Evaluating the resistance to posaconazole by E-test and CLSI broth microdilution methodologies of Candida spp. and pathogenic moulds

Sarocladium and Acremonium infections: New faces of an old opportunistic fungus

The genera Acremonium and Sarocladium comprise a high diversity of morphologically and genetically related fungi generally found in the environment, although a few species, mainly Sarocladium kiliense and Acremonium egyptiacum, can also be involved in many human infections. Clinical management of opportunistic infections caused by these fungi is very complex, since their correct identification is unreliable, and they generally show poor antifungal response. More than 300 clinical cases involving a broad range of Acremonium/Sarocladium infections have so far been published, and with this review we aim to compile and provide a detailed overview of the current knowledge on Acremonium/Sarocladium human infections in terms of presentation, diagnosis, treatments and prognoses. We also aim to summarise and discuss the data currently available on their antifungal susceptibility, emphasising the promising results obtained with voriconazole as well as their impact in terms of animal infections.

Unpredictable susceptibility of emerging clinical moulds to tri-azoles: review of the literature and upcoming challenges for mould identification

Tri-azoles represent the front-line drugs for the treatment of mould diseases; nevertheless, some emerging moulds, such as Fusarium spp., Scedosporium spp., Mucorales and others, may be less susceptible or resistant to these antifungals. A review of the literature was conducted on the susceptibility of rare moulds to the tri-azoles itraconazole, posaconazole and voriconazole. Particular attention was paid to isolates identified by molecular analyses. The range of susceptibility values described for the three tri-azoles was frequently large (from 0.06 to >16), and a high variability was found within each species; isolates were rarely reported as entirely susceptible to all tri-azoles. In addition, the susceptibility of 76 emerging moulds from our collection (including Hypocreales, Dothideomycetes, Scedosporium spp., Mucorales and rare Aspergillus spp.) to itraconazole and voriconazole was determined by the Clinical and Laboratory Standards Institute (CLSI) M38-A2 and European Committee for Antimicrobial Susceptibility Testing (EUCAST) methods. Susceptibility discrepancies (of two dilutions) were found comparing CLSI and EUCAST for Dothideomycetes; the values for the remaining moulds were similar. More practical, faster and inexpensive susceptibility tools are welcome for testing emerging moulds, as these tests still represent a critical tool to support clinicians on the selection of proper antifungal treatment. The susceptibility of emerging moulds to tri-azoles cannot be predicted exclusively following mould identification, as the isolates' susceptibilities showed highly variable values. Some emerging moulds still remain very difficult to identity, even following standard molecular analyses which result in complex fungal collections. This fact limits the definition of epidemiological cut-offs and clinical breakpoints that are still imperative for emerging moulds.

Neonatal intensive care unit candidemia: epidemiology, risk factors, outcome, and critical review of published case series

Evaluation of epidemiological trends, risk factors, and clinical outcome associated with candidemia at a neonatal intensive care unit is reported. From January 2005 to December 2009, forty candidemia cases were identified. C. albicans and C. parapsilosis were the most common species recovered (69 and 24%, respectively). All C. parapsilosis strains were susceptible to antifungals, whereas, C. albicans exhibited higher resistance rates to azoles. Low birth weight, low gestational age, presence of central lines, endotracheal intubation, total parenteral nutrition, previous use of antibiotics, steroids, previous episode(s) of bacteremia and prolonged stay in intensive care unit were common features associated with candidemia. C. albicans was most often isolated from extremely low birth weight neonates as compared to non-albicans Candida (P < 0.01). Mortality rate was 35.7% and was associated with low gestational age (P < 0.01), low birth weight (P < 0.01), and presence of renal failure (P < 0.05). Furthermore, a critical review of recent published case series is presented.

A novel flucytosine-resistant yeast species, Candida pseudoaaseri, causes disease in a cancer patient

Some members of the genus Candida are among the most common human fungal pathogens and cause serious diseases especially in immunocompromised people. A yeast was isolated from a blood culture from an immunocompromised cancer patient who suffered from acute pneumonia. The growth characteristics of the yeast on CHROMagar Candida were similar to those of Candida tropicalis, whereas the API ID 32C system identified the yeast as Candida silvicola. On the basis of the nucleotide divergence in the D1/D2 domain of the 26S nuclear rRNA (nrRNA) gene, as well as the internal transcribed spacer (ITS) domain of the nrRNA gene region, a new species, Candida pseudoaaseri sp. nov. with type strain VK065094 (CBS 11170(T)), which was found to be closely related to Candida aaseri, is proposed. While C. aaseri strains were susceptible to all tested antifungals, the new species is resistant to flucytosine and may also be distinguished from C. aaseri by its ability to assimilate l-rhamnose, whereas its colony morphology on CHROMagar Candida may be helpful for differentiation.

Eleven-year retrospective survey of candidaemia in a university hospital in southwestern Greece

The aim of this study was to investigate the isolation and distribution rate of Candida spp. in blood cultures and evaluate antifungal susceptibility during an 11-year period (1998–2008) at a tertiary-care hospital. The causative species were as follows: Candida albicans, 163 strains (64%); Candida parapsilosis, 35 strains (13.7%); Candida glabrata, 25 strains (9.8%); Candida tropicalis, 19 strains (7.4%); and other Candida spp., 13 strains (5.1%). Candidaemia is predominantly caused by C. albicans. C. parapsilosis is the most common non-albicans Candida isolated in neonatal intensive-care units. All Candida isolates remain susceptible to amphotericin B, whereas the highest degree of resistance was observed for azoles.