Quantification of the herpesvirus content in various tissues and organs, and associated post mortem lesions of psittacine birds which died during an epornithic of pacheco's parrot disease (PPD)

This paper reports on the viral content of up to 52 tissue and organ samples of 18 individual large psittacines which died during an epornithic of Pacheco's parrot disease (PPD) caused by psittacid herpesvirus 1 (PsHV1). Associated clinical signs and pathological lesions are described. The large spectrum of samples found to be positive for PsHVl suggests that birds succumb to PPD during viraemia. Tissues and organs from which the virus could be isolated included the integument and associated structures, the muscular, respiratory and circulatory system, bone marrow, the nervous system, thyroid and adrenal glands, spleen and liver, the urogenital tract and the gastro-intestinal tract. Nevertheless, individual and organ (but not species)-specific variation does occur. Virus isolation appears to be most promising from the respiratory, vascular and nervous system and the liver. Highest titres were obtained from heart blood and liver (up to 7.6 log(10)/g tissue), airsac, Nervus vagus and pulp and quill of pin feathers. Pin feathers may therefore be suitable for in-vivo diagnosis. In contrast, HV could not be isolated from any of the feather vanes examined. For the most part, post mortem lesions do not reflect the organ pattern found to be most permissive for virus replication as judged by the success of virus isolation and virus titres. A closer quantitative correlation is indicated for the lungs, spleen and liver, only. Corresponding findings as to frequency of gross pathological lesions and virus quantification appear to be restricted to the liver. In accordance with clinical observations and experimental findings, tissue virus content indicates that horizontal spread of herpesviruses is mediated by cloacal contents or secretions from the respiratory system.

Towards in vitro potency testing of inactivated erysipelas vaccines

Ph. Eur. Monograph 0064 "Swine erysipelas vaccine (inactivated)" currently advises mouse serology for batch potency testing. However, technological advances in vaccine production, improved quality control systems and comprehensive post marketing surveillance increasingly promote the acceptance of non-animal approaches for batch release testing. Protein and immune profiles of inactivated swine erysipelas vaccines obtained by SDS-PAGE and Western Blot might offer a convenient global and functional in vitro alternative. Characteristic and consistent protein and immune profiles could be obtained for aluminium-adjuvanted vaccines. Immunoreactivity of polyclonal sera raised in mice differs markedly from reactivity of swine sera.

[100 years of erysipelas prophylaxis: significance and reduction of animal experiments]

The history of erysipelas prophylaxis began in 1882 when Pasteur first discovered the attenuating effect of rabbit passages on the erysipelas bacterium. Ten years later, the German veterinarian Lorenz demonstrated the protecting effect of erysipelas antiserum. He developed a method of serovaccination which was successfully used in Germany for more than 50 years. Both scientists employed laboratory animals for the development of their live vaccines. Lorenz additionally recommended an animal model with grey mice to control the potency of erysipelas sera. In 1944, Fortner and Dinter published the results of their investigation on a skin scarification test in swine. This modus of infection was the basis of the first reliable model for efficacy testing of erysipelas vaccines in domestic animals. Shortly after World War II, the first inactivated erysipelas vaccines were being developed. At that time, also a strict quality control was introduced for this product group which required extensive animal experiments in laboratory mice and pigs for the determination of efficacy. WHO established International Standards for erysipelas vaccines and antisera concerning potency testing in mice. These animal models were finally incorporated in pharmacopoeia monographs. Animal experiments have played an important role in the development and quality control of erysipelas vaccines. And the success of this quality control based on animal experiments has had a significant impact on the quality control systems for veterinary vaccines in general. Today, we have a far more detailed knowledge about pathogenesis and immunology of swine erysipelas. This knowledge now allows the introduction of alternative methods according to the 3R concept. With these new methods, animal numbers can be decreased and suffering caused by challenge infection can be reduced. The ultimate goal, i.e. quality control of erysipelas vaccines carried out without routine performance of animal experiments, should be achieved in the near future.

Comparative studies of diagnostic bacteriological methods for the recovery of Salmonella from faecal samples from flocks of layers

Several conventional culture procedures were compared for the recovery of Salmonella from faecal samples of layer flocks. The cultural media employed consisted of Rappaport-Vassiliadis and tetrathionate broth for selective enrichment and three different plating media (Brilliant Green, Xylose-Lysine-Desoxycholate and modified semisolid Rappaport-Vassiliadis medium). The initial enrichment and plating procedures were repeated in a four-stage secondary enrichment. Selective enrichment in Rappaport-Vassiliadis or tetrathionate broth followed by plating on modified semisolid Rappaport-Vassiliadis medium (selective motility enrichment) resulted in a significantly higher isolation rate for Salmonella from faecal samples of layers compared to Brilliant Green and Xylose-Lysine-Desoxycholate medium. The selective enrichment yielded additional Salmonella isolates up to the second stage. Further enrichment did not increase the isolation rate.

Review of the literature and investigations on the prevalence and consequences of yeasts in reptiles

Ninety-one reptiles were examined for the presence of yeasts by standard protocols and pathohistological methods. Yeasts were isolated from 42 of the animals. Representatives of herbivorous families (Testudinidae and Iguanidae) carried yeasts more often than animals belonging to carnivorous taxa (Boidae and Emydidae). Yeasts were most often isolated from the gastrointestinal tract, and in 24-6 per cent of cases they could be cultured from the oral cavity and/or cloaca of living animals. Postmortem examination revealed that the intestines of 80-6 per cent of the animals carried yeasts. In all, 56 isolates, belonging to the genera Candida (32), Trichosporon (11), Torulopsis (9) and Rhodotorula (3), and one perfect yeast were obtained. The species included taxa potentially pathogenic to man. However, no sufficiently reliable criteria could be established to prove that positive culture results were associated with disease. In the reptiles examined postmortem, three cases of dermatomycosis were detected histologically. No case of organ mycosis was identified.

[Polyostotic hyperostosis in a plum-headed parakeet (Psittacula cyanocephala L., 1766]

With emphasis on a case report, the clinical and pathological findings commonly associated with polyostotic hyperostosis as well as its etiology are discussed, and the available literature is reviewed. The diagnostic specifics of the disease are detailed, and a survey of possible differential diagnoses is given.