Aspergillus spp. cause serious invasive lung infections, and Aspergillus fumigatus is the most commonly encountered clinically significant species. Voriconazole is considered to be the drug of choice for treating A. fumigatus infections; however, rising resistance rates have been reported. We evaluated a matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS)-based method for the differentiation between wild-type and non-wild-type isolates of 20 Aspergillus spp. (including 2 isolates of Aspergillus ustus and 1 of Aspergillus calidoustus that were used as controls due their intrinsic low azole susceptibility with respect to the in vitro response to voriconazole). At 30 and 48 h of incubation, there was complete agreement between Cyp51A sequence analysis, broth microdilution, and MALDI-TOF MS classification of isolates as wild type or non-wild type. In this proof-of-concept study, we demonstrated that MALDI-TOF MS can be used to accurately detect A. fumigatus strains with reduced voriconazole susceptibility. However, rather than proving to be a rapid and simple method for antifungal susceptibility testing, this particular MS-based method showed no benefit over conventional testing methods.KEYWORDS Aspergillus, voriconazole resistance, MALDI-TOF MS, antifungal susceptibility testing, composite correlation index, voriconazole A spergillus spp. cause serious invasive lung infections, and Aspergillus fumigatus is the most commonly encountered clinically significant species (1). Voriconazole is considered to be the drug of choice for treating A. fumigatus infections (2); however, rising resistance rates have been reported (3, 4), and antifungal susceptibility testing (AFST) remains limited to a small number of specialized laboratories. Early initiation of appropriate therapy has been shown to lead to better clinical outcomes (5). Additionally, it has been demonstrated that patients infected with resistant strains have poorer outcomes than those infected with susceptible strains (6).Matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) has been widely demonstrated to be an excellent tool for the rapid, accurate, and inexpensive identification of microorganisms (7,8). Groups are now investigating this technology for potentially equally rapid, simple, and inexpensive antimicrobial Citation Gitman MR, McTaggart L, Spinato J, Poopalarajah R, Lister E, Husain S, Kus JV. 2017. Antifungal susceptibility testing of Aspergillus spp. by using a composite correlation index (CCI)-based matrix-assisted laser desorption ionization-time of flight mass spectrometry method appears to not offer benefit over traditional broth microdilution testing. J Clin

Since the 2013 description of Blastomyces gilchristii, research describing the virulence or clinical outcome of B. gilchristii infection has been lacking. We report molecular evidence of B. gilchristii as an etiologic agent of fatal acute respiratory distress syndrome. B. gilchristii infection was confirmed by PCR and sequence analysis.

BackgroundThe increasing emergence of drug-resistant tuberculosis presents a threat to the effective control of tuberculosis (TB). Rapid detection of drug-resistance is more important than ever to address this scourge. The purpose of this study was to genotypically characterize the first-line antitubercular drug-resistant isolates collected over 11 years in Quebec.ResultsThe main mutations found in our resistant strains collection (n = 225) include: the S315T substitution in katG (50.2 %), the -15 C/T mutation in the inhA promoter (29 %); the S531L substitution in rpoB (43 %); the deletion 8 bp 446 / + R140S in pncA (72.9 %); the M306I (35.7 %) and M306V (21.4 %) substitutions in embB. Ten of the mutations in katG and 4 mutations identified in pncA were previously undescribed.ConclusionScreening of mutations conferring resistance to first-line antituberculous drugs using DNA-sequencing approach seems to be feasible and would drastically shorten the time to determine the resistance profile compared to the proportion method.