Infections In Immunocompromised Patients Research Articles

Characterization of virus‒host recombinant variants of the hepatitis E virus.

Hepatitis E virus (HEV) is a major cause of viral hepatitis. HEV can lead to chronic infection in immunocompromised patients. Ribavirin treatment is currently used to treat such chronic infections. Recently, seven virus-host recombinant viruses were characterized in immunocompromised patients. These viruses have incorporated a portion of a human gene fragment into their genome. We studied the consequences of these insertions on the replication capacity. We found that these inserted fragments could enhance virus replication for five of the seven recombinant variants. We also showed that the recombinant variants with replicative advantages were less sensitive to ribavirin in vitro. Finally, we found that the mechanisms leading to such a replicative advantage do not seem to rely on the post-translational modifications introduced by the human gene fragment that could have modified the function of the viral protein. The mechanisms involved in improving the replication of such recombinant viruses remain to be explored.

High-risk clones of Pseudomonas aeruginosa contaminate the drinking water networks of French cities

Pseudomonas aeruginosa is a major opportunistic pathogen responsible for severe infections in immunocompromised patients. The contamination of drinking water networks (DWNs) with this pathogen is underestimated, as it is mostly in the state of persister cells undetected by the recommended monitoring technique. We collected water samples from eight cities distant from each other and searched for P. aeruginosa using a culture-based method that resuscitates persister cells. The genomes of isolates were sequenced. Five DWNs of the eight tested (62.5%) were contaminated with P. aeruginosa, of which four were contaminated with high-risk clones (ST308, ST395). Surprisingly, the ST308 isolates retrieved from the four independent and distant DWNs were clonal. Most P. aeruginosa isolates shared a genomic island conferring tolerance to copper-ions. The population structure of the collection may result from both a common source of contamination by plumbing supplies and the selection of clones sharing genetic elements that presumably aided their propagation in DWNs.

UV-C side-emitting optical fiber-based disinfection: a promising approach for infection control in tight channels.

The growth of pathogenic bacteria in moist and wet surfaces and tubing of medically relevant devices results in serious infections in immunocompromised patients. In this study, we investigated and demonstrated the successful implementation of a UV-C side-emitting optical fiber in disinfecting medically relevant pathogenic bacteria (Pseudomonas aeruginosa and Methicillin-resistant Staphylococcus aureus [MRSA]) within tight channels of polytetrafluoroethylene (PTFE). PTFE is a commonly used material both in point-of-use (POU) water treatment technologies and medical devices (dental unit water line [DUWL], endoscope). For a 1-m-long PTFE channel, up to ≥6 log inactivation was achieved using a 1-m-long UV side-emitting optical fiber (SEOF) with continuous 16-h exposure of low UV-C radiation ranging from ~0.23 to ~29.30 μW/cm2. Furthermore, a linear model was used to calculate the inhibition zone constant (k`), which enables us to establish a correlation between UV dosage and the extent of inactivated surface area (cm2) for surface-bound Escherichia coli on a nutrient-rich medium. The k` value for an irradiance ranging from ~150 to ~271.50 μW/cm2 was calculated to be 0.564 ± 0.6 cm·cm2/mJ. This study demonstrated the efficacy of SEOFs for disinfection of medically relevant microorganisms present in medically and domestically relevant tight channels. The impact of the results in this study extends to the optimization of operational efficiency in pre-existing UV surface disinfection setups that currently operate at UV dosages exceeding the optimal levels.IMPORTANCEGermicidal UV radiation has gained global recognition for its effectiveness in water and surface disinfection. Recently, various works have illustrated the benefit of using UV-C side-emitting optical fibers (SEOFs) for the disinfection of tight polytetrafluoroethylene (PTFE) channels. This study now demonstrates its impact for disinfection of medically relevant organisms and introduces critical design calculations needed for its implementation. The flexible geometry and controlled emission of light in these UV-SEOFs make them ideal for light distribution in tight channels. Moreover, the results presented in this manuscript provide a novel framework that can be employed in various applications, addressing microbial contamination and the disinfection of tight channels.

Kodamaea ohmeri: A rare yeast causing invasive infections in immunocompromised patients.

Kodamaea ohmeri is a rare, recognized pathogen that has previously been isolated from environmental sources. The patients commonly affected by this yeast include immunocompromised as well as immunocompetent patients having several associated risk factors. We report three cases in which K. ohmeri was isolated from blood using Bact T/ALERT. Identification was carried out by MALDI-TOF MS (Vitek-MS, BioMérieux, Marcy-l'Etoile, France) in addition to color characteristics on chromogenic media. The patients had diminished immune response on account of a multitude of comorbidities. K. ohmeri can be misidentified as Candida tropicalis, Candida albicans, or Candida hemolounii by conventional methods; correct and timely identification can be achieved by MALDI-TOF MS. Antifungal susceptibility breakpoints for K. ohmeri are currently not defined. An Echinocandin was added to the treatment regimen of all three of the cases. Identification of K. ohmeri using conventional methods is difficult and unusual yeasts should be carefully observed, especially upon prolonged incubation.

Replacement of sulfonamide by sulfoximine within a helicase-primase inhibitor with restricted flexibility

Helicase-primase is an interesting target for the therapy of herpes simplex virus (HSV) infections. Since amenamevir is already approved for varicella-zoster virus (VZV) and HSV in Japan and pritelivir has received breakthrough therapy status for the treatment of acyclovir-resistant HSV infections in immunocompromised patients, the target has sparked interest in me-too approaches. Here, we describe the attempt to improve nervous tissue penetration in Phaeno Therapeutics drug candidate HN0037 to target the latent reservoir of HSV by installing less polar moieties, mainly a difluorophenyl instead of a pyridyl group, and replacing the primary sulfonamide with a methyl sulfoximine moiety. However, all obtained stereoisomers exhibited a weaker inhibitory activity on HSV-1 and HSV-2.

Noma Masquerading as Squamous Cell Carcinoma - A Case Report in an AIDS Patient

Abstract Rationale: Cancrum oris, also known as noma, is a rare and rapidly progressing gangrenous infection affecting the oral cavity, commonly seen in malnourished children. We discuss the clinical presentation, diagnostic dilemma and management in a 54-year-old male human immunodeficiency virus-positive patient with oral ulceration clinically resembling squamous cell carcinoma (SCC). Patient Concerns: The patient had severe oral ulceration with pain and difficulty eating food. Diagnosis: Histopathological examination was misleading as it revealed features akin to early invasion of SCC. Immunohistochemistry findings were not in favour of SCC. Treatment: Antiretroviral therapy was started owing to the decreased CD4 cell count. Outcomes: Lesions began to show signs of healing on follow-up. Take-Away Lessons: This case aims to highlight the unique challenges of diagnosing and emphasises the importance of considering opportunistic infections in immunocompromised patients presenting with oral ulcerations to prevent misdiagnosis and maltreatment.

Complete sequence of carbapenem-resistant Ralstonia mannitolilytica clinical isolate co-producing novel class D β-lactamase OXA-1176 and OXA-1177 in Japan.

In 2020, the Ralstonia mannitolilytica strain JARB-RN-0044 was isolated from a midstream urine sample of an elderly hospitalized patient in Japan and was highly resistant to carbapenem (i.e., imipenem, meropenem, and doripenem). Whole-genome sequencing revealed that the complete genome consists of two replicons, a 3.5-Mb chromosome and a 1.5-Mb large non-chromosomal replicon which has not been reported in R. mannitolilytica, and referred to as the "megaplasmid" in this study based on Cluster of Orthologous Group of proteins functional analysis. The strain JARB-RN-0044 harbored two novel OXA-60 and OXA-22 family class D β-lactamase genes blaOXA-1176 and blaOXA-1177 on the megaplasmid. Cloning experiments indicated that Escherichia coli recombinant clone expressing blaOXA-1176 gene showed increased minimum inhibitory concentrations (MICs) of imipenem, meropenem, and doripenem, indicating that blaOXA-1176 gene encodes carbapenemase. In contrast, E. coli recombinant clone expressing blaOXA-1177 gene showed increased MICs of piperacillin and cefazolin, but not of carbapenem. Interestingly, the 44.6 kb putative prophage region containing genes encoding phage integrase, terminase, head and tail protein was identified in the downstream region of blaOXA-1176 gene, and comparative analysis with some previously reported R. mannitolilytica isolates revealed that the prophage region was unique to strain JARB-RN-0044. The existence of a highly carbapenem-resistant R. mannitolilytica isolate may raise human health concerns in Japan, where the population is rapidly aging.IMPORTANCERalstonia mannitolilytica is an aerobic non-fermenting Gram-negative rod commonly found in aquatic environments and soil. The bacteria can occasionally cause severe hospital-acquired bloodstream infections in immunocompromised patients and it has been recently recognized as an emerging opportunistic human pathogen. Furthermore, some R. mannitolilytica isolates are resistant to various antimicrobial agents, including β-lactams and aminoglycosides, making antimicrobial therapy challenging and clinically problematic. However, clinical awareness of this pathogen is limited. To our knowledge, in Japan, there has been only one report of a carbapenem-resistant R. mannitolilytica clinical isolate from urine by Suzuki et al. in 2015. In this study, whole-genome sequencing analysis revealed the presence and genetic context of novel blaOXA-1176 and blaOXA-1177 genes on the 1.5 Mb megaplasmid from highly carbapenem-resistant R. mannitolilytica isolate and characterized the overall distribution of functional genes in the chromosome and megaplasmid. Our findings highlight the importance of further attention to R. mannitolilytica isolate in clinical settings.

Secondary bone marrow graft loss after third-party virus-specific T cell infusion: Case report of a rare complication

Virus-specific T cells (VST) from partially-HLA matched donors have been effective for treatment of refractory viral infections in immunocompromised patients in prior studies with a good safety profile, but rare adverse events have been described. Here we describe a unique and severe adverse event of VST therapy in an infant with severe combined immunodeficiency, who receives, as part of a clinical trial (NCT03475212), third party VSTs for treating cytomegalovirus viremia following bone marrow transplantation. At one-month post-VST infusion, rejection of graft and reversal of chimerism is observed, as is an expansion of T cells exclusively from the VST donor. Single-cell gene expression and T cell receptor profiling demonstrate a narrow repertoire of predominantly activated CD4+ T cells in the recipient at the time of rejection, with the repertoire overlapping more with that of peripheral blood from VST donor than the infused VST product. This case thus demonstrates a rare but serious side effect of VST therapy.

Molecular monitoring of viral infections in immunocompromised patients in a large university hospital in Italy: reflections after thirteen years of real-life activity.

This study aimed to investigate the prevalence and viral reactivations of clinical interest in the immunocompromised patient with particular focus on hematologic and solid organ transplant recipients. Molecular screening data of CMV, EBV, JCV and BKV from 2011 to 2023 were analyzed. This extensive time span allowed the access to more than 100,000 samples from over 20,000 patients treated at Policlinico Umberto I. It was possible to temporally investigate patient attendance patterns, average age distribution, seasonality of infections, and positivity rates of the analyzed viruses. Between 2019 and 2022 a significant reduction in organ transplants performed and in the positive molecular detection of EBV, JCV and BKV was observed. Additionally, there has been a noteworthy decrease in CMV reactivations, with a reduction of up to 50% starting in 2019. A remarkable reduction of 39% in the rate of CMV viral reactivation has been also achieved in SOT between 2016 and 2023. The years following 2019 were profoundly impacted by the COVID-19 pandemic era. This period resulted in a substantial reduction in healthcare services and hospital visits. Furthermore, the introduction of the drug Letermovir in Italy in 2019 demonstrated remarkable efficacy, evidenced by a reduction in CMV reactivations. Additionally, the adoption of a novel clinical approach centered on personalized therapy facilitated improved management of immunocompromised patients.

Genotypic Detection of Carbapenems Resistance Genes in Acinetobacter baumannii Isolated from Urinary Tract Infection Patients

Acinetobacter baumannii is a Gram-negative bacterium characterized by its short, round, rod-shaped morphology. It is an opportunistic pathogen that poses a significant threat, particularly to immunocompromised patients, often those with hospital stays lasting less than 90 days. Between June 2022 and July 2023, 214 urine samples were collected from individuals suspected of having urinary tract infections (UTIs). These samples were subjected to antibiotic resistance testing, focusing on detecting specific genes related to carbapenem resistance, namely blaNDM, blaKPC, and blaVIM.The study's results revealed a notable trend in antibiotic resistance among the bacterial isolates. Ceftazidime, cefotaxime, and ceftriaxone, commonly used antibiotics for UTIs, showed a high resistance rate among the tested isolates. This resistance highlights the challenges healthcare professionals face when treating UTIs caused by Acinetobacter baumannii. On the other hand, the isolates displayed a comparatively lower resistance rate to imipenem and meropenem, two necessary carbapenem antibiotics. This lower resistance to carbapenems is encouraging as these drugs are often considered the last line of defense against multidrug-resistant bacterial infections. The presence of carbapenem resistance genes, such as blaNDM, blaKPC, and blaVIM, in the Acinetobacter baumannii isolates is of particular concern. These genes confer resistance to carbapenem antibiotics, crucial for treating severe infections caused by multidrug-resistant bacteria. In conclusion, the study aims to study the growth of antibiotic resistance in Acinetobacter baumannii, especially in urinary tract infections in immunocompromised patients with more extended hospital stays. It also highlights the need for Surveys and periodic examinations to detect the spread of bacteria and their resistance. Keywords: Carbapenems, UTI, genes, blaNDM, blaKPC, and blaVIM.

Genotypic Detection of Carbapenems Resistance Genes in Acinetobacter baumannii Isolated from Urinary Tract Infection Patients

Acinetobacter baumannii is a Gram-negative bacterium characterized by its short, round, rod-shaped morphology. It is an opportunistic pathogen that poses a significant threat, particularly to immunocompromised patients, often those with hospital stays lasting less than 90 days. Between June 2022 and July 2023, 214 urine samples were collected from individuals suspected of having urinary tract infections (UTIs). These samples were subjected to antibiotic resistance testing, focusing on detecting specific genes related to carbapenem resistance, namely blaNDM, blaKPC, and blaVIM.The study's results revealed a notable trend in antibiotic resistance among the bacterial isolates. Ceftazidime, cefotaxime, and ceftriaxone, commonly used antibiotics for UTIs, showed a high resistance rate among the tested isolates. This resistance highlights the challenges healthcare professionals face when treating UTIs caused by Acinetobacter baumannii. On the other hand, the isolates displayed a comparatively lower resistance rate to imipenem and meropenem, two necessary carbapenem antibiotics. This lower resistance to carbapenems is encouraging as these drugs are often considered the last line of defense against multidrug-resistant bacterial infections. The presence of carbapenem resistance genes, such as blaNDM, blaKPC, and blaVIM, in the Acinetobacter baumannii isolates is of particular concern. These genes confer resistance to carbapenem antibiotics, crucial for treating severe infections caused by multidrug-resistant bacteria. In conclusion, the study aims to study the growth of antibiotic resistance in Acinetobacter baumannii, especially in urinary tract infections in immunocompromised patients with more extended hospital stays. It also highlights the need for Surveys and periodic examinations to detect the spread of bacteria and their resistance. Keywords: Carbapenems, UTI, genes, blaNDM, blaKPC, and blaVIM.

Effectiveness of metagenomic next-generation sequencing in the diagnosis of infectious diseases: A systematic review and meta-analysis

ObjectivesEarly diagnosis of infectious diseases remains a challenge. This study assessed the diagnostic value of mNGS in infections and explored the effect of various factors on the accuracy of mNGS. MethodsAn electronic article search of PubMed, Cochrane Library, and Embase was performed. A total of 85 papers were eligible for inclusion and analysis. Stata 12.0 was used for statistical calculation to evaluate the efficacy of mNGS for the diagnosis of infectious diseases. ResultsThe AUC of 85 studies was 0.88 (95%CI, 0.85-0.90). The AUC of the clinical comprehensive diagnosis and conventional test groups was 0.92 (95%CI, 0.89-0.94) and 0.82 (95%CI, 0.78-0.85), respectively. The results of subgroup analysis indicated that the PLR and NLR were 12.67 (95%CI, 6.01-26.70) and 0.05 (95%CI, 0.03-0.10), respectively, in arthrosis infections. The PLR was 24.41 (95%CI, 5.70-104.58) in central system infections and the NLR of immunocompromised patients was 0.08 (95%CI, 0.01-0.62). ConclusionmNGS demonstrated satisfactory diagnostic performance for infections, especially for bone and joint infections and central system infections. Moreover, mNGS also has a high value in the exclusion of infection in immunocompromised patients.

The Relationship of Toxoplasma Gondii Infection with Men Infertility: A Serological and Molecular Study

Background and Aims: Toxoplasma gondii (T. gondii) is one of the most dangerous parasitic infections in immunocompromised patients. It may pass through the bloodstream to various organs, such as the reproductive organs of intermediate hosts, which may lead to male infertility. Therefore, this study aimed to determine the relationship between T. gondii infection and infertility in infertile men referred to the infertility center of Chaharmahal and Bakhtiari province.
 Materials and Methods: In this case-control study,129 men, including 67 infertile and 62 fertile men, participated, and specific anti-Toxoplasma antibodies of IgG and IgM were detected in the serum of all cases using enzyme-linked immunosorbent assay methods. Also, the presence of T.gondii DNA in the seminal fluid samples of these people was detected using the polymerase chain reaction method. Sperm analyses, including sperm count, morphology, motility, and viscosity, were also performed on the seminal fluid.
 Results: Based on the result of the IgG antibody, a significant difference was found in toxoplasmosis in two fertile and infertile groups. Its frequency was 16.1% in the fertile group and 40.3% in the infertile group. Also, Toxoplasma infection showed a relationship with sperm count and sperm morphology, so its frequency was 72.7% in the low sperm group and 24.6% in the high sperm group. The results of IgM and polymerase chain reaction showed, there was no significant relationship between the fertile and infertile groups with toxoplasmosis.
 Conclusion: The serum prevalence of the anti-Toxoplasma antibodies and molecular detection in infertile men is higher than the control group, and it seems that Toxoplasma may be an effective risk factor for causing male infertility and disruption of sperm parameters.

Phenotypic and functional characterization of posoleucel, a multivirus-specific T cell therapy for the treatment and prevention of viral infections in immunocompromised patients

BackgroundDeficits in T cell immunity translate into increased risk of severe viral infection in recipients of solid organ and hematopoietic cell transplants. Thus, therapeutic strategies that employ the adoptive transfer of virus-specific T cells are being clinically investigated to treat and prevent viral diseases in these highly immunocompromised patients. Posoleucel is an off-the-shelf multivirus-specific T cell investigational product for the treatment and prevention of infections due to adenovirus, BK virus, cytomegalovirus, Epstein–Barr virus, human herpesvirus 6 or JC virus. MethodsHerein we perform extensive characterization of the phenotype and functional profile of posoleucel to illustrate the cellular properties that may contribute to its in vivo activity. Results and ConclusionsOur results demonstrate that posoleucel is enriched for central and effector memory CD4+ and CD8+ T cells with specificity for posoleucel target viruses and expressing a broad repertoire of T cell receptors. Antigen-driven upregulation of cell-surface molecules and production of cytokine and effector molecules indicative of proliferation, co-stimulation, and cytolytic potential demonstrate the specificity of posoleucel and its potential to mount a broad, polyfunctional, and effective Th1-polarized antiviral response upon viral exposure. We also show the low risk for off-target and nonspecific effects as evidenced by the enrichment of posoleucel in memory T cells, low frequency of naive T cells, and lack of demonstrated alloreactivity in vitro. The efficacy of posoleucel is being explored in four placebo-controlled clinical trials in transplant recipients to treat and prevent viral infections (NCT05179057, NCT05305040, NCT04390113, NCT04605484).

Epidemiology, Timing, and Secondary Prophylaxis of Recurrent Nocardiosis.

Nocardia tends to cause infection in immunocompromised patients or those with chronic pulmonary disease. Nocardia is known to recur, prompting the practice of secondary prophylaxis in patients perceived at high risk. However, few data exist regarding the epidemiology of recurrent nocardiosis or the effectiveness of secondary prophylaxis. We performed a multicenter, retrospective cohort study of adults diagnosed with nocardiosis from November 2011 to April 2022, including patients who completed primary treatment and had at least 30 days of posttreatment follow-up. Propensity score matching was used to analyze the effect of secondary prophylaxis on Nocardia recurrence. Fifteen of 303 (5.0%) patients developed recurrent nocardiosis after primary treatment. Most recurrences were diagnosed either within 60 days (N = 6/15, 40.0%) or between 2 to 3 years (N = 4/15, 26.7%). Patients with primary disseminated infection tended to recur within 1 year, whereas later recurrences were often nondisseminated pulmonary infection. Seventy-eight (25.7%) patients were prescribed secondary prophylaxis, mostly trimethoprim-sulfamethoxazole (N = 67/78). After propensity-matching, secondary prophylaxis was not associated with reduced risk of recurrence (hazard ratio, 0.96; 95% confidence interval, .24-3.83), including in multiple subgroups. Eight (53.3%) patients with recurrent nocardiosis required hospitalization and no patients died from recurrent infection. Recurrent nocardiosis tends to occur either within months because of the same Nocardia species or after several years with a new species. Although we did not find evidence for the effectiveness of secondary prophylaxis, the confidence intervals were wide. However, outcomes of recurrent nocardiosis are generally favorable and may not justify long-term antibiotic prophylaxis for this indication alone.

Clinicopathological study of pigmented fungal lesions with special reference to subcutaneous phaeohyphomycosis: A 3-year study in a tertiary care hospital of Eastern India

Background: Fungal infections are predominantly opportunistic infections in immunocompromised patients and in immunocompetent adults with a history of trauma. Recently, there is an increase in trends of fungal infections in immunocompetent individuals also without any history of trauma. Pigmented fungi are a group of fungi that have pigment in their cell wall and also known as dematiaceous fungi. These pigmented fungi include phaeohyphomycosis with a differential diagnosis of chromoblastomycosis, cryptococcosis, mycetoma, and aspergillus. Phaeohyphomycosis is a subcutaneous or systemic infection characterized histologically by dark-colored fungal hyphae and yeast forms (black yeast). Aims and Objectives: The aim of the present study is to analyze the clinicopathological features of pigmented fungal infections in biopsy specimen based on their histomorphology. Materials and Methods: This was a prospective study in which we have analyzed the dematiaceous fungal species by their histomorphological characteristics in biopsy specimens. Results: A total of 21 cases of biopsy specimens (with the clinical presentation of cutaneous/subcutaneous lesions) were studied histologically which showed 13 cases of phaeohyp homycosis, seven cases of eumycotic mycetoma, and one case of chromoblastomycosis. There was male predominance (17, 80.95%) and the majority of the patients were >60 years (16, 76.19%). Most common site of infection was foot with predominant clinical presentation as subcutaneous mass lesion. Conclusion: All the cases of dematiaceous fungal infections were diagnosed by histopathological examination. Melanin in the cell wall of dematiaceous fungi is the pathogenic factor. Phaeohyphomycosis is no longer considered as a rare infection rather there is an increasingly incidence of recognized infection. Although culture and histopathological study remain important tools for final diagnosis, various molecular studies might be helpful for accurate diagnosis.

An Acute Infection due to Hepatitis E in the Context of a Patient with Rituximab and Methotrexate Therapy.

This report presents the influence of immunosuppression by new rheumatological therapies on hepatitis E virus infection in a 54-year-old male patient with an anti-synthetase syndrome and treatment with methotrexate and rituximab. The patient arrived at the Emergency Department with epigastric pain, vomiting and dark urine. Initial examination revealed signs of inflammation and hepatic dysfunction. Subsequent laboratory tests and imaging confirmed acute hepatitis E infection in the context of recent initiation of rituximab therapy. Despite initial suspicion of pancreatitis, subsequent investigations ruled out pancreatic involvement. Treatment with ribavirin, along with supportive measures, led to significant clinical improvement with resolution of jaundice, ascites, and oedema. This case underscores the importance of considering hepatitis E in patients with autoimmune conditions, especially when initiating immunosuppressive therapies, a situation that is not well described in scientific literature and is increasingly common, necessitating proper recognition. Suspect hepatitis E virus infection in the presence of persistent liver failure of unknown cause.Recognise immunosuppression as a cause of increased risk of hepatitis E infection.Take into account the repercussions of immunosuppressive therapy such as rituximab regarding hepatitis E infections in immunocompromised patients.

Structure and antigenicity of the divergent human astrovirus VA1 capsid spike.

Human astrovirus (HAstV) is a known cause of viral gastroenteritis in children worldwide, but HAstV can cause also severe and systemic infections in immunocompromised patients. There are three clades of HAstV: classical, MLB, and VA/HMO. While all three clades are found in gastrointestinal samples, HAstV-VA/HMO is the main clade associated with meningitis and encephalitis in immunocompromised patients. To understand how the HAstV-VA/HMO can infect the central nervous system, we investigated its sequence-divergent capsid spike, which functions in cell attachment and may influence viral tropism. Here we report the high-resolution crystal structures of the HAstV-VA1 capsid spike from strains isolated from patients with gastrointestinal and neuronal disease. The HAstV-VA1 spike forms a dimer and shares a core beta-barrel structure with other astrovirus capsid spikes but is otherwise strikingly different, suggesting that HAstV-VA1 may utilize a different cell receptor, and an infection competition assay supports this hypothesis. Furthermore, by mapping the capsid protease cleavage site onto the structure, the maturation and assembly of the HAstV-VA1 capsid is revealed. Finally, comparison of gastrointestinal and neuronal HAstV-VA1 sequences, structures, and antigenicity suggests that neuronal HAstV-VA1 strains may have acquired immune escape mutations. Overall, our studies on the HAstV-VA1 capsid spike lay a foundation to further investigate the biology of HAstV-VA/HMO and to develop vaccines and therapeutics targeting it.

A novel lentiviral vector-based approach to generate chimeric antigen receptor T cells targeting Aspergillus fumigatus.

Invasive aspergillosis (IA) is a common and deadly mold infection in immunocompromised patients. As morbidity and mortality of IA are primarily driven by poor immune defense, adjunct immunotherapies, such as chimeric antigen receptor (CAR) T cells, are direly needed. Here, we propose a novel approach to generate Aspergillus fumigatus (AF)-CAR T cells using the single-chain variable fragment domain of monoclonal antibody AF-269-5 and a lentiviral vector system. These cells successfully targeted mature hyphal filaments of representative clinical and reference AF isolates and elicited a potent release of cytotoxic effectors and type 1 T cell cytokines. Furthermore, AF-CAR T cells generated from peripheral blood mononuclear cells of four healthy human donors and expanded with either of three cytokine stimulation regimens (IL-2, IL-2 + IL-21, or IL-7 + IL-15) significantly suppressed mycelial growth of AF-293 after 18 hours of co-culture and synergized with the immunomodulatory antifungal agent caspofungin to control hyphal growth for 36 hours. Moreover, cyclophosphamide-immunosuppressed NSG mice with invasive pulmonary aspergillosis that received two doses of 5 million AF-CAR T cells (6 and 48 hours after AF infection) showed significantly reduced morbidity on day 4 post-infection (P < 0.001) and significantly improved 7-day survival (P = 0.049) compared with mice receiving non-targeting control T cells, even without concomitant antifungal chemotherapy. In conclusion, we developed a novel lentiviral strategy to obtain AF-CAR T cells with high targeting efficacy, yielding significant anti-AF activity in vitro and short-term protection in vivo. Our approach could serve as an important steppingstone for future clinical translation of antifungal CAR T-cell therapy after further refinement and thorough preclinical evaluation.IMPORTANCEInvasive aspergillosis (IA) remains a formidable cause of morbidity and mortality in patients with hematologic malignancies and those undergoing hematopoietic stem cell transplantation. Despite the introduction of several new Aspergillus-active antifungals over the last 30 years, the persisting high mortality of IA in the setting of continuous and profound immunosuppression is a painful reminder of the major unmet need of effective antifungal immune enhancement therapies. The success of chimeric antigen receptor (CAR) T-cell therapy in cancer medicine has inspired researchers to translate this approach to opportunistic infections, including IA. Aiming to refine anti-Aspergillus CAR T-cell therapy and improve its feasibility for future clinical translation, we herein developed and validated a novel antibody-based CAR construct and lentiviral transduction method to accelerate the production of CAR T cells with high targeting efficacy against Aspergillus fumigatus. Our unique approach could provide a promising platform for future clinical translation of CAR T-cell-based antifungal immunotherapy.

Cupriavidus Pauculus as A Cause of Late Onset Post-Operative Sinusitis

Cupriavidus pauculus is an environmental gram-negative bacilli of low virulence, being increasingly reported to be associated with invasive infections in immunocompromised patients and device related infections. Often undetected or misidentified in most microbiology laboratories, identification of this organism requires increased suspicion and automated identification or molecular methods. We hereby describe a curious case of post-operative acute sinusitis caused by this rare yet emerging human pathogen.