扭角羚肺炎克雷伯氏菌的分离鉴定

本试验旨在报告四川省野生扭角羚自然生存过程中致病性细菌的检测及生物学特征。试验对发病死亡扭角羚病变组织进行细菌学检查及分离,对分别从肝脏、脾脏和肺脏分离得到的4株优势菌进行形态特征、生化特性和16SrDNA分子鉴定,判定为肺炎克雷伯氏菌。这4株菌对供试小白鼠均有致病性。测其LD50,分别为2.9×107、2.9×107、4.5×107和1.1×108 CFU/只。4株分离菌对供试的先锋霉素等敏感,对阿米卡星等中度敏感,对红霉素等耐药。推测这4株肺炎克雷伯氏菌是导致扭角羚死亡的主要病原菌。     

水貂源致病性黏质沙雷氏菌的分离鉴定与遗传进化分析

为确定水貂黏质沙雷氏菌的耐药状况、致病性及其遗传特征,本研究从黑龙江省患病死亡水貂中分离得到3株细菌,根据其形态特征、培养特性、生化试验及16S rRNA序列测定对分离菌进行鉴定;随后用K-B法测试分离株对常见的24种抗菌药的敏感性,并进行了致病性试验和遗传进化分析。结果显示,分离菌为黏质沙雷氏菌,对多种常用抗菌药物具有高度耐药性;可引起试验组小鼠100%死亡;分离株与来自活性污泥与火山堆积物环境的菌株遗传亲缘性最近。表明黑龙江省水貂中存在黏质沙雷氏菌的感染,分离株耐药现象较严重并具有很强的致病性,同时提示该菌株可能来源于环境中。本试验从水貂中分离得到致病性黏质沙雷氏菌为首次报道,研究结果可作为该菌感染水貂导致相关疾病的检测、鉴别和预防依据。     

兔源肺炎克雷伯氏菌的生物学特性研究

为探究兔源肺炎克雷伯氏菌的生物学特性,本研究对从病兔中采集的病料进行细菌的分离培养、细菌特征性基因(Khe基因)的PCR检测、生化鉴定、药敏试验、致病性试验、毒力基因的扩增及序列分析对细菌分离株进行分析。结果显示麦康凯平板上生长有奶油状菌落且镜检为革兰氏阴性菌;Khe基因扩增为阳性;生化鉴定结果表明分离菌为肺炎克雷伯氏菌;药敏结果显示该菌对诺氟沙星、氧氟沙星、头孢曲松等9种药物高敏,对链霉素、卡那霉素、头孢呋辛等5种药物中敏,对先锋V、庆大霉素等7种药物不敏感甚至耐药;致病性结果显示,分离株能使小白鼠在24h内死亡;分离株携带有wabG、uge和fimH三种毒力基因。本研究结果表明该肺炎克雷伯氏菌具有很强的致病性,是导致兔死亡的主要病原菌。     

重庆3个鸡场土壤肠道菌分离鉴定及药物敏感性分析

为了解鸡场土壤菌群数量、肠道菌群种类及其致病性、耐药性,从重庆市荣昌县3个鸡场土壤样品中分离鉴定出9株肠道细菌,有7株肠杆菌科菌:肺炎克雷伯菌、产气肠杆菌、粘质沙雷菌(S.marcescens)、沙门菌、弗格森埃希菌(E.fergusonii)、结肠炎耶尔森菌、普通变形菌(P.vulgaris);弧菌科细菌2株,分别是类志贺邻单胞菌(P.shigelloide)、温和气单胞菌(A.sobria)。9种菌对10日龄雏鸡和白鲢鱼有致病性。9种菌的药物敏感性试验结果显示,温和气单胞菌对选用的多种抗生素均敏感,但沙门菌和弗格森埃希菌等对阿莫西林、氨苄西林等药物有抗性;有5株菌显示多重耐药。3个鸡场土壤样本细菌总数均超出国标规定的清洁土壤标准。     

某牛场奶牛产后败血症的细菌分离鉴定与药敏试验

某牧场母牛产后发生体温升高、呼吸困难、乳汁中带血等症状,发病牛衰竭死亡,针对此种情况,采取病死牛的心脏、肝脏、子宫、乳汁等进行病原菌的分离和纯化,对其进行16S rRNA测序鉴定,毒力基因检测,致病性试验和药敏试验,还对牛的饮用水进行细菌数量的检测。结果显示,致病菌为大肠埃希氏菌、沙雷氏菌和产色葡萄球菌。在毒力基因检测试验中,从病料及饮用水分离出的20株大肠埃希氏菌中有3株携有毒力基因hlyA、STb、F17。致病性试验显示,在分离出的8株大肠埃希氏菌中4株为致病性大肠埃希氏菌,分离出的沙雷氏菌和产色葡萄球菌对小鼠均有致病力,可使部分小鼠死亡。药敏试验显示,分离出的致病性大肠埃希氏菌普遍对庆大霉素、环丙沙星、美罗培南敏感;黏质沙雷氏菌对庆大霉素、环丙沙星、美罗培南等5种药物敏感,产色葡萄球菌对庆大霉素等11种药物敏感。水质检验显示,该牛场牛的饮用水中细菌总数和大肠埃希氏菌数量均严重超出国家标准。研究结果对预防、治疗奶牛产后败血症都具有指导意义。     

雏鸡早期大批死亡病例中的细菌检验

1999-2002年间,从14例雏鸡发生大批死亡病例中,分离到大肠杆菌、沙门氏菌、绿脓杆菌、黏质沙雷氏菌、美国爱文氏菌、蜂房哈夫尼亚氏菌、格高菲氏菌、奇异变形杆菌和肺炎克雷伯氏9种细菌,其中多种细菌未见或鲜见报道,大部分分离株经动物试验证实具有很强的致病性。它们其中一种或多种混合感染,引起雏鸡败血症,使雏鸡在短时间内大批死亡。现将各分离菌株的致病情况、相关特性和药敏结果报道如下。1　各分离菌株的情况1.1　大肠杆菌　14宗病例中有7宗分离到了大肠杆菌,其中4宗为单独感染,3宗为与其他菌株混合感染。1.1.1　培养特性　在营养…     

羊源肺炎克雷伯氏菌的分离与鉴定

本研究通过病死羊的肺脏中进行细菌分离、形态学观察、生化试验、致病性试验、药敏试验和16S rRNA扩增。结果从肺中分离到1株具有致病性的革兰氏阴性短杆菌。生化试验鉴定结果符合肺炎克雷伯氏菌的特征。分离株对头孢噻肟、阿米卡星、头孢曲松和链霉敏感外,对强力霉素等12药物具有耐药性。16S rRNA测序结果分析显示分离株与肺炎克雷伯氏菌的核苷酸同源性为97.1%~99.0%,在核苷酸进化树上与肺炎克雷伯氏菌属于同一分支。结果表明本研究从病死羊的肺脏中分离到1株肺炎克雷伯氏菌。     

灰雁黏质沙雷菌的鉴定及其耐药性分析

为研究2016年武汉地区灰雁粪便中所产红色色素的未知菌的类别及其耐药性,经细菌分离、生化鉴定、细菌16SrDNA通用引物等鉴定,确定1株病原菌为黏质沙雷菌。经药敏试验发现黏质沙雷菌对萘啶酸、头孢噻肟、环丙沙星、阿米卡星、复方新诺明、庆大霉素、甲氧嘧啶等敏感,对头孢他啶、氨曲南、氨苄西林等中介,对头孢曲松、四环素、呋喃妥因、链霉素、磺胺异恶唑耐药。了解黏质灰雁沙雷菌的耐药情况,对环境中食源性肠道菌进行监测,为今后禽源沙雷菌抗生素替代药物的开发提供潜在的候选菌株。     

流产奶牛胎儿肺炎克雷伯氏菌的分离与鉴定

从流产奶牛胎儿组织中分离到1株革兰氏阴性短杆菌,采用细菌分离纯化、生化试验、16S rRNA和16S～23S rRNA测序、药敏试验和小鼠致死性试验对其进行了鉴定。结果显示,该分离菌与GenBank中肺炎克雷伯氏菌16S rRNA和16S～23S rRNA基因序列一致性分别高达99%和96%,16S～23S rRNA基因被扩增出3条不同长度条带;该菌生化特性均符合肺炎克雷伯氏菌的生化反应特性;对头孢曲松、阿米卡星、多粘菌素等敏感,对多西环素、四环素、卡拉霉素等中度敏感,对青霉素、红霉素、米诺环素等耐药;对小鼠有很强的致病性。以上结果表明,该分离细菌为肺炎克雷伯氏菌。     

鲤鱼肺炎克雷伯氏菌分离与鉴定

初步了解肺炎克雷伯氏菌在鲤鱼鱼体中的发病机制并筛选防治药物,为预防和治疗该病提供准确实验数据。对发病鲤鱼进行细菌分离纯化,通过革兰氏染色反应,生理生化反应测定单菌落特性,进行细菌回归试验和药敏试验。对注射菌液后发病的鱼进行细菌再分离,得到革兰氏阴性菌,并且与七叶苷及其它17种指标反应呈阳性,与戊二酰-甘氨酸-精氨酸-AMC及其它11种指标反应呈阴性,注射该菌液48 h后鱼体出现与疑似病例相同病症。分离得到的细菌,按《伯杰氏细菌鉴定手册》进行鉴定,确定为肺炎克雷伯氏菌。药敏试验结果表明该菌对亚胺培南等6种药物高度敏感。本试验首次从鲤鱼体内分离出肺炎克雷伯氏菌,并得到6种高度敏感的药物,同时阐明了肺炎克雷伯氏菌在鲤鱼中发病症状。     

鲤鱼杀鲑气单胞菌的分离鉴定及耐药性分析

为探究鲤鱼病原菌的生物学特性及耐药状况,从患病鲤鱼中分离到菌株CS126,对其进行形态学观察、生理生化性质测定、16SrDNA序列分析及药敏性测定。结果显示,菌株CS126为革兰氏阴性菌,不产生吲哚、不具有动力性,分解半乳糖、甘露醇,VP试验、赖氨酸脱羧酶、氧化酶阴性,七叶苷阳性。16SrDNA序列长度为1 459bp,GenBank登录号为KJ942580,与GenBank中杀鲑气单胞菌的相似性高达100%,进化树显示与杀鲑气单胞菌杀鲑亚种聚为一分支。这表明菌株CS126为杀鲑气单胞菌杀鲑亚种。该菌株对菌必治、诺氟沙星、氟苯尼考等8种药物高度敏感,但对氨苄西林、氨苄西林/舒巴坦、甲氧卞胺嘧啶和磺胺异恶唑等耐药。本试验结果为鱼类杀鲑气单胞菌的快速鉴定及鱼类疾病诊治提供参考依据。     

肺炎克雷伯氏菌强毒株的分离鉴定及16-23SrRNAITS序列分析

为确诊疑似仔猪肺炎克雷伯氏菌(K.pneumonia)感染,并研究其病原的致病性、耐药性、16-23SrRNA ITS系统进化特征,本研究从云南因肺炎、腹泻而大量死亡的仔猪中分离到1株革兰氏阴性短粗杆菌,命名为KP14013,对其进行生化鉴定、16SrRNA鉴定,研究其对小白鼠和仔猪的致病性,并对其16-23SrRNA ITS基因进行测序和遗传进化分析。结果显示,KP14013分离株生化特征与肺炎克雷伯氏菌相符,其16SrRNA与GenBank中23株肺炎克雷伯氏菌代表株之间的同源性均为99%,将KP14013鉴定为肺炎克雷伯氏菌。KP14013对小白鼠半数致死量(LD50)为3×101.8 CFU,腹腔注射3×108 CFU可使仔猪100%致死。16-23SrRNA ITS系统进化关系结果表明,KP14013与GenBank中收录的15株肺炎克雷伯氏菌形成进化树的一个分支,属于同一个亚群,它们之间的核苷酸同源性为98.4%~99.2%。本研究证实了肺炎克雷伯氏菌是该起仔猪腹泻大量死亡的病原;KP14013分离株为毒力极强菌株,具有多重耐药性,其16-23SrRNA ITS与GenBank中收录的肺炎克雷伯氏菌代表株之间核苷酸存在差异,可用于肺炎克雷伯氏菌菌株间的鉴别。     

贵州某野生动物园长臂猿流感病毒、支原体及巴氏杆菌混合感染的诊治

为弄清贵州某野生动物园长臂猿死亡的原因,本试验采用流行病学调查、临床症状观察、病理剖检诊断和RT-PCR检测确诊等方法,对该野生动物园发病长臂猿进行了诊断。试验结果显示,流行病学调查、剖检病理初步诊断该野生动物园长臂猿疑似流感病毒、支原体和细菌混合感染,RT-PCR/PCR检测确诊发病长臂猿为流感病毒、支原体混合感染,细菌分离培养、生化特性鉴定和动物致病性试验确诊为多杀性巴氏杆菌感染。结果表明造成该野生动物园长臂猿发病死亡的原因为流感病毒、支原体和多杀性巴氏杆菌混合感染。根据诊断及药敏试验结果,制定出了免疫预防及治疗措施。     

Synergistic and antagonistic hemolytic activities of bacteria of genus Arcanobacterium and CAMP-like hemolysis of Arcanobacterium phocae and Arcanobacterium haemolyticum with Psychrobacter phenylpyruvicus

A total of 57 bacteria representing eight species of genus Arcanobacterium (A.) were investigated for hemolytic properties on blood agar containing sheep and rabbit blood and for CAMP-like reactions. An enhanced hemolysis on blood agar containing rabbit blood compared to sheep blood could be observed for A. haemolyticum, less pronounced for A. hippocoleae and A. pluranimalium.A synergistic hemolytic reaction with staphylococcal β-hemolysin appeared to be constantly visible for A. hippocoleae, A. pluranimalium and A. pyogenes, with Streptococcus agalactiae for A. phocae and A. haemolyticum, with Rhodococcus equi for A. phocae, A. haemolyticum, A. pluranimalium and A. pyogenes and with A. haemolyticum for A. hippocoleae, A. pluranimalium and A. pyogenes, respectively. A reverse CAMP-reaction in the zone of staphylococcal β-hemolysin could be observed for A. phocae and A. haemolyticum. In addition, a novel CAMP-like reaction could be noted between Psychrobacter phenylpyruvicus, identified by 16S rDNA sequencing, and A. phocae and A. haemolyticum. These synergistic or antagonistic hemolytic properties could possibly be used as additional criteria for identification of bacteria of genus Arcanobacterium.     

Hepatozoon canis infecting dogs in the State of Espírito Santo, southeastern Brazil

From May 2007 to March 2008, blood samples were collected from 92 healthy dogs living in 21 households (17 farms in rural area, and 4 homes in urban area) in 6 counties of the State of Espírito Santo, southeastern Brazil. In addition, ticks were collected from these dogs. A mean of 4.4 ± 3.0 dogs (range: 1–12) were sampled per household; 78 and 14 dogs were from rural and urban areas, respectively. Polymerase chain reaction (PCR) designed to amplify fragments of the 18S rDNA gene of Babesia spp or Hepatozoon spp revealed amplicons of the expected size in 20 (21.7%) dogs for Babesia, and 54 (58.7%) dogs for Hepatozoon. All Babesia-positive dogs were also Hepatozoon-positive. Among the 21 households, 15 (71.4%) from 3 counties had at least one PCR-positive dog, including 13 farms (rural area) and 2 homes (urban area). A total of 40 PCR products from the Hepatozoon-PCR, and 19 products from the Babesia-PCR were submitted to DNA sequencing. All generated sequences from Hepatozoon-PCR were identical to each other, and to corresponding 18S rDNA sequences of H. canis in GenBank. Surprisingly, all generated sequences from the Babesia PCR were also identical to corresponding 18S rDNA sequences of H. canis in GenBank. Dogs from 10 rural and 2 urban households were found infested by Rhipicephalus sanguineus ticks. Immature of Amblyomma cajennense ticks were found in dogs from only 4 rural households (also infested by R. sanguineus). All but one household with R. sanguineus-infested dogs had at least one Hepatozoon-infected dog. Statistical analysis showed that the presence of ticks (i.e. R. sanguineus) infesting dogs in the households was significantly (P < 0.05) associated with at least one PCR-positive dog. There was no significant association (P > 0.05) between PCR-positive dogs and urban or rural households. Canine hepatozoonosis caused by H. canis is a high frequent infection in Espírito Santo, Brazil, where it is possibly vectored by R. sanguineus. Since all infected dogs were found apparently healthy, the pathogenicity of H. canis for dogs in Espírito Santo is yet to be elucidated.     

Identification of the tet(B) resistance gene in Streptococcus suis

The tetracycline resistance gene, tet(B), has been described previously in Gram negative bacteria. In this study tet(B) was detected in plasmid extracts from 17/111 (15%) Streptococcus suis isolates from diseased pigs, representing the first report of this resistance gene in Gram positive bacteria.     

First isolation and identification of Elizabethkingia meningoseptica from cultured tiger frog, Rana tigerina rugulosa

Elizabethkingia meningoseptica has been recognised as an occasional but serious opportunistic bacterial pathogen to human beings. Recently, it was frequently isolated from tiger frog, Rana tigerina rugulosa, with cataract disease, which is the most common disease of unknown aetiology of frogs in Hainan, China. The purpose of this study was to identify and characterise the bacterial strains isolated from the recent outbreaks of cataract disease in farmed tiger frog in Hainan, China, and to evaluate their pathogenicity to the frog and their sensitivity to 20 chemotherapeutic agents.The 16S rRNA gene sequences of strains W0701 (1478 bp), W0702 (1477 bp) and W0703 (1478 bp) showed 98.6–98.7% similarity with the sequence of E. meningoseptica type strain (ATCC 13253) and 99.9–100% similarity with that of E. meningoseptica NTU 870424-IL. Six strains (W0701–W0706) were selected to represent 24 isolates retrieved from six moribund frogs. The morphological, physiological and biochemical characteristics of the six representative isolates were consistent with those of E. meningoseptica strains. The organisms were only susceptible to vancomycin and moderately susceptible to cefoperazone among the 20 investigated chemotherapeutic agents. Virulence test with strain W0702 was conducted and pathogenicity (by intramuscular injection) was demonstrated in the tiger frog. In conclusion, 24 isolates obtained from frogs with cataract disease were the E. meningoseptica strains highly pathogenic to tiger frog, and this is the first report of E. meningoseptica as a pathogen for tiger frog.     

Occurrence and characterization of gastric Helicobacter spp. in naturally infected dogs

Helicobacter-like organisms are frequently observed in the stomach of dogs but the relationship between these microorganisms and gastric pathology has not been clearly established. Different species of helicobacters are known to be present in the canine stomach but their specific prevalence in naturally infected dogs is unknown. The aims of this study were to isolate and characterize helicobacters in canine gastric biopsies, to compare the commonly used tests for the identification of Helicobacter spp. and to determine the occurrence of these species in dogs. Twenty-three out of 25 dogs (92%) were positive for Helicobacter-like organisms in cytological screening. Culture was successful from biopsies of 5/25 dogs. The isolates were analyzed by electron microscopy, biochemical and physiological tests, whole protein analysis and 16S rDNA sequencing. Helicobacter felis was identified in four samples and Helicobacter bizzozeronii in one sample. Only the whole protein analysis in combination with electron microscopy was able to clearly discriminate the two species. Compared to the high prevalence of Helicobacter-like organisms, the occurrence of H. felis and H. bizzozeronii, was low (17 and 4%, respectively). No Flexispira rappini-like organisms or H. salomonis were detected. Electron microscopy revealed that H. bizzozeronii-like microorganisms were present in three additional biopsies where we were unable to culture any Helicobacter-like organisms. These observations indicate that in the stomach of dogs not all helicobacters are culturable. The unculturable bacteria appeared to be the prevalent ones and may represent different spiral organisms. The presence of distinct helicobacters with different characteristics can reflect different roles in the pathogenesis of canine gastric disease.     

Phylogentic analysis of Anaplasma ovis strains isolated from sheep and goats using groEL and mps4 genes

Evidence of Anaplasma spp. in goats and sheep in Cyprus has been demonstrated by previous research. Herein, further research was performed for the identification of the exact Anaplasma spp. resulting in the identification of Anaplasma ovis strains in all samples examined. We used a bioinformatics as well as a molecular approach (study of groEl and mps4 genes) in order to verify the validity of the results. All samples depicted the presence of A. ovis regardless of the host (goat or sheep).