空肠弯曲菌产肠毒素性的研究

通过间接ＥＬＩＳＡ法和ＣＨＯ细胞法和２８６株空肠弯曲菌产生细胞紧张性肠毒素（Ｃｙｔｏｔｏｎｉｃ Ｅｎｔｅｒｏｔｏｘｉｎ,ＣＥ）的检测,ＣＥ的栓出率分别为２４．５％和１２．２％,间接ＥＬＩＳＡ法的敏感性明显高于ＣＨＯ细胞法（Ｐ〈０．００１）,并且特异性较高,即证实间接ＥＬＩＳ法检测,来自健康蛋白鸡、健康后备蛋鸡、腹泻死亡后备蛋鸡、腹泻后备蛋鸡、腹泻死亡仔猪、腹泻仔猪、健康羔羊和腹泻口才菌株的ＣＥ检出     

空肠弯曲菌毒力因子研究进展

空肠弯曲菌(Campylobacter jejuni)是世界范围内广泛流行的人畜共患病,在公共卫生学上具有重要意义。空肠弯曲菌可引发人和多种动物疾病,其抗原结构复杂,致病机理尚不清楚。作者通过对空肠弯曲菌可能的毒力因子及其在致病中的作用作一简要概述,为空肠弯曲菌的诊断防治提供依据。     

空肠弯曲菌致病机理研究进展

空肠弯曲菌是一种人畜共患病病原菌 ,可以引起人和动物发生多种疾病 ,并且是一种食物源性病原菌 ,被认为是引起全世界人类细菌性腹泻的主要原因 ,对空肠弯曲菌的致病机理的研究越来越多。其致病因素包括粘附、侵袭、产生毒素和分子模拟机制等四个方面 ,通过分子分子模拟机制可以引起最严重的并发症 -格林 -巴利综合征。空肠弯曲菌可以通过产生细胞紧张性肠毒素、细胞毒素和细胞致死性膨胀毒素而致病。就空肠弯曲杆菌致病机理研究现状作了概述。     

A national epidemic of campylobacteriosis in Iceland, lessons learned

Epidemics often result in organizational, policy and technical changes within a country. In 1999, an epidemic of campylobacteriosis was reported in Iceland. The recent availability of fresh poultry products in the marketplace was suggested as the source of infection. This paper reports on the context of the epidemic, reviews interventions implemented to prevent campylobacteriosis, and discusses lessons learned. A retrospective study of interventions implemented in Iceland from June 1995 to December 2007 was conducted by interviewing key informants and reviewing Iceland's literature. Cumulative incidence rates of domestic campylobacteriosis by year and average incidence rates per epidemic period were calculated. Interventions included on-farm surveillance of Campylobacter, producer education, enhanced biosecurity measures, changes in poultry processing, a leak-proof packaging policy, a freezing policy for products from Campylobacter-positive poultry flocks, consumer education, and the creation of a legislated inter-organizational response committee. These interventions appear to have collectively contributed to a decrease in campylobacteriosis' incidence rate near pre-epidemic baseline levels. Expert consultations revealed that the implementation of a Campylobacter surveillance program in poultry and the freezing policy were critical to controlling the disease in the Icelandic population. It was also recognized that new multidisciplinary collaborations among public health, veterinary, and food safety authorities and a sustained co-operation from the poultry industry were integral factors to the mitigation of the epidemic. Iceland's response to the campylobacteriosis epidemic is a lesson learned of inter-disciplinary and inter-organizational precautionary public health action in the face of a complex public health issue.     

温度和培养基对空肠弯曲菌冻融耐受性的影响

比较了１５株不同动物来源的空肠弯曲菌的冻融耐受性，结果表明，不同动物来源的菌株间冻融耐受性差异极显著（Ｐ＜０．０１），但与其来源动物不相关．并分析了—１０℃～３７℃、—２５℃～３７℃两种冻融温度和ＦＭＰＧ、Ｐ—基、ＭＳＧ、布氏半固体４种培养基对该菌冻融耐受性的影响，认为温度与培养基间存在极显著的互作现象（Ｐ＜０．０１），４种培养基对该菌耐受性的影响差异极显著，其中以ＦＭＰＧ和Ｐ—基对该菌冻融耐受性的增强效果最佳（６６．２％和６３．９％），ＭＳＧ的效果中等（５２．５％），布氏半固体最差（３１．２％）。在—１０℃～３７℃下，以Ｐ—基最优（６２．７％）．在—２５℃～３７℃下，以ＦＭＰＧ最优（７０．２％）．对ＭＳＧ而言，—１０℃～３７℃下（５９．６％）优于—２５℃～３７℃温度下（４５．３％）。     

Genotypes and antibiotic resistance of canine Campylobacter jejuni isolates

Campylobacter jejuni is the most important cause of bacterial gastroenteritis in humans. It is a commensal in many wild and domestic animals, including dogs. Whereas genotypes of human and chicken C. jejuni isolates have been described in some detail, only little information on canine C. jejuni genotypes is available. To gain more information on genotypes of canine C. jejuni and their zoonotic potential, isolates from routine diagnostics of diarrheic dogs as well as isolates of a prevalence study in non-diarrheic dogs were analyzed. Prevalence of thermophilic Campylobacter among non-diarrheic dogs was 6.3% for C. jejuni, 5.9% for Campylobacter upsaliensis and 0.7% for Campylobacter coli. The C. jejuni isolates were genotyped by multi locus sequence typing (MLST) and flaB typing. Resistance to macrolides and quinolones was genetically determined in parallel. Within the 134 genotyped C. jejuni isolates 57 different sequence types (ST) were found. Five STs were previously unrecognized. The most common STs were ST-48 (11.2%), ST-45 (10.5%) and ST-21 (6.0%). Whereas no macrolide resistance was found, 28 isolates (20.9%) were resistant to quinolones. ST-45 was significantly more prevalent in diarrheic than in non-diarrheic dogs. Within the common time frame of isolation 94% of the canine isolates had a ST that was also found in human clinical isolates. In conclusion, prevalence of C. jejuni in Swiss dogs is low but there is a large genetic overlap between dog and human isolates. Given the close contact between human and dogs, the latter should not be ignored as a potential source of human campylobacteriosis.     

江苏部分地区鸡源与猪源弯曲菌耐药性分析与毒力基因检测

旨在了解江苏省部分地区鸡源与猪源弯曲菌的耐药及毒力基因携带情况。从江苏省25个规模养殖场采集250份粪便样品进行弯曲菌的分离鉴定,采用琼脂平板稀释法测定9种抗菌药物的最小抑菌浓度（minimal inhibitory concentrations,MICs）,PCR方法扩增弯曲菌8种与致病力相关的毒力基因。结果显示：共分离得到93株弯曲菌,包括空肠弯曲菌45株,结肠弯曲菌48株;空肠弯曲菌对萘啶酸（80.0%）、四环素（71.1%）和环丙沙星（66.7%）的耐药率较高,而结肠弯曲菌对红霉素（87.5%）、萘啶酸（79.2%）和阿奇霉素（72.9%）产生较强的耐药性,分离株多重耐药现象严重,多重耐药率达67.7%;8个毒力基因在弯曲菌分离株中的携带率不同,cdtB和cadF携带率为100%,htrB为97.8%,clpP为76.3%,csrA为18.3%,wlaN为5.4%,cstⅡ为2.2%,cgtB为0%。结果提示,江苏省畜禽养殖场弯曲菌分离株多重耐药情况严重,毒力相关基因在弯曲菌中分布广泛。     

Associations between Campylobacter fetus, Haemophilus somnus, Leptospira hardjo and bovine viral diarrhea virus antibody titers in dairy cattle from a California herd

In a cross-sectional study, the associations of age, serological status against Campylobacter fetus (CF), Haemophilus somnus (HS) and Leptospira hardjo (LH) with the seroprevalence of bovine viral diarrhea virus (BVDV) in dairy cattle were evaluated. Six hundred and thirty cattle from a herd in Tulare county of California were included in the study. Blood samples from the cattle were collected in December 1986. Enzyme-linked immunosorbant assay (ELISA) was used to determine the positive or negative status of cows against CF, HS, LH and BVDV antigens. Loglinear analysis was used to describe the relationships of four categorical variables with the seroprevalence of BVDV. The final loglinear model was interpreted as a logit model and obtained by conditioning on explanatory variables in the model found to relate significantly with BVDV seropositivity. The hierarchical logit model included two two-way interactions (BVDV × HS and BVDV × LH) and a three-way interaction (BVDV × CF × age). HS-seronegative cattle had 4.7 times greater odds of being BVDV-seropositive compared with HS-seropositive cattle. In contrast, LH-seropositive cattle had 2.7 times increased odds of BVDV seropositivity compared with LH-seronegative cattle. The presence of the three-way interaction term in the model involving age, CF and BVDV seroprevalence implies that among heifers, CF-seronegative and CF-seropositive animals had about the same odds of BVDV seropositivity (e.g. adjusted odds ratios = 20.5 vs. 24.5), whereas, among cows, CF-seronegative animals had at least twice the odds of being BVDV-seropositive than those of CF-seropositive animals (e.g. adjusted odds ratios = 23.0 vs. 11.0).     

空肠弯曲菌共同抗原单克隆抗体的研制及其在细菌检验中应用的研究——Ⅰ.共同抗原的提取与鉴定

选用鸡源、猪源空肠弯曲菌各4株提取共同抗原。对提取的共同抗原用等电聚焦电泳分析,出现6～7条移行带,其等电点在3.32～5.23之间;免疫原性测定,共同抗原稀释至10～20μg/ml时,ELISA试验,与5株空肠弯曲菌高免血清均出现阳性反应。用共同抗原免疫家兔及BALB/C小鼠,所制免疫血清,以玻片凝集试验、协同凝集试验及免疫酶染色法对56株不同来源(鸡源20株、猪源33株、人源3株)的空弯菌进行鉴定,均出现阳性结果。试验结果还表明,在不同来源的菌株之间,其共同抗原成分的含量及免疫性以无明显差异。     

Effect of Recovery Medium on the Isolation of Campylobacter Jejuni Before and After Heat Treatment

The effect of various concentrations of polymyxin B and Colistin in Skirrow’s or Butzler’s type media, respectively, on the recovery rate of 13 strains of G. jejuni before and after heat treatment was studied. Prior to heating, a Butz-ler’s type medium containing 40 I.U. per ml Colistin was inhibitory for certain strains of C. jejuni. After heating at 48° G for 30 min, media containing 2.5 I.U. per ml polymyxin B or 10 I.U. per ml Colistin were not inhibitory for heat-injured cells. When the concentrations of polymyxin B were increased to 5.0 I.U. per ml or those of Colistin to 20 or 40 I.U. per ml in the selective media, the means of the differences of log cell counts between non-selective Brucella blood agar and the selective media was statistically significant (P < 0.05). The mean D-value of G. jejuni strains in Brucella broth at 48° G was 18.4±5.4 min.