Overview of Infections in the Immunocompromised Host

Virus-specific antibody responses in severe acute respiratory syndrome coronavirus 2-infected and vaccinated individuals

BACKGROUND

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection can have a serious course with many complications, especially in immunocompromised individuals. In such persons, other latent virus infections may contribute to disease pathology, in particular viruses which infect immune cells such as Epstein-Barr virus (EBV) and cytomegalovirus (CMV).

METHODS

In this study, serology-based assays were conducted to analyse antibody responses to SARS-CoV-2 spike protein (SP), EBV Epstein-Barr nuclear antigen (EBNA)-1 and CMV phosphoprotein (pp)52 in naturally SARS-CoV-2-infected individuals, non-infected healthy controls (HCs) and vaccinated healthy controls (VHCs) to identify an association between SARS-CoV-2 antibodies and EBV and CMV antibodies in order to determine whether latent EBV and CMV infected individuals are more prone to become infected with SARS-CoV-2. Moreover, SARS-CoV-2, EBV, and CMV antibody responses were characterized in serum from patients with relapsing-remitting multiple sclerosis (RRMS), a chronic inflammatory disease strongly associated with EBV infections, to determine whether the serologic virus antibody profile varies in immunocompromised RRMS individuals upon SARS-CoV-2 vaccinations compared to VHCs.

RESULTS

Significantly elevated SP IgG, IgM and IgA levels were identified in SARS-CoV-2-infected immunocompetent individuals when compared to non-infected HCs. However, no correlation was found to serum antibodies between SARS-CoV-2, EBV, and CMV in individuals infected with SARS-CoV-2 and in VHCs, suggesting that latent infections with neither EBV nor CMV associates to SARS-CoV-2 infection. Moreover, no significant difference in SP IgG, IgA and IgM levels was observed between vaccinated RRMS patients and VHCs, indicating that the immune system of immune deficient RRMS patients and VHCs respond identical to SARS-CoV-2 vaccinations.

CONCLUSION

Collectively, SARS-CoV-2 SP antibody levels reflect the vaccination and infection history and do not associate with EBV and CMV serostatus.

Reactivation of Latent Tuberculosis Following COVID-19 and Epstein-Barr Virus Coinfection: A Case Report

Background: This case is unique in demonstrating the reactivation of latent tuberculosis (TB) following co-infection with SARS-CoV-2 and Epstein-Barr virus (EBV) in an otherwise healthy young adult. It highlights a rare clinical scenario in which viral immune dysregulation likely facilitated TB progression. To date, few reports have explored the complex interplay between COVID-19, EBV reactivation, and TB in a single patient, particularly with isolated extrapulmonary involvement. Case Presentation: A 24-year-old woman presented with persistent low-grade fever, fatigue, night sweats, unintentional weight loss, and progressive cervical and supraclavicular lymphadenopathy. These symptoms emerged shortly after a moderate COVID-19 infection. Laboratory studies revealed elevated inflammatory markers and pronounced lymphopenia. EBV reactivation was confirmed via serology and PCR. Despite antiviral therapy, symptoms persisted, and imaging revealed necrotic lymphadenopathy. Tuberculous lymphadenitis was diagnosed through fine-needle aspiration cytology and PCR detection of Mycobacterium tuberculosis. The patient was treated with a standard anti-tuberculosis regimen, resulting in clinical, radiological, and immunological improvement. Conclusions: This case underscores the importance of considering latent TB reactivation in patients with persistent lymphadenopathy and recent viral infections, particularly in regions with high TB prevalence. It also emphasizes the need for thorough immunological and microbiological assessment in complex post-viral syndromes. The main clinical takeaway is that COVID-19 and EBV co-infection may create a permissive environment for TB reactivation through immune system compromise.

Mulberry-derived postbiotics alleviate LPS-induced intestinal inflammation and modulate gut microbiota dysbiosis

Mulberry-derived postbiotics (MDP) have demonstrated promising bioactive properties, including antioxidant and anti-inflammatory effects; however, their specific role in modulating gut inflammation and microbiota composition remains underexplored. Given the growing interest in functional food ingredients for gut health and managing inflammatory disorders, this study aims to evaluate the effects of MDP in alleviating intestinal inflammation and altering the gut microbiota in an LPS-induced mouse model of systemic inflammation. MDP administration significantly mitigated LPS-induced pathological changes in the intestine, liver, spleen, and kidneys, thereby improving systemic health and immune function. Histological analysis revealed reduced inflammation and tissue damage in the intestinal epithelium, supporting the potential of MDP to improve gut barrier integrity. An antioxidant assay revealed that MDP decreased the malonaldehyde (MDA) levels and increased the enzymatic activities of CAT, SOD, and GSH in response to LPS administration, indicating enhanced cellular antioxidant defenses. Inflammatory cytokine analysis showed that MDP downregulated proinflammatory markers such as TNF-α, IL-1β, IL-6, MYD88, Nrf2 COX-2, and HO1, while upregulating TLR4, resulting in potential anti-inflammatory effects by modulating the TLR4-NF-κb pathway. Moreover, MDP promoted beneficial alterations in gut microbiota composition by increasing the abundance of Firmicutes and Bacteroidetes, which are linked to gut health and inflammation regulation. The changes in gut microbiota composition suggest a potential mechanism by which MDP may help restore gut homeostasis and reduce systemic inflammation. These findings suggest that MDP may serve as promising functional food ingredients that support immune health, reduce inflammation, and promote gut microbiota balance, offering potential applications in fortified foods and nutraceuticals aimed at mitigating inflammatory and metabolic disorders.

Prognosis of different types of acute infection in the first episode of childhood acute leukemia

Objective

The aim of the present study was to determine the prognosis of different types of acute infection in pediatric leukemia patients.

Methods

A retrospective study was carried out on pediatric leukemia patients with acute infections admitted to the Second Affiliated Hospital of Harbin Medical University between 1 September 2004 and 31 August 2022. Clinical characteristics, diagnostic findings, and prognostic outcomes were extracted from the eligible cases and analyzed.

Results

There were 36 cases of acute myeloid leukemia (AML) and 72 cases of acute lymphoblastic leukemia (ALL) that met the inclusion criteria. There were significant differences in the incidence of pneumonia (47.2% vs. 27.8%, p = 0.045) and sepsis (19.4% vs. 2.8%, p = 0.006) between the AML and ALL groups. There were 10 cases with a poor prognosis and 26 cases with a favorable prognosis in the AML group. There were no significant differences between the poor prognosis and the favorable prognosis groups except for age (14.2 ± 1.2 years vs. 9.6 ± 4.3 years, p = 0.003). There were 14 cases with a poor prognosis and 58 cases with a favorable prognosis in the ALL group. There were no significant differences between the poor prognosis and favorable prognosis groups except for age (13.4 ± 2.7 years vs. 9.2 ± 4.7 years, p = 0.002).

Conclusions

There were significantly more incidence of pneumonia and sepsis in children with AML. Younger AML and ALL children with acute infections have more favorable prognoses than older children.

Brevibacterium Species Infections in Humans-A Narrative Review

Brevibacterium species are Gram-positive, non-sporulating, coryneform, aerobic rods that are catalase positive and exhibit a distinctive transition from diptheroid to coccoid morphology during culture. Infections by these species are seldom identified. Objective: This narrative review aims to present all the reported cases of Brevibacterium spp. infections in humans, focusing on data about epidemiology, antimicrobial resistance, antimicrobial treatment, and mortality. A narrative review based on a literature search of PubMed/MedLine and Scopus databases was performed. In total, 41 studies providing data on 42 patients with Brevibacterium spp. infections were included in the present analysis. The median age was 48 years, while 57.5% were male. The presence of a central venous catheter and malignancy, and end-stage renal disease on peritoneal dialysis were the main predisposing factors. Bacteremia was the most common type of infection, with peritoneal dialysis-associated infections being the second most common. B. casei was the most commonly identified species. Microbial identification required the use of advanced molecular techniques, such as 16s rRNA sequencing or matrix-assisted laser desorption/ionization time of flight mass spectrometry in most cases. Brevibacterium spp. was highly resistant to the combination of trimethoprim with sulfamethoxazole, clindamycin, and common beta-lactams. The most commonly used antimicrobials were vancomycin and aminoglycosides. The mortality was about 10%. Clinicians and laboratory personnel should consider this pathogen in the differential diagnosis in patients with malignancy or peritoneal dialysis-associated peritonitis. Vancomycin should be used for empirical treatment and while antimicrobial susceptibility testing results are pending.

Kytococcus Species Infections in Humans-A Narrative Review

Kytococcus belongs to the family Kytococcaceae, in the order Micrococcales, in the class Actinomycetes, and the phylum Actinomycetota. Kytococcus are aerobic, Gram-positive, non-spore forming bacteria that form coccoid, non-motile, non-encapsulated cells, and their colonies on agar have a yellow color. Infections by these species are increasingly identified nowadays. This narrative review aimed to present all available cases of Kytococcus spp. infections in humans, emphasizing data on the epidemiology, antimicrobial resistance, antimicrobial treatment, and mortality. A narrative review based on a literature search of the PubMed/MedLine and Scopus databases was performed. Results: In total, 26 articles providing data on 30 patients with Kytococcus spp. infections were included in this analysis. The median age was 59.5 years, while 56.7% were male. The presence of a prosthetic cardiac valve was the main predisposing factor in 36.7% of patients (100% among those with infective endocarditis), while immunosuppression due to underlying hematological malignancy under chemotherapy was the second most common. Bacteremia was the most common type of infection, with infective endocarditis being the most common subtype in this infection type, while respiratory tract infections and osteoarticular infections were also relatively common. K. schroeteri was the most commonly identified species. Microbial identification required the use of advanced molecular techniques such as 16s rRNA sequencing in most cases. Kytotoccus spp. was resistant to all beta-lactams with the exception of carbapenems and macrolides. The most commonly used antimicrobials were vancomycin and rifampicin. Mortality was significant (30%). Due to the potential of Kytotoccus spp. to cause infective endocarditis in patients with prosthetic cardiac valves and respiratory tract infections with concomitant bacteremia in patients with hematological malignancy under chemotherapy along with the difficulties in pathogen identification, clinicians and laboratory personnel should consider this pathogen in the differential diagnosis in patients with typical predisposing factors and clinical presentation, especially when traditional microbiological techniques are used for pathogen identification.

Severe community-acquired pneumonia in immunosuppressed patients admitted to the ICU

BACKGROUND

Immunocompromised patients with severe Community-Acquired Pneumonia (sCAP) poses higher risk for poor prognosis. This study details the clinical characteristics and factors linked to immunosuppression and mortality both acutely and long-term.

METHODS

This analysis of the MIMIC-IV database included ICU adult patients with CAP diagnosis categorized by the presence or absence of immunosuppression. Univariable and multivariable analyses determined factors related to immunosuppression and in-hospital, 6-and 12-month mortality post-admission. An adjusted survival analysis assessed the impact of immunosuppression on mortality.

RESULTS

A total of 4742 patients were included, with 1520/4742 (32 %) immunocompromised with a mean age (SD) of 64 (14.7) years, and 896/1520 (58.9 %) males. Solid malignancy was the most frequent immunosuppression cause (797/1520; 52.4 %). The most frequent comorbidities were chronic pulmonary disease (585/1520; 38.5 %) and congestive heart failure (411/1520; 27 %). Immunocompromise was associated with P. jirovecii (0.3 % vs. 1.1 %; p < 0.01) and Aspergillus (1.2 % vs 3.1 %; p 0.03) infection and increased hospital (IH) and solid malignancy (IH: OR 1.98 [95 % CI 1.55-2.52]; 6 M: OR 2.43 [95 % CI: 1.92-3.08]; 12 M: OR: 0.72 [95 % CI 0.47-1.11]; p = 0.14) was consistently associated with mortality at in-hospital and 6M follow-up.

CONCLUSION

Immunocompromised patients with sCAP had higher acute and long-term mortality independent of the disease severity and were frequently infected with opportunistic microorganisms.

Cefepime versus carbapenem for treating complicated urinary tract infection caused by cefoxitin-nonsusceptible ESCPM organisms: a multicenter, real-world study

BACKGROUND

This investigation aimed to compare the efficacy of cefepime and carbapenem for complicated urinary tract infection (cUTI) caused by presumptive AmpC β-lactamase-producing Enterobacter spp., Serratia marcescens, Citrobacter freundii, Providencia spp., and Morganella morganii (ESCPM).

METHODS

Data of 458 individuals with cUTI caused by cefoxitin-nonsusceptible [minimum inhibitory concentration (MIC) > 8 µg/mL] and cefepime-susceptible (MIC ≤ 2 µg/mL) ESCPM was acquired from four Chinese hospitals between 2010 and 2022 and were reviewed retrospectively.

RESULTS

125 and 333 patients received cefepime and carbapenems, respectively, as antimicrobial therapy. The 28-day treatment failure rate was 15.7% (72/458). The following factors were identified as independent predictors for 28-day therapy: age, cefepime MIC = 2 µg/mL, immunocompromised status, infection source control, appropriate empirical therapy, and days from illness onset to active therapy. In patients who required cefepime MIC ≤ 1 µg/mL, a multivariate logistic model indicated that cefepime was linked with a similar risk of 28-day treatment failure [odd ratio (OR) 1.791, 95% confidence interval (CI) 0.600-5.350, p = 0.296] compared with carbapenems after controlling these predictors. Compared with individuals with cefoxitin-nonsusceptible ESCPM, those with isolates of cefepime (MIC = 2 µg/mL) had an enhanced risk of 28-day treatment failure (OR = 2.579, 95% CI = 1.012-6.572, p = 0.047). A propensity score for treatment analysis validated this relationship.

CONCLUSIONS

The cefepime and carbapenem had comparable efficacy for treating cUTI caused by cefoxitin-nonsusceptible ESCPM organisms with cefepime MIC ≤ 1 µg/mL, whereas carbapenems are potentially more effective for isolates with cefepime MIC = 2 µg/mL.

Infectious complications and the utility of serum and cellular markers of infections in the setting of allogeneic hematopoietic stem cell transplantation

INTRODUCTION

Allogeneic hematopoietic stem cell transplantation (allo-HSCT) recipients are severely immunocompromised and susceptible to bacterial, viral, and fungal infections. Despite improved anti-microbial prophylaxis and preemptive strategies, bacterial bloodstream infections (BSIs) occur frequently in allo-HSCT recipients and are associated with increased morbidity and mortality. Cytomegalovirus (CMV) and Epstein Barr virus (EBV) are the most relevant viruses following allo-HSCT and remain major concerns. Fungal infections, including those caused by Candida and Aspergillus species, are persistent and feared complications.

AREAS COVERED

We aim to provide clinicians caring for allo-HSCT recipients with a comprehensive overview of the risk factors that predispose patients to common bacterial, fungal, and viral infections during the first years post-transplant. The focus is on the value of noninvasive diagnostic biomarkers and serological assays in enhancing the early detection and management of these infections.

EXPERT OPINION

Effective management of infectious complications following allo-HSCT relies on continuous immune recovery monitoring and the implementation of advanced diagnostic methods. Utilizing noninvasive diagnostic methods is crucial for early detection and different intervention strategies. The development and integration of reliable microbiological markers into clinical practice is essential for enhancing patient outcomes and mitigating infection-related risks. Emphasizing diagnostic innovation will be pivotal in advancing patient care post-allo-HSCT.

Challenges of concurrent HIV infection in the course and management of Crohn's disease

Crohn's disease (CD) is a chronic transmural bowel inflammation with a multifactorial etiology involving genetic predisposition and immune dysregulation in response to environmental triggers. In patients with human immunodeficiency virus (HIV), an already compromised immune system further complicates the progression and management of CD, creating unique therapeutic challenges. Probiotics have recently gained attention as a potential therapeutic option for CD, especially due to their role in modulating the gut microbiota. However, their effectiveness in patients with HIV, especially in enhancing and maintaining remissions, remains underexplored. This review aimed to examine how HIV infection influences the course of inflammatory bowel disease (IBD) and its impact on CD management strategies. A systematic literature search was conducted using Google Scholar, PubMed, Springer, and Web of Science to identify studies on patients with HIV and CD. HIV infection significantly alters the progression and management of CD due to its impact on the immune system. The immunosuppressed state of patients with HIV can complicate both the diagnosis and treatment of CD, often requiring adjustments in therapeutic approaches, necessitating a careful, tailored approach.

Dynamic proteome and phosphoproteome profiling reveals regulatory mechanisms in LPS-stimulated macrophage inflammatory responses

Macrophage-mediated acute inflammation is crucial for pathogen clearance and tissue repair, yet the underlying molecular mechanisms remain inadequately understood. The present study focused on the dynamic profiles of the proteome and phosphoproteome of macrophages exposed to lipopolysaccharide within 1 h. Gene Set Enrichment Analysis (GSEA) identified significantly enriched pathways in fatty acid metabolism and translation during the early inflammatory phase. Further trend analysis of the differentially expressed proteins revealed patterns associated with translation regulation such as translation initiation. Importantly, the nascent chain experiment demonstrated no significant changes in overall gene translation levels during this phase. These data indicate that macrophages maintain intracellular protein homeostasis through translational regulation, with post-translational modifications (PTMs) playing a crucial role in the rapid cellular response to pathogen invasion. Phosphorylation is a key PTM that regulates protein functions in almost all cellular processes. Time-resolved phosphoproteome analysis identified 367 differentially expressed phosphopeptides involved in immune-related pathways that resist infection. Additionally, weighted gene co-expression network analysis (WGCNA) discovered core modules that regulate translation-related processes such as RNA export from nucleus. Moreover, conjoint analysis of the proteome and phosphoproteome identified the hub protein EF1B that exhibited the largest fold change and is also involved in translation. Our data not only provide a more comprehensive understanding of the dynamic molecular networks of acute macrophage inflammation but also provide a systematic proteomic resource for further studies.

Clinical application of targeted nanopore sequencing in pathogen detection in patients with sepsis

BACKGROUND

Precision in detecting pathogens in sepsis patients is crucial for deploying targeted therapeutic strategies. The objective of the present investigation was to assess the efficacy of targeted nanopore sequencing (TNPseq) as a method for detecting sepsis pathogens.

METHODS

For this investigation, we stratified 90 patients with sepsis into 'improved' and 'unimproved' groups based on their clinical outcomes. Pathogenic microorganisms were detected in various sample types on the day of sepsis diagnosis, utilizing both conventional culture and TNPseq techniques. A comparative analysis of these methodologies was undertaken to assess their performance and efficacy in identifying pathogens in sepsis infections and discern pathogens with significant differences between the distinct patient groups.

RESULTS

The TNPseq analysis demonstrated superior performance in detecting pathogens in sepsis patients, achieving a significantly higher positivity rate (94.4%) compared to the culture method (30.0%, p < 0.001). TNPseq offered enhanced detection capabilities across a diverse array of pathogen types and sample types, outperforming culture particularly in the identification of fungi (35 vs. 8), viruses (46 vs. 1), and atypical pathogens. Both TNPseq and culture yielded concurrent positive results in 26 patient samples, yet TNPseq identified additional pathogens in 14 of these samples. A notable discrepancy in the types of infections was observed between the 'improved' and 'unimproved' groups, with a higher prevalence of single infections among the 'improving' cohort (p < 0.05). Significant differences in the incidence of Acinetobacter baumannii and Clostridium striatum were also evident between the two groups, underscoring the importance of focusing on these two pathogens in future clinical diagnostic efforts.

CONCLUSION

This study underscores the versatility of TNPseq in identifying diverse pathogens in sepsis samples, ensuring its application as a diagnostic when pathogens elude conventional isolation or are difficult to culture. It particularly highlights the significant differences of A. baumannii and C. striatum in the two patient groups, pointing to potential research directions. TNPseq's potential in sepsis diagnosis is promising.

Multicenter Surveillance of Pseudomonas aeruginosa Isolates From Blood: Clinical Distribution Characteristics and Antibiotic Resistance Trends in Hebei Province, China (2016-2021)

Purpose

To analyze the clinical distribution and antimicrobial resistance of Pseudomonas aeruginosa (P. aeruginosa) isolated from blood specimens in 75 hospitals in Hebei Province from 2016 to 2021 to aid in the rational selection of antimicrobial drugs.

Patients and Methods

WHONET 5.6 and SPSS 24.0 were used to retrospectively analyze clinical distribution characteristics and variations in drug-resistance.

Results

Between 2016 and 2021, 2208 P. aeruginosa strains were detected in blood specimens from Hebei Province. The median age of the patients with isolated P. aeruginosa was 63 years, with a male-to-female ratio of 2.1:1. Predominantly, patients were in the hematology (20.7%) and critical care medicine (18.4%) departments. During the monitoring period, the resistance rate of P. aeruginosa to various antibacterial drugs, such as aminoglycosides, fluoroquinolones, and carbapenems, decreased to varying degrees, with an average resistance rate of less than 20.0% over six years. Resistance rates were notably higher in pediatric and intensive care medicine, particularly in neonatal patients, where resistance to antimicrobial drugs, such as piperacillin/tazobactam, gentamicin, ciprofloxacin, and levofloxacin, exceeded 75%.

Conclusion

The main isolates of P. aeruginosa were from elderly and intensive care patients, with a male predominance. From 2016 to 2021, the resistance rate of P. aeruginosa isolated from blood specimens in Hebei Province to various antibiotics such as aminoglycosides, fluoroquinolones, and carbapenems decreased to varying degrees. The resistance rates are high in pediatric and intensive care medicine, especially among neonatal patients. However, resistance to antibiotics varies with age and department, necessitating tailored antimicrobial administration. The issue of antibacterial drug resistance in newborn patients is concerning, and special attention is needed when during treatment.

Microneedle-based arrays - Breakthrough strategy for the treatment of bacterial and fungal skin infections

Currently, fungal and bacterial skin infections rank among the most challenging public health problems due to the increasing prevalence of microorganisms and the development of resistance to available drugs. A major issue in treating these infections with conventional topical medications is the poor penetration through the stratum corneum, the outermost layer of the skin. The concept of microneedles seems to be a future-proof approach for delivering drugs directly into deeper tissues. By bypassing the skin barrier, microneedle systems allow therapeutic substances to reach deeper layers more efficiently, significantly improving treatment outcomes. Nonetheless, the primary challenges regarding the effectiveness of microneedles involve selecting the appropriate size and shape, along with polymer composition and fabrication technology, to enable controlled and efficient drug release. This review offers a comprehensive overview of the latest knowledge on microneedle types and manufacturing techniques, highlighting their potential effectiveness in treating bacterial and fungal skin infections. It includes updated statistics on infection prevalence and provides a detailed examination of common bacterial and fungal diseases, focusing on their symptoms, causative species, and treatment methods. Additionally, the review addresses safety considerations, regulatory aspects, and future perspectives for microneedle-based therapeutic systems. It also underscores the importance of industrialization and clinical translation efforts, emphasizing the significant potential of microneedle technology for advancing medical applications.

E-Cigarette effects on oral health: A molecular perspective

Electronic cigarettes (e-cigarettes) have emerged as a potential alternative to traditional smoking and may aid in tobacco harm reduction and smoking cessation. E-cigarette use has notably increased, especially among young non-tobacco users, raising concerns due to the unknown long-term health effects. The oral cavity is the first and one of the most crucial anatomical sites for the deposition of e-cigarette aerosols. E-cigarette aerosols contain nicotine, flavors, volatile organic compounds, heavy metals, carcinogens, and other hazardous substances. These aerosols impact the oral cavity, disrupting host-microbial interactions and triggering gingivitis and systemic diseases. Furthermore, oral inflammation and periodontitis can be caused by proinflammatory cytokines induced by e-cigarette aerosols. The toxic components of e-cigarette aerosols increase the cellular reactive oxygen species (ROS) levels, reduce antioxidant capacity, increase DNA damage, and disrupt repair processes, which may further contribute to harmful effects on oral epithelum, leading to inflammatory and pre-malignant oral epithelial lesions. In this review, we analyze the toxicological properties of compounds in e-cigarette aerosols, exploring their cytotoxic, genotoxic, and inflammatory effects on oral health and delving into the underlying molecular mechanisms. Further research is essential to understand the impact of e-cigarettes on oral health and make informed regulatory decisions based on reliable scientific evidence.

An overview of immunotoxicity in drug discovery and development

The immune system is one of the common targets of drugs' toxicity (Immunotoxicity) and/or efficacy (Immunotherapy). Immunotoxicity leads to adverse effects on human health, which raises serious concerns for the regulatory agencies. Currently, immunotoxicity assessment is conducted using different in vitro and in vivo assays. In silico and in vitro human cell-based immunotoxicity assays should also be explored for screening purposes as these are time and cost effective as well as for ethical reasons. For in vivo studies, tier 1-3 assessments (Tier 1: hematology, serum globulin levels, lymphoid organ's weight and histopathology; Tier 2: immunophenotyping, TDAR and cell mediated immunity; and Tier 3: host resistance) should be used. These non-clinical in vivo assessments are useful to select immunological endpoints for clinical trials as well as for precautionary labeling. As per regulatory guidelines, adverse immunogenicity information of drug should be included in product's labeling to make health care practitioner aware of safety concerns before prescribing medicines and patient management (USFDA, 2022a, 2022b). This review mainly focuses on the importance of immunotoxicity assessment during drug discovery and development.

Could chronic opioid use be an additional risk of hepatic damage in patients with previous liver diseases, and what is the role of microbiome?

Among illicit drugs, addiction from opioids and synthetic opioids is soaring in an unparalleled manner with its unacceptable amount of deaths. Apart from these extreme consequences, the liver toxicity is another important aspect that should be highlighted. Accordingly, the chronic use of these substances, of which fentanyl is the most frequently consumed, represents an additional risk of liver damage in patients with underlying chronic liver disease. These observations are drawn from various preclinical and clinical studies present in literature. Several downstream molecular events have been proposed, but recent pieces of research strengthen the hypothesis that dysbiosis of the gut microbiota is a solid mechanism inducing and worsening liver damage by both alcohol and illicit drugs. In this scenario, the gut flora modification ascribed to non-alcoholic fatty liver disease performs an additive role. Interestingly enough, HBV and HCV infections impact gut-liver axis. In the end, the authors tried to solicit the attention of operators on this major healthcare problem.

Clinical Manifestations, Antifungal Drug Susceptibility, and Treatment Outcomes for Emerging Zoonotic Cutaneous Sporotrichosis, Thailand

We analyzed clinical manifestations, antifungal susceptibility, and treatment outcomes of cutaneous sporotrichosis in Thailand during 2018-2022. The study included 49 patients whose mean age was 58.7 (SD 16.9) years; 65.3% were female and 34.7% male. A history of cat exposure was reported in 32 (65.3%) patients who had a significantly higher prevalence of upper extremity lesions than did those without cat contact (90.6% vs. 41.7%; adjusted odds ratio 18.9 [95% CI 3.2-92.9]). Among patients >60 years of age, lesions were more likely to be nonpustular than for patients <60 years of age (82.1% vs. 52.4%; p = 0.033). All 9 isolates tested for antifungal drug susceptibility exhibited an itraconazole MIC of <1 μg/mL. Oral itraconazole monotherapy was effective; the median time-to-cure was 180 days (interquartile range 141-240 days). Physicians should heighten their awareness of potential sporotrichosis causes, particularly when a history of animal contact exists.

Cancer treatments as paradoxical catalysts of tumor awakening in the lung

Much of the fatality of tumors is linked to the growth of metastases, which can emerge months to years after apparently successful treatment of primary tumors. Metastases arise from disseminated tumor cells (DTCs), which disperse through the body in a dormant state to seed distant sites. While some DTCs lodge in pre-metastatic niches (PMNs) and rapidly develop into metastases, other DTCs settle in distinct microenvironments that maintain them in a dormant state. Subsequent awakening, induced by changes in the microenvironment of the DTC, causes outgrowth of metastases. Hence, there has been extensive investigation of the factors causing survival and subsequent awakening of DTCs, with the goal of disrupting these processes to decrease cancer lethality. We here provide a detailed overview of recent developments in understanding of the factors controlling dormancy and awakening in the lung, a common site of metastasis for many solid tumors. These factors include dynamic interactions between DTCs and diverse epithelial, mesenchymal, and immune cell populations resident in the lung. Paradoxically, among key triggers for metastatic outgrowth, lung tissue remodeling arising from damage induced by the treatment of primary tumors play a significant role. In addition, growing evidence emphasizes roles for inflammation and aging in opposing the factors that maintain dormancy. Finally, we discuss strategies being developed or employed to reduce the risk of metastatic recurrence.

Dengue fever in immunocompromised patients: A systematic review and meta-analysis

OBJECTIVES

Given the complex role of immunity in dengue severity, we aimed to review the clinical course of dengue infection in immunocompromised patients.

METHODS

We conducted a systematic review of studies reporting outcomes among immunocompromised patients with laboratory-confirmed dengue infection. Meta-analysis using the Mantel-Haenszel method (fixed effects) was performed for studies with control groups. We registered the study with PROSPERO (No. CRD42021258930).

RESULTS

We included 115 studies. Among these, 30 studies compared immunocompromised (cases) and nonimmunocompromised (control) patients, focusing mainly on children (n = 22 studies) with malnutrition (n=18). Immunocompromised patients had a higher likelihood of dengue complications (OR 1.87; 95% CI: 1.04-3.35]) but a lower likelihood of severe dengue (OR 0.83; 95% CI: 0.69-1.00]. No significant difference in mortality was observed. In the 85 studies focused solely on immunocompromised patients, severe dengue and mortality rates were 9% and 4%, respectively, mostly among adult solid organ transplant recipients and those with inflammatory diseases. Immunosuppressive treatment alterations and temporary graft dysfunction were reported.

CONCLUSION

Immunocompromised patients have an increased risk of dengue-related complications. However, definitive conclusions about the comparative severity of dengue across different immunocompromised patient groups are limited by a lack of robust data, highlighting the need for well-designed future studies.

Long-term Risk of Infection Among Patients Colonized With Antimicrobial-Resistant Pathogens: A Population-wide Cohort Study

Background

Antimicrobial-resistant (AMR) pathogens represent an ongoing global health burden. Colonization is often a prerequisite for infection, but the risk of infection after AMR colonization is not well understood. Using population-level health administrative data, we sought to investigate the risk of infection with the same AMR organism after detection of colonization.

Methods

We conducted a retrospective population-wide cohort study among residents of Ontario, Canada, over a 5-year period to determine the risk of infection after detection of colonization with the following AMR pathogens: methicillin-resistant Staphylococcus aureus, vancomycin-resistant Enterococcus, extended-spectrum β-lactamase-producing Enterobacterales, and carbapenemase-producing Enterobacterales. We also examined the effects of age, sex, and health care setting of colonization detection on subsequent infection risk.

Results

There were 69 998 individuals with a positive AMR pathogen surveillance test result during the study period, 15.6% of which subsequently developed a sterile or nonsterile site infection within a median 57 days (IQR, 11-228). Infection rates varied among organisms: 18.3% for methicillin-resistant S aureus within a median 57 days (IQR, 10-239), 2.8% for vancomycin-resistant Enterococcus within a median 37 days (IQR, 11-119), 21.5% for extended-spectrum β-lactamase-producing Enterobacterales within a median 71 days (IQR, 18-231), and 20.3% for carbapenemase-producing Enterobacterales within a median 10 days (IQR, 3-42). A positive surveillance test result detected in a hospital was associated with increased infection risk after colonization as compared with the community setting.

Conclusions

The overall infection rate after colonization with an AMR pathogen was high for most organisms, highlighting the importance of detecting colonization from both an infection control and empiric antibiotic selection perspective.

Decoding the Nexus: Cellular and Molecular Mechanisms Linking Stroke and Neurotoxic Microenvironments in Brain Cancer Patients

Stroke is an often underrecognized albeit significant complication in patients with brain cancer, arising from the intricate interplay between cancer biology and cerebrovascular health. This review delves into the multifactorial pathophysiological framework linking brain cancer to elevated stroke risk, with particular emphasis on the crucial role of the neurotoxic microenvironment (NTME). The NTME, characterized by oxidative stress, neuroinflammation, and blood-brain barrier (BBB) disruption, creates a milieu that promotes and sustains vascular and neuronal injury. Key pathogenic factors driving brain cancer-related stroke include cancer-related hypercoagulability, inflammatory and immunological mechanisms, and other tumor-associated processes, including direct tumor compression, infection-related sequelae, and treatment-related complications. Recent advances in genomic and proteomic profiling present promising opportunities for personalized medicine, enabling the identification of biomarkers-such as oncogenes and tumor suppressor genes-that predict stroke susceptibility and inform individualized therapeutic strategies. Targeting the NTME through antioxidants to alleviate oxidative stress, anti-inflammatory agents to mitigate neuroinflammation, and therapies aimed at reinforcing the BBB could pave the way for more effective stroke prevention and management strategies. This integrative approach holds the potential to reduce both the incidence and severity of stroke, ultimately improving clinical outcomes and quality of life for brain cancer patients. Further research and well-designed clinical trials are essential to validate these strategies and integrate them into routine clinical practice, thereby redefining the management of stroke risk in brain cancer patients.

Modulation of Monocyte Effector Functions and Gene Expression by Human Cytomegalovirus Infection

Monocytes are crucial players in innate immunity. The human cytomegalovirus (CMV) infection has significant impacts on monocyte effector functions and gene expression. CMV, a β-herpesvirus, disrupts key monocyte roles, including phagocytosis, antigen presentation, cytokine production, and migration, impairing their ability to combat pathogens and activate adaptive immune responses. CMV modulates monocyte gene expression, decreasing their capacity for antigen presentation and phagocytosis while increasing pro-inflammatory cytokine production, which can contribute to tissue damage and chronic inflammation. CMV also alters monocyte migration to sites of infection while promoting trans-endothelial migration, thus aiding viral dissemination. Additionally, the virus affects reactive oxygen species (ROS) production, thereby contributing to end-organ disease associated with CMV infection. Overall, these changes enhance viral persistence during acute infection and facilitate immune evasion during latency. We highlight the clinical significance of these disruptions, particularly in immunocompromised patients such as transplant recipients, where the modulation of monocyte function by CMV exacerbates risks for infection, inflammation, and graft rejection. An understanding of these mechanisms will inform therapeutic strategies to mitigate CMV-related complications in vulnerable populations.

Early detection of bloodstream infection in critically ill children using artificial intelligence

BACKGROUND

Despite the high mortality associated with bloodstream infection (BSI), early detection of this condition is challenging in critical settings. The objective of this study was to create a machine learning tool for rapid recognition of BSI in critically ill children.

METHODS

Data were extracted from a derivative cohort comprising patients who underwent at least one blood culture during hospitalization in the pediatric intensive care unit (PICU) of a tertiary hospital from January 2020 to June 2023 for model development. Data from another tertiary hospital were utilized for external validation. Variables selected for model development were age, white blood cell count with segmented neutrophil count, C-reactive protein, bilirubin, liver enzymes, glucose, body temperature, heart rate, and respiratory rate. Algorithms compared were extra trees, random forest, light gradient boosting, extreme gradient boosting, and CatBoost.

RESULTS

We gathered 1,806 measurements and recorded 290 hospitalizations from 263 patients in the derivative cohort. Median age on admission was 43 months, with an interquartile range of 10-118.75 months, and a male predominance was observed (n=160, 55.2%). Candida albicans was the most prevalent pathogen, and median duration to confirm BSI was 3 days (range, 3-4). Patients with BSI experienced significantly higher in-hospital mortality and prolonged stays in the PICU than patients without BSI. Random forest classifier achieved the highest area under the receiver operating characteristic curve of 0.874 (0.762 for the validation set).

CONCLUSIONS

We developed a machine learning model that predicts BSI with acceptable performance. Further research is necessary to validate its effectiveness.

Pneumonia in Transplant Recipients: A Comprehensive Review of Diagnosis and Management

Transplant recipients have an increased risk of complications, including graft dysfunction and infections, which can be life-threatening if not recognized early. Pneumonia ranks as one of the most frequent complications in both solid organ and hematopoietic stem cell transplants. Clinical symptoms manifest late during infections in immunocompromised patients. An aggressive approach centered on early confirmatory diagnosis and a low threshold for empiric therapy is often the most effective strategy. The isolation of a pathogen in an upper airway sample does not necessarily mean the same organism is responsible for pneumonia. Viruses such as CMV (cytomegalovirus virus) may function as co-pathogens for opportunistic infections in transplant recipients in addition to causing their own primary infectious syndrome. Furthermore, some viruses exhibit immunomodulatory effects that can affect the graft function. Given the exhaustive list of causative pathogens responsible for pneumonia, the best approach to the diagnosis is to have a conceptual framework that includes a detailed history, such as the type of transplant, degree of immunosuppression, antimicrobial prophylaxis, risk factors, time of presentation since transplantation and the radiographic pattern on the CT chest (computer tomography of the chest). Management depends predominantly on the degree of antimicrobial resistance, drug-to-drug interaction, and adjustments to the immunosuppression.

Molecular characterization of a novel putative pathogen, Streptococcus nakanoensis sp. nov., isolated from sputum culture

Reports of novel species of α-hemolytic Streptococcus have increased recently. However, limited information exists regarding the pathogenicity of these species, with the exception of Streptococcus pneumoniae and Streptococcus pseudopneumoniae. In this study, a quinolone-resistant α-Streptococcus strain, MTG105, was isolated from the sputum of a patient with pneumonia. This strain was first identified as S. pneumoniae at the hospital laboratory; however, it exhibited unique genetic features upon further analysis. Digital DNA-DNA hybridization and average nucleotide identity based on BLAST values from whole-genome sequencing revealed MTG105 to be a novel species closely related to S. pseudopneumoniae. Although MTG105 carried two copies of the pneumolysin gene, similar to S. pseudopneumoniae, this isolate exhibited susceptibility to optochin under both aerobic and 5% CO2 conditions. Notably, no biochemical features could be used to definitively identify this species. In an infection assay using organotypic lung tissue models, MTG105 induced epithelial damage comparable to that of S. pneumoniae and S. pseudopneumoniae, possibly suggesting its potential as a pathogenic α-Streptococcus. The natural transformation abilities of Streptococcus species facilitate their exchange of genes within the same genus, resulting in the existence of species with increasingly more diverse genome structures. Therefore, the identification of this species highlights the importance of monitoring the emergence of novel species exhibiting virulence and/or multidrug resistance. This isolate was proposed as a novel species, designated Streptococcus nakanoensis sp. nov. The type strain was MTG 105T (= JCM 35953T = CCUG 76894T).

IMPORTANCE

The genus Streptococcus encompasses a wide range of bacteria with more than 60 species. Recently, there has been a notable increase in reports of novel species of α-Streptococcus based on genomic analysis data. However, limited information exists regarding the pathogenicity of these species. In this study, a quinolone-resistant α-hemolytic Streptococcus strain, MTG105, was isolated from a patient with pneumonia. Genetic analysis revealed that this species was a novel species closely related to S. pseudopneumoniae. In an infection assay using organotypic lung tissue models, MTG105 induced epithelial damage comparable to that caused by S. pneumoniae and S. pseudopneumoniae, strongly suggesting its potential as a pathogenic α-Streptococcus. The natural transformation abilities of Streptococcus species facilitate gene exchange within the same genus, leading to the emergence of species with increasingly diverse genome structures. Therefore, the identification of this species underscores the importance of monitoring the emergence of novel species exhibiting virulence and/or multidrug resistance.

Ecological and evolutionary mechanisms driving within-patient emergence of antimicrobial resistance

The ecological and evolutionary mechanisms of antimicrobial resistance (AMR) emergence within patients and how these vary across bacterial infections are poorly understood. Increasingly widespread use of pathogen genome sequencing in the clinic enables a deeper understanding of these processes. In this Review, we explore the clinical evidence to support four major mechanisms of within-patient AMR emergence in bacteria: spontaneous resistance mutations; in situ horizontal gene transfer of resistance genes; selection of pre-existing resistance; and immigration of resistant lineages. Within-patient AMR emergence occurs across a wide range of host niches and bacterial species, but the importance of each mechanism varies between bacterial species and infection sites within the body. We identify potential drivers of such differences and discuss how ecological and evolutionary analysis could be embedded within clinical trials of antimicrobials, which are powerful but underused tools for understanding why these mechanisms vary between pathogens, infections and individuals. Ultimately, improving understanding of how host niche, bacterial species and antibiotic mode of action combine to govern the ecological and evolutionary mechanism of AMR emergence in patients will enable more predictive and personalized diagnosis and antimicrobial therapies.

Coccidioidomycosis and Histoplasmosis in Immunocompetent Individuals: A Comprehensive Review of Clinical Features, Diagnosis, and Management

Coccidioidomycosis and histoplasmosis are endemic mycoses caused by the Coccidioides species and Histoplasma capsulatum, respectively. While these fungal infections are often associated with immunocompromised individuals, they pose significant risks to immunocompetent hosts. This review comprehensively analyzes these infections in immunocompetent individuals, focusing on clinical features, diagnostic approaches, and management strategies. The current understanding of coccidioidomycosis and histoplasmosis in immunocompetent individuals includes their clinical presentations, diagnostic methodologies, and treatment options. A literature review encompassed recent studies, clinical guidelines, and expert opinions. Data were analyzed to highlight critical aspects of the clinical manifestations, diagnostic processes, and management of these infections in immunocompetent patients. Coccidioidomycosis typically presents with pulmonary symptoms that may range from mild to severe and can include chronic and disseminated forms. Histoplasmosis also presents a spectrum of pulmonary symptoms with the potential for extrapulmonary dissemination. Diagnostic approaches for both infections involve clinical evaluation, serological tests, culture, and imaging studies. Management strategies include antifungal therapies such as fluconazole and itraconazole for coccidioidomycosis and itraconazole and amphotericin B for histoplasmosis, with treatment duration and monitoring tailored to the severity of the infection. Coccidioidomycosis and histoplasmosis can significantly affect immunocompetent individuals, with clinical presentations varying widely from mild to severe. Accurate diagnosis and appropriate management are crucial for optimal outcomes. This review underscores the importance of awareness and timely intervention in managing these endemic mycoses and highlights the need for continued research into better diagnostic and therapeutic approaches.

Neurodevelopmental implications of COVID-19-induced gut microbiome dysbiosis in pregnant women

The global public health emergency of COVID-19 in January 2020 prompted a surge in research focusing on the pathogenesis and clinical manifestations of the virus. While numerous reports have been published on the acute effects of COVID-19 infection, the review explores the multifaceted long-term implications of COVID-19, with a particular focus on severe maternal COVID-19 infection, gut microbiome dysbiosis, and neurodevelopmental disorders in offspring. Severe COVID-19 infection has been associated with heightened immune system activation and gastrointestinal symptoms. Severe COVID-19 may also result in gut microbiome dysbiosis and a compromised intestinal mucosal barrier, often referred to as 'leaky gut'. Increased gut permeability facilitates the passage of inflammatory cytokines, originating from the inflamed intestinal mucosa and gut, into the bloodstream, thereby influencing fetal development during pregnancy and potentially elevating the risk of neurodevelopmental disorders such as autism and schizophrenia. The current review discusses the role of cytokine signaling molecules, microglia, and synaptic pruning, highlighting their potential involvement in the pathogenesis of neurodevelopmental disorders following maternal COVID-19 infection. Additionally, this review addresses the potential of probiotic interventions to mitigate gut dysbiosis and inflammatory responses associated with COVID-19, offering avenues for future research in optimizing maternal and fetal health outcomes.

Perioperative infection prevention during inflatable penile prosthesis surgery: a narrative review

Background and Objective

Penile prostheses are an option for the management of erectile dysfunction (ED). Over the years penile prosthesis surgery has become increasingly safe owing to improvements such as antibiotic usage, coated devices, and surgical techniques. However, infection remains a dreaded complication during prosthesis surgery. Efforts to minimize risk of infection in the perioperative period have been extensively studied. Herein, we performed a narrative review on preoperative, intraoperative, and postoperative strategies for infection prevention during placement of a penile prosthesis with a comparison of infection prevention strategies to other surgical fields.

Methods

A literature review was performed using PubMed and Google Scholar. Studies evaluating perioperative management of penile prosthesis infection were included. The following search terms were used to for our literature search: penile prosthesis, inflatable penile prosthesis, infection, prevention, perioperative management. Articles were graded based on the 2011 Oxford Centre for Evidence Based Medicine (OCEBM) guidelines and a table was generated with each intervention discussed and its level of evidence based on current literature.

Key Content and Findings

Optimization of patient's comorbid conditions can help reduce risk during prosthesis operations. Monitoring and optimizing a patient's glycemic control has been investigated, but the current literature does not necessarily support a strict hemoglobin A1c (HbA1c) or pre-operative blood glucose level. Surgical field preparation using chlorhexidine-based solutions has been shown to be superior to iodine-based solutions. Appropriately selected peri-operative antibiotics have also been shown to reduce infection risk. Intraoperatively, the use of coated devices in addition to a 'no touch' technique have been shown to significantly reduce the risk of inflatable penile prosthesis (IPP) infection. Post operatively, available evidence of antibiotic use has not been demonstrated to be effective in reducing infection rates.

Conclusions

Surgical infection following placement of an IPP is a devastating and morbid complication with infection rate up as high as 1-3% in virgin cases and 7-18% in revision cases. While perioperative techniques exist and have reduced risk of infection, more prospective data is needed to evaluate the clinical significance of these different approaches. More research in these areas, along with future options such as nanoparticles, antibiotic coated suture, and next generation sequencing (NGS) for bacterial pathogens, may shed light on further ways to optimize infection reduction strategies for prosthesis surgery.

Therapeutic Potential of Salvia miltiorrhiza Root Extract in Alleviating Cold-Induced Immunosuppression

The interaction between environmental stressors, such as cold exposure, and immune function significantly impacts human health. Research on effective therapeutic strategies to combat cold-induced immunosuppression is limited, despite its importance. In this study, we aim to investigate whether traditional herbal medicine can counteract cold-induced immunosuppression. We previously demonstrated that cold exposure elevated immunoglobulin G (IgG) levels in mice, similar to the effects of intravenous immunoglobulin (IVIg) treatments. This cold-induced rise in circulating IgG was mediated by the renin-angiotensin-aldosterone system and linked to vascular constriction. In our mouse model, the cold-exposed groups (4 °C) showed significantly elevated plasma IgG levels and reduced bacterial clearance compared with the control groups maintained at room temperature (25 °C), both indicative of immunosuppression. Using this model, with 234 mice divided into groups of 6, we investigated the potential of tanshinone IIA, an active compound in Salvia miltiorrhiza ethanolic root extract (SMERE), in alleviating cold-induced immunosuppression. Tanshinone IIA and SMERE treatments effectively normalized elevated plasma IgG levels and significantly improved bacterial clearance impaired by cold exposure compared with control groups injected with a vehicle control, dimethyl sulfoxide. Notably, bacterial clearance, which was impaired by cold exposure, showed an approximately 50% improvement following treatment, restoring immune function to levels comparable to those observed under normal temperature conditions (25 °C, p < 0.05). These findings highlight the therapeutic potential of traditional herbal medicine in counteracting cold-induced immune dysregulation, offering valuable insights for future strategies aimed at modulating immune function in cold environments. Further research could focus on isolating tanshinone IIA and compounds present in SMERE to evaluate their specific roles in mitigating cold-induced immunosuppression.

Activation of neurotoxic A1-reactive astrocytes by SFTS virus infection accelerates fatal brain damage in IFNAR1-/- mice

Severe fever with thrombocytopenia syndrome (SFTS) has a high mortality rate compared to other infectious diseases. SFTS is particularly associated with a high risk of mortality in immunocompromised individuals, while most patients who die of SFTS exhibit symptoms of severe encephalitis before death. However, the region of brain damage and mechanisms by which the SFTS virus (SFTSV) causes encephalitis remains unknown. Here, we revealed that SFTSV infects the brainstem and spinal cord, which are regions of the brain associated with respiratory function, and motor nerves in IFNAR1-/- mice. Further, we show that A1-reactive astrocytes are activated, causing nerve cell death, in infected mice. Primary astrocytes of SFTSV-infected IFNAR1-/- mice also induced neuronal cell death through the activation of A1-reactive astrocytes. Herein, we showed that SFTSV induces fatal neuroinflammation in the brain regions important for respiratory function and motor nerve, which may underlie mortality in SFTS patients. This study provides new insights for the treatment of SFTS, for which there is currently no therapeutic approach.

Bacteria Endocarditis Caused by Mycoplasma hyorhinis in a Juvenile, Immunosuppressed Pig (Sus scrofa domesticus) following Partial Heart Transplantation

Domestic swine (Sus scrofa domesticus) are important translational models for cardiovascular transplant studies. This can be attributed to the anatomic and physiologic similarities of their cardiovascular system to humans. Transplant studies frequently employ clinically relevant immunosuppression regimens to prevent organ rejection postoperatively. Immunosuppression can lead to opportunistic infection, including presentations that are novel or poorly described in immunocompetent hosts. In this study, we describe the first case of Mycoplasma hyorhinis -induced endocarditis affecting the pulmonary valve in a juvenile, immunosuppressed pig following a partial heart transplantation procedure. Clinical signs of infection began at 15 d postoperation, were consistent with a variety of infectious agents, including Mycoplasma hyorhinis, and included lethargy, respiratory signs, and elevated white blood cell counts. By 28 d post procedure, lameness and soft tissue swelling around the left tarsus developed. Joint fluid obtained by arthrocentesis was PCR positive for Mycoplasma hyorhinis and negative for other tested pathogens. Despite antimicrobial treatment, the transplanted pulmonary valve developed leaflet thickening, stenosis, and insufficiency starting at 30 d after the procedure. At 86 d posttransplantation, the pig reached experimental endpoints and was humanely euthanized for necropsy and histopathology. The pulmonary valve had numerous dark red vegetative expansions of all 3 leaflets. Postmortem testing of a vegetative lesion was positive for Mycoplasma hyorhinis, confirming the etiologic agent responsible for endocarditis. Mycoplasma hyorhinis -induced endocarditis of an orthotopic transplanted pulmonary valve has yet to be described in swine. This case report demonstrates that infections following immunosuppression may present with novel or undercharacterized clinical signs.

Erythema Migrans in Patients with Post-Traumatic Splenectomy

Information on asplenic Lyme borreliosis (LB) patients with erythema migrans (EM) is lacking. We compared the course and outcome of 26 EM episodes in 24 post-trauma splenectomized patients (median age 51 years) diagnosed at a single clinical center in Slovenia during 1994-2023 with those of 52 age- and sex-matched patients with EM but with no history of splenectomy. All patients were followed for one year. A comparison of pre-treatment characteristics revealed that EM in splenectomized patients was of shorter duration before diagnosis (4 vs. 8 days, p = 0.034) with a smaller EM diameter (10.5 vs. 14 cm, p = 0.046), and more frequently fulfilled criteria for disseminated LB (3/26, 11.5% vs. 0%, p = 0.034). Treatment failure occurred in 5/26 (19.2%) EM episodes in splenectomized patients versus 0/52 in non-splenectomized patients (p = 0.003). The five treatment failure cases were retreated with antibiotic regimens used to treat EM and had complete resolution of all symptoms/signs. In conclusion, our study showed that splenectomized adult patients with EM differ somewhat in presentation and more often have treatment failure compared with non-splenectomized patients with EM.

Monoclonal Antibody Generation Using Single B Cell Screening for Treating Infectious Diseases

The screening of antigen-specific B cells has been pivotal for biotherapeutic development for over four decades. Conventional antibody discovery strategies, including hybridoma technology and single B cell screening, remain widely used based on their simplicity, accessibility, and proven track record. Technological advances and the urgent demand for infectious disease applications have shifted paradigms in single B cell screening, resulting in increased throughput and decreased time and labor, ultimately enabling the rapid identification of monoclonal antibodies with desired biological and biophysical properties. Herein, we provide an overview of conventional and emergent single B cell screening approaches and highlight their potential strengths and weaknesses. We also detail the impact of innovative technologies-including miniaturization, microfluidics, multiplexing, and deep sequencing-on the recent identification of broadly neutralizing antibodies for infectious disease applications. Overall, the coronavirus disease 2019 (COVID-19) pandemic has reinvigorated efforts to improve the efficiency of monoclonal antibody discovery, resulting in the broad application of innovative antibody discovery methodologies for treating a myriad of infectious diseases and pathological conditions.

Cellulosimicrobium Infections in Humans-A Narrative Review

Cellulosimicrobium species (formerly known as Oerskovia) are Gram-positive filamentous bacteria in the family Promicromonosporaceae and are more commonly found in sewage and soil. The present study aimed to identify all the published cases of Cellulosimicrobium species infections in the literature, describe the epidemiological, clinical, and microbiological characteristics, and provide data regarding its antimicrobial resistance, treatment, and outcomes. A narrative review was performed based on a PubMed and Scopus database search. In total, 38 studies provided data on 40 patients with infections by these species. The median age of patients was 52.5 years, and 55% were male. The most common infection types were bacteremia, infective endocarditis (IE), osteoarticular infections, peritoneal dialysis-associated peritonitis, and endophthalmitis. Antimicrobial resistance to vancomycin and the combination of trimethoprim and sulfamethoxazole was minimal, and vancomycin was the most commonly used antimicrobial for treating these infections. Overall mortality was minimal for all infections, except for bacteremia and IE, which carried high mortality rates.

Ewingella americana Infections in Humans-A Narrative Review

Ewingella americana is a Gram-negative rod that belongs to the order Enterobacterales and the family Yersiniaceae and was first identified in 1983 from 10 clinical strains in the United States of America. The present study aimed to identify all the published cases of E. americana in the literature, describe the epidemiological, clinical, and microbiological characteristics, and provide data regarding its antimicrobial resistance, treatment, and outcomes. A narrative review was performed based on a PubMed and Scopus databases search. In total, 16 studies provided data on 19 patients with infections by E. americana. The median age of the patients was 55 years, and 47.4% were male. The most common infections were those of the bloodstream, the respiratory tract, and the peritoneal cavity. Antimicrobial resistance to cephalosporins, aminoglycosides, and the combination of trimethoprim with sulfamethoxazole was minimal, and these were the most commonly used antimicrobials for treating these infections. No included study provided information on the genetic or molecular mechanism of this pathogen's antimicrobial resistance. The overall mortality was minimal, with only one patient with bacteremia succumbing to the infection. Further studies are needed to better understand this microorganism, its pathogenic potential in humans, and the genetic and molecular mechanisms underlying its antimicrobial resistance, for which very little evidence exists to date.

Unveiling the Uncommon: A Rare Case of Group A Streptococcus Axillary Lymphadenitis With Ambiguous Presentation Leading to Multiple Misdiagnoses

Axillary lymphadenitis in adults presents a diagnostic challenge due to its diverse etiology and variable clinical manifestations. We present a rare case of suppurative Group A Streptococcus (GAS) axillary lymphadenitis secondary to a puncture wound, emphasizing the critical importance of differential diagnosis and immediate intervention. A 36-year-old male initially presented with left axillary pain and discomfort following a traumatic injury to the left thumb. Despite multiple healthcare encounters and misdiagnoses including viral illness and shingles, the patient's condition deteriorated, manifesting as fever, edema, and erythema in the left axilla. This case underscores the paramount significance of considering lymphadenitis in patients with axillary symptoms, particularly following trauma or skin breaches. Early recognition and appropriate management are crucial to prevent grave complications such as abscess formation, thrombophlebitis, and bacteremia. Streptococcal axillary lymphadenitis should be included at the forefront of the differential diagnosis to expedite treatment and mitigate potential life-threatening consequences associated with delayed diagnosis.

Safety profile of recombinant adjuvanted anti-herpes zoster vaccine (RZV) in high-risk groups: Data from active surveillance program. Puglia (Italy), 2021-23

BACKGROUND

Since 2021 a recombinant adjuvanted anti-Herpes Zoster vaccine(Recombinant Zoster Vaccine, RZV) is offered in Italy to high-risk patients. Few real-life data about RZV safety are available in target populations.

OBJECTIVES

This study investigates Adverse Events Following Immunization(AEFIs), baseline disease flare-ups, and Herpes Zoster (HZ) episodes occurring after RZV administration in a heterogeneous population of fragile patients to design its safety profile.

METHODS

This is a retrospective population-based study. RZV-vaccinated patients at Bari Policlinico General Hospital vaccination clinic from October 1st, 2021, to March 31st, 2023, were enrolled. Subjects were screened for reason of RZV eligibility and baseline chronic pathologies. AEFIs occurred in the first 7-days post-vaccination period were collected, and baseline disease flare-ups and post-vaccination HZ episodes were assessed via a 3-month follow-up.

RESULTS

Five-hundred-thirty-eight patients were included and total of 1,031 doses were administered. Most patients were vaccinated due to ongoing immunosuppressive therapy(54.65 %); onco-hematological and cardiovascular conditions were the most common chronic baseline pathologies. Out of 1,031 follow-ups, 441 AEFI cases were reported(42.7/100). The most common symptoms were injection site pain/itching(35.60/100), asthenia/malaise(11.44/100), and fever (10.09/100). Four serious AEFIs occurred(0.38/100). Older age, male sex, and history of cardiovascular diseases(OR:0.71; 95CI:0.52-0.98; p-value <0.05) were found to decrease AEFIs risk, while endocrine-metabolic illnesses(OR:1.61; 95CI:1.15-2.26; p-value <0.05) increased it. Twelve patients(2.23 %) reported a flare-up/worsening of their baseline chronic condition within the first three months after vaccination(mean interval 31.75 days, range 0-68 days). Patients with rheumatological illnesses had a higher risk of relapse(OR:16.56; 95CI:3.58-76.56; p-value <0.001), while male sex behaved as a protective factor. Twelve patients who completed the vaccination cycle(2.43%) had at least one HZ episode by the long-term follow-up.

CONCLUSIONS

The study demonstrates RZV safety in a significant number of high-risk patients. Hence, RZV should be actively offered as part of tailored vaccination programs to decrease the burden of HZ in fragile populations.

Inflammaging in Multidrug-Resistant Sepsis of Geriatric ICU Patients and Healthcare Challenges

Multidrug-resistant sepsis (MDR) is a pressing concern in intensive care unit (ICU) settings, specifically among geriatric patients who experience age-related immune system changes and comorbidities. The aim of this review is to explore the clinical impact of MDR sepsis in geriatric ICU patients and shed light on healthcare challenges associated with its management. We conducted a comprehensive literature search using the National Center for Biotechnology Information (NCBI) and Google Scholar search engines. Our search incorporated keywords such as "multidrug-resistant sepsis" OR "MDR sepsis", "geriatric ICU patients" OR "elderly ICU patients", and "complications", "healthcare burdens", "diagnostic challenges", and "healthcare challenges" associated with MDR sepsis in "ICU patients" and "geriatric/elderly ICU patients". This review explores the specific risk factors contributing to MDR sepsis, the complexities of diagnostic challenges, and the healthcare burden faced by elderly ICU patients. Notably, the elderly population bears a higher burden of MDR sepsis (57.5%), influenced by various factors, including comorbidities, immunosuppression, age-related immune changes, and resource-limited ICU settings. Furthermore, sepsis imposes a significant economic burden on healthcare systems, with annual costs exceeding $27 billion in the USA. These findings underscore the urgency of addressing MDR sepsis in geriatric ICU patients and the need for tailored interventions to improve outcomes and reduce healthcare costs.

Perspectives of emergency department physicians and nurses on reasons for preventable emergency department visits by patients with cancer

BACKGROUND

Patients with cancer frequently visit the emergency department (ED) for medical care, yet approximately half of ED visits for patients with cancer are thought to be preventable. Preventable ED visits are associated with increased healthcare costs and poor patient experiences and outcomes. The voices of ED providers who work with patients with cancer in their everyday practices have not been solicited as it pertains to preventable visits.

OBJECTIVES

The purpose of this study is to describe the perspectives of ED physicians and nurses on reasons for preventable ED visits by patients with cancer.

METHODS

A qualitative descriptive design guided the study. We conducted 23 semi-structured interviews with ED physicians and nurses to query them about their perspectives on the reasons for preventable ED visits by patients with cancer. Content analysis was conducted to list and describe the reasons they discussed.

RESULTS

Participants identified five "medical" and five "non-medical" causes of preventable ED visits. Medical reasons included uncontrolled cancer pain, gastrointestinal symptoms, anemia, fever, and on-going undiagnosed signs and symptoms. Non-medical reasons include patient hesitancy to contact primary care providers, lack of availability or responsiveness of primary providers, lack of access, lack of care coordination, and fears about diagnosis and treatment.

CONCLUSION

The voices of ED providers should be included in discussions about the problem of preventable ED visits by patients with cancer. The reasons supplied by the participants suggest that solutions to the problem will need to occur at the patient, provider, system, and societal levels.

Mathematical modeling in autoimmune diseases: from theory to clinical application

The research & development (R&D) of novel therapeutic agents for the treatment of autoimmune diseases is challenged by highly complex pathogenesis and multiple etiologies of these conditions. The number of targeted therapies available on the market is limited, whereas the prevalence of autoimmune conditions in the global population continues to rise. Mathematical modeling of biological systems is an essential tool which may be applied in support of decision-making across R&D drug programs to improve the probability of success in the development of novel medicines. Over the past decades, multiple models of autoimmune diseases have been developed. Models differ in the spectra of quantitative data used in their development and mathematical methods, as well as in the level of "mechanistic granularity" chosen to describe the underlying biology. Yet, all models strive towards the same goal: to quantitatively describe various aspects of the immune response. The aim of this review was to conduct a systematic review and analysis of mathematical models of autoimmune diseases focused on the mechanistic description of the immune system, to consolidate existing quantitative knowledge on autoimmune processes, and to outline potential directions of interest for future model-based analyses. Following a systematic literature review, 38 models describing the onset, progression, and/or the effect of treatment in 13 systemic and organ-specific autoimmune conditions were identified, most models developed for inflammatory bowel disease, multiple sclerosis, and lupus (5 models each). ≥70% of the models were developed as nonlinear systems of ordinary differential equations, others - as partial differential equations, integro-differential equations, Boolean networks, or probabilistic models. Despite covering a relatively wide range of diseases, most models described the same components of the immune system, such as T-cell response, cytokine influence, or the involvement of macrophages in autoimmune processes. All models were thoroughly analyzed with an emphasis on assumptions, limitations, and their potential applications in the development of novel medicines.

STING dependent BAX-IRF3 signaling results in apoptosis during late-stage Coxiella burnetii infection

STING (STimulator of Interferon Genes) is a cytosolic sensor for cyclic dinucleotides (CDNs) and initiates an innate immune response upon binding to CDNs. Coxiella burnetii is a Gram-negative obligate intracellular bacterium and the causative agent of the zoonotic disease Q fever. The ability of C. burnetii to inhibit host cell death is a critical factor in disease development. Previous studies have shown that C. burnetii inhibits host cell apoptosis at early stages of infection. However, during the late-stages of infection, there is host cell lysis resulting in the release of bacteria to infect bystander cells. Thus, we investigated the role of STING during late-stages of C. burnetii infection and examined STING's impact on host cell death. We show that the loss of STING results in higher bacterial loads and abrogates IFNβ and IL6 induction at 12 days post-infection. The absence of STING during C. burnetii infection significantly reduces apoptosis through decreased caspase-8 and -3 activation. During infection, STING activates IRF3 which interacts with BAX. BAX then translocates to the mitochondria, which is followed by mitochondrial membrane depolarization. This results in increased cytosolic mtDNA in a STING-dependent manner. The presence of increased cytosolic mtDNA results in greater cytosolic 2'-3' cGAMP, creating a positive feedback loop and leading to further increases in STING activation and its downstream signaling. Taken together, we show that STING signaling is critical for BAX-IRF3-mediated mitochondria-induced apoptosis during late-stage C. burnetii infection.

Immune dysfunction in patients with end stage kidney disease; Immunosenescence - Review

The body's defense against environmental factors is realized by physical barriers and cells of both the innate and adaptive immune systems. Patients with end stage kidney disease (ESKD), especially those treated by hemodialysis, have changes in both the function and the number or percent of different leukocyte subsets. Changes were described at the level of monocytes and lymphocyte subsets, which are associated with immunodeficiencies and pro-inflammatory status correlated with degenerative changes and increased cardiovascular risk. These abnormalities have been compared over the past years with alterations appearing as a result ageing. Also, similitudes regarding immunosenescence observed in ESKD patients, in combination with chronic inflammation, are described as the so-called "inflammaging syndrome".

Understanding bacterial pathogenicity: a closer look at the journey of harmful microbes

Bacteria are the most prevalent form of microorganisms and are classified into two categories based on their mode of existence: intracellular and extracellular. While most bacteria are beneficial to human health, others are pathogenic and can cause mild to severe infections. These bacteria use various mechanisms to evade host immunity and cause diseases in humans. The susceptibility of a host to bacterial infection depends on the effectiveness of the immune system, overall health, and genetic factors. Malnutrition, chronic illnesses, and age-related vulnerabilities are the additional confounders to disease severity phenotypes. The impact of bacterial pathogens on public health includes the transmission of these pathogens from healthcare facilities, which contributes to increased morbidity and mortality. To identify the most significant threats to public health, it is crucial to understand the global burden of common bacterial pathogens and their pathogenicity. This knowledge is required to improve immunization rates, improve the effectiveness of vaccines, and consider the impact of antimicrobial resistance when assessing the situation. Many bacteria have developed antimicrobial resistance, which has significant implications for infectious diseases and favors the survival of resilient microorganisms. This review emphasizes the significance of understanding the bacterial pathogens that cause this health threat on a global scale.

Application of plasma metagenomic next-generation sequencing improves prognosis in hematology patients with neutropenia or hematopoietic stem cell transplantation for infection

Introduction

Metagenomic next-generation sequencing (mNGS) is a novel technique for detecting pathogens. This retrospective study evaluated the diagnostic value of mNGS using plasma for infections in hematology patients and its impact on clinical treatment and prognosis in different subgroups of hematology patients.

Methods

A total of 153 hematology patients with suspected infection who underwent mNGS using plasma were enrolled in the study. Their clinical histories, conventional microbiological test (CMT) results, mNGS results, treatment and prognosis were retrospectively analyzed.

Results

In 153 plasma samples, mNGS yielded a higher positivity rate than CMT (total: 88.24% vs. 40.52%, P<0.001; bacteria: 35.95% vs. 21.57%, P < 0.01; virus: 69.93% vs. 21.57%, P<0.001; fungi: 20.26% vs. 7.84%, P<0.01). mNGS had a higher positivity rate for bacteria and fungi in the neutropenia group than in the non-neutropenia group (bacteria: 48.61% vs. 24.69%, P<0.01; fungi: 27.78% vs. 13.58%, P<0.05). mNGS demonstrated a greater advantage in the group of patients with hematopoietic stem cell transplantation (HSCT). Both the 3-day and 7-day efficacy rates in the HSCT group were higher than those in the non-HSCT group (3-day: 82.22% vs. 58.65%, P < 0.01; 7-day: 88.89% vs. 67.31%, P < 0.01), and the 28-day mortality rate was lower in the HSCT group than in the non-HSCT group (6.67% vs. 38.89%, P < 0.000). The neutropenia group achieved similar efficacy and mortality rates to the non-neutropenia group (7-day efficiency rate: 76.39% vs. 71.43%, P > 0.05; mortality rate: 29.17% vs. 29.63%, P > 0.05) with more aggressive antibiotic adjustments (45.83% vs. 22.22%, P < 0.01).

Conclusion

mNGS can detect more microorganisms with higher positive rates, especially in patients with neutropenia. mNGS had better clinical value in patients with hematopoietic stem cell transplantation (HSCT) or neutropenia, which had a positive effect on treatment and prognosis.

Immunogenicity and clinical effectiveness of mRNA vaccine booster against SARS-CoV-2 Omicron in patients with haematological malignancies: A national prospective cohort study

Information regarding the protective anti-SARS-CoV-2 antibody levels and the effectiveness of the mRNA vaccines against the Omicron variant in patients with haematological malignancies is limited. We prospectively followed two times BNT162b2 vaccinated oncohaematological patients (n = 1010) without prior COVID-19 for PCR-confirmed breakthrough infections during the Alpha/Delta and the Omicron phases of the pandemic. Anti-S1-IgG levels were longitudinally monitored in patients who had received the third (booster) vaccine dose. Patients with anti-S1-IgG levels <50 BAU/mL 1 month after the booster had a higher risk of Omicron infections (RR 1.91; 95% CI 1.39-2.63; p = 0.0001) and severe infections (RR 8.74; 95% CI 3.99-19.1; p < 0.0001). Conversely, the risk of severe COVID-19 was <1% with anti-S1-IgG levels >500 BAU/mL and neutralizing antibody concentrations >50 U/mL. The risks of breakthrough Omicron infections (HR 0.55; 95% CI 0.32-0.96; p = 0.034) and severe COVID-19 (HR 0.27; 95% 0.11-0.7; p = 0.0074) were lower among patients who had received the booster dose. In conclusion, low antibody levels are associated with significantly increased risk of both the breakthrough Omicron infections and severe COVID-19. The third mRNA vaccine dose improved the protection against the Omicron and reduced the risk of severe disease.

Antibiotic prophylaxis in immunosuppressed patients - Missed opportunities from trimethoprim-sulfamethoxazole allergy label

Trimethoprim-sulfamethoxazole (TMP-SMX) is a broad spectrum antibiotic in use for more than 50 years. It has an important indication as first line agent in the prophylaxis of opportunistic infections, particularly Pneumocystis jirovecii pneumonia (PJP), in immunosuppressed patients. For those who have a history of allergy or severe intolerance to TMP-SMX, pentamidine, dapsone or atovaquone may be substituted; however there is evidence that TMP-SMX offers superior coverage for PJP, toxoplasmosis, and nocardiosis. Compared to pentamidine, it has the added benefit of cost-effectiveness and self-administration as opposed to required hospital attendance for administration. Many patients who report a history of allergy or adverse reaction to TMP-SMX (or "sulfur allergy") will be found not to be allergic; and even those who are allergic may be able to be desensitized. The evaluation and, where appropriate, removal of TMP-SMX allergy label enables the use of TMP-SMX for prophylaxis against opportunistic infections. This is a cost-effective intervention to optimize antimicrobial prescribing and reduce the risk of opportunistic infections in immunosuppressed patients.

Clinical Analysis of Bacterial Infection Characteristics in Lymphoma Patients with High-dose Chemotherapy Combined with Autologous Hematopoietic Stem Cell Transplantation-A Single-Centered Retrospective Study

BACKGROUND

High-dose chemotherapy combined with autologous hematopoietic stem cell transplantation (HDT/AHSCT) is used to treat lymphoma. Although AHSCT has made considerable strides and become safer, HDT-AHSCT infection continues to be a leading cause of morbidity and mortality associated with transplantation.

OBJECTIVE

To characterise pathogenic bacterial infections in HDT/AHSCT-treated lymphoma patients. The prevalence of pathogenic microorganisms and the timing of foci after transplantation, along with bloodstream infection (BSI) risk factors, can help determine the need for empirical antibiotics after AHSCT.

METHODS

We retrospectively analyzed 133 lymphoma patients treated by HDT/AHSCT from April 2017 to October 2021 at Peking University International Hospital, Beijing, China. We analyzed their clinical characteristics, microbiological distribution characteristics, and BSI risk factors in detail.

RESULTS

In order, intestinal infection (56 cases), BSI (17 cases), pulmonary (12 cases), upper respiratory tract (5 cases), and perianal (4 cases) were the most common locations of infection after HDT/AHSCT. The infection sites yielded 92 putative pathogenic pathogens, with bacteria predominating (61.96%), fungi (28.26%), viruses (5.43%), and mycoplasma (4.35%). Gram-negative bacteria (GNB) strains outnumbered gram-positive bacteria (GPB) strains (73.68%). Two strains of Escherichia coli produced extended-spectrum β-lactamase (ESBL) and one strain of carbapenem-resistant enterobacteriaceae (CRE). Methicillin-resistant Staphylococcus epidermidis (MRSE) had one strain. BSI was caused by Escherichia coli (82.35%), Intestinal mucositis (23.52%), and catheter-associated infections (11.76%). Age, CD34, pretreatment regimen, antibiotic regimen, and past chemotherapeutic agent lung damage were BSI risk variables in univariate analysis. CD34 and past chemotherapeutic drug lung damage were the primary causes of BSI after HDT/AHSCT for lymphoma.

CONCLUSION

High-dose chemotherapy combined with autologous hematopoietic stem cell transplantation (HDT/AHSCT) is used to treat lymphoma. Although AHSCT has made considerable strides and become safer, HDT-AHSCT infection continues to be a leading cause of morbidity and mortality associated with transplantation.