空肠弯曲菌共同抗原单克隆抗体的研制及其在细菌检验中的应用 Ⅱ.杂交瘤细胞株的建立及特性鉴定

应用B-淋巴细胞杂交瘤技术,建立了5株稳定分泌抗空肠弯曲菌共同抗原(CA)单克隆抗体(McAb)的杂交瘤细胞株(4A7,9D6、9C2、11A1、11D4)。在5株杂交瘤分泌的McAb中,有4株(4A7、9D6、11A1、11D4)针对CA中的耐热抗原成分,对其中4A7、9D6两株分泌的McAb进行免疫印迹分析表明,其与CA中大约为7.7×104u的蛋白移行带出现特异反应;一株(9C2)针对CA中的不耐热抗原成分。对杂交瘤细胞的核型分析表明,其染色体数在93-108之间。体外传代4个月,仍保持稳定分泌抗体的特性。这种McAb具有较强的特异性,除与幽门弯曲菌出现弱阳性反应外,与参试的其它31种非弯曲菌属的细菌均为阴性反应。对不同地区、不同来源的516株空肠弯曲菌的鉴定表明,制备的McAb与现有空肠弯曲菌均出现阳性反应,与常规鉴定法的符合率为100％。     

嗜水气单胞菌的致病性及其防治方法

现有研究结果表明,嗜水气单胞菌是一种致病力很强的水生常居细菌,能引起水产动物、水禽、家禽和人类等共患病。文章综合报道了嗜水气单胞菌的细菌学特征及其由该菌引起鱼、鳖、蛙、珍珠蚌、鸭及人类感染致病的情况和一般的防治方法,指出今后应对嗜水气单胞菌的发生、传播等做进一步研究,防范该菌对人类的生产、生活造成的危害。     

Corynebacterium pseudotuberculosis infection in goats. II. The prevalence of caseous lymphadenitis in 36 goat herds in Northern Norway

The precalen-ce of caseous lymphadenitis was surveyed in 36 goat herds in Northern Norway. In each herd, information concerning the occurrence of the disease was obtained from the farmer. Adult animals (1 year of age or older) in 35 herds were examined for superficial swellings, and serum samples were collected from most animals in the herds. The sera were examined for antibodies to Corynebacterium pseudotuber-culosis using the bacterial agglutination test (BAT) and the hemolysis inhibition test (HIT).Gaseous lymphadenitis was diagnosed with certainty in 19 herds. Information from the farmers indicated that the disease indeed oc-curred in these herds, and that the majority had been infected with the disease for many years. The herds had apparently become infected through contact with animals from infected herds. Clinical examina-tions were carried out in 18 of these herds and superficial swellings were found in 26 % of the examined animals. The prevalence of ani-mals with lesions varied from 11 to 40 % among the herds. Of the animals in these herds, 81 % were positive in BAT and 84 % in HIT. The prevalence of positive animals varied from 26 to 99 % in BAT and 28 to 99 % in HIT. The prevalence of seropositive animals was lowest in a herd in which animals were kept separately in stalls.Caseous lymphadenitis could not be diagnosed in 16 herds. In-formation from the farmers indicated that the disease indeed seemed to be absent in 14 of these herds. These 14 herds had no history of contact with animals from herds considered to be infected. However, in the remaining 2 herds, the farmers were somewhat uncertain about the occurrence of the disease. One of these 2 herds had a history of contact with infected herds through participation in a goat “breeding circle”. Only a few of the animals were, however, seropositive and all these had low antibody titres.In 1 newly established herd, a single animal showed a high posi-tive titre in BAT only. All the other animals were negative in both tests. This particular herd consisted of animals obtained both from herds with caseous lymphadenitis and from herds in which the disease was not considered to occur.     

Bench‐top validation testing of selected immunological and molecular Renibacterium salmoninarum diagnostic assays by comparison with quantitative bacteriological culture

No gold standard assay exhibiting error‐free classification of results has been identified for detection of Renibacterium salmoninarum, the causative agent of salmonid bacterial kidney disease. Validation of diagnostic assays for R. salmoninarum has been hindered by its unique characteristics and biology, and difficulties in locating suitable populations of reference test animals. Infection status of fish in test populations is often unknown, and it is commonly assumed that the assay yielding the most positive results has the highest diagnostic accuracy, without consideration of misclassification of results. In this research, quantification of R. salmoninarum in samples by bacteriological culture provided a standardized measure of viable bacteria to evaluate analytical performance characteristics (sensitivity, specificity and repeatability) of non‐culture assays in three matrices (phosphate‐buffered saline, ovarian fluid and kidney tissue). Non‐culture assays included polyclonal enzyme‐linked immunosorbent assay (ELISA), direct smear fluorescent antibody technique (FAT), membrane‐filtration FAT, nested polymerase chain reaction (nested PCR) and three real‐time quantitative PCR assays. Injection challenge of specific pathogen‐free Chinook salmon, Oncorhynchus tshawytscha (Walbaum), with R. salmoninarum was used to estimate diagnostic sensitivity and specificity. Results did not identify a single assay demonstrating the highest analytical and diagnostic performance characteristics, but revealed strengths and weaknesses of each test.     

鲈鱼病毒性神经坏死病的诊断与防治

福建省漳浦县某海水养鱼场饲养的10万尾鲈鱼苗(Lateolabrax japonicus)发生以自转、狂游、侧游等运动失调及大批死亡为特征的疾病。病死鱼眼睛发亮、微肿,部分鱼体表有新鲜的破溃伤口,死亡率高达65%。寄生虫、细菌学检查均为阴性。应用世界动物卫生组织(OIE)推荐的检测引物,采用RT-PCR检测方法扩增出神经坏死病毒特异性的421 bp基因片段,依此诊断为病毒性神经坏死病(Viral nerve necrosis,VNN)。采取及时捞取病死鱼,去除网箱沉渣粪便,中草药吊袋消毒,减食和氯苯尼考、黄芪多糖、益生菌拌料等防治措施,收到很好的防治效果。     

罗布麻生物脱胶过程中的发酵液的色谱分析

在利用高效菌株T85-260对罗布麻韧皮进行脱胶的过程中,每3小时取一次样,分别研究微生物生长和酶解产物变化规律。结果表明,T85-260能在8小时左右完成罗布麻韧皮脱胶,杂菌对其生长规律和脱胶性能不构成明显影响;T85-260分泌胞外酶降解罗布麻韧皮中的半纤维素所形成的单糖类产物,如葡萄糖、甘露糖、木糖等多数被微生物当作碳源消耗了,只有鼠李糖比较难被微生物利用。     

云南冬植亚麻严重发生细菌性病害

对冬植亚麻发生细菌性病害作出初步诊断，调查表明危害严重，主要症状为茎生长点萎蔫下垂变褐干枯死亡，分析出病害发生与当地亚麻田间生态环境、前作等因素关系密切，并对防治措施作初步探讨。     

Aquaculture Biotechnology,by Garth L. Fletcher,Matthew L. Rise,and Wiley-Blackwell

FOOD MICROBIOLOGY: FUNDAMENTALS AND FRONTIERS, Second Edition. Edited by Michael P. Doyle, Larry R. Beuchat, and Thomas J. Montville. Washington, DC, ASM Press, 2001, 888 pages. $124.95. Reviewed by Keith W. Gates.     

Phenotypic Characteristics of Xanthomonas campestris pv. campestris from Nepal

Twenty strains of Xanthomonas campestris pv. campestris (Xcc) were isolated from two major crucifer-growing valleys, Chitwan and Kathmandu in Nepal and characterized by biochemical and pathogenicity tests. Strains were homogeneous in bacteriological characteristics. The ability of a strain to induce high or low disease severity index (DSI) on three host plants, broccoli, cabbage, and cauliflower, was interpreted as virulence. Strains that were associated with high or low virulence were significantly different (P>0.05). No relationship between virulence and biochemical characteristics was observed.