Enhanced neurogenesis after ischemic stroke: The interplay between endogenous and exogenous stem cells

Ischemic stroke is a significant global health crisis, frequently resulting in disability or death, with limited therapeutic interventions available. Although various intrinsic reparative processes are initiated within the ischemic brain, these mechanisms are often insufficient to restore neuronal functionality. This has led to intensive investigation into the use of exogenous stem cells as a potential therapeutic option. This comprehensive review outlines the ontogeny and mechanisms of activation of endogenous neural stem cells within the adult brain following ischemic events, with focus on the impact of stem cell-based therapies on neural stem cells. Exogenous stem cells have been shown to enhance the proliferation of endogenous neural stem cells via direct cell-to-cell contact and through the secretion of growth factors and exosomes. Additionally, implanted stem cells may recruit host stem cells from their niches to the infarct area by establishing so-called "biobridges." Furthermore, xenogeneic and allogeneic stem cells can modify the microenvironment of the infarcted brain tissue through immunomodulatory and angiogenic effects, thereby supporting endogenous neuroregeneration. Given the convergence of regulatory pathways between exogenous and endogenous stem cells and the necessity for a supportive microenvironment, we discuss three strategies to simultaneously enhance the therapeutic efficacy of both cell types. These approaches include: (1) co-administration of various growth factors and pharmacological agents alongside stem cell transplantation to reduce stem cell apoptosis; (2) synergistic administration of stem cells and their exosomes to amplify paracrine effects; and (3) integration of stem cells within hydrogels, which provide a protective scaffold for the implanted cells while facilitating the regeneration of neural tissue and the reconstitution of neural circuits. This comprehensive review highlights the interactions and shared regulatory mechanisms between endogenous neural stem cells and exogenously implanted stem cells and may offer new insights for improving the efficacy of stem cell-based therapies in the treatment of ischemic stroke.

Respiratory syncytial virus vaccination in older adults and patients with chronic disorders: A position paper from the Portuguese Society of Pulmonology, the Portuguese Association of General and Family Medicine, the Portuguese Society of Cardiology, the Portuguese Society of Infectious Diseases and Clinical Microbiology, the Portuguese Society of Endocrinology, Diabetes and Metabolism, and the Portuguese Society of Internal Medicine

BACKGROUND

Respiratory syncytial virus (RSV) is an important cause of lower respiratory tract infection, hospitalisation and death in adults.

METHODS

Based on evidence regarding the impact of RSV on adult populations at risk for severe infection and the efficacy and safety of RSV vaccines, the Portuguese Society of Pulmonology, the Portuguese Association of General and Family Medicine, the Portuguese Society of Cardiology, the Portuguese Society of Infectious Diseases and Clinical Microbiology, the Portuguese Society of Endocrinology, Diabetes and Metabolism, and the Portuguese Society of Internal Medicine endorses this position paper with recommendations to prevent RSV-associated disease and its complications in adults through vaccination.

CONCLUSION

The RSV vaccine is recommended for people aged ≥50 years with risk factors (chronic obstructive pulmonary disease, asthma, heart failure, coronary artery disease, diabetes, chronic kidney disease, chronic liver disease, immunocompromise, frailty, dementia, and residence in a nursing home) and all persons aged ≥60 years. If it cannot be made available to this population, then the vaccine should be prioritised for individuals aged ≥75 years and those aged ≥50 years with risk factors. The vaccine should preferably be given between September and November and can be co-administered with the influenza vaccine. Ongoing studies on RSV vaccines may justify extending these recommendations in the future.

Issue 4 - Impact of air pollution on COVID-19 mortality and morbidity: An epidemiological and mechanistic review

Air pollution is a major global environment and health concern. Recent studies have suggested an association between air pollution and COVID-19 mortality and morbidity. In this context, a close association between increased levels of air pollutants such as particulate matter ≤2.5 to 10 µM, ozone and nitrogen dioxide and SARS-CoV-2 infection, hospital admissions and mortality due to COVID 19 has been reported. Air pollutants can make individuals more susceptible to SARS-CoV-2 infection by inducing the expression of proteins such as angiotensin converting enzyme (ACE)2 and transmembrane protease, serine 2 (TMPRSS2) that are required for viral entry into the host cell, while causing impairment in the host defence system by damaging the epithelial barrier, muco-ciliary clearance, inhibiting the antiviral response and causing immune dysregulation. The aim of this review is to report the epidemiological evidence on impact of air pollutants on COVID 19 in an up-to-date manner, as well as to provide insights on in vivo and in vitro mechanisms.

Vaccination in post-tuberculosis lung disease management: A review of the evidence

INTRODUCTION AND OBJECTIVES

Post-tuberculosis lung disease (PTLD), as other chronic respiratory disorders, may have infectious complications; some of them can be prevented with vaccinations. So far, no document has discussed the potential role of vaccination in PTLD. Therefore, the objective of this review was to describe vaccination recommendations to prevent infections potentially capable of complicating PTLD.

MATERIALS AND METHODS

A non-systematic review of the literature was conducted. The following keywords were used: tuberculosis, vaccination, vaccines and PTLD. PubMed/MEDLINE and Embase were used as the search engine, focusing on English-language literature only.

RESULTS

We identified 9 vaccines potentially useful in PTLD. Influenza, pneumococcal and anti-COVID-19 vaccinations should be recommended. Patients with PTLD can also benefit from vaccination against shingles. Vaccination against pertussis is mainly relevant during childhood. Diphtheria, tetanus and measles vaccination are recommended for general population and should be considered in patients with PTLD not previously vaccinated. Tdap (Tetanus, diphtheria, and pertussis) booster should be repeated in every adult every ten years. Vaccination against BCG retains its importance during early childhood in countries where TB is endemic.

CONCLUSIONS

Vaccination deserves to be considered among the strategies to prevent and/or mitigate PTLD complications. Further evidence is necessary to better understand which vaccines have the greatest impact and cost-benefit.

Clustering patients with COVID-19 according to respiratory support requirements, and its impact on short- and long-term outcome (RECOVID study)

INTRODUCTION

The Spanish Society of Pulmonology and Thoracic Surgery created a registry for hospitalised patients with COVID-19 and the different types of respiratory support used (RECOVID). Objectives. To describe the profile of hospitalised patients with COVID-19, comorbidities, respiratory support treatments and setting. In addition, we aimed to identify varying profiles of patients according to outcomes and the complexity of respiratory support needed.

METHODS

Multicentre, observational study in 49 Spanish hospitals. A protocol collected demographic data, comorbidities, respiratory support, treatment setting and 1-year follow-up. Patients were described using either frequency and percentages or median and interquartile range, as appropriate. A cluster analysis made it possible to identify different types of profile among the patients.

RESULTS

In total, 2148 of 2454 hospitalised patients (87.5%) received care in the conventional ward, whilst 126 in IRCU and 180 in ICU. In IRCU, 30% required high-flow nasal oxygen whilst 25%, non-invasive mechanical ventilation and 17%, mechanical ventilation. Four clusters of patients were identified. Two clusters were more likely to require IRCU/ICU admission, although primarily Cluster 2: Cluster (C) 1 consisted of patients without comorbidities and C2, those with comorbidities. Both presented higher inflammatory levels and lower lymphocyte count and SpO2/FiO2; however, C2 showed worse values. Two different clusters identified patients requiring less complex respiratory support. C3 presented higher comorbidities and elevated lymphocyte count, SpO2/FiO2 and low C-reactive protein (CRP). C4 included those without comorbidities except for arterial hypertension, lymphopenia and an intermediate CRP. In-hospital mortality and subsequent 1-year mortality were greater for C2 (28.6% and 7.1%) and C1 (11.1%, 8.3%) than for C4 (3.3%, 1.8%) and C3 (0%, 0%).

CONCLUSIONS

The cluster analysis identified four clinical phenotypes requiring distinct types of respiratory support, with great differences present per characteristics and outcomes.

Expert consensus and recommendations on the live attenuated hepatitis A vaccine and immunization practices in India

While Hepatitis A Virus (HAV) vaccination in global immunization programs has shown a virtual elimination of the disease within few years of the vaccination program, changing epidemiological landscape in India underscores the need for evidence-based, updated guidance on immunization practices. In May 2024, a panel of 15 distinguished opinion leaders and an organizing committee convened for an intensive, face-to-face advisory board meeting on high burden of HAV infection among adults, increased mortality rate in adolescents, symptomatic presentation in children, and evolving landscape globally and within India. Extensive comparable deliberations on long-term follow-up data from India and data from country of origin advocated immunogenicity, tolerability, and long-term protective effects of single-dose live attenuated HAV vaccine in children. Finally, a consensus was achieved on recognition of increased global attention toward HAV prevention through vaccination coverage. The need for a single dose of live attenuated HAV vaccine was an important outcome of this meeting.

Back to the future? Drastic drop in serotype 19A carriage in daycare centers within two years after a second switch to PCV13 in Belgium

Pneumococcal conjugate vaccines (PCVs) reduce Streptococcus pneumoniae infection and carriage. After switching from PCV13 to PCV10 in 2015-2016, Belgium switched back to PCV13 in 2019. Building on our systematic monitoring of childhood nasopharyngeal carriage since 2016, here, we analyze the serotypes of S. pneumoniae and other pathogens in children attending daycare centers (DCCs) from 2018 to 2021. From the period of 2018-2019 to 2020-2021, we included a total of 2,741 nasopharyngeal swabs collected from children aged 6 to 30 months. We identified S. pneumoniae, Haemophilus influenzae, Moraxella catarrhalis, and Staphylococcus aureus and conducted serotyping and antimicrobial susceptibility assessments of S. pneumoniae strains using culture methods and real-time PCR. S. pneumoniae carriage was frequent and quite stable over the three study years. H. influenzae and M. catarrhalis were more frequently carried than S. pneumoniae. Frequency of all PCV13-serotypes together among S. pneumoniae carriers decreased significantly from 19.4% in 2018-2019 to 9.9% in 2020-2021 (p < .001), largely due to the decreased serotype 19A carriage. Resistance of pneumococcal strains to penicillin increased significantly over the three study years. Two years after the second switch to PCV13 in 2019, pneumococcal serotype 19A carriage decreased again significantly in Belgian children attending daycare centers.

Factors determining first influenza vaccination among individuals with type 2 diabetes in the CONSTANCES cohort by age group (younger than 65 years or 65 and older)

Vaccine coverage against influenza is suboptimal among people with diabetes. Our principal objective was to study and compare the factors related to a first influenza vaccination in individuals with type 2 diabetes according to age group (<65 years and ≥ 65 years) and then to compare the older age group with diabetes to the general population of that age. This is a descriptive cross-sectional study within the French Constances cohort. The study populations were composed of people with type 2 diabetes and individuals without diabetes 65 years and older. Our variable of interest was the first reimbursement for a vaccine against influenza over the period from 2009 to 2019. We identified 2540 cohort members with type 2 diabetes (<65 years n = 1583; ≥65 years n = 957). The population without diabetes (≥65 years) comprised 18,364 individuals. The factors related to the first influenza vaccination differed significantly between the persons with diabetes younger than 65 years and those aged at least 65 years: age (OR = 1.01/OR = 0.89-P-interaction<0.001), poor perceived health (OR = 1.24/OR = 0.79-P-interaction = 0.048), and indicators of diabetes treatment quality [at least 2 hbA1c assays/year (OR = 1.91/0 R = 0.90-P-interaction<0.001), and blood pressure < 140/90 (OR = 1.24/OR = 0.90-P-interaction = 0.059)]. The only factor related to first influenza vaccination significantly different between individuals aged at least 65 years with and without diabetes was age (OR = 0.83/OR = 1.05-P-interaction<0.001). This study shows that trials are now needed to test the effectiveness of age- and sex-specific messages to increase influenza vaccination coverage among people with diabetes.

The natural immune molecules urinary Tamm-Horsfall protein and pentraxin 3 as predictors for recurrent urinary tract infection severity: a single-center self-control study

OBJECTIVE

The innate immune defense plays a pivotal role in protecting the urinary tract from uropathogenic invasion and maintaining immune homeostasis. Dysregulation of the innate immune system can result in recurrent urinary tract infections (RUTI) due to heightened susceptibility to uropathogens. Despite this, predicting the risk of recurrence and the degree of immune compromise in patients who have had one urinary tract infection remains challenging. Also identifying which patients are more susceptible to developing pyelonephritis rather than the more local disease of cystitis is imperfect, although delayed diagnosis of a UTI is a good indicator for developing pyelonephritis. This study aims to assess the potential of urinary Tamm-Horsfall protein (THP) and Pentraxin 3 (PTX3) as predictors of RUTI symptom severity and recurrence, while also evaluating the efficacy of the Chinese herbal formulation Tailin Formula (TLF) as a clinical therapeutic intervention for RUTI.

METHODS

A single-center cohort study was conducted involving 142 participants, consisting of 31 healthy individuals (non-RUTI group, n = 31) and 111 patients with RUTI. The RUTI patients were divided into two groups: one group received continuous low-dose antibiotic therapy (CLAT group, n = 55), and the other group received herbal preparations (Tailin formula) (TLF group, n = 56). All patients received consistent lifestyle guidance. Descriptive analysis was performed on the RUTI cohort.

RESULTS

Urinary THP levels were significantly lower in RUTI patients (TLF and CLAT groups) compared to the non-RUTI, whereas PTX3 levels showed a tendency toward elevation. After treatment, urinary THP levels were markedly higher in the TLF group (27.43 ± 7.07) compared to pretreatment levels (10.00 ± 2.79), while levels remained lower in the CLAT group (8.91 ± 2.23) than in the TLF group. Urinary PTX3 levels decreased post-treatment in both groups after treatment than before (CLAT: 0.30 ± 0.13 vs. 1.04 ± 0.38; TLF: 0.29 ± 0.12 vs. 1.15 ± 0.36). Additionally, THP was negatively correlated with renal tubular injury markers NAG/Cr and β2-MG in RUTI patients (r = -0.5041 and -0.6169, respectively), while PTX3 showed a positive correlation with NAG/Cr and β2-MG (r = 0.28 and 0.498, respectively). Notably, as RUTI symptoms improved and recurrence rates decreased, urinary THP levels increased, while PTX3 levels decreased.

CONCLUSION

This study suggests that urinary THP and PTX3 are likely involved in the pathogenesis of RUTI. These biomarkers may serve as valuable predictors for assessing symptom severity, recurrence risk, and therapeutic efficacy in patients with RUTI at risk of disease progression.

Vaccination strategies for solid organ transplant candidates and recipients: insights and recommendations

INTRODUCTION

Vaccines save lives. They are integral to reducing the morbidity and mortality of vaccine-preventable infections in solid organ transplant recipients. Pre-transplant vaccination provides a unique opportunity for administration of live, viral vaccines, and enhanced vaccine efficacy, compared to the post-transplant period with decreased vaccine response due to immunosuppression.

AREAS COVERED

We discuss a general approach to pre- and post-transplant vaccination in solid organ transplant candidates and recipients. We then review guideline statements and recent literature related to individual vaccines, including the recently developed respiratory syncytial virus vaccine. Travel and occupation-related vaccines are also discussed.

EXPERT OPINION

The challenge of vaccination for immunocompromised patients expands as the prevalence of immunocompromised adults rises, and immunocompromised patients are frequently excluded from vaccine trials. In an age of vaccine hesitancy and reemerging vaccine-preventable infections, well-powered, prospective studies are needed to evaluate the clinical effectiveness of vaccines in solid organ transplant candidates and recipients.

An Italian cost-utility analysis of 20-valent pneumococcal conjugate vaccine for routine vaccination in infants

BACKGROUND

Streptococcus pneumoniae represents a significant global public health threat, causing approximately 45 million lower respiratory tract infections and 350,000 deaths annually among children under 5 years of age. Conjugate pneumococcal vaccines (PCVs), such as PCV15 and PCV20, have been developed to mitigate this burden by providing protection against serotypes responsible for the disease. The present analysis aims to evaluate the cost-utility of PCV20 compared to PCV15 as a vaccination strategy for preventing pneumococcal diseases in children in Italy.

METHODS AND MATERIALS

A cost-utility analysis (CUA) was conducted using a static Markov model adapted to the Italian context to simulate the economic and clinical effects of vaccination over a 10-year time horizon. The study adopted the perspective of the Italian National Health Service (NHS), considering only direct healthcare costs. Deterministic and probabilistic sensitivity analyses were performed to explore parameter uncertainty.

RESULTS

The model showed that PCV20 is a dominant strategy compared to PCV15, generating cost savings of €6.45 million and a gain of 101,708 QALYs (quality-adjusted life years). These benefits are attributed to PCV20's broader serotype coverage, which significantly reduces the incidence of invasive and non-invasive pneumococcal diseases. Vaccination with PCV20 offers substantial clinical and economic advantages over PCV15.

CONCLUSIONS

The introduction of PCV20 as a vaccination strategy for children in Italy represents a cost-effective and clinically advantageous option. Its implementation can reduce the burden of pneumococcal disease and associated healthcare costs, improving public health outcomes and the economic efficiency of the healthcare system.

Differences in virulence and drug resistance between Clostridioides difficile ST37 and ST1 isolates

One of the most common hospital-acquired infections is caused by toxigenic Clostridioides difficile. Although C. difficile ST37 only produces a functional toxin B, it causes disease as severe as that caused by hypervirulent ST1. We aim to compare the differences in virulence and drug resistance between ST37 and ST1 isolates. We conducted whole-genome sequencing on ST37 and ST1 isolates, analyzing their type-specific genes, and the distribution and mutation of genes related to virulence and antibiotic resistance. We compared the in vitro virulence-related phenotypes of ST37 and ST1 isolates, including: TcdB concentration, number of spores formed, aggregation rate, biofilm formation, swimming diameter in semi-solid medium, motility diameter on the surface of solid medium, and their resistance to 14 CDI-related antibiotics. We detected 4 ST37-specific genes related to adherence, including lytC, cbpA, CD3246, and srtB. We detected 97 virulence-related genes in ST37 isolates that exhibit genomic differences compared to ST1. ST37 isolates showed increased aggregation, biofilm formation, and surface motility compared to ST1 in vitro. Chloramphenicol resistance gene catQ and tetracycline resistance gene tetM are present in ST37 but absent in ST1 strains. The resistance rates of ST37 to chloramphenicol and tetracycline were 45.4% and 81.8%, respectively, whereas ST1 isolates were sensitive to both antibiotics. ST1 was more resistant to rifaximin than ST37. ST37 isolates showed stronger aggregation, biofilm formation and surface motility, and had higher resistance rates to chloramphenicol and tetracycline. ST1 isolates showed stronger ability to produce toxin and sporulation, and was highly resistant to rifaximin.

Genomic islands and molecular mechanisms relating to drug-resistance in Clostridioides (Clostridium) difficile PCR ribotype 176

OBJECTIVES

To analyse characteristics of Clostridioides difficile PCR ribotype 176 clinical isolates from Poland, the Czech Republic and Slovakia with regard to the differences in its epidemiology.

METHODS

Antimicrobial susceptibility testing and whole genome sequencing were performed on a selected group of 22 clonally related isolates as determined by multilocus variable-number tandem repeat analysis (n = 509). Heterologous expression and functional analysis of the newly identified methyltransferase were performed.

RESULTS

Core genome multilocus sequence typing found 10-37 allele differences. All isolates were resistant to fluoroquinolones (gyrA_p. T82I), aminoglycosides with aac(6')-Ie-aph(2'')-Ia in six isolates. Erythromycin resistance was detected in 21/22 isolates and 15 were also resistant to clindamycin with ermB gene. Fourteen isolates were resistant to rifampicin with rpoB_p. R505K or p. R505K/H502N, and five to imipenem with pbp1_p. P491L and pbp3_p. N537K. PnimBG together with nimB_p. L155I were detected in all isolates but only five were resistant to metronidazole on chocolate agar. The cfrE, vanZ1 and cat-like genes were not associated with linezolid, teicoplanin and chloramphenicol resistance, respectively. The genome comparison identified six transposons carrying antimicrobial resistance genes. The ermB gene was carried by new Tn7808, Tn6189 and Tn6218-like. The aac(6')-Ie-aph(2'')-Ia were carried by Tn6218-like and new Tn7806 together with cfrE gene. New Tn7807 carried a cat-like gene. Tn6110 and new Tn7806 contained an RlmN-type 23S rRNA methyltransferase, designated MrmA, associated with high-level macrolide resistance in isolates without ermB gene.

CONCLUSIONS

Multidrug-resistant C. difficile PCR ribotype 176 isolates carry already described and unique transposons. A novel mechanism for erythromycin resistance in C. difficile was identified.

All-cause healthcare resource utilization and costs among community-managed adults with long-COVID in France, 2020-2023

BACKGROUND

The clinical and economic burden of long COVID is poorly understood. We aim to assess all-cause healthcare resource utilization (HCRU) and costs in the primary care setting among adults with long COVID in France.

METHODS

A retrospective cohort study using the electronic healthcare records (EHRs) of confirmed and/or probable COVID-19 patients from The Health Improvement Network (THIN) data between March 2020 and December 2022 was conducted. Long COVID was identified per World Health Organization (WHO) definition as suggestive symptoms present ≥3 months following acute SARS-CoV-2 infection. Patients' characteristics, HCRU, direct healthcare and indirect costs (National Health Insurance-based prices) were summarized. Costs between patients with previous SARS-CoV-2 infection who developed long COVID, patients with previous SARS-CoV-2 infection who did not develop long COVID (COVID only), and contemporaneous controls without SARS-CoV-2 infection were compared (Non-COVID).

RESULTS

Long COVID developed among 30,122 (11.6%) adults; mean (SD) age was 50 (17) years, 63.6% were female and 27.5% had a Charlson Comorbidity Index score >2. During the post-infection follow-up (mean = 13 months), 97.3% of patients had general practitioner consultations (GP) and 62.4% had nursing care. Costs were highest during the first post-diagnosis year with per patient per year costs of €2,443 (total cost of €52 million), including costs for GP (€208) and specialist (€170) consultations, outpatient procedures (€413), retail pharmacy use (€595), biological testing (€147), and medical device usage (€172). Patients with long COVID had additional costs of €163 and €176 when compared to patients in the COVID only and Non-COVID cohorts, respectively.

LIMITATIONS

Since the THIN database is generated from GP EHRs, there is the possibility of measurement/documentation errors and missing values which could compromise the validity and accuracy of certain results.

CONCLUSION

Long COVID was associated with non-negligible HCRU, direct and indirect costs to the French healthcare system. These findings reinforce the importance of optimizing long-term resource allocation for patients infected with SARS-CoV-2.

Long-term impact of molecular epidemiology shifts of methicillin-resistant Staphylococcus aureus on severity and mortality of bloodstream infection

A 2019 nationwide study in Japan revealed the predominant methicillin-resistant Staphylococcus aureus (MRSA) types in bloodstream infections (BSIs) to be sequence type (ST)8-carrying SCCmec type IV (ST8-MRSA-IV) and clonal complex 1-carrying SCCmec type IV (CC1-MRSA-IV). However, detailed patient characteristics and how these MRSA types evolve over time remain largely unknown. In this long-term single-center study, MRSA strains isolated from blood cultures at Nagasaki University Hospital from 2012 to 2019 were sequenced and analyzed. Additionally, we compared the SCCmec types and patient characteristics identified in this study with previous data from our hospital spanning 2003-2007 and 2008-2011. Over this 16-year period, SCCmec type II decreased significantly from 79.2% to 15.5%, while type IV increased from 18.2% to 65.5%. This shift in SCCmec types was associated with notable changes in severity and outcomes; the sequential organ failure assessment (SOFA) score decreased from 5.8 to 3.1; in-hospital mortality declined from 39.8% to 15.5%. In contrast, no significant changes in patient demographics, such as age, sex, or underlying diseases, were observed. Between 2012 and 2019, the major combinations of SCCmec type and sequence type were ST8-MRSA-IV, ST8-MRSA-I, CC1-MRSA-IV, and ST5-MRSA-II. Additionally, ST8-MRSA-IV was divided into CA-MRSA/J, t5071-ST8-MRSA-IV, and USA300-like clone based on the results of molecular analysis. These major combinations showed similar drug resistance patterns, molecular characteristics, and phylogenetic features to those identified in nationwide surveillance. This study highlights the evolving nature of MRSA types in bloodstream infections, correlating with improved patient outcomes over time.

Exploration of the feasibility of clinical application of phage treatment for multidrug-resistant Serratia marcescens-induced pulmonary infection

Serratia marcescens (S. marcescens) commonly induces refractory infection due to its multidrug-resistant nature. To date, there have been no reports on the application of phage treatment for S. marcescens infection. This study was conducted to explore the feasibility of phage application in treating refractory S. marcescens infection by collaborating with a 59-year-old male patient with a pulmonary infection of multidrug-resistant S. marcescens. Our experiments included three domains: i) selection of the appropriate phage, ii) verification of the efficacy and safety of the selected phage, iii) confirmation of phage-bacteria interactions. Our results showed that phage Spe5P4 is appropriate for S. marcescens infection. Treatment with phage Spe5P4 showed good efficacy, manifested as amelioration of symptoms, hydrothorax examinations, and chest computed tomography findings. Phage treatment did not worsen hepatic and renal function, immunity-related indices, or indices of routine blood examination. It did not induce or deteriorate drug resistance of the involved antibiotics. Importantly, no adverse events were reported during the treatment or follow-up periods. Thus, phage treatment showed satisfactory safety. Finally, we found that phage treatment did not increase the bacterial load, cytotoxicity, virulence, or phage resistance of S. marcescens, indicating satisfactory phage-bacteria interactions between Spe5P4 and S. marcescens, which are useful for the future application of phage Spe5P4 against S. marcescens. This work provides evidence and a working basis for further application of phage Spe5P4 in treating refractory S. marcescens infections. We also provided a methodological basis for investigating clinical application of phage treatment against multidrug-resistant bacterial infections in the future.

From chaos to order: optimizing fecal microbiota transplantation for enhanced immune checkpoint inhibitors efficacy

The integration of fecal microbiota transplantation (FMT) with immune checkpoint inhibitors (ICIs) presents a promising approach for enhancing cancer treatment efficacy and overcoming therapeutic resistance. This review critically examines the controversial effects of FMT on ICIs outcomes and elucidates the underlying mechanisms. We investigate how FMT modulates gut microbiota composition, microbial metabolite profiles, and the tumor microenvironment, thereby influencing ICIs effectiveness. Key factors influencing FMT efficacy, including donor selection criteria, recipient characteristics, and administration protocols, are comprehensively discussed. The review delineates strategies for optimizing FMT formulations and systematically monitoring post-transplant microbiome dynamics. Through a comprehensive synthesis of evidence from clinical trials and preclinical studies, we elucidate the potential benefits and challenges of combining FMT with ICIs across diverse cancer types. While some studies report improved outcomes, others indicate no benefit or potential adverse effects, emphasizing the complexity of host-microbiome interactions in cancer immunotherapy. We outline critical research directions, encompassing the need for large-scale, multi-center randomized controlled trials, in-depth microbial ecology studies, and the integration of multi-omics approaches with artificial intelligence. Regulatory and ethical challenges are critically addressed, underscoring the imperative for standardized protocols and rigorous long-term safety assessments. This comprehensive review seeks to guide future research endeavors and clinical applications of FMT-ICIs combination therapy, with the potential to improve cancer patient outcomes while ensuring both safety and efficacy. As this rapidly evolving field advances, maintaining a judicious balance between openness to innovation and cautious scrutiny is crucial for realizing the full potential of microbiome modulation in cancer immunotherapy.

Economic analysis of 15-valent and 20-valent pneumococcal conjugate vaccines among older adults in Ontario, Canada

BACKGROUND

Health Canada approved two new pneumococcal conjugate vaccines (PCV), 15-valent (PCV15) and 20-valent (PCV20), and we assessed their cost-effectiveness for older Ontarians.

RESEARCH DESIGN AND METHODS

We conducted a cost-utility analysis using an individual-level state transition model to compare one dose of PCV (alone or in series with PPV23) with PPV23-only. We estimated incremental cost-effectiveness ratios (ICERs) expressed in costs (C$2022) per quality-adjusted life year (QALY) from the healthcare payer perspective, discounted at 1.5% annually.

RESULTS

A sequential comparison of vaccinations with no indirect effect from childhood vaccination resulted in an ICER of $44,324/QALY for PCV15-alone compared to PPV23-only, and $70,751/QALY for PCV20-alone versus PCV15-alone. None of the PCV15/20 combined with PPV23 programs were cost-effective at a C$50,000/QALY threshold. PCV20 alone had an ICER of C$46,961/QALY compared to PPV23-only. When considering indirect effects, PCV15/20 alone or in series with PPV23 were not cost-effective. ICERs were mostly influenced by vaccine characteristics (effectiveness, waning, cost) and the incidence of pneumococcal community-acquired pneumonia.

CONCLUSIONS

Vaccinating older adults with PCV15/20 likely reduces burden of pneumococcal disease and would be cost-effective initially, but is expected to be less economically attractive in the longer term when herd immunity benefits from childhood vaccination programs are considered.

Characterizing the clinical and economic burden of COVID-19 among individuals with immunocompromising conditions in Ontario, Canada - a matched, population-based observational study

AIMS

COVID-19 continues to be associated with substantial burden among immunocompromised patients (IC). This study aimed to describe and compare outcomes during and following COVID-19 hospitalizations among IC and non-IC patients.

METHODS

Patients hospitalized with COVID-19 (January 2020-March 2023) were identified in Ontario health administrative claims databases. All eligible IC (≥1 of solid organ or stem cell transplant; hematological malignancy; rheumatoid arthritis; multiple sclerosis; or primary immunodeficiency) were matched (1:4) to eligible non-IC. Clinical, resource, and costburden were assessed during and post-hospitalization. Multivariate regression models were used to estimate relative risks (RRi), rates (RRa), and corresponding 95% confidence intervals (CIs), adjusting for neighborhood deprivation, long-term care residency, baseline comorbidities, and COVID-19 vaccination status.

RESULTS

9,283 IC hospitalized (mean age 68.7 years; 52.1% female) were matched to 37,127 non-IC. During index hospitalization, IC had greater risks of intensive care unit admission (RRi = 1.06 [1.01-1.12]), ventilation (RRi = 1.27 [1.19-1.36]), and all-cause mortality (RRi = 1.34 [1.27-1.41]) compared to non-IC. Within 30-days post-discharge, IC had greater rates of all-cause readmission (RRa = 1.33 [1.26-1.40]), emergency departments admission (RRa = 1.13 [1.08-1.18]), home oxygen use (RRi = 1.35 [1.15-1.58]), and COVID-19-related rehabilitation (RRa = 1.52 [1.22-1.89]), resulting in 21% (16%-25%) and 51% (45%-58%) greater costs in hospital and post-discharge, respectively. All-cause mortality remained approximately 5% higher for IC vs. non-IC at 30- and 60-days post-discharge (p < .001). Resource use remained elevated among IC with 57% (50%-64%) greater costs within 180 days post-discharge.

LIMITATIONS

Unmeasured confounding remains; hospital prescription data were not available such that treatments for COVID-19 were not captured. Attribution of post-discharge resource use and costs to COVID-19 was subject to greater uncertainty further from the index hospitalization.

CONCLUSION

IC experienced more severe COVID-19 hospitalization outcomes compared to non-IC. COVID-mitigating policies and prophylactic treatments are needed to protect immunocompromised populations.

Cost-effectiveness analysis of implementing 20-valent pneumococcal conjugate vaccine into the Romanian pediatric national immunization program

INTRODUCTION

Despite the inclusion of pneumococcal conjugate vaccines (PCV) in the pediatric national immunization program (NIP) since 2017, Romania continues to face a substantial clinical, economic, and societal burden of pneumococcal disease. Higher-valent vaccines, such as 20-valent PCV (PCV20), offer broader serotype coverage versus the current standard of care (13-valent PCV; PCV13) with the potential to reduce disease burden. To test this, we conducted a cost-effectiveness analysis of switching from PCV13 or a potential future comparator (15-valent PCV; PCV15), both under a 2 + 1 schedule, to PCV20 under a 3 + 1 schedule in the Romanian pediatric NIP.

METHODS

A population-based, multi-cohort Markov model with a target population of children aged <2 years was utilized to estimate the cost and health impact of PCV20 versus lower-valent comparators over 10 years. The model adopted a Romanian societal perspective, encompassing both direct and indirect costs, with an annual cycle. Sensitivity and scenario analyses were conducted to assess the robustness of the model and its assumptions.

RESULTS

In the base-case analysis, PCV20 demonstrated dominance versus PCV13 and PCV15 (i.e. was more effective and less costly), with total predicted cost-savings of 79,123,267 and 206,623,098 Romanian Leu, respectively, plus reduction in pneumococcal disease cases by 246,245 and 223,914, respectively. The majority of sensitivity and scenario analyses of both pairwise comparisons were aligned with the base case.

CONCLUSION

The results of this analysis indicate that PCV20 implementation into the Romanian pediatric NIP would greatly reduce pneumococcal disease burden and would be a cost-effective approach versus PCV13 or PCV15 from a societal perspective over 10 years.

Structural comparison of substrate-binding pockets of serine β-lactamases in classes A, C, and D

β-lactams have been the most successful antibiotics, but the rise of multi-drug resistant (MDR) bacteria threatens their effectiveness. Serine β-lactamases (SBLs), among the most common causes of resistance, are classified as A, C, and D, with numerous variants complicating structural and substrate spectrum comparisons. This study compares representative SBLs of these classes, focusing on the substrate-binding pocket (SBP). SBP is kidney bean-shaped on the indented surface, formed mainly by loops L1, L2, and L3, and an additional loop Lc in class C. β-lactams bind in a conserved orientation, with the β-lactam ring towards L2 and additional rings towards the space between L1 and L3. Structural comparison shows each class has distinct SBP structures, but subclasses share a conserved scaffold. The SBP structure, accommodating complimentary β-lactams, determines the substrate spectrum of SBLs. The systematic comparison of SBLs, including structural compatibility between β-lactams and SBPs, will help understand their substrate spectrum.

The response to desiccation in Acinetobacter baumannii

The long-term resistance to desiccation on abiotic surfaces is a key determinant of the adaptive success of Acinetobacter baumannii as a healthcare-associated bacterial pathogen. Here, the cellular and molecular mechanisms enabling A. baumannii to resist desiccation and persist on abiotic surfaces were investigated. Experiments were set up to mimic the A. baumannii response to air-drying that would occur when bacterial cells contaminate fomites in hospitals. Resistance to desiccation and transition to the "viable but nonculturable" (VBNC) state were determined in the laboratory-adapted strain ATCC 19606T and the epidemic strain ACICU. Culturability, membrane integrity, metabolic activity, virulence, and gene expression profile were compared between the two strains at different stages of desiccation. Upon desiccation, ATCC 19606T and ACICU cells lose culturability and membrane integrity, lower their metabolism, and enter the VBNC state. However, desiccated A. baumannii cells fully recover culturability and virulence in an insect infection model following rehydration in physiological buffers or human biological fluids. Transcriptome and chemical analyses of A. baumannii cells during desiccation unveiled the production of protective metabolites (L-cysteine and L-glutamate) and decreased energetic metabolism consequent to activation of the glyoxylate shunt (GS) pathway, as confirmed by reduced resuscitation efficiency of aceA mutants, lacking the key enzyme of the GS pathway. VBNC cell formation and extensive metabolic reprogramming provide a biological basis for the response of A. baumannii to desiccation, with implications on environmental control measures aimed at preventing the transmission of A. baumannii infection in hospitals.

Anterior cervical discectomy and fusion in treating acute myelopathy caused by Brucella cervical spondylitis: a case series

BACKGROUND AND OBJECTIVES

Cervical disease caused by Brucella infection is rare, with acute spinal cord impairment due to myelitis being a severe complication. If untreated, it can lead to significant patient damage. This study aims to begin to investigate the clinical characteristics of acute cervical myelitis caused by Brucella infection and to evaluate the profile of clinical benefit of anterior cervical discectomy and fusion (ACDF) for this condition.

METHODS

This retrospective case series included 6 patients who underwent surgical treatment for acute cervical spinal cord impairment due to Brucella infection at our institution between January 1, 2013, and January 1, 2023. Clinical data such as age, gender, surgery duration, follow-up period, medication duration, time to bone fusion, ASIA classification, Visual Analog Scale (VAS) score, Japanese Orthopaedic Association (JOA) score, and Neck Disability Index (NDI) score were collected both preoperatively and postoperatively. Statistical analysis was used to assess the clinical benefits of ACDF surgery.

RESULTS

Six patients (4 males, 2 females) underwent successful ACDF. The median age was 52.5 years. The median surgery duration was 130.0 min, and the median hospital stay was 13.5 days. The median follow-up period was 15.0 months, and the median duration of postoperative medication was 16.0 weeks. All patients achieved satisfactory bone graft fusion, with a median fusion time of 4.0 months. ASIA classifications improved in all patients. Three patients improved from grade C to grade E, two from grade B to grades D and E, and one from grade C to grade D. The median VAS score decreased from 6.0 preoperatively to 0.0 at follow-up. The median JOA score increased from 6.0 to 17.0, and the NDI score improved from 29.5 to 4.5. No recurrence of infection or neurological symptoms was observed during follow-up.

CONCLUSION

Acute cervical spinal cord impairment from Brucella infection is rare and challenging to diagnose early. However, early ACDF application effectively relieved spinal cord compression, improved neurological symptoms, and enhanced patient outcomes, demonstrating its efficacy for treating acute myelitis caused by Brucella infection.

Exploring the role of gut microbiota in antibiotic resistance and prevention

BACKGROUND/INTRODUCTION

Antimicrobial resistance (AMR) and the evolution of multiple drug-resistant (MDR) bacteria is of grave public health concern. To combat the pandemic of AMR, it is necessary to focus on novel alternatives for drug development. Within the host, the interaction of the pathogen with the microbiome plays a pivotal role in determining the outcome of pathogenesis. Therefore, microbiome-pathogen interaction is one of the potential targets to be explored for novel antimicrobials.

MAIN BODY

This review focuses on how the gut microbiome has evolved as a significant component of the resistome as a source of antibiotic resistance genes (ARGs). Antibiotics alter the composition of the native microbiota of the host by favouring resistant bacteria that can manifest as opportunistic infections. Furthermore, gut dysbiosis has also been linked to low-dosage antibiotic ingestion or subtherapeutic antibiotic treatment (STAT) from food and the environment.

DISCUSSION

Colonization by MDR bacteria is potentially acquired and maintained in the gut microbiota. Therefore, it is pivotal to understand microbial diversity and its role in adapting pathogens to AMR. Implementing several strategies to prevent or treat dysbiosis is necessary, including faecal microbiota transplantation, probiotics and prebiotics, phage therapy, drug delivery models, and antimicrobial stewardship regulation.

SARS-CoV-2 epidemiology, kinetics, and evolution: A narrative review

Since winter 2019, SARS-CoV-2 has emerged, spread, and evolved all around the globe. We explore 4 y of evolutionary epidemiology of this virus, ranging from the applied public health challenges to the more conceptual evolutionary biology perspectives. Through this review, we first present the spread and lethality of the infections it causes, starting from its emergence in Wuhan (China) from the initial epidemics all around the world, compare the virus to other betacoronaviruses, focus on its airborne transmission, compare containment strategies ("zero-COVID" vs. "herd immunity"), explain its phylogeographical tracking, underline the importance of natural selection on the epidemics, mention its within-host population dynamics. Finally, we discuss how the pandemic has transformed (or should transform) the surveillance and prevention of viral respiratory infections and identify perspectives for the research on epidemiology of COVID-19.

The emergence of highly resistant and hypervirulent Escherichia coli ST405 clone in a tertiary hospital over 8 years

The emergence of carbapenem-resistant Escherichia coli (CREC) poses crucial challenges in clinical management, requiring continuous monitoring to inform control and treatment strategies. This study aimed to investigate the genomic and epidemiological characteristics of CREC isolates obtained from a tertiary hospital in China between 2015 and 2022. Next-generation sequencing was used for genomic profiling, and clinical data from patients were integrated into the analysis. ST405 (21.2%), ST167 (20.3%) and ST410 (15.9%) were the most prevalent of the 30 distinct sequence types (STs) identified among the 113 unique CREC isolates. Infections caused by the ST405 CREC clone and severe underlying diseases were associated with higher in-hospital mortality rates, particularly in patients aged ≥65 years. Furthermore, the ST405 clone exhibited a greater number of virulence and resistance genes than non-ST405 CREC clones. The virulence gene eaeX and resistance genes mph(E) and msr(E) were exclusively found in ST405 clones, while other virulence genes (agn43, ipad and malX) and resistance genes (armA, catB3 and arr-3) were more prevalent in this clones. Additionally, ST405 showed higher minimum inhibitory concentrations for both meropenem and imipenem and showed superior growth under the meropenem challenge. Galleria mellonella virulence assays revealed that the ST405 CREC clone was more virulent than other predominant CREC STs. Our findings underscore the clinical threat posed by the ST405 CREC clone, which exhibits both enhanced virulence and extensive drug resistance. These results highlight the urgent need for stringent surveillance and targeted interventions to curb its further dissemination and prevent potential outbreaks.

Characterization and anti-tuberculosis effects of γδ T cells expanded and activated by Mycobacterium tuberculosis heat-resistant antigen

Tuberculosis (TB) is a chronic infectious disease caused by Mycobacterium tuberculosis (Mtb) that poses a severe threat to human health. A variety of highly immunogenic tuberculosis proteins have been used as targets in vaccine development to mitigate the spread of TB. Although Th1-type immunity has long been considered a crucial part of resistance to Mtb, γδ T cells, the predominant source of IL-17, are not negligible in controlling the early stages of TB infection. In addition to classical phosphoantigens, Mycobacterium tuberculosis heat-resistant antigens (HAg), a complex containing 564 proteins obtained from live tuberculosis bacteria after heat treatment at 121 °C for 20 min, have been confirmed to be highly effective γδ T cell stimulators as well. Several studies have demonstrated that HAg-activated γδ T cells can participate in TB immunity by secreting multiple cytokines against Mtb or by interacting with other innate immune cells. In this review, we present a possible mechanism of HAg stimulation of γδ T cells and the role of HAg-activated γδ T cells in anti-TB immunity. We also highlight the limitations of studies on HAg activation of γδ T cells and suggest further research directions on the relationship between HAg and γδ T cells.

Risk-based triage strategy by extended HPV genotyping for women with ASC-US cytology

OBJECTIVE

We attempted to evaluate the immediate high-grade squamous intraepithelial lesion-cervical intraepithelial neoplasia grade 2/3 or worse (HSIL-CIN2+/3+, hereafter referred to as CIN2+/3+) risk of specific human papillomavirus (HPV) genotype and form the precise risk-based triage strategy for atypical squamous cells of undetermined significance (ASC-US) women.

METHODS

The clinical data of ASC-US women who underwent HPV genotyping testing and colposcopy were retrospectively reviewed. The distribution and CIN2+/3+ risks of specific HPV genotype were assessed by three approaches. The risk-based triage strategy was further established, and its efficacy in detecting CIN2+/3+ was estimated.

RESULTS

Totally, 5553 ASC-US women including 3648 HPV-positive and 1905 HPV-negative were analysed. CIN2+/3+ were 662/319 cases, including 639/306 HPV-positive and 23/13 HPV-negative women. HPV16, HPV52, HPV58 and HPV18 were always among the top 5 ranking genotypes, no matter in HPV-positive women or in HPV-positive CIN2+/3+ cases. HPV16 and HPV33 carried the highest risk, while HPV73 and 26 carried the least risk for CIN2+/3+. Based on the immediate CIN2+/3+ risk of specific HPV genotype, 18 HPVs were divided into three risk-stratified groups. Only women infected with HPVs included in group A were necessary for immediate colposcopy. Compared with conventional strategy, this new risk-based strategy not only had higher specificity (CIN2+: p = .00; CIN3+: p = .01) and positive predictive value (CIN2+: p = .00; CIN3+: p = .03) for detecting CIN2+/3+, but also needed fewer colposcopies to identify each CIN2+/3+.

CONCLUSIONS

A new triage strategy for ASC-US women was successfully constructed based on CIN2+/3+ risks of 14 high-risk and 4 intermediate-risk HPVs, which could significantly reduce unnecessary colposcopies.

Incidence of cytomegalovirus infection after kidney transplantation in the modern era of immunosuppression: the VINTAGE study

Cytomegalovirus (CMV) infection is a frequent complication following kidney transplantation that affects transplant outcomes. This study aimed to (i) estimate the 12-month cumulative incidence of CMV antigenemia (AG) in adult kidney transplant recipients not receiving antiviral prophylaxis, (ii) identify the risk factors for CMV AG, and (iii) assess the impact of CMV AG on transplant outcomes. This study included 128 living donor kidney recipients (aged ≥20 years) who underwent transplantation between 2012 and 2020. The mean recipient age was 52.8 ± 13.0 years. The overall positive CMV AG rates were 10.9%, 35.9%, 45.3%, 53.1%, and 59.4% (95% confidence interval (CI), 50.9-67.9) at 1, 2, 3, 6, and 12 months posttransplantation, respectively. The 12-month incidence rates in D-/R-, D-/R+, D+/R+, and D+/R - were 0%, 25.0%, 62.2%, and 81.3%, respectively. Multivariable analysis revealed that the risk of CMV AG increased with a stepwise increase in CMV serostatus risk category (hazard ratio (HR), 2.65; 95% CI, 1.66-4.21; p < .001) and recipient age (HR, 1.37 per 10-year increase; 95% CI, 1.14-1.65; p < .001). Positive CMV AG was associated with an increased risk of antibody-mediated rejection (HR, 21.40; 95% CI, 2.59-176.2; p = .005) and lower estimated glomerular filtration rate (p = .026). The risk of CMV AG is highest within the first 3 months posttransplant and persists for approximately 7-8 months in D + recipients. These findings underscore the importance of regular CMV monitoring for at least 6 months posttransplantation, particularly in centers employing preemptive therapy.

Closer adult child-parent relations the stronger the vaccine hesitancy: A cross-sectional study of adult Children's attitudes toward pneumococcal vaccination of elderly parents and its determinants in Guangzhou, China

Pneumococcal disease (PD) has a serious effect on older people aged 60 years and above. However, pneumococcal vaccination rates for older people in China remain low. This study aimed to explore adult children's perspectives on the vaccination of their parents and to examine the determinants of vaccine hesitancy. In October 2022, a cross-sectional survey was conducted in Guangzhou, China. The questionnaire assesses data on the sociodemographic characteristics of adult children and their parents, health beliefs about vaccination, and variables measuring adult child-parent relationships. Adult child-parent relationships types were identified by Latent Class Analysis (LCA). Binary logistic regression was employed to examine the factors associated with vaccine hesitancy. A total of 1,597 respondents were enrolled in the study, and 59.8% of the adult children expressed hesitancy about vaccinating their elderly parents. The LCA model identified three distinct types of adult child-parent relations: detached, intimate but distant, and tight-knit. Binary logistic regression analyses revealed that respondents with intimate but distant (OR = 3.04) and tight-knit (OR = 3.01) adult child - parent relationships, high literacy (OR = 2.63), and high perceived barriers of vaccine (OR = 1.18) were more likely to be hesitant. Conversely, those with high income (OR = 0.35) and parents with difficulties in activities of daily living (OR = 0.44) were less likely to exhibit vaccine hesitancy. Close adult child-parent relations were positively associated with vaccine hesitancy. Health education related to the vaccination of older persons should be extended to adult children.

Longitudinal seroprevalence of Crimean-Congo hemorrhagic fever virus in Southern Uganda

Crimean-Congo hemorrhagic fever (CCHF) is a tick-borne disease endemic to many regions of Africa, the Middle East, Southeast Asia and the Balkans. Caused by the CCHF virus (CCHFV), CCHF has been a recognized cause of illness in Uganda since the 1950s and recently, more intensive surveillance suggests CCHFV is widely endemic within the country. Most surveillance has been focused on the Ugandan cattle corridor due to the risk of CCHFV exposure associated with livestock practices. Here we evaluated the seroprevalence of CCHFV in several Southern Ugandan communities outside the cattle corridor combined with longitudinal sample sets to measure the immune response to CCHFV for up to a decade. Interestingly, across three community types, agrarian, trading and fishing, we detected CCHFV seroprevalence in all three but found the highest seroprevalence in fishing communities. We also measured consistent CCHFV-specific antibody responses for up to a decade. Our findings support the conclusion that CCHFV is widely endemic in Uganda and highlight that additional communities may be at risk for CCHFV exposure.

Novel human coronavirus in an infant patient with pneumonia, Republic of Korea

Coronaviruses (CoVs) pose a significant threat to public health, causing a wide spectrum of clinical manifestations and outcomes. Beyond precipitating global outbreaks, Human CoVs (HCoVs) are frequently found among patients with respiratory infections. To date, limited attention has been directed towards alphacoronaviruses due to their low prevalence and fatality rates. Nasal swab and serum samples were collected from a paediatric patient, and an epidemiological survey was conducted. Retrospective surveillance investigated the molecular prevalence of CoV in 880 rodents collected in the Republic of Korea (ROK) from 2018 to 2022. Next-generation sequencing (NGS) and phylogenetic analyses characterized the novel HCoV and closely related CoVs harboured by Apodemus spp. On 15 December 2022, a 103-day-old infant was admitted with fever, cough, sputum production, and rhinorrhea, diagnosed with human parainfluenza virus 1 (HPIV-1) and rhinovirus co-infection. Elevated AST/ALT levels indicated transient liver dysfunction on the fourth day of hospitalization. Metagenomic NGS (mNGS) identified a novel HCoV in nasal swab and serum samples. Retrospective rodent surveillance and phylogenetic analyses showed the novel HCoV was closely related to alphacoronaviruses carried by Apodemus spp. in the ROK and China. This case highlights the potential of mNGS to identify emerging pathogens and raises awareness of possible extra-respiratory manifestations, such as transient liver dysfunction, associated with novel HCoVs. While the liver injury in this case may be attributable to the novel HCoV, further research is necessary to elucidate its clinical significance, epidemiological prevalence, and zoonotic origins.

Eurasian 1C swine influenza A virus exhibits high pandemic risk traits

ABSTRACTRecent surveillance has identified an expansion of swine H1 1C influenza viruses in Eurasian swine. Since 2010, at least 21 spillover events of 1C virus into humans have been detected and three of these occurred from July to December of 2023. Pandemic risk assessment of H1 1C influenza virus revealed that individuals born after 1950 had limited cross-reactive antibodies, confirming that they are antigenically novel viruses. The 1C virus exhibited phenotypic signatures similar to the 2009 pandemic H1N1 virus, including human receptor preference, productive replication in human airway cells, and robust environmental stability. Efficient inter- and intraspecies airborne transmission using the swine and ferret models was observed, including efficient airborne transmission to ferrets with pre-existing human seasonal H1N1 immunity. Together our data suggest H1 1C influenza virus poses a relatively high pandemic risk.

R. M, Poornima S, Narasimhaswamy N, Bairy I, M. M, Hande H. M, Shastry S, Devaki R, M. Varghese G, Saravu K. Persistence of scrub typhus IgM and IgG antibodies among patients from Karnataka, India

BACKGROUND

The longevity of scrub typhus IgM and IgG are not clear. A region-specific diagnostic cut-off for enzyme-linked immunosorbent assay (ELISA) is a necessity for improved diagnosis.

OBJECTIVES

To determine a region-specific optical density (OD) value cut-off for scrub typhus IgM and IgG ELISA and to study the persistence of these antibodies.

METHODS

A prospective cohort study was conducted among patients diagnosed with scrub typhus admitted to Kasturba Hospital, Manipal, Karnataka, India from August 2019 to April 2023. An equal number of scrub typhus patients and healthy volunteers were enrolled to determine region-specific scrub typhus IgM and IgG ELISA OD value cut-off. A receiver operating characteristic (ROC) curve analysis was performed to determine the OD value cut-off with an optimal combination of sensitivity and specificity. The patients were followed up prospectively at varying time points up to 18 months and scrub typhus IgM and IgG ELISA were performed in all the collected samples.

RESULTS

The ROC curve analysis of scrub typhus IgM revealed an optimal OD value cut-off of 1.309 with a sensitivity and specificity of 98.7% (95% CI: 93.1%-100%). The ROC curve analysis of scrub typhus IgG revealed an optimal OD value cut-off of 0.9 with a sensitivity of 71.7% (95% CI: 60.5%-81.4%) and specificity of 93.5% (95% CI: 85.7%-97.9%). At 18 months of follow-up, scrub typhus IgM (OD value > 1.309) and IgG (OD value > 0.9) were above the newly derived diagnostic cut-off in 17 (32%) and 40 (75.4%) patients, respectively.

CONCLUSION

Scrub typhus IgM and IgG antibodies were persistent above the newly derived regional diagnostic cut-off for up to 18 months.

A fresh look at varicella vaccination

The varicella vaccine is a live attenuated varicella zoster virus (VZV), first produced by Michiaki Takahashi (1974). Subsequent development of the fluorescent antibody to VZV membrane antigen test (FAMA), an immune correlate, permitted vaccine efficacy to be established, initially in immunodeficient and then in typical children and adults. Varicella vaccine is effective and safe; universal vaccination has almost eliminated varicella; moreover, endogenous boosting from subclinical VZV reactivation has evidently prevented an anticipated epidemic of zoster from occurring in response to the vaccine-induced loss of circulating varicella. The vaccine virus, moreover, reactivates less frequently than wild-type and an adjuvanted subunit vaccine against VZV gE safely prevents zoster. Doing so is important because VZV establishes latency and reactivates in sympathetic and enteric neurons; therefore, in addition to the painful cutaneous rash and postherpetic neuralgia of zoster, VZV reactivation can be an occult cause of vasculopathy, stroke, intestinal dysmotility, and achalasia.

3'-Sialyllactose and B. infantis synergistically alleviate gut inflammation and barrier dysfunction by enriching cross-feeding bacteria for short-chain fatty acid biosynthesis

Ulcerative colitis (UC) poses significant threats to human health and quality of life worldwide, as it is a chronic inflammatory bowel disease. 3'-sialyllactose (3'-SL) is a key functional component of milk oligosaccharides. This study systematically evaluates the prebiotic effects of 3'-SL and its therapeutic potential in combination with Bifidobacterium infantis (B. infantis) for UC. The findings reveal that 3'-SL and B. infantis synergistically mitigate intestinal inflammation and barrier dysfunction by promoting the production of short-chain fatty acids (SCFAs) through cross-feeding mechanisms among gut microbiota. Individually, 3'-SL, B. infantis, and the synbiotic treatment all effectively alleviated UC symptoms, including reduced weight loss, improved disease activity scores, and prevention of colon shortening. Histopathological and immunofluorescence analyses further demonstrated that the synbiotic treatment significantly ameliorated colonic injury, enhanced barrier function, restored goblet cell counts, increased glycoprotein content in crypt goblet cells, and upregulated the expression of tight junction proteins (ZO-1, occludin, and claudin-1). Notably, the synbiotic treatment outperformed the individual components by better restoring gut microbiota balance, elevating SCFA levels, and modulating serum cytokine profiles, thereby reducing inflammation. These findings provide mechanistic insights into the protective effects of the synbiotic and underscore its therapeutic potential for UC and other intestinal inflammatory disorders.

Synergistic and off-target effects of bacteriocins in a simplified human intestinal microbiome: implications for Clostridioides difficile infection control

Clostridioides difficile is a major cause of nosocomial diarrhea. As current antibiotic treatment failures and recurrence of infections are highly frequent, alternative strategies are needed for the treatment of this disease. This study explores the use of bacteriocins, specifically lacticin 3147 and pediocin PA-1, which have reported inhibitory activity against C. difficile. We engineered Lactococcus lactis strains to produce these bacteriocins individually or in combination, aiming to enhance their activity against C. difficile. Our results show that lacticin 3147 and pediocin PA-1 display synergy, resulting in higher anti-C. difficile activity. We then evaluated the effects of these L. lactis strains in a Simplified Human Intestinal Microbiome (SIHUMI-C) model, a bacterial consortium of eight diverse human gut species that includes C. difficile. After introducing the bacteriocin-producing L. lactis strains into SIHUMI-C, samples were collected over 24 hours, and the genome copies of each species were assessed using qPCR. Contrary to expectations, the combined bacteriocins increased C. difficile levels in the consortium despite showing synergy against C. difficile in agar-based screening. This can be rationally explained by antagonistic inter-species interactions within SIHUMI-C, providing new insights into how broad-spectrum antimicrobials might fail to control targeted species in complex gut microbial communities. These findings highlight the need to mitigate off-target effects in complex gut microbiomes when developing bacteriocin-based therapies with potential clinical implications for infectious disease treatment.

Precision microbiota therapy for IBD: premise and promise

Inflammatory Bowel Disease (IBD) is a spectrum of chronic inflammatory diseases of the intestine that includes subtypes of ulcerative colitis (UC) and Crohn's Disease (CD) and currently has no cure. While IBD results from a complex interplay between genetic, environmental, and immunological factors, sequencing advances over the last 10-15 years revealed signature changes in gut microbiota that contribute to the pathogenesis of IBD. These findings highlight IBD as a disease target for microbiome-based therapies, with the potential to treat the underlying microbial pathogenesis and provide adjuvant therapy to the emerging spectrum of advanced therapies for IBD. Building on the success of fecal microbiota transplantation (FMT) for Clostridioides difficile infection, therapies targeting gut microbiota have emerged as promising approaches for treating IBD; however, unique aspects of IBD pathogenesis highlight the need for more precision in the approach to microbiome therapeutics that leverage aspects of recipient and donor selection, diet and xenobiotics, and strain-specific interactions to enhance the efficacy and safety of IBD therapy. This review focuses on both pre-clinical and clinical studies that support the premise for microbial therapeutics for IBD and aims to provide a framework for the development of precision microbiome therapeutics to optimize clinical outcomes for patients with IBD.

Genomic characterizations of Klebsiella variicola: emerging pathogens identified from sepsis patients in Ethiopian referral hospitals

Healthcare in low- and middle-income countries is becoming problematic due to the emergence of multidrug-resistant bacteria causing serious morbidity and mortality. Klebsiella variicola carrying multiple antimicrobial resistance (AMR) genes were found significantly among sepsis patients in a study done between October 2019 and September 2020 at four Ethiopian hospitals located in the central (Tikur Anbessa and Yekatit 12), southern (Hawassa), and northern (Dessie) parts. Among 1416 sepsis patients, 74 K. variicola isolates were identified using MALDI-TOF, most of them at Dessie (n = 44) and Hawassa (n = 28) hospitals. Whole genome sequencing showed that K. variicola strains identified at Dessie Hospital displayed phylogenetic clonality, carried an IncM1 plasmid and the majority were ST3924. Many K. variicola identified at Hawassa Hospital were clonally clustered and the majority belonged to novel STs and carried IncFIB(K) and IncFII(K) plasmids concurrently. Fifty K. variicola carried ESBL genes while 2 isolates harboured AmpC. Other frequently found genes were aac(3)-lla, blaCTX-M-15, blaTEM-1B, blaLEN2, blaOXA-1, blaSCO-1, catB3, dfrA14, QnrB1, aac(6')-lb-cr and sul2. Virulence genes detected at both sites were mrk operons for biofilm formation and siderophore ABC transporter operons for iron uptake. Capsular alleles varied, with wzi 269 at Dessie and wzi 582 at Hawassa. The isolation of multidrug-resistant K. variicola as an emerging sepsis pathogen calls for strong infection prevention strategies and antimicrobial stewardship supported by advanced bacterial identification techniques.

Clostridioides difficile binary toxin CDT induces biofilm-like persisting microcolonies

Clinical symptoms of Clostridioides difficile infection (CDI) range from diarrhea to pseudomembranous colitis. A major challenge in managing CDI is the high rate of relapse. Several studies correlate the production of CDT binary toxin by clinical strains of C. difficile with higher relapse rates. Although the mechanism of action of CDT on host cells is known, its exact contribution to CDI is still unclear. To understand the physiological role of CDT during CDI, we established two hypoxic relevant intestinal models, Transwell and Microfluidic Intestine-on-Chip systems. Both were challenged with the epidemic strain UK1 CDT+ and its isogenic CDT- mutant. We report that CDT induces mucin-associated microcolonies that increase C. difficile colonization and display biofilm-like properties by enhancing C. difficile resistance to vancomycin. Importantly, biofilm-like microcolonies were also observed in the cecum and colon of infected mice. Hence, our study shows that CDT induces biofilm-like microcolonies, increasing C. difficile persistence and risk of relapse.

Strategies to increase influenza vaccination coverage in the Italian pediatric population: a literature review and expert opinion

INTRODUCTION

Vaccination rates in Italian children must be substantially increased to control the transmission of seasonal influenza and mitigate the associated socio-economic burden. This work aimed to describe strategies to improve the effectiveness and reach of pediatric influenza vaccination campaigns in Italy.

AREAS COVERED

Based on a literature review, influencing factors and potential strategies to enhance vaccination coverage were explored, focusing on settings, logistics, and communication aspects.

EXPERT OPINION

School-based interventions should be deeply implemented in Italy by offering a cost-effective and safe approach to vaccination and successfully overcoming socio-economic and cultural challenges. Scheduled educational programs and institution-supported childhood influenza vaccination awareness campaigns that thoroughly inform about the risk of influenza and its socio-economic consequences, counter vaccine hesitancy, and discuss the benefits of vaccination are desirable, thus concretely prompting all children, families, and healthcare professionals to get vaccinated. Digitalizing procedures could lead to improved adherence by healthcare professionals to immunization programs. Nationwide implementation of these strategies would establish a robust, sustainable system for pediatric influenza vaccination. This would significantly increase childhood vaccination rates, leading to improved disease control and substantially reducing the overall national burden of influenza.

Pathogenicity and virulence of Mycobacterium abscessus

Non-tuberculous mycobacteria (NTM), such as Mycobacterium abscessus (Mab) are an increasing cause of human disease. While the majority of immunocompetent hosts control Mab infections, the robust survival of Mab within the environment has shaped survival in human cells to help drive persistence and cause inflammatory damage in susceptible individuals. With high intrinsic resistance to antibiotics, there is an important need to fully understand how Mab causes infection, define protective host pathways that control disease, and develop new strategies to treat those at high risk. This review will examine the existing literature related to host-Mab interactions with a focus on virulence, the host response, and therapy development. The goal is to highlight key gaps in our understanding and describe novel approaches to encourage new research avenues that better define the pathogenesis and host response against this increasingly important human pathogen.

Emerging antifungal resistance in Trichophyton mentagrophytes: insights from susceptibility profiling and genetic mutation analysis

ABSTRACTTrichophyton species, the leading cause of dermatophytosis globally, are increasingly resistant to antifungal treatments, concerns about effective management strategies. In light of the absence of established resistance criteria for terbinafine and azoles, coupled with a dearth of research on resistance mechanisms in Trichophyton, antifungal susceptibility and drug resistance gene diversity were analyzed across 64 T. mentagrophytes, 65 T. interdigitale, and 2 T. indotineae isolates collected in China between 1999 and 2024 and 101 published T. indotineae strains. Analyses of the minimum inhibitory concentrations (MICs) of terbinafine, itraconazole, voriconazole, posaconazole, and isavuconazole revealed a concerning increase in T. indotineae with terbinafine resistance, including two novel isolates from China. Compared with T. interdigitale, T. mentagrophytes presented higher terbinafine MICs but similar azole susceptibility. Notably, 27 T. interdigitale isolates were classified as non-wild-type for terbinafine. Genetic diversity was analyzed for the SQLE, CYP51A and CYP51B gene. Specifically, T. indotineae isolates presented SQLE protein changes linked to terbinafine resistance. SQLE diversity was linked to terbinafine sensitivity, whereas alterations in CYP51A were associated with itraconazole sensitivity, with notable statistical significance evident across various protein isoforms. The relationship between protein diversity and drug sensitivity is presented in detail. Together, these findings highlight a growing prevalence of antibiotic resistance among Trichophyton and identify potential target genes for new therapies, underscoring the need for ongoing monitoring and offering directions for novel therapeutics.

A modelling framework to characterize the impact of antibiotics on the gut microbiota diversity

Metagenomic sequencing deepened our knowledge about the role of the intestinal microbiota in human health, and several studies with various methodologies explored its dynamics during antibiotic treatments. We compared the impact of four widely used antibiotics on the gut bacterial diversity. We used plasma and fecal samples collected during and after treatment from healthy volunteers assigned to a 5-day treatment either by ceftriaxone (1 g every 24 h through IV route), ceftazidime/avibactam (2 g/500 mg every 8 h through IV route), piperacillin/tazobactam (1 g/500 mg every 8 h through IV route) or moxifloxacin (400 mg every 24 h through oral route). Antibiotic concentrations were measured in plasma and feces, and bacterial diversity was assessed by the Shannon index from 16S rRNA gene profiling. The relationship between the evolutions of antibiotic fecal exposure and bacterial diversity was modeled using non-linear mixed effects models. We compared the impact of antibiotics on gut microbiota diversity by simulation, using various reconstructed pharmacodynamic indices. Piperacillin/tazobactam was characterized by the highest impact in terms of intensity of perturbation (maximal [IQR] loss of diversity of 27.3% [1.9; 40.0]), while moxifloxacin had the longest duration of perturbation, with a time to return to 95% of baseline value after the last administration of 13.2 d [8.3; 19.1]. Overall, moxifloxacin exhibited the highest global impact, followed by piperacillin/tazobactam, ceftazidime/avibactam and ceftriaxone. Their AUC between day 0 and day 42 of the change of diversity indices from day 0 were, respectively, -13.2 Shannon unit.day [-20.4; -7.9], -10.9 Shannon unit.day [-20.4; -0.6] and -10.1 Shannon unit.day [-18.3; -4.6]. We conclude that antibiotics alter the intestinal diversity to varying degrees, both within and between antibiotics families. Such studies are needed to help antibiotic stewardship in using the antibiotics with the lowest impact on the intestinal microbiota.

Modeling the potential public health and economic impact of different COVID-19 vaccination strategies with an adapted vaccine in the Kingdom of Saudi Arabia

BACKGROUND

The dynamic evolution of the virus causing COVID-19 necessitates the development of adapted vaccines to protect against emerging variants.

RESEARCH DESIGN AND METHODS

A combined Markov-decision tree model estimated the outcomes of alternative vaccination strategies. The Saudi Arabian population was stratified into standard-risk and high-risk subpopulations, defined as either the population comprising individuals aged ≥ 65 years and individuals with at least one comorbidity. The model estimated the health and economic outcomes of vaccination based on age-specific inputs taken from published sources and national surveillance data.

RESULTS

The vaccination strategy targeting the elderly and high-risk subpopulation (was estimated to prevent 156,694 cases 12,800 hospitalizations, and 2,919 deaths and result in cost savings of SAR 1,239 million in direct costs and SAR 4,145 million in indirect costs. These gains increased with the vaccination strategies additionally targeting other subpopulations. Compared to the base case (aged ≥65 and those at high-risk), expanding vaccination coverage to 75% of the standard-risk population prevented more cases (323%), hospitalizations (154%), and deaths (60%) and increased the direct (232%) and indirect (270%) cost savings.

CONCLUSIONS

The adoption of broad vaccination strategies using a vaccine adapted to the dominant variant in circulation would yield substantial benefits in Saudi Arabia.

Identification of early prognostic biomarkers in Severe Fever with Thrombocytopenia Syndrome using machine learning algorithms

OBJECTIVE

We aimed at identifying acute phase biomarkers in Severe Fever with Thrombocytopenia Syndrome (SFTS), and to establish a model to predict mortality outcomes.

METHODS

A retrospective analysis was conducted on multicenter clinical data. Group-based trajectory modeling (GBTM) was utilized to demonstrate the overall trend of laboratory indicators and their correlation with mortality. Six different machine learning algorithms were employed to develop prognostic models based on the clinical features during the acute phase, which were reduced using Lasso regression.

RESULTS

Seven indicators (ALT, AST, BUN, LDH, a-HBDH, DD, and PLT) at 7-10 days post-onset and their change slopes were found to be crucial during disease progression. These, along with other clinical features, were reduced to 8 variables using Lasso regression for model construction. The random forest model demonstrated the best performance in both internal validation (AUC: 0.961) and external validation (AUC: 0.948). Decision Curve Analysis indicated a good balance between model benefits and risks.

CONCLUSIONS

a-HBDH and its change slope along with central nervous symptom manifestations within 7-10 days after onset accurately predicted mortality in SFTS. Various algorithms provided a comprehensive overview of disease progression and constructed more stable and efficient models.

Mpox: Global epidemic situation and countermeasures

Mpox, is a zoonotic disease caused by the monkeypox virus and is primarily endemic to Africa. As countries gradually stop smallpox vaccination, resistance to the smallpox virus is declining, increasing the risk of infection with mpox and other viruses. On 14 August 2024, the World Health Organization announced that the spread of mpox constituted a public health emergency of international concern. Mpox's transmission routes and symptoms are complex and pose new challenges to global health. Several vaccines (such as ACAM2000, JYNNEOS, LC16m8, and genetically engineered vaccines) and antiviral drugs (such as tecovirimat, brincidofovir, cidofovir, and varicella immunoglobulin intravenous injection) have been developed and marketed to prevent and control this disease. This review aims to introduce the epidemic situation, epidemiological characteristics, physiological and pathological characteristics, and preventive measures for mpox in detail, to provide a scientific basis for the prevention and control of mpox viruses worldwide.

The role of glutathione for oxidative stress and pathogenicity of Streptococcus suis

Streptococcus suis is an important zoonotic pathogen that threatens human and pig health. During infection, the host can impose oxidative stress to resist pathogen invasion. Resistance to oxidative toxicity is an important factor for pathogens. Glutathione synthesis contributes to reactive oxygen species (ROS) detoxification in bacterial cells. Little is known about the roles of glutathione synthesis and transport in S. suis. In this study, we demonstrated that glutathione treatment increased oxidative stress tolerance in S. suis. GshAB and GshT were found in S. suis glutathione synthesis and import by bioinformatics. In vitro, inactivation of gshAB and gshT led to increased sensitivity to oxidative stress. Inactivation of gshT led to growth defects in the medium. The intracellular glutathione content of gshAB or gshT deletion mutants was lower than that of wild type (WT) strain. The phagocytic resistance of gshAB and gshT mutants was lower than that of the WT strain. Moreover, the virulence of gshAB and gshT deletion mutants was significantly lower than that of the WT strain in mouse survival and tissue loading experiments. In conclusion, these results revealed the functions of GshAB and GshT in the pathogenesis of S. suis. These findings enhance our understanding of bacterial virulence mechanisms and may provide a new avenue for therapeutic intervention aimed at curbing S. suis infections.

A narrative review on the effectiveness of PPSV23 vaccination in adults in China

Pneumococcal Polysaccharide Vaccine (PPSV23) is available for free in some Chinese cities for elderly patients and those with comorbidities. However, there is a lack of studies summarizing its preventive effect specifically in Chinese adults. This review aims to discuss the epidemiology of pneumococcal disease, coverage and effectiveness of PPSV23 vaccination, elderly individuals and patients with comorbidities, coadministration of PPSV23 vaccine with other vaccines, and future directions for its use in China. It was found that the PPSV23 vaccination rate among the elderly ranged from 1.2% to 42.1% depending on location, with an effectiveness of 9.34%(95%CI: 2.05%, 16.62%) to 57.7%(95%CI: 20.7%, 77.5%). There is a need to raise awareness of pneumococcal disease and its prevention, especially in China. To better manage pneumococcal disease in China, developing new vaccines for common serotypes and continuously monitoring serotype distribution associated with the disease is also needed.