Brazilian Journal of Microbiology Brazilian Journal of Microbiology
Braz J Microbiol 2018;49:900-8 - Vol. 49 Num.4 DOI: 10.1016/j.bjm.2018.03.005
Clinical Microbiology
Identification of pathogenic and nonpathogenic Leptospira species of Brazilian isolates by Matrix Assisted Laser Desorption/Ionization and Time Flight mass spectrometry
Daniel Karchera,1, Rafaella C. Grenfella,1, Andrea Micke Morenoc, Luisa Zanolli Morenoc, Silvio Arruda Vasconcellosc, Marcos B. Heinemannc, Joao N. de Almeida Juniorb, Luiz Julianoa,, , , Maria A. Julianoa
a Universidade Federal de São Paulo, Escola Paulista Medicina, Departamento de Biofísica, São Paulo, SP, Brazil
b Universidade de São Paulo, Instituto de Medicina Tropical de São Paulo Laboratório de Micologia Médica Divisão de Laboratório Central – LIM-03, Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo, São Paulo, SP, Brazil
c Universidade de São Paulo, Faculdade de Veterinária e Zootecnia, Departamento Medicina Veterinária Preventiva e Saúde Animal, São Paulo, SP, Brazil
Received 20 November 2016, Accepted 21 March 2018

Matrix Assisted Laser Desorption/Ionization and Time of Flight mass spectrometry (MALDI-TOF MS) is a powerful tool for the identification of bacteria through the detection and analysis of their proteins or fragments derived from ribosomes. Slight sequence variations in conserved ribosomal proteins distinguish microorganisms at the subspecies and strain levels. Characterization of Leptospira spp. by 16S RNA sequencing is costly and time-consuming, and recent studies have shown that closely related species (e.g., Leptospira interrogans and Leptospira kirschneri) may not be discriminated using this technology. Herein, we report an in-house Leptospira reference spectra database using Leptospira reference strains that were validated with a collection of well-identified Brazilian isolates kept in the Bacterial Zoonosis Laboratory at the Veterinary Preventive Medicine and Animal Health Department at Sao Paulo University. In addition, L. interrogans and L. kirschneri were differentiated using an in-depth mass spectrometry analysis with ClinProTools™ software. In conclusion, our in-house reference spectra database has the necessary accuracy to differentiate pathogenic and non-pathogenic species and to distinguish L. interrogans and L. kirschneri.

Leptospira, Brazil, Identification, Mass spectrometry, MALDI-TOF
Braz J Microbiol 2018;49:900-8 - Vol. 49 Num.4 DOI: 10.1016/j.bjm.2018.03.005