A brief history of antibiotics and select advances in their synthesis

Magnetically Driven Hydrogel Microrobots for Targeted Antibiotic Delivery

Precise targeted delivery of antibiotics to infected sites is crucial for enhancing therapeutic efficacy and minimizing side effects. In this work, we present magnetic hydrogel-based microrobots for active antibiotic delivery to achieve targeted bacterial elimination. These microrobots comprise a poly(acrylic acid-co-acrylamide) hydrogel microspheres encapsulating Fe3O4 nanoparticle chains. The hydrogel scaffold offers abundant spaces and binding sites for high-capacity loading of vancomycin via electrostatic interactions. The embedded Fe3O4 nanochains enable magnetic propulsion. Under a rotating magnetic field (Hr(t)), the microrobots can actively deliver vancomycin to infected sites via their swarming motions, and then eliminate the bacteria (e.g., Staphylococcus aureus) utilizing their sustainable vancomycin release on site. These hydrogel-based microrobots hold great promise as a motile antibacterial platform to treat infectious diseases.

A promising agent against wild-type and antibiotic-resistant bacteria using biogenic silver nanoparticles from Marphysa moribidii extract

The antibiotic resistance (AR) crisis has intensified and overshadowed efforts to develop new antibiotics and treatments. Biogenic silver nanoparticles (AgNPs) synthesised using Marphysa moribidii extract offer a promising solution because of their broad-spectrum antibacterial activity and ease of synthesis. However, concerns regarding the physicochemical properties of AgNPs may vary, and the optimal dosage for bacterial inhibition must be determined. This study addresses these gaps by evaluating the physicochemical properties, antibacterial efficacy, and mechanisms of action of biogenic AgNPs against selected bacteria, including wild-type strains (Escherichia coli and Staphylococcus aureus) and antibiotic-resistant strains (ESBL-E. coli and MRSA). Silver nitrate reduction by bioactive compounds in polychaete extract, such as amino acids and fatty acids, resulted in the formation of stable spherical AgNPs. These nanoparticles exhibited surface plasmon resonance peak at 397 nm and zeta potential of -36.48 mV. The AgNPs effectively inhibited the growth of both wild-type and antibiotic-resistant bacteria at concentrations ranging from 0.05-0.40 μg/mL and 0.10-0.40 μg/mL, respectively. Bactericidal effects were observed against wild-type bacteria and bacteriostatic effects against antibiotic-resistant bacteria. Electron microscopies revealed membrane damage in wild-type and AR bacteria, whereas leakage assays confirmed increased membrane permeability. Furthermore, reactive oxygen species detection assay demonstrated that AgNPs induced oxidative stress, suggesting a multifaceted mechanism of action. These findings highlight the potential of M. moribidii-derived AgNPs as effective broad-spectrum antibacterial agents, particularly against AR bacteria, and pave the way for the development of standardised biogenic AgNPs synthesis methods for future applications.

Antibiotic Resistance Genes in Agricultural Soils: A Comprehensive Review of the Hidden Crisis and Exploring Control Strategies

This paper aims to review the sources, occurrence patterns, and potential risks of antibiotic resistance genes (ARGs) in agricultural soils and discuss strategies for their reduction. The pervasive utilization of antibiotics has led to the accumulation of ARGs in the soil. ARGs can be transferred among microorganisms via horizontal gene transfer, thereby increasing the likelihood of resistance dissemination and heightening the threat to public health. In this study, we propose that physical, chemical, and bioremediation approaches, namely electrokinetic remediation, advanced oxidation, and biochar application, can effectively decrease the abundance of ARGs in the soil. This study also highlights the significance of various control measures, such as establishing a strict regulatory mechanism for veterinary drugs, setting standards for the control of ARGs in organic fertilizers, and conducting technical guidance and on-farm soil monitoring to reduce the environmental spread of ARGs and protect public health.

The Spread of Antibiotic Resistance Is Driven by Plasmids Among the Fastest Evolving and of Broadest Host Range

Microorganisms endure novel challenges for which other microorganisms in other biomes may have already evolved solutions. This is the case of nosocomial bacteria under antibiotic therapy because antibiotics are of ancient natural origin and resistances to them have previously emerged in environmental bacteria. In such cases, the rate of adaptation crucially depends on the acquisition of genes by horizontal transfer of plasmids from distantly related bacteria in different biomes. We hypothesized that such processes should be driven by plasmids among the most mobile and evolvable. We confirmed these predictions by showing that plasmid species encoding antibiotic resistance are very mobile, have broad host ranges, while showing higher rates of homologous recombination and faster turnover of gene repertoires than the other plasmids. These characteristics remain outstanding when we remove resistance plasmids from our dataset, suggesting that antibiotic resistance genes are preferentially acquired and carried by plasmid species that are intrinsically very mobile and plastic. Evolvability and mobility facilitate the transfer of antibiotic resistance, and presumably of other phenotypes, across distant taxonomic groups and biomes. Hence, plasmid species, and possibly those of other mobile genetic elements, have differentiated and predictable roles in the spread of novel traits.

Molecular insights into the differential membrane targeting of maximin 1 in prokaryotic and eukaryotic cells

Antimicrobial resistance is a pressing global health concern, underscoring the need for alternative treatments. Antimicrobial peptides (AMPs) have shown promise in this regard, with maximin 1 being a cationic, amphipathic AMP possessing antibacterial, antifungal, and antiviral activities with low hemolytic activity. In this study, we used molecular dynamics simulation to investigate the molecular basis for membrane selectivity of Maximin 1. By studying interactions between maximin 1 and different models of prokaryotic (anionic) and eukaryotic (zwitterionic) membranes, we found that Maximin 1 interacts more strongly with the prokaryotic membrane due to electrostatic attraction, while it weakly interacts with the zwitterionic eukaryotic membrane. Our simulations also revealed that Gly-1, Lys-5, Lys-11, Lys-15, and Lys-19 were identified to play a crucial role in the adsorption of maximin unto the prokaryotic membrane surface. The alpha-helical nature of the peptide, in addition to its amphipathic nature, was necessary for the adsorption of the peptide onto the surface of the prokaryotic membrane. Interestingly, the later transition of the alpha helix into a random coil was crucial in penetrating the prokaryotic membrane while hindering interactions with the eukaryotic membrane. Residues in the middle region of the peptide (residues 9-16) were also responsible for permeating the prokaryotic membrane over the eukaryotic membrane. These findings shed light on the peptide's selective targeting of bacterial membranes over human cell membranes and could inform the design of more effective AMPs.Communicated by Ramaswamy H. Sarma.

Laudable Pus, Cocaine, and the Evolution of Wound Management

PURPOSE

To review the long history of wound management, including the methods of skin closure, asepsis, and anesthesia. Periocular techniques will be emphasized.

METHODS

Literature searches and cross-referencing were used to identify historic reports addressing the management of wounds. Foreign language manuscripts were translated using online resources.

RESULTS

The first written description of suturing dates to around 3000 BC and involved the repair of an eyebrow wound. A wide variety of materials have since been used as ligatures or stitches, including animal intestines, tendons, hair, silk, linen, plant fibers, and metal wire. For much of recorded history, sutures were a primary cause of wound infection and morbidity. There was a time when the resultant drainage was viewed as being beneficial (laudable pus). Many of the discoveries that ultimately led to the practice of asepsis were coincidental. Prior to the development of infiltrative anesthesia in 1894, patients had to endure the discomfort of surgery, occasionally with the sedative effects of wine or cannabis.

CONCLUSIONS

The history of wound closure is a fascinating tale. While there has been a constant evolution, silk and catgut sutures, ligatures, surgical knots, and layered closure have been used for several millennium. Advances in asepsis, in addition to the development of anesthesia, antibiotics, and synthetic sutures, ushered in the modern age of surgery. A knowledge of the past will give us, as oculofacial surgeons, a greater understanding and appreciation of the techniques we use today.

Growing Concerns on Antimicrobial Resistance - Past, Present, and Future Trends

Antimicrobial resistance [AMR] is a global problem that affects multiple domains including healthcare, agriculture, aquaculture, and many more. Every year, 700,000 people die from it. AMR is predicted to claim 10 million lives by 2050 if immediate action is not taken. Thus, to halt the spread of AMR it is important to understand what contributes to its emergence and transmission across borders and domains. The burden is disproportionately higher in Low middle income countries (LMICs) due to multiple factors such as environmental, social, healthcare, and cultural barriers. This review paper describes the comprehensive analysis of the past, present, and future trends in AMR, focusing on the complex interconnectedness of the factors contributing to this issue. Historical trends reveal antibiotic discoveries, resistance periods, resistance genes, and multidrug-resistant pathogens, providing insights into crisis evolution and the emergence of multidrug-resistant pathogens. The present trends reflect the current state of AMR in India and emphasize the negative consequences of AMR for clinical medicine and healthcare systems. It identifies the factors driving the global pandemic surge and examines current global and country-level policies and actions to mitigate its impact. The future trends anticipate the trajectories of AMR and discuss innovative approaches to combat resistance, including the exploration of alternative therapies and the implementation of stewardship programs. Thus, by synthesizing existing knowledge and identifying emerging gaps, this review paper presents a holistic perspective on the evolution of AMR.

Ethical bioprospecting and microbial assessments for sustainable solutions to the AMR crisis

Antimicrobial resistance (AMR) has been declared one of the top 10 global public health challenges of our age by the World Health Organization, and the World Bank describes AMR as a crisis affecting the finance, health, and agriculture sectors and a major threat to the attainment of Sustainable Development Goals. But what is AMR? It is a phenotype that evolves in microbes exposed to antimicrobial molecules and causes dangerous infections. This suggests that scientists and healthcare workers should be on the frontline in the search for sustainable solutions to AMR. Yet AMR is also a societal problem to be understood by everyone. This review aims to explore the need to address the problem of AMR through a coherent, international strategy with buy-in from all sectors of society. As reviewed here, the sustainable solutions to AMR will be driven by better understanding of AMR biology but will require more than this alone to succeed. Some advances on the horizon, such as the use of bacteriophage (phage) to treat AMR infections. However, many of the new technologies and new therapeutics to address AMR require access to biodiversity, where the custodians of that biodiversity-and the traditional knowledge required to access it-are needed as key partners in the scientific, clinical, biotechnological, and international ventures that would treat the problem of AMR and ultimately prevent its further evolution. Many of these advances will be built on microbial assessments to understand the extent of AMR in our environments and bioprospecting to identify microbes that may have beneficial uses. Genuine partnerships for access to this biodiversity and sharing of benefits accrued require a consideration of ethical practice and behavior. Behavior change is needed across all sectors of culturally diverse societies so that rapid deployment of solutions can be implemented for maximum effect against the impacts of AMR.

Cytotoxicity and Antimicrobial Efficacy of Fe-, Co-, and Mn-Doped ZnO Nanoparticles

Zinc oxide nanoparticles (ZnO NPs) are one of the most widely used nanoparticulate materials due to their antimicrobial properties. However, the current use of ZnO NPs is hindered by their potential cytotoxicity concerns, which are likely attributed to the generation of reactive oxygen species (ROS) and the dissolution of particles to ionic zinc. To reduce the cytotoxicity of ZnO NPs, transitional metals are introduced into ZnO lattices to modulate the ROS production and NP dissolution. However, the influence of the doping element, doping concentration, and particle size on the cytotoxicity and antimicrobial properties remains unexplored. This study presents a comprehensive investigation of a library of doped ZnO NPs to elucidate the relationship between their physicochemical properties, antimicrobial activity against Escherichia coli (E. coli), and cytotoxicity to mammalian cells. The library comprises 30 variants, incorporating three different dopant metals-iron, manganese, and cobalt-at concentrations of 0.25%, 1%, and 2%, and calcined at three temperatures (350 °C, 500 °C, and 600 °C), resulting in varied particle sizes. These ZnO NPs were prepared by low temperature co-precipitation followed by high-temperature calcination. Our results reveal that the choice of dopant elements significantly influences both antimicrobial efficacy and cytotoxicity, while dopant concentration and particle size have comparatively minor effects. High-throughput UV-visible spectroscopic analysis identified Mn- and Co-doped ZnO NPs as highly effective against E. coli under standard conditions. Compared with undoped ZnO particles, Mn- and Co-doping significantly increased the oxidative stress, and the Zn ion release from NPs was increased by Mn doping and reduced by Fe doping. The combined effects of these factors increased the cytotoxicity of Mn-doped ZnO particles. As a result, Co-doped ZnO particles, especially those with 2 wt.% doping, exhibited the most favourable balance between enhanced antibacterial activity and minimized cytotoxicity, making them promising candidates for antimicrobial applications.

Antimicrobial resistance in Klebsiella pneumoniae: an overview of common mechanisms and a current Canadian perspective

Klebsiella pneumoniae is a ubiquitous opportunistic pathogen of the family Enterobacteriaceae. K. pneumoniae is a member of the ESKAPEE pathogens (Enterococcus faecium, Staphylococcus aureus, K. pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, Enterobacter spp., and Escherichia coli), a group of bacteria that cause nosocomial infections and are able to resist killing by commonly relied upon antimicrobial agents. The acquisition of antimicrobial resistance (AMR) genes is increasing among community and clinical isolates of K. pneumoniae, making K. pneumoniae a rising threat to human health. In addition to the increase in AMR, K. pneumoniae is also thought to disseminate AMR genes to other bacterial species. In this review, the known mechanisms of K. pneumoniae AMR will be described and the current state of AMR K. pneumoniae within Canada will be discussed, including the impact of the coronavirus disease-2019 pandemic, current perspectives, and outlook for the future.

The challenge of antimicrobial resistance (AMR): current status and future prospects

Antimicrobial resistance (AMR) represents a critical global threat, compromising the effectiveness of antibacterial drugs as bacteria adapt and survive exposure to many classes of these drugs. This phenomenon is primarily fueled by the widespread overuse and misuse of antibacterial drugs, exerting selective pressure on bacteria and promoting the emergence of multi-resistant strains. AMR poses a top-priority challenge to public health due to its widespread epidemiological and economic implications, exacerbated not only by the diminishing effectiveness of currently available antimicrobial agents but also by the limited development of genuinely effective new molecules. In addressing this issue, our research aimed to examine the scientific literature narrating the Italian situation in the common European context of combating AMR. We sought to delineate the current state of AMR and explore future prospects through an analysis of strategies to counter antibacterial drug resistance. Adopting the "One Health" model, our objective was to comprehensively engage diverse sectors, integrate various disciplines, and propose programs, policies, and regulations. This narrative review, based on PubMed research related to antibiotic resistance, emphasizes the urgent need for a coordinated and proactive approach at both national and European levels to mitigate the impact of AMR and pave the way for effective strategies to counter this global health challenge.

Beyond Antibiotics: What the Future Holds

The prevalence of multidrug resistance (MDR) and stagnant drug-development pipelines have led to the rapid rise of hard-to-treat antibiotic-resistant bacterial infections. These infectious diseases are no longer just nosocomial but are also becoming community-acquired. The spread of MDR has reached a crisis level that needs immediate attention. The landmark O'Neill report projects that by 2050, mortality rates associated with MDR bacterial infections will surpass mortality rates associated with individuals afflicted with cancer. Since conventional antimicrobials are no longer very reliable, it is of great importance to investigate different strategies to combat these life-threatening infectious diseases. Here, we provide an overview of recent advances in viable alternative treatment strategies mainly targeting a pathogen's virulence capability rather than viability. Topics include small molecule and immune inhibition of virulence factors, quorum sensing (QS) quenching, inhibition of biofilm development, bacteriophage-mediated therapy, and manipulation of an individual's macroflora to combat MDR bacterial infections.

The Influence of Silver-Containing Bionanomaterials Based on Humic Ligands on Biofilm Formation in Opportunistic Pathogens

The uncontrolled use of antibiotics has led to a global problem of antimicrobial resistance. One of the main mechanisms of bacterial resistance is the formation of biofilms. In order to prevent the growth of antimicrobial resistance, it is crucial to develop new antibacterial agents that are capable of inhibiting the formation of biofilms. This makes this area of research highly relevant today. Promising candidates for these antibacterial agents are new bionanomaterials made from natural humic substances and silver nanoparticles. These substances have the potential to not only directly kill microorganisms but also penetrate biofilms and inhibit their formation. The goal of this study is to synthesize active pharmaceutical substances in the form of bionanomaterials, using ultradispersed silver nanoparticles in a matrix of coal humic substances, perform their characterization (NMR spectroscopy, TEM, and ICP-AES methods), and research their influence on biofilm formation in the most dangerous opportunistic pathogens (E. coli, Methicillin-resistant St. Aureus, K. pneumoniae, P. aeruginosa, St. aureus, A. baumannii, and K. Pneumonia). The results showed that all of the studied bionanomaterials had antibacterial activity against all of the opportunistic pathogens. Furthermore, they were found to have a suppressive effect on both pre-existing biofilms of these bacteria and their formation.

Lessons learnt from broad-spectrum coronavirus antiviral drug discovery

INTRODUCTION

Highly pathogenic coronaviruses (CoVs), such as severe acute respiratory syndrome CoV (SARS-CoV), Middle East respiratory syndrome CoV (MERS-CoV), and the most recent SARS-CoV-2 responsible for the COVID-19 pandemic, pose significant threats to human populations over the past two decades. These CoVs have caused a broad spectrum of clinical manifestations ranging from asymptomatic to severe distress syndromes (ARDS), resulting in high morbidity and mortality.

AREAS COVERED

The accelerated advancements in antiviral drug discovery, spurred by the COVID-19 pandemic, have shed new light on the imperative to develop treatments effective against a broad spectrum of CoVs. This perspective discusses strategies and lessons learnt in targeting viral non-structural proteins, structural proteins, drug repurposing, and combinational approaches for the development of antivirals against CoVs.

EXPERT OPINION

Drawing lessons from the pandemic, it becomes evident that the absence of efficient broad-spectrum antiviral drugs increases the vulnerability of public health systems to the potential onslaught by highly pathogenic CoVs. The rapid and sustained spread of novel CoVs can have devastating consequences without effective and specifically targeted treatments. Prioritizing the effective development of broad-spectrum antivirals is imperative for bolstering the resilience of public health systems and mitigating the potential impact of future highly pathogenic CoVs.

Antibiotics: From Mechanism of Action to Resistance and Beyond

Antibiotics are the super drugs that have revolutionized modern medicine by curing many infectious diseases caused by various microbes. They efficiently inhibit the growth and multiplication of the pathogenic microbes without causing adverse effects on the host. However, prescribing suboptimal antibiotic and overuse in agriculture and animal husbandry have led to the emergence of antimicrobial resistance, one of the most serious threats to global health at present. The efficacy of a new antibiotic is high when introduced; however, a small bacterial population attains resistance gradually and eventually survives. Understanding the mode of action of these miracle drugs, as well as their interaction with targets is very complex. However, it is necessary to fulfill the constant need for novel therapeutic alternatives to address the inevitable development of resistance. Therefore, considering the need of the hour, this article has been prepared to discuss the mode of action and recent advancements in the field of antibiotics. Efforts has also been made to highlight the current scenario of antimicrobial resistance and drug repurposing as a fast-track solution to combat the issue.

Agents Targeting the Bacterial Cell Wall as Tools to Combat Gram-Positive Pathogens

The cell wall is an indispensable element of bacterial cells and a long-known target of many antibiotics. Penicillin, the first discovered beta-lactam antibiotic inhibiting the synthesis of cell walls, was successfully used to cure many bacterial infections. Unfortunately, pathogens eventually developed resistance to it. This started an arms race, and while novel beta-lactams, either natural or (semi)synthetic, were discovered, soon upon their application, bacteria were developing resistance. Currently, we are facing the threat of losing the race since more and more multidrug-resistant (MDR) pathogens are emerging. Therefore, there is an urgent need for developing novel approaches to combat MDR bacteria. The cell wall is a reasonable candidate for a target as it differentiates not only bacterial and human cells but also has a specific composition unique to various groups of bacteria. This ensures the safety and specificity of novel antibacterial agents that target this structure. Due to the shortage of low-molecular-weight candidates for novel antibiotics, attention was focused on peptides and proteins that possess antibacterial activity. Here, we describe proteinaceous agents of various origins that target bacterial cell wall, including bacteriocins and phage and bacterial lysins, as alternatives to classic antibiotic candidates for antimicrobial drugs. Moreover, advancements in protein chemistry and engineering currently allow for the production of stable, specific, and effective drugs. Finally, we introduce the concept of selective targeting of dangerous pathogens, exemplified by staphylococci, by agents specifically disrupting their cell walls.

Something 'Old, New, Borrowed, or Blue', the Search for Mother Nature's Bioactive Agents

In the following examples, the time frames and ultimate results are measured in years, not days or months. In particular, the application of genetic techniques to complex systems requires many investigators and a multitude of false leads. The areas chosen are all related to the identification and use of techniques from many scientific fields. Except for the necessity of describing the many years of work required to identify and then utilize the genetic information from yet uncultivated microbes, and identifying the true sources of the dolastatins, the rest of the examples are quite short with commentaries on most of the references given.

Unearthing new learning opportunities: adapting and innovating through the 'Antibiotics under our feet' citizen science project in Scotland during COVID-19

'Antibiotics under our feet' is a Scottish citizen science project that aimed to raise science capital in primary school learners and their teachers through measurement of microbial diversity in urban soil samples in the search for novel antimicrobial compounds. Resistance to antibiotics is rising, posing a global threat to human health. Furthermore, science, technology, engineering and mathematics (STEM) skills are in crisis, jeopardising our capacity to mobilise as a society to fight antimicrobial resistance (AMR). Originally conceived as a response to the AMR and STEM emergencies, our project was hit by the unprecedented challenge of engaging with schools during the COVID-19 pandemic. We describe how we adapted our project to enable remote participation from primary schools and youth groups, utilising COVID-19 response initiatives as opportunities for multi-level co-creation of resources with learners in primary, secondary, and higher education. We produced portable kit boxes for soil sample collection with learning activities and videos linked to the Scottish Curriculum for Excellence. We also addressed glaring project specific content gaps relating to microbiology on English and Simple English Wikipedia. Our hybrid model of working extended our geographical reach and broadened inclusion. We present here the inception, implementation, digital resource outputs, and discussion of pedagogical aspects of 'Antibiotics under our feet'. Our strategies and insights are applicable post-pandemic for educators to develop STEM skills using soil, microbes, and antibiotics as a theme.

Deciphering the Antibacterial Mechanisms of 5-Fluorouracil in Escherichia coli through Biochemical and Transcriptomic Analyses

The emergence of carbapenem-resistant Gram-negative pathogens presents a clinical challenge in infection treatment, prompting the repurposing of existing drugs as an essential strategy to address this crisis. Although the anticancer drug 5-fluorouracil (5-FU) has been recognized for its antibacterial properties, its mechanisms are not fully understood. Here, we found that the minimal inhibitory concentration (MIC) of 5-FU against Escherichia coli was 32-64 µg/mL, including strains carrying blaNDM-5, which confers resistance to carbapenems. We further elucidated the antibacterial mechanism of 5-FU against E. coli by using genetic and biochemical analyses. We revealed that the mutation of uracil phosphoribosyltransferase-encoding gene upp increased the MIC of 5-FU against E. coli by 32-fold, indicating the role of the upp gene in 5-FU resistance. Additionally, transcriptomic analysis of E. coli treated with 5-FU at 8 µg/mL and 32 µg/mL identified 602 and 1082 differentially expressed genes involved in carbon and nucleic acid metabolism, DNA replication, and repair pathways. The biochemical assays showed that 5-FU induced bacterial DNA damage, significantly increased intracellular ATP levels and the NAD+/NADH ratio, and promoted reactive oxygen species (ROS) production. These findings suggested that 5-FU may exert antibacterial effects on E. coli through multiple pathways, laying the groundwork for its further development as a therapeutic candidate against carbapenem-resistant bacterial infections.

Is shorter also better in the treatment of Clostridioides difficile infection?

OBJECTIVES

To assess the effectiveness of shortened regimens of vancomycin or fidaxomicin in the treatment of Clostridioides difficile infection (CDI).

METHODS

Adult patients with CDI hospitalized from January 2022 to May 2023 were included in this observational study. In patients with CDI treated with vancomycin or fidaxomicin, antibiotic treatment was discontinued after either 5 or 7 days of vancomycin or 5 days of fidaxomicin if there was a clinical response and improvement in laboratory parameters. The control cohort was treated with the standard 10 day regimen of either vancomycin or fidaxomicin. The follow-up was 60 days. Causative C. difficile strains were characterized by ribotyping and toxin gene detection when available.

RESULTS

Twenty-five patients (median age 76 years) received shortened treatment with vancomycin (n = 21), or fidaxomicin (n = 4). Five cases fulfilled the criteria for severe CDI. Twenty-three patients completed follow-up; two died from causes other than CDI, and two developed recurrent CDI (8.0%). Ribotypes (RTs) 001 and 014 were the most prevalent with 20% each. In two C. difficile isolates, binary toxin genes were detected (RTs 078 and 023). In the control group of 22 patients recurrent CDI developed in 5 patients (22.7%). No statistically significant differences were found between the groups.

CONCLUSIONS

Shortened treatment regimens for CDI with vancomycin and fidaxomicin were shown to be effective in our cohort of patients compared with 10 days of treatment. The recurrence rate was lower in the study group. A larger, prospective, double-blind, randomized, multicentre study is needed to support our findings.

Investigating the Antimicrobial Effects of a Novel Peptide Derived From Listeriolysin S on S aureus, E coli, and L plantarum: An In Silico and In Vitro Study

Aims

The emergence of antibiotic resistance is one of the most significant issues today. Modifying antimicrobial peptides (AMPs) can improve their effects. In this study, the active region of Listeriolysin S (LLS) as a peptidic toxin has been recognized, and its antibacterial properties have been evaluated by modifying that region.

Methods

After extracting the sequence, the structure of LLS was predicted by PEP-FOLD3. AntiBP and AMPA servers identified its antimicrobial active site. It was modified by adding arginine residue to its 3- and N-terminal regions. Its antimicrobial properties on Staphylococcus aureus, Escherichia coli, and Lactobacillus Plantarum were estimated.

Findings

The results of AntiBP and AntiBP servers demonstrated that a region of 15 amino acids has the most antimicrobial properties (score = 1.696). After adding arginine to the chosen region, the physicochemical evaluation and antimicrobial properties revealed that the designed peptide is a stable AMP with a positive charge of 4, which is not toxic to human erythrocyte cells and has antigenic properties. The results of in vitro and colony counting indicated that at different hours, it caused a significant reduction in the count of S aureus, E coli, and L Plantarum compared with the control sample.

Conclusions

Upcoming research implies that identifying and enhancing the active sites of natural peptides can help combat bacteria.

What is the role of microbial biotechnology and genetic engineering in medicine?

Microbial products are essential for developing various therapeutic agents, including antibiotics, anticancer drugs, vaccines, and therapeutic enzymes. Genetic engineering techniques, functional genomics, and synthetic biology unlock previously uncharacterized natural products. This review highlights major advances in microbial biotechnology, focusing on gene-based technologies for medical applications.

Antimicrobials: An update on new strategies to diversify treatment for bacterial infections

Ninety-five years after Fleming's discovery of penicillin, a bounty of antibiotic compounds have been discovered, modified, or synthesised. Diversification of target sites, improved stability and altered activity spectra have enabled continued antibiotic efficacy, but overwhelming reliance and misuse has fuelled the global spread of antimicrobial resistance (AMR). An estimated 1.27 million deaths were attributable to antibiotic resistant bacteria in 2019, representing a major threat to modern medicine. Although antibiotics remain at the heart of strategies for treatment and control of bacterial diseases, the threat of AMR has reached catastrophic proportions urgently calling for fresh innovation. The last decade has been peppered with ground-breaking developments in genome sequencing, high throughput screening technologies and machine learning. These advances have opened new doors for bioprospecting for novel antimicrobials. They have also enabled more thorough exploration of complex and polymicrobial infections and interactions with the healthy microbiome. Using models of infection that more closely resemble the infection state in vivo, we are now beginning to measure the impacts of antimicrobial therapy on host/microbiota/pathogen interactions. However new approaches are needed for developing and standardising appropriate methods to measure efficacy of novel antimicrobial combinations in these contexts. A battery of promising new antimicrobials is now in various stages of development including co-administered inhibitors, phages, nanoparticles, immunotherapy, anti-biofilm and anti-virulence agents. These novel therapeutics need multidisciplinary collaboration and new ways of thinking to bring them into large scale clinical use.

Personalized Drug Therapy: Innovative Concept Guided With Proteoformics

Personalized medicine can reduce adverse effects, enhance drug efficacy, and optimize treatment outcomes, which represents the essence of personalized medicine in the pharmacy field. Protein drugs are crucial in the field of personalized drug therapy and are currently the mainstay, which possess higher target specificity and biological activity than small-molecule chemical drugs, making them efficient in regulating disease-related biological processes, and have significant potential in the development of personalized drugs. Currently, protein drugs are designed and developed for specific protein targets based on patient-specific protein data. However, due to the rapid development of two-dimensional gel electrophoresis and mass spectrometry, it is now widely recognized that a canonical protein actually includes multiple proteoforms, and the differences between these proteoforms will result in varying responses to drugs. The variation in the effects of different proteoforms can be significant and the impact can even alter the intended benefit of a drug, potentially making it harmful instead of lifesaving. As a result, we propose that protein drugs should shift from being targeted through the lens of protein (proteomics) to being targeted through the lens of proteoform (proteoformics). This will enable the development of personalized protein drugs that are better equipped to meet patients' specific needs and disease characteristics. With further development in the field of proteoformics, individualized drug therapy, especially personalized protein drugs aimed at proteoforms as a drug target, will improve the understanding of disease mechanisms, discovery of new drug targets and signaling pathways, provide a theoretical basis for the development of new drugs, aid doctors in conducting health risk assessments and making more cost-effective targeted prevention strategies conducted by artificial intelligence/machine learning, promote technological innovation, and provide more convenient treatment tailored to individualized patient profile, which will benefit the affected individuals and society at large.

Evolutionary History of Periodontitis and the Oral Microbiota—Lessons for the Future

Purpose of Review

Currently, periodontal disease is the sixth most prevalent disease in the world. Emerging evidence suggests the possibility of pre-historic humans having relatively low occurrences of oral diseases, particularly periodontitis when compared to modern humans. In this review, we look back into the history of Homo sapiens and explore the emerging scientific literature to discuss the evolution of the human oral microbiota and the prevalence of periodontitis from pre-historic to modern times.

Recent Findings

Most of the scientific literature points to a more health-associated, eubiotic oral microbiota and a seemingly lower prevalence of periodontitis in pre-historic humans compared to modern times. The oral microbiome has evolved along with humans. Humans of the contemporary era are exposed to a far greater number of risk factors for periodontal disease. Also, major lifestyle changes induced by the agricultural revolution and the industrial revolution have led to the development of a more dysbiotic oral microbiota and a rise in the prevalence of periodontitis in modern humans.

Summary

An understanding of the prevalence of periodontitis across human history, the evolution of the oral microbiota, and the factors that influenced its nature and complexity helps identify and modify the disease-associated lifestyle factors acquired through modernization to manage the common worldwide problem of periodontitis.

Stereoselective synthesis of thailandamide A methyl ester

A convergent strategy for the stereoselective synthesis of the methyl ester of the structurally challenging and highly labile antibacterial polyene polyketide natural product thailandamide A has been developed. The key steps include the Zincke aldehyde reaction, Stille cross coupling, Negishi reaction, Julia-Kocienski olefination, cross metathesis, and the less explored Pd(I)-based Heck coupling to access different unsaturation bonds. Additionally, Urpi acetal aldol, Evans methylation, and Crimmins acetate aldol reactions were employed to construct four out of six asymmetric centers of the molecule.

Point prevalence of antibiotic usage in major referral hospital in Turkey

INTRODUCTION

The most important and undesirable consequence of inappropriate antibiotic use is the spread of antibiotic resistance, increased adverse effects, increased mortality and healthcare costs. We aimed to assess antibiotic usage characteristics in inpatient setting in our center.

MATERIALS AND METHODS

A one-day, single center point-prevalence study was carried out on June 9th 2021, in Ankara City Hospital in Turkey. Data of antibiotic consumption, appropriateness of usage and predictors of inappropriate use in adult patients were evaluated.

RESULTS

Out of 2640 adult patients, 893 (33.8%) were receiving at least one antibiotic. A total of 1212 antibiotic prescriptions with an average of 1.44±0.64 were found. Antibiotics were most commonly used for therapeutic purpose (84.7%), followed by surgical prophylaxis (11.6%). Majority of therapeutically used antibiotics were empirical (67.9%). Infectious diseases consultation was present in 68.3% with a compliance rate of 95.7%. Rate of inappropriate use was 20%. The most frequent cause of inappropriateness was unnecessary use (52.5%). Most commonly and most inappropriately used antibiotics were carbapenems (17.5%) and first generation cephalosporins (38.7%), respectively. Most of the inappropriateness observed in first-generation cephalosporins was due to inappropriate longer surgical prophylaxis. While age is an independent risk factor for inappropriate antibiotic use (p = 0.042), COVID-19 unit admission, use for therapeutic purpose and infectious diseases consultation were protective factors (p<0.001, p<0.001, p<0.001).

CONCLUSION

Rate of inappropriate use was low, but inappropriate surgical prophylaxis remains an important problem in surgical units. There is a considerable need to implement an antimicrobial stewardship program that focuses on surgical prophylaxis practices.

Characterization, antibacterial, and cytotoxic activities of silver nanoparticles using the whole biofilm layer as a macromolecule in biosynthesis

Recently, multi-drug resistant (MDR) bacteria are responsible for a large number of infectious diseases that can be life-threatening. Globally, new approaches are targeted to solve this essential issue. This study aims to discover novel antibiotic alternatives by using the whole components of the biofilm layer as a macromolecule to synthesize silver nanoparticles (AgNPs) as a promising agent against MDR. In particular, the biosynthesized biofilm-AgNPs were characterized using UV-Vis spectroscopy, electron microscopes, Energy Dispersive X-ray (EDX), zeta sizer and potential while their effect on bacterial strains and normal cell lines was identified. Accordingly, biofilm-AgNPs have a lavender-colored solution, spherical shape, with a size range of 20-60 nm. Notably, they have inhibitory effects when used on various bacterial strains with concentrations ranging between 12.5 and 25 µg/mL. In addition, they have an effective synergistic effect when combined with phage ZCSE9 to inhibit and kill Salmonella enterica with a concentration of 3.1 µg/mL. In conclusion, this work presents a novel biosynthesis preparation of AgNPs using biofilm for antibacterial purposes to reduce the possible toxicity by reducing the MICs using phage ZCSE9.

Bioengineering the Antimicrobial Activity of Yeast by Recombinant Thanatin Production

The global spread of antibiotic resistance marks the end of the era of conventional antibiotics. Mankind desires new molecular tools to fight pathogenic bacteria. In this regard, the development of new antimicrobials based on antimicrobial peptides (AMPs) is again of particular interest. AMPs have various mechanisms of action on bacterial cells. Moreover, AMPs have been reported to be efficient in preclinical studies, demonstrating a low level of resistance formation. Thanatin is a small, beta-hairpin antimicrobial peptide with a bacterial-specific mode of action, predetermining its low cytotoxicity toward eukaryotic cells. This makes thanatin an exceptional candidate for new antibiotic development. Here, a microorganism was bioengineered to produce an antimicrobial agent, providing novel opportunities in antibiotic research through the directed creation of biocontrol agents. The constitutive heterologous production of recombinant thanatin (rThan) in the yeast Pichia pastoris endows the latter with antibacterial properties. Optimized expression and purification conditions enable a high production level, yielding up to 20 mg/L of rThan from the culture medium. rThan shows a wide spectrum of activity against pathogenic bacteria, similarly to its chemically synthesized analogue. The designed approach provides new avenues for AMP engineering and creating live biocontrol agents to fight antibiotic resistance.

Oligomeric phloroglucinols with hAChE inhibitory and antibacterial activities from tropic Rhodomyrtus tomentosa

Alzheimer's diseases (AD) and other infectious diseases caused by drug-resistance bacteria have posed a serious threat to human lives and global health. With the aim to search for human acetylcholinesterase (hAChE) inhibitors and antibacterial agents from medicinal plants, 16 phloroglucinol oligomers, including two new phloroglucinol monomers (1a and 1b), four new phloroglucinol dimers (3a, 3b, 4b, and 5a), six new phloroglucinol trimers (6a, 6b, 7a, 7b, 8a, and 8b), and two naturally occurring phloroglucinol monomers (2a and 2b), along with two known congeners (4a and 5b), were purified from the leaves of tropic Rhodomyrtus tomentosa. The structures and absolute configurations of these new isolates were unequivocally established by comprehensive analyses of their spectroscopic data (NMR and HRESIMS), ECD calculation, and single crystal X-ray diffraction. Structurally, 3a/3b shared a rare C-5' formyl group, whereas 6a/6b possessed a unique C-7' aromatic ring. In addition, 7a/7b and 8a/8b were rare phloroglucinol trimers with a bis-furan and a C-6' hemiketal group. Pharmacologically, the mixture of 3a and 3b showed the most potent human acetylcholinesterase (hAChE) inhibitory activity with an IC50 value of 1.21 ± 0.16 μM. The molecular docking studies of 3a and 3b in the hAChE binding sites were performed, displaying good agreement with the in vitro inhibitory effects. In addition, the mixture of 3a and 3b displayed the most significant anti-MRSA (methicillin-resistant Staphylococcus aureus) with MIC and MBC values of both 0.50 μg/mL, and scanning electron microscope (SEM) studies revealed that they could destroy the biofilm structures of MRSA. The findings provide potential candidates for the further development of anti-AD and anti-bacterial agents.

A decennial study of the trend of antibiotic studies in China

Antibiotics are one of the greatest inventions in human history and are used worldwide on an enormous scale. Besides its extensive usage in medical and veterinary arenas to treat and prevent the infection, its application is very prominent in other fields, including agriculture, aquaculture, and horticulture. In recent decades, the increased consumption of antibiotics in China saw a vast increase in its production and disposal in various environments. However, in this post-antibiotic era, the abuse and misuse of these valuable compounds could lead to the unreversible consequence of drug resistance. In China, antibiotics are given a broad discussion in various fields to reveal their impact on both human/animals health and the environment. To our knowledge, we are the first paper to look back at the development trend of antibiotic-related studies in China with qualitative and quantitative bibliometric analysis from the past decades. Our study identified and analyzed 5559 papers from its inception (1991) to December 6, 2021, from the Web of Science Core Collection database. However, with few authors and institutions focusing on long-term studies, we found the quality of contributions was uneven. Studies mainly focused on areas such as food science, clinical research, and environmental studies, including molecular biology, genetics and environmental, ecotoxicology, and nutrition, which indicate possible primary future trends. Our study reports on including potentially new keywords, studies' milestones, and their contribution to antibiotic research. We offer potential topics that may be important in upcoming years that could help guide future research.

Exploring the arsenal of antimicrobial peptides: Mechanisms, diversity, and applications

Antimicrobial peptides (AMPs) are essential for defence against pathogens in all living organisms and possessed activities against bacteria, fungi, viruses, parasites and even cancer cells. AMPs are short peptides containing 12-100 amino acids conferring a net positive charge and an amphiphilic property in most cases. Although, anionic AMPs also exist. AMPs can be classified based on the types of secondary structures, charge, hydrophobicity, amino acid composition, length, etc. Their mechanism of action usually includes a membrane disruption process through pore formation (three different models have been described, barrel-stave, toroidal or carpet model) but AMPs can also penetrate and impair intracellular functions. Besides their activity against pathogens, they have also shown immunomodulatory properties in complex scenarios through many different interactions. The aim of this review to summarize knowledge about AMP's and discuss the potential application of AMPs as therapeutics, the challenges due to their limitations, including their susceptibility to degradation, the potential generation of AMP resistance, cost, etc. We also discuss the current FDA-approved drugs based on AMPs and strategies to circumvent natural AMPs' limitations.

National Cohort Study of Resource Utilization in Older Adults With Emergency General Surgery Conditions

INTRODUCTION

Prior studies have sought to describe Emergency General Surgery (EGS) burden, but a detailed description of resource utilization for both operative and nonoperative management of EGS conditions has not been undertaken.

METHODS

Patient and hospital characteristics were extracted from Medicare data, 2015-2018. Operations, nonsurgical procedures, and other resources (i.e., radiology) were defined using Current Procedural Terminology codes.

RESULTS

One million eight hundred two thousand five hundred forty-five patients were included in the cohort. The mean age was 74.7 y and the most common diagnoses were upper gastrointestinal. The majority of hospitals were metropolitan (75.1%). Therapeutic radiology services were available in 78.4% of hospitals and operating rooms or endoscopy suites were available in 92.5% of hospitals. There was variability in resource utilization across EGS subconditions, with hepatobiliary (26.4%) and obstruction (23.9%) patients most frequently undergoing operation.

CONCLUSIONS

Treatment of EGS diseases in older adults involves several interventional resources. Changes in EGS models, acute care surgery training, and interhospital care coordination may be beneficial to the treatment of EGS patients.

Unraveling the Role of Metals and Organic Acids in Bacterial Antimicrobial Resistance in the Food Chain

Antimicrobial resistance (AMR) has a significant impact on human, animal, and environmental health, being spread in diverse settings. Antibiotic misuse and overuse in the food chain are widely recognized as primary drivers of antibiotic-resistant bacteria. However, other antimicrobials, such as metals and organic acids, commonly present in agri-food environments (e.g., in feed, biocides, or as long-term pollutants), may also contribute to this global public health problem, although this remains a debatable topic owing to limited data. This review aims to provide insights into the current role of metals (i.e., copper, arsenic, and mercury) and organic acids in the emergence and spread of AMR in the food chain. Based on a thorough literature review, this study adopts a unique integrative approach, analyzing in detail the known antimicrobial mechanisms of metals and organic acids, as well as the molecular adaptive tolerance strategies developed by diverse bacteria to overcome their action. Additionally, the interplay between the tolerance to metals or organic acids and AMR is explored, with particular focus on co-selection events. Through a comprehensive analysis, this review highlights potential silent drivers of AMR within the food chain and the need for further research at molecular and epidemiological levels across different food contexts worldwide.

ZnO and Au nanoparticles supported highly sensitive and selective electrochemical sensor based on molecularly imprinted polymer for sulfaguanidine and sulfamerazine detection

This study aimed to develop a molecularly imprinted polymer (MIP) sensor using electropolymerization of thiophene acetic acid monomer around template molecules, sulfaguanidine (SGN) and sulfamerazine (SMR), for selective and sensitive detection of both antibiotics. Au nanoparticles were then deposited on the modified electrode surface, and SGN and SMR were extracted from the resulting layer. Surface characterization, changes in the oxidation peak current of both analytes, and investigation of the electrochemical properties of the MIP sensor were examined using scanning electron microscopy, cyclic voltammetry, and differential pulse voltammetry. The developed MIP sensor with Au nanoparticles showed a detection limit of 0.030 µmol L-1 and 0.046 µmol L-1 for SGN and SMR, respectively, with excellent selectivity in the presence of interferents. The sensor was successfully used for SGN and SMR analysis in human fluids, including blood serum and urine, with excellent stability and reproducibility.

Biosynthesis of silver nanoparticles (Ag-NPs) using Senna alexandrina grown in Saudi Arabia and their bioactivity against multidrug-resistant pathogens and cancer cells

There is no doubt that the risk of drug-resistant pathogens and cancer diseases is on the rise. So, the goal of this study was to find out how effective silver nanoparticles (Ag-NPs) made by Senna alexandrina are at fighting these threats. In this work, S. alexandrina collected from Medina, Saudi Arabia was used and the biosynthesis method was applied to produce the Ag-NPs. The characterization of Ag-NPs was done using different analytical techniques, including UV spectroscopy, FT-IR, TEM, and XRD analysis. The MIC, MBC, and MTT protocols were applied to confirm the bioactivity of the Ag-NPs as antibacterial and anticancer bioagents. The findings reported indicating that the aqueous extract of S. alexandrina leaves, grown naturally in Saudi Arabia, is ideal for the production of bioactive Ag-NPs. The hydroxyl, aliphatic, alkene, N-H bend of primary amines, C-H bonds, and C-O bonds of alcohol were detected in this product. The small, sphere-shaped particles (4-7 nm) were the most prevalent among the bioactive Ag-NPs produced in this work. These nanoparticles inhibited some important multidrug-resistant pathogens (MDRPs) (Escherichia coli, Acinetobacter baumanii/haemolyticus, Staphylococcus epidermidis, and Methicillin-resistant Staphylococcus aureus (MRSA)), as well as their ability to inhibit breast cancer cells (MCF-7 cells). The MIC of Ag-NPs ranged from 0.03 to 0.6 mg/mL, while their MBC ranged from 0.06 to 2.5 mg/mL. Anticancer activity test showed that IC₅₀ of the Ag-NPs against tested breast cancer cells was 61.9 ± 3.8 µg/mL. According to the current results, biosynthesis using S. alexandrina leaves grown naturally in Saudi Arabia was an ideal technique for producing bioactive Ag-NPs that could be used to combat a variety of MDRPs and cancer diseases.

Spatial analysis of antimicrobial resistance in the environment. A systematic review

Antimicrobial resistance (AMR) is a global major health concern. Spatial analysis is considered an invaluable method in health studies. Therefore, we explored the usage of spatial analysis in Geographic Information Systems (GIS) in studies on AMR in the environment. This systematic review is based on database searches, a content analysis, ranking of the included studies according to the preference ranking organization method for enrichment evaluations (PROMETHEE) and estimation of data points per km2. Initial database searches resulted in 524 records after removal of duplicates. After the last stage of full text screening, 13 greatly heterogeneous articles with diverse study origins, methods and design remained. In the majority of studies, the data density was considerably less than one sampling site per km2 but exceeded 1,000 sites per km2 in one study. The results of the content analysis and ranking showed a variation between studies that primarily used spatial analysis and those that used spatial analysis as a sec ondary method. We identified two distinct groups of GIS methods. The first was focused on sample collection and laboratory testing, with GIS as supporting method. The second group used overlay analysis as the primary method to combine datasets in a map. In one case, both methods were combined. The low number of articles that met our inclusion criteria highlights a research gap. Based on the findings of this study we encourage application of GIS to its full potential in studies of AMR in the environment.

Translating phage therapy into the clinic: Recent accomplishments but continuing challenges

Phage therapy is a medical form of biological control of bacterial infections, one that uses naturally occurring viruses, called bacteriophages or phages, as antibacterial agents. Pioneered over 100 years ago, phage therapy nonetheless is currently experiencing a resurgence in interest, with growing numbers of clinical case studies being published. This renewed enthusiasm is due in large part to phage therapy holding promise for providing safe and effective cures for bacterial infections that traditional antibiotics acting alone have been unable to clear. This Essay introduces basic phage biology, provides an outline of the long history of phage therapy, highlights some advantages of using phages as antibacterial agents, and provides an overview of recent phage therapy clinical successes. Although phage therapy has clear clinical potential, it faces biological, regulatory, and economic challenges to its further implementation and more mainstream acceptance.

Amino-functionalized Fe(III)-Based MOF for the high-efficiency extraction and ultrasensitive colorimetric detection of tetracycline

In order to achieve the simultaneous extraction and detection of tetracycline (TC) in milk, the amino-functionalized Fe-based metal-organic frameworks (NH₂-MIL-88B) was synthesized via a solvothermal method with Fe³⁺ and 2-aminoterephthalic acid (NH₂-BDC) as precursor. Thanks to the unique structure of NH₂-MIL-88B, it could be used to highly effective extract of TC in milk. More interestedly, the introduced -NH₂ could react with -OH from TC by a hydrogen-bonding interaction to cause the electronic interactions that enhances the peroxidase-like activity of NH₂-MIL-88B, which result in the enhancement of Fenton reaction by the transfer of the electron between TC and NH₂-MIL-88B. Under the optimal testing conditions, the linear absorbance response is well correlated with the TC concentration range of 50-1000 nM, which can reach a low LOD of 46.75 nM. Besides, the sensor exhibits excellent selectivity to TC, and the proposed strategy can also be applied to milk with good recovery (83.33-107.00%). Finally, the NH₂-MIL-88B and cellulose acetate (CA) are combined to form nanozyme hybrid membranes through the non-solvent induced phase separation method, which can be used to prepare point-of-care testing (POCT) for rapid and in-situ detection of TC.

Antimicrobial resistance in methicillin-resistant staphylococcus aureus

In the medical community, antibiotics are revered as a miracle because they stop diseases brought on by pathogenic bacteria. Antibiotics have become the cornerstone of contemporary medical advancements ever since penicillin was discovered. Antibiotic resistance developed among germs quickly, placing a strain in the medical field. Methicillin-resistant Staphylococcus aureus (MRSA), Since 1961, has emerged as the major general antimicrobial resistant bacteria (AMR) worldwide. MRSA can easily transmit across the hospital system and has mostly gained resistance to medications called beta-lactamases. This enzyme destroys the cell wall of beta-lactam antibiotics resulting in resistance against that respective antibiotic. Daptomycin, linezolid and vancomycin were previously used to treat MRSA infections. However, due to mutations and Single nucleotide polymorphisms (SNPs) in Open reading frames (ORFs) and SCCmec machinery of respective antibody, MRSA developed resistance against those antibiotics. The MRSA strains (USA300, CC398, CC130 etc.), when their pan-genomes were analyzed were found the genes involved in invoking resistance against the antibiotics as well as the epidemiology of that respective strain. PENC (penicillin plus potassium clavulanate) is the new antibiotic showing potential in treatment of MRSA though it is itself resistant against penicillin alone. In this review, our main focus is on mechanism of development of AMR in MRSA, how different ORFs are involved in evoking resistance in MRSA and what is the core-genome of different antimicrobial resistant MRSA.

Discovery of Novel Resistance Mechanisms of Vibrio parahaemolyticus Biofilm against Aminoglycoside Antibiotics

Inappropriate use of antibiotics eventually leads to the emergence of antibiotic-resistant strains and invalidates the treatment of infectious diseases. Aminoglycoside antibiotics (AGAs) are a class of broad-spectrum cationic antibiotics widely used for the treatment of Gram-negative bacterial infections. Understanding the AGA resistance mechanism of bacteria would increase the efficacy of treating these infections. This study demonstrates a significant correlation between AGA resistance and the adaptation of biofilms by Vibrio parahaemolyticus (VP). These adaptations were the result of challenges against the aminoglycosides (amikacin and gentamicin). Confocal laser scanning microscope (CLSM) analysis revealed an enclosure type mechanism where the biological volume (BV) and average thickness (AT) of V. parahaemolyticus biofilm were significantly positively correlated with amikacin resistance (BIC) (p < 0.01). A neutralization type mechanism was mediated by anionic extracellular polymeric substances (EPSs). The biofilm minimum inhibitory concentrations of amikacin and gentamicin were reduced from 32 µg/mL to 16 µg/mL and from 16 µg/mL to 4 µg/mL, respectively, after anionic EPS treatment with DNase I and proteinase K. Here, anionic EPSs bind cationic AGAs to develop antibiotic resistance. Transcriptomic sequencing revealed a regulatory type mechanism, where antibiotic resistance associated genes were significantly upregulated in biofilm producing V. parahaemolyticus when compared with planktonic cells. The three mechanistic strategies of developing resistance demonstrate that selective and judicious use of new antibiotics are needed to win the battle against infectious disease.

Point Prevalence Survey of Antimicrobial Use during the COVID-19 Pandemic among Different Hospitals in Pakistan: Findings and Implications

The COVID-19 pandemic has significantly influenced antimicrobial use in hospitals, raising concerns regarding increased antimicrobial resistance (AMR) through their overuse. The objective of this study was to assess patterns of antimicrobial prescribing during the current COVID-19 pandemic among hospitals in Pakistan, including the prevalence of COVID-19. A point prevalence survey (PPS) was performed among 11 different hospitals from November 2020 to January 2021. The study included all hospitalized patients receiving an antibiotic on the day of the PPS. The Global-PPS web-based application was used for data entry and analysis. Out of 1024 hospitalized patients, 662 (64.64%) received antimicrobials. The top three most common indications for antimicrobial use were pneumonia (13.3%), central nervous system infections (10.4%) and gastrointestinal indications (10.4%). Ceftriaxone (26.6%), metronidazole (9.7%) and vancomycin (7.9%) were the top three most commonly prescribed antimicrobials among surveyed patients, with the majority of antibiotics administered empirically (97.9%). Most antimicrobials for surgical prophylaxis were given for more than one day, which is a concern. Overall, a high percentage of antimicrobial use, including broad-spectrums, was seen among the different hospitals in Pakistan during the current COVID-19 pandemic. Multifaceted interventions are needed to enhance rational antimicrobial prescribing including limiting their prescribing post-operatively for surgical prophylaxis.

Tricyclic Fused Lactams by Mukaiyama Cyclisation of Phthalimides and Evaluation of their Biological Activity

We report that phthalimides may be cyclized using a Mukaiyama-type aldol coupling to give variously substituted fused lactam (1,2,3,9b-tetrahydro-5H-pyrrolo[2,1-a]isoindol-5-one) systems. This novel process shows a high level of regioselectivity for o-substituted phthalimides, dictated by steric and electronic factors, but not for m-substituted phthalimides. The initial aldol adduct is prone to elimination, giving 2,3-dihydro-5H-pyrrolo[2,1-a]isoindol-5-ones, and the initial cyclisation can be conducted in such a way that aldol cyclisation-elimination is achievable in a one-pot approach. The 2,3-dihydro-5H-pyrrolo[2,1-a]isoindol-5-ones possess cross conjugation and steric effects which significantly influence the reactivity of several functional groups, but conditions suitable for epoxidation, ester hydrolysis and amide formation, and reduction, which provide for ring manipulation, were identified. Many of the derived lactam systems, and especially the eliminated systems, show low solubility, which compromises biological activity, although in some cases, antibacterial and cytotoxic activity was found, and this new class of small molecule provides a useful skeleton for further elaboration and study.

β-Lactam-Resistant Streptococcus pneumoniae Dynamics Following Treatment: A Dose-Response Meta-analysis

BACKGROUND

Patient exposure to antibiotics promotes the emergence of drug-resistant pathogens. The aim of this study was to identify whether the temporal dynamics of resistance emergence at the individual-patient level were predictable for specific pathogen-drug classes.

METHODS

Following a systematic review, a novel robust error meta-regression method for dose-response meta-analysis was used to estimate the odds ratio (OR) for carrying resistant bacteria during and following treatment compared to baseline. Probability density functions fitted to the resulting dose-response curves were then used to optimize the period during and/or after treatment when resistant pathogens were most likely to be identified.

RESULTS

Studies of Streptococcus pneumoniae treatment with β-lactam antibiotics demonstrated a peak in resistance prevalence among patients 4 days after completing treatment with a 3.32-fold increase in odds (95% confidence interval [CI], 1.71-6.46). Resistance waned more gradually than it emerged, returning to preexposure levels 1 month after treatment (OR, 0.98 [95% CI, .55-1.75]). Patient isolation during the peak dose-response period would be expected to reduce the risk that a transmitted pathogen is resistant equivalently to a 50% longer isolation window timed from the first day of treatment.

CONCLUSIONS

Predictable temporal dynamics of resistance levels have implications both for surveillance and control.

Short- and Long-Term Effects of Different Antibiotics on the Gut Microbiota and Cytokines Level in Mice

BACKGROUND

Antibiotics are the first line of treatment for infectious diseases. However, their overuse can increase the spread of drug-resistant bacteria. The present study analyzed the impact of different types of antibiotics on the gut microbiome and cytokines level of mice.

METHODS

A total of five groups of 8-week-old male BALB/c mice (n = 35) were treated with piperacillin-tazobactam (TZP), ceftriaxone (CRO), tigecycline (TGC), levofloxacin (LEV) or normal saline (Ctrl), respectively, for up to 4 weeks. Fecal samples were analyzed by bacterial 16S rRNA gene sequencing for bacterial identification. Blood samples were used for the determination of 23 serum cytokines using multiplex immunoassay.

RESULTS

Exposure to antibiotics was shown to affect the normal weight gain of mice. Significant changes in gut composition caused by TZP, CRO and TGC treatment included the decreased abundance of Bacteroidetes (p < 0.01), Muribaculaceae (p < 0.01) and Lachnospiraceae (p < 0.01), and the increased abundance of Proteobacteria (p < 0.05), Enterobacteriaceae (including Klebsiella and Enterobacter) (p < 0.01) and Enterococcaceae (including Enterococcus) (p < 0.01). After 4-week treatment, the TZP, CRO and LEV groups had significantly lower concentrations of several serum cytokines. Correlation analysis of the top 30 bacterial genera and cytokines showed that Enterococcus and Klebsiella were strongly positively correlated with tumor necrosis factor-α (TNF-α), interleukins (IL) IL-12p70 and IL-1β. Desulfovibrio, Candidatus Saccharimonas, norank_f__norank_o__Clostridia_UCG-014, Lactobacillus, and Roseburia were strongly negatively correlated with these cytokines.

CONCLUSION

This study demonstrates the effects of various antibiotics on the intestinal microflora and immune status of mice. Compared with TZP, CRO and TGC, LEV had minimal impact on the gut microbiota. In addition to TGC, long-term TZP, CRO and LEV intervention can lead to a decrease in serum cytokine levels, which may depend on the intestinal microflora, antibiotic used and the duration of treatment.

Hipertensión arterial y riesgo cardiovascular

Introducción: la hipertensión arterial es una de las principales enfermedades a nivel mundial y constituye una importante causa de morbilidad y mortalidad para países de bajos y medianos ingresos. Objetivo: determinar la importancia epidemiológica de la hipertensión arterial como factor de riesgo cardiovascular en diferentes estudios realizados a nivel mundial, en Latinoamérica y Colombia. Metodología: se realizó una búsqueda de la literatura científica en las bases de datos de PudMed/Medline, Scielo, LILACS, así como también en revistas médicas y textos publicados por el Ministerio de Salud y Protección Social de Colombia. Discusión y conclusiones: más de 90% de los pacientes hipertensos padecen la forma primaria de la enfermedad, la cual está asociada con un aumento de la resistencia vascular periférica. Las características socioeconómicas de los países y el nivel educativo individual se relacionan con la prevalencia y el manejo adecuado de esta patología. El aumento en la prevalencia de las enfermedades crónicas, sumado a eventos históricos de importancia, fueron determinantes para el desarrollo de estudios epidemiológicos mundiales como el Framingham Heart Study. En América Latina y en Colombia se han realizado diferentes estudios que permiten establecer datos relacionados con la hipertensión arterial, demostrando cifras alarmantes en cuanto al conocimiento, tratamiento y control de esta condición, por lo cual, surge la necesidad de establecer programas para la detección de pacientes hipertensos con el fin de generar estrategias que disminuyan de manera significativa las enfermedades cardiovasculares.

Synthesis and evaluation of novel furanones as biofilm inhibitors in opportunistic human pathogens

Diseases caused by biofilm-forming pathogens are becoming increasingly prevalent and represent a major threat to human health. This trend has prompted a search for novel inhibitors of microbial biofilms which could, for example, be used to potentiate existing antibiotics. Naturally-occurring, halogenated furanones isolated from marine algae have proven to be effective biofilm inhibitors in several bacterial species. In this work, we report the synthesis of a library of novel furanones and their subsequent evaluation as biofilm inhibitors in several opportunistic human pathogens including S. enterica, S. aureus, E. coli, S. maltophilia, P. aeruginosa and C. albicans. A number of the most potent compounds were subjected to further analysis by confocal laser-scanning microscopy for their effects on P. aeruginosa and C. albicans biofilms individually, in addition to mixed polymicrobial biofilms. Lastly, we investigated the impact of a promising candidate on survival rates in vivo using a Galleria mellonella model.

Construction of Electrochemical Sensors for Antibiotic Detection Based on Carbon Nanocomposites

Excessive antibiotic residues in food can cause detrimental effects on human health. The establishment of rapid, sensitive, selective, and reliable methods for the detection of antibiotics is highly in demand. With the inherent advantages of high sensitivity, rapid analysis time, and facile miniaturization, the electrochemical sensors have great potential in the detection of antibiotics. The electrochemical platforms comprising carbon nanomaterials (CNMs) have been proposed to detect antibiotic residues. Notably, with the introduction of functional CNMs, the performance of electrochemical sensors can be bolstered. This review first presents the significance of functional CNMs in the detection of antibiotics. Subsequently, we provide an overview of the applications for detection by enhancing the electrochemical behaviour of the antibiotic, as well as a brief overview of the application of recognition elements to detect antibiotics. Finally, the trend and the current challenges of electrochemical sensors based on CNMs in the detection of antibiotics is outlined.

Covalent Proteomimetic Inhibitor of the Bacterial FtsQB Divisome Complex

The use of antibiotics is threatened by the emergence and spread of multidrug-resistant strains of bacteria. Thus, there is a need to develop antibiotics that address new targets. In this respect, the bacterial divisome, a multi-protein complex central to cell division, represents a potentially attractive target. Of particular interest is the FtsQB subcomplex that plays a decisive role in divisome assembly and peptidoglycan biogenesis in E. coli. Here, we report the structure-based design of a macrocyclic covalent inhibitor derived from a periplasmic region of FtsB that mediates its binding to FtsQ. The bioactive conformation of this motif was stabilized by a customized cross-link resulting in a tertiary structure mimetic with increased affinity for FtsQ. To increase activity, a covalent handle was incorporated, providing an inhibitor that impedes the interaction between FtsQ and FtsB irreversibly. The covalent inhibitor reduced the growth of an outer membrane-permeable E. coli strain, concurrent with the expected loss of FtsB localization, and also affected the infection of zebrafish larvae by a clinical E. coli strain. This first-in-class inhibitor of a divisome protein–protein interaction highlights the potential of proteomimetic molecules as inhibitors of challenging targets. In particular, the covalent mode-of-action can serve as an inspiration for future antibiotics that target protein–protein interactions.

Overcoming Methicillin-Resistance Staphylococcus aureus (MRSA) Using Antimicrobial Peptides-Silver Nanoparticles

Antibiotics are regarded as a miracle in the medical field as it prevents disease caused by pathogenic bacteria. Since the discovery of penicillin, antibiotics have become the foundation for modern medical discoveries. However, bacteria soon became resistant to antibiotics, which puts a burden on the healthcare system. Methicillin-resistant Staphylococcus aureus (MRSA) has become one of the most prominent antibiotic-resistant bacteria in the world since 1961. MRSA primarily developed resistance to beta-lactamases antibiotics and can be easily spread in the healthcare system. Thus, alternatives to combat MRSA are urgently required. Antimicrobial peptides (AMPs), an innate host immune agent and silver nanoparticles (AgNPs), are gaining interest as alternative treatments against MRSA. Both agents have broad-spectrum properties which are suitable candidates for controlling MRSA. Although both agents can exhibit antimicrobial effects independently, the combination of both can be synergistic and complementary to each other to exhibit stronger antimicrobial activity. The combination of AMPs and AgNPs also reduces their own weaknesses as their own, which can be developed as a potential agent to combat antibiotic resistance especially towards MRSA. Thus, this review aims to discuss the potential of antimicrobial peptides and silver nanoparticles towards controlling MRSA pathogen growth.