头孢洛宁的药理作用及其在奶牛乳房炎防治中应用的研究进展

头孢洛宁是第2代头孢菌素类抗生素,是防治干乳期奶牛乳腺炎的有效药物,具有抗菌谱广、杀菌力强、过敏反应少、毒性低等优点,尤其对金黄色葡萄球菌、链球菌展现出良好的抗菌活性。文章综述了头孢洛宁的研究现状、理化性质、药理和毒理、药代动力学、残留及弃奶期及其在奶牛乳房炎防治中的应用,并对其应用前景作了展望。     

The usage of veterinary antibacterial drugs for mastitis in cattle in Norway and Sweden during 1990-1997.

The prescribing patterns and annual incidence of use of antibacterial drugs for the treatment of mastitis in cattle in Norway and Sweden during the period 1990-1997 were estimated from drug wholesaler statistics. Although the drugs included in this study are also used in other species and/or other indications, mastitis in cattle is by far the most-common indication for their use. We used these sales figures to evaluate trends in the use of antibacterial drugs and changes in the incidence of treatment in bovine mastitis in Norway and Sweden. To facilitate comparisons (correcting for differences in activity and dosage) between the relative proportions of antibacterial drugs used in bovine mastitis, we introduced defined daily dose cow (DDDcow) as unit of measurement. Tentative DDDcow for the various injectable drugs were derived from doses recommended in Norway and Sweden. For intramammary drugs administered in the form of single-dose applicators, one applicator was defined as the DDDcow. The prescribing patterns of antibacterial drugs in bovine mastitis in Norway and Sweden during the study period seemed to be influenced by treatment policies, substances and formulations approved and treatment cost; length of the withdrawal period also seemed to play a role.     

The use of some immunomodulators and non-antibiotic drugs in a prophylaxis and treatment of mastitis

Antibiotics are widely used in treatment and prophylaxis of mastitis, but their antibacterial and therapeutic efficacy continues to decrease. New methods of prophylaxis of mastitis with the use of vaccines and biological response modifiers are reviewed. Prophylactic activity of staphylococcal vaccines should be investigated in the future because of difficulties in successful treatment of infections caused by these organisms. Vaccination with J5 bacterin (0111:B4) reduced duration of IMI and local signs of clinical coliform-mastitis. Some immunomodulators proved to be effective in treatment of mastitis during lactating period. Promising results were obtained with the use of giseng saponin, herbal gel, herbal extracts, propolis, lysosubtilin, antibacterial proteins, and lysozyme dimer especially.     

抑制奶牛乳腺炎主要致病菌的中药复方筛选及其抗炎效果研究

为筛选和研究可有效抑制奶牛乳腺炎主要致病菌的中药复方及其抗炎效果,本文通过对黄连、黄柏、赤芍、苦参、连翘等5味中药进行正交试验设计组方,采用平板打孔法、试管二倍稀释法分别研究了各单味中药及其复方对金黄色葡萄球菌、停乳链球菌、无乳链球菌和大肠杆菌的体外抑菌效果,同时研究了筛选出的中药复方的不同剂型对二甲苯致小鼠耳肿胀的急性炎症和棉球致肉芽肿的慢性炎症的抑制效果。结果表明,4株菌对5味中药的敏感性强弱依次为无乳链球菌、停乳链球菌、金黄色葡萄球菌、大肠杆菌;中药方3和方7对4种菌的体外抑菌活性较强,且以方3的搽剂及膏剂对急、慢性炎症具有良好的抑制效果。本研究结果为研制防治临床奶牛乳腺炎的药物提供了试验依据。     

In vitro antimicrobial activity of Combretum molle (Combretaceae) against Staphylococcus aureus and Streptococcus agalactiae isolated from crossbred dairy cows with clinical mastitis

Following the rapidly expanding dairy enterprise, mastitis has remained the most economically damaging disease. The objective of this study was mainly to investigate the in vitro antibacterial activities of ethanol extracts of Combretum molle (R.Br.Ex.G.Don) Engl & Diels (Combretaceae) against antibiotic-resistant and susceptible Staphylococcus aureus and Streptococcus agalactiae isolated from clinical cases of bovine mastitis using agar disc diffusion method. The leaf and bark extracts showed antibacterial activity against S. aureus at concentrations of 3 mg/ml while the stem and seed extract did not show any bioactivity. Although both leaf and bark extracts were handled in the same manner, the antibacterial activity of the bark extract against the bacterial strains had declined gradually to a lower level as time advanced after extraction. The leaf extract had sustained bioactivity for longer duration. The susceptibility of the bacteria to the leaf extract is not obviously different between S. aureus and S. agalactiae. Also, there was no difference in susceptibility to the leaf extract between the antibiotic-resistant and antibiotic-sensitive bacteria. Further phytochemical and in vivo efficacy and safety studies are required to evaluate the therapeutic value of the plant against bovine mastitis.     

头孢噻呋及其在奶牛乳房炎治疗上的应用

奶牛乳房炎是高产奶牛最常见的疾病之一,对奶业的发展危害严重.目前,抗生素疗法是治疗该病的常用方法、头孢噻呋是第一个动物专用的第三代头孢菌素类抗生素,具有抗菌谱广、抗茵活性强、给药后吸收快、生物利用度高及生物半衰期长等特点、本文介绍了头孢噻呋的理化性质、作用机理、药代动力学、不良反应、药物残留等,并阐述了其在奶牛乳房炎治疗上的应用。     

利福昔明对奶牛乳房炎常见病原菌的体外抗菌活性试验

旨在测定利福昔明对奶牛乳房炎常见病原菌的体外抗菌活性。采用琼脂二倍稀释法测定利福昔明对奶牛乳房炎常见病原菌大肠杆菌、葡萄球菌和链球菌的最小抑菌浓度（MIC）。结果显示,利福昔明对19株大肠杆菌的MIC值为8~16μg/m L,对25株葡萄球菌的MIC值为0.002~0.06μg/m L,对18株链球菌的MIC值为0.06~2μg/m L。大部分临床分离菌的MIC值与标准菌的相近,表明分离菌株对利福昔明较为敏感,提示利福昔明对奶牛乳房炎常见病原菌具有较强的体外抗菌活性。     

Bacteriostatic activity of bovine lactoferrin in mastitic milk

The antibacterial activity of milk against a virulent strain of Escherichia coli was investigated using milk fractions from normal or inflamed glands. Mastitic whey exhibited either bactericidal or bacteriostatic activities, depending on whether bacteria were enumerated by the pour plate technique or by surface plating onto sheep blood agar. The former activity was not due to lactoferrin (Lf), which never exerted bactericidal activity, even when assayed in distilled water. Milk whey ultrafiltrate (UF) (mol. wt. less than 5000 d) was used to assay the ability of normal and mastitic milk to support the antibacterial activities of Lf against a strain of E. coli. The addition of purified Lf to UF from mastitic whey resulted in bacteriostasis, whereas Lf was without effect in UF from normal whey. It was concluded that Lf can actually slow down the growth of Lf-sensitive bacteria during mastitis, provided that plasma exudation takes place.     

Mammary expression of new genes to combat mastitis

Continual advances in the ability to produce transgenic animals make it likely that such animals will become important components of animal agriculture. The full benefit of the technology, and justification of its initial cost outlay, will be dependent on the establishment within these animals of new traits not easily achievable by other means. Potential applications include enhanced nutrient digestibility with reduced fecal losses, significantly altered milk composition with superior nutritional properties, and enhanced disease resistance. Our goal is to enhance mastitis resistance of dairy cows by enabling the cells of the mammary gland to secrete additional antibacterial proteins. Proof of concept has been obtained through experimentation with a transgenic mouse model. Three lines of mice were developed that produce varying levels of lysostaphin in their milk. This protein has potent anti-staphylococcal activity and its secretion into milk confers substantial resistance to infection caused by intramammary challenge with Staphylococcus aureus, a major mastitis pathogen. Additional antibacterial proteins are being sought that will complement lysostaphin. A potential benefit of transgenic application of antibacterial proteins is the concomitant sparing in the agricultural use of antibiotics currently used as human therapeutics. Antibacterial proteins, such as lysostaphin, are not typically used as injectable or oral therapeutics because of immune-mediated or digestive destruction of their activity. In contrast, the immune system of transgenic animals will not consider the transgenic protein as being foreign. In addition we are exploring the potential of involution or mastitis responsive promoter elements for use in subsequent transgenic experiments designed to restrict lysostaphin production to these important time points. It is anticipated that genomics will play a role in unveiling candidate genes whose promoter elements will enable desired temporal expression patterns. The transgenic approach to insertion of new genetic material into agriculturally important animals is feasible but requires extensive prior evaluation of the transgene and transgene product in model systems.     

Enhancement of antibacterial activity of tilmicosin against Staphylococcus aureus by solid lipid nanoparticles in vitro and in vivo

This study aimed to enhance the antibacterial activity of tilmicosin by solid lipid nanoparticles (SLN). Tilmicosin-loaded hydrogenated castor oil (HCO)-SLN was prepared using a hot homogenisation and ultrasonication method. The physicochemical characteristics of SLN were investigated by scanning electron microscopy (SEM) and photon correlation spectroscopy (PCS). The antibacterial activity of tilmicosin-SLN against Staphylococcus aureus was evaluated by growth inhibition and colony-counting method. A therapeutic study of tilmicosin-SLN was conducted by subcutaneous injection in a mouse mastitis model infected with S. aureus by teat canal infusion. Therapeutic efficacy was assessed by physical appearance of the mammary gland and measurement of colony-forming units (CFU) per gland. The results showed that the diameter, polydispersivity index, zeta potential, encapsulation efficiency and loading capacity of the nanoparticles were 343±26 nm, 0.33±0.08, -7.9±0.4 mV, 60.4±3.3% and 11.2±0.47%, respectively. Tilmicosin-SLN showed a sustained-release effect and sustained and enhanced antibacterial activity in vitro. SLN significantly enhanced the therapeutic efficacy of tilmicosin determined by lower CFU counts and a decreased degree of inflammation. These results demonstrated that the HCO-SLN is an effective carrier to enhance the antibacterial activity of tilmicosin.     

Antibacterial activity of thionin Thi2.1 from Arabidopsis thaliana expressed by bovine endothelial cells against Staphylococcus aureus isolates from bovine mastitis

Bovine mastitis is mainly caused by Staphylococcus aureus and antimicrobial therapy, commonly used for its control, has resulted in an increase in the frequency of resistant staphylococci in recent years. Thus, alternative therapies are desirable and the antimicrobial peptides represent attractive control agents. In this work, we expressed the antimicrobial peptide thionin Thi2.1 cDNA from Arabidopsis thaliana in the bovine endothelial cell line BVE-E6E7 and evaluated its activity against bovine mastitis S. aureus isolates. A polyclonal population from BVE-E6E7 cells transfected with the pThi2.1 construct was obtained and thionin Thi2.1 expression was confirmed by RT-PCR. From this population, eight stably transfected cell clones were obtained and their conditioned media (CM) were evaluated against the S. aureus ATCC 27543 strain. Clones showed high antibacterial activity (>95%) relative to the activity of the polyclonal population. The C8 clone showed the highest antibacterial activity (>99%) and its CM was evaluated against eleven bovine mastitis S. aureus isolates. A 2.5microg aliquot of total protein from the C8 clone's CM inhibited the growth of S. aureus isolates (>40%) relative to the CM from BVE-E6E7 cells used as control. Growth inhibition of S. aureus isolates was dose-dependent, showing a total inhibition at concentrations higher than 3.12microg/ml. These results suggest that thionin Thi2.1 antimicrobial peptide could be use in the treatment of bovine mastitis.     

新疆石河子地区奶牛乳房炎大肠杆菌的分离鉴定及耐药性分析简

本试验旨在调查新疆石河子地区奶牛乳房炎源大肠杆菌的某些生物学特性及其耐药状况,以提高药物疗效,减少牛奶中药物的残留。试验从新疆石河子地区患乳房炎奶牛的乳样中分离纯化并鉴定出21株大肠杆菌,并对大肠杆菌分离株进行抗菌药物敏感性分析。结果表明,21株大肠杆菌对21种抗菌药物中的6种药物耐药率超过50%,其中最多的耐药15种,最少的耐药5种,耐药6及6种以上的菌株共占到76.19%。提示,该地区奶牛乳房炎源大肠杆菌对多种药物已产生了不同程度的耐药性,且存在严重的多重耐药情况。     

Mastitis therapy and pharmacology.

Mastitis remains the most frequent cause of antibacterial use on dairy farms and contributes to a substantial portion of total drug and veterinary costs incurred by the dairy industry. Ultimately, the best outcome of mastitis therapy is a positive effect on the amount of marketed milk harvested and long-term survival of the cow. This article describes the strategies of therapy for bovine mastitis, with an emphasis on antibacterial and anti-inflammatory therapy.     

中药"乳源康"药理作用研究

为了对“乳源康”的毒理药理学进行研究,进行4种试验——急性毒性试验、抗菌试验、局部刺激试验、抗炎试验。结果表明,①“乳源康”的小鼠口服LD50为36．80g／kg体重,腹腔注射LD50为13．85g／kg体重;②“乳源康”对乳房炎致病菌金黄色葡萄球菌、链球菌等有较强的抑制作用;③无明显刺激作用;④“乳源康”注射液与氢化可的松的消炎效果相同。“乳源康”治疗奶牛乳房炎具有高效、安全、低毒、使用方便、无化学药物和抗生素残留的优点,临床应用对治疗奶牛乳房炎、解决乳制品中的抗生素类药物残留以及病原微生物的耐药性问题具有重要意义。     

中草药对奶牛乳房炎致病菌的体外抑菌效果

选择常用6味中草药煎剂及中药复方制剂,采用试管二倍稀释法,对所分离的3种致病菌进行抑菌试验,并测定了最小抑菌浓度（MIC）和最小杀菌浓度（MBC）. 体外抑菌试验结果表明：鱼腥草对大肠杆菌有较强的抑菌活性,MIC为62.5 g/L.野菊花、连翘、金银花对金黄色葡萄球菌有较强的抑菌活性,MIC分别为15.7、31.3和31.3 g/L.金银花、连翘对无乳链球菌有较强的抑菌活性,MIC为15.7和31.3 g/L.而复方中金银花＋野菊花＋连翘相对其它4个组方对3种致病菌都有较强的抑菌活性.     

Low expression of the antibacterial factor L‐amino acid oxidase in bovine mammary gland

In the mouse, L‐amino acid oxidase (LAO) produces hydrogen peroxide by utilizing free amino acids and is a proven antibacterial factor in mammary glands. Mastitis, a bacterial infection of the mammary gland, is the most frequent disease in dairy cattle. Here, we investigate whether LAO is expressed in the mammary gland of dairy cattle and is antibacterial. In dairy cattle, the expression level of LAO mRNA in the mammary gland was considerably lower than that in mice, and LAO activity was not observed in cattle milk that produced hydrogen peroxide. The expression of LAO mRNA was also low in Japanese Black cattle, the same as in Holstein cattle. A higher LAO mRNA expression was observed in the mastitis glands than in the lactating glands. Furthermore, spleen and lymph nodes expressed high levels of LAO mRNA in dairy cattle. We conclude that mammary glands in dairy cattle have lower ability to express the LAO gene compared to that in mice, which may result in a high incidence of mastitis.     

中草药饲料添加剂对奶牛乳房炎的影响研究进展

奶牛乳房炎制约了奶牛养殖业的快速发展,目前奶牛乳房炎的预防与治疗主要依靠抗生素,抗生素的滥用和乱用对人、动物、生态环境的危害越发严峻,寻找安全有效的防治措施尤为重要。中草药及其提取物具有良好的抗菌、消炎等功效,且安全、绿色、无残留,能有效抑制病原菌,缓解炎症反应,改善泌乳功能,成为防治奶牛乳房炎的热点课题。因此,本文对中草药饲料添加剂对奶牛乳房炎的影响研究进展进行综述,为中草药及其提取物的开发利用、奶牛乳房炎防治提供可行的参考依据。 [关键词] 中草药|提取物|奶牛乳房炎|抗生素|饲料添加剂     

Antibacterial activity of bovine lactoferrin hydrolysate against mastitis pathogens and its effect on superoxide production of bovine neutrophils

Antibacterial activity of bovine lactoferrin hydrolysates (LFH) on microorganisms isolated from bovine mastitis, and superoxide (O(2)(-)) production of bovine neutrophils were evaluated. Antibacterial effects of LFH were measured in vitro against Staphylococcus aureus, coagulase-negative staphylococci, Streptococci, Enterococci, Escherichia coli, Klebsiella pneumoniae, yeast-like fungi and Prototheca zopfii isolated from clinical cases of bovine mastitis. To compare susceptibilities against LFH, minimal inhibitory concentration (MIC) values were determined by a micro-plate assay method. Most organisms were sensitive to LFH. Prototheca zopfii was highly sensitive to LFH; the growth of the microorganism was inhibited completely even at 1 mug/ml. Staphylococcus aureus and Escherichia coli were resistant to LFH. The production of O(2)(-) by bovine neutrophils was used to evaluate the effect of LFH administration on functional activity. Increase in O(2)(-) production by bovine neutrophils occurred upon addition of LFH to neutrophils. These results demonstrate that LFH possesses antibacterial activity against pathogens that cause mastitis and activates neutrophil superoxide production.     

Effect of frequent milkings on milk NAGase, plasmin, trypsin inhibitory capacity and the quality of whey as the growth medium for mastitis pathogens

Unequal milking intervals affected milk somatic cell count and N-acetyl-beta-D-glucosaminidase (NAGase) activity. The total daily output of milk NAGase and plasmin decreased, if quarters were emptied frequently during the day. Mastitis pathogens showed stimulated growth in whey prepared from filled quarters as compared with growth in whey from quarters emptied frequently during the day. The quality of whey as growth medium for mastitis pathogens paralleled plasmin activity in respective milk samples. Adaptation of mastitis pathogens to grow in whey had an enhancing effect on bacterial growth during subsequent inoculations in whey. Bacteria probably "learn" to overcome the effect from endogenous antibacterial factors and to use nutrients present in whey.     

乳酸链球菌素治疗奶牛乳房炎效果观察

乳酸链球菌素（Nisin）是由乳酸链球菌产生的合有34个氨基酸的抗菌肽,对人体无害。本研究将患临床型乳房炎奶牛92头（107个乳区）和隐性乳房炎奶牛90头（90个乳区）随机分成试验组和对照组。试验组的治疗方法是在患病乳区灌注Nisin;临床型乳房炎以庆大霉素乳房内灌注作对照,隐性乳房炎的对照组不作任何处理。临床型乳房炎的Nisin治疗组细菌学治愈率和临床治愈率分别为60．8％和90．2％,而庆大霉素治疗组则分别为44.6％和91．2％,两者无统计学差异。隐性乳房炎经Nisin治疗后,高体细胞数奶牛的数量和牛奶中NAGase的活性均显著下降,细菌转阴率提高。乳酸菌发酵试验表明,经Nisin乳房内灌注治疗临床型乳房炎后,牛奶在第36小时恢复正常发酵,而庆大霉素治疗则需要72h。