[The epizootiology of tuberculosis of cattle in the Federal Republic of Germany]

Mycobacterial strains from different outbreaks of tuberculosis of cattle in Germany from 1996 to 2001 were differentiated by two molecular biological methods (Spoligotyping, RFLP IS6110). The causative agent was in one case Mycobacterium (M.) africanum, in 10 cases M. bovis and in 17 cases M. bovis ssp. caprae, respectively. The results of the molecular biological methods are discussed from the perspective of epizootiology and the particular importance of infections by M. bovis ssp. caprae emphasized. Direct contact of the animals, purchase from infected stocks, infected zoo animals and wildlife, as well as livestock handlers are discussed as possible sources of infection.

Influences of naturally occurring and experimentally induced porcine pneumonia on blood parameters

It had been the objective of the studies described to establish local and systemic changes by naturally occurring pneumonia or pneumonia experimentally induced by Pasteurella multocida and Haemophilus parasuis in swine. Acute and chronic pneumonia was found to alter the cytokine level of lung lavage fluid and affect the composition and function of blood cells, especially with regard to phagocytosis, radical formation and cell surface receptors. Interleukin-6 levels in blood plasma rose 24h after experimental intrabronchial infection. The influences of the changes on growth and meat quality are discussed.

Comparative evaluation of ultrasonography and lung function testing with the clinical signs and pathology of calves inoculated experimentally with Pasteurella multocida

Seventeen calves were inoculated intratracheally with Pasteurella multocida 0 on three consecutive days with 10 ml of an inoculum containing 10(9) colony forming units/ml per day per calf. Before the first inoculation and 24 hours after the third, each calf was examined non-invasively by means of a clinical examination, chest ultrasonography, and impulse oscillometry to measure the impedance of the respiratory system. The inoculation of P multocida caused fever and a significant increase in respiratory rate and a decrease in tidal volume. There were also significant changes in the ultrasonographic results and in the impedance of the respiratory system. The percentage of the total surface area of the lungs showing pathological changes when the calves were euthanased 48 hours after the third inoculation ranged from 0.4 to 39 per cent. There were statistically significant correlations between the ultrasound scores and the pathological findings and between the ultrasound scores and the respiratory rate and tidal volume. The changes in the impedance of the respiratory system were not correlated with either the ultrasonographic or the pathological findings.

[Immunological methods for the diagnosis of bovine tuberculosis--state of the art]

An overview is given about the most common immunological methods for the diagnosis of bovine tuberculosis. These methods are based on cell mediated immune reactions on the one hand (intradermal skin test, interferon-gamma-test, lymphocyte transformation test) or on antibody production against Mycobacterium bovis on the other hand (ELISA). The advantages and disadvantages of the methods as well as their specificity and sensitivity are discussed.

[Mycobacterium avium infections in poultry--a risk for human health or not?]

Avian tuberculosis is an animal disease notifiable for statistical purposes in Germany. Cases notified (between 130 and 230 annually) were primarily related to private flocks of pedigree poultry and layers consisting of less than 20 animals and individual animals in game enclosures and zoological gardens. Mycobacterium (M.) avium infection does not play any role in modern intensive poultry husbandry. Human M. avium infections have considerably gained in importance in the last two decades, mainly in HIV-infected patients. Due to the ubiquitous character of MAIC (Mycobacterium avium intracellulare-Complex), it is difficult to establish confirmed epidemiological associations with infections in humans. Surface and drinking water, soil and also foods as well as direct contact with infected birds (pet birds) have been discussed as possible sources of infection. Recently, strains of the serovars 1, 2 and 3 which have often been isolated from birds (bird-type strains) could be defined as a taxon on its own right among MAIC by using molecular-biological methods for MAIC typing (RFLP--restriction fragment length polymorphism and PFGE-pulsed field gel elektrophoresis). In exceptional cases only, strains of this character have been isolated from humans. Consequently, poultry-to-man transmission of M. avium appears to be a very improbable event. In contrast, extensive conformity has been found to exist between M. avium isolates of human origin and isolates from pigs. This fact has rightly given rise to assumptions of either the presence of epidemiological links between pigs and humans or of infection from common sources. In a summarizing view, it can be stated that M. avium infection of farm poultry is hardly of any importance for poultry production as well as for human disease. The importance of MAIC for infections in other farm animals (cattle and swine) is outlined and discussed.

[Protein patterns of Pasteurella multocida strains in relation to the animal host and the geographic site of isolation]

Protein patterns from 681 Pasteurella multocida strains of different animal species and distinct geographical regions were analyzed by PAGE. We found 9 protein types taking the most intense band as reference. This band represents a protein of the outer membrane (OMP). In assigning the strains to protein types a relation to animal hosts of the strains was established. The majority of isolates from rabbits (88%) belongs to type P6, which is not found in strains isolated from cattle or pigs. Strains from pigs did not include the protein types P2, P4 and P8, in cattle strains type P9 was absent. The distribution of protein types in bovine isolates was shown to be related to the geographical location. The results are discussed with particular emphasis on immuno-prophylaxis. It appears promising to develop P. m. vaccines specific for certain animal species.

[Long-chain fatty acids of Pasteurella multocida nad Pasteurella haemolytica]

The relative contents of long-chain fatty acids in P. multocida and P. haemolytica were investigated. A dependence on the composition of the broth was established. Accordingly, comparative quantitative studies on fatty acid contents have to be conducted using bacteria grown with the same lot of broth medium. As for P. multocida, there were significant differences between the serovars (C14 in TDHM and C16, delta 2C18 in BPL). These differences are, however, not significant to replace serotyping. Highly significant differences were also detected between P. multocida isolates from nasal swabs and pneumonic lungs (interims of C14, delta C16 on BPL and BRU). The largest differences were measured for strains grown on BRU, which is interpreted as an expression of virulence. Significant differences were found between biotypes A and T of P. haemolytica, namely for C14, C16 in TDHM, and C14, delta C16, C16, C18 in BPL medium.

[Detection of dermonecrotic toxin genes in Pasteurella multocida strains using the polymerase chain reaction (PCR)]

A PCR method was developed which allows to distinguish between Pasteurella multocida strains carrying or lacking the dermonecrotic toxin gene. Specific primers were used to amplify a 1501-bp DNA fragment from the genomic dermonecrotic toxin gene region. Isolated DNA, broth cultures and swabs were used as samples. Detection of the toxin gene directly from swab samples accelerates considerably the diagnosis since cultivation steps can be omitted. The results of PCR corresponded to findings obtained by ELISA.

[Proteins from the outer membrane of Pasteurella--1. Polyacrylamide gel electrophoresis of outer membrane proteins--a possibility for differentiation of Pasteurella haemolytica strains]

Using the sodium laurylsarcosinate method, outer membrane proteins (OMPs) of 63 Pasteurella haemolytica strains are isolated and their protein patterns obtained by SDS polyacrylamide gel electrophoresis (SDS-PAGE) are compared. A high degree of similarity became evident both within A and T biotypes in the molecular weight range of 25 to 50 KDa. Strain-to-strain variations are mainly limited to quantitative differences in individual protein bands. It is concluded that within both the A and T biotype groups equal sets of major proteins are present with differing amounts of individual constituents. Biotypes A and T can be clearly distinguished on the basis of marked variations in OMP profiles. OMPs of those AT strains included in comparative studies are exhibiting no general homogeneity, but a relative heterogeneity due to different protein compositions, which are, however, clearly distinct from the patterns of biotypes A and T. It is established unambiguously that isolates belonging to biotypes A or T, as well as AT strains, can be clearly distinguished from each other on the basis of SDS-PAGE analysis of OMP extracts. Thus, polyacrylamide gel electrophoresis of outer membrane proteins can be used for differentiation.

[The typing of Pasteurella from cattle and swine]

A total of 383 Pasteurella strains isolated from calves and pigs were typed by their phenotypic properties and allotted to the following species and subspecies: [table: see text] P. multocida ssp. septica, P. avium biotype 2, P. canis and P. canis biotype 2 could be isolated up till now only from calves, on the other hand P. multocida ssp. gallicida were found in pigs only.

[Toxin-producing pasteurellas in a cattle herd]

Besides other agents, indole-negative Pasteurellae, producing dermonecrotic Pasteurella toxin, were isolated from the noses of calves in a herd with enzootic bronchopneumonia. In some blood sera, antitoxin was detected. According to their biochemical activities, isolated strains were classified as P. multocida ssp. septica (ornithine-negative), P. avium (biovar 2), and P. canis (biovar 2). However, in DNA-DNA hybridisation tests there was much coincidence with P. multocida. In experimental calves, pneumonic lesions were produced with one of the isolates as well as with the dermonecrotic toxin. Therefore, indole negative toxinogenic Pasteurellae are considered pneumonia causing agents. They should be taken into account in bacteriological diagnostic and for production of herd specific bacterins.

Classification of Pasteurella field strains isolated from farms in Germany using traditional methods and DNA-DNA hybridization

410 Pasteurella (P.) field strains isolated from calves and piglets were classified according to Bisgaard et al. (1). 376 strains were assigned to P. multocida ssp. multocida, 34 of them were ornithine- and trehalose+, and 61 of them ornithine- and trehalose-. 4 strains belonged to P. multocida ssp. septica, 4 to P. multocida ssp. gallicida, 6 to P. avium biovar 2 and 20 to P. canis biovar 2. There was no difference in the prevalence of the species in calves and pigs. The fact that strains belonging to P. multocida ssp. septica were isolated only from calves and P. multocida ssp. multocida ornithine- and trehalose- were mostly isolated from piglets could indicate a certain host specificity of these isolates. In genotypic investigations 20 field isolates of P. multocida belonging to different Carter serotypes, as well as serologically negative strains were compared to reference strains in terms of deoxyribonucleic acid (DNA) relatedness. The data obtained by filter hybridization revealed a considerable degree of genotypic intraspecies heterogeneity within P. multocida. No correlations to the respective serotypic classification could be detected.

[Detection of toxin-producing types of Pasteurella multocida--a comparison of methods]

28 Pasteurella multocida strains were examined for production of toxin by 6 different methods. Identical results were obtained using a mice lethality test, a tissue cell culture assay and an ELISA. Different results were received with a dot-blot-immunoassay (1 strain), using a gene probe (6 strains) and a guinea pig skin test (8 strains). Corresponding differences were detected with 2 strains only. Tissue culture, ELISA and dot-blot-immunoassay are effective methods for the diagnosis of toxin-producing Pasteurella multocida strains. Animal experiments should be an exception.

[The effect of toxins from Pasteurella multocida type D in calves in vivo]

By intratracheal injection of purified dermonecrotic toxin from a Pasteurella multocida type D strain, pneumonitis in calves could be produced. This demonstrates the important role of this toxin in the pathogenesis of pneumonitis in calves.

[Possibilities for the establishment of pneumonia-free swine herds by immunization and administration of cefquinome]

The application of Bordetella and Pasteurella inactivated and adsorbed vaccines together with cefquinome to sows, piglets and weaners led to a significant reduction of the incidence of rhinitis atrophicans and pneumonia. The frequency of positive isolates of P. multocida, H. parasuis and A. pleuropneumoniae out of nasal swabs was reduced during the treatment.

[The importance of dermonecrotoxin and dermonecrotoxoid of Pasteurella multocida for the calf]

The i. m. application of dermonecrotoxin of P. multocida var. D led to an atrophy of nasal conchae, liver-swelling and to induration of liver and spleen. The intratracheal application caused a lobular pneumonia. The vaccination with toxoid resulted in an immunity against a challenge with toxin but not with P. multocida var. D. Correlations between antitoxic serum-titers and immunity have to be investigated in future.

[Results of experimental immunization of calves with different Pasteurella antigens]

Calves immunised with different Pasteurella antigens (inactivated whole cells, sodium chloride extract) where challenged two weeks after the second immunization with the homologous strain. The intracutaneous application of whole cells of P. haemolytica A1 and P. multocida A was effective. The incidence of pneumonia was reduced and the pneumonic lesions were less severe. The sodium chloride extract was not effective.

[The significance of antibodies to Pasteurella haemolytica A1 in the colostrum of cows and blood serum of calves]

Antibodies to P. haemolytica were detected in colostral sera of cows and blood sera of calves by means of indirect haemagglutination (IHA) and ELISA. The ELISA titres of the colostral sera of the dams and of the blood sera of the calves showed a significantly positive correlation. There is a positive correlation between the titres of the two serological methods. The results of the challenge infection with P. haemolytica A 1 do not show a correlation between the titres and the severity of the disease. Heifer calves, however, developed more severe pneumonias than calves from older cows.

[The significance of the dermonecrotic toxin of P. multocida serovar D in the pathogenesis of pneumonia in swine]

The intratracheal application of crude and purified toxin of P. multocida serovar D in primary SPF-piglets resulted, apart from turbinate atrophies, in lobular to lobularly confluent catarrhalic pneumonias.

[Further development of P. multocida vaccines for swine]

149 strains with antigen fractions of both A and D type could be found out of 446 P. multocida field strains of porcine origin. Most of them are producing the dermonecrotizing toxin. These A/D strains proved to be virulent in mice and piglets as well. In mice, the vaccination with one of the most virulent and immunogenic A/D strains, inactivated and A1(OH)3 adsorbed caused an immunity against challenge infections with P. multocida of types A, D and A/D. This effect could be confirmed on SPF piglets.

[Immunoprophylaxis against an acute P. multocida type D infection in Cairina moschata]

An acute P. multocida infection led to severe losses in a big Cairina moschata fattening farm. All isolated strains belong to serogroup D. After testing the virulence and immunogenic properties of the isolated strains in NMRI mice, we used an highly virulent and immunogenic strain for developing an inactivated vaccine (formaline inactivated, Al (OH)3 adsorbed, with a content of 3 x 10(9) bacteria/ml). Two sc. immunizations of Cairina at an age of 10 and 24 days resulted in immunity. All immunized animals survived the challenge infection. The immunity was stable till the 8th week after the 2nd immunization, later the intensity of the immunity decreased. A threefold immunization procedure in the Cairina farm was very successful.

A group of indole-negative bovine strains with high deoxyribonucleic acid homology to Pasteurella multocida

A group of nine bovine Pasteurella strains not producing indole were investigated for their taxonomic relationships with Pasteurella multocida, Pasteurella haemolytica and Pasteurella canis. For all strains, DNA-DNA hybridization has revealed a high genetic relatedness at the species level to P. multocida and significantly lower homologies of only 18-41% towards P. haemolytica and 11-15% towards P. canis. Guanine plus cytosine values of 38.0 to 42.1 mol% and several phenotypic characters have been found to be different from the established pattern for P. multocida subspecies. It is suggested that the strains represent a new taxon, possibly another P. multocida subspecies.

[Immuno-prevention of coli infections in swine using live vaccine. 1. Use in coli infections during the 1st days of life]

Live vaccine prepared from streptomycin-dependent mutants of E. coli was well tolerated in various doses and at various times of administration, for there were no adverse reactions. There was no evidence of reversion to a virulent form. Efficacy was closely related to frequency of application of the vaccine. Vaccination must be performed as early as possible to immunize against infection during the first few days of life. It was possible to confer protection against the diarrhoea that occurs at 3-4 weeks of age. The use of an oral vaccine under intensive husbandry systems was shown to be safe. When the piglets were kept in cages, the vaccine could be administered in the existing mixing tanks for water supply, without the need for special equipment. Oral immunization of pigs already infected or already ill did not aggravate the existing infection, whether the animals were housed individually or in pens. Because of the dilution effect of the mixing tank and water supply pipes, the dose of vaccine, given on ten successive days, should be calculated at 10(9) organisms of the E. coli mutant per animal. This should supply a number close to the desired bacterial count of 10(10) organisms per animal daily. Immunization significantly reduced the frequency of gastrointestinal diseases during the first three weeks of age in piglets.

Significance of renewal asymmetry in bone scans: experience in 795 cases

A retrospective study of 795 consecutive bone scans employing either 18F or 99mTc-pyrophosphate to evaluate the diagnostic value of renal asymmetry in such scans has been carried out. It is concluded that asymmetric renal images in bone scans convey relatively specific information regarding renal pathology, especially in the 99mTc-pyrophosphate studies.