Expression and Characterization of Flagella in Nonmotile Enteroinvasive Escherichia coli Isolated from Diarrhea Cases

Abstract

We report that enteroinvasive Escherichia coli (EIEC) serotypes considered to be nonmotile produce an unusually large (77 kDa) flagellin that is assembled into functional flagellum filaments that allow the bacteria to swim in modified motility agar. The EIEC flagellin showed N-terminal identity to most common enterobacterial flagellins, especially those of the E. coli H7 serotype. These data are important in terms of the epidemiology, evolution, and biology of EIEC.

First evidence of polar flagella in Klebsiella pneumoniae isolated from a patient with neonatal sepsis

“…In the present study, the KpBUAP021 strain demonstrated swimming motility in 0.25 % agar notwithstanding that K. pneumoniae has been reported as a non-motile bacterium. Similar results have been reported for E. coli and Shigella (Andrade et al, 2002;Giron, 1995) were flagellar expression has been linked to specific biological micro-environments or different growing conditions in vitro (Andrade et al, 2002;Giron, 1995;Hughes et al, 1993;Schmitt et al, 1994). In our study, only one of 25 K. pneumoniae isolates showed motility as revealed by TEM analysis and Ryu staining (Figs.…”

“…Several studies have reported that the percentage of agar is an essential stimulus for swimming motility after cell differentiation. Some bacteria can display swimming motility at agar concentrations as low as 0.3 % or less (Andrade et al, 2002;Giron, 1995;Tercero-Alburo et al, 2014). In the present study, the KpBUAP021 strain demonstrated swimming motility in 0.25 % agar notwithstanding that K. pneumoniae has been reported as a non-motile bacterium.…”

“…On the other hand, in enterobacterial flagellins, the middle region presents variability among strains (Andrade et al, 2002;McQuiston et al, 2004;Reid et al, 1999). The detection of the fliC gene encoding flagellin (Doll & Frankel, 1993) and sequencing of the N-and C-terminal portions of the fliC gene in KpBUAP021 showed a similarity >90 % compared to the fliC genes from E. coli and Shigella.…”

“…Several studies have revealed that some non-motile bacteria such as clinical isolates of enteroinvasive Escherichia coli, Brucella melitensis, Shigella and Actinobacillus pleuropneumoniae are indeed motile when grown under specific conditions, and this motility has been shown to be mediated by flagella (Andrade et al, 2002;Fretin et al, 2005;Giron, 1995;Negrete-Abascal et al, 2003).…”

Recognition of enteroinvasive Escherichia coli and Shigella flexneri by dendritic cells: distinct dendritic cell activation states

“…Cell-surface TLR-5 recognises flagellin, a structural protein that forms a major portion of flagellar filaments (Ramos et al 2004). Although EIEC are typically immotile, they have been shown to move in modified motility assays conducted at reduced agar concentrations (Andrade et al 2002). Also in accord with our results, Tominaga et al (1994) demonstrated that the flagellin gene is cryptic in the genus Shigella.…”