RESUMEN
2-Aminoacetophneone (2-AA) is a volatile molecule produced in high amounts by the opportunistic pathogen Pseudomonas aeruginosa. We have previously shown that 2-AA activates the quorum sensing (QS) LuxR receptor of Aliivibrio fischeri. In the present study we were able to improve LuxR's affinity and detection limit for 2-AA by genetic modification of three amino acids within the binding pocket of the receptor. Expression of the modified LuxR receptor in a luminescent bacterial biosensor provided an efficient detection assay of 2-AA in clinical P. aeruginosa strains isolated from blood and lung infections, as well as in phlegm samples obtained from subjects suffering from lung infections.
Asunto(s)
Acetofenonas/sangre , Biomarcadores/sangre , Técnicas Biosensibles/métodos , Sitios de Unión , Humanos , Límite de Detección , Luminiscencia , Enfermedades Pulmonares/microbiología , Simulación del Acoplamiento Molecular , Mutación , Pseudomonas aeruginosa/química , Percepción de Quorum/fisiología , Proteínas Represoras/genética , Proteínas Represoras/metabolismo , Infecciones del Sistema Respiratorio/microbiología , Esputo/microbiología , Transactivadores/genética , Transactivadores/metabolismoRESUMEN
INTRODUCTION: The occurrence of some of the clinical complications of tickborne relapsing fever varies with Borrelia species. For example, adult respiratory distress syndrome (ARDS), a newly reported complication, was described so far only with B. hermsii infection. MATERIALS AND METHODS: A previously healthy young Israeli man was admitted for fever and headache and was diagnosed as aseptic meningitis. Shortly before the lumbar puncture was performed he started to experience shortness of breath and developed acute respiratory insufficiency necessitating mechanical ventilation. Radiography, which was normal on admission, demonstrated bilateral lung infiltrates consistent with ARDS. Spirochetes suggestive of Borrelia were seen on a thick blood smear preparation, and polymerase chain reaction was positive for B. persica. CONCLUSION: This is the first reported case of ARDS in association with Borrelia spp. occurring outside the U.S.A. and the first one due to B. persica infection.