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1.
本对中山市养殖中华鳖暴发的以体表产生白膜病症的一种疫病病原体进行分离鉴定及药敏实验。从自然感染症状明显的中华鳖内脏器官中分离所得的菌株，经生理生化特性测定，并参考实验菌菌落、菌体特征，初步鉴定为气单胞菌科维隆气单胞菌温和生物型种(简称为温和气单胞菌Aeromonas sobria)。并且，用多种常用鱼病防治药物对分离菌进行了药敏实验，以期筛选出对该病原菌较敏感的药物用于指导生产上防治疫病。 相似文献
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杂交鳢(斑鳢♀×乌鳢♂)溃疡病病原菌的分离、鉴定及其防治中草药的筛选 总被引：1，自引：0，他引：1
针对2014年发生在广东省中山市三角镇的杂交鳢(Channa maculate♀×Channa argus♂)溃疡病,开展了病原的分离鉴定和致病性研究、药物敏感性试验和中草药抑菌、杀菌试验。实验从杂交鳢脾脏中分离到一个菌株S8,该菌株为革兰氏阴性短杆菌,菌体直、两端钝圆。对该菌进行生理生化鉴定、16S rRNA和gyr B序列和系统发育分析结果表明,此致病菌株为温和气单胞菌(Aeromonas sobria)。人工感染试验结果显示,当人工感染剂量大于1.0×107CFU/尾时,能引起杂交鳢100%发病死亡。抗菌药物敏感性试验表明,温和气单胞菌S8对阿米卡星、头孢拉啶等药物高度敏感,对头孢他啶、氨苄西林、复方新诺明等抗菌药物不敏感。应用二倍稀释法测定了18种中草药对温和气单胞菌S8的最小抑菌浓度和最小杀菌浓度,结果显示:石榴皮、五倍子、黄芩对温和气单胞菌S8的抑菌杀菌效果最佳,其次为山茱萸、地榆和芦荟。 相似文献
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从广东佛山、广州两地养殖场患内脏类结节病杂交鳢(Channa maculata♀×C.argus♂)内脏器官分离到2株细菌,纯化培养后获得2个分离株,编号为WL-1和WL-2,对分离菌株进行了细菌鉴定、致病性分析及药敏实验。应用常规生理生化鉴定和ATB系统细菌自动鉴定仪对分离菌株进行细胞形态学、理化特性分析,初步判定所分离菌为舒伯特气单胞菌。采用16S rRNA基因、DNA促旋酶的B亚单位蛋白(gyrB)基因对分离菌株进行DNA分子鉴定,结果显示,两个菌株间的16S rRNA基因序列相同,gyrB基因序列同源性为99.7%;分离菌株与GenBank上登录的舒伯特气单胞菌16S rRNA基因序列和gyrB基因序列同源性均最高,达99%以上;分离菌株在系统进化树上与舒伯特气单胞菌聚为一族,进一步确认分离株为舒伯特气单胞菌。人工感染健康鱼后出现与自然发病相似的内脏类结节病症状,从发病鱼内脏组织再分离的细菌特性与原感染菌相同。综合理化特性分析、基因鉴定和人工感染实验确认舒伯特气单胞菌是杂交鳢内脏类结节病的致病菌。药敏实验发现分离菌株对头孢唑啉、庆大霉素等14种药物敏感;对青霉素G、苯唑西林2种药物耐受。 相似文献
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对患病中华鳖(Trionyn sinensis)进行病原分离、鉴定及药敏实验。从患病中华鳖肝、肾、脾及腹水分离纯化病原菌,经理化特性测定及16S rRNA序列分析对其进行鉴定,开展人工感染试验,并利用K-B进行药敏特性分析。结果显示分离菌株HD01为本次引发中华鳖病害的病原菌,其对中华鳖的LD50为4.48×106CFU/g。HD01株理化特性与粘质沙雷氏菌一致,16S rRNA序列与粘质沙雷氏菌同源性为99%,综合判定分离菌株为粘质沙雷氏菌(Serratia marcescens)。HD01株对氟苯尼考、多西环素、庆大霉素及苯唑西林等14种抗生素高度敏感;对青霉素、头孢拉定、新霉素等7种抗生素耐药。分离菌株HD01是中华鳖病原菌,养殖时可选用氟苯尼考、庆大霉素及多西环素等药物进行防控。 相似文献
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从患头部溃烂病的淡水白鲨(Pangasius sutchi)肝脏中分离到1株优势菌BS1,分别以腹腔注射、创伤浸泡和直接浸泡三种方式感染淡水白鲨。结果显示:该菌株能感染淡水白鲨,且毒力较强,腹腔注射0.2 m L该菌液(1×108cfu/m L)可导致受试淡水白鲨100%死亡,创伤浸泡感染(1×107cfu/m L)死亡率达83.3%,直接浸泡感染(1×107cfu/m L)死亡率为0%,受感染淡水白鲨出现与自然感染相同的症状。对菌株BS1进行形态特征观察和主要理化特性分析,初步鉴定为嗜水气单胞菌(Aeromonas hydrophila)。进一步选用16S rRNA对该菌进行分子鉴定,序列结果进行BLAST分析并构建进化树,结果表明:16S rRNA基因与Gen Bank上登录的嗜水气单胞菌的相应序列具有很高的同源性,进化树聚为一支。综合生理生化与分子鉴定结果,判定所分离的菌株为嗜水气单胞菌。药敏试验结果显示:该菌株对左氟沙星、诺氟沙星、恩诺沙星、氧氟沙星、庆大霉素、卡那霉素、新霉素、妥布霉素、阿奇霉素9种药物高度敏感。 相似文献
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对一起养殖鲤(Cyprinus carpio)发生的病害进行了发病情况、临床特征、病理变化等方面的检验.以3尾病(死)鲤进行病变组织中的细菌检查及细菌分离,对分离菌进行了形态特征、理化特性等较系统的表观分类学指征鉴定;同时选择代表菌株进行了16S rRNA基因的分子鉴定,测定了16S rRNA基因序列、分析了相关细菌相应序列的同源性、构建了系统发生树.结果表明,分离菌为气单胞菌属(Aeromonas Kluyver and Van Niel 1936)的嗜水气单胞菌[A.hydrophila(Chester 1901)stanier 1943],代表菌株(HC060718-1株)16S rRNA基因序列长度(不包括引物结合区)为1 454 bp(GenBank登录号:EF669478).择代表菌株做对健康鲤的人工感染试验,表明了分离鉴定的嗜水气单胞菌在被检鲤病例的相应原发病原学意义及较强的致病作用.药敏试验结果显示,对供试37种抗菌药物中的头孢噻肟等23种药物高度敏感,对氨苄青霉素等5种药物敏感,对青霉素G等9种药物耐药. 相似文献
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异育银鲫病原温和气单胞菌表型及分子鉴定与溶血素基因检测 总被引：4，自引：0，他引：4
2008年10月江苏盐城大丰精养异育银鲫（Carassius auratus gibelio) 发生严重疾病,从病鱼肝脏、血液及腹水中分离到优势生长的细菌。对分离做纯培养的4株菌(JY081016-1至JY081016-4)进行形态特征、理化特性等表型生物学性状检验;测定了菌株（JY081016-1）的16S rRNA和gyrB基因序列,分析了16S rRNA和gyrB两种基因序列的同源性,并构建了系统发生树。结果表明分离菌对供试健康异育银鲫有强致病性,菌株（JY081016-1）所扩增的16S rRNA基因序列长度为1448bp（GenBank 登录号：GQ232759）,所扩增的gyrB基因序列长度为1177bp（GenBank 登录号：GQ232760）,其16S rRNA和gyrB基因序列与GenBank数据库中维氏气单胞菌和维氏气单胞菌温和生物型的16S rRNA和gyrB基因序列相似性均在97%以上;根据分离菌的表型及分子特征,判定分离鉴定的4株菌为温和气单胞菌（Aeromonas sobria）。胞外酶及溶血活性检测表明分离菌均能产生蛋白酶、卵磷脂酶、脂酶,在含7%家兔脱纤血液营养琼脂培养基上呈β型溶血;设计的特异性引物可扩增出溶血素基因。 相似文献
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为探明引起彭水县某鲟养殖场杂交鲟(Acipenser baerii♀×A.schrencki♂)患病的病原，本研究从患病杂交鲟的腹水中分离出一株细菌(A20)。通过菌落形态观察、革兰氏染色、溶血性实验、生理生化特征、16S rDNA基因和gyrB基因序列分析对菌株A20进行鉴定，同时探究菌株A20的耐受性、毒力基因、半致死浓度和药物敏感性等生物学特性。结果显示：菌株A20鉴定为气单胞菌属(Aeromonas spp.)短杆状革兰氏阴性菌温和气单胞菌(A.sobria);菌株A20生长的最适pH为7,对温度和盐度的耐受力较强；该菌携带hlyA、ompA、alt、aer 4种毒力基因；人工回归感染实验结果表明菌株A20为导致杂交鲟患病的病原菌，LD50为1.37×107 CFU/mL;药敏结果表明，该菌对氟苯尼考、恩诺沙星等15种抗菌药物敏感。 相似文献
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从发病虹鳟(Oncorhynchus mykiss)肾脏组织中分离到了1株优势菌HZS-01,将分离纯化的菌株进行形态、生理生化特征研究和16S rRNA基因鉴定分析。结果显示,HZS-01株菌的形态和生理生化反应结果符合嗜水气单胞菌(Aeromonas hydrophila)的特征。16S rRNA基因序列分析结果显示,分离菌株在系统发育树上与嗜水气单胞菌(A.hydrophila)属同一分支,同源性达99%以上。综合菌株HZS-01的形态学特征和16S rRNA基因分析结果,将其鉴定为嗜水气单胞菌。药敏试验结果表明,分离菌株对强力霉素、诺氟沙星、左氧氟沙星、新生霉素、阿奇霉素敏感度高,对生产用药预防和治疗有实际指导意义。 相似文献
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为了培育马氏珠母贝新品种，开展了不同地理种群内自繁和种群间杂交的工作，获得了3个自繁群体和3个杂交群体，BB1、DD1和SS1分别来自北海野生种群(BW)、大亚湾野生种群(DW)和三亚野生种群(SW)自繁一代；BDl、BS1和DSl分别来自BW与DW、BW与SW以及DW与SW杂交一代。运用方差分析对6个子一代群体的5个主要性状(壳长、壳宽、壳厚、总体重和壳重)进行了比较，3个杂交群体未表现出杂种优势。但获得的6个群体将成为进一步选育的基本群体。子一代的变异性增加为进一步选育奠定了基础。 相似文献
12.
Evaluation of a novel bacterial biomass as a substitution for soybean meal in plant‐based practical diets for Pacific white shrimp Litopenaeus vannamei 
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下载免费PDF全文 Three growth trials and a digestibility trial were designed to evaluate the efficacy of a novel bacterial biomass (BB) in commercial‐type feed formulation for Pacific white shrimp, Litopenaeus vannamei. In trial 1, the basal diet was supplemented with 0, 60 and 120 g/kg BB to replace soybean meal (SBM). Significant improvement was observed in the survival when BB was incorporated in the diets. However, shrimp fed diets containing 120 g/kg BB exhibited significantly lower weight gain (WG) and higher feed conversion ratio (FCR). To confirm the results from trial 1 and explore the effects of BB supplementation at low levels, the basal diet was incorporated with 0, 10, 20, 40, 60 and 120 g/kg BB to replace SBM in trial 2. Significant reductions in WG, FCR, lipid content of whole body, protein retention efficiency and most amino acids retention efficiency were detected in shrimp fed with diet containing 120 g/kg BB. Trial 3 was designed to elucidate whether the digestible protein is the cause of reduced growth. No improvements in terms of growth performance and FCR were detected in the treatments balanced for digestible protein. Apparent digestibility coefficients of energy, protein and amino acid (AA) for BB were determined using chromic oxide as an inert marker and the 70:30 replacement technique. The energy, protein and individual amino acid digestibility coefficients of BB were significantly lower than those of fish meal (FM) and SBM that were given at the same time. Results of this study indicated that BB can be utilized up to 40 g/kg in shrimp feed without causing a decrease in growth. However, supplementations (≥60 g/kg) of BB can result in negative effects on growth response, FCR and protein as well as amino acids retention efficiency. At the lower levels of inclusion, shrimp performance was improved when BB was supplemented on a digestibility basis; however, at the higher level of inclusion, there was no improvement, indicating there may be other nutrients limiting. Based on enhanced survival in the treatment with BB supplementation in trial 1, further research regarding the immune effects of BB in practical shrimp feed will be necessary. 相似文献
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合浦珠母贝双列杂交家系的建立与遗传分析 总被引：4，自引：1，他引：3
以采自广西北海(B)、广东徐闻(X)、海南三亚(S)的3个不同养殖群体的合浦珠母贝为亲贝,按照完全双列杂交的方式,建立了9个交配组合,每个组合10个家系,共90个家系。出苗经60d养殖后,比较各家系的育种值,并对家系进行综合评价。结果表明:壳长的Kung育种值大于20的家系有8个,分别为BX2(表示北海♂×徐闻♀的2号家系,余依此类推)、BX9、BB4、BB5、BB8、BS9、XS3、SB8,其中XS3的壳长及壳宽的Kung育种值和综合评定值均最大,XX3最小。BB4和XS3的综合评定值大于1。壳长的一般配合力为三亚群体17.40,徐闻17.45,北海18.27;壳高为三亚14.74,徐闻14.79,北海15.54。壳长的特殊配合力为三亚—徐闻17.75,三亚—北海18.27,徐闻—北海18.12;壳高为三亚—徐闻14.98,三亚—北海15.51,徐闻—北海15.46。壳长的平均杂种优势为三亚—徐闻1.41,三亚—北海0.96,徐闻—北海0.67;壳高为三亚—徐闻1.13,三亚—北海1.60,徐闻—北海1.19。表明北海的亲本较好。 相似文献
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溶藻弧菌单克隆抗体的制备及应用 总被引：7，自引：0，他引：7
小鼠骨髓瘤细胞系SP2/0与经溶藻弧菌(1.1587)免疫的BALB3/C雌鼠脾细胞在PEG条件下融合,有45.8%的培养孔有杂交瘤细胞生长,其培养上清液抗体阳性率为77.4%.经反复有限稀释法克隆杂交瘤细胞,获得7株抗溶藻弧菌的单克隆抗体杂交瘤细胞株,分别为AC1-C9,AC1-C11,BB4-D4,AD1-A3,AD1-F3,AD2-E7,AD2-F7.取AD1-F3扩大培养,注射小鼠,制备了抗溶藻弧菌的单克隆抗体腹水,滴度为11000.该腹水与其他3株溶藻弧菌菌株有强交叉反应,与其他13株标准菌株无交叉反应.利用制备的单抗腹水,建立了检测溶藻弧菌的单抗-ELISA技术.该反应系统可应用于溶藻弧菌的快速诊断,反应时间为6-7h,检测灵敏度为104cells·-1.并利用该检测方法进行了11份待测菌样本溶藻弧菌的检测. 相似文献
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大口黑鲈肌球蛋白重链基因SNPs的筛选及与生长性状的关联 总被引：2，自引：2，他引：0
肌球蛋白是肌肉细胞的重要组成成分,影响肌纤维的组成和肌肉生长。为了研究肌球蛋白重链(MYH)基因多态性与大口黑鲈生长性状的相关性,本研究采用PCR技术扩增得到编码区序列全长为9759 bp的大口黑鲈MYH基因,该基因包含37个外显子和36个内含子,编码1940个氨基酸。采用直接测序法在MYH基因上筛选到8个单核苷酸多态性标记(SNP)位点(A-305G、G-558C、A-2784C、A-2816G、T-4765A、C-6206T、C-6811T和G-6935T),有4个位于外显子上,其中2个属于同义突变。用SNa Pshot方法对从同批繁殖、同塘养殖的大口黑鲈"优鲈1号"群体中随机选取的430尾个体中各位点的基因型进行检测。结果显示,内含子上的A-2784C和A-2816G位点完全连锁,所有位点在大口黑鲈"优鲈1号"群体中的平均有效等位基因数、平均观测杂合度和平均期望杂合度分别为1.635、0.406和0.373,仅C-6206T、C-6811T和T-4765A位点的基因型频率分布符合Hardy-Weinberg定律。采用一般线性模型分析各位点与大口黑鲈生长性状之间的相关性,研究发现,C-6811T位点CC基因型个体的体质量和全长显著大于TT基因型,CC基因型个体的体高和尾柄长显著大于CT和TT基因型,其余位点不同基因型个体间的生长性状均不存在显著差异。C-6811T位点与生长性状显著相关,可作为大口黑鲈分子标记辅助育种的候选标记。 相似文献
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Do different seagrass species support distinct fish communities in south‐eastern Australia? 总被引：3，自引：0，他引：3
Between spring 1998 and autumn 1999, a fine mesh seine net was used to sample fish communities at three locations in south-eastern Australian estuaries, two located near Sydney [Botany Bay (BB) and Port Hacking (PH)] and one located approximately 150 km to the south [Sussex Inlet (SI)]. At each location, fish were collected from adjacent beds of the seagrasses Posidonia australis Hooker and Zostera capricorni Ascherson. These seagrass species differ markedly in morphology and life history. Fish communities displayed significant differences between seagrass species with respect to abundances and lengths of economically important species, and the structure of assemblages at locations in PH and BB, but not in SI. Differences appeared to be related to the recruitment of juveniles of several inshore species, such as Acanthopagrus australis (Günther), Rhabdosargus sarba (Forskaal) and Girella tricuspidata (Quoy & Gaimard) to Zostera beds at BB and PH during spring and early summer. These differences were not evident over the wider spatial scale, however, the SI location did support a distinct assemblage of fish compared with locations in PH and BB. These results suggested that local recruitment events and differences in estuarine geomorphology may be important in structuring these seagrass fish communities. 相似文献
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Effects of dietary inclusion of yacon,ginger and blueberry on growth,body composition and challenge test of juvenile rockfish (Sebastes schlegeli) against Edwardsiella tarda 下载免费PDF全文
下载免费PDF全文 H.S. Kim K.W. Lee H.S. Jung J. Kim A. Yun S.H. Cho M. Kwon 《Aquaculture Nutrition》2018,24(3):1048-1055
Effects of dietary inclusion of yacon, Polymnia sonchifolia (YC), ginger, Zingiber officinale (GG), and blueberry, Vaccinium ashei (BB), on growth, body composition and challenge test of rockfish against Edwardsiella tarda compared to ethoxyquin were investigated. Three hundred and sixty fish were randomly distributed into 12 flow‐through tanks. Four experimental diets were prepared: the control diet (Con) with 0.1 g/kg ethoxyquin, and YC, GG and BB diets. Each diet was assigned to triplicate tanks of fish and hand‐fed for 8 weeks. Externally normal fish after fourth and eighth weeks of feeding trial were infected with Edwardsiella tarda for challenge test. Weight gain and specific growth rate (SGR) of fish fed the YC diet were greater than those of fish fed all other diets. Feed efficiency, protein efficiency ratio and protein retention of fish fed the YC diet were higher than those of fish fed all other diets. In the both fourth and eighth weeks of infection trials, mortality of fish fed the Con diet was higher than that of fish fed all other diets. In conclusion, dietary inclusion of YC, GG and BB increased weight gain and SGR of fish. YC, GG and BB for 4 and 8 weeks lowered mortality of fish at occurrence of E. tarda. 相似文献
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Effects of intracerebroventricular treatment with oleate or octanoate on fatty acid metabolism in Brockmann bodies and liver of rainbow trout 下载免费PDF全文
下载免费PDF全文 M. Librán‐Pérez C. Otero‐Rodiño M.A. López‐Patiño J.M. Míguez J.L. Soengas 《Aquaculture Nutrition》2015,21(2):194-205
Intracerebroventricular (ICV) treatment with oleate or octanoate induced in Brockmann bodies (BB) and liver of rainbow trout changes in several parameters related to fatty acid (FA) sensing through FA metabolism, FA transport through FA translocase (FAT/CD36) and mitochondrial activity. Changes observed in BB were completely different to those observed in previous studies after treatment with the same FA either intraperitoneal (IP) or in vitro. Therefore, FA sensing in BB is apparently direct and not related to previous FA sensing in hypothalamus, but it could be influenced by changes in the levels of peripheral hormones like insulin. In contrast, results obtained after ICV treatment with FA in liver were comparable to those observed after IP treatment but different to those observed after in vitro treatment. Therefore, FA sensing in liver is apparently indirect and be the consequence of previous hypothalamic FA sensing followed by vagal and/or sympathetic outflow. 相似文献
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Characterization of phenotype variations of luminescent and non‐luminescent variants of Vibrio harveyi wild type and quorum sensing mutants 下载免费PDF全文
下载免费PDF全文 Vibrio harveyi, a luminescent Gram‐negative motile marine bacterium, is an important pathogen responsible for causing severe diseases in shrimp, finfish and molluscs leading to severe economic losses. Non‐luminescent V. harveyi obtained by culturing luminescent strains under static and dark condition were reported to alter the levels of virulence factors and metalloprotease gene and luxR expression when compared to their luminescent variants. Presently, we conducted an in vitro study aiming at the characterization of virulence‐related phenotypic traits of the wild‐type V. harveyi BB120 strain and its isogenic quorum sensing mutants before and after switching to the non‐luminescent status. We measured the production of caseinase, haemolysin and elastase and examined swimming motility and biofilm formation. Our results showed that switching from the bioluminescent to the non‐luminescent state changed the phenotypic physiology or behaviour of V. harveyi resulting in alterations in caseinase and haemolytic activities, swimming motility and biofilm formation. The switching capacity was to a large extent independent from the quorum sensing status, in that quorum sensing mutants were equally capable of making the phenotypic switch. 相似文献
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为研究不同沉水植物盖度下浮游植物群落结构及变化规律,为水域生态修复提供科学依据,在白洋淀选取了4个盖度水平区域,分别为25%、50%、75%和90%(C-25、C-50、C-75、C-90),对照区域(C-0)结合水体理化参数和浮游植物群落结构特征,评价出沉水植物的最佳盖度。结果表明,沉水植物组均可有效降低水体总氮(TN)、总磷(TP)、溶解性固体总量(TDS)和电导率(SPC),而C-50组的TN和TP浓度最低。对浮游植物群落结构分析发现1)沉水植物组浮游植物种类数高于对照组,各组绿藻门比例最高且均在50%以上;2)C-50组蓝藻门优势种最少且比例显著低于其他组(P<0.05);3)浮游植物密度和生物量随沉水植物盖度的增加而降低,且占比最大的分别是蓝藻门和绿藻门;4)Margalef指数随盖度增加表现出先上升后降低的趋势;而Shannon-Weiner指数和Pielou指数随盖度的增加而增大;5)RDA表明,C-90、C-75和C-0组的浮游植物群落主要受TDS、SPC、pH、叶绿素a、高锰酸钾指数和透明度等环境因子的影响;C-50和C-25组浮游植物群落受环境因子的影响较小,说明水生态系统较稳定且受环境的影响小。鉴于盖度为50%时,TDS、SPC、TN和TP浓度最低;蓝藻门比例和优势种较低,Margalef指数最高,在水生态保护或修复时,建议沉水植物盖度以50%为宜。 相似文献