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1.
牛源性无乳链球菌血清型分布及抗生素耐药性研究 总被引：1，自引：1，他引：1
本研究旨在查明牛源性无乳链球菌血清型分布及对常见抗生素的耐药情况,指导临床合理用药。对从中国部分地区奶牛场采集的临床型乳房炎病牛乳中分离鉴定出78株无乳链球菌地方菌株,制备沉淀反应抗原及6株标准血清型无乳链球菌单因子血清抗体,采用环状沉淀试验,对78株无乳链球菌地方菌株进行了血清学分型鉴定;同时采用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,引起奶牛乳房炎的无乳链球菌血清型主要为X型(60.26%),其次为Ⅲ型(10.26%)、R型(7.69%)、Ⅱ型(7.69%)和Ⅰb型(5.13%),Ⅰa型尚未发现。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、氟苯尼考、多黏菌素B、环丙沙星、氟哌酸和头孢他啶/棒酸均较敏感;但对氨苄青霉素、链霉素、恩诺沙星、阿莫西林/棒酸和复方新诺明,有一定的耐药性,其耐药率达50%~100%。本研究对进一步研制有效的药物及疫苗,指导临床合理用药具有重要的意义。 相似文献
2.
为了解昆明地区奶牛隐性乳房炎无乳链球菌分离株对常用抗生素的耐药性及耐药基因携带情况,采集昆明某地区隐性乳房炎患牛乳样71份检测。结果显示,分离到的15株无乳链球菌,对青霉素类、红霉素、林可胺类等抗生素存在不同程度的耐药现象,多重耐药现象也比较严重,分离菌共出现10种耐药谱,其中7耐和8耐的占有60%。对青霉素严重耐药,其耐药率达到了100%。其中,PCR扩增β-内酰胺类和大环内酯类耐药基因,结果显示,15株无乳链球菌均含有pbp1a、pbp2b、erm B基因,表明,本地区不能继续使用青霉素等药物来治疗奶牛乳房炎,应选择敏感性的药物,如头孢类抗生素等。同时应合理交叉用药,以防细菌产生耐药性。本试验为昆明地区无乳链球菌引起的隐性奶牛乳房炎的防治提供了一定的依据。 相似文献
3.
[目的 ]了解宁夏地区奶牛隐性乳房炎主要病原菌流行情况及主要病原菌的耐药特征。[方法 ]采集宁夏地区5个规模化奶牛养殖场乳样共计461份,分离培养后,应用全自动细菌鉴定仪进行鉴定并选择主要致病菌进行药敏试验。[结果 ]隐性乳房炎阳性检出率平均为65.3%(301/461);分离到金黄色葡萄球菌22株、无乳链球菌5株、大肠杆菌10株。这些细菌对阿米卡星、头孢噻肟等药物敏感,对青霉素与环丙沙星耐药。[结论 ]宁夏地区奶牛隐性乳房炎的阳性率较高,主要病原菌对阿米卡星、头孢噻肟等药物敏感。 相似文献
4.
《中国兽医杂志》2020,(3)
为了解春夏季临床型乳房炎主要病原菌感染情况及耐药情况,对兰州地区某规模化奶牛场奶牛临床型乳房炎进行病原菌分离鉴定及耐药性分析。试验通过常规的细菌分离培养方法对110份乳样进行细菌分离纯化,并用16S rDNA手段进行鉴定,对鉴定出的主要病原菌通过K-B纸片药敏试验进行耐药分析。结果表明,主要病原菌包括大肠杆菌(35.5%)、金黄色葡萄球菌(16.1%)、无乳链球菌(14.0%)、停乳链球菌(7.5%)、乳房链球菌(3.2%)。耐药检测结果表明,5种主要病原菌对青霉素G、阿莫西林表现出高度耐药,对链霉素、红霉素表现为中度耐药,对庆大霉素、四环素表现为轻度耐药,而对环丙沙星、头孢噻肟、卡那霉素和氟苯尼考表现为敏感。本试验旨在为该牛场控制和治疗乳房炎提供科学依据。 相似文献
5.
浙江省主要奶牛养殖区奶牛隐性乳房炎病原菌调查 总被引：1，自引：2，他引：1
对浙江省四个主要奶牛养殖区金华、杭州、宁波以及台州的30个奶牛场中846头泌乳牛的3178个乳区进行了奶牛隐性乳房炎病原菌调查.首先用HMT乳房炎诊断试剂检查乳区奶样,采集HMT反应为阳性(++)和强阳性(+++)的乳区奶样进行细菌分离鉴定,对分离到的金黄色葡萄球菌(Staphylococcus aureus)进行药敏试验.结果表明,浙江省奶牛隐性乳房炎的头阳性率为54.3%,乳区阳性率为28.0%.主要病原菌的检出率依次为凝固酶阴性葡萄球菌(Coagulase negative staphylococci)34.0%、无乳链球菌(Streptococcus agalactiae)27.0%、金黄色葡萄球菌(Staphylococcus aureus)12.2%、停乳链球菌(Streptococcus dysgalactiae)13.0%、乳房链球菌(Streptococcus uberis)6.2%等.药敏试验结果表明,对青霉素、氨苄青霉素敏感的金黄色葡萄球菌分离株只有20.3%,对四环素和红霉素的敏感率也较低(34.8%和47.8%).多重耐药现象比较普遍,主要是对青霉素、氨苄青霉素、四环素、红霉素同时耐药. 相似文献
6.
奶牛乳房炎种类繁多,笔者将临床常见的几种乳房炎治疗与各位同仁分享:1链球菌性乳房炎包括无乳链球菌、停乳链球菌和乳房链球菌感染,为临床上最常见乳房感染细菌,乳房常见红肿,发热,疼痛,一般无消化系统症状,乳汁多有絮状物或脓样,产奶量下降,CMT阳性,体细胞增数。本病对青霉素、链霉素、庆大霉素、氨苄青霉素、喹诺酮类、碘胺类药物等敏感,由于上述药物弃奶期长,所以笔者推荐应用头孢噻呋钠, 相似文献
7.
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
8.
青海地区奶牛无乳链球菌的分离与鉴定 总被引：1，自引：0，他引：1
无乳链球菌是导致奶牛乳房炎的常见病原菌之一,为了掌握青海地区无乳链球菌的流行情况及常用药物的敏感性,从而为本地区更好的预防与治疗奶牛乳房炎提供保障。本试验在青海地区16个奶牛场共采集258份乳房炎乳样,经革兰氏染色与绵羊鲜血琼脂培养基培养纯化,获得疑似链球菌137株;随后经玻片法血浆凝固酶试验、CAMP试验、生化试验与动物致病性试验对无乳链球菌进行鉴定,结果显示,137株链球菌中含有无乳链球菌42株,分离率为30.7%;经K-B纸片扩散法对无乳链球菌耐药性检测结果显示,该地区无乳链球菌主要对头孢类高度敏感,对氧氟沙星、磺胺类、氨苄青霉素与阿米卡星中度敏感。 相似文献
9.
10.
《动物医学进展》2016,(12)
为了解吉林省各地区奶牛乳房炎发病情况,以便于科学合理防治该病,对长春市、吉林市、白城市以及延吉等多个大型奶牛场200份乳样进行了细菌分离与鉴定,并对其主要致病菌进行敏感药物筛选试验。结果显示,导致吉林省奶牛乳房炎发生的主要病原菌为大肠埃希菌、金黄色葡萄球菌、无乳链球菌以及停乳链球菌等,在检出的267株病原菌中,金黄色葡萄球菌98株,占36.70%;无乳链球菌65株,占24.34%;停乳链球菌57株,占21.35%;大肠埃希菌43株,占16.10%;其他菌4株,占1.5%。4种病原茵对丁胺卡那霉素、环丙沙星、恩诺沙星、头孢噻肟以及万古霉素均高度敏感,但对青霉素、链霉素、红霉素、庆大霉素等具有较强的耐药性,因此丁胺卡那霉素、环丙沙星、恩诺沙星、头孢噻肟以及万古霉素可以作为吉林省奶牛乳房炎治疗的首选药物。 相似文献
11.
为了调查新疆伊犁某牛场饮水、饲料和粪样中分离的大肠杆菌对临床常用抗菌药物的耐药情况。本试验采用微量肉汤稀释法,对饮水源、饲料源、牛粪源样品中分离出的大肠杆菌进行最小抑菌浓度测定。结果显示,25份牛场饮水源样品,大肠杆菌分离率为100.0%（25/25）,对阿莫西林/克拉维酸（12.0%）、氨苄西林（4.0%）、诺氟沙星（4.0%）、恩诺沙星（8.0%）和安普霉素（8.0%）5种抗菌药物耐药;72份牛场饲料源样品,大肠杆菌分离率为65.3%（47/72）,对阿莫西林/克拉维酸（36.2%）、氨苄西林（19.1%）、诺氟沙星（4.3%）和安普霉素（4.3%）4种抗菌药物耐药;80份牛粪源样品,大肠杆菌分离率为100.0%（80/80）,对阿米卡星（12.5%）、氨苄西林（7.5%）、恩诺沙星（7.5%）、庆大霉素（5.0%）、诺氟沙星（2.5%）、环丙沙星（2.5%）、阿莫西林/克拉维酸（1.3%）和头孢噻呋（1.3%）8种抗菌药物耐药,仅对安普霉素敏感。该牛场分离的大肠杆菌对常用抗菌药物耐药情况一般,但中介率较高,须在临床治疗细菌性疾病中避免使用不敏感和中介率高的抗菌药物,养殖场饮水和饲料有被耐药大肠杆菌污染的风险。 相似文献
12.
XUAN Hui-yong GAO Chao LIN Ya-jun XIA Xu-jin XIA Li-ning WANG Ying-bin MA Yang 《中国畜牧兽医》2016,43(8):2150-2155
In order to understand the resistance of E.coli to clinical antimicrobial drugs from different farms in Kuitun area of Xinjiang,the bovine fecal samples were collected using the anal swab and E.coli was isolated from 123 (30),127 (30) and 128 (30) farms,respectively.The minimum inhibitory concentrations of E coli isolated from fecal samples to 10 antimicrobial drugs were determined by agar dilution method and the difference of resistance rate of E.coli from different farms was compared by chi square test.The results showed that the resistance rates of 128 farm to amoxicillin/clavulanic acid (33.3%) and apramycin (23.3%) were relatively high;The resistance rates of 127 farm to ampicillin (20.0%),amoxicillin/clavulanic acid (16.7%) and florfenicol (16.7%) were relatively high;The resistance rates of 123 farm to ampicillin (13.3%) and the apramycin (13.3%) were relatively high.The chi square test results showed that resistance rates of E.coli to florfenicol and enrofloxacin from 127 farm were significantly higher than that from 123 and 128 farms (P<0.05);The resistance rates of E.coli to amoxicillin/clavulanic acid and apramycin from 128 farm were significantly higher than that from 123 and 127 farms (P<0.05),respectively.The most of the antibiotics resistance pattern of E.coli from different farms was 1 to 2 resistant.The results showed that the drug resistance rates of bovine E.coli in Kuitun was not high,while the resistance rates to commonly used drugs such as amoxicillin/clavulanic acid and apramycin were high.It suggested that this kinds of antimicrobial drugs should be replaced or avoid using to treat bacterial diseases.In addition,the antimicrobial resistance between farms was different,indicating the farms medicine would impact the drug resistance in bacteria. 相似文献
13.
新疆奎屯地区不同团场牛源大肠杆菌耐药情况比较 总被引：2，自引：0，他引：2
为了解新疆奎屯地区不同团场牛源大肠杆菌对临床常用抗菌药物的耐药情况,比较不同养殖场之间牛源大肠杆菌的耐药差异,分别从新疆奎屯地区位于123团、127团和128团的牛场,用肛拭子在直肠采集粪样各30份,并分离大肠杆菌。采用微量肉汤稀释法,对分离出的大肠杆菌进行10种抗菌药物最小抑菌浓度的测定,通过卡方检验对不同养殖场牛源大肠杆菌耐药差异性进行比较分析。结果显示,128团对阿莫西林/克拉维酸（33.3%）和安普霉素（23.3%）耐药率相对较高;127团对氨苄西林（20.0%）、阿莫西林/克拉维酸（16.7%）和氟苯尼考（16.7%）耐药率相对较高;123团场对氨苄西林（13.3%）和安普霉素（13.3%）耐药率相对较高。卡方检验结果显示,127团对氟苯尼考和恩诺沙星的耐药率显著高于123团和128团（P<0.05）;128团对阿莫西林/克拉维酸和安普霉素的耐药率分别显著高于123团和127团（P<0.05）。不同团场多重耐药均以1～2耐为主。结果表明,新疆奎屯地区不同团场牛源大肠杆菌对多数被检药物的耐药率不高,仅对常用药物如阿莫西林/克拉维酸和安普霉素等具有较高耐药率,需在临床治疗细菌疾病时更换或避免使用此类抗菌药物。此外,各养殖场对被检抗菌药物的耐药情况不同,说明养殖场的用药极大程度影响细菌的耐药性。 相似文献
14.
【目的】研究内蒙古地区部分奶牛养殖场乳房炎生鲜乳样本及环境样本致病菌种类和耐药性,为乳房炎的防控提供临床用药指导和参考。【方法】采用平板划线法对内蒙古地区4个规模化养殖场468份(乳房炎生鲜乳样本199份,乳房炎奶牛饲养环境样本269份)样本进行细菌分离培养,采用形态学观察、革兰氏染色镜检以及16S rDNA测序对分离出的细菌进行鉴定,且对引发乳房炎的主要致病菌进行药敏性试验。【结果】高盐甘露醇培养基上呈现出小、白且偏黄色的菌落,经16S rDNA测序比对,与金黄色葡萄球菌高度相似的菌株共56株,分离率为11.97%;在伊红-美蓝培养基上呈现出黑紫色泛有金属光泽的菌落,经16S rDNA测序比对,与大肠杆菌高度相似的菌株共44株,分离率为9.40%。在199份生鲜乳样本中,金黄色葡萄球菌和大肠杆菌的分离率最高,分别为21.11%和17.09%;在269份环境样本中,金黄色葡萄球菌和大肠杆菌的分离率分别为5.20%和3.72%。药敏试验结果显示,金黄色葡萄球菌对青霉素、磺胺异噁唑、氨苄西林、阿莫西林/克拉维酸的耐药性相对较高,耐药率分别为90.63%、78.13%、75.00%、68.75%;对庆大霉素、环丙沙星、复方新诺明的敏感性较高。大肠杆菌对氨苄西林、头孢噻吩、磺胺异噁唑存在明显耐药性,耐药率分别为100%、94.29%、45.71%;对链霉素、卡那霉素、庆大霉素、多粘菌素E、美罗培南、阿莫西林/克拉维酸以及利福昔明表现出较高敏感性。【结论】内蒙古地区引发奶牛乳房炎的主要致病菌为金黄色葡萄球菌、大肠杆菌;金黄色葡萄球菌对青霉素、磺胺异噁唑、氨苄西林、阿莫西林/克拉维酸的耐药性相对较高;大肠杆菌对氨苄西林、头孢噻吩、磺胺异噁唑存在明显的耐药性。 相似文献
15.
Antimicrobial resistance of Salmonella isolated from finishing swine and the environment of 60 Alberta swine farms 总被引：5，自引：0，他引：5
Rajić A McFall ME Deckert AE Reid-Smith R Manninen K Poppe C Dewey CE McEwen SA 《Veterinary microbiology》2004,104(3-4):189-196
The study objective was to describe and evaluate antimicrobial resistance profiles in Salmonella isolated from Alberta swine finishing farms. Salmonella isolates (n = 322) were obtained from 192 fecal and 84 environmental samples of the 60 Salmonella-positive swine finishing farms. Isolates were classified susceptible, intermediate or resistant based on NCCLS guidelines. More than half of the isolates (53.4%) were susceptible to all of the 18 antimicrobials in the testing panel. No resistance was observed to amikacin, amoxicillin/clavulanic acid, cefoxitin, ceftiofur, ceftriaxone, cephalothin, ciprofloxacin, imipenem or nalidixic acid. Less than 1% of isolates were resistant to apramycin, gentamicin and trimethoprim/sulfamethoxazole. Higher frequencies of resistance were observed for chloramphenicol (4.7%), ampicillin (7.8%), kanamycin (11.8%), sulfamethoxazole (21.1%), streptomycin (25.5%) and tetracycline (38.8%). Eleven Salmonella serovars had isolates with resistance to > or =3 antimicrobials. The most frequently resistant serovar was Salmonella Derby, with 27 (38.0%) isolates resistant to > or =3 antimicrobials, including resistance to five and six antimicrobials. An absence of resistance to cephalosporins and fluoroquniolones and a low proportion of isolates resistant to amikacin, amoxicillin/clavulanic acid, apramycin, gentamicin and trimethoprim/sulfamethoxazole are encouraging findings from public health and animal health perspectives. Frequent resistance observed for ampicillin, kanamycin, sulfamethoxazole, streptomycin and tetracycline, antimicrobials commonly used in veterinary medicine for decades, indicates an urgent need to utilize these antimicrobials more prudently if their benefits are to be preserved. 相似文献
16.
Rodrigues J Poeta P Martins A Costa D 《Journal of veterinary medicine. B, Infectious diseases and veterinary public health》2002,49(6):278-280
The purpose of the present study was to determine the prevalence of antibiotic resistance, with special attention to vancomycin, in 104 strains of Enterococcus, which is the sentinel bacterium isolated from dog and cat faeces samples. The phenotypic characterization of the isolates classified them as E. faecium (58%), E. avium (41%) and E. faecalis (1%). Sensitivity testing used the diffusion method according to the recommendations of CASFM (Comite de l'Antibiogramme de la Société Fran?aise de Microbiogie), to oxacillin, amoxycillin, amoxycilin + clavulanic acid, ampicillin, piperacillin, cefoperazone, imipenem, enrofloxacin, ciprofloxacin, ofloxacin, nalidixic acid, tetracycline, lincomycin, erythromicin and vancomycin. Minimum inhibitory concentration (MIC) determination by E test revealed a MIC to vancomycin of between 0.5 microg/ml and 3 microg/ml. All the strains were resistant to nalidixic acid, erythromycin, cefoperazone and oxacillin. We detected resistance to amoxycillin + clavulanic acid in 1.9% of isolates, to amoxycillin in 4.8%, to piperacillin in 13.5%, and to ampicillin in 21.2% of strains. A high prevalence of antibiotic resistance to lincomycin, tetracycline, enrofloxacin, ciprofloxacin and ofloxacin was found in 98.1%, 95.2%, 76.9%, 73.1% and 64.4% of strains, respectively. Resistance to vancomycin was not found, which indicates that there is no transmission risk of vancomycin-resistant enterococcal strains to man or transfer of their resistance genes to other bacteria belonging to the endogenous flora of humans. 相似文献
17.
The objective of this study was to compare Salmonella prevalence and antimicrobial resistance between pasture and conventional poultry farms. We collected the first Salmonella prevalence and antimicrobial resistance data on pasture poultry farms. Fecal droppings were collected from 31 farms from Wisconsin (nine farms from each production type) and the Southeast (North Carolina, Virginia, and South Carolina; five conventional and 10 pasture poultry farms) in a 1-yr period. The specimens were cultured for Salmonella and tested for resistance to 12 antimicrobials. A univariate analysis was conducted to determine the significant differences in prevalence and resistance. At the farm level, no significant difference in Salmonella prevalence was found on 33% pasture and 47% conventional poultry farms (P= 0.4928). On an individual specimen level, flocks reared conventionally had higher prevalence than in pasture (P < 0.0001). Of all the isolates found to have resistance, 80% were from the Southeast. Of all the pasture isolates tested, 5% (8 of 162) were resistant to ceftriaxone, which is higher than previously reported from any production setting. None of the isolates from conventional flocks showed resistance to ceftriaxone. Multidrug resistance (resistance to three or more classes of antimicrobials) was found in 69% of the isolates from conventional farms and 11% on pasture farms in the Southeast (P < 0.0001), with the predominant resistance type of AmCSSuTeAx (ampicillin, chloramphenicol, streptomycin, sulfasoxazole, tetracycline, amoxicillin/clavulanic acid; 62%). About 5% of the pasture isolates from the Southeast showed the AmAxCFCRO (ampicillin, amoxicillin/clavulanic acid, cephalothin, ceftriaxone) multidrug resistance pattern. None of the isolates from Wisconsin were found to be multidrug resistant. 相似文献
18.
The purpose of the present study was to determine the prevalence of antibiotic resistance, with special attention to vancomycin, in 104 strains of Enterococcus, which is the sentinel bacterium isolated from dog and cat faeces samples. The phenotypic characterization of the isolates classified them as E. faecium (58%), E. avium (41%) and E. faecalis (1%). Sensitivity testing used the diffusion method according to the recommendations of CASFM (Comité de l'Antibiogramme de la Société Française de Microbiogie), to oxacillin, amoxycillin, amoxycilin + clavulanic acid, ampicillin, piperacillin, cefoperazone, imipenem, enrofloxacin, ciprofloxacin, οfloxacin, nalidixic acid, tetracycline, lincomycin, erythromicin and vancomycin. Minimum inhibitory concentration (MIC) determination by E test revealed a MIC to vancomycin of between 0.5 μg/ml and 3 μg/ml. All the strains were resistant to nalidixic acid, erythromycin, cefoperazone and oxacillin. We detected resistance to amoxycillin + clavulanic acid in 1.9% of isolates, to amoxycillin in 4.8%, to piperacillin in 13.5%, and to ampicillin in 21.2% of strains. A high prevalence of antibiotic resistance to lincomycin, tetracycline, enrofloxacin, ciprofloxacin and ofloxacin was found in 98.1%, 95.2%, 76.9%, 73.1% and 64.4% of strains, respectively. Resistance to vancomycin was not found, which indicates that there is no transmission risk of vancomycin‐resistant enterococcal strains to man or transfer of their resistance genes to other bacteria belonging to the endogenous flora of humans. 相似文献
19.
Klimiene I Ruzauskas M Spakauskas V Matusevicius A Mockeliūnas R Pereckiene A Butrimaite-Ambrozeviciene C Virgailis M 《Polish journal of veterinary sciences》2011,14(3):467-472
The aim of the study was to isolate gram-positive cocci from cows with mastitis and to determine their resistance to beta-lactamic antibiotics. Eight hundred and nine strains were isolated and identified as staphylococci (n=516), streptococci (n=199) and enterococci (n=94) from sub-clinical and clinical cases of bovine mastitis in Lithuania. The most common causative agents of udder disease included: S. epidermidis (n=176), S. aureus (n=176), S. agalactiae (n=134), S. hyicus (136) and E. hirae (n=68). Isolates were analysed for antimicrobial resistance to penicillin, ampicillin, amoxicillin, cephalothin, cephalexin, amoxicillin + clavulanate. The susceptibility patterns were analysed using the agar disk diffusion method. S. aureus showed the highest level of resistance to amoxicillin (81.3%), penicillin (76.7%) and ampicillin (78.4%). The corresponding values for CNS strains were 59.7%, 59.7% and 50.6% against penicillin, ampicillin and amoxicillin respectively. Streptococci were the most frequently resistant to amoxicillin (29.3%), and enterococci to penicillin (27%), amoxicillin (27.5%) and amoxicillin/clavulanic acid (23.8%). The resistance of all tested mastitis pathogens to aminopenicillins and penicillin highly correlated (r=0.83). Compared with other antibiotics, amoxicillin and clavulanic acid combination tended to be more effective (p<0.05) against all tested bacteria in vitro. However, S. aureus, in 38.1% of cases, was resistant to this combination of antimicrobials. This study demonstrates that S. epidermidis, S. aureus, S. hyicus, S. agalactiae and E. hirae remain the most frequent mastitis causative agents on Lithuanian cattle farms. The highest resistance in vitro to penicillins was demonstrated by S. aureus, S. hyicus and S. intermedius. Resistance to cephalosporins remains low, irrespective of bacterial species of gram-positive cocci. 相似文献
20.
Ray KA Warnick LD Mitchell RM Kaneene JB Ruegg PL Wells SJ Fossler CP Halbert LW May K 《Preventive veterinary medicine》2007,79(2-4):204-223
The objective of this study was to determine the prevalence of antimicrobial resistance among Salmonella isolated from dairy herds in New York, Minnesota, Michigan, and Wisconsin, USA. Serogroup and antimicrobial susceptibility characteristics were determined for Salmonella from cattle and environmental samples collected during August 2000–October 2001 as part of a longitudinal study where 129 herds were visited at 2-month intervals. Salmonella isolates were tested (using a broth microdilution method) for susceptibility to amoxicillin/clavulanic acid, ampicillin, ceftiofur, ceftriaxone, cephalothin, chloramphenicol, ciprofloxacin, gentamicin, kanamycin, nalidixic acid, streptomycin, sulfamethoxazole, tetracycline, and trimethoprim/sulfamethoxazole. Of the 1506 isolates tested for minimum inhibitory concentrations to these 14 antimicrobial agents, 81.2% were pan-susceptible and for most herds (81.6%) the predominant antimicrobial resistance pattern was pan-susceptible. At least 1 Salmonella isolate resistant to 5 or more antimicrobial agents was found on 23.6% of herds. This resistance phenotype was most common among serogroups B and E1 and among samples from calves and farmer-designated sick cows. Resistant samples most frequently exhibited resistance to tetracycline, streptomycin, and/or ampicillin. No samples were resistant to ceftriaxone (though 13 were in the intermediate range), and very few samples were resistant to ciprofloxacin (n = 1), nalidixic acid (n = 5), or trimethoprim/sulfamethoxazole (n = 7). 相似文献