保定地区鸡多杀性巴氏杆菌的分离鉴定及药敏试验

从保定市某养鸡场发病死亡雏鸡采集了病料,通过微生物学的病原分离鉴定,最终确定病原体为禽多杀性巴氏杆菌。并用11种药物做了药敏试验,结果该鸡场分离的鸡多杀性巴氏杆菌除对恩诺沙星、环丙沙星两种药物敏感,对氟派酸中介外,对其余的8种抗生素均产生耐药性。     

保定地区鸡多杀性巴氏杆菌的分离鉴定及药敏试验

从保定市某养鸡场发病死亡雏鸡采集了病料，通过微生物学的病原分离鉴定，最终确定病原体为禽多杀性巴氏杆菌。并用11种药物做了药敏试验，结果该鸡场分离的鸡多杀性巴氏杆菌除对恩诺沙星、环丙沙星两种药物敏感，对氟派酸中介外，对其余的8种抗生素均产生耐药性。     

巴氏杆菌病的综合防治浅谈

巴氏杆菌病又名出血性败血症,是由多杀性巴氏杆菌所引起的一种畜禽败血性传染病。由于气候环境变化和人为因素,导致该病原菌的菌株变化多端,血清型较多,在我地用常规的细菌分离法与生化鉴定得到80多株,用PCR检测确定其中有9株为产毒素多杀巴杆菌,其临床特征是急性败血和组织器官的出血性炎症。因畜禽种类不同,常有不同名称:牛称牛出血性败血症,猪称猪肺疫,禽称禽霍乱。     

大菱鲆源杀鱼爱德华氏菌(Edwardsiella piscicida)的分离鉴定

从患腹水病大菱鲆Scophthalmus maximus的肝脏中分离到一株优势细菌G1,经人工感染实验表明G1为引发大菱鲆腹水病的致病菌,且半致死浓度为LD50=1.21×105 CFU·g-1。采用常规的生理生化鉴定方法及分子生物学方法对G1进行分析,结果表明,G1的16SrRNA基因序列与杀鱼爱德华氏菌Edwardsiella piscicida的同源性达100%,系统发育分析表明菌株G1与杀鱼爱德华氏菌分支聚为一支,结合生理生化鉴定结果确定G1为杀鱼爱德华氏菌。药敏试验表明菌株G1对头孢曲松、环丙氟哌酸、左氧氟沙星等8种抗菌药物高度敏感。     

多杀性巴氏杆菌体内表达基因的研究进展

多杀性巴氏杆菌(Pasteurella multocida)是引起多种畜禽巴氏杆菌病的致病菌。近年来,多杀性巴氏杆菌体内表达基因的筛选研究已经成为国内外研究的热点之一。本文就多杀性巴氏杆菌体内表达基因的研究进展进行了简要的阐述。     

牛蛙黄杆菌IIB群病病原菌的研究

从广东省南澳县西山等养蛙场多次收集息黄杆菌病牛蛙,其症状是：歪头、狂游、双眼白内障和腹水等。从病蛙脑浆、眼底和腹水中分离到多株病原菌,急性毒性试验表明病原菌对健康牛蛙致病力强。取有代表性的981007—2等菌株进行系统的生理生化试验显示,革兰氏染色阴性、无鞭毛、无芽孢的短杆菌;分离菌株内毒素检验阳性;病原菌显示了对青霉素类药物高度耐药、好氧型、利用葡萄糖等生理、生化特性。经VITEK—AMS—60自动化检测系统鉴定为黄杆菌IIb群(Flavobacterium group IIb)。选用47种抗菌药物,通过K—B纸片扩散法对病原菌进行耐药性研究结果,分离菌株对38种抗菌药物显示耐药(占80．85％)、对4种药物中等敏感(占8．51％),仅对利福平、环丙沙星、氧氟沙星、氟啶酸、麦迪霉紊等5种药物(占10．64％)敏感。应用试管稀释法测定上述5种敏感药物的平均MIC分别是0．19、0．27、0．53、2．40和10．2ug/ml。     

湖北省副猪嗜血杆菌分离与鉴定

采集疑似副猪嗜血杆菌感染的病料进行培养、纯化、生化鉴定及致病性观察,实验结果显示:所分离细菌为革兰氏阴性小杆菌,呈细杆状,两端着色,与葡萄球菌同时培养时,有良好的"卫星现象",在TSA培养基上生长时有NAD依赖性,生化鉴定显示:菌株能发酵麦芽糖、木糖、葡萄糖,对阿拉伯糖、鼠李糖、半乳糖、靛基质、氧化酶、精氨酸脱羧酶生化反应均为阴性,共分离菌株9株,经对豚鼠攻毒实验,确认为副猪嗜血杆菌。     

虹鳟皮肤溃烂病的病原菌研究

从患皮肤溃烂病的虹鳟鱼体中分离到多株细菌 ,其中两株经人工感染证实为病原菌。通过形态、生理、生化特性测定 ,鉴定为豚鼠气单胞菌和杀鲑气单胞菌杀鲑亚种。两株菌生长适温分别为 2 5～ 35℃、10～ 30℃。pH值分别为 6 5～ 8 5、 6 5～ 9 0。对氯霉素、环丙沙星、庆大霉素、复方新诺明等药物均高度敏感     

羊巴氏杆菌病的科学防治

羊巴氏杆菌病由多杀性巴氏杆菌感染所引起，主要发生于幼龄羊，病原可经呼吸道、消化道、黏膜接触、伤口、血液等途径进行传播，应激对该病有促发作用，病羊以全身症状和呼吸道症状为主要表现，死亡率较高。从对健康羊群接种疫苗、做好母羊的管理、降低应激对羔羊的影响、加强羊场的生物安全管理以及药物防控等角度详述了羊巴氏杆菌病的预防措施，并阐述了治疗方法。     

鸡大肠杆菌抗药性调查

对2000-2002年分离鉴定的47株鸡大肠杆菌进行了抗药性调查。多数分离菌株对多数抗菌药物具有耐药性;多数抗菌药物的抗菌效力不佳;优选出丁胺卡那霉素、诺氟沙星、磷霉素、庆大霉素、恩诺沙星、环丙沙星6种效果较好的药物;分析了抗药菌株产生的原因;建议治疗大肠杆菌病时先行药敏试验;建议少用或不用药物添加剂,并规范化用药,以提高疗效防止抗药菌株产生。     

地下海水池塘六价铬还原菌的多样性研究

从六价铬超标的地下海水池塘中采集底泥,以2216E培养基添加重铬酸钾为手段,筛选出对六价铬离子具有抗性的特异菌株。用细菌通用16SrDNA引物进行PCR扩增,PCR产物纯化后连接pMD18-T载体,导入大肠杆菌感受态细胞。然后对插入片段测序获得分离培养菌株的16SrDNA碱基全序列。通过NCBI比对,对分离的抗性菌株进行分子鉴定,确定其所属的分类地位。用PHYLIP软件,对16SrDNA碱基序列构建系统进化树,分析地下海水池塘六价铬还原菌的多样性。试验结果获得8株对六价铬有明显抗性的菌株,测序后发现8株菌为不同种的菌株,16SrDNA核酸序列相似度为88%,与已发表的序列或菌株的相似性为98%以上,属于6个属的8个不同的种。研究结果表明,铬超标地下海水池塘的活性底泥中六价铬抗性细菌菌株多样性十分丰富,通过进一步的还原性研究,可以筛选出对六价铬有还原特性的抗性菌株。     

Conchiolin infection and surface coating Vibrio: shell fragility, growth depression and mortalities in cultured oysters and clams, Crassostrea virginica, Ostrea edulis and Mercenaria mercenaria

Abstract. A disease of cultured juvenile European oyster, Ostrea edulis , and American oysters, Crassostrea virginica , was characterized by infection of conchiolinous ligament and periostracum by surface-coating Vibrio spp. bacteria. A similar bacterium was isolated from diseased cultured hard clams, Mercenaria mercenaria , held in a facility about 300 km distance from the oyster hatcheries. The oysters demonstrated fragile, undercalcified peripheral shell and apparently excessive chalky deposits. Histological and scanning electron microscopical examination revealed that the oysters' eroded ligaments and perforated peripheral periostracum were infected with uniform rod-shaped bacteria. The infection appeared to interfere with normal proteinaceous and calcareous shell deposition and possibly with normal ligament function. Histological examination of the digestive system organs suggested that normal digestive processes were also interrupted. Two predominant bacteria were isolated from oyster samples and one predominant bacterium was isolated from clam samples. One of the isolates from oyster culture facilities was found almost exclusively associated with oyster shell surfaces and culture tank surfaces, this isolate was similar to the one taken from clam shell surfaces. The other predominant bacterium was found in water column samples in oyster culture facilities at levels from about 10⁵ to 10⁷ per ml. This isolate had a DNA base ratio (moles % G + C) of 43.6; the two surface-associated isolates had base ratios of 43.6 and 44.5%. These Gram-negative, oxidase positive, fermentive rods have been identified as a Vibrio spp. group. Specific antibody was produced which differentiated these bacteria from each other and from other similar isolates. Practical procedures for controlling the bacteria in shellfish culture systems are described.     

山瑞鳖塞氏柠檬酸杆菌的分离鉴定及药物敏感性研究

从患致死性传染病的山瑞鳖(Palea steindachneri)组织中分离到一株细菌(YL090422),对该菌形态、生理生化特征及致病性进行分析,并用BIOLOG自动微生物鉴定系统及16S rDNA序列分析对其进行了鉴定。结果显示:该菌具有较强的致病性,且为发酵型革兰氏阴性短杆菌,无芽胞及荚膜;具有对葡萄糖、精氨酸双水解酶、鸟氨酸脱羧酶、脲酶、西蒙氏柠檬酸盐、丙二酸盐、卫茅醇、吲哚、动力等反应呈阳性,对氧化酶、赖氨酸脱羧酶、苯丙氨酸脱氨酶、V-P反应等呈阴性的特点。BIOLOG自动微生物鉴定系统显示该菌为塞氏柠檬酸杆菌(Citrobacter sedlakii)。16S rDNA序列分析得到1条长度为1464bp的核苷酸序列(GenBank登录号为GU726186),并显示该分离株与塞氏柠檬酸杆菌(C.sedlakii)的同源性达99.9%,且在系统发育树上与C.sedlakii聚为一支。鉴定结果确认菌株YL090422为塞氏柠檬酸杆菌(Citrobacter sedlakii)。药敏试验结果显示:该菌对供试16种抗菌药物中的阿米卡星等3种药物敏感,对头孢哌酮等3种药物中度敏感,对氨苄青霉素等10种抗生素均存在不同程度的耐药。     

网箱养殖沉积环境中硫氧化菌的分离鉴定及生长特性

从网箱养殖区沉积物中分离硫氧化细菌,并研究其生长特性。从以硫代硫酸钠为唯一能源底物的培养基中分离得到一株硫氧化菌B1-1,经过平板菌落形态观察及其形态学特征研究,并结合16S rRNA基因序列分析及分子系统发育树的构建结果,确定菌株的种类。结果表明,菌株B1-1呈革兰氏阴性,短杆状,鉴定为Halothiobacillus hydrothermalis(GenBank登录号为KU362926)。在28℃、初始pH=8、150 r/min培养条件下,细菌在12 h进入对数生长期,36 h开始氧化硫代硫酸盐(S_2O_3~(2-)),至60 h培养液p H下降到4.8,S_2O_3~(2-)浓度从最初的2.28 g/L降到0.36 g/L,氧化率达84.2%。     

长三角地区罗氏沼虾成虾主要疾病的病原研究

2009年8月-2010年8月在长三角地区开展了罗氏沼虾(Macrobrachium rosenbergii)成虾主要疾病的流行病学调查.结果显示:所采集病样按其症状分为肌肉白浊病(以上海和浙江病样为主)、蓝体病(以江苏病样为主)、红体病(以浙江病样为主)三类.从采集的罗氏沼虾病样中分离到优势细菌11株,人工感染健康罗...     

本地胡子鲶头甲溃烂症病原菌的分离与特性

从患头甲溃烂症的本地胡子鲶(Clarias fuscus)病灶处分离出1株细菌Hu02,用该菌株回归感染健康的本地胡子鲶,死亡率为100%,证明其是该病的致病菌。经细菌形态学观察,培养特征和生理生化反应测定,菌株Hu02被鉴定为嗜水气单胞菌(Aeromonas hydrophila)。经药敏试验结果表明,该菌株对氟哌酸、红霉素、利福平、庆大霉素等敏感。培养温度试验还表明,该菌株在4℃不生长,在17℃、28℃、37℃和42℃中均可生长,其中28℃是其最适生长温度。     

Occurrence and characterization of Aerococcus viridans from lobsters, Homarus gammarus L., dying in captivity

Abstract Dead lobsters from five lobster parks have been examined over a period of 5 months for the occurrence of Aerococcus viridans. Isolated strains of the bacterium were characterized biochemically and by means of intracellular protein patterns using thin layer isoelectric focusing in polyacrylamide gel. In a lobster park where a high mortality occurred, A. viridans was isolated from 29 of 33 dead lobsters. The bacterium was also isolated from 7 of 10 dead lobsters in a lobster park with low mortality. Probably, infection with A. viridans occurs more frequently in Norwegian lobster parks than hitherto suspected. Gram-positive cocci sharing many characteristics with A. viridans were isolated from some dead lobsters. These bacteria did not form tetrads, they were catalase positive and had different protein patterns from A. viridans.     

异育银鲫类志贺邻单胞菌的鉴定

采用API 20E系列生化鉴定、生理生化特征、电镜观察和16S rDNA序列构建系统发育树分析方法,对从濒死的异育银鲫(Carassius auratus gibelio♀×Cyprinus carpio♂)肝脏中分离到的1株致病菌(革兰氏阴性杆菌,YCS07-01株)进行了鉴定。结果显示:菌株主要生化特性为氧化酶阳性,发酵葡萄糖产酸不产气,分解肌醇;不发酵蔗糖、甘露醇、鼠李糖等;β-半乳糖苷酶、精氨酸双水解酶、赖氨酸脱羧酶、鸟氨酸脱羧酶阳性。负染电镜观察,菌株为两端钝圆直杆状,无芽胞,无荚膜,有4根鞭毛,大小为0.8~1.0μm×3.0μm。在以该菌16SrDNA序列(GenBank登录号FJ375179)和GenBank数据库内同源性较高的细菌16S rDNA序列构建的系统发育树中,分离菌YCS07-01与类志贺邻单胞菌ATCC14029T(登录号X74688)的同源性为99%,并聚为一个分支。综合培养特征、形态和生理生化特性、系统发育分析等将该菌鉴定为类志贺邻单胞菌(Plesiomus shigelloides)。药敏试验结果表明菌株对羧苄青霉素和万古霉素耐药;对头孢唑啉、四环素和氨曲南中度敏感;对丁胺卡那霉素、左氟沙星、头孢他啶、复方新诺明等高度敏感。     

氟苯尼考在感染鲁氏耶尔森氏菌的西伯利亚鲟体内的药效学

通过构建鲁氏耶尔森氏菌(Yersinia ruckeri)感染西伯利亚鲟(Acipenser baeri)病理模型,设立阴性对照组(不攻菌不给药)及阳性对照组(攻菌不给药),比较研究了高(50 mg.kg-1)、中(20 mg.kg-1)、低(5 mg.kg-1)氟苯尼考剂量治疗组和氯霉素(10 mg.kg-1)对照组西伯利亚鲟体内的药效学。连续给药3天后,阴性对照组和阳性对照组累计死亡率分别为0%和50%,表明病理模型构建成功;而氟苯尼考低、中、高剂量组和治疗对照组累计死亡率分别为30%、0%、0%、10%。愈后各实验组鱼血液中均无细菌感染;除阴性对照组外,鱼肝、肾组织中均可分离到鲁氏菌,但不致鱼死亡。实验结果表明,氟苯尼考对感染鲁氏耶尔森氏菌的西伯利亚鲟有较好的治疗作用,药效优于氯霉素,可用于治疗鱼类细菌性疾病。     

Immune Responses and Resistance against Vibrio parahaemolyticus Induced by Probiotic Bacterium Arthrobacter XE-7 in Pacific White Shrimp, Litopenaeus vannamei

A 63-d feeding experiment was conducted to determine the effects of dietary supplementation of probiotic bacterium Arthrobacter XE-7 on immune responses and resistance against Vibrio parahaemolyticus in the Pacific white shrimp, Litopenaeus vannamei . The probiotic bacteria were administered orally at four different doses of 0, 10⁶, 10⁸, and 10¹⁰ colony-forming unit (CFU)/g feed for shrimp. On Day 50, the shrimp were challenged with Vibrio parahaemolyticus by bath. On Days 7, 21, 49, and 63, six shrimp per tank were sampled to take intestine and hemolymph. With increasing dietary supplementation of probiotic bacteria, shrimp mortality decreased from 63.16% (the control) to 55.9% (10⁶ CFU/g feed), 51.75% (10⁸ CFU/g feed), and 51.78% (10¹⁰ CFU/g feed), respectively. Vibrio counts in intestine of shrimp fed probiotic bacterium Arthrobacter XE-7 was generally lower than that in the control shrimp ( P  < 0.05). The probiotic bacteria generally increased the immune parameters in shrimp, that is, total hemocyte counts, percentage phagocytosis, respiratory burst activity, and serum phenoloxidase activity. The results showed that probiotic bacterium Arthrobacter XE-7 can be used as probiotic in shrimp feed.