Murine response to the opportunistic bacterium Pseudomonas aeruginosa infection in gut dysbiosis caused by 5-fluorouracil chemotherapy-induced mucositis.

AIMS: This manuscript aims to explain the relationship between mucositis caused by 5-FU over gut bacterial species and susceptibility to opportunistic infection caused by P. aeruginosa. MAIN METHODS: BALB/c mice were intraperitoneally treated with PBS or 5-FU. Bodyweight and faecal consistency were checked daily. Mice faecal DNA was extracted, and bacterial phylogenetic groups were analysed using qPCR or high-throughput sequencing. Immunofluorescence was used to evaluate BMDM activation by mice-treated faecal content. Mice were challenged intratracheally with virulent P. aeruginosa, and the CFU and histology were analysed. Faecal microbiota were transplanted to evaluate the gut microbiota and resistance to pulmonary P. aeruginosa recovery. KEY FINDINGS: The animals treated with 5-FU presented mucositis with great weight loss, altered faecal consistency, bacterial gut dysbiosis and histological changes in the intestinal mucosa. Mice under 5-FU treatment were more susceptible to lung infection by the bacteria P. aeruginosa and had more extensive tissue damage during their lung infection with greater pro-inflammatory gene expression. It was observed that the mucositis remained in the groups with 5-FU even with the FMT. The results caused by mucositis in animals that received allogeneic FMT were reversed, however, with a decrease in P. aeruginosa susceptibility in animals treated with 5-FU and allogeneic FMT compared to animals treated with 5-FU and autologous FMT. SIGNIFICANCE: Treatment with 5-FU in a murine model makes it more susceptible to pulmonary infection by the bacterium P. aeruginosa, FMT offers an opportunity to protect against this susceptibility to infection.

Disseminated Coccidioidomycosis as the First Presentation of a C-Terminal NFKB2 Pathogenic Variant: A Case Report and Review of the Literature.

INTRODUCTION: Although most cases of coccidioidomycosis are subclinical or self-limited respiratory disease, 1% lead to extrathoracic dissemination and become fatal, especially in patients with an associated immunodeficiency. Up to 30%-50% of patients with defects in cell-mediated immunity, those with AIDS and recipients of solid-organ transplants, may develop disseminated coccidioidomycosis (DC). Within the primary immunodeficiencies, an uncommon group is caused by C-terminal NFKB2 pathogenic variants. MATERIALS AND METHODS: We performed a literature search of core databases. Written informed consent for the study and for publication was obtained. CASE PRESENTATION: A 7-year-old Mexican girl, eldest of 3 sisters, no relevant family history, and a history of recurrent upper respiratory infections and alopecia totalis was admitted with DC involving pulmonary, soft tissue, skin, bone and joint compromise. The immunodeficiency assessment showed low IgM and NK cells. We found an NFKB2 de novo heterozygous nonsense mutation of c.2611C>T (p.Gln871*). She was treated with liposomal amphotericin B and itraconazole with surgical debridement. The clinical phenotype of this primary immunodeficiency is characterized by antibody deficiency and associated broncho-pulmonary predisposition to infection, but moreover also opportunistic infections and autoimmunity, most recognizable alopecia and adrenocorticotropic hormone-deficiency. After 1 year of her discharge, she continues under surveillance with antifungal therapy with itraconazole and replacement intravenous immunoglobulin until today. CONCLUSION: This is the first case report of DC in a patient with an NFKB2 pathogenic variant and it illustrates the importance of screening for primary immunodeficiencies in patients with disseminated fungal infections.

NLRP3 Inflammasome Contributes to Host Defense Against Talaromyces marneffei Infection.

Talaromyce marneffei is an important thermally dimorphic pathogen causing disseminated mycoses in immunocompromised individuals in southeast Asia. Previous studies have suggested that NLRP3 inflammasome plays a critical role in antifungal immunity. However, the mechanism underlying the role of NLRP3 inflammasome activation in host defense against T. marneffei remains unclear. We show that T. marneffei yeasts but not conidia induce potent IL-1ß production. The IL-1ß response to T. marneffei yeasts is differently regulated in different cell types; T. marneffei yeasts alone are able to induce IL-1ß production in human PBMCs and monocytes, whereas LPS priming is essential for IL-1ß response to yeasts. We also find that Dectin-1/Syk signaling pathway mediates pro-IL-1ß production, and NLRP3-ASC-caspase-1 inflammasome is assembled to trigger the processing of pro-IL-1ß into IL-1ß. In vivo, mice deficient in NLRP3 or caspase-1 exhibit higher mortality rate and fungal load compared to wild-type mice after systemic T. marneffei infection, which correlates with the diminished recruitment of CD4 T cells into granulomas in knockout mice. Thus, our study first demonstrates that NLRP3 inflammasome contributes to host defense against T. marneffei infection.

Mucormycotic osteomyelitis of maxilla post-COVID patient: a case report.

Fungal osteomyelitis is a life-threatening and seldom seen opportunistic infection. It is commonly an affectation of the nose and paranasal sinuses within the orofacial region. It is an aggressive infection that needs to be addressed promptly to prevent fatal consequences. The mode of infection is via the inhalation route and infection begins initially in the nose and paranasal sinuses with subsequent invasion into the vascular tissue, eventually leading to thrombosis and necrosis of nearby hard and soft tissues. Here, we report a case of a 31-year-old male who presented with pain over the upper jaw that was sudden in onset, continuous, dull aching, radiating towards forehead and neck of the left side, aggravates on mastication and relives on its own. He had a history of uncontrolled diabetes mellitus. On further investigation, using diagnostic and Interventional aids, a final diagnosis of mucormycotic osteomyelitis of the maxilla was made.

Lymphadenopathy Associated With Neutralizing Anti-interferon-gamma Autoantibodies Could Have Monoclonal T-cell Proliferation Indistinguishable From Malignant Lymphoma and Treatable by Antibiotics: A Clinicopathologic Study.

Early recognition of adult-onset immunodeficiency associated with neutralizing anti-interferon gamma autoantibodies (anti-IFNγ Abs) remains difficult, and misdiagnoses have been reported. Although febrile lymphadenopathy is among the most common initial manifestations of this disorder, no comprehensive clinicopathologic analysis of lymphadenopathy in patients with anti-IFNγ Abs has been reported. Here, we describe 26 lymph node biopsy specimens from 16 patients. All patients exhibited concurrent disseminated nontuberculous mycobacterial infections, and 31% received a tentative diagnosis of lymphoma at initial presentation. We found 3 distinct histomorphologic patterns: well-formed granuloma (46%), suppurative inflammation or loose histiocytic aggregates (31%), and lymphoproliferative disorder (LPD, 23%). The latter shared some of the features of malignant T-cell lymphoma, IgG4-related disease, and multicentric Castleman disease. Half of the specimens with LPD had monoclonal T cells, and 33.3% were indistinguishable from angioimmunoblastic T-cell lymphoma as per current diagnostic criteria. All lymphadenopathy with LPD features regressed with antibiotics without administration of cytotoxic chemotherapy or immunotherapy. The median follow-up time was 4.3 years. Our study highlights the substantial challenge of distinguishing between lymphoma and other benign lymphadenopathy in the setting of neutralizing anti-IFNγ Abs. Increased vigilance and multidisciplinary discussion among clinicians and pathologists are required to achieve the most appropriate diagnosis and management.

Rhinocerebral mucormycosis secondary to severe acute pancreatitis and diabetic ketoacidosis: a case report.

INTRODUCTION: Rhinocerebral mucormycosis is a rare and severe form of opportunistic fungal infection that can develop rapidly and cause significant mortality, particularly among diabetic patients suffering from ketoacidosis. Diagnosing rhinocerebral mucormycosis during the early stages of infection is challenging. CASE PRESENTATION: We describe a case of rhinocerebral mucormycosis secondary to severe acute pancreatitis in a patient suffering from diabetic ketoacidosis. In this case, the condition was not diagnosed during the optimal treatment window. we therefore provide a thorough overview of related clinical findings and histopathological characteristics, and we discuss potential differential diagnoses. CONCLUSIONS: In summary, we described a case of rhinocerebral mucormycosis secondary to severe acute pancreatitis in a patient suffering from diabetic ketoacidosis, with the optimal treatment window for this condition having been missed. This report suggests that a definitive mucormycosis diagnosis can be made based upon tissue biopsy that reveals the presence of characteristic hyphae. Early diagnosis and treatment are essential in order to improve patient prognosis.

Co-infection of Pneumocystis jirovecii pneumonia and pulmonary CMV in a infant with X-linked severe combined immunodeficiency.

We herein report a rare case of co-infection of Pneumocystis jirovecii pneumonia and pulmonary CMV in a 3-month-old infant with X-linked severe combined immunodeficiency, in which diagnostic clues were obtained from the bronchoalveolar lavage fluid. We focus on the value of cytological diagnosis of P. jirovecii pneumonia and pulmonary CMV in the bronchoalveolar lavage fluid. Recognizing morphological characteristics of these pathogenic microorganisms is important to get timely diagnosis and treatment for the patients. Furthermore, repeated severe infections in infants should remind us to screen for immunosuppressed states.

EBV-positive Mucocutaneous Ulcer With Small Lymphocytic Infiltration Mimicking Nonspecific Ulceration.

Epstein-Barr virus (EBV)-associated lymphoproliferative disorder may resemble nonspecific inflammation. We report 3 cases of immunosuppressed adult patients with small lymphocytic EBV ulcers in the skin and oral mucosa, characterized by a lack of atypical lymphocytic infiltration. All 3 cases were diagnosed in routine practice. For comparisons, cases of conventional Epstein-Barr virus-positive mucocutaneous ulcer (EBVMCU) were reviewed which were extracted from our pathology archives (n=11). The present patients were 2 females and 1 male, aged above 70 years. The primary disease was rheumatoid arthritis (n=2) and dermatitis herpetiformis (n=1). The main source of immunosuppression was prednisolone (n=2) and methotrexate (n=1). The ulcers were located in the oral cavity, buttock, and/or external genitalia. Histology evaluation revealed nonspecific lymphocytic infiltration. Epstein-Barr virus-encoded small RNA (EBER)-positive cells were small and coexpressed CD20. The number of EBER-positive cells ranged from 52 to 132/HPF, which was within the range of that observed in the reviewed conventional EBVMCUs (range, 48 to 1328; median, 121). All 3 cases regressed spontaneously or by the reduction of immunosuppressants. Although the present cases lacked cytologic atypia, those clinical course and loads of EBER-positive cells (>50/HPF) suggested EBV involvement. Current cases of EBVMCU with small lymphocytic infiltration underscore the need for EBER in situ hybridization when an etiology of ulcer with predominant lymphocytes in an immunosuppressed patient is unclear.

Problemas clínicos en Micología Médica: problema número 55 / Clinical problems in Medical Mycology: problem number 55

Paciente de 31 años y sexo femenino que nació y vivió en la Ciudad Autónoma de Buenos Aires, Argentina, en vivienda con sanitarios completos y necesidades básicas satisfechas. Refirió haber realizado viajes a la costa atlántica (provincia de Buenos Aires). Fue fumadora de 10 cigarrillos al día desde los 18 hasta los 30 años. No consumía alcohol. Como antecedentes acerca de su estado de salud solo dijo haber padecido varicela en la infancia. Acudió a la consulta por disnea clase funcional II/III de 3 semanas de evolución y fiebre durante los últimos 3 días

A 31-year-old woman, with signs of HIV infection (oral thrush, weight loss, asthenia) presented to our hospital with dyspnea and fever. A rapid HIV test yielded a positive result, and cryptococcal capsular antigen was detected in serum. In the mycological study of the clinical respiratory samples, yeasts compatible with Cryptococcus were observed under light microscope in a wet mount; structures compatible with Pneumocystis jirovecii were also observed in Giemsa stain. Treatment for both pathologies was prescribed but, unfortunately, the patient died 7 days after. The finding of two etiologic agents in the same clinical picture is rare but not exceptional, and it always must be considered in immunocompromised hosts

Opportunistic Invasive Fungal Infections Mimicking Progression of Non-Small-Cell Lung Cancer.

BACKGROUND: Many studies have shown that invasive pulmonary aspergillosis, cryptococcosis, and mucormycosis can mimic radiographic and clinical features of primary lung cancer. However, more research surveying the incidence and outcomes of these fungal infections among patients with a history of lung cancer is needed. The aim of this study was to describe the occurrence and clinical outcomes of opportunistic invasive fungal infections that can mimic tumors in non-small-cell lung cancer patients. PATIENTS AND METHODS: Patients seen at Stanford University Medical Center from January 1, 2007, to May 1, 2020, with pulmonary aspergillosis, cryptococcosis, or mucormycosis after non-small-cell lung cancer (NSCLC) diagnosis were reviewed. The European Organization for Research and Treatment of Cancer National Institute of Allergy and Infectious Diseases Mycoses Study Group criteria was used to classify patients with evidence of proven or probable invasive fungal infection within our cohort. RESULTS: A total of 12 patients with proven or probable invasive mold infection (including 8 cases of aspergillosis) and 1 patient with proven cryptococcosis were identified, without any cases of mucormycosis. Of this cohort, 6 patients (46%) showed radiographic findings that were found to be most consistent with lung cancer by radiologists. Eight cases (62%) were suspected of cancer recurrence or progression by the treatment team on the basis of additional considerations of medical history and clinical symptoms. Most patients had active NSCLC or had a history of recurrence without active NSCLC at the time of fungal discovery (11 patients; 85%). Most patients died without full recovery (7 patients; 54%). CONCLUSIONS: Invasive pulmonary aspergillosis and cryptococcosis can often be mistaken as cancer recurrence or progression in patients with a history of NSCLC because of mimicking radiographic and clinical characteristics.

Sarocladium and Acremonium infections: New faces of an old opportunistic fungus.

The genera Acremonium and Sarocladium comprise a high diversity of morphologically and genetically related fungi generally found in the environment, although a few species, mainly Sarocladium kiliense and Acremonium egyptiacum, can also be involved in many human infections. Clinical management of opportunistic infections caused by these fungi is very complex, since their correct identification is unreliable, and they generally show poor antifungal response. More than 300 clinical cases involving a broad range of Acremonium/Sarocladium infections have so far been published, and with this review we aim to compile and provide a detailed overview of the current knowledge on Acremonium/Sarocladium human infections in terms of presentation, diagnosis, treatments and prognoses. We also aim to summarise and discuss the data currently available on their antifungal susceptibility, emphasising the promising results obtained with voriconazole as well as their impact in terms of animal infections.

Are CMV-predictive scores in inflammatory bowel disease useful in clinical practice?

BACKGROUND: Concurrent cytomegalovirus (CMV) in inflammatory bowel disease (IBD)-related colitis is an important scenario associated with high rates of colectomy and other morbidity. Due to the low incidence of CMV, testing of all patients is associated with an unacceptably high consumption of resources and delay in treatment. Therefore, several predictive scores have been developed to identify patients at risk for a CMV infection. METHODS: We performed a retrospective single center study in a German University hospital including all IBD patients with available data on CMV-PCR analysis in whole blood between 2010 and 2018 and evaluated 2 prognostic scores for CMV infection for their diagnostic accuracy. RESULTS: In the study, 907 patients with IBD and CMV-PCR were identified. Of them, 21 patients (2.3 %) had a positive CMV-PCR (≥ 1000 copies/mL), 14 of them in ulcerative colitis and 7 in Crohn's disease. The Berlin Score identified 667 patients (73.1 %) as potentially CMV-positive, resulting in a positive predictive value of 2.5 % and a negative predictive value of 98.3 %. In contrast, the Münster Score identified 60 patients as potentially CMV-positive, resulting in a PPV of 20 % and an NPV of 99.4 %. CONCLUSIONS: Scoring systems can help to identify patients at risk for a CMV infection and minimize resource consumption and delay in treatment. Due to low incidence, a 2-step-algorithm, consisting of the Münster Score followed by a CMV-PCR if the score indicates a CMV infection, is preferable.

Risks and features of secondary infections in severe and critical ill COVID-19 patients.

Objectives Severe or critical COVID-19 is associated with intensive care unit admission, increased secondary infection rate, and would lead to significant worsened prognosis. Risks and characteristics relating to secondary infections in severe COVID-19 have not been described. Methods Severe and critical COVID-19 patients from Shanghai were included. We collected lower respiratory, urine, catheters, and blood samples according to clinical necessity and culture and mNGS were performed. Clinical and laboratory data were archived. Results We found 57.89% (22/38) patients developed secondary infections. The patient receiving invasive mechanical ventilation or in critical state has a higher chance of secondary infections (P<0.0001). The most common infections were respiratory, blood-stream and urinary infections, and in respiratory infections, the most detected pathogens were gram-negative bacteria (26, 50.00%), following by gram-positive bacteria (14, 26.92%), virus (6, 11.54%), fungi (4, 7.69%), and others (2, 3.85%). Respiratory Infection rate post high flow, tracheal intubation, and tracheotomy were 12.90% (4/31), 30.43% (7/23), and 92.31% (12/13) respectively. Secondary infections would lead to lower discharge rate and higher mortality rate. Conclusion Our study originally illustrated secondary infection proportion in severe and critical COVID-19 patients. Culture accompanied with metagenomics sequencing increased pathogen diagnostic rate. Secondary infections risks increased after receiving invasive respiratory ventilations and intravascular devices, and would lead to a lower discharge rate and a higher mortality rate.

[Hepatolienal candidosis as a rare differential diagnosis of disseminated small parenchym lesions]. / Hepatolienale Candidose als seltene Differenzialdiagnose disseminierter kleinherdiger Parenchymveränderungen.

HISTORY: We report about a 17-year-old patient with the secondary malignancy of acute myeloid leukemia (AML). He developed fever of unclear origin during the hematopoietic stem cell transplantation.History We report about a 17-year-old patient with the secondary malignancy of acute myeloid leukemia (AML). He developed fever of unclear origin during the hematopoietic stem cell transplantation. EXAMINATIONS: In the focus search, the routine sonography of the abdomen showed disseminated hypoechoic small- parenchymal lesions of the liver. In the complementary MRI, disseminated small lesions of the liver parenchyma and the spleen were demarked after contrast agent administration. DIAGNOSIS: Imaging revealed suspicion of hepatolienal candiasis.Diagnosis Imaging revealed suspicion of hepatolienal candiasis. THERAPY: Empirical therapy with amphotericin B was used. A sonographic punch biopsy of the liver was performed. The pathological examination showed oval particles in the PAS staining in the sense of an opportunistic mycosis of the Candida infection type. CONCLUSION: The case shows that in immunosuppressed patients, candidiasis must always be considered as a differential diagnosis with simultaneous parenchymal changes in the liver and/or spleen. In addition, in the screening situation, a suitable linear transducer should be used when asking about fungal lesions in the liver and spleen. Alternatively, if suspected hepato-lienal candidiasis could be diagnosed by a contrast-enhanced MRI of the upper abdomen/abdomen.

Prevalence of susceptibility patterns of opportunistic bacteria in line with CLSI or EUCAST among Haemophilus parainfluenzae isolated from respiratory microbiota.

The application of CLSI and EUCAST guidelines led to many discrepancies. Various doubts have already appeared in preliminary stages of microbiological diagnostics of Haemophilus spp. A total of 87 H. parainfluenzae isolates were obtained from throat or nasopharyngeal swabs from adults 18 to 70 years old, both healthy volunteers and patients with chronic diseases between 2013 to 2015 in eastern Poland. Haemophilus spp. were identified by colony morphology, Gram-staining, API NH and MALDI-TOF MS technique. Both susceptibility to various antimicrobials and phenotypes of Haemophilus spp. resistance to beta-lactams were determined. Statistically significant association between applied guidelines and drug resistance patterns were observed to as follows: ampicillin, cefuroxime, cefotaxime, amoxicillin-clavulanate, azithromycin, tetracycline and trimethoprim-sulfamethoxazole. Resistance phenotypes according to CLSI vs. EUCAST were as follows: 3.4% vs. 8.0% for BLNAR and 6.9% vs. 19.5% for BLPACR isolates. In conclusion, this is the first study that reports comparative analysis of drug susceptibility interpretation using CLSI and EUCAST of haemophili rods from human respiratory microbiota in Poland. In case of susceptible, increased exposure (formerly intermediate) category of susceptibility within H. parainfluenzae isolates we have observed EUCAST as more restrictive than CLSI. Moreover, BLNAI and BLPAI phenotype isolates have been observed, as well as BLPBR using only CLSI or EUCAST guidelines, respectively.

Scnn1b-Transgenic BALB/c Mice as a Model of Pseudomonas aeruginosa Infections of the Cystic Fibrosis Lung.

The opportunistic pathogen Pseudomonas aeruginosa is responsible for much of the morbidity and mortality associated with cystic fibrosis (CF), a condition that predisposes patients to chronic lung infections. P. aeruginosa lung infections are difficult to treat because P. aeruginosa adapts to the CF lung, can develop multidrug resistance, and can form biofilms. Despite the clinical significance of P. aeruginosa, modeling P. aeruginosa infections in CF has been challenging. Here, we characterize Scnn1b-transgenic (Tg) BALB/c mice as P. aeruginosa lung infection models. Scnn1b-Tg mice overexpress the epithelial Na+ channel (ENaC) in their lungs, driving increased sodium absorption that causes lung pathology similar to CF. We intranasally infected Scnn1b-Tg mice and wild-type littermates with the laboratory P. aeruginosa strain PAO1 and CF clinical isolates and then assessed differences in bacterial clearance, cytokine responses, and histological features up to 12 days postinfection. Scnn1b-Tg mice carried higher bacterial burdens when infected with biofilm-grown rather than planktonic PAO1; Scnn1b-Tg mice also cleared infections more slowly than their wild-type littermates. Infection with PAO1 elicited significant increases in proinflammatory and Th17-linked cytokines on day 3. Scnn1b-Tg mice infected with nonmucoid early CF isolates maintained bacterial burdens and mounted immune responses similar to those of PAO1-infected Scnn1b-Tg mice. In contrast, Scnn1b-Tg mice infected with a mucoid CF isolate carried high bacterial burdens, produced significantly more interleukin 1ß (IL-1ß), IL-13, IL-17, IL-22, and KC, and showed severe immune cell infiltration into the bronchioles. Taken together, these results show the promise of Scnn1b-Tg mice as models of early P. aeruginosa colonization in the CF lung.

Opportunistic infections complicating immunotherapy for non-small cell lung cancer.

Immunotherapy has produced durable responses in numerous advanced and metastatic cancers, especially advanced non-small cell lung carcinoma (NSCLC). However, opportunistic infection has become a major risk for patients who have received immune checkpoint inhibitors (ICIs). Early diagnosis of infection is difficult due to an acute disease course and heterogeneity in clinical manifestation. We retrospectively analyzed four cases with NSCLC who received ICIs and developed opportunistic infections. Two of our cases received antecedent glucocorticoids to treat immune-related adverse events (irAEs), whereas immunosuppressive agents were not used beforehand in the other cases. We highlight that opportunistic infections complicating immunotherapy can be severe and even fatal. When patients deteriorate after initial remission from irAEs by glucocorticoids, infections should be thoroughly investigated and carefully distinguished from an irAE flare. Bronchoscopy and bronchoalveolar lavage (BAL) are essential. In patients where limited results from traditional microbiological tests have been obtained, next-generation sequencing (NGS) of BAL fluid is beneficial in guiding a precise antimicrobial treatment. An antipneumocystis prophylaxis may also be considered in selected patients.