The first successful isolations and identification of Yersinia enterocolitica from human cases in Japan

Mesenteric Lymphadenitis and Terminal Ileitis is Associated With Yersinia Infection: A Meta-analysis

BACKGROUND

Yersinia infection affects terminal ileum and lymph nodes and could therefore mimic the symptoms of appendicitis. We aimed to systematically characterise the suspected or confirmed abdominal diseases and/or surgeries associated with Yersinia infection.

MATERIALS AND METHODS

This systematic review and meta-analysis was reported following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. A protocol (CRD42016053252) was uploaded to PROSPERO. The searches were conducted in PubMed and EMBASE on October 2, 2020. Original reports on patients with abdominal surgical diseases were included. The primary outcome was to characterise suspected or confirmed abdominal surgical diseases and/or surgeries associated with Yersinia infection, while the secondary outcomes were the positive rate of Yersinia species for each disease and surgery, and to investigate the rate of Yersinia spp. in different geographic regions. We calculated the weighted mean prevalence of positive tests for Yersinia spp. for the different diseases and surgeries according to the detection method and for subgroups based on geographic region.

RESULTS

From the search, 33 studies were included in the systematic review and 18 in the meta-analysis. Across geographic regions, the weighted mean prevalence for Yersinia spp. was 51% (95% CI 34%-69%) in mesenteric lymphadenitis, 65% (95% CI 45%-85%) in terminal ileitis, and 8% (95% CI 2%-15%) in normal appendices.

CONCLUSIONS

Around half of the patients with mesenteric lymphadenitis and terminal ileitis were serologically positive for infections with Yersinia spp. Yersinia infection may cause unnecessary surgery for suspected appendicitis due to symptoms from mesenteric lymphadenitis or terminal ileitis.

Effects of chronic low-dose radiation on cataract prevalence and characterization in wild boar (Sus scrofa) from Fukushima, Japan

This study evaluated cataracts in wild boar exposed to chronic low-dose radiation. We examined wild boar from within and outside the Fukushima Exclusion Zone for nuclear, cortical, and posterior subcapsular (PSC) cataracts in vivo and photographically. Plausible upper-bound, lifetime radiation dose for each boar was estimated from radioactivity levels in each animal's home range combined with tissue concentrations of 134+137Cesium. Fifteen exposed and twenty control boar were evaluated. There were no significant differences in overall prevalence or score for cortical or PSC cataracts between exposed and control animals. Nuclear (centrally located) cataracts were significantly more prevalent in exposed boar (p < 0.05) and had statistically higher median scores. Plausible upper-bound, lifetime radiation dose ranged from 1 to 1,600 mGy in exposed animals, with no correlation between dose and cortical or PSC score. While radiation dose and nuclear score were positively associated, the impact of age could not be completely separated from the relationship. Additionally, the clinical significance of even the highest scoring nuclear cataract was negligible. Based on the population sampled, wild boar in the Fukushima Exclusion Zone do not have a significantly higher prevalence or risk of cortical or PSC cataracts compared to control animals.

[Two Outbreaks of Yersinia enterocolitica O:8 Infections in Tokyo and the Characterization of Isolates]

Although the number of outbreaks caused by Yersinia enterocolitica has been very small in Japan, 4 outbreaks were occurred during the 2 years between 2012 and 2013. We describe herein 2 outbreaks which were examined in Tokyo in the present study. Outbreak 1: A total of 39 people (37 high school students and 2 staff) stayed at a hotel in mountain area in Japan had experienced abdominal pain, diarrhea and fever in August, 2012. The Y. enterocolitica serogroup O:8 was isolated from 18 (64.3%) out of 28 fecal specimens of 28 patients. The infection roots could not be revealed because Y. enterocolitica was not detected from any meals at the hotel or its environment. Outbreak 2: A total of 52 students at a dormitory had diarrhea and fever in April, 2013. The results of the bacteriological and virological examinations of fecal specimens of patients showed that the Y. enterocolitica serogroup O:8 was isolated from 24 fecal specimens of 21 patients and 3 kitchen staff. We performed bacteriological and virological examination of the stored and preserved foods at the kitchen of the dormitory to reveal the suspect food. For the detection of Y. enterocolitica, food samples. together with phosphate buffered saline (PBS) were incubated at 4 degrees C for 21 days. Then, a screening test for Y. enterocolitica using realtime-PCR targeting the ail gene was performed against the PBS culture. One sample (fresh vegetable salad) tested was positive on realtime-PCR. No Y. enterocolitica was isolated on CIN agar from the PBS culture because many bacteria colonies other than Y. enterocolitica appeared on the CIN agar. After the alkaline-treatments of the culture broth or the immunomagnetic beads concentration method using anti-Y. enterocolitica O:8 antibodies, Y. enterocolitica O:8 which was the same serogroup as the patients' isolates was successfully isolated from the PBS culture. The fresh vegetable salad was confirmed as the incrimination food of this outbreak.

Introduction into Japan of pathogenic Yersinia through imported pork, beef and fowl

Yersinia was isolated from imported raw meat and fowl products by HeLa cell treatment and conventional KOH-treatment, to obtain information on the origin of pathogenic Yersinia in Japan. Forty-one strains of Yersinia enterocolitica and one strain of Yersinia pseudotuberculosis, serotype 4b were isolated from 38 (3.0%) of 1278 samples of pork, two (0.3%) of 612 samples of beef and two (0.3%) of 615 samples of chicken. Y. enterocolitica isolates belonged to B:4/O:3 (biotype/serotype, 15 strains), B:3/O:3 (two strains) and B:3 variant/O:3 (17 strains) and B:3/O:5.27 (seven strains). The B:4/O:3 which is globally prevalent among humans and animals was isolated from pork samples from Denmark and the US and from beef samples from Australia, the B:3/O:3 from pork samples from Canada, the B:3 variant/O:3 from pork samples from Taiwan and from chicken samples from Thailand, the B:3/O:5.27 from pork samples from the US and Taiwan and Y. pseudotuberculosis, serotype 4b from pork samples from Canada. These findings suggest that pathogenic Y. enterocolitica strains can be introduced into Japan by the import of pork from pig producing countries. The HeLa cell treatment was found to be superior to the conventional method.

Endoscopic findings in Yersinia enterocolitica enterocolitis

The endoscopic findings in the colon and terminal ileum in eight cases of Yersinia enterocolitica enterocolitis infection were studied. The diagnosis was based on the isolation of Y. enterocolitica in the feces and/or elevated serum antibody titers to the organism. Total colonoscopy was performed between 7 and 38 days (mean, 24 days) after the onset of symptoms. In all patients, the terminal ileum was affected, followed by frequent involvement of the ileocecal valve and the cecum, and less frequently, the ascending colon. In the terminal ileum, round or oval elevations with or without ulcers were detected. Small ulcers were detected on the ileocecal valve and in the cecum. These findings were observed even 4 to 5 weeks after the onset of symptoms, suggesting a relatively long course for this disease.

Haemolytic uraemic syndrome associated with Yersinia enterocolitica infection

Haemolytic uraemic syndrome (HUS) associated with Yersinia enterocolitica gastroenteritis is reported in a 6-year-old girl. Y. enterocolitica of biotype 03 was isolated from the patient's initial stool sample and was subsequently identified as serotype 03 based on the rising agglutinin titres. This paper shows that yersiniosis should be suspected as a possible cause of HUS, and investigations should include the measurement of serum agglutinin titres against antigen preparations of the genus Yersinia.

Widespread occurrence of the restriction endonuclease YenI, an isoschizomer of PstI, in Yersinia enterocolitica serotype O8

The cold-active restriction endonuclease YenI, an isoschizomer of PstI, was found in 12 of 14 Yersinia enterocolitica serotype O8 strains of different origins, but not in other serotypes of Y. enterocolitica, Yersinia pseudotuberculosis, or Yersinia pestis. In spite of the limited number of strains tested, the result suggests that the detection of YenI endonuclease or the gene might result in more rapid determination of the prominently pathogenic serotype of Y. enterocolitica.

Yersinia enterocolitica in milk and dairy products

Yersinia enterocolitica was first recognized during the 1960's as an important human enteropathogen. The species as later redefined includes both pathogenic and nonpathogenic forms. Pathogenic strains that retain the virulence plasmid can be identified in several animal models and four indirect tests (calcium dependency, autoagglutination, Congo red uptake, serological detection of outer membrane antigen) and by tissue culture assay, serotype, and biotype. Y. enterocolitica and related bacteria have frequently been isolated from raw milk, but none of the isolates, with the possible exception of serotype 05,27, are recognizable as pathogens. Under normal circumstances Y. enterocolitica does not survive pasteurization. If introduced into pasteurized milk, it can grow well at refrigeration temperatures. Two outbreaks of yersiniosis have occurred that involved pasteurized milk. Pigs, which frequently carry pathogenic Y. enterocolitica in their throat, were the probable source in one of these outbreaks. The most rapid enrichment procedure available for isolation of Y. enterocolitica requires 6 d. No isolation method is available for selective isolation of pathogenic Y. enterocolitica in the presence of related bacteria common in milk and other foods.

Community outbreak of Yersinia pseudotuberculosis

An outbreak of Yersinia pseudotuberculosis in Kurashiki, Japan is described. This is the first conclusive report of a community outbreak of this microorganism. A total of 535 pupils, five teachers, and one food attendant contracted the organism. Causative organisms were detected in 19 out of 30 patients. All isolated strains belonged to serotype VA. Out of 653 sera of the pupils, 488 showed elevated agglutinin titers ranging from 1:80 to 1:1,280 or more within a period of 3 months.

Psoas muscle abscess due to Yersinia enterocolitica

A psoas muscle abscess due to Yersinia enterocolitica developed in a 71-year-old man with mild type II diabetes mellitus. There was no evidence of gastrointestinal infection or septicemia, and treatment with computed tomography-directed percutaneous drainage and cefoxitin resulted in cure. This represents the first known reported case of psoas abscess due to Y. enterocolitica.

Septicaemia due to Yersinia enterocolitica biotype I in Hong Kong

The clinical histories of four patients with septicaemia due to Yersinia enterocolitica biotype I and the biochemical reactions of the isolates are reported. Three of the isolates were serotype 017 and one was non-typable. These are the first reports of Y. enterocolitica septicaemia from Asia and of septicaemia due to biotype I which has previously been postulated to be non-pathogenic. All four patients had an underlying illness (two with metastatic neoplasms and two with burns). All of the patients recovered fully despite the high mortality associated with this condition. It is postulated that biotype I is of low pathogenicity.

Serological relatedness of mouse-virulent Yersinia enterocolitica

An antiserum (WA-SAA) was produced which agglutinated specifically with mouse-virulent but not with avirulent strains of Yersinia enterocolitica. Expression of the antigenic determinant(s) reaction with WA-SAA was temperature dependent; for growth temperatures of 20 to 40 degrees C, agglutination titers were lowest for cultures grown at 20 degrees C and highest for cultures grown at 35 to 40 degrees C. Addition of Ca2+ (2.5 to 10 mM) to the growth medium had little effect on the agglutination titer, and gel diffusion studies with monospecific anti-V serum indicated that V antigen was not likely to be the determinant reacting with WA-SAA. Immunohistological studies of Peyer's patches of mice infected with Y. enterocolitica WA revealed that the antigenic determinant(s) reacting with WA-SAA was expressed in vivo. The strong correlation of agglutination titer with mouse virulence and the expression in vivo of the antigenic determinant(s) reacting with WA-SAA suggest that the antigen(s) may be associated with the pathogenicity of Y. enterocolitica.

Yersinia enteritis

Y. enterocolitica has been shown to be a fairly common human pathogen in many countries. The clinical picture produced by Y. enterocolitica infections is quite variable. An acute abdominal disease (acute gastroenteritis or colitis, or a pseudoappendicitis due to acute terminal ileitis) and, less commonly, erythema nodosum and arthritis are the most important manifestations of the disease. On radiologic examination mucosal lesions of the terminal ileum are found in most patients with gastrointestinal symptoms. The colon is less frequently involved. The most typical lesions consist of shallow, small, round ulcers characteristic of the disease. Microscopic examination may suggest yersiniosis but does not show pathogenic signs. Y. enterocolitica can be detected by stool cultures or by serologic examinations. The disease is usually mild. If specific therapy is indicated the disease usually responds well to antibiotic therapy.

Characteristics of virulence in human isolates of Yersinia enterocolitica

Yersinia enterocolitica serotypes O:3, O:8, O:9, O:5,27, O:4,32, and O:21 were virulent as determined by autoagglutination and calcium dependency at 35 degrees C and ability to produce guinea pig conjunctivitis and mouse diarrhea.

Adherence of Yersinia enterocolitica to mammalian epithelial cell lines

Yersinia enterocolitica RIMD 2501003 grown at 25 C avidly adhered to various kinds of cultured epithelial cell lines (HeLa, FL, Y-1 adrenal, human intestine, human conjunctiva) but the bacteria grown at 37 C did not adhere. This phenomenon paralleled the temperature-dependent motility of the bacteria. To clarify the adherence mechanism, we obtained two kinds of mutants, an immobile mutant and a nonadherent mutant, by treatment with N-methyl-N'-nitro-N-nitrosoguanidine. The immobile mutant did not move on soft agar but retained the capacity to adhere to cultured epithelial cells when grown at 25 C. The nonadherent mutant did not adhere to cultured epithelial cells but retained the ability to move on soft agar when grown at 25 C. When the bacteria were killed by heat, ultraviolet light irradiation or formaldehyde they lost their capacity to adhere to the cultured epithelial cells. Antiserum against Y. enterocolitica RIMD 2501003 grown at 25 C was absorbed with the bacteria grown at 37 C, with the bacteria grown at 25 C, with the nonadherent mutant grown at 25 C and with the bacteria killed by various means. Only the antiserum absorbed with bacteria grown at 37 C inhibited the adherence of bacteria. These data indicate that motility does not correlate with adherence of Y. enterocolitica. It appears that the adherence factor involves both a temperature-dependent surface factor and a factor synthesized de novo during the interaction of susceptible cells with the bacteria.

Prevalence of enterotoxigenicity in human and nonhuman isolates of Yersinia enterocolitica

A total of 414 cultures of Yersinia enterocolitica isolated from human and nonhuman sources were examined for heat-stable enterotoxin (ST) production to determine whether enterotoxigenicity was related to the source of isolation, serotype, or biochemical characteristics of the organism. A total of 65% of all cultures were found to produce ST. Enterotoxin production was much more prevalent in strains isolated from humans (218/232) than in those isolated from animals (17/34), water (9/49), raw milk (14/44), and food (10/55). Strains belonging to the serotypes O:3; 8; 5,27; 6,30; 9, often isolated from human infections, were almost always enterotoxigenic (191/196), although ST production was also highly prevalent among a few other serotypes. The most significant difference was observed between the groups that differed in the ability to ferment rhamnose; only 13 of 130 rhamnose-positive isolates produced ST (10%) compared to 255 of 284 rhamnose-negative cultures (90%). These results suggest that ST production is ubiquitous in Y. enterocolitica, with the highest prevalence among strains associated with human infections.

Epidemic Yersinia enterocolitica infection due to contaminated chocolate milk

In September and October, 1976, an outbreak of illness due to chocolate milk contaminated with Yersinia enterocolitica resulted in hospitalization of 36 children, 16 of whom had appendectomies. Infection with Y. enterocolitica serotype 0:8 was demonstrated in 38 ill persons. Sixty-one per cent of the persons who were infected had a titer greater than 1:160 OH agglutinins to serotype 8 yersinia, whereas 48 per cent of the hospitalized children had a fourfold change in agglutinin titer. An epidemiologic investigation demonstrated that illness was associated with drinking of chocolate milk purchased in school cafeterias, and Y. enterocolitica 0:8 was subsequently isolated from the milk. The investigation suggested that the bacterium was introduced at the dairy during the mixing by hand of chocolate syrup with previously pasteurized milk.

Acute terminal ileitis and Yersinia enterocolitica infection

Diarrhea, moderate to high fever and pain in the RLQ associated with a tender mass or swelling of the terminal ileum arouse suspicion of acute terminal ileitis. Will diagnostic of the disease be laboratory data compatible with acute inflammatory disease and radiological findings of the terminal ileum, i.e., thickening of mucosal folds, round filling defects on the mucosa indicative of swelling of lymphoid tissue and fine irregularities of the margin without narrowing of the lumen. Yersinia infection was demonstrated in 7 of 10 patients whose stool and/or serum were examined. Yersinia enterocolitica was found to be an important causative agent of acute terminal ileitis. Its detection will be useful for differentiating the disease from acute stage of Crohn's disease.

Recovery of Yersinia enterocolitica from streams and lakes of California

Stream and lake water from the Mammoth Lakes region of California was sampled for Yersinia enterocolitica. From 10 of the 34 sites examined, organisms were isolated that were biochemically identified as Y. enterocolitica. Only one of the ten strains could be serologically confirmed. This strain was identified as Y. enterocolitica serotype 16. Although an outbreak of enteritis in the area prompted this study, no correlation with gastrointestinal disease could be established since the majority of the strains were untypeable.

Biological activities of endotoxins from Yersinia enterocolitica

The chemical properties and the general biological activities of lipopolysaccharide (LPS) and Boivin-type endotoxin obtained respectively by phenol-water and trichloroacetic acid extraction from Yersinia enterocolitica serotypes O3 and O9 were studied. The yield of LPS from the O9 strain was about 10% of the O3 strain possibly because of the lower solubility of O9-LPS in aqueous phase. However, the chemical composition of O9-LPS was similar to that of O3-LPS in the proportions of reducing sugar, glucosamine, heptose, KDO, and lipid A. In pyrogenicity and local Shwartzman reactivity in rabbits and lethality for mice, there was also no difference between O3 and O9-LPS. The anthrone-positive carbohydrate and lipid A contents of Boivin-type endotoxin from O3 were higher than those of the endotoxin from O9. The biological activities of Boivin-type endotoxin from O3 were also remarkably higher than those of the endotoxin from O9. It seems that endotoxin of Y. enterocolitica serotype O3 may play an important role in infection by this organism.

Clinical isolation of Yersinia enterocolitica: cold temperature enrichment

A cold-temperature enrichment procedure was used to isolate Yersinia enterocolitica serotype 6 from a clinical stool specimen. The use of conventional laboratory media and enrichment procedures failed to isolate this organism.

Two community outbreaks of human infection with Yersinia enterocolitica

Two outbreaks of human infection with Yersinia enterocolitica in Shizuoka, Japan are described. This is the first report of community outbreaks of infection with this organism in Japan, and possibly in the world. All the strains isolated in each outbreak belonged to O antigen group 3, biotype 4, of the species. Despite much effort, the source and mode of spread of the infection were not established.