Quorum sensing network in clinical strains of A. baumannii: AidA is a new quorum quenching enzyme
Por:
Lopez, M, Mayer, C, Fernandez-Garcia, L, Blasco, L, Muras, A, Ruiz, FM, Bou, G, Otero, A, Tomas, M, Gurgui M., Pericás R., Pomar V., Cristóbal del Rosario, Q.
Publicada:
22 mar 2017
Resumen:
Acinetobacter baumannii is an important pathogen that causes nosocomial infections generally associated with high mortality and morbidity in Intensive Care Units (ICUs). Currently, little is known about the Quorum Sensing (QS)/Quorum Quenching (QQ) systems of this pathogen. We analyzed these mechanisms in seven clinical isolates of A. baumannii. Micro array analysis of one of these clinical isolates, Ab1 (A. baumanniiST-2_clon_2010), previously cultured in the presence of 3-oxo-C12-HSL (a QS signalling molecule) revealed a putative QQ enzyme (a/beta hydrolase gene, AidA). This QQ enzyme was present in all non motile clinical isolates (67% of which were isolated from the respiratory tract) cultured in nutrient depleted LB medium. Interestingly, this gene was not located in the genome of the only motile clinical strain growing in this medium (A. baumannii strain Ab421_GEIH-2010 [Ab7], isolated from a blood sample). The AidA protein expressed in E. coli showed QQ activity. Finally, we observed downregulation of the AidA protein (QQ system attenuation) in the presence of H2O2 (ROS stress). In conclusion, most of the A. baumanni clinical strains were not surface motile (84%) and were of respiratory origin (67%). Only the pilT gene was involved in surface motility and related to the QS system. Finally, a new QQ enzyme (a/beta hydrolase gene, AidA protein) was detected in these strains.
Filiaciones:
Lopez, M:
Complejo Hosp Univ A Coruna, INIBIC, Dept Microbiol, La Coruna, Spain
Spanish Network Res Infect Dis REIPI, Seville, Spain
Mayer, C:
Univ Santiago de Compostela, Fac Biol CIBUS, Dept Microbiol, Santiago De Compostela, Spain
Fernandez-Garcia, L:
Complejo Hosp Univ A Coruna, INIBIC, Dept Microbiol, La Coruna, Spain
Blasco, L:
Complejo Hosp Univ A Coruna, INIBIC, Dept Microbiol, La Coruna, Spain
Muras, A:
Univ Santiago de Compostela, Fac Biol CIBUS, Dept Microbiol, Santiago De Compostela, Spain
Ruiz, FM:
CSIC, CIB, Biol Res Ctr, Madrid, Spain
Bou, G:
Complejo Hosp Univ A Coruna, INIBIC, Dept Microbiol, La Coruna, Spain
Spanish Network Res Infect Dis REIPI, Seville, Spain
Otero, A:
Univ Santiago de Compostela, Fac Biol CIBUS, Dept Microbiol, Santiago De Compostela, Spain
Tomas, M:
Complejo Hosp Univ A Coruna, INIBIC, Dept Microbiol, La Coruna, Spain
Spanish Network Res Infect Dis REIPI, Seville, Spain
Gurgui M.:
Hospital Sant Pau, Spain
Pericás R.:
Hospital Sant Pau, Spain
Pomar V.:
Hospital Sant Pau, Spain
Cristóbal del Rosario, Q. :
Complejo Hospitalario Materno Insular de Gran Canaria, Spain
Gold, Green Published
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