No abstract

Fungal pathogens threaten human health both directly as infectious agents and indirectly by limiting crop production, and new approaches are desperately needed to combat fungal diseases [1]. There is a growing appreciation that mitochondrial functions contribute to the ability of fungal pathogens to cause disease and may be promising targets for new therapeutic approaches [2,3]. A number of excellent reviews provide insights into the roles of mitochondria in fungal pathogens; readers are directed to these reviews for information on connections between mitochondria and virulence, antifungal drug resistance and susceptibility, and cell wall synthesis [4][5][6][7][8]. Our intention in this review is to focus on recent studies that highlight mitochondrial connections to virulence, metal homeostasis, the response to stress, and metabolic adaptation, as summarized in Fig 1, for a selected set of fungi that are major agents of human disease: Aspergillus fumigatus, Candida albicans, and Cryptococcus neoformans [9]. A. fumigatus is the causative agent of noninvasive pulmonary infections (aspergillomas and chronic aspergillosis), allergic bronchopulmonary aspergillosis, and invasive pulmonary aspergillosis. C. albicans is a commensal in the human gut but can cause invasive candidiasis of the blood stream and internal organs, as well as diseases involving mucosal surfaces. Infections with C. neoformans generally begin in lung tissue, but the fungus has a propensity to disseminate to the brain to cause meningoencephalitis, a disease that is highly prevalent and often fatal in the HIV/AIDS population. These fungi have aerobic lifestyles dependent on mitochondria, and the involvement of the electron transport chain (ETC) emerges as a common theme in their ability to cause disease (Fig 2) [5,10,11].

ImportanceData on the epidemiology of mild to moderately severe COVID-19 are needed to inform public health guidance.ObjectiveTo evaluate associations between 2 or 3 doses of mRNA COVID-19 vaccine and attenuation of symptoms and viral RNA load across SARS-CoV-2 viral lineages.Design, Setting, and ParticipantsA prospective cohort study of essential and frontline workers in Arizona, Florida, Minnesota, Oregon, Texas, and Utah with COVID-19 infection confirmed by reverse transcriptase–polymerase chain reaction testing and lineage classified by whole genome sequencing of specimens self-collected weekly and at COVID-19 illness symptom onset. This analysis was conducted among 1199 participants with SARS-CoV-2 from December 14, 2020, to April 19, 2022, with follow-up until May 9, 2022, reported.ExposuresSARS-CoV-2 lineage (origin strain, Delta variant, Omicron variant) and COVID-19 vaccination status.Main Outcomes and MeasuresClinical outcomes included presence of symptoms, specific symptoms (including fever or chills), illness duration, and medical care seeking. Virologic outcomes included viral load by quantitative reverse transcriptase–polymerase chain reaction testing along with viral viability.ResultsAmong 1199 participants with COVID-19 infection (714 [59.5%] women; median age, 41 years), 14.0% were infected with the origin strain, 24.0% with the Delta variant, and 62.0% with the Omicron variant. Participants vaccinated with the second vaccine dose 14 to 149 days before Delta infection were significantly less likely to be symptomatic compared with unvaccinated participants (21/27 [77.8%] vs 74/77 [96.1%]; OR, 0.13 [95% CI, 0-0.6]) and, when symptomatic, those vaccinated with the third dose 7 to 149 days before infection were significantly less likely to report fever or chills (5/13 [38.5%] vs 62/73 [84.9%]; OR, 0.07 [95% CI, 0.0-0.3]) and reported significantly fewer days of symptoms (10.2 vs 16.4; difference, −6.1 [95% CI, −11.8 to −0.4] days). Among those with Omicron infection, the risk of symptomatic infection did not differ significantly for the 2-dose vaccination status vs unvaccinated status and was significantly higher for the 3-dose recipients vs those who were unvaccinated (327/370 [88.4%] vs 85/107 [79.4%]; OR, 2.0 [95% CI, 1.1-3.5]). Among symptomatic Omicron infections, those vaccinated with the third dose 7 to 149 days before infection compared with those who were unvaccinated were significantly less likely to report fever or chills (160/311 [51.5%] vs 64/81 [79.0%]; OR, 0.25 [95% CI, 0.1-0.5]) or seek medical care (45/308 [14.6%] vs 20/81 [24.7%]; OR, 0.45 [95% CI, 0.2-0.9]). Participants with Delta and Omicron infections who received the second dose 14 to 149 days before infection had a significantly lower mean viral load compared with unvaccinated participants (3 vs 4.1 log10 copies/μL; difference, −1.0 [95% CI, −1.7 to −0.2] for Delta and 2.8 vs 3.5 log10 copies/μL, difference, −1.0 [95% CI, −1.7 to −0.3] for Omicron).Conclusions and RelevanceIn a cohort of US essential and frontline workers with SARS-CoV-2 infections, recent vaccination with 2 or 3 mRNA vaccine doses less than 150 days before infection with Delta or Omicron variants, compared with being unvaccinated, was associated with attenuated symptoms, duration of illness, medical care seeking, or viral load for some comparisons, although the precision and statistical significance of specific estimates varied.

The group D staphylococcal phage P 1 was examined in the electron microscope after preparation by a variety of procedures. The virion was found to have an icosahedral capsid attached to a long contractile tail structure, the viral tail could be seen in partially contracted configurations. Morphological variants in the length of the sheath and needle were frequently found.