The role of vaccines in combatting antimicrobial resistance

Single or double lipid-modified ultra-short antimicrobial peptides for treating infections caused by resistant bacteria

Unmodified ultra-short antimicrobial peptides (AMPs) have difficulty attaining high antimicrobial activity and low toxicity concurrently. Our previous studies have shown that single-site lipid modification can enhance the antimicrobial activity of AMPs. However, research on multi-site modification is scarce. This study designed and synthesized a series of single/double-site lipid-modified ultra-short AMPs. Particularly, the new single-site lipid-modified AMP C12 (C12-KKWW-NH2) and double-site lipid-modified AMP DC8 [(C8)2-KKKWW-NH2] showed high bacterial membrane selectivity and presented high stability. It is worth noting that C12 and DC8 exert excellent antibacterial effects on clinically resistant bacteria and have an extremely low resistance tendency. When combined with conventional antibiotics, they show synergistic antibacterial activity against resistant bacteria and curb the resistance of the antibiotics. Additionally, the novel ultra-short AMPs reveal non-receptor-mediated membrane bactericidal mechanisms and can kill the tested bacteria rapidly. Moreover, both C12 and DC8 have high antibacterial activity and low toxicity in vivo. These results suggest that both single-site and multi-site lipid modifications can produce highly efficient AMPs.

Evaluation of 1-vinyl-3-alkyl imidazolium-based ionic liquid monomers towards antibacterial activity: An in-silico & in-vitro study

In this study 1-vinyl-3-alkyl imidazolium-based ionic liquid monomers (ILs) with different alkyl chain lengths {R = hexyl (A), octyl (B) and decyl (C)} have been synthesized for antibacterial applications. The prepared ILs have been characterized using UV, FT-IR and NMR spectroscopy. The antibacterial activities of the synthesized ILs against Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli) have been examined by measuring their minimal inhibitory concentrations (MICs) and minimum bactericidal concentrations (MBCs). The results exhibit that these ILs have admirable antibacterial activities with MIC values range from < 1.2 to 12.2 μM for S. aureus and < 2.4 to 12.2 μM for E. coli. A notable dependence of antibacterial and antibiofilm efficacy on the alkyl chain length (ILC> ILB > ILA) has been observed. From in-silico evaluation, the binding energies of β-lactamase protein of S. aureus (PDB ID: 1GHP) are found to be -4.4, -4.6, -4.7 kcal/mol for IL A, IL B, and IL C. For dihydrofolate reductase (DHFR) of S. aureus and E. coli the binding energies -4.6, -4.5, -5.3 kcal/mol and -5.3, -5.4, -5.6 kcal/mol have been noted for IL A, IL B, and IL C respectively. MD simulations (100 ns) have been performed to predict the stability and understand the binding mechanism of the docked complexes.

The challenge of antimicrobial resistance in the Asia-Pacific: a pediatric perspective

PURPOSE OF REVIEW

The densely populated Asia Pacific region is home to 600 million children, and suffers from a significant burden of morbidity and mortality due to infections associated with antimicrobial resistance (AMR). We aimed to identify the drivers, challenges and potential opportunities to alter the burden of AMR within the region.

RECENT FINDINGS

Despite the high AMR burden borne by the Asia Pacific region, there are limited (and geographically imbalanced) published data to delineate the contemporary epidemiology of serious multidrug-resistant bacterial infections in children. Furthermore, the region is impacted by overcrowded and poorly resourced healthcare facilities, insufficient microbiological resources, and widespread community and environmental antibiotic use leading to limited efficacy for frequently prescribed antibiotics. Vaccine coverage is also inadequate and inequitable, further driving the burden of infectious disease (and antibiotic overuse) in children.

SUMMARY OF IMPLICATIONS

There are many challenges in implementing antimicrobial stewardship and infection prevention and control programs to reduce the excessive AMR disease burden in children across the Asia Pacific region, yet locally-driven strategies have successfully reduced antibiotic overuse in some settings, and should be replicated. Reducing the AMR disease burden will require improved healthcare resourcing, including better access to microbiological diagnosis, and multidisciplinary approaches to enhance infection prevention and antibiotic prescribing.

Vaccines and AMR: An analysis of the funding landscape for human bacterial vaccines in low-and middle-income countries

BACKGROUND

Vaccines are critical tools to prevent the emergence and spread of antimicrobial resistance (AMR) through prevention of infection and reduction of subsequent antibiotic use. Since AMR is a critical issue disproportionately affecting Low- and Middle- Income Countries (LMICs), we examined investments in research and development for bacterial vaccines with a focus on LMIC-driven research.

METHODS

Publicly available funding data on projects active from January 2007 to 15 January 2024 from the G-FINDER and Global AMR R&D Hub databases were analysed. The investment into human bacterial vaccine R&D was analysed to identify the recipients and geographic distribution of funding provided directly from funders and through intermediary organisations.

FINDINGS

Global funding of vaccine R&D for bacterial pathogens in this dataset totals 4.50 billion USD, with the majority of funding directed towards M. tuberculosis and S. pneumoniae. Most funding was received by organisations in North America and Europe, with Asia, Africa, and Central/South America collectively receiving less than 20 % of the total funding. Philanthropic and intermediary organisations, particularly Product Development Partnerships (PDPs), emerge as critical players in mobilising and coordinating resources for bacterial vaccine R&D in LMICs.

CONCLUSION

Comprehensive and transparent reporting is needed to accurately assess funding to LMICs. Nevertheless, the current analysis shows that PDPs and intermediary funders are pivotal in ensuring investments reach LMIC product developers. Data gaps remain for critical bacterial pathogens on WHO's AMR priority pathogen list.

Rational design of peptides to overcome drug resistance by metabolic regulation

Chemotherapy is widely used clinically, however, its efficacy is often compromised by the development of drug resistance, which arises from prolonged administration of drugs or other stimuli. One of the driven causes of drug resistance in tumors or bacterial infections is metabolic reprogramming, which alters mitochondrial metabolism, disrupts metabolic pathways and causes ion imbalance. Bioactive peptide materials, due to their biocompatibility, diverse bioactivities, customizable sequences, and ease of modification, have shown promise in overcoming drug resistance. This review provides an in-depth analysis of metabolic reprogramming and associated microenvironmental changes that contribute to drug resistance in common tumors and bacterial infections, suggesting potential therapeutic targets. Additionally, we explore peptide-based materials for regulating metabolism and their potential synergic effect with other therapies, highlighting the mechanisms by which these peptides reverse drug resistance. Finally, we discuss future perspectives and the clinical challenges in peptide-based treatments, aiming to offer insights for overcoming drug-resistant diseases.

Broad-spectrum tolerance to disinfectant-mediated bacterial killing due to mutation of the PheS aminoacyl tRNA synthetase

Disinfectants are essential tools for controlling infectious diseases and maintaining sterile conditions in many medical and food-industry settings. Recent work revealed that a deficiency in the carbohydrate phosphotransferase system (PTS) confers pan-tolerance to killing by diverse disinfectant types through its interaction with the cAMP-CRP regulatory network. The present work characterized a pan-tolerance mutant obtained by enrichment using phenol as a lethal probe and an Escherichia coli PTS null mutant as a parental strain. The resulting super-pan-tolerant mutant, which harbored an F158C substitution in PheS, inhibited bacterial killing by multiple disinfectant classes with surprisingly little effect on antimicrobial lethality. The PheS substitution, which was expected to lower substrate recognition efficiency and result in deacylated tRNAphe occupying the ribosomal A site, activated relA expression and synthesis of ppGpp, even in the absence of disinfectant exposure. ppGpp, along with DksA, increased RpoS function by activating promoters of dsrA and iraP, two genes whose products increase the expression and stability of RpoS. Subsequently, RpoS upregulated the expression of genes encoding a universal stress protein (UspB) and an oxidative stress peroxidase (KatE), which preconditioned bacteria to better survive a variety of disinfectants. Disinfectant-mediated accumulation of reactive oxygen species (ROS) and bacterial killing were abolished/reduced by exogenous dimethyl sulfoxide and by a PheS F158C substitution up-regulating genes encoding ROS-detoxifying enzymes (katE, sodA, oxyR, ahpC). These data identify a pheS mutation-triggered, ppGpp-stimulated transcriptional regulatory cascade that negates biocide-mediated lethality, thereby tying the stringent response to protection from ROS-mediated biocide lethality.

Epitope mapping of recombinant Salmonella enterica serotype Heidelberg flagellar hook-associated protein by in silico and in vivo approaches

BACKGROUND

Salmonella is a leading cause of human acute bacterial gastroenteritis worldwide. Outbreaks of human salmonellosis have often been associated with consumption of contaminated poultry products. Various strategies have been explored to control this microorganism during poultry production and processing. Vaccination of broiler chickens is regarded as one of the effectives means to control this microorganism. The aim of the present study was to compare the epitope identification in the Salmonella enterica serotype Heidelberg FlgK protein by in silico prediction and in vivo experiment with mass spectrometry in association with immunoprecipitation proteomics.

RESULTS

The Salmonella serotype Heidelberg FlgK protein contains 553 amino acids with a molecular mass of 61 kDa. This protein is conserved among Salmonella serotype Heidelberg isolates. The results show that both approaches identified three common shared consensus peptide epitope sequences at the positions of 77-95, 243-255 and 358-373 in the Salmonella serotype Heidelberg FlgK protein.

CONCLUSIONS

These findings provide a rational for further evaluation of these shared linear epitopes in vaccine development to cover the chicken population.

Enhancing vaccine clinical trials participation among elderly: challenges and strategies

As the fastest growing demographic worldwide, the elderly population is projected to reach nearly 1 billion by 2030 and double the 2022 number by 2050. Despite being the largest consumers of medications, they have been historically underrepresented in clinical trials. However, we are witnessing a promising shift as their participation in trials is on the rise. In fact, recent megatrials enrolling more than 30,000 elderly participants demonstrated the feasibility of large-scale clinical trials involving this very specific population. However, unique challenges, including multi-morbidities, frailty, and ethically sound informed consent in those with cognitive deficits, require continuous careful reassessments and flexibility. Creative and tailored strategies are of paramount importance to bolster elderly trial participation. This paper highlights challenges and shares our experiences on novel methods and success stories associated with the enrollment and retention of elderly individuals in clinical trials. Successful tactics to balance the burden of clinical trial participation with its benefits encompass regular contact, family and friends' engagement, making travel easier or unnecessary, use of digital tools, and building relationships with community organizations. Through innovative strategies that consider the unique needs and limitations of this population, we can achieve successful participation in clinical trials. This will lead to more effective treatments and interventions for our growing elderly population.

Management and prevention of Neisseria meningitidis and Neisseria gonorrhoeae infections in the context of evolving antimicrobial resistance trends

PURPOSE

To describe the relationships between Neisseria meningitidis (NM) and Neisseria gonorrhoeae (NG) at genetic, population, and individual levels; to review historical trends in antimicrobial resistance (AMR); to review the treatment and preventive landscapes and explore their potential impact on AMR.

METHODS

A narrative literature search was conducted in PubMed, with searches restricted to 2003-2023 and additional articles included based on expertise.

RESULTS

NM and NG are closely related bacterial pathogens causing invasive meningococcal disease (IMD) and gonorrhea, respectively. NM can currently be treated with most antibiotics and generally has a wild-type susceptibility profile, whereas NG is increasingly resistant even in the first line of treatment. These pathogens share 80-90% genetic identity and can asymptomatically cohabit the pharynx. While AMR has historically been rare for NM, recent reports show this to be an emerging clinical concern. Extensively drug-resistant NG are reported globally, with data available from 73 countries, and can lead to treatment failure. Importantly, Neisseria commensals within the normal microbiota in the pharynx can act as a genetic reservoir of resistance to extended-spectrum cephalosporins. Novel oral antibiotics are urgently needed to treat a growing threat from antibiotic-resistant NG, recognized as a major global concern to public health by the World Health Organization. Numerous vaccines are available to prevent IMD, but none are approved for gonorrhea. Research to identify suitable candidates is ongoing.

CONCLUSION

Holistic management of AMR in IMD and gonorrhea should couple judicious use of existing antibiotics, optimization of vaccination programs, and development of novel antibiotics and vaccines.

Vaccine Specifically for Immunocompromised Individuals against Superbugs

Immunocompromised populations, including cancer patients, elderly individuals, and those with chronic diseases, are the primary targets of superbugs. Traditional vaccines are less effective due to insufficient or impaired immune cells. Inspired by the "vanguard" effect of neutrophils (NE) during natural infection, this project leverages the ability of NE to initiate the NETosis program to recruit monocytes and DC cells, designing vaccines that can rapidly recruit immune cells and enhance the immune response. The PLGA microsphere vaccine platform (MSV) with a high level of safety contains whole-bacterial antigens both internally and externally, providing initial and booster effects through programmed distribution and release of antigens after a single injection. Experimental data indicate that immunizing mice with a mixture of MSV and NE induces the formation of spontaneous gel-like neutrophil extracellular traps (NETs) at the inoculation site. These NETs recruit immune cells and prevent the diffusion of vaccine components, thereby reducing damage from bacterial toxins and enhancing vaccine biosafety. This strategy shows excellent efficacy against MRSA-induced infections in not only healthy but also immunocompromised mice.

Towards a unified approach in managing resistance to vaccines, drugs, and pesticides

Everywhere, pests and pathogens evolve resistance to our control efforts, impairing human health and welfare. Developing sustainable solutions to this problem requires working with evolved immune and ecological systems, rather than against these evolutionary forces. We advocate a transdisciplinary approach to resistance based on an evolutionary foundation informed by the concepts of integrated pest management and One Health. Diverse, multimodal management approaches create a more challenging environment for the evolution of resistance. Given our permanent evolutionary and ecological relationships with pests and pathogens, responses to most biological threats to health and agriculture should seek sustainable harm reduction rather than eradication.

Immunoinformatics design of a novel multiepitope vaccine candidate against non-typhoidal salmonellosis caused by Salmonella Kentucky using outer membrane proteins A, C, and F

The global public health risk posed by Salmonella Kentucky (S. Kentucky) is rising, particularly due to the dissemination of antimicrobial resistance genes in human and animal populations. This serovar, widespread in Africa, has emerged as a notable cause of non-typhoidal gastroenteritis in humans. In this study, we used a bioinformatics approach to develop a peptide-based vaccine targeting epitopes from the outer membrane proteins A, C, and F of S. Kentucky. Additionally, we employed flagellin protein (fliC) from Salmonella Typhimurium (S. Typhimurium) as an adjuvant to enhance the vaccine's effectiveness. Through this approach, we identified 14 CD8+ and 7 CD4+ T-cell epitopes, which are predicted to be restricted by various MHC class I and MHC class II alleles. The predicted epitopes are expected to achieve a population coverage of 94.91% when used in vaccine formulations. Furthermore, we identified seven highly immunogenic linear B-cell epitopes and three conformational B-cell epitopes. These T-cell and B-cell epitopes were then linked using appropriate linkers to create a multi-epitope vaccine (MEV). To boost the immunogenicity of the peptide construct, fliC from S. Typhimurium was included at the N-terminal. The resulting MEV construct demonstrated high structural quality and favorable physicochemical properties. Molecular docking studies with Toll-like receptors 1, 2, 4, and 5, followed by molecular dynamic simulations, suggested that the vaccine-receptor complexes are energetically feasible, stable, and robust. Immune simulation results showed that the MEV elicited significant responses, including IgG, IgM, CD8+ T-cells, CD4+ T-cells, and various cytokines (IFN-γ, TGF-β, IL-2, IL-10, and IL-12), along with a noticeable reduction in antigen levels. Despite these promising in-silico findings, further validation through preclinical and clinical trials is required to confirm the vaccine's efficacy and safety.

Pulmonary Delivery of Nonviral Nucleic Acid-Based Vaccines With Spotlight on Gold Nanoparticles

Nucleic acid-based vaccines are leading-edge tools in developing next-generation preventative care. Much research has been done to convert vaccine gene therapy from an invasive to a noninvasive administration approach. The lung's large surface area and permeability make the pulmonary route a promising noninvasive delivery option for vaccines, with systemic and local applications. This review summarizes the challenges and the approaches that have been carried out to optimize the delivery of nucleic acids through the pulmonary route for vaccination purposes in recent years, with a spotlight on gold nanoparticles (AuNPs). Nonviral delivery systems have been widely explored, and AuNPs with their unique properties are emerging as promising tools for nucleic acid vaccines due to surface functionalization with mucus-penetrating polymers and targeting moieties that can bypass the barriers in pulmonary delivery and successfully deliver nucleic acids to the cells of interest. However, while promising, several challenges remain including selectively overcoming the lungs' immunological surveillance and adhesive mucus.

Antimicrobial resistance: a concise update

Antimicrobial resistance (AMR) is a serious threat to global public health, with approximately 5 million deaths associated with bacterial AMR in 2019. Tackling AMR requires a multifaceted and cohesive approach that ranges from increased understanding of mechanisms and drivers at the individual and population levels, AMR surveillance, antimicrobial stewardship, improved infection prevention and control measures, and strengthened global policies and funding to development of novel antimicrobial therapeutic strategies. In this rapidly advancing field, this Review provides a concise update on AMR, encompassing epidemiology, evolution, underlying mechanisms (primarily those related to last-line or newer generation of antibiotics), infection prevention and control measures, access to antibiotics, antimicrobial stewardship, AMR surveillance, and emerging non-antibiotic therapeutic approaches. The Review also discusses the potential roles of artificial intelligence in addressing AMR, including antimicrobial susceptibility testing, AMR surveillance, antimicrobial stewardship, diagnosis, and antimicrobial drug discovery and development. This Review highlights the urgent need for addressing the global effects of AMR and for rapid advancement of relevant technology in this dynamic field.

Enhancing vaccine effectiveness in the elderly to counter antibiotic resistance: The potential of adjuvants via pattern recognition receptors

Vaccines are an effective way to prevent the emergence and spread of antibiotic resistance by preventing diseases and establishing herd immunity. However, the reduced effectiveness of vaccines in the elderly due to immunosenescence is one of the significant contributors to the increasing antibiotic resistance. To counteract this decline and enhance vaccine effectiveness in the elderly, adjuvants play a pivotal role. Adjuvants are designed to augment the effectiveness of vaccines by activating the innate immune system, particularly through pattern recognition receptors on antigen-presenting cells. To improve vaccine effectiveness in the elderly using adjuvants, it is imperative to select the appropriate adjuvants based on an understanding of immunosenescence and the mechanisms of adjuvant functions. This review demonstrates the phenomenon of immunosenescence and explores various types of adjuvants, including their mechanisms and their potential in improving vaccine effectiveness for the elderly, thereby contributing to developing more effective vaccines for this vulnerable demographic.

Community pharmacists' knowledge, beliefs, and perceived barriers toward vaccination services at community pharmacies: A cross-sectional study from Saudi Arabia

Community pharmacists were recently authorized to provide vaccination services in Saudi Arabia. However, the implementation is still limited. Consequently, this study aimed to assess the knowledge, beliefs, and views of community pharmacists in the Qassim region regarding vaccines and vaccination services and to identify the barriers to providing such services. A total of 170 community pharmacists participated in the study (response rate = 73.91%). The mean overall knowledge of vaccines and vaccination was 10.25 ± 1.35 out of a maximum score of 14. The majority stated that vaccines are rigorously tested for their safety (92.94%), go through a stringent approval process to ensure their quality and efficacy (93.53%), and vaccines play a key role in preventing and controlling infectious disease outbreaks (97.06%). However, only 48.82% were aware that community pharmacists are legally authorized to provide adult vaccination services. Few participants were also aware of the dosing of the varicella vaccine (14.12%) and indications of the herpes zoster vaccine (21.18%). The overall mean score on beliefs/views was 31.91 ± 5.53 out of a maximum of 40, indicating positive beliefs/views regarding vaccination services. The study identified many barriers to implementing vaccination services. These included lack of support staff and technicians in community pharmacies (79.41%), lack of requirements and equipment to provide the service (74.11%), the service will add extra workload (72.94%), and lack of formal certification in pharmacy-based immunization delivery (66.48%). Consequently, a holistic strategy is required to improve pharmacists' clinical knowledge of vaccines and to address the barriers to the implementation of vaccination services at community pharmacies.

CLOVER (CLOstridium difficile Vaccine Efficacy tRial) Study: A Phase 3, Randomized Trial Investigating the Efficacy and Safety of a Detoxified Toxin A/B Vaccine in Adults 50 Years and Older at Increased Risk of Clostridioides difficile Infection

BACKGROUND

Clostridioides difficile infection (CDI) causes substantial mortality and healthcare burden. We assessed the detoxified toxin-A/B PF-06425090 vaccine for primary CDI prevention.

METHODS

This phase 3 observer-blinded study randomized (1:1) ≥50-year-olds at increased CDI risk (N = 17 535) to receive 3 PF-06425090 or placebo doses (0, 1, and 6 months). Primary end points were first CDI episode (≥3 unformed stools within 24 hours; central laboratory-confirmed toxin A/B positive) ≥14 days post-dose 3 (PD3; first primary) and post-dose 2 (PD2; second primary). CDI duration, need for CDI-related medical attention (secondary end points), and antibiotic use (post hoc analysis) PD3 were evaluated. Tolerability and safety were assessed.

RESULTS

The primary end point was not met (17 PF-06425090 and 25 placebo recipients had first CDI episode ≥14 days PD3 [vaccine efficacy (VE) = 31.0% (96.4% confidence interval [CI], -38.7% to 66.6%)]; 24 PF-06425090 and 34 placebo recipients had first CDI episode ≥14 days PD2 [VE = 28.6% (96.4% CI, -28.4% to 61.0%)]. Median CDI duration was lower with PF-06425090 (1 day) versus placebo (4 days; 2-sided nominal P = .02). Of participants with first CDI episode, 0 PF-06425090 and 11 placebo recipients sought CDI-related medical attention (post hoc analysis estimated VE = 100%; 95% CI, 59.6% to 100.0%) and 0 PF-06425090 and 10 placebo recipients required antibiotic treatment (VE = 100%; 95% CI, 54.8% to 100.0%). Local reactions were more frequent in PF-06425090 recipients, and systemic events were generally similar between groups; most were mild to moderate. Adverse event rates were similar between groups.

CONCLUSIONS

Three PF-06425090 doses were safe and well tolerated. Although the primary end point was not met, PF-06425090 reduced symptom duration, CDI that required medical attention, and CDI-directed antibiotic treatment, highlighting its potential to reduce CDI-associated healthcare burden.

CLINICAL TRIALS REGISTRATION

NCT03090191.

Routine immunization against Streptococcus pneumoniae and Haemophilus influenzae type B and antibiotic consumption in India: a dynamic modeling analysis

Background

Childhood vaccinations can reduce disease burden and associated antibiotic use, in turn reducing the risk of antimicrobial resistance (AMR). We retrospectively estimated the population-level reductions in antibiotic use in India following the introduction of vaccines against Streptococcus pneumoniae and Haemophilius influenzae type B in the national immunization program for children in the mid-2010s and projected future gains to 2028 if vaccination coverage were to be increased.

Methods

Using IndiaSim, a dynamic agent-based microsimulation model (ABM) for India, we simulated the spread of Streptococcus pneumoniae and Haemophilius influenzae type B (Hib) among children to estimate reductions in antibiotic use under the scenarios of: (i) pneumococcal and Hib vaccine coverage levels equivalent to the national coverage of pentavalent diphtheria-pertussis-tetanus third dose (DPT3) compared to a baseline of no vaccination, and (ii) near-universal (90%) coverage of the vaccines compared to pre-COVID national DPT3-level coverage. Model parameters, including national DPT3 coverage rates, were based on data from the National Family Household Survey 2015-2016 and other published sources. We quantified reductions in antibiotic consumption nationally and by state and wealth quintiles.

Findings

We estimate that coverage of S. pneumoniae and Hib vaccines at the same level as DPT3 in India would translate to a 61.4% [95% UI: 43.8-69.5] reduction in attributable antibiotic use compared to a baseline of zero vaccination coverage. Increases in childhood vaccination coverage between 2004 and 2016 have likely reduced attributable antibiotic demand by as much as 93.4% among the poorest quintile. Increasing vaccination coverage by an additional 11 percentage points from 2016 levels results in mortality and antibiotic use across wealth quintiles becoming increasingly similar (p < 0.05), reducing in health inquities. We project that near-universal vaccine coverage would further reduce inequities in antibiotic demand and may eliminate of outbreak-associated antibiotic use from S. pneumoniae and Hib.

Interpretation

Though vaccination has a complex relationship with antibiotic use because both are modulated by socioeconomic factors, increasing vaccinations for S. pneumoniae and Hib may have a significant impact on reducing antibiotic use and improving health outcomes among the poorest individuals.

Funding

The Bill & Melinda Gates Foundation (grant numbers OPP1158136 and OPP1190803).

Estimating the burden of vaccine-preventable lower respiratory tract disease in UK primary care: protocol for a prospective surveillance study (AvonCAP GP2)

BACKGROUND

The true burden of acute lower respiratory tract disease (aLRTD; includes acute lower respiratory tract infection [aLRTI] and presumed non-infective exacerbations of chronic lung disease and heart failure) among adults presenting to primary care, and the proportion that are potentially vaccine preventable is unknown.

AIM

To describe aLRTD incidence in adults presenting to primary care; estimate proportions caused by respiratory syncytial virus (RSV), severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), and Streptococcus pneumoniae (SP); and investigate disease burden from patient and NHS perspectives.

DESIGN & SETTING

Primary care prospective cohort study conducted in six representative general practices (total ∼86 000 registered adults) in Bristol, UK.

METHOD

Adults (aged ≥18 years) registered at participating general practices and presenting to primary care (in-hours or out-of-hours) or emergency department (if not admitted) with aLRTD will be eligible. They will be identified by real-time primary care record searches. Researchers will screen electronic GP records, including free text, contact patients to assess eligibility, and offer enrolment in a surveillance study and an enhanced diagnostic study (urine, saliva, and respiratory samples; physical examination; and symptom diaries). Data will be collected for all aLRTD episodes, with patients assigned to one of three arms: surveillance; embedded diagnostic; and descriptive dataset. Outcome measures will include clinical and pathogen-defined aLRTD incidence rates, symptom severity and duration, NHS contacts and costs, health-related quality-of-life changes, and mortality (≤30 days post-identification).

CONCLUSION

This comprehensive surveillance study of adults presenting to primary care with aLRTD, with embedded detailed data and sample collection, will provide an accurate assessment of aLRTD burden due to vaccine-preventable infections.

Overexpression of blaSHV-12 caused by tandem amplification contributed to ceftazidime/avibactam resistance in hypervirulent and carbapenem-resistant Klebsiella pneumoniae

We identified a novel ceftazidime/avibactam (CAZ/AVI) resistance mechanism in endemic sequence type 11 hypervirulent and carbapenem-resistant Klebsiella pneumoniae isolated from a patient who had not been exposed CAZ/AVI. Overexpression of blaSHV-12 caused by tandem gene amplification contributed to CAZ/AVI resistance instead of the carriage of blaKPC-2. Enhanced genomic surveillance is essential to identify emerging variants.

Prevalence of antibiotic self-medication and knowledge of antimicrobial resistance among community members in Neno District rural Malawi: A cross-sectional study

Objectives

Despite global efforts to address antibiotic self-medication, it is still significantly prevalent. This study aimed to investigate the prevalence of antibiotic self-medication and assess knowledge of antibiotic resistance among community members in Neno District, rural Malawi.

Methods

A cross-sectional, community-based study was conducted from September to November 2023, using simple random sampling across 169 villages. Participants from two households per village were surveyed using a "drug bag" method, focusing on those who had taken antibiotics within the preceding 6 months. In addition, drug retailers were selected via snowball sampling for interviews.

Results

Of the 531 participants and 39 drug retailers, 71.1% reported antibiotic use, with 69.5% self-medicating in the past 6 months, with convenience (31.5%) and confidence (26.7%) being the reasons. Common symptoms prompting self-medication included cough (29.9%), sore throat (28.6%), and aches and pain (28.6%). Amoxicillin (61.1%) and cotrimoxazole (29.6%) were the most used antibiotics. More than half (53.1%) reused leftover antibiotics from health facilities, with employed participants significantly more likely to self-medicate. Awareness of antibiotic resistance was low (16.1%), mainly learned from hospitals. Unlawful antibiotic sales by drug retailers (46.2%) were noted.

Conclusions

The study highlights the urgent need for government-led efforts to regulate antibiotic use and increase public awareness to mitigate the impact on public health.

mRNA-based platform for preventing and treating Staphylococcus aureus by targeted staphylococcal enterotoxin B

Staphylococcus aureus (S. aureus) possesses numerous virulence factors, with the increasing prevalence of drug-resistant strains heightening the threat posed by this pathogen. Staphylococcal enterotoxin B (SEB), a highly conserved toxin secreted by S. aureus, is also recognized as a potential bioweapon with super-antigenic activity. SEB represents a promising target in efforts to combat infections caused by S. aureus. We developed mRNA-based vaccine and antibody targeting SEB for both prophylactic and therapeutic purposes in varying S. aureus infection conditions. The mSEB mRNA vaccine (10 μg per mouse) induces more robust and persistent immune responses, including higher antibody titers and specific cellular immune responses, compared to immunization with 30 μg of mSEB protein adjuvanted with aluminum phosphate. Additionally, the anti-SEB mRNA antibody maintains secretion of anti-SEB monoclonal antibody (mAb) with a dosage that is 10 times lower than purified protein administration. The mRNA-based antibody exhibits superior pharmacokinetic profiles compared to its protein counterparts, efficiently neutralizing SEB and clearing S. aureus from circulation. Both the mRNA vaccine and mRNA antibody demonstrate preventive and therapeutic effects by eliciting specific immune responses and generating high-affinity antibodies in mice. We have laid the groundwork for the development and evaluation of mRNA-based vaccines and antibodies targeting SEB produced by S. aureus. Our studies demonstrate that these approaches are more effective than traditional protein-based vaccines and antibodies in terms of inducing immune responses, pharmacokinetics, and their prophylactic or therapeutic efficacy against S. aureus infections.

Antibiotic Prescribing Decisions for Upper Respiratory Tract Infections Among Primary Healthcare Physicians in China: A Mixed-Methods Approach Based on the Theory of Planned Behavior

Objectives: In China, primary healthcare (PHC) facilities have high antibiotic prescribing rates for upper respiratory tract infections (URTIs), which are primarily viral and self-limited. This study aimed to identify the main factors influencing PHC physicians' antibiotic decisions for URITs based on the theory of planned behavior. Methods: A convergent mixed-methods study was conducted at 30 PHC facilities across Shaanxi Province, China. A total of 108 PHC physicians completed a five-point Likert Scale questionnaire focused on behavioral components of antibiotic prescribing, including attitudes, subjective norms, perceived behavioral control, belief in past experiences, and prescribing intentions. Twenty-two physicians participated in semi-structured interviews. Results: Respondents had a good awareness of AMR (Mean = 4.49) and a weak belief regarding the benefit of antibiotics (Mean = 2.34). The mean score for subjective norms was 3.36, and respondents had good control over their prescribing behavior (Mean = 4.00). A reliance on past prescribing experiences was observed (Mean = 3.34), and physicians' antibiotic prescribing intention was 3.40 on average. Multiple linear regression revealed that physicians showing a more favorable attitude towards antibiotics (p = 0.042) and relying more on their past experiences (p = 0.039) had a higher antibiotic prescribing intention. Qualitative interviews indicated that most physicians would consider prescribing antibiotics when facing diagnostic uncertainty. Low utilization of diagnostic tests, limited effectiveness of training programs, inadequate knowledge of guidelines, and lack of feedback on antibiotic prescriptions all contributed to antibiotic overprescribing. Conclusions: PHC physicians in China demonstrated strong intentions to prescribe antibiotics for URTIs when facing diagnostic uncertainty. Beliefs about antibiotics and previous prescribing behavior were significantly linked to prescribing intentions. Multifaceted interventions that focus on facilitating diagnostic tests, improving the quality of training, effectively implementing clinical guidelines, and providing practical feedback on antibiotic prescriptions may help reduce antibiotic overprescribing in China's PHC facilities.

Knowledge, Attitudes, Practices on Antimicrobial Use in Animals Among Livestock Sector Stakeholders in Kenya

Background: Antimicrobials are used on farms to manage livestock diseases. In many developing countries, antimicrobial use (AMU) is insufficiently controlled, and antimicrobials are prone to misuse and abuse, thereby fostering the emergence of antimicrobial resistance (AMR). AMR remains a challenge in Kenya, and the extent remains unknown. This study assessed the knowledge, attitudes, and practices (KAP) regarding AMU among multisectoral stakeholders in Kenya. Methods: The cross-sectional survey was conducted in August 2021 among 381 livestock farmers in Busia, Nakuru, and Isiolo Counties, while 47 animal health service providers (AHSPs) and 32 One Health practitioners (OHPs) were enrolled across Kenya. The data collection tool uploaded on KoBoCollect software was used to collect information on demographics, farming systems, KAP on AMR and AMU, and sources of information. Descriptive statistics were performed. Knowledge was either correct or incorrect, while practices were assigned as desirable or undesirable. Bivariable analysis to assess factors associated with KAP using odds ratio (OR) at 95% confidence level (CL). The Pearson correlation test was conducted to test the correlation between demographic independent variables and farmers' KAP, p < 0.05. Results: Most farmers, 234 (61.4%), were young adults between 30 and 49 years old. Additionally, 48.9% of the farmers had less than 5 years of experience in farming. Among the AHSPs, 76.6% were male, with 21 (44.7%) having 2-5 years of experience. All (32) OHPs had over 15 years of experience. Correct knowledge in AMR/AMU was observed in 52.6% of the farmers, 88.2% of AHSPs, and all OHPs. Desirable practices were observed in 133 (34.9%) of farmers, 22 (45.1%) of AHSPs, and 25 (76.4%) of OHPs. Among the farmers, having basic education was associated with correct knowledge (OR 4.07, p=0.0007); however, being male (OR 1.584, p=0.0456) and having a higher education level (OR 1.582, p=0.0165) were associated with desirable practices. There was a significant positive correlation between having correct knowledge and level of education (p < 0.0001), years of farming, and correct knowledge (p < 0.0001). However, years of farming negatively correlated with the desirable practices (p < 0.0001). Farmers' preferred sources of information regarding AMR/AMU were friends 130 (33.9%), farmer meetings/workshops 99 (25.9%), and radio 41 (10.7%). AHSPs obtain information from scientific conferences/trainings (17) (65.4%), workshops (13) (50.0%), and TV and radio (12) (46.2%), while OHSPs mostly get information through college training (14) (58.3%) and workshops (8) (33.3%). Conclusion: Correct knowledge of AMR/AMU did not result in adopting the desirable practices. A better understanding of the socioeconomic aspects of welfare, good livestock production measures, and AMU stewardship will be desired. This study provides a foundation for developing effective antimicrobial stewardship, best farm practices, and intervention programs to reduce inappropriate AMU. Public Implication: Farmers' AHSP practices are likely to promote the emergence of AMR, a health challenge for animals and humans.

Risk Factors for Recurrent Urinary Tract Infections Among Women in a Large Integrated Health Care Organization in the United States

BACKGROUND

Urinary tract infections (UTIs) occur commonly and often recur. However, recent data on the epidemiology of recurrent UTI (rUTI) are scarce.

METHODS

Between 1 January 2016 and 31 December 2020, index uncomplicated UTIs (uUTIs) from office, emergency department, hospital, and virtual care settings were identified from the electronic health records of women at Kaiser Permanente Southern California. We defined rUTI as ≥3 UTIs within 365 days or ≥2 UTIs within 180 days. We determined the proportion of women with cystitis index uUTI who had rUTI, and we examined factors associated with rUTIs using modified multivariable Poisson regression.

RESULTS

Among 374 171 women with cystitis index uUTI, 54 318 (14.5%) had rUTI. A higher proportion of women with rUTI vs those without rUTI were aged 18 to 27 or ≥78 years at index uUTI (19.7% vs 18.7% and 9.0% vs 6.0%, respectively), were immunocompromised, or had a positive urine culture result at index uUTI. In multivariable analyses, characteristics associated with rUTI included younger or older age (48-57 vs 18-27 years: adjusted risk ratio [aRR], 0.83 [95% CI, .80-.85]; ≥78 vs 18-27 years: aRR, 1.07 [95% CI, 1.03-1.11]), Charlson Comorbidity Index (≥3 vs 0: aRR, 1.12 [95% CI, 1.08-1.17]), and diabetes mellitus (aRR, 1.07 [95% CI, 1.04-1.10]). More frequent prior-year outpatient and emergency department encounters, oral antibiotic and oral contraceptive prescriptions, positive culture result at index uUTI, and antibiotic-resistant organisms were also associated with increased risk of rUTI.

CONCLUSIONS

The high risk of rUTI among women with cystitis is concerning, especially given previous reports of increasing UTI incidence. Current assessment of the epidemiology of rUTI may guide the development of preventive interventions against UTI.

One-pot synthesis of monodisperse silver-lignin particles: Enhanced antibacterial agents against antibiotic-resistant bacteria

Lignin-based supports for metal nanoparticles (NPs) have attracted significant attention due to their abundant functional groups that facilitate NPs loading. However, many studies involve a two-step process: fabricating lignin particles and then reducing metal ions to NPs using physical energy consumption or chemical reduction. A one-step in-situ reduction method for NP synthesis on carrier surfaces, eliminating energy consumption, is needed for environmentally friendly and sustainable approach. Herein, we demonstrate that poly-l-lysine (PL) controls the self-assembly kinetics of kraft lignin (KL), and reduces silver ion (Ag+) to silver nanoparticles (AgNPs), forming highly monodisperse, co-self-assembled PL-KL particles (Ag@PL-KLPs) without chemical reducing agents or energy consumption. PL facilitated rapid KL desolvation, promoting intermolecular interactions and silver ion adsorption, followed by an efficient, separate nucleation and growth process yielded Ag@PL-KLPs approximately 270 nm in size with a narrow distribution. Notably, Ag@PL-KLPs exhibited enhanced bacteriostatic and bactericidal properties against antibiotic-resistant bacteria (ARB), including both Gram-negative and Gram-positive strains, at concentrations of 250 μg/mL. Leveraging biomass-derived lignin and this cost-effective, one-step green synthesis approach offers a sustainable method for avoiding antibiotic overuse and environmental contamination.

Combating antimicrobial resistance in osteoarticular infections: Current strategies and future directions

The emergence of antimicrobial resistance (AMR) has profoundly impacted the management of osteoarticular infections (OAIs), presenting significant challenges for healthcare systems worldwide. This review provides a comprehensive overview of the current landscape of AMR in OAIs, emphasizing the necessity for assertive and innovative strategies to combat this escalating health threat. It discusses the evolution of resistance among key pathogens, including ESKAPEE organisms, and the implications for treatment protocols and healthcare outcomes. The importance of antibiotic stewardship programs (ASPs) is highlighted as a core strategy to optimize antibiotic use and mitigate the development of resistance. Additionally, the review explores the potential of pharmacological approaches, including novel antibiotic regimens and combination therapies, alongside surgical interventions and alternative therapies such as bacteriophage-based treatments and probiotics, in managing these complex infections. The role of rapid diagnostic methods in improving treatment accuracy and the critical need for global surveillance to track AMR trends are also examined. By integrating insights from recent literature and expert recommendations, this review underscores the multifaceted approach required to address the challenge of AMR in OAIs effectively. It calls for a concerted effort among clinicians, researchers, and policymakers to foster innovation in treatment strategies, enhance diagnostic capabilities, and implement robust stewardship and surveillance programs. The goal is to adapt to the evolving landscape of OAIs and ensure optimal patient care in the face of rising AMR.

Immunogenicity and safety of an 18-month booster dose of the VLA15 Lyme borreliosis vaccine candidate after primary immunisation in healthy adults in the USA: results of the booster phase of a randomised, controlled, phase 2 trial

BACKGROUND

Incidence rates of Lyme borreliosis, a tickborne disease attributed to infection by Borrelia species, are increasing, and limitations to existing treatments potentiate the possibility of severe outcomes. Nevertheless, there are no licensed vaccines for Lyme borreliosis prevention in humans. This study investigated the immunogenicity and safety of a booster dose of VLA15, an investigational outer surface protein A (OspA)-based Lyme borreliosis vaccine that has previously shown safety and immunogenicity when administered as a primary vaccination series, following a primary VLA15 vaccination series.

METHODS

We report the results of the booster phase of a randomised, observer-blinded, placebo-controlled, multicentre, phase 2 study that enrolled healthy adults aged 18-65 years from five US clinical study centres to receive 135 μg or 180 μg VLA15 or placebo at months 0, 2, and 6 in the main study phase. Participants who received 180 μg VLA15 in the main study phase and did not have relevant protocol deviations were eligible for the booster phase (months 18-30). Participants were randomly reassigned (2:1) to receive an intramuscular injection of a VLA15 booster or placebo 1 year after the completion of primary vaccination (month 18) via a randomisation list generated by an unmasked statistician with a block size of six. Individuals involved in data safety monitoring, rerandomisation, vaccine handling, and vaccine accountability were unmasked; the study sponsor and statisticians were only unmasked after analysis of data up to 1 month after booster administration. All other individuals remained masked throughout the booster phase. The outcomes for the booster phase were the immunogenicity (evaluated in the booster per-protocol population) and safety (evaluated for all participants who received the booster) of the booster dose up to month 30. The study is registered at ClinicalTrials.gov (NCT03970733) and is completed.

FINDINGS

Between Feb 4 and March 23, 2021, 58 participants (28 men and 30 women) were screened, randomly assigned, and received VLA15 (n=39) or placebo (n=19). One participant in the placebo group was lost to follow-up. The IgG geometric mean titres for each OspA serotype (serotypes 1-6) in the VLA15 group peaked at 1 month after the booster dose (1277·0 U/mL [95% CI 861·8-1892·3] to 2194·5 U/mL [1566·8-3073·7] vs 23·6 U/mL [18·1-30·8] to 36·8 U/mL [26·4-51·3] in the placebo group [p<0·0001 for all serotypes]), remained elevated at month 24 (137·4 U/mL [95·8-196·9] to 265·8 U/mL [202·9-348·2] vs 22·3 U/mL [17·7-28·0] to 29·1 U/mL [20·8-40·6] in the placebo group; p<0·0001 for all serotypes), and declined by month 30 (54·1 U/mL [38·6-75·7] to 101·6 U/mL [77·6-133·1] vs 21·9 U/mL [18·0-26·6] to 24·9 U/mL [19·0-32·6] in the placebo group; p<0·0001 for all serotypes except serotype 1 [p=0·0006]). Solicited local adverse events were reported more frequently in the VLA15 group (35 [92%, 95% CI 79-97] of 38 participants) than the placebo group (six [32%, 15-54] of 19 participants; p<0·0001) after booster vaccination. There was no significant difference in the frequency of solicited systemic adverse events between groups (20 [59%, 42-74] of 34 participants in the VLA15 group vs six [38%, 18-61] of 16 participants in the placebo group). Related unsolicited adverse events (none severe) were reported by two (5%, 1-17) of 39 participants in the VLA15 group and none (0%, 0-17) of 19 participants in the placebo group. There were no severe solicited local or systemic adverse events or deaths during the study.

INTERPRETATION

A booster dose of VLA15 is safe and induces substantial anamnestic immune responses against all six OspA serotypes. As with previously investigated OspA-based Lyme borreliosis vaccines, waning immune responses were observed with VLA15, and annual boosters might therefore be required.

FUNDING

Valneva.

Synthesis of the pentasaccharide repeating unit with a conjugation-ready linker corresponding to the O-antigenic polysaccharide of Acinetobacter junii strain 65

A straightforward synthesis of the pentasaccharide with a readily available linker arm corresponding to the O-antigenic polysaccharide of Acinetobacter junii strain 65 has been achieved in good yield. The synthesis has been carried out using thioglycosides as glycosyl donor in the presence of a combination of N-iodosuccinimide (NIS) and trifluoromethanesulfonic acid (TfOH) as thiophilic activator. The yields of the glycosylation steps were very good with satisfactory stereochemistry at the glycosidic linkages. The pentasaccharide derivative has also been obtained using a one-pot iterative glycosylation strategy.

Food Webs and Feedbacks: The Untold Ecological Relevance of Antimicrobial Resistance as Seen in Harmful Algal Blooms

Antimicrobial resistance (AMR) has long been framed as an epidemiological and public health concern. Its impacts on the environment are unclear. Yet, the basis for AMR is altered cell physiology. Just as this affects how microbes interact with antimicrobials, it can also affect how they interact with their own species, other species, and their non-living environment. Moreover, if the microbes are globally notorious for causing landscape-level environmental issues, then these effects could alter biodiversity and ecosystem function on a grand scale. To investigate these possibilities, we compiled peer-reviewed literature from the past 20 years regarding AMR in toxic freshwater cyanobacterial harmful algal blooms (HABs). We examined it for evidence of AMR affecting HAB frequency, severity, or persistence. Although no study within our scope was explicitly designed to address the question, multiple studies reported AMR-associated changes in HAB-forming cyanobacteria (and co-occurring microbes) that pertained directly to HAB timing, toxicity, and phase, as well as to the dynamics of HAB-afflicted aquatic food webs. These findings highlight the potential for AMR to have far-reaching environmental impacts (including the loss of biodiversity and ecosystem function) and bring into focus the importance of confronting complex interrelated issues such as AMR and HABs in concert, with interdisciplinary tools and perspectives.

Recent Development of Nanozymes for Combating Bacterial Drug Resistance: A Review

The World Health Organization has warned that without effective action, deaths from drug-resistant bacteria can exceed 10 million annually, making it the leading cause of death. Conventional antibiotics are becoming less effective due to rapid bacterial drug resistance and slowed new antibiotic development, necessitating new strategies. Recently, materials with catalytic/enzymatic properties, known as nanozymes, have been developed, inspired by natural enzymes essential for bacterial eradication. Unlike recent literature reviews that broadly cover nanozyme design and biomedical applications, this review focuses on the latest advancements in nanozymes for combating bacterial drug resistance, emphasizing their design, structural characteristics, applications in combination therapy, and future prospects. This approach aims to promote nanozyme development for combating bacterial drug resistance, especially towards clinical translation.

Vaccination with a trivalent Klebsiella pneumoniae vaccine confers protection in a murine model of pneumonia

Klebsiella pneumoniae (K. pneumoniae) is an opportunistic pathogen and the major cause of healthcare-associated infections, which are increasingly complicated by the prevalence of highly invasive and hyper-virulent K. pneumoniae strains, necessitating the development of alternative strategies for combatting infections caused by this bacterium. In this study, we successfully constructed a fusion antigen called KP-Ag1, comprising three antigens (GlnH, FimA, and KPN_00466) that were previously identified through reverse vaccinology. Immunization with KP-Ag1 formulated with Al(OH)3 adjuvant elicited robust humoral and cellular immune response in mice, and conferred protective immunity in a murine model of K. pneumoniae lung infection. Further analysis of serum IgG subtypes from mice immunized with KP-Ag1 revealed a predominant IgG1 response, indicating that KP-Ag1 predominantly induces a Th2-biased immune response. Additionally, opsonophagocytic killing assay suggested that humoral immune responses play a pivotal role in mediating protection conferred by KP-Ag1. Moreover, KP-Ag1 was found to promote the activation and maturation of BMDCs in vitro, which is essential for subsequent efficient antigen presentation. More importantly, vaccination with KP-Ag1 demonstrated cross-protective efficacy against clinical isolates of K. pneumoniae varying in serotypes, antibiotic resistance, and virulence profiles. Therefore, KP-Ag1 holds promise as a candidate for K. pneumoniae vaccine development.

Synthesis and antibacterial properties under blue LED light of conjugates between the siderophore desferrioxamine B (DFOB) and an Iridium(III) complex

The decline of antibiotics efficacy worldwide has recently reached a critical point urging for the development of new strategies to regain upper hand on multidrug resistant bacterial strains. In this context, the raise of photodynamic therapy (PDT), initially based on organic photosensitizers (PS) and more recently on organometallic PS, offers promising perspectives. Many PS exert their biological effects through the generation of reactive oxygen species (ROS) able to freely diffuse into and to kill surrounding bacteria. Hijacking of the bacterial iron-uptake systems with siderophore-PS conjugates would specifically target pathogens. Here, we report the synthesis of unprecedented conjugates between the siderophore desferrioxamine B (DFOB) and an antibacterial iridium(III) PS. Redox properties of the new conjugates have been determined at excited states and compared to that of an antibacterial iridium PS previously reported by our groups. Tested on nosocomial pathogen Pseudomonas aeruginosa and other bacteria, these conjugates demonstrated significant inhibitory activity when activated with blue LED light. Ir(III) conjugate and iridium free DFOB-2,2'-dipyridylamine ligands were crystallized in complex with FoxA, the outer membrane transporter involved in DFOB uptake in P. aeruginosa and revealed details of the binding mode of these unprecedented conjugates.

Critical insights from recent outbreaks of Mycoplasma pneumoniae: decoding the challenges and effective interventions strategies

OBJECTIVES

Mycoplasma pneumoniae (M. pneumoniae) continues to pose a significant disease burden on global public health as a respiratory pathogen. The antimicrobial resistance among M. pneumoniae strains has complicated the outbreak control efforts, emphasizing the need for robust surveillance systems and effective antimicrobial stewardship programs.

DESIGN

This review comprehensively investigates studies stemming from previous outbreaks to emphasize the multifaceted nature of M. pneumoniae infections, encompassing epidemiological dynamics, diagnostic innovations, antibiotic resistance, and therapeutic challenges.

RESULTS

We explored the spectrum of clinical manifestations associated with M. pneumoniae infections, emphasizing the continuum of disease severity and the challenges in gradating it accurately. Artificial intelligence and machine learning have emerged as promising tools in M. pneumoniae diagnostics, offering enhanced accuracy and efficiency in identifying infections. However, their integration into clinical practice presents hurdles that need to be addressed. Further, we elucidate the pivotal role of pharmacological interventions in controlling and treating M. pneumoniae infections as the efficacy of existing therapies is jeopardized by evolving resistance mechanisms.

CONCLUSION

Lessons learned from previous outbreaks underscore the importance of adaptive treatment strategies and proactive management approaches. Addressing these complexities demands a holistic approach integrating advanced technologies, genomic surveillance, and adaptive clinical strategies to effectively combat this pathogen.

Unleashing the power of polymeric nanoparticles - Creative triumph against antibiotic resistance: A review

Antibiotic resistance (ABR) poses a universal concern owing to the widespread use of antibiotics in various sectors. Nanotechnology emerges as a promising solution to combat ABR, offering targeted drug delivery, enhanced bioavailability, reduced toxicity, and stability. This comprehensive review explores concepts of antibiotic resistance, its mechanisms, and multifaceted approaches to combat ABR. The review provides an in-depth exploration of polymeric nanoparticles as advanced drug delivery systems, focusing on strategies for targeting microbial infections and contributing to the fight against ABR. Nanoparticles revolutionize antimicrobial approaches, emphasizing passive and active targeting. The role of various molecules, including small molecules, antimicrobial peptides, proteins, carbohydrates, and stimuli-responsive systems, is being explored in recent research works. The complex comprehension mechanisms of ABR and strategic use of nanotechnology present a promising avenue for advancing antimicrobial tactics, ensuring treatment efficacy, minimizing toxic effects, and mitigating development of ABR. Polymeric nanoparticles, derived from natural or synthetic polymers, are crucial in overcoming ABR. Natural polymers like chitosan and alginate exhibit inherent antibacterial properties, while synthetic polymers such as polylactic acid (PLA), polyethylene glycol (PEG), and polycaprolactone (PCL) can be engineered for specific antibacterial effects. This comprehensive study provides a valuable source of information for researchers, healthcare professionals, and policymakers engaged in the urgent quest to overcome ABR.

ESKAPE pathogens: antimicrobial resistance, epidemiology, clinical impact and therapeutics

The rise of antibiotic resistance and a dwindling antimicrobial pipeline have been recognized as emerging threats to public health. The ESKAPE pathogens - Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa and Enterobacter spp. - were initially identified as critical multidrug-resistant bacteria for which effective therapies were rapidly needed. Now, entering the third decade of the twenty-first century, and despite the introduction of several new antibiotics and antibiotic adjuvants, such as novel β-lactamase inhibitors, these organisms continue to represent major therapeutic challenges. These bacteria share several key biological features, including adaptations for survival in the modern health-care setting, diverse methods for acquiring resistance determinants and the dissemination of successful high-risk clones around the world. With the advent of next-generation sequencing, novel tools to track and combat the spread of these organisms have rapidly evolved, as well as renewed interest in non-traditional antibiotic approaches. In this Review, we explore the current epidemiology and clinical impact of this important group of bacterial pathogens and discuss relevant mechanisms of resistance to recently introduced antibiotics that affect their use in clinical settings. Furthermore, we discuss emerging therapeutic strategies needed for effective patient care in the era of widespread antimicrobial resistance.

Nanozymes and their biomolecular conjugates as next-generation antibacterial agents: A comprehensive review

Antimicrobial resistance (AMR), the ability of bacterial species to develop resistance against exposed antibiotics, has gained immense global attention in the past few years. Bacterial infections are serious health concerns affecting millions of people annually worldwide. Therefore, developing novel antibacterial agents that are highly effective and avoid resistance development is imperative. Among various strategies, recent developments in nanozyme technology have shown promising results as antibacterials in several antibiotic-sensitive and resistant bacterial species. Nanozymes offer several advantages over corresponding natural enzymes, such as inexpensive, stable, multifunctional, tunable catalytic properties, etc. Although the use of nanozymes as antibacterial agents has provided promising results, the specific biomolecule-conjugated nanozymes have shown further improvement in catalytic performance and associated antibacterial efficacy. The exclusive design of functional nanozymes with theranostic potential is found to simultaneously inhibit the growth and image of AMR bacterial species. This review comprehensively summarizes the history of nanozymes, their classification, biomolecules conjugated nanozyme, and their mechanism of enzyme-mimetic activity and associated antibacterial activity in antibiotic-sensitive and resistant species. The futureneeds to effectively engineer the existing or new nanozymes to curb AMR have also been discussed.

Healthcare as a driver, reservoir and amplifier of antimicrobial resistance: opportunities for interventions

Antimicrobial resistance (AMR) is a global health challenge that threatens humans, animals and the environment. Evidence is emerging for a role of healthcare infrastructure, environments and patient pathways in promoting and maintaining AMR via direct and indirect mechanisms. Advances in vaccination and monoclonal antibody therapies together with integrated surveillance, rapid diagnostics, targeted antimicrobial therapy and infection control measures offer opportunities to address healthcare-associated AMR risks more effectively. Additionally, innovations in artificial intelligence, data linkage and intelligent systems can be used to better predict and reduce AMR and improve healthcare resilience. In this Review, we examine the mechanisms by which healthcare functions as a driver, reservoir and amplifier of AMR, contextualized within a One Health framework. We also explore the opportunities and innovative solutions that can be used to combat AMR throughout the patient journey. We provide a perspective on the current evidence for the effectiveness of interventions designed to mitigate healthcare-associated AMR and promote healthcare resilience within high-income and resource-limited settings, as well as the challenges associated with their implementation.

An Overview of the Recent Advances in Antimicrobial Resistance

Antimicrobial resistance (AMR), frequently considered a major global public health threat, requires a comprehensive understanding of its emergence, mechanisms, advances, and implications. AMR's epidemiological landscape is characterized by its widespread prevalence and constantly evolving patterns, with multidrug-resistant organisms (MDROs) creating new challenges every day. The most common mechanisms underlying AMR (i.e., genetic mutations, horizontal gene transfer, and selective pressure) contribute to the emergence and dissemination of new resistant strains. Therefore, mitigation strategies (e.g., antibiotic stewardship programs-ASPs-and infection prevention and control strategies-IPCs) emphasize the importance of responsible antimicrobial use and surveillance. A One Health approach (i.e., the interconnectedness of human, animal, and environmental health) highlights the necessity for interdisciplinary collaboration and holistic strategies in combating AMR. Advancements in novel therapeutics (e.g., alternative antimicrobial agents and vaccines) offer promising avenues in addressing AMR challenges. Policy interventions at the international and national levels also promote ASPs aiming to regulate antimicrobial use. Despite all of the observed progress, AMR remains a pressing concern, demanding sustained efforts to address emerging threats and promote antimicrobial sustainability. Future research must prioritize innovative approaches and address the complex socioecological dynamics underlying AMR. This manuscript is a comprehensive resource for researchers, policymakers, and healthcare professionals seeking to navigate the complex AMR landscape and develop effective strategies for its mitigation.

Exploiting human immune repertoire transgenic mice for protective monoclonal antibodies against antimicrobial resistant Acinetobacter baumannii

The use of monoclonal antibodies for the control of drug resistant nosocomial bacteria may alleviate a reliance on broad spectrum antimicrobials for treatment of infection. We identify monoclonal antibodies that may prevent infection caused by carbapenem resistant Acinetobacter baumannii. We use human immune repertoire mice (Kymouse platform mice) as a surrogate for human B cell interrogation to establish an unbiased strategy to probe the antibody-accessible target landscape of clinically relevant A. baumannii. After immunisation of the Kymouse platform mice with A. baumannii derived outer membrane vesicles (OMV) we identify 297 antibodies and analyse 26 of these for functional potential. These antibodies target lipooligosaccharide (OCL1), the Oxa-23 protein, and the KL49 capsular polysaccharide. We identify a single monoclonal antibody (mAb1416) recognising KL49 capsular polysaccharide to demonstrate prophylactic in vivo protection against a carbapenem resistant A. baumannii lineage associated with neonatal sepsis mortality in Asia. Our end-to-end approach identifies functional monoclonal antibodies with prophylactic potential against major lineages of drug resistant bacteria accounting for phylogenetic diversity and clinical relevance without existing knowledge of a specific target antigen. Such an approach might be scaled for a additional clinically important bacterial pathogens in the post-antimicrobial era.

Documenting the Full Value of Vaccination: A Systematic Review of Value Frameworks

OBJECTIVES

Economic evaluations of vaccination may not fully account for nonhealth patient impacts on families, communities, and society (ie, broader value elements). Omission of broader value elements may reflect a lack of established measurement methodology, lack of agreement over which value elements to include in economic evaluations, and a lack of consensus on whether the value elements included should vary by vaccination type or condition. We conducted a systematic review of value frameworks to identify broader value elements and measurement guidance that may be useful for capturing the full value of vaccination.

METHODS

We searched Ovid MEDLINE, PubMed, Embase, and the gray literature to identify value frameworks for all health interventions, and we extracted information on each framework's context, value elements, and any available guidance on how these elements should be measured. We used descriptive statistics to analyze and compare the prevalence of broader value elements in vaccination value frameworks and other healthcare-related value frameworks.

RESULTS

Our search identified 62 value frameworks that met inclusion criteria, 9 of which were vaccination specific. Although vaccination frameworks included several broader value elements, such as reduced transmissibility and public health benefits, the elements were represented inconsistently across the frameworks. Vaccination frameworks omitted several value elements included in nonvaccination-specific frameworks, including dosing and administration complexity and affordability. In addition, guidance for measuring broader value elements was underdeveloped.

CONCLUSIONS

Future efforts should further evaluate inclusion of broader value elements in economic evaluations of vaccination and develop standards for their subsequent measurement.

Immunopeptidomics Mapping of Listeria monocytogenes T Cell Epitopes in Mice

Listeria monocytogenes is a foodborne intracellular bacterial model pathogen. Protective immunity against Listeria depends on an effective CD8+ T cell response, but very few T cell epitopes are known in mice as a common animal infection model for listeriosis. To identify epitopes, we screened for Listeria immunopeptides presented in the spleen of infected mice by mass spectrometry-based immunopeptidomics. We mapped more than 6000 mouse self-peptides presented on MHC class I molecules, including 12 high confident Listeria peptides from 12 different bacterial proteins. Bacterial immunopeptides with confirmed fragmentation spectra were further tested for their potential to activate CD8+ T cells, revealing VTYNYINI from the putative cell wall surface anchor family protein LMON_0576 as a novel bona fide peptide epitope. The epitope showed high biological potency in a prime boost model and can be used as a research tool to probe CD8+ T cell responses in the mouse models of Listeria infection. Together, our results demonstrate the power of immunopeptidomics for bacterial antigen identification.

Electrically polarized nanoscale surfaces generate reactive oxygenated and chlorinated species for deactivation of microorganisms

Because of the decreasing supply of new antibiotics, recent outbreaks of infectious diseases, and the emergence of antibiotic-resistant microorganisms, it is imperative to develop new effective strategies for deactivating a broad spectrum of microorganisms and viruses. We have implemented electrically polarized nanoscale metallic (ENM) coatings that deactivate a wide range of microorganisms including Gram-negative and Gram-positive bacteria with greater than 6-log reduction in less than 10 minutes of treatment. The electrically polarized devices were also effective in deactivating lentivirus and Candida albicans. The key to the high deactivation effectiveness of ENM devices is electrochemical production of micromolar cuprous ions, which mediated reduction of oxygen to hydrogen peroxide. Formation of highly damaging species, hydroxyl radicals and hypochlorous acid, from hydrogen peroxide contributed to antimicrobial properties of the ENM devices. The electric polarization of nanoscale coatings represents an unconventional tool for deactivating a broad spectrum of microorganisms through in situ production of reactive oxygenated and chlorinated species.

Infectious eye disease in the 21st century-an overview

Infectious diseases affecting the eye often cause unilateral or asymmetric visual loss in children and people of working age. This group of conditions includes viral, bacterial, fungal and parasitic diseases, both common and rare presentations which, in aggregate, may account for a significant portion of the global visual burden. Diagnosis is frequently challenging even in specialist centres, and many disease presentations are highly regional. In an age of globalisation, an understanding of the various modes of transmission and the geographic distribution of infections can be instructive to clinicians. The impact of eye infections on global disability is currently not sufficiently captured in global prevalence studies on visual impairment and blindness, which focus on bilateral disease in the over-50s. Moreover, in many cases it is hard to differentiate between infectious and immune-mediated diseases. Since infectious eye diseases can be preventable and frequently affect younger people, we argue that in future prevalence studies they should be considered as a separate category, including estimates of disability-adjusted life years (DALY) as a measure of overall disease burden. Numbers of ocular infections are uniquely affected by outbreaks as well as endemic transmission, and their control frequently relies on collaborative partnerships that go well beyond the remit of ophthalmology, encompassing domains as various as vaccination, antibiotic development, individual healthcare, vector control, mass drug administration, food supplementation, environmental and food hygiene, epidemiological mapping, and many more. Moreover, the anticipated impacts of global warming, conflict, food poverty, urbanisation and environmental degradation are likely to magnify their importance. While remote telemedicine can be a useful aide in the diagnosis of these conditions in resource-poor areas, enhanced global reporting networks and artificial intelligence systems may ultimately be required for disease surveillance and monitoring.

Design of multi-epitope vaccine candidate based on OmpA, CarO and ZnuD proteins against multi-drug resistant Acinetobacter baumannii

Acinetobacter baumannii has been identified as a major cause of nosocomial infections. Acinetobacter infections are often difficult to treat with multidrug resistant phenotypes. One of the most effective ways to combat infectious diseases is through vaccination. In this study, an attempt was made to select the most protective and potent immunostimulatory epitopes based on the epitope-rich domains of the ZnuD, OmpA and CarO proteins of Acinetobacter baumannii to design a vaccine that can protect against this infection. After predicting the epitope of B- and T-cells, seven antigenic regions of three proteins CarO, ZnuD and OmpA, were selected. These regions were bound by a GGGS linker. The binding affinity and molecular interactions of the vaccine with the immune receptors TLR2 and TLR4 were studied using molecular docking analysis. This vaccine design was subjected to in silico immune simulations using C-ImmSim. The designed vaccine was highly antigenic, non-allergenic and stable. TLR2 and TLR4 were selected to analyze the ability of the modeled chimeric protein to interact with immune system receptors. The results showed strong interaction between the designed protein vaccine with TLR2 (-18.8 kcal mol-1) and TLR4 (-15.1 kcal mol-1). To verify the stability of the interactions and the structure of the designed protein, molecular dynamics (MD) simulations were performed for 200 ns. Various analyses using MD showed that the protein structure is stable alone and in interaction with TLR2 and TLR4. The ability of the vaccine candidate protein to stimulate the immune system to produce the necessary cytokines and antibodies against Acinetobacter baumannii was also demonstrated by the ability of the protein designed using the C-ImmSim web server to induce an immune response. Therefore, the designed protein vaccine may be a suitable candidate for in vivo as well as in vitro studies against Acinetobacter baumannii infections.

Integrative genomics would strengthen AMR understanding through ONE health approach

Emergence of drug-induced antimicrobial resistance (AMR) forms a crippling health and economic crisis worldwide, causing high mortality from otherwise treatable diseases and infections. Next Generation Sequencing (NGS) has significantly augmented detection of culture independent microbes, potential AMR in pathogens and elucidation of mechanisms underlying it. Here, we review recent findings of AMR evolution in pathogens aided by integrated genomic investigation strategies inclusive of bacteria, virus, fungi and AMR alleles. While AMR monitoring is dominated by data from hospital-related infections, we review genomic surveillance of both biotic and abiotic components involved in global AMR emergence and persistence. Identification of pathogen-intrinsic as well as environmental and/or host factors through robust genomics/bioinformatics, along with monitoring of type and frequency of antibiotic usage will greatly facilitate prediction of regional and global patterns of AMR evolution. Genomics-enabled AMR prediction and surveillance will be crucial - in shaping health and economic policies within the One Health framework to combat this global concern.

Investigation of cross-opsonic effect leads to the discovery of PPIase-domain containing protein vaccine candidate to prevent infections by Gram-positive ESKAPE pathogens

BACKGROUND

Enterococcus faecium and Staphylococcus aureus are the Gram-positive pathogens of the ESKAPE group, known to represent a great threat to human health due to their high virulence and multiple resistances to antibiotics. Combined, enterococci and S. aureus account for 26% of healthcare-associated infections and are the most common organisms responsible for blood stream infections. We previously showed that the peptidyl-prolyl cis/trans isomerase (PPIase) PpiC of E. faecium elicits the production of specific, opsonic, and protective antibodies that are effective against several strains of E. faecium and E. faecalis. Due to the ubiquitous characteristics of PPIases and their essential function within Gram-positive cells, we hypothesized a potential cross-reactive effect of anti-PpiC antibodies.

RESULTS

Opsonophagocytic assays combined with bioinformatics led to the identification of the foldase protein PrsA as a new potential vaccine antigen in S. aureus. We show that PrsA is a stable dimeric protein able to elicit opsonic antibodies against the S. aureus strain MW2, as well as cross-binding and cross-opsonic in several S. aureus, E. faecium and E. faecalis strains.

CONCLUSIONS

Given the multiple antibiotic resistances S. aureus and enterococci present, finding preventive strategies is essential to fight those two nosocomial pathogens. The study shows the potential of PrsA as an antigen to use in vaccine formulation against the two dangerous Gram-positive ESKAPE bacteria. Our findings support the idea that PPIases should be further investigated as vaccine targets in the frame of pan-vaccinomics strategy.

Targeting plasmid-encoded proteins that contain immunoglobulin-like domains to combat antimicrobial resistance

Antimicrobial resistance (AMR) poses a significant threat to human health. Although vaccines have been developed to combat AMR, it has proven challenging to associate specific vaccine antigens with AMR. Bacterial plasmids play a crucial role in the transmission of AMR. Our recent research has identified a group of bacterial plasmids (specifically, IncHI plasmids) that encode large molecular mass proteins containing bacterial immunoglobulin-like domains. These proteins are found on the external surface of the bacterial cells, such as in the flagella or conjugative pili. In this study, we show that these proteins are antigenic and can protect mice from infection caused by an AMR Salmonella strain harboring one of these plasmids. Furthermore, we successfully generated nanobodies targeting these proteins, that were shown to interfere with the conjugative transfer of IncHI plasmids. Considering that these proteins are also encoded in other groups of plasmids, such as IncA/C and IncP2, targeting them could be a valuable strategy in combating AMR infections caused by bacteria harboring different groups of AMR plasmids. Since the selected antigens are directly linked to AMR itself, the protective effect extends beyond specific microorganisms to include all those carrying the corresponding resistance plasmids.

A synthetic antibiotic class with a deeply-optimized design for overcoming bacterial resistance

The lack of new drugs that are effective against antibiotic-resistant bacteria has caused increasing concern in global public health. Based on this study, we report development of a modified antimicrobial drug through structure-based drug design (SBDD) and modular synthesis. The optimal modified compound, F8, was identified, which demonstrated in vitro and in vivo broad-spectrum antibacterial activity against drug-resistant bacteria and effectively mitigated the development of resistance. F8 exhibits significant bactericidal activity against bacteria resistant to antibiotics such as methicillin, polymyxin B, florfenicol (FLO), doxycycline, ampicillin and sulfamethoxazole. In a mouse model of drug-resistant bacteremia, F8 was found to increase survival and significantly reduce bacterial load in infected mice. Multi-omics analysis (transcriptomics, proteomics, and metabolomics) have indicated that ornithine carbamoyl transferase (arcB) is a antimicrobial target of F8. Further molecular docking, Isothermal Titration Calorimetry (ITC), and Differential Scanning Fluorimetry (DSF) studies verified arcB as a effective target for F8. Finally, mechanistic studies suggest that F8 competitively binds to arcB, disrupting the bacterial cell membrane and inducing a certain degree of oxidative damage. Here, we report F8 as a promising candidate drug for the development of antibiotic formulations to combat antibiotic-resistant bacteria-associated infections.