伊维菌素浇泼剂治疗猪蛔虫及血虱的驱除效果

应用0.5%伊维菌素浇泼剂进行了驱除猪血虱和猪蛔虫的试验。结果:给药后第7d对猪血虱的转阴率达100%;第15d对猪蛔虫的驱虫率达到100%,表明0.5%伊维菌素浇泼剂对驱除猪蛔虫和血虱是高效安全的。     

抗重组猪蛔虫抗原AD41蛋白鼠源性单链抗体库的构建及筛选

为了构建重组猪蛔虫抗原AD41蛋白鼠源性单链抗体库,试验用重组蛋白AD41抗原免疫接种Balb/c小鼠,提取小鼠脾脏总RNA,以总RNA为模板经RT-PCR合成cDNA,再以cDNA为模板,用小鼠免疫球蛋白重链和轻链设计引物,分别扩增重链和轻链可变区基因,利用SOE-PCR法将VH和VL片段随机拼接成单链抗体(ScFv)片段,将其克隆入质粒表达载体pCANTAB5E中,转化于大肠杆菌TG1,通过辅助噬菌体M13K07援救构建噬菌体单链抗体库。结果表明:从30个噬菌体克隆中筛选到25个阳性克隆。说明成功地构建了抗重组猪蛔虫抗原AD41蛋白鼠源性单链抗体库。     

应用RNA干扰技术对猪蛔虫性别相关基因功能的初步研究

针对编码猪蛔虫雌虫卵巢蛋白基因的EST序列设计了1对特异引物及连接T7启动子的引物，经PCR扩增，获得5’端连有T7启动子的双链DNA，在RNA聚合酶的作用下，转录合成dsRNA。通过浸泡的方式将dsRNA导入秀丽新杆线虫中，在浸泡后的5个不同的时间点，采用RT—PCR检测虫体浸泡后靶基因被干扰的效果。试验结果表明，在浸泡后的8～29h能检测到同源靶标的存在；而在浸泡后的43～57h不能检测到靶标RNA。另外，试验组没有观测到虫体明显的表型变化，而对照组在浸泡28h后，发现部分线虫体内有发育成形的虫卵。初步认为导入虫体的dsRNA发生了干扰效应。     

西北部分地区猪蛔虫rDNAITS基因序列测定及遗传变异分析

为了摸清西北部分地区猪蛔虫内转录间隔区(ITS)的遗传变异特点,扩增了猪蛔虫ITS基因,进行测序,依据GenBank公布的ITS序列将测序结果截为ITS1、5.8S及ITS2三段,分析比对各段序列的差异性。结果显示,所有样品ITS序列长约1 000bp,其中ITS1、5.8S和ITS2的长度分别为450bp~453bp、159bp、272bp,种内差异分别为0~0.2%、0、0。基于ITS1的种系发育分析表明,23个猪蛔虫样品均位于同一分支,而与贝蛔属蛔虫分属两个不同分支。ITS1序列不能作为区分西北不同地区猪蛔虫的种内分子标记,但可以作为区分蛔属蛔虫与贝蛔属蛔虫的种间分子标记,研究结果为猪蛔虫的鉴定和分子流行病学调查提供了基础资料。     

使君子提取物对驱除猪蛔虫效果研究及对猪主要生理生化指标的影响

云南使君子提取物作为实验用药,对感染猪蛔虫的动物进行了药效实验研究。结果使君子提取物给药最佳剂量为0．05mg／kg。粪检虫卵数计数表明,每克粪便虫卵数与用药前相比存在差异显著性（P〈0．05）。所检测的血液生化指标在给药前后均没有出现显著性的变化（P〉0．05）。从而可初步推断使君子提取物对猪的肝脏、肾脏、心脏和肌肉等组织器官没有产生明显的影响。使君子提取物对猪蛔虫有较好的驱虫效果,且毒副作用小。     

苏云金芽胞杆菌伴胞晶体毒素对小鼠体内猪蛔虫三期幼虫的作用及其免疫组织化学定位

将培养好的感染性猪蛔虫卵以每只5×103个虫卵感染小鼠,于次日以不同方式(灌胃、肌肉注射、静脉注射和腹腔注射)注入苏云金芽胞杆菌伴胞晶体蛋白(insecticidal crystal proteins,Icps),对照组静脉注射BSA(小牛血清白蛋白),每只0.5mL,连续3d。小鼠于第6天剖杀,肝脏分离幼虫,计算减虫率。取肝脏,以4%多聚甲醛固定48h,制作石蜡切片,应用免疫组织化学SABC法定位蛔虫幼虫体内的Icps。研究结果显示,静脉注射晶体蛋白毒素效果最好,减虫率达到72.7%;肌肉注射、灌胃、腹腔注射效果次之,分别为19.1%、14.6%、14.36%。免疫组织化学研究显示,Icps结合到虫体的体表及肠道。     

Infestation of sheep dung by nematophagous fungi and implications for the control of free-living stages of gastro-intestinal nematodes

A field trial was conducted to assess the rate at which dung becomes infested by fungi which parasitise nematodes (nematophagous fungi) after deposition. Sheep dung was placed on field plots of bare ground, ryegrass (Lolium perenne), browntop (Agrostis capillaris) and white clover (Trifolium repens) in summer (February) and autumn (April), and subsamples were examined at intervals for the presence of nematophagous fungi. Nematophagous fungi occurred in 71% of 129 samples recovered in February and 57% of 58 samples recovered in April. Arthrobotrys oligospora, Monacrosporium candidum and Nematoctonus spp. were the most frequently isolated nematode-trapping fungi in both seasons. The endoparasitic nematophagous fungus Harposporium leptospira also occurred frequently in dung deposited in February, but not April. Fungi entered dung quickly, with 83% and 58% of dung samples containing nematophagous fungi at 3 days after deposition in February and April, respectively. The percentage of dung infested by nematophagous fungi on plots of bare ground, ryegrass, white clover and browntop was 76%, 75%, 61% and 55%, respectively. Results suggest that a number of species of nematophagous fungi are able to enter dung soon after deposition on a variety of types of ground cover.     

A Comparison of the Susceptibility of Growing Mukota and Large White Pigs to Infection with Ascaris suum

The influence of A. suum infection on the haematology, liver-related serum enzymes, blood urea and live weight gain in Mukota and Large White (LW) weaner pigs was compared. Six pigs of each genotype were infected with a single dose of 4000 A. suum eggs per pig and another six were not. The pigs were kept for 100 days. Blood was collected daily for the first 7 days and also after 100 days. In the infected pigs, there was an increase (p<0.05) in alanine aminotransferase (ALT) activity in the LW but not in the Mukota pigs. Although the alkaline phosphatase (ALP) activity rose (p<0.05) in both infected and non-infected LW pigs from day 1 to day 3, the activity in the non-infected LW pigs then decreased, while that of the infected LW pigs remained elevated. The infected LW pigs had higher (p<0.05) levels of ALT, ALP and aspartate aminotransferase than their non-infected counterparts. Non-infected LW pigs tended to have higher (p<0.05) haematological parameters, daily weight gain and urea concentrations than infected LW pigs, but these differences were not significant. These preliminary findings suggest that more A. suum larvae reached the livers in the LW than in the Mukota pigs and that the latter may be more resistant to A. suum infection.     

In vitro analysis of antiangiogenic activity of fungi isolated from clinical cases of equine keratomycosis

OBJECTIVE: The goal of this project was to explore the possibility that fungal organisms produce metabolites that inhibit angiogenesis. Procedures Fungal cultures were obtained from cases of keratomycosis, grown in Sabouraud's dextrose broth, and sterile filtered for use in experiments. The Matrigel assay was used to screen the filtrate samples for antiangiogenic activity. Matrigel is a basement membrane matrix that supports the differentiation of human umbilical vein endothelial (HUVE) cells into a capillary-like network of tubules. HUVE cells were cultured using standard techniques and passaged at confluence, with all cells being used at passage 3-6. HUVE cells (40 000 cells) were pipetted into each well of a 24-well tissue-culture plate coated with Matrigel. An aliquot of fungal media filtrate was added to each well and the plates allowed to incubate for 18 h, at which time they were evaluated for tubule formation. RESULTS: Two fungal isolates showed inhibition of tubule formation. The addition of 100, 200 and 400 &mgr;L of the fungal media filtrate from the first isolate (Fusarium sp. 99A34574) produced a consistent and dose-dependent inhibition of tubule formation. The second isolate (Aspergillus sp. 271599) did not show inhibition of tubule formation with 100 or 200 &mgr;L added to the wells, however, it did show inhibition at 400 &mgr;L/well. The remaining three isolates did not cause inhibition at any concentration. CONCLUSIONS: Our findings suggest that certain fungal organisms produce metabolites that inhibit tubule formation in vitro, and that these metabolites may play a significant role in altering the host vascular response to fungal infections of the cornea.     

In vitro fungistatic and fungicidal activities of silver sulfadiazine and natamycin on pathogenic fungi isolated from horses with keratomycosis

OBJECTIVE: To evaluate the in vitro antifungal properties of silver sulfadiazine (SSD) and natamycin against filamentous fungi isolated from eyes of horses with keratomycosis. SAMPLE POPULATION: Filamentous fungal isolates obtained from eyes of keratomycosis-affected horses. PROCEDURES: Fungal culture of ocular samples yielded 6 Fusarium spp; 7 Aspergillus spp; and 1 isolate each of Curvularia, Scopulariopsis, Penicillium, and Chrysosporium. For each fungal isolate, minimum inhibitory concentration (MIC) and minimum fungicidal concentration (MFC) of SSD and natamycin were determined. RESULTS: For all 17 fungal isolates, SSD MIC distribution ranged from < or = 1 to > 64 microg/mL; MIC50 and MIC90 (MICs at which 50% and 90% of organisms were inhibited) were 4 and 32 microg/mL, respectively. The SSD MFC distribution for all isolates was < or = 1 to > 64 microg/mL; MFC50 and MFC90 (MFCs at which 50% and 90% of organisms were killed) were 8 and > 64 microg/mL, respectively. For all fungal isolates, natamycin MIC distribution ranged from 256 to > 1,000 microg/mL; MIC50 and MIC90 were 512 and > 1,000 microg/mL, respectively. The natamycin MFC distribution for all isolates ranged from 512 to > 1,000 microg/mL; MFC(50) and MFC(90) were each > 1,000 microg/mL. CONCLUSIONS AND CLINICAL RELEVANCE: These in vitro data suggest that SSD is fungicidal against the fungal isolates that were obtained from eyes of horses with keratomycosis and that natamycin is fungicidal against some of the isolates at the drug concentrations evaluated. Silver sulfadiazine may be a therapeutic option for equine keratomycosis.     

瘤胃真菌体外培养条件对其产酶活性的影响

本文主要从环境因素、营养因素和其他因素等方面阐述了瘤胃真菌体外培养条件对其产酶活性的影响。     

In vitro evaluation of the effect of dimethyl sulfoxide on equine articular cartilage matrix metabolism

OBJECTIVE: To evaluate the effects of dimethyl sulfoxide (DMSO) on equine articular cartilage matrix metabolism. STUDY DESIGN: Using a cartilage explant culture system, proteoglycan (PG) synthesis, PG release, lactate metabolism, chondrocyte viability, and metabolism recovery were determined after cartilage exposure to DMSO. SAMPLE POPULATION: Cartilage harvested from metacarpophalangeal and metatarsophalangeal joints of 12 horses (age range, 1 to 10 years). METHODS: Explants were exposed to concentrations of DMSO (1% to 20%) for variable times (3 to 72 hours). PG synthesis and release were determined by a radiolabel incorporation assay and dimethylmethylene blue (DMMB) dye assay, respectively. Lactate released into culture media was measured, and chondrocyte viability was assessed using the Formizan Conversion Assay and a paravital staining protocol. Metabolism recovery was assessed in explants that were allowed to recover in maintenance media after exposure to DMSO. RESULTS: PG synthesis and lactate metabolism were inhibited in a dose- and time-dependent manner after exposure to DMSO concentrations > or = 5%; there was no significant alteration in PG release. No change in chondrocyte viability was detected after incubation with DMSO. PG synthesis and lactate metabolism returned to baseline rates when allowed a recovery period after exposure to DMSO. CONCLUSIONS: DMSO concentrations > or = 5% suppress equine articular cartilage matrix metabolism. Suppression of PG synthesis and lactate metabolism is reversible and does not appear to be the result of chondrocyte death. CLINICAL RELEVANCE: Equine clinicians adding DMSO to intraarticular lavage solutions should be aware that DMSO may have deleterious effects on equine articular cartilage matrix metabolism.     

In vitro algaecide effect of sodium hypochlorite and iodine based antiseptics on Prototheca zopfii strains isolated from bovine milk

Prototheca zopfii has been considered one of the most important causes of environmental mastitis in Brazil. These algae are refractory to conventional therapy and cause great damage to the mammary gland. The present study evaluated the in vitro algaecide effect of sodium hypochlorite and iodine based antiseptics on 27 P. zopfii strains isolated from the milk of cattle. Low concentrations of sodium hypochlorite (0.0390625-0.15625%) and iodine (0.15625-0.625%) were effective against the isolates. These antiseptics may be recommended for hygiene routines, pre and postdipping and cauterization of bovine mammary glands infected by P. zopfii.     

我国牧草种带真菌的检测与防治

种带真菌可影响牧草种子的生活力,降低发芽率及出苗率,在阐述牧草种带真菌所在部位、种类及可能引起危害的同时提出了几种种带真菌的防治措施。     

In vitro evaluation of the effect of the opioid antagonist N-methylnaltrexone on motility of the equine jejunum and pelvic flexure

REASONS FOR PERFORMING STUDY: Although potent analgesics, opioids decrease intestinal activity, leading to ileus in many species. N-methylnaltrexone (MNTX), an opioid antagonist which does not cross the blood-brain barrier and antagonises the morphine effect on the intestine, directly stimulates motility and restores function without affecting analgesic properties. While its use has been reported in human subjects, there is no information with regard to its usage in the horse. OBJECTIVES: To determine whether MNTX has an effect on contractile activity of the equine jejunum and pelvic flexure. METHODS: Using circular smooth muscle strips obtained from 8 mature horses, increasing concentrations of MNTX were added to tissue baths in the range of 1 x 10(-9) to 1 x 10(-5) mol/l, and contractile responses were recorded for 3 mins. Data were analysed using a repeated measures ANOVA to determine whether there was a significant drug effect compared to baseline activity. Data were analysed between the jejunum and pelvic flexure using a Mann-Whitney U test. Statistical significance was established as P < 0.05. RESULTS: The administration of MNTX significantly increased the contractile frequency and amplitude at all concentrations relative to baseline (P < 0.0001) for the jejunum. The response was greatest at 1 x 10(-7) mol/l (P = 0.0005), with a mean difference from baseline of 115.12 g/cm2. The highest concentration evaluated (1 x 10(-5) mol/l) had a mean contractile strength of 69.76 g/cm2, which was significantly greater than baseline activity (P = 0.04). A significant increase in contractile activity for the colon was detected at 3 x 10(-7) mol/l and all subsequent concentrations (P < 0.04). Unlike the jejunum, the contractile activity of the pelvic flexure increased progressively with the addition of each subsequent concentration. CONCLUSIONS: N-methylnaltrexone has a direct effect on circular smooth muscle of the equine jejunum and pelvic flexure resulting in an increase in contractile activity. POTENTIAL RELEVANCE: N-methylnaltrexone could potentially be used in conjunction with morphine to provide potent and effective analgesia without compromising intestinal function. Further in vivo investigations are required to determine whether this agent antagonises morphine's effect on motility.     

蛋鸡日粮中添加富硒酵母对鸡蛋中硒含量及分布的影响

试验选用产蛋率约为80%的罗曼褐蛋鸡35只,随机分为7组,进行为期30d的饲养试验。A组为对照组,饲以基础日粮,其余6组为试验组,B、C、D组在基础蛋鸡日粮中分别添加0.2mg/kg、0.5mg/kg、1mg/kg硒的亚硒酸钠,E、F、G组在基础蛋鸡日粮中分别添加0.2mg/kg、0.5mg/kg、1mg/kg硒的富硒酵母。试验过程中记录蛋鸡的生产性能,每隔7d从各试验组鸡所产的鸡蛋中任取3枚,测定鸡蛋中硒的含量,并于试验的第14、15天,28、29天从A、C、F组每组各取5枚鸡蛋分别测定蛋黄和蛋清的硒含量。结果显示,日粮中添加硒对蛋鸡生产性能无显著影响,能极显著提高鸡蛋中硒含量,并且硒主要存在蛋黄中,添加富硒酵母组蛋硒含量较亚硒酸钠组提高更为显著。     

新鲜牛粪便中食线虫真菌的分离和鉴定

从78个新鲜牛粪样中分离到4株食线虫真菌（nematophagous fungi)，通过对其菌丝体、孢子、捕食器官等的形态学观察、测定，2株鉴定为节丛孢属（Arthrobotrys)的寡孢节丛孢菌（A.oligospora)，1株为指状节丛孢菌（A.dactyloides),1株为圆锥状节丛孢菌（A.conoides)。     

In vitro and in vivo effects of lufenuron on dermatophytes isolated from cases of canine and feline dermatophytoses

Lufenuron is a benzyl-urea phenol compound that inhibits chitin synthesis and is used as an insecticide. Its efficacy in the therapy of dermatophytosis in dogs and cats was evaluated in several clinical studies, with contradictory results. We assessed the in vitro susceptibility of dermatophytes isolated from dogs and cats to lufenuron, and the clinical response of skin lesions to the drug. Dermatophyte cultures isolated from clinical cases were exposed to lufenuron by three different methods: direct application and application of whole blood or subcutaneous tissue samples obtained from a lufenuron-treated healthy dog. No inhibition of dermatophyte growth was observed in any of the samples after 1 week of incubation. Eight dogs and six cats with skin lesions were included in the in vivo survey. Results indicated that six of seven skin lesions that were diagnosed as being caused by dermatophytes did not respond to lufenuron whereas six of seven skin lesions that were not caused by dermatophytes improved. We concluded that lufenuron, in the way it was administered in this study, had no inhibitory activity on dermatophytes in vitro or in vivo and its clinical use as an anti-fungal agent is questionable. An immunomodulatory effect of the drug is, however, possible.     

恩诺沙星对土壤细菌数量及耐药性的影响

兽药吸收进入动物机体后,少部分药物将残留于动物组织细胞内,而大部分药物将排泄到体外,最终进入生态环境中,且可能造成环境污染。为了解恩诺沙星在环境中残留对土壤细菌的影响,在恩诺沙星作用于土壤后第35天,对纯培养法分离的土壤细菌进行了计数,并对土壤细菌进行了抗菌药物敏感性试验。结果表明,添加药物组的细菌总数均低于空白对照组,且药物浓度越高,细菌数量越少;在供试的19种抗菌药中,恩诺沙星敏感菌对其中的16种药物的敏感性均显著高于恩诺沙星耐药菌（P〈0.01）。     

诺氟沙星对土壤细菌数量及耐药性影响

为了解诺氟沙星在环境中残留对土壤细菌的影响,在诺氟沙星作用于土壤后第35天对纯培养法分离的土壤细菌进行计数,并对土壤细菌进行抗菌药物敏感性试验。结果表明,添加药物组的细菌总数均低于对照组,且药物浓度越高,细菌数量越少;在供试的20种抗菌药中,诺氟沙星敏感菌对其中18种药物的敏感性与诺氟沙星耐药菌差异不显著(P>0.05)。