Candida tropicalis is the most prevalent yeast species causing candidemia in Algeria: The urgent need for antifungal stewardship and infection control measures

BackgroundDespite being associated with a high mortality and economic burden, data regarding candidemia are scant in Algeria. The aim of this study was to unveil the epidemiology of candidemia in Algeria, evaluate the antifungal susceptibility pattern of causative agents and understand the molecular mechanisms of antifungal resistance where applicable. Furthermore, by performing environmental screening and microsatellite typing we sought to identify the source of infection.MethodsWe performed a retrospective epidemiological-based surveillance study and collected available blood yeast isolates recovered from the seven hospitals in Algiers. To identify the source of infection, we performed environmental screening from the hands of healthcare workers (HCWs) and high touch areas. Species identification was performed by API Auxa-Color and MALDI-TOF MS and ITS sequencing was performed for species not reliably identified by MALDI-TOF MS. Antifungal susceptibility testing followed CLSI M27-A3/S4 and included all blood and environmental yeast isolates.ERG11sequencing was performed for azole-resistantCandidaisolates. Microsatellite typing was performed for blood and environmentalCandidaspecies, where applicable.ResultsCandida tropicalis(19/66) was the main cause of candidemia in these seven hospitals, followed byCandida parapsilosis(18/66), Candida albicans(18/66), andCandida glabrata(7/66). The overall mortality rate was 68.6% (35/51) and was 81.2% forC. tropicalis-infected patients (13/16). Fluconazole was the main antifungal drug used (12/51); 41% of the patients (21/51) did not receive any systemic treatment.Candida parapsilosiswas isolated mainly from the hands of HCWs (7/28), and various yeasts were collected from high-touch areas (11/47), includingNaganishia albida, C. parapsilosisandC. glabrata. Typing data revealed interhospital transmission on two occasions forC. parapsilosisandC. glabrata, and the same clone ofC. parapsilosisinfected two patients within the same hospital. Resistance was only noted forC. tropicalisagainst azoles (6/19) and fluconazole-resistantC. tropicalisisolates (≥8 μg/ml) (6/19) contained a novel P56S (5/6) amino acid substitution and a previously reported one (V234F; 1/6) in Erg11p.ConclusionsCollectively, our data suggest an urgent need for antifungal stewardship and infection control strategies to improve the clinical outcome of Algerian patients with candidemia. The high prevalence ofC. tropicalisjoined by fluconazole-resistance may hamper the therapeutic efficacy of fluconazole, the frontline antifungal drug used in Algeria.