Impact of the COVID-19 Pandemic on the Clinical Profile of Candidemia and the Incidence of Fungemia Due to Fluconazole-Resistant Candida parapsilosis

COVID-19 associated candidemia: From a shift in fungal epidemiology to a rise in azole drug resistance

Our understanding of fungal epidemiology and the burden of antifungal drug resistance in COVID-19-associated candidemia (CAC) patients is limited. Therefore, we conducted a retrospective multicenter study in Iran to explore clinical and microbiological profiles of CAC patients. Yeast isolated from blood, were identified by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry and subjected to antifungal susceptibility testing (AFST) using the broth microdilution method M27-A3 protocol. A total of 0.6% of the COVID-19 patients acquired CAC (43/6174). Fluconazole was the most widely used antifungal, and 37% of patients were not treated. Contrary to historic candidemia patients, Candida albicans and C. tropicalis were the most common species. In vitro resistance was high and only noted for azoles; 50%, 20%, and 13.6% of patients were infected with azole-non-susceptible (ANS) C. tropicalis, C. parapsilosis, and C. albicans isolates, respectively. ERG11 mutations conferring azole resistance were detected for C. parapsilosis isolates (Y132F), recovered from an azole-naïve patient. Our study revealed an unprecedented rise in ANS Candida isolates, including the first C. parapsilosis isolate carrying Y132F, among CAC patients in Iran, which potentially threatens the efficacy of fluconazole, the most widely used drug in our centers. Considering the high mortality rate and 37% of untreated CAC cases, our study underscores the importance of infection control strategies and antifungal stewardship to minimize the emergence of ANS Candida isolates during COVID-19.

Fluconazole-resistant Candida parapsilosis genotypes from hospitals located in five Spanish cities and one in Italy: Description of azole-resistance profiles associated with the Y132F ERG11p substitution

BACKGROUND

Fluconazole-resistant Candida parapsilosis is a matter of concern.

OBJECTIVES

To describe fluconazole-resistant C. parapsilosis genotypes circulating across hospitals in Spain and Rome and to study their azole-resistance profile associated with ERG11p substitutions.

PATIENTS/METHODS

We selected fluconazole-resistant C. parapsilosis isolates (n = 528 from 2019 to 2023; MIC ≥8 mg/L according to EUCAST) from patients admitted to 13 hospitals located in five Spanish cities and Rome. Additionally, we tested voriconazole, posaconazole, isavuconazole, amphotericin B, micafungin, anidulafungin and ibrexafungerp susceptibility.

RESULTS

Of the 53 genotypes found, 49 harboured the Y132F substitution, five of which were dominating city-specific genotypes involving almost half the isolates. Another genotype involved isolates harbouring the G458S substitution. Finally, we found two genotypes with the wild-type ERG11 gene sequence and one with the R398I substitution. All isolates were fully susceptible/wild-type to amphotericin B, anidulafungin, micafungin and ibrexafungerp. The azole-resistance patterns found were: voriconazole-resistant (74.1%) or voriconazole-intermediate (25.2%), posaconazole-resistant (10%) and isavuconazole non-wild-type (47.5%). Fluconazole-resistant and voriconazole non-wild-type isolates were likely to harbour substitution Y132F if posaconazole was wild type; however, if posaconazole was non-wild type, substitution G458S was indicated if isavuconazole MIC was >0.125 mg/L or substitution Y132F if isavuconazole MIC was ≤0.125 mg/L.

CONCLUSIONS

We detected a recent clonal spread of fluconazole-resistant C. parapsilosis across some cities in Spain, mostly driven by dominating city-specific genotypes, which involved a large number of isolates harbouring the Y132F ERG11p substitution. Isolates harbouring substitution Y132F can be suspected because they are non-susceptible to voriconazole and rarely posaconazole-resistant.

First Canadian report of transmission of fluconazole-resistant Candida parapsilosis within two hospital networks confirmed by genomic analysis

Candida parapsilosis is a common cause of non-albicans candidemia. It can be transmitted in healthcare settings resulting in serious healthcare-associated infections and can develop drug resistance to commonly used antifungal agents. Following a significant increase in the percentage of fluconazole (FLU)-nonsusceptible isolates from sterile site specimens of patients in two Ontario acute care hospital networks, we used whole genome sequence (WGS) analysis to retrospectively investigate the genetic relatedness of isolates and to assess potential in-hospital spread. Phylogenomic analysis was conducted on all 19 FLU-resistant and seven susceptible-dose dependent (SDD) isolates from the two hospital networks, as well as 13 FLU susceptible C. parapsilosis isolates from the same facilities and 20 isolates from patients not related to the investigation. Twenty-five of 26 FLU-nonsusceptible isolates (resistant or SDD) and two susceptible isolates from the two hospital networks formed a phylogenomic cluster that was highly similar genetically and distinct from other isolates. The results suggest the presence of a persistent strain of FLU-nonsusceptible C. parapsilosis causing infections over a 5.5-year period. Results from WGS were largely comparable to microsatellite typing. Twenty-seven of 28 cluster isolates had a K143R substitution in lanosterol 14-α-demethylase (ERG11) associated with azole resistance. As the first report of a healthcare-associated outbreak of FLU-nonsusceptible C. parapsilosis in Canada, this study underscores the importance of monitoring local antimicrobial resistance trends and demonstrates the value of WGS analysis to detect and characterize clusters and outbreaks. Timely access to genomic epidemiological information can inform targeted infection control measures.

Clonal spread of fluconazole-resistant C. parapsilosis in patients admitted to a referral hospital located in Burgos, Spain, during the COVID-19 pandemic

BACKGROUND

Fluconazole-resistant Candida parapsilosis (FRCP) is a matter of concern in Spain.

OBJECTIVES

We here report a FRCP spread across a 777-bed referral hospital located in Burgos, Spain, during the COVID-19 pandemic.

PATIENTS/METHODS

In April 2021, an FRCP isolate (MIC = 64 mg/L, E-test®) from a hospitalised patient was detected. Up to June 2022, all C. parapsilosis isolates (n = 35) from hospitalised patients (n = 32) were stored and genotyped using microsatellite markers, and their antifungal susceptibilities were studied (EUCAST); FRCP isolates were molecularly characterised.

RESULTS

We detected 26 FRCP isolates collected between 2021 (n = 8) and 2022 (n = 18); isolates were susceptible to amphotericin B, echinocandins and ibrexafungerp. FRCP isolates were grouped into three genotypes: CP-707 and CP-708 involved isolates harbouring the Y132F + R398I ERG11p substitutions (n = 24) and were clonally related; the remaining CP-675 genotype involved isolates harbouring the G458S ERG11p substitution (n = 2). FRCP genotypes were genetically related to the FRCP genotypes found in Madrid and were unrelated to fluconazole-susceptible ones. Patients harbouring FRCP were mainly (n = 22/23) admitted to intensive care units. Most patients had received broad-spectrum antibiotics (n = 22/23), and/or antifungal therapy with azoles (n = 14/23) within the 30 days prior to FRCP isolation. Thirteen patients were colonised, 10 of whom were infected and presented candidaemia (n = 8/10), endovascular infection (n = 1/10) or complicated urinary infection (n = 1/10). Overall nonattributable 30-day mortality was 17% (n = 4/23).

CONCLUSIONS

We report an outbreak caused by FRCP affecting patients admitted to the ICU of a referral hospital located in Burgos. Patients harbouring FRCP had a higher fluconazole use than those carrying susceptible isolates.

Fluconazole-resistant Candida parapsilosis complex candidemia and analysis of mutations in the ERG11 gene from Pakistan

BACKGROUND

Recent reports of the emergence of fluconazole resistance in Candida parapsilosis species complex poses a challenge, more specifically in settings where echinocandin-based treatment regime is not feasible.

OBJECTIVE

This study reported emergence of fluconazole resistance in C. parapsilosis species complex strains isolated from blood cultures.

MATERIALS AND METHODS

This retrospective observational study was conducted from 2018 to 2020 at a tertiary care laboratory from Pakistan. Fluconazole-resistant C. parapsilosis species complex fungemia cases were identified from laboratory database and clinical details were collected. Identification of C. parapsilosis species complex was done using API 20C AUX and Cornmeal Tween80 agar morphology. Minimum inhibitory concentrations (MICs) were determined using Sensititre YeastONE and interpretation was done with CLSI M60 ED1:2017. ERG11 gene region was amplified and sequenced by Sanger sequencing and analysed by MEGA 11 Software.

RESULTS

A total of 13 (8.5%) fluconazole-resistant isolates were identified from 152 C. parapsilosis species complex candidemia cases. Fluconazole MICs of resistant isolates ranged between 8 and 256 μg/mL. Analysis of ERG11 gene revealed nonsynonymous mutations at position Y132F in 86% of the fluconazole-resistant isolates. Diabetes and hospitalization were important risk factors for candidemia with fluconazole-resistant C. parapsilosis complex.

CONCLUSION

This is the first report of the emergence and molecular mechanisms of fluconazole resistance in C. parapsilosis species complex from Pakistan. Y132F mutation in the ERG11 gene was the most common mutation in fluconazole-resistant strains. These findings are concerning and necessitate better diagnostics, newer antifungals, ongoing surveillance and further insights on resistance mechanisms in the country.

Candida parapsilosis complex in the clinical setting

Representatives of the Candida parapsilosis complex are important yeast species causing human infections, including candidaemia as one of the leading diseases. This complex comprises C. parapsilosis, Candida orthopsilosis and Candida metapsilosis, and causes a wide range of clinical presentations from colonization to superficial and disseminated infections with a high prevalence in preterm-born infants and the potential to cause outbreaks in hospital settings. Compared with other Candida species, the C. parapsilosis complex shows high minimal inhibitory concentrations for echinocandin drugs due to a naturally occurring FKS1 polymorphism. The emergence of clonal outbreaks of strains with resistance to commonly used antifungals, such as fluconazole, is causing concern. In this Review, we present the latest medical data covering epidemiology, diagnosis, resistance and current treatment approaches for the C. parapsilosis complex. We describe its main clinical manifestations in adults and children and highlight new treatment options. We compare the three sister species, examining key elements of microbiology and clinical characteristics, including the population at risk, disease manifestation and colonization status. Finally, we provide a comprehensive resource for clinicians and researchers focusing on Candida species infections and the C. parapsilosis complex, aiming to bridge the emerging translational knowledge and future therapeutic challenges associated with this human pathogen.

European candidaemia is characterised by notable differential epidemiology and susceptibility pattern: Results from the ECMM Candida III study

The objectives of this study were to assess Candida spp. distribution and antifungal resistance of candidaemia across Europe. Isolates were collected as part of the third ECMM Candida European multicentre observational study, conducted from 01 to 07-07-2018 to 31-03-2022. Each centre (maximum number/country determined by population size) included ∼10 consecutive cases. Isolates were referred to central laboratories and identified by morphology and MALDI-TOF, supplemented by ITS-sequencing when needed. EUCAST MICs were determined for five antifungals. fks sequencing was performed for echinocandin resistant isolates. The 399 isolates from 41 centres in 17 countries included C. albicans (47.1%), C. glabrata (22.3%), C. parapsilosis (15.0%), C. tropicalis (6.3%), C. dubliniensis and C. krusei (2.3% each) and other species (4.8%). Austria had the highest C. albicans proportion (77%), Czech Republic, France and UK the highest C. glabrata proportions (25-33%) while Italy and Turkey had the highest C. parapsilosis proportions (24-26%). All isolates were amphotericin B susceptible. Fluconazole resistance was found in 4% C. tropicalis, 12% C. glabrata (from six countries across Europe), 17% C. parapsilosis (from Greece, Italy, and Turkey) and 20% other Candida spp. Four isolates were anidulafungin and micafungin resistant/non-wild-type and five resistant to micafungin only. Three/3 and 2/5 of these were sequenced and harboured fks-alterations including a novel L657W in C. parapsilosis. The epidemiology varied among centres and countries. Acquired echinocandin resistance was rare but included differential susceptibility to anidulafungin and micafungin, and resistant C. parapsilosis. Fluconazole and voriconazole cross-resistance was common in C. glabrata and C. parapsilosis but with different geographical prevalence.

Severe Candida infections in critically ill patients with COVID-19

The frequency of co-infections with bacterial or fungal pathogens has constantly increased among critically ill patients with coronavirus disease 2019 (COVID-19) during the pandemic. Candidemia was the most frequently reported invasive fungal co-infection. The onset of candidemia in COVID-19 patients was often delayed compared to non-COVID-19 patients. Additionally, Candida invasive infections in COVID-19 patients were more often linked to invasive procedures (e.g., invasive mechanical ventilation or renal replacement therapy) during the intensive care stay and the severity of illness rather than more "classic" risk factors present in patients without COVID-19 (e.g., underlying diseases and prior hospitalization). Moreover, apart from the increased incidence of candidemia during the pandemic, a worrying rise in fluconazole-resistant strains was reported, including a rise in the multidrug-resistant Candida auris. Regarding outcomes, the development of invasive Candida co-infection had a negative impact, increasing morbidity and mortality compared to non-co-infected COVID-19 patients. In this narrative review, we present and critically discuss information on the diagnosis and management of invasive fungal infections caused by Candida spp. in critically ill COVID-19 patients.

Paradigm Shift: Candida parapsilosis sensu stricto as the Most Prevalent Candida Species Isolated from Bloodstream Infections with Increasing Azole-Non-Susceptibility Rates: Trends from 2015-2022 Survey

Candidemia is the fourth most common healthcare-related bloodstream infection. In recent years, incidence rates of Candida parapsilosis have been on the rise, with differences in prevalence and antifungal susceptibility between countries. The aim of the present study was to evaluate temporal changes in prevalence and antifungal susceptibility of C. parapsilosis among other species causing candidemia. All candidemia episodes from January 2015 to August 2022 were evaluated in order to depict time trends in prevalence of C. parapsilosis sensu stricto among all Candida species recovered from blood cultures as well as fluconazole- and voriconazole-non-susceptibility rates. Secondary analyses evaluated time trends in prevalence and antifungal non-susceptibility according to clinical settings. The overall prevalence of C. parapsilosis was observed to increase compared to the prevalence of other Candida species over time (p-trend = 0.0124). From 2019, the number of C. parapsilosis sensu stricto isolates surpassed C. albicans, without an increase in incidence rates. Overall rates of fluconazole- and voriconazole-non-susceptible C. parapsilosis sensu stricto were both 3/44 (6.8%) in 2015 and were 32/51 (62.7%) and 27/51 (52.9%), respectively, in 2022 (85% cross-non-susceptibility). The risk of detecting fluconazole- or voriconazole-non-susceptibility was found to be higher in C. parapsilosis compared to other Candida species (odds ratio (OR) = 1.60, 95% CI [1.170, 2.188], p-value < 0.0001 and OR = 12.867, 95% CI [6.934, 23.878], p-value < 0.0001, respectively). This is the first study to report C. parapsilosis sensu stricto as the most prevalent among Candida spp. isolated from blood cultures, with worrisome fluconazole- and voriconazole-non-susceptibility rates, unparalleled among European and North American geographical regions.

Fungal pathogens and COVID-19

COVID-19 pandemic highlighted the complications of secondary fungal infections that occurred globally in severe cases of coronavirus disease managed in the intensive care units. Furthermore, varied underlying host factors, such as preexisting immunosuppression, the use of immunomodulatory agents, and invasive procedures predisposing lung tissues to fungal colonization and proliferation, caused increased susceptibility to fungal infections in COVID-19 patient populations. These invasive fungal infections directly impact the overall length of hospitalization and mortality. The most commonly reported fungal infections in patients with COVID-19 include aspergillosis, invasive candidiasis, and mucormycosis. An overall worldwide increase in the prevalence of candidiasis and aspergillosis was observed in COVID-19 patients , whereas outbreaks of mucormycosis were mainly recorded from India. Diagnostic challenges and limited antifungal treatment options make secondary fungal infections among COVID-19 patients more burdensome, which results in improper management and increased mortality.

Invasive Fungal Infections Associated with COVID-19

The COVID-19 pandemic caused >6 million deaths worldwide, often from respiratory failure. Complications frequently occurred in hospitalized patients, particularly in the intensive care unit. Among these, fungal infections were a cause of high morbidity and mortality. Invasive aspergillosis, candidiasis and mucormycosis were the most serious of these infections. Risk factors included alterations in immune defense mechanisms by COVID-19 itself, as well as immunosuppression due to various therapies utilized in severely ill patients. Diagnosis was often challenging due to lack of sensitivity of current testing. Outcomes were generally poor, due to significant co-morbidities and delayed diagnosis, with mortality rates >50% in some studies. High index of clinical suspicion is needed to facilitate early diagnosis and initiation of appropriate antifungal therapy.

The Clinical Characteristics of Bloodstream Infections Due to Candida spp. in Patients Hospitalized in Intensive Care Units during the SARS-CoV-2 Pandemic: The Results of a Multicenter Study

Candidemia is a serious health threat. Whether this infection has a greater incidence and a higher mortality rate in patients with COVID-19 is still debated. In this multicenter, retrospective, observational study, we aimed to identify the clinical characteristics associated with the 30-day mortality in critically ill patients with candidemia and to define the differences in candidemic patients with and without COVID-19. Over a three-year period (2019-2021), we identified 53 critically ill patients with candidemia, 18 of whom (34%) had COVID-19 and were hospitalized in four ICUs. The most frequent comorbidities were cardiovascular (42%), neurological (17%), chronic pulmonary diseases, chronic kidney failure, and solid tumors (13% each). A significantly higher proportion of COVID-19 patients had pneumonia, ARDS, septic shock, and were undergoing an ECMO procedure. On the contrary, non-COVID-19 patients had undergone previous surgeries and had used TPN more frequently. The mortality rate in the overall population was 43%: 39% and 46% in the COVID-19 and non-COVID-19 patients, respectively. The independent risk factors associated with a higher mortality were CVVH (HR 29.08 [CI 95% 3.37-250]) and a Charlson's score of > 3 (HR 9.346 [CI 95% 1.054-82.861]). In conclusion, we demonstrated that candidemia still has a high mortality rate in patients admitted to ICUs, irrespective of infection due to SARS-CoV-2.

Multicentre Surveillance of Candida Species from Blood Cultures during the SARS-CoV-2 Pandemic in Southern Europe (CANCoVEU Project)

Introduction: Surveillance of Candida species isolates from blood cultures (BCs) in Europe is considered fragmented, unable to allow the definition of targets of antifungal stewardship recommendations especially during the SARS-CoV-2 pandemic. Methods: We performed a multicentric retrospective study including all consecutive BC Candida isolates from six Southern European tertiary hospitals (1st January 2020 to 31st December 2021). Etiology, antifungal susceptibility patterns, and clinical setting were analyzed and compared. Results: C. albicans was the dominant species (45.1%), while C. auris was undetected. Candida species positive BC events increased significantly in COVID-19 ICUs in 2021 but decreased in other ICUs. Resistance to azole increased significantly and remained very high in C. albicans (fluconazole from 0.7% to 4.5%, p = 0.03) and C. parapsilosis complex (fluconazole up to 24.5% and voriconazole up to 8.9%), respectively. Resistance to caspofungin was remarkable in C. tropicalis (10%) and C. krusei (20%), while resistance to at least one echinocandin increased in 2021, especially in C. parapsilosis complex (from 0.8% to 5.1%, p = 0.05). Although no significant differences were observed over the study period, fluconazole and echinocandin resistance increased in COVID-19 ICUs by up to 14% and 5.8%, respectively, but remained undetected in non-intensive COVID-19 wards. Conclusions: Antifungal stewardship activities aimed at monitoring resistance to echinocandin in C. tropicalis and C. krusei, and against the spread of fluconazole resistant C. parapsilosis complex isolates are highly desirable. In COVID-19 patients, antifungal resistance was mostly present when the illness had a critical course.

The impact of COVID-19 on multidrug-resistant organisms causing healthcare-associated infections: a narrative review

Coronavirus disease 2019 (COVID-19) changed healthcare across the world. With this change came an increase in healthcare-associated infections (HAIs) and a concerning concurrent proliferation of MDR organisms (MDROs). In this narrative review, we describe the impact of COVID-19 on HAIs and MDROs, describe potential causes of these changes, and discuss future directions to combat the observed rise in rates of HAIs and MDRO infections.

Candida Genotyping of Blood Culture Isolates from Patients Admitted to 16 Hospitals in Madrid: Genotype Spreading during the COVID-19 Pandemic Driven by Fluconazole-Resistant C. parapsilosis

BACKGROUND

Candidaemia and invasive candidiasis are typically hospital-acquired. Genotyping isolates from patients admitted to different hospitals may be helpful in tracking clones spreading across hospitals, especially those showing antifungal resistance.

METHODS

We characterized Candida clusters by studying Candida isolates (C. albicans, n = 1041; C. parapsilosis, n = 354, and C. tropicalis, n = 125) from blood cultures (53.8%) and intra-abdominal samples (46.2%) collected as part of the CANDIMAD (Candida in Madrid) study in Madrid (2019-2021). Species-specific microsatellite markers were used to define the genotypes of Candida spp. found in a single patient (singleton) or several patients (cluster) from a single hospital (intra-hospital cluster) or different hospitals (widespread cluster).

RESULTS

We found 83 clusters, of which 20 were intra-hospital, 49 were widespread, and 14 were intra-hospital and widespread. Some intra-hospital clusters were first detected before the onset of the COVID-19 pandemic, but the number of clusters increased during the pandemic, especially for C. parapsilosis. The proportion of widespread clusters was significantly higher for genotypes found in both compartments than those exclusively found in either the blood cultures or intra-abdominal samples. Most C. albicans- and C. tropicalis-resistant genotypes were singleton and presented exclusively in either blood cultures or intra-abdominal samples. Fluconazole-resistant C. parapsilosis isolates belonged to intra-hospital clusters harboring either the Y132F or G458S ERG11p substitutions; the dominant genotype was also widespread.

CONCLUSIONS

the number of clusters-and patients involved-increased during the COVID-19 pandemic mainly due to the emergence of fluconazole-resistant C. parapsilosis genotypes.

Global Emergence of Resistance to Fluconazole and Voriconazole in Candida parapsilosis in Tertiary Hospitals in Spain During the COVID-19 Pandemic

BACKGROUND

Candida parapsilosis is a frequent cause of candidemia worldwide. Its incidence is associated with the use of medical implants, such as central venous catheters or parenteral nutrition. This species has reduced susceptibility to echinocandins, and it is susceptible to polyenes and azoles. Multiple outbreaks caused by fluconazole-nonsusceptible strains have been reported recently. A similar trend has been observed among the C. parapsilosis isolates received in the last 2 years at the Spanish Mycology Reference Laboratory.

METHODS

Yeast were identified by molecular biology, and antifungal susceptibility testing was performed using the European Committee on Antimicrobial Susceptibility Testing protocol. The ERG11 gene was sequenced to identify resistance mechanisms, and strain typing was carried out by microsatellite analysis.

RESULTS

We examined the susceptibility profile of 1315 C. parapsilosis isolates available at our reference laboratory between 2000 and 2021, noticing an increase in the number of isolates with acquired resistance to fluconazole, and voriconazole has increased in at least 8 different Spanish hospitals in 2020-2021. From 121 recorded clones, 3 were identified as the most prevalent in Spain (clone 10 in Catalonia and clone 96 in Castilla-Leon and Madrid, whereas clone 67 was found in 2 geographically unrelated regions, Cantabria and the Balearic Islands).

CONCLUSIONS

Our data suggest that concurrently with the coronavirus disease 2019 pandemic, a selection of fluconazole-resistant C. parapsilosis isolates has occurred in Spain, and the expansion of specific clones has been noted across centers. Further research is needed to determine the factors that underlie the successful expansion of these clones and their potential genetic relatedness.

Fluconazole-resistant Candida parapsilosis: A new emerging threat in the fungi arena

Candida parapsilosis is a leading cause of invasive candidiasis in southern Europe, Latin America and Asia. C. parapsilosis has been mostly considered susceptible to triazoles, but fluconazole resistance is on the rise in some countries. The main mechanism related to fluconazole resistance is the presence of ERG11p substitutions, dominated by the Y132F amino acid substitution. Isolates harbouring this substitution mimic C. auris given that they may cause hospital outbreaks, become endemic, and emerge simultaneously in distant areas around the world. At the moment, Spain is experiencing a brusque emergence of fluconazole resistance in C. parapsilosis; isolates harbouring the Y132F substitution were detected for the first time in 2019. A recent study on Candida spp isolates from blood cultures collected in 16 hospitals located in the Madrid metropolitan area (2019 to 2021) reported that fluconazole resistance in C. parapsilosis reached as high as 13.6%. Resistance rates rose significantly during those three years: 3.8% in 2019, 5.7% in 2020, and 29.1% in 2021; resistant isolates harboured either the dominant Y132F substitution (a single clone found in four hospitals) or G458S (another clone found in a fifth hospital). The COVID-19 pandemic may have increased the number of candidaemia cases. The reason for such an increase might be a consequence of uncontrolled intra-hospital patient-to-patient transmission in some hospitals, as an increase not only in C. parapsilosis candidaemia episodes but also in the spread of clonal fluconazole-resistant isolates might have occurred in other hospitals during the pandemic period. Patients affected with fluconazole-resistant C. parapsilosis harbouring the Y132F substitution presented a mortality rate ranging from 9% to 78%, were mainly admitted to intensive care wards but did not have differential risk factors compared to those infected by susceptible isolates. With scarce exceptions, few patients (≤20%) infected with fluconazole-resistant isolates had previously received fluconazole, thus supporting the fact that, although fluconazole might have been a key factor to promote resistance, the main driver promoting the spread of fluconazole-resistant isolates was patient-to-patient transmission.

Current Issues in Fungal Infections and COVID-19

The COVID-19 pandemic has brought up a new host for fungal invasive infections [...].

Blood and intra-abdominal Candida spp. from a multicentre study conducted in Madrid using EUCAST: emergence of fluconazole resistance in Candida parapsilosis, low echinocandin resistance and absence of Candida auris

OBJECTIVES

We prospectively monitored the epidemiology and antifungal susceptibility of Candida spp. from blood cultures and intra-abdominal samples in patients admitted to hospitals in the Madrid area.

METHODS

Between 2019 and 2021, we prospectively collected incident isolates [one per species, patient and compartment (blood cultures versus intra-abdominal samples)] from patients admitted to any of 16 hospitals located in Madrid. We studied the antifungal susceptibilities to amphotericin B, triazoles, micafungin, anidulafungin and ibrexafungerp following the EUCAST E.Def 7.3.2 procedure.

RESULTS

A total of 2107 Candida spp. isolates (1895 patients) from blood cultures (51.7%) and intra-abdominal samples were collected. Candida albicans, the Candida glabrata complex, the Candida parapsilosis complex, Candida tropicalis and Candida krusei accounted for 96.9% of the isolates; in contrast, Candida auris was undetected. Fluconazole resistance in Candida spp. was higher in blood cultures than in intra-abdominal samples (9.1% versus 8.2%; P > 0.05), especially for the C. parapsilosis complex (16.6% versus 3.6%, P < 0.05), whereas echinocandin resistance tended to be lower in blood cultures (0.5% versus 1.0%; P > 0.05). Resistance rates have risen, particularly for fluconazole in blood culture isolates, which increased sharply in 2021. Ibrexafungerp showed in vitro activity against most isolates. Species distributions and resistance rates varied among hospitals.

CONCLUSIONS

Whereas no C. auris isolates were detected, fluconazole-resistant C. parapsilosis isolates have been spreading across the region and this has pulled up the rate of fluconazole resistance. In contrast, the rate of echinocandin resistance continues to be low.

Global Prevalence of Antifungal-Resistant Candida parapsilosis: A Systematic Review and Meta-Analysis

A reliable estimate of Candida parapsilosis antifungal susceptibility in candidemia patients is increasingly important to track the spread of C. parapsilosis bloodstream infections and define the true burden of the ongoing antifungal resistance. A systematic review and meta-analysis (SRMA) were conducted aiming to estimate the global prevalence and identify patterns of antifungal resistance. A systematic literature search of the PubMed, Scopus, ScienceDirect and Google Scholar electronic databases was conducted on published studies that employed antifungal susceptibility testing (AFST) on clinical C. parapsilosis isolates globally. Seventy-nine eligible studies were included. Using meta-analysis of proportions, the overall pooled prevalence of three most important antifungal drugs; Fluconazole, Amphotericin B and Voriconazole resistant C. parapsilosis were calculated as 15.2% (95% CI: 9.2–21.2), 1.3% (95% CI: 0.0–2.9) and 4.7% (95% CI: 2.2–7.3), respectively. Based on study enrolment time, country/continent and AFST method, subgroup analyses were conducted for the three studied antifungals to determine sources of heterogeneity. Timeline and regional differences in C. parapsilosis prevalence of antifungal resistance were identified with the same patterns among the three antifungal drugs. These findings highlight the need to conduct further studies to assess and monitor the growing burden of antifungal resistance, to revise treatment guidelines and to implement regional surveillance to prevent further increase in C. parapsilosis drug resistance emerging recently.

Evidence of Fluconazole-Resistant Candida parapsilosis Genotypes Spreading across Hospitals Located in Madrid, Spain and Harboring the Y132F ERG11p Substitution

We have been monitoring the antifungal resistance in Candida parapsilosis isolates collected from inpatients at Madrid metropolitan area hospitals for the last 3 years. The study aimed to elucidate the presence of fluconazole-resistant C. parapsilosis genotypes in Madrid. From January 2019 to December 2021, a total of 354 C. parapsilosis isolates (n = 346 patients) from blood (76.6%) or intraabdominal samples were collected and genotyped using species-specific microsatellite markers. Antifungal susceptibilities to amphotericin B, the triazoles, micafungin, anidulafungin, and ibrexafungerp were performed according to EUCAST E.Def 7.3.2; the ERG11 gene was sequenced in fluconazole-resistant isolates. A total of 13.6% (n = 48/354) isolates (one per patient) were found to be resistant to fluconazole and non-wild-type to voriconazole but fully susceptible to ibrexafungerp. Resistant isolates were mostly sourced from blood (n = 45/48, 93.8%) and were detected in five hospitals. Two hospitals accounted for a high proportion of resistant isolates (n = 41/48). Resistant isolates harbored either the Y132F ERG11p amino acid substitution (n = 43) or the G458S substitution (n = 5). Isolates harboring the Y132F substitution clustered into a clonal complex involving three genotypes (one genotype accounted for n = 39/43 isolates) that were found in four hospitals. Isolates harboring the G458S substitution clustered into another genotype found in a fifth hospital. C. parapsilosis genotypes demonstrating resistance to fluconazole have been spreading across hospitals in Madrid, Spain. Over the last 3 years, the frequency of isolation of such isolates and the number of hospitals affected is on the rise.

Risk factors and outcomes of fungal superinfections in patients with severe COVID-19: an observational study from Pisa academic hospital

Background

Superinfections acquired during the hospital course represent common complications in COVID-19 patients. Several studies reported an increasing incidence of COVID-19 associated pulmonary aspergillosis (CAPA) and candidaemia. The aim of this study is to describe fungal superinfections in a large cohort of hospitalized patients with COVID-19 and identify factors independently associated with the risk of fungal superinfections.

Methods

Observational study including patients with COVID-19 admitted to the tertiary-care, University Hospital of Pisa, Italy from April 2020 to May 2021. Patients with pneumonia and laboratory confirmed SARS-CoV-2 infection with a RT-PCR test on a nasopharyngeal swab, were eligible for the study. Patients who died within 24 hours from admission and those with missing data were excluded. Data about fungal superinfections were collected. To identify factors independently associated with the development of fungal superinfections, a multivariate regression analysis was performed.

Results

Among 983 patients with COVID-19, 52 (5.3%) fungal superinfections were detected. Fungal superinfections included: 24/52 (46%) CAPA, 27/52 (51.9%) episodes of candidaemia and 1 case of pulmonary pneumocystosis in a haematological patient. All patients with CAPA were cared for in intensive care unit (ICU). The majority of patients received liposomal amphotericin B as antifungal treatment (83.3%). In-hospital mortality was 41.7%. Among 27 episodes of candidaemia, 16 (59.3%) occurred in ICU while 11 (40.7%) in medical wards. In-hospital mortality was 14.8%. Overall, patients with fungal superinfections had a median age of 73 (IQRs 59-77) years and a median length of ICU stay of 40 (17-50) days. In-hospital mortality among all patients with superinfections was 28.8%. On multivariable analysis, ICU stay (OR 17.63, 95% CI 8.3-37.41, p<0.001), high-dose steroids (OR 13.48, 95% CI 6.68-27.26, p<0.001), and diabetes mellitus (OR 2.14, 95% CI 1.09-4.17, p=0.026) were factors independently associated with the risk of developing a fungal superinfection.

Conclusions

Fungal superinfections may complicate the hospital course of COVID-19 patients, especially of those admitted to ICU. Surveillance with detection of galactomannan on bronchoalveolar lavage in patients with clinical deterioration should be performed. A rational use of steroids is essential to avoid the risk of developing a fungal superinfection.