Role of type IV pilin biosynthesis genes in biofilm formation of Aeromonas hydrophila

Abstract

Aeromonads resides in aquatic environments and infect humans and fish among other animals. This opportunistic pathogen is predicted to have several pili and fimbriae genes which may promote biofilm formation and attachment affecting the infection process. The present study compares biofilm formation and subsequent infection on MDCK cell lines using wildtype Aeromonas hydrophila and putative type IV pilin biosynthesis gene mutant generated by standard protocol. The results indicate the involvement of putative pilus biosynthesis operon AHA0686-AHA0696 in biofilm formation of Aeromonas hydrophila and infection of MDCK cells. In silico analysis of the operon predicts to contain putative type IV pili and pilin biosynthetic genes. Detailed analysis of these genes is required to evaluate the applicability of these mutant strains as potential vaccine candidates.

Antimicrobial resistance in aeromonads and new therapies targeting quorum sensing

“…Provides protection against immune defenses such as serum-mediated killing and macrophage cytotoxicity Mendoza-Barberá et al ( 2021 ); Paquet et al ( 2019 ) Capsule Outer layer of polysaccharides Aids in host colonization and invasion; prevents phagocytosis by host macrophages Heiss et al ( 2019 ); Mendoza-Barberá et al ( 2021 ) Fimbriae/Pilli Filamentous structures on the bacterial surface that aid in adhesion. Have been implicated in other functions, such as phage binding, DNA transfer, biofilm formation, cell aggregation, host cell invasion, and twitching motility Garg et al ( 2023 ) Non-filamentous Adhesins Outer membrane proteins/porins Promote binding of the bacteria to carbohydrate-rich surfaces like erythrocytes and intestinal human cells Ebanks et al ( 2005 ) Secretion systems/effectors T3SS Structural components that result in effector secretion A complex bacterial machine that transports small proteins directly from the bacterial cytoplasm across the inner and outer bacterial membrane to the extracellular environment or directly into the target host cell Pillai ( 2006 ) aexT/aexU T3SS effector protein A T3SS effector, homologous to the P . aeruginosa effectors ExoT/ExoS, with ADP-ribosyltransferase and GTPase activities Braun et al ( 2002 ); Burr et al ( 2003 ); Sha et al ( 2007 ) aopP and other T3SS effector proteins T3SS effector protein Interferes with host cell signaling and in other ways modifies/regulates pathogenicity Matys et al ( 2020 ); Rangel et al ( 2019 ); Zhang et al ( 2022a ) T6SS Structural Components that result in effector secretion A bacterial machine that constitute...…”