Johannes F van den Bosch

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Actinobacillus pleuropneumoniae serotype reference strains and 204 A. pleuropneumoniae field strains representing all 12 serotypes and both biovars 1 and 2, obtained from laboratories from various countries worldwide, were analyzed for the presence of the toxin genes apxIC, apxIA, apxIB, apxID, apxIIC, apxIIA, apxIIIC, apxIIIA, apxIIIB, and apxIIID by(More)
The two studies presented here were done to determine the prevalence of the alpha, beta, epsilon and enterotoxin genes and the novel beta2 toxin gene of Clostridium perfringens in neonatal or pre-weaned piglets with diarrhoea or necrotic enteritis. All C. perfringens isolates were positive for the alpha and negative for the epsilon and enterotoxin gene,(More)
The feasibility of a single-shot, low-dose vaccination against pandemic influenza was investigated. The immunogenicity and safety of whole inactivated, cell culture-derived H5N1 virus plus CoVaccine HT™ as adjuvant was tested in various animal species. In ferrets, doses of 4.0 and 7.5 μg H5N1 (NIBRG-14; A/Vietnam/1194/04; clade 1) without adjuvant gave low(More)
The virulence of faecal and urinary Escherichia coli strains was studied in relation to serotype, haemolysin production and haemagglutination pattern. By means of an experimental mouse model E. coli strains can be divided into avirulent (I), mouse nephropathogenic (II), and generally virulent (III) strains. Virulent group II and group III strains were more(More)
The influence of haemolysin production on virulence was studied in an experimental mouse model. Urinary strains of Escherichia coli can be divided into three virulence groups by determining their kinetics in the mouse kidney after intravenous injection. Virulent strains of groups II and III were more often haemolytic than avirulent group-I strains.(More)
Differences in nephropathogenicity between Escherichia coli strains were studied by following the kinetics of the viable count in the mouse kidney during 8 h after intravenous injection. Assuming as a reference point that at zero time 0.1% of the inoculum was lodged in the kidney, we found that strains fell into three main groups with different behavior(More)
The importance of K antigens of Escherichia coli as virulence factors was studied by comparing groups of mice given either strains of E. coli isolated from urinary tract infection in humans or mutant strains differing only in the absence of the K antigen. K antigens proved to be of minor importance for mouse nephropathogenicity; however, with the exception(More)
Monoclonal antibodies (MAbs) against seven serologically different P fimbriae (F7(1), F7(2), F8, F9, F11, F12, and F13) of uropathogenic Escherichia coli were tested for their ability to detect the P fimbriae on wild-type strains. In a plate agglutination test the MABs could detect the fimbriae on strains which expressed cloned fimbriae but not on wild-type(More)
The Escherichia coli P fimbriae F71, F72, F9, and F11 from four cloned strains were purified, and polyclonal antisera were raised in rabbits. Cross-reactions of these antisera with eight different cloned and purified fimbriae were measured in an enzyme-linked immunosorbent assay. These antisera showed a reaction with the homologous fimbriae and also with(More)
The nephropathogenic Escherichia coli strain P673 was shown to harbor two plasmids with molecular sizes of 70 and 41 megadaltons, respectively. The 70-megadalton plasmid, pCW1, coded for tetracycline resistance, whereas hemolysin production was coded by the 41-megadalton plasmid, pCW2. Plasmid pCW1 proved to be self-transmissible, in contrast to pCW2.(More)