title: Interferometry as a tool for evaluating effects of antimicrobial doses on Mycobacterium bovis growth.
abstract: Interferometry was used together with the conventional microplate resazurin assay to evaluate the antimycobacterial properties of essential oil (EO) from fruits of Pterodon emarginatus and also of rifampicin against Mycobacterium bovis. The aim of this work is not only to investigate the potential antimycobacterial activity of this EO, but also to test the interferometric method in comparison with the conventional one. The Minimum Inhibitory Concentration (MIC) values of EO (625 μg/mL) and rifampicin (4 ng/mL) were firstly identified with the microplate method. These values were used as parameters in Drug Susceptibility Tests (DST) with interferometry. The interferometry confirmed the MIC value of EO identified with microplate and revealed a bacteriostatic behavior for this concentration. At 2500 μg/mL interferometry revealed bactericidal activity of the EO. Mycobacterial growth was detected with interferometry at 4 ng/mL of rifampicin and even at higher concentrations. One important difference is that the interferometric method preserves the sample, so that after weeks of quantitative observation, the sample can be used to evaluate the bactericidal activity of the tested drug.
authors.affiliation: Programa de Pós Graduação em Biotecnologia Vegetal, Centro de Ciências da Saúde, Bloco K-30, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, 21941-902, Brazil; Hospital e Maternidade Therezinha de Jesus, Faculdade de Ciências Médicas e da Saúde de Juiz de Fora, Juiz de Fora, MG, 36025-330, Brazil. Electronic address: rachel.machado@suprema.edu.br.
authors.forename: Rachel R P
authors.initials: RRP
authors.lastname: Machado
authors.affiliation: Laboratório de Autoimunidade e Imunofarmacologia (LAIF), Universidade Federal de Santa Catarina, Araranguá, SC, 88900-000, Brazil. Electronic address: rafaelcdutra@gmail.com.
authors.forename: Rafael C
authors.initials: RC
authors.lastname: Dutra
authors.affiliation: Núcleo de Pesquisa e Inovação em Ciências da Saúde, Universidade Federal de Juiz de Fora, Juiz de Fora, MG, 36036-900, Brazil. Electronic address: nadiafox@gmail.com.
authors.forename: Nádia R B
authors.initials: NRB
authors.lastname: Raposo
authors.affiliation: Departamento de Física, Instituto de Ciências Exatas, Universidade Federal de Juiz de Fora, Juiz de Fora, MG, 360036-900, Brazil. Electronic address: lesche@fisica.ufjf.br.
authors.forename: Bernhard
authors.initials: B
authors.lastname: Lesche
authors.affiliation: Laboratório de Micobactérias, Instituto de Microbiologia Paulo Góes, Centro de Ciências da Saúde, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, 21941-902, Brazil. Electronic address: marlei_gomes@yahoo.com.br.
authors.forename: Marlei S
authors.initials: MS
authors.lastname: Gomes
authors.affiliation: Laboratório de Micobactérias, Instituto de Microbiologia Paulo Góes, Centro de Ciências da Saúde, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, 21941-902, Brazil. Electronic address: rsduarte@ufrj.br.
authors.forename: Rafael S
authors.initials: RS
authors.lastname: Duarte
authors.affiliation: Departamento de Botânica, Instituto de Biociências, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, 91501-970, Brazil. Electronic address: glgsoares@gmail.com.
authors.forename: Geraldo Luiz G
authors.initials: GLG
authors.lastname: Soares
authors.affiliation: Instituto de Pesquisa de Produtos Naturais, Centro de Ciências da Saúde, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, 21941-902, Brazil. Electronic address: imkaplan@uol.com.br.
authors.forename: Maria Auxiliadora C
authors.initials: MAC
authors.lastname: Kaplan
mesh_terms: D000995:Antitubercular Agents / Q000302:isolation & purification / Q000494:pharmacology*; D007887:Fabaceae / Q000737:chemistry; D005638:Fruit; D007368:Interferometry / Q000379:methods*; D008826:Microbial Sensitivity Tests; D009163:Mycobacterium bovis / Q000187:drug effects* / Q000254:growth & development; D009822:Oils, Volatile / Q000302:isolation & purification / Q000494:pharmacology*; D008517:Phytotherapy; D010936:Plant Extracts / Q000302:isolation & purification / Q000494:pharmacology*; D010938:Plant Oils / Q000302:isolation & purification / Q000494:pharmacology*; D010946:Plants, Medicinal; D012293:Rifampin / Q000494:pharmacology*; D013997:Time Factors
chemical_list: D000995:Antitubercular Agents; D009822:Oils, Volatile; D010936:Plant Extracts; D010938:Plant Oils; D012293:Rifampin
keywords: Bacterial growth; Drug susceptibility test; Essential oil; LASER application; Microplate; Pterodon emarginatus