Invasive Fungal Infections Complicating COVID-19: A Narrative Review

"A decade of candidaemia: A comprehensive analysis of prognosis and risk factors at a Belgian tertiary hospital"

Candidemia, predominantly caused by C. albicans, poses a significant threat in hospitals. Yet, non-albicans candidemia (NAC) and antifungal resistance are increasing concerns. This retrospective study at CHU UCL Namur Mont-Godinne, a Belgian university hospital, from January 2013 to February 2023, analyzed 148 candidemia cases. The mean annual incidence was 0.94 per 1000 admissions, with a notable surge in C. albicans cases in 2020, possibly due to COVID-19. Candidemia was most prevalent in the ICU (48 %), with C. albicans (57.1 %) and C. glabrata (18.4 %) being the predominant species and a 30-day mortality rate of 38 %. NAC was significantly higher in the hematology unit (81 %). Notably, no echinocandin resistance was observed, while fluconazoleresistance remained stable at 10 %. NAC was associated with azole resistance. This study provides a decade-long overview of candidemia at CHU UCL Namur Mont-Godinne, offering valuable insights into its epidemiology and clinical characteristics in Belgian hospital settings.

A prediction model for secondary invasive fungal infection among severe SARS-CoV-2 positive patients in ICU

Background

The global COVID-19 pandemic has resulted in over seven million deaths, and IFI can further complicate the clinical course of COVID-19. Coinfection of COVID-19 and IFI (secondary IFI) pose significant threats not only to healthcare systems but also to patient lives. After the control measures for COVID-19 were lifted in China, we observed a substantial number of ICU patients developing COVID-19-associated IFI. This creates an urgent need for predictive assessment of COVID-19 patients in the ICU environment for early detection of suspected fungal infection cases.

Methods

This study is a single-center, retrospective research endeavor. We conducted a case-control study on severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) positive patients. The cases consisted of patients who developed any secondary IFI during their ICU stay at Jilin University China-Japan Union Hospital in Changchun, Jilin Province, China, from December 1st, 2022, to August 31st, 2023. The control group consisted of SARS-CoV-2 positive patients without secondary IFI. Descriptive and comparative analyses were performed, and a logistic regression prediction model for secondary IFI in COVID-19 patients was established. Additionally, we observed an increased incidence of COVID-19-associated pulmonary aspergillosis (CAPA) during this pandemic. Therefore, we conducted a univariate subgroup analysis on top of IFI, using non-CAPA patients as the control subgroup.

Results

From multivariate analysis, the prediction model identified 6 factors that are significantly associated with IFI, including the use of broad-spectrum antibiotics for more than 2 weeks (aOR=4.14, 95% CI 2.03-8.67), fever (aOR=2.3, 95%CI 1.16-4.55), elevated log IL-6 levels (aOR=1.22, 95% CI 1.04-1.43) and prone position ventilation (aOR=2.38, 95%CI 1.15-4.97) as independent risk factors for COVID-19 secondary IFI. High BMI (BMI ≥ 28 kg/m2) (aOR=0.85, 95% CI 0.75-0.94) and the use of COVID-19 immunoglobulin (aOR=0.45, 95% CI 0.2-0.97) were identified as independent protective factors against COVID-19 secondary IFI. The Receiver Operating Curve (ROC) area under the curve (AUC) of this model was 0.81, indicating good classification.

Conclusion

We recommend paying special attention for the occurrence of secondary IFI in COVID-19 patients with low BMI (BMI < 28 kg/m2), elevated log IL-6 levels and fever. Additionally, during the treatment of COVID-19 patients, we emphasize the importance of minimizing the duration of broad-spectrum antibiotic use and highlight the potential of immunoglobulin application in reducing the incidence of IFI.

Demographic characteristics and risk factors for invasive fungal sinusitis in the context of COVID-19: A systematic review and meta-analysis

OBJECTIVES

To identify the demographic characteristics and potential risk factors of invasive fungal sinusitis (IFS) patients with Coronavirus Disease in 2019 (COVID-19).

METHODS

Web of Science, Embase, the Cochrane Library, and PubMed were searched from database inception to August 2023 using the combination of medical searching heading terms "invasive fungal sinusitis" and "COVID-19" and their free words. The research protocol was registered on PROSPERO (CRD42023467175).

RESULTS

A total of 53 studies were included. The mean age of IFS patients with COVID-19 was 53.72 (95% credible interval [CI]: 51.08, 56.36), with 66% males (95% CI: 0.62, 0.70), and 81% diabetes (95% CI: 0.77, 0.86). The mean time from COVID-19 diagnosis to IFS onset was 19.09 days (95% CI: 16.96, 21.22). The percentage of patients with COVID-19 PCR positivity was 33% (95% CI: 0.21, 0.45). Overall, 71% of patients receiving steroid therapy during COVID-19 infection (95% CI: 0.63, 0.78). The odds ratio of diabetes mellitus, steroid administration, and COVID-19 PCR positivity were 6.09, 2.21, and 1.82, respectively. COVID-19 infection did not affect the IFS stage.

CONCLUSION

IFS patients with COVID-19 had an average age of 53.72 years and were predominantly males, with a mean interval of 19.09 days from COVID-19 diagnosis to IFS onset. Diabetes, steroid administration, and COVID-19 PCR positivity were risk factors.

Persistent fever after coronavirus disease 2019 in liver/kidney transplant recipient

In this case, a 64-year-old male with a history of simultaneous orthotopic liver transplant and cadaveric renal transplant presented five years prior presented with persistent fevers two days after a positive SARS-CoV-2 nasal PCR. A CT scan of the chest on hospital day nine revealed innumerable 1-2 mm nodules in a miliary pattern throughout the lung. (1,3)-β-D-glucan on hospital day 11 was 133 pg/mL. In this article, the approach, diagnostic and management strategies for patients with persistent fevers after diagnosis of COVID-19 in a transplant recipient are discussed.

The potential for rapid antigen testing for mucormycosis in the context of COVID-19

INTRODUCTION

Mucormycosis is a highly aggressive angio-invasive disease of humans caused by Mucorales fungi. Prior to the COVID-19 pandemic, mucormycosis was a rare mycosis typically seen in immunocompromised patients with hematological malignancies or in transplant recipients. During the second wave of the pandemic, there was a dramatic increase in the disease, especially in India where a unique set of circumstances led to large numbers of life-threatening and disfiguring rhino-orbital-cerebral mucormycosis (ROCM) infections.

AREAS COVERED

The review examines mucormycosis as a super-infection of COVID-19 patients, and the risk factors for COVID-19-associated mucormycosis (CAM) that drove the ROCM epidemic in India. The limitations of current diagnostic procedures are identified, and the measures needed to improve the speed and accuracy of detection discussed.

EXPERT OPINION

Despite increased awareness, global healthcare systems remain unprepared for further outbreaks of ROCM. Current diagnosis of the disease is slow and inaccurate, negatively impacting on patient survival. This is most evident in low- to middle-income countries which lack suitably equipped diagnostic facilities for rapid identification of the infecting pathogens. Rapid antigen testing using point-of-care lateral-flow assays could potentially have aided in the quick and accurate diagnosis of the disease, allowing earlier intervention with surgery and Mucorales-active antifungal drugs.

Long-term survival following medical management of Aspergillus endocarditis with dissemination as a consequence of steroid therapy in severe COVID-19 pneumonia

A male in his 40's with no known comorbidities developed severe COVID-19 pneumonia and received a four-week course of methylprednisolone. The patient subsequently developed disseminated Aspergillus endocarditis, manifesting as multiple organ involvement including the heart, eyes, and brain. Despite the poor prognosis generally associated with fungal endocarditis, the patient survived following aggressive medical management with a combination of liposomal amphotericin b and voriconazole therapy and is now doing well for over two years and is off antifungal therapy for a year.

Coronavirus disease 2019 (COVID-19)-associated brain abscesses caused by Pseudomonas aeruginosa and Aspergillus fumigatus: two case and a review of the literature

BACKGROUND

Bacterial and fungal superinfections are commonly reported in patients with coronavirus disease 2019.

CASE PRESENTATION

We report the first case of brain and intramedullary abscesses caused by Pseudomonas aeruginosa and a rare case of brain abscesses caused by Aspergillus fumigatus in two post-coronavirus disease 2019 patients. The first patient-34-year-old Iranian woman-presented with weakness of the left upper limb, headaches, and lower limb paresthesia. She had a history of undiagnosed diabetes and had received corticosteroid therapy. The second patient-45-year-old Iranian man-presented with right-sided weakness and had a history of intensive care unit admission. Both patients passed away despite appropriate medical therapy.

CONCLUSION

The immune dysregulation induced by coronavirus disease 2019 and its' treatments can predispose patients, especially immunosuppressed ones, to bacterial and fungal infections with unusual and opportunistic pathogens in the central nervous system. Pseudomonas aeruginosa and Aspergillus fumigatus should be considered as potential causes of brain infection in any coronavirus disease 2019 patient presenting with neurological symptoms and evidence of brain abscess in imaging, regardless of sinonasal involvement. These patients should get started on appropriate antimicrobial therapy as soon as possible, as any delay in diagnosis or treatment can be associated with adverse outcomes.

Antifungal Activities of Natural Products and Their Hybrid Molecules

The increasing cases of drug resistance and high toxicity associated with the currently used antifungal agents are a worldwide public health concern. There is an urgent need to develop new antifungal drugs with unique target mechanisms. Plant-based compounds, such as carvacrol, eugenol, coumarin, cinnamaldehyde, curcumin, thymol, etc., have been explored for the development of promising antifungal agents due to their diverse biological activities, lack of toxicity, and availability. However, researchers around the world are unable to fully utilize the potential of natural products due to limitations, such as their poor bioavailability and aqueous solubility. The development of hybrid molecules containing natural products is a promising synthetic approach to overcome these limitations and control microbes' capability to develop resistance. Based on the potential advantages of hybrid compounds containing natural products to improve antifungal activity, there have been different reported synthesized hybrid compounds. This paper reviews different literature to report the potential antifungal activities of hybrid compounds containing natural products.

Genomic Epidemiology Identifies Azole Resistance Due to TR34/L98H in European Aspergillus fumigatus Causing COVID-19-Associated Pulmonary Aspergillosis

Aspergillus fumigatus has been found to coinfect patients with severe SARS-CoV-2 virus infection, leading to COVID-19-associated pulmonary aspergillosis (CAPA). The CAPA all-cause mortality rate is approximately 50% and may be complicated by azole resistance. Genomic epidemiology can help shed light on the genetics of A. fumigatus causing CAPA, including the prevalence of resistance-associated alleles. We present a population genomic analysis of 21 CAPA isolates from four European countries with these isolates compared against 240 non-CAPA A. fumigatus isolates from a wider population. Bioinformatic analysis and antifungal susceptibility testing were performed to quantify resistance and identify possible genetically encoded azole-resistant mechanisms. The phylogenetic analysis of the 21 CAPA isolates showed that they were representative of the wider A. fumigatus population with no obvious clustering. The prevalence of phenotypic azole resistance in CAPA was 14.3% (n = 3/21); all three CAPA isolates contained a known resistance-associated cyp51A polymorphism. The relatively high prevalence of azole resistance alleles that we document poses a probable threat to treatment success rates, warranting the enhanced surveillance of A. fumigatus genotypes in these patients. Furthermore, potential changes to antifungal first-line treatment guidelines may be needed to improve patient outcomes when CAPA is suspected.

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.

Secondary pulmonary infection by Fusarium solani and Aspergillus niger during systemic steroid treatment for COVID-19: A case report

BACKGROUND

Coronavirus disease 2019 (COVID-19)-associated invasive pulmonary aspergillosis presents a diagnostic challenge due to its non-specific clinical/ imaging features, as well as the fact that the proposed clinically diagnostic algorithms do not necessarily apply to COVID-19 patients. In addition, Fusarium spp. is a rare cause of opportunistic life-threatening fungal infections. Disseminated Fusarium infection in an immunocompromised host is intractable, with a high likelihood of resulting mortality. To our knowledge, this is the first case of secondary pulmonary infection by Fusarium solani (F. solani) and Aspergillus niger (A. niger) during systemic steroid treatment for COVID-19.

CASE SUMMARY

A 62-year-old male was transported to our hospital by ambulance with a complaint of fever and dyspnea. We established a diagnosis of pneumococcal pneumonia, complicated with COVID-19 and septic shock, together with acute renal failure. He was admitted to the intensive care unit, to be treated with piperacillin/tazobactam, vancomycin, and 6.6 mg per day of dexamethasone sodium phosphate, along with noradrenaline as a vasopressor, ventilator management, and continuous hemodiafiltration. His condition improved, and we finished the vasopressor on the fifth hospital day. We administered dexamethasone for ten days, and finished the course of treatment. On the eleventh day, patient respiratory deterioration was observed, and a computed tomography scan showed an exacerbation of bilateral ground-glass-opacity-like consolidation, together with newly appeared cavitary lesions in the lung. we changed antibiotics to meropenem plus vancomycin. In addition, a fungal infection was considered as a possibility based on microscopic findings of sputum, and we began coadministration of voriconazole. However, the pneumonia worsened, and the patient died on the seventeenth day of illness. Later, F. solani and A. niger were identified from sputum collected on the twelfth day. It was believed that he developed a cell-mediated immune deficiency during COVID-19 treatment, which led to the complication of pneumonia caused by the above-mentioned fungi, contributing to his death.

CONCLUSION

Because early initiation of intense antifungal therapy offers the best chance for survival in pulmonary fusariosis, computed tomography scans and appropriate microbiologic investigations should be obtained for severely immunocompromised patients.

Insights on Covid-19 with superimposed pulmonary histoplasmosis: The possible nexus

A novel coronavirus (CoV) known as severe acute respiratory syndrome CoV type 2 is the causative agent for the development of CoV disease 2019 (Covid-19). Covid-19 may increase the risk of developing pulmonary histoplasmosis due to immune dysregulation. In addition, Covid-19 may enhance the propagation of acute pulmonary histoplasmosis due to lung injury and inflammation, and using corticosteroids in severely affected Covid-19 patients may reactivate latent pulmonary histoplasmosis. Likewise, activation of inflammatory signaling pathways during H. capsulatum infection may increase the severity of Covid-19 and vice versa. Furthermore, lymphopenia in Covid-19 may increase the risk for the progress of pulmonary histoplasmosis besides activation of inflammatory signaling pathways during H. capsulatum infection may increase the severity of Covid-19 and vice versa. Therefore, this critical review aimed to find the potential link between Covid-19 pneumonia and pulmonary histoplasmosis concerning the immunological response.

Trends in the Epidemiology of Pneumocystis Pneumonia in Immunocompromised Patients without HIV Infection

The increasing morbidity and mortality of life-threatening Pneumocystis pneumonia (PCP) in immunocompromised people poses a global concern, prompting the World Health Organization to list it as one of the 19 priority invasive fungal diseases, calling for increased research and public health action. In response to this initiative, we provide this review on the epidemiology of PCP in non-HIV patients with various immunodeficient conditions, including the use of immunosuppressive agents, cancer therapies, solid organ and stem cell transplantation, autoimmune and inflammatory diseases, inherited or primary immunodeficiencies, and COVID-19. Special attention is given to the molecular epidemiology of PCP outbreaks in solid organ transplant recipients; the risk of PCP associated with the increasing use of immunodepleting monoclonal antibodies and a wide range of genetic defects causing primary immunodeficiency; the trend of concurrent infection of PCP in COVID-19; the prevalence of colonization; and the rising evidence supporting de novo infection rather than reactivation of latent infection in the pathogenesis of PCP. Additionally, we provide a concise discussion of the varying effects of different immunodeficient conditions on distinct components of the immune system. The objective of this review is to increase awareness and knowledge of PCP in non-HIV patients, thereby improving the early identification and treatment of patients susceptible to PCP.

Xanthone synthetic derivatives with high anticandidal activity and positive mycostatic selectivity index values

With the current massive increases in drug-resistant microbial infection as well as the significant role of fungal infections in the death toll of COVID-19, discovering new antifungals is extremely important. Natural and synthetic xanthones are promising derivatives, although only few reports have demonstrated their antifungal mechanism of action in detail. Newly synthetized by us xanthone derivative 44 exhibited strong antifungal activity against reference and fluconazole resistant C. albicans strains. Our results indicate that the most active compounds 42 and 44 are not substrates for fungal ABC transporters (Cdr1p and Cdr2p) and Mdr1p, the main representative of the major facilitator superfamily efflux pumps, membrane proteins that are responsible for the development of resistance. Moreover, fungicidal mode of action reduces the probability of persistent or recurrent infections and resistance development. In this light, the demonstrated killing activity of the examined derivatives is their undoubted advantage. Novel synthesized compounds exhibited moderate cytotoxicity against human cell lines, although the selectivity index value for human pathogenic strains remained favourable. Our results also indicate that novel synthetized compounds 42 and 44 with antifungal activity target yeast topoisomerase II activity. In summary, further validation of xanthones applicability as antifungals is highly valuable.

The Impact of COVID-19 on the Epidemiology and Outcomes of Candidemia: A Retrospective Study from a Tertiary Care Center in Lebanon

Invasive fungal infections, notably candidemia, have been associated with COVID-19. The epidemiology of candidemia has significantly changed during the COVID-19 pandemic. We aim to identify the microbiological profile, resistance rates, and outcomes of COVID-19-associated candidemia (CAC) compared to patients with candidemia not associated with COVID-19. We retrospectively collected data on patients with candidemia admitted to the American University of Beirut Medical Center between 2004 and 2022. We compared the epidemiology of candidemia during and prior to the COVID-19 pandemic. Additionally, we compared the outcomes of critically ill patients with CAC to those with candidemia without COVID-19 from March 2020 till March 2022. Among 245 candidemia episodes, 156 occurred prior to the pandemic and 89 during the pandemic. Of the latter, 39 (43.8%) were CAC, most of which (82%) were reported from intensive care units (ICU). Non-albicans Candida (NAC) spp. were predominant throughout the study period (67.7%). Candida auris infection was the most common cause of NAC spp. in CAC. C. glabrata had decreased susceptibility rates to fluconazole and caspofungin during the pandemic period (46.1% and 38.4%, respectively). The mortality rate in the overall ICU population during the pandemic was 76.6%, much higher than the previously reported candidemia mortality rate observed in studies involving ICU patients. There was no significant difference in 30-day mortality between CAC and non-CAC (75.0% vs. 78.1%; p = 0.76). Performing ophthalmic examination (p = 0.002), CVC removal during the 48 h following the candidemia (p = 0.008) and speciation (p = 0.028) were significantly associated with a lower case-fatality rate. The epidemiology of candidemia has been significantly affected by the COVID-19 pandemic at our center. Rigorous infection control measures and proper antifungal stewardship are essential to combat highly resistant species such as C. auris.

Bacterial and fungal superinfections are detected at higher frequency in critically ill patients affected by SARS CoV-2 infection than negative patients and are associated to a worse outcome

Patients with viral infections are at higher risk to acquire bacterial and fungal superinfections associated with a worse prognosis. We explored this critical point in the setting of patients with severe COVID-19 disease. The study included 1911 patients admitted to intensive care unit (ICU) during a 2-year study period (March 2020-March 2022). Of them, 713 (37.3%) were infected with SARS-CoV-2 and 1198 were negative (62.7%). Regression analysis was performed to determine risk factors associated with the presence of bacterial and/or fungal superinfections in SARS-CoV-2 patients and to evaluate predictors of ICU mortality. Of the 713 patients with SARS-CoV-2 infection, 473 (66.3%) had respiratory and/or bloodstream bacterial and/or fungal superinfections, while of the 1198 COVID-19-negative patients, only 369 (30%) showed respiratory and/or bloodstream bacterial and/or fungal superinfections (p < 0.0001). Baseline characteristics of COVID-19 patients included a median age of 66 (interquartile range [IQR], 58-73), a predominance of males (72.7%), and the presence of a BMI higher than 24 (median 26; IQR, 24.5-30.4). Seventy-four percent (527, 73.9%) had one or more comorbidities and 135 (18.9%) of them had received previous antibiotic therapy. Furthermore, most of them (473, 66.3%) exhibited severe radiological pictures and needed invasive mechanical ventilation. Multivariate logistic regression analysis showed that 1 unit increment in BMI rises the risk of bacterial and/or fungal superinfections acquisition by 3% and 1-day increment in ICU stays rises the risk of bacterial and/or fungal superinfections acquisition by 11%. Furthermore, 1-day increment in mechanical ventilation rises the risk of bacterial and/or fungal superinfection acquisition by 2.7 times. Furthermore, patients with both bacterial and fungal infections had a significantly higher mortality rate than patients without superinfections (45.8% vs. 26.2%, p < 0.0001). Therefore, bacterial and fungal superinfections are frequent in COVID-19 patients admitted to ICU and their presence is associated with a worse outcome. This is an important consideration for targeted therapies in critically ill SARS-CoV-2 infected patients to improve their clinical course.

Antifungal Activity and Potential Action Mechanism of Allicin against Trichosporon asahii

Trichosporon asahii is an emerging opportunistic pathogen that causes potentially fatal disseminated trichosporonosis. The global prevalence of coronavirus disease 2019 (COVID-19) poses an increasing fungal infection burden caused by T. asahii. Allicin is the main biologically active component with broad-spectrum antimicrobial activity in garlic. In this study, we performed an in-depth analysis of the antifungal characteristics of allicin against T. asahii based on physiological, cytological, and transcriptomic assessments. In vitro, allicin inhibited the growth of T. asahii planktonic cells and biofilm cells significantly. In vivo, allicin improved the mean survival time of mice with systemic trichosporonosis and reduced tissue fungal burden. Electron microscopy observations clearly demonstrated damage to T. asahii cell morphology and ultrastructure caused by allicin. Furthermore, allicin increased intracellular reactive oxygen species (ROS) accumulation, leading to oxidative stress damage in T. asahii cells. Transcriptome analysis showed that allicin treatment disturbed the biosynthesis of cell membrane and cell wall, glucose catabolism, and oxidative stress. The overexpression of multiple antioxidant enzymes and transporters may also place an additional burden on cells, causing them to collapse. Our findings shed new light on the potential of allicin as an alternative treatment strategy for trichosporonosis. IMPORTANCE Systemic infection caused by T. asahii has recently been recognized as an important cause of mortality in hospitalized COVID-19 patients. Invasive trichosporonosis remains a significant challenge for clinicians, due to the limited therapeutic options. The present work suggests that allicin holds great potential as a therapeutic candidate for T. asahii infection. Allicin demonstrated potent in vitro antifungal activity and potential in vivo protective effects. In addition, transcriptome sequencing provided valuable insights into the antifungal effects of allicin.

Changing Trends in the Incidence and Clinical Features of Pneumocystis jirovecii Pneumonia in Non-HIV Patients before and during the COVID-19 Era and Risk Factors for Mortality between 2016 and 2022

Fungal superinfections have been reported in patients with coronavirus disease 2019 (COVID-19). We analyzed the incidence and clinical characteristics of Pneumocystis jirovecii pneumonia (PCP) in non-human immunodeficiency virus patients at a tertiary hospital between 2016 and 2022 to evaluate the impact of the COVID-19 pandemic on PCP. The study period was divided into pre-COVID-19 and COVID-19 eras based on the pandemic declaration by the World Health Organization. Among the 113 patients included, the incidence of PCP in the COVID-19 era (37/1000 patient-years) was significantly higher than that in the pre-COVID-19 era (13.1/1000 patient-years) (p < 0.001). Co-infection with invasive pulmonary aspergillosis (IPA) also increased (2.4% vs. 18.3%, p = 0.013). Independent risk factors for PCP-related mortality were previous glucocorticoid use, hypoxemia, acute kidney injury, and IPA co-infection. Risk factors for IPA in patients with PCP included previous use of tyrosine kinase inhibitors, COVID-19 infection within 30 days, leukopenia, and intensive care unit admission. In the COVID-19 era, 12 (16.9%) patients with PCP had a history of COVID-19 infection within 90 days; however, infection was not associated with mortality. Active evaluation of patients with suspected PCP and assessment of IPA co-infection risk may help improve the outcomes of patients with PCP.

Fungal Infections in the ICU during the COVID-19 Pandemic in Mexico

Background: Invasive Fungal Infections (IFI) are emergent complications of COVID-19. In this study, we aim to describe the prevalence, related factors, and outcomes of IFI in critical COVID-19 patients. Methods: We conducted a nested case-control study of all COVID-19 patients in the intensive care unit (ICU) who developed any IFI and matched age and sex controls for comparison (1:1) to evaluate IFI-related factors. Descriptive and comparative analyses were made, and the risk factors for IFI were compared versus controls. Results: We found an overall IFI prevalence of 9.3% in COVID-19 patients in the ICU, 5.6% in COVID-19-associated pulmonary aspergillosis (CAPA), and 2.5% in invasive candidiasis (IC). IFI patients had higher SOFA scores, increased frequency of vasopressor use, myocardial injury, and more empirical antibiotic use. CAPA was classified as possible in 68% and 32% as probable by ECMM/ISHAM consensus criteria, and 57.5% of mortality was found. Candidemia was more frequent for C. parapsilosis Fluconazole resistant outbreak early in the pandemic, with a mortality of 28%. Factors related to IFI in multivariable analysis were SOFA score > 2 (aOR 5.1, 95% CI 1.5-16.8, p = 0.007) and empiric antibiotics for COVID-19 (aOR 30, 95% CI 10.2-87.6, p = <0.01). Conclusions: We found a 9.3% prevalence of IFIs in critically ill patients with COVID-19 in a single center in Mexico; factors related to IFI were associated with higher SOFA scores and empiric antibiotic use for COVID-19. CAPA is the most frequent type of IFI. We did not find a mortality difference.

Coccidioidomycosis and Host Microbiome Interactions: What We Know and What We Can Infer from Other Respiratory Infections

Between 70 and 80% of Valley fever patients receive one or more rounds of antibiotic treatment prior to accurate diagnosis with coccidioidomycosis. Antibiotic treatment and infection (bacterial, viral, fungal, parasitic) often have negative implications on host microbial dysbiosis, immunological responses, and disease outcome. These perturbations have focused on the impact of gut dysbiosis on pulmonary disease instead of the implications of direct lung dysbiosis. However, recent work highlights a need to establish the direct effects of the lung microbiota on infection outcome. Cystic fibrosis, chronic obstructive pulmonary disease, COVID-19, and M. tuberculosis studies suggest that surveying the lung microbiota composition can serve as a predictive factor of disease severity and could inform treatment options. In addition to traditional treatment options, probiotics can reverse perturbation-induced repercussions on disease outcomes. The purpose of this review is to speculate on the effects perturbations of the host microbiome can have on coccidioidomycosis progression. To do this, parallels are drawn to aa compilation of other host microbiome infection studies.

COLONIZATION AND AZOLE RESISTANCE OF OROPHARYNGEAL CANDIDA FUNGI IN INTENSIVE CARE PATIENTS WITH COVID-19

Patients with COVID-19 are susceptible to developing oropharyngeal candidiasis and invasive candidiasis. Invasive fungal infections can complicate the clinical course of COVID-19 and are associated with a substantially increased mortality. An important reason for the successful treatment of candidiasis is to determine the sensitivity of clinical fungal isolates to antimycotics. A microbiological study of oropharyngeal swabs was performed in 54 patients aged 33 to 94 years (mean age 67.4 years) with severe and extremely severe COVID-19, who were treated in the intensive care unit at the height of clinical manifestations. Most patients (95%) had comorbidities: hypertension (68.5%), diabetes mellitus (24%), coronary artery disease (22.2%), chronic heart failure (38.9%), obesity (23.8%), cardiac arrhythmias (20.4%), chronic cerebral ischemia (56.1%), varicose veins of the lower extremities (5.5%), chronic kidney disease (20.4%), liver cirrhosis (5.5%), HIV infection (5.5%). A comparative analysis of oropharyngeal microbial biocenosis showed differences in the frequency of occurrence of opportunistic microbial species, as well as in the number of members in microbial associations. Polyspecific fungal-bacterial associations were more common and dominated polyspecific bacterial associations. According to the results, a high frequency of oropharyngeal colonization in patients with severe COVID-19 by strains of fungi of the genus Candida was established. The vast majority of strains of fungi of the genus Candida (85.2%) were resistant to antimycotics of the azole group. A high frequency (85.2%) of oropharyngeal colonization in resuscitation patients with azole-resistant strains of fungi of the genus Candida was revealed. C. albicans dominated among Candida. C. albicans was isolated in 37 (68.5%) patients, C. pararapsilosis - in 6 (11.1%), C. tropicalis - in 3 (5.5%), C. krusei - in 2 (3.7%) %), C. kefyr - in 1 (1.9%), C. glabrata - in 1 (1.9%) patient. In 11 (20.4%) patients, associations of C. albicans and other Candida species were identified. The level of fungi in the material was etiologically significant (104 105 CFU/tamp.) in 80% of patients. The vast majority of strains (more than 70%) were resistant to fluconazole and voriconazole, which should be taken into account when prescribing candidiasis therapy in patients with COVID-19. The MIC for fluconazole against C. albicans strains was 1024 g/ml for 4 isolates, 512 g/ml for 7 isolates, and 128 g/ml for 15 isolates. The maximum MIC values ​​for voriconazole against C. albicans was 256 g/ml.

Microbial and clinical epidemiology of invasive fungal rhinosinusitis in hospitalized COVID-19 patients, the divergent causative agents

Since COVID-19 spread worldwide, invasive fungal rhinosinusitis (IFRS) has emerged in immunocompromised patients as a new clinical challenge. In this study, clinical specimens of 89 COVID-19 patients who presented clinical and radiological evidence suggestive of IFRS were examined by direct microscopy, histopathology, and culture, and the isolated colonies were identified through DNA sequence analysis. Fungal elements were microscopically observed in 84.27% of the patients. Males (53.9%) and patients over 40 (95.5%) were more commonly affected than others. Headache (94.4%) and retro-orbital pain (87.6%) were the most common symptoms, followed by ptosis/proptosis/eyelid swelling (52.8%), and 74 patients underwent surgery and debridement. The most common predisposing factors were steroid therapy (n = 83, 93.3%), diabetes mellitus (n = 63, 70.8%), and hypertension (n = 42, 47.2%). The culture was positive for 60.67% of the confirmed cases, and Mucorales were the most prevalent (48.14%) causative fungal agents. Different species of Aspergillus (29.63%) and Fusarium (3.7%) and a mix of two filamentous fungi (16.67%) were other causative agents. For 21 patients, no growth was seen in culture despite a positive result on microscopic examinations. In PCR-sequencing of 53 isolates, divergent fungal taxons, including 8 genera and 17 species, were identified as followed: Rhizopus oryzae (n = 22), Aspergillus flavus (n = 10), A. fumigatus (n = 4), A. niger (n = 3), R. microsporus (n = 2), Mucor circinelloides, Lichtheimia ramosa, Apophysomyces variabilis, A. tubingensis, A. alliaceus, A. nidulans, A. calidoustus, Fusarium fujikuroi/proliferatum, F. oxysporum, F. solani, Lomentospora prolificans, and Candida albicans (each n = 1). In conclusion, a diverse set of species involved in COVID-19-associated IFRS was observed in this study. Our data encourage specialist physicians to consider the possibility of involving various species in IFRS in immunocompromised and COVID-19 patients. In light of utilizing molecular identification approaches, the current knowledge of microbial epidemiology of invasive fungal infections, especially IFRS, may change dramatically.

Yeast Bloodstream Infections in the COVID-19 Patient: A Multicenter Italian Study (FiCoV Study)

Fungemia is a co-infection contributing to the worsening of the critically ill COVID-19 patient. The multicenter Italian observational study FiCoV aims to estimate the frequency of yeast bloodstream infections (BSIs), to describe the factors associated with yeast BSIs in COVID-19 patients hospitalized in 10 hospitals, and to analyze the antifungal susceptibility profiles of the yeasts isolated from blood cultures. The study included all hospitalized adult COVID-19 patients with a yeast BSI; anonymous data was collected from each patient and data about antifungal susceptibility was collected. Yeast BSI occurred in 1.06% of patients, from 0.14% to 3.39% among the 10 participating centers. Patients were mainly admitted to intensive or sub-intensive care units (68.6%), over 60 years of age (73%), with a mean and median time from the hospitalization to fungemia of 29 and 22 days, respectively. Regarding risk factors for fungemia, most patients received corticosteroid therapy during hospitalization (61.8%) and had a comorbidity (25.3% diabetes, 11.5% chronic respiratory disorder, 9.5% cancer, 6% haematological malignancies, 1.4% organ transplantation). Antifungal therapy was administered to 75.6% of patients, mostly echinocandins (64.5%). The fatality rate observed in COVID-19 patients with yeast BSI was significantly higher than that of COVID-19 patients without yeast BSI (45.5% versus 30.5%). Candida parapsilosis (49.8%) and C. albicans (35.2%) were the most fungal species isolated; 72% of C. parapsilosis strains were fluconazole-resistant (range 0-93.2% among the centers). The FiCoV study highlights a high prevalence of Candida BSIs in critically ill COVID-19 patients, especially hospitalized in an intensive care unit, a high fatality rate associated with the fungal co-infection, and the worrying spread of azole-resistant C. parapsilosis.

Mucorales/Fusarium Mixed Infection in Hematologic Patient with COVID-19 Complications: An Unfortunate Combination

Hematological diseases, especially those causing severe neutropenia, represent the main factor in the development of invasive fungal infections (IFIs). Furthermore, COVID-19 has been considerably associated with IFIs due to immunological dysregulation, prolonged hospitalization in intensive care units, and immunomodulatory therapies. Opportunistic molds are correlated with elevated morbidity and mortality rates in these patients, due to immune impairment, diagnostic complexity, and therapeutic challenges. Among opportunistic fungal infections, the Mucorales and Fusarium species are considered particularly aggressive, especially during severe neutropenia. A mixed Mucorales/Fusarium infection has been rarely described in scientific literature. Herein, we report a case of Mucorales and Fusarium co-infection in a patient with acute leukemia whose clinical history was also complicated by COVID-19. Herein, we report a challenging case in order to encourage the clinical suspicion of combined fungal infections in immunosuppressed patients, performing a punctual microbiological diagnosis, and promptly administering the correct empiric and targeted antifungal therapy.

Pneumocystis pneumonia in COVID-19 patients: A comprehensive review

The admitted patients of intensive care units with coronavirus disease 2019 (COVID-19) meet the challenges of subsequent infections. Opportunistic fungal infections such as Pneumocystis pneumonia (PCP) are among the important factors in the context of COVID-19 patients affecting illness severity and mortality. We reviewed the literature on COVID-19 patients with PCP to identify features of this infection. Although studies confirmed at least the presence of one immunosuppressive condition in half of PCP patients, this disease can also occur in immunocompetent patients who developed the immunosuppressive condition during Covid-19 treatment. The major risk factors associated with COVID-19 patients with PCP can be considered low lymphocyte counts and corticosteroid therapy. Diagnostic and treatment options are complicated by the overlapping clinical and radiologic characteristics of PCP and COVID-19 pneumonia. Therefore, physicians should comprehensively evaluate high-risk patients for PCP prophylaxis.

Epidemiological Characteristics, Pathogenesis and Clinical Implications of Sinusitis in the Era of COVID-19: A Narrative Review

Sinusitis is a common condition with various forms and different etiologies. In the era of COVID-19, a large number of studies covered the association between sinusitis and COVID-19, while others reported the impact of COVID-19 on the development of acute invasive fungal rhinosinusitis (AIFR), together with the most commonly associated predisposing factors. Fungal sinusitis, particularly AIFR, can be life-threatening. It is important to dissect this association and improve current evidence and management. Therefore, we conducted this literature review to highlight the association between COVID-19 and sinusitis based on evidence from the available studies in the literature. Evidence shows that chronic sinusitis might have a negative impact on COVID-19 outcomes. However, current results are conflicting, and further studies are needed. On the other hand, COVID-19 can also cause olfactory dysfunction, which is usually temporary. In addition, we found several studies that indicated the association between COVID-19 and AIFR. The condition is usually associated with severe morbidities, as affected patients are usually immunocompromised, including those with uncontrolled diabetes, malignancy, immunosuppression, AIDS, the administration of chemotherapy and other immunosuppressive drugs, and COVID-19.

Invasive Fungal Infections in Hospitalized Patients with COVID-19: A Non-Intensive Care Single-Centre Experience during the First Pandemic Waves

Invasive fungal infections (IFIs) represent a severe complication of COVID-19, yet they are under-estimated. We conducted a retrospective analysis including all the COVID-19 patients admitted to the Infectious Diseases Unit of the Federico II University Hospital of Naples until the 1 July 2021. Among 409 patients, we reported seven cases of IFIs by Candida spp., seven of Pneumocystis jirovecii pneumonia, three of invasive pulmonary aspergillosis, and one of Trichosporon asahii. None of the cases presented underlying predisposing conditions, excluding one oncohematological patient treated with rituximab. Ten cases showed lymphopenia with high rates of CD4+ < 200/µL. All cases received high-dose steroid therapy (mean duration 33 days, mean cumulative dosage 1015 mg of prednisone equivalent), and seven cases had severe COVID-19 disease (OSCI ≥ 5) prior to IFI diagnosis. The cases showed a higher overall duration of hospitalization (63 vs 24 days) and higher mortality rate (23% vs. 7%) compared with the COVID-19 patients who did not developed IFIs. Cases showed a higher prevalence of high-dose steroid therapy and lymphopenia with CD4+ < 200/µL, primarily due to SARS-CoV-2 infection and not related to underlying comorbidities. IFIs strongly impact the overall length of hospitalization and mortality. Therefore, clinicians should maintain a high degree of suspicion of IFIs, especially in severe COVID-19 patients.

Can bronchial secretion cultures identify the etiologic agent of COVID-19-associated pulmonary aspergillosis in ICU patients? Comparison with a species-specific Aspergillus PCR in serum

Aspergillus spp. isolated from non-BAL cultures of coronavirus disease 2019 (COVID-19)-associated pulmonary aspergillosis (CAPA) patients may reflect colonization rather than infection. Sera (n = 181) from 49 adult ICU CAPA patients (24 probable and 25 possible CAPA) with bronchial secretions (BS) culture positive for Aspergillus spp. were collected and tested for Aspergillus DNA detection by species-specific real-time PCR. Overall, 30/49 (61%) patients were PCR positive. BS culture/serum PCR agreement was moderate (21/30; 70%). Based on serum PCR positive patients, all CAPAs were due to A. fumigatus (80%), A. flavus (10%), and A. terreus (10%). No A. niger/A. nidulans or mixed infections were found despite positive BS cultures.

Effectiveness of front line and emerging fungal disease prevention and control interventions and opportunities to address appropriate eco-sustainable solutions

Fungal pathogens contribute to significant disease burden globally; however, the fact that fungi are eukaryotes has greatly complicated their role in fungal-mediated infections and alleviation. Antifungal drugs are often toxic to host cells and there is increasing evidence of adaptive resistance in animals and humans. Existing fungal diagnostic and treatment regimens have limitations that has contributed to the alarming high mortality rates and prolonged morbidity seen in immunocompromised cohorts caused by opportunistic invasive infections as evidenced during HIV and COVID-19 pandemics. There is a need to develop real-time monitoring and diagnostic methods for fungal pathogens and to create a greater awareness as to the contribution of fungal pathogens in disease causation. Greater information is required on the appropriate selection and dose of antifungal drugs including factors governing resistance where there is commensurate need to discover more appropriate and effective solutions. Popular azole fungal drugs are widely detected in surface water and sediment due to incomplete removal in wastewater treatment plants where they are resistant to microbial degradation and may cause toxic effects on aquatic organisms such as algae and fish. UV has limited effectiveness in destruction of anti-fungal drugs where there is increased interest in the combination approaches such as novel use of pulsed-plasma gas-discharge technologies for environmental waste management. There is growing interest in developing alternative and complementary green eco-biocides and disinfection innovation. Fungi present challenges for cleaning, disinfection and sterilization of reusable medical devices such as endoscopes where they (example, Aspergillus and Candida species) can be protected when harboured in build-up biofilm from lethal processing. Information on the efficacy of established disinfection and sterilization technologies to address fungal pathogens including bottleneck areas that present high risk to patients is lacking. There is a need to address risk mitigation and modelling to inform efficacy of appropriate intervention technologies that must consider all contributing factors where there is potential to adopt digital technologies to enable real-time analysis of big data, such as use of artificial intelligence and machine learning. International consensus on standardised protocols for developing and reporting on appropriate alternative eco-solutions must be reached, particularly in order to address fungi with increasing drug resistance where research and innovation can be enabled using a One Health approach.

Clinical Phenotypes of COVID-19 Associated Mucormycosis (CAM): A Comprehensive Review

A mucormycosis surge was reported during the COVID-19 pandemic in India. A literature search until 14 July 2022, with the aim of updating COVID-19-associated mucormycosis (CAM), identified 663 studies and 88 met inclusion criteria (8727 patients). India reported 8388 patients, Egypt 208 and Europe 40. Rhino-orbito-cerebral mucormycosis (ROCM) was identified among 8082 (98.3%) patients, followed by 98 (1.2%) with pulmonary. In India, 82.6% of patients had diabetes mellitus, with 82% receiving corticosteroids. In Europe, 75% presented pulmonary CAM, 32.5% had diabetes and 40% were immunocompromised. CAM was identified at a median of 17.4 days (IQR 7.5 days) post COVID-19 diagnosis, and PCR was performed in five studies. Rhino-orbital invasion is clinically obvious, while cerebral involvement presents with cavernous sinus thrombosis, meningitis and cerebrovascular disease. Symptoms of pulmonary CAM usually overlap with severe COVID-19 pneumonia. High-dose liposomal Amphotericin B (and early surgical debridement in ROCM) are the mainstay of therapy. The median mortality rate was estimated to be 21.4% (IQR 31.9%), increased by the presence of pulmonary (80% (IQR 50%) or cerebral involvement (50% (IQR 63.9%). In summary, different CAM clinical phenotypes need to be distinguished, influenced by geographical presentation. Opportunities exist for diagnosis and therapy optimization, based on earlier high-dose antifungal therapy, early source control, strict glycemic control and restriction of steroids to COVID-19 patients with oxygen requirements.

Targeting DNA Topoisomerase II in Antifungal Chemotherapy

Topoisomerase inhibitors have been in use clinically for the treatment of several diseases for decades. Although those enzymes are significant molecular targets in antibacterial and anticancer chemotherapy very little is known about the possibilities to target fungal topoisomerase II (topo II). Raising concern for the fungal infections, lack of effective drugs and a phenomenon of multidrug resistance underlie a strong need to expand the range of therapeutic options. In this review paper, we discussed the usefulness of fungal topo II as a molecular target for new drug discovery. On the basis of previously published data, we described structural and biochemical differences between fungal and human enzymes as well as a molecular basis of differential sensitivity to known anticancer drugs targeting the latter. This review focuses especially on highlighting the differences that may underlie the selectivity of action of new inhibitors. Distinct sites within fungal topo II in comparison with human counterparts are observed and should be further studied to understand the significance of those sites and their possible usage in design of new drugs.

Clinical Challenges of Emerging and Re-Emerging Yeast Infections in the Context of the COVID-19 Pandemic

During the geological eras, some fungi, through adaptation and/or environmental/ecological pressure, interacted directly and indirectly with humans, through occasionally harmful interaction interdependent on the individual’s immunological condition. Infections caused by yeasts are underreported, subjugated, and underdiagnosed, and treatment is restricted to a few drugs, even after the significant progress of medicine and pharmacology. In the last centuries, antagonistically, there has been an exponential increase of immunocompromised individuals due to the use of immunosuppressive drugs such as corticosteroids, increased cases of transplants, chemotherapeutics, autoimmune diseases, neoplasms, and, more recently, coronavirus disease 2019 (COVID-19). This review aims to survey emerging and re-emerging yeast infections in the current clinical context. Currently, there is an immense clinical challenge for the rapid and correct diagnosis and treatment of systemic mycoses caused by yeasts due to the terrible increase in cases in the current context of COVID-19.

Current Issues in Fungal Infections and COVID-19

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

Pathogenicity & Virulence of Histoplasma capsulatum - a multifaceted organism adapted to intracellular environments

Histoplasmosis is a systemic mycosis caused by the thermally dimorphic fungus Histoplasma capsulatum. Although healthy individuals can develop histoplasmosis, the disease is particularly life-threatening in immunocompromised patients, with a wide range of clinical manifestations depending on the inoculum and virulence of the infecting strain. In this review, we discuss the established virulence factors and pathogenesis traits that make H. capsulatum highly adapted to a wide variety of hosts, including mammals. Understanding and integrating these mechanisms is a key step towards devising new preventative and therapeutic interventions.

Deadly Fungi: Invasive Fungal Rhinosinusitis in the Head and Neck

Invasive fungal rhinosinusitis (IFRS) is a serious infection that is associated with high morbidity and mortality rates. The incidence of IFRS has been increasing, mainly because of the increased use of antibiotics and immunosuppressive drugs. Rhino-orbital cerebral mucormycosis has recently reemerged among patients affected by COVID-19 and has become a global concern. The detection of extrasinus involvement in its early stage contributes to improved outcomes; therefore, imaging studies are essential in establishing the degree of involvement and managing the treatment properly, especially in immunocompromised patients. The common sites of extrasinus fungal invasion are the intraorbital, cavernous sinus, and intracranial regions. Fungi spread directly to these regions along the blood vessels or nerves, causing devastating complications such as optic nerve ischemia or compression, optic neuritis or perineuritis, orbital cellulitis, cavernous sinus thrombosis, mycotic aneurysm, vasculitis, internal carotid arterial occlusion, cerebral infarction, cerebritis, and brain abscess. IFRS has a broad imaging spectrum, and familiarity with intra- and extrasinonasal imaging features, such as loss of contrast enhancement of the affected region, which indicates tissue ischemia due to angioinvasion of fungi, and the surrounding anatomy is essential for prompt diagnosis and management. The authors summarize the epidemiology, etiology, risk factors, and complications of IFRS and review the anatomy and key diagnostic imaging features of IFRS beyond the sinonasal regions. ^©RSNA, 2022.

Updates on Histoplasmosis in Solid Organ Transplantation

Purpose of Review

Recent Findings

Summary

Risk Factors and Clinical Outcomes of Candidemia Associated With Severe COVID-19

COVID-19 can cause serious illness requiring multimodal treatment and is associated with secondary infections. Studies have suggested an increased risk of fungal infections, including candidemia following severe COVID-19 though understanding of risk factors and clinical outcomes remains unclear.

Challenges in Diagnosing COVID-19-Associated Pulmonary Aspergillosis in Critically Ill Patients: The Relationship between Case Definitions and Autoptic Data

Critically ill COVID-19 patients can develop invasive pulmonary aspergillosis (CAPA). Considering the weaknesses of diagnostic tests/case definitions, as well as the results from autoptic studies, there is a debate on the real burden of aspergillosis in COVID-19 patients. We performed a retrospective observational study on mechanically ventilated critically ill COVID-19 patients in an intensive care unit (ICU). The primary objective was to determine the burden of CAPA by comparing clinical diagnosis (through case definitions/diagnostic algorithms) with autopsy results. Twenty patients out of 168 (11.9%) developed probable CAPA. Seven (35%) were females, and the median age was 66 [IQR 59–72] years. Thirteen CAPA patients (65%) died and, for six, an autopsy was performed providing a proven diagnosis in four cases. Histopathology findings suggest a focal pattern, rather than invasive and diffuse fungal disease, in the context of prominent viral pneumonia. In a cohort of mechanically ventilated patients with probable CAPA, by performing a high rate of complete autopsies, invasive aspergillosis was not always proven. It is still not clear whether aspergillosis is the major driver of mortality in patients with CAPA.

Distinct Cohorts of Aspergillus fumigatus Transcription Factors Are Required for Epithelial Damage Occurring via Contact- or Soluble Effector-Mediated Mechanisms

Damage to the lung epithelium is a unifying feature of disease caused by the saprophytic fungus Aspergillus fumigatus. However, the mechanistic basis and the regulatory control of such damage is poorly characterized. Previous studies have identified A. fumigatus mediated pathogenesis as occurring at early (≤ 16 hours) or late (>16 hours) phases of the fungal interaction with epithelial cells, and respectively involve direct contact with the host cell or the action of soluble factors produced by mature fungal hyphae. Both early and late phases of epithelial damage have been shown to be subject to genetic regulation by the pH-responsive transcription factor PacC. This study sought to determine whether other transcriptional regulators play a role in modulating epithelial damage. In particular, whether the early and late phases of epithelial damage are governed by same or distinct regulators. Furthermore, whether processes such as spore uptake and hyphal adhesion, that have previously been documented to promote epithelial damage, are governed by the same cohorts of epithelial regulators. Using 479 strains from the recently constructed library of A. fumigatus transcription factor null mutants, two high-throughput screens assessing epithelial cell detachment and epithelial cell lysis were conducted. A total of 17 transcription factor mutants were found to exhibit reproducible deficits in epithelial damage causation. Of these, 10 mutants were defective in causing early phase damage via epithelial detachment and 8 mutants were defective in causing late phase damage via epithelial lysis. Remarkably only one transcription factor, PacC, was required for causation of both phases of epithelial damage. The 17 mutants exhibited varied and often unique phenotypic profiles with respect to fitness, epithelial adhesion, cell wall defects, and rates of spore uptake by epithelial cells. Strikingly, 9 out of 10 mutants deficient in causing early phase damage also exhibited reduced rates of hyphal extension, and culture supernatants of 7 out of 8 mutants deficient in late phase damage were significantly less cytotoxic. Our study delivers the first high-level overview of A. fumigatus regulatory genes governing lung epithelial damage, suggesting highly coordinated genetic orchestration of host-damaging activities that govern epithelial damage in both space and time.

Co-Infections and Superinfections in COVID-19 Critically Ill Patients Are Associated with CT Imaging Abnormalities and the Worst Outcomes

Background: Bacterial and fungal co-infections and superinfections have a critical role in the outcome of the COVID-19 patients admitted to the Intensive Care Unit (ICU). Methods: The present study is a retrospective analysis of 95 patients admitted to the ICU for COVID-19-related ARDS during the first (February−May 2020) and second waves of the pandemic (October 2020−January 2021). Demographic and clinical data, CT imaging features, and pulmonary and extra-pulmonary complications were recorded, as well as the temporal evolution of CT findings when more than one scan was available. The presence of co-infections and superinfections was registered, reporting the culprit pathogens and the specimen type for culture. A comparison between patients with and without bacterial and/or co-infections/superinfections was performed. Results: Sixty-three patients (66.3%) developed at least one confirmed co-infection/superinfection, with 52 (82.5%) developing pneumonia and 43 (68.3%) bloodstream infection. Gram-negative bacteria were the most common co-pathogens identified and Aspergillus spp. was the most frequent pulmonary microorganism. Consolidations, cavitations, and bronchiectasis were significantly associated with the presence of co-infections/superinfections (p = 0.009, p = 0.010 and p = 0.009, respectively); when considering only patients with pulmonary co-pathogens, only consolidations remained statistically significative (p = 0.004). Invasive pulmonary aspergillosis was significantly associated with the presence of cavitations and bronchiectasis (p < 0.001). Patients with co-infections/superinfections presented a significantly higher mortality rate compared to patients with COVID-19 only (52.4% vs. 25%, p = 0.016). Conclusions: Bacterial and fungal co-infections and superinfections are frequent in COVID-19 patients admitted to ICU and are associated with worse outcomes. Imaging plays an important role in monitoring critically ill COVID-19 patients and may help detect these complications, suggesting further laboratory investigations.

COVID-19-Associated Fungal Infections: An Urgent Need for Alternative Therapeutic Approach?

Secondary fungal infections may complicate the clinical course of patients affected by viral respiratory diseases, especially those admitted to intensive care unit. Hospitalized COVID-19 patients are at increased risk of fungal co-infections exacerbating the prognosis of disease due to misdiagnosis that often result in treatment failure and high mortality rate. COVID-19-associated fungal infections caused by predominantly Aspergillus and Candida species, and fungi of the order Mucorales have been reported from several countries to become significant challenge for healthcare system. Early diagnosis and adequate antifungal therapy is essential to improve clinical outcomes, however, drug resistance shows a rising trend highlighting the need for alternative therapeutic agents. The purpose of this review is to summarize the current knowledge on COVID-19-associated mycoses, treatment strategies and the most recent advancements in antifungal drug development focusing on peptides with antifungal activity.

Concurrent Infection with SARS-CoV-2 and Pneumocystis jirovecii in Immunocompromised and Immunocompetent Individuals

Coronavirus disease 2019 (COVID-19) may occur with concurrent infections caused by bacterial and fungal microorganisms. This systematic review evaluated studies reporting concomitant COVID-19 and Pneumocystis jirovecii pneumonia (PJP). We found 39 patients (74% male, median age: 56.8 (range: 11-83) years), including 66% immunosuppressed individuals (23% HIV-infected and 41% on long-term corticosteroid therapy). Patients were characteristically severely ill (mechanical ventilation: 70%), associated with 41% mortality. The median lymphocyte count was 527 cells/mm3 (range: 110-2200), and the median CD4+ T cell count was 206 cells/mm3 (range: 8-1021). We identified three patterns of concurrent COVID-19 and P. jirovecii infection. The first pattern (airway colonization with a low burden of P. jirovecii) does not seem to modify the COVID-19 course of illness. However, P. jirovecii superinfection, typically occurring weeks after COVID-19 diagnosis as a biphasic illness, and P. jirovecii coinfection characteristically results in progressive multilobar pneumonia, which is associated with poor outcomes. To support this categorization, we reported three patients with concurrent PJP and COVID-19 identified in our institution, presenting these clinical scenarios. The diagnosis of PJP requires a high index of suspicion, since clinical and radiological characteristics overlap with COVID-19. Observational studies are necessary to determine the PJP burden in patients with COVID-19 requiring hospitalization.

Prospective Medicines against the Widespread, Emergent and Multidrug-Resistant Opportunistic Fungal Pathogen Candida auris: A Breath of Hope

The emergence of the pathogen Candida auris is a real concern worldwide, especially due to its multidrug resistance profile, besides the difficulties in establishing the correct identification by conventional laboratory methods and its capacity of causing outbreaks in healthcare settings. The limited arsenal of available antifungal drugs, coupled with the lack of momentum for the development of new reagents, represent a challenge in the management of such a pathogen. In this perspective, we have focused on discussing new, promising treatment options for C. auris infections. These novel drugs include an antifungal agent already approved for medical use in the United States of America, compounds that are already in clinical trials and those with potential for repurposing use against this important fungal pathogen.

Invasive Respiratory Fungal Infections in COVID-19 Critically Ill Patients

Patients with coronavirus disease 19 (COVID-19) admitted to the intensive care unit (ICU) often develop respiratory fungal infections. The most frequent diseases are the COVID-19 associated pulmonary aspergillosis (CAPA), COVID-19 associated pulmonary mucormycosis (CAPM) and the Pneumocystis jirovecii pneumonia (PCP), the latter mostly found in patients with both COVID-19 and underlying HIV infection. Furthermore, co-infections due to less common mold pathogens have been also described. Respiratory fungal infections in critically ill patients are promoted by multiple risk factors, including epithelial damage caused by COVID-19 infection, mechanical ventilation and immunosuppression, mainly induced by corticosteroids and immunomodulators. In COVID-19 patients, a correct discrimination between fungal colonization and infection is challenging, further hampered by sampling difficulties and by the low reliability of diagnostic approaches, frequently needing an integration of clinical, radiological and microbiological features. Several antifungal drugs are currently available, but the development of new molecules with reduced toxicity, less drug-interactions and potentially active on difficult to treat strains, is highly warranted. Finally, the role of prophylaxis in certain COVID-19 populations is still controversial and must be further investigated.

Fungal Infections in Critically Ill COVID-19 Patients: Inevitabile Malum

Patients with severe COVID-19 belong to a population at high risk of invasive fungal infections (IFIs), with a reported incidence of IFIs in critically ill COVID-19 patients ranging between 5% and 26.7%. Common factors in these patients, such as multiple organ failure, immunomodulating/immunocompromising treatments, the longer time on mechanical ventilation, renal replacement therapy or extracorporeal membrane oxygenation, make them vulnerable candidates for fungal infections. In addition to that, SARS-CoV2 itself is associated with significant dysfunction in the patient's immune system involving both innate and acquired immunity, with reduction in both CD4+ T and CD8+ T lymphocyte counts and cytokine storm. The emerging question is whether SARS-CoV-2 inherently predisposes critically ill patients to fungal infections or the immunosuppressive therapy constitutes the igniting factor for invasive mycoses. To approach the dilemma, one must consider the unique pathogenicity of SARS-CoV-2 with the deranged immune response it provokes, review the well-known effects of immunosuppressants and finally refer to current literature to probe possible causal relationships, synergistic effects or independent risk factors. In this review, we aimed to identify the prevalence, risk factors and mortality associated with IFIs in mechanically ventilated patients with COVID-19.

SARS-CoV-2 Associated Immune Dysregulation and COVID-Associated Pulmonary Aspergilliosis (CAPA): A Cautionary Tale

As the global SARS-CoV-2 pandemic continues to plague healthcare systems, it has become clear that opportunistic pathogens cause a considerable proportion of SARS-CoV-2-associated mortality and morbidity cases. Of these, Covid-Associated Pulmonary Aspergilliosis (CAPA) is a major concern with evidence that it occurs in the absence of traditional risk factors such as neutropenia and is diagnostically challenging for the attending physician. In this review, we focus on the immunopathology of SARS-CoV-2 and how this potentiates CAPA through dysregulation of local and systemic immunity as well as the unintended consequences of approved COVID treatments including corticosteroids and IL-6 inhibitors. Finally, we will consider how knowledge of the above may aid in the diagnosis of CAPA using current diagnostics and what treatment should be instituted in probable and confirmed cases.

Fungal Colonization and Infections-Interactions with Other Human Diseases

Candida albicans is a commensal fungus that asymptomatically colonizes the skin and mucosa of 60% of healthy individuals. Breaches in the cutaneous and mucosal barriers trigger candidiasis that ranges from asymptomatic candidemia and mucosal infections to fulminant sepsis with 70% mortality rates. Fungi influence at least several diseases, in part by mechanisms such as the production of pro-carcinogenic agents, molecular mimicking, and triggering of the inflammation cascade. These processes impact the interactions among human pathogenic and resident fungi, the bacteriome in various organs/tissues, and the host immune system, dictating the outcomes of invasive infections, metabolic diseases, and cancer. Although mechanistic investigations are at stages of infancy, recent studies have advanced our understanding of host-fungal interactions, their role in immune homeostasis, and their associated pathologies. This review summarizes the role of C. albicans and other opportunistic fungi, specifically their association with various diseases, providing a glimpse at the recent developments and our current knowledge in the context of inflammatory-bowel disease (IBD), cancers, and COVID-19. Two of the most common human diseases where fungal interactions have been previously well-studied are cancer and IBD. Here we also discuss the emerging role of fungi in the ongoing and evolving pandemic of COVID-19, as it is relevant to current health affairs.