内蒙古地区奶牛子宫内膜炎大肠杆菌的分离及其耐药性研究

子宫内膜炎是奶牛常发的一种生殖系统疾病,不仅影响机体正常的生理功能,而且会导致患牛长期不孕,有的甚至造成终生不孕.据调查,我国奶牛子宫内膜炎的平均发病率约为20%.在奶牛不孕症中,由子宫内膜炎所致的不孕奶牛约占60.1%～92.0%[1].该病主要由分娩或产后子宫感染病原微生物引起,其中以大肠杆菌、葡萄球菌、链球菌等感染最为常见[2].     

子宫内膜炎不孕症奶牛子宫内细菌分离鉴定

在调查奶牛不孕症的基础上,进行分离鉴定临床确诊的子宫内膜炎不孕症奶牛子宫内细菌。普查了共853头奶牛,不孕症奶牛占普查牛11.8%,子宫内膜炎不孕症奶牛占不孕症奶牛的66.3%,其它原因不孕症奶牛占不孕症奶牛的33.7%。被测奶牛子宫内容物均有细菌存在。从临床确诊的子宫内膜炎不孕症奶牛的子宫内容物中,分离到细菌菌株119株,其中葡萄球菌36株、链球菌40株、大肠杆菌36株、变形杆菌4株、芽孢杆菌1株、化脓棒状杆菌1株。     

奶牛子宫内膜炎致病性大肠杆菌的分离鉴定及耐药性分析

试验为了解和掌握大庆及其周边奶牛场奶牛子宫内膜炎致病性大肠杆菌对14种药物的敏感程度,进行了药敏试验检测,对部分药物产生的耐药性进行了分析,同时筛选出的敏感药物,为该地区合理用药提供科学指导。     

奶牛子宫内膜炎病原菌分离试验

子宫内膜炎是奶牛易患的一种生殖系统疾病。美国每年因奶牛不孕症造成的经济损失近2．5亿美元，英国不孕牛中约95％是因子宫内膜炎而致，我国奶牛子宫内膜炎的发病率也很高，1981～1987年奶牛子宫内膜炎发生率平均为18．97％。现代医学研究表明，奶牛子宫内膜炎的发生除了与饲养管理、环境卫生、配种技术等因素有关外，主要与传染性因素、继发因素、营养因素等有关。奶牛子宫内膜炎的直接病因是病原微生物的感染。病原菌种类较多，本试验主要目的是了解安徽省合肥市奶牛子宫内膜炎的病原菌种类，为今后进一步制定治疗和预防措施提供理论和技术支持。现将试验结果报告如下。     

奶牛子宫内膜炎厌氧菌的分离鉴定

子宫内膜炎是奶牛子宫内膜的炎症,是危害奶牛业发展的四大疾病之一.该病的发病率很高,国外许多资料报道,发病率在30%～40%,而90%的不孕症是由隐性子宫内膜炎引起的. 为了探讨产后正常奶牛和一些屡配不孕的、被临床诊断为隐性子宫内膜炎的奶牛体内都有哪些细菌,哪些是致病菌,设计了此试验.     

南京某奶牛场子宫内膜炎病原菌分离鉴定及药敏试验

子宫内膜炎是奶牛易患的一种生殖系统疾病，不仅影响其正常生理功能，还会导致其长期不能正常怀孕，有时还会继发其他生殖系统疾病造成终生不孕。美国每年因奶牛不孕症造成的经济损失近2．5亿美元，英国不孕牛中约95％是由于子宫内膜炎引起，1980-1985年间成年奶牛子宫内膜炎发生率平均为37％；     

内蒙古局部地区奶牛不孕症的调查及子宫内膜炎性不孕症奶牛子宫内细菌分离鉴定

在调查奶牛不孕症的基础上，对临床确诊的子宫内膜炎性不孕症奶牛子宫内细菌进行分离鉴定。共普查了853头奶牛，不孕症奶牛占普查牛的11．8％，子宫内膜炎性不孕症奶牛占不孕症奶牛的66．3％，其他原因不孕症奶牛占不孕症奶牛的33．7％。被测奶牛子宫内容物均有细菌存在。从临床确诊的子宫内膜炎性不孕症奶牛的子宫内容物中，分离到细菌菌株119株，其中葡萄球菌36株，链球菌40株，大肠杆菌36株，变形杆菌4株，芽孢杆菌2株，化脓棒状杆菌1株。     

奶牛子宫内膜炎致病菌的分离鉴定及耐药性分析

本试验通过对四个大型奶牛场的60头子宫内膜炎患牛进行调查、采样，并用常规的方法对细菌进行分离、培养、鉴定。共分离到细菌59株，其中分离率最高的是埃希氏大肠杆菌14株（23．7％）、葡萄球菌属12株（20.3％）、链球菌属7株（11．8％）（其中溶血性链球菌2株）、棒状杆菌属7株（11．8％）、双球菌5株（8．5%）、肠杆菌属6株（10．16％）、沙门氏菌3株（5．1％）、克雷伯氏杆菌属2株（3．4％），而且分离到了梭菌属3株（严格厌氧菌），药敏试验分析显示，大多数致病菌对喹诺酮类药物、阿莫西林及氨苄青霉素等药物耐药率较高．而对头孢菌素类药物和氨基糖苷类药物耐药率则较低。     

河北省奶牛子宫内膜炎致病性大肠杆菌的耐药性及可移动遗传元件检测

从河北省各地采集患有子宫内膜炎奶牛的病料,对大肠杆菌进行分离鉴定,并对其致病性、血清型、耐药性及可移动遗传原件进行检测。结果显示,分离得到了29株致病性大肠杆菌。在这些菌株中,检测出4种血清型,其中O89与O128为优势血清型。分离菌对新霉素耐药率高达68.97%(20/29);17株为多重耐药菌,它们对β-内酰胺类和四环素类抗生素耐药率均高于58.82%(10/17);qnrB耐药基因的检出率高达86.21%(25/29);共检测出intI1、tnpU、tnp513、traA、ISEcp1和trbC 6种可移动遗传原件,携带可移动遗传原件越多的细菌,细菌的耐药基因数量越多,多重耐药性越强。本试验分析了河北地区奶牛子宫内膜炎大肠杆菌的耐药表型与耐药基因的传播情况,为奶牛子宫内膜炎的治疗提供了理论依据。     

黑龙江省鸡西地区奶牛子宫内膜炎病原菌分离鉴定及耐药性研究

从黑龙江省鸡西地区部分奶牛场选取25头临床诊断为子宫内膜炎的患牛,并从这25头患牛体内分离得到39株细菌,其中大肠杆菌17株、葡萄球菌13株、链球菌5株、其他菌4株。耐药性试验表明,大肠杆菌、葡萄球菌和链球菌都对头孢曲松钠和头孢噻呋钠敏感,对庆大霉素比较敏感,对其他几种常用抗生素存在不同程度耐药性。     

水禽源致病性大肠杆菌流行病学调查及耐药性分析

为了解江苏省水禽源大肠杆菌毒力基因分布情况,并分析其耐药性,采集了江苏部分地区64个养殖场疑似大肠杆菌性腹泻鸭的泄殖腔拭子510份,制备DNA模板,运用PCR技术进行检测,利用药敏纸片琼脂扩散法对100株分离株进行药敏试验.结果 表明:江苏部分地区水禽养殖场致病性大肠杆菌阳性率65％左右;分离株对磷霉素、多黏菌素B比较...     

Serotyping of O and pilus antigens of Escherichia coli strains isolated from chickens with coli-septicemia.

One hundred and fifty one Escherichia coli strains were isolated from broiler chickens with coli-septicemia in Aichi (63 strains), Shizuoka (58 strains), and Kagoshima (30 strains) prefectures from 1980 to 1987, and their O and pilus antigens were serologically typed. One hundred and twenty five strains (82.8%) were typed into 23 O serogroups, and twenty six strains (17.2%) remained untypable. The predominant O serogroups were O2 (35 strains, 23.2%) and O78 (24 strains, 15.9%). Distribution of O serogroup was different, depending on prefectures where they are isolated. In total, 109 strains (72.2%) possessed Type 1 and/or Fmsha pili (Type 1; 41 strains, Fmsha; 22 strains, and Type 1 and Fmsha; 46 strains), and 42 strains (27.2%) were non-piliated. All the strains lacked K88, K99, 987P, F41, and Att25 pili. The ratios of piliated strains to non-piliated ones were almost the same among the three prefectures. Strains possessing Type 1 pili showed variety of O antigens, but most of the strains with Fmsha pili belonged to O2 serogroup.     

Incidence of drug resistance and transmissible R factors in strains of E. coli isolated from faeces of healthy pigs

Two hundred and twenty-six strains of E. coli were isolated from faeces of 107 pigs at different ages and without clinical signs of infectious diseases. The resistance of the strains to sulphonamide, tetracycline, streptomycin, chloramphenicol, ampicillin, and nalidixic acid was determined. In 74 % of the animals the predominant E. coli flora was found to be resistant to one or more of the drugs mentioned. Fifty-three % of the strains were resistant. Multiple resistance was predominant among resistant strains (67 %). R factors transmissible to a sensitive strain of E. coli K12 W3132 were demonstrated in 28 %. The proportion of resistant strains was largest in young animals (0–14 weeks) accounting for 65 % of the strains isolated, as compared to 43 % of strains from pigs and sows (6 months or more). The incidence of resistance to sulphonamide, tetracycline, and streptomycin was high, whereas most of the strains were sensitive to ampicillin and chloramphenicol. All strains were sensitive to nalidixic acid.The incidence of resistance to antibiotics in a population of pigs to whom these drugs are not fed but applied as therapeutic agents solely seems rather high. When based on clinical findings only, the value is therefore questionable of sulphonamide, tetracycline and streptomycin treatment of infectious diseases caused by E. coli.     

新疆奶牛乳房炎大肠杆菌种系分类群和基因相似性研究

为了研究新疆地区奶牛乳房炎病例中大肠杆菌的种系分类群及其基因相似性,从新疆4个地区7个牛场奶牛乳房炎奶样分离的大肠杆菌中选出90株,用PCR扩增具有种系分类群标记的chuA、yiaA基因和TSPE4.C2 DNA片段.试验结果显示,所检测菌株中A群占93.33%,B1群占6.67%,未检测到属于B2和D群的肠外毒力株.进一步用RAPD技术分别以3个随机引物对这些菌株进行基因相似性分析并构建系统发育树,当相对基因相似性为0.25时,被检菌株分为10(A-J)个亚群,其中41.1%的菌株属于A亚群,21.1%的属于B亚群,17.8%的属于C亚群,其它20%的菌株不均匀的分布在7(D-J)个亚群中.其中,乌鲁木齐周边3个牛场50%的菌株、伊犁地区55.6%的菌株分布在A亚群,昌吉地区2个牛场66.7%分离菌株平均分布在A亚群和B亚群,库尔勒地区牛场25%分离菌株分布在A亚群,58.3%分布于C亚群.根据种系分类群标记研究结果显示,本次从奶牛乳房炎奶样中分离出的被检菌株均属于共生性大肠杆菌.基因相似性研究结果显示,大部分菌株分布在3个亚群中,不同地区分离菌株的基因相似性存在差异.     

邵阳地区宠物犬源致病性大肠杆菌的血清型鉴定及耐药性分析

为了分析邵阳地区宠物犬源致病性大肠杆菌的血清型与耐药性,采用细菌分离鉴定的方法对38家宠物医院中无菌采集的87份腹泻宠物犬肛拭子及粪便样品进行大肠杆菌分离鉴定,采用人工感染动物试验、玻板凝集试验和K-B药敏纸片法分别检测分离菌株的致病性、血清型及耐药性。结果显示:分离得到了49株大肠杆菌,其中34株为致病性;34株致病性大肠杆菌分离株属于9种血清型,以O_2、O_9、O_(13)和O_(20)为主要的优势血清型;34株致病性大肠杆菌分离株对阿莫西林、氨苄西林、美罗培南等4种药物耐药率在82.4%～94.1%之间,对丁胺卡那、头孢他啶、恩诺沙星等6种药物的耐药率在41.2%～79.4%之间,对头孢曲松、头孢噻肟耐药率在14.7%～23.5%之间。研究结果为该地区宠物犬大肠杆菌病防治提供参考。     

大肠杆菌性子宫内膜炎对山羊血液和子宫内膜的影响

用致病性大肠杆菌经子宫角插管灌入子宫腔,以建立山羊子宫内膜炎疾病模型。经检测发现,致病性大肠杆菌在子宫静脉血液中呈一过性存在;子宫卵巢静脉和颈静脉血液中性粒细胞数量明显增加。其中,颈静脉血液嗜中性粒细胞增多明显于子宫静脉血液,颈静脉血液淋巴细胞降低明显于子宫静脉血液。病羊子宫黏膜损伤、炎性细胞浸润,子宫内膜上皮分泌细胞微绒毛和纤毛成片或部分脱落。     

Penetration of drug resistance in Escherichia coli isolated from laboratory animals

A total of 713 strains of fecal Escherichia coli (E. coli) isolated from laboratory animals in the colonies of 4 research laboratories and 4 commercial breeders in Japan in 1994 were examined in regard to resistance to 8 antibacterial agents. The incidence of resistance to sulfadimethoxine (Su), streptomycin (Sm), ampicillin, cephaloridine, tetracycline, chloramphenicol, kanamycin, and gentamicin was 99.9%, 32.5%, 6.7%, 0.7%, 7.0%, 2.6%, 6.6% and 0.7%, respectively. These results indicated that Su and Sm resistance are penetrating into normal E. coli strains isolated from laboratory animals.     

Distribution of oxytetracycline resistance genes in E. coli isolated from pigeon faecal samples

Tetracycline- resistant bacteria have emerged due to the selective pressure of antimicrobial use. The aim of this study was to determine the prevalence of oxytetracycline resistance of Escherichia coli from pigeon faecal samples. All strains were examined for the presence and types of oxytetracycline resistance determinants using disc diffusion and polymerase chain reaction methods. Of 50 faecal E. coli isolates, 30 (60%) were resistant to oxytetracycline. Polymerase chain reaction analyses indicated that the most common genes found in these isolates were tetB (43.3%) and tetA (30%). Only 10% and 3.3% of the isolates contained otrA and otrB, respectively. In conclusion, our findings suggest that oxytetracycline-resistant strains of E. coli are disseminated in pigeons.     

鹅致病性大肠杆菌耐药性与整合子研究

为研究鹅致病性大肠杆菌(E.coli)耐药性及其整合子,本实验采用Kirby-Bauer法检测1株鹅致病性E.coli对22种抗菌药物的敏感性,并对Ⅰ类整合子和qacE△1-sul1基因进行PCR检测及序列分析。结果表明该菌株只对阿莫西林/棒酸、头孢孟多、氧氟沙星、左氧氟沙星4种药物敏感,对环丙沙星、洛美沙星中度敏感,而对其他16种药物表现多重耐药性。PCR检测结果表明Ⅰ类整合子和qacE△1-sul1基因为阳性,Ⅰ型整合子扩增出约1 200 bp的基因盒插入区片段,将该片段测序与GenBank中的相关序列进行比对,结果表明该基因盒插入区携带arr-3和dfrA27的基因盒,它们分别是编码对利福平和甲氧氨苄嘧啶耐药的蛋白,这提示我们应从基因水平上监测细菌的耐药情况。     

Characterization of integrons-mediated antimicrobial resistance among Escherichia coli strains isolated from bovine mastitis

To assess the prevalence of antimicrobial resistance and class I integrons in Escherichia coli strains (n=58) isolated from bovine mastitis in Inner Mongolia, antimicrobial susceptibility and the presence of various types of integrons were characterized. Most isolates were susceptible to amikacin, colistin, ceftazidime, gentamicin and kanamycin, while those also exhibited high resistant incidence rates to ampicillin, amoxicillin, sulfadiazine and sulfamethoxydiazine. The integrase gene of integrons was amplified by PCR using degenerate primers. The integrons were confirmed by restriction fragment length polymorphism (RFLP) analysis of positive PCR products. Neither class II nor class III integron was detected, while 56.90% (n=33) of the isolates were positive for the presence of intI1 gene. Sequencing analysis of gene cassettes revealed that seven gene cassettes were found, which encoded resistance to trimethoprim (dfrA1 and dfrA17), aminoglycosides (aacA4, aadA1 and aadA5) and chloramphenicol (catB3), respectively. Of them, the gene cassette array dfrA17-aadA5 was found most prevalent (62.96%). The percentage of positive-integron among the isolates whose resistant profile was relatively broad (n> or =7) is 100.00%, while the one in narrow-profile isolates (n=2-6) is 30.56%. The correlation analysis revealed the incidence of integrons among the isolates were highly related to the resistant profile, indicating integrons play an important role in the dissemination and spread of the antimicrobial resistant strains.