Invasive Candidiasis and the Utility of Antifungal Susceptibility Testing in the ICU

2010 ◽  
Vol 23 (1) ◽  
pp. 33-37 ◽  
Author(s):  
Elizabeth A. Coyle

Invasive fungal infections are a major cause of health care–associated morbidity and mortality in the ICU. In particular, Candida spp. are among one of the leading causes of bloodstream infections and sepsis. Advances in antifungal therapy in the last decade have led to many more options in the treatment of fungal infections, yet increasing resistance and clinical failures are common, especially in the management of invasive candidiasis in the ICU. Prompt diagnosis of these infections and appropriate antifungal treatment are imperative for improving survival. Although reliable antifungal susceptibility testing is available to aid in the therapy of fungal infections, testing is not always recommended. This review addresses the epidemiology of Candida infections in the ICU, antifungal resistance, therapy, and the usefulness of antifungal susceptibility testing in the ICU setting.

2020 ◽  
Vol 7 (1) ◽  
pp. 17
Author(s):  
Frederic Lamoth ◽  
Russell E. Lewis ◽  
Dimitrios P. Kontoyiannis

Invasive fungal infections (IFIs) are associated with high mortality rates and timely appropriate antifungal therapy is essential for good outcomes. Emerging antifungal resistance among Candida and Aspergillus spp., the major causes of IFI, is concerning and has led to the increasing incorporation of in vitro antifungal susceptibility testing (AST) to guide clinical decisions. However, the interpretation of AST results and their contribution to management of IFIs remains a matter of debate. Specifically, the utility of AST is limited by the delay in obtaining results and the lack of pharmacodynamic correlation between minimal inhibitory concentration (MIC) values and clinical outcome, particularly for molds. Clinical breakpoints for Candida spp. have been substantially revised over time and appear to be reliable for the detection of azole and echinocandin resistance and for outcome prediction, especially for non-neutropenic patients with candidemia. However, data are lacking for neutropenic patients with invasive candidiasis and some non-albicans Candida spp. (notably emerging Candida auris). For Aspergillus spp., AST is not routinely performed, but may be indicated according to the epidemiological context in the setting of emerging azole resistance among A. fumigatus. For non-Aspergillus molds (e.g., Mucorales, Fusarium or Scedosporium spp.), AST is not routinely recommended as interpretive criteria are lacking and many confounders, mainly host factors, seem to play a predominant role in responses to antifungal therapy. This review provides an overview of the pre-clinical and clinical pharmacodynamic data, which constitute the rationale for the use and interpretation of AST testing of yeasts and molds in clinical practice.


1993 ◽  
Vol 6 (4) ◽  
pp. 367-381 ◽  
Author(s):  
J H Rex ◽  
M A Pfaller ◽  
M G Rinaldi ◽  
A Polak ◽  
J N Galgiani

Unlike antibacterial susceptibility testing, reliable antifungal susceptibility testing is still largely in its infancy. Many methods have been described, but they produce widely discrepant results unless such factors as pH, inoculum size, medium formulation, incubation time, and incubation temperature are carefully controlled. Even when laboratories agree upon a common method, interlaboratory agreement may be poor. As a result of numerous collaborative projects carried out both independently and under the aegis of the Subcommittee on Antifungal Susceptibility Testing of the National Committee for Clinical Laboratory Standards, the effects of varying these factors have been extensively studied and a standard method which minimizes interlaboratory variability during the testing of Candida spp. and Cryptococcus neoformans has been proposed. This review summarizes this work, reviews the strengths and weaknesses of the proposed susceptibility testing standard, and identifies directions for future work.


2019 ◽  
Author(s):  
Christopher Heuer ◽  
Heidi Leonard ◽  
Nadav Nitzan ◽  
Ariella Lavy-Alperovitch ◽  
Naama Massad-Ivanir ◽  
...  

AbstractThe increasing number of invasive fungal infections among immunocompromised patients and the emergence of antifungal resistant pathogens has resulted in the need for rapid and reliable antifungal susceptibility testing (AFST). Accelerating antifungal susceptibility testing allows for advanced treatment decisions and the reduction in future instances of antifungal resistance. In this work, we demonstrate the application of a silicon phase grating as sensor for the detection of growth of Aspergillus niger (A. niger) by intensity-based reflectometric interference spectroscopy and its use as an antifungal susceptibility test. The silicon gratings provide a solid-liquid interface to capture micron-sized Aspergillus conidia within microwell arrays. Fungal growth is optically tracked and detected by the reduction in the intensity of reflected light from the silicon grating. The growth of A. niger in the presence of various concentrations of the antifungal agents voriconazole and amphotericin B is investigated by intensity-based reflectometric interference spectroscopy and used for the determination of the minimal inhibitory concentrations (MIC), which are compared to standard broth microdilution testing. This assay allows for expedited detection of fungal growth and provides a label-free alternative to standard antifungal susceptibility testing methods, such as broth microdilution and agar diffusion methods.


Author(s):  
Dhanapal Nandini ◽  
J. Manonmoney ◽  
J. Lavanya ◽  
K.V. Leela ◽  
Sujith

Candida spp. is one among the major causes of nosocomial infection, with candidemia gaining increasing prevalence worldwide in parallel with mortality rates ranging from 10-49%. Epidemiology and predisposing factors of candidemia have changed since the number of patients receiving transplants and immunosuppressive therapy, the use of broadspectrum antimicrobials, and the number of AIDS patients have increased. Candidemia is more common among patients with subcutaneous and cutaneous candida infections, through percutaneous inoculation. Major predisposing factors for invasive candidiasis includes neutropenia, haematological malignancies, bone marrow transplantation, total parenteral nutrition, chemotherapy, invasive procedures, and immune-suppressive agents. This study analyses the risk factors of immunocompromised patients with candidemia and antibiogram of Candida spp. isolated from ICU patients. To evaluate the prevalence, distribution and antibiogram of Candida spp., associated risk factors, and outcome in candidemia patients. Blood samples received from patients with clinically suspected fungal infections were subjected to gram staining, culture, sugar assimilation & fermentation, Candida Chrome agar (CCA) & Corn meal agar for identification and speciation. Antifungal susceptibility tests were performed by disk-diffusion tests. Among a total of 337 samples received, 22 (6.5%) samples were positive for candida infections, of which Candida tropicalis 9 (41%) was the predominant isolate followed by C. albicans 5 (23%), Candida glabrata 4 (18%), Candida parapsilosis 2 (9%) and Candida krusei 2 (9%). Male patients had a higher prevalence of candidemia 15 (68.2%). Among the age group of 51-70 years, uncontrolled DM(Diabetes mellitus) and CKD (chronic kidney disease) were found to be the predominant co-morbidities with candidemia.


2019 ◽  
Vol 57 (5) ◽  
pp. e8-e10 ◽  
Author(s):  
María Ángeles Bordallo-Cardona ◽  
Carlos Sánchez-Carrillo ◽  
Patricia Muñoz ◽  
Emilio Bouza ◽  
Pilar Escribano ◽  
...  

2015 ◽  
Vol 57 (suppl 19) ◽  
pp. 57-64 ◽  
Author(s):  
Ana ALASTRUEY-IZQUIERDO ◽  
Marcia S.C. MELHEM ◽  
Lucas X. BONFIETTI ◽  
Juan L. RODRIGUEZ-TUDELA

SUMMARYDuring recent decades, antifungal susceptibility testing has become standardized and nowadays has the same role of the antibacterial susceptibility testing in microbiology laboratories. American and European standards have been developed, as well as equivalent commercial systems which are more appropriate for clinical laboratories. The detection of resistant strains by means of these systems has allowed the study and understanding of the molecular basis and the mechanisms of resistance of fungal species to antifungal agents. In addition, many studies on the correlation of in vitro results with the outcome of patients have been performed, reaching the conclusion that infections caused by resistant strains have worse outcome than those caused by susceptible fungal isolates. These studies have allowed the development of interpretative breakpoints for Candida spp. and Aspergillus spp., the most frequent agents of fungal infections in the world. In summary, antifungal susceptibility tests have become essential tools to guide the treatment of fungal diseases, to know the local and global disease epidemiology, and to identify resistance to antifungals.


2015 ◽  
Vol 53 (11) ◽  
pp. 3654-3659 ◽  
Author(s):  
Maria Siopi ◽  
Marilena Tsala ◽  
Nikolaos Siafakas ◽  
Loukia Zerva ◽  
Joseph Meletiadis

The “dip effect” phenomenon complicates antifungal susceptibility testing with gradient concentration strips. Of 60Candidaisolates tested with the three echinocandins, this phenomenon was observed only for caspofungin with most (>90%)Candida albicans,Candida glabrata, andCandida tropicalisisolates and for isolates with CLSI MICs of ≤0.25 mg/liter. In order to facilitate MIC determination, a practical approach was developed using the inhibition zones at 32, 8, 2, and 1 mg/liter, increasing the agreement with the CLSI method >86%.


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