Characterization of Enterococcus species isolated from marine recreational waters by MALDI-TOF MS and Rapid ID API® 20 Strep system.
MALDI-TOF Mass Spectrometry Biotyping has proven to be a reliable method for identifying bacteria at the species level based on the analysis of the ribosomal proteins mass fingerprint. We evaluate the usefulness of this method to identify Enterococcus species isolated from marine recreational water at Brazilian beaches. A total of 127 Enterococcus spp. isolates were identified to species level by bioMérieux's API® 20 Strep and MALDI-TOF systems. The biochemical test identified 117/127 isolates (92%), whereas MALDI identified 100% of the isolates, with an agreement of 63% between the methods. The 16S rRNA gene sequencing of isolates with discrepant results showed that MALDI-TOF and API® correctly identified 74% and 11% of these isolates, respectively. This discrepancy probably relies on the bias of the API® has to identify clinical isolates. MALDI-TOF proved to be a feasible approach for identifying Enterococcus from environmental matrices increasing the rapidness and accuracy of results.
CETESB - Companhia Ambiental do Estado de São Paulo, Department of Environmental Analysis, São Paulo - SP, Brazil.
Ana Paula Guarnieri
APG
Christ
CETESB - Companhia Ambiental do Estado de São Paulo, Department of Environmental Analysis, São Paulo - SP, Brazil.
Solange Rodrigues
SR
Ramos
UNIFESP - Universidade Federal de São Paulo, Department of Medicine, ALERTA Laboratory, São Paulo - SP, Brazil.
Rodrigo
R
Cayô
UNIFESP - Universidade Federal de São Paulo, Department of Medicine, ALERTA Laboratory, São Paulo - SP, Brazil.
Ana Cristina
AC
Gales
CETESB - Companhia Ambiental do Estado de São Paulo, Department of Environmental Analysis, São Paulo - SP, Brazil.
Elayse Maria
EM
Hachich
CETESB - Companhia Ambiental do Estado de São Paulo, Department of Environmental Analysis, São Paulo - SP, Brazil. Electronic address: misato@sp.gov.br.
Maria Inês Zanoli
MIZ
Sato
D001493:Bathing Beaches; D001938:Brazil; D016983:Enterococcus / Q000145:classification / Q000302:isolation & purification*; D006801:Humans; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D012623:Seawater / Q000382:microbiology*; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D014871:Water Microbiology
D012336:RNA, Ribosomal, 16S
16S rRNA gene sequencing; Beaches; Enterococci; Gram-positive; MALDI-TOF MS; Species identification