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(Reference retrieved automatically from Web of Science through information on FAPESP grant and its corresponding number as mentioned in the publication by the authors.)

Direct identification of bovine mastitis pathogens by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry in pre-incubated milk

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Barreiro, Juliana R. [1] ; Goncalves, Juliano L. [1] ; Grenfell, Rafaella [2] ; Leite, Renata F. [1] ; Juliano, Luiz [2] ; Santos, V, Marcos
Total Authors: 6
[1] V, Univ Sao Paulo, Fac Med Vet & Zootecnia, Dept Nutr & Prod Anim, Pirassununga, SP - Brazil
[2] Univ Fed Sao Paulo, Dept Biofis, Sao Paulo, SP - Brazil
Total Affiliations: 2
Document type: Journal article
Source: Brazilian Journal of Microbiology; v. 49, n. 4, p. 801-807, OCT-DEC 2018.
Web of Science Citations: 2

ABSTRACT The present study aimed to compare two MALDI-TOF identification methods [(a) direct sample identification after pre-incubation; or (b) use of bacteria isolated on pre-culture)] to standard, traditional bench microbiology. A total of 120 quarter milk samples from 40 Holstein lactating cows were screened based on culture-positive results obtained by microbiological culture (reference method) with the following numbers of quarters positive per cow: 4 cows with 1, 8 cows with 2, 12 cows with 3 and 16 cows with 4 infected quarters per cow. For direct identification method, quarter milk samples (n = 120) were skimmed by centrifugation (10,000 × g/10 min) and pre-incubated at 37 ºC for 12 h. After pre-incubation, quarter milk samples were submitted to total bacterial count by flow cytometry and for a preparation protocol for bacterial ribosomal protein extraction followed by MALDI-TOF MS analysis. The direct MALDI-TOF MS identification method compared to microbiological culture correctly identified isolates of coagulase-negative Staphylococci (27.2%), Streptococcus agalactiae (21.8%), Staphylococcus aureus (14.2%), and Streptococcus uberis (5.2%). The pre-incubation protocol of milk samples, associated to the direct identification method by MALDI-TOF MS, did not increase the identification at species level (score >2.0) of pathogens causing subclinical mastitis in comparison to the method without previous incubation. (AU)

FAPESP's process: 11/15815-4 - Rapid identification of microorganisms by mastitis causing mass spectrometry
Grantee:Marcos Veiga dos Santos
Support Opportunities: Regular Research Grants
FAPESP's process: 11/14456-0 - Rapid identification of microorganisms causing mastitis by mass spectrometry
Grantee:Juliana Regina Barreiro
Support Opportunities: Scholarships in Brazil - Doctorate