Oral immunization with a dam mutant of Yersinia pseudotuberculosis protects against plague.
Inactivation of the gene encoding DNA adenine methylase (dam) has been shown to attenuate some pathogens such as Salmonella enterica serovar Typhimurium and is a lethal mutation in others such as Yersinia pseudotuberculosis strain YPIII. In this study the dam methylase gene in Yersinia pseudotuberculosis strain IP32953 was inactivated. Unlike the wild-type, DNA isolated from the mutant could be digested with MboI, which is consistent with an altered pattern of DNA methylation. The mutant was sensitive to bile salts but not to 2-aminopurine. The effect of dam inactivation on gene expression was examined using a DNA microarray. In BALB/c mice inoculated orally or intravenously with the dam mutant, the median lethal dose (MLD) was at least 10(6)-fold higher than the MLD of the wild-type. BALB/c mice inoculated with the mutant were protected against a subcutaneous challenge with 100 MLDs of Yersinia pestis strain GB and an intravenous challenge with 300 MLDs of Y. pseudotuberculosis IP32953.
Taylor
Victoria L
VL
Defence Science and Technology Laboratory, Porton Down, Salisbury, Wiltshire SP4 0JQ, UK.
Titball
Richard W
RW
Department of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, Keppel St, London WC1E 7HT, UK.|Defence Science and Technology Laboratory, Porton Down, Salisbury, Wiltshire SP4 0JQ, UK.
Oyston
Petra C F
PCF
Defence Science and Technology Laboratory, Porton Down, Salisbury, Wiltshire SP4 0JQ, UK.
D015075:2-Aminopurine / Q000494:pharmacology; D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D001428:Bacterial Vaccines / Q000008:administration & dosage / Q000235:genetics / Q000276:immunology*; D001647:Bile Acids and Salts / Q000494:pharmacology; D004269:DNA, Bacterial / Q000378:metabolism; D015252:Deoxyribonucleases, Type II Site-Specific / Q000378:metabolism; D004195:Disease Models, Animal; D005260:Female; D051379:Mice; D008807:Mice, Inbred BALB C; D020411:Oligonucleotide Array Sequence Analysis; D010930:Plague / Q000517:prevention & control*; D015265:Site-Specific DNA-Methyltransferase (Adenine-Specific) / Q000235:genetics*; D016019:Survival Analysis; D014613:Vaccines, Attenuated / Q000008:administration & dosage / Q000235:genetics / Q000276:immunology; D014774:Virulence; D015010:Yersinia pestis / Q000276:immunology / Q000472:pathogenicity; D015011:Yersinia pseudotuberculosis / Q000201:enzymology* / Q000235:genetics / Q000276:immunology* / Q000472:pathogenicity
D000900:Anti-Bacterial Agents; D001428:Bacterial Vaccines; D001647:Bile Acids and Salts; D004269:DNA, Bacterial; D014613:Vaccines, Attenuated; D015075:2-Aminopurine; C058693:Dam methyltransferase; D015265:Site-Specific DNA-Methyltransferase (Adenine-Specific); D015252:Deoxyribonucleases, Type II Site-Specific; C024405:GATC-specific type II deoxyribonucleases