Has the Optimal Therapy for Invasive Candidiasis Now Been Defined?

Initial micafungin treatment does not improve outcomes compared to fluconazole treatment in immunocompromised and critically ill patients with candidaemia

BACKGROUND

Candidaemia is associated with poor outcomes including high mortality rates. Controversy remains regarding whether fluconazole or an echinocandin is the optimal choice for initial candidaemia treatment, particularly among high-risk patients such as the immunocompromised or critically ill.

OBJECTIVES

To understand optimal initial treatment of candidaemia.

METHODS

We conducted a retrospective study of immunocompromised or ICU adult patients with candidaemia from 2010 to 2014. Patients who received ≥3 consecutive days of initial treatment with fluconazole or micafungin were included. The primary outcome was complete response at day 14, defined as clinical improvement and blood culture sterilization. Secondary outcomes included microbiological and clinical success, survival and recurrent candidaemia.

RESULTS

A total of 197 patients were included; 76 received fluconazole and 121 received micafungin. There was no difference in complete response between the fluconazole and micafungin groups (ICU: 38% versus 40%, P = 0.87; immunocompromised: 57% versus 59%, P = 0.80). Secondary outcomes including survival were also similar. In multivariable analysis, among ICU patients, Pitt bacteraemia score < 4 (P = 0.002) and time to antifungal (P = 0.037) were associated with meeting the primary outcome; white blood cell count > 11 cells × 103/µL on day 0 (P < 0.001) and Candida isolated from a non-blood site (P = 0.025) were associated with not meeting the primary outcome. Among immunocompromised patients, white blood cells > 11 × 103/µL (P = 0.003) and Candida isolated from a non-blood site (P = 0.026) were associated with not meeting the primary outcome.

CONCLUSIONS

These data suggest that among ICU or immunocompromised patients, severity of illness rather than initial antifungal choice drove clinical outcomes.

Antifungal activity of vitamin D3 against Candida albicans in vitro and in vivo

The incidence of intra-abdominal candidiasis (IAC), characterized by high morbidity and mortality, has become a serious concern. The limitations of current antifungal drugs on the market underscores the importance of the development of novel antifungal agents. In the present study, the antifungal activity of vitamin D₃ (VD₃) against various Candida species was investigated. In vitro, the broth microdilution method and solid plate assay confirmed that VD₃ inhibited the growth of Candida spp. in a broad-spectrum, dose-dependent manner. VD₃ also had a significant antifungal effect on the initiation, development, and maturation phases of biofilm formation in Candida albicans. The mechanism of VD₃ action was explored by transcriptomics and reverse transcription quantitative PCR (RT-qPCR) analysis, and showed that VD₃ affects ribosome biogenesis, coenzyme metabolism, and carbon metabolism. These results suggested that VD₃ may have multitarget effects against C. albicans. In the murine IAC model, VD₃ reduced the fungal burden in the liver, kidneys, and small intestine. Further histopathological analysis and quantification of plasma cytokine levels confirmed that VD₃ treatment significantly decreased the infiltration of inflammatory cells and the levels of plasma interferon (IFN)-γ and tumor necrosis factor (TNF)-α. Taken together, these findings suggest a new antifungal mechanism for VD₃ and indicate that VD₃ could be an effective therapeutic agent for use in IAC treatment.

Adherence to National Consensus Guidelines and Association with Clinical Outcomes in Patients with Candidemia

Background:

National consensus guidelines outline recommendations for best practices in treating patients with candidemia. This study evaluated the impact of receiving care adherent to the best practice recommendations on clinical outcomes in patients with candidemia.

Methods:

This retrospective, multicenter study included patients with candidemia from 2010 to 2015 at 9 hospitals. The primary outcome was the composite of 30-day in-hospital mortality and 90-day candidemia recurrence. Outcomes were compared between those receiving and not receiving care adherent to the guideline recommendations. Inverse probability weights with regression adjustment were utilized to determine the average treatment effect of adherent care on the composite outcome

Results:

295 patients were included with 14.2% meeting criteria for the composite outcome (11.9% mortality and 2.4% recurrence). The average treatment effect of adherent care was not significant (P = .75). However, receiving appropriate initial antifungal treatment and central venous catheter removal were both associated with the composite (average treatment effect of −17.5%, P = .011 and −8.8%, P = .013, respectively). In patients with a source of infection other than the central line, central venous catheter removal was not associated with the composite (P = .95). The most common reason for failure to receive appropriate initial antifungal treatment was omission of the loading dose.

Conclusions:

Central venous catheter removal and appropriate initial antifungal treatment were associated with a lower incidence of the composite of mortality and recurrence. Additional studies are needed to determine the optimal duration of therapy following candidemia clearance.

A Systematic Screen Reveals a Diverse Collection of Medications That Induce Antifungal Resistance in Candida Species

The increasing incidence of and high mortality rates associated with invasive fungal infections (IFIs) impose an enormous clinical, social, and economic burden on humankind. In addition to microbiological resistance to existing antifungal drugs, the large number of unexplained treatment failures is a serious concern. Due to the extremely limited therapeutic options available, it is critical to identify and understand the various causes of treatment failure if patient outcomes are to improve. In this study, we examined one potential source of treatment failure: antagonistic drug interactions. Using a simple screen, we systematically identified currently approved medications that undermine the antifungal activity of three major antifungal drugs-fluconazole, caspofungin, and amphotericin B-on four prevalent human fungal pathogens-Candida albicans, Candida glabrata, Candida parapsilosis, and Candida tropicalis This revealed that a diverse collection of structurally distinct drugs exhibit antagonistic interactions with fluconazole. Several antagonistic agents selected for follow-up studies induce azole resistance through a mechanism that depends on Tac1p/Pdr1p zinc-cluster transcription factors, which activate the expression of drug efflux pumps belonging to the ABC-type transporter family. Few antagonistic interactions were identified with caspofungin or amphotericin B, possibly reflecting their cell surface mode of action that should not be affected by drug efflux mechanisms. Given that patients at greatest risk of IFIs usually receive a multitude of drugs to treat various underlying conditions, these studies suggest that chemically inducible azole resistance may be much more common and important than previously realized.