Burkholderia cenocepacia is a virulent species belonging to the Burkholderia cepacia complex (Bcc) and one of the most problematic agents of chronic lung infection in cystic fibrosis patients. B. cenocepacia possesses a large panel of virulence traits that include trimeric autotransporter adhesins (TAAs). Such proteins are obligate homotrimeric anchored in the outer membrane. They are players in the adhesion events that occur between bacteria and biotic/abiotic surfaces. In this study, we constructed two insertional-mutants for TAA bcaC and Histidine kinase (HK) BCAM0218 genes, which are clustered together within the B. cenocepacia K56-2 TAA cluster. The bcaC-mutant affects B. cenocepacia adhesion to extracellular matrix proteins and red blood cells hemagglutination. BcaC contributes to enhancing B. cenocepacia K56-2 adhesion to bronchial epithelial cells. The expression of bcaC seems to affect biofilm formation negatively. Due to a BCAM0218 disruption, the bcaC expression increases significantly, indicating that they are functionally linked. The overexpression of bcaC in the BCAM0218-mutant background rescues at least part of the BcaC functions. Altogether, these findings reveal the multifunctionality of BcaC as a novel B. cenocepacia K56-2 virulence factor and postulate the involvement of a sensor HK (BCAM0218) in the control of this TAA gene.

Burkholderia cenocepacia是属于Burkholderia cepacia复合体（Bcc）的一种有毒物种，是囊性纤维化患者慢性肺部感染最成问题的病原之一。B. cenocepacia具有大量的毒力特性，其中包括三聚体自转运粘附素（TAA）。这样的蛋白质是固定在外膜中的专性同源三聚体。它们是细菌与生物/非生物表面之间发生粘附事件的参与者。在这项研究中，我们构建了两个TAA bcaC和组氨酸激酶（HK）BCAM0218基因的插入突变体，它们在B. cenocepacia K56-2 TAA集群中聚集在一起。该bcaC-突变体会影响洋葱伯克霍尔德菌对细胞外基质蛋白的粘附以及红细胞的血凝反应。BcaC有助于增强嗜酒双歧杆菌K56-2对支气管上皮细胞的粘附。bcaC的表达似乎会对生物膜的形成产生负面影响。由于BCAM0218破坏，bcaC表达显着增加，表明它们在功能上相连。的过表达bcaC在BCAM0218 -mutant背景在救援的BcaC功能至少一部分。总而言之，这些发现揭示了BcaC作为一种新型的洋葱新芽孢杆菌的多功能性。 K56-2毒力因子并假定传感器HK（BCAM0218）参与了该TAA基因的控制。