Enteropathogenicity of Plesiomonas shigelloides and Aeromonas spp. in experimental mono- and coinfection with Cryptosporidium parvum in the intestine of neonatal BALB/c mice.

Enteropathogenicity of Plesiomonas shigelloides, Aeromonas hydrophila, A. caviae and A. sobria was studied both in monoinfections and in coinfections with coccidium Cryptosporidium parvum in neonatal BALB/c mice. In monoinfection experiments, neonatal BALB/c mice were orally infected with 7 x 10(7) or 7 x 10(8) CFU, respectively, of a strain of P. shigelloides or a strain of an Aeromonas spp. In coinfection experiments, the neonatal mice were, in addition to being orally infected with one of the four bacterial species, orally infected with an inoculum containing 10(5) oocysts of C. parvum. Results from monoinfections with P. shigelloides revealed long-term colonisation of the neonatal mouse intestine by this pathogen, along with associated pathological lesions. The lesions varied in severity from atrophy to necrosis of the mucosal inner surface of the ileum and colon, with predilection to the colon and brush border of colonic enterocytes. The effects of coinfection of P. shigelloides with C. parvum were characterised by bacteremia and heavy colonisation of the intestine by P. shigelloides. In addition, extensive necrotising inflammatory changes in the ileum and colon were accompanied by diarrhoea and deaths of coinfected mice. In contrast, the results from monoinfections of neonatal mice with Aeromonas spp. showed only a short-term colonisation of the intestine by the pathogen. However, when mice were coinfected with A. hydrophila and C. parvum, then the growth of the bacterial species was prolonged, and occurred in both the spleen and intestine. However, no substantial clinical or histopathological changes were observed in mice, whether monoinfected with Aeromonas spp. or coinfected with C. parvum. Our study suggests that experimental monoinfections of neonatal BALB/c mice with P. shigellodes, Aeromonas spp. and C. parvum, together with coinfections (each bacterial species with the protozoan C. parvum), may serve as a useful model to study the initial steps of gastrointestinal colonisation and diarrhoeal disease syndromes caused by enteropathogenic bacteria and protozoa, individually and in combination.

[Use of the anticoccidial agent, tortrazuril (Baycox, Bayer) in coccidiosis in suckling pigs]. / Pouzití antikokcidika tortrazuril (Baycox, Bayer) pri kokcidióze sajících selat.

At present neonatal coccidiosis caused by Isospora suis is known to be an important disease in piglets. The coccidium I. suis was diagnosed as the causative agent of diarrhoeic disease in piglets on a large pig farm with continuous farrowing operation. The diagnosis of coccidiosis was based on clinical history, gross lesions, histopathology, stained impression smears and aided by detection of oocysts in the faeces. Coccidiosis was associated with diarrhoea in piglets at the age of five to fourteen days. The disease was characterized by variable morbidity and only a portion of the litters was usually affected at one time. The piglets appeared listless, and suffered from yellow watery scours progressing to yellow pasty scours over a three- to five-day period. The lack of response to common antimicrobial therapy, and/or vaccination of sows for E. coli was observed. The prophylactic and therapeutic efficacy of tortrazuril (Baycox, Bayer) against coccidiosis was evaluated in naturally infected piglets. Tortrazuril at a dose of 20 mg/kg, given perorally to each piglet on days 6 and 8 of age, proved to be efficacious in preventing clinical coccidiosis in piglets. Tortrazuril fully controlled the oocyst output, prevented the development of diarrhoea but not improved the weight gains in three-week-old piglets if compared to the untreated controls. The prophylactic and therapeutic efficacy of tortrazuril was compared with another drug--amprolium (Amprovin, MSD). Amprolium at a dose of 100 mg/kg, given perorally to piglets from day 6 to 8 of age, was not efficacious in preventing clinical porcine neonatal coccidiosis. Amprolium reduced the oocyst output, but not prevented the development of diarrhoea. Tortrazuril (Baycox, Bayer) is clearly effective against porcine neonatal coccidiosis caused by I. suis.

Interaction of Cryptosporidium parvum and Campylobacter jejuni in experimentally infected neonatal mice.

By the method of scanning electron microscopy (SEM), the inner mucosal surface of the ileum, ceacum and colon was studied in inbred BALB/c mice. Two-day-old mice were infected with either 10(6) oocysts of Cryptosporidium parvum and 10(8) CFU of porcine and human strains of the bacterium Campylobacter jejuni or with a combination of both enteropathogens. Pathological changes in infection with C. parvum were related to enterocytes and villous atrophy appeared. In infection with C. jejuni, pathological changes were related to goblet cells. In combined infections, pathological changes were similar to those in monoinfections and occurred simultaneously within the intestine. Synergistic interaction of C. parvum and C. jejuni manifested itself morphologically in a more intense colonization of the inner surface of the small and large intestine by C. jejuni, in a more intense infection of the caecum and colon by C. parvum, and in prolongation of severe, massive infection of the small and large intestine, and also a prolongation of the patent period.

[Detection of Yersinia ruckeri in rainbow trout in Czechoslovakia]. / Nález Yersinia ruckeri u pstruhu duhových v Ceskoslovensku.

At the end of 1988 eight rainbow trouts Pd1 and nine rainbow trouts Pd2 were investigated at localities N and D with the increased mortality of rainbow trout. The pathological finding in dead and killed trout corresponded to the changes which are described in the so called ERM (enteric redmouth) salmonids. At the beginning of the year a similar case was found at locality B where 12 rainbow trouts Pd2 were examined. In the same period 15 trouts Pd2 at locality M were examined in which no large pathomorphological changes were observed. From the organs and intestines of locality N trout, from the intestines of locality D trout and the organs of locality B trout, in total 16 bacterial cultures were isolated, the morphological and biochemical characteristics of which correspond to the description of Y. ruckeri (Ross et al., Ewing et al., 1978). Fifteen sorbitol-nonfermenting strains came from the cases with clinical and pathomorphological findings while the only sorbitol-fermenting strain was isolated from a symptom-free carrier. These findings demonstrate that in the Czechoslovak conditions it is not possible to omit the difference in the virulence of sorbitol-fermenting and sorbitol-nonfermenting strains to rainbow trout.

[Microbiological diagnosis of microorganisms tentatively designated as "SP organisms"]. / Príspevek k mikrobiologické diagnostice mikroorganismu provizorne oznacovaného jako "SP organismus".

The authors describe the biochemical characteristics of two strains described as "SP organism". This microorganism incertae sedis resembles from the biochemical aspect (oxidase+, mannite-, dextrose+ with gas) the species Pasteurella aerogenes; contrary to the latter it does not break down urea and differs also as regards the morphology of colonies, which on blood agar are coarser; it also has a higher content of G + C in DNA than Pasteurella. It is a pathogen of rodents. The authors describe two isolates, the first is obviously an incidental finding from the faeces of a 5-year-old girl who was symptom-free, the second is from the contents of an abscess of a nutria. For comparison also biochemical characteristics of known aerogenic pasteurellae and Pasteurella-like strains are given.

The gnotobiotic piglet as a model for the pathogenesis of Campylobacter jejuni infection.

The pathogenesis of enteric changes was studied in gnotobiotic piglets which, after hysterectomy had been infected orally with Campylobacter jejuni on the first day of their life. The involvement of the entire large intestine became clinically manifest by scouring on days post infection (DPI) 4 to DPI 5, and pathomorphologically, by simultaneous inflammation and severe edema of the intestinal wall. Histology and SEM revealed inflammatory edema with abundant neutrophils, microulcerations, focal propagation and activation of goblet cells, and a presence of mucin-positive material within the intestinal lumen. TEM examination revealed disconnected interdigitating folds and wide dilated intercellular spaces between enterocytes. The endothelial cells of small blood vessels in the lamina propria showed hypertrophy with increase in the thickness of their basal lamina. Ultrastructural lesions of the large intestinal microcirculation also support the hypothesis that disturbances in the vascular system are responsible for edema in the cecum and colon. Gnotobiotic piglets may be used as a suitable animal model to study colitis induced by C. jejuni.

[Finding of the bacterial species Edwardsiella tarda in the aquarium fish Betta splendens]. / Nález bakteriálního druhu Edwardsiella tarda u akvarijních rybek Betta splendens.

A case of the mass occurrence of a disease in the aquarium fish species Betta splendens is described; morphologically the disease was characterized by the finding of large dermal changes located mainly in the dorsal part and by miliary granulomata in liver, spleen and kidneys. The granulomata consisted of epitheloid light cells with centrally located necrosis. Gram-negative bacteria with morphological and biochemical characteristics corresponding to the bacterial species Edwardsiella tarda were isolated from the kidneys, liver and from the dermal lesion. The characteristics of the strains isolated by us were compared with the reference Edwardsiella strain (Bth 1/64) obtained from the Czechoslovak collection of type cultures, Prague.

[Maduromycotic mycetoma in a horse]. / Maduromykotický mycetom kone.

A case of maduromycotic mycetoma (eumycetoma) in seven years old draught horse is described. The disease was localized in anal region and healed after surgical treatment. Attention is drawn to the necessity of distinguishing three types of mycosis in horses, characterized by the origin of tumor lesions - mycetomas, hyphomycosis and entomophthoromycosis - and information was gathered on their etiology and geographical occurrence. On the basis of the morphology of fungal elements traced in inflammated changed tissues and with regard to the existing findings on the origin of eumycetoma in animals, it was concluded that the disease described was probably caused by fungus Allescheria boydii Shear. Exact definition of the causative agent was impossible without mycological cultivation.

Actinobacilli in domestic fowl.

Reports on haemolytic rods from salpingitis in hens and from organs of died chicks may be found since the year 1950 (Kjos-Hanssen). Correct systematic classification on these microorganisms is still lacked because not all relations to the nearest pasteurellae were known as well as the clear differences in the Pasteurella-Actinobacillus group. The authors have isolated 34 suspected strains from 14 localities; 25 strains were from salpingitis or internal organs of died fowl inclusively chicks, and 9 strains from choanas of pullets clinically healthy. Bacteriological, serological, chemical and biological tests gave the results as follows: 1) All strains exhibit fundamental properties of Pasteurella-Actinobacillus group, and moreover, they show ability to grow on MacConkey agar with crystal violet (BioQuest) being a significant feature of the genus Actinobaccillus (Mráz, 1975). 2) From the nearest species Actinobacillus haemolyticus (Newsom and Cross, 1932) Mráz, 1969, they differ with expressive haemolysis on agar with sheep blood, single haemolytic zone on agar with lamb blood according to Smith (1962), structure of somatic antigen, with natural hosts (gallinaceous birds) and pathogenicity for 5-day-old chicks. The GC content in DNA was determined in the range 39,6-42,9% (mean value 41,5%). 3) The first who presumed an independent state of these microorganisms, was Kohlert (1968), from the work of which the epithet for correct name, i.e. Actinobacillus salpingitidis (Kohlert, 1968) comb. nov., was accepted.

[Outbreak of paraventricular and ventricular mucormycosis in fattening bulls]. / Hromadny výskyt paraventrikulární a ventrikulární mukormykózy u býkü ve výkrmu

There is a description of mass occurrence of nine cases of acute, fatal paraventricular and ventricular mucormycosis in fattened bulls at the age of about 18 months. In the reticulum, the disease was characterized by numerous ulcerations penetrating into the submucosa. In rumen the deposits were of hemorrhagic character penetrating through a thick muscular layer into the subserosa. Hemorrhagic peritonitis was within the range of those changes. Thromboses of arteries and veins prevailed in the microscopic picture. Inflammatory reparative changes were formed by neutrophile leucocytes. Mucoraceum fibres were demonstrated in pathological manifestations. In three cases, strains of Rhizopus cohnii and Absidia ramosa were cultivated simultaneously from the sub-ulcerous layers in the reticulum. A number of findings testify that the mass occurrence of mucormycosis followed the feeding of mouldy bakery wastes on the basis of acidosis.

[Morphological study of 70 cases of brucellosis in rabbits caused by Brucella suis].

Seventy cases of morphologically developed cases or brucellosis in hares are described. Twenty-five of the cases were tested by the cultivation methods and the causative agent was identified as Brucella suis. In females the authors found 57 cases, in males 13 cases. Brucellosis of hares was characterized by a chronical course, by a conspicuous local progression, and by a predominance of pathological changes in the reproductive organs of both sexes. Males showed changes mainly on testes. Nodal, solitary as well as multiple lesions in the parametrium near the uterine wall were particularly typical of females. The hematogenous propagation of brucellosis affected mostly liver and spleen, frequently showing conspicuously large nodes with irregular sides resulting from the growh of the deposits through apposition. The microscopic basis of the changes due to brucellosis was represented by granulomas of histiocytic character with a conspicuously small pyogenic component penetrated by necrosis of a caseous character, rich in lipoids. In comparison with tuberculosis, the brucellosis inflammation in hares shows a conspicuous cellular and nuclear variability in the histiocytic layer of granulomas, prevalent caryloytic disintegration of cellular elements, frequent finding of eosinophiles, and non-constant occurrence of giant multinuclear elements of Langhans cell type.

[Colitis cystica profunda in inflammatory psedomembraneous dysentery in pigs]. / Colitis cystica profunda v pablánovém zánétu pri dyzentérii prasat

The authors examined 32 cases of dysentery in pigs at the age of about 16 weeks. From the morphological viewpoints, the lesion was a disease of the large intestine characterized by a pseudomembranous, croupous, or even diphtheric inflammation of the intestine and by a conspicuously small pyogenic component in the inflammatory exudate in propria mucosae. The colon contained glandular intestinal structures, corresponding to the human disease colitis cystica profunda, situated exclusively at the sites of lymphatic folicles. The study of series incisions demonstrated that in the given cases of the dysentery of pigs colitis cystica profunda is the result of the entropium of intestinal mucous membrane into the submucosa. The residues of pressed lymphatic tissue contained multiple Russell's corpuscles of plasmocellulal origin--this is proved by oxyphilla and by the positive finding in the PAS reaction and in the Weigert method of fibrin testing.

[Biochemical characteristics of Vibrio coli isolated from inflammatory pseudomembraneous swine dysentery]. / Biochemická charakteristika vibrio coli izolovaného z pablánového zánetu pri dyzenterii prasat

The paper presents the basic morphological and biochemical characteristics of seven microaerophilic vibrio cultures isolated by the membrane filtration method from the colon mucous membrane of pigs diseased with dysentery. For growth, the cultivated strains needen oxygen reduction; in the dark field they showed a typical active movement producing catalase and oxidase, reducing nitrates to nitrites, and tolerating the presence of 1% and 3% sodium chloride concentrations in the growth medium. No culture grew in the presence of 1% glycine and 5% NaCl and no culture produced hydrogen monosulphide. All showed good growth in media with carbohydrates which, however, were not attacked. With respect to these characteristics and to literature data, the microbes were classified as Vibro coli, whose isolation had been reported by some authors in relation with dysentery in pigs (Roberts, 1956; Deas, 1960; Lussier, 1962).