Thomsen Line E, Chadfield Mark S, Bispham Jennifer, Wallis Timothy S, Olsen John E, Ingmer Hanne
Department of Veterinary Microbiology, Stigboejlen 4, The Royal Veterinary and Agricultural University, DK-1870 Frederiksberg C, Denmark.
FEMS Microbiol Lett. 2003 Nov 21;228(2):225-31. doi: 10.1016/S0378-1097(03)00762-6.
Signature-tagged mutagenesis (STM) is a widely used technique for identification of virulence genes in bacterial pathogens. While this approach often generates a large number of mutants with a potential reduction in virulence a major task is subsequently to determine the mechanism by which the mutations influence virulence. Presently, we have characterised a Salmonella enterica serovar Dublin STM mutant that, in addition to having reduced virulence, was also impaired when growing under various stress conditions. The mutation mapped to the manC (rfbM) gene of the O-antigen gene cluster involved in O-antigen synthesis. The O-antigen is a component of the lipopolysaccharide (LPS) forming a unique constituent of the outer membrane of Gram-negative bacteria. While mutations in the O-antigen genes usually eliminate the entire O-antigen side chain we found that the transposon mutant produced intact O-antigen, however, the mutation reduced the amount of LPS.
签名标签诱变（STM）是一种广泛用于鉴定细菌病原体毒力基因的技术。虽然这种方法通常会产生大量毒力可能降低的突变体，但随后的一项主要任务是确定突变影响毒力的机制。目前，我们已经鉴定了一株肠炎沙门氏菌都柏林血清型STM突变体，该突变体除了毒力降低外，在各种应激条件下生长时也受到损害。该突变定位于参与O抗原合成的O抗原基因簇的manC（rfbM）基因。O抗原是脂多糖（LPS）的一个组成部分，构成革兰氏阴性菌外膜的独特成分。虽然O抗原基因的突变通常会消除整个O抗原侧链，但我们发现转座子突变体产生了完整的O抗原，然而，该突变减少了LPS的量。
