Current status of immunisation for herpes zoster

Herpes zoster (HZ) is increasingly common in the aging and is experienced by approximately one in three people in their lifetime. It is also relatively common in immune-compromised people. Acute HZ causes severe pain, reduced quality of life and severe complications, including prolonged pain, or postherpetic neuralgia (PHN), and ocular zoster, which may rarely progress to blindness. In severely immune-compromised people disseminated zoster may affect the brain and liver. A second-generation vaccine, the Recombinant Zoster Vaccine, consisting of recombinant viral glycoprotein E and the Adjuvant System 01 (AS01B), now offers >90% efficacy against HZ and associated complications in immune-competent people. Efficacy persists above 80% for 11 years. In severely immune-compromised patients, the vaccine is safe with efficacy and/or immunogenicity of 68-87%. There is also excellent immunogenicity for those on JAK inhibitors and corticosteroid therapy. The vaccine offers a paradigm for successful and durable immunization in the aging and immune-compromised.

A novel mannan-specific chimeric antigen receptor M-CAR redirects T cells to interact with Candida spp. hyphae and Rhizopus oryzae spores

Invasive fungal infections (IFIs) are responsible for elevated rates of morbidity and mortality, causing around of 1.5 million deaths annually worldwide. One of the main causative agents of IFIs is Candida albicans, and non-albicans Candida species have emerged as a spreading global public health concernment. Furthermore, COVID-19 has contributed to a boost in the incidence of IFIs, such as mucormycosis, in which Rhizopus oryzae is the most prevalent causative agent. The effector host immune response against IFIs depends on the activity of T cells, which are susceptible to the regulatory effects triggered by fungal virulence factors. The fungal cell wall plays a crucial role as a virulence factor, and its remodeling compromises the development of a specific T-cell response. The redirection of Jurkat T cells to target Candida spp. by recognizing targets expressed on the fungal cell wall can be facilitated using chimeric antigen receptor (CAR) technology. This study generated an M-CAR that contains an scFv with specificity to α-1,6 mannose backbone of fungal mannan, and the expression of M-CAR on the surface of modified Jurkat cells triggered a strong activation against Candida albicans (hyphae form), Candida tropicalis (hyphae form), Candida parapsilosis (pseudohyphal form), and Candida glabrata (yeast form). Moreover, M-CAR Jurkat cells recognized Rhizopus oryzae spores, which induced high expression of cell activation markers. Thus, a novel Mannan-specific CAR enabled strong signal transduction in modified Jurkat cells in the presence of Candida spp. or R. oryzae.

Genomic insights into the rapid rise of Pseudomonas aeruginosa ST463: A high-risk lineage's adaptive strategy in China

High-risk lineages of Pseudomonas aeruginosa pose a serious threat to public health, causing severe infections with high mortality rates and limited treatment options. The emergence and rapid spread of the high-risk lineage ST463 in China have further exacerbated this issue. However, the basis of its success in China remains unidentified. In this study, we analyzed a comprehensive dataset of ST463 strains from 2000 to 2023 using whole genome sequencing to unravel the epidemiological characteristics, evolutionary trajectory, and antibiotic resistance profiles. Our findings suggest that ST463 likely originated from a single introduction from North America in 2007, followed by widespread domestic dissemination. Since its introduction, the lineage has undergone significant genomic changes, including the acquisition of three unique regions that enhanced its metabolism and adaptability. Frequent recombination events, along with the burden of bacteriophages, antibiotic resistance genes, and the spread of c1-type (blaKPC-2) plasmid-carrying strains, have played crucial roles in its expansion in China. Mutation analysis reveals adaptive responses to antibiotics and selective pressures on key virulence factors, indicating that ST463 is evolving toward a more pathogenic lifestyle.

Stenotrophomonas maltophilia of clinical origin display higher temperature tolerance comparing with environmental isolates

Stenotrophomonas maltophilia is a gram-negative, multidrug-resistant, opportunistic human pathogen responsible for hard-to-treat infections in immunocompromised individuals. Besides being recognized as an important clinical pathogen, S. maltophilia is also widespread in the natural environment, with knowledge of the pathogenic potential of the environmental S. maltophilia pool still lacking. In this study, we aimed to identify the differences in virulence-related traits between clinical and environmental S. maltophilia isolates by assessing their genotypic and phenotypic features. For this purpose, 40 S. maltophilia isolates from natural environment and 34 clinical isolates obtained from patients were analysed. We observed a high degree of genotypic diversity among the isolates irrespective of their origin. Although antibiotic resistance- and virulence-related genes were more prevalent in the clinical isolates, the majority of the analysed genes were also present in the environmental isolates. Most importantly, the phenotypic features, specifically the ability to form biofilms and display twitching motility at human body temperature were predominantly characteristic to the clinical isolates. Our study indicates that adaptation to endure human body temperature is a feature strongly linked to S. maltophilia strains of clinical origin, and is significant when differentiating harmless environmental bacteria from pathogenic S. maltophilia isolates.

Pathogenicity and virulence of Pseudomonas aeruginosa: Recent advances and under-investigated topics

Pseudomonas aeruginosa is a model for the study of quorum sensing, protein secretion, and biofilm formation. Consequently, it has become one of the most intensely reviewed pathogens, with many excellent articles in the current literature focusing on these aspects of the organism's biology. Here, though, we aim to take a slightly different approach and consider some less well appreciated (but nonetheless important) factors that affect P. aeruginosa virulence. We start by reminding the reader of the global importance of P. aeruginosa infection and that the "virulome" is very niche-specific. Overlooked but obvious questions such as "what prevents secreted protein products from being digested by co-secreted proteases?" are discussed, and we suggest how the nutritional preference(s) of the organism might dictate its environmental reservoirs. Recent studies identifying host genes associated with genetic predisposition towards P. aeruginosa infection (and even infection by specific P. aeruginosa strains) and the role(s) of intracellular P. aeruginosa are introduced. We also discuss the fact that virulence is a high-risk strategy and touch on how expression of the two main classes of virulence factors is regulated. A particular focus is on recent findings highlighting how nutritional status and metabolism are as important as quorum sensing in terms of their impact on virulence, and how co-habiting microbial species at the infection site impact on P. aeruginosa virulence (and vice versa). It is our view that investigation of these issues is likely to dominate many aspects of research into this WHO-designated priority pathogen over the next decade.

Characterizing the epidemiology of Mycoplasma pneumoniae infections in China in 2022-2024: a nationwide cross-sectional study of over 1.6 million cases

Mycoplasma pneumoniae (MP) is a leading cause of community-acquired pneumonia (CAP), accounting for 10-40% of cases in children. In China, the high prevalence of macrolide-resistant MP (MRMP) and recurrent MP epidemics place a significant burden on the healthcare system. Leveraging data from over 1.6 million cases, this study provides a comprehensive analysis of the epidemiological characteristics of MP across China. Seasonal patterns analysis revealed three distinct transmission zones in China. Transmission Zone 1 exhibited two annual epidemic peaks, while Zones 2 and 3 showed a single annual peak of distinct timings. Notably, winter travel to popular tourist destinations appears to influence MP infection patterns in China. Age- and sex- specific analysis indicated male newborns aged [0-1) years face a 1.67 times higher risk of MP infection compared to females. Conversely, females aged [23-38) years have a higher infection risk, likely due to their caregiving roles. The proportion of MRMP surged from 80.00% to 93.02% between July 2023 and May 2024, with a median growth rate of 10.21%. This rapid increase contrasts sharply with the modest 5.3% rise observed from 2011 to 2019, and we attribute this escalation in part to the growing prevalence of the T1-3R clade strain in China. These findings have important implications for the identification of high-risk population, place, and time for more targeted efforts of prevention and treatment. Furthermore, the rapidly increased proportion of MRMP in the 2023-2024 season raises a concerning signal regarding antibiotic use.

Mini-review on the therapeutic vaccines targeting chronic infectious diseases: Evaluation system of therapeutic vaccines targeting HPV and EBV-related cancers

Chronic infectious diseases are threatening human health today, and their public health severity is increasing. The efficacy issues of drugs and the increase in drug-resistant pathogens require new response strategies for chronic infectious diseases, and therapeutic vaccines have recently been proposed as an effective alternative. However, research on therapeutic vaccines is still relatively underdeveloped. To solve this problem, an accurate understanding of the status and the challenge at hand of therapeutic vaccines targeting chronic infectious diseases is needed. In the present review, we provide an overview of the latest research trends in therapeutic vaccines targeting chronic infectious diseases and summarize the development status of therapeutic vaccines currently undergoing clinical research, focusing on the cases of human papillomavirus (HPV) and Epstein-Barr virus (EBV) as representative examples. We highlight the importance of standard methods for the evaluation of therapeutic vaccine, focusing on the cell-mediated immune response, which might accelerate therapeutic vaccine development.

Exploring parents' knowledge, attitudes and practices on honey and botulism in the West Bank, Palestine: a cross-sectional study

BACKGROUND

Although nutritionally beneficial, honey may harbor Clostridium botulinum spores, posing risks to infant botulism (IB). Infants under one year are vulnerable due to immature gut flora, with IB potentially causing severe symptoms, such as respiratory failure. Despite global awareness, cultural beliefs influenced caregivers' practices in Palestine. This study evaluated Palestinian parents' knowledge, beliefs, and feeding practices regarding honey to guide targeted interventions.

METHODS

This cross-sectional study  (August-September 2024) surveyed 469 Palestinian parents (aged ≥18 years) from 10 West Bank cities, excluding 88 ineligible responses. A validated questionnaire assessed their knowledge, attitudes, and practices. Data were analyzed using the R software (frequency, Chi-squared/Fisher's tests; p < 0.05).

RESULTS

Most participants were female (89%), under 30 years old (53%), and highly educated (77%). While 58% knew of honey-linked IB, only 32% identified C. botulinum as the causative agent. Notably, 15.8% fed honey to infants aged <12 months and 62.5% introduced complementary feeding at 6-12 months. Age and income-influenced practices, with many believing that honey aids digestion or supplements nutrition.

CONCLUSIONS

The findings reveal gaps in knowledge and widespread cultural beliefs about the benefits of honey, which contribute to unsafe feeding practices. Health interventions in Palestine should incorporate these insights to improve awareness and to prevent IB.

Sepsis-induced inflammasome impairment facilitates development of secondary A. baumannii pneumonia

BACKGROUND

Acinetobacter baumannii has become one of the most critical pathogens causing nosocomial pneumonia. Existing animal models of A. baumannii pneumonia are not relevant to the majority of critical care patients. We aimed to develop a novel model of secondary A. baumannii pneumonia in post-sepsis mice.

METHODS

A two-hit model of sepsis induced by cecal ligation and puncture followed by A. baumannii pneumonia on day 5 was established. In addition, the two-hit model was established in humanized mice. A period of 2 h of mechanical ventilation followed by observation was used in additional experiments. Lung histopathology, bacterial cultures, and cellular infiltration were analysed as well as markers of the inflammasome activity in vivo and ex vivo.

RESULTS

A. baumannii infection caused mortality and loss of body weight and temperature in post-sepsis mice. Increased lung bacterial burden and dissemination together with signs of enhanced inflammatory injury were observed in post-sepsis mice but not control mice that were challenged with A. baumannii. Post-sepsis mice were unable to mount inflammasome activation in response to secondary pneumonia to the level of control mice. Transfer of wild-type but not capsase-1 KO alveolar macrophages was able to restore the pulmonary protection against A. baumannii. Mechanical ventilation exacerbated the pathological response to pneumonia in post-sepsis mice but enhanced inflammasome signalling in non-sepsis mice with pneumonia.

CONCLUSIONS

We established a novel model of A. baumannii pneumonia that revealed sepsis-induced impairment of inflammasome activation in alveolar macrophages is critical for the control of secondary A. baumannii pneumonia.

Identification of host genetic factors modulating β-lactam resistance in Escherichia coli harbouring plasmid-borne β-lactamase through transposon-sequencing

Since β-lactam antibiotics are widely used, emergence of bacteria with resistance to them poses a significant threat to society. In particular, acquisition of genes encoding β-lactamase, an enzyme that degrades β-lactam antibiotics, has been a major contributing factor in the emergence of bacteria that are resistant to β-lactam antibiotics. However, relatively few genetic targets for killing these resistant bacteria have been identified to date. Here, we used a systematic approach called transposon-sequencing (Tn-Seq), to screen the Escherichia coli genome for host genetic factors that, when mutated, affect resistance to ampicillin, one of the β-lactam antibiotics, in a strain carrying a plasmid that encodes β-lactamase. This approach enabled not just the isolation of genes previously known to affect β-lactam resistance, but the additional loci skp, gshA, phoPQ and ypfN. Individual mutations in these genes modestly but consistently affected antibiotic resistance. We have identified that these genes are not only implicated in β-lactam resistance by itself but also play a crucial role in conditions associated with the expression of β-lactamase. GshA and phoPQ appear to contribute to β-lactam resistance by regulating membrane integrity. Notably, the overexpression of the uncharacterized membrane-associated protein, ypfN, has been shown to significantly enhance β-lactam resistance. We applied the genes identified from the screening into Salmonella Typhimurium and Pseudomonas aeruginosa strains, both critical human pathogens with antibiotic resistance, and observed their significant impact on β-lactam resistance. Therefore, these genes can potentially be utilized as therapeutic targets to control the survival of β-lactamase-producing bacteria.

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.

Pathogenicity and virulence of lumpy skin disease virus: A comprehensive update

Lumpy skin disease (LSD), which was confined to the Africa for many decades, has expanded its geographical distribution to numerous countries across Asia and Europe in recent years. The LSD virus (LSDV) is a relatively poorly studied virus. Its 151 Kb genome encodes 156 open reading frames (ORF); however, the exact number of the proteins encoded by the viral genome and their specific functions remain largely unknown. Arthropod vectors primarily transmit the LSDV mechanically, but the precise nature of these vectors in different regions and their role in transmission is not fully understood. Homologous live-attenuated vaccines prepared using LSDV have proven to be highly efficacious compared to heterologous vaccines based on sheep pox virus or goatpox virus, in protecting cattle against LSD. This review offers the latest insights into the molecular biology and transmission of LSDV and discusses the safety and efficacy of available vaccines, along with the challenges faced in controlling and eradicating the disease in endemic regions.

Dilemma in prevention of pertussis infection among infants under six months in China

INTRODUCTION

Pertussis poses a significant threat to infants under six months due to their immature immune systems, limited maternal antibody protection, and constraints in the vaccination schedule. Despite vaccination efforts, this group remains highly susceptible to severe complications. Addressing these challenges is crucial for improving the health outcomes of infants in China.

AREAS COVERED

This review examines the primary challenges in preventing pertussis infections among infants under six months in China, focusing on factors such as underdeveloped immune system and inadequate maternal antibody protection. It analyzes limitations in current vaccination strategies and the impact of socio-cultural factors, healthcare resource distribution, and surveillance inadequacies. A comprehensive literature search was conducted to identify potential solutions, including enhancing maternal immunization, adjusting early vaccination strategies, increasing vaccine coverage, and developing new vaccines. The review synthesizes current research findings and data to provide a detailed overview of these issues.

EXPERT OPINION

Infants under six months are particularly vulnerable to pertussis. Early and effective prevention strategies, such as enhanced maternal immunization and adjusted vaccination schedules, are needed. Increasing vaccine coverage and developing safer, more immunogenic vaccines are essential. Policymakers should prioritize these measures to reduce pertussis incidence and complications among infants in China.

The T-type voltage-gated Ca2+ channel CaV3.1 involves in the disruption of respiratory epithelial barrier induced by Pasteurella multocida toxin

Pasteurella multocida toxin (PMT) is an exotoxin produced by several members of the zoonotic respiratory pathogen P. multocida. The role of PMT in disrupting the mammalian respiratory barrier remains to be elucidated. In this study, we showed that inoculation of recombinantly expressed PMT increased the permeability of the respiratory epithelial barrier in mouse and respiratory cell models. This was evidenced by a decreased expression of tight junctions (ZO-1, occludin) and adherens junctions (β-catenin, E-cadherin), as well as enhanced cytoskeletal rearrangement. In mechanism, we demonstrated that PMT inoculation induced cytoplasmic Ca2+ inflow, leading to an imbalance of cellular Ca2+ homoeostasis and endoplasmic reticulum stress. This process further stimulated the RhoA/ROCK signalling, promoting cytoskeletal rearrangement and reducing the expression of tight junctions and adherens junctions. Notably, the T-type voltage-gated Ca2+ channel CaV3.1 was found to participate in PMT-induced cytoplasmic Ca2+ inflow. Knocking out CaV3.1 significantly reduced the cytotoxicity induced by PMT on swine respiratory epithelial cells and mitigated cytoplasmic Ca2+ inflow stimulated by PMT. These findings suggest CaV3.1 contributes to PMT-induced respiratory epithelial barrier disruption.

Salmonella utilizes L-arabinose to silence virulence gene expression for accelerated pathogen growth within the host

Carbon source is an important nutrient for bacteria to sustain growth and often acts as a signal that modulates virulence expression. L-arabinose is produced by plants and plays an important role in regulating the global gene expression of bacteria. Previously, we have shown that L-arabinose induces a more severe systemic infection in Salmonella-infected mice with normal microbiota, but does not affect the disease progression in mice with microbiota depleted by antibiotic treatment. The underlying mechanism remains elusive. In this study, we demonstrate that L-arabinose represses the expression of Salmonella type III secretion system 1 (T3SS-1) genes by negatively regulating the activity of the cyclic 3' 5'-AMP (cAMP)-cAMP receptor protein (CRP) complex. The cAMP-CRP complex can activate ribosome-associated inhibitor A, encoded by yfiA, to maintain the stability of HilD, a key transcriptional regulator of T3SS-1. L-arabinose supplementation promotes Salmonella initial bloom in the antibiotic-pretreated mouse gut and ultimately compensates for reduced virulence within the host. These results decipher the molecular mechanism by which cAMP-CRP directs regulatory changes of virulence in response to L-arabinose in Salmonella. It further implies that Salmonella exploits L-arabinose both as a nutrient and a regulatory signal to maintain a balance between growth and virulence within the host.

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.

Interplay of Mycobacterium abscessus and Pseudomonas aeruginosa in experimental models of coinfection: Biofilm dynamics and host immune response

The incidence of infection by nontuberculous mycobacteria, mainly Mycobacterium abscessus, is increasing in patients with cystic fibrosis and other chronic pulmonary diseases, leading to an accelerated lung function decline. In most cases, M. abscessus coinfects Pseudomonas aeruginosa, the most common pathogen in these conditions. However, how these two bacterial species interact during infection remains poorly understood. This study explored their behaviour in three relevant pathogenic settings: dual-species biofilm development using a recently developed method to monitor individual species in dual-species biofilms, coinfection in bronchial epithelial cells, and in vivo coinfection in the Galleria mellonella model. The results demonstrated that both species form stable mixed biofilms and reciprocally inhibit single-biofilm progression. Coinfections in bronchial epithelial cells significantly decreased cell viability, whereas in G. mellonella, coinfections induced lower survival rates than individual infections. Analysis of the immune response triggered by each bacterium in bronchial epithelial cell assays and G. mellonella larvae revealed that P. aeruginosa induces the overexpression of proinflammatory and melanization cascade responses, respectively. In contrast, M. abscessus and P. aeruginosa coinfection significantly inhibited the immune response in both models, resulting in worse consequences for the host than those generated by a single P. aeruginosa infection. Overall, this study highlights the novel role of M. abscessus in suppressing immune responses during coinfection with P. aeruginosa, emphasizing the clinical implications for the management of cystic fibrosis and other pulmonary diseases. Understanding these interactions could inform the development of new therapeutic strategies to mitigate the severity of coinfections in vulnerable patients.

Attitudes and acceptance of vaccination against neglected tropical diseases: A multi-country study in Asia

This study aims to explore the willingness of individuals to be vaccinated against NTDs in Asian countries and China. Between June and December 2023, an anonymous cross-sectional survey was carried out in five Asian countries alongside China. Overall, 48.4% indicated being somewhat willing and 29.2% expressing extreme willingness to receive NTDs vaccination. High attitude scores (adjusted odds ratio [aOR] = 1.54, 95% confidence interval (CI): 11.35-1.75) was associated with higher willingness to be vaccinated against NTDs. The odds of accepting the NTDs vaccine increased among individuals without occupational exposure to NTDs (aOR = 1.46, 95% CI: 1.27-1.68). Those residing in very clean environments exhibited heightened odds of willingness (aOR = 2.94, 95% CI: 2.10-4.11), whereas individuals in somewhat dirty environments demonstrated reduced odds of willingness (aOR = 0.74, 95% CI: 0.56-0.98) compared to the baseline group (very dirty local environment). Moreover, a higher score in sanitation facilities also correlated with increased odds of willingness to receive the NTDs vaccine (aOR = 1.41, 95% CI: 1.21-1.64). The study highlighted key strategies for improving NTDs vaccine uptake in Asian countries, including China, such as fostering positive attitudes toward the vaccine and enhancing perception of infection risks.

Bacteriophage-driven DNA inversions shape bacterial functionality and long-term co-existence in Bacteroides fragilis

Bacterial genomic DNA inversions, which govern molecular phase-variations, provide the bacteria with functional plasticity and phenotypic diversity. These targeted rearrangements enable bacteria to respond to environmental challenges, such as bacteriophage predation, evading immune detection or gut colonization. This study investigated the short- and long-term effects of the lytic phage Barc2635 on the functional plasticity of Bacteroides fragilis, a gut commensal. Germ-free mice were colonized with B. fragilis and exposed to Barc2635 to identify genomic alterations driving phenotypic changes. Phage exposure triggered dynamic and prolonged bacterial responses, including significant shifts in phase-variable regions (PVRs), particularly in promoter orientations of polysaccharide biosynthesis loci. These shifts coincided with increased entropy in PVR inversion ratios, reflecting heightened genomic variability. In contrast, B. fragilis in control mice exhibited stable genomic configurations after gut adaptation. The phase-variable Type 1 restriction-modification system, which affects broad gene expression patterns, showed variability in both groups. However, phage-exposed bacteria displayed more restrained variability, suggesting phage-derived selection pressures. Our findings reveal that B. fragilis employs DNA inversions to adapt rapidly to phage exposure and colonization, highlighting a potential mechanism by which genomic variability contributes to its response to phage. This study demonstrates gut bacterial genomic and phenotypic plasticity upon exposure to the mammalian host and to bacteriophages.

Scarless excision of an insertion sequence in the OmpK36 promoter restores meropenem susceptibility in a non-carbapenemase-producing Klebsiella pneumoniae

Carbapenem-resistant Klebsiella pneumoniae (CRKP) poses a significant global health challenge due to its limited treatment options and high mortality rates. Meanwhile, the prevalence of non-carbapenemase-producing CRKP (NC-CRKP) strains is increasing, but their resistance mechanisms remain less understood compared to those of carbapenemase-producing CRKP (CP-CRKP). In this study, KP-469, an NC-CRKP strain, was found to lack the major porins OmpK35 and Ompk36 but possessed OmpK37, coexisting with ESBL resistance genes CTX-M and SHV. Membrane porin coding sequence alignment revealed a minor deletion in Ompk35 and a 768 bp insertion sequence in the promoter region (IS-PR) of Ompk36, located between the -10 region and the ribosome-binding site (RBS). In the KO-469 strain with scarless excision of IS-PR and the constructed pHSG396-promoter-Ompk36 strain that incorporated wild-type Ompk36 promoter into KP-469, the transcription levels of Ompk36 were significantly higher than that in KP-469 strain, and His-tag antibody quantification further confirmed the regular expression of Ompk36 in KO-469. These results demonstrated that IS-PR markedly reduced the transcriptional and translational efficiency of Ompk36 in the KP-469 strain, leading to decreased permeability to meropenem. Moreover, the restored susceptibility to meropenem in the KO-469 strain was validated by in vitro antimicrobial susceptibility tests and an in vivo intraperitoneal infection model constructed in neutrophil-depleted mice. The novel carbapenem resistance mechanism of NC-CRKP caused by the insertion sequence in the OmpK36 promoter will facilitate the development of antibacterial regimens for treating NC-CRKP infections.

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.

Emerging epidemic of the Africa-type plasmid in penicillinase-producing Neisseria gonorrhoeae in Guangdong, China, 2013-2022

The prevalence of penicillinase-producing Neisseria gonorrhoeae (PPNG) is a crucial public health concern because of its resistance to penicillin and cephalosporins. From 2013 to 2022, a total of 1748 N. gonorrhoeae isolates from Guangdong, China, were examined for their antibiotic susceptibility and molecular epidemiological characteristics. PPNG prevalence increased markedly from 37.25% to 63.87%. This increase was accompanied by a shift in predominant plasmid types carried by PPNG isolates: the rate of PPNG isolates carrying the Africa-type plasmid increased from 18.42% to 91.55%, whereas the rate of isolates carrying the Asia-type plasmid decreased from 81.58% to 7.58%. The prevalence of blaTEM-135, which is linked to cephalosporin resistance, declined from 52.63% to 4.37%, whereas that of blaTEM-1 increased from 47.37% to 86.88%, and new blaTEM variants emerged (10.99% by 2022). Most blaTEM-1 (88.26%) and new blaTEM alleles (83.70%) were associated with the Africa-type plasmid, whereas 86.79% of blaTEM-135 alleles were linked to the Asia-type plasmid. Resistance to ceftriaxone was higher in the Asia-type group (11.67%) than in the Africa-type, Toronto/Rio-type and non-PPNG groups. Genotyping identified diverse sequence types (STs) among PPNGs, in which MLST ST7363, NG-STAR ST2477, NG-MAST ST17748, and NG STAR CC1124 were predominant. This study underscores the rising prevalence of PPNG in Guangdong driven by clonal expansion and changing plasmid dynamics, affecting cephalosporin resistance and highlighting the need for continued surveillance and research into effective treatment strategies.

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.

M28 family peptidase derived from Peribacillus frigoritolerans initiates trained immunity to prevent MRSA via the complosome-phosphatidylcholine axis

Methicillin-resistant Staphylococcus aureus (MRSA) represents a major global health threat due to its resistance to conventional antibiotics. The commensal microbiota maintains a symbiotic relationship with the host, playing essential roles in metabolism, energy regulation, immune modulation, and pathogen control. Mammals harbor a wide range of commensal bacteria capable of producing unique metabolites with potential therapeutic properties. This study demonstrated that M28 family peptidase (M28), derived from commensal bacteria Peribacillus frigoritolerans (P. f), provided protective effects against MRSA-induced pneumonia. M28 enhanced the phagocytosis and bactericidal activity of macrophages by inducing trained immunity. RNA sequencing and metabolomic analyses identified the CFB-C3a-C3aR-HIF-1α axis-mediated phosphatidylcholine accumulation as the key mechanism for M28-induced trained immunity. Phosphatidylcholine, like M28, also induced trained immunity. To enhance M28-mediated therapeutic potential, it was encapsulated in liposomes (M28-LNPs), which exhibited superior immune-stimulating properties compared to M28 alone. In vivo experiments revealed that M28-LNPs significantly reduced bacterial loads and lung damage following MRSA infection, which also provided enhanced protection against Klebsiella pneumoniae and Candida albicans. We first confirmed a link between complement activation and trained immunity, offering valuable insights into the treatment and prevention of complement-related autoimmune diseases.

Genomic island-encoded LmiA regulates acid resistance and biofilm formation in enterohemorrhagic Escherichia coli O157:H7

Enterohemorrhagic Escherichia coli (EHEC) O157:H7 is an important intestinal pathogen that causes severe foodborne diseases. We previously demonstrated that the genomic island-encoded regulator LmiA activates the locus of enterocyte effacement (LEE) genes to promote EHEC O157:H7 adherence and colonization in the host intestine. However, whether LmiA is involved in the regulation of any other biological processes in EHEC O157:H7 remains largely unexplored. Here, we compared global gene expression differences between the EHEC O157:H7 wild-type strain and an lmiA mutant strain using RNA-seq technology. Genes whose expression was affected by LmiA were identified and classified using the Cluster of Orthologous Groups (COG) database. Specifically, the expression of acid resistance genes (including gadA, gadB, and gadC) was significantly downregulated, whereas the transcript levels of biofilm-related genes (including Z_RS00105, yadN, Z_RS03020, and fdeC) were increased, in the ΔlmiA mutant compared to the EHEC O157:H7 wild-type strain. Further investigation revealed that LmiA enhanced the acid resistance of EHEC O157:H7 by directly activating the transcription of gadA and gadBC. In contrast, LmiA reduced EHEC O157:H7 biofilm formation by indirectly repressing the expression of biofilm-related genes. Furthermore, LmiA-mediated regulation of acid resistance and biofilm formation is highly conserved and widespread among EHEC and enteropathogenic E. coli (EPEC). Our findings provide essential insight into the regulatory function of LmiA in EHEC O157:H7, particularly its role in regulating acid resistance and biofilm formation.

Staphylococcus warneri dampens SUMOylation and promotes intestinal inflammation

Gut bacteria play key roles in intestinal physiology, via the secretion of diversified bacterial effectors. Many of these effectors remodel the host proteome, either by altering transcription or by regulating protein post-translational modifications. SUMOylation, a ubiquitin-like post-translational modification playing key roles in intestinal physiology, is a target of gut bacteria. Mutualistic gut bacteria can promote SUMOylation, via the production of short- or branched-chain fatty acids (SCFA/BCFA). In contrast, several pathogenic bacteria were shown to dampen SUMOylation in order to promote infection. Here, we demonstrate that Staphylococcus warneri, a natural member of the human gut microbiota, decreases SUMOylation in intestinal cells. We identify that Warnericin RK, a hemolytic toxin secreted by S. warneri, targets key components of the host SUMOylation machinery, leading to the loss of SUMO-conjugated proteins. We further demonstrate that Warnericin RK promotes inflammation in intestinal and immune cells using both SUMO-dependent and SUMO-independent mechanisms. We finally show that Warnericin RK regulates the expression of genes involved in intestinal tight junctions. Together, these results highlight the diversity of mechanisms used by bacteria from the gut microbiota to manipulate host SUMOylation. They further highlight that changes in gut microbiota composition may impact intestinal inflammation, by altering the equilibrium between bacterial effectors promoting or dampening SUMOylation.

High glucose heightens vulnerability to Leishmania braziliensis infection in human macrophages by hampering the production of reactive oxygen species through TLR2 and TLR4

Diabetes increases susceptibility to infections, including Leishmania braziliensis (Lb). Our group previously demonstrated that diabetic patients with cutaneous leishmaniasis (CL) take longer to heal lesions compared to non-diabetics. Since macrophages play a critical role in CL pathogenesis, we investigated how high glucose levels impact their response during Lb infection. Macrophages cultured in high glucose conditions showed increased parasite load than those in normal glucose conditions. The production of inflammatory mediators was similar between glucose conditions, but basal reactive oxygen species (ROS) production was elevated under high glucose conditions and remained unchanged after Lb infection, indicating glucose-induced oxidative stress does not control the parasite. In contrast, macrophages in normal glucose conditions, exhibited increased ROS production only after infection. Additionally, high glucose reduced TLR2 and TLR4 expression, which was also observed after Lb infection. TLR2/4 inhibition increased Lb infection in normal glucose conditions, mediated by TLR-dependent ROS production. However, this mechanism was absent under high glucose conditions, where elevated basal ROS production appeared TLR-independent. Biopsies from diabetic CL patients corroborated these findings, showing decreased TLR2 and TLR4 expression compared to non-diabetics. These findings suggest that high glucose levels induce oxidative stress and reduces TLR expression, impairing macrophage functions and rendering them less effective at controlling Lb infection.

Interkingdom signaling between gastrointestinal hormones and the gut microbiome

The interplay between the gut microbiota and gastrointestinal hormones plays a pivotal role in the health of the host and the development of diseases. As a vital component of the intestinal microecosystem, the gut microbiota influences the synthesis and release of many gastrointestinal hormones through mechanisms such as modulating the intestinal environment, producing metabolites, impacting mucosal barriers, generating immune and inflammatory responses, and releasing neurotransmitters. Conversely, gastrointestinal hormones exert feedback regulation on the gut microbiota by modulating the intestinal environment, nutrient absorption and utilization, and the bacterial biological behavior and composition. The distributions of the gut microbiota and gastrointestinal hormones are anatomically intertwined, and close interactions between the gut microbiota and gastrointestinal hormones are crucial for maintaining gastrointestinal homeostasis. Interventions leveraging the interplay between the gut microbiota and gastrointestinal hormones have been employed in the clinical management of metabolic diseases and inflammatory bowel diseases, such as bariatric surgery and fecal microbiota transplantation, offering promising targets for the treatment of dysbiosis-related diseases.

Effects of bacteriophages on gut microbiome functionality

The gut microbiome, composed of bacteria, fungi, and viruses, plays a crucial role in maintaining the delicate balance of human health. Emerging evidence suggests that microbiome disruptions can have far-reaching implications, ranging from the development of inflammatory diseases and cancer to metabolic disorders. Bacteriophages, or "phages", are viruses that specifically infect bacterial cells, and their interactions with the gut microbiome are receiving increased attention. Despite the recently revived interest in the gut phageome, it is still considered the "dark matter" of the gut, with more than 80% of viral genomes remaining uncharacterized. Today, research is focused on understanding the mechanisms by which phages influence the gut microbiota and their potential applications. Bacteriophages may regulate the relative abundance of bacterial communities, affect bacterial functions in various ways, and modulate mammalian host immunity. This review explores how phages can regulate bacterial functionality, particularly in gut commensals and pathogens, emphasizing their role in gut health and disease.

Pneumococcal vaccine hyporesponsiveness in people living with HIV: A narrative review of immunological mechanisms and insights from minimally invasive lymph node sampling

Despite highly effective antiretroviral therapy, people living with HIV (PLWH) remain at elevated risk for invasive pneumococcal disease. Clinical studies show that, even with high CD4+ counts, PLWH exhibit diminished serological responses and rapid antibody decline following pneumococcal vaccination, plausibly due to underlying immune dysfunction. Germinal centers (GCs), located within lymph nodes, are essential for generating high-affinity antibodies, but are structurally and functionally disrupted in PLWH. These local impairments, combined with systemic immune dysregulation, contribute to vaccine hyporesponsiveness in PLWH. This narrative review links immunological findings from experimental and in vivo studies to clinical pneumococcal vaccine trials, to investigate mechanisms that may be leveraged to strengthen vaccine-induced immunity in PLWH. We also highlight the application of fine needle aspiration (FNA) of the lymph node as a way to study pneumococcal vaccine hyporesponsiveness in the GC and provide potential direction to improve responses for next-generation pneumococcal conjugate vaccines in PLWH.

Metagenomic analysis reveals distinct patterns of gut microbiota features with diversified functions in C. difficile infection (CDI), asymptomatic carriage and non-CDI diarrhea

Clostridioides difficile infection (CDI) has been recognized as a leading cause of healthcare-associated infections and a considerable threat to public health globally. Increasing evidence suggests that the gut microbiota plays a key role in the pathogenesis of CDI. The taxonomic composition and functional capacity of the gut microbiota associated with CDI have not been studied systematically. Here, we performed a comprehensive shotgun metagenomic sequencing in a well-characterized human cohort to reveal distinct patterns of gut microbiota and potential functional features associated with CDI. Fecal samples were collected from 104 inpatients, including : (1) patients with clinically significant diarrhea and positive nucleic acid amplification testing (NAAT) and received CDI treatment (CDI, n = 47); (2) patients with positive stool NAAT but without diarrhea (Carrier, n = 17); (3) patients with negative stool NAAT but with diarrhea (Diarrhea, n = 14); and (4) patients with negative stool NAAT and without diarrhea (Control, n = 26). Downstream statistical analyses (including alpha and beta diversity analysis, differential abundance analysis, correlation network analysis, and potential functional analysis) were then performed. The gut microbiota in the Control group showed higher Chao1 index (p < 0.05), while Shannon index at KEGG module level was higher in CDI than in Carrier and Control (p < 0.05). Beta diversity for species composition differed significantly between CDI vs Carrier/Control cohorts (p < 0.05). Microbial Linear discriminant analysis Effect Size and ANCOM analysis both identified 8 species (unclassified_f_Enterobacteriaceae, Veillonella_parvula, unclassified_g_Klebsiella and etc.) were enriched in CDI, Enterobacter_aerogenes was enriched in Diarrhea, Collinsella_aerofaciens, Collinsella_sp_4_8_47FAA, Collinsella_tanakaei and Collinsella_sp_CAG_166 were enriched in Control (LDA >3.0, adjusted p < 0.05). Correlation network complexity was higher in CDI with more negative correlations than in other three cohorts. Modules involved in iron complex transport system (M00240) was enriched in CDI, ABC-2 type transport system (M00254), aminoacyl-tRNA biosynthesis (M00359), histidine biosynthesis (M00026) and inosine monophosphate biosynthesis (M00048) were enriched in Carrier, ribosome (M00178 and M00179) was enriched in Diarrhea, fluoroquinolone resistance (M00729) and aminoacyl-tRNA biosynthesis (M00360) were enriched in Control (LDA > 2.5, adjusted p < 0.05). Resistance functions of acriflavine and glycylcycline were enriched in CDI, while resistance function of bacitracin was enriched in Carrier (LDA > 3.0, adjusted p < 0.05), and the contributions of phylum and species to resistance functions differed among the four groups. Our results reveal alterations of gut microbiota composition and potential functions among four groups of differential colonization/infection status of Clostridioides difficile. These findings support the potential roles of gut microbiota and their potential functions in the pathogenesis of CDI.

Unveiling the potential bacteriophage therapy: a systematic review

INTRODUCTION

Antimicrobial resistance renders conventional therapy, demanding the need for alternative therapeutic techniques. A potential strategy for treating infections caused by multi-drug-resistant bacteria is using bacteriophages, viruses that only multiply and infect specific bacteria. This review aims to evaluate the findings of clinical studies on phage therapy for bacterial illnesses.

METHODS

A comprehensive search method was utilized to identify 11 appropriate trials, which were then assessed for safety, efficacy, and treatment outcomes. The Joann-Briggs-Institute checklist and PRISMA criteria were used to evaluate these studies thoroughly. The results were summarized by extracting and analyzing data on trial design, treatment outcomes, safety profiles, and therapeutic effectiveness.

RESULTS

Phage treatment had a strong safety profile, with few side effects recorded across many routes, including oral, intravenous, and topical. Clinical studies demonstrated its effectiveness in lowering bacterial loads, resolving infections, and destroying biofilms. However, diversity in trial designs hampered the generalizability of the findings.

CONCLUSION

This study emphasizes the promise of phage therapy as a safe and efficient treatment for bacterial-illnesses. Despite its potential, there are still significant gaps in clinical application, long-term efficacy assessment, and trial standardization. Addressing these issues is critical to developing phage therapy as an effective alternative treatment for multidrug-resistant-illnesses.

Defining enteric bacterial pathogenesis using organoids: Citrobacter rodentium uses EspC, an atypical mucinolytic protease, to penetrate mouse colonic mucus

Enteric bacterial pathogens pose significant threats to human health; however, the mechanisms by which they infect the mammalian gut in the face of daunting host defenses remain to be fully defined. For the attaching and effacing (A/E) bacterial family member and murine pathogen Citrobacter rodentium, its virulence strategy appears to involve penetration of the colonic mucus barrier to reach the underlying epithelium. To better define these interactions, we grew colonoids under air-liquid interface (ALI) conditions, producing a thick mucus layer that mimicked in vivo mucus composition and glycosylation. C. rodentium's penetration of ALI-derived mucus was dramatically enhanced upon exposure to sialic acid, in concert with the secretion of two serine protease autotransporter of Enterobacteriaceae (SPATE) proteins, Pic and EspC. Despite Pic being a class II SPATE, and already recognized as a mucinase, it was EspC, a class I SPATE family member, that degraded ALI-derived mucus, despite class I SPATEs not previously shown to possess mucinase activity. Confirming this finding, E. coli DH5α carrying a plasmid that expresses C. rodentium-derived EspC was able to degrade the mucus. Moreover, recombinant EspC alone also displayed mucinolytic activity in a dose-dependent manner. Collectively, our results reveal the utility of ALI-derived mucus in modeling microbe-host interactions at the intestinal mucosal surface, as well as identify EspC as an atypical class I SPATE that shows significant mucinolytic activity toward ALI-derived mucus.

Helicobacter pylori infection induces DNA double-strand breaks through the ACVR1/IRF3/POLD1 signaling axis to drive gastric tumorigenesis

Helicobacter pylori (H. pylori) infection plays a pivotal role in gastric carcinogenesis through inflammation-related mechanisms. Activin A receptor type I (ACVR1), known for encoding the type I receptor for bone morphogenetic proteins (BMPs), has been identified as a cancer diver gene across various tumors. However, the specific role of AVCR1 in H. pylori-induced gastric tumorigenesis remains incompletely understood. We conducted a comprehensive analysis of the clinical relevance of ACVR1 by integrating data from public databases and our local collection of human gastric tissues. In vitro cell cultures, patient-derived gastric organoids, and transgenic INS-GAS mouse models were used for Western blot, qRT-PCR, immunofluorescence, immunohistochemistry, luciferase assays, ChIP, and comet assays. Furthermore, to investigate the therapeutic potential, we utilized the ACVR1 inhibitor DM3189 in our in vivo studies. H. pylori infection led to increased expression of ACVR1 in gastric epithelial cells, gastric organoid and gastric mucosa of INS-GAS mice. ACVR1 activation led to DNA double-strand break (DSB) accumulation by inhibiting POLD1, a crucial DNA repair enzyme. The activation of POLD1 was facilitated by the transcription factor IRF3, with identified binding sites. Additionally, treatment with the ACVR1 inhibitor DM3189 significantly ameliorated H. pylori-induced gastric pathology and reduced DNA damage in INS-GAS mice. Immunohistochemistry analysis showed elevated levels of ACVR1 in H. pylori-positive gastritis tissues, showing a negative correlation with POLD1 expression. This study uncovers a novel signaling axis of AVCR1/IRF3/POLD1 in the pathogenesis of H. pylori infection. The upregulation of ACVR1 and the suppression of POLD1 upon H. pylori infection establish a connection between the infection, genomic instability, and the development of gastric carcinogenesis.

Simulating rabies post-exposure prophylaxis among patients with human immunodeficiency virus infection using a six-dose Essen regimen administrated with human diploid cell vaccine: A single-arm pilot study in Chinese population

To explore the immunogencity and safety of HDCV using a six-dose Essen regimen in human immunodeficiency virus (HIV) infected patients. We conducted a single-arm pilot study by simulating post-exposure prophylaxis (PEP) in HIV-infected patients. All patients were administrated with HDCV using a 6-dose Essen regimen (consisting of 2 doses on day 0, and 4 doses each on day 3, 7, 14, and 28). Rabies virus-neutralizing antibody (RVNA) titers were detected on day 0, 7, 14, and 45, separately. The adverse reactions were also observed. In addition, we divided the patients with the baseline CD4+ T-cell counts of 500 cells/μL to examine the correlation between primary CD4+ T-cell counts and RVNA titers among HIV patients. Thirty patients included in the study were mostly male (96.7%), with a median age of 30.5 years and stable antiretroviral therapy (ART) treatment. Patients had RVNA titers of 0.84 IU/mL on day 7, 9.94 IU/mL on day 14, and 4.02 IU/mL on day 45 after vaccination, with significant differences between day 7 and day 14. The seroconversion rate reached 100% on day 14. Only three patients developed transient adverse reactions（including fever and redness, swelling, pain, and induration at the injection site）. There was no significant difference in antibody titers and safety profile between patients with CD4+T-cell counts below and above 500 cells/μL. A favorable immune response was achieved in HIV patients using the six-dose Essen regimen with HDCV. The safety profile of HDCV is satisfactory, with no major adverse events.

Impact of complement C3 levels on the development of healthcare-associated infections in intensive care patients: a retrospective case-control study

PURPOSE

The immune system serves as a critical line of defence against pathogenic microorganisms. To investigate the impact of immune markers, measured within the first 48 h of intensive care unit (ICU) admission, on the incidence of healthcare-associated infections (HAIs) in ICU patients.

METHODS

This case-control study included 364 patients admitted from 1 January 2020 to 30 November 2023, receiving immune marker testing within 48 h of ICU admission. Cox proportional hazard models and propensity score matching evaluated immune markers' association with HAIs risk. Log-rank tests compared time-to-event by C3 levels. All data processing and analysis were performed using R version 4.2.0 (R Foundation for Statistical Computing, Vienna, Austria) and Python version 3.11 (Python Software Foundation, Wilmington, DE).

RESULTS

In total, 258 patients without HAIs (mean [SD] age, 67.24 [17.79] years) and 106 patients with HAIs (mean [SD] age, 73.80 [14.93] years) were included in the final analysis. The HAIs group had older age, longer hospital stay, lower Sequential Organ Failure Assessment (SOFA) scores, and a higher rate of comorbid infections than the non-HAIs group. Also, the HAIs group had a higher proportion of basophils, lymphocytes, monocytes and T suppressor cells (CD3 + CD8+), while the proportion of neutrophils and B cells (CD19+) was lower. After Cox regression analysis and propensity score adjustment, we found that C3 complement levels (HR: 0.40; 95%CI, 0.16-0.98; p = .044) influenced the incidence of HAIs. Patients were then divided into high C3 and low C3 groups based on a cut-off value of 0.455 for C3. A time-to-event plot showed that the median time to HAIs occurrence was nine days in the high C3 group and six days in the low C3 group (p = .048).

CONCLUSIONS

Elevated complement C3 levels may associat with a reduced incidence of HAIs in ICU patients.

A Colombian strain of Clostridioides difficile ribotype 002 induces a highly inflammatory response in a mouse infection model

Clostridioides difficile causes diarrhea associated with antibiotic use in hospitalized patients. Recent studies have identified that C. difficile ribotypes RT002, RT106, and RT591 as the most prevalent circulating strains in Colombia; thus, we aimed to assess the capability of these ribotypes to elicit an inflammatory response during in vivo infection. To achieve this, C57BL/6 mice were treated with cefoperazone (CPZ) for 5 d to develop C. difficile infection (CDI) model. Two days post-antibiotic treatment, the mice were orally inoculated with 1 × 105 spores of C. difficile strains belonging to ribotypes RT002, RT106, RT591, and RT027 (ATCC strain, used as control). A group of animals was euthanized on day 7 post-infection to determine the bacterial load, total leukocyte number, and chemokines/cytokines levels in situ, and for histopathological analysis. RT002-infected groups showed significantly higher bacterial load, CD45+ leukocytes, and RANTES, eotaxin, MCP-1, G-CSF, and IL-2 levels compared to the other groups, suggesting a robust immune response. Furthermore, histopathological analysis of colonic tissue from the group infected with RT002 revealed the presence of an inflammatory response similar to the hypervirulent strain RT027. These results suggest that RT002 of C. difficile, one of the main circulating strains in Colombia, can induce a severe inflammatory response, potentially correlating with increased virulence and severity of these strains in CDI cases.

Global foot-and-mouth disease risk assessment based on multiple spatial analysis and ecological niche model

Foot-and-Mouth Disease is a highly contagious transboundary animal disease. FMD has caused a significant economic impact globally due to direct losses and trade restrictions on animals and animal products. This study utilized multi-distance spatial cluster analysis, kernel density analysis, directional distribution analysis to investigate the spatial distribution patterns of historical FMD epidemics. A multi-algorithm ensemble model considering climatic, geographic, and social factors was developed to predict the suitability area for FMDV, and then risk maps of FMD for each species of livestock were generated in combination with the distribution of livestock. The results show that all serotypes of FMD exhibit significant clustering with a clear tendency toward a directional distribution. Serotypes A and O are widespread in Asia, Europe, Africa, and South America. Serotype Asia 1 is prevalent in Asia. Serotype SAT2 is prevalent in Africa and the Middle East, while Serotypes SAT1 and SAT3 are restricted to Africa. Ecological niche modeling reveals temperature, precipitation, wind speed, and vegetation are important factors influencing the occurrence of FMD. Except for buffaloes, the distribution of high-risk areas for FMD occurrence in other livestock species is quite widespread. The areas primarily include the southern region of North America, the northern, southern, and eastern regions of South America, the Mediterranean region, the eastern region of Europe, the central and southern regions of Africa, the central, eastern, and southern regions of Asia, and parts of Australia. These findings will provide valuable insights into the prevention and control of FMD.

Chemosensory protein 16 has an immune function and participates in host-pathogen interaction in Galleria mellonella infected with Pseudomonas entomophila

Chemosensory protein 16 was identified in the hemolymph of Galleria mellonella as a protein with an amount increasing after oral infection with 10^3 CFU of Pseudomonas entomophila, and decreasing after infection with a higher dose (10^5 CFU) of bacteria. The expression of the CSP16 gene occurred in the fat body and in the gut and correlated with changes in the protein level in the hemolymph. The CSP16 protein inhibited P. entomophila growth in the concentration range from 0.15 to 6 nM. Additionally, the CSP16 protein showed bactericidal activity against P. entomophila, Bacillus thuringiensis, and Escherichia coli in the range of 2-18 μM, but only in the presence of protease inhibitors, otherwise it was degraded by extracellular proteases secreted by P. entomophila. We demonstrated that the bactericidal activity of CSP16 was related to its ability to perforate bacterial cellular membranes in a dose-dependent manner. The antimicrobial properties of this protein were also confirmed with the use of Atomic Force Microscopy, which showed significant changes in the topology of different bacterial cell surfaces. Finally, when CSP16 was injected in vivo into G. mellonella larvae one hour after infection with P. entomophila, more survivors were observed at particular time-points. Taking into account its immune properties and putative ability to bind bacteria-derived compounds, the possible function of CSP16 in the host-pathogen interaction is discussed.

Extracorporeal therapies in sepsis: a comprehensive review of the Selective Cytopheretic Device, Polymyxin B and Seraph cartridges

Sepsis, a dysregulated host response to infection, is a leading cause of morbidity and mortality in critically ill patients, despite advancements in antimicrobial therapies. Recent innovations in extracorporeal blood purification therapies, such as the Selective Cytopheretic Device (SCD), Polymyxin B Hemoperfusion Cartridge (PMX-HP), and Seraph 100 Microbind Affinity Blood Filter (Seraph), have demonstrated promising potential as adjuncts to conventional therapies. The SCD targets activated white blood cells, while PMX-HP binds endotoxins in Gram-negative sepsis. The Seraph targets a broad range of pathogens, including viruses, bacteria and fungi. Evidence from several clinical trials and observational studies indicate that these therapies can improve organ function, and potentially improve survival in patients with sepsis. Despite the strong pathophysiological rationale for using these devices in sepsis, conclusive evidence of their effectiveness remains limited. Multicenter randomized controlled trials are currently underway with each of these devices to establish their role in improving patient outcomes. Further research is needed to establish optimal protocols for their initiation, duration, and integration into standard sepsis management.

Global burden and trends of the Clostridioides difficile infection-associated diseases from 1990 to 2021: an observational trend study

BACKGROUND

This study was aimed to explore the global burden and trends of Clostridioides difficile infections (CDI) associated diseases.

METHODS

Data for this study were obtained from the Global Burden of Disease Study 2021. The burden of CDI was assessed using the age-standardized rates of disability-adjusted life years (ASR-DALYs) and deaths (ASDRs). Trends in the burden of CDI were presented using average annual percentage changes (AAPCs).

RESULTS

The ASR-DALYs for CDI increased from 1.83 (95% UI: 1.53-2.18) per 100,000 in 1990 to 3.46 (95% UI: 3.04-3.96) per 100,000 in 2021, with an AAPC of 2.03% (95% CI: 1.67-2.4%). The ASDRs for CDI rose from 0.10 (95% UI: 0.08-0.11) per 100,000 in 1990 to 0.19 (95% UI: 0.16-0.23) per 100,000 in 2021, with an AAPC of 2.26% (95% CI: 1.74-2.79%). In 2021, higher burdens of ASR-DALYs (10.7 per 100,000) and ASDRs (0.53 per 100,000) were observed in high socio-demographic index (SDI) areas, and among age group over 70 years (31.62/100,000 for ASR-DALYs and 2.45/100,000 for ASDRs). During the COVID-19 pandemic, the global ASR-DALYs and ASDRs slightly decreased. However, in regions with low SDI, low-middle and middle SDI, those rates slightly increased.

CONCLUSION

The global burden of CDI has significantly increased, particularly in regions with high SDI and among individuals aged 70 years and above. During the COVID-19 pandemic period from 2020 to 2021, the burden of CDI further increased in regions with low, low-middle, and middle SDI. These findings underscore the need for increased attention and intervention, especially in specific countries and populations.

The prevalence of low-level viraemia and its association with virological failure in people living with HIV: a systematic review and meta-analysis

Low-level viraemia (LLV) following antiretroviral therapy (ART) in people living with HIV (PLWH) has not received sufficient attention. To the determine the prevalence of LLV and its association with virological failure (VF), we systematically reviewed evidence-based interventions for PLWH. We searched PubMed, the Cochrane Library, Embase, and Web of Science from inception to 22 May 2024. Cohorts with samples sizes smaller than 1000 in size were excluded. Data from 16 cohort studies, encompassing 13,49,306 PLWH, revealed a pooled prevalence of LLV of 13.81%. Relative risk (RR) and 95% confidence intervals (CI) identified the following risk factors for LLV: viral load (VL) ≥ 105 copies/mL at baseline (1.79, 1.11-2.88), AIDS-defined illness at baseline (1.24, 1.10-1.40), and protease inhibitor-based regimen at ART initiation (1.53, 1.45-1.62) are the risk factors for LLV. Conversely, CD4 count ≥200 cells/μL at baseline (0.90, 0.82-0.98), non-nucleoside reverse transcriptase inhibitor-based regimen (0.81, 0.68-0.96) and the integrase strand transfer inhibitor (INSTI)-based regimen (0.60, 0.42-0.85) were associated with a reduced risk of LLV. Pooling the adjusted hazard ratio (aHR) and the 95% CI, we found that LLV increased the risk of VF with rising VL among 96,711 PLWH (aHR 2.77, 95% CI 2.03-3.76) and increased the risk of all-cause mortality at high VL levels among 14,229 PLWH (aHR 1.66, 95% CI 1.16-2.37). Therefore, the prevalence of LLV in PLWH should not be overlooked. This study aims to guide better management strategies to improve clinical outcomes in patients with LLV.

Chemical composition, antioxidant activities, and enzyme inhibitory effects of Lespedeza bicolour Turcz. essential oil

Lespedeza bicolour Turcz. is a traditional medicinal plant with a wide range of ethnomedicinal values. The main components of L. bicolour essential oil (EO) were β-pinene (15.41%), β-phellandrene (12.43%), and caryophyllene (7.79%). The EO of L. bicolour showed antioxidant activity against ABTS radical and DPPH radical with an IC50 value of 0.69 ± 0.03 mg/mL and 10.44 ± 2.09 mg/mL, respectively. The FRAP antioxidant value was 81.96 ± 6.17 μmol/g. The EO had activities against acetylcholinesterase, α-glucosidase, and β-lactamase with IC50 values of 309.30 ± 11.16 μg/mL, 360.47 ± 35.67 μg/mL, and 27.54 ± 1.21 μg/mL, respectively. Molecular docking showed methyl dehydroabietate docked well with all tested enzymes. Sclareol and (+)-borneol acetate showed the strongest binding affinity to α-glucosidase and β-lactamase, respectively. The present study provides a direction for searching enzyme inhibitors for three tested enzymes and shows L. bicolour EO possesses the potential to treat a series of diseases.

Clinical analysis and risk factors associated with poor prognosis in nontuberculous mycobacterial infection

Recently, the incidence and prevalence of NTM have been increasing nationwide in many countries. This study aimed to identify risk factors associated with the prognosis and mortality of non-HIV nontuberculous mycobacterial disease patients. This retrospective study was conducted at Peking Union Medical College Hospital. The electronic medical records in the hospital's database from January 2013 to December 2022 were retrospectively reviewed. Relevant data, including clinical characteristics, laboratory findings, microbiological tests, treatments, and outcomes were collected and subjected to statistical analyses. The search identified 745 patients diagnosed with NTM infection, of whom 147 met the inclusion criteria. NTM pulmonary disease was the most commonly observed (n = 93; 63.3%), followed by disseminated infection (n = 43; 29.3%). The most frequent NTM species was Mycobacterium avium complex (55.8%), followed by Mycobacterium abscessus (21.2%). The incidence of Aspergillus and Pseudomonas aeruginosa infection was significantly higher in the NTM pulmonary disease group than in the disseminated NTM group. Cumulative mortality in the total patients was 24.49% at 5 years. High Charlson Comorbidity Index (CCI), high neutrophil-to-lymphocyte-ratio (NLR), haematological disease, and disseminated infection were identified as independent predictors of unfavourable outcomes. The area under the curve (AUC) values for NLR and neutrophil-to-monocyte-plus-lymphocyte-ratio (NMLR) were 0.751 and 0.763 with optimal cut-off values of 9.50 and 3.83, respectively, for prediction of mortality in patients with NTM disease.

Fusobacterium sphaericum sp. nov., isolated from a human colon tumor adheres to colonic epithelial cells and induces IL-8 secretion

Cancerous tissue is a largely unexplored microbial niche that provides a unique environment for the colonization and growth of specific bacterial communities, and with it, the opportunity to identify novel bacterial species. Here, we report distinct features of a novel Fusobacterium species, F. sphaericum sp. nov. (Fs), isolated from primary colon adenocarcinoma tissue. We acquire the complete closed genome and associated methylome of this organism and phylogenetically confirm its classification into the Fusobacterium genus, with F. perfoetens as its closest neighbor. Fs is phenotypically and genetically distinct, with morphological analysis revealing its coccoid shape, that while similar to F. perfoetens is rare for most Fusobacterium members. Fs displays a metabolic profile and antibiotic resistance repertoire consistent with other Fusobacterium species. In vitro, Fs has adherent and immunomodulatory capabilities, as it intimately associates with human colon cancer epithelial cells and promotes IL-8 secretion. An analysis of the prevalence and abundance of Fs in > 20,000 human metagenomic samples shows that it is a rarely detected member within human stool with variable relative abundance, found in both healthy controls and patients with colorectal cancer (CRC). Our study sheds light on a novel bacterial species isolated directly from the human CRC tumor niche and given its in vitro interaction with cancer epithelial cells suggests that its role in human health and disease warrants further investigation.

Marques A, Mora-Jiménez I, Álvarez-Rodríguez J, Soguero-Ruiz C. Multimodal interpretable data-driven models for early prediction of multidrug resistance using multivariate time series

Electronic Health Records (EHRs) serve as a comprehensive repository of multimodal patient health data, combining static demographic attributes with dynamic, irregular Multivariate Time Series (MTS), characterized by varying lengths. While MTS provide critical insights for clinical predictions, their integration with static features enables a more nuanced understanding of patient health trajectories and enhances predictive accuracy. Deep Neural Networks (DNNs) have proven highly effective in capturing complex patterns in healthcare data, offering a framework for multimodal data fusion. However, their adoption in clinical practice is limited by a lack of interpretability, as transparency and explainability are essential for supporting informed medical decisions. This study presents interpretable multimodal DNN architectures for predicting and understanding the emergence of Multidrug Resistance (MDR) in Intensive Care Units (ICUs). The proposed models integrate static demographic data with temporal variables, providing a holistic view of baseline patient characteristics and health progression. To address predictive performance and interpretability challenges, we introduce a novel methodology combining feature selection techniques with attention mechanisms and post-hoc explainability tools. This approach not only reduces feature redundancy but also highlights key risk factors, thereby improving model accuracy and robustness. Experimental results demonstrate the effectiveness of the proposed framework, achieving a Receiver Operating Characteristic Area Under the Curve of 76.90 ± 3.10, a significant improvement over baseline models. Beyond MDR prediction, this methodology offers a scalable and interpretable framework for addressing various clinical challenges involving EHR data. By integrating predictive accuracy with explanatory insights-such as the identification of key risk factors-this work supports timely, evidence-based interventions to improve patient outcomes in ICU settings.

Genomic and functional co-diversification imprint African Hominidae microbiomes to signal dietary and lifestyle adaptations

In the diverse landscape of African hominids, the obligate relationship between the host and its microbiome narrates signals of adaptation and co-evolution. Sequencing 546 African hominid metagenomes, including those from indigenous Hadza and wild chimpanzees, identified similar bacterial richness and diversity surpassing those of westernized populations. While hominids share core bacterial communities, they also harbor distinct, population-specific bacterial taxa tailored to specific diets, ecology and lifestyles, differentiating non-indigenous and indigenous humans and chimpanzees. Even amongst shared bacterial communities, several core bacteria have co-diversified to fulfil unique dietary degradation functions within their host populations. These co-evolutionary trends extend to non-bacterial elements, such as mitochondrial DNA, antimicrobial resistance, and parasites. Our findings indicate that microbiome-host co-adaptations have led to both taxonomic and within taxa functional displacements to meet host physiological demands. The microbiome, in turn, transcends its taxonomic interchangeable role, reflecting the lifestyle, ecology and dietary history of its host.

The mRNA-1647 vaccine: A promising step toward the prevention of cytomegalovirus infection (CMV)

Cytomegalovirus (CMV) is a leading cause of congenital infections and significant health complications in immunocompromised individuals. With no licensed CMV vaccine available, the development of the mRNA-1647 offers promising advancements in CMV prevention. We have reviewed results from Phase 1 and 2 clinical trials of the mRNA-1647 vaccine, demonstrating robust immune responses in both seronegative and seropositive participants. Vaccines exhibited significantly elevated neutralizing antibody titers against CMV, particularly in fibroblast and epithelial cells, with sustained responses lasting up to 18 months post-vaccination. The mRNA-1647 vaccine triggered strong T-cell and memory B-cell responses, suggesting its potential for long-term protection against CMV infection. The ongoing Phase 3 CMVictory trial evaluates the safety and immunogenicity of mRNA-1647 in women of childbearing age, with preliminary data showing promise in preventing congenital CMV transmission. This vaccine could significantly reduce CMV-related morbidity and mortality, particularly in newborns and immunocompromised individuals, addressing a critical unmet medical need.