a1 Applied and Molecular Immunology Unit, Central Veterinary Laboratory (Weybridge), Addlestone, Surrey KT15 3NB, UK
a2 Department of Bacteriology, Institute of Immunology and Infectious Diseases, University of Utrecht, 3508 TD Utrecht, The Netherlands
The mechanisms by which Campylobacter jejuni rapidly spreads through large broiler flocks are unknown. Recent evidence suggests that the minimum infective oral dose for 100% caecal colonization is about 104 cfu, which, with such a ‘fragile’ organism, may limit transmissibility. However, the colonization potential of laboratory-adapted strains may be anomalous compared with fresh isolates or those passaged in vivo. The colonization potential of two chicken and one human C. jejuni isolates, which were minimally passaged, have been investigated using a quantitative model of chicken colonization. There was no detectable difference between these strains but all were more efficient colonizers than a laboratory-adapted strain 81116. In addition, the colonization potential of C. jejuni strain 81116 following a passage in vivo was also determined. The results indicated this increased C. 10000 fold following a single passage in vivo, such that a dose of only 40 cfu caused maximal colonization. Enhanced colonization potential may, therefore, account for the rapid rate of transmission within large flocks.
(Accepted March 06 1996)
c1 Author for correspondence.
p1 Institut für Medizinische Mikrobiologie, Johannes Interstinal tractenburg Universitate, Hochhaus am Augustusplatz, 55101 Mainz, Germany.