Hospital Outbreak of Fluconazole-Resistant Candida parapsilosis: Arguments for Clonal Transmission and Long-Term Persistence

The worldwide emergence of multidrug-resistant pathogenic fungi is a threat to human health. At this very moment, an emergence of Candida parapsilosis isolates harboring a resistance to fluconazole, one of the most popular antifungal drugs, is being described in several countries. We seek to better understand the epidemiology, pathogenicity, and transmission of resistant Candida parapsilosis. Faced with an outbreak of invasive infections due to resistant isolates of C. parapsilosis, we performed a 7-year retrospective and prospective analysis of 283 C. parapsilosis isolates collected in 240 patients, among whom 111 had invasive candidiasis. The study included a review of hospital records, genotyping analysis, and susceptibility testing that allowed us to determine the type and outcome of infections, as well as the spatial and temporal spread of clusters. Overall, the incidence of azole resistance was 7.5%. Genotyping analysis unveiled several previously undetected outbreaks and clonal spread of susceptible and resistant isolates over a long period of time. In comparison with susceptible isolates, resistant ones have a more restricted genetic diversity and seem to be more likely to spread and more frequently associated with invasive infections. In intensive care units, patients with invasive infections due to resistant isolates had poorer outcomes (overall mortality at day 30 of 40%; 4/10) than susceptible ones (overall mortality at day 30 of 26.5%; 9/34). Our results suggest that the propensity of C. parapsilosis to spread in an epidemic fashion is underestimated, which warrants reinforced control and epidemiological survey of this species.

Automated summary

Research on multidrug-resistant Candida parapsilosis revealed a higher spread rate and increased likelihood of invasive infections among resistant isolates, emphasizing the need for enhanced monitoring and control measures for this species.