f Classical microbiological diagnosis of human brucellosis is time-consuming, hazardous, and subject to variable interpretation. Intactcell matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) was evaluated for the routine identification of Brucella spp. Analysis of mass peak patterns allowed accurate identification to the genus level. However, statistical models based on peak intensities were needed for definite species differentiation. Interlaboratory comparison confirmed the reproducibility of the results. Brucellosis is a major zoonotic disease with 500,000 human cases reported worldwide annually (1). The genus Brucella comprises six classical species, i.e., Brucella abortus (biovars 1 to 6 and 9), B. melitensis (biovars 1 to 3), B. suis (biovars 1 to 5), B. canis, B. ovis, and B. neotomae (2), and four newly described species, i.e., B. pinnipedialis, B. ceti, B. microti, and B. inopinata (3-5). The isolation of "atypical" strains seems to increase (6-11) probably because of the higher discriminatory power of up-to-date laboratory methods and more comprehensive surveillance strategies.Although hazardous, time-consuming, labor-intensive, and expensive, the isolation of bacteria from blood cultures and identification by classical microbiological tube testing are the current gold standards in the diagnosis of human brucellosis (12, 13). Since brucellosis is one of the most frequent laboratory-acquired infections (14), the prompt identification of a Brucella isolate is crucial to protect the staff members of clinical microbiology laboratories. Furthermore, brucellae are classified as category B bioterrorism agents by the Centers for Disease Control and Prevention (http://www.bt.cdc.gov /agent/agentlist-category.asp) and early detection is essential to establish effective countermeasures after an intentional release. Intact-cell matrix-assisted laser desorption ionization-time of flight mass spectrometry (ICMS) can provide an immediate tentative diagnosis based on inactivated bacterial cultures, minimizing the risk of laboratoryacquired infection and reducing the time to the treatment of affected patients (15, 16). Furthermore, appropriate sample preparation can inactivate highly infectious agents (17), simplifying the exchange of specimens.In 1996, ICMS was used for the first time to analyze potential bioterrorism agents (18). Several years elapsed before Ferreira and colleagues (16) demonstrated its usefulness for the identification of Brucella isolates to the genus level. As brucellae are very closely related bacteria, with genome homologies of Ͼ90% among the members of the genus (19), the development of laboratory methods for isolate discrimination to the species and biovar levels is a challenge. Nevertheless, Lista and colleagues were able to differentiate Brucella species by using ICMS (15); however, primary identification to the species level was based on multilocus variable-number tandem-repeat analysis (MLVA) so that taxonomic designation remained questionable.The a...

Marek’s disease virus (MDV) is an oncogenic alphaherpesvirus that infects chickens and causes the most frequent clinically diagnosed cancer in the animal kingdom. Not only is MDV an important pathogen that threatens the poultry industry but it is also used as a natural virus-host model for herpesvirus-induced tumor formation. In order to visualize MDV-induced lymphoma and to identify potential biomarkers in an unbiased approach, we performed imaging mass spectrometry (IMS) and noncontact laser capture microdissection. This study provides a first description of the visualization of MDV-induced tumors by IMS that could be applied also for diagnostic purposes. In addition, we identified and validated potential biomarkers for MDV-induced tumors that could provide the basis for future research on pathogenesis and tumorigenesis of this malignancy.