Revista Iberoamericana De Micologia最新文献

Background

Voriconazole (VRC) is widely recommended as the first-line therapy for invasive aspergillosis. However, surveillance studies have demonstrated that there is an increase in the frequency of azole resistance among Aspergillus fumigates isolates. In recent years, more studies on effective synergisms between natural agents and antifungal drugs have been published.

Aims

To evaluate the synergistic antifungal effect of glabridin (Gla) and VRC against A. fumigatus isolates.

Methods

Potential interactions between Gla and VRC were studied by using a microdilution checkerboard method based on the CLSI reference technique. To assess the interaction of drugs the fractional inhibitory concentration index (FICI) was calculated based on the Loewe Additivity model.

Results

The minimum inhibitory concentrations (MIC) obtained with Gla alone were relatively high (MIC₅₀ 16 μg/ml). However, our results showed synergistic interaction between Gla and VRC against A. fumigatus strains, with FICI range values between 0.15 and 0.5.

Conclusions

Synergistic activity of Gla and VRC against both VRC-sensitive and -resistant A. fumigatus isolates may lead to design new antifungal agents, especially for inhibiting those azole-resistant strains.

Background

Candida auris is an emerging multidrug-resistant and highly virulent yeast that spreads easily among patients.

Aims

To describe the characteristics of candidemia caused by C. auris in the southeast of Spain (Autonomous Community of Valencia – ACV) through a 5-year population-based study.

Methods

An analysis of all the episodes of candidemia diagnosed in the ACV, with approximately 4,500,000 inhabitants, during 2013–2017, was done. Data were obtained from the Epidemiological Surveillance Valencian Network, a network that collects all the microbiological data from the hospitals in the study region.

Results

Based on the records, 1.9% of the isolates recovered from the positive blood cultures (corresponding to 1789 patients) were yeasts. This implies an annual rate of 7.09 cases/100,000 inhabitants. Of the 23 yeast species isolated, Candida albicans was the most frequent (37.3%), showing a higher frequency than Candida parapsilosis (28.4%) and Candida glabrata (15.6%) (p < 0.0001). It is remarkable the emergence of C. auris during 2016 and 2017, as this species became the fourth more prevalent in 2016 (9.2%), and the third in 2017 (15.7%). Fungemia was more common in hospitals with >500 beds (63.3% versus 36.7% in small hospitals) (p < 0.0001), and C. auris was mostly isolated in large hospitals (8.5% versus 0.3%); its incidence was higher in autumn and among the age group of 65–84 years.

Conclusions

The information about the local epidemiology of candidemia is essential in order to decide the best empirical treatment approach. This study reports the novel presence of C. auris in large hospitals. This pathogen has usually resistance to several antifungals and causes severe fungemia, so the results of this work reveal the need to monitor the presence of this species systematically.

Background

The fungi present in the decaying remains enable a better understanding of the processes of decomposition after death. There are not many studies about fungi on decaying bodies and it is not known which fungal sampling methods are effective.

Aims

The main objective of this study was to find the best method for sampling fungi in carcasses, prove the effectiveness of this method and identify the fungal colonies in animal carcasses from experimental burials.

Methods

Samples from 13 carcasses of Sus scrofa domestica, from the experimental project Taphos-m, were taken with different materials: spatula, sterile swabs and RODAC contact plates.

Results

RODAC contact plates with the RBA culture medium showed higher proliferation of fungal colonies. Thirty genera of fungi were isolated from different substrates (bone, tissue, lime). Most of the fungi genera or groups identified have been described before in the literature, but the substrates they came from were different in some cases.

Conclusions

Sampling with RODAC contact plates was found to be the most effective method, as it provides a nutritional culture medium that may allow growth since the moment of sampling. Fungi colonies grew better in RBA culture medium because bacterial growth is inhibited. Most of the observed fungi are related to the environment but some others have been found related to decomposing bodies for the first time.

Background

Liver abscesses caused by Candida species are mainly found in immunocompromised hosts, associated with conditions (such as neutropenia and mucositis) that facilitate the spreading of microorganisms from the gastrointestinal tract.

Case report

We present the case of a non-immunocompromised 72-year-old woman with a liver abscess caused by Candida haemulonii var. vulnera, in whom potential associated conditions could be polycystic kidney disease and renal replacement therapy. The patient experienced clinical resolution after percutaneous drainage and treatment with caspofungin.

Conclusions

To our knowledge, this is the first case reported in Peru of a liver abscess due to Candida haemulonii var. vulnera, a clinical presentation that has not been described previously. This finding should prompt us to establish active surveillance of causal agents of systemic candidiasis.

A review on the current evidence of the efficacy and security of liposomal amphotericin B (L-AmB) for the treatment of visceral leishmaniasis (VL) has been performed. In the Indian subcontinent, a single dose of 10 mg/kg has shown effectiveness in the treatment of VL due to Leishmania donovani. In contrast, higher doses of L-AmB (up to 30 mg/kg) are required in Africa to treat a VL of the same etiology. When treating VL by Leishmania infantum acquired in the Americas and Europe the usual dose of L-AmB is 20-21 mg/kg. In HIV co-infected patients the required doses are usually higher, up to 60 mg/kg, and if it is administered in a prophylactic schedule after the treatment of VL relapses are reduced. L-AmB has shown synergism with other antiparasitic drugs, especially with paromomycin in the Indian subcontinent and with miltefosin in patients coinfected with HIV in East Africa. Due to its efficacy and safety profile, L-AmB is the first therapeutic option for VL.

The treatment of invasive fungal infections remains a challenge, both for the diagnosis and for the need of providing the appropriate antifungal therapy. Candida auris is a pathogenic yeast that is responsible for hospital outbreaks, especially in intensive care units; it is characterized by a high resistance to the antifungal agents and can become multidrug-resistant. At present, the recommended antifungal agents for the invasive infections with this pathogen are echinocandins, always after carrying out an antifungal susceptibility testing. In case of no clinical response or persistent candidemia, the addition of liposomal amphotericin B or isavuconazole may be considered. Both fungal infection of the central nervous system and that associated with biomedical devices remain rare entities affecting mainly immunocompromised patients. However, an increase in their incidence in recent years, along with high morbidity and mortality, has been shown. The treatment of these infections is conditioned by the limited knowledge of the pharmacokinetic properties of antifungals. A better understanding of the pharmacokinetic and pharmacodynamic parameters of the different antifungals is essential to determine the efficacy of the antifungal agents in the treatment of these infections.

Infections caused by mucorales, with an increasing incidence after candidiasis and aspergillosis, are characterized by the fast angioinvasion of blood vessels and invasion of neighboring organs or structures. Mucorales most commonly cause rhinocerebral, pulmonary, cutaneous, digestive or disseminated infections, and their spread is favored by certain underlying diseases (diabetes, kidney failure) and risk factors (neutropenia, immunosuppression, iron overload). These infections have a high mortality rate, over 40% in many series, and the key to their cure depends on both an early diagnosis and an antifungal treatment, associated in most cases with extensive surgical debridement and other adjunctive therapies. Currently, there are international guidelines, not only local ones, for the management of mucormycosis, in which it is considered by consensus and with a strong recommendation that first-line treatment with high-dose liposomal amphotericin B is the best choice. The combined antifungal treatment of polyene agents with triazoles or candins remains in open debate.