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Microbiology Spectrum Feb 2024spp. are host obligate fungal pathogens that can cause severe pneumonia in mammals and rely heavily on their host for essential nutrients. The lack of a sustainable...
spp. are host obligate fungal pathogens that can cause severe pneumonia in mammals and rely heavily on their host for essential nutrients. The lack of a sustainable culture system poses challenges in understanding their metabolism, and the acquisition of essential nutrients from host lungs remains unexplored. Transmission electron micrographs show that extracellular vesicles (EVs) are found near spp. within the lung. We hypothesized that EVs transport essential nutrients to the fungi during infection. To investigate this, EVs from - and -infected rodents were biochemically and functionally characterized. These EVs contained host proteins involved in cellular, metabolic, and immune processes as well as proteins with homologs found in other fungal EV proteomes, indicating that may release EVs. Notably, EV uptake by indicated their potential involvement in nutrient acquisition and a possibility for using engineered EVs for efficient therapeutic delivery. However, EVs added to did not show increased growth or viability, implying that additional nutrients or factors are necessary to support their metabolic requirements. Exposure of macrophages to EVs increased proinflammatory cytokine levels but did not affect macrophages' ability to kill or phagocytose . These findings provide vital insights into and host EV interactions, yet the mechanisms underlying 's survival in the lung remain uncertain. These studies are the first to isolate, characterize, and functionally assess EVs from -infected rodents, promising to enhance our understanding of host-pathogen dynamics and therapeutic potential.IMPORTANCE spp. are fungal pathogens that can cause severe pneumonia in mammals, relying heavily on the host for essential nutrients. The absence of an culture system poses challenges in understanding their metabolism, and the acquisition of vital nutrients from host lungs remains unexplored. Extracellular vesicles (EVs) are found near spp., and it is hypothesized that these vesicles transport nutrients to the pathogenic fungi. proteins within the EVs showed homology to other fungal EV proteomes, suggesting that spp. release EVs. While EVs did not significantly enhance growth , displayed active uptake of these vesicles. Moreover, EVs induced proinflammatory cytokine production in macrophages without compromising their ability to combat . These findings provide valuable insights into EV dynamics during host-pathogen interactions in pneumonia. However, the precise underlying mechanisms remain uncertain. This research also raises the potential for engineered EVs in therapeutic applications.
Topics: Rats; Animals; Pneumocystis carinii; Proteome; Pneumonia, Pneumocystis; Pneumocystis; Macrophages; Mammals; Cytokines; Extracellular Vesicles
PubMed: 38236033
DOI: 10.1128/spectrum.03653-23 -
Chest Jun 2024Pneumocystis jirovecii pneumonia (PcP) remains associated with high rates of mortality, and the impact of immunocompromising underlying disease on the clinical... (Observational Study)
Observational Study
BACKGROUND
Pneumocystis jirovecii pneumonia (PcP) remains associated with high rates of mortality, and the impact of immunocompromising underlying disease on the clinical presentation, severity, and mortality of PcP has not been adequately evaluated.
RESEARCH QUESTION
Does the underlying disease and immunosuppression causing PcP impact the outcome and clinical presentation of the disease?
STUDY DESIGN AND METHODS
In this multicenter retrospective observational study, conducted from January 2011 to December 2021, all consecutive patients admitted with a proven or probable diagnosis of PcP according to the European Organisation for Research and Treatment of Cancer consensus definitions were included to assess the epidemiology and impact of underlying immunosuppressive diseases on overall and 90-day mortality.
RESULTS
Overall, 481 patients were included in the study; 180 (37.4%) were defined as proven PcP and 301 (62.6%) were defined as probable PcP. Patients with immune-mediated inflammatory diseases (IMIDs) or solid tumors had a statistically poorer prognosis than other patients with PcP at day 90. In multivariate analysis, among the HIV-negative population, solid tumor underlying disease (OR, 5.47; 95% CI, 2.16-14.1; P < .001), IMIDs (OR, 2.19; 95% CI, 1.05-4.60; P = .037), long-term corticosteroid exposure (OR, 2.07; 95% CI, 1.03-4.31; P = .045), cysts in sputum/BAL smears (OR, 1.92; 95% CI, 1.02-3.62; P = .043), and SOFA score at admission (OR, 1.58; 95% CI, 1.39-1.82; P < .001) were independently associated with 90-day mortality. Prior corticotherapy was the only immunosuppressant associated with 90-day mortality (OR, 1.67; 95% CI, 1.03-2.71; P = .035), especially for a prednisone daily dose ≥ 10 mg (OR, 1.80; 95% CI, 1.14-2.85; P = .010).
INTERPRETATION
Among patients who were HIV-negative, long-term corticosteroid prior to PcP diagnosis was independently associated with increased 90-day mortality, specifically in patients with IMIDs. These results highlight both the needs for PcP prophylaxis in patients with IMIDs and to early consider PcP curative treatment in severe pneumonia among patients with IMIDs.
Topics: Humans; Pneumonia, Pneumocystis; Male; Female; Retrospective Studies; Middle Aged; Prognosis; Aged; Pneumocystis carinii; Immunocompromised Host; Risk Factors
PubMed: 38215935
DOI: 10.1016/j.chest.2024.01.015 -
Diagnostic Microbiology and Infectious... Mar 2024Accurate differentiation between Pneumocystis jirovecii (Pj) infection and colonization is crucial for effective treatment.
BACKGROUND
Accurate differentiation between Pneumocystis jirovecii (Pj) infection and colonization is crucial for effective treatment.
METHODS
From September 2016 to June 2022, 89 immunocompromised patients with unexplained lung infiltrates and clinical suspicion of Pj pneumonia were enrolled at Peking University People's Hospital. Bronchoalveolar lavage fluid (BALF) of these patients were detected by quantitative PCR (qPCR) and droplet digital PCR (ddPCR).
RESULTS
The performance of ddPCR was superior to qPCR in detecting Pj infection. Area under the curve was 0.97 (95 %CI: 0.94-1) for ddPCR of the BALF in all patients. The optimal threshold value for discriminating Pj infection from colonization by ddPCR was 13.98 copies/test, with a sensitivity of 97.96 %, specificity of 85.71 %. No obvious correlation between ddPCR copy number and disease severity was observed.
CONCLUSION
BALF ddPCR exhibits robust potential in detecting Pj and effectively discriminating colonization and infection.
Topics: Humans; Pneumonia, Pneumocystis; Pneumocystis carinii; Bronchoalveolar Lavage Fluid; Diagnosis, Differential; Real-Time Polymerase Chain Reaction; Sensitivity and Specificity
PubMed: 38184984
DOI: 10.1016/j.diagmicrobio.2023.116168 -
BMC Pulmonary Medicine Jan 2024Pneumocystis jirovecii pneumonia (PCP) could be fatal to patients without human immunodeficiency virus (HIV) infection. Current diagnostic methods are either invasive or... (Randomized Controlled Trial)
Randomized Controlled Trial
BACKGROUND
Pneumocystis jirovecii pneumonia (PCP) could be fatal to patients without human immunodeficiency virus (HIV) infection. Current diagnostic methods are either invasive or inaccurate. We aimed to establish an accurate and non-invasive radiomics-based way to identify the risk of PCP infection in non-HIV patients with computed tomography (CT) manifestation of pneumonia.
METHODS
This is a retrospective study including non-HIV patients hospitalized for suspected PCP from January 2010 to December 2022 in one hospital. The patients were randomized in a 7:3 ratio into training and validation cohorts. Computed tomography (CT)-based radiomics features were extracted automatically and used to construct a radiomics model. A diagnostic model with traditional clinical and CT features was also built. The area under the curve (AUC) were calculated and used to evaluate the diagnostic performance of the models. The combination of the radiomics features and serum β-D-glucan levels was also evaluated for PCP diagnosis.
RESULTS
A total of 140 patients (PCP: N = 61, non-PCP: N = 79) were randomized into training (N = 97) and validation (N = 43) cohorts. The radiomics model consisting of nine radiomic features performed significantly better (AUC = 0.954; 95% CI: 0.898-1.000) than the traditional model consisting of serum β-D-glucan levels (AUC = 0.752; 95% CI: 0.597-0.908) in identifying PCP (P = 0.002). The combination of radiomics features and serum β-D-glucan levels showed an accuracy of 95.8% for identifying PCP infection (positive predictive value: 95.7%, negative predictive value: 95.8%).
CONCLUSIONS
Radiomics showed good diagnostic performance in differentiating PCP from other types of pneumonia in non-HIV patients. A combined diagnostic method including radiomics and serum β-D-glucan has the potential to provide an accurate and non-invasive way to identify the risk of PCP infection in non-HIV patients with CT manifestation of pneumonia.
TRIAL REGISTRATION
ClinicalTrials.gov (NCT05701631).
Topics: Humans; Pneumonia, Pneumocystis; Retrospective Studies; Pneumocystis carinii; Radiomics; beta-Glucans; HIV Infections; Glucans; Tomography
PubMed: 38167022
DOI: 10.1186/s12890-023-02827-4 -
Annals of Hematology Apr 2024Patients with multiple myeloma (MM) are at high risk for infections, including opportunistic infections such as Pneumocystis jirovecii pneumonia (PJP). We conducted a...
Patients with multiple myeloma (MM) are at high risk for infections, including opportunistic infections such as Pneumocystis jirovecii pneumonia (PJP). We conducted a retrospective analysis of patients with MM developing PJP over a 6-year period between January 2016 and December 2021 at the University Hospital of Würzburg by screening cases of microbiologically documented PJP. A total of 201 positive results for P. jirovecii in respiratory specimens were retrospectively retrieved through our microbiology database. Of these cases, 13 patients with MM fulfilled the definition of probable PJP according to EORTC fungal disease definitions. We observed two peaks in PJP incidence, one after stem cell transplantation during first-line treatment (n = 5) and the other in heavily pretreated patients with six or more prior lines of therapy (n = 6). There was high morbidity with nine (69%) patients admitted to the ICU, seven of whom (78%) required mechanical ventilation, and high mortality (62%, n = 8). Notably, only two of the 13 patients (15%) had received PJP prophylaxis. The main reason for discontinuation of prophylaxis with trimethoprim-sulfamethoxazole was grade IV neutropenia. The observed morbidity and mortality of PJP in MM patients are significant and even higher than reported for patients with other hematologic malignancies. According to most current guidelines, the use of prophylaxis would have been clearly recommended in no more than three (23%) of the 13 patients. This illustrates the need to critically reconsider the indications for PJP prophylaxis, which remain incompletely defined.
Topics: Humans; Pneumonia, Pneumocystis; Retrospective Studies; Pneumocystis carinii; Multiple Myeloma; Prognosis
PubMed: 38123879
DOI: 10.1007/s00277-023-05586-8 -
International Journal of Molecular... Nov 2023pneumonia (PCP) is a significant cause of morbidity and mortality in immunocompromised people. The widespread use of trimethoprim-sulfamethoxazole (TMP-SMZ) for the...
pneumonia (PCP) is a significant cause of morbidity and mortality in immunocompromised people. The widespread use of trimethoprim-sulfamethoxazole (TMP-SMZ) for the treatment and prophylaxis of opportunistic infections (including PCP) has led to an increased selection of TMP-SMZ-resistant microorganisms. Sulfa/sulfone resistance has been demonstrated to result from specific point mutations in the gene. This study aims to investigate the presence of gene mutations among isolates from Bulgarian patients with PCP. A total of 326 patients were examined via real-time PCR targeting the mitochondrial large subunit gene and further at the locus. DNA was detected in 50 (15.34%) specimens. A 370 bp locus fragment was successfully amplified in 21 samples from 19 PCP-positive patients, which was then purified, sequenced, and used for phylogenetic analysis. Based on the sequencing analysis, all ( = 21) isolates showed genotype 1 (the wild type, with the nucleotide sequence ACA CGG CCT at codons 55, 56, and 57, respectively). In conclusion, infections caused by mutants potentially resistant to sulfonamides are still rare events in Bulgaria. genotype 1 at codons 55 and 57 is the predominant strain in the country.
Topics: Humans; Pneumocystis carinii; Pneumonia, Pneumocystis; Dihydropteroate Synthase; Bulgaria; Phylogeny; Mutation; Trimethoprim, Sulfamethoxazole Drug Combination; Codon
PubMed: 38069248
DOI: 10.3390/ijms242316927 -
BMC Infectious Diseases Nov 2023Droplet digital PCR (ddPCR) is a novel assay to detect pneumocystis jjrovecii (Pj) which has been defined to be more sensitive than qPCR in recent studies. We aimed to...
OBJECTIVE
Droplet digital PCR (ddPCR) is a novel assay to detect pneumocystis jjrovecii (Pj) which has been defined to be more sensitive than qPCR in recent studies. We aimed to explore whether clinical features of pneumocystis pneumonia (PCP) were associated with ddPCR copy numbers of Pj.
METHODS
A total of 48 PCP patients were retrospectively included. Pj detection was implemented by ddPCR assay within 4 h. Bronchoalveolar fluid (BALF) samples were collected from 48 patients with molecular diagnosis as PCP via metagenomic next generation sequencing (mNGS) or quantitative PCR detection. Univariate and multivariate logistic regression were performed to screen out possible indicators for the severity of PCP. The patients were divided into two groups according to ddPCR copy numbers, and their clinical features were further analyzed.
RESULTS
Pj loading was a pro rata increase with serum (1,3)-beta-D glucan, D-dimmer, neutrophil percentage, procalcitonin and BALF polymorphonuclear leucocyte percentage, while negative correlation with albumin, PaO2/FiO2, BALF cell count, and BALF lymphocyte percentage. D-dimmer and ddPCR copy number of Pj were independent indicators for moderate/severe PCP patients with PaO2/FiO2 lower than 300. We made a ROC analysis of ddPCR copy number of Pj for PaO2/FiO2 index and grouped the patients according to the cut-off value (2.75). The high copy numbers group was characterized by higher level of inflammatory markers. Compared to low copy number group, there was lower level of the total cell count while higher level of polymorphonuclear leucocyte percentage in BALF in the high copy numbers group. Different from patients with high copy numbers, those with high copy numbers had a tendency to develop more severe complications and required advanced respiratory support.
CONCLUSION
The scenarios of patients infected with high ddPCR copy numbers of Pj showed more adverse clinical conditions. Pj loading could reflect the severity of PCP to some extent.
Topics: Humans; Pneumonia, Pneumocystis; Retrospective Studies; DNA Copy Number Variations; Bronchoalveolar Lavage Fluid; Polymerase Chain Reaction; Pneumocystis; Respiratory Distress Syndrome; Pneumocystis carinii
PubMed: 38012564
DOI: 10.1186/s12879-023-08580-7 -
BMC Pulmonary Medicine Nov 2023Pneumocystis pneumonia (PCP) is a life-threatening pulmonary fungal infection that predominantly affects immunocompromised individuals, including kidney transplant...
BACKGROUND
Pneumocystis pneumonia (PCP) is a life-threatening pulmonary fungal infection that predominantly affects immunocompromised individuals, including kidney transplant recipients. Recent years have witnessed a rising incidence of PCP in this vulnerable population, leading to graft loss and increased mortality. Immunosuppression, which is essential in transplant recipients, heightens susceptibility to viral and opportunistic infections, magnifying the clinical challenge. Concurrently, the global impact of coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has been profound. Kidney transplant recipients have faced severe outcomes when infected with SARS-CoV-2, often requiring intensive care. Co-infection with COVID-19 and PCP in this context represents a complex clinical scenario that requires precise management strategies, involving a delicate balance between immunosuppression and immune activation. Although there have been case reports on management of COVID-19 and PCP in kidney transplant recipients, guidance on how to tackle these infections when they occur concurrently remains limited.
CASE PRESENTATIONS
We have encountered four kidney transplant recipients with concurrent COVID-19 and PCP infection. These patients received comprehensive treatment that included adjustment of their maintenance immunosuppressive regimen, anti-pneumocystis therapy, treatment for COVID-19 and other infections, and symptomatic and supportive care. After this multifaceted treatment strategy, all of these patients improved significantly and had favorable outcomes.
CONCLUSIONS
We have successfully managed four kidney transplant recipients co-infected with COVID-19 and PCP. While PCP is a known complication of immunosuppressive therapy, its incidence in patients with COVID-19 highlights the complexity of dual infections. Our findings suggest that tailored immunosuppressive regimens, coupled with antiviral and antimicrobial therapies, can lead to clinical improvement in such cases. Further research is needed to refine risk assessment and therapeutic strategies, which will ultimately enhance the care of this vulnerable population.
Topics: Humans; Pneumonia, Pneumocystis; COVID-19; Kidney Transplantation; Retrospective Studies; Transplant Recipients; SARS-CoV-2; Immunosuppressive Agents; Pneumocystis carinii
PubMed: 37990199
DOI: 10.1186/s12890-023-02764-2 -
Annals of Clinical Microbiology and... Nov 2023The current study evaluated the diagnostic performance of serum (1,3)-beta-D Glucan (BDG) in differentiating PJP from P. jirovecii-colonization in HIV-uninfected...
OBJECTIVE
The current study evaluated the diagnostic performance of serum (1,3)-beta-D Glucan (BDG) in differentiating PJP from P. jirovecii-colonization in HIV-uninfected patients with P. jirovecii PCR-positive results.
METHODS
This was a single-center retrospective study between 2019 and 2021. The diagnosis of PJP was based on the following criteria: detection of P. jirovecii in sputum or BAL specimen by qPCR or microscopy; Meet at least two of the three criteria: (1) have respiratory symptoms of cough and/or dyspnea, hypoxia; (2) typical radiological picture findings; (3) receiving a complete PJP treatment. After exclusion, the participants were divided into derivation and validation cohorts. The derivation cohort defined the cut-off value of serum BDG. Then, it was verified using the validation cohort.
RESULTS
Two hundred and thirteen HIV-uninfected patients were enrolled, with 159 PJP and 54 P. jirovecii-colonized patients. BDG had outstanding specificity, LR, and PPV for PJP in both the derivation (90.00%, 8.900, and 96.43%) and the validation (91.67%, 9.176, and 96.30%) cohorts at ≥ 117.7 pg/mL. However, it had lower sensitivity and NPV in the derivation cohort (89.01% and 72.97%), which was even lower in the validation cohort (76.47% and 57.89%). Of note, BDG ≥ 117.7 pg/mL has insufficient diagnostic efficacy for PJP in patients with lung cancer, interstitial lung disease (ILD) and nephrotic syndrome. And although lymphocytes, B cells, and CD4 T cells in PJP patients were significantly lower than those in P. jirovecii-colonized patients, the number and proportion of peripheral blood lymphocytes did not affect the diagnostic efficacy of serum BDG.
CONCLUSIONS
Serum BDG ≥ 117.7 pg/mL could effectively distinguish P. jirovecii-colonization from infection in qPCR-positive HIV-uninfected patients with infectious diseases, solid tumors (excluding lung cancer), autoimmune or inflammatory disorders, and hematological malignancies. Of note, for patients with lung cancer, ILD, and nephrotic diseases, PJP should be cautiously excluded at BDG < 117.7 pg/mL.
Topics: Humans; Pneumonia, Pneumocystis; Pneumocystis carinii; Glucans; Retrospective Studies; beta-Glucans; Lung Neoplasms; HIV Infections; Lung Diseases, Interstitial
PubMed: 37986091
DOI: 10.1186/s12941-023-00650-7 -
BMC Infectious Diseases Nov 2023Cancer case during pregnancy is rare, but it is the second leading cause of maternal mortality. (Review)
Review
BACKGROUND
Cancer case during pregnancy is rare, but it is the second leading cause of maternal mortality.
CASE PRESENTATION
A-32-year old pregnant woman with a gestational age of 37 weeks was admitted to the hospital due to repeated coughing for 5 months. She received Veno-Venous Extracorporeal Membrane Oxygenation (V-V ECMO) treatment for severe hypoxemia after delivery. She was diagnosed with non-small cell lung cancer (NSCLC) with bone metastasis and pneumocystis pneumonia (PCP). She subsequently received anti-tumor therapy and anti-infective therapy. After treatment, her condition improved and she was weaned from ECMO. Two weeks after weaning ECMO, her condition worsened again. Her family chose palliative treatment, and she ultimately died.
CONCLUSIONS
NSCLC is rare during pregnancy. At present, there is still a lack of standardized methods to manage these cases. For theses cases, the clinician should be wary of opportunistic infections, such as pneumocystis jirovecii (P. jirovecii) and Elizabethkingia spp. Specialized medical teams with abundant experience and multidisciplinary discussions from the perspectives of the patient's clinical characteristics as well as preferences are crucial for developing individualized and the best approach.
Topics: Humans; Pregnancy; Female; Infant, Newborn; Pneumonia, Pneumocystis; Carcinoma, Non-Small-Cell Lung; Pregnant Women; Lung Neoplasms; Pneumocystis carinii
PubMed: 37964211
DOI: 10.1186/s12879-023-08790-z