Fig 2.

(A) Transcriptional analysis of the intergenic regions of the fim gene cluster. The intergenic regions within fimAICDHF are linked on one transcript. RT-PCRs were carried out on RNA isolated from wild-type SL1344. The intergenic regions amplified are indicated by the underlined genes. Primers amplifying rpoD were included as a control. RT +/− indicates the presence or absence, respectively, of reverse transcriptase in reaction mixtures. (B) Transcription of fim genes in S. Typhimurium SL1344 mutants. RT-PCRs were carried out on RNA isolated from wild-type S. Typhimurium SL1344 and Fim mutants. The numbers indicate the strains from which RNA was prepared, and RT-PCRs were performed with (+) or without (−) reverse transcriptase: 1, S. Typhimurium SL1344; 2, SL1344ΔfimA; 3, SL1344fimA::TT; 4, SL1344ΔfimH; 5, SL1344ΔfimF; 6, SL1344ΔfimA+ (pfimA). RT-PCRs were performed with fimA-specific primers (a), fimH primers (b), or fimF primers (c).