-
Methods in Molecular Biology (Clifton,... 2024Antimicrobial resistance (AMR) poses a serious threat to global health, potentially causing 10 million deaths per year globally by 2050. To tackle AMR, researchers from...
Antimicrobial resistance (AMR) poses a serious threat to global health, potentially causing 10 million deaths per year globally by 2050. To tackle AMR, researchers from all around the world have generated a selection of various formulated (viz. nanoparticulate, liposomal) therapeutic combinations to be evaluated for new antimicrobial drug discovery. To meet the urgent need for accelerating new antibacterial drug development, we need rapid but reliable whole-cell assay methods and models to test formulated therapeutic combinations against several pathogens in different in vitro conditions as models of actual infections.Over the past two decades, high-throughput spot-culture growth inhibition assay (HT-SPOTi) has been demonstrated to be a gold-standard drug susceptibility method for evaluating novel chemotherapeutic entities and existing drugs against various microbes of global concern. Our modified HT-SPOTi method serves the purpose of evaluating drug combinations against Gram-positive/negative microorganisms as well as acid-fast bacilli. The newly developed and modified HT-SPOTi assay builds upon the limitations of our previously published method to incorporate antimicrobial susceptibility testing with formulated therapeutic combinations. The modified HT-SPOTi is compared with a range of other antimicrobial susceptibility testing methods and validated using a library of existing antibiotics as well as formulated therapeutic combinations. The modified HT-SPOTi assay can serve as an efficient and reliable high-throughput drug screening platform to discover new potential antimicrobial molecules, including as part of therapeutic formulations.This chapter describes the generation of drug susceptibility profile for formulated therapeutic combinations using modified HT-SPOTi in a semi-automated system.
Topics: Microbial Sensitivity Tests; Anti-Bacterial Agents; High-Throughput Screening Assays; Humans; Bacteria
PubMed: 38949698
DOI: 10.1007/978-1-0716-3981-8_4 -
Methods in Molecular Biology (Clifton,... 2024Mycobacterium tuberculosis is the main causative agent of tuberculosis (TB)-an ancient yet widespread global infectious disease to which 1.6 million people lost their...
Mycobacterium tuberculosis is the main causative agent of tuberculosis (TB)-an ancient yet widespread global infectious disease to which 1.6 million people lost their lives in 2021. Antimicrobial resistance (AMR) has been an ongoing crisis for decades; 4.95 million deaths were associated with antibiotic resistance in 2019. While AMR is a multi-faceted problem, drug discovery is an urgent part of the solution and is at the forefront of modern research.The landscape of drug discovery for TB has undoubtedly been transformed by the development of high-throughput gene-silencing techniques that enable interrogation of every gene in the genome, and their relative contribution to fitness, virulence, and AMR. A recent advance in this area is CRISPR interference (CRISPRi). The application of this technique to antimicrobial susceptibility testing (AST) is the subject of ongoing research in basic science.CRISPRi technology can be used in conjunction with the high-throughput SPOT-culture growth inhibition assay (HT-SPOTi) to rapidly evaluate and assess gene essentiality including non-essential, conditionally essential (by using appropriate culture conditions), and essential genes. In addition, the HT-SPOTi method can develop drug susceptibility and drug resistance profiles.This technology is further useful for drug discovery groups who have designed target-based inhibitors rationally and wish to validate the primary mechanisms of their novel compounds' antibiotic action against the proposed target.
Topics: Microbial Sensitivity Tests; Mycobacterium tuberculosis; Drug Discovery; Gene Silencing; Humans; CRISPR-Cas Systems; Antitubercular Agents; Anti-Bacterial Agents; High-Throughput Screening Assays; Drug Resistance, Bacterial; Tuberculosis
PubMed: 38949697
DOI: 10.1007/978-1-0716-3981-8_3 -
Methods in Molecular Biology (Clifton,... 2024There is an increasing need for new treatment regimens to combat antibiotic-resistant strains of bacteria. Staphylococcus aureus is a clinically important, opportunist...
There is an increasing need for new treatment regimens to combat antibiotic-resistant strains of bacteria. Staphylococcus aureus is a clinically important, opportunist pathogen that has developed resistance to a range of antibiotics. The zebrafish larval model of systemic disease has been increasingly utilized to elucidate S. aureus virulence mechanisms and host-pathogen interactions. Here, we outline how this model can be used to investigate the effects of different antibiotics alone and in combination against S. aureus.
Topics: Animals; Zebrafish; Anti-Bacterial Agents; Staphylococcus aureus; Larva; Staphylococcal Infections; Disease Models, Animal; Drug Therapy, Combination; Host-Pathogen Interactions; Microbial Sensitivity Tests
PubMed: 38949695
DOI: 10.1007/978-1-0716-3981-8_1 -
Critical Care Medicine Jul 2024In sepsis treatment, antibiotics are crucial, but overuse risks development of antibiotic resistance. Recent guidelines recommended the use of procalcitonin to guide...
Benefits and Harms of Procalcitonin- or C-Reactive Protein-Guided Antimicrobial Discontinuation in Critically Ill Adults With Sepsis: A Systematic Review and Network Meta-Analysis.
OBJECTIVES
In sepsis treatment, antibiotics are crucial, but overuse risks development of antibiotic resistance. Recent guidelines recommended the use of procalcitonin to guide antibiotic cessation, but solid evidence is insufficient. Recently, concerns were raised that this strategy would increase recurrence. Additionally, optimal protocol or difference from the commonly used C-reactive protein (CRP) are uncertain. We aimed to compare the effectiveness and safety of procalcitonin- or CRP-guided antibiotic cessation strategies with standard of care in sepsis.
DATA SOURCES
A systematic search of PubMed, Embase, CENTRAL, Igaku Chuo Zasshi, ClinicalTrials.gov, and World Health Organization International Clinical Trials Platform.
STUDY SELECTION
Randomized controlled trials involving adults with sepsis in intensive care.
DATA EXTRACTION
A systematic review with network meta-analyses was performed. The Grading of Recommendations, Assessments, Developments, and Evaluation method was used to assess certainty.
DATA SYNTHESIS
Eighteen studies involving 5023 participants were included. Procalcitonin-guided and CRP-guided strategies shortened antibiotic treatment (-1.89 days [95% CI, -2.30 to -1.47], -2.56 days [95% CI, -4.21 to -0.91]) with low- to moderate-certainty evidence. In procalcitonin-guided strategies, this benefit was consistent even in subsets with shorter baseline antimicrobial duration (7-10 d) or in Sepsis-3, and more pronounced in procalcitonin cutoff of "0.5 μg/L and 80% reduction." No benefit was observed when monitoring frequency was less than half of the initial 10 days. Procalcitonin-guided strategies lowered mortality (-27 per 1000 participants [95% CI, -45 to -7]) and this was pronounced in Sepsis-3, but CRP-guided strategies led to no difference in mortality. Recurrence did not increase significantly with either strategy (very low to low certainty).
CONCLUSIONS
In sepsis, procalcitonin- or CRP-guided antibiotic discontinuation strategies may be beneficial and safe. In particular, the usefulness of procalcitonin guidance for current Sepsis-3, where antimicrobials are used for more than 7 days, was supported. Well-designed studies are needed focusing on monitoring protocol and recurrence.
PubMed: 38949476
DOI: 10.1097/CCM.0000000000006366 -
Pharmacotherapy Jul 2024Antibiotic resistance has become a global threat as it is continuously growing due to the evolution of β-lactamases diminishing the activity of classic β-lactam (BL)... (Review)
Review
Antibiotic resistance has become a global threat as it is continuously growing due to the evolution of β-lactamases diminishing the activity of classic β-lactam (BL) antibiotics. Recent antibiotic discovery and development efforts have led to the availability of β-lactamase inhibitors (BLIs) with activity against extended-spectrum β-lactamases as well as Klebsiella pneumoniae carbapenemase (KPC)-producing carbapenem-resistant organisms (CRO). Nevertheless, there is still a lack of drugs that target metallo-β-lactamases (MBL), which hydrolyze carbapenems efficiently, and oxacillinases (OXA) often present in carbapenem-resistant Acinetobacter baumannii. This review aims to provide a snapshot of microbiology, pharmacology, and clinical data for currently available BL/BLI treatment options as well as agents in late stage development for CRO harboring various β-lactamases including MBL and OXA-enzymes.
PubMed: 38949413
DOI: 10.1002/phar.2950 -
Journal of Natural Products Jul 2024Combination therapy is an effective strategy to combat antibiotic resistance. Multiple synergistic antimicrobial combinations are produced by enzymes encoded in...
Combination therapy is an effective strategy to combat antibiotic resistance. Multiple synergistic antimicrobial combinations are produced by enzymes encoded in biosynthetic gene clusters (BGCs) that co-localize on the bacterial genome. This phenomenon led to the hypothesis that mining co-localized BGCs will reveal new synergistic combinations of natural products. Here, we bioinformatically identified 38 pairs of co-localized BGCs, which we predict to produce natural products that are related to known compounds, including polycyclic tetramate macrolactams (PoTeMs). We further showed that ikarugamycin, a PoTeM, increases the membrane permeability of and , which suggests that ikarugamycin might be an adjuvant that facilitates the entry of other natural products. Our work outlines a promising avenue to discover synergistic combinations of natural products by mining bacterial genomes.
PubMed: 38949271
DOI: 10.1021/acs.jnatprod.3c01231 -
Critical Reviews in Microbiology Jul 2024is a common pathogen associated with hospital-acquired pneumonia showing increased resistance to carbapenem and colistin antibiotics nowadays. Infections with cause... (Review)
Review
is a common pathogen associated with hospital-acquired pneumonia showing increased resistance to carbapenem and colistin antibiotics nowadays. Infections with cause high patient fatalities due to their capability to evade current antimicrobial therapies, emphasizing the urgency of developing viable therapeutics to treat -associated pneumonia. In this review, we explore current and novel therapeutic options for overcoming therapeutic failure when dealing with -associated pneumonia. Among them, antibiotic combination therapy administering several drugs simultaneously or alternately, is one promising approach for optimizing therapeutic success. However, it has been associated with inconsistent and inconclusive therapeutic outcomes across different studies. Therefore, it is critical to undertake additional clinical trials to ascertain the clinical effectiveness of different antibiotic combinations. We also discuss the prospective roles of novel antimicrobial therapies including antimicrobial peptides, bacteriophage-based therapy, repurposed drugs, naturally-occurring compounds, nanoparticle-based therapy, anti-virulence strategies, immunotherapy, photodynamic and sonodynamic therapy, for utilizing them as additional alternative therapy while tackling -associated pneumonia. Importantly, these innovative therapies further require pharmacokinetic and pharmacodynamic evaluation for safety, stability, immunogenicity, toxicity, and tolerability before they can be clinically approved as an alternative rescue therapy for -associated pulmonary infections.
PubMed: 38949254
DOI: 10.1080/1040841X.2024.2369948 -
Analytical Chemistry Jul 2024Plastic pollution represents a critical threat to soil ecosystems and even humans, as plastics can serve as a habitat for breeding and refuging pathogenic microorganisms...
Plastic pollution represents a critical threat to soil ecosystems and even humans, as plastics can serve as a habitat for breeding and refuging pathogenic microorganisms against stresses. However, evaluating the health risk of plastispheres is difficult due to the lack of risk factors and quantification model. Here, DNA sequencing, single-cell Raman-DO labeling, and transformation assay were used to quantify key risk factors of plastisphere, including pathogen abundance, phenotypic resistance to various stresses (antibiotic and pesticide), and ability to acquire antibiotic resistance genes. A Bayesian network model was newly introduced to integrate these three factors and infer their causal relationships. Using this model, the risk of pathogen in the plastisphere is found to be nearly 3 magnitudes higher than that in free-living state. Furthermore, this model exhibits robustness for risk prediction, even in the absence of one factor. Our framework offers a novel and practical approach to assessing the health risk of plastispheres, contributing to the management of plastic-related threats to human health.
PubMed: 38949233
DOI: 10.1021/acs.analchem.4c01433 -
International Wound Journal Jul 2024Patients with chronic limb-threatening ischaemia (CLTI) are at risk of foot infections, which is associated with an increase in amputation rates. The use of antibiotics...
Patients with chronic limb-threatening ischaemia (CLTI) are at risk of foot infections, which is associated with an increase in amputation rates. The use of antibiotics may lead to a higher incidence of antimicrobial resistance (AMR) in subsequent episodes of ischaemic foot infections (IFI). This retrospective single-centre cohort study included 130 patients with IFI undergoing endovascular revascularisation. Staphylococcus aureus and Pseudomonas aeruginosa were the two most common pathogens, accounting for 20.5% and 10.8% of cases, respectively. The prevalence of antimicrobial resistance (AMR) and multi-drug resistance did not significantly increase between episodes (10.2% vs. 13.4%, p = 0.42). In 59% of subsequent episodes, the identified pathogens were unrelated to the previous episode. However, the partial concordance of identified pathogens significantly increased to 66.7% when S. aureus was identified (p = 0.027). Subsequent episodes of IFI in the same patient are likely to differ in causative pathogens. However, in the case of S. aureus, the risk of reinfection, particularly with S. aureus, is increased. Multi-drug resistance does not appear to change between IFI episodes. Therefore, recommendations for empirical antimicrobial therapy should be based on local pathogen and resistance statistics without the need to broaden the spectrum of antibiotics in subsequent episodes.
Topics: Humans; Male; Retrospective Studies; Female; Aged; Middle Aged; Ischemia; Anti-Bacterial Agents; Aged, 80 and over; Cohort Studies; Staphylococcus aureus; Drug Resistance, Bacterial; Pseudomonas aeruginosa
PubMed: 38949168
DOI: 10.1111/iwj.14961 -
Chemistry, An Asian Journal Jul 2024Antimicrobial resistance (AMR) poses a serious threat to human health worldwide. It is now more challenging than ever to introduce a potent antibiotic to the market...
Antimicrobial resistance (AMR) poses a serious threat to human health worldwide. It is now more challenging than ever to introduce a potent antibiotic to the market considering rapid emergence of antimicrobial resistance, surpassing the rate of antibiotic drug discovery. Hence, new approaches need to be developed to accelerate the rate of drug discovery process and meet the demands for new antibiotics, while reducing the cost of their development. Machine learning holds immense promise of becoming a useful tool, especially since in the last two decades, exponential growth has occurred in computational power and biological big data analytics. Recent advancements in machine learning algorithms for drug discovery have provided significant clues for potential antibiotic classes. Apart from discovery of new scaffolds, machine learning protocols will significantly impact prediction of AMR patterns and drug metabolism. In this review, we outline power of machine learning in antibiotic drug discovery, metabolic fate, and AMR prediction to support researchers engaged and interested in this field.
PubMed: 38948939
DOI: 10.1002/asia.202400102