Epidemiology of Candida kefyr in Patients with Hematologic Malignancies

Abstract

g Candida kefyr is an emerging pathogen among patients with hematologic malignancies (HM). We performed a retrospective study at Johns Hopkins Hospital to evaluate the epidemiology of C. kefyr colonization and infection in HM patients between 2004 and 2010. Eighty-three patients were colonized and/or infected with C. kefyr, with 8 (9.6%) having invasive candidiasis (IC). The yearly incidence of C. kefyr colonization and candidemia increased over the study period (P < 0.01), particularly after 2009. In 2010, C. kefyr caused 16.7% of candidemia episodes. The monthly incidence of C. kefyr was higher during the summer throughout the study. In a cohort of patients with acute myelogenic leukemia receiving induction chemotherapy, risks for C. kefyr colonization included the summer season (odds ratio [OR], 3.1; P ‫؍‬ 0.03); administration of an azole (OR, 0.06; P < 0.001) or amphotericin B (OR, 0.35; P ‫؍‬ 0.05) was protective. Fingerprinting of 16 isolates by repetitive sequence-based PCR showed that all were different genotypes. The epidemiology of C. kefyr candidemia was evaluated in another hospital in Montreal, Canada; data confirmed higher rates of C. kefyr infection in the summer. C. kefyr appears to be increasing in HM patients, with prominent summer seasonality. These findings raise questions about the effect of antifungal agents and health care exposures (e.g., yogurt) on the epidemiology of this yeast.

Target Enzyme Mutations Confer Differential Echinocandin Susceptibilities in Candida kefyr

“…Our center's experience over the last 5 years confirmed an increase in isolation of this species from patients with severe mucositis and neutropenia (19). Data generated in this analysis of FSC and bloodstream isolates reveal two important findings: (i) FKS1 HS1 mutations in C. kefyr are consistent with those in other Candida species that generate high-level echinocandin resistance, and these mutations render the GS enzyme complex as relatively resistant to drug inhibition in vitro; and (ii) a novel HS1 mutation confers relative resistance of C. kefyr to micafungin but preserves activity of the other echinocandin drugs.…”

“…This observation prompted a retrospective review of all C. kefyr infections in two major hematologic wards between 2004 and 2010 (19). Notable findings of that study included a striking seasonality in isolate recovery, with high rates during summer months.…”

The risk and clinical outcome of candidemia depending on underlying malignancy

“…Overall, a higher proportion of C. tropicalis and C. krusei [7, 31–34], C. kefyr [35], and sometimes C. glabrata [32] fungemia is found in hematology, and multi-species episodes are more frequent in oncology [36]. We and others evidenced the impact of preexposure to antifungals on the distribution of Candida species [22, 37, 38], and that duration of fluconazole exposure influences the risk of C. krusei fungemia in hematology [6, 39].…”

Biochemical characteristics, virulence traits and antifungal resistance of two major yeast species isolated from kefir: Kluyveromyces marxianus and Saccharomyces unisporus

“…; Dufresne et al . ). In total, it was reported that 16% of candidemia cases were caused by this species in group of haematologic malignancy patients from 2009 to 2010, putting it the third most common species of candidemia (Pfeiffer et al .…”

“…; Dufresne et al . ). However, it should be noted that the aforementioned cases occurred nosocomially – these yeasts were not kefir‐originated and the patients were not associated with kefir consumption.…”