Use of lung resection and voriconazole for successful treatment of invasive pulmonary Aspergillus ustus infection

What do We Know about Cryptic Aspergillosis?

Cryptic Aspergillus species are increasingly recognized as pathogens involved in human disease. They are ubiquitarian fungi with high tenacity in their environment and can express various resistance mechanisms, often due to exposure to antifungal agents employed in agriculture and farming. The identification of such species is increasing thanks to molecular techniques, and a better description of this type of pathogen is granted. Nevertheless, the number of species and their importance in the clinical setting still need to be well studied. Furthermore, their cross-sectional involvement in animal disease, plants, and human activities requires a multidisciplinary approach involving experts from various fields. This comprehensive review aims to provide a sharp vision of the cryptic Aspergillus species, from the importance of correct identification to the better management of the infections caused by these pathogens. The review also accentuates the importance of the One Health approach for this kind of microorganism, given the interconnection between environmental exposure and aspergillosis, embracing transversely the multidisciplinary process for managing the cryptic Aspergillus species. The paper advocates the need for improving knowledge in this little-known species, given the burden of economic and health implications related to the diffusion of these bugs.

Drug-Resistant Aspergillus spp.: A Literature Review of Its Resistance Mechanisms and Its Prevalence in Europe

Infections due to the Aspergillus species constitute an important challenge for human health. Invasive aspergillosis represents a life-threatening disease, mostly in patients with immune defects. Drugs used for fungal infections comprise amphotericin B, triazoles, and echinocandins. However, in the last decade, an increased emergence of azole-resistant Aspergillus strains has been reported, principally belonging to Aspergillus fumigatus species. Therefore, both the early diagnosis of aspergillosis and its epidemiological surveillance are very important to establish the correct antifungal therapy and to ensure a successful patient outcome. In this paper, a literature review is performed to analyze the prevalence of Aspergillus antifungal resistance in European countries. Amphotericin B resistance is observed in 2.6% and 10.8% of Aspergillus fumigatus isolates in Denmark and Greece, respectively. A prevalence of 84% of amphotericin B-resistant Aspergillus flavus isolates is reported in France, followed by 49.4%, 35.1%, 21.7%, and 20% in Spain, Portugal, Greece, and amphotericin B resistance of Aspergillus niger isolates is observed in Greece and Belgium with a prevalence of 75% and 12.8%, respectively. The prevalence of triazole resistance of Aspergillus fumigatus isolates, the most studied mold obtained from the included studies, is 0.3% in Austria, 1% in Greece, 1.2% in Switzerland, 2.1% in France, 3.9% in Portugal, 4.9% in Italy, 5.3% in Germany, 6.1% in Denmark, 7.4% in Spain, 8.3% in Belgium, 11% in the Netherlands, and 13.2% in the United Kingdom. The mechanism of resistance is mainly driven by the TR34/L98H mutation. In Europe, no in vivo resistance is reported for echinocandins. Future studies are needed to implement the knowledge on the spread of drug-resistant Aspergillus spp. with the aim of defining optimal treatment strategies.

Management of Invasive Infections in Diabetes Mellitus: A Comprehensive Review

Patients with diabetes often have more invasive infections, which may lead to an increase in morbidity. The hyperglycaemic environment promotes immune dysfunction (such as the deterioration of neutrophil activity, antioxidant system suppression, and compromised innate immunity), micro- and microangiopathies, and neuropathy. A greater number of medical interventions leads to a higher frequency of infections in diabetic patients. Diabetic individuals are susceptible to certain conditions, such as rhino-cerebral mucormycosis or aspergillosis infection. Infections may either be the primary symptom of diabetes mellitus or act as triggers in the intrinsic effects of the disease, such as diabetic ketoacidosis and hypoglycaemia, in addition to increasing morbidity. A thorough diagnosis of the severity and origin of the infection is necessary for effective treatment, which often entails surgery and extensive antibiotic use. Examining the significant issue of infection in individuals with diabetes is crucial. Comprehensive research should examine why infections are more common amongst diabetics and what the preventive treatment strategies could be.

Trends in the Prevalence of Amphotericin B-Resistance (AmBR) among Clinical Isolates of Aspergillus Species

The challenges of the invasive infections caused by the resistant Aspergillus species include the limited access to antifungals for treatment and high mortality. This study aimed to provide a global perspective of the prevalence of amphotericin B resistance (AmBR), geographic distribution, and the trend of AmBR from 2010 to 2020. To analyze the prevalence of in vitro AmBR in clinical Aspergillus species, we reviewed the literature and identified a total of 72 articles. AmBR was observed in 1128 out of 3061 Aspergillus terreus (36.8%), 538 out of 3663 Aspergillus flavus (14.9%), 141 out of 2691 Aspergillus niger (5.2%), and 353 out of 17,494 Aspergillus fumigatus isolates (2.01%). An increasing trend in AmB-resistant isolates of A. fumigatus and a decreasing trend in AmB-resistant A. terreus and A. flavus isolates were observed between 2016 and 2020. AmB-resistant A. terreus and A. niger isolates, accounting for 40.4% and 20.9%, respectively, were the common AmB-resistant Aspergillus species in Asian studies. However, common AmB-resistant Aspergillus species reported by European and American studies were A. terreus and A. flavus isolates, accounting for 40.1% and 14.3% in 31 studies from Europe and 25.1% and 11.7% in 14 studies from America, respectively. The prevalence of AmB-resistant A. niger in Asian isolates was higher than in American and European. We found a low prevalence of A. terreus in American isolates (25.1%) compared to Asian (40.4%) and European (40.1%). Future studies should focus on analyzing the trend of AmBR on a regional basis and using the same methodologies.

Invasive Aspergillosis Due to Aspergillus Section Usti: A Multicenter Retrospective Study

BACKGROUND

Aspergillus spp. of section Usti (A. ustus) represent a rare cause of invasive aspergillosis (IA). This multicenter study describes the epidemiology and outcome of A. ustus infections.

METHODS

Patients with A. ustus isolated from any clinical specimen were retrospectively identified in 22 hospitals from 8 countries. When available, isolates were sent for species identification (BenA/CaM sequencing) and antifungal susceptibility testing. Additional cases were identified by review of the literature. Cases were classified as proven/probable IA or no infection, according to standard international criteria.

RESULTS

Clinical report forms were obtained for 90 patients, of whom 27 had proven/probable IA. An additional 45 cases were identified from literature review for a total of 72 cases of proven/probable IA. Hematopoietic cell and solid-organ transplant recipients accounted for 47% and 33% cases, respectively. Only 8% patients were neutropenic at time of diagnosis. Ongoing antimold prophylaxis was present in 47% of cases. Pulmonary IA represented 67% of cases. Primary or secondary extrapulmonary sites of infection were observed in 46% of cases, with skin being affected in 28% of cases. Multiple antifungal drugs were used (consecutively or in combination) in 67% of cases. The 24-week mortality rate was 58%. A. calidoustus was the most frequent causal agent. Minimal inhibitory concentrations encompassing 90% isolates (MIC90) were 1, 8, >16, and 4 µg/mL for amphotericin B, voriconazole, posaconazole, and isavuconazole, respectively.

CONCLUSIONS

Aspergillus ustus IA mainly occurred in nonneutropenic transplant patients and was frequently associated with extrapulmonary sites of infection. Mortality rate was high and optimal antifungal therapy remains to be defined.

Opportunistic invasive fungal disease in patients with type 2 diabetes mellitus from Southern China: Clinical features and associated factors

AIMS/INTRODUCTION

A retrospective study was carried out to investigate the clinical characteristics and associated factors for invasive fungal disease in patients with type 2 diabetes mellitus.

MATERIALS AND METHODS

Demographic and clinical data were recorded. Associated factors were analyzed by logistic regression analysis.

RESULTS

Invasive fungal disease was diagnosed in 120 patients with type 2 diabetes mellitus (prevalence, 0.4%). Yeast infection (56/120, 46.7%), including candidiasis (31/56, 55.4%) and cryptococcosis (25/56, 44.6%), was the most common. The urinary tract was mainly involved in candidiasis (12/31, 38.7%). More than half of the cryptococcosis (16/25, 64.0%) presented as pneumonia. Mold infection accounted for 40.8% of the cases, and predominantly involved the lung (34/49, 69.4%). A total of 15 (12.5%) patients had mixed fungal infection. Candida albicans (24/111, 21.6%), Cryptococcus neoformans (19/111, 17.1%) and Aspergillus fumigatus (14/111, 12.6%) were the leading agents. Co-infection occurred in 58 (48.3%) patients, mainly presenting as pneumonia caused by Gram-negative bacteria. The inpatient mortality rate of invasive fungal disease was 23.3% (28/120). Glycated hemoglobin levels were higher in non-survivors than survivors (8.8 ± 2.5 vs 7.7 ± 2.1%, P = 0.02). Anemia (adjusted odds ratio, 3.50, 95% confidence interval 1.95-6.27, P < 0.001), hypoalbuminemia (adjusted odds ratio, 5.42, 95% confidence interval 3.14-9.36, P < 0.001) and elevated serum creatinine (adjusted odds ratio, 2.08, 95% confidence interval 1.07-4.04, P = 0.03) were associated with invasive fungal disease in type 2 diabetes mellitus patients.

CONCLUSIONS

Invasive fungal disease is a life-threatening complication in type 2 diabetes mellitus patients. C. a albicans, C. neoformans, and A. fumigatus are the leading agents. Prolonged hyperglycemia results in unfavorable outcomes. Correction of anemia and hypoalbuminemia might improve prognosis.

Global Aspects of Triazole Resistance in Aspergillus fumigatus with Focus on Latin American Countries

Azole resistance in Aspergillus has emerged as an escalating problem in health care, and it has been detected in patients exposed, or not, to these drugs. It is known that azole antifungals are widely applied not only in clinical treatments for fungal infections, but also as agricultural fungicides, resulting in a significant threat for human health. Although the number of cases of azole-resistant aspergillosis is still limited, various resistance mechanisms are described from clinical and environmental isolates. These mechanisms consist mainly of alterations in the target of azole action (CYP51A gene)—specifically on TR₃₄/L98H and TR₄₆/Y121F/T289A, which are responsible for over 90% of resistance cases. This review summarizes the epidemiology, management, and extension of azole resistance in A. fumigatus worldwide and its potential impact in Latin American countries, emphasizing its relevance to clinical practice.

Current status of antifungal resistance and its impact on clinical practice

Mortality linked to invasive fungal diseases remains very high despite the availability of novel antifungals and new therapeutic strategies. Candida albicans and Aspergillus fumigatus account for most invasive mycosis produced by yeast or moulds, respectively. Other Candida non-albicans are increasingly being reported and newly emerging, as well as cryptic, filamentous fungi often cause disseminated infections in immunocompromised hosts. Management of invasive fungal infections is becoming a challenge as emerging fungal pathogens generally show poor response to many antifungals. The ability of reference antifungal susceptibility testing methods to detect emerging resistance patterns, together with the molecular characterization of antifungal resistance mechanisms, are providing useful information to optimize the effectiveness of antifungal therapy. The current status of antifungal resistance epidemiology with special emphasis on the molecular resistant mechanisms that have been described in the main pathogenic fungal species are reviewed.

Lung resection in hematologic patients with pulmonary invasive fungal disease

BACKGROUND

Pulmonary invasive fungal disease is a frequent complication in patients with hematologic malignancies. Surgical resection in addition to antifungal therapy is an option for selected cases but often feared because of immunosuppression.

METHODS

We analyzed the outcome of 71 patients undergoing lung resection for pulmonary invasive fungal disease. Most patients had leukemia, 44 underwent high-dose chemotherapy, and 18 underwent stem cell transplantation.

RESULTS

On the day of surgery, 44 patients were neutropenic, and 41 had a platelet count < 50 × 109/L. Forty-five nonanatomic (atypical) resections and 26 lobectomies were performed. Fungal infection was histologically proven in 53 patients. Reoperation was needed in four patients (bronchial stump dehiscence, persistent air leak, chylothorax, and seroma). Minor complications at the site of surgery occurred in 14 patients. In only two, there was an uncontrolled disseminated fungal infection. Overall, mortality at 30 days was 7% (five of 71). Long-term survival was mainly influenced by the underlying hematologic disease.

CONCLUSIONS

Lung resection is a therapeutic option for hematologic patients with pulmonary fungal infection. Despite immunosuppression, the perioperative morbidity and mortality is acceptable, and, therefore, the prognosis is not determined by the surgical intervention.

Voriconazole in the management of nosocomial invasive fungal infections

Voriconazole is a new triazole developed for the treatment of life-threatening fungal infections. The drug is available for both oral and intravenous administration; the oral formulation has excellent bioavailability. The side-effect profile of voriconazole presents an acceptable safety and tolerability spectrum: transient visual disturbances, liver enzyme abnormalities, and skin rashes are the most frequently reported side effects but rarely lead to discontinuation. The potential for drug–drug interactions is high, because of its extensive hepatic metabolism. Careful attention to dosage is required, and serum levels and the effects of interacting drugs should be monitored. Review of 25 470 isolates of yeasts and 3216 isolates of filamentous fungi showed voriconazole to have broad-spectrum activity against pathogenic yeasts including intrinsically fluconazole-resistant isolates such as Candida krusei, dimorphic fungi, and opportunistic moulds like Aspergillus spp, amphotericin-B-resistant Aspergillus terreus, Fusarium spp, and Scedosporium apiospermum. It displays excellent clinical efficacy in patients with fluconazole-resistant and -susceptible Candida infections, invasive bone and central nervous system aspergillosis, and various refractory fungal infections. Voriconazole has been approved by the US Food and Drug Administration and by the European Medicines Agency for the treatment of invasive aspergillosis, serious infections caused by Fusarium and S. apiospermum, fluconazole-resistant invasive Candida infections, and candidemia in nonneutropenic patients.

Invasive Aspergillosis of the Hand Caused by Aspergillus ustus: a Case Report

This is a case report of a 61-year-old cardiac transplant patient who developed a disseminated infection involving the upper extremity with a rare fungus known as Aspergillus ustus. The patient was successfully treated with aggressive serial debridements, antifungal medications, and reduction of immunosuppression. With these interventions, the patient avoided amputation despite the aggressive nature of this infection.

Indicaciones actuales de voriconazol en pacientes onco-hematológicos

Invasive fungal infections (IFI) are the main cause of infectious death in cancer patients, especially in hematological malignancies and hematopoietic transplant recipients. Current epidemiology is characterized by a predominance of IFI caused by molds, mainly aspergillosis, along with a emergence of hard-to-treat fungi such are Zygomicetes, Fusarium and Scedosporium. Voriconazole is a broad spectrum antifungal agent with oral and intravenous formulations, approved by the EMEA for the treatment of invasive aspergillosis, candidemia in non-neutropenic patients, IFI caused by fluconazole-resistant species of Candida as well as Scedosporium and Fusarium infections. However, its use in clinical practice is broader, as empirical antifungal treatment and as secondary prophylaxis. It should be kept in mind the possibility of breakthrough IFI, particularly zygomycosis, in patients treated with voriconazole for long periods.

Interleukin-10 promoter polymorphism as risk factor to develop invasive pulmonary aspergillosis

This present study was undertaken to examine the role of the host response to Aspergillus fumigatus in the development of clinical symptoms of invasive pulmonary aspergillosis (IPA). The natural outcome and response to IPA infection varies between individuals. Whereas some variation may be attributable to fungi and environmental variables, it is probable that host genetic background also plays a significant role. Interleukin (IL)-10 has a key function in the regulation of cellular immune responses and is involved in various inflammatory diseases. IL-10 promoter carries a polymorphism that has been associated to production levels. Our aim was to investigate the role of this polymorphism in susceptibility to develop IPA infection. The study included 120 haematological patients and 124 age and sex-matched controls and bi-allelic IL-10 -1082(G/A) polymorphism was examined. Genotypic (p=0.385) and allelic frequencies (p=0.527, OR=0.89, 95% CI=0.78-1.60) were similar between patients and healthy controls. IPA was diagnosed in 59 of the 120 patients according to consensus criteria published by the European Organization for Research and Treatment of Cancer/Invasive Fungal Infections Cooperative Group (EORTC/IFICG). Our results provide evidence that IL-10 -1082(AA) genotype is associated with resistance to develop IPA (p=0.001). Allele frequency of IL-10 -1082A allele was weakly associated with susceptibility to develop IPA infection (p=0.052). In conclusion, these results suggest that differential production of IL-10 may alter the risk for IPA in haematological patients.

Clustering of invasiveAspergillus ustuseye infections in a tertiary care hospital: A molecular epidemiologic study of an uncommon species

Aspergillus infections are being increasingly recognized as an important cause of morbidity and blindness. We report here the first cluster of Aspergillus ustus endophthalmitis cases which occurred in a large tertiary care hospital during the period October 2003 to June 2004. In three of the cases, the patients required enucleation following cataract surgery, while the fourth involved a fatal infection in a pediatric patient hospitalized for osteopetrosis. Patient charts from the four cases were reviewed retrospectively and indicated that postoperative signs of fungal endophthalmitis developed in the patients 1-11 weeks after surgery. The molecular characterization of the isolates and their epidemiological relatedness were evaluated by Random Amplification of Polymorphic DNA (RAPD). A source investigation of this mini outbreak was performed by environmental sampling, but no isolates of A. ustus were recovered from these studies. All A. ustus strains isolated from three patients with fungal endophthalmitis had the same RAPD pattern suggesting a common source. The strain from the pediatric patient differed from the ophthalmic isolates in five electrophoretic loci. The latter was included solely as an outbreak, unrelated control to evaluate the discriminatory power of the molecular typing method employed in the analysis of the ophthalmic strains. These cases illustrate the potential for uncommon species like A. ustus to cause high morbidity and mortality in some clinical settings. Aspergillus ustus endophthalmitis is a serious and devastating complication of ocular surgery. It is unknown whether ongoing hospital construction may have contributed to this cluster of cases. Random amplification of polymorphic DNA may give valuable clues about the clonality of A. ustus strains.

Invasive pulmonary aspergillosis: role of early diagnosis and surgical treatment in patients with acute leukemia

BACKGROUND

Aspergillus is a ubiquitous soil-dwelling fungus known to cause significant pulmonary infection in immunocompromised patients. The incidence of aspergillosis has increased during the past two decades and is a frequently lethal complication of acute leukemia patients that occurs following both chemotherapy and bone marrow transplantation. The diagnosis of invasive pulmonary aspergillosis (IPA) according to the criteria that are established by European Organization for the Research and Treatment of Cancer and Mycoses Study Group raise difficulties in severely ill patients. Despite established improvements in field of diagnosis (galactomannan antigen, quantitative PCR, real-time PCR for Aspergillus spp., and findings of computed tomography) and treatment with new antifungals, it is still a major problem in patients with acute leukemia. However, prompt and effective treatment of IPA is crucial because most patients will need subsequent chemotherapy for underlying hematologic disease as soon as possible.

CASE PRESENTATION

We report a 33-year-old male patient with acute promyelocytic leukemia diagnosed in 1993 that developed invasive pulmonary aspergillosis due to A. flavus at relapse in 2003. The patient was successfully treated with liposomal amphotericin B and underwent surgical pulmonary resection. The operative course was uneventful.

CONCLUSION

This report emphasizes the clinical picture, applicability of recent advances in diagnostic and therapeutic approaches for IPA. For early identification of a patient infected with IPA, a high index of suspicion and careful clinical and radiological examinations with serial screening for galactomannan should be established. If aspergillosis is suspected, anti-aspergillosis drug should be administered immediately, and if a unique pulmonary lesion remains, surgical resection should be considered to prevent reactivation during consecutive chemotherapy courses and to improve the outcome.

Aspergillus ustus infections among transplant recipients

This is the first report of clustered Aspergillus ustus causing systemic disease in transplant patients.

Aspergillus ustus is a mold that rarely infects humans; only 15 systemic cases have been reported. We report the first outbreak of invasive infection caused by A. ustus among hematopoietic stem cell transplant (HSCT) recipients. Six patients with infections were identified; 3 infections each occurred in both 2001 and 2003. Molecular typing by using randomly amplified polymorphic DNA (RAPD) and antifungal drug susceptibility testing were performed on clinical and environmental isolates recovered from our hospital from 1999 to 2003. The highest overall attack rate in HSCT patients was 1.6%. The overall death rate was 50%, and death occurred within 8 days after diagnostic culture collection. Clinical isolates exhibited decreased susceptibility to antifungal drugs, especially azoles. RAPD and phylogenetic analysis showed genetic similarity between isolates from different patients. Based on the clustering of cases in space and time and molecular data, common-source acquisition of this unusual drug-resistant species is possible.

Fungal endophthalmitis caused byAspergillus ustusin a patient following cataract surgery

The first case of postoperative endophthalmitis after cataract surgery caused by Aspergillus ustus, a species that has only rarely been implicated in human disease, is described. Six weeks after cataract surgery, a 67-year-old medically controlled diabetic patient presented with uveitis, mild ciliary injection and ocular discomfort. Anterior chamber paracentesis, vitreous tap and finally complete vitrectomy with removal of the capsular bag including the intraocular lens were performed and several sets of culture yielded A. ustus. Despite vigorous systemic (itraconazole and caspofungin) and intravitreal (amphotericin B and caspofungin) antifungal therapy, the endophthalmitis did not improve. The painful eye with marked inflammation was finally enucleated. In vitro susceptibility testing of the isolate showed that it appeared resistant to amphotericin B, caspofungin, itraconazole, voriconazole, and posaconazole, and susceptible to terbinafine.

Breakthrough disseminated Aspergillus ustus infection in allogeneic hematopoietic stem cell transplant recipients receiving voriconazole or caspofungin prophylaxis

Aspergillus ustus is an uncommon clinical species which is poorly susceptible to antifungals. We report two cases of A. ustus infections that occurred in allogeneic stem cell transplant recipients while they were receiving either voriconazole or caspofungin. Prolonged use of these new antifungal agents may increase the risk of the emergence of resistant organisms.

Voriconazole: review of a broad spectrum triazole antifungal agent

Voriconazole is a second-generation triazole antifungal agent, structurally derived from fluconazole with an extended spectrum of activity against a wide variety of yeasts and moulds. Developed for the treatment of life-threatening fungal infections, it appears to be an effective therapy option for invasive aspergillosis, fluconazole-resistant candidiasis and refractory or less-common invasive fungal infections. It is available for both oral and intravenous administration and is characterised by an acceptable safety and tolerability spectrum.