In the present study 443 strains of Ornithobacterium rhinotracheale, a causative agent of respiratory disease in fowl, were investigated biochemically and serologically. In both ways O. rhinotracheale could be differentiated from other gram-negative rods and, more particularly, from the Pasteurella-like bacteria potentially pathogenic for fowl. For the biochemical characterization of O. rhinotracheale the API 2ONE identification strip proved to be useful, although O. rhinotracheale is not included in the API system. Serologically, by using monovalent antisera in agar gel precipitation (AGP) tests and enzyme-linked immunosorbent assays (ELISAs), seven serotypes (serotypes A to G) of O. rhinotracheale could be discriminated. The AGP test was chosen as the preferred method to be used for serotyping. Isolates of serotype A were found to be the most prevalent, especially in chickens. Isolates from turkeys were more heterogeneously divided over the serotypes. Some strains showed cross-reactivity between serotypes A, B, and E. Five O. rhinotracheale strains could not be serotyped with the available antisera. Relationships between the geographic origin and the serotypes were found. By the ELISA the presence of antibodies against O. rhinotracheale could be detected in 1-day-old birds as well as in birds with clinical signs, and therefore, it might be useful for diagnostic purposes. Respiratory problems, together with purulent pneumonia, airsacculitis, severe growth retardation, and rapidly increasing mortality, were reported in meat turkeys and broilers in South Africa, Germany, the United States, France, and The Netherlands (1, 2, 4, 6). A gram-negative, pleomorphic rod could repeatedly be isolated from affected organs. This Pasteurellalike organism has recently been referred to as Ornithobacterium rhinotracheale gen. nov. sp. nov. (7). In experimental infections, it was possible to evoke severe growth retardation and airsacculitis in turkeys and chickens with this bacterium (8). O. rhinotracheale strains from different countries reporting fowl infected with the organism were investigated for their bacteriological, biochemical, and serological relationships and their differences from other gram-negative rods.

No abstract

SUMMARY19 independent recombination-deficient mutants were isolated. 7 carried mutations that mapped near or in the recB and recC genes between thyA and argA. IO mutants carried mutations cotransducible with pheA and exhibited no complementation with recA in temporary zygotic diploids.Two new genes controlling recombination have been identified. Strain PC 0297 carried a mutation designated recGz62, and was UV-and X-ray-sensitive. It was located between pyrE and ilvA. Strain PC 125o was only slightly UV-sensitive, was X-ray-resistant and carried the mutation designated recHI66 which was located between pheA and cysQ.

we showed that among 34 isolates from swine the membrane protein and lipopolysaccharide (LPS) patterns, as analyzed by sodium dodecyl sulfate-gel electrophoresis, could be classified into three and six patterns, respectively. In all cases a certain LPS pattern was correlated with a certain protein pattern. Certain combinations of types of cell surface proteins and LPSs were correlated with pathogenicity, the latter property being judged by the guinea pig skin test. In the present paper the immunological and biochemical properties of cell surface constituents were analyzed. The reaction between electrophoretically separated cell surface constituents with guinea pig and sow antisera showed that LPS as well as several proteins were immunogenic. Among these is protein H, whose electrophoretic mobility is the main criterium for typing of cell envelope protein patterns. Protein H was the most heavily labeled component when whole cells were iodinated by the Iodo-Gen procedure, showing its accessibility at the cell surface. These properties of protein H make it an attractive vaccine candidate. Further biochemical analyses revealed that protein H shares many properties with pore proteins of members of the family Enterobacteriaceae. One of these properties, association between pore proteins and peptidoglycan, was used as the basis for a simple procedure developed to partially purify protein H.

Fimbriae were purified from Escherichia coli strains isolated from chickens with septicemia or colibacillosis. When grown on solid media, these strains expressed fimbriae with an apparent subunit molecular mass of 18 kDa. Morphological, biochemical, serological, functional, and molecular characterization revealed that these 18-kDa fimbriae are identical to Fil fimbriae, which were previously found to be involved in the pathogenesis of human urinary tract infection. Screening of a large strain collection showed that 78% of chicken E. coli strains expressed Fll fimbriae, whereas this percentage increased to 96% when the only strains taken into account were those with the serotypes most commonly encountered in avian colibacillosis (01:K1, 02:K1, 035, and 078:K80). The prevalence of Fll fimbrial expression appeared to be independent of the country of isolation of the strains, except for the United States, where the prevalence seemed higher. Expression of Fll fimbriae by chicken E. coli strains could not be correlated with adherence to chicken tracheal or pharyngeal cells.