Background and methods: Our group has continuously studied the epidemiology of visceral mycoses (VM) among autopsy cases in Japan from 1989 to 2013. Results: First, from a total of 11,149 autopsied cases, 571 (5.1%) cases of VM were observed in 2013. It was significantly higher than those of 2005 (p < 0.05) and earlier. Notably, incidence of cases with mucormycetes (Muc) in 2013 was higher than that of 1997 and earlier (p < 0.001), especially in leukemia cases. Muc cases also showed higher rate of “severe infection” compared with other cases (p < .0001). Emerging diseases were also observed. Severe fever with thrombocytopenia syndrome cases showed high incidence of VM as a complication. In addition, we observed cases with the rare mycoses caused by Phialopohra verrucosa and Rhodotorula spp. in our analysis. Moreover, the predominant fungal agent of central nervous system infections changed from Cryptococcus spp. to Aspergillus spp. in 2013. This may be considered a breakthrough infection. Conclusion: The prevalence of VM in 2013 became higher than those of 2005 (p < 0.05) and earlier, with a notable increase of incidence in cases with Muc. The occurrence of breakthrough VM and emerging mycoses deserve attention.
Stress responses and pathogenicity have been extensively studied in Aspergillus fumigatus, the main causative pathogen of life-threatening aspergillosis. The heterogeneity in this pathogen's biology has recently attracted increasing attention. In the present work, we used 16 clinically isolated strains to investigate several properties relevant to the pathogenicity of A. fumigatus, namely, gliotoxin production, elastase activity, hypoxia growth, adaptation to iron-limiting conditions, and growth upon nitrosative, oxidative, and high osmotic stresses. The range of phenotypes was diverse across the strains, with gliotoxin production and elastase activity being negatively correlated at an intermediate index (R=−0.4717). Notably, there were strains that showed extraordinary high production of gliotoxin or elastase activity and hypersensitivity to nitrosative or oxidative stresses. Clustering analysis showed that the 7 potentially pathogenicity-related phenotypes were not correlated with the genetic sub-group or pathotype. These results contribute to the growing awareness of the genetic and phenotypic diversity in A. fumigatus isolates.
Aspergillus fumigatus is a saprophytic fungus that is a major causative pathogen for aspergillosis. Only a few classes of antifungals are used for treating this life-threatening fungal infection. Azoles are the first-line drugs and are widely used for the management and prophylaxis of aspergillosis. An emerging issue is the increasing incidence of resistant isolates worldwide. In particular, environmentally derived tandem-repeat-type azole-resistant mutations, such as Cyp51A TR34/L98H, and Cyp51A TR46/Y121F/T289A, have emerged over the last decade. In particular, azole-resistant isolates were prevalent in clinical settings in European countries; many of the reports are from the Netherlands, UK, and Germany. In contrast, reports on azole-resistant A. fumigatus isolates from East Asian countries are still few and have only recently begun to increase. Herein, all literature on East Asian azole-resistant A. fumigatus isolates were reviewed, and a complete list of resistant isolates from China, Japan, Taiwan, and Korea is provided. As of this report, the total numbers of tandem-repeat-type azole-resistant isolates are 26, 3, 32, and 1 in China, Japan, Taiwan, and Korea, respectively.
A 26-year-old female homemaker presented with an approximately 2-month history of an erythematous lesion with agminated seropapules in the right popliteal fossa associated with scales and crusts. The lesion was initially treated as contact dermatitis, but there was no improvement. KOH examination revealed filamentous fungi. The fungal culture was positive, and the morphological characteristics were identical to those of Trichophyton mentagrophytes complex. The fungus was identified as T. erinacei based on genetic analysis. This is the second case report of human tinea corporis due to this fungus in Japan.