Estudo comparativo de técnicas de screening para avaliação da atividade anti-bacteriana de extratos brutos de espécies vegetais e de substâncias puras

In this work, the effectiveness of four screening techniques (three techniques of the diffusion method and one microdilution broth method) were compared. Evaluated were the ethanolic and dichloromethanic extracts of Miconia rubiginosa (Melastomataceae) against six standard bacteria (ATCC). The results showed statistical disagreement among the three diffusion techniques. Among the diffusion techniques, the well technique displayed the best result. However the microdilution broth method demonstrated to be the most adequate method to evaluate the antibacterial activity of plant crude extracts and pure compounds when compared to the other methodologies

Insertion sequences disrupting mgrB in carbapenem-resistant Klebsiella pneumoniae strains in Brazil

Objectives: This study aimed to characterise insertional mutations disturbing themgrB gene in carbapenem-resistant Klebsiella pneumoniae (CRKp). Methods: A total of 118 clinical CRKp isolates were surveyed for polymyxin resistance and insertion sequence (IS) elements disruptingmgrB. Results: Of the 118 isolates, 78 (66.1%) displayed polymyxin resistance, of which 54% (42/78) hadmgrB::IS inserts. Sequencing analyses showed 13 insertion sites in mgrB. mgrB::ISSen4(IS3) was observed for the first time in CRKp. Conclusions: Ten different IS elements disruptedmgrB, with a predominance (76%) of IS5 sequences