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Antimicrobial effect evaluation in planktonic cells and biofilm of Klebsiella pneumoniae

Grant number: 14/24708-5
Support type:Scholarships in Brazil - Scientific Initiation
Effective date (Start): January 01, 2015
Effective date (End): December 31, 2016
Field of knowledge:Biological Sciences - Microbiology - Applied Microbiology
Principal researcher:André Pitondo da Silva
Grantee:Maria Julia Alves Batista
Home Institution: Faculdade de Ciências Farmacêuticas de Ribeirão Preto (FCFRP). Universidade de São Paulo (USP). Ribeirão Preto , SP, Brazil
Associated research grant:13/22581-5 - Study of pathogenic mechanisms and correlation with antimicrobial resistance of Klebsiella pneumoniae from Brazil and other countries across five continents, AP.JP


Bacteria organized into biofilms may have a different behavior from that observed for the same microorganisms when they are in the free form (planktonic), favoring bacterial colonization and survival in the host organism. This would be one of the reasons why many antimicrobials evaluated in planktonic cells show inefficiency in clinical studies in vivo. Infections caused by these pathogens can generate various clinical complications including urinary tract infections, pneumonia, septicemia and, in many cases, death of patients. This study will evaluate the action of an antimicrobial in biofilms of Klebsiella pneumoniae. After the growth of biofilms, they will be collected and homogenized by sonication. Bacterial viability will be monitored by bacteria counting in agar Müller Hinton. Polysaccharides and extracellular proteins of biofilms will be extracted and quantified. The tests will be documented by confocal and electronic scanning microscopy. The groups will be initially compared and both homogeneity and variability of results will be established. If the distribution of values is normal, the ANOVA test will be applied, followed by post-hoc test for comparison among groups. If the distribution is not normal, a comparison will be made by using the Kruskal-Wallis test. The acceptable level of significance will be 5%. (AU)