The trimeric autotransporter adhesin BadA is required for in vitro biofilm formation by Bartonella henselae

Abstract

Bartonella henselae (Bh) is a Gram-negative rod transmitted to humans by a scratch from the common house cat. Infection of humans with Bh can result in a range of clinical diseases including lymphadenopathy observed in cat-scratch disease and more serious disease from persistent bacteremia. It is a common cause of blood-culture negative endocarditis as the bacterium is capable of growing as aggregates, and forming biofilms on infected native and prosthetic heart valves. The aggregative growth requires a trimeric autotransporter adhesin (TAA) called Bartonella adhesin A (BadA). TAAs are found in all Bartonella species and many other Gram-negative bacteria. Using Bh Houston-1, Bh Houston-1 ∆badA and Bh Houston-1 ∆badA/pNS2PTrcbadA (a partial complement of badA coding for a truncated protein of 741 amino acid residues), we analyze the role of BadA in adhesion and biofilm formation. We also investigate the role of environmental factors such as temperature on badA expression and biofilm formation. Real-time cell adhesion monitoring and electron microscopy show that Bh Houston-1 adheres and forms biofilm more efficiently than the Bh Houston-1 ∆badA. Deletion of the badA gene significantly decreases adhesion, the first step in biofilm formation in vitro, which is partially restored in Bh Houston-1 ∆badA/pNS2PTrcbadA. The biofilm formed by Bh Houston-1 includes polysaccharides, proteins, and DNA components and is susceptible to enzymatic degradation of these components. Furthermore, both pH and temperature influence both badA expression and biofilm formation. We conclude that BadA is required for optimal adhesion, agglutination and biofilm formation.

Antibacterial Mechanism of Dellaglioa algida against Pseudomonas fluorescens and Pseudomonas fragi

“…Suppression During the Development Stage: In the experiments on the influence of various concentrations, including 0 MIC, 0.5 MIC, 1 MIC, and 2 MIC, of the CFS of D. algida on the capability of generation and growth of biofilm, the crystal violet staining method was utilized, where the approach to assay was inspired by [26][27][28]. Under the pathogen-free condition, stationary bacteria solution of 200 µL was put into a 96-well cell culture plate and cultured at 28 • C, while the TSB medium was utilized as blank control.…”

Coaggregation properties of trimeric autotransporter adhesins

“…Auto‐ or coaggregation is often a step on the developmental pathway leading to biofilm formation (Trunk et al, 2018). TAAs are known to mediate the formation of biofilm (Leo et al, 2011; Mil‐Homens & Fialho, 2012; Okaro, Green, Mohapatra, & Anderson, 2019). We, therefore, tested the ability of our model TAAs to promote biofilm formation when expressed from our dual‐expression constructs.…”

A Trimeric Autotransporter Enhances Biofilm Cohesiveness in Yersinia pseudotuberculosis but Not in Yersinia pestis

“…YPTB2394 is annotated as a predicted lipoprotein with homology to type Vc autotransporter proteins. Trimeric autotransporter adhesins are membrane-anchored proteins known to mediate cell-cell attachments in other Gram-negative bacteria and promote greatly enhanced biofilm production in diverse species [22][23][24]. YPTB2394 is predicted to have a C-terminal YadA-like anchor, and several YadA-like stalk domains.…”