Recent developments in less known and multi-resistant fungal opportunists.

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.

Microbiological quality of Argentinian paprika / Calidad microbiológica del pimentón argentino

The aim of this study was to evaluate the microbiological quality of paprika produced in Catamarca, Argentina. Microbiological analyses were carried out for the enumeration of total aerobic mesophilic bacteria, coliforms, yeasts and molds, and the detection of Salmonella in samples obtained from different local producers during three consecutive years. The mycobiota was identified paying special attention to the mycotoxigenic molds. Standard plate counts of aerobic mesophilic bacteria ranged from 2.7 x 10(5) to 3.7 x 10(7)CFU/g. Coliform counts ranged from <10 to 8.1 x 10(4) CFU/g. Salmonella was not detected in any of the samples tested. Fungal counts (including yeasts and molds) ranged between 2 x 10² and 1.9 x 10(5) CFU/g. These results showed a high level of microbial contamination, exceeding in several samples the maximum limits set in international food regulations. The study of the mycobiota demonstrated that Aspergillus was the predominant genus and Aspergillus niger (potential producer of ochratoxin A) the most frequently isolated species, followed by Aspergillus flavus (potential producer of aflatoxins). Other species of potential toxigenic fungi such as Aspergillus ochraceus, Aspergillus westerdijkiae, Penicillium chrysogenum, Penicillium crustosum, Penicillium commune, Penicillium expansum and Alternaria tenuissima species group were encountered as part of the mycobiota of the paprika samples indicating a risk of mycotoxin contamination. A. westerdijkiae was isolated for the first time in Argentina.

El pimentón es considerado una de las especias más proclives a contaminarse con diversos tipos de microorganismos, incluyendo patógenos como Salmonella y hongos capaces de producir micotoxinas. Existen muy pocos datos acerca de la contaminación microbiana del pimentón producido en nuestro país. El objetivo del presente trabajo fue evaluar la calidad microbiológica del pimentón (Capsicum annum L.) producido en la provincia de Catamarca, una de las principales zonas productoras del norte argentino. Se realizó el recuento de bacterias aerobias mesófilas, coliformes totales y mohos y levaduras, y la búsqueda de Salmonella en muestras obtenidas de diferentes establecimientos productores locales durante 3 años consecutivos. Se identificaron todas las cepas fúngicas (1.622 aislamientos) a nivel de género y se determinaron las especies pertenecientes a los géneros potencialmente toxinógenos. Los recuentos totales de bacterias aerobias mesófilas variaron entre 2,7 x 10(5)y3,7 x 10(7)UFC/g. Los coliformes totales estuvieron en el rango de < 10 a 8,1 x 10(4) UFC/g. Salmonella no fue detectada en ninguna de las muestras analizadas. Los resultados obtenidos muestran un alto nivel de contaminación, que excede en varias de las muestras los límites máximos establecidos en las regulaciones alimentarias internacionales. El estudio de la micobiota demostró que Aspergillus fue el género predominante. Otros géneros encontrados fueron Cladosporium, Rhizopus, Alternaría y Penicillium. Aspergillus niger (potencial productor de ocratoxina A) fue la especie aislada con mayor frecuencia, seguida de Aspergillus flavus (potencial productor de aflatoxinas). También se encontraron otras especies toxinógenas, lo que indica un riesgo potencial de contaminación con micotoxinas. Aspergillus westerdijkiae fue aislado por primera vez en Argentina.

Microbiological quality of Argentinian paprika.

The aim of this study was to evaluate the microbiological quality of paprika produced in Catamarca, Argentina. Microbiological analyses were carried out for the enumeration of total aerobic mesophilic bacteria, coliforms, yeasts and molds, and the detection of Salmonella in samples obtained from different local producers during three consecutive years. The mycobiota was identified paying special attention to the mycotoxigenic molds. Standard plate counts of aerobic mesophilic bacteria ranged from 2.7×105 to 3.7×107CFU/g. Coliform counts ranged from <10 to 8.1×104CFU/g. Salmonella was not detected in any of the samples tested. Fungal counts (including yeasts and molds) ranged between 2×102 and 1.9×105CFU/g. These results showed a high level of microbial contamination, exceeding in several samples the maximum limits set in international food regulations. The study of the mycobiota demonstrated that Aspergillus was the predominant genus and Aspergillus niger (potential producer of ochratoxin A) the most frequently isolated species, followed by Aspergillus flavus (potential producer of aflatoxins). Other species of potential toxigenic fungi such as Aspergillus ochraceus, Aspergillus westerdijkiae, Penicillium chrysogenum, Penicillium crustosum, Penicillium commune, Penicillium expansum and Alternaria tenuissima species group were encountered as part of the mycobiota of the paprika samples indicating a risk of mycotoxin contamination. A. westerdijkiae was isolated for the first time in Argentina.

Ochratoxin A production by a mixed inoculum of Aspergillus carbonarius at different conditions of water activity and temperature.

Growth rate, lag phase and OTA production of a mixed inoculum of four Aspergillus carbonarius strains were compared to the behaviour of the single strains at 30 degrees C on Czapek Yeast Extract Agar. Significant differences between radial growth rates and lag phases of the different isolates were observed; however, no significant differences between growth rates of each strain and the mixed inoculum were detected. When the four strains were inoculated simultaneously, the lag phase was the same than the higher value obtained for individual strains, suggesting mycelial interactions between the A. carbonarius isolates. The four strains differed in maximum OTA yield, and the toxin accumulation by the mixed inoculum showed intermediate levels at each time point. The effects of water activity (0.83, 0.85, 0.87, 0.89, 0.90, 0.93 and 0.95) and temperature (15, 20, 25, 30, and 35 degrees C) on OTA production by the mixed inoculum were studied at 7, 14, 21 and 28days of incubation. The limiting water activity for OTA production by the mixed inoculum was 0.87, showing xerotolerant behaviour of the strains isolated from dried vine fruits. Results obtained were similar to those reported for single A. carbonarius strains from European countries, Israel, Australia and South America. The similar trend in the response of the different isolates to the variation of environmental parameters may be of interest for the building of predictive models.