RT Journal Article
T1 Relationship Between the Quorum Network (Sensing/Quenching) and Clinical Features of Pneumonia and Bacteraemia Caused by A. baumannii.
A1 Fernandez-Garcia, Laura
A1 Ambroa, Anton
A1 Blasco, Lucia
A1 Bleriot, Ines
A1 Lopez, Maria
A1 Alvarez-Marin, Rocio
A1 Fernandez-Cuenca, Felipe
A1 Martinez-Martinez, Luis
A1 Vila, Jordi
A1 Rodriguez-Baño, Jesus
A1 Garnacho-Montero, Jose
A1 Cisneros, Jose Miguel
A1 Pascual, Alvaro
A1 Pachon, Jeronimo
A1 Bou, German
A1 Smani, Younes
A1 Tomas, Maria
K1 Acinetobacter
K1 Bacteraemia
K1 Pneumonia
K1 Quorum
K1 Sensing/quenching
AB Acinetobacter baumannii (Ab) is one of the most important pathogens associated with nosocomial infections, especially pneumonia. Interest in the Quorum network, i.e., Quorum Sensing (QS)/Quorum Quenching (QQ), in this pathogen has grown in recent years. The Quorum network plays an important role in regulating diverse virulence factors such as surface motility and bacterial competition through the type VI secretion system (T6SS), which is associated with bacterial invasiveness. In the present study, we investigated 30 clinical strains of A. baumannii isolated in the “II Spanish Study of A. baumannii GEIH-REIPI 2000-2010” (Genbank Umbrella Bioproject PRJNA422585), a multicentre study describing the relationship between the Quorum network in A. baumannii and the development of pneumonia and associated bacteraemia. Expression of the aidA gene (encoding the AidA protein, QQ enzyme) was lower (P < 0.001) in strains of A. baumannii isolated from patients with bacteraemic pneumonia than in strains isolated from patients with non-bacteraemic pneumonia. Moreover, aidA expression in the first type of strain was not regulated in the presence of environmental stress factors such as the 3-oxo-C12-HSL molecule (substrate of AidA protein, QQ activation) or H2O2 (inhibitor of AidA protein, QS activation). However, in the A. baumannii strains isolated from patients with non-bacteraemic pneumonia, aidA gene expression was regulated by stressors such as 3-oxo-C12-HSL and H2O2. In an in vivo Galleria mellonella model of A. baumannii infection, the A. baumannii ATCC 17978 strain was associated with higher mortality (100% at 24 h) than the mutant, abaI-deficient, strain (carrying a synthetase enzyme of Acyl homoserine lactone molecules) (70% at 24 h). These data suggest that the QS (abaR and abaI genes)/QQ (aidA gene) network affects the development of secondary bacteraemia in pneumonia patients and also the virulence of A. baumannii.
PB Frontiers Research Foundation
SN 1664-302X
YR 2018
FD 2018-11-30
LK http://hdl.handle.net/10668/13389
UL http://hdl.handle.net/10668/13389
LA en
NO Fernandez-Garcia L, Ambroa A, Blasco L, Bleriot I, López M, Alvarez-Marin R, et al. Relationship Between the Quorum Network (Sensing/Quenching) and Clinical Features of Pneumonia and Bacteraemia Caused by A. baumannii. Front Microbiol. 2018 Dec 17;9:3105
NO This study was funded by grant PI16/01163 awarded to MT within the State Plan for R+D +I 2013-2016 (National Plan for Scientific Research , Technological Development and Innovation 2008-2011) and co-financed by the ISCIII-Deputy General Directorate for Evaluation and Promotion of Research —European Regional Development Fund A way of Making Europe and Instituto de Salud Carlos III FEDER, Spanish Network for the Research in Infectious Diseases (REIPI, RD16/0016/0001, RD16/0016/0006, RD16/0016/0008, RD16/0016/0009, and RD16/0016/0010) and by the Study Group on Mechanisms of Action and Resistance to Antimicrobials, GEMARA (SEIMC, http://www.seimc.org/). MT was financially supported by the Miguel Servet Research Programme (SERGAS and ISCIII). LF-G was financially supported by a predoctoral fellowship from the Xunta de Galicia (GAIN, Axencia de Innovación).
DS RISalud
RD Apr 19, 2025