Impact of vaccines on antimicrobial resistance

How well does vaccine literacy predict intention to vaccinate and vaccination status? A systematic review and meta-analysis

This review quantified the association of vaccine literacy (VL) and vaccination intention and status. PubMed, Scopus, and Web of Science were searched. Any study, published until December 2022, that investigated the associations of interest were eligible. For each outcome, articles were grouped according to the vaccine administrated and results were narratively synthesized. Inverse-variance random-effect models were used to compare standardized mean values in VL domain(s) between the two groups: individuals willing vs. unwilling to get vaccinated, and individuals vaccinated vs. unvaccinated. This review of 18 studies shows that VL strongly predicts the vaccination intention while its association with vaccination status is attenuated and barely significant, suggesting that other factors influence the actual vaccination uptake. However, given the scarce evidence available, the heterogeneity in the methods applied and some limitations of the studies included, further research should be conducted to confirm the role of VL in the vaccination decision-making process.

Non-Canonical Aspects of Antibiotics and Antibiotic Resistance

The understanding of antibiotic resistance, one of the major health threats of our time, is mostly based on dated and incomplete notions, especially in clinical contexts. The "canonical" mechanisms of action and pharmacodynamics of antibiotics, as well as the methods used to assess their activity upon bacteria, have not changed in decades; the same applies to the definition, acquisition, selective pressures, and drivers of resistance. As a consequence, the strategies to improve antibiotic usage and overcome resistance have ultimately failed. This review gathers most of the "non-canonical" notions on antibiotics and resistance: from the alternative mechanisms of action of antibiotics and the limitations of susceptibility testing to the wide variety of selective pressures, lateral gene transfer mechanisms, ubiquity, and societal factors maintaining resistance. Only by having a "big picture" view of the problem can adequate strategies to harness resistance be devised. These strategies must be global, addressing the many aspects that drive the increasing prevalence of resistant bacteria aside from the clinical use of antibiotics.

Escherichia coli isolates from vegetable farms in Addis Ababa, Ethiopia: Antimicrobial susceptibility profile and associated resistance genetic markers

The use of animal manure to fertilize soil is an emerging concern contributing to the transfer of antimicrobial-resistant pathogens to vegetables. Hence, assessing antimicrobial susceptibility profile of Escherichia coli in vegetable farms is essential to design appropriate interventions against antimicrobial resistance (AMR) in the food chain. This study assessed antimicrobial resistance profile and associated genetic markers among E. coli isolated from vegetable farms fertilized with animal manure in Addis Ababa, Ethiopia. A total of 1044 samples were collected using convenience sampling: soil (n = 271), manure (n = 375), and vegetables (n = 398) from 81 vegetable farms in Addis Ababa, Ethiopia. Antimicrobial susceptibility test was conducted for 100 E. coli isolates and antimicrobial resistance genes (ARGs) were tested by polymerase chain reaction (PCR). Of the 1044 collected samples, 25.3% were positive for E. coli, with significantly higher prevalence in the manure sample and samples collected from Akaki Kality sub-city (p < .05). The highest resistance rate was recorded for tetracycline (72%), followed by streptomycin (63%), and sulfamethoxazole +trimethoprim (56%). Multidrug resistance was detected in 61% of the E. coli isolates. The aac(3)-IV (76.9%), bla TEM (65.4%), aadA (60.3%), tet(A) (58.3%), and sulI (51.7%) were the commonly detected resistance genes. The current study showed a high burden of antimicrobial resistance among E. coli isolated from manure-amended vegetable farms, with potential of playing a significant role in the dissemination of antimicrobial resistance in the food chain. Efforts should be made to reduce the burden of resistant organisms and ARGs through prudent use of antimicrobials in livestock and application of appropriate composting techniques before using manure as fertilizer.

Clinical and economic burden of invasive pneumococcal disease and noninvasive all-cause pneumonia in hospitalized US adults: A multicenter analysis from 2015 to 2020

OBJECTIVES

To evaluate the clinical and economic outcomes in adults hospitalized with invasive pneumococcal disease (IPD) and noninvasive all-cause pneumonia (ACP) overall and by antimicrobial resistance (AMR) status.

METHODS

Hospitalized adults from the BD Insights Research Database with an ICD10 code for IPD, noninvasive ACP or a positive Streptococcus pneumoniae culture/urine antigen test were included. Descriptive statistics and multivariable analyses were used to evaluate outcomes (in-hospital mortality, length of stay [LOS], cost per admission, and hospital margin [costs - payments]).

RESULTS

The study included 88,182 adult patients at 90 US hospitals (October 2015-February 2020). Most (98.6%) had noninvasive ACP and 40.2% were <65 years old. Of 1450 culture-positive patients, 37.7% had an isolate resistant to ≥1 antibiotic class. Observed mortality, median LOS, cost per admission, and hospital margins were 8.3%, 6 days, $9791, and $11, respectively. Risk factors for mortality included ≥50 years of age, higher risk of pneumococcal disease (based on chronic or immunocompromising conditions), and intensive care unit admission. Patients with IPD had similar mortality rates and hospital margins compared with noninvasive ACP, but greater costs per admission and LOS.

CONCLUSION

IPD and noninvasive ACP are associated with substantial clinical and economic burden across all adult age groups. Expanded pneumococcal vaccination programs may help reduce disease burden and decrease hospital costs.

Antimicrobial resistance profiles of Escherichia coli isolated from clinical and environmental samples: findings and implications

Background

The overuse and misuse of antimicrobials has worsened the problem of antimicrobial resistance (AMR) globally. This study investigated the AMR profiles of Escherichia coli isolated from clinical and environmental samples in Lusaka, Zambia.

Methods

This was a cross-sectional study conducted from February 2023 to June 2023 using 450 samples. VITEK® 2 Compact was used to identify E. coli and perform antimicrobial susceptibility testing. Data analysis was done using WHONET 2022 and SPSS version 25.0.

Results

Of the 450 samples, 66.7% (n = 300) were clinical samples, whereas 33.3% (n = 150) were environmental samples. Overall, 47.8% (n = 215) (37.8% clinical and 10% environmental) tested positive for E. coli. Of the 215 E. coli isolates, 66.5% were MDR and 42.8% were ESBL-producers. Most isolates were resistant to ampicillin (81.4%), sulfamethoxazole/trimethoprim (70.7%), ciprofloxacin (67.9%), levofloxacin (64.6%), ceftriaxone (62.3%) and cefuroxime (62%). Intriguingly, E. coli isolates were highly susceptible to amikacin (100%), imipenem (99.5%), nitrofurantoin (89.3%), ceftolozane/tazobactam (82%) and gentamicin (72.1%).

Conclusions

This study found a high resistance of E. coli to some antibiotics that are commonly used in humans. The isolation of MDR and ESBL-producing E. coli is a public health concern and requires urgent action. Therefore, there is a need to instigate and strengthen interventional strategies including antimicrobial stewardship programmes to combat AMR in Zambia.

Revolutionizing and identifying novel drug targets in Citrobacter koseri via subtractive proteomics and development of a multi-epitope vaccine using reverse vaccinology and immuno-informatics

Citrobacter koseri is a gram-negative rod that has been linked to infections in people with significant comorbidities and immunocompromised immune systems. It is most commonly known to cause urinary tract infections. Thus, the development of an efficacious C. koseri vaccine is imperative, as the pathogen has acquired resistance to current antibiotics. Subtractive proteomics was employed during this research to identify potential antigenic proteins to design an effective vaccine against C. koseri. The pipeline identified two antigenic proteins as potential vaccine targets: DP-3-O-acyl-N-acetylglucosamine deacetylase and Arabinose 5-phosphate isomerase. B and T cell epitopes from the specific proteins were forecasted employing several immunoinformatic and bioinformatics resources. A vaccine was created using a combination of seven cytotoxic T cell lymphocytes (CTL), five helper T cell lymphocyte (HTL), and seven linear B cell lymphocyte (LBL) epitopes. An adjuvant (β-defensin) was added to the vaccine to enhance immunological responses. The created vaccine was stable for use in humans, highly antigenic, and non-allergenic. The vaccine's molecular and interactions binding affinity with the human immunological receptor TLR3 were studied using MMGBSA, molecular dynamics (MD) simulations, and molecular docking analyses. E. coli (strain-K12) plasmid vector pET-28a (+) was used to examine the ability of the vaccine to be expressed. The vaccine shows great promise in terms of developing protective immunity against diseases, based on the results of these computer experiments. However, in vitro and animal research are required to validate our findings.Communicated by Ramaswamy H. Sarma.

Monoclonal Antibodies as a Therapeutic Strategy against Multidrug-Resistant Bacterial Infections in a Post-COVID-19 Era

The development of severe multidrug-resistant bacterial infections has recently intensified because of the COVID-19 pandemic. According to the guidelines issued by the World Health Organization (WHO), routine antibiotic administration is not recommended for patients with supposed or confirmed mild SARS-CoV-2 infection or pneumonia, unless bacterial infection is clinically suspected. However, recent studies have pointed out that the proportion of non-essential antibiotic use in patients infected with SARS-CoV-2 remains high. Therefore, the silent pandemic of antibiotic resistance remains a pressing issue regardless of the present threats presented by the COVID-19 pandemic. To prevent or delay entry into the postulated post-antibiotic era, the long-term advocacy for the rational use of antibiotics, the optimization of infection control procedures, and the development of new antibacterial agents and vaccines should be underscored as vital practices of the antibacterial toolbox. Recently, the development of vaccines and monoclonal antibodies has gradually received attention following the advancement of biotechnology as well as enhanced drug discovery and development in cancer research. Although decent progress has been made in laboratory-based research and promising results have been obtained following clinical trials of some of these products, challenges still exist in their widespread clinical applications. This article describes the current advantages of antibacterial monoclonal antibodies, the development of associated clinical trials, and some perceived future perspectives and challenges. Further, we anticipate the development of more therapeutic agents to combat drug-resistant bacterial infections as well as to increase the resilience of current or novel agents/strategies.

An insights into emerging trends to control the threats of antimicrobial resistance (AMR): an address to public health risks

Antimicrobial agents are used to treat microbial ailments, but increased use of antibiotics and exposure to infections in healthcare facilities and hospitals as well as the excessive and inappropriate use of antibiotics at the society level lead to the emergence of multidrug-resistant (MDR) bacteria. Antimicrobial resistance (AMR) is considered a public health concern and has rendered the treatment of different infections more challenging. The bacterial strains develop resistance against antimicrobial agents by limiting intracellular drug accumulation (increasing efflux or decreasing influx of antibiotics), modification and inactivation of drugs and its targets, enzymatic inhibition, and biofilm formation. However, the driving factors of AMR include the sociocultural and economic circumstances of a country, the use of falsified and substandard medicines, the use of antibiotics in farm animals, and food processing technologies. These factors make AMR one of the major menaces faced by mankind. In order to promote reciprocal learning, this article summarizes the current AMR situation in Pakistan and how it interacts with the health issues related to the COVID-19 pandemic. The COVID-19 pandemic aids in illuminating the possible long-term impacts of AMR, which are less immediate but not less severe since their measures and effects are equivalent. Impact on other sectors, including the health industry, the economy, and trade are also discussed. We conclude by summarizing the several approaches that could be used to address this issue.

Mass-immigration shapes the antibiotic resistome of wastewater treatment plants

Wastewater treatment plants (WWTPs) are the hotspots for the spread of antibiotic resistance genes (ARGs) into the environment. Nevertheless, a comprehensive assessment of the city-level and short-term daily (inter-day) variations of ARG profiles in the whole process (influent-INF, activated sludge-AS and effluent-EF) of WWTPs is still lacking. Here, 285 ARGs and ten mobile gene elements were monitored in seven WWTPs in Xiamen for seven days via high-throughput qPCR. The average daily load of ARGs to WWTPs was about 1.32 × 1020 copies/d, and a total of 1.56 × 1018 copies/d was discharged to the environment across the entire city. Stochastic processes were the main force determining the assembly of ARG communities during sampling campaign, with their relative importance ranked in the order of INF > EFF > AS. There're little daily variations in ARG richness, abundance, β-diversity composition as well as assembly mechanisms. The results of SourceTracker, variation partitioning analysis, and hierarchical partitioning analysis indicated that bacteria and ARGs from upstream treatment processes played an increasingly dominant role in shaping ARG communities in AS and EFF, respectively, suggesting the importance of mass-immigration of bacteria and ARGs from the source on ARG transport in wastewater treatment processes. This emphasizes the need to revise the way we mitigate ARG contamination but focus on the source of ARGs in urban wastewater.

Cost-effectiveness and impact on infections and associated antimicrobial resistance of 20-valent pneumococcal conjugate vaccine in US children previously immunized with PCV13

AIM

The US Food and Drug Administration approved the 20-valent pneumococcal conjugate vaccine (PCV20) to prevent pneumococcal disease. In the context of routine PCV20 vaccination, we evaluated the cost-effectiveness and public health and economic impact of a PCV20 catch-up program and estimated the number of antibiotic prescriptions and antibiotic-resistant infections averted.

MATERIALS AND METHODS

A population-based, multi-cohort, decision-analytic Markov model was developed using parameters consistent with previous PCV20 cost-effectiveness analyses. In the intervention arm, children aged 14-59 months who previously completed PCV13 vaccination received a supplemental dose of PCV20. In the comparator arm, no catch-up PCV20 dose was given. The direct and indirect benefits of vaccination were captured over a 10-year time horizon.

RESULTS

A PCV20 catch-up program would prevent 5,469 invasive pneumococcal disease cases, 50,286 hospitalized pneumonia cases, 218,240 outpatient pneumonia cases, 582,302 otitis media cases, and 1,800 deaths, representing a net gain of 30,014 life years and 55,583 quality-adjusted life years. Furthermore, 720,938 antibiotic prescriptions and 256,889 antibiotic-resistant infections would be averted. A catch-up program would result in cost savings of $800 million. These results were robust to sensitivity and scenario analyses.

CONCLUSIONS

A PCV20 catch-up program could prevent pneumococcal infections, antibiotic prescriptions, and antimicrobial-resistant infections and would be cost-saving in the US.

Crisis averted: a world united against the menace of multiple drug-resistant superbugs -pioneering anti-AMR vaccines, RNA interference, nanomedicine, CRISPR-based antimicrobials, bacteriophage therapies, and clinical artificial intelligence strategies to safeguard global antimicrobial arsenal

The efficacy of antibiotics and other antimicrobial agents in combating bacterial infections faces a grave peril in the form of antimicrobial resistance (AMR), an exceedingly pressing global health issue. The emergence and dissemination of drug-resistant bacteria can be attributed to the rampant overuse and misuse of antibiotics, leading to dire consequences such as organ failure and sepsis. Beyond the realm of individual health, the pervasive specter of AMR casts its ominous shadow upon the economy and society at large, resulting in protracted hospital stays, elevated medical expenditures, and diminished productivity, with particularly dire consequences for vulnerable populations. It is abundantly clear that addressing this ominous threat necessitates a concerted international endeavor encompassing the optimization of antibiotic deployment, the pursuit of novel antimicrobial compounds and therapeutic strategies, the enhancement of surveillance and monitoring of resistant bacterial strains, and the assurance of universal access to efficacious treatments. In the ongoing struggle against this encroaching menace, phage-based therapies, strategically tailored to combat AMR, offer a formidable line of defense. Furthermore, an alluring pathway forward for the development of vaccines lies in the utilization of virus-like particles (VLPs), which have demonstrated their remarkable capacity to elicit a robust immune response against bacterial infections. VLP-based vaccinations, characterized by their absence of genetic material and non-infectious nature, present a markedly safer and more stable alternative to conventional immunization protocols. Encouragingly, preclinical investigations have yielded promising results in the development of VLP vaccines targeting pivotal bacteria implicated in the AMR crisis, including Salmonella, Escherichia coli, and Clostridium difficile. Notwithstanding the undeniable potential of VLP vaccines, formidable challenges persist, including the identification of suitable bacterial markers for vaccination and the formidable prospect of bacterial pathogens evolving mechanisms to thwart the immune response. Nonetheless, the prospect of VLP-based vaccines holds great promise in the relentless fight against AMR, underscoring the need for sustained research and development endeavors. In the quest to marshal more potent defenses against AMR and to pave the way for visionary innovations, cutting-edge techniques that incorporate RNA interference, nanomedicine, and the integration of artificial intelligence are currently under rigorous scrutiny.

The Role of Adult Vaccines as Part of Antimicrobial Stewardship: A Scoping Review

BACKGROUND

Antimicrobial resistance (AMR) is a significant global health concern, causing an estimated 700,000 deaths annually. Although immunisation has been shown to significantly reduce AMR, the role of vaccines as part of antimicrobial stewardship (AMS) practices is often overlooked.

OBJECTIVE

To identify and examine the available literature on the role of vaccines as part of AMS practices.

METHOD

A scoping review was conducted in the following databases: MEDLINE, Embase, Scopus, CINAHL, CCRCT, IPA, and WoS, along with grey literature sources. The review was conducted using the JBI Methodology for Scoping Reviews and reported in line with the PRISMA-SCr checklist.

RESULTS

Among the 1711 records identified, 34 met the inclusion criteria; 8 discussed only the concept, while 26 discussed both the concept and the vaccine implementation method in AMS practices. There were eight recommended and/or utilised types of AMS activities identified involving vaccines, under four key themes of vaccine-related AMS strategies: Education, Screening, Vaccination, and Monitoring. Influenza and pneumococcal vaccines had the most evidence for inclusion.

CONCLUSION

Overall, the evidence supports the role of vaccines as part of AMS practices and the value of their inclusion in creating improved and comprehensive AMS strategies to further combat the development of AMR.

Multi-epitope vaccine against drug-resistant strains of Mycobacterium tuberculosis: a proteome-wide subtraction and immunoinformatics approach

Mycobacterium tuberculosis (Mtb) is the causative agent of tuberculosis, one of the most deadly infections in humans. The emergence of multidrug-resistant and extensively drug-resistant Mtb strains presents a global challenge. Mtb has shown resistance to many frontline antibiotics, including rifampicin, kanamycin, isoniazid, and capreomycin. The only licensed vaccine, Bacille Calmette-Guerin, does not efficiently protect against adult pulmonary tuberculosis. Therefore, it is urgently necessary to develop new vaccines to prevent infections caused by these strains. We used a subtractive proteomics approach on 23 virulent Mtb strains and identified a conserved membrane protein (MmpL4, NP_214964.1) as both a potential drug target and vaccine candidate. MmpL4 is a non-homologous essential protein in the host and is involved in the pathogen-specific pathway. Furthermore, MmpL4 shows no homology with anti-targets and has limited homology to human gut microflora, potentially reducing the likelihood of adverse effects and cross-reactivity if therapeutics specific to this protein are developed. Subsequently, we constructed a highly soluble, safe, antigenic, and stable multi-subunit vaccine from the MmpL4 protein using immunoinformatics. Molecular dynamics simulations revealed the stability of the vaccine-bound Toll-like receptor-4 complex on a nanosecond scale, and immune simulations indicated strong primary and secondary immune responses in the host. Therefore, our study identifies a new target that could expedite the design of effective therapeutics, and the designed vaccine should be validated. Future directions include an extensive molecular interaction analysis, in silico cloning, wet-lab experiments, and evaluation and comparison of the designed candidate as both a DNA vaccine and protein vaccine.

The need for Africa to develop capacity for vaccinology as a means of curbing antimicrobial resistance

The high prevalence of infectious diseases in Africa, combined with weak healthcare systems, poor antimicrobial stewardship, and an unchecked drug supply chain, is steadily reversing the trend in the fight against infectious diseases in this part of the world, posing severe threats to antimicrobial resistance (AMR). AMR continuously evolves and threatens to undermine antimicrobial efficacy and undo advances against infectious diseases. This brewing pandemic is now recognized as a significant worldwide health danger, implicated in several cases of morbidity, mortality, and increasing healthcare costs. Vaccine technology has been proven to be the principal remedy to this imminent danger since it prevents microbial infections. However, since Africa cannot produce its vaccines, it relies on external sources and, as a result, it is significantly affected by vaccine nationalism, hoarding, and instabilities in global supply chains. This has further adversely impacted the ability of African governments to regulate rollouts, protect their citizens, and ultimately rejoin the global economy. This dependency is a severe challenge to Africa's health resilience, as it is unsustainable. Given the inevitability of potential global pandemics and the alarming incidences of multi-drug resistance infections reported daily, Africa must develop the capability to produce its vaccines. The review utilized a systematic search of academic databases and grey literature, as well as a manual search of relevant reports and articles. In this review, we outline the public health threats and concerns that AMR poses to Africans, and the hurdles and advances achieved in vaccine development over the years. We also highlight possible strategies, particularly collaborative efforts, that will accelerate vaccine production and ease the strain of infectious diseases and antimicrobial resistance in Africa. Key findings indicate that Africa has significant gaps in its vaccine manufacturing and distribution capacity, with only a few countries having the ability to produce vaccines. Additionally, existing vaccine production facilities are often outdated and require significant investment to meet international standards. The review also highlights successful initiatives in Africa, such as the mRNA vaccine hub and the African Vaccine Manufacturing Initiative, which have demonstrated the potential for building local vaccine manufacturing capacity. The study concludes that Africa needs to prioritize investment in vaccine research and development, regulatory capacity, and infrastructure to build a sustainable vaccine manufacturing ecosystem. Overall, this review emphasizes the urgent need for Africa to develop its vaccine manufacturing capacity to improve vaccine access and strengthen its ability to respond to future pandemics. The findings underscore the importance of collaboration between African governments, international organizations, and the private sector to build a resilient vaccine ecosystem in Africa.

CRISPR-Based Gene Editing in Acinetobacter baumannii to Combat Antimicrobial Resistance

Antimicrobial resistance (AMR) poses a significant threat to the health, social, environment, and economic sectors on a global scale and requires serious attention to addressing this issue. Acinetobacter baumannii was given top priority among infectious bacteria because of its extensive resistance to nearly all antibiotic classes and treatment options. Carbapenem-resistant A. baumannii is classified as one of the critical-priority pathogens on the World Health Organization (WHO) priority list of antibiotic-resistant bacteria for effective drug development. Although available genetic manipulation approaches are successful in A. baumannii laboratory strains, they are limited when employed on newly acquired clinical strains since such strains have higher levels of AMR than those used to select them for genetic manipulation. Recently, the CRISPR-Cas (Clustered regularly interspaced short palindromic repeats/CRISPR-associated protein) system has emerged as one of the most effective, efficient, and precise methods of genome editing and offers target-specific gene editing of AMR genes in a specific bacterial strain. CRISPR-based genome editing has been successfully applied in various bacterial strains to combat AMR; however, this strategy has not yet been extensively explored in A. baumannii. This review provides detailed insight into the progress, current scenario, and future potential of CRISPR-Cas usage for AMR-related gene manipulation in A. baumannii.

Antimicrobial use for the management of varicella in Thailand: a retrospective observational study

OBJECTIVE

To describe the clinical characteristics of varicella patients seeking medical consultation and the use of antimicrobials for their management in Thailand in the absence of universal varicella vaccination (UVV).

METHODS

A multicenter, retrospective chart review of 260 children and adults with a primary diagnosis of varicella was conducted at one private and three public hospitals in Bangkok, Thailand. Charts of varicella patients (inpatient or outpatient) were randomly selected over a 5-year period. Key outcomes included clinical complications and the use of antibiotics, antivirals, and other medications.

RESULTS

Charts of 200 children (mean age 5.7 years, range 0.3-16 years) and 60 adults (mean age 27.9 years, range 18-50 years) were reviewed. Fourteen patients (including 8 children) were hospitalized. Five percent of the children and none of the adults were immunocompromised. At least 1 varicella-related complication was reported by 7.3% (7% of children, 8.3% of adults, p = .778) of all patients, including 57.1% (62.5% of children, 50% of adults) of inpatients (p < .001, compared with outpatients). Skin/soft tissue infection (47.7%) and dehydration (47.4%) were the most common complications. Antivirals (mainly oral acyclovir) were prescribed to 46.5% of patients (31.5% of children, 96.7% of adults, p < .001). Antibiotics were prescribed to 20.8% of patients (19% of children, 26.7% of adults, p = .199). Topical, oral, and intravenous antibiotics were prescribed to 12.3%, 8.5%, and 1.2% of patients, respectively. Antimicrobial prescriptions were higher among adults (p < .001) and immunocompromised patients (p = .025). Apart from antimicrobials, acetaminophen (62.3%) and oral antihistamines (51.5%) were the most prescribed.

CONCLUSION

A considerable number of varicella patients, both children and adults, seeking medical consultation in Thai hospitals are prescribed antibiotics and antivirals, with one-fifth of patients being prescribed an antibiotic and almost half prescribed an antiviral. The study may be of interest to policymakers in Thailand and other Asia-Pacific countries considering UVV implementation.

Drivers of inappropriate antibiotic use in low- and middle-income countries

Antimicrobial resistance (AMR) is a global security threat that accounts for about 700 000 deaths annually. Studies have shown that antimicrobial resistance could result in a 2% to 3.5% reduction in global Gross Domestic Product by 2050 and a loss of between 60 and 100 trillion US dollars, worth of economic output resulting in significant and widespread human suffering. Low- and middle-income countries (LMICs) will be worse hit by an unchecked rise of AMR. For example, it is predicted that AMR could kill about 4.1 million people in Africa by 2050 if it is not curbed. Similarly rising rates of AMR will lead to increased treatment costs and an inability to attain universal health coverage, in LMICs with fragile health systems. Sadly, AMR is driven by the inappropriate use of antimicrobials, especially antibiotics. Inappropriate antibiotic use is a pertinent problem in LMICs where regulatory frame works are weak. Inappropriate antibiotic use in LMICs is a multifaceted problem that cuts across clinical and veterinary medicine and agriculture. Therefore, efforts geared at curbing inappropriate antibiotic use in LMICs must identify the factors that drive this problem (i.e. inappropriate antibiotic use) in these countries. A clear knowledge of these factors will guide effective policy and decision making to curb inappropriate antibiotic use and ultimately AMR. The focus of this review is to discuss the factors that drive inappropriate antibiotic use in LMICs.

Estimating the effect of increasing ambient temperature on antimicrobial resistance in China: A nationwide ecological study with the difference-in-differences approach

Antimicrobial resistance (AMR) and the possible consequences of rising ambient temperatures brought on by global warming have been extensively discussed. However, the epidemiological evidence on the effects of temperature on AMR is rare and little is known about the role of socioeconomic inequities. This ecological study obtained 31 provinces AMR data of Escherichia Coli (E. coli) from the China Antimicrobial Resistance Surveillance System (CARSS) over the period from 2014 to 2020, which were linked to the meteorological and socioeconomic data published in the China Statistical Yearbook. Modified difference-in-differences (DID) analyses were performed to estimate the effect of ambient temperature on AMR of E. coli to third-generation cephalosporins (ceftriaxone and cefotaxime), carbapenems, and quinolones, adjusting for variations in meteorological and socioeconomic factors. We estimated that every 1 °C increase in average ambient temperature was associated with 2.71 % (95 % confidence interval [CI]: 1.20-4.24), 32.92 % (95 % CI: 15.62-52.81), and 1.81 % (95 % CI: 0.47-3.16) increase in the prevalence of E. coli resistance to third-generation cephalosporins (ceftriaxone and cefotaxime), carbapenems and quinolones, respectively. The link was more profound in the regions with lower temperature and a median level of average humidity, and the regions with lower income, lower expenditure (in economics), lower health resources, and lower hospital admissions. Neither the replacement of the temperature variable nor the alternative approaches for confounding adjustment changed the positive association between ambient temperature and AMR. In general, there exists a positive association between ambient temperature and AMR, although the strength of such an association varies by socioeconomic and health services factors. The association is possibly nonlinear, especially for E. coli resistance to third-generation cephalosporins. The findings suggest that AMR control programs should explicitly incorporate weather patterns to increase their effectiveness.

The spread of antibiotic resistance to humans and potential protection strategies

Antibiotic resistance is currently one of the greatest threats to human health. Widespread use and residues of antibiotics in humans, animals, and the environment can exert selective pressure on antibiotic resistance bacteria (ARB) and antibiotic resistance gene (ARG), accelerating the flow of antibiotic resistance. As ARG spreads to the population, the burden of antibiotic resistance in humans increases, which may have potential health effects on people. Therefore, it is critical to mitigate the spread of antibiotic resistance to humans and reduce the load of antibiotic resistance in humans. This review briefly described the information of global antibiotic consumption information and national action plans (NAPs) to combat antibiotic resistance and provided a set of feasible control strategies for the transmission of ARB and ARG to humans in three areas including (a) Reducing the colonization capacity of exogenous ARB, (b) Enhancing human colonization resistance and mitigating the horizontal gene transfer (HGT) of ARG, (c) Reversing ARB antibiotic resistance. With the hope of achieving interdisciplinary one-health prevention and control of bacterial resistance.

Vaccine development for bacterial pathogens: Advances, challenges and prospects

The advent and use of antimicrobials have played a key role in treating potentially life-threatening infectious diseases, improving health, and saving the lives of millions of people worldwide. However, the emergence of multidrug resistant (MDR) pathogens has been a significant health challenge that has compromised the ability to prevent and treat a wide range of infectious diseases that were once treatable. Vaccines offer potential as a promising alternative to fight against antimicrobial resistance (AMR) infectious diseases. Vaccine technologies include reverse vaccinology, structural biology methods, nucleic acid (DNA and mRNA) vaccines, generalised modules for membrane antigens, bioconjugates/glycoconjugates, nanomaterials and several other emerging technological advances that are offering a potential breakthrough in the development of efficient vaccines against pathogens. This review covers the opportunities and advancements in vaccine discovery and development targeting bacterial pathogens. We reflect on the impact of the already-developed vaccines targeting bacterial pathogens and the potential of those currently under different stages of preclinical and clinical trials. More importantly, we critically and comprehensively analyse the challenges while highlighting the key indices for future vaccine prospects. Finally, the issues and concerns of AMR for low-income countries (sub-Saharan Africa) and the challenges with vaccine integration, discovery and development in this region are critically evaluated.

Outer Membrane Vesicle-Coated Nanoparticle Vaccine Protects Against Acinetobacter baumannii Pneumonia and Sepsis

The highly multidrug-resistant (MDR) Gram-negative bacterial pathogen Acinetobacter baumannii is a top global health priority where an effective vaccine could protect susceptible populations and limit resistance acquisition. Outer membrane vesicles (OMVs) shed from Gram-negative bacteria are enriched with virulence factors and membrane lipids but heterogeneous in size and cargo. We report a vaccine platform combining precise and replicable nanoparticle technology with immunogenic A. baumannii OMVs (Ab-OMVs). Gold nanoparticle cores coated with Ab-OMVs (Ab-NPs) induced robust IgG titers in rabbits that enhanced human neutrophil opsonophagocytic killing and passively protected against lethal A. baumannii sepsis in mice. Active Ab-NP immunization in mice protected against sepsis and pneumonia, accompanied by B cell recruitment to draining lymph nodes, activation of dendritic cell markers, improved splenic neutrophil responses, and mitigation of proinflammatory cytokine storm. Nanoparticles are an efficient and efficacious platform for OMV vaccine delivery against A. baumannii and perhaps other high-priority MDR pathogens.

Antimicrobial Resistance and Recent Alternatives to Antibiotics for the Control of Bacterial Pathogens with an Emphasis on Foodborne Pathogens

Antimicrobial resistance (AMR) is one of the most important global public health problems. The imprudent use of antibiotics in humans and animals has resulted in the emergence of antibiotic-resistant bacteria. The dissemination of these strains and their resistant determinants could endanger antibiotic efficacy. Therefore, there is an urgent need to identify and develop novel strategies to combat antibiotic resistance. This review provides insights into the evolution and the mechanisms of AMR. Additionally, it discusses alternative approaches that might be used to control AMR, including probiotics, prebiotics, antimicrobial peptides, small molecules, organic acids, essential oils, bacteriophage, fecal transplants, and nanoparticles.

Density functional theory and molecular docking study to lutein molecule for COVID-19 protease inhibitors

Since the beginning of the corona pandemic, numerous scientific projects have been conducted worldwide to investigate how the new virus can be combated. Researchers are developing various vaccines and drugs at full speed - with varying degrees of success. In this work, silico screening (molecular docking analysis) is performed on twenty natural compounds, which are expected to provide valuable lead molecules and medication to treat a new condition SARS-CoV-2. Our results indicate that out of the 20 compounds on the candidate list, lutein and Polydatin, natural components of fruits and vegetables (especially egg yolk and maize) have shown an excellent performance in our docking studies through a minimum binding energy of - 9.8 kcal/mol also - 7.4 kcal/mol, separately. This indicates their potential for the inhibitory molecular interactions against COVID-19. The main intent of the research is to analyse the protein components and investigate the molecules.

Social and cognitive factors influencing commercial chicken farmers' antimicrobial usage in Bangladesh

Adapting the Social Cognitive Theory framework, we conducted a cross-sectional study on 137 commercial chicken farms in Bangladesh to investigate factors influencing the behaviour of farmers towards the application of antimicrobials to their birds. Almost all farmers used antimicrobials to treat poultry diseases, while 38.6% also were using them to promote healthy growth of chickens and 10.2% to increase egg production or improve meat quality. Using Structural Equation Modeling (SEM), we identified that inappropriate usage of antimicrobials (behaviour) was strongly driven by farmers' short-term goals to maintain the health of their chickens in a production cycle (β = 0.813, p = 0.029), rather than long-term concerns. Farmers' perception about their ability to control antimicrobial administration based on their skills and opportunities (self-efficacy) marginally influenced the short-term goals of antimicrobial usage (β = 0.301, p = 0.073). The results of this study can be used to develop targeted education programs for farmers, to reduce the application of antimicrobials in their poultry flocks.

Determinants of Knowledge, Attitude, and Practices of Veterinary Drug Dispensers toward Antimicrobial Use and Resistance in Main Cities of Malawi: A Concern on Antibiotic Stewardship

Antimicrobial resistance (AMR) is an emerging challenge to global public health. The use of antibiotics in the veterinary field is one of the contributing factors to AMR mostly due to poor knowledge, attitudes, and practices (KAP) of dispensers. Veterinary drug dispensers are expected to guide clients on indications, contraindications, and withdrawal periods of veterinary drugs. This study assessed veterinary drug dispensers' KAP toward AMR and associated potential contributing factors. A cross-sectional study, using a structured questionnaire, was conducted in three main cities of Malawi, namely Mzuzu, Lilongwe, and Blantyre. A total of 68 agrovet shops were selected using a simple random sampling technique. The KAP level was presented descriptively. Bivariate and multivariable analyses were run to investigate the relationships between the independent and outcome variable. Overall, the KAP score for knowledge, attitude, and practices was 46.7%, 49.2%, and 41.6%, respectively. The significant determinants of the knowledge were the practice of asking for a written prescription (OR: 16.291, 95% CI: 11.6-24.2) (p = 0.024), female (OR: 0.609, 95% CI: 0.3-0.9) (p = 0.001), and old age (≥35) (OR: 0.227, 95% CI: 0.1-0.5) (p = 0.04). Poor knowledge, negative attitude, and poor practices were observed among most of the participants. Sensitization and training on AMR and antimicrobial stewardship are recommended to address the KAP score gaps and the observed determinants among veterinary drug dispensers.

A review of evidence for pneumococcal vaccination in adults at increased risk of pneumococcal disease: risk group definitions and optimization of vaccination coverage in the United Kingdom

INTRODUCTION

Pneumococcal disease (PD) significantly contributes to morbidity and mortality, carrying substantial economic and public health burden. This article is a targeted review of evidence for pneumococcal vaccination in the UK, the definitions of groups at particular risk of PD and vaccine effectiveness.

AREAS COVERED

Relevant evidence focusing on UK data from surveillance systems, randomized controlled trials, observational studies and publicly available government documents is collated and reviewed. Selected global data are included where appropriate.

EXPERT OPINION

National vaccination programs have reduced the incidence of vaccine-type PD, despite the rising prominence of non-vaccine serotypes in the UK. The introduction of higher-valency conjugate vaccines provides an opportunity to improve protection against PD for adults in risk groups. Several incentives are in place to encourage general practitioners to vaccinate risk groups, but uptake is low-suboptimal particularly among at-risk individuals. Wider awareness and understanding among the public and healthcare professionals may increase vaccination uptake and coverage. National strategies targeting organizational factors are urgently needed to achieve optimal access to vaccines. Finally, identifying new risk factors and approaches to risk assessment for PD are crucial to ensure those at risk of PD can benefit from pneumococcal vaccination.

Available evidence and potential for vaccines for reduction in antibiotic prescriptions

Bacterial antibiotic resistance is a public health issue. It means that drugs become ineffective, infections persist and have a huge impact on the health of patients and their spreading increases. To address a complex threat such as bacterial antibiotic resistance different and integrated approaches are needed including discovery of new antibiotics, improvement of diagnostics tools and improvement of antibiotic stewardship. Absolutely relevant are prevention of infections as well as decrease in the use of antibiotics. Vaccines are an important tool in the fight against bacterial antibiotic resistance and can help prevent it in several ways. Indeed, vaccines are highly effective in preventing diseases that might otherwise require the use of antibiotics to treat symptoms and associated complications. Preventing infections through vaccination helps reduce the need for and widespread and inappropriate use of antibiotics, including for secondary bacterial infections.

New putative therapeutic targets against Serratia marcescens using reverse vaccinology and subtractive genomics

The Gram-negative bacillus Serratia marcescens, a member of Enterobacteriaceae family, is an opportunistic nosocomial pathogen commonly found in hospital outbreaks that can cause infections in the urinary tract, bloodstream, central nervous system and pneumonia. Because S. marcescens strains are resistant to several antibiotics, it is critical the need for effective treatments, including new drugs and vaccines. Here, we applied reverse vaccinology and subtractive genomic approaches for the in silico prediction of potential vaccine and drug targets against 59 strains of S. marcescens. We found 759 core non-host homologous proteins, of which 87 are putative surface-exposed proteins, 183 secreted proteins, and 80 membrane proteins. From these proteins, we predicted seven candidates vaccine targets: a sn-glycerol-3-phosphate-binding periplasmic protein UgpB, a vitamin B12 TonB-dependent receptor, a ferrichrome porin FhuA, a divisome-associated lipoprotein YraP, a membrane-bound lytic murein transglycosylase A, a peptidoglycan lytic exotransglycosylase, and a DUF481 domain-containing protein. We also predicted two drug targets: a N(4)-acetylcytidine amidohydrolase, and a DUF1428 family protein. Using the molecular docking approach for each drug target, we identified and selected ZINC04259491 and ZINC04235390 molecules as the most favorable interactions with the target active site residues. Our findings may contribute to the development of vaccines and new drug targets against S. marcescens. Communicated by Ramaswamy H. Sarma.

The Development of Technology to Prevent, Diagnose, and Manage Antimicrobial Resistance in Healthcare-Associated Infections

There is a growing risk of antimicrobial resistance (AMR) having an adverse effect on the healthcare system, which results in higher healthcare costs, failed treatments and a higher death rate. A quick diagnostic test that can spot infections resistant to antibiotics is essential for antimicrobial stewardship so physicians and other healthcare professionals can begin treatment as soon as possible. Since the development of antibiotics in the last two decades, traditional, standard antimicrobial treatments have failed to treat healthcare-associated infections (HAIs). These results have led to the development of a variety of cutting-edge alternative methods to combat multidrug-resistant pathogens in healthcare settings. Here, we provide an overview of AMR as well as the technologies being developed to prevent, diagnose, and control healthcare-associated infections (HAIs). As a result of better cleaning and hygiene practices, resistance to bacteria can be reduced, and new, quick, and accurate instruments for diagnosing HAIs must be developed. In addition, we need to explore new therapeutic approaches to combat diseases caused by resistant bacteria. In conclusion, current infection control technologies will be crucial to managing multidrug-resistant infections effectively. As a result of vaccination, antibiotic usage will decrease and new resistance mechanisms will not develop.

The impact of vaccination on the burden of invasive pneumococcal disease from a nationwide surveillance program in Lebanon: an unexpected increase in mortality driven by non-vaccine serotypes

BACKGROUND

The impact of pneumococcal conjugate vaccines (PCVs) on the burden of invasive pneumococcal disease (IPD) and serotype distribution was examined across age groups from data collected by the Lebanese Inter-Hospital Pneumococcal Surveillance Program.

METHODS

Between 2005 and 2020, 593 invasive Streptococcus pneumoniae isolates were collected from 79 hospitals throughout Lebanon. Serotypes and antimicrobial resistance (AMR) profiles were identified, and trends compared over 3 eras: PCV7, post-PCV7/ pre-PCV13, and PCV13 eras.

RESULTS

The prevalence of PCV7 serotypes decreased significantly from 43.6% in the PCV7 era to 17.8% during the PCV13 era (p<0.001). PCV13-only serotypes remained stable in the PCV13 compared to the post-PCV7 eras, especially serotypes 1 and 3, whereas non-vaccine types (NVT) increased throughout the study period, especially 24 and 16F. The mortality rate increased substantially from 12.5% (PCV7 era) to 24.8% (PCV13 era). A significant decrease in AMR was observed across the three study eras.

CONCLUSION

PCVs substantially impacted IPD and AMR in vaccinated and unvaccinated populations despite an increase in mortality driven by NVT. Broadening the recommendation of vaccination to include older age-groups, using higher valency vaccines, and implementing stringent antimicrobial stewardship are likely to further impact the burden of IPD.

Isolation and identification of endophytic actinobacteria from Citrullus colocynthis (L.) Schrad and their antibacterial properties

BACKGROUND

Antibiotic resistance poses a major threat to human health globally. Consequently, new antibiotics are desperately required to discover and develop from unexplored habitats to treat life-threatening infections. Microbial natural products (NP) are still remained as primary sources for the discovery of new antibiotics. Endophytic actinobacteria (EA) which are well-known producers of bioactive compounds could provide novel antibiotic against pathogenic bacteria. This research aimed to isolate EA from the Citrullus colocynthis plant and explore the antibacterial properties of their metabolites against pathogenic bacteria.

RESULTS

The healthy samples were collected, dissected and surface-sterilized before cultured on four different selection media at 28 °C. Six endophytic actinobacteria were isolated from Citrullus colocynthis plant. They were taxonomically classified into two family namely Streptomycetaceae and Nocardiopsaceae, based on colony morphological features, scanning electron microscope analysis and molecular identification of isolates. This is the first report on the identification of EA form Citrullus colocynthis and their antibacterial activity. The strains generated a chain of vibrio-comma, cubed or cylindrical shaped spores with indenting or smooth surfaces. Three of those were reported as endophytes for the first time. The strain KUMS-C1 showed 98.55% sequence similarity to its closely related strains which constitutes as a novel species/ strain for which the name Nocardiopsis colocynthis sp. was proposed for the isolated strain. Five isolated strains had antagonist activity against S. aureus, P. aeruginosa, and E. coli. Among those, stain KUMS-C6 showed the broadest spectrum of antibacterial activity against all test bacteria, whereas the strain KUMS-C4 had no antibacterial activity.

CONCLUSIONS

NPs have a long history of safe and efficient use for development of pharmaceutical products. Our study highlights that Citrullus colocynthis is an untapped source for the isolation of EA, generating novel and bioactive metabolites by which might lead to discovery of new antibiotic(s). This study reveals the future of new antibiotic developments looks bright against multi-drug resistance diseases by mining under- or unexplored habitats.

A national online survey of Filipinos' knowledge, attitude, and awareness of antibiotic use and resistance: A cross-sectional study

BACKGROUND

Antibiotic resistance is one of the 21st century's most challenging clinical and public health issues. However, this health issue remains underreported in the Philippines.

AIM

This study examined Filipinos' knowledge, attitude, and awareness regarding antibiotic use and resistance and the associated predictive variables of antibiotic resistance.

METHODS

A cross-sectional design and Strengthening the Reporting of Observational Studies in Epidemiology guidelines were used in this study. Convenience sampling of 3767 participants completed the Eurobarometer survey on antibiotic resistance from October 2021 to February 2022. χ² and regression analysis were used to analyze the data.

RESULTS

Most participants were familiar with the popular types of available antibiotics. Males and healthcare workers had a higher percentage of correct responses on antibiotic resistance knowledge. Participants had moderate to high knowledge levels of antibiotic resistance. Age, educational attainment, profession, antibiotic use in the previous year, and household members taking antibiotics were significant predictors of the level of knowledge of antibiotic resistance. There was a significant difference in participants' sex, age, and educational attainment in their attitudes toward acquisition, hygienic practices, and the role of health professionals in antibiotic resistance.

CONCLUSION

Government agencies and policymakers should consider the identified predictors when establishing policies on antibiotic resistance. This will ensure that antibiotic use is safe and effective.

Written Briefing and Oral Counseling Increase the Willingness to Receive the SARS-CoV-2 Vaccination among Women in Puerperium: A Qualitative Prospective Cohort Study

(1) Background: Vaccination rates for severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2) are low in Austria. International obstetric societies recommend the SARS-CoV-2 mRNA vaccination for women in puerperium. (2) Methods: A prospective two-stage cohort study was conducted at the Medical University of Vienna between October 2022 and December 2022. Firstly, women in puerperium were assigned to the evaluation group (step 1), and secondly, another cohort of unvaccinated women were randomly assigned to study group A (written briefing) or B (written and oral briefing) (step 2). We evaluated the vaccination status among women in the evaluation group and the willingness to receive the vaccination in all three cohorts. (3) Results: We included 217 women in puerperium (evaluation: n = 69, A: n = 68; B: n = 80). In the evaluation group, 66.7% (n = 46/69) of the women were unvaccinated. A total of 45.7% (21/46) of the unvaccinated women categorically declined the SARS-CoV-2 vaccination. A total of 26.5% (n = 18/68) of women in study group A, and 43.8% (n = 35/80) of women in study group B expressed their willingness to receive the vaccination (p = 0.029). There were no differences in willingness to receive the vaccination between different age strata of women in study groups A and B. (D) Conclusion: Our qualitative data demonstrate a benefit from oral counseling in addition to written briefing in order to increase the willingness to receive the vaccination among women in puerperium.

A Multicenter Evaluation of Trends in Antimicrobial Resistance among Streptococcus pneumoniae Isolates from Adults in the United States

Background

Management of pneumococcal disease is complicated by high rates of antimicrobial resistance (AMR). This study assessed AMR trends for Streptococcus pneumoniae isolates from adults with pneumococcal disease.

Methods

From January 2011 to February 2020, we evaluated 30-day nonduplicate S. pneumoniae isolates from 290 US hospitals (BD Insights Research Database) from adults (≥18 years) in inpatient and outpatient settings. Isolates were required to have ≥1 AMR result for invasive (blood, cerebrospinal fluid/neurologic) or noninvasive (respiratory or ear/nose/throat) pneumococcal disease samples. Determination of AMR was based on facility reports of intermediate or resistant. Descriptive statistics and generalized estimated equations were used to assess variations over time.

Results

Over the study period, 34 039 S. pneumoniae isolates were analyzed (20 749 [61%] from noninvasive sources and 13 290 [39%] from invasive sources). Almost half (46.6%) of the isolates were resistant to ≥1 drug, and noninvasive isolates had higher rates of AMR than invasive isolates. Total S. pneumoniae isolates had high rates of resistance to macrolides (37.7%), penicillin (22.1%), and tetracyclines (16.1%). Multivariate modeling identified a significant increasing trend in resistance to macrolides (+1.8%/year; P < .001). Significant decreasing trends were observed for penicillin (−1.6%/year; P < .001), extended-spectrum cephalosporins (ESCs; −0.35%/year; P < .001), and ≥3 drugs (−0.5%/year; P < .001).

Conclusions

Despite decreasing trends for penicillin, ESCs, and resistance to ≥3 drugs, AMR rates are persistently high in S. pneumoniae isolates among US adults. Increasing macrolide resistance suggests that efforts to address AMR in S. pneumoniae may require antimicrobial stewardship efforts and higher-valent pneumococcal conjugate vaccines.

Regulation of innate and adaptive immunity using herbal medicine: benefits for the COVID-19 vaccination

Vaccination is a major achievement that has become an effective prevention strategy against infectious diseases and active control of emerging pathogens worldwide. In response to the coronavirus disease 2019 (COVID-19) pandemic, several diverse vaccines against severe acute respiratory syndrome coronavirus 2 have been developed and deployed for use in a large number of individuals, and have been reported to protect against symptomatic COVID-19 cases and deaths. However, the application of vaccines has a series of limitations, including protective failure for variants of concern, unavailability of individuals due to immune deficiency, and the disappearance of immune protection for increasing infections in vaccinated individuals. These aspects raise the question of how to modulate the immune system that contributes to the COVID-19 vaccine protective effects. Herbal medicines are widely used for their immune regulatory abilities in clinics. More attractively, herbal medicines have been well accepted for their positive role in the COVID-19 prevention and suppression through regulation of the immune system. This review presents a brief overview of the strategy of COVID-19 vaccination and the response of the immune system to vaccines, the regulatory effects and mechanisms of herbal medicine in immune-related macrophages, natural killer cells, dendritic cells, and lymphocytes T and B cells, and how they help vaccines work. Later in the article, the potential role and application of herbal medicines in the most recent COVID-19 vaccination are discussed. This article provides new insights into herbal medicines as promising alternative supplements that may benefit from COVID-19 vaccination.

Graphical abstract

http://links.lww.com/AHM/A31.

Tackling antimicrobial resistance across sub-Saharan Africa: current challenges and implications for the future

INTRODUCTION

Antimicrobial resistance (AMR) is a concern as this increases morbidity, mortality, and costs, with sub-Saharan Africa having the highest rates globally. Concerns with rising AMR have resulted in international, Pan-African, and country activities including the development of national action plans (NAPs). However, there is variable implementation across Africa with key challenges persisting.

AREAS COVERED

Consequently, there is an urgent need to document current NAP activities and challenges across sub-Saharan Africa to provide future guidance. This builds on a narrative review of the literature.

EXPERT OPINION

All surveyed sub-Saharan African countries have developed their NAPs; however, there is variable implementation. Countries including Botswana and Namibia are yet to officially launch their NAPs with Eswatini only recently launching its NAP. Cameroon is further ahead with its NAP than these countries; though there are concerns with implementation. South Africa appears to have made the greatest strides with implementing its NAP including regular monitoring of activities and instigation of antimicrobial stewardship programs. Key challenges remain across Africa. These include available personnel, expertise, capacity, and resources to undertake agreed NAP activities including active surveillance, lack of focal points to drive NAPs, and competing demands and priorities including among donors. These challenges are being addressed, with further co-ordinated efforts needed to reduce AMR.

Antibiotics and Carbohydrate-Containing Drugs Targeting Bacterial Cell Envelopes: An Overview

Certain bacteria constitute a threat to humans due to their ability to escape host defenses as they easily develop drug resistance. Bacteria are classified into gram-positive and gram-negative according to the composition of the cell membrane structure. Gram-negative bacteria have an additional outer membrane (OM) that is not present in their gram-positive counterpart; the latter instead hold a thicker peptidoglycan (PG) layer. This review covers the main structural and functional properties of cell wall polysaccharides (CWPs) and PG. Drugs targeting CWPs are discussed, both noncarbohydrate-related (β-lactams, fosfomycin, and lipopeptides) and carbohydrate-related (glycopeptides and lipoglycopeptides). Bacterial resistance to these drugs continues to evolve, which calls for novel antibacterial approaches to be developed. The use of carbohydrate-based vaccines as a valid strategy to prevent bacterial infections is also addressed.

Capturing the value of vaccination within health technology assessment and health economics: Literature review and novel conceptual framework

BACKGROUND

Vaccination provides significant health gains to individuals and society and can potentially improve health equity, healthcare systems and national economies. Policy decisions, however, are rarely informed by comprehensive economic evaluations (EE) including vaccination's wide-ranging value. The objective of this analysis was to focus on health technology assessment systems to identify relevant value concepts in order to improve current EE of non-pandemic vaccines.

METHODS

Following a literature review, a novel Value of Vaccination (VoV) framework was developed with experts in vaccine EE from developed countries with established health technology assessment systems.

RESULTS

Forty-four studies presenting value frameworks or concepts applicable to vaccination were included. Eighteen unique value concepts relevant to EE were identified and defined. These were categorised within the VoV framework using three dimensions, moving from a narrow payer perspective to a more expansive and societal perspective. The dimensions were: (I) conventional payer perspective concepts (e.g., health gains in vaccinees, direct medical costs); (II) conventional societal perspective concepts (e.g., indirect health/economic gains to caregivers/households, productivity in vaccinees); and (III) novel societal concepts (e.g., financial risk protection, peace of mind, societal health gains, healthcare systems security, political stability, social equity and macroeconomic gains). While good quality evidence and methods are available to support concepts in Dimensions I and II, further work is needed to generate the required evidence for vaccination impact on Dimension III concepts.

CONCLUSIONS

The devastating effect on nations of the COVID-19 pandemic has helped to highlight the potential far-reaching benefits that many vaccination programmes can offer. This VoV framework is particularly relevant to policy decisions considering EE, and the potential future expansion of non-pandemic vaccination value considerations. The framework helps to understand and compare current value considerations across countries and payer versus societal perspectives. It provides decision-makers with a transparent and logical path to broaden consideration of VoV in EE.

Next-Generation Approaches Needed to Tackle Antimicrobial Resistance for the Development of Novel Therapies Against the Deadly Pathogens

The advent of antimicrobials was a miracle that saved millions of lives across the globe. With the discovery of penicillin, varieties of other antimicrobials came into play one after another. However, the injudicious use of antimicrobials for therapeutics and prophylactics and overuse in agriculture and animal husbandry industries resulted in its gloominess and rise of antimicrobial resistance. The microbes have slowly outsmarted the human race with diverse mechanisms to evade the antimicrobial effects of the drugs in use. The review aims to discuss the emergence of resistance in bacterial species with time and the various means by which bacterial cells had safeguarded themselves. In addition to that, we have also highlighted new approaches currently used to tackle antimicrobial resistance or practices that could be useful in identifying new treatment options.

MODELING THE ROLE OF VACCINATION, ENVIRONMENTAL SANITATION, AND SATURATED TREATMENT ON THE SPREAD OF TYPHOID FEVER

A deterministic nonlinear mathematical model is developed for typhoid transmission dynamics in human hosts, coupled with multiple transmission routes. The model aims to examine the role of control interventions such as vaccination, environmental sanitation, and saturated treatment on the prevalence of typhoid. First, the qualitative analysis of the model with constant control interventions is performed. The model exhibits a backward bifurcation phenomenon. Sensitivity analysis is also conducted to identify impactful parameters for effective control of the disease. Then, the model is extended to a corresponding optimal control problem to investigate the optimum intervention strategies by assessing their effects on typhoid prevalence and economic load. The characterization of the optimal controls is determined using Pontryagin’s Maximum Principle, and the optimality system is developed. Numerical results suggest that, in the absence of treatment, the combination of vaccination and environmental sanitation controls plays an important role in reducing the typhoid burden and economic load. Moreover, the comprehensive use of the three control interventions is more effective than using any single or two combined control interventions. It reduces the number of infective humans and environmental bacteria as well as the cost burden associated with applied controls and opportunity loss. Thus, the comprehensive effect of the three control interventions is found to be more economical during typhoid outbreaks.

Targeting protein tyrosine phosphatases for the development of antivirulence agents: Yersinia spp. and Mycobacterium tuberculosis as prototypes

Protein phosphorylation mediated by protein kinases and phosphatases has a central regulatory function in many cellular processes in eukaryotes and prokaryotes. As a result, several diseases caused by imbalance in phosphorylation levels are known, especially due to protein tyrosine phosphatases (PTPs) activity, an important family of signaling enzymes. Furthermore, over the last decades several studies have shown the main role of PTPs in pathogenic bacteria: they are associated with growth, cell division, cell wall biosynthesis, biofilm formation, metabolic processes, as well as virulence factor. In this way, PTPs have ascended as targets for antibacterial drug design, particularly in view of the antibiotic resistance in pathogenic bacteria, which demands novel therapeutics strategies. Targeting secreted PTPs is an antivirulence strategy to combat the emergence of antimicrobial resistance (AMR). This review focuses on the recent advances in understanding the role of PTPs and the approaches to target them, with an emphasis in Yersinia spp. and Mycobacterium tuberculosis pathogenesis.

Attitudes towards vaccination and knowledge about antibiotics: Analysis of Wellcome Monitor survey data

Vaccine hesitancy and antimicrobial resistance are biomedically connected public health challenges, but to date minimal research has examined social connections between the UK public's attitudes towards vaccination and attitudes towards antibiotic use. Understanding the extent to which these issues are attitudinally parallel would be valuable for implementing and evaluating public health interventions. Using data from the Wellcome Trust Monitor Wave 4 this study examined social associations between these two areas. An ordinal logistic regression model predicting knowledge level about antibiotics was fitted using 2,654 observations, controlling for known outcome covariates, with perceptions of the risk of side-effects from vaccination and of the efficacy of vaccination as a preventative intervention as independent variables. Compared to the modal response category of 'Fairly low', respondents who rated the risk of serious side-effects from vaccination as 'Very high' (OR = 2.87, 95% CI = 1.71-4.89) or 'Fairly high' (OR = 1.51, 95% CI = 1.21-1.88) were more likely to have provided incorrect responses to questions about the utility of antibiotics for treating different types of infection. Conversely, respondents who felt there was 'No risk at all' (OR = 0.69, 95% CI = 0.50-0.95) were less likely to have provided incorrect responses about the utility of antibiotics. Compared to the modal category of 'Almost always effective', only respondents who felt that vaccines were 'Sometimes effective' (OR = 1.26, 95% CI = 1.05-1.51) or 'Almost never or never effective' (OR = 2.32, CI = 1.32-4.19) were more likely provide incorrect responses regarding antibiotics' utility. Negative perceptions of vaccination and misperceptions about the role of antibiotics for treating infections are associated with one other within the general UK public. Qualitative research is needed to understand the nature of this association and identify areas of public understanding that are not exclusive to specific health interventions but that may be targeted to improve responsiveness to vaccine- and antibiotic-related public health interventions.

Review of Label-Free Monitoring of Bacteria: From Challenging Practical Applications to Basic Research Perspectives

Novel biosensors already provide a fast way to detect the adhesion of whole bacteria (or parts of them), biofilm formation, and the effect of antibiotics. Moreover, the detection sensitivities of recent sensor technologies are large enough to investigate molecular-scale biological processes. Usually, these measurements can be performed in real time without using labeling. Despite these excellent capabilities summarized in the present work, the application of novel, label-free sensor technologies in basic biological research is still rare; the literature is dominated by heuristic work, mostly monitoring the presence and amount of a given analyte. The aims of this review are (i) to give an overview of the present status of label-free biosensors in bacteria monitoring, and (ii) to summarize potential novel directions with biological relevancies to initiate future development. Optical, mechanical, and electrical sensing technologies are all discussed with their detailed capabilities in bacteria monitoring. In order to review potential future applications of the outlined techniques in bacteria research, we summarize the most important kinetic processes relevant to the adhesion and survival of bacterial cells. These processes are potential targets of kinetic investigations employing modern label-free technologies in order to reveal new fundamental aspects. Resistance to antibacterials and to other antimicrobial agents, the most important biological mechanisms in bacterial adhesion and strategies to control adhesion, as well as bacteria-mammalian host cell interactions are all discussed with key relevancies to the future development and applications of biosensors.

Measuring the Link Between Vaccines and Antimicrobial Resistance in Low Resource Settings – Limitations and Opportunities in Direct and Indirect Assessments and Implications for Impact Studies

The importance of vaccines in combatting antimicrobial resistance (AMR) is commonly accepted. Although scientific reasoning supports the putative connection between vaccines and reduction of AMR, reliably measuring the magnitude and effect of vaccines on antimicrobial resistance is inherently challenging, especially in low resource settings. We review the intrinsic challenges in estimating the effect of vaccines on AMR and discuss the limitations and opportunities in current methods from the host, pathogen, and environment perspectives. We highlight advantages and pitfalls in different epidemiological study designs with a specific focus on impact studies in low resource settings and suggest how these perspectives could be considered in future research.

Progress in Alternative Strategies to Combat Antimicrobial Resistance: Focus on Antibiotics

Antibiotic resistance, and, in a broader perspective, antimicrobial resistance (AMR), continues to evolve and spread beyond all boundaries. As a result, infectious diseases have become more challenging or even impossible to treat, leading to an increase in morbidity and mortality. Despite the failure of conventional, traditional antimicrobial therapy, in the past two decades, no novel class of antibiotics has been introduced. Consequently, several novel alternative strategies to combat these (multi-) drug-resistant infectious microorganisms have been identified. The purpose of this review is to gather and consider the strategies that are being applied or proposed as potential alternatives to traditional antibiotics. These strategies include combination therapy, techniques that target the enzymes or proteins responsible for antimicrobial resistance, resistant bacteria, drug delivery systems, physicochemical methods, and unconventional techniques, including the CRISPR-Cas system. These alternative strategies may have the potential to change the treatment of multi-drug-resistant pathogens in human clinical settings.

Factors Associated with Antimicrobial Stewardship Practices on California Dairies: One Year Post Senate Bill 27

BACKGROUND

The current study is aimed at identifying the factors associated with antimicrobial drug (AMD) use and stewardship practices on conventional California (CA) dairies a year after CA Senate Bill 27.

METHODS

Responses from 113 out of 1282 dairies mailed a questionnaire in 2019 were analyzed to estimate the associations between management practices and six outcomes including producer familiarity with medically important antimicrobial drugs (MIADs), restricted use of MIADs previously available over the counter (OTC), use of alternatives to AMD, changes in on-farm management practices, changes in AMD costs, and animal health status in dairies.

RESULTS

Producers who reported having a veterinarian-client-patient relationship (VCPR) and tracking AMD withdrawal intervals had greater odds of being familiar with the MIADs. Producers who began or increased the use of preventive alternatives to AMD in 2019 had higher odds (OR = 3.23, p = 0.04) of decreased use of MIADs previously available OTC compared to those who did not. Changes in management practices to prevent disease outbreak and the use of diagnostics to guide treatment were associated with producer-reported improved animal health. In addition, our study identified record keeping (associated with familiarity with MIADs), use of alternatives to AMD (associated with management changes to prevent diseases and decreased AMD costs), and use of diagnostics in treatment decisions (associated with reported better animal health) as factors associated with AMD stewardship.

CONCLUSIONS

Our survey findings can be incorporated in outreach education materials to promote antimicrobial stewardship practices in dairies.

Antibacterial Activity of Cerium Oxide Nanoparticles against ESKAPE Pathogens

We studied the antimicrobial characteristics of cerium oxide (CeO2) nanoparticles synthesized by hydrothermal technique. The versatile characterization techniques were employed to study the CeO2 nanoparticle structural and optical properties. These techniques included field emission scanning electron microscopy, Raman spectroscopy, X-ray diffraction, and transmission electron microscopy. The X-ray diffraction and Raman studies validated the cubic structure of the synthesized CeO2 nanoparticles with average diameters ~3–5 nm. The antibacterial activities and minimal inhibition concentrations (MICs) of CeO2 nanoparticles were tested against ESKAPE pathogens (Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter sp.). Our data revealed that CeO2 nanoparticles at a concentration of 50 µg/mL generated a maximum inhibition zone against all tested pathogens. However, S. aureus, P. aeruginosa, and K. pneumoniae exhibited the higher sensitivity, while E. cloacae, E. faecium, and A. baumannii were the least sensitive to CeO2 nanoparticles. In conclusion, our results demonstrate that CeO2 nanoparticles possess an effective antibacterial activity against ESKAPE pathogens and may be used as a potential bionanomaterial for in vivo therapeutic applications.

Antimicrobial Resistance (AMR) of Bacteria Isolated from Dogs with Canine Parvovirus (CPV) Infection: The Need for a Rational Use of Antibiotics in Companion Animal Health

Canine parvovirus type 2 (CPV-2) represents a major viral threat to dogs. Considering the potential effects of pets on antimicrobial resistance, information on the CPV and associated bacterial co-infections is limited. The aim of this study was to analyze the antimicrobial susceptibility and multidrug-resistance profiles of bacterial species from tissue samples of dogs with canine parvovirus infection. A set of PCR assays and sequence analyses was used for the detection and the molecular characterization of the CPV strains and other enteric viruses. Bacterial isolation, the determination of antimicrobial susceptibility via the disk diffusion method, and the determination of the minimum inhibitory concentration were performed. The detection of β-lactamase genes and toxin genes for specific bacteria was also carried out. CPV infection was confirmed in 23 dogs. Forty-three bacterial strains were isolated and all showed phenotypic resistance. Seventeen multidrug-resistant bacteria and bacteria with high resistance to third- and fourth-generation cephalosporins and metronidazole were detected. Almost 50% of the isolated Enterobacteriaceae were positive for at least one β-lactamase gene, with the majority carrying more genes as well. The evidence for multi-resistant bacteria with the potential for intra- or cross-species transmission should be further considered in a One Health approach.