Antifungal Drug Susceptibility and Genetic Characterization of Fungi Recovered from COVID-19 Patients

Fungal infections are common complications of respiratory viral infections and are associated with the increased need for intensive care and elevated mortality. Data regarding microbiological and molecular characteristics of such infections in COVID-19 patients are scarce. Here, we performed a comprehensive analysis, including species identification, antifungal susceptibility testing, molecular resistance determinants analysis, typing, and retrospective clinical data review, of fungal isolates recovered from 19 COVID-19 patients, who were hospitalized at the Hackensack University Medical Center (HUMC) in Hackensack, New Jersey, USA, in the initial phase of the pandemic from April–May 2020. In total, 17 Candida albicans, two C. parapsilosis, and two Aspergillus fumigatus were analyzed. All Candida spp. isolates were susceptible to micafungin and azole drugs (fluconazole, voriconazole, posaconazole, itraconazole, isavuconazole). A. fumigatus isolates were susceptible to micafungin and all triazole drugs except fluconazole (intrinsic resistance). Multilocus sequence typing (MLST) of C. albicans isolates revealed 15 different sequence types (STs), which clustered below the clade-defining limit of p-distance < 0.04. Pulsed-field gel electrophoresis (PFGE) karyotyping revealed no chromosomal rearrangements in these isolates. A. fumigatus isolates were of different, non-related genotypes. We speculate that virus- and drug-induced immunosuppression (94.7% of the patients received corticosteroids), together with prolonged hospital stay (median duration of 29 days) and mechanical ventilation (median duration of 24 days) likely increased the susceptibility to secondary respiratory and bloodstream infections in the studied patient population. The presence of fungi in blood or respiratory tract fluid was a prognosticator for poor clinical outcome, which presented as an 89.5% 30-day mortality in our patient cohort.

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277. Identification and Antifungal Susceptibility of Candida Species Isolated from Bloodstream Infections Over a 14-Year Period

Open Forum Infectious Diseases ◽

10.1093/ofid/ofz360.352 ◽

2019 ◽

Vol 6 (Supplement_2) ◽

pp. S152-S152

Author(s):

Ahnika Kline ◽

Clark Andrew ◽

Michail S Lionakis ◽

Adrian Zelazny

Keyword(s):

Candida Species ◽

Molecular Mechanisms ◽

Antifungal Susceptibility ◽

Frozen Storage ◽

Retrospective Chart Review ◽

Bloodstream Infections ◽

Intrinsic Resistance ◽

Candida Spp ◽

Fluconazole Resistance ◽

Invasive Infections

Abstract Background Invasive infections caused by Candida species are associated with significant morbidity and mortality. Historically, C. albicans has been the predominant species recovered from patients with candidemia. However, the changing epidemiology of invasive candidiasis now includes more non-C. albicans species, which may exhibit intrinsic resistance or reduced susceptibility to antifungal agents used for therapeutic intervention. We sought to evaluate the epidemiology and susceptibility of invasive Candida ssp. isolates causing bloodstream infections at the NIH Clinical Center over a 14 year period. Methods Candida spp. isolates causing bloodstream infections between 2004 and 2018 were identified. Retrospective chart review was performed for infected patients in accordance with the IRB. All Candida isolates were recovered from frozen storage by plating onto Sabouraud Dextrose Agar, and isolate identities were confirmed by MALDI-TOF MS. Antifungal susceptibility testing was performed by broth microdilution and MICs were interpreted using current CLSI criteria. Results Between 2004–2018, we identified 98 unique clinical isolates from 77 patients with candidemia. Records from 75 of these patients were able to be reviewed, and the 30-day and 90-day mortalities were 24% and 52%, respectively. The average age at the time of culture positivity was 41.3 years (range 6.5 to 76.9 years). Thirty-one of the patients were female and 44 were male. C. albicans only constituted 18% of isolates (N = 18) and was the third-most prevalent Candida species identified behind C. parapsilosis (28%, N = 27) and C. glabrata (23%, N = 23), and followed by C. tropicalis (8%, N = 8) and C. krusei (6%, N = 6). As expected, fluconazole resistance was prevalent among C. glabrata (70%, N = 16) and C. krusei (100%, N = 6); however, a sizable proportion of C. parapsilosis (11%, N = 3), C. tropicalis (63%, N = 5) and C. albicans (22%, N = 4) strains also exhibited fluconazole resistance. Conclusion Our findings illustrate a high prevalence of non-C. albicans Candida spp. as the causative agents of bloodstream infections among patients at our institution. The clinical risk factors associated with the development of candidemia and azole resistance, as well as the molecular mechanisms of antifungal resistance are under investigation. Disclosures All authors: No reported disclosures.

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

Journal of Pharmacy Practice ◽

10.1177/0897190009356552 ◽

2010 ◽

Vol 23 (1) ◽

pp. 33-37 ◽

Cited By ~ 1

Author(s):

Elizabeth A. Coyle

Keyword(s):

Health Care ◽

Invasive Candidiasis ◽

Susceptibility Testing ◽

Fungal Infections ◽

Antifungal Susceptibility ◽

Bloodstream Infections ◽

Antifungal Susceptibility Testing ◽

Candida Spp ◽

Candida Infections ◽

Prompt Diagnosis

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.

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Bloodstream infections caused by Magnusiomyces capitatus and Magnusiomyces clavatus: epidemiological, clinical and microbiological features of two emerging yeast species

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.01834-21 ◽

2021 ◽

Author(s):

Janina Noster ◽

Martin Köppel ◽

Marie Desnos-Olivier ◽

Maria Aigner ◽

Oliver Bader ◽

...

Keyword(s):

Antifungal Susceptibility ◽

Bloodstream Infections ◽

Its Sequencing ◽

Intrinsic Resistance ◽

Columbia Blood Agar ◽

Maldi Tof ◽

Invasive Infections ◽

Few Data

Background: Magnusiomyces clavatus and Magnusiomyces capitatus are emerging yeasts with intrinsic resistance to many commonly used antifungal agents. Identification is difficult, and determination of susceptibility patterns with commercial and reference methods is equally challenging. For this reason, few data on invasive infections by Magnusiomyces spp. are available. Objectives: To determine the epidemiology and susceptibility of Magnusiomyces isolates from bloodstream infections (BSI) isolated in Germany and Austria from 2001-2020. Methods: In seven institutions a total of 34 Magnusiomyces BSI were identified. Identification was done by ITS sequencing and MALDI-TOF MS. Antifungal susceptibility was determined by EUCAST broth microdilution and gradient tests. Results: Of the 34 isolates, M. clavatus was more common (N=24) compared to M. capitatus (N=10). BSI by Magnusiomyces spp. were more common in men (62%) and mostly occurred in patients with haemato-oncological malignancies (79%). The highest in vitro antifungal activity against M. clavatus / M. capitatus was observed for voriconazole (MIC 50 0.03/0.125 mg/L), followed by posaconazole (MIC 50 0.125/0.25 mg/L). M. clavatus isolates showed overall lower MICs compared to M. capitatus . With the exception of amphotericin B, low essential agreement between gradient test and microdilution was recorded for all antifungals (0-70%). Both species showed distinct morphologic traits on ChromAgar Orientation and Columbia blood agar, which can be used for differentiation if no MALDI-TOF or molecular identification is available. Conclusion: Most BSI were caused by M. clavatus. The lowest MICs were recorded for voriconazole. Gradient tests demonstrated unacceptably low agreement and should preferably not be used for susceptibility testing of Magnusiomyces spp.

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Intrinsic resistance to terbinafine among human and animal isolates of Trichophyton mentagrophytes related to amino acid substitution in the squalene epoxidase

Infection ◽

10.1007/s15010-020-01498-1 ◽

2020 ◽

Vol 48 (6) ◽

pp. 889-897 ◽

Cited By ~ 1

Author(s):

Dominik Łagowski ◽

Sebastian Gnat ◽

Aneta Nowakiewicz ◽

Marcelina Osińska ◽

Mariusz Dyląg

Keyword(s):

Amino Acid ◽

Fungal Infections ◽

Single Point ◽

Antifungal Susceptibility ◽

Point Mutations ◽

Trichophyton Mentagrophytes ◽

Single Amino Acid ◽

Squalene Epoxidase ◽

Intrinsic Resistance ◽

Resistant Strains

Abstract Background Dermatomycoses are the most common fungal infections in the world affecting a significant part of the human and animal population. The majority of zoophilic infections in humans are caused by Trichophyton mentagrophytes. Currently, the first-line drug for both oral and topical therapy is terbinafine. However, an increasing number of cases that are difficult to be cured with this drug have been noted in Europe and Asia. Resistance to terbinafine and other allylamines is very rare and usually correlated with point mutations in the squalene epoxidase gene resulting in single amino acid substitutions in the enzyme, which is crucial in the ergosterol synthesis pathway. Purpose Here, we report terbinafine-resistant T. mentagrophytes isolates among which one was an etiological factor of tinea capitis in a man and three were obtained from asymptomatic foxes in Poland. Methods We used the CLSI protocol to determine antifungal susceptibility profiles of naftifine, amphotericin B, griseofulvin, ketoconazole, miconazole, itraconazole, voriconazole, and ciclopirox. Moreover, the squalene epoxidase gene of the terbinafine-resistant strains was sequenced and analysed. Results In the genomes of all four resistant strains exhibiting elevated MICs to terbinafine (16 to 32 µg/ml), single-point mutations leading to Leu393Phe substitution in the squalene epoxidase enzyme were revealed. Among the other tested substances, a MIC50 value of 1 µg/ml was shown only for griseofulvin. Conclusion Finally, our study revealed that the terbinafine resistance phenomenon might not be acquired by exposure to the drug but can be intrinsic. This is evidenced by the description of the terbinafine-resistant strains isolated from the asymptomatic animals.

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2106. Evaluation of Isavuconazole for the Prophylaxis and Treatment of Invasive Fungal Infections at a Large Academic Medical Center

Open Forum Infectious Diseases ◽

10.1093/ofid/ofz360.1786 ◽

2019 ◽

Vol 6 (Supplement_2) ◽

pp. S712-S713

Author(s):

Christine Vu ◽

Meenakshi Rana ◽

Patricia Saunders-Hao

Keyword(s):

Fungal Infections ◽

Medical Center ◽

Academic Medical Center ◽

Retrospective Chart Review ◽

Invasive Fungal Infections ◽

Prescribing Practices ◽

Candida Spp ◽

Antifungal Stewardship ◽

Hospital Formulary

Abstract Background Isavuconazole is an azole antifungal with in vitro activity against various fungi, including Candida spp, Aspergillus, and Mucormycetes. Currently, isavuconazole is FDA approved for the treatment of invasive aspergillosis and mucormycosis; however, there remains limited data to support prophylaxis use. Compared with other first-line azoles, isavuconazole’s broad spectrum of activity, favorable safety profile, and oral bioavailability makes it an attractive antifungal option. In July 2017, isavuconazole was added to our hospital formulary as a restricted antimicrobial. Since then, we have seen increased use for both prophylaxis and treatment of invasive fungal infections. Methods A single-center, retrospective chart review was conducted on adult patients who received at least 1 dose of isavuconazole at The Mount Sinai Hospital between July 1, 2017 and December 31, 2018. The electronic medical record was utilized to collect information on therapeutic indication, dosing, formulation, duration, reasons for switching to isavuconazole, prior antifungals, and proven or probable breakthrough invasive fungal infections (bIFIs) based on EORTG/MTG definitions. Results 54 patients received 61 courses of isavuconazole. Reasons for switching to isavuconazole are described in Table 1. Eleven patients received inappropriate intravenous formulations and 14% of orders were prescribed isavuconazole without a loading dose (Table 2). We identified 4 proven/probable bIFIs, representing 7.4% of patients and 6.6% of courses (Table 3). All patients died within 60 days of bIFI onset. Conclusion Since its addition to hospital formulary, we have observed varying isavuconazole prescribing practices, highlighting the need for improved antifungal stewardship. Rates of bIFIs on isavuconazole were lower than previously reported studies. Additional studies are needed to provide guidance on isavuconazole use and determine its role as prophylaxis therapy. Disclosures All authors: No reported disclosures.

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Antimicrobial resistance among fungi from patients with urinary tract infections in Ojo, Lagos, Nigeria

GSC Biological and Pharmaceutical Sciences ◽

10.30574/gscbps.2021.14.3.0082 ◽

2021 ◽

Vol 14 (03) ◽

pp. 254-264

Author(s):

Dauphin Dighitoghi Moro ◽

Oluwole Moses David

Keyword(s):

Urinary Tract ◽

Amphotericin B ◽

Urinary Tract Infections ◽

Fungal Pathogens ◽

Fungal Infections ◽

Antifungal Susceptibility ◽

Candida Spp ◽

Fungal Isolates ◽

Vaginal Swabs ◽

Tract Infections

The incidence of fungal urinary tract infections has risen gradually and has thus constituted a public health challenge. The aim of this study was to determine the prevalence of urinary tract infections by fungi in two health centres in Ojo, Lagos. A total of 200 patients attending the health centers constituting 160 males’ urines and 40 females’ vaginal swabs were recruited for this study. Midstream urine samples and vaginal swabs were aseptically collected and processed using standard mycological techniques. Fungal isolates were identified based on cultural characteristics, lactophenol blue stain, chlamydospore formation, colony colour on CHROM agar Candida medium and API yeast identification. Antifungal susceptibility testing of the isolates was performed by using the Broth dilution and Kirby-Bauer disk diffusion methods using two of the most commonly used antifungal agents. A total of 122 fungal isolates, of which 68 (55.7%) were Candida spp. and 54(44.3%) Aspergillus spp. were recovered. The Candida spp. included 64 (52.5%) C. albicans and 4(3.3%) C. glabrata while Aspergillus spp. included A. flavus, 20(16.4%), A. fumigatus, 24 (19.8%) and A niger, 10(8.2%). The most common fungal pathogens in the urinary tracts of the subjects were Candida albicans and Aspergillus fumigatus. Both C. albicans and A. fumigatus were highly susceptible to both fluconazole and amphotericin B in dimethyl sulphoxide and water (90-100%). Similarly, all Aspergillus spp. were susceptible to both antifungals except A. flavus which showed a slight resistance (10-15%), which appears to be emerging. Both fluconazole and amphotericin B still show high chances of therapeutic efficacy against fungal infections of the urinary tracts.

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680. Month Long Fungemia due to Candida auris Endocarditis

Open Forum Infectious Diseases ◽

10.1093/ofid/ofab466.877 ◽

2021 ◽

Vol 8 (Supplement_1) ◽

pp. S443-S443

Author(s):

Haseeba khan ◽

Christy Varughese ◽

Hemil Gonzalez

Keyword(s):

Fungal Infections ◽

Antifungal Susceptibility ◽

Acute Care Hospital ◽

Sigmoid Resection ◽

Blood Cultures ◽

Multi Drug Resistance ◽

Care Hospital ◽

Candida Auris ◽

Candida Spp ◽

First Case

Abstract Background Candida auris (C. auris) is a multidrug resistant Candida species, reported to cause persistent fungemia along with a multitude of invasive fungal infections. We report the first case of C. auris fungemia due to endocarditis. Methods 61 year old man with a history of diverticulitis that required sigmoid resection and was complicated by abdominal abscesses due to multi drug resistant organisms warranting heavy antibiosis. Prolonged hospitalisation for that surgery was followed by a stay at a long term acute care hospital. He was readmitted at an outside hospital with sepsis where blood cultures grew C.auris. Upon evaluation, was found to have aortic valve endocarditis. Per patient’s preference, surgery was initially deferred. Despite escalation of therapy with a combination of antifungals, he remained fungemic for five weeks with repeat blood cultures showing changing antifungal susceptibility patterns. Patient eventually underwent surgical intervention at our facility, with valve cultures being positive for C.auris. After the surgery he was treated with 6 weeks of intravenous combination antifungal therapy. Results C.auris’s pathogenicity stems from multiple mechanisms with multi drug resistance being most pertinent. What adds to the complexity of the management is the absence of C.auris specific minimum inhibitory concentration breakpoints. Therefore treatment is based on Center for Disease Control’s (CDC) proposed breakpoints that have been extrapolated from other Candida spp. It is further complicated by lack of C.auris specific data showing essential agreement among different commercially available antifungal susceptibility testing (AFST). Heteroresistance of the microbial population is an issue that must be considered in such protracted fungemia. Conclusion Invasive infections due to Candida auris presents as a diagnostic and therapeutic challenge to clinicians. Disclosures All Authors: No reported disclosures

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A Study on Prevalence and Characterization of Candida Species in Immunocompromised Patients

Journal of Pure and Applied Microbiology ◽

10.22207/jpam.15.4.29 ◽

2021 ◽

Author(s):

Dhanapal Nandini ◽

J. Manonmoney ◽

J. Lavanya ◽

K.V. Leela ◽

Sujith

Keyword(s):

Risk Factors ◽

Fungal Infections ◽

Antifungal Susceptibility ◽

Predisposing Factors ◽

Immunocompromised Patients ◽

Candida Spp ◽

Gram Staining ◽

Number Of Patients ◽

Candida Infections ◽

Associated Risk Factors

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.

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SUSCEPTIBILITY TEST FOR FUNGI: CLINICAL AND LABORATORIAL CORRELATIONS IN MEDICAL MYCOLOGY

Revista do Instituto de Medicina Tropical de São Paulo ◽

10.1590/s0036-46652015000700011 ◽

2015 ◽

Vol 57 (suppl 19) ◽

pp. 57-64 ◽

Cited By ~ 57

Author(s):

Ana ALASTRUEY-IZQUIERDO ◽

Marcia S.C. MELHEM ◽

Lucas X. BONFIETTI ◽

Juan L. RODRIGUEZ-TUDELA

Keyword(s):

Susceptibility Testing ◽

Fungal Infections ◽

Antifungal Susceptibility ◽

Fungal Species ◽

Medical Mycology ◽

Candida Spp ◽

Disease Epidemiology ◽

Resistant Strains ◽

European Standards

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.

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The Trends in the Distribution of Candida species Causing Candidemia at a Community Hospital in 2005 and 2014

Open Forum Infectious Diseases ◽

10.1093/ofid/ofx163.043 ◽

2017 ◽

Vol 4 (suppl_1) ◽

pp. S87-S87

Author(s):

Celestine Ishiekwene ◽

Maxine Seales Kasangana ◽

Monica Ghitan ◽

Margaret Kuhn-Basti ◽

Edward Chapnick ◽

...

Keyword(s):

New York ◽

Antifungal Therapy ◽

Candida Species ◽

Fungal Infections ◽

Medical Center ◽

Retrospective Chart Review ◽

Common Species ◽

Published Data ◽

Candida Spp ◽

Common Cause

Abstract Background Candida remains the most common cause of invasive fungal infections, with an attributable morality of 15–35%. Although five Candida species (C. albicans, C. tropicalis, C. parapsilosis, C. glabrata, and C. krusei) account for 92% of cases of candidemia, Candida albicans remains the most common cause of candidemia. However, recent studies report that the frequency of non albicans species are increasing globally and the distribution of Candida spp. varies significantly among different geographic regions and hospitals units. Objective We determine the distribution of Candida species causing candidemia at an adult level 1 Trauma Center in Brooklyn, New York and compared the trends of Candida species between 2005 and 2014. The results were compared with trends of US data collected in 2004 and 2012. Knowledge of the frequency of causative species would facilitate appropriate selection of empiric antifungal therapy. Methods We performed a retrospective chart review of patients with candidemia who were admitted in 2005 and 2014. We determined the frequency of Candida species and compared 2005 data with those in 2014. Results In total, 226 and 109 patients with candidemia were admitted to our hospital in 2005 and 2014, respectively. Although, C. albicans was the most common species (43% of candidemia in 2005), its frequency decreased to 33% in 2014. The frequencies of C. glabrata and C. parapsilosis increased in 2014 compared with those in 2005 (24% vs. 16% and 33% vs. 26%, respectively). Figure 1 compared the proportion of Candida species in Maimonides Medical Center to National data. Conclusion Our finding of an increase in non-albicans spp. causing candidemia is consistent with published reports. We saw more cases of C. parapsilosis compared with published data. Our results may be used to inform empiric antifungal therapy. Disclosures All authors: No reported disclosures.

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