus spp. 12%/14%, for Micrococcus spp. 6%/2% and for Streptococcus/Enterococcus spp. 2%/2%. Mycoplasma conjunctivae was isolated from 16 animals with keratoconjunctivitis (37%) and from 3 animals without clinical signs (7%) in farms with keratoconjunctivitis. In farms without clinical signs of keratoconjunctivitis, M. conjunctivae was isolated in 4 animals (8%). To our knowledge, this is the first time M. conjunctivae has been isolated in Norway. Other predisposing agents found were Moraxella (Branhamella) ovis and Listeria monocytogenes. The etiological importance of different microorganisms in ovine keratoconjunctivitis seems to vary; some are probably only present as secondary invaders. Other possible causes of ovine keratoconjunctivitis in Norway, such as Chlamydia psittaci, remain to be investigated. 相似文献
8.
OBJECTIVE: To describe the detection of Ehrlichia platys in free-roaming dogs in Central Australia. PROCEDURE: Blood samples were collected from four dogs and examined for bacterial 16S ribosomal DNA using Polymerase Chain Reaction (PCR)-based assays. The three positive samples obtained were then sequenced and identification of the PCR product carried out. As a result of all three samples being identical to or closely related to part of the 16S rRNA gene of E. platys, blood samples were subsequently obtained from a further 24 dogs. These samples were screened using a PCR-assay to determine the presence of Ehrlichia DNA using genus-specific primers. The positive samples obtained from the screening process were then subjected to a further PCR-assay using E. platys specific primers. RESULTS: Of 28 dogs sampled, Ehrlichia DNA was detected in the blood of 13 dogs. Sequencing of the amplicons obtained indicated a high homology with the 16S rRNA gene for E. platys. When the E. platys-specific PCR was performed for 10 of those dogs, the 678 bp product obtained from the PCR amplification confirmed the identification as part of the 16S rRNA gene of E. platys in all 10 dogs. CONCLUSION: This study reports for the first time Ehrlichia carriage by dogs in Australia. It also indicates the usefulness of the PCR technique in rapidly and accurately identifying diseases that are otherwise difficult to detect. By using universal primers directed against bacterial 16S ribosomal DNA and sequencing analysis, the detection of potentially pathogenic Ehrlichia organisms that had not previously been found in Australia has been made possible. 相似文献
9.
温氏附红细胞体部分16S rRNA基因的序列测定和分析 总被引：2，自引：0，他引：2
从确诊为附红细胞体感染的黄牛无菌采集血样，抽提附红细胞体基因组DNA，用实验设计的能扩增多种动物血营养菌部分16SrRNA基因的通用引物进行PCR扩增，结果扩增出大小约为370bp的DNA片段。PCR产物序列测定和系统进化分析显示，实验获得的核苷酸序列为温氏附红细胞体的16SrRNA基因，与国外报道的温氏附红细胞体的同源性为97％。反映出不同地理株的温氏附红细胞体存在一定的遗传差异，为牛附红细胞体病的诊断和分子流行病学研究提供科学依据。 相似文献
10.
重庆市某肉牛场新进育肥牛群发生以呼吸系统感染为主的传染性疾病,为确诊病因,对表现明显临床症状的病牛进行迫杀,无菌采集肺脏、肝脏、血液和心肌进行病原分离,共分离到4株菌,分别编号为CQ1、CQ2、CQ3、CQ4.经16S rRNA序列比对,CQ1与牛支原体同源性达99.9％,CQ2与羊创伤球菌同源性达99.8％,CQ3、CQ4分别与大肠杆菌和沙门氏菌同源性达99％.通过培养特性、菌落形态观察、牛支原体特异性引物PCR扩增,确定CQ1为牛支原体;药物敏感性试验和动物试验表明,该分离株对环丙沙星、氧氟沙星、四环素、壮观霉素敏感,不致死小白鼠.按牛支原体肺炎临床用药后,疫情很快得到控制,结合实验室检测结果,确认该场爆发的是以牛支原体感染为主的牛支原体肺炎. 相似文献
11.
Tell LA Leutenegger CM Larsen RS Agnew DW Keener L Needham ML Rideout BA 《Avian diseases》2003,47(4):1406-1415
Diagnosis of avian mycobacteriosis, caused by Mycobacterium genavense or species belonging to the Mycobacterium avium complex (MAC), is problematic. Polymerase chain reaction (PCR) offers rapid and sensitive detection of minute quantities of DNA, and conventional protocols have been used for evaluating avian specimens. The recent development of real-time PCR offers several advantages over conventional PCR. In attempts to improve diagnosing avian mycobacteriosis, a real-time TaqMan PCR assay was developed targeting the 65-kD heat shock protein gene of M. genavense and MAC spp. Nineteen reference isolates, 16 clinical isolates, and 32 avian tissue samples were used to evaluate the assay. When sufficient amplicons were produced, the species of mycobacteria was determined by standard sequencing of TaqMan PCR products and compared with results from commercial mycobacteriology laboratories and/or standard sequencing of conventional PCR products. The TaqMan PCR detected DNA from reference isolates of M. genavense, MAC spp., and Mycobacterium tuberculosis complex spp. Of the clinical isolates, the TaqMan PCR detected DNA from 10 of 12 Mycobacterium avium avium isolates and two of three Mycobacterium avium intracellulare isolates. For the tissue samples, the TaqMan PCR amplified DNA in six of nine samples that were identified by sequencing of conventional PCR products and/or by commercial mycobacteriology laboratories as being MAC spp. positive and three of four samples that were positive for M. genavense. There was some disagreement between speciation results from the TaqMan PCR and those from commercial mycobacteriology laboratories or conventional PCR or both. This disagreement was suspected to be because of relatively small numbers of base pairs in the TaqMan PCR products. The TaqMan PCR may provide a useful tool for evaluating clinical samples for DNA from mycobacteria species that most commonly infect birds; however, further refinement is needed in order to improve sensitivity and provide more accurate speciation. 相似文献
12.
Borel N Thoma R Spaeni P Weilenmann R Teankum K Brugnera E Zimmermann DR Vaughan L Pospischil A 《Veterinary pathology》2006,43(5):702-708
In 2001, the first case of bovine chlamydial abortion was reported in canton Graubunden, Switzerland. In this region, Chlamydophila (Cp.) abortus is endemic in small ruminants. Hence, we aimed to investigate the incidence of chlamydia-related abortions in cattle from Graubunden. During breeding seasons of 2003-2004, formalin-fixed and paraffin-embedded placenta specimens (n = 235) from late-term abortions in cattle were analyzed by histopathology, immunohistochemistry with a Chlamydiaceae-specific monoclonal antibody against chlamydial lipopolysaccharide (LPS), and 2 different polymerase chain reaction (PCR) methods (16 S ribosomal ribonucleic acid [rRNA] PCR, intergenic spacer [IGS-S] PCR), followed by PCR product sequencing. In 149 of 235 cases (63.4%), histopathologic lesions such as purulent and/or necrotizing placentitis were observed. Chlamydial antigen was clearly demonstrated in immunohistochemistry in only 1 of 235 cases (0.4%). Cp. abortus or Cp. psittaci was found in 12 of 235 (5.1%) and 10 of 235 cases (4.2%) by 16 S rRNA PCR and IGS-S PCR, respectively. However, we detected, by 16 S rRNA PCR, 43 of 235 cases (18.3%) to be positive for chlamydia-like organisms. In contrast to the situation in small ruminants in the canton Graubunden, bovine abortion from Cp. abortus seems not to play an important role. Nevertheless, zoonotic potential should be taken into account when handling abortion material from cattle. The significance of chlamydia-like isolates other than Waddlia chondrophila remains an open question in abortion and needs further investigation. 相似文献
13.
Accurate identification of mastitis pathogens is often compromised when using conventional culture-based methods. Here, we report a novel, rapid assay tested for speciation of bacterial mastitis pathogens using high-resolution melt analysis (HRMA) of 16S rDNA sequences. Real-time PCR amplification of 16S rRNA gene fragment, spanning the variable region V5 and V6 was performed with a resulting amplicon of 290bp. First, a library was generated of melt curves of 9 common pathogens that are implicated in bovine mastitis. Six of the isolates, Escherichia coli, Streptococcus agalactiae, Klebsiella pneumoniae, Streptococcus uberis, Staphylococcus aureus and Mycoplasma bovis, were type strains while the other 3, Arcanobacterium pyogenes, Corynebacterium bovis and Streptococcus dysgalactiae, were bovine mastitis field isolates. Four of the type strains, E. coli, S. agalactiae, K. pneumoniae and S. aureus, were found to be of human origin, while the other 3 type strains were isolated from bovine infections. Secondly, the melt curves and corresponding amplicon sequences of A. pyogenes, E. coli, S. agalactiae, S. dysgalactiae, K. pneumoniae, S. uberis and S. aureus were compared with 10 bovine mastitis field isolates of each pathogen. Based on the distinct differences in melt curves and sequences between human and bovine isolates of E. coli and K. pneumoniae, it was deemed necessary to select a set of bovine strains for these pathogens to be used as reference strains in the HRMA. Next, the HRMA was validated by three interpreters analyzing the differential clustering pattern of melt curves of 60 bacterial cultures obtained from mastitis milk samples. The three test interpreters were blinded to the culture and sequencing results of the isolates. Overall accuracy of the validation assay was 95% as there was difficulty in identifying the streptococci due to heterogeneity observed in the PCR amplicons of S. uberis. The present study revealed that broad-range real-time PCR with HRMA can be used as a powerful, fast and low-cost tool for the differentiation of clinically important bacterial mastitis pathogens. 相似文献
14.
M?rit Pringle Christer Bergsten Lise-Lotte Fernstr?m Helena H??k Karl-Erik Johansson 《Acta veterinaria Scandinavica》2008,50(1):40
Background
Digital dermatitis in cattle is an emerging infectious disease. Ulcerative lesions are typically located on the plantar skin between the heel bulbs and adjacent to the coronet. Spirochetes of the genus Treponema are found in high numbers in the lesions and are likely to be involved in the pathogenesis. The aim of this study was to obtain pure cultures of spirochetes from cattle with digital dermatitis and to describe them further.Methods
Tissue samples and swabs from active digital dermatitis lesions were used for culturing. Pure isolates were subjected to, molecular typing through 16S rRNA gene sequencing, pulsed-field gel electrophoresis (PFGE), random amplified polymorphic DNA (RAPD) and an intergenic spacer PCR developed for Treponema spp. as well as API-ZYM and antimicrobial susceptibility tests. The antimicrobial agents used were tiamulin, valnemulin, tylosin, aivlosin, lincomycin and doxycycline.Results
Seven spirochete isolates from five herds were obtained. Both 16S rRNA gene sequences, which were identical except for three polymorphic nucleotide positions, and the intergenic spacer PCR indicated that all isolates were of one yet unnamed species, most closely related to Treponema phagedenis. The enzymatic profile and antimicrobial susceptibility pattern were also similar for all isolates. However it was possible to separate the isolates through their PFGE and RAPD banding pattern.Conclusion
This is the first report on isolation of a Treponema sp. from cattle with digital dermatitis in Scandinavia. The phylotype isolated has previously been cultured from samples from cattle in the USA and the UK and is closely related to T. phagedenis. While very similar, the isolates in this study were possible to differentiate through PFGE and RAPD indicating that these methods are suitable for subtyping of this phylotype. No antimicrobial resistance could be detected among the tested isolates. 相似文献15.
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
16.
肉牛粪污中纤维素降解菌的分离筛选 总被引：1，自引：0，他引：1
肉牛粪污中纤维素降解菌的分离筛选 《畜牧与饲料科学》2019,40(11):79-83
为了获得有效降解肉牛粪污中纤维素的细菌,采用以羧甲基纤维素钠为碳源的方法对牛粪及其自然堆肥样品进行纤维素降解菌的分离,对已分离菌株进行形态学和分子生物学鉴定,再结合纤维素刚果红水解圈测定和滤纸条降解试验做进一步研究。结果表明,以羧甲基纤维素钠为碳源,初步分离得到牛粪样品及堆肥中32株纤维素降解菌,进一步筛选得到有刚果红水解圈菌株4株,分别为XQ-1、XQ-2、XQ-3、XQ-4,其对滤纸条具有一定的降解能力,经16S rDNA鉴定,4株菌株分别为大肠埃希菌（Escherichia coli）、黏质沙雷菌（Serratia marcescens）、雷氏普罗威登斯菌（Providencia rettgeri）和费格森埃希菌（Escherichia fergusonii）。 相似文献
17.
Infectious bovine keratoconjunctivitis (IBK) is a common ocular disease of cattle, which is generally thought to be caused by Moraxella bovis. However, a recently characterized Moraxella, M. bovoculi, has been isolated from animals with IBK. The aim of this study was to identify and characterize strains of Moraxella spp. obtained from IBK cases in different geographic locations within Uruguay. Ribosomal gene sequencing indicated that there were two groups of isolates that showed homology with either M. bovis or M. bovoculi. Phylogenetic analysis confirmed the presence of two species as the isolates grouped in different branches of the dendrogram. Conventional biochemical characterization did not distinguish between the species; only 9/25 isolates which had genetic homology with M. bovoculi showed any differences in biochemistry. 相似文献
18.
19.
《Veterinary microbiology》2015,175(2-4):294-303
The human oral microbiome is known to play a significant role in human health and disease. While less well studied, the feline oral microbiome is thought to play a similarly important role. To determine roles oral bacteria play in health and disease, one first has to be able to accurately identify bacterial species present. 16S rRNA gene sequence information is widely used for molecular identification of bacteria and is also useful for establishing the taxonomy of novel species.The objective of this research was to obtain full 16S rRNA gene reference sequences for feline oral bacteria, place the sequences in species-level phylotypes, and create a curated 16S rRNA based taxonomy for common feline oral bacteria.Clone libraries were produced using “universal” and phylum-selective PCR primers and DNA from pooled subgingival plaque from healthy and periodontally diseased cats. Bacteria in subgingival samples were also cultivated to obtain isolates. Full-length 16S rDNA sequences were determined for clones and isolates that represent 171 feline oral taxa. A provisional curated taxonomy was developed based on the position of each taxon in 16S rRNA phylogenetic trees.The feline oral microbiome curated taxonomy and 16S rRNA gene reference set will allow investigators to refer to precisely defined bacterial taxa. A provisional name such as “Propionibacterium sp. feline oral taxon FOT-327” is an anchor to which clone, strain or GenBank names or accession numbers can point. Future next-generation-sequencing studies of feline oral bacteria will be able to map reads to taxonomically curated full-length 16S rRNA gene sequences. 相似文献