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%。     

奶牛乳房炎的诊治

近年来．随着集约化养殖业的不断发展，抗生素预防和治疗水平的提高和中兽医研究的进一步深入，通过中草药的免疫调节和严格的泌乳期和干奶期乳房抗生素预防和乳头药浴．奶牛隐性乳房炎的检出率有所下降，但由于引起奶牛乳房炎的病原较为复杂、病因也很多．受不同地区、不同气候的影响，导致临床性乳房炎的发病率和危害性仍然居高不下，也给乳房炎的防治工作带来了很大的困难．     

地塞米松及抗生素治疗奶牛乳房炎

1991～ 1998年 ,笔者使用地塞米松磷酸钠及抗菌素注入奶牛乳房内治疗奶牛乳房炎 80例 ,其中泌乳期患乳房炎 72例、干奶期 2例、分娩期乳房炎 6例。1　治疗方法　　先将患病乳房内残留液挤净 ,再用 2 5 %酒精将乳头消毒 ,取加温 5～ 10℃生理盐水 2 0 0～ 40 0ｍＬ ,用通乳针注入乳房然后至上而下进行按摩 3～ 5ｍｉｎ ,再挤净清洗液。重症者可增加清洗次数 1～ 2次。　　用青霉素钠 80～ 12 80万单位、链霉素 10 0～ 80 0万单位、地塞米松磷酸钠 2 5～ 2 0 0ｍｇ、生理盐水 5 0～ 40 0ｍＬ混合后送入乳房内 ,剂量按炎症程度来加减用量。注入…     

奶牛乳房炎抗生素防治失败原因探讨

奶牛乳房炎主要由病原微生物引起,抗生素的应用在奶牛乳房炎控制中起了重要作用。本文着重从病原微生物—宿主—抗生素三个方面及相互作用关系中论述了奶牛乳房炎抗生素治疗失败的机制,包括:抗生素的选择、吸收、分布及抗生素的细胞内分布;细菌的被动选择、耐药性和细胞内寄生;细菌对吞噬细胞功能的影响,抗生素对吞噬细胞功能的影响及乳腺的重新感染。     

奶牛乳房炎的抗菌药物防治（续）

3抗菌药物的选用及其防治乳房炎的临床药效不同的病原微生物所引起的临床型乳房炎常具有相似的临床症状,病原菌的确诊只能靠细菌学检查。对于临床型乳房炎,治疗一开始选用广谱抗菌药物,或通过抗菌药物的联合达到广谱抗菌效果。由于多数革兰氏阴性菌,特别是大肠杆菌引起的乳房感染有较高的自愈率,有时也选用针对革兰氏阳性菌有效的抗菌药物卜‘。抗菌药物选用是否恰当,可通过体外药敏试验来确定。与治疗任何感染一样,治疗乳房炎药物必须能在感染的乳房内达到足够浓度以超过对已知病原的最小抑菌浓度（MIC）,并维持适当时间。因此,…     

奶牛乳房炎无药残治疗方法

奶牛乳房炎是危害奶牛生产最主要的疾病之一.传统治疗奶牛乳房炎的方法是注射抗生素,此法虽有一定的治疗效果,但也带来了奶中易残留抗生素和病原易产生抗药性等弊端.下面介绍几种无药残治疗奶牛乳房炎的方法.     

奶牛乳房炎研究进展

奶牛乳房炎是体内外环境因素作用下,多种非特定病原微生物感染所致奶牛乳腺的炎性过程。正常乳房应是外部无任何病变,从乳房挤出的乳中没有病原微生物,细胞数正常者。认为乳中体细胞数(特别是白细胞数)是最适当的标准,当挤出的乳中的细胞数每毫升在50万以下,无病原微生物时为正常分泌,有病原微生物时为隐性感染,当挤出的乳中细胞数每毫升在50万以上,无病原微生物     

奶牛乳房炎防治

本镇饲养奶牛有悠久的历史 ,随着人民的生活水平不断提高 ,奶牛存栏数逐年上升 ,东北塘镇饲养奶牛在江苏省享有奶牛之乡之称。本病是成年泌乳奶牛的常见病、多发病 ,严重危害奶牛业健康发展 ,影响产奶量 ,造成较大的经济损失。笔者经多年 (二千余病例 )的实践与探讨 ,谈下列体会 :1　病因本病在临床上表现有急性期、亚急性期和慢性期。引起牛乳房炎的原因很多 ,主要表现以下几种 :( 1 )细菌和真菌的感染。如葡萄球菌、化脓性棒状杆菌、绿脓杆菌、链球菌、大肠杆菌、布氏杆菌等 ,通过乳头管进入乳腺组织 ,带菌的手、毛巾、桶等都是感染源 ,机…     

奶牛化脓性乳房炎的诊治

本文使用中西结合的方法,在巴里冲县大河兽医站工作期间,对接诊的三例化脓性乳房炎的疾病进行了治疗,其中一例完全治愈,另外二例基本好转,为乳房炎的治疗效果的研究提供了有关的临床资料,并在临床具有一定的意义.     

Bovine mastitis caused by Prototheca zopfii: a case study

An outbreak of severe indurative mastitis in newly calved cows, from which Prototheca zopfii was isolated, is described. The refractory nature of this type of mastitis and the ineffectiveness of the presently available intramammary preparations are highlighted.     

Field experience with d‐biotin supplementation to gilt and sow feeds

At a pig breeding farm with 130 sows, the culling rate in respect of the young replacement stock was more than 50% and was in particular caused by lameness.

The effect was investigated of d‐biotin supplementation of the feed on culling percentage, reproduction, claw lesions and lameness of gills (young replacement stock) and sows, and piglet mortality. The young pigs were divided into a group of 23 young replacement pigs aged 2.5 months (12 controls and 11 treated) and a group of 47 gilts aged 7 months (23 controls and 24 treated). Both treatment groups received feed supplemented with 1250 mcg / kg d‐biotin. Furthermore, all sows received feed supplemented with 500 mcg / kg d‐biotin. The basic feed contained 175 mcg / kg biotin, of which about 100 mcg / kg was biologically available biotin.

Biotin supplementation resulted in an increase in the plasma biotin levels from the critical deficiency level of about 50 ng / 100 ml to about 300 ng / 100 ml in young replacement stock, to about 179 ng / 100 ml in the gilts, and to about 123 ng / 100 ml in the sows.

After 2.5 months of biotin supplementation the claw lesion score of the gilts had decreased by 28% (p < 0.001). In the young replacement stock a reduction of the claw lesion score by 52% (p<0.001) was found after 4 months supplementation.

The effect of biotin supplementation was greatest in the soft heel region (improved by 35%) and somewhat less on the claw wall (improved by 23%).

After 11 months’ supplementation with 500 mcg / kg biotin the effects on production performance of the sows compared to the previous year can be summarized as follows: - the overall culling rate dropped from 54.0% tot 30.8%,

- the culling rate due to lameness decreased by 11% from 25% to 14%,

- the culling as a result of ‘insufficient production’ was reduced from 11% to 4%,

- a positive trend in piglet mortality was observed (17.7% compared to 19.2%).

An increase of the biotin content of Dutch pig feeds and regular monitoring of its biotin content would appear to be advisable.     

Bovine Mastitis due to Prototheca zopfii: Clinical,Epidemiological and Pathological Aspects in a Brazilian Dairy Herd

The clinical, epidemiological and pathological aspects of protothecal mastitis in a Brazilian dairy herd are described. Prototheca zopfii infection was diagnosed in 11 of 121 milking cows. Clinical mastitis refractory to usual therapy was observed in 7 cows. Several environmental conditions conducive to the growth of Prototheca spp., such as wetness, muddiness and the presence of organic material, were present in the dairy. Improper milking practices and insanitary infusion of the intramammary antibiotics were also observed. Six cows with protothecal mastitis were slaughtered and the affected quarters of each cow were examined by histology and immunohistochemical staining for bovine keratin and P. zopfii. The histological lesions were characterized by interstitial infiltrates of macrophages, plasma cells and lymphocytes; algae were seen in the alveolar lumen and interstitium. The lack of a positive reaction with an antiserum against bovine keratin in the mammary alveolar epithelial layer in some affected areas suggests destruction of milk-producing tissues, which may be related to the low milk production observed. The algal organisms stained positively with a polyclonal antibody against P. zopfii.     

A survey of Prototheca bovis infection in dairy farms of the Hubei province,China

Bovine mastitis, caused by Prototheca bovis, has received much attention worldwide. To investigate the status of P. bovis infection in dairy farms of Hubei, we collected 1,158 milk samples and 90 environmental samples from 14 dairy farms of Hubei, China. The isolates were identified with traditional biological methods and molecular biological techniques, and their pathogenicity was tested through mice infection experiments. Isolates from 57 milk and 20 environmental samples were identified as P. bovis. The mice infection tests proved that the isolated P. bovis could cause mastitis in mice, manifesting as severe red swelling of the mammary glands. Histopathological analysis of tissue sections showed necrosis and nodules lesions formed in the infected mice mammary tissue, accompanied by macrophage and neutrophil infiltration. These results suggested the existence of pathogenic P. bovis in dairy farms of the Hubei province, China, with brewer’s grains and fresh feces possibly playing important roles in the spread of this disease.     

Prototheca zopfii mastitis in a herd of dairy cows

Mastitis caused by the colourless alga Prototheca zopfii was diagnosed in 17 of 120 cows in a dairy herd. Infection occurred in animals varying from 3-14 years old and was present in one to four quarters of each cow. Nine cases were associated with clinical mastitis characterised by the presence in milk of flakes or small clots. Somatic cell counts consistent with subclinical mastitis (>500 x 10(3) cells/ml) were recorded in five of the eight remaining cows. Histological examination of udder tissue showed the presence of granulomatous lesions associated with the presence of Prototheca. The problem was identified and controlled by repeated microbiological examination of milk samples from all lactating cows and immediate culling of infected animals. P. zopfii was also recovered from environmental water samples on this farm. It is suggested that infection may have occurred as a result of teat sores caused by trauma from a milking machine, and the tendency for cows to lay down on a race, the surface of which was sometimes flooded by drain water in which Prototheca were present.     

Prototheca zopfii mastitis in a herd of dairy cows

Mastitis caused by the colourless alga Prototheca zopfii was diagnosed in 17 of 120 cows in a dairy herd. Infection occurred in animals varying from 3–14 years old and was present in one to four quarters of each cow.

Nine cases were associated with clinical mastitis characterised by the presence in milk of flakes or small clots. Somatic cell counts consistent with subclinical mastitis (>500 × 10³ cells/ml) were recorded in five of the eight remaining cows.

Histological examination of udder tissue showed the presence of granulomatous lesions associated with the presence of Prototheca.

The problem was identified and controlled by repeated microbiological examination of milk samples from all lactating cows and immediate culling of infected animals.

P. zopfii was also recovered from environmental water samples on this farm. It is suggested that infection may have occurred as a result of teat sores caused by trauma from a milking machine, and the tendency for cows to lay down on a race, the surface of which was sometimes flooded by drain water in which Prototheca were present.     

Prototheca zopfii mastitis in dairy herds under continental climatic conditions

In the last 2 years 223 cases of bovine mastitis caused by Prototheca zopfii infection were identified in 32 large-scale dairy herds. All of these farms were in Hungary, which has a continental type, temperate zone climate. Both the sporadic and epidemic forms of P. zopfii mastitis were observed. All the herds affected by the epidemic form had poor hygienic conditions and suffered from several managerial faults, but no specific predisposing factors could be identified. In almost all of the cases, the type II variant of this pathogen was isolated; however, the type III variant was isolated from three cows. The cows had a higher chance of new infection in the early weeks of lactation and in the summer. The P. zopfii infection usually resulted in a chronic subclinical, or mild clinical, inflammatory process in the udder, and was followed by a dramatic loss in milk production and a permanent increase in somatic cell count. The histopathological findings could be characterized as a progressive interstitial mastitis associated with alveolar atrophy. The self-recovery rate was very low.     

MALDI-TOF MS identification of Prototheca algae associated with bovine mastitis

We evaluated the use of MALDI-TOF MS for the identification of 3 major, dairy-associated Prototheca species, namely, Prototheca bovis (formerly P. zopfii genotype 2), P. blaschkeae, and P. ciferrii (formerly P. zopfii genotype 1). The MALDI-TOF MS spectra established for those species were introduced into the reference spectra library of the Bruker Biotyper MALDI-TOF MS analysis software. Next, 31 Prototheca isolates from Holstein cows with mastitis, from herds located in the midwestern area of São Paulo State, Brazil, were subjected to MALDI-TOF MS profiling. MALDI-TOF MS allowed identification of 22 of 27 P. bovis and 3 of 4 P. blaschkeae isolates with scores >2.0, with 5 of 27 P. bovis and 1 of 4 P. blaschkeae isolates identified only to the genus level. With our extended algae database, MALDI-TOF MS can contribute to quick and effective speciation of Prototheca from mastitis cases.     

Review of the microbiological, pathological, and clinical aspects of bovine mastitis caused by the alga Prototheca zopfii

The mastitis caused by P. zopfii alga is a disease of high-producing, machine-milked dairy cows. It occurs worldwide in tropical and temperate climatic areas, and mostly appears sporadically in a therapy-resistant form. However, in poorly managed dairy herds it may be endemic, causing serious economic losses as a result of decreased milk quality and quantity and culling of infected animals. The biological properties of this pathogenic alga, the laboratory methods available for its isolation and identification, the pathological and clinical features of this form of mastitis, and the principles of its control are reviewed in this paper.     

Occurrence of Prototheca zopfii, a mastitis pathogen, in milk

Prototheca zopfii was isolated from cow-composite milk and bulk tank milk by a new selective Prototheca enrichment method. Repeated testing of cow-composite milk from individual cows resulted in P. zopfii isolation data indicating a strong statistical correlation of P. zopfii with specific cows. Prototheca sp. were isolated from the milk of 31 of 79 cows in a single herd, and contamination was discounted as the source. Prototheca sp. were also recovered from 28 of 787 bulk tank milk samples from the Eastern U.S.A., and 22 of 69 temperature control milk samples from pooled dairy farm milk from delivery trucks.