鸡滑液囊支原体不同地区分离株对常用抗菌药物的敏感性试验

为调查不同地区鸡滑液囊支原体的耐药情况,从河南、江苏、安徽、河北和广东五省204份疑似鸡滑液囊支原体感染鸡的病料中分离到20株鸡滑液囊支原体,每省随机取1株进行了12种常用抗菌药物的敏感性测定。结果表明,5株鸡滑液囊支原体均对泰乐菌素较为敏感,而对恩诺沙星、氧氟沙星、盐酸环丙沙星具有不同程度的耐受性。本实验可为临床合理用药提供参考。     

河南许昌地区规模化肉鸡场滑液囊支原体的分离鉴定及耐药性检测

为了分析河南许昌地区规模化肉鸡场滑液囊支原体流行情况及耐药情况，本试验从许昌地区规模化肉鸡场采集疑似鸡滑液囊支原体感染的病料组织179份，采用细菌分离培养、形态观察及PCR等方法进行滑液囊支原体鉴定，采用K-B药敏纸片法对分离的滑液囊支原体进行耐药性检测。结果显示，分离得到87株鸡滑液囊支原体，其对金霉素、土霉素、吉他霉素、替米考星、多西环素、泰乐菌素和林可霉素耐药率分别为98.8%、94.3%、90.7%、78.2%、61.5%、58.8%和57.7%,对其他抗菌药的耐药率介于10.3%～17.9%;分离菌株呈现多重耐药性，以耐8、7、6种抗菌药分离菌株最多，分别占分离菌株的16.1%、17.2%和19.5%。结果表明许昌地区规模化肉鸡场滑液囊支原体流行严重，对临床中常用药物出现严重耐药性。本试验结果可为该地区的规模化肉鸡场滑液囊支原体防控提供指导。     

鸡滑液囊支原体感染的流行及其防控措施

正近年来,鸡滑液囊支原体感染在我国的一些养鸡场中呈现出发病率不断攀升的流行趋势,并给我国的养鸡业带来了较大的危害。为引起养鸡场对鸡滑液囊支原体感染防控的高度重视,现特就鸡滑液囊支原体感染的流行及其防控措施作一介绍,以供养鸡场参考。1鸡滑液囊支原体的病原特点     

复方中草药制剂对鸡滑液支原体病的治疗效果

选取健康的28日龄鸡滑液支原体阴性鸡,分为治疗组、阳性对照组和空白组,采用鸡滑液支原体分离株感染治疗组和对照组构建鸡滑液支原体病病理模型,通过临床症状检查及血清抗体水平检测均为阳性,成功复制了鸡滑液支原体病病理模型。用自制复方中药对治疗组进行口服饲喂治疗,感染不治疗为阳性对照组。结果显示,治疗组鸡体温较对照组鸡有明显下降趋势,平均增重有所提高,对照组分离出鸡滑液支原体病原,治疗组病原分离验证未见鸡滑液支原体病原。结果表明,自制复方中草药制剂对鸡滑液支原体病治疗有明显的临床治疗效果。     

鸡滑液囊支原体的分离和鉴定研究

从河南某肉种鸡场疑似鸡滑液囊支原体感染的病鸡跗关节样品进行病原的分离与鉴定.分离菌经瑞氏染色,在油镜下呈球形或椭圆形.在固体培养基上表现为细小、光滑、致密的小菌落,菌落形态为“煎蛋状”.L型细菌鉴定发现菌体仍保持原有形态.菌体能够吸附红细胞,分解葡萄糖,但不能分解精氨酸和尿素,还可致SPF鸡胚死亡,说明该分离菌为支原体.进一步的血清学试验结果表明,该分离菌为鸡滑液囊支原体,而不是鸡毒支原体.根据已发表的鸡滑液囊支原体血凝素基因序列vlhA设计合成一对引物,经PCR扩增,该菌体能够扩增出鸡滑液囊支原体(773 bp)的特异性片段.人工感染试验结果显示,SPF鸡能够复制出自然病例.     

一起蛋鸡滑液囊支原体病的诊疗、跟踪监测及体会

本文对青岛市某蛋鸡场发生的一例鸡滑液囊支原体病进行了诊疗分析,并跟踪监测阳性率变化情况。分析结果显示,该鸡群感染滑液囊支原体后抗生素治疗效果甚微,免疫鸡滑液囊支原体活疫苗(MS-H株)后1周未出现临床症状,实验室跟踪监测检测病原,阳性率逐渐降为0。鸡滑液囊支原体病是由鸡滑液囊支原体(Mycoplasma Synoviae,MS)引起的一种以关节渗出性的滑液囊膜炎及腱鞘滑膜炎为特征的急性或慢性传染性疾病,既可以垂直传播又可以水平传播,3~14周龄蛋鸡易感。感染后的鸡关节肿大、腿瘫、生长发育迟缓,死淘率高达10%~30%,产蛋鸡产蛋率下降,给蛋鸡养殖带来较大的经济损失。     

某蛋鸡养殖场鸡滑液囊支原体的分离鉴定及跗关节病理组织学观察

用改良Frey培养基对采集的跗关节渗出物进行病原分离,设计滑液囊支原体16S rRNA通用引物和vlhA特异性引物进行基因序列扩增并测序,用MEGA6.0软件中的Neighbor-joining法依据16S rRNA和vlhA序列构建分离株系统发育树进行遗传进化分析;对采集的跗关节组织进行固定和脱钙处理后制作石蜡切片,HE染色镜检。结果发现,分离的病原菌落呈油煎蛋样;依据16S rRNA和vlhA基因序列构建的系统发育树与滑液囊支原体在同一分支;病变的跗关节组织主要出现滑膜上皮增厚,炎性细胞渗出,血管轻度增生,血细胞渗出和滑膜组织脱落等病变。表明引发鸡群发病的病原为滑液囊支原体,为临床和实验室诊断滑液囊支原体引起的疾病提供了参考。     

鸡滑液囊支原体感染的流行病学调查与分析

为了解国内近年来鸡滑液囊支原体感染的流行情况,自2010年3月~2015年12月,对华北、华中、华南、东北、西北、华东地区11个省份不同养鸡场进行了流行病学调查。结果显示,该病在我国6个地区11个省均有发生,鸡滑液囊支原体感染鸡群多见于1~4月龄,平均发病日龄为62日龄;发病率为5.75%~25.77%,6个品种鸡(海兰褐、海兰白、罗曼、白羽肉种鸡、AA肉种鸡及三黄鸡)的平均发病率为13.92%;死亡率为4.09%~15.68%,平均死亡率为9.79%;发病率和死亡率均存在地区差异。血清学检测结果显示,血清阳性率为30.23%~54.67%。对临床病料进行病原菌的分离鉴定,共分离到鸡滑液囊支原体39株,分离率为37.1%。流行病学调查结果表明,鸡滑液囊支原体感染在我国6个地区的不同养殖场呈逐年上升趋势,应引起关注。     

山东省部分地区蛋种鸡鸡白痢和滑液囊支原体病的流行病学调查

[目的 ]了解鸡白痢和滑液囊支原体病在山东省部分地区种鸡场的流行情况。[方法 ]采用血清平板凝集试验,对济宁、泰安、聊城和菏泽4个市13个种鸡场16 312只鸡进行了鸡白痢沙门氏菌感染调查,对泰安和聊城2个市6个种鸡场2 849只鸡进行了鸡滑液囊支原体感染调查,并对其中的6个种公鸡场进行了鸡白痢沙门氏菌和滑液囊支原体共感染调查。对鸡白痢和滑液囊支原体血清阳性的鸡只进行了临床病理组织学检查。[结果]鸡白痢的平均感染率为8.39%(1 368/16 312),其中公鸡的感染率为9.32%(398/4 270),母鸡的感染率为8.06%(970/12 042),90日龄以下鸡的感染率为11%(206/1 872),90日龄以上鸡的感染率为8%(1 160/14 440)。滑液囊支原体的平均感染率为16.71%(476/2 849),其中公鸡感染率为27.11%(398/1 409),母鸡感染率为6.53%(94/1 440),90日龄以下鸡的感染率为7.26%(119/1 640),90日龄以上鸡的感染率为29.53%(357/1 209)。鸡白痢和滑液囊支原体的共感率为0.91%(11/1 209)。疑似病鸡病理学检查,观察到以白痢结节为特征的鸡白痢和跗关节、趾关节及胸部滑膜囊炎性肿胀为特征的滑液囊支原体病。[结论 ]山东省部分种鸡场普遍存在鸡白痢和滑液囊支原体病;青年鸡、产蛋鸡都不同程度地受到鸡白痢和鸡滑液囊支原体病的威胁;对这两种垂直传染性疾病的净化,势在必行。     

一例庄河大骨鸡滑液囊支原体与非典型新城疫混合感染的诊治

滑液囊支原体病程长,造成鸡只免疫力下降,严重影响鸡只生长发育。同时并发或继发感染是本病引起死亡的重要原因。本文根据1例庄河大骨鸡滑液囊支原体与非典型新城疫混合感染发病鸡群,根据鸡群的发病情况、临床症状、剖检病变,并分别进行了滑液囊支原体的剖检诊断与非典型新城疫的抗体检测,结果检出本鸡群为滑液囊支原体与非典型新城疫混合感染。     

Genotyping of Japanese field isolates of Mycoplasma synoviae and rapid molecular differentiation from the MS-H vaccine strain

Mycoplasma synoviae is an important causative agent of avian mycoplasmosis. In the present study the conserved domain of the variable lipoprotein and hemagglutinin (vlhA) gene of M. synoviae was sequenced and analyzed for 19 field strains of M. synoviae isolated from chickens across Japan. This analysis revealed that there were at least nine genotypes of M. synoviae present in Japan. Furthermore, we found a single nucleotide polymorphism (SNP) within this region in all the Japanese isolates, and based on this finding, we established a PCR method with cycling probe technology to differentiate between these field isolates and the live M. synoviae vaccine strain Mycoplasma synoviae-H (MS-H).     

Detection of Mycoplasma synoviae in clinically normal pheasants

Mycoplasma synoviae was isolated from the tracheas of seven clinically normal pheasants found in the vicinity of a chicken farm infected with M synoviae, but not from 120 pheasants and partridges with respiratory disease. When specimens were examined by the polymerase chain reaction only two additional pheasants infected with M synoviae were identified, one healthy and one diseased.     

Persistence of Mycoplasma synoviae in hens after two enrofloxacin treatments and detection of mutations in the parC gene

The ability of Mycoplasma synoviae, an avian pathogen, to persist despite fluoroquinolone treatments was investigated in hens. Groups of Mycoplasma-free hens were experimentally infected with the M. synoviae 317 strain and treated twice with enrofloxacin at the therapeutic dose. The results show that the two treatments did not have any influence on this strain of M. synoviae recovery from tracheal swabs. Mycoplasmas were isolated from tracheal swab cultures, but not from inner organs such as the liver or spleen, suggesting that this strain of M. synoviae was not able to cross the mucosal barrier to disseminate throughout the host. A significant increase of the resistance level to enrofloxacin of five re-isolated mycoplasma clones, was observed after the second treatment. This increase was associated in two clones to a Ser81-->Pro substitution, found in the ParC quinolone-resistance determining region (QRDR) of DNA topoisomerase IV. This is the first time that a mutation in a gene coding for topoisomerase IV is described in M. synoviae after in vivo enrofloxacin treatments in experimentally infected hens.     

Experimental evidence of indirect transmission of Mycoplasma synoviae

The aim of the study was to analyse experimental transmission of Mycoplasma synoviae, an avian pathogen. Three experiments using specific pathogen-free day-old chicks placed in isolators were conducted. In the first experiment, the birds were introduced in an isolator previously contaminated with a M. synoviae broth culture. After 34 days, these birds were eliminated and, for the second trial, the chicks were introduced in the same isolator without disinfecting. In the third assay, the chicks were placed in an isolator containing a mixture of food, feathers and dust collected less than an hour earlier from a M. synoviae infected laying hen flock. In the second and third experiments in order to exacerbate the M. synoviae infection, the birds were inoculated with infectious bronchitis (IB) virus. The presence of M. synoviae in the environment and in tracheal swabs was monitored by culture, a multiplex PCR (mPCR) detecting M. synoviae and Mycoplasma 16S rDNA and a multiplex RT-PCR (mRT-PCR) detecting the M. synoviae mRNA coding for a membrane protein and Mycoplasma 16S rRNA. In in vitro experimental conditions, M. synoviae mRNA and 16S rRNA were detected up to 20 min and 23 h respectively after mycoplasma death. In the first assay, the first infected bird was detected on the 13th day. In the second trial, culturable M. synoviae or viable M. synoviae were detected in the isolator for 3 or 4 to 5 days respectively after depopulation of the birds of the first assay whereas the first culture positive tracheal swabs were detected on the 33rd day, after IB inoculation. In the third experiment, the first infected birds were detected on the 54th day. Thus, the different assays showed that M. synoviae contaminated material (dust, feathers and food) can infect chicks, sometimes after remarkably long silent periods.     

Turkey sinusitis: synergism between Mycoplasma synoviae and Mycoplasma meleagridis

Sinusitis was produced experimentally in turkeys after intrasinus inoculation with broth cultures of both Mycoplasma synoviae and Mycoplasma meleagridis. No evidence of sinusitis was observed in other turkeys exposed to each of these organisms separately- indicating pathogenic synergism with these mycoplasmas.     

The isolation of Mycoplasms synoviae from chickens with infectious synovitis and air-sacculitis in the Republic of South Africa.

Mycoplasma synoviae was isolated from the trachea of chickens showing either typical infectious synovitis lesions or air-sacculitis. M. synoviae was identified by means of the direct plate fluorescent antibody technique and its growth-dependence on nicotine-amide-adenine dinucleotide. This is the first documented report on the isolation and identification of M. synoviae in the Republic of South Africa.     

A survey of avian Mycoplasma species for neuraminidase enzymatic activity

Among 23 currently recognized avian Mycoplasma (AM) species only Mycoplasma gallisepticum, Mycoplasma synoviae, Mycoplasma meleagridis and Mycoplasma iowae cause disease and loss of production in chickens and/or turkeys. Because neuraminidases are considered virulence factors in many pathogenic microorganisms the aim of our study was to determine which AM species possess neuraminidase enzymatic activity (NEAC). Small samples of AM cells were assayed for NEAC using the chromogenic substrate 5-bromo-4-chloro-3-indolyl-alpha-d-N-acetylneuraminic acid. In the case of positive NEAC reaction the substrate gave the insoluble indigoblue product what enabled simple test and easy estimation of NEAC. M. gallisepticum and M. synoviae which share sequences of the gene encoding neuraminidase (sialidase NanH) exhibited considerable levels of NEAC. However, NEAC levels differed among their strains, as well as among cultures of different strains. Only certain cultures of the type strain of M. meleagridis showed NEAC, whereas among six serovars of M. iowae only serovar I (type strain 695) showed NEAC. Weak NEAC was detectable in M. anseris, M. cloacale and M. pullorum, whereas the type strain of M. corogypsi (BV1) showed strong NEAC. Our study provides novel informations about NEAC in AM species and suggests that higher invasiveness and possibly, the pathological processes might be associated with their NEAC.     

Haemadsorption inhibition test for the identification of Mycoplasma gallisepticum and Mycoplasma synoviae

Summary Colonies of the avian mycoplasma strains Mycoplasma gallisepticum S6 and Mycoplasma synoviae WVU 1853 and two Mycoplasma synoviae isolates from this laboratory were shown to be haemadsorption positive for chicken erythrocytes. Three Mycoplasma synoviae isolates from this laboratory proved to be haemadsorption and haemagglutination negative. The haemadsorption of the mycoplasma colonies mentioned above was inhibited with specific antisera of either high or low titre. No cross-inhibition was observed. It is suggested that this test could be used for a quick tentative identification of the two avian mycoplasmas on primary solid-medium cultures.     

Haemadsorption inhibition test for the identification of Mycoplasma gallisepticum and Mycoplasma synoviae

Summary

Colonies of the avian mycoplasma strains Mycoplasma gallisepticum S6 and Mycoplasma synoviae WVU 1853 and two Mycoplasma synoviae isolates from this laboratory were shown to be haemadsorption positive for chicken erythrocytes. Three Mycoplasma synoviae isolates from this laboratory proved to be haemadsorption and haemagglutination negative. The haemadsorption of the mycoplasma colonies mentioned above was inhibited with specific antisera of either high or low titre. No cross‐inhibition was observed. It is suggested that this test could be used for a quick tentative identification of the two avian mycoplasmas on primary solid‐medium cultures.