Summary of the data received at the WHO Reference Center for Yersinia enterocolitica.
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Animals↗
Biomedical subjects
H Bercovier
Publications and source records attributed to H Bercovier.
[Experimental infection in mice with Yersinia enterocolitica (strain biotype 4, serogroup O:3, phage type VIII): growth of the inoculum in athymic or cyclophosphamide treated mice (author's transl)].
Intravenous infection of Swiss mice with a strain of Yersinia enterocolitica unable to colonize normal mice by the oral route, induced a systemic infection. Viable bacteria were isolated from homogenates of liver, spleen and lungs, as early as one hour after the challenge and have been detected during two weeks. On the other hand, the number of viable bacteria isolated from the blood has always been very low. Faecal samples permitted the isolation of Y. enterocolitica even after two weeks, while at this time no more bacteria were isolated from the tissues. The duration of the infection remained unchanged with an inoculum of 10(3), 10(4) or 10(5) viable bacteria. Depending on the size of the inoculum, liver macroscopic abscesses occurred more or less rapidly after the challenge. These abscesses disappeared spontaneously. A single intravenous injection of cyclophosphamide (200 mg/kg) six days after the challenge was followed by an important rise of the number of bacteria in all the tissues. Comparative studies of intravenously infected athymic (Nude) mice and controls showed a higher number of bacteria in the liver and spleen of the athymic animals.
Animals↗
[Experimental pathogenicity of "Yersinia enterocolitica" for athymic nude mice (author's transl)].
Amongst the 4,500 strains of our collection of Yersinia enterocolitica usually non-pathogenic for laboratory animals, 5 or 6 strains appeared to be naturally pathogenic for mice. Using these strains and non-pathogenic strains representing more than 90 per cent of human isolates in the world (biotype 4, serotype 0:3, phagocyte VIII; biotype 2, serotype 0:9, phagotype X3), the pathogenicity for cyclophosphamid treated mice and athymic Nude mice has been tested. Highly pathogenic strains killed conventional as well as cyclophosphamid treated mice. Non-pathogenic strains for conventional mice did not show any pathogenicity for cyclophosphamid treated mice (strain IP161 excepted) but killed 30 athymic Nude mice inoculated with 5 x 10(8) and 5 x 10(5) organisms by the oral or intraperitoneal routes. Nude mice infected intragastrically or intraperitoneally showed signs of enteritis and bronchopneumonia followed by a septicemia. Abscesses were found in the liver, the spleen and the ileal wall. The infection of Nude mice with Y. enterocolitica resembles naturally acquired human infection where 2/3 of the cases are enteritis among under 4-year-old children and where septicemia occurs among immunologically deficient adults. The role of T-lymphocytes and of immune functions in Y. enterocolitica infection is discussed through our model.
Animals↗
Prevalence of anti-hepatitis A antibodies, hepatitis B viral markers, and anti-hepatitis C antibodies among immigrants from the former USSR who arrived in Israel during 1990-1991.
The goal of this study was to assess the susceptibility of the sub-population of over 500,000 immigrants from the former USSR who came to Israel during 1989-94 to HAV infection, and to provide military physicians with estimates of the prevalence of HBV and HCV carriage in this sub-population. 987 males aged 17-49 and 195 females aged 17-19, reporting to military recruitment offices between December 1991 and March 1992 were tested. Anti-HAV, anti-HBV antibodies and hepatitis B surface antigen (HBsAg) were detected by using standard enzyme immunoassay (EIA) tests, and anti-HCV antibodies by a second-generation EIA and confirmed by a third-generation INNO-LIA test. It was found that in the 17-19-year age-group the prevalence of anti-HAV antibodies was 37%, anti-HBV was 12.8%, HBsAg was 3.0% and anti-HCV 1.3%. All markers were higher among males. The prevalence of anti-HAV and anti-HBs antibodies increased with age among males. That of HBsAg and anti-HCV antibodies increased with age overall. In the multiple logistic regression analysis, HAV and HBV seropositivity were significantly associated with the mother's education and republic of origin. It was concluded that the prevalence of anti-HAV antibodies is similar to that among the local population, which should not be considered at a higher risk of infection during military service. On the other hand, the higher prevalence of HBsAg and anti-HCV antibodies in this sub-population should heighten the awareness of the possibility of chronic liver pathology.
Adolescent↗
Immune status against diphtheria among immigrants from the former USSR who arrived in Israel during 1990-1991.
Large outbreaks of diphtheria occurred recently in the former USSR. Between 1989 and 1994, a total of about 600,000 Soviet immigrants arrived in Israel. The immune status against diphtheria in a sample of 992 men aged 17-49 and 195 women aged 17-19, who arrived in Israel during 1990-91, was studied in order to evaluate the need for vaccination. Participants completed a self-administered questionnaire and diphtheria antitoxin antibody levels were measured by means of ELISA. At age 17-19, the prevalence of antitoxin antibody levels below the protective level of 0.01 IU/ml was 4.8% in the men and 2.1% in the women. Among the men, the percentage lacking protection declined from 4.8% at age 17-19 years to 1.6% at age 20-24, and increased to 18.2% at age 35-49. In the oldest group, the prevalence of those lacking protection was considerably higher than for the general Israeli population. In the multivariate analysis, age, mother's education and republic of origin were significantly associated with the absence of protection. Immigrants from the former USSR appear to be more susceptible to diphtheria, thus increasing the possibility of clinical disease, and it is recommended that they receive booster doses of diphtheria toxoid.
Adolescent↗
Death of Mycobacterium lepraemurium after multiplication in CBA, BALB/c and nude mice.
The unexpected death of Mycobacterium lepraemurium in the course of systemic infection of mice, previously noted in the spleens of CBA mice, has been demonstrated in the spleens of BALB/c nu/+ and BALB/c nu/nu mice and also in the livers and other organs of mice of all three strains. That the same phenomenon was observed in nu/nu mice indicates that the mechanism of bacterial death does not involve a T-lymphocyte-mediated cellular immune response on the part of the mice.
Animals↗
Reduction of tellurite and deesterification of fluorescein diacetate are not well correlated with the viability of mycobacteria.
Both Mycobacterium leprae and M. lepraemurium (MLM) were capable of reducing tellurium as tellurite ion (Te4+) to elemental tellurium (Te), seen by electron microscopy as fine crystals within the bacterial cells. There appeared to be close correspondence between the capacity to reduce tellurite, bright green fluorescence after staining with fluorescein diacetate (FDA) and the ability of M. smegmatis to multiply in culture. Likewise, there appeared to be correspondence between tellurite reduction and fluorescence after FDA staining for MLM subjected to prolonged storage in the cold or to heating at 70 degrees C. However, correspondence with tellurite-reduction or fluorescence after FDA staining was not observed when death of MLM occurred in vivo.
Fluoresceins↗
Biological characterization of Actinobacillus species and Pasteurella ureae.
Forty-seven strains of Actinobacillus and eleven strains of Pasteurella urea were studied using 119 morphological, physiological and biochemical characters. The resulting data were subjected to numerical analysis using the complement of Gower's coefficient excluding negative matches. Clustering was by unweighted pair group average linkage. At distance level 0.30, seven phenons and five isolated strains (including one strain of "A. seminis ") were obtained. The seven phenons correspond to Actinobacillus lignieresii , A. suis, A. equuli , A. capsulatus, "A. salpingitidis ", Actinobacillus sp. (Ross) and P. ureae. The characteristics allowing identification of the seven phenons are tabulated.
Actinobacillus↗
[Presence of Heligmosomoides glareoli Baylis, 1928 in Clethrionomys glareolus; first observation in France].
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Animals↗
Polymyxin B reduces total parenteral nutrition-associated hepatic steatosis by its antibacterial activity and by blocking deleterious effects of lipopolysaccharide.
Overgrowth of Gram-negative bacteria as a result of total parenteral nutrition (TPN) and bowel rest could be responsible for the release of a variety of hepatotoxic substances such as endotoxin or tumor necrosis factor (TNF) and the ensuing TPN-associated liver function derangements. Polymyxin B is an effective antimicrobial agent as well as a blocking agent for endotoxin (lipopolysaccharide) activity and TNF production. In the present study we compared the oral and intravenous effects of polymyxin in rats receiving TPN in an attempt to define these two possible mechanisms of action of polymyxin on TPN-associated hepatic steatosis. Both oral, as well as intravenous polymyxin B, significantly reduced total hepatic fat and triglyceride accumulation in TPN rats, more so in the intravenous group exhibiting close to control levels. Both polymyxin-treated groups exhibited significantly lower Gram-negative bacterial counts in the cecum, with the oral group exhibiting a lower count than the IV group. The spontaneous production of TNF by peritoneal macrophages was markedly increased in rats receiving TPN and very close to being undetected in both groups receiving TPN and polymyxin. We believe polymyxin B protects the liver during TPN by both its antimicrobial effect which prevents overgrowth of gut Gram-negative bacteria and the subsequent translocation of endotoxin, and by its specific antilipopolysaccharide activity which, in the present study, completely abolished hepatic steatosis and TNF production during TPN.
Administration, Oral↗
Antitumor necrosis factor antibodies reduce hepatic steatosis during total parenteral nutrition and bowel rest in the rat.
BACKGROUND: In previous studies, we demonstrated the overgrowth of gram-negative bacteria in the gut and an enhanced release of tumor necrosis factor (TNF) by peritoneal macrophages, suggesting that endotoxin, TNF, or both, may act as hepatotoxins to produce hepatic steatosis during total parenteral nutrition (TPN) and bowel rest. The present study attempts to better define the role of each of these two mediators. The first part examines the LD50 for various doses of endotoxin in TPN-treated rats compared with free-feeding and free-feeding saline-infused rats. In the second part we repeatedly administered anti-TNF monoclonal antibodies to rats subjected to TPN and bowel rest. METHODS: In the first set of experiments, 87 male Sabra rats were randomized into three groups: free-feeding, infused with normal saline, and infused with TPN. On day 7 of the experiment, all rats received an IV injection of endotoxin at various doses (1.5, 2.5, 5.0, 7.5, and 10 mg/kg). The LD50 in the three groups and at the various doses of lipopolysaccharide tested was determined at 24 hours postinjection. In the second set of experiments, 38 male Sabra rats were randomized into three groups: infused with normal saline and fed rat food ad libitum, infused with TPN, and infused with TPN but also receiving monoclonal antibodies against TNF. RESULTS: Lower endotoxin doses were required to achieve LD50 in the two IV-infused groups (2.5 to 5.0 mg/kg) compared with the free-feeding group (7.5 mg/kg) (p < .03). These findings suggest a moderate increase in susceptibility to the lethal effect of endotoxin in IV-treated rats. The total hepatic fat and triglyceride levels, which were markedly increased in TPN rats, were significantly reduced by using anti-TNF antibodies. Enhanced TNF production by peritoneal macrophages during TPN was completely eliminated by anti-TNF antibodies, probably the result of suppressed TNF production. CONCLUSIONS: The continuous translocation of endotoxin from gram-negative bacterial overgrowth in the gut during TPN and bowel rest results in enhanced release of TNF by macrophages. TNF causes hepatic dysfunction, portrayed in the present experimental model as hepatic steatosis. TPN-induced hepatic steatosis was significantly reduced by the administration of monoclonal antibodies against TNF-alpha.
Animals↗
Pentoxifylline and thalidomide fail to reduce hepatic steatosis during total parenteral nutrition and bowel rest in the rat.
BACKGROUND: We suggested that the continuous translocation of endotoxin from Gram-negative bacterial overgrowth during bowel rest and total parenteral nutrition (TPN) causes the release of tumor necrosis factor (TNF), resulting in liver damage and hepatic dysfunction. Because TPN-induced hepatic steatosis was significantly reduced by the monoclonal antibodies against TNF, we attempted a more clinically applicable approach using pentoxifylline and thalidomide. METHODS: A control group (group I) fed rat chow and four groups of rats receiving TPN were studied. Group II received TPN only; group III, TPN and 100 mg/kg/d pentoxifylline; group IV, TPN and 200 mg/kg/d pentoxifylline; and group V, TPN and 5 mg/kg/d thalidomide. On day 7, total liver fat was determined. RESULTS: Bowel rest and TPN resulted in a significant (p < .0005) increase in liver fat content that was unaltered by either pentoxifylline or thalidomide. CONCLUSIONS: Our results show no role for pentoxifylline or thalidomide in reducing TPN-associated hepatic steatosis.
Animals↗
[Differentiation of "Pasteurella" and "Actinobacillus" from Enterobacteriaceae" by use of the O/129 vibriostatic agent (author's transl)].
Out of 134 Pasteurella and Actinobacillus strains studied, 132 are found to be susceptible to the O/129 vibriostatic agent with growth inhibition diameter ranging from 10 to 42 mm (86% in the range 25 to 32 mm); 46 reference strains of Enterobacteriaceae including Yersinia are resistant to the O/129 vibriostatic agent. This test can quickly differentiate between typical or atypical Enterobacteriaceae and the genus Pasteurella or Actinobacillus.
Actinobacillus↗
[A simple technique for raising ticks on micromammals].
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Animals↗
[gamma Glutamyltransferase activity in the genus "Yersinia" (author's transl)].
The expression of gamma-glutamyltransferase activity was studied among 87 strains representing all the Yersinia species. Y. pestis lacked constantly this enzyme, while y. pseudotuberculosis expressed it as a rule. This test, when positive, is useful for the exclusion of a suspected Y. pestis diagnosis. All the other Yersinia species, like most of the Enterobacteriaceae, showed a gamma-glutamyltransferase activity.
Yersinia↗
[Resistance to plague of mice experimentally infected with "Yersinia enterocolitica" (author's transl)].
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Administration, Oral↗
[Experimental infection of axenic mice by "Yersinia enterocolitica" (author's transl)].
Although most of Yersinia enterocolitica strains isolated from man have no pathogenicity for laboratory animals, it has been demonstrated that some strains are pathogenic for conventional mice and that most of the strains are probably pathogenic for Nude mice. The authors report the results of the infection of germ-free mice with a strain of Y. enterocolitica which is non pathogenic for holoxenic mice. It appears that C3H/He mice are sensitive to the infection by gavage or aerogenic and peritoneal routes. They all die within 8 to 12 days after injection of an inoculum of 5.10(5) viable cells. Germ-free NCS mice were also sensitive to the oral and aerogenic infection but not to the peritoneal infection; the difference between C3H/He and NCS sensitivity to this way of infection could be explained by a higher bactericidal activity of the peritoneal phagocytes of the latter. The C3H/He and NCS holoxenic control mice infected with the same inoculum of the same strain, did not show any symptoms and all attempts to isolate Y. enterocolitica failed three months after the challenge. Germ-free mice killed by the infection showed histopathological findings, i.e. abscesses involving intestinal wall. liver and spleen; they were similar to those described in experiments with pathogenic strains for conventional mice (holoxenic) and to those observed in infection of athymic Nude mice with strains non pathogenic for conventional mice. This infectious disease model is discussed in regards to the natural human infection.
Animals↗