Imperial College London


Faculty of MedicineDepartment of Infectious Disease

Senior Research Fellow



+44 (0)20 7594 1803j.bosse




234Wright Fleming WingSt Mary's Campus






BibTex format

author = {Bosse, J and Li, Y and Walker, S and Atherton, T and Fernandez, Crespo R and Williamson, SM and Rogers, J and Chaudhuri, RR and Weinert, LA and Oshota, O and Holden, MTG and Maskell, DJ and Tucker, AW and Wren, BW and Rycroft, AN and Langford, PR and BRaDP1T, Consortium},
doi = {jac/dkv121},
journal = {Journal of Antimicrobial Chemotherapy},
pages = {2217--2222},
title = {Identification of dfrA14 in two distinct plasmids conferring trimethoprimresistance in Actinobacillus pleuropneumoniae},
url = {},
volume = {70},
year = {2015}

RIS format (EndNote, RefMan)

AB - Objectives The objective of this study was to determine the distribution and genetic basis of trimethoprim resistance in Actinobacillus pleuropneumoniae isolates from pigs in England.Methods Clinical isolates collected between 1998 and 2011 were tested for resistance to trimethoprim and sulphonamide. The genetic basis of trimethoprim resistance was determined by shotgun WGS analysis and the subsequent isolation and sequencing of plasmids.Results A total of 16 (out of 106) A. pleuropneumoniae isolates were resistant to both trimethoprim (MIC >32 mg/L) and sulfisoxazole (MIC ≥256 mg/L), and a further 32 were resistant only to sulfisoxazole (MIC ≥256 mg/L). Genome sequence data for the trimethoprim-resistant isolates revealed the presence of the dfrA14 dihydrofolate reductase gene. The distribution of plasmid sequences in multiple contigs suggested the presence of two distinct dfrA14-containing plasmids in different isolates, which was confirmed by plasmid isolation and sequencing. Both plasmids encoded mobilization genes, the sulphonamide resistance gene sul2, as well as dfrA14 inserted into strA, a streptomycin-resistance-associated gene, although the gene order differed between the two plasmids. One of the plasmids further encoded the strB streptomycin-resistance-associated gene.Conclusions This is the first description of mobilizable plasmids conferring trimethoprim resistance in A. pleuropneumoniae and, to our knowledge, the first report of dfrA14 in any member of the Pasteurellaceae. The identification of dfrA14 conferring trimethoprim resistance in A. pleuropneumoniae isolates will facilitate PCR screens for resistance to this important antimicrobial.
AU - Bosse,J
AU - Li,Y
AU - Walker,S
AU - Atherton,T
AU - Fernandez,Crespo R
AU - Williamson,SM
AU - Rogers,J
AU - Chaudhuri,RR
AU - Weinert,LA
AU - Oshota,O
AU - Holden,MTG
AU - Maskell,DJ
AU - Tucker,AW
AU - Wren,BW
AU - Rycroft,AN
AU - Langford,PR
AU - BRaDP1T,Consortium
DO - jac/dkv121
EP - 2222
PY - 2015///
SN - 1460-2091
SP - 2217
TI - Identification of dfrA14 in two distinct plasmids conferring trimethoprimresistance in Actinobacillus pleuropneumoniae
T2 - Journal of Antimicrobial Chemotherapy
UR -
UR -
VL - 70
ER -