Experimental infection of weaned piglets with Campylobacter coli – Excretion and translocation in a pig colonisation trial

Campylobacter (C.) is one of the most common food-borne pathogen causing bacterial enteric infections in humans. Consumption of meat and meat products that have been contaminated with Campylobacter are the major source of infection. Pigs are a natural reservoir of Campylobacter spp. with C. coli as the dominant species. Even though some studies focussed on transmission of C. coli in pig herds and the excretion in faeces, little is known about the colonisation and excretion dynamics of C. coli in a complex gut microbiota present in weaned piglets and the translocation to different tissues.     

空肠弯曲杆菌PCR-ELISA检测方法的建立

针对空肠弯曲杆菌(Campylobacter jejuni)旋转酶基因(gyrA gene)设计特异性引物和探针,将生物素和地高辛分别标记上游引物5＇端和核酸探针3 ＇端,并对反应条件进行优化,建立空肠弯曲杆菌PCR-ELISA检测方法.结果表明:该方法能特异的检测空肠弯曲杆菌基因组DNA,检测阈值为2fg,敏感性是常规PCR的10倍.对模拟泄殖腔样本进行检测,检测限为50 cfu/mL.对100份临床样品进行检测,PCR和PCR-ELISA方法阳性检出率分别为60％和69％.     

鸡弯曲菌性肝炎的病理学研究

对30例40日龄自然感染弯曲菌性肝炎鸡的肝脏、胆囊及主要脏器进行了眼观、病理组织学、肝脏的透射电镜、胆囊的扫描电镜和透射电镜的观察.根据病变特点分为急性肝炎和亚急性肝炎.30例患鸡肝脏石蜡切片应用免疫过氧化物酶染色,空弯菌的检出率为100%;肝脏断面触片应用石炭酸复红稀释液及Warthin-Starry染色时,可检出弧形、弯曲状或螺旋状病菌.提出了以肝脏肉眼变化,结合肝断面触片石炭酸复红稀释液染色检出弯曲菌,作为宰后快速检验方法.     

A detection assay forCampylobacter fetus in bovine semen by restriction analysis of PCR amplified DNA

A rapid screening assay forCampylobacter fetus in bull semen was developed using the polymerase chain reaction (PCR) and restriction endonuclease analysis (REA) to complement isolation by culture. An oligonucleotide primer pair (C₁/C₂) from the hypervariable region of 16S rRNA ofC. fetus was used to amplify a 362 base pair fragment by PCR. The PCR/REA assay, which is completed in 10 hours, detected as few as threeC. fetus subsp.venerealis cells in experimentally infected raw bull semen and in semen diluted with milk or egg yolk Tris (EYT). All the strains tested, of both subspecies ofC. fetus, were amplified, as were some otherCampylobacter species. Restricting the amplified products byAluI differentiatedC. fetus from the other organisms. There was no visible product generated by PCR fromC. sputorum subsp.bubulus, a saprophytic organism found in the prepuce of bulls, or from seven other species of bacteria found in semen. A modification of the PCR assay, using another primer pair (C₃/C₂) and two temperature PCR cycling conditions, increased the probability of detectingC. fetus subsp.venerealis. PCR amplification followed by REA could be used to screen bovine semen rapidly forC. fetus. In most cases, sequencing of C₁/C₂ PCR generated products would be preferable for distinguishing between the two subspecies ofC. fetus.Abbreviations AI artificial insemination - bp base pair - Cff Campylobacter fetus subsp.fetus - Cfv Campylobacter fetus subsp.venerealis - EYT egg yolk Tris - MH Mueller-Hinton - PCR polymerase chain reaction - REA restriction endonuclease analysis - TE Tris-EDTA     

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。     

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。     

Prevalence of gastrointestinal bacterial pathogens in a population of zoo animals

Faecal prevalence of gastrointestinal bacterial pathogens, including Campylobacter, Escherichia coli O157:H7, Salmonella, Shigella, Yersinia, as well as Arcobacter, were examined in 317 faecal specimens from 44 animal species in Belfast Zoological Gardens, during July-September 2006. Thermophilic campylobacters including Campylobacter jejuni, Campylobacter coli and Campylobacter lari, were the most frequently isolated pathogens, where members of this genus were isolated from 11 animal species (11 of 44; 25%). Yersinia spp. were isolated from seven animal species (seven of 44; 15.9%) and included, Yersinia enterocolitica (five of seven isolates; 71.4%) and one isolate each of Yersinia frederiksenii and Yersinia kristensenii. Only one isolate of Salmonella was obtained throughout the entire study, which was an isolate of Salmonella dublin (O 1,9,12: H g, p), originating from tiger faeces after enrichment. None of the animal species found in public contact areas of the zoo were positive for any gastrointestinal bacterial pathogens. Also, water from the lake in the centre of the grounds, was examined for the same bacterial pathogens and was found to contain C. jejuni. This study is the first report on the isolation of a number of important bacterial pathogens from a variety of novel host species, C. jejuni from the red kangaroo (Macropus rufus), C. lari from a maned wolf (Chrysocyon brachyurus), Y. kristensenii from a vicugna (Vicugna vicugna) and Y. enterocolitica from a maned wolf and red panda (Ailurus fulgens). In conclusion, this study demonstrated that the faeces of animals in public contact areas of the zoo were not positive for the bacterial gastrointestinal pathogens examined. This is reassuring for the public health of visitors, particularly children, who enjoy this educational and recreational resource.     

Campylobacteriosis in dogs and cats: a review

Campylobacter species are commonly isolated from faecal samples collected from dogs and cats, with the most prevalent species being C. upsaliensis, C. helveticus, and C. jejuni. Although the majority of dogs and cats are subclinically infected, some will develop mild to moderate enteritis. Immature animals, animals from intensive housing backgrounds, and animals with concurrent disease are especially predisposed to infection and the development of clinical signs. Bacterial culture methods applied in diagnostic laboratories remain biased to C. jejuni and C. coli detection, but molecular methods to diagnose Campylobacter spp. infections in dogs and cats have become widely available and can aid rapid and accurate diagnosis. Multilocus sequence typing has also been developed for subtyping different strains and has been used in epidemiological investigations. In the majority of cases, clinical signs are self-limiting and antimicrobial treatment is not warranted. Campylobacter spp. isolated from dogs and cats have shown resistance to commonly used antimicrobials, so antimicrobial therapy should only be administered where this is justified. Contact with dogs and cats is a recognised risk factor for human campylobacteriosis, thus people living or working in close contact with cats and dogs should be made aware of the zoonotic organisms these animals can shed.     

Pet‐associated Campylobacteriosis: A persisting public health concern

Campylobacter is regarded as a leading cause of human bacterial gastroenteritis in the United States. We report on a case of laboratory‐confirmed Campylobacter jejuni infection in the Commonwealth of Pennsylvania among members of a household living with a laboratory‐confirmed but non‐speciated Campylobacter‐infected puppy. We describe an outbreak of likely dog‐associated campylobacteriosis, the risk factors, potential routes of exposure and the clinical features in the exposed family members, which began shortly after exposure to the recently purchased dog. We also provide public health recommendations to prevent Campylobacter infections in veterinary care providers, pet owners and those planning to adopt pets in the future. Finally, this report underscores the importance of the One Health approach when public health responders, human and animal healthcare providers and clinical diagnostic laboratories are tasked with developing effective strategies when investigating, detecting and responding to zoonoses (diseases shared between animals and humans).     

Seroprevalence in Chickens against Campylobacter jejuni Flagellar Capping Protein (FliD) in Selected Areas of the United States

Campylobacter jejuni is a causative pathogen of human acute bacterial gastroenteritis. Infected poultry products are regarded as a major source for human C. jejuni infection. The flagellar capping protein (FliD) is highly conserved among C. jejuni strains/isolates and is antigenic as analysed by immunoblot. In this study, we used the FliD protein as a probe to survey the prevalence of C. jejuni antibodies in chickens from two areas in the United States. A total of 394 samples were tested. Sera from layer breeders of 44–52 weeks of age tested 100% positive, while 4‐ to 6‐week broilers from 22 premises showed 7–100% positivity. These results demonstrate that anti‐FliD antibodies were prevalent in the poultry population in the areas of serum samples collected.