Characterisation of an acapsular mutant of Burkholderia pseudomallei identified by signature tagged mutagenesis.
A Burkholderia pseudomallei mutant which was attenuated in a mouse model of melioidosis was identified by a signature tagged mutagenesis approach. The transposon was shown to be inserted into a gene within the capsular biosynthetic operon. Compared with the wild-type bacteria this mutant demonstrated a 10(5)-fold increase in the median lethal dose in a mouse model and it did not react with a monoclonal antibody against high mol. wt polysaccharide of B. pseudomallei. To determine the kinetics of infection, mice were dosed intraperitoneally (i.p.) and intravenously (i.v.) with mutant and wild-type bacteria. After i.p challenge, the number of mutant bacteria in the peritoneal cavity declined, whereas wild-type bacteria proliferated. When administered by the i.v. route, the mutant was able to cause disease but the time to death was increased compared with the wild type. Mice were dosed with the mutant and subsequently challenged with wild-type B. pseudomallei, but the mutant failed to induce a protective immune response.
Timothy
T
Atkins
Richard
R
Prior
Kerri
K
Mack
Paul
P
Russell
Michelle
M
Nelson
Joann
J
Prior
Jill
J
Ellis
Petra C F
PCF
Oyston
Defence Science and Technology Laboratory, CBS Porton Down, Salisbury, Wiltshire, SP4 OJQ, *Department of Biological Sciences, Centre for Molecular Microbiology and Infection, Flowers Building, Imperial College of Science Technology and Medicine, Exhibition Road, London, SW7 2AY and †Department of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, Keppel Street, London WC1E 7HT.
Gordon
G
Dougan
Defence Science and Technology Laboratory, CBS Porton Down, Salisbury, Wiltshire, SP4 OJQ, *Department of Biological Sciences, Centre for Molecular Microbiology and Infection, Flowers Building, Imperial College of Science Technology and Medicine, Exhibition Road, London, SW7 2AY and †Department of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, Keppel Street, London WC1E 7HT.
Richard W
RW
Titball
D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology; D016667:Bacterial Capsules / Q000235:genetics / Q000276:immunology; D016957:Burkholderia pseudomallei / Q000235:genetics* / Q000276:immunology / Q000472:pathogenicity*; D004195:Disease Models, Animal; D005260:Female; D015151:Immunoblotting; D007274:Injections, Intraperitoneal; D007275:Injections, Intravenous; D007700:Kinetics; D008554:Melioidosis / Q000382:microbiology*; D051379:Mice; D008807:Mice, Inbred BALB C; D016296:Mutagenesis; D009154:Mutation; D014774:Virulence / Q000235:genetics / Q000276:immunology
D000911:Antibodies, Monoclonal