Immunohistochemical and electron microscopic study of interaction of Yersinia enterocolitica serotype O8 with intestinal mucosa during experimental enteritis

The experimental infection of mice with Yersinia enterocolitica serotype O8 was investigated in a quantitative and histological study. The course of bacterial penetration and spreading was precisely determined by immunohistochemical staining. After oral administration, the bacteria passed the epithelial barrier of the ileum and spread into the lamina propria. By preference they entered Peyer's patches, which were about 1,000 times more heavily colonized than the surrounding epithelium of a comparable surface area. The bacteria proliferated in the follicles, from which they spread into the lamina propria of the villi. At either site most of the bacteria multiplied extracellularly, with only a small percentage observed to be present within the phagocytes. The bacteria did not appear to be able to pass the intact basement membrane; hence, the integrity of the basement membrane is likely to play a role in determining the route of entry and limit of spread of Y. enterocolitica infection.

Early treatment of Campylobacter jejuni enteritis

The bacteriologic and clinical effects of early antibiotic treatment of Campylobacter jejuni enteritis were studied. Erythromycin rapidly eliminated C. jejuni from stools, whereas trimethoprim-sulfamethoxazole did not. Despite its bacteriologic effectiveness, erythromycin did not reduce the duration or severity of diarrhea, abdominal pain, or other symptoms.

Characterization of cross-reacting serotypes of Campylobacter jejuni

Some strains of Campylobacter jejuni react with more than one reference antiserum from the serotyping scheme based on heat-stable lipopolysaccharide antigens. To investigate the molecular basis of these cross-reactions, lipopolysaccharides from the reference strains for serotypes 4, 13, 16, 43, and 50 and isolates recovered during two different outbreaks of C. jejuni enteritis were analyzed by passive haemagglutination and sodium dodecyl sulphate-polyacrylamide gel electrophoresis coupled with silver staining or immunoblotting. The results showed that lipopolysaccharides from the reference strains and the isolates reacted with antisera prepared against heterologous strains in various combinations and that both silver-stainable, low Mr and non-silver-stainable, high Mr lipopolysaccharide components provided the antigenic determinants associated with the cross-reactions. There were strain-to-strain differences in the structural and antigenic properties of these macromolecules and shared antigenic determinants were not always provided by a common structure. Analysis of the silver-stained lipopolysaccharide profiles, outer membrane protein patterns, and chromosomal DNA restriction patterns indicated that strains with the same lipopolysaccharide profile could have the same outer membrane protein pattern and the same DNA restriction pattern. These results provided evidence for the presence of clones within this antigenic complex and implicated antigenic variation in some strains as the phenomenon responsible for the multiplicity of cross-reactions.

[Clinical efficacy of clarithromycin in the field of pediatrics]

A new macrolide antibiotic, clarithromycin (TE-031, A-56268), was studied for its clinical efficacy in the field of pediatrics. Patients treated were infants and children ranging from 2 months to 11 years old suffering from acute bronchitis in 5 cases, acute tonsillitis in 2 cases, Mycoplasma pneumonia in 2 cases, pertussis in 6 cases, scarlatina in 1 case and acute enteritis in 2 cases, a total of 18 cases. TE-031 was administered 19.7-43.5 mg/kg in daily doses and lengths of treatment ranged from 4 to 19 days. As regards to its clinical efficacy, good or excellent results were obtained in all cases: excellent in 11 cases and good in 7 cases. No clinical side effects nor abnormal laboratory test values obviously attributable to TE-031 were observed.

[A clinical evaluation of clarithromycin in the treatment of pediatric infections]

Clarithromycin (TE-031, A-56268) granules were used to treat various infections in the pediatric field and the results obtained are summarized as follows. 1. TE-031 was administered to a total of 10 patients (5 cases of enteritis, 4 cases of bronchitis and 1 case of tonsillitis). Clinical efficacies were excellent in 6 patients and good in 4 with an efficacy rate of 100%. 2. Neither side effects nor abnormal laboratory test values were observed. There was no rejection of drug disturbing the therapy.

Reproduction of proliferative enteritis in gnotobiotic pigs

Gnotobiotic pigs dosed orally with filtrates (0.8 and 0.65 micron) of intestinal mucosa from a pig affected by proliferative haemorrhagic enteropathy developed lesions of proliferative enteritis, affecting mainly the ilea. Other piglets dosed with filtrates of affected mucosa from the same source and from other proliferative haemorrhagic enteropathy or intestinal adenomatosis mucosae, did not develop lesions. All inocula contained numerous campylobacter-like organisms evident in stained smears, Campylobacter coli and C mucosalis. C coli colonised the intestines of all the pigs, C hyointestinalis (which was not detected in the inocula) did so in some affected and unaffected pigs while C mucosalis was not recovered from any of the intestines. Although other explanations are possible the number and viability of the intracellular campylobacter-like forms is likely to be the critical factor in infectivity. In affected intestines the crypts were colonised by campylobacter-like organisms, and their attachment and entry into enterocytes was associated with cellular proliferation. Immunofluorescence reactions suggested that the intracellular campylobacter-like organisms were antigenically distinct from the known Campylobacter species. It is possible, therefore, that porcine proliferative enteritis is caused by a further unidentified Campylobacter species, or that there is a marked antigenic change of C hyointestinalis or C coli on entry into porcine enterocytes.

Occurrence and significance of Clostridium difficile in faecal specimens of hospitalized children

Stool specimens from 766 hospitalized children, 418 with diarrhoea and 348 controls, were investigated for C. difficile. In both groups the rate of isolation was highest (about 30%) during the first year of life, dropping to nearly 5% in older children. There was no significant difference in the frequency of C. difficile in children with diarrhoea and the controls nor was there a significant influence of previous antibiotic therapy on the rate of isolation. 111/135 strains (82.2%) produced toxin B and 58/135 strains (43%) produced toxin A measured by Y-1- cell culture (toxin B) and rabbit ileal loop test (toxin A). We did not find any significant difference in the toxin production between strains isolated from diarrhoeal children and from the controls. A total of 285 stool specimens was investigated for toxin B production in vivo. There was no significant difference of toxin B in the stool specimens of both groups.

An enteric infection by Salmonella typhimurium: a multiple typing study

A multiple typing analysis was carried out on 14 apparently heterogeneous Salmonella typhimurium strains recovered during a 3 week period from an enteritis case. Conjugational transfer of resistance determinants and restriction endonuclease fingerprinting of plasmids allowed the different isolates of S. typhimurium to be attributed to a single clone.

[The significance of the incidence of coccidia of the Cryptosporidium species in the etiopathogenesis of neonatal diarrhea syndrome and enteritis in calves on the basis of simultaneous histopathologic and parasitologic studies]

In 1985, a histopathological examination was conducted in the ileum and a parasitological examination in the ileum and rectum of 345 emergency slaughtered calves. The pathogenic role of cryptosporidia was compared in two groups of calves: group A contained 184 calves (53.3%) with scours and enteritis, group B contained 161 calves (46.7%) with other types of disease. In both groups the calves were divided into four age categories: 7 to 10 days (7.8%), 11 to 14 days (29.3%), 15 to 21 days (53.0%), 22 days and older (9.9%). During the parallel examination by both methods, cryptosporidia were detected in 124 cases, i.e. at the total invasion extensity of 35.93%; in group A the cryptosporidia were found in 76 cases (22.02%) and in the group B in 48 cases (13.91%). As indicated by the results, cryptosporidiosis is a disease of polyfactorial origin and cryptosporidia must be taken into account as one of the enteropathogenic factors in the etiology of scours. It is confirmed by the positive findings of cryptosporidia in the calves of group B (29.81%) and the negative finding in group A (31.3%) that no clear relationship was demonstrated to exist between the positive findings of these protozoans and the clinical symptoms of the diseases and enteritis. The pathogenesis of cryptosporidiosis includes significant regressive changes in the microvillous layer and enterocytes, which were a common finding at heavy invasions. The total positivity of the findings of cryptosporidia in the ileum was significantly higher (by 14.8%) during the histopathological examination, as compared with the parasitological examination. Out of the total positive findings, 39 cases (31.5%) were demonstrated histopathologically. During the parasitological examination, the positivity of the findings of cryptosporidia was higher by 4.3% in the rectum than in the ileum. When there was conducted a parallel parasitological examination of the ileum and rectum, the total positivity was higher by 7.5% than at the histopathological examination in the ileum. The highest invasion extensity was found at the age of 7 to 10 days in both groups of calves. The highest invasion intensity was found at the age of 11 to 21 days in both groups. The age until the 21st day when the parasitosis is intensively spread is considered as the most dangerous age of the calves from the epizootological point of view. Cryptosporidia occurred all the year round, no characteristic seasonal patterns were observed. The total average invasion extensity of the 24 farms from where the calves came was 42.3%, its range being from 0 to 85.7%.

Correlation of the suicide phenomenon in Aeromonas species with virulence and enteropathogenicity

Certain strains of mesophilic aeromonads (Aeromonas hydrophila, A. sorbria, and A. caviae), when grown in broth containing 0.5% glucose, undergo growth inhibition concomitant with acetate accumulation. Because these strains are nonviable after 24 h, this phenomenon is termed suicide. We investigated suicidal strains of Aeromonas species as a means of understanding animal virulence and enteropathogenicity. To assess virulence, batches of five white mice were inoculated intraperitoneally with 10(7) cells (washed) of suicidal and nonsuicidal strains of A. hydrophila and A. sobria and suicidal strains of A. caviae. The three nonsuicidal strains of A. sobria tested showed lethality as early as 12 h and were uniformly fatal within 36 h postinoculation. After 36 h, the three suicidal strains killed only 1 of 15 mice inoculated. Four A. hydrophila strains tested which showed the suicide phenomenon at 37 degrees C were variably lethal (40 to 100%). None of three suicidal strains of A. caviae were lethal. Enteropathogenicity was studied by orally inoculating three white mice each with the same Aeromonas strains (10(8) cells, in skim milk) and assessing diarrhea and intestinal fluid accumulation. Diarrhea and fluid accumulation were present in all mice inoculated with two nonsuicidal strains of A. sobria and in 4 of 12 mice given four suicidal strains of A. hydrophila. Two suicidal strains each of A. sorbria and A. caviae failed to elicit any gastrointestinal disturbances. These data suggest that the suicide phenomenon may explain strain-specific (A. sobria and A. hydrophila) and species-specific (A. caviae) virulence and enteropathogenicity.

In vitro lecithinase activity and sensitivity to 22 antimicrobial agents of Clostridium perfringens isolated from necrotic enteritis of broiler chickens

Viable Clostridium perfringens ranging from 10(5) to 10(8) g-1 was detected in all of 88 intestinal content specimens of necrotic enteritis in broiler chickens. In vitro lecithinase activity and sensitivity to 22 antimicrobial agents were determined for the 88 isolates. The activities of lecithinase in the culture filtrate of isolates were estimated to be 0.5 to 4.0 AE ml-1 as alpha-antitoxin equivalent. With reference to antimicrobial activity penicillins and cephazolin showed excellent activity and no resistance; peptides, of the agents used as growth promoters, showed that all except bacitracin had low minimum inhibitory concentration levels (1.6 micrograms ml-1 or less) against this organism; polyethers of monensin, salinomycin and lasalocid were generally adequate in low concentrations while there was a high level of resistance to three tetracyclines in 90 per cent of the strains and all isolates were insusceptible to streptomycin of the aminoglycoside antibiotics.

Ulcerative enteritis in broiler chickens caused by Clostridium colinum and in vitro activity of 19 antimicrobial agents in tests on isolates

Ulcerative enteritis in broiler chickens occurred at five poultry farms in Kagoshima Prefecture, southern Japan, in February and March, 1987. This is the first incidence of this disease reported for chickens in Japan. The mortality rate was estimated to be 1 to 5%. Ulcerative enteritis in the intestines, and necrosis in the liver and spleen, were observed mainly in autopsied broilers. Identification involving tests of biochemical properties and production of metabolic endproducts using gas-liquid chromatography were consistent with an identification of Clostridium colinum. Antimicrobial agent susceptibility tests on the isolates showed that all were highly sensitive to the agents, with the exception of aminoglycoside antibiotics. Minimum inhibitory concentrations of penicillin-G and ampicillin ranged from .025 microgram/mL to .05 microgram/mL. No resistant strains were isolated.

[Significance of adenovirus infections in infancy and early childhood]

Of 418 stool specimens of infants tested, 45 specimens contained adenoviruses, mainly the types 1 and 2, 40 and 41. Infections by these types caused symptoms of the gastrointestinal and the respiratory tract to varying degrees: adenoviruses 40 and 41 frequently caused gastroenteritis, adeno 2 was often associated with diarrhoea, adeno 1 mostly caused illness of the respiratory tract necessitating hospitalization of the infants. As adenoviruses may produce--especially during the first years of life--severe diseases of the respiratory and the gastro-intestinal tract, their detection will be of major importance to the pediatrician, the more so as today's methods of detection of adenoviruses are easier and less time-consuming than in the past.

Apparent lack of effect of vaccination against mink enteritis virus (MEV). A challenge study

The mink enteritis virus part of a triple vaccine was tested in mink. No raise in antibody response was measured after vaccination. Subsequent challenge of groups of vaccinated or not-vaccinated animals revealed no differences in virus excretion or antibody response in the different animals.

Enteropathogenicity of plesiomonas shigelloides by oral inoculation in adult conditioned rabbits

To study presumptive diarrhoeagenic and invasive properties of Plesiomonas shigelloides, adult conditioned rabbits (n = 75) were fed 10(10) CFU of 3 isolates (2 from diarrhoea patients and one from river water) of the organism, and one isolate of Shigella sonnei (from a dysentery patient as positive control) or brain-heart infusion broth (as negative control). Each rabbit received in succession i.v. cimetidine (50 mg/kg body weight), two 15 ml oral doses of 5% NaHCO3 at 15 and 30 minutes respectively, prompt bacterial or sham inoculum followed 30 minutes by 2 ml of i.p. tincture of opium. Rabbits fed with P. shigelloides did not die or develop diarrhoea, but in a majority of them, histopathological examinations of the intestine revealed mild acute inflammation of the mucosa, mainly in the ileum. There was no serum antibody response by indirect haemagglutination against the lipopolysaccharide of the homologous strains of P. shigelloides. The culture filtrates of the organism also did not show any cytotoxic morphological changes on CHO and Y1 adrenal cell cultures. By contrast, rabbits fed with S. sonnei developed clinical diarrhoea, small to widespread severe acute inflammation of the gut mucosa, and all died on day 7. It may be concluded that P. shigelloides are able to provoke a mild inflammatory lesions of the gut mucosa in this rabbit model; but there is little prospect of using this model to assess easily the virulence of the organism.

[Bacteriologic and serologic diagnosis of enteral infections]

Infections of the gastrointestinal tract still are numerous, ranging on the second place after infections of the respiratory tract. Some of them show quite severe or prolonged course. In contrast to other infections, especially those of the urinary tract, laboratory diagnostic of enteritis is only scarcely ordered. During the last ten years new methods and knowledge of etiologic germs like Campylobacter, Yersinia, various types of E. coli, Clostridium difficile, Rotavirus, Adenovirus, Giardia, Blastomyces and Cryptosporidia have been accumulated. A better etiologic diagnosis of these infections should enable the clinician to start a more precise and therefore more effective therapy.

Lymphocytic-plasmacytic enteritis associated with bacterial overgrowth in a dog

Lymphocytic-plasmacytic enteritis, associated with small intestinal bacterial overgrowth, was diagnosed in a 3.5-year-old German Shepherd Dog with chronic intermittent diarrhea, using bacteriologic culture of duodenal juice and histologic examination of jejunal biopsy specimens. Oral administration of oxytetracycline alone resulted in clinical improvement and a marked decrease in the jejunal mononuclear cell infiltrate. Additional treatment with prednisolone administered orally resulted in almost complete clinical and histologic recovery. This case illustrates that small intestinal bacterial overgrowth may have to be considered as an underlying cause of lymphocytic-plasmacytic enteritis in the dog and that antibiotic treatment may be necessary to attain remission.