Erhard F. Kaleta

Bio: Erhard F. Kaleta is an academic researcher from University of Giessen. The author has contributed to research in topics: Newcastle disease & Outbreak. The author has an hindex of 23, co-authored 67 publications receiving 2420 citations.

Newcastle Disease in Free-Living and Pet Birds

Abstract: Newcastle disease (ND) has economic and ecologic impact on pet and free-living as well as on domestic birds. Virtually all of the approximately 8,000 species of birds seem to be susceptible to infection with Newcastle disease viruses (NDVs).

Avian host range of Chlamydophila spp. based on isolation, antigen detection and serology.

Abstract: Published reports and our own diagnostic data on the avian host range of avian Chlamydophila spp. are presented in an attempt to provide evidence for the large number of bird species that have been naturally infected with chlamydia. The term 'chlamydia-positive' is based on either isolation of the organism and antigen detection or on serological detection of circulating antibodies. The list of chlamydia-positive birds contains the six major domestic species (chicken, turkey, Pekin duck, Muscovy duck, goose, and pigeon), the three minor domestic species (Japanese quail, bobwhite quail, and peafowl) and a total of 460 free-living or pet bird species in 30 orders. The order Psittaciformes contains by far the most (153 of 342; 45%) chlamydia-positive bird species. More than 20% of all species per order are positive for chlamydia in the orders Lariformes (gulls, 26 of 92 species; 28%), Alciformes (alks, six of 23 species; 26%), Sphenisciformes (penguins, four of 16 species; 25%), and Anseriformes (ducks and geese, 33 of 157 species; 21%). Only 5% of all bird species (14 of 259 species) in the order Phasianiformes (gallinaceus birds) are chlamydia-positive. The different percentages of chlamydia-positive bird species reflect: (i) a high rate of investigations (e.g. of domestic birds) compared with infrequent testing (e.g. of Charadriiformes or Cuculiformes), (ii) frequent zoonotic implications (e.g. psittacine and columbiform birds), and (iii) an assumed high susceptibility to infection and subsequent seroconversion (e.g. waterfowl).

Newcastle disease outbreaks in recent years in Western Europe were caused by an old (VI) and a novel genotype (VII)

Abstract: Newcastle disease virus (NDV) strains, isolated from outbreaks during epizootics between 1992 and 1996 in Western European countries, were compared by restriction enzyme cleavage site mapping of the fusion (F) protein gene between nucleotides 334 and 1682 and by sequence analysis between nucleotides 47 and 435 Both methods revealed that NDV strains responsible for these epizootics belong to two distinct genotypes Strains derived from sporadic cases in Denmark, Sweden, Switzerland and Austria were classified into genotype VI [6], the same group which caused outbreaks in the Middle East and Greece in the late 1960's and in Hungary in the early 1980's In contrast, viruses that caused epizootics in Germany, Belgium, The Netherlands, Spain and Italy could be classified into a novel genotype (provisionally termed VII), hitherto undetected in Europe It is possible that the genotype VII viruses originated in the Far East because they showed a high genetic similarity (97%) to NDV strains isolated from Indonesia in the late 1980's

Avian host spectrum of avipoxviruses.

Abstract: A review is given of the occurrence of poxviruses in different bird species. The first publications appeared in Europe around 1850. At that time, pox as a definite disease entity was diagnosed on the basis of clinical signs, while later the detection of Bollinger's inclusion bodies (1877) allowed an aetiological diagnosis by microscopically visible viral aggregates. Virus isolation in embryonated chicken eggs and direct electron microscopy gained importance as diagnostic tools in the 1950s. Also briefly described are avipoxvirus taxonomy, virus characteristics, clinical signs, modes of prevention and diagnostic procedures. Of the approximately 9000 bird species, about 232 species in 23 orders have been reported to have acquired a natural poxvirus infection. However, it is likely that many more birds are susceptible to avipoxviruses.

Newcastle disease and other avian paramyxoviruses.

Abstract: Newcastle disease (ND), caused by avian paramyxovirus serotype 1 (APMV-1) viruses, is included in List A of the Office International des Epizooties. Historically, ND has been a devastating disease of poultry, and in many countries the disease remains one of the major problems affecting existing or developing poultry industries. Even in countries where ND may be considered to be controlled, an economic burden is still associated with vaccination and/or maintaining strict biosecurity measures. The variable nature of Newcastle disease virus strains in terms of virulence for poultry and the different susceptibilities of the different species of birds mean that for control and trade purposes, ND requires careful definition. Confirmatory diagnosis of ND requires the isolation and characterisation of the virus involved. Assessments of virulence conventionally require in vivo testing. However, in vitro genetic characterisation of viruses is being used increasingly now that the molecular basis of pathogenicity is more fully understood. Control of ND is by prevention of introduction and spread, good biosecurity practices and/or vaccination. Newcastle disease viruses may infect humans, usually causing transient conjunctivitis, but human-to-human spread has never been reported. Eight other serotypes of avian paramyxoviruses are recognised, namely: APMV-2 to APMV-9. Most of these serotypes appear to be present in natural reservoirs of specific feral avian species, although other host species are usually susceptible. Only APMV-2 and APMV-3 viruses have made a significant disease and economic impact on poultry production. Both types of viruses cause respiratory disease and egg production losses which may be severe when exacerbated by other infections or environmental stresses. No reports exist of natural infections of chickens with APMV-3 viruses.

Cephalopods: Ecology and Fisheries

Abstract: Preface.Acknowledgements.Introduction.Form and Function.Origin and Evolution.Nautilus: The Survivor.Biodiversity and Zoogeography.Life Cycle.Growth.Physiological Ecology.Reproductive.From Egg to Recruitment.Coastal and Shelf Species.Oceanic and Deep-Sea Species.Cephalopods as Predators.Cephalopods as Prey.Fishing Methods and Scientific Sampling.Fishery Resources.Fisheries Oceanography.Assessment and Management.Conclusions.Appendix A: Classification of Living Cephalopod Families.Appendix B: Synopsis of Living Cephalopod Families.References.Index.

Development of a Real-Time Reverse-Transcription PCR for Detection of Newcastle Disease Virus RNA in Clinical Samples

Abstract: A real-time reverse-transcription PCR (RRT-PCR) was developed to detect avian paramyxovirus 1 (APMV-1) RNA, also referred to as Newcastle disease virus (NDV), in clinical samples from birds. The assay uses a single-tube protocol with fluorogenic hydrolysis probes. Oligonucleotide primers and probes were designed to detect sequences from a conserved region of the matrix protein (M) gene that recognized a diverse set (n = 44) of APMV-1 isolates. A second primer-probe set was targeted to sequences in the fusion protein (F) gene that code for the cleavage site and detect potentially virulent NDV isolates. A third set, also directed against the M gene, was specific for the North American (N.A.) pre-1960 genotype that includes the common vaccine strains used in commercial poultry in the United States. The APMV-1 M gene, N.A. pre-1960 M gene, and F gene probe sets were capable of detecting approximately 103, 102, and 104 genome copies, respectively, with in vitro-transcribed RNA. Both M gene assays could detect approximately 101 50% egg infective doses (EID50), and the F gene assay could detect approximately 103 EID50. The RRT-PCR test was used to examine clinical samples from chickens experimentally infected with the NDV strain responsible for a recent epizootic in the southwestern United States. Overall, a positive correlation was obtained between the RRT-PCR results and virus isolation for NDV from clinical samples.

An annotated checklist of pathogenic microorganisms associated with migratory birds

Abstract: The potential for transport and dissemination of certain pathogenic microorganisms by migratory birds is of concern. Migratory birds might be involved in dispersal of microorganisms as their biological carriers, mechanical carriers, or as carriers of infected hematophagous ecto- parasites (e.g., ixodid ticks). Many species of microorganisms pathogenic to homeothermic ver- tebrates including humans have been associated with free-living migratory birds. Migratory birds of diverse species can play significant roles in the ecology and circulation of some arboviruses (e.g., eastern and western equine encephalomyelitis and Sindbis alphaviruses, West Nile and St. Louis encephalitis flaviviruses), influenza A virus, Newcastle disease virus, duck plague herpes- virus, Chlamydophila psittaci, Anaplasma phagocytophilum, Borrelia burgdorferi sensu lato, Campylobacter jejuni, Salmonella enterica, Pasteurella multocida, Mycobacterium avium, Candida spp., and avian hematozoans. The efficiency of dispersal of pathogenic microorganisms depends on a wide variety of biotic and abiotic factors affecting the survival of the agent in, or disap- pearance from, a habitat or ecosystem in a new geographic area.