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Fungi in the order Chaetothyriales are renowned for their ability to cause human infections. Nevertheless, they are not regarded as primary pathogens, but rather as opportunists with a natural habitat in the environment. Extremotolerance is a major trend in the order, but quite different from black yeasts in Capnodiales which focus on endurance, an important additional parameter is advancing toxin management. In the ancestral ecology of rock colonization, the association with metabolite-producing lichens is significant. Ant-association, dealing with pheromones and repellents, is another mainstay in the order. The phylogenetically derived family, Herpotrichiellaceae, shows dual ecology in monoaromatic hydrocarbon assimilation and the ability to cause disease in humans and cold-blooded vertebrates. In this study, data on ecology, phylogeny, and genomics were collected and analyzed in order to support this hypothesis on the evolutionary route of the species of Chaetothyriales. Comparing the ribosomal tree with that of enzymes involved in toluene degradation, a significant expansion of cytochromes is observed and the toluene catabolism is found to be complete in some of the Herpotrichiellaceae. This might enhance human systemic infection. However, since most species have to be traumatically inoculated in order to cause disease, their invasive potential is categorized as opportunism. Only in chromoblastomycosis, true pathogenicity might be surmised. The criterion would be the possible escape of agents of vertebrate disease from the host, enabling dispersal of adapted genotypes to subsequent generations.

Biodeterioration is related to several biological systems and metabolic activities of fungi and bacteria. Fungal contamination is determined by the availability of water and temperature. Aspergillus is a fungus with great enzymatic capacity and with a high biodeterioration power. For this reason, it represents a threat to the conservation of cultural heritage objects. In this work, an exhaustive search of all the species involved was carried out, describing in detail the deterioration produced in different objects (wooden objects, glasses, paper, paintings, textiles, audiovisuals, glasses, human remains) as well preventive treatments. Like an opportunistic fungus it might cause some illness related to workers, a situation that is also addressed. Since the number of species increased from 180 to over 400 in the last 20 years, a taxonomy update has been done.

Fungal infections have increased in recent years due to host factors, such as oncohaematological and transplant-related disorders, immunosuppressive therapy, and AIDS. Additionally, molecular and proteomic facilities have become available to identify previously unrecognizable opportunists. For these reasons, reports on less-known and recalcitrant mycoses, such as those caused by black fungi, hyaline filamentous fungi, coelomycetes, Mucorales, and non-Candida yeasts have emerged. In this review, novel taxonomy in these groups, which often are multi-resistant to one or several classes of antifungals, is discussed. Clinical presentations, diagnosis and current treatment of some major groups are summarised.

COVID-19-associated pulmonary aspergillosis (CAPA) incidence varies depending on the country. Serum galactomannan quantification is a promising diagnostic tool since samples are easy to obtain with low biosafety issues. A multicenter prospective study was performed to evaluate the CAPA incidence in Argentina and to assess the performance of the lateral flow assay with digital readout (Sōna Aspergillus LFA) as a CAPA diagnostic and screening tool. The correlation between the values obtained with Sōna Aspergillus LFA and Platelia® EIA was evaluated. In total, 578 serum samples were obtained from 185 critically ill COVID patients. CAPA screening was done weekly starting from the first week of ICU stay. Probable CAPA incidence in critically ill patients was 10.27% (19/185 patients when LFA was used as mycological criteria) and 9% (9/100 patients when EIA was used as mycological criteria). We found a very good correlation between the two evaluated galactomannan quantification methods (overall agreement of 92.16% with a Kappa statistic value of 0.721). CAPA diagnosis (>0.5 readouts in LFA) were done during the first week of ICU stay in 94.7% of the probable CAPA patients. The overall mortality was 36.21%. CAPA patients' mortality and length of ICU stay were not statistically different from for COVID (non-CAPA) patients (42.11 vs 33.13% and 29 vs 24 days, respectively). These indicators were lower than in other reports. LFA-IMMY with digital readout is a reliable tool for early diagnosis of CAPA using serum samples in critically ill COVID patients. It has a good agreement with Platelia® EIA. Lay Summary The incidence of COVID-associated pulmonary aspergillosis (CAPA) in critically-ill Argentinian patients was established (10.27%). Serum galactomannan quantification was useful as a screening tool for this mycosis. A good agreement between Platelia® EIA and Sōna Aspergillus LFA is reported.

A serie of N-acetyl phenothiazines and related compounds was synthesized by means of the acetylation reaction of the corresponding phenothiazine with the appropriate reagent using microwave irradiation. Structural elucidation of these heterocyclic derivatives was done using 1 H, 13C NMR spectra. The equilibra between conformationals enantiomers were studied as a possible atropisomerism case. The single crystal X-ray diffraction of some derivatives was also recorded and the presence of enantiomers could be confirmed. The antifungal activity evaluation of all N-acetyl phenothiazines prepared by us in this and in a previous work, was performed in vitro against 163 isolated human pathogenic yeasts and filamentous fungi, including: Cryptococcus neoformans, Candida albicans, Candida non-albicans, Aspergillus and Acremonium-Fusarium. The most promising compounds were those bearing one chlorine or bromine atom attached to the N-acetyl group. These compounds were as active as 5-fluorocitosine (5-FC) or fluconazole (FCZ), currently in clinical use. A structure-activity relationship (SAR) and a quantitative structure-activity relationship (QSAR) for antifungal activity of each genus were established. Fil: Sarmiento, Gabriela Pabla. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Farmacología. Cátedra de Química Medicinal; Argentina Fil: Martini, María Florencia. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Química y Metabolismo del Fármaco. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Instituto de Química y Metabolismo del Fármaco; Argentina. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Farmacología. Cátedra de Química Medicinal; Argentina Fil: Vitale, Roxana Gabriela. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Gobierno de la Ciudad de Buenos Aires. Hospital General de Agudos "Ramos Mejía"; Argentina Fil: Fabian, Lucas Emanuel. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Química y Metabolismo del Fármaco. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Instituto de Química y Metabolismo del Fármaco; Argentina. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Farmacología. Cátedra de Química Medicinal; Argentina Fil: Afeltra, Javier. Gobierno de la Ciudad de Buenos Aires. Hospital General de Agudos "Ramos Mejía"; Argentina. Universidad de Buenos Aires. Facultad de Medicina. Departamento de Microbiología; Argentina Fil: Vega, Daniel. Comisión Nacional de Energía Atómica; Argentina. Universidad Nacional de San Martín. Escuela de Ciencia y Tecnología; Argentina Fil: Moltrasio, Graciela Yolanda. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica; Argentina Fil: Moglioni, Albertina Gladys. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Química y Metabolismo del Fármaco. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Instituto de Química y Metabolismo del Fármaco; Argentina. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Farmacología. Cátedra de Química Medicinal; Argentina

Fungal infections are responsible for high mortality rates in immunocompromised and high-risk surgical patients. Therapy failures during the last decades due to increasing multidrug resistance demand innovative strategies for novel and effective antifungal drugs. Synergistic combinations of antifungals with non-antifungal agents highlight a pragmatic strategy to reduce the development of drug resistance and potentially repurpose known compounds with other functions to bypass costly and time-consuming novel drug development.

Primary central nervous system phaeohyphomycosis is a fatal fungal infection due mainly to the neurotropic melanized fungiCladophialophora bantiana,Rhinocladiella mackenziei, andExophiala dermatitidis.Despite the combination of surgery with antifungal treatment, the prognosis continues to be poor, with mortality rates ranging from 50 to 70%. Therefore, a search for a more-appropriate therapeutic approach is urgently needed. Ourin vitrostudies showed that with the combination of amphotericin B and flucytosine against these species, the median fractional inhibitory concentration (FIC) indices for strains ranged from 0.25 to 0.38, indicating synergy. By use of Bliss independence analysis, a significant degree of synergy was confirmed for all strains, with the sum ΔE ranging from 90.2 to 698.61%. No antagonism was observed. These results indicate that amphotericin B, in combination with flucytosine, may have a role in the treatment of primary cerebral infections caused by melanized fungi belonging to the orderChaetothyriales Furtherin vivostudies and clinical investigations to elucidate and confirm these observations are warranted. Fil: Deng, S.. First Hospital of Xinjiang Medical University; China. Second Military Medical University. Shanghai Institute of Medical Mycology; China Fil: Pan, W.. Second Military Medical University. Shanghai Institute of Medical Mycology; China Fil: Liao, W.. Second Military Medical University. Shanghai Institute of Medical Mycology; China Fil: de Hoog, G. S.. CBS-KNAW Fungal Biodiversity Centre; Países Bajos. University of Amsterdam; Países Bajos. King Abdulaziz University; Arabia Saudita Fil: Gerrits van den Ende, A. H. G.. CBS-KNAW Fungal Biodiversity Centre; Países Bajos. University of Amsterdam; Países Bajos Fil: Vitale, Roxana Gabriela. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Gobierno de la Ciudad de Buenos Aires. Hospital General de Agudos "Ramos Mejía"; Argentina Fil: Rafati, H.. Erasmus University Medical Center; Países Bajos Fil: Ilkit, M.. University of Çukurova; Turquía Fil: Van der Lee, A. H.. Radboud University Medical Center; Países Bajos Fil: Rijs, A. J. M. M.. Radboud University Medical Center; Países Bajos Fil: Verweij, P. E.. Radboud University Medical Center; Países Bajos Fil: Seyedmousavi, S.. Radboud University Medical Center; Países Bajos. Erasmus University Medical Center; Países Bajos. Mazandaran University of Medical Sciences; Irán

Chromoblastomycosis is a mutilating infection of the skin and subcutaneous tissues caused by melanized fungi belonging to the order Chaetothyriales. Proven cases of the main agent, Fonsecaea pedrosoi are mainly limited to (sub)tropical, humid climates of Latin and Central America and the Caribbean. Fonsecaea monophora has a global distribution along the equator. Cases outside the (sub)tropics have thus far mostly been considered to have been imported, but here we report the first endemic case by F. monophora from Argentina. Patient was a 82-year-old rural female worker from Corrientes, a province with a dry continental climate. Keywords: Dematiaceous fungi, Chromoblastomycosis, Fonsecaea monophora, South America, Argentina

Chromoblastomycosis (CBM) is a recalcitrant fungal skin disease which is difficult to treat, the infection leading to excessive proliferation of host tissues. Therefore, search for appropriate antifungal strategies is urgently needed. Our in vitro studies showed that combination of amphotericin B and terbinafine had synergistic effects against the majority of melanized fungi associated with CBM and similar infections, including Cladophialophora carrionii, C. arxii, Exophiala dermatitidis, E. spinifera, Fonsecaea monophora, F. nubica, F. pedrosoi, and Phialophora verrucosa, with a fractional inhibitory concentration (FIC) value ranging from 0.25 to 1. No synergistic interaction was found for Veronaea botryosa isolates. The results of FIC analysis were supported by response surface analysis using Bliss independence no-interaction model for the isolates tested. Our study suggests that amphotericin B, when combined with terbinafine, allows a significant reduction of MICs. This could provide an option for treatment of severe or unresponsive cases of CBM, particularly in cases due to species of Fonsecaea and Cladophialophora. Fil: Deng, S.. Department of Medical Microbiology, People's Hospital of Suzhou National New and Hi-Tech Industrial; China Fil: Lei, W.. Shanghai Institute Of Medical Mycology; China Fil: de Hoog, G. S.. Universidade Federal do Paraná; Brasil. Radboud Universiteit Nijmegen; Países Bajos. Westerdijk Fungal Biodiversity Institute; Países Bajos. Shanghai Institute Of Medical Mycology; China Fil: Yang, L.. Westerdijk Fungal Biodiversity Institute; Países Bajos Fil: Vitale, Roxana Gabriela. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Gobierno de la Ciudad de Buenos Aires. Hospital Gral.de Agudos "ramos Mejia". Departamento de Diagnostico y Tratamiento; Argentina Fil: Rafati, H.. Center of Excellence for Infection Biology and Antimicrobial Pharmacology; Irán Fil: Seyedmousavi, M.. Center of Excellence for Infection Biology and Antimicrobial Pharmacology; Irán Fil: Tolooe, A.. Center of Excellence for Infection Biology and Antimicrobial Pharmacology; Irán Fil: van der Lee, H.. Radboud Universiteit Nijmegen; Países Bajos Fil: Liao, W.. Shanghai Institute Of Medical Mycology; China Fil: Verweij, P. E.. Radboud Universiteit Nijmegen; Países Bajos Fil: Seyedmousavi, S.. Radboud Universiteit Nijmegen; Países Bajos. Mazandaran University of Medical Sciences; Irán. Center of Excellence for Infection Biology and Antimicrobial Pharmacology; Irán

Recent changes in the Fungal Code of Nomenclature and developments in molecular phylogeny are about to lead to dramatic changes in the naming of medically important molds and yeasts. In this article, we present a widely supported and simple proposal to prevent unnecessary nomenclatural instability.

Patients with invasive fungal infections still have high morbidity and mortality despite an increasing number of antifungals and other therapies. Because of this problem, an accurate and rapid diagnosis is mandatory in order to improve clinical outcome in these patients. In this paper we review the tools for the diagnosis of candidemia, including blood culture systems, chromogenic media, commercial kits for species identification, and newer technologies for the diagnosis of candidemia such as MALDI-TOF, PNA FISH and the T2 system. Fil: Vitale, Roxana Gabriela. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Gobierno de la Ciudad de Buenos Aires. Hospital General de Agudos "Ramos Mejía"; Argentina Fil: Nucci, Marcio. Universidade Federal do Rio de Janeiro; Brasil. Hospital Universitário Clementino Fraga Filho; Brasil

Background No phenotypic methods are available to unequivocally differentiate species within the Candida glabrata complex. Aims To develop a new multiplex PCR method to differentiate between the three species of the C. glabrata species complex, as well as using it to study a C. glabrata collection to discover strains of the newly described species. Methods The method was developed based on the Internal Transcribed Spacer (ITS) sequence differences between the species. It was validated by using a blinded collection of strains and, finally, the new molecular method was used to study a collection of 192 C. glabrata species complex strains. The obtained results were compared with ITS sequencing. Results The proposed method showed 100% concordance with ITS sequencing and proved to be effective for clinical and epidemiological applications. Two Candida bracarensis and three Candida nivariensis were found out of the 192 studied strains (0.93% and 1.40% prevalence, respectively). Conclusions A fast, inexpensive, robust and highly reproducible multiplex PCR method is presented. Its usefulness is demonstrated by studying a large collection of C. glabrata sensu lato strains.

Cryptococcosis causes disseminated disease in AIDS patients. In contrast to what occurs in laboratory conditions, a large capsule is produced by Cryptococcus neoformans in vivo during infection. The aim of this study was to compare the in vitro activity of different antifungal agents against 34 clinical isolates of C. neoformans var. grubii without or with capsule induction (CLSI, CLSI-C, respectively), following the CLSI M27A3 document. Capsule induction was obtained by addition of NaHCO 3 and incubation with CO 2. The geometric means of the MICs, in μg ml -1, for CLSI and CLSI-C cultures, respectively, were 1.9 and 9.8 for fluconazole; 0.04 and 0.08 for itraconazole; 0.04 and 0.05 for voriconazole; 0.16 and 0.38 for amphotericin B; and 1.6 and 5.6 for 5-flucytosine. Thus fluconazole showed the highest MICs after capsule induction. Determination of antifungal activity after capsule induction may be clinically relevant and could be used to evaluate the correlation between in vitro results and clinical outcome. Fil: Vitale, Roxana Gabriela. Gobierno de la Ciudad de Buenos Aires. Hospital General de Agudos "Ramos Mejía"; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina Fil: Pascuccelli, Veronica. Gobierno de la Ciudad de Buenos Aires. Hospital General de Agudos "Ramos Mejía"; Argentina Fil: Afeltra, Javier. Universidad de Buenos Aires. Facultad de Medicina. Departamento de Microbiología; Argentina. Gobierno de la Ciudad de Buenos Aires. Hospital General de Agudos "Ramos Mejía"; Argentina

Several phenothiazines and related compounds were synthesized and their antifungal activity was evaluated in vitro. The results observed for α-chloro-N-acetyl phenothiazine led us to choose this compound as a lead in the search of antifungal agents. Fil: Sarmiento, Gabriela Pabla. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica; Argentina Fil: Vitale, Roxana Gabriela. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad de Buenos Aires. Facultad de Medicina. Centro Universitario de Neurología "Dr. José María Ramos Mejía".; Argentina Fil: Afeltra, Javier. Universidad de Buenos Aires. Facultad de Medicina. Centro Universitario de Neurología "Dr. José María Ramos Mejía".; Argentina Fil: Moltrasio, Graciela Yolanda. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica; Argentina Fil: Moglioni, Albertina Gladys. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica; Argentina

Chromoblastomycosis is one of the most frequent infections caused by melanized fungi. It is a subcutaneous fungal infection, usually an occupational related disease, mainly affecting individuals in tropical and temperate regions. Although several species are etiologic agents, Fonsecaea pedrosoi and Cladophialophora carrionii are prevalent in the endemic areas. Chromoblastomycosis lesions are polymorphic and must be differentiated from those associated with many clinical conditions. Diagnosis is confirmed by the observation of muriform cells in tissue and the isolation and the identification of the causal agent in culture. Chromoblastomycosis still is a therapeutic challenge for clinicians due to the recalcitrant nature of the disease, especially in the severe clinical forms. There are three treatment modalities, i.e., physical treatment, chemotherapy and combination therapy but their success is related to the causative agent, the clinical form and severity of the chromoblastomycosis lesions. There is no treatment of choice for this neglected mycosis, but rather several treatment options. Most of the patients can be treated with itraconazole, terbinafine or a combination of both. It is also important to evaluate the patient's individual tolerance of the drugs and whether the antifungal will be provided for free or purchased, since antifungal therapy must be maintained in long-term regimens. In general, treatment should be guided according to clinical, mycological and histopathological criteria.

Item does not contain fulltext The combined effects of antifungal and antibiotic drugs against Exophiala spinifera were evaluated in vitro by the chequer-board method, calculated as a fractional inhibitory concentration (FIC) index. Amphotericin B was combined with flucytosine and ciprofloxacin, whereas itraconazole was combined with ciprofloxacin, levofloxacin, lomefloxacin and sulfadiazine. Synergic effects were observed for the combinations of itraconazole with ciprofloxacin and levofloxacin, and amphotericin B with ciprofloxacin and flucytosine. No antagonism was observed for any combination tested.

We have evaluated and compared the activity of amphotericin B (AMB) by time-kill curve methodology against 20 clinical Cryptococcus neoformans isolates in which capsule induction in vitro was performed. Overall, large capsulated isolates were more resistant to killing by AMB over time when compared with those small capsulate ones.

Clinical echinocandin resistance among Candida glabrata strains is increasing, especially in the United States. Antifungal susceptibility testing is considered mandatory to guide therapeutic decisions. However, these methodologies are not routinely performed in the hospital setting due to their complexity and the time needed to obtain reliable results. Echinocandin failure in C. glabrata is linked exclusively to Fks1p and Fks2p amino acid substitutions, and detection of such substitutions would serve as a surrogate marker to identify resistant isolates. In this work, we report an inexpensive, simple, and quick classical PCR set able to objectively detect the most common mechanisms of echinocandin resistance in C. glabrata within 4 h. The usefulness of this assay was assessed using a blind collection of 50 C. glabrata strains, including 16 FKS1 and/or FKS2 mutants. Fil: Dudiuk, Catiana Beatriz. Universidad Nacional del Litoral. Facultad de Bioquímica y Ciencias Biológicas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe; Argentina Fil: Gamarra, Maria Soledad. Universidad Nacional del Litoral. Facultad de Bioquímica y Ciencias Biológicas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe; Argentina Fil: Leonardelli, Florencia. Universidad Nacional del Litoral. Facultad de Bioquímica y Ciencias Biológicas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe; Argentina Fil: Jimenez Ortigoza, Cristina. State University of New Jersey; Estados Unidos Fil: Vitale, Roxana Gabriela. Gobierno de la Ciudad de Buenos Aires. Hospital General de Agudos ; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina Fil: Afeltra, Javier. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica; Argentina Fil: Perlin, David S.. State University of New Jersey; Estados Unidos Fil: Garcia, Guillermo Manuel. Universidad Nacional del Litoral. Facultad de Bioquímica y Ciencias Biológicas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe; Argentina

The in vitro susceptibilities of 66 molecularly identified strains of the Mucorales to eight antifungals (amphotericin B, terbinafine, itraconazole, posaconazole, voriconazole, caspofungin, micafungin, and 5-fluorocytosine) were tested. Molecular phylogeny was reconstructed based on the nuclear ribosomal large subunit to reveal taxon-specific susceptibility profiles. The impressive phylogenetic diversity of the Mucorales was reflected in susceptibilities differing at family, genus, and species levels. Amphotericin B was the most active drug, though somewhat less against Rhizopus and Cunninghamella species. Posaconazole was the second most effective antifungal agent but showed reduced activity in Mucor and Cunninghamella strains, while voriconazole lacked in vitro activity for most strains. Genera attributed to the Mucoraceae exhibited a wide range of MICs for posaconazole, itraconazole, and terbinafine and included resistant strains. Cunninghamella also comprised strains resistant to all azoles tested but was fully susceptible to terbinafine. In contrast, the Lichtheimiaceae completely lacked strains with reduced susceptibility for these antifungals. Syncephalastrum species exhibited susceptibility profiles similar to those of the Lichtheimiaceae. Mucor species were more resistant to azoles than Rhizopus species. Species-specific responses were obtained for terbinafine where only Rhizopus arrhizus and Mucor circinelloides were resistant. Complete or vast resistance was observed for 5-fluorocytosine, caspofungin, and micafungin. Intraspecific variability of in vitro susceptibility was found in all genera tested but was especially high in Mucor and Rhizopus for azoles and terbinafine. Accurate molecular identification of etiologic agents is compulsory to predict therapy outcome. For species of critical genera such as Mucor and Rhizopus , exhibiting high intraspecific variation, susceptibility testing before the onset of therapy is recommended.

The in vitro activities of amphotericin B (AMB), itraconazole (ITC), voriconazole (VCZ) and terbinafine (TBF) alone and in the combinations AMB + VCZ, TBF + ITC and TBF + VCZ were evaluated against 29 clinical isolates of Fusarium spp. (15 Fusarium solani, 7 Fusarium oxysporum, 2 Fusarium decemcellulare, 2 Fusarium dimerum and 3 other Fusarium spp.). Minimum inhibitory concentrations were determined using the method of the Clinical and Laboratory Standards Institute and the interaction activity was calculated using the fractional inhibitory concentration index. The four antifungal drugs tested alone showed very limited activity against most of the isolates. In contrast, the combination TBF + VCZ showed synergy for 21 isolates. The combination AMB + VCZ showed synergism for only five strains. No interaction or antagonism was observed among the remaining strains. TBF + ITC showed no interaction for 18 strains. The in vitro antifungal activity of the drugs alone and in combination varied for different species. These results corroborate previous in vitro studies in which the combination TBF + VCZ showed synergy against Fusarium spp., although further studies are needed to elucidate its potential usefulness for therapy.

Item does not contain fulltext The phenothiazine compounds chlorpromazine and trifluopherazine are antipsychotic agents that exhibit antimicrobial activity against bacteria, some protozoa and yeasts. Data of activity against filamentous fungi are lacking. The in vitro activity and postantifungal effect (PAFE) of chlorpromazine and trifluopherazine was determined against Aspergillus species, zygomycetes and Scedosporium species. In vitro susceptibility testing was performed with CLSI M38A and the PAFE was determined with previously established methods. Both drugs inhibited the growth of all fungi tested at concentrations of 16 to 64 microg ml(-1). For Aspergillus species the mean PAFE was 3.7 and 4.7 h; for zygomycetes, 3.1 and 3.4 h; for Scedosporium, 4.3 and 5.3 h for chlorpromazine and trifluoroperazine respectively. These are the first drugs shown to induce PAFE against Scedosporium. We show that phenothiazine compounds have in vitro antifungal activity and exhibit PAFE against a broad range of filamentous fungal pathogens. Although the exact mechanism of action is unknown, further studies are needed to explore the clinical usefulness of phenothiazine compounds.

The increase in fungal infections and the change in fungal epidemiology is caused by the extensive use of antifungal agents to treat fungal infections that are being diagnosed in severly immunocompromised hosts. In addition, opportunistic fungal infections resistant to antifungal drugs have become increasingly common, and the armamentarium for treatment remains limited. A possible approach to overcoming these problems is to combine antifungal drugs, especially if the mechanisms of action are different. The in vitro test is the first step to evaluate possible antifungal combinations. In this chapter, the three most frequently used metholodologies are described: checkerboard, E-test, and time-kill curves. The description of each technique and intrepretaion of the results are addressed in detail.

Postantifungal effect (PAFE) is the evaluation of antifungal activity after the suppression of fungal growth when the drug is removed from the fungal suspension. In vitro, this effect might simulate the in vivo situation when the concentration of the drug falls to less than the minimum inhibitory concentration values and could be another tool, together with the classic in vitro susceptibility tests, to optimize the interaction of drugs-fungi. In this chapter, two model methods to evaluate the PAFE of yeasts and filamentous fungi are described in which practical advices and tricks are given to help the worker to develop the techniques. The procedures outlined include preparation of stock solutions of the drugs, concentration medium, exposure time colony count determination, and interpretation of the results to quantify the PAFE.

Postantifungal effect (PAFE) is the evaluation of antifungal activity after the suppression of fungal growth when the drug is removed from the fungal suspension. In vitro, this effect might simulate the in vivo situation when the concentration of the drug falls to less than the minimum inhibitory concentration values and could be another tool, together with the classic in vitro susceptibility tests, to optimize the interaction of drugs-fungi. In this chapter, two model methods to evaluate the PAFE of yeasts and filamentous fungi are described in which practical advices and tricks are given to help the worker to develop the techniques. The procedures outlined include preparation of stock solutions of the drugs, concentration medium, exposure time colony count determination, and interpretation of the results to quantify the PAFE.

To develop new approaches for the treatment of invasive infections caused by Aspergillus fumigatus , the in vitro interactions between itraconazole (ITZ) and seven different nonantimicrobial membrane-active compounds—amiodarone (AMD), amiloride, lidocaine, lansoprazole (LAN), nifedipine (NIF), verapamil, and fluphenazine—against seven ITZ-susceptible and seven ITZ-resistant (ITZ-R) strains were evaluated by the checkerboard microdilution method based on National Committee for Clinical Laboratory Standards M-38A guidelines. The nature and the intensity of the interactions were assessed by a nonparametric approach (fractional inhibitory concentration [FIC] index model), a fully parametric response surface approach (Greco model) of the Loewe additivity no-interaction theory, and the nonparametric (Prichard model) and semiparametric response surface approaches of the Bliss independence (BI) no-interaction theory. Statistically significant synergy was found for the combination of ITZ and AMD and the combination of LAN and NIF, although with different intensities against ITZ-R strains. The FIC index values ranged from 1 to 0.02 for ITZ-AMD, 0.53 to 0.04 for ITZ-LAN, and 0.28 to 0.06 for ITZ-NIF. By use of the BI-based model, the strongest synergy was found for the combination of ITZ with AMD, followed by the combination of ITZ and NIF. The parametric models could not be fit adequately because most of the drugs alone did not show any effect and, thus, no sigmoid dose-response. In general, the combination of ITZ with calcium pump blockers displayed in vitro synergistic activity, primarily against ITZ-R strains, and warrants further investigation.

Item does not contain fulltext Antifungal susceptibility profiles were determined for 16 strains of the black yeast Exophiala spinifera applying different temperature regimens. Fluconazole was the least effective in vitro. Lowest minimal inhibitory concentration (MIC) values were found with itraconazole. The activities of antifungal agents against environmental and clinical strains were similar. Post-antifungal effect (PAFE) of four drugs was determined for 11 clinical strains. PAFE was observed only for amphotericin B, with extended inhibition times seen at high drug concentrations.

Item does not contain fulltext The post-antifungal effect (PAFE) of amphotericin B and nystatin against 30 clinical zygomycetes was evaluated using two different media. PAFE is a suppression of fungal growth after limited drug exposure. The MICs of both drugs were determined using NCCLS M38-P guidelines. A spectrophotometric method was used to determine PAFE in vitro. Spores were exposed to amphotericin B and nystatin in RPMI-1640 or AM3 at concentrations of 4 x and 1 x MIC for 4 h for Absidia sp. and at 1 x and 0.5 x MIC for 1 h for the other strains. Drugs were eliminated by washing. Exposed and control spores were cultured in microtitre wells and incubated for 48 h. PAFE was calculated as T - C (Delta t) between the control and the exposure fungi. The first increase in optical density (OD0) was used to calculate PAFE and was considered significant when the value of the lower 95%CI of the exposed strain was greater than the upper 95%CI of the control. MIC ranges in RPMI-1640 were: 0.06-4 mg/L for amphotericin B and 0.5-8 mg/L for nystatin; MIC ranges in AM3 were: 0.06-2 mg/L for amphotericin B and 0.5-4 mg/L for nystatin. Killing was not observed at the concentration and exposure time used. In RPMI-1640, for amphotericin B the rank order for PAFE was Absidia corymbifera (5.6 h) > Rhizopus oryzae (5.2 h) > Mucor spp. (3.5 h) > Rhizopus microsporus (3 h), and for nystatin the rank order was Mucor spp. (5.8 h) > R. oryzae (3.3 h) > A. corymbifera (2.9 h) > R. microsporus (1.7 h). PAFE was not induced in Rhizomucor spp. PAFE was dependent on drug concentration.

An in vitro method for determination of postantifungal effect (PAFE) in molds was developed by using three isolates each of Aspergillus fumigatus , A. flavus , A. terreus , A. nidulans , and A. ustus . MICs of amphotericin B and itraconazole were determined by using National Committee for Clinical Laboratory Standards guidelines (M38-P). The inoculum was prepared in RPMI 1640 broth buffered with MOPS (morpholinepropanesulfonic acid) at pH 7.0, and conidia were exposed to amphotericin B and itraconazole at concentrations of 4, 1, and 0.25 times the MIC, each for 4, 2, and 1 h at 37°C. The same procedure was followed for controls with drug-free medium. Following exposure, the conidia were washed three times in saline and the numbers of CFU per milliliter were determined. Exposed and control conidia were then inoculated into microtitration plates and incubated at 37°C for 48 h in a spectrophotometer reader. The optical density (OD) was measured automatically at 10-min intervals, resulting in growth curves. PAFE was quantified by comparing three arbitrary points in the control growth curve, the first increase of OD and the points when 20 and 50% of the maximal growth were reached, with the growth curve of drug-exposed conidia. Amphotericin B induced PAFE in A. fumigatus at four times the MIC after 2 and 4 h of exposure ranging from 1.83 to 6.00 h and 9.33 to 10.80 h, respectively. Significantly shorter PAFEs or lack of PAFE was observed for A. terreus , A. ustus , and A. nidulans . Itraconazole did not induce measurable PAFE in the Aspergillus isolates at any concentration or exposure time tested. Further studies are warranted to investigate the implications of PAFE in relation to clinical efficacy and dosing frequency.

The susceptibilities of 70 strains of Aspergillus species were tested against seven different sulfa drugs and pentamidine by a microdilution method with RPMI 1640 and yeast nitrogen base media. Sulfamethoxazole, sulfadiazine, and pentamidine were active in vitro. The MICs obtained with RPMI 1640 were significantly higher than those with yeast nitrogen base. More studies are needed to further elucidate the action of these drugs.

Invasive fungal infections present a great challenge in modern medicine. The recent devel-opment of serologic markers represents a clear advance in the field. Two serological tests have been developed: (1,3)-β-D glucan and Aspergillus galactomannan. This review discusses highlights of both tests.