Analysis of Bartonella adhesin A expression reveals differences between various B. henselae strains.
Bartonella henselae causes cat scratch disease and the vasculoproliferative disorders bacillary angiomatosis and peliosis hepatis in humans. One of the best known pathogenicity factors of B. henselae is Bartonella adhesin A (BadA), which is modularly constructed, consisting of head, neck/stalk, and membrane anchor domains. BadA is important for the adhesion of B. henselae to extracellular-matrix proteins and endothelial cells (ECs). In this study, we analyzed different B. henselae strains for BadA expression, autoagglutination, fibronectin (Fn) binding, and adhesion to ECs. We found that the B. henselae strains Marseille, ATCC 49882, Freiburg 96BK3 (FR96BK3), FR96BK38, and G-5436 express BadA. Remarkably, BadA expression was lacking in a B. henselae ATCC 49882 variant, in strains ATCC 49793 and Berlin-1, and in the majority of bacteria of strain Berlin-2. Adherence of B. henselae to ECs and Fn reliably correlated with BadA expression. badA was present in all tested strains, although the length of the gene varied significantly due to length variations of the stalk region. Sequencing of the promoter, head, and membrane anchor regions revealed only minor differences that did not correlate with BadA expression, apart from strain Berlin-1, in which a 1-bp deletion led to a frameshift in the head region of BadA. Our data suggest that, apart from the identified genetic modifications (frameshift deletion and recombination), other so-far-unknown regulatory mechanisms influence BadA expression. Because of variations between and within different B. henselae isolates, BadA expression should be analyzed before performing infection experiments with B. henselae.
Riess
Tanja
T
Institut für Medizinische Mikrobiologie und Hygiene, Elfriede-Aulhorn-Str. 6, D-72076 Tübingen, Germany.
Raddatz
Günter
G
Linke
Dirk
D
Schäfer
Andrea
A
Kempf
Volkhard A J
VA
D018829:Adhesins, Bacterial / Q000096:biosynthesis* / Q000235:genetics*; D000371:Agglutination / Q000502:physiology; D000595:Amino Acid Sequence; D001422:Bacterial Adhesion / Q000502:physiology; D018416:Bartonella henselae / Q000235:genetics* / Q000378:metabolism* / Q000472:pathogenicity; D015153:Blotting, Western; D042783:Endothelial Cells / Q000378:metabolism; D005353:Fibronectins / Q000378:metabolism; D005455:Fluorescent Antibody Technique; D015870:Gene Expression; D015964:Gene Expression Regulation, Bacterial; D006801:Humans; D008969:Molecular Sequence Data; D016133:Polymerase Chain Reaction; D011401:Promoter Regions, Genetic
D018829:Adhesins, Bacterial; D005353:Fibronectins