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E F Kaleta

Publications and source records attributed to E F Kaleta.

At least 37 records · Page 2Linked to original sources
PubMed2001

Identification and analysis of a new hepadnavirus in white storks.

We identified, cloned, and functionally characterized a new avian hepadnavirus infecting storks (STHBV). STHBV has the largest DNA genome of all avian hepadnaviruses and, based on sequence and phylogenetic analysis, is most closely related to, but distinct from, heron hepatitis B virus (HHBV). Unique for STHBV among the other avian hepadnaviruses is a potential HNF1 binding site in the preS promoter. In common only with HHBV, STHBV has a myristylation signal on the S and not the preS protein, two C terminally located glycosylation sites on the precore/core proteins and lacks the phosphorylation site essential for the transcriptional transactivation activity of duck-HBV preS protein. The cloned STHBV genomes were competent in gene expression, replication, and viral particle secretion. STHBV infected primary duck hepatocytes very inefficiently suggesting a restricted host range, similar to other hepadnaviruses. This discovery of stork infections unravels novel evolutionary aspects of hepadnaviruses and provides new opportunities for hepadnavirus research.

Amino Acid Sequence↗
PubMed2001

Comparison of 16 chelonid herpesviruses by virus neutralization tests and restriction endonuclease digestion of viral DNA.

A total of 16 chelonid herpesviruses that were isolated between 1992 and 1998 were compared with one another on the basis of serology and restriction enzyme digestion patterns of viral DNA. The viruses stem from tortoises of three different species in four different European countries and the United States of America. The majority of the isolates were similar to one another. One isolate, however, differed strongly from all others both serologically and in the restriction cleavage pattern of its DNA, showing that there are at least two different sero- and genotypes of herpesviruscs that infect tortoises.

Animals↗
PubMed2001

Serological status for Chlamydophila psittaci, Newcastle disease virus, avian polyoma virus, and Pacheco disease virus in scarlet macaws (Ara macao) kept in captivity in Costa Rica.

From 1998 to 1999, a total of 128 blood samples were collected from scarlet macaws (Ara macao), kept in captivity in 11 different aviaries located in six provinces of Costa Rica. The sera were examined for antibodies directed against Chlamydophila psittaci, Newcastle disease virus (NDV), avian polyoma virus (APV), and Pacheco disease virus (PDV). Testing by enzyme-linked immunosorbent assay (ELISA), showed 16 (12.39%) of the samples (n = 129) exhibited antibodies directed against C. psittaci. Employing haemagglutination inhibition tests for NDV antibodies, all of the samples were found to be negative. The prevalence of antibodies specific for APV was tested with a blocking ELISA and serum neutralization tests (SNT) and 12 of 128 samples (9.37%) were found to be positive with both tests. In SNT, two out of 128 samples (1.56%) were positive for PDV. This is the first description of the serological status in scarlet macaws in captivity in Costa Rica. The study demonstrates the absence of NDV antibodies in the birds investigated on one hand, but also indicates a health hazard for numerous avian species due to the risk of infections with C. psittaci, APV or PDV.

Animals↗
PubMed2001

Response of domestic geese to lentogenic and velogenic strains of Newcastle disease virus.

A total of 54 domestic white meat-type geese were included in vaccination/challenge trials to evaluate susceptibility to disease and humoral immune responses using the haemagglutination inhibition (HI) and virus neutralization (VN) tests against Newcastle disease (ND). Two groups of twenty geese, five weeks of age, were conjunctivally vaccinated with either 100 x 10(6) or 2.5 x 10(6) EID50 (egg infectious dose 50 per cent) per bird of live La Sota virus, respectively, and 14 geese remained unvaccinated. At 15 weeks of age all vaccinated geese and seven unvaccinated geese were subcutaneously injected with 0.5 ml of inactivated oil emulsion ND vaccine, whereas seven geese remained as negative controls. At an age of 20 weeks, all 54 geese were challenged with 10(8.0) EID50 per bird of the viscerotropic velogenic NDV strain Herts 33/56. Live virus application as well as the oil emulsion vaccine did not induce discernible clinical signs and have no detrimental effect on body weight gains. At days 1, 3, 5, 8, 13, 16, 20, 23 and 27 after the application of lentogenic vaccine pharyngeal and cloacal swabs were taken, after challenge samples were taken at days 2, 5 and 8. Lentogenic as well as velogenic virus were never reisolated. Low and shortlived antibody responses post vaccination were equally well measured in HI and VN tests. Only two out of seven unvaccinated but challenged geese developed signs of ND whereas all vaccinated/challenged geese remained normal but developed high to moderate levels of HI and VN antibodies. Since domestic geese do not readily excrete NDV's in detectable amounts and since they do not contain detectable amounts of the challenge virus fourteen days post challenge in their tissues the assumption is promoted that geese do not play a major role in the epidemiology of Newcastle disease.

Animals↗
PubMed2001

[Immunisation of fancy chickens against Newcastle disease].

The German Regulation on Fowl plague which is in force since 1994 laid down that any chicken of all races and all hybrids must be vaccinated against Newcastle disease (ND) in a mode that an adequate immunity is achieved. Onset, duration, and resistance to challenge of immunity induced by vaccination is well documented in the scientific literature for hybrid chicken of the layer and meat types. These data prove also innocuity and efficacy of the registered vaccines. In contrast, only a few and incomplete data exist on the development of ND directed immunity in fancy chickens. The present study describes vaccinations of chickens of 14 different hobby breeds with live LaSota vaccine (conjunctival application of 10(6) embryo-infective dose50 per bird) and with an inactivated oil-emulsion vaccine (intramuscular application of 0.5 ml per bird) and subsequent intramuscular challenge infections using the highly virulent NDV strain Herts 33/66. Chickens of all 14 breeds tolerated the application of both vaccines. All fancy chickens reacted with the production of serum antibodies which were measured in the haemagglutination inhibition (HI) and virus neutralisation (VN) tests. According to the scientific literature, maximal antibody levels are reached in hybrid chickens between day 10 and 20 post vaccination. In contrast, in fancy chickens the antibody maxima are delayed to the seventh to eighth week post vaccination. All fancy chickens vaccinated either once with live LaSota virus or with live and inactivated vaccines resisted challenge with the highly virulent Herts 33/66 strain of NDV and did not develop any signs of disease. There are indications for gradual differences in susceptibility of different breeds of fancy chickens. The levels of non-specific neutralisation as measured in the virus neutralisation test differ between breed. Also, the viral content in tissues obtained from non-vaccinated but challenged birds differ markedly. It is concluded from the results of this study that fancy chickens can also successfully protected against Newcastle disease by using live and inactivated vaccines which are licensed for hybrid chickens. However, the optimal time for the detection of maximal antibody levels in fancy chickens is reached seven to eight weeks post vaccination.

Animals↗
PubMed2000

Multiplex-PCR-based differentiation and characterization of Candida-isolates derived from tortoises (Testudinidae).

Candida isolates (n=23) derived from Testudinidae were investigated by multiplex-polymerase chain reaction (PCR). The isolates comprised 13 Candida (C.) tropicalis, nine C. albicans and one C. parapsilosis. In addition, five reference strains C. albicans (ATCC 10231), C. tropicalis (DSM 4238), C. parapsilosis (DSM 4237), C. glabrata (ATCC 70614) and C. krusei (ATCC 70075) were investigated. PCR revealed easily distinguishable species-specific amplicons of the chs1-gene and resulted in a clear identification in all cases. No discrepancies between conventional identification techniques and the PCR-based system were seen. The described PCR offers a rapid alternative to conventional techniques for the identification of C. albicans, C. glabrata, C. tropicalis, C. parapsilosis and C. krusei.

Animals↗
PubMed2000

Development of a blocking enzyme-linked immunosorbent assay for the detection of avian polyomavirus-specific antibodies.

Avian polyomavirus, described originally as budgerigar fledgling disease virus, has been associated with devastating contagious disease outbreaks in budgerigar aviaries. At present, this virus affects a wide range of psittacine and non-psittacine birds worldwide, and the serum neutralisation test is used for the serodiagnosis of avian polyomavirus infections. A blocking enzyme-linked immunosorbent assay was developed for the screening of large numbers of sera collected from various avian species. The assay employs a monoclonal antibody directed against the major structural protein VP1 as a blocking antibody in a sandwich blocking procedure. Either purified avian polyomavirus particles or avian polyomavirus VP1 expressed in recombinant baculovirus-infected Sf9 cells were used as antigen. The specificity of the blocking enzyme-linked immunosorbent assay was evaluated by testing sera directed against mammalian polyomaviruses. Using sera obtained from chicken infected experimentally with avian polyomavirus and a collection of psittacine field-origin sera, a good correlation was observed between the results of the blocking enzyme-linked immunosorbent assay and the serum neutralisation test. However, the blocking enzyme-linked immunosorbent assay is more rapid and more economic. Both, avian polyomavirus particles and VP1 produced by recombinant DNA technology proved to be suitable antigens.

Animals↗
PubMed1999

Comparison of commercial ELISA test kits from Australia and the USA with the serum neutralization test in cell cultures for the detection of antibodies to the infectious laryngotracheitis virus of chickens.

The objective of this work was the evaluation under our conditions of two commercial ELISA kits for the detection of antibodies to avian infectious laryngotracheitis (ILT) virus, one from Australia (Trop-ELISA, TropBio) and one from the USA (ProFLOK-ELISA, KPL), and to compare their performance with the conventional serum neutralization test (SNT) in chick embryo liver cells. Repeatability varied considerably, particularly when using the Trop-ELISA. Therefore, if individual results are important, at least two parallel measurements per serum sample are recommended. In 89.3% of the sera tested by SNT, results of two parallel measurements did not vary by more than one 2-fold dilution step. There was good linear correlation between both ELISAs and the SNT, the correlation coefficient for the Trop-ELISA being r = 0.758 and for the ProFLOK-ELISA r = 0.867. The negative/positive cut-off was redefined to suit our conditions. Sera with a SN titre of > or = 1:4 were considered positive. Sera with < or = 15% absorption in the ProFLOK-ELISA were considered clearly negative. For the Trop-ELISA, extinctions of > or = 0.477 were considered positive, < or = 0.168 clearly negative. Values in between were regarded as doubtful for young chickens and as possibly due to non-specific reactions in older chickens. The sensitivity and specificity of the ELISAs relative to the SNT were 87 and 77% for the Trop-ELISA, and 95 and 60%, respectively, for the ProFLOK-ELISA. However, the results indicate that the sensitivity of the ELISA is higher than that of the SNT, because most sera showed similar deviations from SNT results with both ELISAs. Generally, both ELISAs were a suitable alternative to the SNT under our conditions, as long as only negative/positive results are required.

Journal Article↗
PubMed1999

[Vaccination of ostriches (Struthio camelus, Linnaeus, 1758) against Newcastle disease: evidence for vaccine compatibility and seroconversion after vaccinations using the hemagglutination inhibition and virus neutralization tests].

Newcastle disease (ND) remains to be the worldwide most important infectious disease of poultry. This epizootic is in Germany and many other countries a notifiable disease. Prophylactic vaccination is the major tool for the control of ND in poultry and other birds. Eighty-three ostriches (Struthio camelus) which were kept on farms in Germany were checked for the presence of NDV-specific antibodies. Some of these birds are said to be vaccinated against Newcastle disease. Only some of these ostriches contained antibodies which were measurable in haemagglutination inhibition and virus neutralisation tests. Twenty-three previously unvaccinated ostriches were vaccinated with commercially available vaccines. Both the LaSota live and inactivated oil emulsion vaccines were well tolerated following conjunctival or subcutaneous application, respectively. Neither local nor systemic side reactions were observed. After the vaccinations high antibody titres were detected in hemagglutination inhibition and virus neutralisation tests. A strong correlation between both established methods (r = 0.92; < 0.001) were noted.

Animals↗
PubMed1998

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

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.

Amino Acid Sequence↗
PubMed1998

Paramyxoviral and reoviral infections of iguanas on Honduran Islands.

Thirty-five free-ranging healthy spiny-tailed iguanas (31 Ctenosaura bakeri, 4 C. similis) and 14 green iguanas (Iguana iguana rhinolopha) were caught and held in captivity for 2 days. Blood was collected from all animals and their sera were evaluated for antibody titres against reptilian reoviruses, reptilian paramyxoviruses, and avian paramyxovirus-1 (PMV-1). Cloacal and pharyngeal swabs also were collected and examined for viral content by incubation on chicken embryo fibroblasts (CEF) and terrapene heart cells (TH-1). No virus was isolated from the pharyngeal and cloacal swabs on CEF and TH-1. Twenty-three (47%) of 49 sera samples tested positive for reptilian reoviruses by virus neutralization tests. Twenty (41%) of 49 samples had antibodies against one reptilian PMV isolate by virus neutralization tests and 3 (9%) of 34 by hemagglutination inhibition tests. No antibodies were detected against the other PMV isolate of reptilian origin nor against avian PMV-1. This is the first description of serum antibodies against reptilian reoviruses and PMV in wild iguanas.

Animals↗
PubMed1998

[The serologic detection of virus-induced infections in the domestic goose (Anser anser dom.)].

The most important virus-induced diseases associated with heavy losses in the domestic goose are Derzsy's disease which is caused by a goose parvovirus and duck plague (duck viral enteritis) which is caused by an avian herpesvirus. Both diseases still occur but can be prevented by timely vaccinations. Antibodies against Influenza A viruses of the subtypes H1, H5, and H7 as well as against avian paramyxoviruses of the serogroups 4, 6, and 8, respectively, were not detected in any of the examined sera. However, antibodies against paramyxovirus type 1 were detected in sera of one source. Haemagglutination inhibition or neutralizing antibodies against avian adenoviruses (EDS76 virus and goose adenovirus of the serotypes 1, 2, and 3) were quite often detected. Based on the present knowledge their pathogenic potential is minor. Neutralizing antibodies against a reovirus originating from Muscovy ducks and against a chicken reovirus (strain U Con S 1133) were quite frequently detected. In 35 of 564 examined geese sera hepatitis B virus was found.

Animals↗
PubMed1998

[Psittacosis (chlamydiosis) of birds and the necessity of government disease control].

Psittacosis--induced by Chlamydia psittaci--occurs at present as individual cases but not any more as an endemic or epidemic disease. The diagnosis does not pose unsurmountable difficulties. The dominant sources of infection for men are--unlike in previous times--now budgerigars and cockatiels from domestic breeding sources but also--as far as it is known at all--different domestic mammals. A targeted therapy of diseases in humans and birds is successfully possible with chlortetracycline, doxycycline or fluoroquinolone-containing drugs. Therefore, government-imposed control measures focussing entirely on imported psittacines such as quarantine, long-term medication and possibly eradication of Chlamydia psittaci-positive psittacine birds are not essential any more. It is suggested that psittacosis in birds should not be a notifiable disease any longer. The derogation of mandatory treatment during quarantine is also recommended. Governmental control of psittacosis should be replaced by a privately organized eradication program by breeders.

Animals↗
PubMed1997

Herpesviruses in tortoises: investigations into virus isolation and the treatment of viral stomatitis in Testudo hermanni and T. graeca.

Various studies were done during a spontaneous outbreak of stomatitis-rhinitis-complex (mouth rot) in a collection of Mediterranean land tortoises (21 Testudo hermanni, Hermann's tortoises, and three Testudo graeca, spur-thighed tortoises) in southern Germany. These studies were intended to help diagnose the causative agent, establish a possible diagnostic method in vivo and provide information on the efficacy of aciclovir and ganciclovir against chelonian herpesviruses. Thirteen T. hermanni and no T. graeca died within a period of 6 weeks following the introduction of one apparently healthy T. graeca. Two of the dead Testudo hermanni were submitted for post-mortem examination. In addition, blood samples from 11 of the 12 tortoises still surviving at the beginning of this study were cultured for virus content and for the presence of neutralizing antibodies to chelonian herpesviruses and swabs from conjunctiva, pharynx and cloaca were cultured for the presence of viruses. Herpesviruses were isolated from tissues of the two dead Testudo hermanni (tongue, intestine, trachea, lung, spleen, heart and brain). Peripheral leukocytes from one of 11 blood samples were positive for herpesvirus isolation, indicating viremia in at least one animal. Nine of 11 pharyngeal swabs but none of the conjunctival and cloacal swabs yielded herpesviruses. Circulating neutralizing antibodies were present in two of two tested T. graeca, but absent in all of the nine samples from T. hermanni. Aciclovir and ganciclovir were effective when tested in vitro against one of the herpesvirus isolates.

Acyclovir↗
PubMed1997

Failure to induce formation of proteinase K resistant fibrils in pigeons through experimental infection with paramyxovirus type 1.

Ten racing pigeons were infected experimentally with the paramyxovirus (PMV) type 1 of the pigeon. Within twelve weeks of observation, they were euthanized at different times. Their brains were examined for proteinase K resistant fibrils and histopathologically for spongiform lesions. No proteinase K resistant fibrils and no spongiform lesions could be detected in any case. Therefore, it is estimated that PMV type 1 of the pigeon is not likely to induce pathogenic mechanisms assumed for transmissible spongiform encephalopathies.

Animals↗
PubMed1997

Epidemiology of avian diseases.

A large number of diseases occur in domestic, farm-raised poultry. Only two of the many different diseases are notifiable and subject to governmental control: highly pathogenic avian influenza and Newcastle disease. Diagnosis and treatment or prevention of all other conditions are left to the skills of farmers and their veterinarians. Poultry production is aimed at providing more and tastier food for the ever growing human community. Infectious diseases and technical errors during production and processing need to be minimised. The concept of hazard analysis critical control point (HACCP) has already been introduced into food processing and quality assessment. The regulations laid down in ISO 9000 will soon become a powerful and practical tool for monitoring and improving the productivity of live poultry. Approved epidemiological concepts and tools will enable the poultry industry to achieve constant and safe production. Certification on the basis of ISO 9000 of all areas of poultry production is a new approach for maintaining the health of poultry, for tracing and subsequently eliminating breaks in productivity, and securing production without health hazards for the consumer.

Animals↗
PubMed1997

[Prevalence of Salmonella enteritidis and Salmonella typhimurium in laying hen flocks battery and on floor housing. Comparative studies using bacteriological and serological demonstration methods].

The prevalence of Salmonella (S.) enteritidis and Salmonella typhimurium is described in 34 flocks of laying chickens. In an attempt to detect the rate of infection comparative bacteriological and serological methods were employed. By cultural methods 47.0% of the floor flocks and 35.3% of the battery flocks were S.e. or S. tm. infected. The same tendency was established with the Bommeli ELISA. Flocks on floor were positive in 64.7% and flocks in batteries were positive in 47.0%. Both methods--bacteriological isolation and serology--yielded more S.e. positive flocks kept on the floor than in battery systems. Long-term studies of four flocks demonstrate a long persistence of antibodies against S.e. in serum and yolk even after one year. Almost all S.e. infected flocks prove a correlation between increase of positive cultures and antibody positive sera. Also, a correlation between levels of absorption values of sera tested in the Bommeli ELISA and positive fecal samples is evident. This is particularly true for eight of 10 flocks. If S.e. infected laying flocks need to be detected, then high absorption values in sera or yolk and a high rate of antibody positive hens provide reasonable good conditions to attempt subsequent bacteriological examinations.

Animals↗