Polymerase chain reaction for detection of guinea pig adenovirus.

Lack of in vitro cultivation methods has inhibited the development of rapid, reliable diagnostic procedures for adenovirus-associated necrotizing bronchopneumonia in guinea pigs. Because polymerase chain reaction (PCR) techniques are well established for human adenoviruses, primers for the amplification of guinea pig adenovirus DNA were evaluated. The DNA for PCR was purified from the lung tissue of spontaneously infected and healthy guinea pigs. Adenovirus DNA could only be detected in the lungs of the infected animals. Subsequent sequence analysis of PCR products revealed that the guinea pig adenovirus is a distinct adenovirus.

Gene expression of aphrodisin in female hamster genital tract segments.

Aphrodisin is a glycoprotein originally isolated from hamster vaginal discharge which was demonstrated to be involved in pheromonal effects on male hamsters. In the present study, we investigated the localization of aphrodisin-synthesizing and -storing cells in the entire genital tract of the female golden hamster using immunohistochemical and molecular biological methods. By use of immunohistochemical methods, significant aphrodisin immunoreactivity was detected within the cervical glandular tissue. Western blot analysis revealed high concentration of aphrodisin in vaginal discharge and in tissue extracts from the vagina and the cervix uteri. According to intracellular localization of aphrodisin, this protein is confined to cytoplasm of the immunoreactive cells. Immunoreactivity was also detected extracellularly on the surface of the anterior vaginal pluristratified epithelium. Semiquantitative reverse transcriptase polymerase chain reaction (RT-PCR) analysis showed an extremely high level of aphrodisin gene expression in the vagina and in the lower part of the uterus comprising the cervix. However, aphrodisin gene expression was also demonstrated in the middle part of the uterus and at a low level even in the ovaries. No aphrodisin gene expression was detectable in the upper part of the uterus and the uterine horns. In situ hybridization confirmed that the maximum expression of the aphrodisin gene is encountered in glandular cells of the cervix uteri. These results indicate that within the female hamster genital tract aphrodisin is predominantly synthesized throughout the vagina and cervical uterus. The protein is then secreted into the vaginal lumen. It is under discussion whether the accumulation of aphrodisin in the vaginal discharge facilitates the transfer of pheromone of low molecular weight to the male hamster's vomeronasal organ during investigatory behavior.

Fungus Paecilomyces: a new agent in laboratory animals.

The fungus Paecilomyces has not yet been considered a health problem in laboratory animals. However, this agent known as a 'spoiler' of fruit beverages and other foodstuffs is an opportunistic pathogen especially in immunocompromised humans. Since 1985, we have isolated Paecilomyces, most probably P. variotti, from six laboratory animal species, mainly rats. In about 90% of cases the organism was localized in the respiratory tract and there are some other findings favouring the hypothesis of an airborne infection. During this long observation period no consequences for the health of rats in one closed 'infected' SPF breeding unit (A) could be observed. In a controlled histological study on five infected rats, no lesions attributable to this mycotic agent could be detected. However, a self-limiting spontaneous outbreak of papular skin lesions associated with Paecilomyces was observed in a breeding colony (F) of hairless mice. The role of this fungus in an acute outbreak of respiratory signs in another colony of conventional rats (B) was considered to be secondary. Bearing in mind its occasionally harmful role in humans, relatively high resistance to disinfectants and toxigenicity, this new agent should be monitored and considered a potential health risk for laboratory animals.

[Science needs experimental animals]. / Die Wissenschaft braucht die Versuchstiere.

Data on the number of animals used in experiments are compared with data on meat consumption. The usefulness of laboratory animals for past achievements in biological sciences is presented. The negative effect of the rather disapproving attitude of the general public and the restrictive Animal Protection Law on Germany as a place of science is demonstrated in the general decrease of the number of registrated scientific projects. Some psychological reasons for the widespread disapproval of animal experiments are listed. The arguments of the opponents and supporters of animal experiments are confronted. Finally, the limits of so-called alternative methods are briefly mentioned and some proposals to ameliorate the keeping conditions of laboratory animals are enumerated.

[Dorsal recumbency in dogs--a circulatory risk during surgical treatment?]. / Rückenlage des Hundes--ein Kreislaufrisiko bei operativen Eingriffen?

In this study, changes in hemodynamic, blood gas, and metabolic variables recorded during right lateral and dorsal recumbency in beagles anaesthetised with thiopental are presented. Other than reported in human beings, dorsal recumbency in these dogs resulted in an increase (33%) in heart rate, decrease (30%) in systolic, diastolic, and mean systemic arterial pressure, a decrease (17%) in systemic vascular resistance, and a decrease in both right (31%) and left (39%) ventricular work in comparison with lateral recumbency. Furthermore, mixed-venous PO2, oxygen saturation and respiratory quotient were lower in dorsal than in lateral recumbency while O2 consumption and lipolysis were increased in the former. The changes presented may have been caused by beta-adrenergic stimulation in dorsal recumbency. It needs to be studied if capillary perfusion can be maintained adequately during surgery in dorsal recumbency or if this predisposes to cardiovascular shock.

Granulomatous dermatitis and mastitis in two SPF rats associated with a slowly growing Staphylococcus aureus--a case report.

An isolated occurrence of multifocal severe granulomatous dermatitis and mastitis accompanied by extensive calcifications is described in 2 female Sprague-Dawley, SPF breeding rats. Poorly growing Staphylococcus aureus of uncertain lysotype (probably lysotype II) was isolated from the lesions of both rats. The source of infection could not be determined. No further cases in the closed barrier maintained breeding colony occurred in the following 7 months. Difficulties in interpreting these findings and the practical consequences relating to the hygienic status of the barrier breeding colony are discussed.

Inefficacy of enrofloxacin in the elimination of Pasteurella multocida in rabbits.

The administration of enrofloxacin (5 mg/kg subcutaneously every 12 h for 10 days) failed to eliminate Pasteurella multocida from all naturally and experimentally infected rabbits. Although the enrofloxacin concentrations in serum and in turbinate bones were greater than the determined minimal inhibitory concentrations, P. multocida could be detected in nasal cavities, turbinates, trachea, middle ear and outer ear of experimentally infected rabbits after treatment. It is to be supposed that P. multocida colonizes organs or tissues in which an effective enrofloxacin concentration cannot be achieved. Such sites could be the paranasal sinuses, the auditory tube and the middle ear. This finding underlines the indispensibility of in vivo testing of antibiotic effectiveness.

Influence of MHC on the oncogenicity and immunogenicity of polyoma virus BK in rats.

The oncogenicity of the human papovavirus, type BK, was examined in the Lewis strain of inbred rats, possessing the recombinant alleles "a" and "u" on the MHC TR1 locus. It was found that only haplotypes containing "a" within the B/D locus but not within the A and the C locus of the RT1 region were associated with resistance to the oncogenic potential of BKV and with the capacity of animals to form BKV T antigen antibody. By contrast, the presence of "u" or "l" within the MHC B/D region was linked to the reverse phenotype characterized by sensitivity to the oncogenic effect of BKV and failure to yield T antibody response up to 6 months after inoculation with BK. These results present further evidence of the function as an immune control gene of the B/D region of the RT1 locus of rat MHC.

Characterization of two Metabacterium sp. from the gut of rodents. 1. Morphology and histochemical examination of a new Metabacterium sp. from the gut of the European hamster (Cricetus cricetus)

A new giant Gram-negative non-cultivatable symbiotic endospore-forming bacterium was found in the gut of the European hamster. This "Metabacterium" sp., provisionally named "Metabacterium criceti", sp. n., has a length of approximately 20 microns and thickness of 4 microns. It forms 1 to 2 cylindrical endospores, approximately 9 microns long and 1.4 microns thick. TEM-micrographs show a cell wall structure characteristic of Gram-negative bacteria. Vegetative cells are filled with granules 0.3 micron in diameter which resemble starch granules. The reproduction occurs with binary fission and by formation of two endospores. Of thirteen biochemical components sought, four, i.e. glycogen, triacylglycerols, peroxidase and alkaline phosphatase, were not found. Starch, acid mucosubstances, DNA, RNA, lipids, proteins, adenosine triphosphatase and acid phosphatase were found in different patterns, depending on the developmental stage of the bacterium. In the vegetative cell stage all these components, with the exception of starch, were found. In the endospore-bearing cell stage, only the starch-like cell component granules could be detected. In free endospores only DNA, RNA and acid phosphatase were found. Some of the components, i.e. DNA, lipids, starch-like granules, were linked to certain cell substructures, the distribution of others, viz. polysaccharides, RNA, adenosine triphosphatase and proteins was diffuse. The lipids, found only in vegetative cells, were associated with the cell wall.

Characterization of two "Metabacterium" sp. from the gut of rodents. 2. Heteroxenic cultivation and proof of dipicolinic acid in "M. polyspora".

The vegetative cell of "Metabacterium polyspora" is "cucumber-shaped", about 21 x 5.7 microns, Gram-negative. Cylindrical endospores are best stained by Rakette and Ziehl-Neelsen staining. The bacterium reproduces by sporulation (2 to 8 endospores per cell) and by binary fission. Lateral, bow-like "hatching" of the endospores was seen. About 52% of guinea pigs harbor 5 x 10(6), 36% below 2 x 10(6) and 1% more than 1 x 10(8) "M. polyspora" in 1 g of caecal content. Dipicolinic acid was demonstrated using HPLC in the caecum homogenate from a guinea pig. The amount of it was proportional to the number of spores. Cultivation under strict anaerobic conditions did not succeed. It was possible to cultivate this giant endosymbiont in vitro in a heteroxenic culture incubated in a 5% CO2 atmosphere using liquid medium supplemented with cell-free filtrate of the caecum. The caecum filtrate containing undefined growth factor(s) is necessary for long-term culture. The replication rate was low. These findings suggest that the giant endosymbiont "M. polyspora" is a spore-forming prokaryote without the attributes of a strict anaerobe.

Host specificity of cloned Spironucleus sp. originating from the European hamster.

In vivo experiments with a clone of the intestinal flagellate Spironucleus sp. originating from the laboratory European hamster (Cricetus cricetus), and the comparison with a spontaneous infection from laboratory bred European hamsters suggest high specificity of this clone for the homologous host. Only the Syrian golden hamster (Mesocricetus auratus) could be infected experimentally, though the mean intensity of infection was lower. Other heterologous recipients, mice and rats of one outbred and one inbred strain each, could not be infected. Even immunodeficient mice (athymic and C.B-17-scid) remained uninfected after inoculation of 5 x 10(5) cysts per mouse. This is the second Spironucleus clone, after the rat isolate (Schagemann et al., 1990), with a high level of host specificity suggesting heterogeneity within the genus Spironucleus.

[Laboratory animals--suggestions, views, warnings]. / Pokusná zvírata--podnety, výhledy, varování.

Basic informations are given on the Central Laboratory Animal Facility at the Hannover Medical School, Lower Saxony, which served as a model for similar facilities in nearly all medical schools in former West-Germany. Centralized facilities for laboratory animals as a service for bio-medical research are meanwhile common and well established in all universities of western countries. The lack of money is, certainly the paramount limiting factor hampering a soon realization of similar central facilities at czech and slovak medical schools. Another serious obstacle which could soon emerge comes from the psychologic-ethical area. It is the emotional and unreasonable shift in the society's consciousness in western countries pertaining the use of animals for research which si promoted and perpetuated by plenty of legal and illegal actions of many potent organizations of so called animal rightists or activists or antivivisectionists. Such organizations do not yet exist in Czechoslovakia but the situation can change abruptly. The second part of this article consists in the description of the roots of such organizations and the description of their activities in the western countries in order to develop successful contra-strategies.

Streptobacillus moniliformis isolated from otitis media of conventionally kept laboratory rats.

Streptobacillus moniliformis (Sm) was isolated from the middle ear of two inbred albino rats (strain CAP/Kuv) suffering from murine respiratory mycoplasmosis and purulent bilateral otitis media. The animals were kept under conventional conditions and used for immunological studies. The biochemical pattern of the isolate was identical with that of four other Sm strains of different origin but differed in its ability to lyse erythrocytes in sheep blood agar. This is the first Sm strain with hemolysis described. Pathogenicity of the strain was demonstrated in C57BL/6Han mice known to be susceptible to streptobacillosis. Three of five mice inoculated orally developed characteristic signs of a septic lymphadenitis. In the homologous system and with Sm strain ATCC 49567 as antigen, all five sera showed positive titers in the indirect immunofluorescence assay. Possible improvements in the diagnosis and the role of this "forgotten pathogen" in laboratory animal medicine are discussed.

Host specificity of Giardia muris isolates from mouse and golden hamster.

One isolate of Giardia muris from a naturally infected laboratory mouse (Mus musculus) and one from a naturally infected golden hamster (Mesocricetus auratus) were passaged three times by the inoculation of ten cysts (the minimal infectious dose) into barrier-maintained homologous hosts. Both of the resultant isolates were tested for infectivity by intragastric inoculation of 3-5 x 10(5) cysts into 40 mice (2 inbred strains), 40 rats (2 inbred strains), and 19 golden hamsters (1 outbred strain). Rats were not susceptible to infection with either isolate. Mice and golden hamsters did develop infections following their inoculation with the heterologous isolates. The mean intensity of heterologous infections with the hamster isolates was significantly lower than that of homologous infections. The mouse isolate induced a higher mean intensity of infection in hamsters as compared with homologous recipients. The mean intensity of infections induced by both isolates was greater in male hamsters than in females.

Streptococcus canis arthritis in a cat breeding colony.

This is the first description of a pathologic condition--arthritis in cats affecting mainly one joint, i.e. monarthritis--caused by Streptococcus canis (S. canis), of the Lancefield serologic group G. Six cases were recorded in a closed cat breeding colony during a 6 month period in 1988, and one additional case in 1990. Therapy with penicillin and streptomycin led to full recovery in four of six cases. The bacterium had been detected from different purulent processes sporadically--including one case of purulent arthritis in 1982--as a nosocomial infection since 1980, the year the breeding colony was established. A possible genetic predisposition (high inbreeding) may have contributed to the accumulation of the six cases in 1988. Although S. canis was isolated in mouse, rat, rabbit and dog, cat and man seem to be more frequently affected. There are some similarities between S. canis-arthritis in cat and man.

Host specificity of cloned Spironucleus muris in laboratory rodents.

With three clones of Spironucleus muris (S. muris)--established from a mouse, hamster, and rat--homologous and heterologous host species were experimentally infected. Each host was susceptible to the clone originating from the homologous donor. In addition, both mice and hamsters were susceptible to the reciprocal heterologous clones. In contrast, infections of the rat with both heterologous clones were very poor, i.e. quantitatively low and ephemeral. It was not possible to infect hamsters and mice, not even athymic, with S. muris from the rat. This suggests a strain heterogeneity within the genus S. muris. In general, the genetic background of the host influenced the infection, the sex of the host did not.

Mastomys natalensis or Mastomys coucha. Correct species designation in animal experiments.

Haemoglobin electrophoresis and chromosome analysis indicate that the widely used multimammate rat (chamois coloured) as experimental animal belongs to the species Mastomys coucha (Smith, 1836) and not, as commonly assumed, to Mastomys natalensis (Smith, 1834).

Characterization of some previously unclassified Pasteurellaceae isolated from hamsters.

Bacteria isolated from purulent processes on the jaws of European hamsters (Cricetus cricetus) and from intestinal inflammatory processes in Syrian hamsters (Mesocricetus auratus), bred as laboratory animals have been shown to be phenotypically similar but not identical with Pasteurella pneumotropica. Deoxyribonucleic acid (DNA)-DNA hybridization studies indicate that with one exception, the strains represent two new species of the family Pasteurellaceae. In the absence of a close genomic relatedness to members of the genera Actinobacillus or Pasteurella or allied organisms, however, the two new taxa are described without any formal designation. The one exception was identified as Actinobacillus capsulatus, a species not previously isolated from hamsters.

Spontaneous tumours of the European hamster (Cricetus cricetus L.).

The incidence and spectrum of spontaneously occurring neoplasms was evaluated in 285 European hamsters (strain Mhh:EPH) ranging in age between 1 and 5 years. The mean lifespan of the 107 male and 135 female hamsters examined amounted to 122 and 135 weeks, respectively. The overall incidence of tumour-bearing animals was 51.2% (males: 57.9%, females: 47.2%). Malignant tumours were more frequent than benign neoplasms and affected more males than females. Neoplasms of the haematopoietic/lymphoreticular system were the most common tumours (males: 16.8%, females: 13.5%). In males, these were followed in a decreasing order of incidence by pheochromocytomas (15.9%), malignant schwannomas (8.4%) and tumours of the prostate (6.5%). In females, pheochromocytomas as well as granulosa cell tumours were the second commonest tumour types (6.2% each), followed by malignant schwannomas (5.1%). Other tumours did not exceed the 5% incidence level. Two unusual rare tumours were a locally invasive cementoblastoma arising in the maxilla and a carcinosarcoma of the skin with components of a squamous cell carcinoma and a neurofibrosarcoma. The results of the study are compared with data on the Syrian and Chinese hamster.