奶牛乳腺炎病原的分离鉴定及耐药性分析

奶牛乳腺炎是奶牛最常见的疾病之一,它不仅影响奶牛的产奶量,降低奶牛养殖经济效益,导致泌乳功能丧失,使奶牛被迫淘汰,同时影响牛奶品质、危害人类健康。据我国北京、上海、广州、西安、兰州等城市调查,乳腺炎是乳牛场最严重的疾病之一,发病率达20-70%。据国外报道,奶牛乳腺炎的发病率约为25-60%,在美国,100万头泌乳奶牛约50%患有乳腺炎,因奶牛乳腺炎每年造成的损失估计达20亿美元。在世界范围内,每年牛奶损失估计可达380万吨。奶牛乳腺炎不仅造成重大的经济损失,还影响到乳的品质,危及人的健康。国内外对奶牛乳腺炎病原、检测、防治方面的…     

奶牛乳腺炎无乳链球菌的分离鉴定与耐药性分析

奶牛乳腺炎是奶牛养殖业的常见疾病,而无乳链球菌是乳腺炎的重要病原体之一。本试验从江苏和河北地区的规模化奶牛场中共收集67份乳腺炎奶样,经分离培养和鉴定,共分离出33株无乳链球菌。药敏试验表明:河北地区和江苏地区奶牛场的分离株对阿莫西林、头孢氨苄等β-内酰胺类药物以及恩诺沙星等喹诺酮类药物高度敏感,而对链霉素、庆大霉素、卡那霉素以及丁胺卡那等氨基糖苷类药物均表现出较高的耐药性。此外,河北地区分离株对四环素、多西环素这两种药物比较敏感,但在江苏地区无乳链球菌对这两种药物表现出了较强的耐药性,耐药率均高达74.1%。说明不同地区的无乳链球菌耐药情况有一定的差异。本研究结果可为临床上用抗生素预防和治疗乳腺炎提供参考。     

奶牛隐性乳腺炎调查及病原分离鉴定

随着畜牧业的不断发展,我市奶牛养殖业也有较快增长,但是饲养量多不成规模,管理水平较差,疾病的防治技术落后,奶牛乳腺炎发生率居高不下。近几年在广大兽医工作者的努力下,临床型乳腺炎明显得到控制,但奶牛饲养主乱用和滥用抗生素的现象十分普遍,给乳腺炎的防治带来很大的困难。为了查明信阳地区乳腺炎的发生情况和主要致病菌,有效控制奶牛乳腺炎的发生,作者以本地区奶牛场、奶牛养殖小区和个体户的奶牛为对象,进行了隐性乳腺炎及其病原调查。     

奶牛隐性乳腺炎病原菌的分离鉴定

用兰州乳房炎试验(LMT)对来自西安市某个牛场的76份奶样作隐性乳房炎检验，并对乳样进行细菌分离鉴定。结果表明，该牛场的隐性乳房炎检出率为33％，阳性乳样中细菌检出率为93．4％。阴性乳样中病原菌检出率为28％，在检出的94株细菌中，共有5种菌22株是与乳房炎有关的病原菌。其中葡萄球菌和链球菌占病原菌总数的90％以上。是引起该场奶牛隐性乳房炎的主要病原菌。     

奶牛急性乳腺炎病原菌的分离与鉴定研究

对6头患有急性乳腺炎奶牛的24个乳区进行细菌的分离培养和初步的生化鉴定,检出葡萄球菌7株,无乳链球菌6株,大肠杆菌10株,棒状杆菌2株,分别占细菌检出数的28%,24%,40%,8%。     

宁夏部分地区奶牛乳腺炎病原菌的分离鉴定

从宁夏9个县(区)的16个规模化牛场采集327份患乳腺炎奶牛乳样,通过分离培养和生化试验,检出含细菌乳样226份,乳样细菌检出率69.11％(226/327);鉴定出奶牛乳腺炎病原菌5大类9种260株,确认宁夏部分地区奶牛乳腺炎主要病原菌为凝固酶阴性葡萄球菌、停乳链球菌、金黄色葡萄球菌、大肠埃希菌和酵母菌.乳腺炎的发生以单一病原感染为主,占84.96％(192/226);混合感染较少,占15.04％(34/226).     

奶牛急性乳腺炎病原菌的分离与鉴定研究

对6头患有急性乳腺炎奶牛的24个乳区进行细菌的分离培养和初步的生化鉴定，检出葡萄球菌7株，无乳链球菌6株，大肠杆菌10株，棒状杆菌2株，分别占细菌检出数的28%，24%，40%，8%。     

绵阳市奶牛乳房炎病原菌的分离鉴定及耐药性分析

奶牛乳房炎是对奶牛危害最大、最为常见的疾病之一，也是影响世界乳业的主要因素之一。据报道，国内外乳房炎发病率在46％～80％之间；而且降低奶产量，影响奶品质，危害人类健康，给奶牛业造成巨大的经济损失。奶牛乳房炎是病原微生物、环境、管理等多因素综合作用的结果，其中病原微生物是最主要的因素，也是导致奶牛乳房炎难以控制的一个最主要的原因。迄今为止，人们已从奶牛乳房中分离到了130多种微生物，根据其来源和传播方式通常分为两类：一类是接触传染性病原微生物，它植于乳腺并通过挤奶工或挤奶机传播，包括无乳链球菌、停乳链球菌、     

长春市某奶牛场乳腺炎病原菌的分离鉴定及耐药性分析

奶牛乳腺炎是制约奶牛养殖效益和奶品质的主要疾病之一,为了解当前长春市某大型集约化奶牛场奶牛乳腺炎病原菌流行和耐药情况,本试验对该场奶牛乳腺炎发病情况进行了调查,对采集的119份临床型乳腺炎乳样进行细菌分离鉴定并对分离鉴定的病原菌进行小鼠致病性试验和药敏试验。结果显示：该场奶牛乳腺炎发病率在4%左右,初产牛乳腺炎发病率明显高于经产牛,乳腺炎发病率还与胎次、年龄等因素相关。本试验共分离鉴定出木糖葡萄球菌49株(42.2%)、松鼠葡萄球菌39株(33.6%)、大肠杆菌15株(12.9%)、金黄色葡萄球菌5株(4.3%)、无乳链球菌3株(2.6%)、菠萝泛菌3株(2.6%)、产酸克雷伯菌1株(0.9%)和铜绿假单胞菌1株(0.9%);其中菠萝泛菌、无乳链球菌和铜绿假单胞菌对小鼠具有较强致病性。药敏试验结果显示,分离菌株的耐药性普遍存在,大肠杆菌和铜绿假单胞菌耐药种类最多。除无乳链球菌外,其他菌株均对庆大霉素或阿米卡星敏感,可作为该场奶牛乳腺炎治疗首选药物。本试验通过对该场乳腺炎调查、分离菌鉴定和耐药性分析,为该场乳腺炎的防治提供了参考依据。     

奶牛大肠杆菌性乳腺炎耐药性试验

为了研究山东省临朐县奶牛大肠杆菌耐药性情况,采集了5个奶牛规模场总共60份临床型乳腺炎患牛奶样,进行了培养和细菌分离鉴定,对分离的大肠杆菌进行分离纯化和药敏试验,表明该县奶牛主要致病菌为大肠杆菌和链球菌;大肠杆菌对多种抗生素具有耐药性但对头孢噻呋仍敏感。     

Prevalence and antibiotic resistance of mastitis pathogens isolated from dairy herds transitioning to organic management

Changes in udder health and antibiotic resistance of mastitis pathogens isolated from dairies upon conversion from conventional to organic management over a 3-year period was studied. Coagulase-negative staphylococci (CNS) were the most prevalent mastitis pathogens isolated. CNS were significantly less resistant to β-lactam antibiotics when isolated from milk after the herd transitioned to organic management. Cessation of the use of antimicrobial therapies in dairies in combination with organic management could lead to a reduction in the antimicrobial resistance of mastitis pathogens.     

奶牛乳房炎的病原菌分离鉴定与药敏试验

对山东济南市 5个奶牛场的 1 65份临床型和 1 4 7份隐性型乳房炎奶样进行了病原菌分离鉴定。临床型未用利福平复合新药奶样 48份 ,细菌检出率为 83 33 % ;用该药 2d内采集的奶样 1 1 7份 ,细菌检出率 60 68%。隐性乳房炎奶样细菌检出率 72 2 9%。用新研制的利福平复合新药对未用该药奶样分离菌 35株和用该药后有代表性的分离菌 40株 ,共 75株临床型分离菌进行药敏试验 ,结果 84%为高度敏感 (63/ 75) ,1 6 %为中度敏感 (1 2 / 75)。鉴定的细菌有葡萄球菌 ,链球菌 ,大肠杆菌 ,棒状杆菌 ,芽孢杆菌等。根据用药后患病奶牛的临床表现和奶样细菌分离情况 ,表明该药对奶牛乳房炎具有显著的治疗效果     

我国奶牛乳房炎无乳链球菌抗生素耐药性研究

为了查明我国奶牛乳房炎无乳链球菌对抗生素耐药情况,指导临床合理用药,从我国部分地区奶牛场采集的临床型奶牛乳房炎病乳中分离鉴定出无乳链球菌115株,采用K-B纸片法测定了这些菌株对抗生素的耐药情况。结果表明,无乳链球菌对目前临床上使用的大部分抗生素,如头孢唑啉、头孢噻肟、丁胺卡那霉素、卡那霉素、庆大霉素、四环素、强力霉素、麦迪霉素、林可霉素、氟苯尼考、多黏菌素B、环丙沙星、氟哌酸、氨苄青霉素/舒巴坦、头孢噻肟/棒酸和头孢他啶/棒酸均比较敏感;但对青霉素G、氨苄青霉素、链霉素、恩诺沙星、阿莫西林/棒酸和复方新诺明等有一定耐药性,其耐药率达50%～100%。     

Genetic analyses of pathogen-specific mastitis

The aims of this study were to investigate the presence of genetic variation for susceptibility to pathogen-specific mastitis and to examine whether haplotypes of an identified quantitative trait locus with effect on unspecific mastitis resistance had different effects on specific mastitis pathogens. Bacteriological data on mastitis pathogens were obtained from the diagnostic laboratory at the Swedish National Veterinary Institute. The data were mainly from subclinical cases of mastitis but also clinical cases were included. Variance components were estimated for incidence of the six most frequent pathogens using Markov Chain Monte Carlo methodology via Gibbs sampling. Genetic variation for susceptibility to pathogen-specific mastitis was higher compared to estimates of general resistance to clinical mastitis in most other studies. However, because of the non-random nature of data collection, comparisons to other studies should be made by caution. The effect of haplotype on the risk of being infected by a given mastitis pathogen, relative to other pathogens, was studied using an allele substitution model. Although there were no significant haplotype substitution effects on the resistance to any of the six mastitis pathogens, there was a significant difference between the effects of two of the haplotypes regarding the risk of acquiring a Streptococcus dysgalactiae infection.     

The spread and antimicrobial resistance of Staphylococcus aureus in South African dairy herds – A review

Staphylococcus aureus is internationally recognised as a principal agent of mastitis and the foremost reason for economic loss in the dairy industry. The limited data available on organism-specific antibiotic resistance surveillance in dairy cattle have stimulated the need for such a review article. The objective of this study was to review relevant literature on antimicrobial resistance of mastitis-causing staphylococci isolated from dairy cows in South Africa compared to other countries. Factors relating to the incidence of mastitis and treatment strategies in terms of the One Health concept and food security were included. The Web of Science (all databases) and relevant websites were used, and articles not written in English were excluded. The incidence of mastitis varied between South Africa and other countries. Antimicrobial resistance patterns caused by S. aureus also varied in regions within Southern Africa and those of other countries although some similarities were shown. Antimicrobial resistance differed between S. aureus bacteria that were maltose positive and negative (an emerging pathogen). The results highlighted the importance of the availability of organism-specific surveillance data of the incidence of mastitis and antibiotic resistance for specific countries and within similar climatic conditions. Accurate knowledge about whether a specific pathogen is resistant to an antibiotic within a certain climate, country, area or farm should reduce the incidence of unnecessary or incorrect treatment with antibiotics. This should enable dairy farmers to deal with these organisms in a more effective manner. Therefore such research should be ongoing.     

The incidence of antibiotic resistance among coliform bacteria isolated from food.

Three-hundred-and-seventy-eight strains of coliform bacteria were isolated from specimens of commonly sold milk and food products. Klebsiella and Enterobacter spp. were predominating. Resistance to sulphonamides, streptomycin, and chloramphenicol occurred in only 5, 1, and 2 strains, respectively. No tetracycline-resistant strains were found. Two-hundred-and-two strains (54 %) were resistant to ampicillin. In genetic crosses with a sensitive strain of E. coli Κ 12 W 3132 transmissible R factors could not be demonstrated in any of the resistant coliform strains.It is concluded that food is not a significant source of antibiotic resistant enteric bacteria. It may, however, be suggested that food is a source of potentially pathogenic gram-negative bacteria which points out the importance of strict hygienic surveillance of food production.     

细菌排出泵、TolC家族和生物薄膜的作用机制研究进展

在多种重要病原体中存在抗生素排出泵,它与其它抗性一起构成了细菌显著的耐药性,其识别的底物非常广泛.G-菌中还存在与排出泵不同的另一种以蛋白质构成的排出系统,通过底物特异性内膜蛋白和外膜蛋白TolC家族的可逆性互作,也可以直接将包括小分子药物和大分子蛋白毒素等的多种分子从胞浆经周质区运到体外.粘附在内置医疗装置或组织中的细菌因其形成生物薄膜结构和以蛋白质、多糖为主的水性基质包裹的菌体也可以产生长期感染以及对抗生素的持久抗性,这种抗性与经典的质粒、转座子或突变产生的抗性不同.本文对细菌TolC家族和生物薄膜引起的抗性机制进行了综述.     

浅析动物源细菌抗生素耐药性的现状与对策

抗生素的滥用使细菌耐性问题日趋恶化,从细菌耐药性的定义、耐药机理及危害出发,简要阐述和分析了动物源细菌抗菌药物耐药性的现状及对策,并简述我国动物源细菌耐药性研究进展。     

奶牛乳房炎的防治

奶牛乳房炎是一种常见病和多发病,是目前严重危害和困扰奶牛养殖业及产奶业最常见的疾病之一,此病的发生不仅严重地影响了奶牛产奶量和奶质,而且还会造成奶牛使用年限减少,淘汰提前,饲料汇报率降低,治疗和管理成本增加,乳中兽药和抗生素残留,危及人类健康和环境安全等巨大经济损失,直接影响着养殖业的经济收入。为了减少该病的发生,提高乳质量,对我场奶牛进行了奶牛乳房炎的发病规律和治疗情况的调查,并且提出相应的防治措施,有效的控制了乳房炎的发生。     

冀东地区奶牛隐性乳房炎病原菌的分离鉴定

通过LMT法、乳汁pH检验法和体细胞直接计数等方法相结合,对冀东地区3个大型奶牛场、8个奶牛养殖户选取的1 021头奶牛进行隐性乳房炎流行病学调查与病菌分离鉴定。结果表明,隐性乳房炎发病率为60.63%(619/1021),乳房炎阳性乳样品中细菌分离率达88.21%(546/619)。从543头隐性乳房炎患牛的阳性乳区乳样中分得细菌共4类14种菌82株,其中葡萄球菌36株,占43.90%;链球菌33株,占40.24%;肠杆菌类8株,占9.76%;棒状杆菌5株,占6.10%。冀东地区奶牛隐性乳房炎主要病原菌为金黄色葡萄球菌和无乳链球菌。