The antibiotic resistance crisis and the development of new antibiotics.

The Global Burden of Disease report of 2019 estimated 14 million infection-related deaths, making it the second leading cause of death after ischaemic heart disease. Bacterial pathogens accounted for 7.7 million deaths and deaths attributable to bacterial antibiotic resistance amounted to 1.3 million, describing a clear demand for novel antibiotics. Antibiotic development had its golden age in 1930-1960. Following failures in the screening of chemical libraries for novel antibiotics at the beginning of this century, the high cost of launching new antibiotics (estimated at US$ 1.4 billion per registered drug) and difficulties in achieving a return of investment for novel antibiotics, pharmaceutical industry has mostly left the field. The current Lilliput review analyses the question whether scientific or economic hurdles prevented the registration of new antibiotics. Scientifically, substantial progress has been achieved over recent years to define the chemical properties needed to overcome the permeation barrier in Gram-negative pathogens; in extending the chemical space of antibiotic candidates by full modular synthesis of suitable molecules; by extending bioprospecting to previously 'unculturable' bacteria or unusual bacteria; by attacking bacterial targets on the outer bacterial membrane; and by looking for support from structural biology, genomics, molecular genetics, phylogenetic analyses and deep machine learning approaches. However, these research activities were mostly conducted by academic researchers and biotech companies with limited financial resources. It thus seems that the development of new antibiotics, frequently described as the drying of the pipeline, is less limited by lack of scientific insight than by lack of the mobilization of the monetary resources needed to bring these discoveries to the market despite recent financial push and pull efforts of the public sector.

The role of bacterial genital infections in spontaneous preterm delivery: a case-control study.

Background: Spontaneous preterm delivery is defined as the beginning of the birth process before the 37th week of pregnancy. The presence of microorganisms in the fetal membranes is accompanied by an increase in the production of prostaglandin, one of the important factors associated with the prevalence of preterm birth. The invasion of microorganisms leads to the production of protease, coagulase, and elastase, which directly stimulate the onset of childbirth. We investigated the role of genital infections in women with preterm birth. Methods: The present case-control study was conducted in the west of Iran on 100 women with spontaneous preterm delivery (following 24 weeks of gestation and before 36 weeks and 6 days) as the case group and 100 women with normal delivery as controls. A questionnaire was applied to collect the data. Polymerase chain reaction and pathological examination of the placenta were performed. Results: The average age in women with normal delivery (30.92 ± 5.10) in women with spontaneous preterm delivery (30.27 ± 4.93). The prevalence of Chlamydia trachomatis, Neisseria gonorrhea, Listeria monocytogenes, and Mycoplasma genitalium infections was zero in both groups. The highest prevalence of Gardnerella vaginalis was 19 (19%) in the case group and Ureaplasma parvum 15 (15%) in the control group. Also, Placental inflammation was zero in controls and 7(7%) in the patient group. There was a significant relationship between Gardnerella vaginalis bacteria and spontaneous preterm delivery. Conclusion: The results of our study showed that except for Gardnerella vaginalis bacteria, there is no significant relationship between the above bacterial infections and spontaneous preterm birth. Moreover, despite the significant reduction in the prevalence of many sexually transmitted infections in this research, it is still suggested to increase the awareness of people, including pregnant women, about the ways it can be transmitted by gynecologists and health and treatment centers.

Recent advances in gene-editing approaches for tackling antibiotic resistance threats: a review.

Antibiotic resistance, a known global health challenge, involves the flow of bacteria and their genes among animals, humans, and their surrounding environment. It occurs when bacteria evolve and become less responsive to the drugs designated to kill them, making infections harder to treat. Despite several obstacles preventing the spread of genes and bacteria, pathogens regularly acquire novel resistance factors from other species, which reduces their ability to prevent and treat such bacterial infections. This issue requires coordinated efforts in healthcare, research, and public awareness to address its impact on human health worldwide. This review outlines how recent advances in gene editing technology, especially CRISPR/Cas9, unveil a breakthrough in combating antibiotic resistance. Our focus will remain on the relationship between CRISPR/cas9 and its impact on antibiotic resistance and its related infections. Moreover, the prospects of this new advanced research and the challenges of adopting these technologies against infections will be outlined by exploring its different derivatives and discussing their advantages and limitations over others, thereby providing a corresponding reference for the control and prevention of the spread of antibiotic resistance.

Microbiological profile of diabetic foot infections in China and worldwide: a 20-year systematic review.

Introduction: Pathogens causing diabetic foot infections (DFIs) vary by region globally; however, knowledge of the causative organism is essential for effective empirical treatment. We aimed to determine the incidence and antibiotic susceptibility of DFI pathogens worldwide, focusing on Asia and China. Methods: Through a comprehensive literature search, we identified published studies on organisms isolated from DFI wounds from January 2000 to December 2020. Results: Based on our inclusion criteria, we analyzed 245 studies that cumulatively reported 38,744 patients and 41,427 isolated microorganisms. DFI pathogens varied according to time and region. Over time, the incidence of Gram-positive and Gram-negative aerobic bacteria have decreased and increased, respectively. America and Asia have the highest (62.74%) and lowest (44.82%) incidence of Gram-negative bacteria, respectively. Africa has the highest incidence (26.90%) of methicillin-resistant Staphylococcus aureus. Asia has the highest incidence (49.36%) of Gram-negative aerobic bacteria with species infection rates as follows: Escherichia coli, 10.77%; Enterobacter spp., 3.95%; and Pseudomonas aeruginosa, 11.08%, with higher local rates in China and Southeast Asia. Linezolid, vancomycin, and teicoplanin were the most active agents against Gram-positive aerobes, while imipenem and cefoperazone-sulbactam were the most active agents against Gram-negative aerobes. Discussion: This systematic review showed that over 20 years, the pathogens causing DFIs varied considerably over time and region. This data may inform local clinical guidelines on empirical antibiotic therapy for DFI in China and globally. Regular large-scale epidemiological studies are necessary to identify trends in DFI pathogenic bacteria. Systematic review registration: https://www.crd.york.ac.uk/prospero/, identifier CRD42023447645.

Bacterial persisters: molecular mechanisms and therapeutic development.

Persisters refer to genetically drug susceptible quiescent (non-growing or slow growing) bacteria that survive in stress environments such as antibiotic exposure, acidic and starvation conditions. These cells can regrow after stress removal and remain susceptible to the same stress. Persisters are underlying the problems of treating chronic and persistent infections and relapse infections after treatment, drug resistance development, and biofilm infections, and pose significant challenges for effective treatments. Understanding the characteristics and the exact mechanisms of persister formation, especially the key molecules that affect the formation and survival of the persisters is critical to more effective treatment of chronic and persistent infections. Currently, genes related to persister formation and survival are being discovered and confirmed, but the mechanisms by which bacteria form persisters are very complex, and there are still many unanswered questions. This article comprehensively summarizes the historical background of bacterial persisters, details their complex characteristics and their relationship with antibiotic tolerant and resistant bacteria, systematically elucidates the interplay between various bacterial biological processes and the formation of persister cells, as well as consolidates the diverse anti-persister compounds and treatments. We hope to provide theoretical background for in-depth research on mechanisms of persisters and suggest new ideas for choosing strategies for more effective treatment of persistent infections.

Preserving the efficacy of antibiotics to tackle antibiotic resistance.

Different international agencies recognize that antibiotic resistance is one of the most severe human health problems that humankind is facing. Traditionally, the introduction of new antibiotics solved this problem but various scientific and economic reasons have led to a shortage of novel antibiotics at the pipeline. This situation makes mandatory the implementation of approaches to preserve the efficacy of current antibiotics. The concept is not novel, but the only action taken for such preservation had been the 'prudent' use of antibiotics, trying to reduce the selection pressure by reducing the amount of antibiotics. However, even if antibiotics are used only when needed, this will be insufficient because resistance is the inescapable outcome of antibiotics' use. A deeper understanding of the alterations in the bacterial physiology upon acquisition of resistance and during infection will help to design improved strategies to treat bacterial infections. In this article, we discuss the interconnection between antibiotic resistance (and antibiotic activity) and bacterial metabolism, particularly in vivo, when bacteria are causing infection. We discuss as well how understanding evolutionary trade-offs, as collateral sensitivity, associated with the acquisition of resistance may help to define evolution-based therapeutic strategies to fight antibiotic resistance and to preserve currently used antibiotics.

Roles of Critical Amino Acids Metabolism in The Interactions Between Intracellular Bacterial Infection and Macrophage Function.

Macrophages, as crucial participants in the innate immune system, respond to pathogenic challenges through their dynamic metabolic adjustments, demonstrating the intimate interplay between cellular metabolism and immune function. Bacterial infection of macrophages causes changes in macrophage metabolism, affecting both macrophage function and bacterial virulence and intracellular survival. This review explores the reprogramming of amino acid metabolism in macrophages in response to bacterial infection, with a particular focus on the influence of critical amino acids such as serine, glutamine, and arginine on the immune functions of macrophages; highlights the roles of these metabolic pathways in macrophage functions such as phagocytosis, inflammatory response, immune regulation, and pathogen clearance; reveals how pathogens exploit and manipulate the amino acid metabolism within macrophages to support their own growth and replication, thereby showcasing the intricate interplay between macrophages and pathogens. It provides a foundation for understanding the interactions between macrophages amino acid metabolism and pathogens, offering potential strategies and therapeutic targets for the development of novel anti-infection therapies.

Towards pharmacokinetic boosting of phenoxymethylpenicillin (penicillin-V) using probenecid for the treatment of bacterial infections.

In the face of increasing antimicrobial tolerance and resistance there is a global obligation to optimise oral antimicrobial dosing strategies including narrow spectrum penicillins, such as penicillin-V. We conducted a randomised, crossover study in healthy volunteers to characterise the influence of probenecid on penicillin-V pharmacokinetics and estimate the pharmacodynamics against Streptococcus pneumoniae. Twenty participants took six doses of penicillin-V (250 mg, 500 mg or 750 mg four times daily) with and without probenecid. Total and free concentrations of penicillin-V and probenecid were measured at two timepoints. A pharmacokinetic model was developed, and the probability of target attainment (PTA) calculated. The mean difference (95% CI) between penicillin-V alone and in combination with probenecid for serum total and free penicillin-V concentrations was significantly different at both timepoints (total: 45 min 4.32 (3.20-5.32) mg/L p < 0.001, 180 min 2.2 (1.58-3.25) mg/L p < 0.001; free: 45 min 1.15 (0.88-1.42) mg/L p < 0.001, 180 min 0.5 (0.35-0.76) mg/L p < 0.001). There was no difference between the timepoints in probenecid concentrations. PTA analysis shows probenecid allows a fourfold increase in MIC cover. Addition of probenecid was safe and well tolerated. The data support further research into improved dosing structures for complex outpatient therapy and might also be used to address penicillin supply shortages.

Clinical characteristics, risk factor analysis and peripheral blood cell changes for early warning of multidrug-resistant bacteria (MDR) infection in elderly patients.

OBJECTIVE: To explore peripheral blood indicators that may serve as early indicators for multidrug-resistant bacteria (MDR) infections in this demographic, with the goal of providing reference suggestions for the clinical prevention of MDR infections in elderly inpatients. METHODS: Clinical data of patients were divided into the MDR-infected group (n = 488) and the MDR-uninfected group (n = 233) according to the results of drug sensitivity experiments, risk factors for MDR infection, and peripheral blood indicators related to MDR infections were analyzed using univariate and multivariate logistic regression in conjunction with the construction of a Chi-squared automatic interaction detector (CHAID) decision tree model, considering statistical significance at p < .05. RESULTS: Of 721 patients, 488 multidrug-resistant strains were identified. Among them, with Staphylococcus spp. the most prevalent in 148 strains. The most frequent detection of MDR occurred in puncture fluid samples (167 cases). Univariate and multivariate regression analyses revealed that prolonged hospitalization, use of antibiotics preadmission, duration of antibiotics, invasive procedures or recent surgery, and coexisting lung disease were independent risk factors for contracting MDR. Subsequent analysis comparing the aforementioned influences with peripheral blood cells revealed associations between the number of antibiotic treatment days and increased neutrophil-to-lymphocyte ratio (NLR), platelet count-to-lymphocyte ratio (PLR), neutrophils, decreased lymphocytes, and increased eosinophils; preadmission antibiotic use correlated with increased PLR, NLR, neutrophils, and decreased lymphocytes; and invasive manipulation or surgery correlated with increased PLR and NLR. CONCLUSIONS: Elevated NLR, PLR, neutrophils, lowered lymphocytes, and eosinophils may serve as early indicators of MDR infections in elderly hospitalized patients.

Antibiotic Alternatives: Multifunctional Ultra-Small Metal Nanoclusters for Bacterial Infectious Therapy Application.

The prevalence of major bacterial infections has emerged as a significant menace to human health and life. Conventional treatment methods primarily rely on antibiotic therapy, but the overuse of these drugs has led to a decline in their efficacy. Moreover, bacteria have developed resistance towards antibiotics, giving rise to the emergence of superbugs. Consequently, there is an urgent need for novel antibacterial agents or alternative strategies to combat bacterial infections. Nanoantibiotics encompass a class of nano-antibacterial materials that possess inherent antimicrobial activity or can serve as carriers to enhance drug delivery efficiency and safety. In recent years, metal nanoclusters (M NCs) have gained prominence in the field of nanoantibiotics due to their ultra-small size (less than 3 nm) and distinctive electronic and optical properties, as well as their biosafety features. In this review, we discuss the recent progress of M NCs as a new generation of antibacterial agents. First, the main synthesis methods and characteristics of M NCs are presented. Then, we focus on reviewing various strategies for detecting and treating pathogenic bacterial infections using M NCs, summarizing the antibacterial effects of these nanoantibiotics on wound infections, biofilms, and oral infections. Finally, we propose a perspective on the remaining challenges and future developments of M NCs for bacterial infectious therapy.

Integrating bacterial molecular genetics with chemical biology for renewed antibacterial drug discovery.

The application of dyes to understanding the aetiology of infection inspired antimicrobial chemotherapy and the first wave of antibacterial drugs. The second wave of antibacterial drug discovery was driven by rapid discovery of natural products, now making up 69% of current antibacterial drugs. But now with the most prevalent natural products already discovered, ∼107 new soil-dwelling bacterial species must be screened to discover one new class of natural product. Therefore, instead of a third wave of antibacterial drug discovery, there is now a discovery bottleneck. Unlike natural products which are curated by billions of years of microbial antagonism, the vast synthetic chemical space still requires artificial curation through the therapeutics science of antibacterial drugs - a systematic understanding of how small molecules interact with bacterial physiology, effect desired phenotypes, and benefit the host. Bacterial molecular genetics can elucidate pathogen biology relevant to therapeutics development, but it can also be applied directly to understanding mechanisms and liabilities of new chemical agents with new mechanisms of action. Therefore, the next phase of antibacterial drug discovery could be enabled by integrating chemical expertise with systematic dissection of bacterial infection biology. Facing the ambitious endeavour to find new molecules from nature or new-to-nature which cure bacterial infections, the capabilities furnished by modern chemical biology and molecular genetics can be applied to prospecting for chemical modulators of new targets which circumvent prevalent resistance mechanisms.

Beyond antibiotics: CRISPR/Cas9 triumph over biofilm-associated antibiotic resistance infections.

A complex structure known as a biofilm is formed when a variety of bacterial colonies or a single type of cell in a group sticks to a surface. The extracellular polymeric compounds that encase these cells, often consisting of proteins, eDNA, and polysaccharides, exhibit strong antibiotic resistance. Concerns about biofilm in the pharmaceutical industry, public health, and medical fields have sparked a lot of interest, as antibiotic resistance is a unique capacity exhibited by these biofilm-producing bacteria, which increases morbidity and death. Biofilm formation is a complicated process that is controlled by several variables. Insights into the processes to target for the therapy have been gained from multiple attempts to dissect the biofilm formation process. Targeting pathogens within a biofilm is profitable because the bacterial pathogens become considerably more resistant to drugs in the biofilm state. Although biofilm-mediated infections can be lessened using the currently available medications, there has been a lot of focus on the development of new approaches, such as bioinformatics tools, for both treating and preventing the production of biofilms. Technologies such as transcriptomics, metabolomics, nanotherapeutics and proteomics are also used to develop novel anti-biofilm agents. These techniques help to identify small compounds that can be used to inhibit important biofilm regulators. The field of appropriate control strategies to avoid biofilm formation is expanding quickly because of this spurred study. As a result, the current article addresses our current knowledge of how biofilms form, the mechanisms by which bacteria in biofilms resist antibiotics, and cutting-edge treatment approaches for infections caused by biofilms. Furthermore, we have showcased current ongoing research utilizing the CRISPR/Cas9 gene editing system to combat bacterial biofilm infections, particularly those brought on by lethal drug-resistant pathogens, concluded the article with a novel hypothesis and aspirations, and acknowledged certain limitations.

Necroptosis in bacterial infections.

Necroptosis, a recently discovered form of cell-programmed death that is distinct from apoptosis, has been confirmed to play a significant role in the pathogenesis of bacterial infections in various animal models. Necroptosis is advantageous to the host, but in some cases, it can be detrimental. To understand the impact of necroptosis on the pathogenesis of bacterial infections, we described the roles and molecular mechanisms of necroptosis caused by different bacterial infections in this review.

Emerging insights into macrophage extracellular traps in bacterial infections.

Macrophages possess a diverse range of well-defined capabilities and roles as phagocytes, encompassing the regulation of inflammation, facilitation of wound healing, maintenance of tissue homeostasis, and serving as a crucial element in the innate immune response against microbial pathogens. The emergence of extracellular traps is a novel strategy of defense that has been observed in several types of innate immune cells. In response to infection, macrophages are stimulated and produce macrophage extracellular traps (METs), which take the form of net-like structures, filled with strands of DNA and adorned with histones and other cellular proteins. METs not only capture and eliminate microorganisms but also play a role in the development of certain diseases such as inflammation and autoimmune disorders. The primary objective of this study is to examine the latest advancements in METs for tackling bacterial infections. We also delve into the current knowledge and tactics utilized by bacteria to elude or endure the effects of METs. Through this investigation, we hope to shed light on the intricate interactions between bacteria and the host's immune system, particularly in the context of microbicidal effector mechanisms of METs. The continued exploration of METs and their impact on host defense against various pathogens opens up new avenues for understanding and potentially manipulating the immune system's response to infections.

Role and significance of virus-bacteria interactions in disease progression.

Understanding disease pathogenesis caused by bacteria/virus, from the perspective of individual pathogen has provided meaningful insights. However, as viral and bacterial counterparts might inhabit the same infection site, it becomes crucial to consider their interactions and contributions in disease onset and progression. The objective of the review is to highlight the importance of considering both viral and bacterial agents during the course of coinfection. The review provides a unique perspective on the general theme of virus-bacteria interactions, which either lead to colocalized infections that are restricted to one anatomical niche, or systemic infections that have a systemic effect on the human host. The sequence, nature, and underlying mechanisms of certain virus-bacteria interactions have been elaborated with relevant examples from literature. It also attempts to address the various applied aspects, including diagnostic and therapeutic strategies for individual infections as well as virus-bacteria coinfections. The review aims to aid researchers in comprehending the intricate interplay between virus and bacteria in disease progression, thereby enhancing understanding of current methodologies and empowering the development of novel health care strategies to tackle coinfections.

Biomedical applications of prokaryotic carbonic anhydrases: an update.

INTRODUCTION: This review offers an updated perspective on the biomedical applications of prokaryotic carbonic anhydrases (CAs), emphasizing their potential as targets for drug development against antibiotic-resistant bacterial infections. A systematic review of literature from PubMed, Web of Science, and Google Scholar has been conducted to provide a comprehensive analysis. AREA COVERED: It delves into the pivotal roles of prokaryotic CAs in bacterial metabolism and their distinctions from mammalian CAs. The review explores the diversity of CA classes in bacteria, discusses selective inhibitors targeting bacterial CAs, and explores their potential applications in biomedical research. Furthermore, it analyzes clinical trials investigating the efficacy of carbonic anhydrase inhibitors (CAIs) and patented approaches for developing antibacterial CAIs, highlighting their translational potential in creating innovative antibacterial agents. EXPERT OPINION: Recent years have witnessed increased recognition of CA inhibition as a promising strategy against bacterial infections. Challenges persist in achieving selectivity over human isoforms and optimizing therapeutic efficacy. Structural biology techniques provide insights into unique active site architectures, guiding selective inhibitor design. The review underscores the importance of interdisciplinary collaborations, innovative drug delivery systems, and advanced drug discovery approaches in unlocking the full therapeutic potential of prokaryotic CA inhibitors. It emphasizes the significance of these efforts in addressing antibiotic resistance and improving patient outcomes.

Antibiotic resistance: A key microbial survival mechanism that threatens public health.

Antibiotic resistance (AMR) is a global public health threat, challenging the effectiveness of antibiotics in combating bacterial infections. AMR also represents one of the most crucial survival traits evolved by bacteria. Antibiotics emerged hundreds of millions of years ago as advantageous secondary metabolites produced by microbes. Consequently, AMR is equally ancient and hardwired into the genetic fabric of bacteria. Human use of antibiotics for disease treatment has created selection pressure that spurs the evolution of new resistance mechanisms and the mobilization of existing ones through bacterial populations in the environment, animals, and humans. This integrated web of resistance elements is genetically complex and mechanistically diverse. Addressing this mode of bacterial survival requires innovation and investment to ensure continued use of antibiotics in the future. Strategies ranging from developing new therapies to applying artificial intelligence in monitoring AMR and discovering new drugs are being applied to manage the growing AMR crisis.

Host stress drives tolerance and persistence: The bane of anti-microbial therapeutics.

Antibiotic resistance, typically associated with genetic changes within a bacterial population, is a frequent contributor to antibiotic treatment failures. Antibiotic persistence and tolerance, which we collectively term recalcitrance, represent transient phenotypic changes in the bacterial population that prolong survival in the presence of typically lethal concentrations of antibiotics. Antibiotic recalcitrance is challenging to detect and investigate-traditionally studied under in vitro conditions, our understanding during infection and its contribution to antibiotic failure is limited. Recently, significant progress has been made in the study of antibiotic-recalcitrant populations in pathogenic species, including Mycobacterium tuberculosis, Staphylococcus aureus, Salmonella enterica, and Yersiniae, in the context of the host environment. Despite the diversity of these pathogens and infection models, shared signals and responses promote recalcitrance, and common features and vulnerabilities of persisters and tolerant bacteria have emerged. These will be discussed here, along with progress toward developing therapeutic interventions to better treat recalcitrant pathogens.