Article
Resveratrol Susceptibility of Streptococcus pneumoniae and Neisseria meningitidis Strains Isolated in the State of Minas Gerais, Brazil, from 2007 to 2013
Registro en:
CAMARGO, Dhian Renato Almeida et al. Resveratrol Susceptibility of Streptococcus pneumoniae and Neisseria meningitidis Strains Isolated in the State of Minas Gerais, Brazil, from 2007 to 2013. J Meningitis, v. 1, n. 1, 1000101, 2015. DOI: 10.4172/2572-2050.1000101
2572-2050
10.4172/2572-2050.1000101
Autor
Camargo, Dhian Renato Almeida
Sales Junior, Policarpo Ademar
Oliveira, Marluce Aparecida Assunção
Coimbra, Roney Santos
Resumen
Objective: Evaluation of the in vitro susceptibility to Resveratrol of a bacterial collection representing the S. pneumoniae and N. meningitidis strains prevalent in the Brazilian state of Minas Gerais from 2007 to 2013.
Methods: One reference strain of S. pneumoniae (ATCC 49619), and sixty-three strains (31 S. pneumoniae, and 32 N. meningitidis) isolated from patients with meningitis and available at the certified strains collection of Ezequiel Dias Foundation were tested. The susceptibility to Resveratrol was tested on blood agar containing this drug at eight concentrations ranging from 25 mg/L to 200 mg/L diluted in 0.5% ethanol, and control plates with blood agar with 0.5% ethanol. Pneumococci were also tested for susceptibility to currently available antimicrobials used to treat meningitis using E-test and disc diffusion methods. The association between pneumococcal susceptibility to Resveratrol and to any other antibiotic tested was assessed with chi-square test, and the toxic doses of Resveratrol were determined upon L929 mammalian cells.
Results: The MIC100 for Resveratrol was 75 mg/L for meningococci (range: 50-75 mg/L), and 200 mg/L for pneumococci (range: 125-200 mg/L). There was no association between pneumococcal susceptibility to Resveratrol and to any currently available antimicrobials tested suggesting different modes of action. However, low selectivity indices (SI) calculated as the ratio between the IC100 in L929 cells and the MIC values were found for meningococci (0.332) and pneumococci (0.125).
Conclusion: Resveratrol inhibited the growth of all N. meningitidis and S. pneumoniae strains causing meningitis in the state of Minas Gerais, Brazil, from 2007 to 2013. Our results, despite the low selectivity indices observed, may warrant further studies to assess the potential of Resveratrol derivates as antimicrobial alternatives to treat meningococcal and pneumococcal infections.