The Matrix-Assisted Laser Desorption Ionization-Time of Flight Mass Spectrometry (MALDI-TOF MS) identification versus biochemical tests: a study with enterobacteria from a dairy cattle environment.
Mastitis adversely affects milk production and in general cows do not regain their full production levels post recovery, leading to considerable economic losses. Moreover the percentage decrease in milk production depends on the specific pathogen that caused the infection and enterobacteria are responsible for this greater reduction. Phenotypic tests are among the currently available methods used worldwide to identify enterobacteria; however they tend to misdiagnose the species despite the multiple tests carried out. On the other hand The Matrix-Assisted Laser Desorption Ionization-Time of Flight Mass Spectrometry (MALDI-TOF MS) technique has been attracting attention for its precise identification of several microorganisms at species level. In the current study, 183 enterobacteria were detected in milk (n=47) and fecal samples (n=94) from cows, and samples from water (n=23) and milk lines (n=19). All these samples were collected from a farm in Rio de Janeiro with the specific purpose of presenting the MALDI-TOF MS technique as an efficient methodology to identify Enterobacteriaceae from bovine environments. The MALDI-TOF MS technique results matched the biochemical test results in 92.9% (170/183) of the enterobacteria species and the gyrB sequencing confirmed 100% of the proteomic technique results. The amino acid decarboxylation test made the most misidentifications and Enterobacter spp. was the most misidentified genus (76.9%, 10/13). These results aim to clarify the current biochemical errors in enterobacteria identification, considering isolates from a bovine environment, and show the importance for more careful readings of phenotypic tests which are often used in veterinary microbiology laboratories.
Universidade Federal Rural do Rio de Janeiro, Departamento de Microbiologia e Imunologia Veterinária, Seropédica, RJ, Brazil.
Naiara Miranda Bento
NM
Rodrigues
Universidade Federal Rural do Rio de Janeiro, Departamento de Microbiologia e Imunologia Veterinária, Seropédica, RJ, Brazil.
Greiciane França
GF
Bronzato
Universidade Federal Rural do Rio de Janeiro, Departamento de Microbiologia e Imunologia Veterinária, Seropédica, RJ, Brazil.
Gabrielli Stefaninni
GS
Santiago
Laboratório de Investigação em Microbiologia Médica - LIMM, Instituto de Microbiologia Paulo de Goés, Rio de Janeiro, RJ, Brazil.
Larissa Alvarenga Batista
LA
Botelho
Laboratório de Investigação em Microbiologia Médica - LIMM, Instituto de Microbiologia Paulo de Goés, Rio de Janeiro, RJ, Brazil.
Beatriz Meurer
BM
Moreira
Universidade Federal Rural do Rio de Janeiro, Departamento de Microbiologia e Imunologia Veterinária, Seropédica, RJ, Brazil.
Irene da Silva
ID
Coelho
Universidade Federal Rural do Rio de Janeiro, Departamento de Microbiologia e Imunologia Veterinária, Seropédica, RJ, Brazil.
Miliane Moreira Soares de
MM
Souza
Universidade Federal Rural do Rio de Janeiro, Departamento de Microbiologia e Imunologia Veterinária, Seropédica, RJ, Brazil. Electronic address: shana@ufrrj.br.
Shana de Mattos de Oliveira
SM
Coelho
D000818:Animals; D002417:Cattle; D027081:DNA Gyrase / Q000235:genetics; D004755:Enterobacteriaceae / Q000145:classification* / Q000302:isolation & purification / Q000378:metabolism*; D005260:Female; D005798:Genes, Bacterial; D008414:Mastitis, Bovine / Q000175:diagnosis / Q000382:microbiology; D008892:Milk / Q000382:microbiology; D010641:Phenotype; D040901:Proteomics / Q000379:methods; D017422:Sequence Analysis, DNA; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
D027081:DNA Gyrase
Bovine mastitis; Enterobacteria identification; Matrix-Assisted Laser Desorption Ionization–Time of Flight Mass Spectrometry