16S rDNA Gene and Drug Resistance Analysis of Vibrio anguillarum Isolated from Tincaeus

Strain SK-1 was isolated from naturally infected Tincaeus. Its morphological, physiological and biochemical experiments, 16S rDNA sequence were performed, and its antibiotic sensitivity was analyzed by Kriby-Bauer disc diffusion method. The results showed that strain SK-1 was gram negative bacteria,with short rod shape and oxidase-positive.Its physiological and biochemical characteristics were consistent with the physiological and biochemical characteristics of Vibrio anguillarum. The length of this 16S rDNA sequence was 1447 bp, which showed 99% homology with Vibrio anguillarum, GenBank database number was KF978124. Phylogenetic analysis indicated it grouped together with Vibrio anguillarum. So it was confirmed that strain SK-1 was Vibrio anguillarum. The antibiotic sensitivity presented that strain SK-1 was highly sensitive to 13 antibiotics such as doxycycline,tetracycline,minocycline, and middle sensitive to 9 antibiotics such as streptomycin, ceftriaxone, trimethoprim, and resistant to bacitracin and lincomycin. These results will be beneficial to the identification of Vibrio anguillarum and prevention and control of bacterial disease in Tincaeus.     

猪源大肠杆菌耐药性质粒的监测研究

在１１５株猪大肠杆菌耐药性监测的基础上,提取耐药类型最普遍的５株耐药菌的质粒进行质粒指纹图谱分析。结果表明：同一来源、耐药类型相同的菌株有相似的质粒图谱,来源不同者,酶切图谱有提示出它们之间的同源性,说明质粒指纹图谱可作为流行病学调查的工具。     

河南省猪链球菌的分离鉴定及耐药性分析

为探讨河南省猪链球菌的血清型分布和耐药性情况,本试验对2016年5月~2017年5月从河南省猪场采集的各种组织病料进行猪链球菌的分离培养、生化鉴定及PCR鉴定,并进行了血清群的分群鉴定和血清型的分型鉴定,对其中的2型猪链球菌进行了药敏试验。结果显示,试验共鉴定出189株猪链球菌,流行的猪链球菌的血清群主要以D群为主,其次是G群和C群;优势的血清型是2型、7型、9型和1型。其中87株为2型猪链球菌,超过90%的2型菌株对β-内酰胺类（青霉素G、阿莫西林和头孢菌素类）、氯霉素、万古霉素、环丙沙星敏感,超过40%的2型菌株对多西环素、四环素、红霉素、复方新诺明、丁胺卡那霉素、克林霉素、链霉素、米诺环素产生耐药性。以上结果为指导猪场使用敏感药物及时控制疫情、选择血清型相符的疫苗进行预防及减少损失提供参考依据。     

Experimental infection by Vibrio anguillarum in mice and guinea pigs.

The fish pathogen Vibrio anguillarum causes a lethal infection in farmed fish characterized by hemorrhagic septicemia. There are no reports of experimental laboratory infections in warm-blooded animals. We investigated the effects of an intraperitoneal infection with different doses of a V. anguillarum suspension in mice and guinea pigs. The infection caused a 95-100% of mortality in 24-48 h. Hemorrhagic septicemia was observed at necropsy and confirmed by histological and hematological examination. Immunohistochemically positive bacterial clumps were detected exclusively in vessel lumen in all examined organs, including brain, and V. anguillarum was reisolated in pure culture from all organs, particularly from the kidney. Blood analysis showed erythropenia and leukopenia with granulocytosis in mice, platelet reduction and leukopenia with lymphocytosis in guinea pigs.     

犬基因疫苗与犬抗生素抗性

2000年10-12月，华南地区某犬场一部份曾经接受犬基因疫苗免疫的犬九，虽然含有对犬病毒病的抗体，但在细菌病发病时对氨苄青霉素及新霉素产生抗性反应，对此现象作了研究和分析。     

丁酸梭菌对肠道上皮细胞黏附及对鳗弧菌抑制的研究

本试验以鱼肠道上皮细胞为模型,以肠道的致病鳗弧菌为对照,研究了丁酸梭菌对鱼肠道上皮细胞的黏附作用及黏附对细胞的损伤和成活率的影响。结果表明∶丁酸梭菌对鱼的肠道上皮的黏附率为7.39±1.85,低于鳗弧菌的黏附率(P<0.05);对细胞的损伤率为1.02±0.35,显著低于鳗弧菌对细胞的损伤率(P<0.05);黏附后丁酸梭菌组对细胞的成活率的影响与正常对照组比较,差异不显著;当酪酸菌、鳗弧菌与肠道上皮细胞共同培养时,使鳗弧菌的黏附率下降7.03%(P<0.05)。因此,该株丁酸梭菌可以安全地黏附鱼肠道上皮细胞,并能有效抑制鳗弧菌的黏附。     

Characterization of Vibrio anguillarum Strains Isolated from Diseased Fish in Finland

Characterization of V anguillarum strains (n=109) isolated from diseased salmonids was performed. Eight O serovars were found among the strains. Serovar Ol was predominant (90 %), while serovars O2, O3, O5, O8, O9, and a new serovar Va NT2, were represented by 1 or 2 strains. Two strains remained non-typeable. One of these was cross-reactive with several antisera, but had a LPS profile identical to that of serovar O8. All serovars showed specific LPS profiles. All but 1 of the Ol strains had a plasmid comparable in size to the pJMl virulence plasmid, while plasmids of different sizes were found in O2, Va NT2 and the non-typeable strains. Apart from a single strain resistant to tetracycline, all the strains were sensitive to oxolinic acid, tetracycline, and trimethoprim-sulfonamides. By their biochemical and antigenic properties strains causing vibriosis among salmonids in Finland closely resemble Scandinavian strains. Predominance of the serovars Ol and O2 suggests that commercial vaccines containing these serovars should afford sufficient protection against vibriosis in Finland.     

Vibrio anguillarum: prevalence of typical and atypical strains in marine recipients with special reference to carbohydrate pollution

Primary isolates of Vibrio anguillarum-like organisms could be separated into typical V. anguillarum (VA) and atypical V. anguillarum (AVA) by biochemical tests. The prevalence of the fish pathogenic V. anguillarum was highly influenced by carbohydrate pollution as compared to the AVA. Water an sediment counts of VA generally increased at the polluted sites during April-May and persisted at a level of approx. 100/ml water and 1,000/g sediment until October-November. A further increase in VA counts could be registered locally at the time when the sugar beet processing season started (September-October). At the control site VA counts increased during June-July to a level of 10/ml persisting until August, while the only increase in sediment counts occurred in September (100/g). The maximum counts in water and sediment were at the control site 10/ml and 100/g and the polluted sites 100,000/ml and 50,000/g, respectively.     

Virulence, cytotoxic and inflammatory activities of Vibrio anguillarum and Aeromonas salmonicida isolated from cultivated salmonid fish in Sweden

Extracellular products in culture filtrates of Aeromonas salmonicida subsp. achromogenes and Vibrio anguillarum isolated from infected fish have been shown to possess skin inflammatory factor. The extracellular products from Vibrio anguillarum were cytotoxic in HeLa and CHO cells. In addition to the skin lesions, the culture filtrates of V. anguillarum caused necrotic reaction on the rabbit skin. Five of 6 strains of V. anguillarum were lethal to mice after intraperitoneal administration of 3×10⁷ CFU. Only 1 strain of 5 A. salmonicida subsp. achromogenes produced extracellular products which elicited cytotoxic effects in the CHO cells. None of the A. salmonicida subsp. achromogenes strains were lethal to mice. The cytotoxins were inactivated when heated at 65°C for 30 min. The results indicate that the thermolabile exotoxins are non-enterotoxic since they failed to stimulate fluid accumulation in the rabbit ileal loop and did not cause elongation of the CHO cells. The rounding off of CHO cells, as well as of HeLa cells indicate that the exotoxins may play an important role in fish diseases.     

Vaccination experiments in the gadoid haddock, Melanogrammus aeglefinus L., against the bacterial pathogen Vibrio anguillarum

Vibrio anguillarum is one of the primary pathogens responsible for high levels of fish mortality in the aquaculture industry, and among gadoids O2a and b are the most common pathogenic serotypes. In this paper a variety of studies were performed to assess the optimal route by which to challenge haddock against this pathogen, and an optimal regime to vaccinate haddock. The most efficient method to challenge haddock with V. anguillarum in this study was immersion in a bath containing 10(7)cfu/ml, where 60% mortality was seen. Subsequent experiments showed that juvenile haddock could be protected against bacterial challenge with V. anguillarum, with a significant reduction in mortalities observed amongst the vaccination treatments when compared to the unvaccinated controls. However, as seen previously in cod studies, vaccination did not induce a specific antibody response.     

Binding of Vibrio anguillarum to neutral glycosphingolipids from intestinal mucosa of rainbow trout (Oncorhynchus mykiss)

To test whether glycosphingolipids (GSLs) on the intestinal mucosa of rainbow trout (Oncorhynchus mykiss) serve as a binding receptor for Vibrio anguillarum, we analyzed neutral GSLs from rainbow trout intestinal mucosa and investigated the binding of bacteria to neutral GSLs. Two kinds of neutral GSLs, designated N-1 and N-2, were identified on high-performance thin-layer chromatography (TLC) plates. In TLC immunostaining tests, V. anguillarum bound only to galactosylceramide (GalCer), lactosylceramide and N-1 having the same TLC mobility as GalCer, but neither to glucosylceramide nor to N-2. These results suggest that N-1 is GalCer (Gal beta 1-1Cer) and also that N-1 (GalCer) on rainbow trout intestinal mucosa act as a receptor for V. anguillarum.     

双组分系统CpxR影响禽致病性大肠杆菌的耐药性、抗血清杀菌能力及毒力

CpxR是细菌中Cpx双组分系统（two component system,TCS）的反应调控蛋白,通过调控靶基因的转录表达,在细菌细胞膜稳定及毒力方面发挥作用。本研究旨在探究TCS CpxR对禽致病性大肠杆菌（avian pathogenic Escherichia coli,APEC）基本生物学特性、抗血清杀菌能力及致病性的影响。利用Red同源重组系统及互补质粒构建cpxR基因缺失株、互补株,然后比较分析野生株、基因缺失株与互补株的生长曲线、运动性、生物被膜形成能力、药物敏感性、抗血清杀菌能力、动物致病性的差异。结果显示：cpxR基因缺失株与野生株、互补株的生长速度和运动性能无明显差异,且缺失cpxR基因不影响APEC的生物被膜形成能力。然而,缺失CpxR导致APEC对阿米卡星和卡那霉素耐药性降低。血清杀菌试验结果显示,CpxR有助于APEC的抗血清杀菌能力。动物感染试验结果显示,野生株、cpxR基因缺失株和互补株对雏鸭的半数致死量（LD₅₀）分别为7.50×10⁵、7.50×10⁶、1.33×10⁶ CFU,表明CpxR缺失显著降低APEC的毒力。综上表明,TCS CpxR在APEC耐药性、抗血清杀菌能力及毒力方面发挥作用,为阐明APEC的环境适应性、生存能力及致病机制提供参考。     

牦牛乳中沃氏葡萄球菌的分离鉴定与耐药性分析

在利用Baird-Parker(BP)琼脂平板培养基分离牦牛乳中金黄色葡萄球菌的过程中分离得到经基质解析电离飞行时间质谱(matrix-assisted laser desorption ionization-time of flight-mass spectrometry,MALDI-TOF-MS)鉴定为沃氏葡萄球菌的微生物,对其进行生化鉴定和抗生素药敏及抑菌实验,同时对牦牛乳样品中的抗生素残留进行测定。结果表明:该菌具有沃氏葡萄球菌的生化特征,对大部分抗生素极敏感,仅复方新诺明对其没有抑制作用;牦牛乳样品均为抗生素残留阴性。虽然在牦牛乳中检测出了条件致病菌沃氏葡萄球菌,但因乳样品来源的环境纯净使其对大部分抗生素敏感。     

鸡蛋壳蜡样芽孢杆菌的分离鉴定及耐药性分析

【目的】分析不同环境下鸡蛋外壳携带蜡样芽孢杆菌的情况和分离菌株的基本特征。【方法】从养殖场和超市各采集9种新鲜鸡蛋,对鸡蛋表面携带的蜡样芽孢杆菌进行分离鉴定、基因分型、毒力基因筛查和耐药性分析。采用基质辅助激光解吸电离飞行时间质谱(MALDI-TOF MS)技术对分离菌株进行初步鉴定,全基因组测序后进行菌种鉴定并确定基因分型、筛选毒力基因和耐药基因,同时采用微量肉汤稀释法测定分离株对头孢曲松、红霉素、万古霉素等12种抗菌药物的耐药性。【结果】经MALDI-TOF MS初步鉴定和基因组菌种鉴定,确定从养殖场3种未经清洁加工的鲜蛋中分离出的6个菌株为蜡样芽孢杆菌,其序列分型(ST)较为多样,其中有2株新的ST型。在毒力基因筛查方面,6株蜡样芽孢杆菌均检出了非溶血型肠毒素nheB基因、腹泻型毒力因子hlyⅡ基因和侵袭免疫系统的inhA基因;nheA和nheC基因携带率为83.3%,编码溶血型肠毒素HBL的hblA、hblC和hblD基因携带率均为66.7%;cytK和hlyⅢ基因携带率分别为33.3%和50.0%;肠毒素基因BceT、entFM和致吐毒素基因ces均未检出。耐药性方面,6株菌...     

广州市农贸市场猪肉源伦敦沙门菌的流行情况及耐药性分析

本研究旨在探究广州市2016年5-10月农贸市场猪肉源伦敦沙门菌的流行和耐药情况.从广州市农贸市场采集样品198份,分离得到28株猪肉源伦敦沙门菌,用K-B法测定其对18种抗菌药物的耐药性,用PCR方法鉴定其所携带的耐药基因.结果表明,市场猪肉样品中沙门菌的阳性率为74.2％(147/198),伦敦沙门菌的分离率为19...     

空肠弯曲菌耐药机制研究进展

空肠弯曲菌是一种全球关注的人兽共患病病原菌,由于滥用抗生素而造成其耐药性不断增强,成为公共卫生日益关注的问题.各类抗生素作用位点的基因突变是诱发空肠弯曲菌对各类临床常用的抗生素产生耐药的主要原因,同时细菌对药物的外排机制也在其对抗生素耐药过程中发挥了一定的作用.文章对空肠弯曲菌对各类临床常用抗生素的耐药机制做一综述.     

种鹅大肠杆菌分离鉴定及耐药性分析

为了解种鹅致病性大肠杆菌病的病原及其药物敏感性,2012年从广东地区患病种鹅器官和粪便中分离鉴定了62株大肠杆菌,采用琼脂稀释法测定了大肠杆菌对17种抗菌药物的敏感性。结果发现大肠杆菌耐药性严重,对大部分药物的耐药率超过60.0%,仅对头孢西丁、头孢他啶和黏菌素较敏感。联合药敏试验结果显示多西环素和氟苯尼考联用对耐药大肠杆菌产生协同抑菌作用,FIC指数为0.375～0.75。采用脉冲场凝胶电泳（PFGE）法对24株大肠杆菌进行分型,结果分为17种不同的PFGE型别。大肠杆菌系统进化分群结果显示43.5%属于系统进化组群的D组,其次是A组和B1组,分别为34.8%和21.7%,B2组未检测到。通过对种鹅大肠杆菌耐药性、PFGE分型及其系统发育群进行综合分析,为临床用药提供了参考依据。     

细菌耐药性的产生机理及控制对策

随着抗生素的广泛应用,细菌的耐药性越来越高,给临床治疗带来诸多困难,因此了解细菌耐药的产生机理具有重要意义。本文主要对抗生素的作用机理,细菌耐药性产生的生化机理和基因机理,耐药性的控制对策进行了阐述,希望能为临床上的合理用药提供科学的依据。     

抗菌药耐药性预测框架的构成要素

结合抗菌药耐药性研究前沿,从抗菌药作用、耐药性的产生、耐药菌的适应性、耐药性的转移、耐药性的流行监测五个方面,系统介绍了抗菌药耐药性预测框架的构成环节和形成要素,为新药入市前的耐药性风险评定以及耐药性控制办法的制定提供与参考。