Faecal carriage rate of Yersinia species.

A total of 1,203 unselected routine faecal samples from 1,006 patients were cultured for Yersinia species by a cold enrichment technique. Seventy-five specimens (6.1%) from 63 patients were culture-positive for Yersinia spp. Fifty-two were Yersinia enterocolitica, 22 Yersinia frederiksenii and 1 Yersinia intermedia. The predominant Y. enterocolitica isolates belonged to biotype 1 - serotype 0:6, 30 or serotype 0:5, 27. Y. frederiksenii strains were non-typable. Forty isolates were recovered from 33 patients with gastroenteritis. During the study period 83 Salmonella spp. from 33 patients, 17 Shigella sonnei from 13 patients and 13 Campylobacter jejuni from 12 patients were cultured. Yersinia spp. was isolated in association with salmonella on three occasions, twice with rotavirus and once each with Shigella sonnei, Campylobacter jejuni and Trichuris trichiura.     

Faecal carriage rate of Yersinia species

A total of 1,203 unselected routine faecal samples from 1,006 patients were cultured for Yersinia species by a cold enrichment technique. Seventy-five specimens (6.1%) from 63 patients were culture-positive for Yersinia spp. Fifty-two were Yersinia enterocolitica, 22 Yersinia frederiksenii and 1 Yersinia intermedia. The predominant Y. enterocolitica isolates belonged to biotype 1 - serotype 0:6, 30 or serotype 0:5, 27. Y. frederiksenii strains were non-typable. Forty isolates were recovered from 33 patients with gastroenteritis. During the study period 83 Salmonella spp. from 33 patients, 17 Shigella sonnei from 13 patients and 13 Campylobacter jejuni from 12 patients were cultured. Yersinia spp. was isolated in association with salmonella on three occasions, twice with rotavirus and once each with Shigella sonnei, Campylobacter jejuni and Trichuris trichiura.     

徐州市小肠结肠耶氏菌的病原性实验研究

目的：研究徐州地区从腹泻病人、家养动物中分离的16株、5种血清型的小肠结肠耶氏菌的病原性。方法：用生化生物分型，自凝性（AA）试验、钙依赖性（CD）试验，PCR检测毒力基因来检验不同菌株的致病性。用ATB Expression自动鉴定系统对致病菌株做药敏试验。结果：仅2株狗源性菌与1株人源性菌为致病菌，他们均为生物3型／血清型O：3，二者耐药模型完全一致。结论：徐州地区，小肠结肠耶氏菌生物3型／血清型O：3是致病菌型，他在狗和人群之间分布关系密切，其他型别菌株可能不致病或潜在致病。     

进口冻肉中小肠结肠炎耶尔森氏菌检出情况分析

目的：了解我国进口冻肉产品中小肠结肠炎耶尔森氏菌的检出情况，为此类产品的风险分析和检验检疫工作提供依据。方法：通过采用小肠结肠炎耶尔森氏菌的国标检验方法和VITEK、API生化鉴定仪对247份进口冻肉产品进行检测。结果：247份样品中共检出耶尔森属菌33份，其中17份为小肠结肠炎耶尔森氏菌，检出率为6．88％，均属于生物1A型，其中3株为血清O：8型，其余均属非常见血清型。阳性样品中16份为冻鸡类样品，1份为冻猪肉类样品。94份海产样品无一份检出。结论：通过实验数据分析我国进口的冻肉产品中冻鸡类产品检出小肠结肠炎耶尔森氏菌比率较高，而海产品和冻猪肉产品中检出率相对较低，所以认为冻鸡类产品小肠结肠炎耶尔森氏菌污染风险较高，应加强此类产品检验监管力度。     

东阳市鼠类中小肠结肠炎耶尔森菌的分子生物学浅探

目的:了解东阳市鼠类中分离的40株小肠结肠炎耶尔森菌的生物分型、血清分型、毒力基因和抗生素敏感性。方法:采用生化微量管、诊断血清凝集法、PCR方法及ATB G-5药敏系统进行相应的检测。结果:40株菌株可以分生物1A型、生物2型和生物3型3个生物型;血清型以O:8型为主、其次O:1,2、O:5和无法分型的;利用PCR方法检测得到ail-、ystA-、ystB+、yadA-、virF-和ail-、ystA-、ystB-、yadA-、virF-两个毒力基因型别;抗生素除对头孢噻吩、阿莫西林和替卡西林有较强的耐药性外,其余抗生素的敏感率较高。结论:东阳市鼠类中分离的小肠结肠炎耶尔森菌,虽然存在多种生物型和血清型,但都是不携带毒力基因的菌株,为非致病菌;对部分抗生素有一定的耐药性,但绝大部分抗生素敏感。     

1997-2010年宁夏回族自治区小肠结肠炎耶尔森菌致病性的基因特征

目的 了解宁夏回族自治区小肠结肠炎耶尔森菌主要毒力基因分布情况和致病性小肠结肠炎耶尔森菌分子分型特征。方法 于1997-2010年在宁夏回族自治区共分离得到283株小肠结肠炎耶尔森菌,用PCR法分析其黏附侵袭位点基因(ail)、耐热肠毒素A基因（ystA）、ystB、黏附素基因（yadA）、毒力活化因子基因（virF）;应用限制性内切酶Not Ⅰ酶切致病性小肠结肠炎耶尔森菌染色体DNA进行脉冲场凝胶电泳(PFGE),利用BioNumerics软件进行聚类分析。结果 209株O∶3、O∶9血清型小肠结肠炎耶尔森菌中ail、ystA、yadA、virF毒力基因阳性,ystB为阴性的占97.6％( 204/209);O∶8血清型和未开展血清分型的菌株5种毒力基因全部阴性;11株O∶5血清型有9株5种毒力基因全部阴性。将致病性菌株进行PFGE分型,根据染色体DNA的Not Ⅰ酶切图谱,将29株O∶3血清型分成12个PFGE带型,包含5株以上的优势PFGE带型有2种。180株O∶9血清型菌株分成13个PFGE带型,包含10株以上的优势PFGE带型有4种,各自是从同一地区猪与家鼠、猪与犬、猪与野兔分离。结论 宁夏地区O∶3、O∶9血清型小肠结肠炎耶尔森菌具有致病性,O∶3逐步成为如今的优势血清型;O∶5、O∶8与血清未分型的菌株无致病性。     

Duration of carriage and transmission of Yersinia enterocolitica biotype 4, serotype 0:3 in dogs.

Human infections with pathogenic strains of Yersinia enterocolitica have been linked to contact with dogs excreting these microorganisms. This study examines the carriage and transmission of Y. enterocolitica biotype 4, serotype 03 in dogs. Fourteen 6-month-old cross-bred dogs were separated into 5 groups, 2 containing 4 dogs (I and II) and the others 2 dogs (III-V). Each of the 4 dogs in Group I and 2 of the dogs in Group II were inoculated orally with the test strain. Bacteriological examination of faecal samples showed that dogs can be readily infected and can carry the organism for up to 23 days. The two in-contact dogs in Group II started to shed the test organism after 5 days. Subsequent transfer of these dogs to Group III and those in Group III to Group IV showed that Y. enterocolitica biotype 4, serotype 03 can be readily transmitted between dogs. At no time did any of the dogs show clinical signs of infection. Group V served as a negative control for the trial. These findings suggest that dogs can carry Y. enterocolitica biotype 4, serotype 03 asymptomatically and hence might act as a potential source of infection for people.     

An evaluation of methods for the isolation of Yersinia enterocolitica from surface waters in the Grand River watershed

Yersinia enterocolitica is a foodborne pathogen, but the importance of water as a route of exposure for human infection is not well known. Y. enterocolitica isolation methods were developed primarily for food and clinical samples, and may not be effective for use with environmental samples. The objective of this study was to assess the recovery of Y. enterocolitica from surface water used for drinking water treatment. Four enrichment broths and an alkaline treatment protocol were compared for the isolation of Y. enterocolitica bioserogroup 4/O:3 spiked into surface water samples. Results showed that the methods tested were not effective for the recovery of Y. enterocolitica, primarily due to inadequate inhibition of interfering background microorganisms. Using one method that showed the most potential for recovery, Yersinia spp. were isolated from rivers in southwestern Ontario, Canada, over a 17-month period. Of 200 samples analysed, Yersinia spp. were isolated from 52 samples. All river isolates belonged to non-pathogenic sub-groups, including Y. enterocolitica biotype 1A, Y. aldovae, Y. bercovieri, Y. frederiksenii, Y. intermedia, Y. kristensenii and Y. mollaretii. Results of this study show that method improvements are required to more fully understand the role of water as a source of clinically important Yersinia strains.     

Characterization of Yersinia enterocolitica strains isolated from cattle, sheep and pigs in the United Kingdom.

The properties of 48 cultures identified as Yersinia enterocolitica or Y. enterocolitica-like organisms, including Y. frederiksenii, Y. intermedia and Y. kristensenii, were examined. Of these, 39 were isolated from faeces of apparently healthy pigs, five from healthy cattle, one from an aborted bovine fetus, one from an aborted lamb and one from a lamb suffering from acute enteritis. Most isolates from healthy animals were of Y. enterocolitica biotype 1 or Y. intermedia and belonged to O serogroups not usually associated with disease in man or animals. The isolates from abortion or enteritis cases were of Y. enterocolitica biotypes 3, 4 and 5 and belonged to the pathogenic serogroups 0:5b and 0:2a, 2b, 3. No organisms of serogroup 0:9 were found.     

An outbreak of Yersinia enterocolitica infections caused by contaminated tofu (soybean curd)

The authors investigated 50 Yersinia enterocolitica infections during an outbreak of illness due to contaminated tofu (soybean curd) in Washington State between December 15, 1981 and February 22, 1982. The most common clinical syndrome (36 patients) was gastrointestinal infection for which two patients underwent appendectomies and one a partial colectomy. Of the remaining 14 patients, six had extraintestinal infections, two had fever alone, and six were asymptomatic. The patients with enteric infections were younger (median age three years) than those with extraintestinal infections (median age 28 years). In a case-control study of enteritis patients, illness was associated with ingestion of one brand of tofu (p less than 0.01). Ninety-two per cent of patients with gastrointestinal infections and 33% with extraintestinal infections recalled having eaten the implicated product. Y. enterocolitica serotype O:8, the most common serotype isolated from patients, was also isolated from tofu and the plant's untreated spring water. There was little clinical or laboratory evidence of secondary spread to family members who did not eat tofu. The outbreak demonstrates the transmission of Y. enterocolitica from nature to man and the potential of "natural" foods as vehicles for environmental pathogens.     

Identification and typing of Yersinia enterocolitica biotypes and serotypes isolated

OBJECTIVE: To assess the presence of Yersinia enterocolitica in otherwise healthy pigs slaughtered for human consumption. METHODS: One hundred pharyngeal tonsils were sampled in a slaughterhouse in the state of Mexico. The minimum sample size (n=100) was calculated based on a preliminary sample of 20 cases, which had 20% positive cases. The collected tonsil samples were inoculated in Rappaport broth, and Salmonella-Shigella and McConkey media. The biotyping identification process was based on biochemical and serological tests using O:3, O:8 and O:9 antisera. RESULTS: Twenty-two isolates were obtained. Most were biotype 1 (8 cases of O:3 and 8 cases of O:9), but 6 cases could not be serotyped. None of the isolates were of O:8 group. CONCLUSIONS: This was the first time that Y. enterocolitica serotypes were isolated from pig tonsils in Mexico. Its importance rely on the fact that the isolated serotypes are the most commonly found in public health problems.     

浙江省部分地区小肠结肠炎耶尔森菌(动物株)分子生物学特征初探

目的：了解浙江省部分地区小肠结肠炎耶尔森菌的血清型别、毒力基因分布等情况。方法：利用常规细菌分离方法从家禽、家畜和鼠类粪便标本中分离小肠结肠炎耶尔森菌，并进行毒力基因检测，同时对血清型O：3、O：5和O：8的菌株进行脉冲场凝胶电泳分析。结果：2004～2005年，从全省各点采集的动物标本中共分离到22株小肠结肠炎耶尔森菌，分布于11个血清型，并以O：8和O：3为主。PCR检测将分离到的22株小肠结肠炎耶尔森菌毒力携带情况分为4型：Ⅰ型（ail^＋、ystA^＋、ystB^-、yadA^＋、virF^＋），Ⅱ型（ail^＋、ystA^＋、ystB^-、yadA^-、virF^-），Ⅲ型（ail^-、ystA^-、ystB^＋、yadA^-、virF^-），Ⅳ型（ail^-、ystA^-、ystB^-、yadA^-、virF^-）。脉冲场凝胶电泳分析，O：3型菌株显示有2种带型，O：5型菌株的带型完全相同，O：8型菌株的带型则存在明显差异。结论：浙江省的从动物分离的小肠结肠炎耶尔森菌以非致病性菌株居多，且存在一定的地区差异。猪是致病性小肠结肠炎耶尔森菌的重要携带者，应警惕致病性小肠结肠炎耶尔森菌通过猪感染人和其它动物以及环境的危险。     

登封市屠宰场生猪小肠结肠炎耶尔森菌病原学研究

目的 了解登封市屠宰场生猪小肠结肠炎耶尔森菌带菌率、血清分型、毒力基因分布等情况,为制定预防措施提供参考依据。方法 从屠宰场生猪扁桃体及回盲部内容物中分离小肠结肠炎耶尔森菌,并进行生化鉴定、血清分型、毒力基因PCR检测。结果 从196份生猪咽拭子中分离出107株小肠结肠炎耶尔森菌,检出率为54.59%;从196份生猪肛拭子中分离出36株小肠结肠炎耶尔森菌,检出率为18.37%。检出菌血清型为O∶3,生物型为3型,Ⅰ型（ail＋、ystA＋、ystB-、yadA＋、virF＋）占93.71%（134/143）,Ⅱ型（ail＋、ystA＋、ystB-、yadA-、virF-）占6.29%（9/143）。结论 登封市生猪小肠结肠炎耶尔森菌以致病性菌株为主,今后应加强该菌的进一步监测工作。     

The serological relationship between Yersinia enterocolitica O9 and Escherichia coli O157 using sera from patients with yersiniosis and haemolytic uraemic syndrome

Sera from patients with yersiniosis, shown to contain antibodies to Yersinia enterocolitica O9; and sera from patients with haemolytic uraemic syndrome (HUS) caused by Escherichia coli O157, were used to investigate serological cross-reactions between Y. enterocolitica O9 and E. coli O157. Lipopolysaccharide (LPS) was isolated from strains of Y. enterocolitica O9 and E. coli O157 and reacted with sera by immunoblotting and ELISA. Sera from patients with HUS contained antibodies to the LPS of E. coli O157 only; 80% of sera from patients with yersiniosis contained antibodies to the LPS of Y. enterocolitica O9 and E. coli O157. This one-way cross-reaction was also detected using hyperimmune rabbit antisera.     

首次发现0:9血清型小肠结肠炎耶尔森氏菌引起的腹泻爆发流行

本文首次报告由0:9血清型、生物3型小肠结肠炎耶尔森氏菌引起的一起食物源性急性腹泻爆发流行。发病率为64.44%、病人的主要临床表现为腹痛(95.17%)、腹泻(56.25%)、头昏。头痛(53.40%)及发热(29.29%)。从33名病人粪便标本中分离出13株0:9血清型小肠结肠炎耶尔森氏菌。这些菌株具有典型的生化反应,大多数具有病原性。病人恢复期血清抗体滴度多在1:160以上。     

我国5岁以下儿童小肠结肠炎耶尔森菌感染临床特征及病原学分析

目的 了解我国5岁以下儿童小肠结肠炎耶尔森菌腹泻病例临床与病原学特征,分析其可能的感染来源,为小肠结肠炎耶尔森菌病的防控与诊断提供科学依据。 方法 收集2010—2020年间来自全国10个省市自治区哨点医院儿童腹泻标本、调查及回访问卷;对标本进行小肠结肠炎耶尔森菌的分离鉴定;菌株进行生物分型、血清型鉴定;毒力基因检测以及脉冲场凝胶电泳(pulsed field gel electrophoresis,PFGE)分型。 结果 2010—2020年共监测11 377例,分离到致病性小肠结肠炎耶尔森菌63株,包括61株O:3血清型、2株O:9血清型菌株,5岁以下腹泻儿童感染率0.55%(63/11 377)。不同性别儿童对致病性小肠结肠炎耶尔森菌的感染率差异无统计学意义,1～5岁感染率高于≤1岁病例(χ²=44.836,P＜0.05),感染患儿中1～5岁发热比例高于≤1岁(χ²=11.508 ,P<0.05),随访病例未发现后遗症。我国儿童感染O:3血清型致病性小肠结肠炎耶尔森菌的PFGE带型存在多样性,优势带型为K6GN11C30021、K6GN11C30012。 结论 我国5岁以下儿童感染致病性小肠结肠炎耶尔森菌的生物血清型以3/O:3为主,偶有4/O:3与2/O:9。根据患儿感染特点与高发季节推测食源为主要感染来源,需进一步调查研究。     

2011～2012年赤峰市松山区动物中检出41株小肠结肠炎耶尔森菌

目的了解赤峰市松山区境内鼠类,家畜家禽携带小肠结肠炎耶尔森菌情况,为疾病预防控制工作提供科学依据。方法采集鼠类、家畜家禽的粪便、脏器等样品,进行小肠结肠炎耶尔森菌的分离、培养、鉴定和生物血清分型,并用PCR方法进行毒力因子检测。结果 2011～2012年共检验各类样品412份,检出小肠结肠炎耶尔森菌41株,皆来自猪咽拭子。2011年总检出率为16.02%,猪咽拭子的检出率高达28.28%。41株小肠结肠炎耶尔森菌中,携带了ail,ystA,yadA,virF,rfbc基因的3/O：3生物血清型菌株占95.12%;4/O：4生物血清型菌株占2.32%;其他占2.32%。结论赤峰市松山区境内的猪咽部携带小肠结肠炎耶尔森菌,猪是致病性小肠结肠炎耶尔森菌的重要携带者。     

Different enteropathogenic Yersinia strains found in wild boars and domestic pigs

Yersinia enterocolitica and Yersinia pseudotuberculosis strains isolated from wild boars and fattening pigs were characterized and compared with each other. In wild boars, ail-positive Y. enterocolitica strains belonged to bioserotypes 4/O:3 (36%, 5/14), 2/O:9 (29%, 4/14), and 2/O:5,27 (21%, 3/14). Additionally, two ail-positive strains were untypable. Among fattening pigs, the bioserotype 4/O:3 was dominating (91%, 71/78), and bioserotypes 2/O:5,27 (8%, 6/78) and 2/O:9 (1%, 1/78) were rare. inv-positive Y. pseudotuberculosis strains of serotypes O:1 and O:2 were isolated only from wild boars. Antimicrobial resistance patterns between wild boar and fattening pig strains differed. Most of the ail-positive Y. enterocolitica strains carried yst, hreP, and virF genes. Several genotypes of Y. enterocolitica strains were obtained by PFGE using NotI, ApaI, XhoI, and SpeI enzymes. All genotypes of wild boar strains differed from fattening pig strains. Especially strains of bioserotype 4/O:3 were clearly different with all four enzymes. These results show that wild boar strains differed from domestic pig strains. More wild boar strains should be isolated to show that wild boars and domestic pigs are reservoirs for different Y. enterocolitica and Y. pseudotuberculosis strains.     

Association between clinical presentation, biogroups and virulence attributes of Yersinia enterocolitica strains in human diarrhoeal disease.

Traditionally the enteric pathogen Yersinia enterocolitica has been differentiated into biogroups. Despite being considered as non-pathogenic, biogroup 1A isolates have constituted a sizeable fraction of strains from patients with gastroenteritis in many reports. To establish a potential clinical significance for biogroup 1A isolates of Y. enterocolitica, clinical disease in patients with gastroenteritis excreting such isolates was compared with symptoms among patients found infected with pathogenic biogroups. Clinical data and isolates of 66 patients from whom Y. enterocolitica had been isolated by direct plating were available for study. There was an association between patient age below 3 years and infection with ''pathogenic'' Y. enterocolitica. The severity of gastroenteritis and other symptoms, however, did not depend on the biogroup, or the presence of the virulence plasmid in the yersinia strain isolated from the patients. Strains belonging to biogroup 1A of Y. enterocolitica showed two clusters of ribotypes, one of which encompassed most isolates recovered from humans, the other being associated with environmental isolates. This might indicate the existence of human-adapted and potentially pathogenic strains among biogroup 1A of Y. enterocolitica.     

Low prevalence of yadA-positive Yersinia enterocolitica in sows

Yersinia enterocolitica 4/O:3 is commonly isolated from fattening pigs in Finland, but its prevalence in sows is relatively unknown. The current study determined the prevalence of yadA-positive Y. enterocolitica in sows and fattening pigs with polymerase chain reaction (PCR) and culture methods. The strains were characterized with pulsed-field gel electrophoresis (PFGE) using NotI DNA-restriction enzyme. Pathogenic Y. enterocolitica was detected in only 14% of sow tonsils compared with 56% of tonsils of fattening pigs. The prevalence varied between seven slaughterhouses from 0% to 30% in sows and from 30% to 87% in fattening pigs. A total of 37 NotI profiles were obtained from 148 Y. enterocolitica 4/O:3 strains isolated from 134 tonsil samples: eight profiles were obtained from 26 sow strains and 34 from 122 fattening pig strains. Two types predominated in both sows and fattening pigs. The prevalence of yadA-positive Y. enterocolitica in fattening pigs increased from 1995 versus 1999; the mean prevalence in five slaughterhouses for the 2 years was 33% and 64%, respectively. Seven NotI profiles, including the two common types, were found both years. In conclusion, pathogenic Y. enterocolitica was detected at a significantly lower rate in sows than in fattening pigs. Moreover, the prevalence of this pathogen in fattening pigs was significantly higher in 1999 than in 1995. Some Y. enterocolitica 4/O:3 strains persisting among slaughter swine were demonstrated to be very stable genetically. This study shows that fattening pigs are an important reservoir of different genotypes of Y. enterocolitica 4/O:3 strains.