Effect of the Association and Evaluation of the Induction to Adaptation of the (+)-α-pinene with Commercial Antimicrobials against Strains of Escherichia coli.

BACKGROUND: The increasing and inappropriate use of antibiotics has increased the number of multidrug-resistant microorganisms to these drugs, causing the emergence of infections that are difficult to control and manage by health professionals. As an alternative to combat these pathogens, some monoterpenes have harmful effects on the bacterial cell membrane, showing themselves as an alternative in combating microorganisms. Therefore, the positive enantiomer α -pinene becomes an alternative to fight bacteria, since it was able to inhibit the growth of the species Escherichia coli ATCC 25922, demonstrating the possibility of its use as an isolated antimicrobial or associated with other drugs. AIMS: The aim of this study is to evaluate the sensitivity profile of E. coli ATCC 25922 strain against clinical antimicrobials associated with (+) -α-pinene and how it behaves after successive exposures to subinhibitory concentrations of the phytochemicals. METHODS: The minimum inhibitory concentration (MIC) was determined using the microdilution method. The study of the modulating effect of (+) -α-pinene on the activity of antibiotics for clinical use in strains of E. coli and the analysis of the strain's adaptation to the monoterpene were tested using the adapted disk-diffusion method. RESULTS: The results demonstrate that the association of monoterpene with the antimicrobials ceftazidime, amoxicillin, cefepime, cefoxitin and amikacin is positive since it leads to the potentiation of the antibiotic effect of these compounds. It was observed that the monoterpene was able to induce crossresistance only for antimicrobials: cefuroxime, ceftazidime, cefepime and chloramphenicol. CONCLUSION: It is necessary to obtain more concrete data for the safe use of these combinations, paying attention to the existence of some type of existing toxicity reaction related to the herbal medicine and to understand the resistance mechanisms acquired by the microorganism.

Dried plasma spots for therapeutic monitoring of amikacin: Validation of an UHPLC-MS/MS assay and pharmacokinetic application.

Amikacin (AMI) is an aminoglycoside antibiotic widely used in the treatment of severe infections caused by multi-resistant bacteria, with established exposition targets in therapeutic drug monitoring (TDM). The usual specimen for AMI concentration measurement is plasma or serum. The access to TDM of AMI in Developing Countries is constrained by the limited availability of laboratories performing the quantitation of this drug. In this context, the use of dried microsamples, such as dried plasma spots (DPS) could be an alternative to allow reduced specimen transportation and storage costs in resource-limited settings, increasing the access to TDM of AMI. This study aimed to develop and validate the first report of simultaneous determination of AMI and creatinine (CRE) in DPS, using UHPLC-MS/MS. Precision, accuracy and stability assays showed acceptable results. AMI was stable in DPS for 14 days at 6 °C, 2 days at 22 °C, and one day at 42 °C. CRE was stable during 14 days at all tested temperatures. AMI and CRE concentrations in DPS and plasma were compared by Passing-Bablok regression and Bland and Altmann plots and presented comparable results. Estimates of patient's clearance, volume of distribution and suggested doses of AMI were also similar using DPS or plasma concentrations. The assay provides a useful logistic alternative to allow more widespread access to dose individualization of AMI in limited resources settings.