The intestinal microbiota is a complex community of bacteria, archaea, viruses, protists and fungi
. Although the composition of bacterial constituents has been linked to immune homeostasis and ...infectious susceptibility
, the role of non-bacterial constituents and cross-kingdom microbial interactions in these processes is poorly understood
. Fungi represent a major cause of infectious morbidity and mortality in immunocompromised individuals, although the relationship of intestinal fungi (that is, the mycobiota) with fungal bloodstream infections remains undefined
. We integrated an optimized bioinformatics pipeline with high-resolution mycobiota sequencing and comparative genomic analyses of fecal and blood specimens from recipients of allogeneic hematopoietic cell transplant. Patients with Candida bloodstream infection experienced a prior marked intestinal expansion of pathogenic Candida species; this expansion consisted of a complex dynamic between multiple species and subspecies with a stochastic translocation pattern into the bloodstream. The intestinal expansion of pathogenic Candida spp. was associated with a substantial loss in bacterial burden and diversity, particularly in the anaerobes. Thus, simultaneous analysis of intestinal fungi and bacteria identifies dysbiosis states across kingdoms that may promote fungal translocation and facilitate invasive disease. These findings support microbiota-driven approaches to identify patients at risk of fungal bloodstream infections for pre-emptive therapeutic intervention.
As of 10 April 2020, New York State had 180,458 cases of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and 9,385 reported deaths. Patients with cancer comprised 8.4% of deceased ...individuals
. Population-based studies from China and Italy suggested a higher coronavirus disease 2019 (COVID-19) death rate in patients with cancer
, although there is a knowledge gap as to which aspects of cancer and its treatment confer risk of severe COVID-19
. This information is critical to balance the competing safety considerations of reducing SARS-CoV-2 exposure and cancer treatment continuation. From 10 March to 7 April 2020, 423 cases of symptomatic COVID-19 were diagnosed at Memorial Sloan Kettering Cancer Center (from a total of 2,035 patients with cancer tested). Of these, 40% were hospitalized for COVID-19, 20% developed severe respiratory illness (including 9% who required mechanical ventilation) and 12% died within 30 d. Age older than 65 years and treatment with immune checkpoint inhibitors (ICIs) were predictors for hospitalization and severe disease, whereas receipt of chemotherapy and major surgery were not. Overall, COVID-19 in patients with cancer is marked by substantial rates of hospitalization and severe outcomes. The association observed between ICI and COVID-19 outcomes in our study will need further interrogation in tumor-specific cohorts.
Anemia is a common complication of malaria that is characterized by the loss of infected and uninfected erythrocytes. In mouse malaria models, clearance of uninfected erythrocytes is promoted by ...autoimmune anti-phosphatidylserine (PS) antibodies produced by T-bet
B-cells, which bind to exposed PS in erythrocytes, but the mechanism in patients is still unclear. In
patients with anemia, we show that atypical memory FcRL5
T-bet
B-cells are expanded and associate both with higher levels of anti-PS antibodies in plasma and with the development of anemia in these patients. No association of anti-PS antibodies or anemia with other B-cell subsets and no association of other antibody specificities with FcRL5
T-bet
B-cells is observed, revealing high specificity in this response. We also identify FcRL5
T-bet
B-cells as producers of anti-PS antibodies in ex vivo cultures of naïve human peripheral blood mononuclear cells (PBMC) stimulated with
-infected erythrocyte lysates. These data define a crucial role for atypical memory B-cells and anti-PS autoantibodies in human malarial anemia.
Ghana is among the high-burden countries for malaria infections and recently reported a notable increase in malaria cases. While asymptomatic parasitaemia is increasingly recognized as a hurdle for ...malaria elimination, studies on asymptomatic malaria are scarce, and usually focus on children and on non-falciparum species. The present study aims to assess the prevalence of asymptomatic Plasmodium falciparum and non-falciparum infections in Ghanaian adults in the Ashanti region during the high transmission season.
Asymptomatic adult residents from five villages in the Ashanti Region, Ghana, were screened for Plasmodium species by rapid diagnostic test (RDT) and polymerase chain reaction (PCR) during the rainy season. Samples tested positive were subtyped using species-specific real-time PCR. For all Plasmodium ovale infections additional sub-species identification was performed.
Molecular prevalence of asymptomatic Plasmodium infection was 284/391 (73%); only 126 (32%) infections were detected by RDT. While 266 (68%) participants were infected with Plasmodium falciparum, 33 (8%) were infected with Plasmodium malariae and 34 (9%) with P. ovale. The sub-species P. ovale curtisi and P. ovale wallikeri were identified to similar proportions. Non-falciparum infections usually presented as mixed infections with P. falciparum.
Most adult residents in the Ghanaian forest zone are asymptomatic Plasmodium carriers. The high Plasmodium prevalence not detected by RDT in adults highlights that malaria eradication efforts must target all members of the population. Beneath Plasmodium falciparum, screening and treatment must also include infections with P. malariae, P. o. curtisi and P. o. wallikeri.
We analyzed the genomes of 170 C. parapsilosis isolates and identified multiple copy number variations (CNVs). We identified two genes,
(
) and
(
), each of which was the target of multiple ...independent amplification events. Phylogenetic analysis shows that most of these amplifications originated only once. For
, which encodes a putative arsenate transporter, 8 distinct CNVs were identified, ranging in size from 2.3 kb to 10.5 kb with 3 to 23 copies. For
, 16 distinct CNVs were identified, ranging in size from 0.3 kb to 4.5 kb with 2 to ~50 copies. One unusual amplification resulted in a DUP-TRP/INV-DUP structure similar to some human CNVs.
encodes a putative phosphatidylcholine (PC) floppase which is known to regulate the inward translocation of PC in Candida albicans. We found that an increased copy number of
correlated with resistance to miltefosine, an alkylphosphocholine drug that affects PC metabolism. Additionally, we conducted an adaptive laboratory evolution experiment in which two C. parapsilosis isolates were cultured in increasing concentrations of miltefosine. Two genes,
and
, coding for putative PC flippases homologous to S. cerevisiae
gained homozygous protein-disrupting mutations in the evolved strains. Overall, our results show that C. parapsilosis can gain resistance to miltefosine, a drug that has recently been granted orphan drug designation approval by the United States Food and Drug Administration for the treatment of invasive candidiasis, through both CNVs or loss-of-function alleles in one of the flippase genes.
Copy number variations (CNVs) are an important source of genomic diversity that have been associated with drug resistance. We identify two unusual CNVs in the human fungal pathogen Candida parapsilosis. Both target a single gene (
or
), and they have occurred multiple times in multiple isolates. The copy number of
, a putative floppase that controls the inward translocation of lipids in the cell membrane, correlates with resistance to miltefosine, a derivative of phosphatidylcholine (PC) that was originally developed as an anticancer drug. In 2021, miltefosine was designated an orphan drug by the United States Food and Drug Administration for the treatment of invasive candidiasis. Importantly, we find that resistance to miltefosine is also caused by mutations in flippases, which control the outward movement of lipids, and that many C. parapsilosis isolates are prone to easily acquiring an increased resistance to miltefosine.
Allogeneic haematopoietic cell transplantation (allo-HCT) induces profound shifts in the intestinal bacterial microbiota. The dynamics of intestinal fungi and their impact on clinical outcomes during ...allo-HCT are not fully understood. Here we combined parallel high-throughput fungal ITS1 amplicon sequencing, bacterial 16S amplicon sequencing and fungal cultures of 1,279 faecal samples from a cohort of 156 patients undergoing allo-HCT to reveal potential trans-kingdom dynamics and their association with patient outcomes. We saw that the overall density and the biodiversity of intestinal fungi were stable during allo-HCT but the species composition changed drastically from day to day. We identified a subset of patients with fungal dysbiosis defined by culture positivity (n = 53) and stable expansion of Candida parapsilosis complex species (n = 19). They presented with distinct trans-kingdom microbiota profiles, characterized by a decreased intestinal bacterial biomass. These patients had worse overall survival and higher transplant-related mortality independent of candidaemia. This expands our understanding of the clinical significance of the mycobiota and suggests that targeting fungal dysbiosis may help to improve long-term patient survival.
Previous studies have documented a spectrum of brain magnetic resonance imaging (MRI) abnormalities in patients with cerebral malaria, but little is known about the prevalence of such abnormalities ...in patients with non-cerebral malaria. The aim of this study was to assess the frequency of brain MRI findings in returning travellers with non-cerebral malaria.
A total of 17 inpatients with microscopically confirmed Plasmodium falciparum non-cerebral malaria underwent structural brain MRI at 3.0 Tesla, including susceptibility-weighted imaging (SWI). Presence of imaging findings was recorded and correlated with clinical findings and parasitaemia.
Structural brain abnormalities included a hyperintense lesion of the splenium on T2-weighted imaging (n = 3) accompanied by visible diffusion restriction (n = 2). Isolated brain microhaemorrhage was detected in 3 patients. T2-hyperintense signal abnormalities of the white matter ranged from absent to diffuse (n = 10 had 0-5 lesions, n = 5 had 5-20 lesions and 2 patients had more than 50 lesions). Imaging findings were not associated with parasitaemia or HRP2 levels.
Brain MRI reveals a considerable frequency of T2-hyperintense splenial lesions in returning travellers with non-cerebral malaria, which appears to be independent of parasitaemia.
Parenteral artesunate has been shown to be a superior treatment option compared to parenteral quinine in adults and children with severe malaria. Little evidence, however, is available on long-term ...safety. Recently, cases of late-onset haemolysis after parenteral treatment with artesunate have been reported in European travellers with imported Plasmodium falciparum malaria. Therefore, an extended follow-up of adult patients treated for severe imported malaria was started in August 2011 at the University Medical Center Hamburg-Eppendorf. Until January 2012, three patients with hyperparasitaemia (range: 14-21%) were included for analysis. In all three patients, delayed haemolysis was detected in the second week after the first dose of intravenous artesunate. Reticulocyte production index remained inadequately low in the 7 - 14 days following the first dose of artesunate despite rapid parasite clearance. Post-treatment haemolysis after parenteral artesunate may be of clinical relevance in particular in imported severe malaria characterized by high parasite levels. Extended follow-up of at least 30 days including controls of haematological parameters after artesunate treatment seems to be indicated. Further investigations are needed to assess frequency and pathophysiological background of this complication.
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