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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 F11 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 F11 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 (O1:K1, O2:K1, O35, and O78:K80). The prevalence of F11 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 F11 fimbriae by chicken E. coli strains could not be correlated with adherence to chicken tracheal or pharyngeal cells.

The present report describes the identification, purification, and characterization of a hemolysin produced by Streptococcus suis type 2. The hemolysin was purified from the culture supernatant by using different filtration steps, Superose-12 column chromatography, and selective (NH4)2SO4 precipitation. The purified hemolysin, designated suilysin, had an apparent molecular mass of 54,000 Da and exhibited a specific activity of 0.7 x 10(6) hemolytic units per mg. Suilysin appeared to belong to a family of toxins known as the thiol-activated toxins, with which it had several characteristics in common: loss of activity upon oxidation, reactivation upon reduction, and inhibition of activity by small amounts of cholesterol. The N-terminal amino acid sequence of suilysin showed many similarities with parts of the deduced N-terminal amino acid sequences of perfringolysin O, streptolysin O, listeriolysin O, alveolysin, and pneumolysin. Mice immunized with a vaccine containing purified suilysin appeared to be completely protected against a lethal S. suis type 2 challenge, indicating that suilysin is an important factor and that the neutralization of this single factor is sufficient to protect mice against the detrimental effects of an S. suis type 2 infection. Most of the different (serotype) strains appeared to secrete hemolytic activity which was biochemically and immunologically indistinguishable from suilysin into the culture supernatant in vitro, indicating that suilysin might be a cross-protection factor.

Since August 1993 moderate to serious respiratory problems with necrotic pneumonia, growth depression and fast increasing mortality are seen in commercial turkeys (2-8 weeks of age) and broilers (4-6 weeks of age). An unidentified pleiomorphic Gram-negative rod was isolated from affected tissues. This Pasteurella-like organism, with yet unknown taxonomy, is recently named Ornithobacterium rhinotracheale gen. nov. sp. nov. or 'Taxon 28'. Experimentally severe growth depression and arthritis could be evoked in commercial turkeys and chickens. Respiratory signs caused by O. rhinotracheale could not (yet) be reproduced experimentally. This is the first report of the isolation of this organism in poultry in the Netherlands findings.

In 50 piglets with weaning diarrhoea, the heat-labile fraction of the enterotoxin is detected by ELISA test, from 28 E. coli strains considered as containing only the heat-stable fraction. These results are confirmed by the rabbit cutaneous test. The comparative interest of the various diagnosis methods is discussed, and also the consequences in matter of piglets vaccination., Les auteurs, chez 50 porcelets atteints de colibacillose du sevrage, mettent en évidence, par le test ELISA (méthode immuno-enzymatique) la fraction thermolabile (LT) de l'entérotoxine à partir de 28 souches d’Escherichia coli, comme la 0141 : K 85 ac, considérées comme étant pourvues seulement de la fraction thermostable (ST). Ces résultats sont confirmés pour 26 d'entre elles par le test épicutané sur lapin. Les auteurs discutent ensuite de l’intérêt comparatif des méthodes de diagnostic ainsi que des conséquences à tirer de leurs résultats en matière de vaccination des porcelets., Renault Lucien, Storm P. K., Le Bourhis Elizabeth, Mathieu D., Constantin A. Mise en évidence chez les porcelets atteints de la colibacillose du sevrage de la fraction thermolabile de souches d’Escherichia coli réputées en être dépourvues. In: Bulletin de l'Académie Vétérinaire de France tome 134 n°4, 1981. pp. 451-457.

A radiation sensitive mutant of E. coli K-12 was isolated. It has properties in common with several Uvr mutants (Table 2) and therefore we propose to denote this mutant as uvrF.

19 independent recombination-deficient mutants were isolated. 7 carried mutations that mapped near or in the recB and recC genes between thyA and argA . 10 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 recG162 , and was UV- and X-ray-sensitive. It was located between pyrE and ilvA . Strain PC 1250 was only slightly UB-sensitive, was X-ray-resistant and carried the mutation designated recH166 which was located between pheA and cysQ .