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1.
为分离东北民猪源停乳链球菌(Streptococcus dysgalactiae)并鉴定其生物学特性,从齐齐哈尔市某东北民猪场死亡仔猪的肝脏及其关节液样品中分离病原菌,通过生理生化试验和分子生物学试验鉴定分离菌,研究了分离菌的致病性和药物敏感性。结果表明,分离到革兰阳性球菌1株,生化指标与停乳链球菌停乳亚种相符。系统进化树分析表明,分离菌株与停乳链球菌停乳亚种参考菌株的同源性为97%~98%,其中与AB537921.1(Japan)同源性最高,达到98.99%,进一步从分子水平鉴定该菌为停乳链球菌停乳亚种。以0.2mL/只(3.2×10^9CFU/mL)接种量感染小鼠,发病率和病死率均为100%。分离菌对多黏菌素B、阿莫西林、氨苄西林、环丙沙星、氧氟沙星、庆大霉素、氟苯尼考、林可霉素、新霉素均敏感,仅对罗红霉素耐药。  相似文献   

2.
为分离东北民猪停乳链球菌(Streptococcus dysgalactiae)并鉴定其生物学特性,从齐齐哈尔市某东北民猪场死亡仔猪的肝脏及其关节液样品中分离病原菌,通过生理生化试验和分子生物学方法鉴定分离菌,研究了分离菌的致病性和药物敏感性。结果表明,分离到革兰阳性球菌1株,生化指标与停乳链球菌停乳亚种相符。系统进化树分析表明,分离菌株与停乳链球菌停乳亚种参考菌株的同源性为97%~98%,其中与AB537921.1(Japan)同源性最高,达到98.99%,进一步从分子水平鉴定该菌为停乳链球菌停乳亚种。以0.2 mL/只(3.2×10~9 CFU/mL)接种量感染小鼠,发病率和死亡率均为100%。分离菌对多黏菌素B、阿莫西林、氨苄西林、环丙沙星、氧氟沙星、庆大霉素、氟苯尼考、林可霉素、新霉素均敏感,仅对罗红霉素耐药。研究结果为东北民猪停乳链球菌停乳亚种病的诊断与防治提供了依据。  相似文献   

3.
在实验室条件下,对金黄色葡萄球菌、链球菌(无乳链球菌和停乳链球菌)、化脓隐秘杆菌用不同规格的重组溶葡萄球菌酶粉以常规使用剂量进行抑杀菌实验.结果表明:重组溶葡萄球菌酶粉在常规药物剂量下,对金黄色葡萄球菌具有良好的抑杀菌效果,对链球菌、化脓隐秘杆菌有一定的抑杀效果.  相似文献   

4.
新疆伊犁某地区一些马群中不断出现以全身多发性脓肿为特征的患病马匹,为了查明其是否为马腺疫,以及由何种马链球菌感染所致,无菌采集典型患病马匹脓汁样品,常规THB增菌,绵羊鲜血平板划线分离单菌落后,用透射电镜对分离菌的微观形态进行观察,PCR对其fneB基因进行克隆与序列分析,最后用生化试验进行验证。结果表明,从12匹患病马的脓肿组织中,共采集了25份样品,从中分离鉴定出来源于不同患病马的2株马链球菌马亚种菌株,这2株菌的形态均符合链球菌的特点;基因克隆测序结果表明,其中1株与英国源的兽疫亚种H70和马亚种4047核苷酸同源性较高,均达97%~98%,另1株与英国源的马亚种4047和瑞典源某马亚种核苷酸同源性较高,均达98%~99%。这2株菌之间核苷酸序列同源性达98.3%,氨基酸同源性则达99.3%。马链球菌马亚种是引起伊犁某地区这些患马全身多发性脓肿的主要致病菌,它们可能来源于之前从欧洲和美洲引进的马匹,提示在进行疫病防控工作时,要特别注意海关检疫,积极防止疫病的传入。  相似文献   

5.
为了解马源马链球菌兽疫亚种(S.zooepidemicus)新疆分离株马链球菌兽疫亚种类M蛋白(SzM)基因的分子进化与变异情况,为该菌引起的感染性疾病的防控提供依据,本试验对新疆地区某马场采集的病马淋巴结样品进行病原菌的分离培养和生化鉴定,并对分离菌株进行药物敏感性试验。根据已发表的马源SzM基因序列设计引物,对其SzM基因进行PCR扩增及序列测定。将获得的SzM序列与GenBank中不同动物源马链球菌兽疫亚种分离株序列进行同源性比对和遗传进化分析。结果显示,分离得到了一株革兰氏阳性链球菌,将其命名为马链球菌兽疫亚种ZMSY15-1。药物敏感性试验结果表明,分离菌株对青霉素、磺胺嘧啶钠耐药,对其他14种药物均敏感。序列分析结果显示,马链球菌兽疫亚种ZMSY15-1与国内外不同动物源分离株SzM基因氨基酸同源性为56.0%~70.0%。遗传进化分析结果显示,这些菌株可分为4个群。马链球菌兽疫亚种ZMSY15-1与猪源分离株SzM蛋白的氨基酸同源性为59.9%,分别属于2个不同的群,其与美国马源分离株NH55426亲缘关系最近。本试验结果可丰富国内马源马链球菌兽疫亚种SzM基因的信息数据,为马链球菌兽疫亚种的致病机制研究和预防控制提供参考依据。  相似文献   

6.
为了解马源马链球菌兽疫亚种(S.zooepidemicus)新疆分离株马链球菌兽疫亚种类M蛋白(SzM)基因的分子进化与变异情况,为该菌引起的感染性疾病的防控提供依据,本试验对新疆地区某马场采集的病马淋巴结样品进行病原菌的分离培养和生化鉴定,并对分离菌株进行药物敏感性试验。根据已发表的马源SzM基因序列设计引物,对其SzM基因进行PCR扩增及序列测定。将获得的SzM序列与GenBank中不同动物源马链球菌兽疫亚种分离株序列进行同源性比对和遗传进化分析。结果显示,分离得到了一株革兰氏阳性链球菌,将其命名为马链球菌兽疫亚种ZMSY15-1。药物敏感性试验结果表明,分离菌株对青霉素、磺胺嘧啶钠耐药,对其他14种药物均敏感。序列分析结果显示,马链球菌兽疫亚种ZMSY15-1与国内外不同动物源分离株SzM基因氨基酸同源性为56.0%~70.0%。遗传进化分析结果显示,这些菌株可分为4个群。马链球菌兽疫亚种ZMSY15-1与猪源分离株SzM蛋白的氨基酸同源性为59.9%,分别属于2个不同的群,其与美国马源分离株NH55426亲缘关系最近。本试验结果可丰富国内马源马链球菌兽疫亚种SzM基因的信息数据,为马链球菌兽疫亚种的致病机制研究和预防控制提供参考依据。  相似文献   

7.
从患乳房炎和子宫内膜炎奶牛的奶或子宫黏液中分离菌株,鉴定后选取金黄色葡萄球菌105株、表皮葡萄球菌20株、大肠埃希氏菌20株、链球菌38株(其中停乳链球菌8株,无乳链球菌30株)和牛源多杀巴氏杆菌5株,在体外用重组溶葡萄球菌酶、苯唑西林、氨苄西林、庆大霉素按照微量肉汤稀释法进行了杀菌试验。结果表明,重组溶葡萄球菌酶对奶牛乳房炎和子宫内膜炎分离的金黄色葡萄球菌和表皮葡萄球菌具有良好抑杀效果,对链球菌(包括无乳链球菌和停乳链球菌)和牛源多杀巴氏杆菌具有一定的抑杀效果,对大肠杆菌作用较差;苯唑西林、氨苄西林、庆大霉素都有一定量的耐药菌株产生,而重组溶葡萄球菌酶对苯唑西林、氨苄西林、庆大霉素耐药菌株同样具有良好抑杀效果。  相似文献   

8.
从患乳房炎和子宫内膜炎奶牛的奶或子宫黏液中分离菌株后经鉴定选取金黄色葡萄球菌105株、表皮葡萄球菌20株、大肠埃希氏菌20株、链球菌38株(其中停乳链球菌8株,无乳链球菌30株)和牛多杀性巴氏杆菌5株。在体外用重组溶葡萄球菌酶、苯唑西林、氨苄西林、庆大霉素按照微量肉汤稀释法进行抑杀菌实验。结果表明:重组溶葡萄球菌酶对奶牛乳房炎和子宫内膜炎分离的金黄色葡萄球菌和表皮葡萄球菌(包括耐药菌株和敏感菌株)具有良好抑杀效果,对链球菌(包括无乳链球菌和停乳链球菌)和牛多杀性巴氏杆菌具有一定的抑杀效果,对大肠杆菌作用较差;苯唑西林、氨苄西林、庆大霉素都有一定量的耐药菌株产生,而重组溶葡萄球菌酶对苯唑西林、氨苄西林、庆大霉素耐药菌株同样具有良好抑杀效果。  相似文献   

9.
奶牛乳房炎是奶牛常见病和多发病之一,给奶牛养殖业带来了巨大的经济损失。本试验对昆明地区多个奶牛场的奶牛临床型乳房炎病原菌进行分离、鉴定,从114份乳样中共分离出13种305株细菌,经培养特性、染色镜检、生化鉴定等试验,鉴定出金黄色葡萄球菌63株,占20.66%;表皮葡萄球菌26株,占8.52%;无乳链球菌53株,占17.38%;停乳链球菌23株,占7.54%;乳房链球菌19株,占6.23%;乳链球菌14株,占4.59%;粪链球菌15株,占4.92%;化脓链球菌14株,占4.59%;大肠杆菌48株,占15.74%;真菌12株,占3.93%。分别对所有分离菌株进行17种药物的敏感性试验,结果表明,除真菌外所有菌株对庆大霉素、新霉素、环丙沙星、诺氟沙星、林可霉素、乳肿康均高度敏感,对临床常用的青霉素、链霉素、鱼腥草等具有较强的耐药性。  相似文献   

10.
对昆明地区多个奶牛场的奶牛临床型乳房炎病原菌进行分离、鉴定,从114份乳样中共分离出细菌13种305株,经培养特性、染色镜检、生化鉴定等,鉴定出金黄色葡萄球菌63株,占20.66%;表皮葡萄球菌26株,占8.52%;无乳链球菌53株,占17.38%;停乳链球菌23株,占7.54%;乳房链球菌19株,占6.23%;乳链球菌14株,占4.59%;粪链球菌15株,占4.92%;化脓链球菌14株,占4.59%;大肠杆菌48株,占15.74%;真菌12株,占3.93%。分别对分离菌株进行17种药物的敏感性试验,除真菌外,所有菌株对庆大霉素、新霉素、环丙沙星、诺氟沙星、林可霉素、乳肿康均高度敏感,对临床常用的青霉素、链霉素、鱼腥草等具有较强的耐药性。  相似文献   

11.
为鉴定从临床病料中分离的两株细菌(XL株、XT株)的种属、致病性及耐药性等生物学特征,本研究对分离菌进行了纯化、革兰氏染色、迁徙生长试验、16S rDNA的序列比对、小鼠致病试验、药敏试验以及耐药基因Ⅰ类整合子的扩增。结果表明:两株细菌均为奇异变形杆菌;与NCBI登录的猪源奇异变形杆菌的16S rDNA的同源性高达99.9%~100%;两株细菌致病性均很强;两株细菌均存在多重耐药,仅有丁胺卡那对它们高敏;两株细菌均能扩增出Ⅰ类整合子。该研究结果为进一步研究变形杆菌的耐药性提供了科学依据。  相似文献   

12.
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   

13.
14.
为了研究引起水貂肺炎死亡的病因,对送检的病死水貂进行剖检。从病死水貂病料中分离出了一株革兰阳性球菌,对其进行菌落形态观察、生化鉴定以及16S rDNA序列分析,构建系统进化树并进行同源性分析,同时对该菌株进行药敏试验。结果表明:根据分离菌的形态特征、生物化学特性,结合16S rDNA序列测定与进化树分析,将其鉴定为链球菌属的停乳链球菌似马亚种。药敏试验结果显示,该菌株对青霉素、阿莫西林、莫西沙星等药物敏感,但对四环素有较强的耐药性。  相似文献   

15.
Streptococci pathogenic for the horse include S. equi (S. equi subsp. equi), S. zooepidemicus (S. equi subsp. zooepidemicus), S. dysgalactiae subsp. equisimilis and S. pneumoniae capsule Type III. S. equi is a clonal descendent or biovar of an ancestral S. zooepidemicus strain with which it shares greater than 98% DNA homology and therefore expresses many of the same proteins and virulence factors. Rapid progress has been made in identification of virulence factors and proteins uniquely expressed by S. equi. Most of these are expressed either on the bacterial surface or are secreted. Notable examples include the antiphagocytic SeM and the secreted pyrogenic superantigens SePE-I and H. The genomic DNA sequence of S. equi will greatly accelerate identification and characterization of additional virulence factors and vaccine targets. Although it is the most frequently isolated opportunist pyogen of the horse, S. zooepidemicus has been the subject of few contemporary research studies. Variation in the protectively immunogenic SzP proteins has, however, been well characterized. Given its opportunist behavior, studies are urgently needed on regulation of virulence factors such as capsule and proteases. Likewise, information is also very limited on virulence factors and associated gene regulation of S. dysgalactiae subspecies equisimilis. It has recently been shown that equine isolates of Streptococcus pneumoniae are clonal, a feature shared with S. equi. All equine isolates express capsule Type III, are genetically similar, and have deletions in the genes for autolysin and pneumolysin. In summary, the evolving picture of the interaction of the equine pathogenic streptococci and their host is that of multiple virulence factors active at different stages of pathogenesis. The inherent complexity of this interaction suggests that discovery of effective combinations of immunogens from potential targets identified in genomic sequence will be laborious.  相似文献   

16.
从天津地区某猪场病猪肺脏脓肿中分离到一株具有β溶血特性的细菌,经形态学与生化特性分析,初步确定为化脓隐秘杆菌(Arcanobacterium pyogenes),并命名为TJjh1913.利用PCR扩增16S rRNA基因,经Blast序列分析,其序列与GenBank数据库中猪源化脓隐秘杆菌的核苷酸序列同源性高达99....  相似文献   

17.
An outbreak of strangle-like disease involving 26 horses farmed in central Italy was investigated by clinic examination, endoscopy, cytology, bacteriology and polymerase chain reaction (PCR). At weekly interval, a total of three nasal swabs and one guttural pouches lavage fluid (GPLF) were collected, and no Streptococcus equi subsp. equi carrier was found. Some horses showed upper airways disease and endoscopic signs of pharyngeal lymphoid hyperplasia of different grade and/or abnormal endoscopic appearance of guttural pouches. Streptococcus dysgalactiae subsp. equisimilis was isolated from 14 horses while S. equi subsp. zooepidemicus was isolated from six horses. PCR confirmed the biochemical and serological identification of all isolates and was positive in 10 bacteriological negative samples. The absence of S. equi and the frequent detection of S. equisimilis and S. zooepidemicus suggest that beta-haemolytic streptococci other than S. equi could be the causative agent of strangle-like disease.  相似文献   

18.
Streptococcus pyogenes, S. agalactiae, S. dysgalactiae, S. equi, S. equisimilis, S. zooepidemicus, Streptococcus group G and L were found to produce deoxyribonucleases (DNases) which were demonstrated using the Toluidine Blue DNA Agar (TDA) described for staphylococcal DNases. The activity of streptococcal DNases increased in the presence of Mg++ and Ca++ ions, the pH optimum was about 7.5 and native DNA was the best enzyme substrate. It is consequently recommended to modify the TDA according to these results for the demonstration of streptococcal DNases. All streptococcal DNases, except the DNase of S. zooepidemicus, were found to be heat-stable. Isoelectric focusing was a convenient technique for separation of streptococcal DNases and for estimation of the pI values of the DNases. S. agalactiae and S. dysgalactiae generally exhibited distinct species specific patterns in the isoelectric focusing experiments. The DNases produced by S. pyogenes were serologically related to the DNases of S. dysgalactiae and Streptococcus group G. A similar relationship was demonstrated between the DNases produced by S. equisimilis and Streptococcus group L.  相似文献   

19.
Bacterial superantigens are one of the major virulence factors produced by Streptococcus pyogenes and Staphylococcus aureus. The two novel superantigen encoding genes seeM and seeL were described for S. equi subsp. equi which is known as the causative agent of strangles in equids. In the present study previously characterized S. equi subsp. equi strains and strains of various other animal pathogenic streptococcal species and subspecies were investigated for the presence of the superantigen encoding genes seeM and seeL by polymerase chain reaction. According to these studies seeL and seeM appeared to be a constant characteristic of all investigated S. equi subsp. equi strains. Surprisingly, one S. equi subsp. zooepidemicus strain (S.z. 122) was also positive for both genes. The species identity of this S. equi subsp. zooepidemicus strain could additionally be confirmed by sequencing the 16S rRNA gene and the 16S-23S rDNA intergenic spacer region. The superantigen encoding genes could not be found among additionally investigated S. equi subsp. zooepidemicus strains or among strains of seven other streptococcal species. The seeL and seeM genes of the S. equi subsp. equi strain S.e. CF32 and the genes szeL and szeM of the S. equi subsp. zooepidemicus strain S.z. 122 were cloned and sequenced. A sequence comparison revealed a high degree of sequence homology between seeL, szeL, speL and seeM, szeM and speM, respectively. The superantigenic toxins L and M seemed to be widely distributed virulence factors of S. equi subsp. equi, rare among S. equi subsp. zooepidemicus but did not occur among a number of other animal pathogenic streptococcal species.  相似文献   

20.
Bèta-hemolytic streptococci from pigs: bacteriological diagnosis   总被引:1,自引:0,他引:1  
Bèta-hemolytic streptococci from lesions in pigs were identified as S. dysgalactiae biotype "equisimilis" and S. dysgalactiae serovar L, S. porcinus, S. agalactiae, E. faecalis and CO2 dependent and broad bèta-hemolytic S. suis. Data are provided which can be used in the interpretation of commercial identification systems. Tests results and physiological characteristics which complete identification procedures using coagglutination tests are proposed and discussed.  相似文献   

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