C. Winstanley et al., Detection of type III secretion system genes in animal isolates of Bordetella bronchiseptica, VET MICROB, 72(3-4), 2000, pp. 329-337
A cosmid clone bank of Bordetella bronchiseptica genomic DNA was screened f
or the presence of type III secretion (TTS) genes using a probe derived fro
m the TTS system genes of Ralstonia solanacearum. A 3.35 kb PstI fragment,
sub-cloned from a hybridising cosmid clone, was sequenced and found to cont
ain a 97 bp overlap with the previously reported B. bronchiseptica bscIJKLN
O TTS gene cluster. DNA and predicted protein homology analysis suggests th
at a bscPQRST cluster lies immediately downstream of bscIJKLNO. A PCR ampli
fication assay indicated that the bscT locus was present in 27 B, bronchise
ptica animal isolates tested (100%). Dot-blot DNA hybridisation using probe
s for bscT and bscP confirmed the presence of these loci in six canine isol
ates associated with a variety of clinical signs. Although TTS has been imp
licated in the pathogenicity of B, bronchiseptica, it is likely that differ
ent clinical manifestations may be due to variations in gene expression or
host factors, rather than the absence or presence of TTS genes. (C) 2000 El
sevier Science B.V. All rights reserved.