奶牛乳房炎金黄色葡萄球菌荚膜多糖研究概况

金黄色葡萄球菌是引起奶牛乳房炎的一种主要致病菌,其中94%～100%的金黄色葡萄球菌都含有荚膜多糖.荚膜多糖共分11个血清型(CP1～CP11),而5型和8型占临床分离株的70%～80%,为优势血清型;由于荚膜多糖的抗吞噬作用和黏附作用,决定了金黄色葡萄球菌的致病性和免疫原性.因此,基于荚膜多糖的疫苗可能是更有效的抗奶...     

Phage typing of Staphylococcus aureus strains isolated in Sweden from bovine milk.

Both the human and the bovine international sets of phages were used for typing of 372 bovine Staphylococcus aureus (Sa) strains, whereas the bovine set alone was used for typing of a further 1183 strains. In addition, 338 of the strains were tested for antibiotic sensitivity. Out of 372 Sa strains 85.5% could be typed with the human and 89.8% with the bovine phage set. Of all the 1555 Sa strains used 92.4% were lysed by the bovine phage set. Several phage types can be present in one and the same herd and some of them can predominate. Resistance to most of the tested antibiotics was very low. The incidence of resistance to penicillin and ampicillin was 10.0% and 4.4% respectively.     

环状RNA Circ0000316在大肠埃希氏菌和金黄色葡萄球菌诱导的奶牛乳腺上皮细胞炎症模型中的表达研究

奶牛乳腺炎是奶牛场的多发病和常发病,在世界各地的养殖场均有很高的发病率.环状RNA(circular RNA,circRNA)作为近年来被广泛研究的非编码RNA在奶牛乳腺炎发生过程中也发挥了 一定的作用.采集患有乳腺炎的奶牛乳腺组织和健康乳腺组织检测circ0000316的表达量,同时采用大肠埃希氏菌(Escheric...     

分光光度法测定金黄色葡萄球菌菌液浓度方法的建立

为了建立一种通过吸光度测定,能够快速准确检测奶牛乳房炎多联苗中金黄色葡萄球菌抗原浓度的方法。用血平板培养至生长高峰期的金黄色葡萄球菌用生理盐水将菌苔洗下,稀释成不同浓度的细菌悬浮液,然后用平板计数法测定不同浓度菌液的活菌数,同时在波长450 nm 条件下测定其相应的吸光度,进而研究两者之间的相关性。结果表明,金黄色葡萄球菌的细菌数与其吸光度呈直线线性相关。建立了金黄色葡萄球菌菌液浓度与吸光度之间的回归方程式 y＝8．4106x－0．2726（R2＝0．9758）。通过测定细菌悬浮液的吸光度,可以快速计算出该菌的菌液浓度。为了验证该方法的准确性,通过平板培养了4批金黄色葡萄球菌菌液,进行了传统平板计数方法和吸光度法的比较和验证,证明吸光度测定法更为简单、快速和准确,且优于平板计数法,可以作为奶牛乳房炎多联苗中金黄色葡萄球菌抗原浓度的测定方法。     

原料乳和临床乳房炎金黄色葡萄球菌毒力基因检测及药敏分析

对临床乳房炎（57株）和原料乳（44株）金黄色葡萄球菌菌株,用PCR方法检测mecA基因、PVL基因、ETs基因、SEs基因和TSST-1基因;采用CLSI指导说明执行琼脂稀释法药敏性试验。结果显示原料乳菌株中,84.09%携带有毒素基因,其中PVL的检出率为84.09%,肠毒素的检出率为52.27%,主要流行的肠毒素基因为sea（56.82%）,均未检测到携带mecA、ETs、TSST-1、sei和sej基因的菌株;同时得到10种毒素基因型,其主要流行的毒素基因型为PVL＋sea（29.55%）和PVL（27.27%）。临床菌株中,78.95%携带有毒素基因,其中PVL的检出率为28.07%,肠毒素的检出率为77.19%,主要流行的肠毒素基因为sea（47.37%）,没有检测到携带ETs、TSST-1和seh基因菌株;同时得到25种毒素基因型,其主要流行的毒素基因型为sea（19.30%）,其次是seb（7.02%）,sea＋sed＋sej（3.51%）和PVL＋sea＋seb＋sec＋seg＋sei（3.51%）。6株（10.53%）携带有mecA基因菌株均含有较多毒素基因。原料乳分离株对甲氧苄啶和头孢西丁的耐药率较高,分别为100%和86.36%,其次对氯霉素、红霉素、苯唑西林、头孢哌酮和庆大霉素的耐药率分别为11.36%、4.55%、2.27%、2.27%和6.82%,所有原料乳菌株均对环丙沙星敏感,同时得到8种耐药谱,多重耐药率达22%;临床乳房炎菌株对红霉素和甲氧苄啶的耐药率较高,分别为100%和71.93%,其次对氯霉素、庆大霉素、环丙沙星、头孢西丁和苯唑西林的耐药率分别为28.07%、26.07%、24.56%、19.30%和7.02%,临床乳房炎菌株对头孢哌酮和四环素的敏感率为100%,同时得到13种耐药谱,多重耐药率达77.19%。所有原料乳和临床乳房炎菌株均对万古霉素和阿米卡星敏感。临床乳房炎菌株携带的毒素基因和多重耐药率比原料奶菌株高,同时在临床乳房炎乳中检测到MRSA菌株,提示我们应加强乳及其乳制品的管理,并对奶牛乳房炎加以重视。     

Enhanced virulence of Staphylococcus aureus from bovine mastitis induced by growth in milk whey

The virulence towards mice of Staphylococcus aureus strains from bovine mastitis was enhanced upon growth in milk whey compared to homologous organisms grown in tryptic soy broth (TSB). In the mouse mastitis model, S. aureus grown in milk whey caused more severe lesions than homologous strains grown in TSB. Staphylococcus aureus strain F1440 grown in milk whey induced 75% mortality and local necrotic reaction in subcutaneously inoculated mice, whereas the homologous strain grown in TSB caused only 5% mortality and slight skin reaction. Extracellular capsule on milk whey-grown, S. aureus could not be demonstrated. However, diffuse type colony morphology could be correlated with an increased virulence of S. aureus towards mice.     

利用体外抑菌试验确立奶牛乳腺炎抗菌蒙药组方

为使治疗奶牛乳腺炎的抗菌蒙药组方达到最佳抑菌效果,针对从乳房炎牛奶中分离出的大肠埃希菌和金黄色葡萄球菌,采用牛津杯法对23味蒙药进行体外抑菌试验,筛选出对这两种致病菌均敏感的12味蒙药.根据部分药物抑菌浓度试验选取其中7味蒙药,结合体外抑菌试验,通过L8(27)正交试验设计,筛选出最佳抑菌药物组合,并通过L9(34)正交试验设计优化用药剂量.结果表明,结合正交设计和体外抑菌试验所确立的抗菌蒙药组方的抗菌效果显著强于各单药抑菌效果.     

Induction of anti-phagocytic surface properties of Staphylococcus aureus from bovine mastitis by growth in milk whey

The respiratory burst activity of bovine polymorphonuclear (PMN) cells in response to milk whey- and TSB-grown S. aureus strains isolated from bovine mastitis was studied in whole blood chemiluminescence (CL) and in a CL system with purified bovine neutrophils. In both cases milk whey-grown S. aureus strains elicited significantly less CL than homologous strains grown in TSB. Ingestion of milk whey-grown S. aureus strains by bovine neutrophils was also considerably lower than that of the corresponding homologous organisms grown in TSB. Binding of complement factor C3 to serum-opsonized milk whey-grown S. aureus strains was lower compared with TSB-grown homologous organisms. Moreover, 5 of 6 S. aureus strains grown in milk whey were significantly more resistant to in vivo clearance from the peritoneal cavity of mice compared with homologous bacteria grown in TSB. S. aureus strains grown in TSB exhibited hydrophobic surface properties, whereas homologous strains grown in milk whey were hydrophilic.     

奶牛乳房炎金黄色葡萄球菌的分离鉴定

为检测江苏省某奶牛场中乳房炎是否为金黄色葡萄球菌所致,采取4份患病乳汁样本进行试验分离和鉴定,并针对金黄色葡萄球菌采用分离后鉴定,结果显示,分离到的2株致病菌为金黄色葡萄球菌,其他菌株还包括大肠杆菌、肠球菌等,为多种致病病原菌同时引起,主要为金黄色葡萄球菌感染。     

Mastitis in mink due to Staphylococcus aureus and Escherichia coli

An epizootic of mastitis in mink due to Staphylococcus aureus and Escherichia coli associated with food poisoning was studied on a Connecticut ranch with 3,500 mink. In the course of the epizootic, approximately 2,000 mink kits and 480 adult mink, mostly nursing females, died within 10 days. Affected females had swollen mammary glands due to acute mastitis; S. aureus was isolated in pure culture from 2 mink and E. coli in pure culture from a 3rd. Staphylococcus aureus was isolated from the organs of 1 mink kit, S. aureus and E. coli from a 2nd kit, and E. coli from a 3rd. The organs of the remaining 7 kits examined did not contain bacteria. Both isolates were pathogenic when inoculated intraperitoneally into mice and mink, causing fatal septicemia within 16 to 24 hours. The meat from a septicemic bovine carcass fed prior to the epizootic was considered a possible source of infection, since it was found to be heavily contaminated with E. coli, S. aureus, and Streptococcus spp.     

牛源金黄色葡萄球菌凝固酶基因的分型

为了了解我国不同地区奶牛场金黄色葡萄球菌基因型的分布情况,采用凝固酶基因（Coa）扩增的分型方法,对在奶牛乳房炎奶样中所分离到的26株金黄色葡萄球菌进行了分型。结果显示,26株金黄色葡萄球菌共分为5个基因型,黑龙江省分离株以PCR 3型为主（10/16）。发现在同一牛群中的分离株可以存在相同的基因型,也可以存在不同的基因型;而不同牛群中的分离株也可属于同一基因型。这种结果提示,在某个或某些牛群中存在某一金黄色葡萄球菌的流行型,但也可能存在多个金黄色葡萄球菌的克隆。     

Improved rapid and efficient method for Staphylococcus aureus DNA extraction from milk for identification of mastitis pathogens

A rapid and efficient DNA extraction method was developed for detecting mastitis pathogens in milk. The first critical step involved cell wall disruption by bead-beating, as physical disruption using beads was more effective for DNA extraction from Gram-positive bacteria, such as Staphylococcus aureus, than enzymatic disruption using proteinase K. The second critical step involves the use of acetic acid and ammonium sulfate in the purification process, as these reagents effectively and efficiently remove the lipids and proteins in milk. Using these methods, DNA suitable for loop-mediated isothermal amplification was obtained within 30 min. Also, the rapid and sensitive detection of S. aureus in milk was possible at levels as low as 200 cfu/ml.     

spa typing and enterotoxin gene profile of Staphylococcus aureus isolated from bovine raw milk in Korea

Staphylococcus aureus is a major etiological pathogen of bovine mastitis, which triggers significant economic losses in dairy herds worldwide. In this study, S. aureus strains isolated from the milk of cows suffering from mastitis in Korea were investigated by spa typing and staphylococcal enterotoxin (SE) gene profiling. Forty-four S. aureus strains were isolated from 26 farms in five provinces. All isolates grouped into five clusters and two singletons based on 14 spa types. Cluster 1 and 2 isolates comprised 38.6% and 36.4% of total isolates, respectively, which were distributed in more than four provinces. SE and SE-like toxin genes were detected in 34 (77.3%) isolates and the most frequently detected SE gene profile was seg, sei, selm, seln, and selo genes (16 isolates, 36.3%), which was comparable to one of the genomic islands, Type I νSaβ. This is a first report of spa types and the prevalence of the recently described SE and SE-like toxin genes among S. aureus isolates from bovine raw milk in Korea. Two predominant spa groups were distributed widely and recently described SE and SE-like toxin genes were detected frequently.     

牛源金黄色葡萄球菌凝固酶分型与致病因子检测

为了解青海和甘肃地区奶牛养殖场的金黄色葡萄球菌(S.aureus)基因型分布状况,本研究对来自该两个地区的210份奶样进行了S.aureus的分离与鉴定,利用凝固酶基因(Coa)扩增和限制性内切酶AluⅠ酶切方法对所有分离株进行了凝固酶多态性分型。并对不同凝固酶基因型的S.aureus进行了白细胞毒素F (LukF)、白细胞毒素S (LukS)、α溶血素(α-hemolysin)、β溶血素(β-hemolysin)等主要致病因子检测。结果显示,共分离鉴定出35株S.aureus (青海13株,甘肃22株),所有分离株均能够扩增出Coa基因片段,并有5种PCR分型结果(本文简称PCR1～PCR5型),其中PCR 1、4和5型只有1种亚型,而PCR 2型有3种亚型,PCR 3型有2种亚型。PCR3型是青海(6/13)和甘肃地区(8/22)主要流行的基因型。致病因子检测结果显示,所有分离株均携带致病因子LukS和α溶血素;致病因子LukF和β溶血素检出率也很高,分别是30株(85.7%)和31株(88.6%)。β溶血素基因在甘肃地区检出率为95.5%(21/22),青海地区检出率为76.9%(10/13),致病因子LukF在甘肃地区检出率为91.0%(20/22),青海地区检出率为76.9%(10/13),且在各基因型中均有分布,甘肃地区S.aureus致病因子LukF和β溶血素检出率高于青海地区。本研究首次对青海和甘肃地区致奶牛乳房炎S.aureus进行了鉴定分析,为这两个地区奶牛乳房炎的防治提供了参考依据。     

奶牛乳腺炎源金黄色葡萄球菌噬菌体P82的分离及特性研究

【目的】 为开发噬菌体"鸡尾酒"制剂防治奶牛乳腺炎提供生物学材料。【方法】 以实验室分离的奶牛乳腺炎源金黄色葡萄球菌82为宿主菌,通过点滴法和双层平板法在奶牛场的污水、弃奶和粪便混合物中分离并纯化其噬菌体,通过噬菌斑及透射电子显微镜对该株噬菌体的形态特征进行观察。利用核酸酶处理分析该噬菌体核酸类型,并对其裂解谱、最佳感染复数、一步生长曲线、热稳定性、pH稳定性进行研究。【结果】 分离筛选出金黄色葡萄球菌82的裂解性噬菌体P82,电镜下观察其头部为二十面体,大小约为120 nm×83 nm,有一条带可伸缩尾鞘的长尾,长约126 nm,属于有尾噬菌体目,肌尾噬菌体科。通过琼脂糖凝胶电泳鉴定其核酸类型为双链DNA （dsDNA）。噬菌体P82的最佳感染复数为0.001,对奶牛乳腺炎源金黄色葡萄球菌裂解率为36.51%（23/63）,宿主谱较广;其生长潜伏期约为25 min,爆发期约为45 min,裂解量约为74 PFU/cell;在pH 4.0~12.0时活性稳定,在pH 2.0和13.0时则完全失去活性。噬菌体P82热稳定性较高,在70 ℃作用60 min后仍有裂解能力,在80 ℃作用40 min时则失去裂解能力。【结论】 本研究分离的噬菌体P82效价较高、裂解能力强、增殖速度快、噬菌谱广,对不同温度和pH均有较好的耐受度,能作为专一性裂解奶牛乳腺炎源金黄色葡萄球菌的噬菌体候选株,可与其他噬菌体混合制成噬菌体"鸡尾酒"制剂用于防治奶牛乳腺炎,为奶牛乳腺炎的噬菌体疗法提供材料。     

正己酸对大肠杆菌与金黄色葡萄球菌的抑制效果研究

对大肠杆菌和金黄色葡萄球菌进行正己酸的抗性试验,以研究正己酸对病原菌的抑制作用。试验采用等浓度梯度稀释、光密度值测定、平板涂布方法、牛津杯法,分别测定大肠杆菌及金黄色葡萄球菌的的最小抑菌浓度(minimum inhibitory concentration,MIC)以及最小杀菌浓度(minimum bactericidal concentration,MBC),绘制1/2MIC以及MIC处理过的大肠杆菌以及金黄色葡萄球菌的生长曲线,抑菌圈直径,结合扫描电镜图片分析最小杀菌浓度处理后的细胞形态结构的变化。结果表明:正己酸对大肠杆菌的最小抑菌浓度为700μg/mL、对金黄色葡萄球菌的最小抑菌浓度为1 000μg/mL;对大肠杆菌的最小杀菌浓度为1 000μg/mL、对金黄色葡萄球菌的最小杀菌浓度为1 300μg/mL;当正己酸浓度为1 600μg/mL时,电镜下,大肠杆菌数量较少,金黄色葡萄球菌数量少且呈现出细胞破裂萎缩现象。综上,正己酸对大肠杆菌和金黄葡萄球菌有抑制作用,破坏了金黄葡萄球菌的细胞膜结构。     

上海地区奶牛的乳房炎金黄色葡萄球菌耐药性

为调查上海地区奶牛乳房炎金黄色葡萄球菌的耐药性,采集上海地区乳房炎患病乳样60 份,进行金黄色葡萄球菌的分离鉴定及药敏实验。结果表明：经分离鉴定,共检出8 株金黄色葡萄球菌,分离率为13.33%;药敏实验结果表明,分离得到的金黄色葡萄球菌对青霉素G和氨苄西林的耐药率最高,均为100.00%,对磺胺甲恶唑的耐药率次之,为50.00%,对头孢克洛、头孢唑肟、洛美沙星、诺氟沙星、四环素、庆大霉素、红霉素、克林霉素和氯霉素的耐药率均为37.50%,对环丙沙星和氧氟沙星的耐药率均为25.00%,对头孢噻肟、头孢他啶     

Assessment of risk factors and isolation of Staphylococcus aureus and Escherichia coli from bovine subclinical mastitic milk in and around Gondar,Northwest Ethiopia

Tropical Animal Health and Production - A cross-sectional study with simple random sampling approach was conducted from November 2017 to May 2018 with the objectives of estimating the prevalence of...     

宁夏地区奶牛乳房炎金黄色葡萄球菌耐药性分析

为了解宁夏地区奶牛乳房炎金黄色葡萄球菌的耐药情况,采用药敏纸片扩散法,测定了50株奶牛乳房炎金黄色葡萄球菌对常用的17种抗茵药物的耐药性.同时采用产色头孢菌素法进行β-内酰胺酶的检测,并采用苯唑西林纸片法进行耐甲氧西林金黄色葡萄球菌(MRSA)的检测.结果表明,所有菌株除了对利福平、万古霉素100％敏感以外,对其他15...