title: Rifaximin-induced alteration of virulence of diarrhoea-producing Escherichia coli and Shigella sonnei.
abstract: Rifaximin shortens the duration of travellers' diarrhoea without important alteration of colonic flora. This study investigated the expression of virulence factors [heat-stable (ST) and heat-labile (LT) enterotoxins, surface adhesion factors (CS2/CS3, CS6) and matrix metalloproteinase-9 (MMP-9)] as well as the interleukin (IL)-8 induction potential of diarrhoeagenic Escherichia coli and Shigella sonnei strains exposed to rifaximin (8, 32 and 64mg/L) for 4, 8, 18 and 24h. Following exposure to rifaximin, enterotoxigenic E. coli (ETEC) isolates did not express ST/LT, CS2/CS3 or CS6, whereas enteroaggregative E. coli (EAEC) and S. sonnei isolates did not produce detectable amounts of MMP-9. Moreover, induction of IL-8 was undetectable. At subinhibitory concentrations, rifaximin alters the virulence of ETEC, EAEC and S. sonnei isolates. These findings help explain the efficacy of rifaximin despite minimal alteration of colonic flora.
authors.affiliation: Center for Infectious Diseases, The University of Texas School of Public Health, 1200 Herman Pressler, Room 706, Houston, TX 77030, USA. zhi-dong.jiang@uth.tmc.edu
authors.forename: Zhi-Dong
authors.initials: ZD
authors.lastname: Jiang
authors.forename: Shi
authors.initials: S
authors.lastname: Ke
authors.forename: Herbert L
authors.initials: HL
authors.lastname: Dupont
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology; D001426:Bacterial Proteins / Q000096:biosynthesis; D045744:Cell Line, Tumor; D054324:Enterohemorrhagic Escherichia coli / Q000187:drug effects* / Q000472:pathogenicity*; D004847:Epithelial Cells / Q000276:immunology / Q000382:microbiology; D004926:Escherichia coli / Q000187:drug effects* / Q000472:pathogenicity*; D020869:Gene Expression Profiling; D006801:Humans; D016209:Interleukin-8 / Q000378:metabolism; D012294:Rifamycins / Q000494:pharmacology*; D000078262:Rifaximin; D012764:Shigella sonnei / Q000187:drug effects* / Q000472:pathogenicity*; D014774:Virulence / Q000187:drug effects; D037521:Virulence Factors / Q000096:biosynthesis
chemical_list: D000900:Anti-Bacterial Agents; D001426:Bacterial Proteins; D016209:Interleukin-8; D012294:Rifamycins; D037521:Virulence Factors; D000078262:Rifaximin