猪源致病性大肠杆菌的分离鉴定及多价油苗的研制

从我省滇中地区11个县区所送检的66份可疑猪大肠杆菌病病料中分离到35株致病菌株。采用24种主要引起致病性大肠杆菌因子血清作平板凝集试验后鉴定出29株，其中O107 19株（1株含K88抗原）、O149 9株（4株含K88抗原）、O2 1株，占所分离致病菌株数百分比分别为54．0％（19／35）、25．7％（9／35）、2．9％（1／35）。从中挑战出含K88抗原菌株O107：K88、O149：K88与标准菌株K88、K99、F41、987P混合制备多价油苗，在以上分离地区应用1万头份，效果显著，平均保护率达70％以上，且免疫后猪只无不良反应。     

农村养猪场仔猪黄痢的防治

仔猪黄痢是由一定血清型的大肠杆菌引起的初生仔猪的一种急性、致死性传染病。本病在我国较多的地区和猪场都有发生,是哺乳仔猪的常见病,血清型较多,常见的有:O8:K88,K99,O60:K88,O138:K81,O139:K82,O141:K88,K85,O45,O115,O147,O101,O149等血清型,这些菌株大多数能形成肠毒素,该病具有较高的发病率和死亡率,严重阻碍着养猪业的     

动物性食品源大肠杆菌O血清型鉴定及其K88菌毛基因检测

本研究对河北省冀东地区农贸市场和超市采集的生猪肉、生鸡蛋和生羊肉等分离得到的20株大肠杆菌进行大肠杆菌血清型鉴定;并检测不同血清型大肠杆菌的K88菌毛基因。采用常规方法进行大肠杆菌的O血清型鉴定,用PCR方法检测K88菌毛基因。分离鉴定的20株大肠杆菌有7种血清型,包括O38、O78、O88、O11、O107、O91、O9,其中O38、O78为优势血清型菌,均占分离菌株的25%(5/20)。在分离的动物性食品源大肠杆菌中有30%(6/20)的菌株K88菌毛基因扩增呈阳性。结果表明,O78、O38为冀东地区动物性食品源大肠杆菌常见血清型,30%(6/20)的菌株K88菌毛基因扩增阳性。     

仔猪腹泻致病性大肠埃希氏菌血清型及其日龄分布的调查研究

我们从本省88例病猪采集了1177个菌株,对42例病猪的138个菌株,用自制的大肠埃希氏菌抗血清鉴定出O8:K87,K88ac血清型是引起我省乳猪腹泻的优势血清型。调查了八个地区,其中七个地区分离到O8血清群,说明分布极广,主要危害3—6日龄的初生乳猪。大肠埃希氏菌O141:K85ac     

猪源乳酸菌对致病性大肠杆菌的体外抑制作用

对从健康仔猪肠道分离的12株乳酸菌菌株进行耐酸试验和耐胆盐试验,筛选出4株有效菌株。分别将这4株乳酸菌单独、混合与K88共培养;取4种乳酸菌单独和混合培养的菌液、发酵滤液和菌体用牛津杯做K88抑制试验;分别将培养滤液经过乳酸脱氢酶和碱处理做K88抑制试验。结果表明:4种乳酸菌皆具有抑菌功能,但相互之间有差异;用乳酸脱氢酶或碱处理后抑菌能力明显下降,说明乳酸菌是通过产生有机酸尤其是乳酸对K88进行有效抑制。4种菌混合培养的抑菌能力强于单独培养。     

皖北地区仔猪黄痢大肠杆菌血清型的分离鉴定与免疫保护试验

为探明皖北地区导致仔猪黄痢的大肠杆菌的主要血清型,从皖北地区仔猪黄痢病料中,分离到37株致病性大肠杆菌菌株,并用O抗原单价血清、ELISA试验和菌毛抗原进行了血清型鉴定。结果表明,引发该地区仔猪黄痢的优势血清型为O8、O9、O141,这3种血清型占全部分离菌株的63.6%,其余血清型为O45、O147、O20、O101、O157、O119,占36.4%;对O8、O9、O141分离菌株进行了菌毛抗原的鉴定,菌毛抗原主要有K88、K99、F41。采用分离的优势菌株制成灭活疫苗,免疫妊娠猪,进行疫苗免疫效果比较试验。结果显示,自制分离株灭活苗组、K88-LTB基因工程苗组和对照组仔猪黄痢的发病率分别为11.5%、18.3%和28.4%,死亡率为8.6%、12.0%和18.1%,表明自制分离株灭活苗有较好的保护效果,为下一步有针对性地防制仔猪黄痢提供科学依据。     

抗大肠埃希氏菌(Escherichia coli)K88抗原特异单克隆抗体的研究

用淋巴细胞杂交瘤技术得到了株抗E.coli K88抗原的特异单克隆抗体(MCA):JLZK-7,-10和-178。小鼠腹水中MCA的免疫荧光滴度达10~(-5)～10~(-6),直接凝集滴度为 1:500～1:5000,比用常规方法生产的因子血清高100～1000倍。JLZK-7为IgG_1亚类,JLZK-10为IgG_(26)亚类,JLZK-178为IgG_3亚类。这3株MCA与K88阴性大肠杆菌和肠杆菌科中的其他细菌无交叉反应。对K88阳性菌株的反应性测定表明,JLZK-7是对K88ab、K88ac和K88ad菌株都起反应的群特异MCA,JLZK-10和-178是分别仅与部分K88ab菌株和部分K88ac菌株反应的型特异MCA。试验结果表明,这3株MCA可用于初生仔猪下痢病的诊断和大肠杆菌K88血清型鉴定。     

鸡源大肠埃希氏菌部分生物学特性研究

对从天津地区分离到的71株鸡大肠杆菌的部分生物学特性包括致病性、血清型、耐药特性和免疫原性等进行了研究。结果表明其中60株为致病性菌株,占分离菌株的84.5%;60个致病性菌株共定型出45个菌株,分属O1、O2、O5、O6、O20、O45、O53、O74、O75、O78、O88、O89、O92、O107、O111、O145等16个血清型,其中O78、O88、O2、O45、O53和O145为优势血清型,占定型菌株的73.4%;试验菌株具有广泛的耐药性,60个致病性菌株均为多重耐药。免疫原性测定试验结果表明,O2、O78、O88血清型菌株均可对相同血清型菌株提供很好的保护,但3个血清型菌株之间缺乏有效的保护。     

猪抗病育种的可能性

关于猪抗病力的报道,一般只涉及对特定疾病抵抗力的品种差异或遗传力的估测。唯一的例外是英国学者研究的对大肠埃希氏菌K88菌株的抵抗力。K88是某些大肠杆菌的一种细胞表面蛋白质。如果猪具有K88受体,则大肠杆菌K88菌株就会粘     

仔猪腹泻源大肠杆菌贵州株K_(88)菌毛研究

通过玻片凝集试验、抗D_甘露糖微量血凝试验 (MRMH)、离体细胞粘附试验、菌体蛋白的聚丙烯酰胺凝胶电泳(SDS_PAGE)和免疫印迹、质粒DNA提取及电泳等 ,分析了仔猪腹泻源大肠杆菌贵州株 (4 0 9_11)所产K88菌毛的血凝谱、对肠上皮细胞粘附特性、菌毛蛋白亚单位分子量 ,并对其K88基因进行了初步定位。结果表明 :其所产K88菌毛的血凝谱能凝集豚鼠和鸡红细胞 ;能介导细菌粘附于仔猪离体肠上皮细胞 ,这种粘附作用能被特异的K88抗血清阻断 ;菌毛蛋白亚单位的分子量为2 35 0 0Da;K88基因位于一个分子量为 85kb(5 4× 10 6Da)的大质粒上。当菌株于 18℃生长时 ,其K88菌毛不能表达     

Hemolytic assay for goat (caprine) and swine (porcine) complement

Optimal conditions for assaying hemolytic complement of goat (caprine) and swine (porcine) sera were determined. Effects of the following were tested: pH, ionic strength, calcium and magnesium ion concentrations, time and temperature of incubation, and ethylenediamine tetracetate concentration. Guinea pig erythrocytes sensitized with goat or cattle antibodies were the most sensitive target cells for goat complement. Sheep and cattle erythrocytes sensitized with rabbit hemolysin were the best target cells for swine complement. Barbital buffer, pH 7.3, ionic strength of 90 nmM relative salt concentration, containing 0.5 mM CaCl2 and 1 mM MgCl2 was the best for swine complement assay. Goat complement lysed best in a barbital buffer, pH 8, ionic strength of 90 to 120 mM of relative salt concentration, in presence of 0.5 mM CaCl2 and 1 mM MgCl2. The optimal incubation temperature was 37 degrees C for both complements. The complement dependent lysis required 75 minutes to reach its maximum. Ethylenediamine tetracetate in 4 mM concentration completely inhibited lysis by both species complements. The CH50 for goat sera varied between 18 and 75 per ml, in swine sera between 75 and 210 per ml.     

Protogynous hermaphroditism in Chrysoblephus laticeps (Cuvier) and C. cristiceps (Cuvier) (Teleostei: Sparidae)

A histological study of the gonads of two sparid fishes, Chrysoblephus laticeps and C. cristiceps showed that these species are protogynous hermaphrodites. Both species are also monandric in which all males are derived from functional females. Intersexual individuals were restricted to a narrow size range between females and males, and no evidence for simultaneous hermaphroditism was found. Similar to other sparids, the development of the ovary and testis was delimited by a connective tissue layer.     

抗CP型、NCP型牛病毒性腹泻病毒高免卵黄抗体的制备

本研究采用致细胞病变（cytopathic,CP）型牛病毒性腹泻病毒（bovine viral diarrhea virus,BVDV）标准毒和非致细胞病变（noncytopathic,NCP）型新疆优势毒株免疫产蛋鸡,用改良PEG法提取卵黄抗体(IgY),并对提取的IgY采用SDS-PAGE检测纯度,间接ELISA检测免疫后每隔7 d的抗体效价,并测定所得抗体对NCP型BVDV的中和效价。结果表明,用该法提取的IgY纯度较高;间接ELISA结果证明,经过4次免疫后,抗CP型BVDV的效价达到1∶32000,抗NCP型BVDV的效价达到1∶40000,3个月后再次检测,卵黄抗体效价未见明显下降。最后一次免疫14 d的抗体对NCP型BVDV的中和效价达到1×10_^-3。     

Immunogenicity of equine herpesvirus type 1 (EHV1) and equine rhinovirus type 1 (ERhV1) following inactivation by betapropiolactone (BPL) and ultraviolet (UV) light

Some kinetic data on the inactivation of equine herpesvirus type 1 (EHV1) and equine rhinovirus type 1 (ERhV1) by betapropiolactone (BPL) and ultraviolet (UV) irradiation are reported. 0.25% BPL at 37 degrees C for 1 h reduced the titre of EHV1 by greater than 10(3 . 4) and of ERhV1 by greater than 10(4 . 1) TCID50/ml. UV irradiation (334 microW/cm2) produced similar reductions in titre after 2 min. These data were used as a basis for inactivating EHV1 and ERhV1 by the combined action of BPL and UV irradiation. Viruses were exposed to 0.1% BPL for 1 h at 4 degrees C with constant stirring, followed by UV irradiation for 2 min, followed by incubation for 3 h at 37 degrees C. Inactivated EHV1 elicited secondary immune responses only in horses whereas ERhV1 produced primary immune responses in mice (including athymic nu/nu mice), rabbits and probably in horses.     

Butylhydroxyanisol (BHA), butylhydroxytoluene (BHT) and ethoxyquin (EMQ) tested for mutagenicity.

The antioxydants butylhydroxyanisol (BHA), butylhydroxytoluene (BHT) and ethoxyquin (EMQ) were tested for mutagenicity in the so-called “Ames test”. The test was performed with and without the addition of microsomal mixed function oxidase system from rat liver. The compounds were found not to be mutagenic in this test. At high concentration of BHA and EMQ toxic effects on the growth of the bacteria were observed.     

柑橘大实蝇的发生及综合防治

柑橘大实蝇是柑橘生产的重大害虫,目前柑橘大实蝇疫情呈逐年加重趋势,特别是“蛆柑事件”（大实蝇幼虫）给广大橘农造成了巨大的经济损失,严重制约了柑橘产业的健康发展。本文论述了柑橘大实蝇的形态特征、发生规律、传播途径和综合防控措施。     

Calicophoron microbothrioides (Price and McIntosh, 1944) (Paramphistomidae: Paramphistominae) in Malaysian sambar deer (Cervus unicolor)

Amphistomes of Calicophoron microbothrioides were recovered from the rumen of a Malaysian sambar deer (Cervus unicolor). Some measurements and illustrations of C. microbothrioides are given. This is a new host record for the species C. microbothrioides.