恩诺沙星防治水生动物疫病的研究进展

综述了恩诺沙星在防治水生动物疫病中最新的研究进展,为在水产养殖生产中科学合理地使用该药提供参考.     

牛生长激素基因向“缩骨鲫”受精卵转移的初步研究

用显微注射方法,将带有小鼠重金属结合蛋白基因启动子的牛生长激素基因导入“缩骨鲫”受精卵。分析了外源基因在受体胚胎发育过程中的行为及在仔鱼体内的整合。初步结果显示了外源基因对受体的加速生长效应。     

Quantitative analysis of ruminal methanogenic microbial populations in beef cattle divergent in phenotypic residual feed intake（RFI）offered contrasting diets

Background：Methane（CH_4） emissions in cattle are an undesirable end product of rumen methanogenic fermentative activity as they are associated not only with negative environmental impacts but also with reduced host feed efficiency.The aim of this study was to quantify total and specific rumen microbial methanogenic populations in beef cattle divergently selected for residual feed intake（RFI） while offered（i） a low energy high forage（HF） diet followed by（ii） a high energy low forage（LF） diet.Ruminal fluid was collected from 14 high（H）and 14 low（L） RFI animals across both dietary periods.Quantitative real time PCR（qRT-PCR） analysis was conducted to quantify the abundance of total and specific rumen methanogenic microbes.Spearman correlation analysis was used to investigate the association between the relative abundance of methanogens and animal performance,rumen fermentation variables and diet digestibility.Results：Abundance of methanogens,did not differ between RFI phenotypes.However,relative abundance of total and specific methanogen species was affected（P〈 0.05） by diet type,with greater abundance observed while animals were offered the LF compared to the HF diet.Conclusions：These findings suggest that differences in abundance of specific rumen methanogen species may not contribute to variation in CH_4 emissions between efficient and inefficient animals,however dietary manipulation can influence the abundance of total and specific methanogen species.     

Advances in pathophysiology of gut microbiota

Before the technique of advanced high-throughput sequencing comes up, less is known about the human gut microbiota. It has been understood that trillions of microbes, in which 99% are bacteria, inhabit the human gut, forming a complicated ecological community. The gut microbiota has a great impact on human physiology and susceptibility to disease through its integrative metabolic activities and interactions with the host. In physiology, gut microbiota contributes to the host acquisition of nutrition and energy from diets, promoting development and maturation of gastrointestinal tract and immune system, and protecting host from invasion of enteropathogens. In pathology, dysbiosis underlying altered gut microbiota is associated with the susceptibilities to various diseases, including inflammatory bowel disease, type 1 diabetes, asthma, obesity, metabolic syndrome, autism and cancer. Understanding of the factors that underlie alterations in the composition and function of gut microbiota will be helpful in the development of drugs and the design of therapies that target it. This goal is formidable. It is because that the compositions of gut microbiota are immensely diverse, varying between individuals in a population and fluctuating over time in an individual, especially during early development and diseases. Viewing the gut microbiota with an ecological perspective will provide new insights into how to improve our health by targeting this microbial community in clinical treatments.     

二比空栽培模式对玉米弯孢菌叶斑病流行动态影响

根据植物病害流行学原理,通过田间试验设计及人工接种技术,对二比空栽培模式与常规栽培模式下玉米弯孢菌叶斑病发生流行动态进行比较研究。结果表明,二比空栽培模式的发病程度轻于常规栽培模式,病害初始病情与传播速率均低于常规模式。病害流行时间动态模型拟合发现,Weibull模型较好,其中,两种栽培模式下病害指数增长期(始发期)相同,二比空栽培模式下病害Weibull增长期(盛发期)短于常规模式,且衰退期出现较早。     

基于iTRAQ定量蛋白质组学技术的不同感染状态结核病牛血清蛋白质组学分析

为了探明不同感染状态结核病牛血清蛋白质水平的差异,揭示结核病牛在不同感染状态下的生理状态.本研究通过皮内变态反应、IFN-γ释放试验从临床筛选结核病阳性牛(TB)和阴性牛(NC),根据牛鼻拭子巢式PCR检测结果将临床阳性牛(TB)分为PCR阳性结核病牛(TBP)和PCR阴性结核病牛(TBN),每组20头,采集血清.应用...     

徐州地区新城疫流行病学调查与分析

对徐州地区三个禽病门诊2012年资料进行了初步统计,发现新城疫门诊量占15．1％,其中20日龄以内发病占51．6％,发病率和病死率也以20日龄以内居高。20日龄以内病鸡多表现败血症症状,20日龄以上以非典型症状为主。结合当地养殖和防疫状况,对当前新城疫流行形势进行了分析,旨在为业内同行提供借鉴。     

区域性南方水稻黑条矮缩病发生情况预测预报模型

依据湖南省汉寿县和永州市2010年和2011年白背飞虱虫量与南方黑条矮缩病的发生面积的相关性,建立南方黑条矮缩病发生情况的区域性预测预报模型。结果表明,该模型相关系数高(R=0.8764),适用于湖南省南方水稻黑条矮缩病发生的预测预报。     

A blind test of the serological response of dogs to infection with Taenia ovis

Fifty six dogs of mixed age and sex were acquired from farms in the Otago/Southland region, and maintained at the Hydatid Research Unit, Taieri, where 43 were each fed two Taenia ovis cysts. All were bled fortnightly for six or 12 weeks. Coded sera were sent to Wallaceville Animal Research Centre for testing using ELISA, with antigen from T. ovis scoleces. Dog treatments were identified after all tests were complete. A discriminant level was derived from the mean absorbance value plus three standard deviations of 56 sera taken at time zero and 78 sera from serially bled uninfected dogs. None of these 134 sera registered as a false positive using this discriminant level. The data showed no significant deviation from normality, and the expected frequency of the occurrence of false positives is therefore less than 0.14%. Four weeks after infection 63% of dogs proved to be infected were serologically positive, rising to 78% after 6 weeks. When worms were removed by anthelmintic treatment, ELISA absorbance levels decreased. Four weeks after removal 70% of previously infected dogs remained positive, decreasing to 30% after 6 weeks.

Six weeks after infection the sensitivity of the test was 78%, and the specificity 63%. However, if dogs with positive ELISA absorbance levels, but which did not purge worms, were regarded as having had worms, the respective figures would be 82% and 100%. The latter figures are similar to our previously published laboratory results. The test is of comparable efficiency to arecoline purgation for surveillance, and has the additional advantage of detecting infection in the majority of those dogs that have been infected for three weeks or more but fail to pass worms on purgation, and a substantial proportion of those infected dogs that were treated by their owners prior to presenting them for purgation in order to avoid detection of infection.     

The activity of albendazole against adult and larval gastrointestinal nematodes in naturally infected calves in the Netherlands

Summary

The activity of albendazole against gastrointestinal helminths in naturally infected calves in the Netherlands was tested. The calves were in their fist grazing season and kept in two groups of ten. One of these groups was grazed alternately with sheep. Five out of each group were drenched with albendazole (7.5 mg/kg) on the day they were housed (November 1). Before and 2, 14, and 28 days after treatment individual faecal samples were taken from all calves and larval cultures were made. Ten calves, six treated and four untreated, were killed for post mortem studies 14 days after treatment The remaining calves were slaughtered 14 days later.

The drug was highly effective in reducing the egg output, measured as the number of larvae cultured per gram of faeces. Compared with the untreated calves, the reduction was more than 99% two days after treatment, 100% at 14 days, and 99% after 28 days. It was shown that egg output 28 days after treatment came from worms which had developed from arrested larvae of Ostertagia ostertagi that had survived treatment. Post mortem results showed an efficacy of 100% against adult O. ostertagi, of almost 100% against Trichostrongylus axei, and 100% against adult and larval Cooperia oncophora.

Twenty‐eight days after treatment, the reduction of arrested early fourth stages of O. ostertagi was 85% in comparison with the untreated calves. Apparently less effect was found against Trichuris ovis at the given dose rate.