Bacterial motility

Bacterial motility is a sophisticated physiological process that enables microorganisms to navigate their environments in response to chemical, physical, or nutritional stimuli. This movement is primarily achieved through complex molecular machinery, such as the flagellar apparatus, which functions as a rotary motor, or type IV pili, which facilitate 'twitching' motility through a grappling-hook extension and retraction mechanism [7, 10]. In the context of human health, motility is a critical virulence factor for many pathogens, including Pseudomonas aeruginosa, Helicobacter pylori, and Vibrio cholerae, as it is required for host colonization, penetration of protective mucus barriers, and the initiation of biofilm formation [1, 14]. As a therapeutic target, inhibiting motility—often referred to as an 'anti-virulence' strategy—aims to paralyze pathogens or disorient their movement to prevent the establishment or spread of infection [1, 10]. This approach is particularly attractive because it targets pathogenicity without necessarily killing the bacteria, theoretically exerting less selective pressure for the development of antimicrobial resistance compared to traditional bactericidal agents [1, 16]. Current research focuses on small molecules that block ion-driven motor stators, disrupt the structural integrity of the flagellar hook, or interfere with the chemotaxis signaling networks that guide directed movement [3, 4, 13].

Other names

Bacterial movementBacterial locomotionFlagellar motilityTwitching motilitySwarming motilityGliding motilityChemotaxisBacterial flagellar motor (BFM)Taxis

Inhibitors of bacterial motility act through several distinct mechanisms: (1) blocking the translocation of ions (H+ or Na+) through the flagellar motor stator complexes, such as MotA/MotB or PomA/PomB, which stops rotation; (2) disrupting the structural assembly of the flagellar hook or filament by inhibiting protein cross-linking (e.g., lysinoalanine bonds) or glycosylation pathways (e.g., pseudaminic acid synthesis); (3) interfering with chemotaxis signaling networks, such as allosteric inhibition of sensor kinases like QseC; and (4) downregulating the expression of genes involved in the biogenesis of motility appendages through anti-virulence or repurposed drug effects [1, 3, 4, 14, 16].