The adherence of bladder uroepithelial cells, subsequent expression, and regulation of type 1 fimbrial genes (key mediator of attachment) in clinical multidrug-resistant uropathogenic Escherichia coli (MDR-UPECs) isolated from individuals with asymptomatic bacteriuria (ABU) remain unexplored till date. Therefore, this study aimed to investigate the underlying molecular mechanisms associated with the adherence of clinical MDR-ABU-UPECs to human a uroepithelial cell line (HTB-4), both in the absence and presence of D-Mannose. These investigations focused on phase variation, expression, and regulation of type 1 fimbriae and were compared to a prototype ABU-strain (E. coli 83972) and symptomatic MDR-UPECs. Discordant to the ABU prototype strain, MDR-ABU-UPECs exhibited remarkable adhesive capacity that was significantly reduced after D-mannose exposure, fairly like the MDR symptomatic UPECs. The type 1 fimbrial phase variation, determined by the fim switch analysis, asserted the statistically significant incidence of "both OFF and ON" orientation among the adherent MDR-ABU-UPECs with a significant reduction in phase-ON colonies post-D-mannose exposure, akin to the symptomatic ones. This was indicative of an operative and alternating type 1 fimbrial phase switch. The q-PCR assay revealed a coordinated action of the regulatory factors; H-NS, IHF, and Lrp on the expression of FimB and FimE recombinases, which further controlled the function of fimH and fimA genes in ABU-UPECs, similar to symptomatic strains. Therefore, this study is the first of its kind to provide an insight into the regulatory crosstalk of different cellular factors guiding the adhesion of ABU-UPECs to the host. Additionally, it also advocated for the need to accurately characterize ABU-UPECs.

• Klíčová slova
• Adhesive capacity, Asymptomatic uropathogenic Escherichia coli, FimBE recombinases, Symptomatic uropathogenic Escherichia coli, Type 1 fimbriae-regulating factors, Type 1 fimbrial phase variation,
• MeSH
• adheziny Escherichia coli genetika   metabolismus   MeSH
• bakteriální adheze * MeSH
• bakteriální fimbrie * genetika   metabolismus   MeSH
• bakteriurie mikrobiologie   MeSH
• buněčné linie MeSH
• epitelové buňky * mikrobiologie   MeSH
• infekce vyvolané Escherichia coli * mikrobiologie   MeSH
• lidé MeSH
• mannosa metabolismus   farmakologie   MeSH
• mnohočetná bakteriální léková rezistence * genetika   MeSH
• proteiny fimbrií * genetika   metabolismus   MeSH
• proteiny z Escherichia coli genetika   metabolismus   MeSH
• regulace genové exprese u bakterií MeSH
• uropatogenní Escherichia coli * genetika   účinky léků   izolace a purifikace   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• adheziny Escherichia coli MeSH
• mannosa MeSH
• proteiny fimbrií * MeSH
• proteiny z Escherichia coli MeSH