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Cryptococcosis is an opportunistic systemic mycosis caused by Cryptococcus neoformans and C. gattii species complexes and is of increasing global importance. Maintaining continued surveillance of the antifungal susceptibility of environmental C. neoformans and C. gattii isolates is desirable for better managing cryptococcosis by identifying resistant isolates and revealing the emergence of intrinsically resistant species. Relevant research data from Egypt are scarce. Thus, this study aimed to report the genetic diversity of C. neoformans and C. gattii species complexes originating from different environmental sources in Egypt, antifungal susceptibility profiles, antifungal combinations, and correlations of susceptibility with genotypes. A total of 400 environmental samples were collected, 220 from birds and 180 from trees. Cryptococcus spp. were found in 58 (14.5%) of the samples, 44 (75.9%) of the isolates were recovered from birds and 14 (24.1%) from trees. These isolates were genotyped using M13 polymerase chain reaction-fingerprinting and URA5 gene restriction fragment length polymorphism analysis. Of the 31 C. neoformans isolates, 24 (77.4%), 6 (19.4%) and one (4.4%) belonged to VNI, VNII, and VNIII genotypes, respectively. The 27 C. gattii isolates belonged to VGI (70.4%), VGII (18.5%), and VGIII (11.1%) genotypes. Non-wild type C. neoformans and C. gattii isolates that may have acquired resistance to azoles, amphotericin B (AMB), and terbinafine (TRB) were observed. C. gattii VGIII was less susceptible to fluconazole (FCZ) and itraconazole (ITZ) than VGI and VGII. C. neoformans isolates showed higher minimum inhibitory concentrations (MICs) to FCZ, ITZ, and voriconazole (VRZ) than those of C. gattii VGI and VGII. Significant (P < 0.001) correlations were found between the MICs of VRZ and ITZ (r = 0.64) in both C. neoformans and C. gattii isolates, FCZ and TRB in C. neoformans isolates, and FCZ and TRB (r = 0.52) in C. gattii isolates. There is no significant differences in the MICs of TRB in combination with FCZ (P = 0.064) or in combination with AMB (P = 0.543) and that of TRB alone against C. gattii genotypes. By calculating the fractional inhibitory concentration (FIC) index, the combination of FCZ + AMB was synergistic against all tested genotypes. These findings expand our knowledge of ecological niches, genetic diversity, and resistance traits of C. neoformans and C. gattii genotypes in Egypt. Further investigations into how they are related to clinical isolates in the region are warranted. [ABSTRACT FROM AUTHOR]

In vitro interactions of broad-spectrum azole isavuconazole with flavonoid isoquercitrin were evaluated by a broth microdilution checkerboard technique based on the European Committee on Antimicrobial Susceptibility Testing (EUCAST) reference methodology for antifungal susceptibility testing against 60 Candida strains belonging to the species Candida albicans (n = 10), Candida glabrata (n = 30), Candida kefyr (n = 6), Candida krusei (n = 5), Candida parapsilosis (n = 4), and Candida tropicalis (n = 5). The results were analyzed with the fractional inhibitory concentration index and by response surface analysis based on the Bliss model. Synergy was found for all C. glabrata strains, when the results were interpreted by the fractional inhibitory concentration index, and for 60% of the strains when response surface analysis was used. Interaction for all other species was indifferent for all strains tested, whatever interpretation model used. Importantly, antagonistic interaction was never observed. [ABSTRACT FROM AUTHOR]

Systemic fungal infections are associated with high mortality rates despite adequate treatment. Moreover, acquired resistance to antifungals is increasing, which further complicates the therapeutic management. One strategy to overcome antifungal resistance is to use antifungal combinations. In vitro, several techniques are used to assess drug interactions, such as the broth microdilution checkerboard, agar-diffusion methods, and time-kill curves. Currently, the most widely used technique is the checkerboard method. The aim of all these techniques is to determine if the interaction between antifungal agents is synergistic, indifferent, or antagonistic. However, the interpretation of the results remains difficult. Several methods of analysis can be used, based on different theories. The most commonly used method is the calculation of the fractional inhibitory concentration index. Determination of the usefulness of combination treatments in patients needs well-conducted clinical trials, which are difficult. It is therefore important to study antifungal combinations in vivo, in experimental animal models of fungal infections. Although mammalian models have mostly been used, new alternative animal models in invertebrates look promising. To evaluate the antifungal efficacy, the most commonly used criteria are the mortality rate and the fungal load in the target organs. [ABSTRACT FROM AUTHOR]

The interaction of isavuconazole with immunosuppressors (tacrolimus, cyclosporin A, orsirolimus) against 30Aspergillusisolates belonging to the most common species responsible for invasiveaspergillosis in humans (Aspergillus flavus, Aspergillus fumigatus, Aspergillus nidulans, Aspergillus niger, and Aspergillus terreus) was evaluated in vitro by a microdilution checkerboard technique based on the EUCAST reference method for antifungal susceptibility testing. The interpretation of theresults was performed based on the fractional inhibitory concentration index. The combination of isavuconazole with tacrolimus, cyclosporin A, or sirolimus, was synergistic for 56, 20, or 10% of theisolates, respectively. Interestingly synergy of the combination of isavuconazole with tacrolimus was also achieved for the majority of azole-resistant isolates of A. fumigatus, and for all A. nigerisolates with isavuconazole minimal inhibitory concentrations ≥ 8μg/mL. Antagonistic interactions were never observed for any combination tested. [ABSTRACT FROM AUTHOR]

Summary: Mucormycosis mostly affects immunocompromised patients and is associated with a high morbidity and mortality despite currently available treatments. In that context, combination therapy might be the key to a better outcome for these patients. Purpose of this review is to summarise and to discuss the current combination data obtained in vitro, in vivo in animal models of mucormycosis, and in patients. In vitro combination studies showed that most of the interactions between antifungal drugs were indifferent, even though that some synergistic interactions were achieved for the combination of echinocandins with either azoles or amphotericin B. Importantly, antagonism was never observed. Animal models of mucormycosis focused on infections caused by Rhizopus arrhizus, neglecting most other species responsible for human disease. In these experimental animal models, no strong interactions have been demonstrated, although a certain degree of synergism has been reported in some instances. Combinations of antifungals with non‐antifungal drugs have also been largely explored in vitro and in animal models and yielded interesting results. In patients with ketoacidosis and rhino‐orbito‐cerebral infection, combination of polyene with caspofungin was effective. In contrast, despite promising experimental data, adjunctive therapy with the iron chelator deferasirox was unfavourable and was associated with a higher mortality than monotherapy with liposomal amphotericin B. More combinations have to be tested in vitro and a much larger panel of Mucorales species has to be tested in vivo to give a valuable statement if antifungal combination therapy could be an effective treatment strategy in patients with mucormycosis. [ABSTRACT FROM AUTHOR]

Abstract: Studies have demonstrated excellent in vivo efficacy of terbinafine combined with other antifungal agents against dematiaceous molds; however, there is a lack of in vitro studies. Most studies evaluated conidia inocula, but susceptibility testing of hyphae could mimic the fungal status in infected tissues and might reflect the therapeutic potential of the agent. We investigated the in vitro susceptibility of terbinafine alone and in combination with amphotericin B, itraconazole, or voriconazole against conidia by microdilution and dynamic measurement of hyphae growth of dematiaceous molds. The MIC values for hyphae were, until 3 dilutions, below the MIC obtained for conidia. The results indicated 100% synergistic interactions between terbinafine and azoles or amphotericin B in all tests, but lower MICs for hyphae. In conclusion, our findings allow us to say that the hyphal form of tested dematiaceous molds showed high susceptibility to all antifungal agents evaluated, alone and in combination with terbinafine. [Copyright &y& Elsevier]

Background and objective: Invasive pulmonary aspergillosis (IPA) is a serious cause of death among immune-compromised patients such as organ-transplant recipients. Recently, voriconazole has been approved for first-line therapy in IPA. Theoretically, optimal voriconazole blood level (superior to 1 mg/L according to recent studies) should be reached within 24 h. In practice, a significantly longer time seems to be needed in lung-transplant recipients. Therefore, caspofungin is now used in combination with voriconazole to provide cover against Aspergillus spp. infection during this gap. The first aim of this study was to investigate Aspergillus spp. infection treated with this combination and the atter’s tolerability. The median time for attainment of apparently active blood levels in lung transplant recipients were compared between those with cystic fibrosis and those without. Methods: Lung-transplant recipients who received a combination of voriconazole and caspofungin between 2002 and 2008 as primary therapy were identified retrospectively. The median number of days to reach active voriconazole blood levels was compared between cystic fibrosis and other patients by Student’s t-test. Statistical significance was defined by P-value <0·05. Results: Four patients were treated for Aspergillus colonization before transplantation and their culture were negative at 90 days. Eleven patients were treated for proven or probable invasive aspergillosis and 14 of them had a complete response. Hallucinations ( n = 2) and significant hepatic toxicity ( n = 2) were reported. Among the 15 studied transplant recipients, a median of 12·3 days was observed for active voriconazole blood levels to be reached. With cystic fibrosis patients, time tended to be longer than with other recipients (14·9 days vs. 8·3 days). Tacrolimus blood levels (between 5 and 15 ng/mL) may have been increased by voriconazole. Conclusion: This retrospective study describes practical experience in the management of this rare and severe disease in a referral centre for cystic fibrosis lung transplantation. Voriconazole and caspofungin combination was acceptably safe and was associated with good clinical outcomes in almost all patients. We showed that in 15 lung-transplant recipients a median of 12·3 days was required for voriconazole to reach high enough blood levels. Caspofungin in combination with voriconazole provides cover against Aspergillus infection during the period when voriconazole may be at subtherapeutic levels with good tolerability. [ABSTRACT FROM AUTHOR]

The combination of resection of infected tissue and antifungal therapy is the treatment of choice in mucormycosis. In disseminated mucormycosis, where surgery is impossible, the mortality is almost 90%. We report the first case of disseminated mucormycosis that was cured with a combination therapy of liposomal amphotericin B and posaconazole without surgical intervention. [ABSTRACT FROM AUTHOR]

Abstract: Anidulafungin, an echinocandin, is in late stage development for the treatment of fungal infections. We investigated the activity of anidulafungin in combination with other antifungal agents (fluconazole, itraconazole, ketoconazole, amphotericin B and 5-fluorocytosine) against four isolates each of Candida albicans, Candida glabrata, Candida parapsilosis and Candida tropicalis, and two isolates of Candida krusei using a macrobroth chequerboard method with interactions evaluated by fractional inhibitory concentration indices (FICIs). Additive activity (FICI>0.5 to 1) or indifference (FICI>1 to <4) was observed in 85 of 90 interactions of anidulafungin with another antifungal agent. Synergy with itraconazole (FICI≤0.5) was observed for one strain of C. glabrata, and antagonism with ketoconazole (FICI≥4), a drug rarely used systemically, was noted for four strains of C. tropicalis. The combination of anidulafungin and amphotericin B demonstrated additive activity for each of the 18 isolates of Candida tested. These results suggest additional studies are warranted, for example in animal models, to evaluate further the potential of combination antifungal therapy with anidulafungin for Candida infections. [Copyright &y& Elsevier]

The in-vitro activity of nikkomycin Z was investigated in combination with polyenes, triazoles or echinocandins against 20 clinical isolates ofAspergillus fumigatuswith the fractional inhibitory concentration index (FICI) method. The drug interactions were classified as synergic (FICI ≤ 0.5), no interaction (FICI > 0.5, but FICI ≤ 4) or antagonistic (FICI > 4). The fungicidal activity of nikkomycin Z alone and in combination with a representative echinocandin (caspofungin) or triazole (voriconazole) was also examined with time-kill experiments and fungal cell viability assays. Two-drug combinations of nikkomycin Z with amphotericin B (FICI 3.59 ± 0.57), amphotericin B lipid complex (FICI 3.95 ± 0.74), liposomal amphotericin B (FICI 3.62 ± 0.98), itraconazole (FICI 2.0 ± 0.0), voriconazole (FICI 1.07 ± 0.37), posaconazole (FICI 2.20 ± 0.44) or ravuconazole (FICI 1.76 ± 0.44) showed no interactions, but the pairwise combination of nikkomycin Z with caspofungin (FICI 0.22 ± 0.19) or micafungin (FICI 0.35 ± 0.27) showed synergic activity againstA. fumigatus. Time-kill studies and fungal cell viability assays showed that neither nikkomycin Z nor caspofungin alone possessed fungicidal activity againstA. fumigatus, whereas a combination of these two drugs at concentrations≥ 2 mg/L (≥ 0.031 × the concentration of drug that produced no visible growth) killed germinated conidia within 24 h in a concentration-dependent manner. These data suggest that two-drug combinations of nikkomycin Z with echinocandins, but not with polyenes and triazoles, have a synergic effect againstA. fumigatus. [ABSTRACT FROM AUTHOR]

The aim of this study was to evaluate the effect of the combination of amphotericin B (AmB) and various non-ionic surfactants on the anti-Mucorales activity of AmB, the toxicity of the combination on eukaryotic cells and the modification of AmB aggregation states. Checkerboards were performed on five genera of Mucorales (12 strains) using several combinations of different surfactants and AmB. These data were analyzed by an Emax model. The effect of surfactants on the cytotoxic activity of AmB was then evaluated for red blood cells and two eukaryotic cell lines by absorbance and propidium iodide internalization. Finally, the effect of polyethylene glycol (15)-hydroxystearate (PEG15HS) on the aggregation states of AmB was evaluated by UV-visible spectrometry. PEG15HS increased the efficacy of AmB on four of the five Mucorales genera, and MICs of AmB were decreased up to 68-fold for L. ramosa. PEG15HS was the only surfactant to not increase the cytotoxic activity of AmB. Finally, the analysis of AmB aggregation states showed that the increased efficacy of AmB and the absence of toxicity are related to an increase in monomeric and polyaggregated forms of AmB at the detriment of the dimeric form. In conclusion, PEG15HS increases the in vitro efficacy of AmB against Mucorales at low concentration, without increasing its toxicity; this combination could therefore be evaluated in the treatment of mucormycosis. [ABSTRACT FROM AUTHOR]

The in vitro interaction of amphotericin B in combination with colistin was evaluated against a total of 86 strains comprising of 47 Candida species (10 Candida albicans, 15 Candida auris, five Candida glabrata, three Candida kefyr, five Candida krusei, four Candida parapsilosis and five Candida tropicalis), 29 Aspergillus species (five Aspergillus flavus, 10 Aspergillus fumigatus, four Aspergillus nidulans, five Aspergillus niger, and five Aspergillus terreus), and 10 Rhizopus species (seven Rhizopus arrhizus, one Rhizopus delemar and two Rhizopus microsporus) strains. For the determination of the interaction, a microdilution checkerboard technique based on the European Committee on Antimicrobial Susceptibility Testing (EUCAST) reference method for antifungal susceptibility testing was used. Results of the checkerboard technique were evaluated by the fractional inhibitory concentration index (FICI) based on the Loewe additivity model for all isolates. Different inhibition endpoints were used to capture both the interaction at MIC and sub-MIC levels. Additionally, checkerboard technique results for Candida species were evaluated by response surface analysis based on the Bliss independence model. Against common Candida species, the combination was synergistic for 75% of the strains by FICI and for 66% of the strains by response surface analysis. For C. tropicalis, the interaction was antagonistic for three isolates by FICI, but antagonism was not confirmed by response surface analysis. Interestingly, synergistic and antagonistic FICIs were simultaneously present on checkboard microplates of all three strains. Against C. auris the combination was synergistic for 73% of the strains by response surface analysis and for 33% of the strains by FICI. This discrepancy could be related to the insensitivity of the FICI to detect weak interactions. Interaction for all other strains was indifferent. For Aspergillus and Rhizopus species combination exhibited only indifferent interactions against all tested strains. [ABSTRACT FROM AUTHOR]

Abstract: Opportunistic invasive fungal infections (IFIs) have changed. Moreover, a significantly greater therapeutic armamentarium is now available, with liposomal amphotericin B (L-AmB) administered in new ways, for example in higher doses, in combination with other compounds or inhaled. The objective of this study was to review these three aspects. The AmBiLoad study was designed to clarify whether higher doses of L-AmB could be more efficacious than the licensed dose of 3–5 mg/kg. It was a multicentric study where patients were randomised to receive a 14-day course of 3 mg/kg/day or 10 mg/kg/day L-AmB. A total of 339 patients were enrolled during the study period (April 2003 to October 2004). Discontinuation of treatment, mainly due to adverse events, was frequent (13% in the standard dose group vs. 24% in the high dose group), and only 66% and 50%, respectively, completed 14 days of randomised treatment. There was no statistically significant difference with regard to favourable overall responses between the treatment groups (50% in the standard dose group vs. 46% in the high dose group; P = 0.65). In addition, there was no significant difference according to type of IFI (invasive aspergillosis, 50% vs. 46% in the standard and high dose groups, respectively). The obvious conclusion of this study was that administration of 10 mg/kg/day L-AmB to patients with IFI does not improve efficacy but increases toxicity and price. In vitro and experimental data suggest that the combination of AmB with other antifungal agents may be more effective than monotherapy; however, data regarding the clinical efficacy of L-AmB in combination with other agents are scarce. The use of inhaled L-AmB has shown promising results for use as antifungal prophylaxis in high-risk patients. [Copyright &y& Elsevier]