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1.
The effect of a pathogenic Vibrio pelagius, isolated during a mass mortality of turbot larvae, on the non-specific immune response of turbot, Scophthalmus maximus (L.), macrophages was studied both in vitro and in vivo. The in vitro treatment of head kidney (HK) macrophages with viable V. pelagius caused a significant inhibition of the chemiluminescence (CL) response in comparison with untreated macrophages, while incubation with heat-killed bacteria did not affect this response. In vivo, the intraperitoneal injection of V. pelagius resulted in a significant inhibition of the CL response in infected fish at days 1 and 4 post-infection compared with the control fish response. The HK macrophage nitric oxide (NO) production was enhanced by in vitro incubation with intermediate doses of viable V. pelagius (5 x 10(3) and 5 x 10(4) bacteria mL(-1)) and higher doses of the heat-killed bacteria (5 x 10(4)-5 x 10(6) bacteria mL(-1)). In both cases, the NO inhibitor N-omega -nitro-L-arginine was capable of down-regulating the specific NO induction caused by incubation with the bacterial treatments. In contrast, incubation with ECPs at higher doses caused a reduction in NO production. In vivo, a significant enhancement in NO production was also observed in macrophage supernatants at day 10 post-infection. Lysozyme concentration in the serum was also significantly increased in the experimentally infected fish at days 4 and 10 post-injection. In addition, viable V. pelagius and its ECPs significantly reduced HK macrophage viability in vitro, whereas no significant differences in viability were observed during the incubation with heat-killed bacteria. As NO production was enhanced in the experimentally infected fish, the inhibitory effect of the NO donor, S-nitroso-acetyl-penicillamine (SNAP), was tested in vitro in a cell-free assay. The results showed that growth of V. pelagius was significantly inhibited using SNAP at a high concentration (1 mM). 相似文献
2.
养殖大菱鲆肠道中大菱鲆弧菌的分离鉴定及药敏试验 总被引：1，自引：0，他引：1
2014年11月,大连地区某大菱鲆养殖场发生病害并伴有死亡,主要症状为吻部下颌明显出血,腹腔积水,肝脏充血,肠道出血有白便。从患病大菱鲆肠道中分离出1株可在硫代硫酸盐—柠檬酸盐—胆盐—蔗糖琼脂培养基上生长的菌株HZ-C1,人工回接感染试验证明其对健康大菱鲆具有较强致病性。通过形态学观察、16SrDNA序列同源性分析及生理生化试验确定菌株HZ-C1为大菱鲆弧菌。药敏检测结果显示,大菱鲆弧菌HZ-C1对氯霉素、丁胺卡那及头孢曲松等11种抗生素敏感,但对青霉素、四环素及诺氟沙星等15种抗生素耐药。本研究为大连地区养殖大菱鲆细菌性病害防治提供了一定病原学依据。 相似文献
3.
大菱鲆仔稚鱼发育早期肠道菌群结构形成的影响因素 总被引：1，自引：0，他引：1
为研究鱼类发育早期肠道菌群结构的演变过程及影响因素,运用高通量测序技术,分析了处于不同发育阶段的大菱鲆(Scophthalmus maximus)仔稚鱼肠道、受精卵、不同类型的饵料和水源中的菌群结构,以及它们之间的相关性。结果显示,以不同的OTU(Operational Taxonomic Units,可操作分类单元)作为分类依据,发现大菱鲆仔稚鱼的肠道菌群结构在开口摄食后不久已趋于稳定,其优势菌与受精卵所携带的细菌关联较大。并且在大菱鲆仔稚鱼不同的发育时期,这一菌群的结构非常稳固,几乎不受水和饵料中优势细菌的影响而发生改变。乳球菌属的Lactococcus piscium菌株一直是大菱鲆仔稚鱼肠道中的优势菌种,在不同发育时期的优势度高达45%~65%。本研究还发现,大菱鲆仔稚鱼肠道可能对定植的菌种具有选择性,一些水环境和饵料中的非优势菌,如Streptococcus sp.,Pseudomonas sp.,Carnobacterium sp.等细菌也会定植于肠道,成为大菱鲆肠道中的次优势菌。 相似文献
4.
Vibrio splendidus is a pathogen that can cause major losses during the early stages of larval turbot rearing when live feed (rotifers or Artemia) is used. As haemolytic bacteria have often been associated with larval rearing losses, we studied the role of the V. splendidus haemolysin in infection of larvae. From a bank of over 10,000 transposon mutants of V. splendidus, two different types of haemolysin-negative mutants were obtained. Both had lost virulence for larval fish, and immunohistochemistry showed that the transposon mutant studied colonized the turbot larval intestinal tract at a similar level to the wild-type organism but did not cause damage or signs of enteritis found with the wild-type organism. One transposon insertion site was located within a gene with high homology to aerolysin, the cytolytic toxin produced by several Aeromonas spp. The haemolysin, which we have termed vibrioaerolysin, had properties similar to aerolysin and osmotic protection studies showed that it formed pores in the membranes of erythrocytes of similar diameter to those of aerolysin. The Tn10 insertion site of the second transposon mutant was in an adjacent ToxR-like gene, suggesting that this might control expression of the vibrioaerolysin. The gastroenteritis caused by Aeromonas spp. in humans is considered to be due to production of aerolysin causing cyclic AMP-dependent chloride secretion in cells of the gastrointestinal tract. Damage to the intestinal tract of marine fish larvae could occur in a similar way, and it is possible that several Vibrio spp. found in the developing bacterial flora of the larval fish gut can secrete aerolysin-like toxins leading to death of larvae in the early rearing stages. Routine bacteriological screening on blood agar plates of live feed is recommended with measures to reduce the concentrations of haemolytic bacteria in rearing systems. 相似文献
5.
Colonization of the gut in first feeding turbot by bacterial strains added to the water or bioencapsulated in rotifers 总被引：2，自引：0，他引：2
Pavlos Makridis Anders Jon Fjellheim Jorunn Skjermo Olav Vadstein 《Aquaculture International》2000,8(5):367-380
Two bacterial strains, 4:44 and PB52, isolated from turbot(Scophthalmus maximus L.) were used during a first feedingexperiment with turbot larvae. Bacteria were either added directly tothe water on the day of hatching of the larvae (day 0), orbioencapsulated in rotifers (Brachionus plicatilis) distributedon day 2 after hatching. The two bacterial strains were found to bepresent in the water of the rearing tanks throughout the experiment. Theaddition of bacteria influenced the species-composition of themicroflora associated with intensively produced rotifers added to thetanks, and resulted in colonization of the gut of the larvae by theadded bacterial strains. The strain 4:44 showed a peak on day 9 afterhatching, and reached a mean(sem) of 2.5(1.4) × 104bacteria per larva, when added in a mixture with PB52, and 0.4(0.1)× 104 bacteria per larva, when added alone. The strainPB52, on day 12 after hatching, reached 5.2(1.5) × 104bacteria per larva when added in a mixture with strain 4:44, and12.5(0.7) × 104 bacteria per larva, when added alone.The added bacteria colonized the gut turbot larvae, whereas thebacterial land, the survival and growth of the larvae were in most casesnot influenced in a negative way by the addition of bacteria. 相似文献
6.
7.
A. S. Mahious F. J. Gatesoupe M. Hervi R. Metailler F. Ollevier 《Aquaculture International》2006,14(3):219-229
Preliminary experiments were undertaken to investigate the effect of dietary inulin (Raftiline ST), oligofructose (Raftilose P95) and lactosucrose on the growth and intestinal bacteria of the marine carnivorous turbot, Psetta maxima. Turbot larvae were weaned on compound diets containing 2% Rafiline ST, 2% Raftilose P95 or 2% lactosucrose; 2% cellulose was the carbon source in the control group. The final mean weight of the group weaned with Raftilose P95 was significantly higher than those observed with the other diets. The bacterial load was highly variable in weaning turbot, especially with respect to the putative Vibrio spp. growing on TCBS agar which, in general, seemed to be dominant. Of the total load of bacterial isolates from turbot weaned on oligofructose, 14% consisted of a strain of Bacillus spp. This strain could use Raftilose P95 as a single source of carbon, and it might play a role in the beneficial effect of oligofructose on turbot growth, since Bacillus spp. have been documented as probiotics in fish. 相似文献
8.
从“急性死亡脱落症”发病期的杂色鲍幼苗体内和病苗附着的薄膜上，共分离到4株优势菌，即NA0301、NA0302、NA0303和NA0304。经人工浸泡感染实验证明，从病幼苗体内和苗附着的薄膜上分离到的优势菌株NA0301和NA0302是杂色鲍幼苗的致病菌，它们均为革兰氏阴性、短杆状、极生鞭毛，能运动。常规生理生化和Biolog细菌鉴定系统测试结果表明，菌株NA0301与溶珊瑚弧菌（Vibrio coralliilyticus）的亲缘关系最近，而菌株NA0302与溶藻弧菌（Vibrio alginolyticus）的亲缘关系最近。为了进一步确定它们的分类学地位，分别测定了溶珊瑚弧菌和溶藻弧菌的16S rDNA序列，分析相关细菌相应序列的同源性，并构建系统进化树。结果表明，菌株NA0301与溶珊瑚弧菌的亲缘关系最近，菌株NA0302与溶藻弧菌的亲缘关系最近。因此，菌株NA0301和菌株NA0302分别鉴定为：溶珊瑚弧菌和溶藻弧菌。[中国水产科学，2006，13（4）：655—661] 相似文献
9.
The susceptibility of larvae and post-larvae of Penaeus indicus, P. monodon , and P. semisulcatlls to a Vibrio campbellii-like bacterium was studied by immersion challenge. Exposure to bacteria caused up to 100% mortality, depending upon bacterial dose and time of exposure. Mortality rate was higher for nauplius and protozoeal stages than for mysis and post-larval stages. Based upon LC50 values at different time intervals, P. monodon was found to be the most sensitive of the three shrimp species to this pathogen. 相似文献
10.
The presence of a lethal extracellular 39-kDa protease, a virulence determinant of a Listonella pelagia strain which produces vibriosis in turbot, was determined in the extracellular products (ECP) of 33 Vibrionaceae strains. Both immunological and enzymatic techniques distinguished this specific protease from other Vibrionaceae proteins. It was detected in 15% (5/33) of the ECPs assayed belonging to strains of the Vibrio splendidus-V. lentus related group isolated in Galician aquaculture systems (NW Spain). As these strains were associated with diseased octopus and cultured turbot, were able to colonize the internal organs of fish and produced a lethal ECP for fish, they are a potential risk for the health of reared aquatic organisms. 相似文献
11.
Abstract. A dot-blot hybridization test has been developed for the detection of infectious pancreatic necrosis virus (IPNV) in infected fish. For this purpose, cloning of the dsRNA of the West Buxton strain of IPNV was carried out. Two cDNA clones (WB and A4) were characterized for use as diagnostic probes and corresponded to IPNV genome segments A and B. respectively. Clone WB1, with an insert of 812 base pairs, showed an 87 and 77% nuclcotidc sequence homology with the corresponding sequences of Jasper and N1 strains, respectively. Clone A4, with an insert size of 596bp, presented a nuclcotidc sequence homology of 90 and 80% with the corresponding sequences of the Jasper and Sp strains, respectively. Both probes were able to detect 15 ng of purified dsRNA, and were highly efficient in detecting the RNA of American IPNV strains. However, the A4 probe was less effective than WB1 in hybridizing to RNA from European and Spanish strains of IPNV. Both probes detected IPNV RNA in cells 4–8h post-infection with the homologous West Buxton strain, 8–12h post-infection with other American strains and 24h post-infection with the European strains of IPNV. The method was less sensitive in detecting IPNV RNA directly in infected fish tissues. However, the present authors obtained a 100% effectiveness to detect viral RNA in cells inoculated with fish tissues confirmed by conventional diagnostic methods as being infected with IPNV. Therefore, the hybridization test is appropriate if combined with conventional diagnostic procedures, e.g. applying the dot blot hybridization test on tissue cultures 12–24 h after inoculation with infected fish tissue homogenates. 相似文献
12.
The susceptibility of turbot, Psetta maxima, to infection with two strains of viral haemorrhagic septicaemia virus (VHSV) obtained from wild Greenland halibut, Reinhardtius hippoglossoides, and from farmed turbot was examined. A marine VHSV strain known to be highly pathogenic for turbot was also utilized for comparative purposes. Fish were infected by intra-peritoneal (i.p.), immersion or cohabitation, and maintained at two different temperatures (8 and 15 degrees C). Infection trials showed that the three VHSV isolates were pathogenic for turbot fingerlings by i.p. injection at both temperatures, with high levels of mortality. Virus was recovered from most pools of dead fish i.p. challenged, but not from surviving fish. Although clinical signs were not induced following waterborne exposure, viral growth was obtained from some pools of surviving fish challenged by immersion with strain GH40 from Greenland halibut, which indicates that the virus can survive in sea water and infect other fish via horizontal transmission. Furthermore, although low, the clinical signs and mortality observed in fish cohabitating with turbot challenged with strain GH40 confirms horizontal transmission and indicates that the passage through fish increases the virulence of this strain for turbot. These findings indicate that Greenland halibut, as other wild fish, may play an important role in the epizootiology of VHSV and suggest a potential risk for the turbot farming industry. 相似文献
13.
Before transfer to larval incubators, water was membrane filtered to remove >95% of the bacteria and then transiently maintained
in a biofilter that promoted recolonization of the water by non-opportunistic bacteria. The process is termed microbial maturation
of the water. Hypothetically the bacterial flora in the matured water should protect the marine larvae from colonization and
proliferation by opportunistic bacteria. Testing of the hypothesis demonstrated 76% higher survival of yolk sac larvae of
Atlantic halibut (Hippoglossus hippoglossus) in matured than in membrane filtered water. Proliferation of opportunistic bacteria was observed in the rearing water after
hatching of turbot eggs (Scophthalmus maximus), but to a less extent in the microbially matured water. In the early phase of first feeding of turbot larvae, the matured
water induced qualitative differences in the gut microflora. Significantly higher initial growth rate of the turbot larvae
in the matured water affected 51% higher average weight of 13 days old larvae than in membrane filtered water. Algal addition
to the matured water enhanced the larval growth further. The experiments conducted supported the proposed hypothesis that
microbial maturation selects for non-opportunistic bacteria, which protects the marine larvae from proliferation of detrimental
opportunistic bacteria. 相似文献
14.
15.
细菌性疾病是中国海水养殖鲆鲽类的主要病害,为全面了解病原菌种类,本研究对1999~2012年从山东、江苏、河北、天津等沿海地区养殖场发病鲆鲽鱼类中分离得到的124株优势菌株进行了16S rRNA基因测序和系统发育学分析。将基因序列与GenBank核酸序列数据库进行相似度比对分析,结果显示,有83株与弧菌属(Vibriosp.)细菌相似度最高,11株与气单胞菌属(Aeromonas sp.)细菌相似度最高,4株与爱德华氏菌属(Edwardsiella sp.)细菌相似度最高,26株为其他15种属的细菌。根据系统发育学分析结果,进一步将66株菌鉴定为16个种,优势种为溶藻弧菌(V.alginolyticus)、哈氏弧菌(V.harveyi)、鳗弧菌(V.anguillarum)、杀鲑气单胞菌(A.salmonicida)和迟缓爱德华氏菌(E.tarda)。选择其中的9株鳗弧菌和4株迟缓爱德华氏菌进行人工感染实验,结果显示,其中7株鳗弧菌和3株迟缓爱德华氏菌对大菱鲆(Scophthalmus maximus)有较强的致病性。研究结果可为阐明中国海水养殖鲆鲽类的流行病发生历史、病原种类、病原监测及疾病控制提供重要参考。 相似文献
16.
采用基于Illumina测序平台的高通量测序技术,对大菱鲆(Scophthalmus maximus)幼鱼肠道及其养殖水体、生物饵料中细菌种类及丰度进行研究。测序结果显示,养殖水体、生物饵料和大菱鲆幼鱼肠道等19个样品共获得有效序列547621条,可聚类于3771个可分类操作单元(OTUs),归属于养殖水体、生物饵料、健康幼鱼和发病幼鱼的操作分类单元(OTU)个数分别为3038、1090、87和777,其中,健康幼鱼与生物饵料、健康幼鱼与养殖水体特有的OTU个数分别为57和0,发病幼鱼与生物饵料、发病幼鱼与养殖水体特有的OTU个数分别为481和31。表明幼鱼肠道微生物多样性与生物饵料密切相关。根据细菌注释结果,拟杆菌门(Bacteroidetes)、厚壁菌门(Firmicutes)和变形菌门(Proteobacteria)在大菱鲆幼鱼肠道中占优势地位,其中,健康幼鱼肠道微生物共聚类为8个门,发病幼鱼的肠道微生物可聚类为19个门。与健康幼鱼相比,发病幼鱼肠道门水平上的3种主要优势菌群落结构出现失衡。此外,对各样品中丰度最高的100位OTU分析显示,幼鱼肠道优势菌种类与生物饵料中的优势菌种类密切相关,而每个发病幼鱼肠道优势菌种类具有一定的独立性。本研究旨在为大菱鲆健康养殖和微生态调控提供实验依据。 相似文献
17.
Hongman Hou Jie Ding Gongliang Zhang Li Chen 《Journal Of Aquatic Food Product Technology》2013,22(6):530-541
The microbial flora in turbot (Scophthalmus maximus) cultured in deepwell seawater from Liaodong Peninsula, China was studied for the first time. The total amount of aerobic meso- and psychrophilic microflora from the culturing water, gills, and skin were 3.46–3.82, 3.19–4.28, and 1.70–1.95 log cfu/g, respectively. Out of 204 strains isolated from fresh turbot meat with skin, Gram-positive bacteria accounted for 19.2% of the total aerobic meso- and psychrophilic microflora, and 72.1% were Gram-negative bacteria. Phylogenetic analysis was performed using 16S rDNA sequences of microbial flora isolated from turbot. The predominant bacteria in fresh turbot were Micrococcus, Serratia liquefaciens, and Enterobacteriaceae. Meanwhile, the bacterial flora of refrigerated turbot fish were investigated, and the results indicated that Shewanella putrefaciens was the predominant spoilage bacteria. 相似文献
18.
J. Iglesias G. Ojea J. J. Otero & L. Fuentes T. Ellis 《Fisheries Management and Ecology》2003,10(1):51-59
Abstract Marked reared turbot, Scophthalmus maximus (L.) (594) were released onto an exposed beach nursery ground together with marked wild fish (438) of approximately the same size (4–6 cm TL) and were sampled at intervals for 38 days. A consistent ratio of marked wild: unmarked wild indicated that marking did not increase mortality. The wild 0-group turbot population size was estimated at 1540 at the time of release, indicating that hatchery-reared individuals could theoretically make a significant contribution to the local population size. However, the absolute and relative catches of the marked, reared fish were lower than those of the marked wild fish, and no reared fish were caught after 23 days. The higher mortality rate was attributed to both a smaller size and their hatchery-reared origin. The population dynamics of the 1994–1995 year-classes of wild turbot were also studied. Recruitment of post-larvae (3 cm) to the beach started in March and continued until October. Population size peaked over the August–October period. Juvenile turbot remained on the nursery beach until June of the following year when they presumably emigrated to deeper water. During this 15-month period their length increased from 3 to 12–15 cm. 相似文献
19.
栉孔扇贝血清中的免疫因子的研究↑（*） 总被引：2，自引：0，他引：2
本文对栉孔扇贝血清的细菌凝集活性、抑菌活性和溶菌活性进行研究。选用２４种细菌和真菌进行凝集试验,发现栉孔扇贝血清能够对金黄色葡萄球菌和代远洋弧菌产生凝集作用,血清的细菌凝集作用经数种细菌刺激没有发生改变,说明这种凝集作用是不可诱导的。栉孔扇贝的血清对某些细菌的生长有一定的抑制作用,但在体外彻底杀灭细菌的效果极差,经大肠杆菌和副溶血弧菌刺激后,抑菌效果基本不变。栉孔扇贝血清还具有一定的溶菌作用,而且大肠杆菌的刺激可以明显提高这种溶菌作用。 相似文献