In vitro antimicrobial efficacy of a fixed-dose combination of RHZE against M. tuberculosis

The use of drugs in fixed-dose combination (FDC) is now recommended by the World Health Organization (WHO) due to the emergence of multidrug-resistant strains of Mycobacterium tuberculosis. FDC uses different drugs against tuberculosis (TB) in a single tablet for phase-intensive therapeutic intervention. This therapy aims to optimize treatment, to prevent inappropriate use of drugs, and to prevent the emergence of new resistant strains. This study aims to evaluate the susceptibility of clinical isolates of M. tuberculosis against rifampicin, isoniazid, ethambutol, and pyrazinamide. The antimicrobials were tested separately and in associations according to FDC. This was used for broth microdilution method, which was compared to the proportions method previously considered as the gold standard. In antimicrobials testing alone, several strains were resistant to one, two, or three drugs. However, when applied to association of drugs in FDC, there was no antimicrobial resistance. The results strengthen the FDC's concept, which aims to unite the four anti-TB drugs to combat bacterial resistance

ANTIMYCOBACTERIAL, ANTIMICROBIAL AND ANTIFUNGAL ACTIVITIES OF GERANIUM OIL-LOADED NANO CAPSULES

Objective: The aim of this study was to perform the first ever investigation of the effect of activities in the nano capsules containing Geranium oil (NC1) against different species of pathogens such as Mycobacterium genus (both fast growing and slow growing), bacterial, and yeasts.Methods: The GO was analyzed by GC and GC/MS. Nano capsule suspensions (NC) were prepared by interfacial deposition of a preformed polymer method and the MICs were determined for the antimycobacterial, antimicrobial, and antifungal activities.Results: GO-loaded nano capsules (NC1) presented nano metric mean diameters (188 nm), polydispersity indices below 0.149, pH (5.5), and zeta potentials (about-10.8 mV). The MICs were determined for the antimycobacterial, antimicrobial, and antifungal activities. The NC1 was effective to Mycobacterium smegmatis (149.7 µg ml-1), M. abscessos (35.9 µg ml-1), M. massiliense (35.9 µg ml-1), M. avium (71.8 µg ml-1), Enterococcus faecalis, Streptococcus sp. (149.7 µg ml-1) and Listeria monocytogenes (35.9 µg ml-1). The NC1 was able to significantly reduce the number of cells of C. albicans (by approximately 5 log), 4 log the number of cells of C. dublinensis, C. glabrata, and C. krusei, and 2 log the number of cells of C. parapsilosis compared to the control group.Conclusion: Our study showed that the geranium oil-loaded nano capsules have antimycobacterial activities similar to free oil. The GO was effective in inhibiting the formation of germ tubes of Candida albicans, yet the nano capsule containing GO failed to inhibit the formation of this important virulence factor.Â

In vitro antimicrobial efficacy of a fixed-dose combination of RHZE against M. tuberculosis

ABSTRACT The use of drugs in fixed-dose combination (FDC) is now recommended by the World Health Organization (WHO) due to the emergence of multidrug-resistant strains of Mycobacterium tuberculosis. FDC uses different drugs against tuberculosis (TB) in a single tablet for phase-intensive therapeutic intervention. This therapy aims to optimize treatment, to prevent inappropriate use of drugs, and to prevent the emergence of new resistant strains. This study aims to evaluate the susceptibility of clinical isolates of M. tuberculosis against rifampicin, isoniazid, ethambutol, and pyrazinamide. The antimicrobials were tested separately and in associations according to FDC. This was used for broth microdilution method, which was compared to the proportions method previously considered as the gold standard. In antimicrobials testing alone, several strains were resistant to one, two, or three drugs. However, when applied to association of drugs in FDC, there was no antimicrobial resistance. The results strengthen the FDC's concept, which aims to unite the four anti-TB drugs to combat bacterial resistance

Detection and analysis of different interactions between resistance mechanisms and carbapenems in clinical isolates of Klebsiella pneumoniae

Carbapenems are considered last-line agents for the treatment of serious infections caused by Klebsiella pneumoniae, and this microorganism may exhibit resistance to beta-lactam antibiotics due to different mechanisms of resistance. We evaluated 27 isolates of K. pneumoniae resistant to carbapenems recovered from inpatients at the University Hospital of Santa Maria-RS from July 2013 to August 2014. We carried out antimicrobial susceptibility, carbapenemase detection, testing for the presence of efflux pump by broth microdilution and loss of porin by sodium dodecyl sulfate polyacrylamide gel electrophoresis. Genetic similarity was evaluated by ERIC-PCR. High levels of resistance were verified by the minimum inhibitory concentration for the antimicrobials tested. The blaKPC gene was present in 89% of the clinical isolates. Blue-Carba and combined disk with AFB tests showed 100% concordance, while the combined disk test with EDTA showed a high number of false-positives (48%) compared with the gold-standard genotypic test. Four isolates showed a phenotypic resistance profile consistent with the overexpression of the efflux pump, and all clinical isolates had lost one or both porins. The ERIC-PCR dendrogram demonstrated the presence of nine clusters. The main mechanism of resistance to carbapenems found in the assessed isolates was the presence of the blaKPC gene. (C) 2017 Sociedade Brasileira de Microbiologia. Published by Elsevier Editora Ltda.AstraZenecaMSDNovartisUniv Fed Santa Maria, Lab Micobacteriol, Santa Maria, RS, BrazilUniv Fed Sao Paulo UNIFESP, Lab ALERTA, Sao Paulo, SP, BrazilUniv Fed Sao Paulo UNIFESP, Lab ALERTA, Sao Paulo, SP, BrazilAstraZenecaMSDNovartisWeb of Scienc