Laura Trovato

Environmental distribution of Cryptococcus neoformans and C. gattii around the Mediterranean basin

In order to elucidate the distribution of Cryptococcus neoformans and C. gattii in the Mediterranean basin, an extensive environmental survey was carried out during 2012-2015. A total of 302 sites located in 12 countries were sampled, 6436 samples from 3765 trees were collected and 5% of trees were found to be colonized by cryptococcal yeasts. Cryptococcus neoformans was isolated from 177 trees and C. gattii from 13. Cryptococcus neoformans colonized 27% of Ceratonia, 10% of Olea, Platanus and Prunus trees and a lower percentage of other tree genera. The 13 C. gattii isolates were collected from five Eucalyptus, four Ceratonia, two Pinus and two Olea trees. Cryptococcus neoformans was distributed all around the Mediterranean basin, whereas C. gattii was isolated in Greece, Southern Italy and Spain, in agreement with previous findings from both clinical and environmental sources. Among C. neoformans isolates, VNI was the prevalent molecular type but VNII, VNIV and VNIII hybrid strains were also isolated. With the exception of a single VGIV isolate, all C. gattii isolates were VGI. The results confirmed the presence of both Cryptococcus species in the Mediterranean environment, and showed that both carob and olive trees represent an important niche for these yeasts.

Experience with the Platelia Candida ELISA for the diagnosis of invasive candidosis in neonatal patients

This preliminary study evaluated the use of the Platelia Candida antigen kit for the diagnosis of invasive candidosis in 70 of 184 pre-term infants admitted to a neonatal intensive care unit between March 2004 and March 2006. The frequency of confirmed candidaemia was 6.5%. The sensitivity and specificity of the assay were 94.4% and 94.2%, respectively, with a positive predictive value of 85% and a negative predictive value of 98%. These results suggest that the inclusion of regular serological surveillance for mannanaemia in some pre-term infants would complement blood cultures for the early detection of candidosis.

Malassezia furfur fungaemia in a neonatal patient detected by lysis‐centrifugation blood culture method: first case reported in Italy

Malassezia yeast typically colonise the skin of healthy individuals (Morishita N, Sei Y. Mycopathologia 2006; 162: 373–6). However, under some conditions, they are associated with a number of skin infections in adults (Tarazooie B et al., BMC Dermatol 2004; 4: 5). Also newborns can be colonised. In a study of hospitalised neonates, Malassezia spp. were isolated from 68.7%, with Malassezia furfur the most isolated species. The high prevalence of colonisation encountered in hospitalised neonates highlights the potential danger of nosocomial infections caused by Malassezia sp., particularly in those instances in which intravenous lipids or indwelling catheters are needed (Gupta AK et al., J Am Acad Dermatol 2004; 51: 785–98). These yeast are important agents of catheter-associated sepsis, primarily in low-birth-weight infants receiving lipids through a central venous line (Zomorodain K et al., Pediatric Dermatology 2008; 3: 312–6). Invasive infections caused by species of Candida or Malassezia have been documented in the neonatal intensive care units (NICU) and are often associated with significant morbidity and mortality (Devlin RK, Adv Neonatal Care 2006; 6: 68– 77). Malassezia sp. remains probably underdiagnosed, as it does not routinely grow in the usual cultures and requires lipid-supplemented media for in vitro growth. The Isolator system has been reported to provide greater sensitivity than conventional broth blood culture systems in recovering fungal organisms from the blood (Berenguer J et al., Diagn Microbiol Infect Dis 1993; 17: 103–9). In the literature, cases of Malassezia fungaemia in Italy have not been reported. Case report

Looking for Candida nivariensis and C. bracarensis among a large Italian collection of C. glabrata isolates: results of the FIMUA working group

Two recently described pathogenic Candida species, C. nivariensis and C. bracarensis, share many phenotypic characteristics with C. glabrata and are easily misidentified as such. The aim of this study was to determine the occurrence of these cryptic species in Italy. One thousand yeast isolates collected in 14 Italian regions and identified as C. glabrata by phenotypic and biochemical methods were included in this study: 928 were screened on CHROMagar and 72 were analysed by a multiplex PCR. None of these cryptic species was identified despite the nationwide distribution and the variety of biological origin of the isolates.

Detection of fungal DNA in lysis–centrifugation blood culture for the diagnosis of invasive candidiasis in neonatal patients

We report data concerning the detection of fungal DNA directly from lysis-centrifugation blood culture to assess its value in the detection of fungaemia in 86 of the 347 patients admitted to the neonatal intensive-care unit between January 2009 and December 2010. The sensitivity and specificity of the PCR were 87.5% and 98.5%, respectively, with a positive predictive value of 93.3% and a negative predictive value of 97.1%. Detection of fungal DNA directly from blood culture Isolator 1.5 microbial tubes, without prior cultivation, is a promising approach for the rapid detection of Candida spp. in neonates with suspected candidaemia.

Evaluation of the disk diffusion method compared to the microdilution method in susceptibility testing of anidulafungin against filamentous fungi.

ABSTRACT Susceptibility testing of anidulafungin (AFG) against 32 mold isolates showed an excellent correlation between disk diffusion (DD) and broth microdilution methods. Based on our data, a 2-μg disk of AFG and a 24-h reading time might represent the best parameters for AFG DD testing against filamentous fungi.

Fundamental niche prediction of the pathogenic yeasts cryptococcus neoformans and cryptococcus gattii in europe

Fundamental niche prediction of Cryptococcus neoformans and Cryptococcus gattii in Europe is an important tool to understand where these pathogenic yeasts have a high probability to survive in the environment and therefore to identify the areas with high risk of infection. In this study, occurrence data for C. neoformans and C. gattii were compared by MaxEnt software with several bioclimatic conditions as well as with soil characteristics and land use. The results showed that C. gattii distribution can be predicted with high probability along the Mediterranean coast. The analysis of variables showed that its distribution is limited by low temperatures during the coldest season, and by heavy precipitations in the driest season. C. neoformans var. grubii is able to colonize the same areas of C. gattii but is more tolerant to cold winter temperatures and summer precipitations. In contrast, the C. neoformans var. neoformans map was completely different. The best conditions for its survival were displayed in sub-continental areas and not along the Mediterranean coasts. In conclusion, we produced for the first time detailed prediction maps of the species and varieties of the C. neoformans and C. gattii species complex in Europe and Mediterranean area.

Azole-Resistance in Aspergillus terreus and Related Species: An Emerging Problem or a Rare Phenomenon?

Objectives: Invasive mold infections associated with Aspergillus species are a significant cause of mortality in immunocompromised patients. The most frequently occurring aetiological pathogens are members of the Aspergillus section Fumigati followed by members of the section Terrei. The frequency of Aspergillus terreus and related (cryptic) species in clinical specimens, as well as the percentage of azole-resistant strains remains to be studied. Methods: A global set (n = 498) of A. terreus and phenotypically related isolates was molecularly identified (beta-tubulin), tested for antifungal susceptibility against posaconazole, voriconazole, and itraconazole, and resistant phenotypes were correlated with point mutations in the cyp51A gene. Results: The majority of isolates was identified as A. terreus (86.8%), followed by A. citrinoterreus (8.4%), A. hortai (2.6%), A. alabamensis (1.6%), A. neoafricanus (0.2%), and A. floccosus (0.2%). One isolate failed to match a known Aspergillus sp., but was found most closely related to A. alabamensis. According to EUCAST clinical breakpoints azole resistance was detected in 5.4% of all tested isolates, 6.2% of A. terreus sensu stricto (s.s.) were posaconazole-resistant. Posaconazole resistance differed geographically and ranged from 0% in the Czech Republic, Greece, and Turkey to 13.7% in Germany. In contrast, azole resistance among cryptic species was rare 2 out of 66 isolates and was observed only in one A. citrinoterreus and one A. alabamensis isolate. The most affected amino acid position of the Cyp51A gene correlating with the posaconazole resistant phenotype was M217, which was found in the variation M217T and M217V. Conclusions: Aspergillus terreus was most prevalent, followed by A. citrinoterreus. Posaconazole was the most potent drug against A. terreus, but 5.4% of A. terreus sensu stricto showed resistance against this azole. In Austria, Germany, and the United Kingdom posaconazole-resistance in all A. terreus isolates was higher than 10%, resistance against voriconazole was rare and absent for itraconazole.

Environmental distribution of Cryptococcus neoformans and Cryptococcus gattii around the Mediterranean basin

In order to elucidate the distribution of Cryptococcus neoformans and C. gattii in the Mediterranean basin, an extensive environmental survey was carried out during 2012-2015. A total of 302 sites located in 12 countries were sampled, 6436 samples from 3765 trees were collected and 5% of trees were found to be colonized by cryptococcal yeasts. Cryptococcus neoformans was isolated from 177 trees and C. gattii from 13. Cryptococcus neoformans colonized 27% of Ceratonia, 10% of Olea, Platanus and Prunus trees and a lower percentage of other tree genera. The 13 C. gattii isolates were collected from five Eucalyptus, four Ceratonia, two Pinus and two Olea trees. Cryptococcus neoformans was distributed all around the Mediterranean basin, whereas C. gattii was isolated in Greece, Southern Italy and Spain, in agreement with previous findings from both clinical and environmental sources. Among C. neoformans isolates, VNI was the prevalent molecular type but VNII, VNIV and VNIII hybrid strains were also isolated. With the exception of a single VGIV isolate, all C. gattii isolates were VGI. The results confirmed the presence of both Cryptococcus species in the Mediterranean environment, and showed that both carob and olive trees represent an important niche for these yeasts.

Blastoschizomyces capitatus pneumonia in a patient with untreated chronic lymphocytic leukemia

Several cases have been reported of B. capitatus infections in immunocompromised patients. Acute leukemia is the main predisposing factor. Chronic lymphocytic leukemia (CLL) is not usually associated with opportunistic infections. We report a case of pulmonary infection by B. capitatus in a patient with untreated chronic lymphocytic leukemia. Although the patient had a complete recovery, we believe that this report will alert clinicians to consider B. capitatus as possible cause of severe pneumonia in untreated CLL.