共查询到19条相似文献,搜索用时 62 毫秒
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本研究旨在分离鉴定来自北京某奶牛场死亡奶牛肺脏的1株疑似病原菌CVCC 3982,并测定其致病性。通过分离培养获得疑似病原菌,采用Biolog鉴定系统和16S rDNA序列分析对其进行了鉴定,人工接种CD-1小鼠测定了其致病性,合成引物对其主要毒力基因进行了检测。结果显示,该疑似病原菌为革兰氏阳性杆菌,β溶血,Biolog鉴定结果显示其为化脓隐秘杆菌,其16S rDNA序列与化脓隐秘杆菌模式菌株NCTC 5224的同源性达100%,系统发育分析显示其与化脓隐秘杆菌处于同一分支。腹腔注射该菌可致小鼠死亡。分离菌株基因组中含有溶血素(PLO)基因,神经氨酸酶H(NanH)基因,神经氨酸酶P(NanP)基因,菌毛基因(fimA、fimC和fimE),但缺失胶原结合蛋白(CbpA)基因和菌毛fimG基因。结果表明该分离菌株为化脓隐秘杆菌且具有致病性。 相似文献
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摘要:为分离鉴定牛源化脓隐秘杆菌(Arcanobacterium pyogenes)并建立其PCR检测方法,本研究从某规模化奶牛场患牛肺组织中分离出两株细菌,根据其形态特征、培养特性及生化特性,结合16S rRNA分析确定分离茵为A.pyogenes.对小鼠致病性试验显示纯培养物对小鼠致死率较高,药敏试验表明分离茵仅对少数种类抗生素如头孢唑啉、氧氟沙星、阿奇霉素等敏感.本研究同时建立了快速检测A.pyogenes溶血素(PLO)基因的PCR方法,敏感性试验显示最低检出菌数为9.2×103 cfu/mL,特异性试验表明与其他细菌如布鲁氏茵、大肠杆菌等无交叉反应,通过对已知临床样本检测评估显示该方法适用于临床感染样品的检测. 相似文献
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《中国兽医杂志》2015,(6)
通过对重庆某羊场送检病死羊只进行病原菌的分离培养、形态学鉴定、生化鉴定、药敏试验、致病性试验及16S r RNA序列分析。结果从病变组织中分离到1株革兰阳性短棒状杆菌,其对多种抗生素敏感,能够引起小鼠肝脏和肺脏发生病变,PCR扩增出长为1 434 bp的目的序列,已被Gen Bank数据库收录,序列号为KJ842125,将该序列与NCBI中公布的序列进行比对,发现所得序列与化脓隐秘杆菌(Arcanobacterium pyogenes,登陆编号为HQ712123)同源性高达98%,将该序列与其相关性较高菌株的16S r RNA构建系统发育进化树,与化脓隐秘杆菌聚为一簇。本研究为化脓隐秘杆菌致病机理、诊断技术和疾病控制奠定了基础。 相似文献
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为确定重庆地区1株患病梅花鹿的致病菌,并探究其主要生物学特性,本试验采集病死梅花鹿肺脏,通过细菌分离、生化鉴定和16S rDNA测序对分离菌进行鉴定,随后对其致病性、毒力基因、药物敏感性以及生长曲线等主要特性进行分析。致病菌经鉴定为化脓隐秘杆菌,对小鼠具有较强的致病性,皮下和腹腔均能感染并产生典型症状,病死小鼠肝脏、脾脏、肺脏、肾脏产生坏死、出血和炎性细胞浸润为主要特征的组织病理学变化,对小鼠的半数致死量(LD50)为6.80×1010 CFU/mL,将其命名为YC-1;毒力基因检测显示,YC-1菌株具有2个神经氨酸酶(NanH、NanP)、2个菌毛蛋白(FimA、FimE)和1个溶血素(PLO)共5个毒力基因,其中PLO全长1 605 bp(GenBank编号OK513198),氨基酸进化树与霍加狓源化脓隐秘杆菌最为接近;药敏试验显示,YC-1对多种抗生素均敏感,耐药特征不明显;细菌的生长曲线显示在37℃,含有5%胎牛血清的TSB培养基中,培养6~10 h为该菌的对数生长期。本试验解析我国梅花鹿源化脓隐秘杆菌主要生物学特性有助于深入研究该菌... 相似文献
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从天津地区某猪场病猪肺脏脓肿中分离到一株具有β溶血特性的细菌,经形态学与生化特性分析,初步确定为化脓隐秘杆菌(Arcanobacterium pyogenes),并命名为TJjh1913.利用PCR扩增16S rRNA基因,经Blast序列分析,其序列与GenBank数据库中猪源化脓隐秘杆菌的核苷酸序列同源性高达99.... 相似文献
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猪化脓隐秘杆菌的分离与鉴定 总被引:2,自引:1,他引:2
从一例肝、肺化脓性结节,脾出血性肿大的病猪体内分离到一株革兰氏阳性、细长、形态不规则的杆菌,该菌在TSA平板、普通绵羊血琼脂、巧克力平板上生长缓慢,在普通绵羊血琼脂上呈α-溶血。对该菌的16S rDNA进行PCR扩增、测序、比较,结果显示该菌与化脓隐秘杆菌的16S rDNA有99%的同源性,进一步用API生化鉴定,结果也与其相符。该菌在24~52 h内100%致死小白鼠,腹腔接种新西兰兔,接种兔72 h内死亡,表明该菌为致病性细菌。 相似文献
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化脓隐秘杆菌是引起家畜乳房炎、子宫内膜炎、肺炎等感染的重要病原菌之一,给养殖业带来了较大的损失。在我国,90%以上的奶牛子宫内膜炎是由病原微生物引起的,经鉴定其中23.5%微生物是化脓隐秘杆菌,因此,深入地研究和探索化脓隐秘杆菌不仅对有效防治奶牛子宫内膜炎具有指导意义,而且对控制病原菌的传播提供重要的理论依据。 相似文献
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Renan B. Paiano Jeannine Bonilla Andrea M. Moreno Pietro S. Baruselli 《Reproduction in domestic animals》2021,56(12):1536-1542
The aim of this study was to identify the impact of Trueperella pyogenes in cows with clinical endometritis (CE) on reproductive performance and milk production in affected cows. In total, 230 lactating Holstein dairy cows from six commercial dairy herds were sampled once between 28 and 33 days post-partum. Cows included in the present study did not receive antibiotic or anti-inflammatory treatments prior to the experimental period. Clinical endometritis (CE) was characterized as cow with vaginal mucus score = 3 (>50% of purulent vaginal discharge) and >18% polymorphonuclear neutrophilic leukocyte (PMNL). The body condition scores (BCS) and milk production were evaluated at the time of enrolment. The identification of isolated bacteria was carried out through the analysis of MALDI-TOF MS (matrix-assisted laser desorption ionization time-of-flight mass spectrometry). According to uterine health, three groups of dairy cows were formed: healthy control cows without T. pyogenes (n = 147), CE cows with T. pyogenes (n = 22) and CE cows without T. pyogenes (n = 61). CE cows with T. pyogenes had lower BCS, milk production and conception at first AI (p < .01) than CE cows without T. pyogenes and control cows. Furthermore, CE cows with T. pyogenes had higher (p < .01) service per pregnancy and had greater (p < .01) days to get pregnant than CE cows without T. pyogenes and control cows. This study demonstrates that CE cows with T. pyogenes had impaired reproductive performance and milk production when compared to cows without CE and CE cows without T. pyogenes. This information can contribute to a strategic treatment in cows affected by clinical endometritis, favouring the rational use of antibiotics on dairy farms. 相似文献
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Turk R Juretic D Geres D Turk N Rekic B Simeon-Rudolf V Svetina A 《Research in veterinary science》2004,76(1):57-61
The effect of early lactation on serum paraoxonase activity was studied on 21 postpartum dairy cows and 19 non-pregnant late lactating dairy cows. A significant decrease of the paraoxonase activity was found in the early postpartum period compared to the late non-pregnant lactation. The serum triglyceride, cholesterol and LDL-cholesterol concentration were also markedly reduced during the postpartum period, while the serum HDL-cholesterol concentration showed no significant change. The results indicate that lower serum paraoxonase activity is associated with lipid metabolic disorders in the early postpartum period. A decreased serum paraoxonase activity may lead to the reduction of the antioxidative capacity and antioxidative protection during the early postpartum period. 相似文献
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利用16SrDNA结合PCR-DGGE技术分析比较了产后45d健康奶牛和患子宫内膜炎奶牛阴道内细菌群落多样性及其差异,并通过切胶、克隆测序等步骤分析了奶牛阴道细菌种类。研究结果表明,患病奶牛DGGE图谱的条带数量、多样性指数均显著高于健康奶牛;健康奶牛阴道优势菌主要有清酒乳杆菌(Lactobacillus sakei subsp.)、魏斯杆菌(Weissella koreensis sp.)和地衣芽孢杆菌(Bacillus licheniformis),而患病组奶牛阴道内此3种优势菌含量显著降低或缺失,且也无其他明显优势菌存在;从健康和患病奶牛阴道内均分离出脆弱拟杆菌(Bacteroides fragilis)、溃疡拟杆菌(Bacteroides helcogenes)、无乳支原体(Mycoplasma agalactiae)、普氏菌(Prevotella dentalis)、产气荚膜梭菌(Clostridium perfringens str.)和肠球菌(Enterococcus hirae)等常见病原微生物,在患病奶牛阴道内分离出大肠杆菌(Escherichia coli str.K-12 substr.)、梭杆菌(Fusobacterium nucleatum subsp.)等特定致病菌。研究结果提示,子宫内膜炎奶牛阴道内菌群结构比健康奶牛更为复杂,且无优势菌,阴道菌群结构失衡可能是奶牛发生子宫内膜炎的原因。 相似文献
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Lipid mobilization and inflammatory responses during the transition period of dairy cows 总被引:1,自引:0,他引:1
Contreras GA Sordillo LM 《Comparative immunology, microbiology and infectious diseases》2011,34(3):281-289
The transition period of dairy cattle is characterized by dramatic changes in metabolism and host defense mechanisms that are associated with increased disease. Intense lipid mobilization from tissue stores is an important metabolic adaptation during the transition period that results in significant release of non-esterified fatty acids (NEFA) into the blood stream. Whereas these fatty acids are important sources of energy during times of increased metabolic demands, elevated concentrations of NEFA are known to disrupt several immune and inflammatory functions. This review will discuss the implications of lipid mobilization on inflammatory responses with special emphasis on leukocytes and endothelial cell functions during the transition period of dairy cows. 相似文献
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P. Gregorini B. DelaRue K. McLeod C.E.F. Clark C.B. Glassey J. Jago 《Livestock Science》2012,146(1):95-98
The short-term adaptations of cattle behavior to time restrictions at pasture are poorly understood. This study explored the diurnal rumination pattern of dairy cows in response to restrictions to time at pasture. Six groups of eight Holstein–Friesian cows (470 ± 47 kg, 35 ± 9 days in milk) were strip-grazed on a perennial ryegrass (Lolium perenne L.) pasture over 21 days (2 groups per treatment) for either 4 h after each milking (2 × 4), one period of 8 h between milkings (1 × 8), or 24 h excluding milking times (control, CTL). All cows were equipped with HR Tag™ rumination collars which recorded chewing activity and regurgitation of digesta boluses during rumination. Cows in 1 × 8 reduced daily rumination time by 36% compared with cows in 2 × 4 and CTL (304, 402 and 423 SED 26.3 min, respectively). There were no differences in the average intervals between regurgitation of digesta boluses (48.9 ± 0.96 s) and average interval between chewing actions was also similar (0.7 ± 0.02 s) between treatments. Treatment affected the diurnal rumination pattern. There was little rumination during the time at pasture for the restricted cows (1 × 8 and 2 × 4), whereas the CTL cows ruminated for almost a third of the time between the am and pm milking. In all treatments, cows ruminated the longest during the night. These results suggest grazing dairy cows modulate their time for rumination to compensate for a reduction in available grazing time. This behavioral study contributes to the understanding of changes in rumination behavior and associated effects in grazing dairy cattle in response to hunger. 相似文献
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Chong Wang ;Zhen Liu ;Diming Wang ;Jianxin Liu ;Hongyun Liu ;Zhiguo Wu 《畜牧与生物技术杂志(英文版)》2014,(4):479-484
Background:Phosphorus(P) supplementation is costly and can result in excess P excretion.This study investigated the effects of reducing dietary P on milk production and P excretion in dairy cows over a full lactation.Method:Forty-five multiparous Holstein dairy cows were divided into 15 blocks according to expected calving date and previous milk yield,and assigned randomly to one of the three dietary treatments:0.37,0.47,and 0.57%P(DM basis);these P levels represent the NRC recommendations,Chinese recommendations,and the amount of dietary P commonly fed by Chinese dairy farmers,respectively.Average daily feed intake was calculated from monthly data on feed offered and refused.Milk yields of individual cows were recorded weekly,and milk samples were taken for analysis of protein,fat,solids-not-fat,lactose,and somatic cell count.Blood samples were collected on days-6,-3,0,3,6 relative to calving,and then monthly throughout lactation,and analyzed for P and Ca concentrations.Spot samples of feces and urine were collected for 3 consecutive d during weeks 12,24,and 36,and P concentrations were analyzed.Reproduction and health data were recorded.Results:Dietary P did not affect dry matter intake or milk yield(P〉 0.10).Milk fat content was slightly higher in cows fed 0.37%P than in cows fed 0.47%P(P = 0.05).Serum concentrations of P and Ca did not reflect dietary P content(P〉 0.10).Fecal and urinary P both declined linearly(P〈 0.05) as dietary P decreased from 0.57 to0.37%.Fecal P content was 25%less when dietary P was 0.37%compared to 0.57%.Health events and reproductive performance were not associated with dietary P content(P〉 0.05).Conclusions:Lowering dietary P from 0.57 to 0.37%did not negatively affect milk production,but did significantly reduce P excretion into environment. 相似文献
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E. Kebreab M.A. Shah D.E. Beever J.D. Sutton I. Mueller-Harvey 《Livestock Production Science》2005,93(2):125-135
The effects of different forage mixtures on duodenal flow and faecal output of phosphorus (P) were measured in lactating dairy cows in two experiments. The forages comprised grass silage (GS) alone or mixtures of GS and urea-treated whole crop wheat (WCW). Replacement of GS by high levels of WCW resulted in a significant decrease in total P (TP), water-soluble P (WSP) and acid-soluble P (ASP) intakes, but increased phytate P (PP) and acid-insoluble P (AIP) intakes. Duodenal flows of all P fractions were unaffected by dietary treatments. However, the amounts of all fractions flowing to the intestine were much higher than the amounts consumed—with the exception of AIP, which was unchanged, and PP, which was considerably reduced. Diets did not significantly affect faecal outputs of TP, ASP, PP and AIP; however, faecal outputs of WSP were significantly higher on WCW than GS diets. Inclusion of WCW significantly decreased TP and WSP availabilities in the total tract but did not affect PP and AIP availabilities. A new fraction of P, which was not present in the feeds, was found in significant amounts in the intestines and proved to be soluble in dilute acid but insoluble in water. Estimated annual excretions for a herd of 100 cows ranged from 1550 to 1721 kg for total P of which 337-786 kg was WSP. The results suggest that GS based diets deposit more P in the environment. However, the potential to cause P pollution depends not only on the quantity but also on the nature of faecal P and on soil parameters. 相似文献