RESUMO
The study investigated the antimicrobial activity of the essential oil extract of Ocimum gratissimum L. (EOOG) against multiresistant microorganisms in planktonic and biofilm form. Hydrodistillation was used to obtain the EOOG, and the analysis of chemical composition was done by gas chromatography coupled with mass spectrometry (GC/MS) and flame ionization detection (GC/FID). EOOG biological activity was verified against isolates of Staphylococcus aureus and Escherichia coli, using four strains for each species. The antibacterial action of EOOG was determined by disk diffusion, microdilution (MIC/MBC), growth curve under sub-MIC exposure, and the combinatorial activity with ciprofloxacin (CIP) and oxacillin (OXA) were determined by checkerboard assay. The EOOG antibiofilm action was performed against the established biofilm and analyzed by crystal violet, colony-forming unit count, and SEM analyses. EOOG yielded 1.66% w/w, with eugenol as the major component (74.83%). The MIC was 1000 µg/mL for the most tested strains. The growth curve showed a lag phase delay for both species, mainly S. aureus, and reduced the growth level of E. coli by half. The combination of EOOG with OXA and CIP led to an additive action for S. aureus. A significant reduction in biofilm biomass and cell viability was verified for S. aureus and E. coli. In conclusion, EOOG has relevant potential as a natural alternative to treat infections caused by multiresistant strains.
Assuntos
Escherichia coli/efeitos dos fármacos , Ocimum/química , Óleos Voláteis/farmacologia , Staphylococcus aureus/efeitos dos fármacos , Anti-Infecciosos/farmacologia , Biofilmes/efeitos dos fármacos , Ciprofloxacina/farmacologia , Oxacilina/farmacologiaRESUMO
Abstract In this review, we explore some aspects of Pseudomonas aeruginosa virulence factors that are related to disease development in healthy organisms and resistance to antibiotics. This pathogen is one of the most clinically and epidemiologically important bacteria in Brazil, being the major cause of opportunistic infections. Among the virulence factors, biofilm formation acting of manner different in the organism. Furthermore, we review several P. aeruginosa genes that act in antimicrobial resistance, such as β-lactamases against β-lactamers. The resistance to pied-lactamases in P. aeruginosa is associated to resistance to the broad-spectrum cephalosporin. On the other hand, there is a group of synthetic broad-spectrum antibiotics acting on DNA synthesis is the quinolones that destroy the microorganism. We also explore the occurence of super bacterium: P. aerufinosa carrying genes blaKPC and blaNDM, which are associated with patient death above the average of other bacterial infections in hospitals. Those genes encode carbapenemases that can potentially hydrolyse all β-lactam antibiotics