石鲽鱼创伤弧菌病的病原分离鉴定与防治

山东荣成某渔场饲养的石碟鱼大批发病死亡，其体表鳞片局部出血，肝、胰、脾肿胀坏死，腹腔积水等；从病死及濒死石碟鱼的肝、脾中分离到3株细菌，经形态学、生理生化特性及致病因子检测，鉴定为创伤弧菌（Vibrio sulnificus biovar)；3株细菌均不能致死小白鼠。药敏试验表明，3株细菌对环丙沙星、丁胺卡那霉素、卡那霉素、新霉素高度敏感；对氯霉素不敏感。经投喂环丙沙星药饵和腹腔注射卡那霉素，收到良好的防治效果。     

鳀鱼中摩氏摩根菌的分离鉴定及药敏试验

从鱼粉原料鳀鱼中分离到1株细菌,通过形态观察、生化鉴定、16S rDNA及系统发育树,确定是摩氏摩根菌,命名为TY.并采用Kriby-Bauer纸片扩散法进行耐药性分析.结果显示,生理生化鉴定中葡萄糖发酵、运动性、鸟氨酸及氰化钾阳性,其余项目均为阴性.16S rDNA基因序列与摩氏摩根菌同源性达99.73％,被鉴定为摩...     

鱼嗜水气单胞菌的分离鉴定

从陕西省甘养殖场送检的病鱼中分离到1株革兰氏阴性杆菌，培养特征观察笔生化特性分析结果证实为嗜水气单胞菌；小鼠和金鱼致病性试验证实分离菌具有致病性；药敏试验结果表明该菌对链毒素、万古霉素等高度敏感，对羧苄青霉素、氟哌酸等不敏感。用该菌制成灭活免疫金鱼保护力可达到80％以上。     

一株猪链球菌的分离与鉴定

从疑似发生猪链球菌病患猪的肺脏和淋巴结中分离到1株细菌。该细菌经形态学观察、培养特性、溶血试验、生化试验和动物试验鉴定为偏向厌氧型链球菌。该菌株对小白鼠存在致病性。药敏试验表明：分离菌株对阿莫西林和先锋V高度敏感,对菌必治、呋喃妥因、磺胺类药中敏,对青霉素、链霉素、卡那霉素和恩诺沙星等药物不敏感。     

蓝曼龙鱼致病性维氏气单胞菌的分离鉴定与系统进化分析

从患病蓝曼龙鱼(Trichogaster trichopterus)体内分离到1株细菌CC0323,经人工感染试验对蓝曼龙鱼有一定致病力。采用形态学观察,生理生化鉴定,16S r RNA序列分析,构建系统发育树等方法进行鉴定。结果分离株CC0323为革兰阴性短杆菌,具多形性,在RS琼脂上可生长,呈中等大小,表面光滑的淡黄色湿润菌落;理化特性和药敏试验结果与维氏气单胞菌基本相同;系统发育树可见CC0323与维氏气单胞菌QXL0711B进化关系最近。试验结果,证明分离株CC0323为维氏气单胞菌(Aeromonas veronii)。     

一例猪链球菌的分离与鉴定

从鲁北地区某猪场疑似患链球菌的仔猪群中采取病料组织,进行病原菌的分离;对分离细菌进行形态观察、染色镜检、生化试验、药敏试验、PCR鉴定与动物致病性试验。镜检结果发现,分离菌为革兰氏阳性、长链、球菌;生化试验该菌可发酵葡萄糖、果糖、半乳糖、山梨醇、麦芽糖、柳醇、水杨素、蔗糖、海藻糖和乳糖等;接种试验动物小白鼠全部死亡;药敏试验显示,该菌对头孢噻呋、万古霉素、红霉素、庆大霉素、克林霉素、克拉霉素等高度敏感。确定分离到一株猪链球菌,临床采用敏感药物治疗迅速控制疫情蔓延,取得良好效果。     

一株犬种布鲁氏菌的分离与鉴定

对从一只流产贵宾犬全血中分离到的一株布鲁氏菌进行了形态结构、培养特性、生化特性研究以及凝集试验鉴定和多种属聚合酶链式反应(AMOS-PCR)鉴定.结果表明,分离菌为革兰氏阴性菌,在胰际琼脂培养基生长并呈典型的粗糙型布鲁氏菌菌落,菌落能被结晶紫溶液染成紫色.分离菌在琉瑾和复红培养基上生长,不产生H2S,与粗糙型布鲁氏菌阳性血清凝集,与光滑型布鲁氏菌阳性血清无凝集.用AMOS-PCR方法对分离菌进行鉴定,该分离菌具有犬种布鲁氏菌特有条带.鉴定结果表明分离菌符合犬种布鲁氏菌特性,将其命名为B.canis GB1.     

黄颡鱼迟钝爱德华菌的分离鉴定及其致病性研究

为了确定黄颡鱼发病的原因,试验从患病黄颡鱼体内分离得到1株病原菌,命名为GDYM20160809,通过形态学观察、生理生化特性鉴定、16S rDNA分析及系统进化树构建等方法对分离菌进行鉴定,采用滤纸片扩散法对分离菌进行药敏试验。结果显示,该分离菌为革兰氏阴性短杆菌,PCR扩增其16S rDNA片段,经测序及BLAST比对,显示其与迟钝爱德华菌（Edwardsiella tarda）的同源性达100%,结合生理生化鉴定结果确定分离菌为迟钝爱德华菌。药敏试验结果显示,分离菌对磺胺类药物、头孢类药物、青霉素、复方新诺明等药物敏感,对磺胺间甲氧嘧啶钠、新生霉素、多黏菌素B、阿米卡星、卡那霉素和万古霉素6种药物耐药;人工感染试验结果证实,菌株对罗非鱼、禾花鲤、草鱼和黄颡鱼都有很强的致病性。本试验结果为有效防控黄颡鱼细菌性疾病提供了理论依据,并可指导养殖户合理用药。     

进口饲料中沙门氏菌的分离与鉴定

沙门氏菌属是一群形态、培养、生化反应和抗原构造相类似的革兰氏阴性杆菌,种类繁多。迄今已发现的沙门氏菌有2000多个种(或型),我国发现近200多种菌型[1]。世界上,每年由沙门氏菌引起的食物中毒病例多达几千万。在我国,沙门氏菌引起的食物中毒占首位,沙门氏菌食物中毒和动物感染沙门氏菌十分严重,已引起各界学者的广泛重视[2]。肉制品是人类沙门氏菌中毒的主要食品之一,而肉制品中的沙门氏菌污染与动物所食饲料中沙门氏菌的污染有直接关系。为了解沙门氏菌在动物饲料中的分布情况,从而判明其对人们健康的潜在威胁程度,保护国内的人畜健康,…     

一株猪链球菌的分离鉴定

从河北某猪场送检的一份病猪病料中分离出1株链球菌,革兰氏染色表现为G+球菌,该菌在普通琼脂绵羊血平板上形成圆形、乳白色、表面光滑整齐、具有溶血环的小菌落,通过对该菌进行细菌16SRNA、PCR扩增,测序结果表明分离菌是一链球菌,对该分离菌株的毒力因子检测中发现,其荚膜多糖CPS2J+、gdh+、sly+、epf+、mrp+均为阳性、该菌一定剂量对小白鼠有致死性,对阿莫西林、青霉素、复方新诺明比较敏感,对四环素耐药。该结果对今后该猪场猪链球菌病的临床防治具有一定的指导意义。     

The isolation and preliminary characterization of a rhabdovirus in Australia related to bovine ephemeral fever virus

CSIRO 368 virus was isolated from blood collected in the Northern Territory from a healthy cow and electron microscope studies showed that the isolate had rhabdovirus morphology. Fluorescent antibody studies and complement fixation tests related the virus to bovine ephemeral fever (BEF) virus. Neutralization tests in both suckling mice and Vero cells showed that the virus was not BEF virus. Antibodies to CSIRO 368 virus were found in cattle sera from northern and eastern Australia and Papua New Guinea. Antibodies were found in 16 out of 45 buffalo, some of which also had antibodies to BEF virus. In contrast, none of the 419 deer tested had antibodies to CSIRO 368 virus, although 142 of the same deer had antibodies to BEF virus. No antibodies to CSIRO 368 virus were detected in 16 goats, 54 horses, 10 pigs, 31 sheep, 25 kangaroos, or 14 human beings. Both CSIRO 368 and BEF viruses were found to be sensitive to ether and chloroform, but were not affected by the DNA inhibitor 5-bromo-2'-deoxyuridine, showing that they probably had the same type of nucleic acid--namely RNA. CSIRO 368 was also shown to grow to higher titres in BHK21 cells than in Vero cells. Temperature sensitivity studies at -20, 4 and 37 degrees C showed that the presence of foetal calf serum increased the survival time markedly at -20 degrees C, but only slightly at 4 and 37 degrees C. The virus survived the longest at -20 degrees C in the presence of foetal calf serum.     

Initial sequence characterization of the rhabdoviruses of squamate reptiles, including a novel rhabdovirus from a caiman lizard (Dracaena guianensis)

Rhabdoviruses infect a variety of hosts, including non-avian reptiles. Consensus PCR techniques were used to obtain partial RNA-dependent RNA polymerase gene sequence from five rhabdoviruses of South American lizards; Marco, Chaco, Timbo, Sena Madureira, and a rhabdovirus from a caiman lizard (Dracaena guianensis). The caiman lizard rhabdovirus formed inclusions in erythrocytes, which may be a route for infecting hematophagous insects. This is the first information on behavior of a rhabdovirus in squamates. We also obtained sequence from two rhabdoviruses of Australian lizards, confirming previous Charleville virus sequence and finding that, unlike a previous sequence report but in agreement with serologic reports, Almpiwar virus is clearly distinct from Charleville virus. Bayesian and maximum likelihood phylogenetic analysis revealed that most known rhabdoviruses of squamates cluster in the Almpiwar subgroup. The exception is Marco virus, which is found in the Hart Park group.     

The isolation, propagation and characterization of tissue-cultured equine rotaviruses

From 105 field cases of diarrhea in neonatal or young foals, rotavirus was detected by electron microscopy (EM) and/or by enzyme-linked immunosorbent assay (ELISA) in the feces of 65 foals on 16 different premises. ELISA was performed with Rotazyme test kits developed by Abbot and Company for the detection of rotaviruses. Twenty-four field isolates from the feces of diarrheic foals with equine rotavirus infection as ascertained by EM were placed in MA-104 cell cultures after pretreatment of the viral suspension with 10 micrograms ml-1 of trypsin and incorporation of 0.5 micrograms ml-1 or 1 microgram ml-1 of trypsin in Earle's minimal essential medium (MEM), 2% lactalbumen hydrolysate, and antibiotics. The isolates that replicated in cell culture produced varying degrees of cytopathic effect. After the 24 isolates had been transferred 5 or 7 times in cell culture, viral particles were observed in 17 by EM, and 22 had positive ELISA tests as determined by visual color chart and spectrophotometric readings. Concentrated tissue-cultured viral antigen of 9 isolates fixed complement using Nebraska calf diarrhea rotavirus calf antiserum while four isolates gave negative results. The same 13 tissue-cultured viral suspensions failed to fix complement using reovirus antiserum. The 9th passages of two isolates (EID1 and EID2) yielded titers of 10(4.45) ml-1 TCID50 and of 10(4.95) ml-1 TCID50, respectively, as measured by cytopathic effect. After 13 tissue-cultured passages, 2 other isolates, EID3 and EID4, each had titers of 10(6.2) ml-1 TCID50 and of 10(5.95) ml-1 TCID, respectively. Cytoplasmic or intranuclear inclusions were not seen in any cells of the MA-104 infected cell cultures. Small, but distinct, plaques in MA-104 cell cultures were produced by the EID1 isolate. Polyacrylamide gel electrophoresis tests of EID1 and EID2 isolates at the 9th cell passage and EID3 and EID4 isolates at the 13th cell passage each showed that the RNA genome had 11 segments with a migrating pattern that was identical for each isolate and characteristic of rotaviruses. These 4 equine tissue-cultured isolates when tested by ELISA, utilizing a monoclonal antibody serum pool that cross-reacted with many rotavirus isolates, each gave positive values comparable to rotavirus antigen controls.     

The isolation and characterization of porcine enteroviruses

Eleven enteroviruses representing four serotypes were isolated in a porcine kidney cell-line from swabs collected from a litter of apparently healthy piglets in New Zealand. One serotype produced type 2 cytopathic effect and was neutralized by type 8 porcine enterovirus antiserum. Of the remaining three serotypes which produced type 1 cytopathic effect, one was neutralized by type 1 antiserum and two were not neutralized at all by antisera types 1 to 8. Cross neutralization tests were not carried out. Nervous disease or reproductive disorders have not yet been associated with these viruses in New Zealand.     

Isolation of tibrogargan virus,a new Australian rhabdovirus,from Culicoides brevitarsis

CSIRO 132 virus, which is new to science in Australia, and probably the world, has been isolated from Culicoides brevitarsis. Electron micrographs show that it resembles a rhabdovirus. Antibodies to the new virus have been detected in water buffaloes and cattle, but not in 58 human beings, 14 camels, 21 dogs, 67 goats, 15 horses, 43 pigs, 154 sheep, 98 wallabies or 38 possums. The distribution of antibodies in cattle lies within the distribution range of C. brevitarsis. It has not so far been associated with disease. The name Tibrogargan is proposed for the new virus.     

Stability and inactivation of vesicular stomatitis virus,a prototype rhabdovirus

Viruses may remain infectious outside the host cell for considerable time and represent a source of accidental infection if not properly inactivated. In this study, the survival of vesicular stomatitis virus (VSV) in suspension and dried on surfaces was analyzed. In addition, the sensitivity of VSV to disinfectants and physicochemical changes was investigated. VSV showed a notable stability in suspension at 4 °C with virus titers remaining high over several weeks. The presence of serum proteins had a stabilizing effect on virus infectivity, whereas elevated temperatures reduced survival times. VSV dried on polystyrene, glass or stainless steel surfaces remained infectious for at least 6 days at ambient temperature. VSV showed a remarkable resistance to extreme pH in particular in the alkaline range, but could be rapidly inactivated by heating at 55 °C or higher. The virus was highly sensitive to inactivation by commonly used disinfectants such as aldehydes, alcohols, and detergents. The high stability of VSV on surfaces and in suspension may facilitate dissemination of the virus in livestock by contaminated feeding and water troughs, hands, and milking equipment. This knowledge on the sensitivity of VSV to disinfectants will help to set up appropriate hygiene measures.     

The isolation and characterization of a strain of infectious bovine rhinotracheitis virus from stillbirth in swine.

A virus, designated 5089, which was isolated from tissue samples from two stillborn pig fetuses was identified on the basis of its morphology, cytopathology, physiocochemical and serological characteristics as a strain of infectious bovine rhinotracheitis (IBR) virus. Three piglets inoculated intranasally with 5089 virus did not respond serologically and no virus was isolated from their tissues at intervals after inoculation. They showed neither clinical signs nor significant lesions. A colostrum deprived calf which was inoculated intranasally with the same virus developed clinical signs typical of the respiratory form of IBR and the virus was reisolated on several occasions from nasal swabs.