Newer information about several aspects of animal epidemic disinfection]

The amendment of the German Veterinary Legislation concerning the eradication of notifiable diseases demanded also an updating of the relevant disinfection measures and technologies. Some hints are given, based on own experimental results, for the choice of chemical disinfectants, on some special problems of disinfection in livestock buildings and of disinfection of animal slurry and farm-yard manure as well as on biotechnological disinfection methods and environment-friendly disinfectants.     

The influence of stunted body size on the reproductive ecology of bluegill Lepomis macrochirus

Abstract – Although stunting is a common phenomenon in fish populations, the consequences of stunted body size on the reproductive ecology of individuals has received little attention. The present study compares the reproductive ecology of bluegill in established stunted and non-stunted populations. Three ponds (two non-stunted and one stunted) were monitored for spawning activity throughout the summer. Parental male bluegill from both non-stunted populations were older, larger, and had greater mating success (number of eggs or fry within nests) than parental males in the stunted population. Stunted bluegill also experienced a shortened reproductive season owing to the delay in onset of spawning. The present study demonstrates that individual size and population size structure can have a marked influence on the reproductive ecology of bluegill.     

Ribozyme-catalyzed transcription of an active ribozyme

A critical event in the origin of life is thought to have been the emergence of an RNA molecule capable of replicating a primordial RNA "genome." Here we describe the evolution and engineering of an RNA polymerase ribozyme capable of synthesizing RNAs of up to 95 nucleotides in length. To overcome its sequence dependence, we recombined traits evolved separately in different ribozyme lineages. This yielded a more general polymerase ribozyme that was able to synthesize a wider spectrum of RNA sequences, as we demonstrate by the accurate synthesis of an enzymatically active RNA, a hammerhead endonuclease ribozyme. This recapitulates a central aspect of an RNA-based genetic system: the RNA-catalyzed synthesis of an active ribozyme from an RNA template.     

Comparison of acid-detergent lignin,alkaline-peroxide lignin,and acid-detergent insoluble ash as internal markers for predicting fecal output and digestibility by cattle offered bermudagrass hays of varying nutrient composition

Background:The potential for acid-detergent insoluble ash(ADIA),alkaline-peroxide lignin(APL),and acid-detergent lignin(ADL) to predict fecal output(FO) and dry matter digestibility(DMD) by cattle offered bermudagrass[Cynodon dactylon(L.) Pers.]hays of different qualities was evaluated.Eight ruminally cannulated cows(594 ± 35.5 kg) were allocated randomly to 4 hay diets:low(L),medium low(ML),medium high(MH),and high(H) crude protein(CP)concentration(79,111,131,and 164 g CP/kg on a DM basis,respectively).Diets were offered in 3 periods with 2 diet replicates per period and were rotated across cows between periods.Cows were individually fed 20 g DM/kg of body weight in equal feedings at 08:00 and 16:00 h for a 10-d adaptation followed by a 5-d total fecal collection.Actual DM intake(DMI),DMD,and FO were determined based on hay offered,ort,and feces excreted.These components were then analyzed for ADL,APL,and ADIA concentration to determine marker recovery and marker-based estimates of FO and DMD.Results:Forage DMI was affected by diet(P = 0.02),and DMI from MH and H was greater(P 0.05) than from L.Apparent DMD tended(P = 0.08) to differ among diets while FO(P = 0.20) was not affected by diet treatments.Average ADL recovery(1.16) was greater(P 0.05) than that of ADIA(1.03) and APL(1.06),but ADIA and APL did not differ(P = 0.42).Estimates of FO and DMD derived using APL and ADIA were not different(P 0.05) from total fecal collection while those using ADL differed(P 0.05).There was no diet by marker interaction(P 0.22)for either FO or DMD.Conclusion:Acid-detergent insoluble ash and APL accurately predicted FO and DMD of cattle fed bermudagrass hay of varying nutrient composition.These internal markers may facilitate studies involving large numbers of animals and forages.Results from such studies may be used to develop improved equations to predict energy values of forages based on the relationship of dietary components to digestibility across a wide range of forages.     

Poxvirus infection in a cat with presumptive human transmission

The present report describes a case of generalized cowpox virus infection with necrotizing facial dermatitis in a cat and a likely transmission to an animal keeper. The viral aetiology was confirmed by histopathology, immunohistochemistry, PCR, virus isolation, DNA sequencing and electron microscopy. Histopathological examination of the cat's skin revealed a severe, necrotizing dermatitis with ballooning degeneration and hyperplasia of epithelial cells with pathognomonic cytoplasmic eosinophilic inclusion bodies. Additionally, at post-mortem examination, a systemic poxvirus infection was detected affecting pancreas, thymus, lymph node, liver and lung. The human patient's skin biopsy revealed an ulcerative dermatitis with epidermal hyperplasia and ballooning degeneration. Serological investigation displayed a high orthopoxvirus-specific antibody titre in the human patient. Environmental factors increase the natural reservoir host population for cowpox viruses, such as voles, which results in a higher risk of infection for cats and subsequently for humans. Due to this zoonotic potential, a cowpox virus infection must be considered as an aetiological differential in cases of necrotizing dermatitis in cats.     

High prevalence of Sarcocystis calchasi sporocysts in European Accipiter hawks

The emerging Sarcocystis calchasi induces a severe and lethal central nervous disease in its intermediate host, the domestic pigeon (Columba livia f. domestica). Experimental studies have identified the Northern goshawk (Accipiter g. gentilis) as final host. Phylogenetically closely related European sparrowhawks (Accipiter n. nisus) and wood pigeons (Columba palumbus) have been found to harbor genetically closely related Sarcocystis spp. However, data on the prevalence and potential interspecies occurrence of these parasites are lacking. Here, we report that European Accipiter hawks (Accipitrinae) are highly infected with S. calchasi, S. columbae and Sarcocystis sp. ex A. nisus in their small intestine. Thirty-one of 50 (62%) Northern goshawks necropsied during 1997-2008 were positive for S. calchasi in a newly established species-specific semi-nested PCR assay based on the first internal transcribed spacer region. Unexpectedly, 14 of 20 (71.4%) European sparrowhawks tested also positive. In addition, birds of both species were found to be infested with S. columbae and an, as yet, unnamed Sarcocystis sp. recently isolated from European sparrowhawks. These findings raise new questions about the host specificity of S. calchasi and its high virulence in domestic pigeons, since sparrowhawks only rarely prey on pigeons. Notably, isolated sporocysts from both infected Accipiter spp. measured 8 μm × 11.9 μm, precluding a preliminary identification of S. calchasi in feces of Accipiter hawks based on morphology alone. Importantly, three of four Northern goshawks used in falconry tested positive for S. calchasi. In conclusion, the results indicate that both European Accipter spp. in Germany serve as natural final hosts of S. calchasi and suggest that falconry and pigeon sport may serve as risk factors for the spread of this pathogen in domestic pigeons.     

Molecular epidemiology and virulence assessment of Aspergillus fumigatus isolates from white stork chicks and their environment

Aspergillus fumigatus is a common pathogen in poultry and captive wild birds and an emerging opportunistic fungal pathogen in immunocompromised humans. Although invasive aspergillosis is frequently reported in free-ranging wild birds, the incidence and epidemiology of the disease in a natural setting is unknown. We recently reported endemic outbreaks of invasive aspergillosis at white stork nesting sites close to human habitation in Germany with significant subsequent breeding losses. Therefore, we hypothesized that A. fumigatus strains with higher virulence in birds may have evolved in this environment and performed the first epidemiological analysis of invasive aspergillosis in free-ranging wild birds. Sixty-one clinical and environmental A. fumigatus isolates from six affected nesting sites were genotyped by microsatellite analysis using the STRAf-assay. The isolates showed a remarkable high genomic diversity and, contrary to the initial hypothesis, clinical and environmental isolates did not cluster significantly. Interestingly, storks were infected with two to four different genotypes and in most cases both mating types MAT-1.1 and MAT-1.2 were present within the same specimen. The majority of selected clinical and environmental strains exhibited similar virulence in an in vivo infection model using embryonated chicken eggs. Noteworthy, virulence was not associated with one distinct fungal mating type. These results further support the assumption that the majority of A. fumigatus strains have the potential to cause disease in susceptible hosts. In white storks, immaturity of the immune system during the first three weeks of age may enhance susceptibility to invasive aspergillosis.