GC-MS Profile and Enhancement of Antibiotic Activity by the Essential Oil of Ocotea odorífera and Safrole: Inhibition of Staphylococcus aureus Efflux Pumps.

Considering the evidence that essential oils, as well as safrole, could modulate bacterial growth in different resistant strains, this study aims to characterize the phytochemical profile and evaluate the antibacterial and antibiotic-modulating properties of the essential oil Ocotea odorífera (EOOO) and safrole against efflux pump (EP)-carrying strains. The EOOO was extracted by hydrodistillation, and the phytochemical analysis was performed by gas chromatography coupled to mass spectrometry (GC-MS). The antibacterial and antibiotic-modulating activities of the EOOO and safrole against resistant strains of Staphylococcus aureus, Escherichia coli and Pseudomonas aeruginosa were analyzed through the broth microdilution method. The EP-inhibiting potential of safrole in association with ethidium bromide or antibiotics was evaluated using the S. aureus 1199B and K2068 strains, which carry genes encoding efflux proteins associated with antibiotic resistance to norfloxacin and ciprofloxacin, respectively. A reduction in the MIC of ethidium bromide or antibiotics was used as a parameter of EP inhibition. The phytochemical analysis identified 16 different compounds in the EOOO including safrole as the principal constituent. While the EOOO and safrole exerted clinically relevant antibacterial effects against S. aureus only, they potentiated the antibacterial activity of norfloxacin against all strains evaluated by our study. The ethidium bromide and antibiotic assays using the strains of S. aureus SA1119B and K2068, as well as molecular docking analysis, indicated that safrole inhibits the NorA and MepA efflux pumps in S. aureus. In conclusion, Ocotea odorifera and safrole presented promising antibacterial and antibiotic-enhancing properties, which should be explored in the development of drugs to combat antibacterial resistance, especially in strains bearing genes encoding efflux proteins.

Paradoxical Embolism in a Patient with Aortic Valve Endocarditis: A Case Report.

This report describes a case of aortic valve endocarditis with systemic and paradoxical pulmonary embolism in a patient with congenital interventricular communication. The patient underwent cardiac surgery and did not have a favorable outcome, presenting refractory cardiogenic shock and subsequently dying while in the hospital. This is an extremely rare case of paradoxical embolism in a patient with infective endocarditis; only four similar cases have been reported in the literature.

Myocardial Infarction in a Young Cocaine User with Atrial Myxoma: What is the Central Cause?

The differential diagnosis of myocardial infarction in patients with a number of potential causes can be challenging, especially when there is no angiographic evidence of coronary obstruction. We describe a case of extensive anterior ST-elevation myocardial infarction in a young male smoker who had a left atrial myxoma and a history of cocaine use 10 hours before the event. Clinical reasoning during a myocardial infarction investigation should be oriented by the probability of the causal relationship between the ischemic event and each factor present in the clinical context.