Antimicrobial and antibiofilm action of the alternative Melaleuca extract on multiresistant clinical strains of Pseudomonas aeruginosa

• Grant number: 20/05475-0
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: October 01, 2020
• End date: September 30, 2021
• Field of knowledge: Biological Sciences - Microbiology - Applied Microbiology
• Principal Investigator: Luciane Dias de Oliveira
• Grantee: Allanis Mota da Silva
• Host Institution: Instituto de Ciência e Tecnologia (ICT). Universidade Estadual Paulista (UNESP). Campus de São José dos Campos. São José dos Campos , SP, Brazil

Abstract

Herbal medicine has received notoriety due to the various medicinal properties of its compounds. Relating this aspect to the high rate of antimicrobial resistant strains of conventional microorganisms, natural extracts become an alternative in the search for a new antimicrobial compound. The objective of this work will be to evaluate the antimicrobial and antibiofilm action of Melaleuca alternifolia extract on three multidrug resistant Pseudomonas aeruginosa strains. Antimicrobial activity on planktonic cultures will be verified by broth microdilution according to CLSI. For this, serial dilutions of the extracts will be made in 96-well plates, in which the 106 cells / mL standardized microorganism suspension will be added. After 24h of incubation, the turbidity of the wells will be verified, evaluating the presence of the MIC (Minimum Inhibitory Concentration). From the MIC, aliquots of the wells will be sown to determine the MMC (Minimum Microbicide Concentration). Monotypic biofilm tests will be performed with 107 cells / mL standardized suspensions distributed in in 96-well plates with BHI broth. After biofilm formation, the extract will be applied at the concentrations predetermined by the MMC. As controls will be used chlorhexidine solution and BHI broth. All treatments will be applied for 5 min and 24h in independent experiments. Measurement of the biofilms viability after treatments will be performed by MTT test. The statistical analysis will be performed with a 5% significance level (p <0.05%), and data with both normal distribution and homogeneity will be analyzed by the ANOVA method complemented by the Tukey test and data that do not pass both tests will be evaluated by Kruskall Wallis and Dunn's test.