MALDI-TOF typing highlights geographical and fluconazole resistance clusters in Candida glabrata

Abstract

Utilizing matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectra for Candida glabrata typing would be a cost-effective and easy-to-use alternative to classical DNA-based typing methods. This study aimed to use MALDI-TOF for the typing of C. glabrata clinical isolates from various geographical origins and test its capacity to differentiate between fluconazole-sensitive and -resistant strains.Both microsatellite length polymorphism (MLP) and MALDI-TOF mass spectra of 58 C. glabrata isolates originating from Marseilles (France) and Tunis (Tunisia) as well as collection strains from diverse geographic origins were analyzed. The same analysis was conducted on a subset of C. glabrata isolates that were either susceptible (MIC ≤ 8 mg/l) or resistant (MIC ≥ 64 mg/l) to fluconazole.According to the seminal results, both MALDI-TOF and MLP classifications could highlight C. glabrata population structures associated with either geographical dispersal barriers (p < 10(-5)) or the selection of antifungal drug resistance traits (<10(-5)).In conclusion, MALDI-TOF geographical clustering was congruent with MPL genotyping and highlighted a significant population genetic structure according to fluconazole susceptibility in C. glabrata. Furthermore, although MALDI-TOF and MLP resulted in distinct classifications, MALDI-TOF also classified the isolates with respect to their fluconazole susceptibility profile. Further prospective studies are required to evaluate the capacity of MALDI-TOF typing to investigate C. glabrata infection outbreaks and predict the antifungal susceptibility profile of clinical laboratory isolates.

Opportunistic fungal pathogen Candida glabrata circulates between humans and yellow-legged gulls

“…glabrata populations isolated from patients in Paris and Montpellier, which are 800 km apart, displayed genetic differentiation ( F ST  = 0.11, P  = 0.054). Using the same MLVA scheme as in the present study, Dhieb et al 32. have shown highly significant genetic differentiation ( F ST  = 0.359, P  < 10 −5 ) between C .…”

Molecular Epidemiology and Antifungal Susceptibility of Candida glabrata in China (August 2009 to July 2014): A Multi-Center Study

“…Many studies have likewise found no association between C. glabrata genotypes and antifungal resistance (Dodgson et al, 2003; Abbes et al, 2011). However, Dhieb et al noted that both microsatellite genotypes and MALDI-TOF MS analysis could highlight C. glabrata population structures associated with specific geographic origin or antifungal drug resistance pattern (Dhieb et al, 2015). In our study, we noticed that during 2010–2011 in one hospital (Hospital BD) 80.8% (21/26) C. glabrata isolates were of the same genetic type (ST7 and T25), suggesting possible clonal presence/transmission of C. glabrata .…”

Outbreak of Saprochaete clavata Sepsis in Hematology Patients: Combined Use of MALDI-TOF and Sequencing Strategy to Identify and Correlate the Episodes

“…To date many papers have shown the ability of MALDI-TOF in accurately distinguishing different clusters of Candida strains, geographically grouped as in the case of Candida auris (Pracash et al, 2016) or in the case of multidrug resistant Candida glabrata (Dhieb et al, 2015) and Candida parapsilosis complex (De Carolis et al, 2014). MALDI-TOF mass spectra for genotyping would represent a rapid, first-level, easy, and cost-effective way to support clinicians, during uncommon fungal outbreaks, in treatment decision-making and in a clinical microbiology lab, although only WGS can confirm it.…”