Flavio De Maio1, Sali M1, Tarantino M3, Garofolo G2, Pasquali P3, Petrucci P3, Sanguinetti M1, Di Giannatale E2, Tittarelli M2 and Adone R3
Posters-Accepted Abstracts: J Bacteriol Parasitol
Six species, some of which subdivided into biovars are traditionally assigned to the Brucella genus: B. melitensis, B. abortus, B.
suis, B. ovis, B. canis, B. neotomae. Recently, B. pinnipedialis and B. ceti from marine mammals have been added. B. melitensis,
B. abortus, B. suis and B. ovis, can infect humans mainly through the consumption of contaminated dairy products. Procedures
for microbiological identification and typing of Brucella spp. are expensive, time-consuming and require biohazard containment
facilities to minimize the risk for operators. The MALDI-TOF-MS (Matrix-Assisted Laser Desorption/Ionization Time-Of-Flight
Mass Spectrometry) assay based on the characterization of species-specific protein profiles is a rapid, cost-effective, accurate
and reproducible method for the biological samples analysis. In this study, we assessed a new protein extraction protocol and
constructed a home-made reference database to improve the efficiency of the method. To test the new library, different reference
Brucella species and biovars previously characterized by genotyping assay MLVA (Multiple Locus Variable-number Tandem Repeat
Analysis) were used. The reliability of this database was evaluated by testing blind-coded Brucella field isolates and reference strains.
The identification results at the genus level was always correct. At the species level, a total of 94% bacterial samples were correctly
identified. In contrast, incorrect biovar assignments resulted in 23 out of 39 B. abortus strains and in 4 out of 53 B. melitensis strains.
These results indicate that MALDI-TOF-MS assay is a reliable approach to identify Brucella genus and species and an increasing of
different Brucella strains in the database could provide a higher discriminatory power.
Flavio De Maio has completed Medical Biotechnology degree at the age of 24 from Catholic University of Rome and presently he is engaged in microbiology and virology
specialization school. He has published some papers in reputed journals and some posters in recognized congresses.