上海地区奶牛乳房炎病原菌的分离鉴定及药敏试验

奶牛乳房炎是由于病原微生物侵入奶牛乳腺组织所引起的奶牛乳房炎症.研究通过调查上海地区部分奶牛场乳房炎情况,对引起奶牛乳房炎的主要病原菌进行了分离鉴定和药敏试验,从而为该地区奶牛乳房炎的防治提供了科学的依据.     

奶牛胃肠道菌群与奶牛乳房炎关联性及其对乳房炎调控潜力的研究进展

乳房炎是严重影响奶牛机体健康状态及乳品质量的疾病之一。一直以来,外源致病菌入侵乳房并引发感染被认为是奶牛乳房炎发病的主要因素。然而,最近的研究表明,胃肠道菌群同样能够影响奶牛乳房炎的发病并对炎症进行调控。其主要机制可能涉及"肠道-乳腺"内源途径,即来自胃肠道的某些细菌可以通过涉及单核免疫细胞（主要是吞噬细胞）机制进行转移,通过内源性细胞途径（细菌性肠-乳途径）迁移到乳腺。本文就奶牛乳房炎的致病因素及其影响、胃肠道菌群与奶牛乳房炎的关联性及其对乳房炎的调控（包括饮食、短链脂肪酸（short-chain fatty acids,SCFAs）、益生菌及共生菌等因素）等方面进行了综述,旨在为奶牛乳房炎的发病机制及缓解措施提供新的思路。     

奶牛临床型乳房炎病原菌的分离与鉴定

奶牛乳房炎是奶牛常见病和多发病之一，其病因复杂，难以防制，给奶牛饲养业带来了巨大的经济损失。作者通过对某奶牛场的奶牛临床型乳房炎病原菌进行分离、鉴定，从105份样品中共分离出76株细菌，经培养特性、染色镜检、生化鉴定等试验，鉴定出无乳链球菌58株，占分离菌的76.32%；大肠杆菌18株，占分离菌的23.68%。本试验结果表明，无乳链球菌是奶牛临床型乳房炎的主要病原菌，其次是大肠杆菌。这为奶牛乳房炎的防制提供了重要依据。     

浅谈奶牛乳房炎的防治技术

奶牛乳房炎是奶牛养殖场面临的主要健康问题之一,更是限制奶牛养殖产业创收的元凶之一.其不仅能够导致奶牛的产奶量和奶质量显著下降,还会对养殖户造成严重的经济损失.因此,本文主要从奶牛乳房炎的诊断、预防和治疗三个方面对奶牛乳房炎的防治技术进行讨论分析.     

浅谈奶牛乳房炎的危害和防治措施分析

奶牛乳房炎也被称为奶牛乳腺炎,主要是因为奶牛感染病原微生物而引起的,其主要症状就是奶牛的乳房组织和乳头出现炎症.乳房炎是奶牛养殖中最常见的疾病,也是危害最严重且防止最困难的一种疾病.经常会给奶牛养殖户造成严重的经济损失.本文将对奶牛乳房炎的危害进行分析,并探讨其防治措施.     

安徽部分地区奶牛乳房炎病原菌的分离鉴定和药敏试验

为了调查安徽地区奶牛乳房炎流行情况和筛选病原菌敏感药物.采集了安徽省奶牛主要养殖区的隐性乳房炎奶样,分离、鉴定了主要病原菌,并筛选了敏感药物.结果表明,乳房炎主要病原菌为金黄色葡萄球菌、大肠埃希菌和无乳链球菌,且2种或2种以上病原菌混合感染占大部分,这些主要病原菌对环丙沙星、恩诺沙星、头孢曲松钠和卡那霉素等抗菌药物高度敏感,为奶牛乳房炎的治疗药物的选择提供了直接依据.     

规模化奶牛场临床型乳房炎病原菌的分离鉴定

为监测辽宁省某奶牛场奶牛乳房炎的主要致病菌,试验分离和鉴定奶牛乳房炎的主要致病菌.结果 显示,分离到致病菌为金黄色葡萄球菌、链球菌和大肠杆菌.研究结果表明,该养殖场奶牛乳房炎是由多种病原菌引起的.     

绿草素对奶牛乳房炎治疗效果

奶牛乳房炎是长期以来困扰奶牛养殖的主要常见病,据有关报道我国奶牛乳房炎临床型发病率达20%～60%.笔者应用绿草素治疗奶牛乳房炎,结果证明,绿草素与常用药青链霉素、氨苄青霉素等比较,对奶牛乳房炎的治疗有其明显的优势.     

奶牛乳房炎链球菌的分离与鉴定

奶牛乳房炎作为奶牛生产中最为常见、危害最大、经济损失最严重的一种疾病,给奶牛业造成了巨大的损失.对多种痛原菌引起的乳房炎的免疫效果不理想,抗生素仍是治疗奶牛乳房炎的首选药物.为此笔者利用实验室手段,对奶牛乳房炎病原菌进行分离与鉴定.通过对送检的乳样选择和接种适宜培养基分离细菌,进行药敏试验和菌种鉴定,以确定病原菌感染,达到对症治疗的目的.     

奶牛乳房炎病原菌抗生素耐药性研究进展

奶牛乳房炎是影响世界奶牛养殖业发展的最重要疾病之一,病原菌感染,尤其是葡萄球菌、链球菌和肠道菌感染是其最主要的病因。目前,抗生素治疗奶牛乳房炎仍然是最常用及最有效的方法,然而,由于抗生素不合理及大量滥用,导致奶牛乳房炎病原菌产生耐药性,且耐药菌株呈不断增多趋势,甚至出现超级耐药菌株,为奶牛乳房炎的临床治疗带来了很大的挑战。因此,文章从奶牛乳房炎主要致病菌耐药现状、耐药变化规律、产生耐药性的原因及如何减少耐药性等方面进行了综述,以期为规范临床使用抗生素和进一步提高奶牛乳房炎治疗效果提供帮助。     

Staphylococcus aureus isolates from dairy cows and humans on a farm differ in coagulase genotype

Staphylococcus aureus is a frequent cause of animal and human infections. The aim of the present study was to test diversity of the populations of S. aureus colonising cattle and humans sharing an infected environment. Eighty-six S. aureus isolates obtained from dairy cows, from people coming into contact with dairy cows on the farm and the other farm personnel were characterized by restriction fragment length polymorphism of the coagulase gene. Molecular analyses identified ten polymorphism types with prevalent presentation of type II in isolates from cow's milk and type IV in isolates from people coming into contact with dairy cows on the farm (the cattlemen) and the other farm personnel. Seven further genotypes were identified among the isolates from the cattlemen. The results indicate that the strains dominating in human population did not equate to the causative agents of bovine mastitis.     

奶牛金黄色葡萄球菌性乳房炎研究进展

奶牛乳房炎是对世界奶牛业造成经济损失最大的疾病之一,它不仅直接导致乳品工业的经济损失,而且由于患乳房炎的奶牛其乳汁中经常含有大量的毒素、病原微生物以及治疗后残留的抗生素,使得该病日益引起公众的关注。金黄色葡萄球菌是奶牛乳房炎的主要病原,由于其极易产生耐药性,使得治疗变得相当困难,因此使用预防或治疗性疫苗防治乳房炎就成为首选。金黄色葡萄球菌对上皮细胞的黏附和侵袭力被认为是奶牛金黄色葡萄球菌性乳房炎的主要致病机制,金黄色葡萄球菌的致病力涉及到许多不同的毒力因子,如黏附素、荚膜、各种毒素和酶类等。研究表明,以这些毒力因子为靶位进行疫苗研究,可能是预防奶牛金黄色葡萄球菌性乳房炎的有效途径。     

Coagulase-negative staphylococci-emerging mastitis pathogens

Coagulase-negative staphylococci (CNS) have become the most common bovine mastitis isolate in many countries and could therefore be described as emerging mastitis pathogens. The prevalence of CNS mastitis is higher in primiparous cows than in older cows. CNS are not as pathogenic as the other principal mastitis pathogens and infection mostly remains subclinical. However, CNS can cause persistent infections, which result in increased milk somatic cell count (SCC) and decreased milk quality. CNS infection can damage udder tissue and lead to decreased milk production. Staphylococcus simulans and Staphylococcus chromogenes are currently the predominant CNS species in bovine mastitis. S. chromogenes is the major CNS species affecting nulliparous and primiparous cows whereas S. simulans has been isolated more frequently from older cows. Multiparous cows generally become infected with CNS during later lactation whereas primiparous cows develop infection before or shortly after calving. CNS mastitis is not a therapeutic problem as cure rates after antimicrobial treatment are usually high. Based on current knowledge, it is difficult to determine whether CNS species behave as contagious or environmental pathogens. Control measures against contagious mastitis pathogens, such as post-milking teat disinfection, reduce CNS infections in the herd. Phenotypic methods for identification of CNS are not sufficiently reliable, and molecular methods may soon replace them. Knowledge of the CNS species involved in bovine mastitis is limited. The dairy industry would benefit from more research on the epidemiology of CNS mastitis and more reliable methods for species identification.     

凉州区奶牛乳房炎主要病原分离鉴定及药敏试验

乳房炎是奶牛最常见的疾病,随着奶牛产业的蓬勃发展,乳房炎已经成为制约该产业的瓶颈之一。从甘肃省武威市凉州区5个奶牛养殖场采集了1 000头荷斯坦奶牛共计3 991份奶样,对临床型和非临床型(隐性)乳房炎分别通过临床症状和兰州隐性乳房炎诊断液(LMT)进行诊断。结果显示:该地区奶牛临床型乳房炎发病率18.20%,亚临床型乳房炎发病率36.50%,总阳性率54.70%,总阳性乳区率54.72%。从阳性奶样中分离纯化得到的主要病原菌为链球菌属、金黄色葡萄球菌和大肠杆菌,且在不同类型乳房炎中的分布情况不同,临床型中链球菌属最多(54.37%),亚临床型中金黄色葡萄球菌最多(48.56%)。对主要病原菌进行药敏试验,结果表明治疗凉州区奶牛乳房炎的最佳药物应为喹诺酮类和庆大霉素类。     

奶牛乳腺炎的细菌学研究

在对山东7个地区14个奶牛场临床型和隐性乳腺炎调查的基础上采集234头临床乳腺炎病牛乳样、241个隐性乳腺炎乳样并分别做了细菌学检查,结果表明:泌乳期临床型乳腺炎病原菌以凝固酶阴性葡萄球菌、金黄色葡萄球菌、链球菌、酵母菌和棒状杆菌为主;干奶期临床型乳腺炎病原菌以大肠杆菌、链球菌、金黄色葡萄球菌、凝固酶阴性葡萄球菌和酵母菌为主;隐性乳腺炎病原菌以凝固酶阴性葡萄球菌、金黄色葡萄球菌链球菌、酵母菌、假单胞菌和棒状杆菌为主;厌氧菌在隐性乳腺炎、干奶期乳腺炎和干奶期乳腺炎乳样的捡出率分别为 5．82％,4．17%,10．16％;隐性乳腺炎、干奶期乳腺炎细菌的共感染率较高,与泌乳期乳腺炎病原菌的差异极显著(P<0．01),隐性乳腺炎与干奶期乳腺炎病原菌共感染率差异不显著(P >0．05)。     

Altered leukocyte responsiveness in dairy cows with naturally occurring chronic Staphylococcus aureus mastitis

Changes in inflammatory parameters, leukocyte surface markers, functional responses and cytokine mRNA expression of leukocytes of dairy cows with naturally occurring chronic Staphylococcus aureus (S. aureus) mastitis and healthy cows were determined to elucidate the leukocyte responses to S. aureus infection of the mammary gland. Increased values in inflammatory parameters and matrix metalloproteinase activities in milk revealed the characteristics of cows with chronic mastitis. Expression of L-selectin and CD18 molecules on neutrophils and proportion of CD8 cells in milk from cows with S. aureus mastitis were significantly (P<0.05) increased compared with those found in healthy cows. The FcR-stimulated CL response of blood neutrophils was significantly (P<0.05) decreased in cows with S. aureus mastitis. Significantly (P<0.05) decreased mitogenic responses of lymphocytes were found in cows with S. aureus mastitis; however, the values were not restored to those of healthy cows when stimulated with both mitogens and the cytokine IL-1β. The mRNA expression of TNF-α, IL-1β and IL-8 on milk leukocytes from cows with S. aureus was found to be increased compared with that of healthy cows. The changes of immune responses found in cows with S. aureus mastitis appear to be influenced by the severity and duration of inflammation in infected quarters. The down-regulation of the leukocyte functions found in cows with S. aureus mastitis appears to be associated with the progress of the chronic stage of S. aureus mastitis.     

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...     

Longitudinal evaluation of CD4+ and CD8+ peripheral blood and mammary gland lymphocytes in cows experimentally inoculated with Staphylococcus aureus.

Staphylococcus aureus is a major pathogen associated with mastitis, a disease affecting both women and dairy cows. The longitudinal profiles of bovine peripheral blood and mammary gland lymphocyte phenotypes in response to S. aureus-induced mastitis were investigated in dairy cows. Increased percentage of CD4 lymphocytes in the mammary gland between 1 and 8 days post-inoculation, increased milk CD4 protein density per cell between 1-8 days post-inoculation, and a statistically significant negative correlation between post-inoculation bacterial counts in milk and blood lymphocyte CD4 protein density were found. Together with blood and milk leukocyte counts, the milk lymphocyte CD4/CD8 ratio and the milk lymphocyte CD4 protein density were more informative indicators than milk somatic cell counts and bacteriology for identification of early vs. late inflammatory phases. These findings suggest that CD4+ lymphocytes play a protective role in the early stages of S. aureus-induced mastitis.     

Staphylococcus aureus lipotechoic acid induces differential expression of bovine serum amyloid A3 (SAA3) by mammary epithelial cells: Implications for early diagnosis of mastitis

Mastitis is one of the most costly diseases of agriculturally important animals and is a common problem for lactating cows. Current methods used to detect clinical and especially subclinical mastitis are either inadequate or problematic. Pathogens such as the gram-positive bacterium Staphylococcus aureus or the gram-negative bacterium Escherichia coli typically cause mastitis. E. coli induces clinical mastitis, whereas, S. aureus causes a subclinical, chronic infection of the mammary gland. In this study we report the differential expression and secretion of mammary-derived serum amyloid A3 (SAA3) by bovine mammary epithelial cells following stimulation with the S. aureus cell wall component, lipotechoic acid (LTA). Two-dimensional immunoblot analyses confirmed that bovine SAA3 is the predominant SAA isoform produced by LTA stimulated mammary epithelial cells. Our previous study showed that bovine SAA3 is also differentially expressed in response to the gram-negative bacterial endotoxin lipopolysaccharide. Collectively, these data indicate that the local production of SAA3 by mammary epithelial cells in response to either gram-positive or gram-negative bacterial components may provide a sensitive indicator for early detection and treatment of mastitis in vivo, minimizing chronic cases of infection, the spread of mastitis to other animals, and economic losses.     

Effect of intramammary injection of RbIL-8 on milk levels of somatic cell count, chemiluminescence activity and shedding patterns of total bacteria and S. aureus in Holstein cows with naturally infected-subclinical mastitis

Summary The effect of intramammary injection of recombinant bovine interleukin-8 (rbIL-8, 1 mg/10 ml of saline) on quarter milk levels of somatic cell count (SCC), chemiluminescence (CL) activity and counts of total bacteria and Staphylococcus aureus (S. aureus) was investigated, using 10 Holstein cows with an early stage or a late stage of subclinical mastitis naturally infected with S. aureus. In the late-stage group, milk SCC and CL activity had significant rises with maximum levels at 6 h, following maintained high levels thereafter post-cytokine injection. The counts in milk total bacteria and S. aureus were insignificantly decreased, being increased back on day 7 post-cytokine injection. Thus, the cytokine was inefficient for the late-stage subclinical mastitis. However, in the early-stage group milk SCC and CL activity declined to under pre-injection levels on day 7 after marked and significant rises at 6 h and day 1 post-cytokine injection. The milk total bacterial count decreased significantly on days 0.25 and 2. Furthermore, the milk S. aureus count was decreased significantly on days 1, 2, 3 and 7 by the cytokine injection. These results suggest that the rbIL-8 has a potential as a therapeutic agent of the subclinical mastitis of dairy cows, if the cytokine is applied at an initial stage of infection.