RESUMO

OBJECTIVES: Literature is limited regarding ideal micafungin dosing in pediatric patients with hematologic malignancies receiving chemotherapy or hematopoietic stem cell transplantation. Micafungin is an intravenous echinocandin with activity against Candida and Aspergillus species and has a favorable safety profile compared with other antifungal classes. Our objective was to evaluate the breakthrough invasive fungal infection (IFI) rate in pediatric patients who received a prophylactic micafungin course at our institution. METHODS: A single-center, retrospective study was conducted between January 1, 2011, and July 31, 2017, to determine the IFI rate in patients receiving micafungin prophylaxis. Patients with suspected IFI were evaluated for probable or proven infection based on 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 Consensus Group invasive fungal disease definitions. Statistical analyses were descriptive. RESULTS: A total of 170 prophylactic micafungin courses from 129 unique patients ages <12 years at a median dose of 3 mg/kg daily were identified. The rate of probable or proven breakthrough IFIs was 2.4% as determined by clinical, radiologic, microbiologic, and histopathologic criteria. CONCLUSIONS: A low rate of breakthrough IFI was seen with micafungin prophylaxis that is consistent with prior published adult hematopoietic stem cell transplantation studies. Micafungin was well tolerated, with liver function test elevations being transient in most cases and thought to be related to alternative factors.

RESUMO

Fungi are becoming increasingly resistant, especially the new strains. Therefore, this work developed nanoemulsions (NE) containing micafungin (MICA), in order to improve its action against infections caused by Candida auris. The NEs were composed of the surfactants polyoxyethylene (20) cetyl ether (Brij 58®)/soy phosphatidylcholine at 10%, sunflower oil/cholesterol at 10%, and 80% PBS. The NEs were characterized by Dynamic Light Scattering (DLS). For the microbiological in vitro evaluation the determination of the minimum inhibitory concentration (MIC), ergosterol/sorbitol, time kill and biofilms tests were performed. Additionally, the antifungal activity was also evaluated in a Galleria mellonella model. The same model was used in order to evaluate acute toxicity. The NE showed a size of ∼ 42.12 nm, a polydispersion index (PDI) of 0.289, and a zeta potential (ZP) of -3.86 mV. NEM had an average size of 41.29 nm, a PDI of 0.259, and a ZP of -4.71 mV. Finally, both nanoemulsions showed good stability in a storage period of 3 months. Although NEM did not show activity in planktonic cells, it exhibited action against biofilm and in the in vivo infection model. In the alternative in vivo model assay, it was possible to observe that both, NEM and free MICA at 0.2 mg/l, was effective against the infection, being that NEM presented a better action. Finally, NEM and free MICA showed no acute toxicity up to 4 mg/l. NEM showed the best activities in in vitro in mature antibiofilm and in alternative in vivo models in G. mellonella. Although, NEs showed to be attractive for MICA transport in the treatment of infections caused by C. auris in vitro and in vivo studies with G. mellonella, further studies should be carried out, in mice, for example.

Candida auris is a fungus that can cause infections in the human body. As it is a microorganism with a high potential for resistance, it is extremely important to develop new therapeutic alternatives. Thus, nanotechnology, the science that studies materials with extremely small sizes, can be considered a promising method in the treatment of these infections.

Assuntos

RESUMO

Candida auris is an emerging global public health threat. It is an opportunistic yeast that usually affects critically ill patients in healthcare settings and is characterized by reduced susceptibility to multiple antifungal classes. Combination therapy with antifungals and repurposed drugs is a feasible alternative to overcome this problem. The aim of this study was to examine the in vitro interactions and potential synergy of micafungin (MFG) and voriconazole (VRC) plus the antidepressant sertraline (SRT) against clinical isolates of C. auris. Conventional antifungal testing was first performed with the three drugs according to the CLSI methodology. Drug interactions were determined by the checkerboard microdilution assay using the fractional inhibitory concentration (FIC) index. Synergistic interactions were noted with the combination of MFG and SRT plus VRC with FIC values of 0.37 to 0.49 for some strains. Indifferent interactions were observed when MFG was combined with SRT with just one exception (FIC 0.53). No antagonism was observed for any combination. The combination of VRC with MCF or SRT may be relevant for treating C. auris infections.

Assuntos

RESUMO

Candida albicans and Staphylococcus aureus are pathogens commonly isolated from bloodstream infections worldwide. While coinfection by both pathogens is associated with mixed biofilms and more severe clinical manifestations, due to the combined expression of virulence and resistance factors, effective treatments remain a challenge. In this study, we evaluated the activity of echinocandins, especially caspofungin, against mixed biofilms of C. albicans and methicillin-resistant (MRSA) or methicillin-susceptible S. aureus (MSSA) and their effectiveness in vivo using the Galleria mellonella coinfection model. Although caspofungin (CAS) and micafungin (MFG) inhibited the mixed biofilm formation, with CAS exhibiting inhibitory activity at lower concentrations, only CAS was active against preformed mixed biofilms. CAS significantly decreased the total biomass of mixed biofilms at concentrations of ≥2 µg/ml, whereas the microbial viability was reduced at high concentrations (32 to 128 µg/ml), leading to fungus and bacterium cell wall disruption and fungal cell enlargement. Notably, CAS (20 or 50 mg/kg of body weight) treatment led to an increased survival and improved outcomes of G. mellonella larvae coinfected with C. albicans and MRSA, since a significant reduction of fungal and bacterial burden in larval tissues was achieved with induction of granuloma formation. Our results reveal that CAS can be a therapeutic option for the treatment of mixed infections caused by C. albicans and S. aureus, supporting additional investigation. IMPORTANCE Infections by microorganisms resistant to antimicrobials is a major challenge that leads to high morbidity and mortality rates and increased time and cost with hospitalization. It was estimated that 27 to 56% of bloodstream infections by C. albicans are polymicrobial, with S. aureus being one of the microorganisms commonly coisolated worldwide. About 80% of infections are associated with biofilms by single or mixed species that can be formed on invasive medical devices, e.g., catheter, and are considered a dissemination source. The increased resistance to antimicrobials in bacterial and fungal cells when they are in biofilms is the most medically relevant behavior that frequently results in therapeutic failure. Although there are several studies evaluating treatments for polymicrobial infections associated or not with biofilms, there is still no consensus on an effective antimicrobial therapy to combat the coinfection by bacteria and fungi.

Assuntos

RESUMO

Micafungin is characterized as one of the most active available drugs for candidemia treatment; however, their use is also associated in prophylaxis protocols in cases of invasive fungal infections. The use of this drug is widely appreciated in the medical field due to be the most active echinocandin available for invasive fungal infections. In order to provide important parameters related to the chemical, physical, biological and therapeutic characteristics, this review article gathers important research results that demonstrate the biological potential of this drug, as well as to present analytical methods that can be used to determine the antifungal potential and a monitoring of administered dosages. Important studies about the methods most commonly used in biological activity evaluation and determination/quantification by analytical methods are provided in this review article. With the data provided, the scientific community will have the possibility to choose the analytical methods and biological that can be employed in clinical and scientific research to provide greater safety and reliability of the results to be found.

Assuntos

RESUMO

Candida haemulonii complex (C. haemulonii, C. duobushaemulonii and C. haemulonii var. vulnera) is well-known for its resistance profile to different available antifungal drugs. Although echinocandins are the most effective class of antifungal compounds against the C. haemulonii species complex, clinical isolates resistant to caspofungin, micafungin and anidulafungin have already been reported. In this work, we present a literature review regarding the effects of echinocandins on this emergent fungal complex. Published data has revealed that micafungin and anidulafungin were more effective than caspofungin against the species forming the C. haemulonii complex. Subsequently, we investigated the susceptibilities of both planktonic and biofilm forms of 12 Brazilian clinical isolates of the C. haemulonii complex towards caspofungin and micafungin (anidulafungin was unavailable). The planktonic cells of all the fungal isolates were susceptible to both of the test echinocandins. Interestingly, echinocandins caused a significant reduction in the biofilm metabolic activity (viability) of almost all fungal isolates (11/12, 91.7%). Generally, the biofilm biomasses were also affected (reduction range 20-60%) upon exposure to caspofungin and micafungin. This is the first report of the anti-biofilm action of echinocandins against the multidrug-resistant opportunistic pathogens comprising the C. haemulonii complex, and unveils the therapeutic potential of these compounds.

RESUMO

RESUMO Objetivo: Determinar os níveis plasmáticos e o comportamento farmacocinético da micafungina em pacientes tratados com oxigenação por membrana extracorpórea. Métodos: As amostras foram colhidas por meio de pontos de acesso antes e depois da membrana, em dois hospitais espanhóis de nível terciário. Os momentos para o cálculo das curvas farmacocinéticas foram antes da administração do fármaco, e 1, 3, 5, 8, 18 e 24 horas após o início da infusão nos dias 1 e 4 de tratamento. Calcularam-se a área sob a curva, a depuração do fármaco, o volume de distribuição e a meia-vida plasmática por meio de análise farmacocinética não compartimental. Resultados: Os valores farmacocinéticos analisados no primeiro e quarto dias de tratamento não mostram qualquer diferença de concentração entre amostras colhidas antes da membrana e após a membrana, e o comportamento farmacocinético foi similar na vigência de diferentes falências de órgãos. A área sob a curva antes da membrana no dia 1 foi de 62,1 (IC95% 52,8 - 73,4) e a área sob a curva após a membrana nesse mesmo dia foi de 63,4 (IC95% 52,4 - 76,7), com p = 0,625. A área sob a curva antes da membrana no dia 4 foi de 102,4 (IC95% 84,7 - 142,8), enquanto a área sob a curva após a membrana nesse mesmo dia foi de 100,9 (IC95% 78,2 - 138,8), com p = 0,843. Conclusão: Os parâmetros farmacocinéticos da micafungina não foram alterados significantemente.

ABSTRACT Objective: To determine micafungin plasma levels and pharmacokinetic behavior in patients treated with extracorporeal membrane oxygenation. Methods: The samples were taken through an access point before and after the membrane in two tertiary hospitals in Spain. The times for the calculation of pharmacokinetic curves were before the administration of the drug and 1, 3, 5, 8, 18 and 24 hours after the beginning of the infusion on days one and four. The area under the curve, drug clearance, volume of distribution and plasma half-life time with a noncompartmental pharmacokinetic data analysis were calculated. Results: The pharmacokinetics of the values analyzed on the first and fourth day of treatment did not show any concentration difference between the samples taken before the membrane (Cin) and those taken after the membrane (Cout), and the pharmacokinetic behavior was similar with different organ failures. The area under the curve (AUC) before the membrane on day 1 was 62.1 (95%CI 52.8 - 73.4) and the AUC after the membrane on this day was 63.4 (95%CI 52.4 - 76.7), p = 0.625. The AUC before the membrane on day 4 was 102.4 (95%CI 84.7 - 142.8) and the AUC was 100.9 (95%CI 78.2 - 138.8), p = 0.843. Conclusion: The pharmacokinetic parameters of micafungin were not significantly altered.

Assuntos

RESUMO

Pseudomonas aeruginosa and Candida spp. are biofilm-forming pathogens commonly found colonizing medical devices, being mainly associated with pneumonia and bloodstream infections. The coinfection by these pathogens presents higher mortality rates when compared to those caused by a single microbial species. This study aimed to evaluate the antibiofilm activity of echinocandins and polymyxin B (PMB) against polymicrobial biofilms of carbapenem-resistant (CR) Pseudomonas aeruginosa and Candida spp. (C. albicans, C. parapsilosis, C. tropicalis, and C. glabrata). In addition, we tested the antimicrobial effect on their planktonic and monomicrobial biofilm counterparties. Interestingly, beyond inhibition of planktonic [minimum inhibitory concentration (MIC) = 0.5 µg/ml] and biofilm [minimum biofilm inhibitory concentration (MBIC)50 ≤ 2-8 µg/ml] growth of P. aeruginosa, PMB was also effective against planktonic cells of C. tropicalis (MIC = 2 µg/ml), and polymicrobial biofilms of CR P. aeruginosa with C. tropicalis (MBIC50 ≤ 2 µg/ml), C. parapsilosis (MBIC50 = 4-16 µg/ml), C. glabrata (MBIC50 = 8-16 µg/ml), or C. albicans (MBIC50 = 8-64 µg/ml). On the other hand, while micafungin (MFG) showed highest inhibitory activity against planktonic (MIC ≤ 0.008-0.5 µg/ml) and biofilm (MBIC50 ≤ 2-16 µg/ml) growth of Candida spp.; caspofungin (CAS) displays inhibitory activity against planktonic cells (MIC = 0.03-0.25 µg/ml) and monomicrobial biofilms (MBIC50 ≤ 2-64 µg/ml) of Candida spp., and notably on planktonic and monomicrobial biofilms of CR P. aeruginosa (MIC or MBIC50 ≥ 64 µg/ml). Particularly, for mixed biofilms, while CAS reduced significantly viable cell counts of CR P. aeruginosa and Candida spp. at ≥32 and ≥ 2 µg/ml, respectively; PMB was effective in reducing viable cells of CR P. aeruginosa at ≥2 µg/ml and Candida spp. at ≥8 µg/ml. Similar reduction of viable cells was observed for CAS (32-64 µg/ml) combined with PMB (2 µg/ml). These findings highlight the potential of PMB and CAS for the treatment of polymicrobial infections caused by Candida spp. and critical priority CR P. aeruginosa.

RESUMO

Treatment of fungal infections is difficult due to several reasons, such as side effects of drugs, emergence of resistant strains, and limited number of molecular targets for the drug compounds. In fungi, heat shock proteins (Hsps) have been implicated in several processes with the conserved molecular chaperone Hsp90 emerging as a potential target for antifungal therapy. It plays key cellular roles by eliciting molecular response to environmental changes, morphogenesis, antifungal resistance, and fungal pathogenicity. Here, we evaluated the transcription profiles of hsp genes of the most prevalent dermatophyte Trichophyton rubrum in response to different environmental challenges including nutrient availability, interaction with cells and molecules of the host tissue, and drug exposure. The results suggest that each Hsp responds to a specific stress condition and that the cohort of Hsps facilitates fungal survival under various environmental challenges. Chemical inhibition of Hsp90 resulted in increased susceptibility of the fungus to itraconazole and micafungin, and decreased its growth in human nails in vitro. Moreover, some hsp and related genes were modulated by Hsp90 at the transcriptional level. We are suggesting a role of Hsp90 in the pathogenicity and drug susceptibility of T. rubrum as well as the regulation of other Hsps. The synergism observed between the inhibition of Hsp90 and the effect of itraconazole or micafungin in reducing the fungal growth is of great interest as a novel and potential strategy to treat dermatophytoses.

RESUMO

Invasive fungal infections are an important cause of morbidity and mortality in SOT and HSCT recipients. The main species involved are Candida spp. and Aspergillus spp, less frequently Cryptococcus spp., causal agents of mucormycosis and Fusarium spp. Usually occur within the first six months post-transplant, but they do it later, especially during episodes of rejection, which maintains the state of immune system involvement. Prophylaxis recommendations are specific to each type of transplant. In liver transplantation use of fluconazole is recommended only in selected cases by high risk factor for invasive fungal infections (A1). If the patient has a high risk of aspergillosis, there are some suggestions for adults population to use amphotericin B-deoxycholate, liposomal amphotericin B or caspofungin (C2) without being validated none of these recommendations in pediatric population. In adult lung transplant patients where the risk of aspergillosis is higher than in other locations, we recommend universal prophylaxis with itraconazole 200 mg/day, nebulised liposomal amphotericin B or voriconazole (C2), no validated recommendations for pediatrics. In HSCT, universal prophylaxis is recommended only in allogeneic and autologous selected cases. The most accepted indication is fluconazole (A1), and posaconazole (A1) or micafungin (A1) in selected cases with high risk of aspergillosis.

Las infecciones fúngicas invasoras constituyen una importante causa de morbilidad y mortalidad en los pacientes receptores de TOS y TPH. Los principales agentes involucrados son Candida spp. y Aspergillus spp, menos frecuentemente Cryptococcus spp., agentes causales de mucormicosis y Fusarium spp. Se presentan habitualmente dentro de los primeros seis meses posttrasplante, pero también lo hacen en forma más tardía, especialmente durante episodios de rechazo, en que se mantiene el estado de compromiso del sistema inmune. Existen recomendaciones de proilaxis especíicas para cada tipo de trasplante. En trasplante hepático se recomienda el uso de fluconazol sólo en casos seleccionados por factores de riesgo (A1). Si existe riesgo de asper-gilosis, hay algunas sugerencias en adultos para el uso de anfotericina B-deoxicolato, anfotericina liposomal o caspofungina (todo en categoría C2), sin estar validada ninguna de estas recomendaciones en pediatría. En trasplante pulmonar en paciente adulto, donde el riesgo de aspergilosis es superior a otras localizaciones, se recomienda proilaxis universal, con itraconazol 200 mg/día, anfotericina liposomal nebulizada o voriconazol (C2), sin recomendaciones validadas para pediatría. En TPH, se recomienda proilaxis universal en trasplante alogénico y sólo para casos seleccionados en trasplantes autólogos. La indicación más aceptada es fluconazol (A1), siendo alternativas a evaluar dependiendo del riesgo de aspergilosis, posaconazol (A1) y micafungina (A1).

Assuntos

RESUMO

The echinocandins show comparable efficacy in the treatment of candidemia and invasive candidiasis. Caspofungin and micafungin appear to be similarly efficacious in salvage therapy in aspergillosis; anidulafungin has excellent in vitro activity against Aspergillus species but as yet there are no sufficient clinical data for anidulafungin in this disease state. Each drug has minor advantages and disadvantages compared to the others of the same classe; however, there are large differences in the approved indications for the different drugs. The formulary selection process should consider the direct and indirect costs of the single agents; the characteristics of the patient population at risk for invasive mycosis, such as frequent use of interacting drugs and the burden of monitoring plasma drug levels of drugs; and the implications of using products for indications which have not been still approved (off-label indications)

Assuntos