Invasive fungal infections among organ transplant recipients: results of the Transplant-Associated Infection Surveillance Network (TRANSNET)

Specificities of Meningitis and Meningo-Encephalitis After Kidney Transplantation: A French Retrospective Cohort Study

Kidney transplant recipients develop atypical infections in their epidemiology, presentation and outcome. Among these, meningitis and meningoencephalitis require urgent and adapted anti-infectious therapy, but published data is scarce in KTRs. The aim of this study was to describe their epidemiology, presentation and outcome, in order to improve their diagnostic and management. We performed a retrospective, multicentric cohort study in 15 French hospitals that included all 199 cases of M/ME in KTRs between 2007 and 2018 (0.9 case per 1,000 KTRs annually). Epidemiology was different from that in the general population: 20% were due to Cryptococcus neoformans, 13.5% to varicella-zoster virus, 5.5% to Mycobacterium tuberculosis, and 4.5% to Enterobacteria (half of which produced extended spectrum beta-lactamases), and 5% were Post Transplant Lymphoproliferative Disorders. Microorganisms causing M/ME in the general population were infrequent (2%, for Streptococcus pneumoniae) or absent (Neisseria meningitidis). M/ME caused by Enterobacteria, Staphylococci or filamentous fungi were associated with high and early mortality (50%-70% at 1 year). Graft survival was not associated with the etiology of M/ME, nor was impacted by immunosuppression reduction. Based on these results, we suggest international studies to adapt guidelines in order to improve the diagnosis and the probabilistic treatment of M/ME in SOTRs.

Invasive Pulmonary Aspergillosis

Invasive pulmonary aspergillosis is growing in incidence, as patients at risk are growing in diversity. Outside the classical context of neutropenia, new risk factors are emerging or newly identified, such as new anticancer drugs, viral pneumonias and hepatic dysfunctions. Clinical signs remain unspecific in these populations and the diagnostic work-up has considerably expanded. Computed tomography is key to assess the pulmonary lesions of aspergillosis, whose various features must be acknowledged. Positron-emission tomography can bring additional information for diagnosis and follow-up. The mycological argument for diagnosis is rarely fully conclusive, as biopsy from a sterile site is challenging in most clinical contexts. In patients with a risk and suggestive radiological findings, probable invasive aspergillosis is diagnosed through blood and bronchoalveolar lavage fluid samples by detecting galactomannan or DNA, or by direct microscopy and culture for the latter. Diagnosis is considered possible with mold infection in lack of mycological criterion. Nevertheless, the therapeutic decision should not be hindered by these research-oriented categories, that have been completed by better adapted ones in specific settings. Survival has been improved over the past decades with the development of relevant antifungals, including lipid formulations of amphotericin B and new azoles. New antifungals, including first-in-class molecules, are awaited.

COVID-19-associated pulmonary aspergillosis in immunocompetent patients: A virtual patient cohort study

Purpose

The opportunistic fungus Aspergillus fumigatus infects the lungs of immunocompromised hosts, including patients undergoing chemotherapy or organ transplantation. More recently however, immunocompetent patients with severe SARS-CoV2 have been reported to be affected by COVID-19 Associated Pulmonary Aspergillosis (CAPA), in the absence of the conventional risk factors for invasive aspergillosis. This paper explores the hypothesis that contributing causes are the destruction of the lung epithelium permitting colonization by opportunistic pathogens. At the same time, the exhaustion of the immune system, characterized by cytokine storms, apoptosis, and depletion of leukocytes may hinder the response to A. fumigatus infection. The combination of these factors may explain the onset of invasive aspergillosis in immunocompetent patients.

Methods

We used a previously published computational model of the innate immune response to infection with Aspergillus fumigatus . Variation of model parameters was used to create a virtual patient population. A simulation study of this virtual patient population to test potential causes for co-infection in immunocompetent patients.

Results

The two most important factors determining the likelihood of CAPA were the inherent virulence of the fungus and the effectiveness of the neutrophil population, as measured by granule half-life and ability to kill fungal cells. Varying these parameters across the virtual patient population generated a realistic distribution of CAPA phenotypes observed in the literature.

Conclusions

Computational models are an effective tool for hypothesis generation. Varying model parameters can be used to create a virtual patient population for identifying candidate mechanisms for phenomena observed in actual patient populations.

Molecular epidemiology of clinical filamentous fungi in Qatar beyond Aspergillus and Fusarium with notes on the rare species

Due to an increasing number of patients at risk (i.e., those with a highly compromised immune system and/or receiving aggressive chemotherapy treatment), invasive fungal infections (IFI) are increasingly being reported and associated with high mortality rates. Aspergillus spp., particularly A. fumigatus, is the major cause of IFI caused by filamentous fungi around the world followed by Fusarium spp., however, other fungi are emerging as human pathogens. The aim of this study was to explore the epidemiology and prevalence of the non-Aspergillus and non-Fusarium filamentous fungi in human clinical samples over an 11-year period in Qatar using molecular techniques. We recovered 53 filamentous fungal isolates from patients with various clinical conditions. Most patients were males (75.5%), 9.4% were immunocompromised, 20.7% had IFI, and 11.3% died within 30 days of diagnosis. The fungal isolates were recovered from a variety of clinical samples, including the nasal cavity, wounds, respiratory samples, body fluids, eye, ear, tissue, abscess, and blood specimens. Among the fungi isolated, 49% were dematiaceous fungi, followed by Mucorales (30%), with the latter group Mucorales being the major cause of IFI (5/11, 45.5%). The current study highlights the epidemiology and spectrum of filamentous fungal genera, other than Aspergillus and Fusarium, recovered from human clinical samples in Qatar, excluding superficial infections, which can aid in the surveillance of uncommon and emerging mycoses.

Stimulating the autophagic-lysosomal axis enhances host defense against fungal infection in a zebrafish model of invasive Aspergillosis

The increasing prevalence of antifungal-resistant human pathogenic fungi, particularly azole-resistant Aspergillus fumigatus, is a life-threatening challenge to the immunocompromised population. Autophagy-related processes such as LC3-associated phagocytosis have been shown to be activated in the host response against fungal infection, but their overall effect on host resistance remains uncertain. To analyze the relevance of these processes in vivo, we used a zebrafish animal model of invasive Aspergillosis. To confirm the validity of this model to test potential treatments for this disease, we confirmed that immunosuppressive treatments or neutropenia rendered zebrafish embryos more susceptible to A. fumigatus. We used GFP-Lc3 transgenic zebrafish to visualize the autophagy-related processes in innate immune phagocytes shortly after phagocytosis of A. fumigatus conidia, and found that both wild-type and melanin-deficient conidia elicited Lc3 recruitment. In macrophages, we observed GFP-Lc3 accumulation in puncta after phagocytosis, as well as short, rapid events of GFP-Lc3 decoration of single and multiple conidia-containing vesicles, while neutrophils covered single conidia-containing vesicles with bright and long-lasting GFP-Lc3 signal. Next, using genetic and pharmacological stimulation of three independent autophagy-inducing pathways, we showed that the antifungal autophagy response improves the host survival against A. fumigatus infection, but only in the presence of phagocytes. Therefore, we provide proof-of-concept that stimulating the (auto)phagolysosomal pathways is a promising approach to develop host-directed therapies against invasive Aspergillosis, and should be explored further either as adjunctive or stand-alone therapy for drug-resistant Aspergillus infections.Abbreviations: DMSO: dimethyl sulfoxide; HR: hazard ratio; HDT: host-directed therapy; Hpf: hours post fertilization; IA: invasive Aspergillosis; LAP: LC3-associated phagocytosis; MTZ: metronidazole; PTU: N-phenylthiourea; ROS: reactive oxygen species.

Demonstration of the Rationale for Therapeutic Drug Monitoring of Isavuconazole: A Case Report with a Lung Transplant Recipient

Mucormycosis is a rare invasive fungal disease diagnosed in immunocompromised patients, including those with diabetes or iron overload, and in patients treated for hematological malignancies or after transplantation. Isavuconazole is a triazole antifungal effective against Mucorales with good tolerability, but with potential for relatively high interindividual variability in pharmacokinetics. This report demonstrates the case of a lung transplant recipient treated with isavuconasole that exhibits a very long elimination half-life of 159 hours, and discusses the practical implications of this finding for dosage adjustment and need for therapeutic drug monitoring.

Pulmonary aspergillosis: diagnosis and treatment

Aspergillusspecies are the most frequent cause of fungal infections of the lungs with a broad spectrum of clinical presentations including invasive pulmonary aspergillosis (IPA) and chronic pulmonary aspergillosis (CPA). IPA affects immunocompromised populations, which are increasing in number and diversity with the advent of novel anti-cancer therapies. Moreover, IPA has emerged as a complication of severe influenza and coronavirus disease 2019 in apparently immunocompetent hosts. CPA mainly affects patients with pre-existing lung lesions and is recognised increasingly frequently among patients with long-term survival following cure of tuberculosis or lung cancer. The diagnosis of pulmonary aspergillosis is complex as it relies on the presence of clinical, radiological and microbiological criteria, which differ according to the type of pulmonary aspergillosis (IPA or CPA) and the type of patient population. The management of pulmonary aspergillosis is complicated by the limited number of treatment options, drug interactions, adverse events and the emergence of antifungal resistance.

Human Airway Epithelium Responses to Invasive Fungal Infections: A Critical Partner in Innate Immunity

The lung epithelial lining serves as the primary barrier to inhaled environmental toxins, allergens, and invading pathogens. Pulmonary fungal infections are devastating and carry high mortality rates, particularly in those with compromised immune systems. While opportunistic fungi infect primarily immunocompromised individuals, endemic fungi cause disease in immune competent and compromised individuals. Unfortunately, in the case of inhaled fungal pathogens, the airway epithelial host response is vastly understudied. Furthering our lack of understanding, very few studies utilize primary human models displaying pseudostratified layers of various epithelial cell types at air-liquid interface. In this review, we focus on the diversity of the human airway epithelium and discuss the advantages and disadvantages of oncological cell lines, immortalized epithelial cells, and primary epithelial cell models. Additionally, the responses by human respiratory epithelial cells to invading fungal pathogens will be explored. Future investigations leveraging current human in vitro model systems will enable identification of the critical pathways that will inform the development of novel vaccines and therapeutics for pulmonary fungal infections.

Fungal Tracheobronchitis in Lung Transplant Recipients: Incidence and Utility of Diagnostic Markers

Fungal tracheobronchitis caused by Aspergillus and Candida spp. is a recognized complication after lung transplantation, but knowledge of the incidence of Candida tracheobronchitis is lacking. The diagnosis relies on fungal cultures in bronchoalveolar lavage fluid (BALF), but cultures have low specificity. We aimed to evaluate the one-year incidence of fungal tracheobronchitis after lung transplantation and to assess the utility of diagnostic markers in serum and BALF to discriminate fungal tracheobronchitis from colonization. Ninety-seven consecutively included adult lung-transplant recipients were prospectively followed. BALF and serum samples were collected at 1, 3 and 12 months after transplantation and analyzed for betaglucan (serum and BALF), neutrophils (BALF) and galactomannan (BALF). Fungal tracheobronchitis was defined according to consensus criteria, modified to include Candida as a mycologic criterion. The cumulative one-year incidence of Candida and Aspergillus tracheobronchitis was 23% and 16%, respectively. Neutrophils of >75% of total leukocytes in BALF had 92% specificity for Candida tracheobronchitis. The area under the ROC curves for betaglucan and galactomannan in BALF to discriminate Aspergillus tracheobronchitis from colonization or no fungal infection were high (0.86 (p < 0.0001) and 0.93 (p < 0.0001), respectively). To conclude, the one-year incidence of fungal tracheobronchitis after lung transplantation was high and dominated by Candida spp. Diagnostic markers in BALF could be useful to discriminate fungal colonization from tracheobronchitis.

Evaluation of the Diagnostic Accuracy and Clinical Utility of Fungal Profile Plus Polymerase Chain Reaction Assay in Pulmonary Infections

Background

Pulmonary infections due to Aspergillus, Mucorales, and Nocardia have high morbidity and mortality, in part due to diagnostic challenges. Commercially available molecular assays on bronchoalveolar lavage fluid (BALF) may have increased sensitivity over currently available diagnostic options. Our aim was to characterize the diagnostic performance of assays for each of these pathogens in our patient population.

Methods

The medical records of patients whose BALF was tested by polymerase chain reaction (PCR) for Aspergillus, Mucorales, and Nocardia between 2019 and 2021 were reviewed in a cross-sectional manner. European Organization for Research and Treatment of Cancer and the Mycoses Study Group (EORTC/MSG) definitions of "proven," "probable," and "possible" infection were used, including histopathology, serology, and culture. We used (1) "proven" or "probable" infection by EORTC criteria, (2) improvement or stabilization on targeted antimicrobial therapy, and (3) absence of a more likely diagnosis as the reference standard.

Results

The Aspergillus PCR assay demonstrated the highest agreement with the diagnostic reference standard, with 31.25% (10/32) sensitivity and 97.17% (206/212) specificity. Positive and negative predictive values were 62.50% (10/16) and 90.35% (206/228), respectively. No Mucorales or Nocardia infections were identified by the diagnostic reference standard, so the sensitivity could not be calculated. The specificity of Mucorales and Nocardia targets was 98.35% and 96.69%, respectively.

Conclusions

Our data demonstrated relatively poor clinical sensitivity for all 3 constituent PCR assays in our patient population, suggesting a limited role for this test in the diagnosis of Aspergillus, Mucorales, or Nocardia.

Therapeutic Approaches for Combating Aspergillus Associated Infection

Now-a-days fungal infection emerges as a significant problem to healthcare management systems due to high frequency of associated morbidity, mortality toxicity, drug-drug interactions, and resistance of the antifungal agents. Aspergillus is the most common mold that cause infection in immunocompromised hosts. It's a hyaline mold that is cosmopolitan and ubiquitous in nature. Aspergillus infects around 10 million population each year with a mortality rate of 30-90%. Clinically available antifungal formulations are restricted to four classes (i.e., polyene, triazole, echinocandin, and allylamine), and each of them have their own limitations associated with the activity spectrum, the emergence of resistance, and toxicity. Consequently, novel antifungal agents with modified and altered chemical structures are required to combat these invasive fungal infections. To overcome these limitations, there is an urgent need for new antifungal agents that can act as potent drugs in near future. Currently, some compounds have shown effective antifungal activity. In this review article, we have discussed all potential antifungal therapies that contain old antifungal drugs, combination therapies, and recent novel antifungal formulations, with a focus on the Aspergillus associated infections.

Liposomal amphotericin B—the future

Advances in medicine have led to a growing number of people with compromised or suppressed immune systems who are susceptible to invasive fungal infections. In particular, severe fungal infections are becoming increasingly common in ICUs, affecting people within and outside of traditional risk groups alike. This is exemplified by the emergence of severe viral pneumonia as a significant risk factor for invasive pulmonary aspergillosis, and the recognition of influenza-associated pulmonary aspergillosis and, more recently, COVID-19-associated pulmonary aspergillosis.

The treatment landscape for haematological malignancies has changed considerably in recent years, and some recently introduced targeted agents, such as ibrutinib, are increasing the risk of invasive fungal infections. Consideration must also be given to the risk of drug–drug interactions between mould-active azoles and small-molecule kinase inhibitors.

At the same time, infections caused by rare moulds and yeasts are increasing, and diagnosis continues to be challenging. There is growing concern about azole resistance among both moulds and yeasts, mandating continuous surveillance and personalized treatment strategies.

It is anticipated that the epidemiology of fungal infections will continue to change and that new populations will be at risk. Early diagnosis and appropriate treatment remain the most important predictors of survival, and broad-spectrum antifungal agents will become increasingly important. Liposomal amphotericin B will remain an essential therapeutic agent in the armamentarium needed to manage future challenges, given its broad antifungal spectrum, low level of acquired resistance and limited potential for drug–drug interactions.

Protective interaction of human phagocytic APC subsets with Cryptococcus neoformans induces genes associated with metabolism and antigen presentation

Cryptococcal meningitis is the most common cause of meningitis among HIV/AIDS patients in sub-Saharan Africa, and worldwide causes over 223,000 cases leading to more than 181,000 annual deaths. Usually, the fungus gets inhaled into the lungs where the initial interactions occur with pulmonary phagocytes such as dendritic cells and macrophages. Following phagocytosis, the pathogen can be killed or can replicate intracellularly. Previous studies in mice showed that different subsets of these innate immune cells can either be antifungal or permissive for intracellular fungal growth. Our studies tested phagocytic antigen-presenting cell (APC) subsets from the human lung against C. neoformans. Human bronchoalveolar lavage was processed for phagocytic APCs and incubated with C. neoformans for two hours to analyze the initial interactions and fate of the fungus, living or killed. Results showed all subsets (3 macrophage and 3 dendritic cell subsets) interacted with the fungus, and both living and killed morphologies were discernable within the subsets using imaging flow cytometry. Single cell RNA-seq identified several different clusters of cells which more closely related to interactions with C. neoformans and its protective capacity against the pathogen rather than discrete cellular subsets. Differential gene expression analyses identified several changes in the innate immune cell's transcriptome as it kills the fungus including increases of TNF-α (TNF) and the switch to using fatty acid metabolism by upregulation of the gene FABP4. Also, increases of TNF-α correlated to cryptococcal interactions and uptake. Together, these analyses implicated signaling networks that regulate expression of many different genes - both metabolic and immune - as certain clusters of cells mount a protective response and kill the pathogen. Future studies will examine these genes and networks to understand the exact mechanism(s) these phagocytic APC subsets use to kill C. neoformans in order to develop immunotherapeutic strategies to combat this deadly disease.

Invasive Aspergillosis in the Intensive Care Unit

Invasive pulmonary aspergillosis (IPA) is a serious condition resulting in significant mortality and morbidity among patients in intensive care units (ICUs). There is a growing number of at-risk patients for this condition with the increasing use of immunosuppressive therapies. The diagnosis of IPA can be difficult in ICUs, and relies on integration of clinical, radiological, and microbiological features. In this review, we discuss patient populations at risk for IPA, as well as the diagnostic criteria employed. We review the fungal biomarkers used, as well as the challenges in distinguishing colonization with Aspergillus from invasive disease. We also address the growing concern of multidrug-resistant Aspergillosis and review the new and novel therapeutics which are in development to combat this.

Immunogenicity and protective efficacy of a pan-fungal vaccine in preclinical models of aspergillosis, candidiasis, and pneumocystosis

Invasive fungal infections cause over 1.5 million deaths worldwide. Despite increases in fungal infections as well as the numbers of individuals at risk, there are no clinically approved fungal vaccines. We produced a "pan-fungal" peptide, NXT-2, based on a previously identified vaccine candidate and homologous sequences from Pneumocystis, Aspergillus,Candida, and Cryptococcus. We evaluated the immunogenicity and protective capacity of NXT-2 in murine and nonhuman primate models of invasive aspergillosis, systemic candidiasis, and pneumocystosis. NXT-2 was highly immunogenic and immunized animals had decreased mortality and morbidity compared to nonvaccinated animals following induction of immunosuppression and challenge with Aspergillus, Candida, or Pneumocystis. Data in multiple animal models support the concept that immunization with a pan-fungal vaccine prior to immunosuppression induces broad, cross-protective antifungal immunity in at-risk individuals.

Impact of revised EORTC/MSGERC 2020 criteria on diagnosis and prognosis of invasive pulmonary aspergillosis in patients with hematological malignancies undergoing bronchoscopy

INTRODUCTION

The first consensus definitions for invasive fungal diseases (IFD) were published in 2002. Advances in diagnostic tests and a clear need for improvement in certain areas led to a revision of these definitions in 2008. However, growing data on Aspergillus galactomannan (GM) thresholds and the introduction of new polymerase chain reaction-based diagnostic tests resulted in a further update by EORTC and Mycoses Study Group Education and Research Consortium (MSGERC) in 2020. Compared to the 2008 version, the 2020 EORTC/MSGERC criteria have stricter definitions, especially regarding GM levels, which should lead to improved specificity. Thus, our study aimed to evaluate diagnostic changes, based on GM levels, resulting from these new definitions and ascertain the impact of the new classification on mortality rates.

METHOD

Patients hospitalized in a single tertiary care center with hematologic malignancies and undergoing bronchoscopy for suspected IPA between April 2004 and December 2019 were included in this retrospective study.

RESULTS

The study population consisted of 327 patients with 31 patients (nine patients with proven IPA and 22 patients with no IPA) excluded from the study. 194 patients were classified as probable IPA cases according to 2008 EORTC/MSG criteria. However, 53 (27.3%) of these patients were re-classified as possible IPA according to 2020 EORTC/MSGERC criteria, due to novel galactomannan cut-off levels. Compared to re-classified possible IPA patients, those remaining in the probable IPA category experienced a higher incidence of septic shock (34.0% vs 16.9%, p=0.02), and required more non-invasive (12.0% vs 0.0%, p=0.004) and invasive (44.6 vs 24.5%, p=0.01) mechanical ventilation. There was a higher in-hospital mortality rate in probable IPA patients than in the re-classified possible IPA group (42.5% vs 22.6%, p=0.01). Patients reassigned to possible IPA had similar underlying diseases, radiological features and prognosis to patients already classified as possible IPA. Independent risk factors for mortality were classification as probable IPA according to 2020 EORTC/MSGERC criteria, lack of remission from hematologic malignancy, and number of nodules in Thorax CT.

CONCLUSION

The use of 2020 EORTC/MSGERC criteria resulted in a 27.3% significant reduction in probable IPA diagnoses and created a more homogeneous category of patients with respect to treatment response, prognosis and mortality. Therefore, 2020 EORTC/MSGERC criteria afford more reliable mortality prediction than 2008 EORTC/MSG criteria.

Management of early graft candidiasis in a kidney transplant recipient

Balancing adequate immunosuppression with the risk of infection after renal transplantation remains a challenge. The presence of comorbidities adds to the challenge. Although infrequent, invasive fungal infections result in high morbidity and mortality risk in renal transplant recipients. This can be attributed to the intense immunosuppression in the first 6 months after renal transplantation, minimal symptomatology and the high mortality associated with fungal infections.

Due to minimal available evidence, clinical judgement guides management of graft candidiasis. There is a need to develop evidence-based management guidelines for the treatment of fungal infections in renal transplants. Here, we report a case of early-onset candidiasis in a transplanted kidney and present the histological findings, multidisciplinary discussions and treatment given.

Genomic and Molecular Identification of Genes Contributing to the Caspofungin Paradoxical Effect in Aspergillus fumigatus

Aspergillus fumigatus is a deadly opportunistic fungal pathogen responsible for ~100,000 annual deaths. Azoles are the first line antifungal agent used against A. fumigatus, but azole resistance has rapidly evolved making treatment challenging. Caspofungin is an important second-line therapy against invasive pulmonary aspergillosis, a severe A. fumigatus infection. Caspofungin functions by inhibiting β-1,3-glucan synthesis, a primary and essential component of the fungal cell wall. A phenomenon termed the caspofungin paradoxical effect (CPE) has been observed in several fungal species where at higher concentrations of caspofungin, chitin replaces β-1,3-glucan, morphology returns to normal, and growth rate increases. CPE appears to occur in vivo, and it is therefore clinically important to better understand the genetic contributors to CPE. We applied genomewide association (GWA) analysis and molecular genetics to identify and validate candidate genes involved in CPE. We quantified CPE across 67 clinical isolates and conducted three independent GWA analyses to identify genetic variants associated with CPE. We identified 48 single nucleotide polymorphisms (SNPs) associated with CPE. We used a CRISPR/Cas9 approach to generate gene deletion mutants for seven genes harboring candidate SNPs. Two null mutants, ΔAfu3g13230 and ΔAfu4g07080 (dscP), resulted in reduced basal growth rate and a loss of CPE. We further characterized the dscP phosphatase-null mutant and observed a significant reduction in conidia production and extremely high sensitivity to caspofungin at both low and high concentrations. Collectively, our work reveals the contribution of Afu3g13230 and dscP in CPE and sheds new light on the complex genetic interactions governing this phenotype. IMPORTANCE This is one of the first studies to apply genomewide association (GWA) analysis to identify genes involved in an Aspergillus fumigatus phenotype. A. fumigatus is an opportunistic fungal pathogen that causes hundreds of thousands of infections and ~100,000 deaths each year, and antifungal resistance has rapidly evolved in this species. A phenomenon called the caspofungin paradoxical effect (CPE) occurs in some isolates, where high concentrations of the drug lead to increased growth rate. There is clinical relevance in understanding the genetic basis of this phenotype, since caspofungin concentrations could lead to unintended adverse clinical outcomes in certain cases. Using GWA analysis, we identified several interesting candidate polymorphisms and genes and then generated gene deletion mutants to determine whether these genes were important for CPE. Two of these mutant strains (ΔAfu3g13230 and ΔAfu4g07080/ΔdscP) displayed a loss of the CPE. This study sheds light on the genes involved in clinically important phenotype CPE.

Structural and functional investigation of ABC transporter STE6-2p from Pichia pastoris reveals unexpected interaction with sterol molecules

Adenosine triphosphate (ATP)-binding cassette (ABC) transporters are multidomain transmembrane proteins, which facilitate the transport of various substances across cell membranes using energy derived from ATP hydrolysis. They are important drug targets since they mediate decreased drug susceptibility during pharmacological treatments. For the methylotrophic yeast Pichia pastoris, a model organism that is a widely used host for protein expression, the role and function of its ABC transporters is unexplored. In this work, we investigated the Pichia ABC-B transporter STE6-2p. Functional investigations revealed that STE6-2p is capable of transporting rhodamines in vivo and is active in the presence of verapamil and triazoles in vitro. A phylogenetic analysis displays homology among multidrug resistance (MDR) transporters from pathogenic fungi to human ABC-B transporters. Further, we present high-resolution single-particle electron cryomicroscopy structures of an ABC transporter from P. pastoris in the apo conformation (3.1 Å) and in complex with verapamil and adenylyl imidodiphosphate (AMP-PNP) (3.2 Å). An unknown density between transmembrane helices 4, 5, and 6 in both structures suggests the presence of a sterol-binding site of unknown function.

Epidemiology of Invasive Fungal Infections in Solid Organ Transplant Recipients: an Indian Perspective

Purpose of Review

This review summarizes the available Indian data on epidemiology of invasive fungal infections (IFI) in recipients of solid organ transplants (SOT). The epidemiology is further compared with studies from other parts of the world for each SOT type.

Recent Findings

The available studies on Indian epidemiology of IFI in SOT are scarce, though the number of SOTs performed in India have increased tremendously in recent years. The limited data from India present a distinct spectrum of infection in transplant recipients with high incidence of mucormycosis. During COVID-19 outbreak, IFI rate increased and renal transplant recipients acquired mucormycosis earlier than previous studies.

Summary

Maximum data on IFI was available from renal transplant recipients, wherein mucormycosis was the predominant IFI in Indian patients in contrast to invasive candidiasis in majority countries. The other IFIs had varied spectrum. With the increasing number of SOTs being performed and the already persisting high burden of IFI in India, there is an urgent need of larger prospective studies on epidemiology of IFI in transplant recipients.

Demographic and Socioeconomic Factors Associated with Fungal Infection Risk, United States, 2019

Diagnosis disproportionately affected minority and low-income populations, underscoring the need for broad public health interventions.

Fungal infections cause substantial rates of illness and death. Interest in the association between demographic factors and fungal infections is increasing. We analyzed 2019 US hospital discharge data to assess factors associated with fungal infection diagnosis, including race and ethnicity and socioeconomic status. We found male patients were 1.5–3.5 times more likely to have invasive fungal infections diagnosed than were female patients. Compared with hospitalizations of non-Hispanic White patients, Black, Hispanic, and Native American patients had 1.4–5.9 times the rates of cryptococcosis, pneumocystosis, and coccidioidomycosis. Hospitalizations associated with lower-income areas had increased rates of all fungal infections, except aspergillosis. Compared with younger patients, fungal infection diagnosis rates, particularly for candidiasis, were elevated among persons > 65 years of age. Our findings suggest that differences in fungal infection diagnostic rates are associated with demographic and socioeconomic factors and highlight an ongoing need for increased physician evaluation of risk for fungal infections.

Antifungal stewardship in solid organ transplantation

BACKGROUND

Antifungal stewardship (AFS) has emerged as an important component of quality in managing invasive fungal infections (IFIs), and cost-benefit calculations suggest regular training in AFS is well worth the effort.

METHODS

This review will discuss the most common IFIs in solid organ transplantation (SOT)-recipients, how to diagnose them, and current recommendations for antifungal treatment and prophylaxis before demonstrating key takeaway points of AFS in this high-risk population.

RESULTS

Effective AFS starts before a patient is admitted for SOT, through education and regular interactions of the interdisciplinary clinical team involved in patient management, considering local factors such as epidemiological data and knowledge of diagnostic options including local turnaround times. Understanding the spectrum of antifungal agents, their efficacy and safety profiles, and pharmacokinetics, as well as duration of therapy is hereby essential. The most frequent IFIs in SOT recipients are caused by Candida species, followed by Aspergillus species, both with increasing resistance rates. Diagnosis of IFI can be challenging due to unspecific clinical presentation and difficult interpretation of microbiological findings and biomarkers. Prophylactic strategies, such as those for invasive aspergillosis in lung transplantation or invasive candidiasis (IC) in certain liver transplant settings, as well as the selection of the appropriate therapeutic agents require detailed knowledge on the pharmacokinetics and drug-drug interactions of antifungals.

CONCLUSIONS

Here in this review, we address what constitutes good AFS in this heterogeneous field of solid organ transplant recipients.

Efficacy of anti-fungal agents for invasive fungal infection prophylaxis in liver transplant recipients: A network meta-analysis

At present, there is still a lack of effective invasive fungal prophylaxis therapy in liver transplant recipients (LTRs). This study aimed to analysis the latest evidence on efficacy of current prophylactic anti-fungal therapy, and systematically compare between anti-fungal agents and placebo by a fixed-effects meta-analysis in all randomised controlled trials. A network meta-analysis was performed for invasive fungal infection (IFI) among different agents in 14 randomised controlled trials, in which 10 anti-fungal approaches were identified. Overall, anti-fungal prophylaxis reduced the rate of IFI (RR 0.30, 95% CI 0.18-0.52) and proven IFI (RR 0.27, 95% CI 0.14-0.53) when compared to placebo. In the network meta-analysis, an equivalent reduction in the rate of IFI was observed in fluconazole (OR 4.70, 95% CI 1.22-18.10), itraconazole (OR 5.82, 95% CI 1.10-30.71) and Liposomal amphotericin B (LAmB, OR 5.74, 95% CI 1.29-25.58) groups when compared with placebo. Anidulafungin might be the most effective agents in IFI prevention; however, this superiority did not meet statistically significance. Our study indicated that fluconazole, echinocandins and LAmB are equivalent in efficacy. Of which, fluconazole is recommended for the prevention of IFI in LTRs due to its efficacy, economics and compliance.

What is the optimal antimicrobial prophylaxis to prevent postoperative infectious complications after liver transplantation? A systematic review of the literature and expert panel recommendations

BACKGROUND

Antimicrobial prophylaxis is well-accepted in the liver transplant (LT) setting. Nevertheless, optimal regimens to prevent bacterial, viral, and fungal infections are not defined.

OBJECTIVES

To identify the optimal antimicrobial prophylaxis to prevent post-LT bacterial, fungal, and cytomegalovirus (CMV) infections, to improve short-term outcomes, and to provide international expert panel recommendations.

DATA SOURCES

Ovid MEDLINE, Embase, Scopus, Google Scholar, and Cochrane Central.

METHODS

Systematic review following PRISMA guidelines and recommendations using the GRADE approach derived from an international expert panel.

PROSPERO ID

CRD42021244976.

RESULTS

Of 1853 studies screened, 34 were included for this review. Bacterial, CMV, and fungal antimicrobial prophylaxis were evaluated separately. Pneumocystis jiroveccii pneumonia (PJP) antimicrobial prophylaxis was analyzed separately from other fungal infections. Overall, eight randomized controlled trials, 21 comparative studies, and five observational noncomparative studies were included.

CONCLUSIONS

Antimicrobial prophylaxis is recommended to prevent bacterial, CMV, and fungal infection to improve outcomes after LT. Universal antibiotic prophylaxis is recommended to prevent postoperative bacterial infections. The choice of antibiotics should be individualized and length of therapy should not exceed 24 hours (Quality of Evidence; Low | Grade of Recommendation; Strong). Both universal prophylaxis and preemptive therapy are strongly recommended for CMV prevention following LT. The choice of one or the other strategy will depend on individual program resources and experiences, as well as donor and recipient serostatus. (Quality of Evidence; Low | Grade of Recommendation; Strong). Antifungal prophylaxis is strongly recommended for LT recipients at high risk of developing invasive fungal infections. The drug of choice remains controversial. (Quality of Evidence; High | Grade of Recommendation; Strong). PJP prophylaxis is strongly recommended. Length of prophylaxis remains controversial. (Quality of Evidence; Very Low | Grade of Recommendation; Strong).

Pulmonary Aspergillosis Silently Presenting as Pneumothorax in Children with Leukemia: A Report of Three Cases

Aspergillosis causes invasive pulmonary disease in patients with hematological malignancies. Children with invasive pulmonary aspergillosis (IPA) usually have nonspecific radiographic findings unlike cavitary lesions commonly seen in adults. Pneumothorax due to rupture of peripheral fungal lesion may be a severe complication in patients with neutropenia. Here, we describe three children during induction chemotherapy for B-lymphoblastic leukemia with pneumothorax as a presenting feature of pulmonary aspergillosis.

A common vesicle proteome drives fungal biofilm development

Candida species are commensal organisms commonly interacting in the same host niche. In the pathogenic state, they frequently grow as a biofilm, often in mixed infections. The present studies observe a reliance upon common extracellular vesicle cargo for biofilm structure and function supporting interactions among species. The results reveal a vesicle cargo-driven coordination among Candida species during biofilm formation.

Extracellular vesicles mediate community interactions among cells ranging from unicellular microbes to complex vertebrates. Extracellular vesicles of the fungal pathogen Candida albicans are vital for biofilm communities to produce matrix, which confers environmental protection and modulates community dispersion. Infections are increasingly due to diverse Candida species, such as the emerging pathogen Candida auris, as well as mixed Candida communities. Here, we define the composition and function of biofilm-associated vesicles among five species across the Candida genus. We find similarities in vesicle size and release over the biofilm lifespan. Whereas overall cargo proteomes differ dramatically among species, a group of 36 common proteins is enriched for orthologs of C. albicans biofilm mediators. To understand the function of this set of proteins, we asked whether mutants in select components were important for key biofilm processes, including drug tolerance and dispersion. We found that the majority of these cargo components impact one or both biofilm processes across all five species. Exogenous delivery of wild-type vesicle cargo returned mutant phenotypes toward wild type. To assess the impact of vesicle cargo on interspecies interactions, we performed cross-species vesicle addition and observed functional complementation for both biofilm phenotypes. We explored the biologic relevance of this cross-species biofilm interaction in mixed species and mutant studies examining the drug-resistance phenotype. We found a majority of biofilm interactions among species restored the community’s wild-type behavior. Our studies indicate that vesicles influence the development of protective monomicrobial and mixed microbial biofilm communities.

Moonlighting proteins in medically relevant fungi

Moonlighting proteins represent an intriguing area of cell biology, due to their ability to perform two or more unrelated functions in one or many cellular compartments. These proteins have been described in all kingdoms of life and are usually constitutively expressed and conserved proteins with housekeeping functions. Although widely studied in pathogenic bacteria, the information about these proteins in pathogenic fungi is scarce, but there are some reports of their functions in the etiological agents of the main human mycoses, such as Candida spp., Paracoccidioides brasiliensis, Histoplasma capsulatum, Aspergillus fumigatus, Cryptococcus neoformans, and Sporothrix schenckii. In these fungi, most of the described moonlighting proteins are metabolic enzymes, such as enolase and glyceraldehyde-3-phosphate dehydrogenase; chaperones, transcription factors, and redox response proteins, such as peroxiredoxin and catalase, which moonlight at the cell surface and perform virulence-related processes, contributing to immune evasion, adhesions, invasion, and dissemination to host cells and tissues. All moonlighting proteins and their functions described in this review highlight the limited information about this biological aspect in pathogenic fungi, representing this a relevant opportunity area that will contribute to expanding our current knowledge of these organisms' pathogenesis.

Fatal disseminated mucormycosis due to Cunninghamella bertholletiae infection after ABO-incompatible living donor liver transplantation: a case report

Background

Fungal infection may develop because of immunosuppression after organ transplantation, in which invasive types, such as Aspergillus and Mucorales, fungi cause morbidity. We present a case of disseminated mucormycosis due to Cunninghamella bertholletiae after ABO-incompatible living donor liver transplantation (LDLT).

Case presentation

A 47-year-old man with decompensated liver cirrhosis and hepatocellular carcinoma underwent an ABO-incompatible LDLT using a graft procured from his son, who had a different blood type. Rituximab and mycophenolate mofetil were administered 3 weeks before LDLT as immunosuppressive therapy. Although liver graft function improved, mass-like infiltrates appeared in the lungs following intubation for > 1 week due to impaired consciousness. The brain magnetic resonance imaging findings were normal. Decreased ejection fraction and ST elevation were detected on echocardiography and electrocardiography, respectively. There was no dominant stenosis on coronary arteriography. The recipient underwent segmentectomy of the right lung 20 days after LDLT. C. bertholletiae was identified from a specimen using polymerase chain reaction, thus establishing a diagnosis of mucormycosis. Multiple infarctions in the brain, heart, and kidney developed within 2 weeks. Treatment with amphotericin B was ineffective. The patient developed circulatory collapse, and a temporary pacemaker and percutaneous coronary intervention were required for cardiac infarction. The recipient died of cardiac failure 27 days after the LDLT. Autopsy revealed disseminated mucormycosis involving the brain, thyroid, heart, lung, liver, gastrointestinal tract, and both kidneys. In addition, fungal endocarditis may have been responsible for septic emboli in multiple organs, resulting in multiple organ invasion. Hypothrombocytopenia was present since the pre-transplant period, and the recipient was diagnosed posthumously with myelodysplastic syndrome due to hereditary abnormalities. Multiple factors such as organ transplantation, bone marrow dysfunction, immunosuppression, and inadequate administration of antifungal reagents might have promoted mucormycosis development in our patient.

Conclusions

Mucormycosis by C. bertholletiae is a fatal complication; thus, early diagnosis and treatment are warranted before multiple organ invasion.

Critical Care of the Lung Transplant Patient

Lung transplantation is a therapeutic option for end-stage lung disease that improves survival and quality of life. Prelung transplant admission to the intensive care unit (ICU) for bridge to transplant with mechanical ventilation and extracorporeal membrane oxygenation (ECMO) is common. Primary graft dysfunction is an important immediate complication of lung transplantation with short- and long-term morbidity and mortality. Later transplant-related causes of respiratory failure necessitating ICU admission include acute cellular rejection, atypical infections, and chronic lung allograft dysfunction. Lung transplantation for COVID-19-related ARDS is increasingly common..

Therapeutic drug monitoring and CYP2C19 genotyping guide the application of voriconazole in children

BACKGROUND

This study used therapeutic drug monitoring (TDM) and CYP2C19 gene polymorphism analysis to explore the efficacy and safety of different doses of voriconazole (VCZ) for the clinical treatment of pediatric patients, with the aim of providing guidelines for individualized antifungal therapy in children.

METHODS

Our study enrolled 94 children with 253 VCZ concentrations. The genotyping of CYP2C19 was performed by polymerase chain reaction (PCR)-pyrosequencing. VCZ trough concentration (C_trough) was detected by high-performance liquid chromatography-tandem mass spectrometry. SPSS 23.0 was used to analyze the correlations between VCZ concentration, CYP2C19 phenotype, adverse effects (AEs), and drug-drug interactions.

RESULTS

A total of 94 children aged between 1 and 18 years (median age 6 years) were enrolled in the study. In total, 42.6% of patients reached the therapeutic range at initial dosing, while the remaining patients reached the therapeutic range after the adjustment of the dose or dosing interval. CYP2C19 gene polymorphism was performed in 59 patients. Among these patients, 24 (40.7%) had the normal metabolizer (NM) phenotype, 26 (44.1%) had the intermediate metabolizer (IM) phenotype, and 9 (15.3%) had the poor metabolizer (PM) phenotype. No cases of the rapid metabolizer (RM) or ultrarapid metabolizer (UM) phenotypes were found. The initial VCZ C_trough was significantly higher in patients with the PM and IM phenotypes than in those with the NM phenotype. The combination of immunosuppressive drugs (ISDs) did not affect VCZ C_trough. The incidence of AEs was 25.5%, and liver function damage (46.2%) and gastrointestinal reactions (19.2%) were the most common.

CONCLUSIONS

Our study showed significant individual differences of VCZ metabolism in children. Combining TDM with CYP2C19 gene polymorphism has important guiding significance for individualized antifungal therapy in pediatric patients.

Novel agents in the treatment of invasive fungal infections in solid organ transplant recipients

PURPOSE OF REVIEW

Recipients of solid organ transplants (SOTs) suffer a significant burden of invasive fungal infections (IFIs). The emergence of drug-resistant fungi and toxicities of currently used antifungal agents as well as drug-drug interactions with immunosuppressants make their treatment challenging. This review discusses selected novel antifungal agents in the development pipeline that can currently be used through clinical trials or may be commercially available in the near future.

RECENT FINDINGS

These agents in development have novel pharmacokinetics and pharmacodynamics, expanded spectra of activity and excellent safety profiles.

SUMMARY

The properties of novel antifungal agents have the potential to expand the therapeutic options for IFIs in recipients of SOTs.

Computational Modeling of Macrophage Iron Sequestration during Host Defense against Aspergillus

Iron is essential to the virulence of Aspergillus species, and restricting iron availability is a critical mechanism of antimicrobial host defense. Macrophages recruited to the site of infection are at the crux of this process, employing multiple intersecting mechanisms to orchestrate iron sequestration from pathogens. To gain an integrated understanding of how this is achieved in aspergillosis, we generated a transcriptomic time series of the response of human monocyte-derived macrophages to Aspergillus and used this and the available literature to construct a mechanistic computational model of iron handling of macrophages during this infection. We found an overwhelming macrophage response beginning 2 to 4 h after exposure to the fungus, which included upregulated transcription of iron import proteins transferrin receptor-1, divalent metal transporter-1, and ZIP family transporters, and downregulated transcription of the iron exporter ferroportin. The computational model, based on a discrete dynamical systems framework, consisted of 21 3-state nodes, and was validated with additional experimental data that were not used in model generation. The model accurately captures the steady state and the trajectories of most of the quantitatively measured nodes. In the experimental data, we surprisingly found that transferrin receptor-1 upregulation preceded the induction of inflammatory cytokines, a feature that deviated from model predictions. Model simulations suggested that direct induction of transferrin receptor-1 (TfR1) after fungal recognition, independent of the iron regulatory protein-labile iron pool (IRP-LIP) system, explains this finding. We anticipate that this model will contribute to a quantitative understanding of iron regulation as a fundamental host defense mechanism during aspergillosis.

IMPORTANCE Invasive pulmonary aspergillosis is a major cause of death among immunosuppressed individuals despite the best available therapy. Depriving the pathogen of iron is an essential component of host defense in this infection, but the mechanisms by which the host achieves this are complex. To understand how recruited macrophages mediate iron deprivation during the infection, we developed and validated a mechanistic computational model that integrates the available information in the field. The insights provided by this approach can help in designing iron modulation therapies as anti-fungal treatments.

Cryptococcal Meningitis in Kidney Transplant Recipients: A Two-Decade Cohort Study in France

Cryptococcosis is the third most common cause of invasive fungal infection in solid organ transplant recipients and cryptococcal meningitis (CM) its main clinical presentation. CM outcomes, as well as its clinical features and radiological characteristics, have not yet been considered on a large scale in the context of kidney transplantation (KT). We performed a nationwide retrospective study of adult patients diagnosed with cryptococcosis after KT between 2002 and 2020 across 30 clinical centers in France. We sought to describe overall and graft survival based on whether KT patients with cryptococcosis developed CM or not. Clinical indicators of CNS involvement and brain radiological characteristics were assessed. Eighty-eight cases of cryptococcosis were diagnosed during the study period, with 61 (69.3%) cases of CM. Mortality was high (32.8%) at 12 months (M12) but not significantly different whether or not patients presented with CM. Baseline hyponatremia and at least one neurological symptom were independently associated with CM (p < 0.001). Positive serum cryptococcal antigen at diagnosis was also significantly associated with CM (p < 0.001). On magnetic resonance imaging (MRI), three patterns of brain injury were identified: parenchymal, meningeal, and vascular lesions. Although CM does not affect graft function directly, it entails a grim prognosis.

Clinical Characteristics of Transplant Recipients Infected with Talaromyces Marneffei: 2 Case Reports and a Literature Review

Purpose

To summarize the clinical characteristics, treatment and outcomes of transplant recipients infected with Talaromyces marneffei (TM).

Materials and Methods

A retrospective analysis was performed on 2 patients with Talaromycosis marneffei (TSM) and transplants at the First Affiliated Hospital of Guangxi Medical University, and a systematic literature review was conducted simultaneously.

Results

This article reported two patients after kidney transplantation who developed fever, cough within 3-4 months. Their haemoglobin was decreased. Their chest computed tomography (CT) showed nodules. TM was detected in their blood or bronchoalveolar lavage fluid samples by next-generation sequencing (NGS). After antifungal treatment with voriconazole (VOR), one patient worsened, the other patient died. A total of 21 patients with TSM after transplants were reported in the literature review. Fourteen underwent kidney transplantation, 4 underwent liver transplantation, 2 underwent lung transplantation, and 1 underwent bone marrow transplantation. The median time from initiating the postoperative immunosuppressive therapy to the onset of symptoms or disease changes was 18 (0.5-140) months. Among them, 9 patients developed fever, 7 patients developed cough or expectoration and 4 patients developed dyspnoea. Haemoglobin was decreased in 10 patients. Pulmonary nodules were found in 7 patients. Among the 21 patients, 7 were diagnosed by positive culture, 6 by biopsy, 5 by culture and biopsy. Of the 21 patients, 13 patients improved by antifungal therapy, 8 patients worsened or died. Seven patients who received amphotericin B followed by itraconazole (ITR) therapy all improved. Regarding the use of immunosuppressants in 12 patients, 9 patients had to discontinue or reduce their medications (6 patients improved, 3 patients worsened or died).

Conclusion

Patients with TSM after transplant often have disseminated infections, involving the respiratory, hematopoietic and so on. Fever, cough, decreased haemoglobin and pulmonary nodules often occur approximately 18 months after surgery. The combined applications of culture, biopsy, NGS are helpful for an early diagnosis. Antifungal therapy with amphotericin B followed by itraconazole is recommended, and the dosage of the immunosuppressant should be adjusted timely.

How Has the Aspergillosis Case Fatality Rate Changed over the Last Two Decades in Spain?

(1) Background: Aspergillus produces high morbidity and mortality, especially in at-risk populations. In Spain, the evolution of mortality in recent years due to this fungus is not well established. The aim of this study was to estimate the case fatality rate of aspergillosis in inpatients from 1997 to 2017 in Spain. (2) Methodology: A retrospective descriptive study was conducted with records of inpatients admitted to the National Health System with a diagnosis of aspergillosis. (3) Principal findings: Of 32,960 aspergillosis inpatients, 24.5% of deaths were registered, and 71% of the patients who died were men. The percentage of deaths increased progressively with age. The case fatality rate progressively decreased over the period, from 25.4 and 27.8% in 1997–1998 to values of 20.6 and 20.8% in 2016 and 2017. Influenza and pneumonia occurrence/association significantly increased case fatality rates in all cases. (4) Conclusions: Our study shows that lethality significantly decreased in the last two decades despite the increase in cases. This highlights the fact that patients with solid and/or hematological cancer do not have a much higher mortality rate than the group of patients with pneumonia or influenza alone, these two factors being the ones that cause the highest CFRs. We also need studies that analyze the causes of mortality to decrease it and studies that evaluate the impact of COVID-19.

Diagnosis and Treatment of Invasive Candidiasis

Candida species, belonging to commensal microbial communities in humans, cause opportunistic infections in individuals with impaired immunity. Pathogens encountered in more than 90% cases of invasive candidiasis include C. albicans, C. glabrata, C. krusei, C. tropicalis, and C. parapsilosis. The most frequently diagnosed invasive infection is candidemia. About 50% of candidemia cases result in deep-seated infection due to hematogenous spread. The sensitivity of blood cultures in autopsy-proven invasive candidiasis ranges from 21% to 71%. Non-cultural methods (beta-D-glucan, T2Candida assays), especially beta-D-glucan in combination with procalcitonin, appear promising in the exclusion of invasive candidiasis with high sensitivity (98%) and negative predictive value (95%). There is currently a clear deficiency in approved sensitive and precise diagnostic techniques. Omics technologies seem promising, though require further development and study. Therapeutic options for invasive candidiasis are generally limited to four classes of systemic antifungals (polyenes, antimetabolite 5-fluorocytosine, azoles, echinocandins) with the two latter being highly effective and well-tolerated and hence the most widely used. Principles and methods of treatment are discussed in this review. The emergence of pan-drug-resistant C. auris strains indicates an insufficient choice of available medications. Further surveillance, alongside the development of diagnostic and therapeutic methods, is essential.

Severe Bartonella henselae bone infection in a kidney transplanted young man

We present a case of a young kidney transplanted man. He was admitted with lymphadenopathy, fluctuating fever and night sweats 2 months after a cat bite. After admission, he developed severe pain around his right hip. An 18F-fluorodeoxyglucose (FDG)-positron emission tomography/CT revealed intense FDG-uptake in lymph nodes, spleen and bone, suggestive of lymphoma. An extracted lymph node showed confluent granulomas, microabscesses with neutrophils and scattered multinucleated giant cells histologically. The patient had history of latent tuberculosis and proteinase 3 -anti-neutrophil cytoplasmic antibodies associated (PR3-ANCA) vasculitis, making differential diagnostic considerations complicated. Bartonella henselae antibodies was detected in blood and B. henselae DNA in a lymph node. He was started on doxycycline and rifampicin. Due to severe drug interactions with both tacrolimus and increasing morphine doses, rifampicin was changed to azithromycin. He received 12 days of relevant antibiotic treatment and responded well. He was discharged after 16 days with close follow-up and was still in habitual condition 12 months later.

Voriconazole Therapeutic Drug Monitoring Among Lung Transplant Recipients Receiving Targeted Therapy for Invasive Aspergillosis

BACKGROUND

Voriconazole is the first line treatment for invasive aspergillosis (IA) Current guidelines suggest performing regular voriconazole therapeutic drug monitoring (TDM) to optimize treatment efficacy. We aimed to determine if TDM was predictive of clinical outcome in LTRs.

METHODS

Retrospective chart review was performed for all LTRs with probable or proven IA, treated with voriconazole monotherapy and who underwent TDM during therapy. Clinical outcome and toxicity were measured at 12 weeks. Classification and regression tree (CART) analysis was used to determine the most predictive voriconazole level thresholds for successful outcome.

RESULTS

118 TDM samples from 30 LTRs with IA were analyzed. Three LTRs were excluded due to early treatment discontinuation. The median TDM level was 1.2 μg/mL (range 0.06-7.3). At 12 weeks, 62% (17/27) of patients had a successful outcome, while 37% (10/27) of patients failed therapy. CART analysis determined that the best predictor for successful outcome was a median TDM level > 0.72 μg/mL. Seventy percent (14/20) of patients with median TDM above 0.72 μg/mL had a successful outcome, compared to 42.9% (3/7) of patients with a median TDM below 0.72 μg/mL (OR 3.11; 95% CI: 0.53-20.4; P = 0.21). CART analysis determined that a TDM level greater than 2.13 μg/mL was predictive of hepatotoxicity.

CONCLUSIONS

Our data suggests that a voriconazole TDM range between 0.72 μg/mL and 2.13 μg/mL may be associated with improved outcomes. Our study is in line with current recommendations on the use of voriconazole TDM in improving outcome and minimizing toxicity in LTR with IA. This article is protected by copyright. All rights reserved.

Incidences of infectious events in a renal transplant cohort of the German Center of Infectious Diseases (DZIF)

Background

Infectious complications are a major cause of morbidity and mortality after kidney transplantation.

Methods

In this transplant cohort study at the German Center of Infectious Diseases (DZIF), we evaluated all infections occurring during the first year after renal transplantation. We assessed microbial etiology, incidence rates, and temporal occurrence of these infections.

Results

Of 804 renal transplant recipients (65.2% male, 51 ± 14 years), 439 (54.6%) had 972 infections within the first year after transplantation. Almost half of these infections (47.8%) occurred within the first three months. Bacteria were responsible for 66.4% (645/972) of all infections, followed by viral (28.9%[281/972]) and fungal (4.7%[46/972]) pathogens. The urinary tract was the most common site of infection (42.4%). Enterococcus was most frequently isolated bacteria (20.9%), followed by E.coli (17.6%) and Klebsiella (12.5%). E.coli was the leading pathogen in recipients &lt;50 years of age, whereas Enterococcus predominated in older recipients. Resistant bacteria were responsible for at least one infection in 9.5% (76/804) of all recipients. Viral infections occurred in 201 recipients (25.0%). Of these, herpes viruses predominated (140/281[49.8%]) and cytomegalovirus had the highest incidence rate (12.3%). In the 46 fungal infections, Candida albicans (40.8%) was most commonly isolated. Other fungal opportunistic pathogens, including Aspergillus fumigatus and Pneumocystis, were rare.

Conclusions

Renal allograft recipients in Germany experience a high burden of infectious complications in the first year after transplantation. Bacteria were the predominating pathogen, followed by opportunistic infections such as cytomegalovirus. Microbial etiology varied between age groups and resistant bacteria were identified in 10% of recipients.

Invasive and Subcutaneous Infections Caused by Filamentous Fungi: Report from a Portuguese Multicentric Surveillance Program

Invasive fungal infections (IFI) have significantly increased over the past years due to advances in medical care for the at-risk immunocompromised population. IFI are often difficult to diagnose and manage, and can be associated with substantial morbidity and mortality. This study aims to contribute to understanding the etiology of invasive and subcutaneous fungal infections, their associated risk factors, and to perceive the outcome of patients who developed invasive disease, raising awareness of these infections at a local level but also in a global context. A laboratory surveillance approach was conducted over a seven-year period and included: (i) cases of invasive and subcutaneous fungal infections caused by filamentous/dimorphic fungi, confirmed by either microscopy or positive culture from sterile samples, (ii) cases diagnosed as probable IFI according to the criteria established by EORTC/MSG when duly substantiated. Fourteen Portuguese laboratories were enrolled. Cases included in this study were classified according to the new consensus definitions of invasive fungal diseases (IFD) published in 2020 as follows: proven IFI (N = 31), subcutaneous fungal infection (N = 23). Those proven deep fungal infections (N = 54) totalized 71.1% of the total cases, whereas 28.9% were classified as probable IFI (N = 22). It was possible to identify the etiological fungal agent in 73 cases (96%). Aspergillus was the most frequent genera detected, but endemic dimorphic fungi represented 14.47% (N = 11) of the total cases. Despite the small number of cases, a high diversity of species were involved in deep fungal infections. This fact has implications for clinical and laboratory diagnosis, and on the therapeutic management of these infections, since different species, even within the same genus, can present diverse patterns of susceptibility to antifungals.

Fungal Infections in Lung Transplantation

Purpose of Review

We aim to understand the most common fungal infections associated with the post-lung transplant period, how to diagnose, treat, and prevent them based on the current guidelines published and our center’s experience.

Recent Findings

Different fungi inhabit specific locations. Diagnosis of invasive fungal infections (IFIs) depends on symptoms, radiologic changes, and a positive microbiological or pathology data. There are several molecular tests that have been used for diagnosis. Exposure to fungal prophylaxis can predispose lung transplant recipients to these emerging molds. Understanding and managing medication interactions and drug monitoring are essential in successfully treating IFIs.

Summary

With the increasing rate of lung transplantations being performed, and the challenges posed by the immunosuppressive regimen, understanding the risk and managing the treatment of fungal infections are imperative to the success of a lung transplant recipient. There are many ongoing clinical trials being conducted in hopes of developing novel antifungals.