Mucormycosis is an angioinvasive fungal infection, due to fungi of the order Mucorales. Its incidence cannot be measured exactly, since there are few population-based studies, but multiple studies have shown that it is increasing. The prevalence of mucormycosis in India is about 80 times the prevalence in developed countries, being approximately 0.14 cases per 1000 population. Diabetes mellitus is the main underlying disease globally, especially in low and middle-income countries. In developed countries the most common underlying diseases are hematological malignancies and transplantation. Τhe epidemiology of mucormycosis is evolving as new immunomodulating agents are used in the treatment of cancer and autoimmune diseases, and as the modern diagnostic tools lead to the identification of previously uncommon genera/species such as Apophysomyces or Saksenaea complex. In addition, new risk factors are reported from Asia, including post-pulmonary tuberculosis and chronic kidney disease. New emerging species include Rhizopus homothallicus, Thamnostylum lucknowense, Mucor irregularis and Saksenaea erythrospora. Diagnosis of mucormycosis remains challenging. Clinical approach to diagnosis has a low sensitivity and specificity, it helps however in raising suspicion and prompting the initiation of laboratory testing. Histopathology, direct examination and culture remain essential tools, although the molecular methods are improving. The internal transcribed spacer (ITS) region is the most widely sequenced DNA region for fungi and it is recommended as a first-line method for species identification of Mucorales. New molecular platforms are being investigated and new fungal genetic targets are being explored. Molecular-based methods have gained acceptance for confirmation of the infection when applied on tissues. Methods on the detection of Mucorales DNA in blood have shown promising results for earlier and rapid diagnosis and could be used as screening tests in high-risk patients, but have to be validated in clinical studies. More, much needed, rapid methods that do not require invasive procedures, such as serology-based point-of-care, or metabolomics-based breath tests, are being developed and hopefully will be evaluated in the near future.

Zygomycosis (mucormycosis) is being increasingly recognized as causing infection in recent years. National and multinational European surveys attempting to analyse the epidemiological parameters of this potentially devastating infection are very few. Although the exact incidence could not be defined due to the different methodologies used in these studies and the absence of a denominator, there were some useful observations made regarding the clinical presentation, sites of infection and diagnostic practices. Moreover, the importance for a prompt and accurate diagnosis has been stressed. As early diagnosis can significantly affect the initiation of treatment and decrease mortality, future research should focus on the development of an epidemiological risk assessment tool and novel diagnostic methods.

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.

Mucormycetes (formerly known as zygomycetes of the order Mucorales) and hyaline moulds such as those of the genus Fusarium or Paecilomyces are emerging as significant human pathogens. The aim of the study was to determine the in vitro antifungal susceptibility of these fungi to older and newer antifungals and to investigate the antifungal activity of amphotericin B, posaconazole and anidulafungin in dual combinations. Twenty-one clinical isolates of mucormycetes and 16 of rare hyaline moulds were tested. MICs were determined by EUCAST methodology for conidia-forming moulds and Etesting. For antifungal combinations a chequerboard method based on EUCAST methodology was used. Against mucormycetes, amphotericin B exhibited the lowest MICs, followed by posaconazole. Ravuconazole was active against eight of the Rhizopus isolates (MIC 1 mg/L). Resistance to amphotericin B (MIC ≥2 mg/L) and posaconazole (MICs ≥4 mg/L) was observed in five and three Rhizopus isolates, respectively. Among Fusarium species variable susceptibility patterns were detected. Amphotericin B exhibited the lowest MICs, followed by voriconazole. Etesting for amphotericin B and posaconazole had excellent agreement with EUCAST methodology (78.6%–100%). Synergy between amphotericin B and anidulafungin was observed against two isolates (one Mucor circinelloides and one Fusarium proliferatum). Synergy or antagonism was not detected in any other combination. The study showed that mucormycetes and other rare hyaline moulds exhibit variable susceptibilities to antifungals, and hence antifungal testing is valuable. The fact that the combination of amphotericin B with anidulafungin was found synergistic in some cases merits further investigation.

Cutaneous mucormycosis is the third most common clinical type of mucormycosis. The signs and symptoms vary widely, and it is important to make the diagnosis as early as possible in order to achieve a better outcome. We present a systematic review of its epidemiology, clinical presentation, diagnosis, and treatment, analyzing cases published from 1958 until 2021. The review was conducted according to the PRISMA guidelines and included 693 cases from 485 articles from 46 countries. Most publications were from North America (256 cases, 36.9%) and Asia (216 cases, 31.2%). The most common risk factors were diabetes mellitus (20%) and hematological malignancies (15.7%). However, a large proportion of published cases (275, 39.6%) had no identified underlying disease. The most common mode of transmission was trauma (54%), and 108 (15.6%) cases were healthcare-associated. In this review, 291 (42.5%) patients had localized infection, and 90 (13%) had disseminated mucormycosis. In Europe, N. America and S. America, the most common genus was Rhizopus spp., while in Asia it was Apophysomyces spp. (34.7%). Treatment was performed with antifungals, mainly amphotericin B, and/or surgery. Mortality was significantly lower when both antifungals and surgery were applied (29.6%).