Epidemiology of invasive fungal infections in the mediterranean area

Growth Performance and Recovery of Nosocomial Aspergillus spp. in Blood Culture Bottles

Theoretically, Aspergillus spp. grow in culture media, but frequently, blood cultures of patients with invasive Aspergillosis are negative, even if until now, the reasons are not clear. This aspect underlines the lack of a good strategy for the cultivation and isolation of Aspergillus spp. In order to develop a complete analytical method to detect Aspergillus in clinical and pharmaceutical samples, we investigated the growth performance of two blood culture systems versus the pharmacopeia standard method. At <72 h, all test systems showed comparable sensitivity, about 1−2 conidia. However, the subculture analysis showed a suboptimal recovery for the methods, despite the positive growth and the visualization of the “Aspergillus balls” in the culture media. To investigate this issue, we studied three different subculture approaches: (i) the use of a sterile subculture unit, (ii) the use of a sterile subculture unit and the collection of a larger aliquot (100 µL), following vigorous agitation of the vials, and (iii) to decapsulate the bottle, withdrawing and centrifuging the sample, and aliquot the pellet onto SDA plates. Our results showed that only the third procedure recovered Aspergillus from all positive culture bottles. This work confirmed that our strategy is a valid and faster method to culture and isolate Aspergillus spp. from blood culture bottles.

Oral mycobiome identification in atopic dermatitis, leukemia, and HIV patients - a systematic review

INTRODUCTION

Oral mycobiome profiling is important to understand host-pathogen interactions that occur in various diseases. Invasive fungal infections are particularly relevant for patients who have received chemotherapy and for those who have HIV infection. In addition, changes in fungal microbiota are associated with the worsening of chronic conditions like atopic dermatitis (AD). This work aims, through a systematic review, to analyze the methods used in previous studies to identify oral fungi and their most frequent species in patients with the following conditions: HIV infection, leukemia, and atopic dermatitis.

METHODS

A literature search was performed on several different databases. Inclusion criteria were: written in English or Portuguese; published between September 2009 and September 2019; analyzed oral fungi of HIV-infected, leukemia, or AD patients.

RESULTS

21 studies were included and the most identified species was Candida. The predominant methods of identification were morphological (13/21) and sugar fermentation and assimilation tests (11/21). Polymerase chain reaction (PCR) was the most used molecular method (8/21) followed by sequencing techniques (3/21).

CONCLUSIONS

Although morphological and biochemical tests are still used, they are associated with high-throughput sequencing techniques, due to their accuracy and time saving for profiling the predominant species in oral mycobiome.

Biological exploration of a novel 1,2,4-triazole-indole hybrid molecule as antifungal agent

(2-(2,4-Dichlorophenyl)-3-(1H-indol-1-yl)-1-(1,2,4-1H-triazol-1-yl)propan-2-ol (8 g), a new 1,2,4-triazole-indole hybrid molecule, showed a broad-spectrum activity against Candida, particularly against low fluconazole-susceptible species. Its activity was higher than fluconazole and similar to voriconazole on C. glabrata (MIC₉₀ = 0.25, 64 and 1 µg/mL, respectively), C. krusei (MIC₉₀ = 0.125, 64 and 0.125 µg/mL, respectively) and C. albicans (MIC₉₀ = 0.5, 8 and 0.25 µg/mL, respectively). The action mechanisms of 8 g were also identified as inhibition of ergosterol biosynthesis and phospholipase A2-like activity. At concentration as low as 4 ng/mL, 8g inhibited ergosterol production by 82% and induced production of 14a-methyl sterols, that is comparable to the results obtained with fluconazole at higher concentration. 8 g demonstrated moderate inhibitory effect on phospholipase A2-like activity being a putative virulence factor. Due to a low MRC5 cytotoxicity, this compound presents a high therapeutic index. These results pointed out that 8 g is a new lead antifungal candidate with potent ergosterol biosynthesis inhibition.

Evaluation of Commercially Available Real-Time Polymerase Chain Reaction Assays for the Diagnosis of Invasive Aspergillosis in Patients with Haematological Malignancies

Early diagnosis of invasive aspergillosis (IA) is a challenge. Non-specific clinical and radiologic findings, as well as difficulties in conventional diagnostic method application, may delay correct diagnosis. Nowadays, nucleic acid-based assays have reduced the need for conventional antigen detection and culture-based methods and provided new opportunities for patient care. Aspergillus PCR is now included in the latest European Cancer Research and Treatment Organization/Mycosis Study Group definition updates. We evaluated the performance of commercial real-time polymerase chain reaction (PCR) MycAssay Aspergillus PCR and Artus Aspergillus RG PCR assays and compared the results with galactomannan enzyme immunoassay. During 41 febrile neutropenic episodes, 168 serum samples were collected from 32 patients with haematological malignancies. IA diagnosis was established according to the revised guidelines of the European Organization for Research and Treatment of Cancer/Mycoses Study Group. Twenty-one probable episodes were identified. There were no proven IA cases in the study. In 20 episodes, patients did not fulfil the established criteria for the IA diagnosis. Artus Aspergillus RG PCR assay had a sensitivity of 47.6% and specificity of 100%, while those of MycAssay Aspergillus PCR were 61.9% and 100%, respectively. Two different PCR assays were used in this study. Although there are many studies that evaluated MycAssay Aspergillus PCR, data regarding Artus Aspergillus RG PCR assay are scarce. We found moderate sensitivity and high specificity in the diagnosis of IA in patients with haematological malignancy in both PCR methods. Our results demonstrated that commercial PCR assays can be applied for the early diagnosis and pre-emptive treatment of IA.

Clinical features in proven and probable invasive fungal disease in children and adolescents at a pediatric referral center: a 5-year experience

BACKGROUND

There is limited information concerning the overall epidemiology of invasive fungal disease (IFD) in children. The aim of this study was to clarify the clinical features of IFD in a tertiary pediatric care hospital.

METHODS

Patients diagnosed with proven or probable IFD at our hospital between 2011 and 2015 were retrospectively reviewed. Proven and probable IFD were defined according to the European Organization for Research and Treatment of Cancer/Cancer/Invasive Fungal Infections Cooperative Group and the National Institute of Allergy and Infectious Diseases Mycoses Study Group consensus. Patients with possible IFD were excluded.

RESULTS

The incidence of proven or probable IFD was 26 of 20,079 hospitalized patients (0.13%). The predominant underlying disease was malignancy (54%) and congenital anomaly (27%). The most common diagnosis was candidemia among the patients with proven IFD (8 of 13, 62%). All the isolated pathogens in the candidemia patients were non-albicans Candida spp. The most common site of infection was the lungs in patients with probable IFD (11 of 13 patients, 85%). In probable IFD episodes, positive β-D-glucan and galactomannan were found in 12 of 13 (92%) and 5 of 13 (38%) patients, respectively. All but one patient (96%) received empirical antifungal therapy. No patients underwent surgical resection of residual lesions. The overall mortality was 23% and the attributable mortality of IFD was 12%.

CONCLUSION

Our results suggest the emergence of non-albicans Candida species as important pathogens in childhood IFD.

Targeting the fungal cell wall: current therapies and implications for development of alternative antifungal agents

Fungal infections are a worldwide problem associated with high morbidity and mortality. There are relatively few antifungal agents, and resistance has emerged within these pathogens for the newest antifungal drugs. As the fungal cell wall is critical for growth and development, it is one of the most important targets for drug development. In this review, the currently available cell wall inhibitors and suitable drug candidates for the treatment of fungal infections are explored. Future studies of the fungal cell wall and compounds that have detrimental effects on this important outer structural layer could aid in antifungal drug discovery and lead to the development of alternative cell wall inhibitors to fill gaps in clinical therapies for difficult-to-treat fungal infections.

Presence of Candida spp. and candidiasis in liver transplant patients

BACKGROUND

Candidiasis is the most common opportunistic fungal infection of the oral cavity caused by fungi of the genus Candida and usually associated with immunosuppressed individuals.

OBJECTIVES

To evaluate the presence of oral candidiasis and identify the presence of Candida spp. in liver transplant recipients and assess the association between the presence of the fungus and sociodemographic variables, dietary habits and environmental exposure.

METHODS

A cross-sectional study was performed with 49 patients who had undergone liver transplants at Hospital São Vicente de Paulo in Passo Fundo - RS. Patient information was collected to obtain sociodemographic data, eating habits and environmental exposure. Fungal infections were screened by oral clinical examination and the presence of Candida spp by the collection of oral samples with a sterile swab, seeded in Sabouraud Dextrose Agar, incubated at 25°C and observed at 48 hours. To identify Candida albicans, the germ tube test was performed.

RESULTS

In 49 patient samples, 39% had the yeast of the genus Candida isolated and, of these patients, 12% had candidiasis, 66% of atrophic type and 34% pseudomembranous. Eleven yeast species were (58%) Candida non-albicans and eight (42%) Candida albicans.

STUDY LIMITATIONS

The present study presents as a limitation the inclusion of patients in different stages of immunosuppression.

CONCLUSION

The high incidence of Candida non-albicans in the oral cavity of transplant patients with a long period of transplantation is warning to a more effective control of the health of these individuals, especially those with older age.

Cost-effectiveness of posaconazole tablets versus fluconazole as prophylaxis for invasive fungal diseases in patients with graft-versus-host disease after allogeneic hematopoietic stem cell transplantation

BACKGROUND

The cost-effectiveness of posaconazole oral suspension versus fluconazole capsules for the prophylaxis of invasive fungal diseases (IFDs) in immunosuppressed allogeneic hematopoietic stem cell transplantation (HSCT) recipients has already been proven. Now, a new solid oral tablet formulation for posaconazole has been developed with improved bioavailability, allowing a reduced daily dosage that can be taken independently of food intake. However, the efficacy of this new formulation should be evaluated since it is associated with a higher cost than the posaconazole oral suspension.

OBJECTIVES

To evaluate the cost-effectiveness of solid oral tablets of posaconazole versus fluconazole capsules for the prophylaxis of IFDs in allogeneic HSCT recipients with graft-versus-host disease (GVHD) in Spain.

METHODOLOGY

A mathematical model comparing the efficacy and costs of posaconazole versus fluconazole was adapted to the Spanish National Healthcare System. Clinical data were obtained from the pivotal clinical trial of posaconazole oral suspension for allogeneic HSCT recipients, while pharmacological costs and use of resources were obtained from national sources. Deterministic and probabilistic sensitivity analyses (PSA), as well as two alternative scenarios, were run to evaluate the robustness of the results under varying input values.

RESULTS

Posaconazole tablets reduced the number of IFD events and enhanced overall survival, while maintaining a controlled budget. When compared to fluconazole, it was found to be a cost-effective alternative, with an incremental cost-effectiveness ratio of €13,193/life years gained. The PSA showed that posaconazole remained cost-effective in 74.6% of the cases, while alternatives scenarios yielded similar results as the base case.

CONCLUSIONS

Posaconazole tablets are a cost-effective alternative to fluconazole and may show better results than the oral suspension formulation.

Isolation frequency of Candida present on the surfaces of mobile phones and handsx

BACKGROUND

It is known that mobile phones may play a role in microorganism transmission. The aim of this study was to analyze the relationship between the number of Candida genera/species isolated from samples collected from the surfaces of mobile phones and the hands of the staff as well as the preferred health-related behavior.

METHODS

The mycological evaluation included 175 mobile telephones and the hands of staff members at the University Hospital in Białystok, Poland. We used the Count-Tact(TM) applicator, with CandiSelect (Bio-Rad). Self-administered questionnaire was used to gather data on mobile phones disinfection practices. Assessment of the preferred health-related behavior was based on The Multidemensional Health Locus of Control Scale (MHLC).

RESULTS

Out of 175 mobile phones, 131 (74.9 %) were colonized. Candida glabrata, C. albicans and C.krusei were isolated more frequently from the hand as well as phone surface. The mean number of Candida colonies was higher in samples collected from hand surfaces than mobile phone surfaces. No significant correlation was found between the preferred health-related behavior and the frequency of washing hands, the way of using a mobile phone, the number of colonies or the isolation frequency for the fungi collected from the surface of the phones and hands of their owners. Only 19.4 % of the participants cleaned the surface of their phones.

CONCLUSION

The prevalence of mobile phone contamination by Candida is high in the University Hospital in Białystok, Poland. Candida albicans, C. glabrata, and C. krusei were the dominant species in the samples collected from mobile phones and hands. These results pose the need to develop guidelines for mobile phone disinfection.

Invasive fungal infection caused by geotrichum capitatum in patients with acute lymphoblastic leukemia: a case study and literature review

Geotrichum capitatum infection has a very low incidence rate with atypical clinical symptoms, making diagnosis difficult, and it has a poor prognosis. The incidence is even more rare in China. This paper reports the first case of infection caused by G. capitatum during bone marrow suppression after chemotherapy in a Chinese patient with acute lymphoblastic leukemia. In addition, it reports a systematic literature review of diagnosis and treatment. The patient with acute lymphoblastic leukemia was confirmed to be infected with G. capitatum, involving lung, liver and skin, through a blood culture test. Caspofungin, amphotericin B loposome, and a combination therapy of amphotericin B liposome and voriconazole were used in succession for treatment. Despite normal body temperature and a slight improvement of clinical symptoms with the combination therapy treatment, the patient died 40 days after chemotherapy due to heart and lung failure.

Clinical significance of the isolation of Candida species from hospitalized patients

In this study, we isolated and phenotypically identified 108 yeast strains from various clinical specimens collected from 100 hospitalized patients at three tertiary hospitals in São Luís-Maranhão, Brazil, from July to December 2010. The isolates were analyzed for their susceptibility to four of the most widely used antifungal agents in the surveyed hospitals, amphotericin B, fluconazole, 5-flucytosine and voriconazole. The species identified were Candida albicans (41.4%), Candida tropicalis (30.1%), C. glabrata (7.4%), Candida parapsilosis (5.5%), Candida krusei (4.6%), Cryptococcus neoformans (4.6%), Trichosporon spp . (3.7%), Candida norvegensis (0.9%), Rhodotorula glutinis (0.9%) and Pichia farinosa (0.9%). A higher isolation rate was observed in the following clinical specimens: urine (54 isolates; 50%), respiratory tract samples (21 isolates; 19.4%) and blood (20 isolates; 18.6%). Candida albicans isolates were 100% sensitive to all antifungal agents tested, whereas Candida krusei and Crytococcus neoformans displayed intermediate resistance to 5-flucytosine, with Minimal Inhibitory Concentration (MIC) values of 8 mg/mL and 16 mg/mL, respectively. Both strains were also S-DD to fluconazole with an MIC of 16 mg/mL. C. tropicalis was resistant to 5-flucytosine with an MIC of 32 μg/mL. This study demonstrates the importance of identifying the yeast species involved in community and nosocomial infections.

Utility of PCR in diagnosis of invasive fungal infections: real-life data from a multicenter study

Prospective studies addressing the clinical value of broad-range PCR using the internal transcribed spacer region (ITS) for diagnosis of microscopy-negative fungal infections in nonselected patient populations are lacking. We first assessed the diagnostic performance of ITS rRNA gene PCR compared with that of routine microscopic immunofluorescence examination. Second, we addressed prospectively the impact and clinical value of broad-range PCR for the diagnosis of infections using samples that tested negative by routine microscopy; the corresponding patients' data were evaluated by detailed medical record reviews. Results from 371 specimens showed a high concordance of >80% for broad-range PCR and routine conventional methods, indicating that the diagnostic performance of PCR for fungal infections is comparable to that of microscopy, which is currently considered part of the "gold standard." In this prospective study, 206 specimens with a negative result on routine microscopy were analyzed with PCR, and patients' clinical data were reviewed according to the criteria of the European Organization for Research and Treatment of Cancer/Invasive Fungal Infections Cooperative Group and the National Institute of Allergy and Infectious Diseases Mycoses Study Group. We found that broad-range PCR showed a sensitivity, specificity, positive predictive value, and negative predictive value of 57.1%, 97.0%, 80%, and 91.7%, respectively, for microscopy-negative fungal infections. This study defines a possible helpful role of broad-range PCR for diagnosis of microscopy-negative fungal infections in conjunction with other tests.

Antibody Peptide based antifungal immunotherapy

Fungal infections still represent relevant human illnesses worldwide and some are accompanied by unacceptably high mortality rates. The limited current availability of effective and safe antifungal agents makes the development of new drugs and approaches of antifungal vaccination/immunotherapy every day more needed. Among them, small antibody(Ab)-derived peptides are arousing great expectations as new potential antifungal agents. In this topic, the search path from the study of the yeast killer phenomenon to the production of Ab-derived peptides characterized by in vitro and in vivo fungicidal activity will be focused. In particular, Abs that mimic the antimicrobial activity of a killer toxin (“antibiobodies”) and antifungal peptides derived from antibiobodies (killer peptide) and other unrelated Abs [complementarity determining regions (CDR)-based and constant region (Fc)-based synthetic peptides] are described. Mycological implications in terms of reevaluation of the yeast killer phenomenon, roles of antibiobodies in antifungal immunity, of β-glucans as antifungal targets and vaccines, and of Abs as sources of an unlimited number of sequences potentially active as new immunotherapeutic tools against fungal agents and related mycoses, are discussed.

Bench-to-bedside review: Rapid molecular diagnostics for bloodstream infection--a new frontier?

Among critically ill patients, the diagnosis of bloodstream infection poses a major challenge. Current standard bacterial identification based on blood culture platforms is intrinsically time-consuming and slow. The continuous evolvement of molecular techniques has the potential of providing a faster, more sensitive and direct identification of causative pathogens without prior need for cultivation. This may ultimately impact clinical decision-making and antimicrobial treatment. This review summarises the currently available technologies, their strengths and limitations and the obstacles that have to be overcome in order to develop a satisfactory bedside point-of-care diagnostic tool for detection of bloodstream infection.