Salmonella Fimbriae: What is the Clue to Their Hairdo?

Abstract

Fimbriae are important virulence factors for Salmonella pathogenesis. They mediate adhesion to host cells (including plants), food, stainless steel and much more. The fimbrial systems are organised in gene clusters of four to fifteen genes that code for structural, assembly and regulatory proteins. There are three kinds of fimbriae depending on their mode of assembly. The chaperone/usher (CU) fimbriae use a dedicated chaperone and usher protein to coordinate the subunit biogenesis on the cell surface. The curli fimbriae are assembled by nucleation/precipitation pathway. The type IV fimbria assembly requires a transmembrane apparatus and ATP to energise the reaction. Several fimbriae are conserved among Salmonella serovars, while some are present in a limited set or only specific serovars. Expression and regulation of fimbrial genes are not well understood, and most Salmonella fimbriae are poorly expressed during in vitro culture, which further complicates research concerning their regulation and role during infection. However, Salmonella fim gene cluster, coding for type-1 fimbriae, was widely studied and presents its own set of regulators. Investigating fimbrial distribution, expression and regulation will further elucidate their roles in bacterial pathogenesis and host specificity. Furthermore, fimbriae are important for developing efficient diagnostic tests and antimicrobial strategies against Salmonella.

Functional Analysis of the Chaperone-Usher Fimbrial Gene Clusters of Salmonella enterica serovar Typhi

“…Std and Stc fimbriae are widely distributed in Salmonella enterica ssp. I, forming the core fimbriae with Csg (curli fimbriae), Fim, Sth, Bcf, and Stb (Dufresne, 2017 ). Interestingly, S .…”

A review of Salmonella enterica with particular focus on the pathogenicity and virulence factors, host specificity and antimicrobial resistance including multidrug resistance

“…Fimbriae play an important role in the pathogenesis of Salmonella , and recently it has been shown to represent a source of diversity among Salmonella serovars [102,103]. Fimbriae represent the most common adhesion systems, which are differentially expressed and are found in specific patterns among each serovar [104,105].…”

“…Fimbriae represent the most common adhesion systems, which are differentially expressed and are found in specific patterns among each serovar [104,105]. They mediate adhesion of Salmonella to hosts’ cells, food, stainless steel, etc., and have been implicated in a variety of other roles namely biofilm formation, seroconversion, hemagglutination, cellular invasion, and macrophage interactions [73,102,106-110]. The fimbrial systems are normally organized in gene clusters of 4 to 15 genes encoding for structural, assembly and regulatory proteins.…”

“…The fimbrial systems are normally organized in gene clusters of 4 to 15 genes encoding for structural, assembly and regulatory proteins. With the exception of few fimbriae that are only present in specific serovars, several fimbriae are conserved among Salmonella serovars [102]. Until today, the expression, regulation, and roles played by fimbrial genes during the pathogenesis of Salmonella infections are poorly understood partly because most Salmonella fimbriae are poorly expressed during in vitro culture, which further complicates research concerning their regulations and roles [102].…”

Detection of virulence genes and plasmid replicons in Salmonella enterica subsp. enterica, which were allocated during 2014–2017 on the territory of Ukraine

“…Необхідним елементом для здійснення адгезії є фімбрії. Адгезивний апарат організовано у вигляді кластерів по 4-15 генів, в складі кожного є гени регуляторних білків та структурні (Dufresne and France, 2017). Деякі типи фімбрій є консервативними для окремих сероварів.…”