黑鲷肠炎病原恶臭假单胞菌的分离和鉴定

2008年3月,浙江省象山港养殖黑鲷暴发了严重的肠炎病情,病鱼肠道肿胀,充满黄色黏液。以ZoBell2216E平板自病鱼肠道黏液分离到4株菌BB01、BB02、BB03和BB04。通过人工感染试验验证了前3株为病原菌,其中BB01菌株96h的半数致死浓度LD50为4.61×104CFU/g鱼体重。3株分离菌革兰氏染色阴性,短杆状,氧化酶试验阳性,氧化葡萄糖,不产气,4℃生长,精氨酸双水解酶阳性,利用麦芽糖、柠檬酸盐,硝酸盐降解阳性,DNA酶、乙酰胺酶阴性;与已发表的恶臭假单胞菌16SrRNA序列的同源性达99%以上;经形态和理化特性鉴定及16SrDNA序列测定,此3株菌同属于恶臭假单胞菌。药敏试验结果表明,菌株BB01对头孢类等多数抗生素种类敏感,而对氧氟沙星耐药。     

福州地区大黄鱼变形假单胞菌的分离与鉴定

为研究2013年春夏之际罗源湾海区网箱养殖大黄鱼(Pseudosciaena crocea)内脏出现白点症状的病原,从具有临床症状的大黄鱼内脏中分离到优势菌,经回接感染试验证实该菌为病原菌;分析该病原菌的形态特征、理化特性、分类地位及药物敏感性等特性,结合16S r DNA序列构建的进化树与假单胞菌属恶臭群中的变形假单胞菌同源性最高,在99%以上,并通过看家基因gyr B序列分析进一步验证该菌为变形假单胞菌(Pseudomonas plecoglossicida);该菌对强力霉素、诺氟沙星、恩诺沙星3种抗生素敏感,对奥氟沙星、左氟沙星、四环素3种抗生素中度敏感。     

中华鳖源粘质沙雷氏菌分离、鉴定及药敏特性研究

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。     

网箱养殖大黄鱼假单胞菌病病原的分离与鉴定

浙江宁波、台州等地相继发生网箱养殖大黄鱼的大量死亡,主要症状为脾脏、肾脏有许多白色结节,大小为0.1～1mm。从病鱼体内分离出致病力极强的菌株GYCWS,人工感染试验证实为大黄鱼的病原菌,其半数致死量(LD50)为8.5×104CFU/ml。对该细菌进行了形态、生理生化特性的测定,并进行了全自动微生物分析系统(ID32GN)及16S rRNA分子鉴定。经PCR扩增获得了大小约1.5Kb的16S rRNA部分基因片段,产物经回收纯化,克隆到pMD18-T载体,转化大肠杆菌TG1,对阳性克隆子进行酶切及PCR鉴定确认阳性重组质粒,将测定的序列递交NCBI进行BLAST同源序列比对,与恶臭假单胞菌的16S rRNA基因(DQ201403、AY785244)具有较高的同源性(99%),该序列在Genbank上的登录号为DQ648602。结合细菌的生理生化特性,GYCWS菌株属于恶臭假单胞菌(Pseudo monas putida)。药敏试验结果表明,病原菌GYCWS对卡那霉素、庆大霉素、丁胺卡那、氟派酸、四环素、链霉素药物敏感。     

大鲵恶臭假单胞菌的分离及鉴定

以分离大鲵感染的病原菌并进行菌株鉴定和药敏实验为目的,通过从患病大鲵的不同部位取样,分离培养到可疑菌落,然后进行鉴定和药敏试验。根据药敏试验结果指导养殖场进行治疗。结果鉴定为恶臭假单胞菌,中等大小、光滑、湿润的灰白色革兰氏阴性长杆菌,排列不规则。药敏试验证实对舒普深、诺氟沙星、呋喃妥因等敏感。     

一株草鱼源荧光假单胞菌的分离鉴定及其耐药特性分析

为探究临沂市某草鱼养殖场发生病害的原因，从患病的草鱼(Ctenopharyngodon idellus)肝脏和肾脏混合组织中分离得到一株优势致病菌G-13,通过细菌形态学观察、革兰氏染色、生理生化特征、16S rRNA基因测序，以及系统发育分析等完成菌株鉴定，并测定其耐药特性。形态特征显示G-13是一种短杆状的革兰氏阴性菌，在LB固体平板上形成乳白色、圆形、整体呈隆起状、边缘较为整齐、表面光滑湿润的菌落；16S rRNA系统发育进化分析发现G-13与荧光假单胞菌(Pseudomonas fluorescens)聚在一支，序列同源性高达100%;生理生化试验显示葡萄糖、精氨酸双水解酶、鸟氨酸脱羧酶、赖氨酸脱羧酶、氧化酶、无盐和3%NaCl胰胨水等7项指标为阳性，与假单胞菌属特征相近，确定分离株G-13为P.fluorescens。药敏试验结果显示菌株G-13对丁胺卡那、多西环素、四环素、新霉素、环丙沙星、氧氟沙星等13种抗生素敏感，对氨苄西林、头孢拉定、克林霉素、呋喃唑酮等7种抗生素耐药。     

鲟源迟钝爱德华氏菌的分离鉴定与药敏特性研究

从患病鲟鱼的肾脏组织中分离到菌株K9,通过菌株的形态特征、生理生化鉴定及16S rDNA序列分析等,鉴定菌株K9为迟钝爱德华氏菌。人工感染试验证明该菌株为引起鲟鱼疾病及死亡的病原菌;药敏特性研究表明,K9对链霉素、阿米卡星、左氧氟沙星、阿齐霉素、新霉素、氯霉素(禁药)等6种抗生素敏感,而对青霉素G、妥布霉素、麦迪霉素等9种抗生素具有耐药性。本研究结果为有效防控鲟鱼迟钝爱德华氏菌病害提供参考。     

金鱼类志贺邻单胞菌的分离鉴定及药敏试验

从患病金鱼肝脏中分离获得一株细菌,编号为ZP-1,通过细菌形态学观察、理化特征、16SrDNA克隆测序以及系统进化树分析等方法进行鉴定。试验结果表明,ZP-1菌株为革兰氏阴性短杆菌,可以发酵葡萄糖、乳糖产酸、还原硝酸盐、产生吲哚等。进一步采用PCR方法扩增ZP-1菌株16SrDNA,将其亚克隆至pMD18-T载体中测序,获得长度为1464bp(登录号:KM458852),与鱼源致病性类志贺邻单胞菌(KC825322)同源性为99.80%,最终确定ZP-1菌株为类志贺邻单胞菌。采用30种抗生素进行药敏试验,ZP-1菌株对头孢噻肟、头孢克肟、头孢孟多、庆大霉素、丁胺卡那霉素、萘啶酸、氯霉素、氧氟沙星等药物敏感。     

黄颡鱼溶酪巨型球菌的鉴定与药敏试验

自患病黄颡鱼中分离出一株优势菌HS1,根据细菌形态学观察、生理生化、16SrDNA基因序列分析、动物回感试验及药敏试验等方法对其菌株进行研究。试验结果表明,菌株HS1为动力阳性,革兰氏阴性球菌。扩增的16SrDNA序列大小为1466bp,登录号为KP191046,与溶酪巨型球菌同源性超过99%,进化树上与溶酪巨型球菌聚为一支,从而可判定HS1为溶酪巨型球菌。用溶酪巨型球菌HS1感染健康黄颡鱼,发现该菌具有较强的致病性。药敏试验表明,该菌对四环素、米诺环素和强力霉素等11种药物敏感,对复方新诺明、甲氧苄啶和氨磺甲基异恶唑3种药物耐药。这为黄颡鱼巨型球菌病的预防和治疗提供科学参考。     

老化参池刺参腐皮综合征致病原的分离与鉴定

从患病刺参体表病灶组织分离出菌株060330B,其优势度高达90%,人工回接感染试验证实其具有较强的致病性,可导致健康刺参出现与自然患病刺参相同的症状。通过形态学观察、API半自动化鉴定和常规生理生化试验的结果表明,菌株060330B具有假单胞菌属的特征,其表型特征与恶臭假单胞菌相似。对该菌株进行16SrRNA基因序列分析和构建系统发育树,结果显示其与恶臭假单胞菌的亲缘关系最近,相似率达到99.5%。菌株060330B可鉴定为恶臭假单胞菌,并视为养殖刺参腐皮综合征的致病原之一。通过对多起不同来源患病刺参的研究表明,使用年限长、淤泥层厚呈黑色并伴有腥味的养殖池塘在该时期容易导致刺参腐皮综合征的发生。     

Effects of glycinin on growth performance,immunity and antioxidant capacity in juvenile golden crucian carp,Cyprinus carpio × Carassius auratus

This study was designed to examine the effects of glycinin on growth, digestive ability, immune responses, antioxidant capacity and gene expression levels of golden crucian carp. Golden crucian carp were fed diets containing glycinin at 0, 30, 60, 90 and 120 g/kg, respectively, for 8 weeks. Body weight, weight gain percentage, specific growth rate and feed efficiency ratio were negatively related to the content of glycinin in diet. Activities of protease, acid phosphatase, alkaline phosphatase, lysozyme in hepatopancreas, and activities of catalase, glutathione peroxidase, superoxide dismutase, and total antioxidant capacity in the proximal intestine, mid intestine, distal intestine and hepatopancreas were negatively related to the content of glycinin in diet, whereas malondialdehyde in proximal intestine, mid intestine, distal intestine and hepatopancreas increased directly with the content of glycinin in diet. Furthermore, the relative expressions of TNF‐α and IL‐1β in proximal intestine, mid intestine and distal intestine increased directly with the content of glycinin in diet, whereas the relative expressions of TNF‐α and IL‐1β in hepatopancreas were negatively related to the content of glycinin in diets. The relative expressions of IL‐10 in proximal intestine, mid intestine, distal intestine and hepatopancreas all were negatively related to the content of glycinin in diets. In conclusion, reductions in growth, immunity and antioxidant capacity, intestine inflammation with dysfunction of digestive system occurred in golden crucian carp that fed a diet containing glycinin at 30 g/kg or higher after 8 weeks.     

Complex habitat generated by marine bryozoans: a review of its distribution,structure, diversity,threats and conservation

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Synchronized effect of citric acid and phytase supplementation on growth performance and nutrient digestibility of Labeo rohita

A 2‐month trial was conducted to record the effect of citric acid and phytase supplementation on growth performance and nutrient digestibility in labeo rohita. Nine treatment (T) diets having 0, 500 and 1,000 FTU/KG phytase and 0, 15 and 30 g/kg citric acid were prepared and were designated as T1, T2, T3, T4, T5, T6, T7, T8 and T9 diets. There were three replicates for each of the test diets. Fish samples (n = 324) were stocked in different tanks and were fed with T1, T2, T3, T4, T5, T6, T7, T8 and T9 diets. Significant (p < .05) increase in growth parameters, apparent digestibility of dry matter, crude protein, crude fat, gross energy and minerals (Na, K, Fe, Mg, Mn, Zn) was recorded in fish fed with T9 diets.     

Development of Digestive Enzymes in California Halibut <Emphasis Type="Italic">Paralichthys californicus</Emphasis> Larvae

California halibut Paralichthys californicus is an important commercial species with high aquaculture potential in Baja California Sur, México. To optimize the feeding process using live prey and/or inert diets, we evaluated alkaline proteases, pepsin, trypsin, chymotrypsin, leucine aminopeptidase, lipase, α-amylase, and acid and alkaline phosphatase activities on starved larvae and larvae fed live prey. Highest activities were observed for alkaline protease, trypsin, chymotrypsin, leucine aminopeptidase, and alkaline phosphatase in feeding larvae than starved larvae on day 4 after hatching. At day 5, a sizeable increase in all enzymatic activities was detected in feeding larvae. Alkaline protease, trypsin, chymotrypsin, and alkaline phosphatase decreases progressively from day 5 until day 18. At day 18, a slight pepsin activity was observed. This was considered an indicator of the start of digestive system maturation. We concluded that total enzymatic equipment for this species is complete between day 18 and 30 after hatching. Based on this evidence, early weaning from live prey to inert feed would be possible at this time.     

Effect of cage culture environment on farmed fish in terms of metal accumulation

Metal pressure under farm conditions was examined on the gill and muscle tissues of farmed Sparus aurata and compared with their wild counterparts (Sparus aurata, Trachurus trachurus, Mullus barbatus). Al, Mn, Cd, Co, Cr, Cu, Ni, Pb and Zn accumulation amounts in gill tissue of farmed fish were 28.821, 37.620, 0.136, 0.300, 3.730, 2.441, 3.222, 2.474 and 127.494 mg/kg respectively. Among them, Cd, Cr, Cu and Pb concentrations in gill tissue of farmed fish were higher than that in wild fishes. Metal depositions in muscle tissue of farmed fish were far below that in the gill tissue. The accumulated Al (6.700 mg/kg) in the muscle tissue of farmed fish was higher than in wild ones. The results showed that metal accumulation levels (especially Cd, Cr, Cu and Pb) in the gill tissue of farmed fish indicate metal pressure under captive conditions. Furthermore, the calculated hazard index (HI) and total hazard index (THI) of the considered elements in the edible part of farmed fish were below the level considered safe, which elucidates that farmed fish do not pose any threat to the human consumer in terms of metal toxicity.     

Economies of scale for juvenile production of common snook (Centropomus undecimalis Bloch)

Abstract

Construction and operating costs for three common snook (Centropomus undecimalis) hatcheries in Florida, USA, are illustrated. Hypothetical capacities and targets of the three hatcheries (Scenarios I, II and III respectively) were 615, 000 juveniles (8 ‐ 10 g in weight) for stock enhancement, and 1, 275, 000 and 3, 000, 000 juveniles (1‐g in weight) for commercial grow‐out. Estimated production costs were lower than for many marine finfish species. The 20‐year mean costs per 1, 000 juveniles were estimated to be $324, $215, and $159, for hatcheries I, II, and III respectively, and the initial capital investments were $731, 660, $1, 162, 460, and $1, 896, 030¹, respectively. Major cost items of annual production were labor (22 ‐ 33%), supplies (14 ‐ 20%), fixed costs (15 ‐ 17%), and interest (13 ‐ 15%). The most profitable hatchery was the 3 million 1‐g juvenile hatchery due to the hatchery size effect, with a net present value (NPV) of $1, 760, 000, an internal rate of return (ERR) of 81%, a payback period of 3.6 years, and a profitability index of $2.86 for every dollar invested. Possible cost reductions to increase financial profitability were discussed.     

长江鲢、鳙、草鱼和青鱼原种亲鱼标准与检测的研究

主要报导长江原种亲鱼鲢、鳙、草鱼和青鱼的形态特征、年龄生长和繁殖特性。通过可数可量参数的测定，年龄生长、性成熟年龄、繁殖力、成熟系数及卵比重等单项的相对关系的研究，讨论并提出了原种亲鱼鲢、鳙、草鱼、青鱼的标准参数，可供原种场生产管理、原种检测及种质资源保护的依据。     

2013年中国典型对虾养殖区白斑综合征病毒流行株高变异区序列的分析比较

为了解中国不同地区白斑综合征病毒的流行变异情况,本研究取用2013年3—12月从7个省市发病地区采集到的64份WSSV阳性样本,以特异的引物扩增目的片段,通过测序分析不同样本的缺失及变异差异。结果显示,在开放阅读框ORF14/15的扩增中,分别有6530 bp、6533 bp和5138 bp的片段缺失,而在ORF23/24扩增中有12070bp大片段的缺失,不同地区样本中未能成功扩增ORF75,而ORF94的重复单元数目分别为0、3、4、12不等,ORF125的重复单元数目为0、7。SNP分析表明,含有3个重复单元的ORF94在48位的碱基为T、T、T,重复单元数为4的在48位的碱基为T、T、T、T,重复单元数为12的在48位的碱基分别为T及11个A。而ORF125所有重复单元数为7的情况在8、18、25、66、69位置的碱基均为G、G、G、G、A,在9、50、53、61位的碱基也普遍出现了变异。结果表明,WSSV在中国不同地区存在一定程度的变异,其在序列中的缺失、重复单元数目以及SNP的差异较为明显。