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。     

空肠弯曲杆菌感染的研究现状

空肠弯曲杆菌是弯曲杆菌属的一种，是几十年来倍受国内外广泛重视的人畜共患病原菌之一。近几年，其感染率在全世界呈上升趋势。为阐明空肠弯曲杆菌感染的致病作用以及如何进行防治，本文从其病原学、传染源、传播途径、临床表现以及预防与控制方面对空肠弯曲菌及该菌引起疾病的相关情况作一阐述。     

禽弯曲杆菌性肝炎及其防治措施

1病原及流行特点嗜热弯曲杆菌有空肠弯曲杆菌、结肠弯曲杆菌和鸥弯曲杆菌,以空肠弯曲杆菌为禽的病原菌。该菌呈S型或海鸥翼形,革兰氏染色阴性,无芽孢、荚膜,有单极鞭毛,菌体纤细。对热敏感,一般消毒药可将其杀灭。禽是嗜热弯曲杆菌重要的贮存宿主。本病主要通过染菌的粪便、饲料、饮水等水平传播途径而经消化道感染。发病率高,死亡率2%～15%。     

雪貂空肠弯曲杆菌的分离与鉴定

从试验用雪貂分离到一株弯曲杆菌,通过菌落、菌体形态、生化特征、培养特性等生物学特性和PCR方法对所分离菌株进行鉴定,分离株经空肠弯曲杆菌VS1基因特异性引物PCR扩增为阳性,测序结果显示与空肠弯曲杆菌序列同源性达100%,结合生物学特性和PCR结果确定所分离菌株为空肠弯曲杆菌,该菌的分离鉴定为雪貂微生物检测标准的建立提供了理论依据。     

空肠弯曲菌flaA基因的原核表达及抗原性鉴定

空肠弯曲菌是一种在世界范围广泛流行的常见的人畜共患病病原菌,大量存在于各种野生或家养动物的肠道内, 引起牛和绵羊流产,雏鸡、犊牛、仔猪的腹泻等多种疾病[1].空肠弯曲菌的抗原结构比较复杂,具有广泛的抗原多样性或差异性,目前已知有近60个血清型,且还有增加的趋势.空肠弯曲菌的菌体外膜上的抗原成分主要为蛋白质和脂多糖(O抗原)及鞭毛(H抗原)[2].     

鸡空肠弯曲杆菌病的诊治

弯曲杆菌病是由弯曲杆菌引起的家禽、野禽、哺乳动物及人类共患的一种重要传染病。空肠弯曲杆菌作为人类肠炎的病因,仅次于沙门氏菌和痢疾杆菌。禽类弯曲杆菌感染十分普遍,鸡弯曲杆菌病又称鸡弧菌性肝炎,是由空肠弯曲杆菌、结肠弯曲杆菌和鸥弯曲杆菌引起的细菌性疾病。其中空肠弯曲杆菌致病力最强,引起肝脏病变最严重,笔者现将遇到的鸡空肠弯曲杆菌病的诊治情况介绍如下。     

空肠弯曲杆菌毒力因子及其致病机制研究进展

空肠弯曲杆菌是一种重要的人兽共患病原菌,其引起的弯曲杆菌病是最常见的食源性细菌感染之一,可导致多种临床症状,包括腹泻、发烧、呕吐以及血便等。空肠弯曲杆菌主要通过黏附、定植、侵袭、产毒素等方式对宿主造成致病性,是多个毒力因子共同参与的结果。文章详细介绍了空肠弯曲杆菌致病性相关的毒力因子及其致病机制,为空肠弯曲杆菌病的诊断与防治和相关疫苗研制提供科学参考。     

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。     

鸡弧菌性肝炎的发生与防治

<正>弧菌性肝炎,主要是由空肠弯曲杆菌引起的各种年龄鸡的一种传染病。近年来无论是肉仔鸡、产蛋鸡还是后备鸡群,其发病率均有增加的趋势,本病常以肝被膜脱落,肝脏出血,腹腔内常积聚大量血水为特征,故又称"出血病"。1病原空肠弯曲杆菌为禽的病原菌。该菌呈螺旋形或弧形菌或S形,革兰氏阴性,无芽胞、荚膜,有单极鞭毛,菌体纤细。对热敏感,一般消毒药可杀灭。2流行特点该菌广泛分布于各种动物的肠道内,经粪便污     

牛弯曲杆菌性腹泻的诊治

牛弯曲杆菌病是由弯曲杆菌属细菌所引起的牛及其他动物的不同疾病的总称。与人畜有关的有2种病型，由胎儿弯曲杆菌引起的牛只不育与流产和主要由空肠弯曲杆菌引起牛及其他动物的急性肠炎。空肠弯曲杆菌目前有2个亚种，即空肠亚种和多伊尔亚种。空肠亚种与兽医学有关的是人畜共患病的重要病原菌。现介绍牛弯曲杆菌性腹泻的诊治方法。     

空肠弯曲杆菌感染流行病学研究进展

空肠弯曲杆菌是一种人畜共患病原菌，可以引起人和动物发生各种疾病，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。本文就空肠弯曲杆菌病原学、传染源、传播途径、感染范围、致病性以及治疗方法的研究进展作一概述。     

Enteric campylobacter infection in gnotobiotic calves and lambs

Gnotobiotic calves and lambs were infected orally with Campylobacter jejuni, C coli or C hyointestinalis to assess pathogenicity. All animals were successfully colonised and excreted mucoid faeces but showed no other clinical signs. Campylobacters colonised the large intestine better than the small intestine, in which bacterial numbers decreased with time after infection. Campylobacters were found occasionally in the lumen of crypts in close proximity to epithelial cells and included in a mucus-like material. Lesions were mostly in the large intestine in calves whereas in lambs they were present in the ileum. In animals inoculated with C jejuni or C coli scattered crypt abscesses, focal inflammatory infiltrates in the lamina propria and goblet cell discharge were found. In lambs inoculated with C hyointestinalis only minor changes were found in the small intestine. Serum antibody response was either absent or present at a low level only from the 19th day after infection.     

Phenotypes and genotypes of campylobacter strains isolated after cleaning and disinfection in poultry slaughterhouses

Campylobacter is responsible for human bacterial enteritis and poultry meat is recognised as a primary source of infection. In slaughterhouses, cleaning and disinfection procedures are performed daily, and it has been suggested that disinfectant molecules might select for antibiotic resistant strains if shared targets or combined resistance mechanisms were involved. The aim of the study was to investigate if cleaning and disinfection procedures in poultry slaughterhouses select for antibiotic resistance in Campylobacter jejuni and C. coli and to determine the genotypes of isolates collected after cleaning and disinfection. Nine sampling visits were made to four French slaughterhouses. Samples were collected from transport crates and equipment surfaces, before and after cleaning and disinfection. Minimal inhibitory concentrations of the recovered C. jejuni and C. coli isolates to six antibiotics and two disinfectants were measured. The C. jejuni isolates collected from equipment surfaces after cleaning and disinfection were subjected to PCR-RFLP typing. Twenty-five C. jejuni isolates and 1 C. coli were recovered from equipment surfaces after cleaning and disinfection during five visits to three different slaughterhouses. Those isolates did not show an increased resistance to the tested antibiotics compared to isolates collected before cleaning and disinfection. Only one or two genotypes were recovered after cleaning and disinfection during single visits to each slaughterhouse. This observation suggests that such genotypes may be particularly adapted to survive cleaning and disinfection stress. Understanding the survival mechanisms of Campylobacter should facilitate the implementation of better-targeted strategies and reduce the public health burden associated with Campylobacter infection.     

Campylobacter jejuni is associated with, but not sufficient to cause vibrionic hepatitis in chickens

Vibrionic hepatitis is a disease of poultry which is characterised by the presence of focal lesions in the liver, usually 1-2mm in size and greyish-white in colour. The cause of the disease remains unclear, as do the reasons for its recent re-emergence. We examined the livers of commercial broiler chickens taken during processing and found Campylobacter spp. in both normal livers and those displaying signs indicative of focal hepatitis. Livers with signs of hepatitis had significantly more Campylobacter spp. present than those without and other bacterial genera were infrequently present. We were unable to replicate the disease in a healthy host following experimental infection with a Campylobacter jejuni strain isolated from a liver showing signs of focal hepatitis. However, a significant T cell response to C. jejuni was seen in the liver of Campylobacter infected birds. We conclude that the presence of Campylobacter spp. in the liver alone is not sufficient to cause vibrionic hepatitis, but that a predisposing factor, possibly within the host is required. We also provide evidence that chickens mount an adaptive T cell response to systemic C. jejuni.     

Campylobacter colonization in poultry: sources of infection and modes of transmission

Since its recognition as a human pathogen in the early 1970s, Campylobacter jejuni has now emerged as the leading bacterial cause of food-borne gastroenteritis in developed countries. Poultry, particularly chickens, account for the majority of human infections caused by Campylobacter. Reduction or elimination of this pathogen in the poultry reservoir is an essential step in minimizing the public health problem; however, farm-based intervention measures are still not available because of the lack of understanding of the ecological aspects of C. jejuni on poultry farms. Although Campylobacter is highly prevalent in poultry production systems, how poultry flocks become infected with this organism is still unknown. Many investigations indicate that horizontal transmission from environmental sources is the primary route of flock infections by Campylobacter. However, some recent studies also suggest the possibility of vertical transmission from breeder to progeny flocks. The transmission of the organism is not well understood, but it is likely to be through both vertical and horizontal transmission and may be affected by the immune status of the poultry host and the environmental conditions in the production system. Intervention strategies for Campylobacter infection in poultry should consider the complex nature of its transmission and may require the use of multiple approaches that target different segments of the poultry production system.     

空肠弯曲菌耐药机制研究进展

空肠弯曲菌是一种全球关注的人兽共患病病原菌,由于滥用抗生素而造成其耐药性不断增强,成为公共卫生日益关注的问题.各类抗生素作用位点的基因突变是诱发空肠弯曲菌对各类临床常用的抗生素产生耐药的主要原因,同时细菌对药物的外排机制也在其对抗生素耐药过程中发挥了一定的作用.文章对空肠弯曲菌对各类临床常用抗生素的耐药机制做一综述.     

Epidemiologic features of Campylobacter infection among cats in the upper midwestern United States

OBJECTIVE: To describe the epidemiologic features of Campylobacter infection among cats in the Minneapolis-Saint Paul metropolitan area. DESIGN: Prevalence survey. ANIMALS: 152 cats examined at 3 private veterinary clinics and an animal humane society. PROCEDURES: Fecal samples were submitted for bacterial culture for Campylobacter spp. To determine the duration of Campylobacter carriage, follow-up fecal samples were collected from cats with positive Campylobacter culture results. RESULTS: Campylobacter organisms were cultured from 37 of the 152 (24%) fecal samples. Campylobacter isolates were identified as Campylobacter upsaliensis (29 cats), Campylobacter jejuni (2), and Campylobacter coli (1); species of the remaining 5 isolates could not be determined. Campylobacter organisms were isolated from 36 of the 122 (30%) cats that were < or = 1 year old but from only 1 of the 30 (3%) cats that were > 1 year old, and shedding was more common during the summer and fall months. No association between Campylobacter shedding and clinical signs of disease was identified. For 4 of 13 cats from which follow-up fecal samples were obtained, duration of Campylobacter carriage could not be determined because Campylobacter organisms were isolated from all follow-up samples. For the remaining 9 cats, median duration of Campylobacter carriage was 44 days. CONCLUSIONS AND CLINICAL RELEVANCE: C. upsaliensis can commonly be isolated from the feces of overtly healthy kittens in the Midwest United States. Because carriage may be prolonged, veterinarians should encourage good hand hygiene among owners of cats, especially among owners with new kittens in their household.     

Occurrence of Campylobacter spp. in young gulls, duration of Campylobacter infection and reinfection by contact.

Two groups of three week old Herring Gulls (Larus argentatus) were held to observe the carrier state with Campylobacter. All 27 birds of group I excreted Campylobacter jejuni biotype III when they were caught from their colony. Four weeks later all but one were negative, indicating that the carrier state lasts until about the seventh week of life, with self-elimination if infection with another Campylobacter species is prevented by housing in a closed environment as in this study. Only one bird became reinfected one year later when gulls from group I were brought into contact with gulls from group II, consisting of ten freshly caught gulls, four of which were infected with the same biotype of Campylobacter, indicating that there might be some kind of immunity protection against infection with the same biotype of Campylobacter spp.     

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PEB1A蛋白的原核表达及间接ELISA方法的建立

为了建立检测血清中空肠弯曲菌（Campylobacter jejuni）抗体的间接ELISA方法,试验通过PCR扩增并克隆空肠弯曲菌PEB1A基因,构建原核表达载体pET32a-PEB1A,将该表达载体转化大肠杆菌BL21（DE3）感受态细胞,诱导表达获得约47 ku的可溶性目的蛋白,通过Western blotting证明所表达的重组蛋白具有良好的生物学活性。以纯化后的重组蛋白作为包被抗原,建立空肠弯曲菌抗体间接ELISA方法,对其特异性、敏感性、重复性进行检测。结果表明,本试验建立的空肠弯曲菌抗体间接ELISA检测方法临界值为0.3424,本方法仅与空肠弯曲菌阳性血清发生特异性反应,与其他抗血清无交叉反应,具有较强的特异性,批内、批间的重复性试验变异系数均<5%,具有较好的重复性和稳定性。该方法的建立可应用于血清中空肠弯曲菌抗体的快速检测,为进一步防制空肠弯曲菌腹泻提供依据。