Current Clinical Microbiology Reports最新文献

Purpose of review: For human fungal pathogens, sensory perception of extracellular pH is essential for colonisation of mammalian tissues and immune evasion. The molecular complexes that perceive and transmit the fungal pH signal are membrane-proximal and essential for virulence and are therefore of interest as novel antifungal drug targets. Intriguingly, the sensory machinery has evolved divergently in different fungal pathogens, yet spatial co-ordination of cellular components is conserved.

Recent findings: The recent discovery of a novel pH sensor in the basidiomycete pathogen Cryptococcus neformans highlights that, although the molecular conservation of fungal pH sensors is evolutionarily restricted, their subcellular localisation and coupling to essential components of the cellular ESCRT machinery are consistent features of the cellular pH sensing and adaptation mechanism. In both basidiomycetes and ascomycetes, the lipid composition of the plasma membrane to which pH sensing complexes are localised appears to have pivotal functional importance. Endocytosis of pH-sensing complexes occurs in multiple fungal species, but its relevance for signal transduction appears not to be universal.

Summary: Our overview of current understanding highlights conserved and divergent mechanisms of the pH sensing machinery in model and pathogenic fungal species, as well as important unanswered questions that must be addressed to inform the future study of such sensing mechanisms and to devise therapeutic strategies for manipulating them.

Purpose of review: Human fungal pathogens are rapidly increasing in incidence and readily able to evade the host immune responses. Our ability to study the genetic behind this has been limited due to the apparent lack of a sexual cycle and forward genetic tools. In this review, we discuss the evolution of mating, meiosis, and pathogenesis and if these processes are advantageous to pathogens.

Recent findings: This review summarises what is currently known about the sexual cycles of two important human fungal pathogens, Candida albicans and Candida glabrata. This includes the identification of parasexual cycle in C. albicans and the observed low levels of recombination in C. glabrata populations.

Summary: In this review, we present what is currently known about the mating types and mating/sexual cycles of two clinically important human fungal pathogens, Candida albicans and Candida glabrata. We discuss the evolution of meiosis using the knowledge that has been amassed from the decades of studying Saccharomyces cerevisiae and how this can be applied to fungal pathogens. We further discuss how the evolution of pathogenesis has played a role in influencing mating processes in human fungal pathogens and compare sexual cycles between C. albicans and C. glabrata, highlighting knowledge gaps and suggesting how these two fungi have evolved distinct mating niches to allow the development of disease in a human host.

Purpose of review: For this review, we use a One Health approach to examine two globally emerging public health threats related to antifungal drug resistance: triazole-resistant Aspergillus fumigatus infections, which can cause a life-threatening illness in immunocompromised hosts, and antifungal-resistant dermatophytosis, which is an aggressive skin infection caused by dermatophyte molds. We describe the state of current scientific knowledge and outline necessary public health actions to address each issue.

Recent findings: Recent evidence has identified the agricultural use of triazole fungicides as an important driver of triazole-resistant A. fumigatus infections. Antifungal-resistant dermatophyte infections are likely driven by the inappropriate use of antifungal drugs and antibacterial and corticosteroid creams.

Summary: This review highlights the need for a One Health approach to address emerging antifungal resistant infections, emphasizing judicious antifungal use to preserve available treatments; strengthened laboratory capacity to identify antifungal resistance; and improved human, animal, and environmental surveillance to detect emerging resistance, monitor trends, and evaluate the effectiveness of efforts to decrease spread.

Purpose of review: The introduction of MinION whole-genome sequencing technology greatly increased and simplified complete genome sequencing in various fields of science across the globe. Sequences have been generated from complex organisms to microorganisms and are stored in genome databases that are readily accessible by researchers. Various new software for genome analysis, along with upgrades to older software packages, are being generated. New protocols are also being validated that enable WGS technology to be rapidly and increasingly used for sequencing in field settings.

Recent findings: MinION WGS technology has been implemented in developed countries due to its advantages: portability, real-time analysis, and lower cost compared to other sequencing technologies. While these same advantages are critical in developing countries, MinION WGS technology is still under-utilized in resource-limited settings.

Summary: In this review, we look at the applications, advantages, challenges, and opportunities of using MinION WGS in resource-limited settings.

Purpose of review: Severe-acute respiratory coronavirus 2 (SARS-CoV-2) has been driving the health care delivery system for over 2 years. With time, many issues related to co-infections in COVID-19 patients are constantly surfacing. There have been numerous reports about various fungal co-infections in patients with COVID-19. The extent of severity of fungal pathogens has been recognized as a substantial cause of morbidity and mortality in this population. Awareness, understanding, and a systematic approach to managing fungal co-infections in COVID-19 patients are important. No guidelines have enumerated the stepwise approach to managing the fungal infections co-occurring with COVID-19. This review is intended to present an overview of the fungal co-infections in COVID-19 patients and their stepwise screening and management.

Recent findings: The most common fungal infections that have been reported to co-exist with COVID-19 are Candidemia, Aspergillosis, and Mucormycosis. Prevalence of co-infections in COVID-19 patients has been reported to be much higher in hospitalized COVID-19 patients, especially those in intensive care units. While clear pathogenetic mechanisms have not been delineated, COVID-19 patients are at a high risk of invasive fungal infections.

Summary: As secondary fungal infections have been challenging to treat in COVID-19 patients, as they tend to affect the critically ill or immunocompromised patients, a delay in diagnosis and treatment may be fatal. Antifungal drugs should be initiated with caution after carefully assessing the immune status of the patients, drug interactions, and adverse effects. The crucial factors in successfully treating fungal infections in COVID-19 patients are optimal diagnostic approach, routine screening, and timely initiation of antifungal therapy.