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合成鱼腥草素注射液对引起奶牛乳房炎的常见致病菌有一定的抗菌效果。它对无乳链球菌和金黄色葡萄球菌的抑菌浓度，在牛奶培养基中为0．5mg／ml，在肉汤培养基中为0．25mg／ml。同时以青霉素G为对照，在肉汤培养基中对无乳链球菌和金黄色葡萄球菌的抑菌浓度分别为0．006国际单位和0．1国际单位／ml；在牛奶培养基中，对无乳链球菌和金黄色葡萄菌球菌的抑菌浓度分别为0．025国际单位／ml和0．04国际单位／ml。试验表明：鱼腥草素对两种细菌具有同等的抑菌效果，而青霉素对无乳链球菌的抑菌效果明显优于金黄色葡萄球菌。在牛奶培养基的抑菌浓度均高于相应的在肉汤培养基的抑菌浓度。 相似文献
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从患乳房炎和子宫内膜炎奶牛的奶或子宫黏液中分离菌株后经鉴定选取金黄色葡萄球菌105株、表皮葡萄球菌20株、大肠埃希氏菌20株、链球菌38株（其中停乳链球菌8株，无乳链球菌30株）和牛多杀性巴氏杆菌5株。在体外用重组溶葡萄球菌酶、苯唑西林、氨苄西林、庆大霉素按照微量肉汤稀释法进行抑杀菌实验。结果表明：重组溶葡萄球菌酶对奶牛乳房炎和子宫内膜炎分离的金黄色葡萄球菌和表皮葡萄球菌（包括耐药菌株和敏感菌株）具有良好抑杀效果，对链球菌（包括无乳链球菌和停乳链球菌）和牛多杀性巴氏杆菌具有一定的抑杀效果，对大肠杆菌作用较差；苯唑西林、氨苄西林、庆大霉素都有一定量的耐药菌株产生，而重组溶葡萄球菌酶对苯唑西林、氨苄西林、庆大霉素耐药菌株同样具有良好抑杀效果。 相似文献
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为了解奶牛乳房炎重要致病菌和常用抗菌药物在乳房内的分布情况,本试验分析了一次挤奶过程中不同时间段牛奶的主要乳成分变化,并研究了金黄色葡萄球菌和大肠杆菌以及常用抗菌药物体外在牛奶中的分布。结果表明,随着挤奶过程的进行,牛奶中的脂肪含量逐渐升高,挤奶后期显著高于挤奶前期和中期(P0.05),而乳蛋白和乳糖含量变化不大;金黄色葡萄球菌和大肠杆菌主要富集在牛奶的上部,细菌计数上部显著高于中部和下部(P0.01);常用抗菌药物盐酸林可霉素、青霉素钠、硫酸庆大霉素、盐酸四环素、氨苄西林钠、乳糖酸红霉素、乳酸环丙沙星、头孢噻呋钠在牛奶中下部显著高于上部和中部,乳酸链球菌素Nisin Z在牛奶中分布比较均匀,并在上部略高。本研究结果提示,经奶牛乳头管进入的细菌可以随牛奶中的脂肪滴上浮,侵入乳腺的深层组织;乳房炎致病菌和常用治疗药物在乳房中分别向上下两极移动,这种分布上的分离现象可导致抗菌药物和致病菌不能充分接触,可能是临床上乳房炎治疗失败的一个原因。 相似文献
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湖北地区奶牛乳房炎病原菌的分离鉴定与耐药性分析 总被引：15，自引：1，他引：15
本研究旨在分离鉴定湖北地区致奶牛乳房炎的病原菌，鉴定细菌的耐药特征．为奶牛乳房炎防治提供理论依据。从湖北两个主要奶牛小区的9个不同规模的奶牛场采集牛奶样本200份，经检测．其中3份为临床乳房炎样本，49份为隐性乳房炎。两地区隐性乳房炎的检出率分别为36．4％（20／55）与20％（29／145）。两地区乳房炎牛奶的细菌种类分布也各不同。其中武汉东西湖地区停乳链球菌的分离率最高，占33.3％（8／24）．而宜昌夷陵区以金黄色葡萄球菌分离率最高，占29％（9／31），其次为无乳链球菌，占25．8％（8／31）。从乳房炎牛奶中共分离到7种细菌共55株，其中金黄色葡萄球菌11株，表皮葡萄球菌10株，无乳链球菌10株，停乳链球菌14株，乳房链球菌2株，大肠埃希氏菌4株，克雷伯氏菌4株。分别对所有分离株进行12种药物的敏感性试验，结果表明所有菌株对先锋V、氧氟沙星均高度敏感．对临床常用的青霉素、链霉素具有较高的耐药性。 相似文献
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为建立同时快速检测奶牛奶样中无乳链球菌、停乳链球菌、乳房链球菌和金黄色葡萄球菌的方法,根据无乳链球菌sip基因、停乳链球菌isp基因、乳房链球菌pauA基因和金黄色葡萄球菌nuc基因各设计1对特异性引物,建立多重PCR检测体系。结果显示,该检测方法具有高特异性,无乳链球菌、停乳链球菌、乳房链球菌和金黄色葡萄球菌敏感性分别为105、104、105、105 CFU/mL。对临床采集的460份奶样检测结果表明,建立的多重PCR体系可以用于临床上无乳链球菌、停乳链球菌、乳房链球菌和金黄色葡萄球菌感染引起的奶牛乳房炎的检测。 相似文献
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宁波市奶牛乳房炎发病及综合防治试验研究 总被引：1，自引：0，他引：1
为了解宁波地区奶牛乳房炎发病及主要病原菌构成,采用乳房炎诊断试剂(HMT)对宁波市8个奶牛场307头泌乳牛的1249个乳区进行了隐性乳房炎流行情况调查,采集HMT反应阳性(++)及强阳性(+++)乳区奶样进行细菌分离与鉴定;用纸片扩散法检测主要病原菌对常用抗菌药物敏感性,并选择具代表性牧场进行乳房炎综合防治试验。结果显示,宁波市奶牛隐性乳房炎的头阳性率为71.3%,乳区阳性率为33.5%。主要病原菌的检出率依次为:凝固酶阴性葡萄球菌47.1%、无乳链球菌20.4%、停乳链球菌17.3%、金黄色葡萄球菌5.1%和乳房链球菌3.9%。主要病原菌对青霉素、氨苄青霉素、庆大霉素、复方新诺明和链霉素等药物有不同程度的耐药性,对头孢类及苯唑青霉素敏感。综合防治措施的实施可以明显降低桶奶总细菌数,改善牛奶品质。 相似文献
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重组溶葡萄球菌酶对奶牛乳房炎和子宫内膜炎常见病原菌的体外杀菌试验 总被引：1，自引：1，他引：1
从患乳房炎和子宫内膜炎奶牛的奶或子宫黏液中分离菌株,鉴定后选取金黄色葡萄球菌105株、表皮葡萄球菌20株、大肠埃希氏菌20株、链球菌38株(其中停乳链球菌8株,无乳链球菌30株)和牛源多杀巴氏杆菌5株,在体外用重组溶葡萄球菌酶、苯唑西林、氨苄西林、庆大霉素按照微量肉汤稀释法进行了杀菌试验。结果表明,重组溶葡萄球菌酶对奶牛乳房炎和子宫内膜炎分离的金黄色葡萄球菌和表皮葡萄球菌具有良好抑杀效果,对链球菌(包括无乳链球菌和停乳链球菌)和牛源多杀巴氏杆菌具有一定的抑杀效果,对大肠杆菌作用较差;苯唑西林、氨苄西林、庆大霉素都有一定量的耐药菌株产生,而重组溶葡萄球菌酶对苯唑西林、氨苄西林、庆大霉素耐药菌株同样具有良好抑杀效果。 相似文献
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Recovery of Streptococcus agalactiae and Staphylococcus aureus from fresh and frozen bovine milk 总被引：4，自引：0，他引：4
M R Villanueva J W Tyler M C Thurmond 《Journal of the American Veterinary Medical Association》1991,198(8):1398-1400
Three hundred seventy-three milk samples were screened for Streptococcus agalactiae and Staphylococcus aureus. After sample storage at -20 C for 23 days, the frequency of Str agalactiae isolation increased 2.50 times. The frequency of S aureus isolation increased 1.48 times in the same interval. Increases in the proportion of these isolates were highly significant (P = 0.000006 and 0.0001, respectively). Results of the study indicate that optimal procedures for microbiological testing for these mastitis pathogens may include preculture freezing. The magnitude of the increase in the proportion of isolates indicates the existence of an important population of infected cattle shedding bacteria at concentrations not detected by use of standard microbiological techniques. 相似文献
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Antimicrobial resistance in streptococcal species isolated from bovine mammary glands 总被引：1，自引：0，他引：1
Streptococcal species isolated from dairy cows with clinical mastitis were obtained from mastitis research workers in Florida, Louisiana, New York, Vermont, Washington, and West Virginia. Seventy-one streptococcal isolates were tested, including 39 strains of Streptococcus agalactiae, 21 strains of S dysgalactiae, and 11 strains of S uberis. The minimal inhibitory concentration of erythromycin, lincomycin, oxytetracycline, penicillin, spectinomycin, streptomycin, and tetracycline was determined for each isolate. Differences were not detected among strains with respect to geographic origin. None of the strains was resistant to penicillin. Lincomycin was the next most effective antimicrobial, with only 2 resistant strains of each streptococcal species. There were no differences among the streptococcal species with respect to resistance to either penicillin or lincomycin. Streptococcus uberis was more likely to be resistant to erythromycin than were S agalactiae and S dysgalactiae (P less than 0.02). Streptococcus agalactiae and S uberis had similar distributions for resistance to oxytetracycline, tetracycline, spectinomycin, and streptomycin. Strains of S dysgalactiae were more likely to have intermediate resistance to oxytetracycline and streptomycin than were strains of S agalactiae and S uberis, which were highly resistant to oxytetracycline and streptomycin (P less than 0.001). Differences were not detected among the streptococcal species with respect to resistance to spectinomycin. Resistance to multiple antimicrobials was observed in all streptococcal species tested. Although S dysgalactiae appeared to have a greater percentage of strains (73%) that were resistant to multiple antimicrobials than did S agalactiae (31%) or S uberis (45%), differences were not statistically significant. 相似文献
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P. J. Mylrea R. J. T. Hoare † Patricia Colquhoun † I. J. Links R. J. Richards Mary Barton‡ 《Australian veterinary journal》1977,53(11):534-537
Bacteriological examinations were made on quarter samples from cows in 35 herds over a 3 year period to monitor the response in a mastitis control program. Initially, Staphylococcus aureus predominated in 32 of the herds and the mean herd prevalence was 26%. The control measures halved this rate but there was considerable variation in response between herds. The decline occurred rapidly and there was a significant reduction (P less than 0.01) by 3 months. Streptococcus agalactiae predominated in 3 herds and the overall infection rate was 4.9%. Control measures eliminated the infection completely from most herds but reinfection occurred in 2 herds. The greatest decline occurred in the first 6 months and was significant (P less than 0.05). The measures had little effect upon Str. uberis and Str. dysgalactiae which remained fairly consistently at low levels. Initially, strains of Staph. aureus resistant to penicillin were dominant in most herds. In a minority of herds strains resistant to streptomycin predominated and in these herds there was a concurrent resistance to penicillin. These patterns did not change greatly over the control period. Resistance by Str. agalactiae to streptomycin occurred in most herds at the start of the program. 相似文献
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Biofilm bacteria: formation and comparative susceptibility to antibiotics 总被引：17，自引：0，他引：17 
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下载免费PDF全文 Merle E. Olson Howard Ceri Douglas W. Morck Andre G. Buret Ronald R. Read 《Canadian journal of veterinary research》2002,66(2):86-92
The Calgary Biofilm Device (CBD) was used to form bacterial biofilms of selected veterinary gram-negative and gram-positive pathogenic bacteria from cattle, sheep, pigs, chicken, and turkeys. The minimum inhibitory concentration (MIC) and minimum biofilm eradication concentration (MBEC) of ampicillin, ceftiofur, cloxacillin, oxytetracycline, penicillin G, streptomycin, tetracycline, enrofloxacin, erythromycin, gentamicin, tilmicosin, and trimethoprim-sulfadoxine for gram-positive and -negative bacteria were determined. Bacterial biofilms were readily formed on the CBD under selected conditions. The biofilms consisted of microcolonies encased in extracellular polysaccharide material. Biofilms composed of Arcanobacterium (Actinomyces) pyogenes, Staphylococcus aureus, Staphylococcus hyicus, Streptococcus agalactiae, Corynebacterium renale, or Corynebacterium pseudotuberculosis were not killed by the antibiotics tested but as planktonic bacteria they were sensitive at low concentrations. Biofilm and planktonic Streptococcus dysgalactiae and Streptococcus suis were sensitive to penicillin, ceftiofur, cloxacillin, ampicillin, and oxytetracycline. Planktonic Escherichia coli were sensitive to enrofloxacin, gentamicin, oxytetracycline and trimethoprim/ sulfadoxine. Enrofloxacin and gentamicin were the most effective antibiotics against E. coli growing as a biofilm. Salmonella spp. and Pseudomonas aeruginosa isolates growing as planktonic populations were sensitive to enrofloxacin, gentamicin, ampicillin, oxytetracycline, and trimethoprim/sulfadoxine, but as a biofilm, these bacteria were only sensitive to enrofloxacin. Planktonic and biofilm Pasteurella multocida and Mannheimia haemolytica had similar antibiotic sensitivity profiles and were sensitive to most of the antibiotics tested. The CBD provides a valuable new technology that can be used to select antibiotics that are able to kill bacteria growing as biofilms. 相似文献
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R L Boddie J L Watts S C Nickerson 《Journal of the American Veterinary Medical Association》1990,196(6):890-893
The activity of a 0.5% chlorhexidine gluconate postmilking teat germicide in reducing the numbers of Staphylococcus aureus and Streptococcus agalactiae on the skin of excised teats from cows was determined. The product yielded logarithmic reductions of 4.09 and 4.10 against S aureus and Str agalactiae, respectively, compared with 3.80 and 3.81 reductions, using a 1% iodophor dip. Germicide tolerance to an organic load containing Serratia marcescens or Pseudomonas spp was also determined. Organisms were not recovered from the product 8 hours after introduction of a simulated organic load containing either species of bacteria. The germicide was further evaluated against S aureus and Str agalactiae, using experimental challenge-exposure procedures in a research dairy herd. Efficacy was 73.4% (P less than 0.001) against S aureus and 68.1% (P less than 0.005) against Str agalactiae. 相似文献
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OBJECTIVE: To determine whether antimicrobial resistance patterns of major mastitis pathogens isolated from milk samples from dairy cows have changed over time. DESIGN: Retrospective study. SAMPLE POPULATION: 8905 bacterial isolates obtained from milk samples submitted to the Wisconsin Veterinary Diagnostic Laboratory between January 1994 and June 2001. PROCEDURE: Antimicrobial susceptibility was determined by means of the Kirby-Bauer disk diffusion method. Logistic regression was used to determine whether percentages of isolates resistant to various antimicrobials changed over time. RESULTS: For the gram-positive mastitis pathogens, percentages of isolates resistant to various flactam antimicrobials did not increase over the course of the study. Percentage of Staphylococcus aureus isolates resistant to penicillin decreased from 49 to 30%; percentage of Streptococcus isolates resistant to penicillin decreased from 6 to 1%. Percentage of isolates resistant to erythromycin increased for S aureus, Escherichia coli, Enterobacter spp, Enterococcus spp, and Pasteurella spp. Percentage of isolates resistant to lincomycin increased for S aureus and Staphylococcus spp. Percentage of coagulase-negative Staphylococcus isolates resistant to pirlimycin increased from 6 to 19%. For several pathogens, percentages of isolates resistant to sulfisoxazole and to trimethoprim-sulfamethoxazole decreased. No pathogens had a significant increase in the percentage of isolates resistant to novobiocin-penicillin. CONCLUSIONS AND CLINICAL RELEVANCE: Results did not indicate a trend toward increased antimicrobial resistance among mastitis pathogens isolated from milk samples from dairy cows between 1994 and 2001. Reduced resistance to flactam antimicrobials was identified for several gram-positive mastitis pathogens. 相似文献
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Denamiel G Llorente P Carabella M Rebuelto M Gentilini E 《Journal of veterinary medicine. B, Infectious diseases and veterinary public health》2005,52(3):125-128
The in vitro susceptibility to penicillin G, erythromycin and clindamycin was determined by the disc diffusion test and by E-test for a total of 47 streptococcal strains (three Streptococcus uberis, 36 Streptococcus agalactiae, eight Streptococcus dysgalactiae spp. dysgalactiae) isolated from bovine intramammary infections in Argentina. Moreover, resistance phenotypes of erythromycin-resistant streptococcal isolates was characterized. MIC90 of penicillin G, erythromycin and clindamycin for S. agalactiae were 0.75, 8.0 and 12.0 microg/ml respectively. Resistance to erythromycin and clindamycin was detected in 13 (27.6%) and 12 (25.5%) isolates respectively. No isolate was resistant to penicillin G. Resistance against macrolides, lincosamides and streptogramin B (MLS(B)) represented by the constitutive MLS(B) phenotype was present in 11 (23.4%) erythromycin-resistant isolates and two isolates (4.3%) expressed the M phenotype. The inducible MLS(B) phenotype was not identified. Results suggest that beta-lactams are the first-line antibiotics when treating streptococcal udder infections; however, the continuous monitoring of the antibiotic resistance is essential, as the emergence of resistant strains has become a growing concern on the therapy of bovine mastitis. 相似文献