奶牛主要病原菌耐药性及控制技术研究进展

抗菌药仍是治疗病原菌引起的奶牛疾病的常用方法。抗菌药的不合理使用使得细菌产生耐药性已成为全球性的问题,应引起人们的足够重视。奶牛的主要病原菌金黄色葡萄球菌、链球菌、大肠杆菌等也显现出多重耐药的趋势,给奶牛疾病的临床治疗带来困难,同时也威胁人类健康。细菌产生耐药性的速度远超过人们研发抗菌药的速度,因此,保持现有抗菌药的疗效很有必要。一方面应该掌握细菌的耐药机制,如细菌分子耐药机制、抗菌药物外排机制或降低摄入机制、生物膜等,以便找到合适的治疗方法;另一方面采用不同措施减少耐药细菌的出现,如质粒消除、抗菌药替代品、开发高效安全的抗菌药物、临床合理用药（联合治疗）等。作者对奶牛主要病原菌的耐药情况、耐药机制、耐药控制技术进行综述,以期为减少耐药性、规范抗菌药的使用和提高治疗效果提供参考。     

Antimicrobial susceptibility patterns and sensitivity to tulathromycin in goat respiratory bacterial isolates

Bacterial pneumonia is a common and often life-threatening respiratory problem in both meat and dairy goats. Options for approved antibiotic therapy in goats to combat these bacterial infections are severely limited and frequently drugs must be used in an extra-label manner. Tulathromycin, a triamilide macrolide antimicrobial drug shown to be effective against swine and cattle respiratory bacterial agents, has been identified as a potentially useful drug in caprines. The present study was conducted to determine the susceptibility of recognized bacterial respiratory pathogens to commonly prescribed antimicrobials, with a particular emphasis on the efficacy of tulathromycin against these agents. Minimum inhibitory concentration (MIC) testing using microbroth dilution was performed on a collection of 45 Mannheimia haemolytica, 11 Pasteurella multocida, and 11 Bibersteinia trehalosi isolates from the lungs of goats with clinical pneumonia. To further characterize efficacy of tulathromycin against these pathogens, minimum bactericidal concentration (MBC) testing and kinetic killing assays were conducted. Most isolates were susceptible to the antimicrobials tested; however, increased resistance as demonstrated by higher MIC values was seen in all species to penicillin, in P. multocida to sulfadimethoxine, and in B. trehalosi to the tetracyclines. All isolates were susceptible to tulathromycin, which demonstrated a high killing efficiency in both bactericidal assays. Results of this study indicate that most goat pneumonic bacterial pathogens remain susceptible to commonly prescribed antibiotics, although some evidence of resistance was seen to certain drugs; and that tulathromycin is highly effective against goat respiratory pathogens which could make it a valuable medication in this species.     

奶牛乳房炎主要病原菌感染流行规律研究进展

乳房炎作为全球性奶牛养殖业的重要疾病,因对社会经济、养殖行业和人类健康的巨大影响使人们从发病机理、疾病诊断、预防等方面对其进行了不断的研究与探讨。作者立足于前期尤其是近几年的研究文献,以引起奶牛乳房炎的重要原因——病原菌为中心展开,探讨其感染类型、奶牛与病原菌及病原菌相互之间的关系。奶牛乳房炎是由包括病原菌的侵袭及宿主奶牛自身抵抗力等多种因素共同作用导致,乳腺对病原菌的入侵应答能力,病原与病原之间或促进或抑制都对其发生产生影响。金黄色葡萄球菌是公认的奶牛乳房炎的主要传染性病原菌,其独特的生物学特性使得其在体内难以治疗,并且耐药性普遍存在;无乳链球菌是环境性还是传染性病原尚有争议,在中国感染率较高,对大部分抗生素仍旧敏感,相对于其他病原菌治愈率较高,畜群清除容易;大肠埃希氏菌被作为环境性病原体,乳房炎感染的分离率仍较高,抗生素治疗结果还有待商榷,耐药性普遍存在并增强;牛支原体近十年的感染率有所上升,在国内外都是严重的乳房炎致病因素,治疗效果不佳,且耐药性正在增强,疫苗开发困难。文章对上述几种主要病原菌的流行、危害与防治等研究进行综述,以期为奶牛生产管理和科学研究方面提供参考。     

兰州地区部分奶牛场子宫内膜炎病原菌分离鉴定及抗生素耐药性研究简

为了探明兰州地区奶牛子宫内膜炎病原菌区系分布及抗生素耐药情况,指导临床合理用药。笔者对从兰州地区3个规模化奶牛场采集的47份奶牛子宫内膜炎样品进行了细菌分离鉴定,同时对分离鉴定出的4种主要病原菌采用纸片扩散法（K-B法）进行了抗生素耐药性检测。病原菌区系分布结果表明,引起兰州地区奶牛子宫内膜炎的病原菌主要为化脓隐秘杆菌（37.1%）、大肠杆菌（24.2%）、屎肠球菌（22.6%）和无乳链球菌（16.1%）。抗生素耐药性结果表明,4种主要病原菌对大部分抗生素均产生了不同程度的耐药性,尤其是对青霉素、复方新诺明、奥复星和杆菌肽耐药性最为严重,其耐药率为60%～100%。对4种病原菌均较敏感的药物主要有头孢他啶、先锋霉素V和氟苯尼考,其敏感度达100%。     

四川凉山地区奶牛乳房炎主要病原菌分离鉴定及药敏情况分析

通过开展凉山地区奶牛乳房炎主要病原菌的分离鉴定和药敏情况试验,为指导凉山地区奶牛场临床合理使用抗生素以及提高抗生素的防治效果提供理论指导。通过采样、增菌培养、细菌鉴定、药敏试验、数据统计分析等方法,结果发现193 份患有乳房炎的乳样中有134 份分离出12 种病原菌,其中65 份检出两种及以上菌,占检出数的48.50%﹔共分离出234 株不重复菌株。分离率居前五位为：葡萄球菌63 株（26.9%）、大肠杆菌56 株（23.8%）、肺炎克雷伯菌42 株（17.9%）、肠球菌24 株（10.3%）、链球菌13 株（5.6%）。对本试验分离到的大肠杆菌、葡萄球菌、肺炎克雷伯菌等12 种菌中的10 种细菌药敏试验结果显示,不论是革兰氏阳性菌还是革兰氏阴性菌对试验选取的17 种常见抗生素均表现不同程度的耐药,有部分菌株还表现严重的多重耐药,有些菌株对部分药物耐药率达100.00%。     

辽宁地区奶牛乳房炎细菌性病原分离鉴定及大肠杆菌药敏试验

为了掌握辽宁地区奶牛乳房炎主要细菌性病原种类及致奶牛乳房炎大肠杆菌药物敏感性特征,本研究选取辽宁地区某大型奶牛场75头临床表现为乳房炎的奶样进行细菌培养与分离,通过生化方法对分离到的细菌进行鉴定,并对分离到的奶牛源大肠杆菌进行体外药物敏感性试验研究。结果发现,该场奶牛乳房炎细菌性病原主要为大肠杆菌、葡萄球菌和链球菌,其检出率分别为58.7%、64.0%和54.7%,存在二重感染和三重感染等混合感染的情况。大肠杆菌药物敏感性试验结果表明,该场分离株对磺胺类药物（耐药率>85%）及氯霉素类药物（耐药率>30%）耐药性较高,对氨苄西林（9.5%）、环丙沙星（9.5%）、头孢噻呋（7.1%）和氧氟沙星（4.8%）比较敏感。上述研究结果为该地区奶牛乳房炎的防制提供可靠的理论依据。     

Isolation and Identification of Pathogenic Bacteria Causing Dairy Cow Mastitis in Liaoning and Drug Sensibility Test of Pathogenic E.coli

In order to understand the main bacterial pathogen species causing dairy cow mastitis in Liaoning, as well as the characteristics of drug sensitivity of the pathogenic E.coli,the milk samples from 75 dairy cows with clinical manifestations for mastitis in certain large-scale dairy farm in Liaoning were collected.The bacteria in milk were cultured and isolated with biochemical methods and in vitro drug sensitivity tests were processed with the isolated E.coli strains.The results showed that the main bacterial pathogen for dairy cow mastitis were E.coli（separation rate 58.7%),S.aureus（64.0%）and S.agalactiae（54.7%),and multiple infection including double and triple infection were identified.The drug sensitivity tests on the isolated E.coli indicated that the E.coli isolates were highly resistant to sulfonamides（resistance rate>85%）and chloramphenicol（resistance rate>30%),and they were relatively low resistant to ampicillin（9.5%),ciprofloxacin（9.5%),ceftiofur（7.1%）and ofloxacin（4.8%).The results was able to provide reliable theoretical basis for prevention and control of dairy cow mastitis in Liaoning area.     

江苏地区奶牛源葡萄球菌耐药性分析与红霉素诱导的克林霉素耐药检测

为指导江苏地区奶牛场奶牛乳房炎的临床用药,本研究对2015-2018年江苏地区部分奶牛场的牛奶样品进行细菌分离,使用基质辅助激光解析电离飞行时间质谱(MALDI-TOFMS)方法和纸片法对分离菌株进行鉴定和药物敏感性分析,对分离得到的葡萄球菌进行了葡萄球菌D环实验,并且使用PCR技术检测了D环实验阳性菌株携带的耐药基因...     

中药防治奶牛乳房炎的研究进展

乳房炎是奶牛的一种常见病,是导致牛奶产量和质量下降的主要原因之一。目前,奶牛乳房炎的防治多以抗生素为主,但抗生素的滥用不仅导致了乳汁中病原菌耐药性的产生,同时也造成了乳汁中抗生素的残留。中药由于无残留、无毒副作用和较少出现耐药性等特点而备受科研学者的关注。本文主要从奶牛乳房炎的危害、中药防治奶牛乳房炎的研究现状和作用机理三个方面探讨了当前中药防治奶牛乳房炎的研究进展,旨在为临床上奶牛乳房炎的防治提供客观的参考。     

奶牛隐性乳房炎病原菌的分离鉴定及药敏试验

为了解贵阳市某乳业有限公司奶牛场隐性乳房炎流行情况及其主要病原菌,采用CMT方法检出隐性乳房炎乳样后,对阳性乳样进行细菌分离与鉴定,同时对其主要病原菌进行了体外药敏试验。结果表明,该公司奶牛场隐性乳房炎的感染率为40％,主要病原菌为葡萄球菌属和链球菌属细菌,其敏感的抗菌药物有先锋V霉素、利福平、丙氟哌酸、氟哌酸、新霉素、卡那霉素、庆大霉素等,经临床用药观察,有效地控制了该公司奶牛场隐性乳房炎。     

胸腺嘧啶依赖型金黄色葡萄球菌小菌落突变株的分离鉴定

本试验对由患慢性奶牛乳房炎奶样中分离出的1株疑似金黄色葡萄球菌小菌落突变株(SCVs)进行形态观察、金黄色葡萄球菌相关保守基因片段(nuc、nucA、16S rDNA) 多重PCR扩增鉴定、药敏试验、生理生化特性研究及补偿试验。结果显示分离出1株金黄色葡萄球菌SCVs,该菌含有金黄色葡萄球菌菌种特异性基因nuc和nucA;与金黄色葡萄球菌质控菌株ATCC 25923的抑菌圈大小明显不同;菌落形态主要表现为菌落细小、生长缓慢、溶血能力下降;凝固酶活性下降;耐盐能力降低;革兰氏染色为革兰氏阳性球菌,呈葡萄状排列;补偿试验鉴定该金黄色葡萄球菌SCVs为胸腺嘧啶依赖型。结果表明成功分离鉴定出1株胸腺嘧啶依赖型金黄色葡萄球菌SCVs,为由金黄色葡萄球菌SCVs引起的奶牛慢性乳房炎的预防和控制及其致病机制的研究奠定前期基础。     

Stakeholder position paper: dairy producer

Bacterial antimicrobial resistance is a problem common to both animal and public health. An important public policy issue is to develop and implement prudent use practices where antimicrobials are used. As policy develops, there are questions regarding the use of antimicrobials in animal agriculture and whether these uses constitute prudent use. A series of papers assessing the risk to the public health from agricultural use of antimicrobials have consistently concluded that risk estimation is hampered by the lack of data that describe the amount, types, and uses of antimicrobials in animal agriculture. The absence of information has spurred efforts to develop a framework to collect these data. However, the reasons and benefit of collecting these data should be carefully defined. The dairy industry, contrasted to other major animal commodities, is not focused on meat production but on milk production. Milk production is constrained by disease and antimicrobial treatment is a common management tool, but unlike many other animal agricultural systems where the value and safety of the product is measured in the future; the value of milk is zero when an antimicrobial is used in a lactating cow and milk must be discarded because of residues. While there are exceptions, e.g. non-lactating cow therapy, this difference results in antimicrobials being used sporadically and directed at therapy rather than prophylactic uses. In the dairy industry, antimicrobial use data and its consequences may exist in sufficient detail or could be estimated from existing datasets without the expense of additional surveys. Finally, the main food product milk is mainly pasteurized and all shipments of milk from the farm to the processing plant are tested for the presence of antimicrobials. This makes the likelihood of farm-origin antimicrobials or bacteria appearing in finished product very low. This suggests that the use and quantity of antimicrobials in the dairy system has little impact on public health. This does not imply that the dairy industry does not have a significant role in developing guidelines for appropriate and careful application of antimicrobials, but the effort and cost to collect additional data should be used to fund efforts that improve our diagnostic and managerial skills. These data would change the use of antimicrobials by decreasing the rates of disease and ultimately decreasing prophylactic, metaphylactic and therapeutic use of antimicrobial. These studies and outcome are as important to the dairy industry as to public health.     

植物有效成分提取工艺及其对细菌性奶牛乳房炎的治疗作用机制研究进展

利用植物提取物防治奶牛乳房炎符合“减抗、限抗”的国家要求和行业趋势。总结了植物有效成分常用的提取方法,介绍了细菌性乳房炎的发生机理,综述了植物有效成分的抑菌机制以及抗炎和免疫调节机制,以期为兽医临床奶牛乳房炎治疗药物的选择提供新思路。     

奶牛乳房炎溶血性病原菌分离培养及药敏试验

本试验旨在确定吉林市某奶牛场奶牛乳房炎的主要致病菌及致病菌对某些抗生素的敏感性。无菌采集奶牛乳房炎病例的奶样,进行细菌分离培养和细菌的药敏试验。试验结果显示,该奶牛场奶牛乳房炎的主要致病菌为2种溶血性的链球菌,分别是α溶血性链球菌和β溶血性链球菌,且致病菌的耐药性较强,对大多数抗生素均有耐药性。试验结果表明,该奶牛场奶牛乳房炎致病菌具有强致病性和耐药性。     

奶牛子宫内膜炎研究进展

子宫内膜炎是奶牛中一种常见的产科疾病,它可引起奶牛不孕,给奶牛养殖带来严重经济损失。引起奶牛子宫内膜炎的主要原因可概括为理化性和生物性二类,病原菌的侵入可通过上行性感染和下行性感染的途径造成子宫炎的发生,主要致病菌有葡萄球菌、大肠埃希菌、链球菌等。直肠检查和内窥镜检查仍是奶牛子宫内膜炎的常规的诊断方法,但仍有待于探索简便准确的新诊断方法。恢复子宫张力,促进子宫血液循环和炎性分泌物排出,抑制或消除子宫内感染病菌是子宫内膜炎的主要治疗原则,常用的治疗方法有冲洗子宫,全身疗法,抗生素和激素疗法以及中药治疗等。创建新的治疗和诊断方法,开发疗效好的药物将是提高奶牛子宫内膜炎诊疗水平的努力方向。     

奶牛乳房炎防治的研究进展

奶牛乳房炎作为奶牛较为常见且影响较大的一种疾病,给畜牧业与食品业带来了严重的经济损失。传统的抗生素治疗方法因其在临床上容易出现广谱耐药和药物残留等问题受到广泛争议。所以,探索新型的治疗方案迫在眉睫。以中草药制剂、疫苗等为代表的生物制剂因具有较多的优点而被人们广泛关注。本文作者基于前人的研究成果,阐述了奶牛乳房炎的新型治疗方法,为进一步研究奶牛乳房炎的治疗提供一定的参考与帮助。     

乳酸菌防治奶牛乳房炎的作用效果及前景展望

乳房炎是奶牛常见的疾病之一,患病奶牛因其废弃奶的产生,以及治疗和淘汰等相关费用的增加,给奶牛养殖业带来了巨大的经济损失.目前,对于奶牛临床性乳房炎的治疗主要依赖于抗生素,而抗生素的长期大量使用会导致耐药性病原菌的产生和牛奶中的药物残留等问题.作为抗生素的潜在替代品,乳酸菌在防治病原微生物方面很有潜力,现综述了乳酸菌防治...     

Antimicrobial susceptibility of mastitis pathogens from first lactation and older cows

Increasing antimicrobial resistance has become a serious concern worldwide and antimicrobial use in animal agriculture is currently under scrutiny. Mastitis is the most common reason for antibiotic use in dairy herds and thus, antimicrobial resistance of mastitis pathogens has received recent attention. The purpose of this study was to describe and compare antimicrobial susceptibility of mastitis pathogens isolated at calving from first lactation and older cows. A total of 202 bacteria were isolated from intramammary infections (IMIs) within 3 days after calving over a 16-month study period in the Krauss Dairy Research Herd at the Ohio Agricultural Research and Development Center (OARDC) in Wooster, OH. Of these IMIs, 78% were caused by coagulase-negative staphylococci (CNS). Forty-four percent of them were resistant to at least one antibiotic. Most resistance was observed against penicillin, 39% of the isolates from older cows and 26% from first lactation cows being resistant to penicillin (P > 0.05). Also MIC90 for penicillin was higher among isolates from older cows. On the other hand, resistance to tetracycline was more common and MIC90 higher among isolates from first lactation cows than from older cows. Differences in the proportions of resistant isolates between first lactation and older cows were not statistically significant, though. The resistance patterns of the CNS isolated during the study are concordant with antimicrobial usage in the study herd. This is in agreement with the generally accepted notion that selection pressure from the use of antibiotics is a main factor in development of antibiotic resistance.     

Antimicrobial susceptibility of Escherichia coli isolates from dairy farms using organic versus conventional production methods

OBJECTIVE: To compare antimicrobial susceptibility patterns of Escherichia coli isolates cultured from fecal samples from cows and calves on dairy farms that used organic (ie, no or severely limited antimicrobial use) versus conventional production methods. DESIGN: Cross-sectional study. SAMPLE POPULATION: Fecal samples from 10 cows and 10 calves on each of 30 organic dairy farms and 30 neighboring conventional dairy farms in Wisconsin. PROCEDURE: E. coli isolates obtained from the fecal samples were tested for susceptibility to 17 antimicrobials by means of a microbroth dilution test. Prevalence of antimicrobial resistance was compared between organic and conventional dairy farms. RESULTS: E. coli was isolated from 1,121 (94%) fecal samples. Farm type (organic vs conventional) and animal age (cow vs calf) were significantly associated with odds that E. coli isolates would be resistant to various antimicrobials. After controlling for age, logistic regression analyses indicated that isolates from conventional dairy farms had significantly higher rates of resistance to ampicillin, streptomycin, kanamycin, gentamicin, chloramphenicol, tetracycline, and sulfamethoxazole than did isolates from organic dairy farms. However, no significant differences were detected for the 10 other antimicrobials that were tested. CONCLUSIONS AND CLINICAL RELEVANCE: Results indicated that compared with isolates from conventional dairy farms, E. coli isolates from organic dairy herds have significantly lower prevalences of resistance to 7 antimicrobials; however, prevalence of resistance was not significantly different for 10 other antimicrobials. Resistance was more common for isolates from calves than for isolates from adult dairy cows.     

细菌性牛呼吸道疾病的研究进展

牛呼吸道疾病(BRD)是由多种病毒和细菌与外界环境相互作用而引起的一种严重的呼吸系统疾病,是引起舍饲牛发病和死亡的主要原因,给北美和世界养牛业造成巨大的经济损失。作者就引起BRD的主要细菌性病原体如溶血性曼氏杆菌、多杀性巴氏杆菌、昏睡嗜血杆菌、牛支原体及其他相关病原体和临床症状、病理学变化、饲养管理和治疗药物的选择等进行了阐述,以期为该病的治疗和防控提供参考。