ABSTRACT
Background & objectives: Pseudomonas aeruginosa is an opportunistic pathogen that can cause nosocomial bloodstream infections in humans. This study was aimed to explore the association of furanone C-30 with biofilm formation, quorum sensing (QS) system and antibiotic resistance in P. aeruginosa. Methods: An in vitro model of P. aeruginosa bacterial biofilm was established using the standard P. aeruginosa strain (PAO-1). After treatment with 2.5 and 5 ?g/ml of furanone C-30, the change of biofilm morphology of PAO-1 was observed, and the expression levels of QS-regulated virulence genes (lasB, rhlA and phzA2), QS receptor genes (lasR, rhlR and pqsR) as well as QS signal molecule synthase genes (lasI, rhlI, pqsE and pqsH) were determined. Besides, the AmpC expression was quantified in planktonic and mature biofilm induced by antibiotics. Results: Furanone C-30 treatment significantly inhibited biofilm formation in a dose-dependent manner. With the increase of furanone C-30 concentration, the expression levels of lasB, rhlA, phzA2, pqsR, lasI, rhlI pqsE and pqsH significantly decreased in mature biofilm bacteria while the expression levels of lasR and rhlR markedly increased. The AmpC expression was significantly decreased in both planktonic and biofilm bacteria induced by imipenem and ceftazidime. Interpretation & conclusions: Furanone C-30 may inhibit biofilm formation and antibiotic resistance in P. aeruginosa through regulating QS genes. The inhibitory effect of furanone C-30 on las system appeared to be stronger than that on rhl system. Further studies need to be done with different strains of P. aeruginosa to confirm our findings.
ABSTRACT
BACKGROUND: Delayed presentation of carotid artery pseudoaneurysm following many years after self-inflicted penetrating injury of the neck is extremely rare. Open surgical carotid repair may involve sternotomy for proximal vascular control. Endovascular treatment is evolving as a less-invasive treatment option. METHODS: We report a 55-year-old man with a history of paranoid schizophrenia who presented with a progressively enlarging left sided neck mass many years after attempted suicide. CT scan confirmed a 6 cm pseudoaneurysm arising from the common carotid artery. RESULTS: Through an open retrograde puncture of the distal common carotid artery, the common carotid pseudoaneurysm was successfully repaired with a BARD fluency carotid stentgraft of 8 mm×80 mm (BARD, Tempe, AZ). The patient recovered well with no neurological deficits and was discharged on postoperative day 4. Dual antiplatelet agents of aspirin and clopidogrel were given for six months and then clopidogrel was administered lifelong. The neck mass decreased in size gradually and became non pulsatile upon follow-up. CONCLUSION: Endovascular stenting of giant carotid pseudoaneurysm is an acceptable less invasive treatment option for giant carotid pseudoaneurysm. Long-term follow-up and a greater number of cases are mandatory to establish the safety of this strategy.