空肠弯曲杆菌基因分型方法的研究进展

空肠弯曲杆菌(campylobacter jejuni)是最重要的人类肠道致病菌之一。随着近年来分子生物学及相关技术的迅猛发展,空肠弯曲杆菌基因分型的方法因其分辨力、特异性、分型率、敏感性显著高于传统检测方法而越来越受到人们的重视。作者就空肠弯曲杆菌基因分型方法(RFLP 分型、AFLP 分型、RAPD 分型、PFGE分型、MLST分型)的研究进展作一简要综述。     

禽源空肠弯曲杆菌ERIC-PCR分型及毒力因子研究

[目的] 通过对禽源空肠弯曲杆菌分子分型和毒力研究,了解禽源空肠弯曲杆菌在禽肉产品生产过程中的主要传播途径和携带的主要致病因子。[方法] 对从家禽养殖场、屠宰场等采集的720份泄殖腔拭子和禽肉表面拭子样品分离的311株空肠弯曲杆菌进行ERIC-PCR分型和16种毒力因子检测。[结果] 禽源空肠弯曲杆菌的分离率为43.19%;肉鸡生产链中空肠弯曲杆菌沿生产链传播,且有优势菌株型;90%以上分离菌株携带11种毒力基因。[结论] 肉鸡生产链中空肠弯曲杆菌存在水平传播现象,且没有外源性污染;16种毒力基因中,14种毒力基因的携带率均在50%以上。加强禽源空肠弯曲菌的监测是控制空肠弯曲菌的前提,对公共卫生具有重要意义。     

空肠弯曲杆菌特异性基因研究综述

空肠弯曲杆菌是人兽共患病原菌,对公共卫生安全和畜牧业,特别是养鸡产业造成一定危害。本文从基因研究的角度出发,对空肠弯曲杆菌的病原生长与流行病学特征、致病机理、致病基因、检测技术、耐药性、防治等方面的研究现状进行了综述,以期对我国空肠弯曲菌肠炎的防治工作提供借鉴。     

空肠弯曲杆菌分子生物学检测方法研究进展

空肠弯曲杆菌是一种人畜共患病原菌，快速而特异性地对空肠弯曲杆菌进行检测，具有重要的流行病学意义和临床应用价值。随着分子生物学技术的飞速发展，应用PCR及其相关技术检测空肠弯曲杆菌，因其敏感性、特异性和分辨力高于传统的检测方法，而且操作简便快速，故备受重视。作者就空肠弯曲杆菌检测方法的研究进展作一简要综述。     

猪源空肠弯曲杆菌的分离及鉴定

为了研究更快、更加准确分离空肠弯曲杆菌的方法,试验同时采用常规生化法对由12份猪盲肠内容物中分离的可疑菌进行检测,得到了6个阳性样品,经特异性PCR检测,2个样品可定性为空肠弯曲杆菌,检测时间为7 d;而对所得菌株直接进行PCR检测,检测结果相同,检测时间为2 d。结果表明:PCR可以快速、特异性地检测空肠弯曲杆菌,与常规生化检测法相比是一种更有效的方法。     

空肠弯曲杆菌对动物性食品的污染及检测

空肠弯曲杆菌(Campyobater fetus sub- sp.jejuni)是人的肠炎和腹泻病原之一,世界各国均有报道,引起医学界广泛的关注.1 空肠弯曲杆菌的生物学特性空肠弯曲杆菌的革兰氏阴性菌,在感染组织中呈孤型或S型,幼龄者较短,老龄者较长.不形成芽胞和荚膜,具有一根鞭毛.本菌为微需氧菌,在10%～20%CO_2环境中生长良好,生长最适温度37℃,最适pH7.0.普通培养基上一般生长不良,需在培养基中添加血清或血液.空肠弯曲杆菌在选择性培养基上具有两种类型;一种菌落不溶血,灰白色.     

空肠弯曲杆菌对喹诺酮类药物耐药性研究进展

在全球范围内,空肠弯曲杆菌感染是急性胃肠炎最常见的病因之一。喹诺酮类药物因其抗菌谱广、杀菌力强、价格低廉、副作用小而被广泛应用于人、畜、水生动物感染性疾病的治疗与预防。但由于抗生素的使用不当等多种原因,加之空肠弯曲杆菌广泛存在于动物体内及环境中,很快造成了空肠弯曲杆菌对该药的耐药性,且增长速度很快。耐药流行病学调查显示空肠弯曲杆菌对喹诺酮和红霉素等耐药。作者就空肠弯曲杆菌对喹诺酮类药物耐药性的研究进展展开综述。     

空肠弯曲杆菌鞭毛的研究进展

空肠弯曲杆菌是一种人畜共患的食物源性病原菌,可引起人和动物细菌性腹泻,且该菌的感染率逐年递增。鞭毛是细菌菌体的一种特殊结构,与菌体的运动性密切相关,有助于其躲避有害环境,同时鞭毛在细菌的致病性等方面也起着重要作用。研究发现,空肠弯曲杆菌的发病机制与鞭毛在宿主上皮细胞的定植力、黏附、侵袭力及毒素的产生密切相关。文章概述了空肠弯曲杆菌鞭毛结构、功能、调控机制及相关基因等方面的研究进展,通过归纳总结已知基因缺失突变对鞭毛的影响,从分子水平了解鞭毛的调控机制,从而探讨空肠弯曲杆菌的致病机理,以期为降低其感染率提供理论依据。     

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。     

空肠弯曲菌保存方法的研究

本文研究了１５株不同菌株和同一菌株在不同保存温度和培养基中的保存效果，结果表明：用同一菌株作该菌保存方法研究缺乏整体代表性；在所试的两种冰冻温度中，以－２５℃极显著地优于－１０℃保存（Ｐ＜０．０１）。在－２５℃下冻融１次保存该菌是最佳保存条件，于Ｐ－基、ＦＭＰＧ和ＭＳＧ培养基中，菌株１００％存活的期限分别为１２个月以上、６～９个月间（ＦＭＰＧ和ＭＳＧ），菌株５０％存活的期限三者均在１２个月以上。     

Prevalence of Campylobacter jejuni and its resistance to antibiotics in poultry in the Czech Republic

Thermotolerant Campylobacter spp., in particular Campylobacter jejuni, are among the most frequently identified pathogens, found to be causing human gastrointestinal infections in Europe, with the Czech Republic being no exception. The presented work aimed at assessing results of the first nationwide monitoring of prevalence and antibiotic resistance of Campylobacter spp. in broiler flocks in the Czech Republic, including a comparison of antibiotic resistance of C. jejuni isolates collected from poultry and the human community. The monitoring was carried out in poultry slaughterhouses in 2006 and 2007. From broilers, cloacal swabs were collected and examined. The human isolates of C. jejuni were acquired from rectal swabs in community patients with diarrhoeal diseases. Suspected isolates of both animal and human origin were confirmed by the PCR methods. Antibiotic resistance to selected anti-microbial agents was tested by the microdilution method. In the monitored period, the prevalence of thermotolerant Campylobacter spp. in broilers in the Czech Republic reached almost 50%. In 2006, C. jejuni was detected in 46% and Campylobacter coli in 3% of the tested samples. In 2007, C. jejuni was found in 43% and C. coli in 2% of the samples. The results of anti-microbial susceptibility testing of C. jejuni showed higher resistance in animals when compared with humans. The only exception was tetracycline with higher resistance in isolates of human origin. The highest resistance detected was to quinolone antibiotics. Resistance to oxolinic acid was 77% in animal and 60% in human isolates, to ciprofloxacin 72% in isolates from poultry and 55% in those from humans. In ampicillin, 26% of poultry isolates and 16% of human isolates were resistant. Moreover, 9% of animal isolates demonstrated resistance to streptomycin, undetected in human isolates. In erythromycin, resistance was found in 6% of poultry and 1% of human isolates.     

应用PCR技术检测空肠弯曲菌及结肠弯曲菌的研究

本研究根据空肠弯曲菌及结肠弯曲菌的16s rRNA基因相同保守序列来设计引物,建立了一种PCR检测方法,该方法具有较强的特异性及灵敏性,其对空肠弯曲菌及结肠弯曲菌的最低检测限度为5 CFU/mL,它无需增菌培养过程可以直接对样品进行检验,在对鸡肉样品空肠弯曲菌及结肠弯曲菌的检测中取得了较好的效果.     

Genetic diversity among Campylobacter jejuni isolates from healthy livestock and their links to human isolates in Spain

This study was aimed at determining the genetic diversity of Campylobacter jejuni from healthy ruminants and poultry, and study by multilocus sequence typing (MLST) their links to human isolates in Spain. MLST analysis of 160 animal isolates generated 45 sequence types (STs, nine of them new to this study), that clustered into 18 clonal complexes (CC) and nine singletons. The 71 isolates from humans generated 28 STs (13 CC plus four singletons). Only 11 STs and nine CCs were shared by humans and animals (particularly from dairy cattle and sheep), mainly corresponding to sporadic cases rather than outbreaks, probably as an adaptation of the general human population to the types commonly circulating in livestock. PCR analysis of the distribution of four virulence-associated genes detected the cdtABC gene cluster in all 160 isolates but with a 700-bp deletion in four of them, and amplified the virB11, cgtB and wlaN genes in 4.7%, 21.3% and 21.9% respectively. A subset of 87 C. jejuni animal isolates analysed using flaA PCR-RFLP, MLST and pulsed-field gel electrophoresis generated 31, 38 and 55 types respectively. The combined typing approach used provided reliable inter-strain relationships, confirming the co-existence of several strains in some farms, but also identifying identical genotypes sampled over a wide temporal span in different environments and hosts. Typing results confirmed a high genetic diversity of C. jejuni in our region and suggested that ruminants are also important sources for human infection. MLST data provided will help to obtain a more comprehensive image of the population structure of C. jejuni and establish reliable source attribution schemes.     

空肠弯曲杆菌耐药性及其主要相关基因初步分析

从307份鸡盲肠内容物样品中分离到47株空肠弯曲杆菌,并测定这些空肠弯曲杆菌耐药性,结果显示对喹诺酮类药(环丙沙星)耐药性为31.9%;对氨苄青霉素,克林霉素和红霉素耐药性较高,分别达到85.1%、83.0%和83.0%;而对痢特灵和庆大霉素则较为敏感,敏感度分别为85.1%和74.5%。有89.4%的菌株显示多重耐药性。利用MAMAPCR技术,对获得的47株空肠弯曲杆菌进行检测,结果显示对环丙沙星耐药的15株空肠弯曲杆菌均检测出其在gyrA基因257位发生点突变,30株对喹诺酮药物敏感的菌株均未检出。另外2株对环丙沙星耐药的菌株,有1株检测出点突变。     

鸡空肠弯曲菌灭活苗的制备及其免疫保护试验研究

用分离到的空肠弯曲菌制备鸡空肠弯曲菌甲醛灭活疫苗 ,并进行了该病的免疫保护实验。制备 2× 10 9个 / m L浓度的细菌悬液 ,4m L / L浓度的甲醛溶液作用 12 h灭活后制成空肠弯曲菌灭活苗 ,免疫 2周龄的 SPF雏鸡 ,14 d后 ,进行攻击实验 ,观察其临床症状 ;并分别于感染后 7d和 14 d捕杀 ,观察病理学变化及进行细菌分离实验以揭示其保护率。结果表明 ,鸡空肠弯曲菌灭活苗的保护率可达 10 0 % ,说明该苗经口免疫后安全可靠 ,无毒副作用     

地高辛标记空肠弯曲菌DNA探针的研究

应用地高辛标记核酸技术将地高辛结合到空肠弯曲菌染色体ＤＮＡ上,制备了地高辛标记的ＤＮＡ探针。地高辛标记的空肠弯曲菌ＤＮＡ探针仅与空肠弯曲菌ＣＪ１、ＣＪ２发生反应,而与大脾性杆菌、鼠沙门氏菌、金黄色葡萄球菌、副结核分枝杆功不发生反应,具有很高的特异性,其敏感性可检测出０．２２ｎｇ的样品ＤＮＡ,较光敏生物素（８ｎｇ）、＾３２Ｐ同位素（４ｎｇ）标记的核酸探针高。