副猪嗜血杆菌血清7型菌株毒力及耐药性分析

【目的】了解河南地区副猪嗜血杆菌(Haemophilus parasuis,Hps)血清7型流行菌株的毒力及耐药情况。【方法】以Hps血清7型参考菌株为对照,对6株Hps血清7型临床分离菌株进行16S rRNA基因扩增、序列分析、毒力基因检测、致病性试验和药敏试验研究。【结果】16S rRNA基因测序及相似性比对结果显示,菌株1436与参考菌株0007相似性为100%,菌株1565、1624与参考菌株0007相似性均为98.6%。系统发育树分析表明,菌株1436与参考菌株0007亲缘关系最近;菌株1624与参考菌株0007亲缘关系最远。6株临床菌株与参考菌株表现为2种毒力基因型,菌株均携带有vta1、vta2、vta3、wza、nanH、cdtA、cdtB、cdtC和espP2毒力基因,其中5株临床菌株还携带ompP2毒力基因。豚鼠致病性试验结果显示,临床菌株毒力较参考菌株表现出不同程度的增强,参考菌株不能感染豚鼠发病,未表现任何临床症状;临床菌株可感染豚鼠发病,表现出一定的临床症状,发病率为20%~40%,死亡率为0。参考菌株和临床菌株均对头孢他啶和头孢噻呋敏感,对强力霉素、氟苯尼考中介,对新霉素、卡那霉素、阿米卡星、红霉素、替米考星等耐药,且均表现出多重耐药现象。【结论】Hps血清7型临床菌株有一定的致病性,但毒力较弱,对头孢类药物敏感,有明显的多重耐药现象,临床上应注意对该血清型的防控。本研究为Hps血清7型流行病学、致病机制研究奠定了基础,为Hps血清7型的临床防控提供了参考依据。     

家养野猪副猪嗜血杆菌的分离鉴定及16S rRNA序列分析

对江西省某家养野猪场临诊疑似副猪嗜血杆菌（Haemophilusparasuis,Hps）感染的病例进行细菌分离鉴定,PCR扩增分离菌株的16SrRNA并进行测序分析,并对分离菌进行细菌形态、生化鉴定和PCR鉴定及序列比对分析。结果显示,获得1株家养野猪源Hps分离株（命名为HPJXYZ01）,该分离株与国内外参考菌株序列之闻的同源性为93．1％～99．2％,与本实验室江西省家猪源分离株的同源性为84％～92．1％。结果表明,江西省家养野猪中存在Hps感染,分离株与国内外家猪源Hps间的16SrRNA序列差异不大,Hps16SrRNA核苷酸序列比较稳定,其进化不存在明显的地域相关性。     

1株副猪嗜血杆菌血清4型的分离鉴定及耐药性分析

【目的】阐明引起河南漯河某规模化猪场仔猪呼吸道症状的主要细菌性病原体及其生物学特性。【方法】无菌采集发病仔猪的口鼻拭子及病死猪的胸腔积液及肺脏、肝脏、脾脏等组织器官,进行病原的PCR检测,并通过细菌分离培养、形态学观察、卫星试验、16S rDNA基因PCR扩增、系统进化树构建、多重PCR鉴定分离菌的血清型、致病性试验和药敏试验等对分离菌株进行生物学特性分析。【结果】在含有V因子的BHI固体平板上生长出圆形、表面光滑湿润、无色透明的微小菌落,在不含V因子的培养基上不生长;分离菌株经革兰染色,镜下可见革兰阴性菌,多呈单个存在的球杆、长杆状;在金黄色葡萄球菌的培养物周围形成典型的“卫星菌落”;16S rDNA基因序列分析表明,分离菌株与副猪嗜血杆菌(Haemophilus parasuis,Hps)处于同一分支,相似性>97%,亚型鉴定结果判定分离菌为Hps血清4型;将分离的Hps腹腔注射感染小鼠,可导致感染小鼠多个器官不同程度出血,以肺脏最为明显;高剂量感染可导致小鼠死亡。药敏试验发现,该菌株对四环素、环丙沙星、复方新诺明具有较强抗性,合理用药后,取得了良好的治疗效果。【结论】试验成...     

副猪嗜血杆菌的分离鉴定与药敏试验

对一例临床症状、病理剖检变化疑似副猪嗜血杆菌病的仔猪病料进行实验室诊断,进行了细菌培养特性和生化特性等鉴定,初步怀疑为副猪嗜血杆菌,根据副猪嗜血杆菌的16 S rRNA基因设计特异性引物进行PCR扩增鉴定,结果表明,分离菌为副猪嗜血杆菌.药敏试验显示,该分离菌对阿米卡星、头孢氨苄、新霉素高度敏感.     

副猪嗜血杆菌的分离鉴定及16S rRNA序列分析

从云南某规模化养猪场病猪肺脏分离到1株革兰氏阴性小杆菌,经细菌生化鉴定、PCR鉴定和16S rRNA序列比对鉴定为副猪嗜血杆菌。抗生素药物敏感试验结果表明,分离菌株对四环素、红霉素、氯霉素、头孢噻吩高敏;对庆大霉素、氧氟沙星、诺氟沙星中敏;对磺胺甲唑耐药。16S rRNA分析结果表明,该分离株与GenBank中的Hps参考株AB078973(基因登录号)同源性为100%,将分离菌株鉴定为副猪嗜血杆菌。16S rRNA遗传进化关系表明,分离株与副猪嗜血杆菌3株血清5型参考株AB078972、AB078973、AB078974的16S rRNA序列位于一个分支上,遗传进化关系最近,它们之间的核苷酸同源性在99.0%~99.4%之间,初步鉴定为血清5型副猪嗜血杆菌,致病性试验结果表明,分离菌株对小白鼠有强致病性,命名为YN-1株。     

猪繁殖与呼吸综合征病毒与副猪嗜血杆菌混合感染的诊断

为确诊广东省阳江市某规模化猪场（存栏800头母猪）保育猪发病死亡的原因,本试验对从该发病猪场采集的3份肺脏、肝脏、脾脏临床样品进行细菌学检测及药敏试验,采用PCR/RT-PCR检测临床样品中猪伪狂犬病病毒（PRV）、猪瘟病毒（CSFV）、猪繁殖与呼吸综合征病毒（PRRSV）、猪圆环病毒2型（PCV2）、猪圆环病毒3型（PCV3）和猪肺炎支原体等病原。对特异性扩增的3株PRRSV的ORF5基因产物进行序列测定,与VR2332、HuN4、JXA1、CH-1a等代表毒株进行核苷酸序列同源性分析,并构建系统进化树。结果表明,试验分离鉴定出1株副猪嗜血杆菌（Hps）,对7种临床常用药如阿莫西林、头孢拉定等均有较强的敏感性。同源性比对结果表明,3株PRRSV （LJW1、LJW2和LJW3）ORF5基因核苷酸同源性为99.3%~99.8%,与欧洲型代表毒株Lelystad核苷酸同源性为64.0%~64.2%,与HP-PRRSV毒株JXA1、HuN4、CH-1a和TJ核苷酸同源性较高,分别为99.2%~99.5%、99.0%~99.3%、94.5%~94.9%和98.8%~99.2%;与中国河南和广西分离的HP-PRRSV毒株HeNzm1-16和GXLZ05-2015核苷酸同源性较高,分别为99.3%~99.7%和99.2%~99.7%,与美洲型经典疫苗株MLV、美洲型标准株NC、美洲型经典株VR2332核苷酸同源性较低,分别为88.5%~88.8%、85.2%~85.5%和82.3%~82.6%。PRRSV ORF5基因系统进化树分析表明,3株PRRSV均属于美洲型毒株,与国内HP-PRRSV代表毒株JXA1、HuN4和TJ等处于同一分支,亲缘关系较近。本研究揭示了该场保育猪发病病原,并从分子水平上明确了分离的3株PRRSV与不同代表毒株的亲缘关系,为弱毒疫苗的合理选择使用和综合防控PRRSV提供了参考依据。     

Molecular characterization of Streptococcus suis strains by 16S–23S intergenic spacer polymerase chain reaction and restriction fragment length polymorphism analysis

We developed a new molecular method of typing Streptococcus suis based on polymerase chain reaction (PCR) amplification of a large fragment of rRNA genes, including a part of the 16S and 23S genes and the 16S-23S intergenic spacer region (ISR), followed by restriction fragment length polymorphism (RFLP) analysis with RsaI or MboII endonuclease. The 16S-23S ISRs of 5 S. suis isolates were sequenced and compared. Size and sequence polymorphisms were observed between the S735 reference strain and the 4 wild-type strains. The genetic relationships between 138 independent S. suis strains belonging to various serotypes, isolated from swine or human cases, were determined. The discriminatory power of the method was > 0.95, the threshold value for interpreting typing results with confidence (0.954 with RsaI and 0.984 with RsaI plus MboII). The in vitro reproducibility was 100%. The strains isolated from humans were less genetically diverse than the strains isolated from pigs. For the first time, 2 molecular patterns (R6, M9) were significantly associated with S. suis serotype 2 strains. This genetic tool could be valuable in distinguishing individual isolates of S. suis during epidemiologic investigations.     

Isolation and Identification of Haemophilus parasuis SD02 strain

A bacterial strain was isolated from the sick pigs suspiciously infected by polyserositis and arthritis in a pig farm in Shandong Province,and identified through morphological observation,culture traits,biochemical characteristics and PCR amplification.Additionally,primers were de-signed according to the 16S rRNA sequence of Haemophilus parasuis,and the bacterial strain was amplified by PCR.The amplified fragments of approximately 1 400 bp was sequenced,and aligned with the sequence in Gen Bank.The results showed that it shared the homology of 97%-99%with the 16S rRNA sequence of foreign H.parasuis,and confirmed as H.parasuis(HPS).The strain was determined as serotype 4 through serotype identification.The strain was named SD02.     

Comparative sequence analysis of 16S rRNA gene of Pasteurella multocida serogroup B isolates from different animal species

The phylogenetic relationships of five isolates of Pasteurella multocida serotype B:2 belonging to buffalo, cattle, pig, sheep and goat were investigated by comparative sequence analysis of 16S rRNA gene. The 1468bp fragment of 16S rRNA gene sequence comparison showed that the isolates of cattle (PM75), pig (PM49) and sheep (PM82) shared 99.9% homology with the buffalo isolate (vaccine strain P52) whereas, the goat isolate (PM86) shared 99.8% homology with the vaccine strain. The 16S rRNA gene sequences of these isolates were also found monophyletic with type B reference strain NCTC 10323 of P. multocida subsp. multocida. The present study indicated the close relationships of haemorrhagic septicaemia causing P. multocida serotype B:2 isolates of buffalo and cattle with other uncommon hosts (pig, sheep and goat).     

副猪嗜血杆菌广东流行株的分离鉴定与基因分析

本研究从广东省各个地区送检病料中成功分离鉴定了4株副猪嗜血杆菌,并且针对副猪嗜血杆菌16S rRNA基因特异性进行PCR检测和基因测序同源性分析,通过GenBank联机比对分析,所分离的菌株与国内外菌株16S rRNA序列同源性在98.2%以上,分离菌株之间同源性在99.6%~100%之间,证明了所暴发的菌株是副猪嗜血杆菌。     

华南地区肉鸽源沙门氏菌的鉴定及遗传进化分析

本试验从华南地区发病肉鸽肠道和肝脏中用BS培养基分离、纯化沙门氏菌,并进行多项生化试验和血清型鉴定试验,结果显示各项生化检测指标均符合沙门氏菌的特点;血清型鉴定试验结果表明该分离菌属沙门氏菌属A-F群。进一步对该分离菌的16S rRNA片段测序及遗传进化分析,确定该分离菌为沙门氏菌菌株,与鼠伤寒沙门氏菌同源性为100%。对该分离菌进行动物回归试验,结果表明该沙门氏菌菌株为华南地区肉鸽的致病菌株。该结果为进一步研究华南地区肉鸽沙门氏菌的致病机理和防控奠定了基础。     

牦牛肺炎病原多杀性巴氏杆菌和殊异支原体的分子鉴定与分析

青海省刚察县某牦牛产业基地牦牛发生咳嗽,鼻孔有分泌物流出,呼吸困难等症状的疾病。为快速确诊发病牛的致病原因,及时防控和治疗,从发病和病死的牦牛中,采集鼻腔拭子和肺脏、胸腔积液,利用PCR方法进行分子鉴定与分析。结果显示:此牛场中引发肺炎的病原是A型多杀性巴氏杆菌和殊异支原体两种病原体混合感染,测序结果显示5个有效样品中鉴定的为完全相同的病原,P.multocida-GC1的Kmt基因与参考序列中国株CP031554/3/2/1同源性在99%以上,M.dispar-GC1与参考序列的16S rRNA基因同源性在97%以上。同时在遗传进化角度再次分析确认了鉴定的P.multocida与中国和俄罗斯的A型多杀性巴氏杆菌聚成一大支;鉴定的M.dispar与殊异支原体聚为一支。结果表明,青海刚察地区牦牛存在感染多杀性巴氏杆菌和殊异支原体的潜在风险,该研究为牦牛呼吸道疾病与肺炎的病原学调查和病原的流行病学调查提供了参考数据。     

Isolation，Identification and Antibiotics Resistance Analysis of Enterococcus from Yak

17 feces samples of yak which were collected in Hongyuan county were measured with Gram staining method and 16S rRNA molecular identification in this study.8 suspected Enterococcus were separate from feces samples by bacteria purification and PCR amplification with 1 500 bp specific band. 6Enterococcus faecalis and 2Enterococcus faecium were identified through 16S rRNA sequencing.The homology analysis of the strains revealed that the homology between Enterococcus faecalis and reference strains sequence were 99.7% to 100%,that of Enterococcus faecium and reference sequence were 98.2% to 99.2%,indicating that the yak Enterococcus was highly conserved in the process of genetic evolution.The drug sensitive test results showed that the isolated strains were highly resistance to aminoglycoside antibiotics.Enterococcus faecium 11-1-2 strain was not only 5 multi-resistant,but also showed resistence to vancomycin.Enterococcus faecalis strains was most 3 multi-resistant.The antibiotics resistance results revealed that the resistance of yak Enterococcus was serious and should be taken seriously.     

牦牛源肠球菌的分离鉴定及耐药性分析

试验结合革兰氏染色及16S rRNA分子鉴定,对分离自红原县的17份牦牛粪便样中的肠球菌进行鉴定。结果显示,通过细菌分离纯化及PCR扩增,从牦牛粪便样品中分离出8株疑似肠球菌,分离菌的扩增产物经凝胶电泳后均产生1 500 bp特异性条带。16S rRNA测序结果显示,8株疑似肠球菌中,6株为粪肠球菌,2株为屎肠球菌。同源性比对分析显示,粪肠球菌与参考序列同源性为99.7%~100.0%,屎肠球菌与参考序列同源性为98.2%~99.2%,说明牦牛源肠球菌在遗传进化过程中高度保守。运用K-B纸片法进行药敏试验,结果显示,分离株对氨基糖苷类抗生素耐受性较高,2株屎肠球菌中,11-1-2菌株表现为5重耐药,且该菌株耐万古霉素,粪肠球菌主要表现为3重耐药,药敏结果提示牦牛源肠球菌耐药较严重,应引起高度重视。     

屠宰生猪副猪嗜血杆菌的分离鉴定及药物敏感性分析

为调查屠宰生猪副猪嗜血杆菌（Hps）的隐性感染情况,本研究从陕西省某规模化生猪屠宰场采集80份病变肺脏,应用PCR方法进行Hps核酸检测,无菌取阳性肺脏,通过平板划线分离获得疑似Hps,进一步对分离菌进行形态观察、培养特性分析、卫星现象观察、生化试验和分离菌核酸片段序列分析,纯化获得Hps分离菌;用药敏纸片法分析Hps分离菌株对常用药物的敏感性。结果显示,从80份病变肺脏中检出39份Hps阳性,阳性率48.75%（39/80）;从39份Hps阳性肺脏中分离获得3株疑似Hps,分离菌在显微镜下呈革兰氏阴性、短杆状;在添加有胎牛血清和NAD的TSA平板上生长良好;在金黄色葡萄球菌周围呈现出典型的"卫星现象"生长;能发酵葡萄糖、蔗糖、果糖、半乳糖、麦芽糖和阿拉伯糖,不发酵甘露醇;PCR扩增序列与Hps同源性在98%以上。药物敏感性试验结果显示,3株分离菌对环丙沙星、恩诺沙星和氟苯尼考等抗菌药物高度敏感,对青霉素、林可霉素和甲氧苄啶等抗菌药物耐药。本研究获得的Hps分离株为疫苗研制提供了基础材料,为生猪养殖场选择敏感药物防控Hps感染提供了参考依据。     

1株信鸽源鼠伤寒沙门氏菌的分离鉴定及其耐药性和毒力分析

本试验旨在鉴定临床疑似沙门氏菌感染致死信鸽的病原菌并确定致病菌的耐药及毒力状况。通过细菌分离培养、菌落形态观察、染色镜检、生化鉴定、血清分型、16S rRNA基因测序分析和康复信鸽血清平板凝集试验进行鉴定,并通过药敏试验、耐药基因和毒力基因检测进行耐药性和毒力分析。结果显示,分离纯化的细菌在BS、XLD、HE培养基上为黑色菌落,镜检为无荚膜、无芽孢的革兰氏阴性短杆菌;分离菌株生化反应结果符合沙门氏菌生化特性;分离菌株血清型为1,4,12：i：1,2;分离菌株16S rRNA基因序列系统进化树分析显示,该分离菌株与鼠伤寒沙门氏菌聚为一支,同源性>99%,康复信鸽血清与分离菌株发生特异性凝集,结合生化反应和血清分型结果该菌株鉴定为鼠伤寒沙门氏菌;分离菌株对氟苯尼考耐药,经耐药基因检测携带floR、cmlA氯霉素类耐药基因,与耐药表型相符;分离菌株mogA等17种毒力基因检测均为阳性。本试验成功分离到1株信鸽源鼠伤寒沙门氏菌,分离菌株对氟苯尼考耐药且具有较强毒力,为下一步信鸽沙门氏菌的防治和研究提供了参考依据。     

Detection and molecular typing of Streptococcus suis in tonsils from live pigs in France

Streptococcus suis is an important pathogen of swine, causing meningitis, arthritis, polyserositis, septicemia, and sudden death in weaning piglets as well as fattening pigs. Recently, 3 molecular tests have been developed in our laboratory: a multiplex polymerase chain reaction (m-PCR) assay for the detection of S. suis species and serotypes 2 and 1/2, and 2 molecular typing methods, pulsed-field gel electrophoresis and an approach based on PCR amplification of a fragment of rRNA genes, including a part of the 16S and 23S genes and the 16S-23S rDNA intergenic spacer region (ISR), followed by restriction fragment length polymorphism (RFLP) analysis (ISR-RFLP). In the present study, we used these tests to analyze tonsil samples from clinically healthy pigs and to identify individual isolates of S. suis during epidemiologic investigations of 8 related herds with a history of septicemia caused by S. suis serotype 2. Capsular typing showed that 58% of the strains were nontypable. Of the 17 serotypes present, serotype 22 was the most prevalent. In the 7 farms without clinical signs on the day of sampling, we detected S. suis serotype 2 or 1/2, or both, in less than 5% of the pigs by m-PCR or by bacteriologic culture. In the 8th farm, on which 2 pigs had clinical signs of septicemia on the day of sampling, we detected S. suis serotype 2 or 1/2, or both, by m-PCR in the tonsils of 40% of fattening pigs (21 wk old) that lacked symptoms. Molecular typing of the serotype 2 strains showed a common origin of contamination in these herds, given that 1 pattern (C1) was detected in the isolates from 6 of the 8 herds. However, up to 4 patterns were associated with septicemia and sudden death. Several patterns of S. suis serotype 2 can be responsible for disease in the same herd. These molecular tools may be useful for confident studies of the transmission of S. suis, thereby contributing to the control of S. suis infection.     

猪源奇异变形杆菌的分离鉴定及集群运动分析

本试验从发病猪肝脏中分离到1株细菌,经革兰氏染色镜检、生化试验、药敏分析、16S rDNA测序,确认该菌为1株多重耐药奇异变形杆菌。该菌与GenBank中其他9株不同来源的奇异变形杆菌进行16S rDNA比对分析,从遗传进化规律方面证明不同来源的的奇异变形杆菌亲缘性极其相近。周期性群集运动分析结果表明在含0.5%和1.0%琼脂平板上,该菌不以圆环样周期运动;在含1.5%和2.0%琼脂平板上,该菌以圆环样周期运动。     

猪附红细胞体16S rRNA基因的序列测定和系统进化分析

从确诊为猪附红细胞体感染的猪场，无菌采集血样，抽提猪附红细胞体基因组DNA，采用真细菌的通用引物进行16S rRNA基因扩增，对扩增产物进行克隆和测序。从3个地理位置不同的猪场均成功地扩增出长度为1469bp的核苷酸序列。系统进化分析表明，3个猪场样品所测序列一致性达99．52％以上，具有相同的基因型，但与国外报道的猪附红细胞体Illinois株同源性为95％，属于同一基因群，但基因型不同；所有种类的附红细胞体和血巴尔通氏体组成同一进化分支，这类血营养菌与支原体科，支原体属的病原最靠近(75％)，而与立克次氏体目的病原较远(70％)。上述研究证实，广东所流行的猪附红细胞体是一种新基因型的猪附红细胞体，建议命名为猪附红细胞体广东株型；为反映进化关系，猪附红细胞体和其它血营养菌应划归于支原体科的支原体属。     

鸭源多杀性巴氏杆菌的分离鉴定及耐药性分析

为鉴定临床疑似鸭多杀性巴氏杆菌感染肉鸭的病原菌，本试验通过细菌分离培养、菌体形态观察、细菌生化鉴定、16S rRNA基因测序分析、细菌种特异性鉴定、荚膜分型鉴定和动物回归试验进行鉴定，并通过药敏试验和耐药基因检测进行耐药性分析。结果显示，从患病鸭肝脏组织分离到的细菌在鲜血琼脂培养基中呈现表面光滑凸起、灰白色菌落，为革兰氏阴性短小杆菌，瑞氏染色呈两极浓染；生化鉴定结果显示，分离菌能发酵葡萄糖、蔗糖和甘露醇，硫化氢、氧化酶和吲哚等试验阳性；16S rRNA基因序列系统进化树分析显示，该分离菌与多杀性巴氏杆菌聚为一支，同源性 > 99%；细菌种特异性鉴定结果与多杀性巴氏杆菌相符；荚膜分型鉴定结果仅扩增到约为1 050 bp的目的基因片段，与荚膜血清A型相符；动物回归试验显示，该分离菌有较强的致病性；药敏试验结果显示，该分离菌对羧苄西林、氨苄西林、复方新诺明和四环素等12种药物耐药；经耐药基因PCR检测显示，该分离菌携带Sul1、Sul3、tet（X）和Intl1 4种耐药基因，与药敏表型相符。本试验成功分离到1株鸭源荚膜血清A型多杀性巴氏杆菌，为鸭多杀性巴氏杆菌病的防治提供参考依据。