The fungal infections are relatively common in humans that can range from common, mild superficial infections to life-threatening invasive infections. Most of the pathogenic fungi are opportunistic that cause disease under immunocompromised conditions such as HIV infection, cancer, chemotherapy, transplantation and immune suppressive drug users. Efficient detection and treatment of high-risk population remain the highest priority to avert most of the deaths. Majority of invasive infections are caused by Candida, Aspergillus and Cryptococcus species. Lack of effective vaccines, standardised diagnostic tools, efficient antifungal drugs and the emergence of drug-resistant species/strains pose a global threat to control Invasive fungal infections (IFI). A better understanding of the host immune response is one of the major approaches to developing new or improved antifungal strategies to control the IFIs. In this review, we have discussed pathogenesis of medically important fungi, fungal interaction with the host through pattern recognition receptors (PRRs) and the interplay of innate and adaptive immune cells in shaping host immunity to IFI. Further, we emphasized the role of memory cells by offering long-term protection in secondary or subsequent infections. Moreover, we depicted the role of unconventional innate-like immune cells in anti-fungal immunity. We also summarize the available information on the current vaccine strategies, genetic susceptibility to fungal infections, recent co-infections studies and the emergence of drug-resistance, a growing trend throughout the world. Finally, we emphasized the steps to be taken for the control of IFIs.
During the past decade, a prolonged and serious outbreak of dermatophytosis due to a terbinafine-resistant novel species in the Trichophyton mentagrophytes - T. interdigitale complex has been ongoing in India, and it has spread to several European countries. The objective of this study was to investigate the molecular background of the squalene epoxidase ( SQLE ) gene in order to understand the risk of emergence and spread of multiresistance in dermatophytes.
Summary: As the pandemic progresses, the pathophysiology of coronavirus disease 2019 (COVID‐19) is becoming clearer and the potential for immunotherapy is increasing. However, clinical efficacy and safety of immunosuppressants (including tocilizumab, sarilumab and anakinra) treatment in COVID‐19 patients are not yet known. We searched PubMed, Embase Medline, Web of Science and MedRxiv using specific search terms in studies published from 1 January 2020 to 20 December 2020. In total, 33 studies, including 3073 cases and 6502 controls, were selected for meta‐analysis. We found that immunosuppressant therapy significantly decreased mortality in COVID‐19 patients on overall analysis (odds ratio = 0.71, 95% confidence interval = 0.57–0.89, p = 0.004). We also found that tocilizumab and anakinra significantly decreased mortality in patients without any increased risk of secondary infection. In addition, we found similar results in several subgroups. However, we found that tocilizumab therapy significantly increased the risk of fungal co‐infections in COVID‐19 patients. This represents the only systematic review and meta‐analysis to investigate the efficacy and secondary infection risk of immunosuppressant treatment in COVID‐19 patients. Overall, immunosuppressants significantly decreased mortality but had no effect on increased risk of secondary infections. Our analysis of tocilizumab therapy showed a significantly increased risk of fungal co‐infections in these patients.
Trichophyton rubrum and T. violaceum are prevalent agents of human dermatophyte infections, the former being found on glabrous skin and nail, while the latter is confined to the scalp. The two species are phenotypically different but are highly similar phylogenetically. The taxonomy of dermatophytes is currently being reconsidered on the basis of molecular phylogeny. Molecular species definitions do not always coincide with existing concepts which are guided by ecological and clinical principles. In this article, we aim to bring phylogenetic and ecological data together in an attempt to develop new species concepts for anthropophilic dermatophytes. Focus is on the T. rubrum complex with analysis of rDNA ITS supplemented with LSU, TUB2, TEF3 and ribosomal protein L10 gene sequences. In order to explore genomic differences between T. rubrum and T. violaceum, one representative for both species was whole genome sequenced. Draft sequences were compared with currently available dermatophyte genomes. Potential virulence factors of adhesins and secreted proteases were predicted and compared phylogenetically. General phylogeny showed clear gaps between geophilic species of Arthroderma, but multilocus distances between species were often very small in the derived anthropophilic and zoophilic genus Trichophyton. Significant genome conservation between T. rubrum and T. violaceum was observed, with a high similarity at the nucleic acid level of 99.38 % identity. Trichophyton violaceum contains more paralogs than T. rubrum. About 30 adhesion genes were predicted among dermatophytes. Seventeen adhesins were common between T. rubrum and T. violaceum, while four were specific for the former and eight for the latter. Phylogenetic analysis of secreted proteases reveals considerable expansion and conservation among the analyzed species. Multilocus phylogeny and genome comparison of T. rubrum and T. violaceum underlined their close affinity. The possibility that they represent a single species exhibiting different phenotypes due to different localizations on the human body is discussed.