Multidrug-Resistant Bacteria and Alternative Methods to Control Them: An Overview

Design, synthesis and biological evaluation of amphiphilic benzopyran derivatives as potent antibacterial agents against multidrug-resistant bacteria

Antimicrobial resistance has emerged as a significant threat to global public health. To develop novel, high efficiency antibacterial alternatives to combat multidrug-resistant bacteria, A total of thirty-two novel amphiphilic benzopyran derivatives by mimicking the structure and function of antimicrobial peptides were designed and synthesized. Among them, the most promising compounds 4h and 17e displayed excellent antibacterial activity against Gram-positive bacteria (MICs = 1-4 μg/mL) with weak hemolytic activity and good membrane selectivity. Additionally, compounds 4h and 17e had rapid bactericidal properties, low resistance frequency, good plasma stability, and strong capabilities of inhibiting and eliminating bacterial biofilms. Mechanistic studies revealed that compounds 4h and 17e could effectively disrupt the integrity of bacterial cell membranes, and accompanied by an increase in intracellular reactive oxygen species and the leakage of proteins and DNA, ultimately leading to bacterial death. Notably, compound 4h exhibited comparable in vivo antibacterial potency in a mouse septicemia model infected by Staphylococcus aureus ATCC43300, as compared to vancomycin. These findings indicated that 4h might be a promising antibacterial candidate to combat antimicrobial resistance.

Immune response against bacterial infection in organ transplant recipients

This comprehensive review delves into the intricate dynamics between the immune system and bacterial infections in organ transplant recipients. Its primary objective is to fill existing knowledge gaps while critically assessing the strengths and weaknesses of current research. The paper accentuates the delicate balance that must be struck between preventing graft rejection through immunosuppression and maintaining robust immunity against bacterial threats. In this context, personalized medicine emerges as a transformative concept, offering the potential to revolutionize clinical outcomes by tailoring immunosuppressive regimens and vaccination strategies to the unique profiles of transplant recipients. By emphasizing the pivotal role of continuous monitoring, the review underscores the necessity for vigilant surveillance of transplant recipients to detect bacterial infections and associated immune responses early, thereby reducing the risk of severe infections and ultimately improving patient outcomes. Furthermore, the study highlights the significance of the host microbiome in shaping immune responses, suggesting that interventions targeting the microbiome hold promise for enhancing bacterial immunity in transplant recipients, both in research and clinical practice. In terms of future research directions, the review advocates for large-scale, longitudinal studies encompassing diverse patient cohorts to provide more comprehensive insights into post-transplant immune responses. It also advocates integrating multi-omics approaches, including genomics, transcriptomics, proteomics, and microbiome data, to understand immune responses and their underlying mechanisms. In conclusion, this review significantly enriches our understanding of immune responses in transplant recipients. It paves the way for more effective and personalized approaches to managing infections in this complex setting.

Antibacterial and therapeutic potential of historic deposits of silesian healing clay - terra sigillataSilesiaca

ETHNOPHARMACOLOGICAL RELEVANCE

The increasing evolution of pathogen resistance is a global problem that requires novel solutions. Recently, an increased interest in ethnomedicinal sources can be observed in the derivation of new medicines. The return to traditional medicinal formulations handed down for generations is being followed, but it is necessary to revise them again, taking into account the generally accepted research protocol.

AIM OF THE STUDY

We aimed to evaluate the antimicrobial potential of historical deposits of Silesian healing clay (SHC), used in ethnomedicine against Gram-positive bacteria and to assess their biological activity using a primary dermal fibroblast line (NHDF) and a model monocyte line (THP1).

MATERIALS AND METHODS

Information on medicinal clay deposits that occur in Silesia and are traditionally used in ethnomedicine or ancient medicine and known as terra sigillata Silesiaca or SHC, was selected on available source materials and old prints and maps from the archives of the Polish Geological Institute (Wrocław, Poland). Subsequently, their places of occurrence were identified and traced in the field by taking three deposits from the Silesia territory: Upper Silesia (D1), Opole Silesia (D2), and Lower Silesian (D3) Voivodeships for analysis. Their basic parameters and antimicrobial efficacy against pathogenic bacteria, Gram-positive streptococci and staphylococci, including methicillin-resistant strains, were examined. The study evaluated the effects of clays on growth and vitality using a primary dermal fibroblast line (NHDF) and a monocytic line (THP1). Studies were performed on a cell culture model to determine the effects on tissue regeneration (fibroblasts) and anti-inflammatory effects (monocytes). The study attempted to identify the mechanism of antimicrobial action, especially the textural characteristics and geochemical composition, as well as the environmental reaction (pH).

RESULTS

SHCs were classified into the following textural classes: clay loam (D1), clay (D2), and sand (D3). The tested deposits have antimicrobial properties that reduce the bacterial population (104 CFU) compared to the control (108 CFU). The antimicrobial effect depends on the type of clay and the species or strain of bacteria used. In-house studies clearly showed that Staphylococcus aureus Pcm 2054 and Staphylococcus epidermidis MRSE ATCC 2538 cells were completely adsorbed by clay minerals from clay D3.13. Furthermore, 10% leachates also showed an antimicrobial effect, as a reduction in bacterial populations was observed ranging from 91 to 100%. The results showed stimulation of fibroblast culture proliferation and inhibition of the growth of inflammatory cells (monocytes).

CONCLUSION

SHCs tested have antimicrobial potential, in particular D2.7, D2.11, and D3.13. The D3.13 deposit had a bactericidal effect against the staphylococci tested. Aqueous solutions of clays also showed bacteriostatic effect. The results obtained in cell culture model tests indicate properties that modulate the healing process - stimulation of fibroblast growth (NHDF line) and inhibition of monocyte growth (THP1 line).

Antibacterial, antibiofilm, and antivirulence potential of the main diterpenes from Copaifera spp. oleoresins against multidrug-resistant bacteria

To evaluate the antibacterial, antibiofilm and antivirulence potential of the main diterpenes from Copaifera spp. oleoresins against multidrug-resistant (MDR) bacteria. Antimicrobial assays included determination of the Minimum Inhibitory Concentration (MIC), Minimum Bactericidal Concentration (MBC), Minimum Inhibitory Concentration of Biofilm (MICB50), as well as synergistic and antivirulence assays for eight diterpenes against MDR. The tests revealed that two diterpenes (named 1 and 5) showed the best results, with MIC and MBC between 12.5 and 50 μg/mL against most MDR bacteria. These diterpenes exhibited promising MICB50 in concentration between 3.12-25 μg/mL but showed no synergistic antimicrobial activity. In the assessment of antivirulence activity, diterpenes 1 and 5 inhibited only one of the virulence factors evaluated (Dnase) produced by some strains of S. aureus at subinhibitory concentration (6.25 μg/mL). Results obtained indicated that diterpenes isolated from Copaifera oleoresin plays an important part in the search of new antibacterial and antibiofilm agents that can act against MDR bacteria.

Exploring the Antimicrobial Potential of Hallachrome, a Defensive Anthraquinone from the Marine Worm Halla parthenopeia (Polychaeta)

Antimicrobial resistance is a critical global health issue, with rising resistance among bacteria and fungi. Marine organisms have emerged as promising, but underexplored, sources of new antimicrobial agents. Among them, marine polychaetes, such as Halla parthenopeia, which possess chemical defenses, could attract significant research interest. This study explores the antimicrobial properties of hallachrome, a unique anthraquinone found in the purple mucus of H. parthenopeia, against Gram-negative bacteria (Escherichia coli ATCC 25922, Pseudomonas aeruginosa ATCC 9027), Gram-positive bacteria (Enterococcus faecalis ATCC 29212, Staphylococcus aureus ATCC 6538, Staphylococcus epidermidis ATCC 12228), and the most common human fungal pathogen Candida albicans ATCC 10231. Antibacterial susceptibility testing revealed that Gram-negative bacteria were not inhibited by hallachrome at concentrations ≤2 mM. However, Gram-positive bacteria showed significant growth inhibition at 0.12-0.25 mM, while C. albicans was inhibited at 0.06 mM. Time-kill studies demonstrated dose-dependent growth inhibition of susceptible strains by hallachrome, which exerted its effect by altering the membrane permeability of C. albicans, E. faecalis, and S. epidermidis after 6 h and S. aureus after 24 h. Additionally, hallachrome significantly reduced biofilm formation and mature biofilm in S. aureus, E. faecalis, and C. albicans. Additionally, it inhibited hyphal growth in C. albicans. These findings highlight hallachrome's potential as a novel antimicrobial agent, deserving further exploration for clinical experimentation.

Light-Responsive and Antibacterial Graphenic Materials as a Holistic Approach to Tissue Engineering

While the continuous development of advanced bioprinting technologies is under fervent study, enhancing the regenerative potential of hydrogel-based constructs using external stimuli for wound dressing has yet to be tackled. Fibroblasts play a significant role in wound healing and tissue implants at different stages, including extracellular matrix production, collagen synthesis, and wound and tissue remodeling. This study explores the synergistic interplay between photothermal activity and nanomaterial-mediated cell proliferation. The use of different graphene-based materials (GBM) in the development of photoactive bioinks is investigated. In particular, we report the creation of a skin-inspired dressing for wound healing and regenerative medicine. Three distinct GBM, namely, graphene oxide (GO), reduced graphene oxide (rGO), and graphene platelets (GP), were rigorously characterized, and their photothermal capabilities were elucidated. Our investigations revealed that rGO exhibited the highest photothermal efficiency and antibacterial properties when irradiated, even at a concentration as low as 0.05 mg/mL, without compromising human fibroblast viability. Alginate-based bioinks alongside human fibroblasts were employed for the bioprinting with rGO. The scaffold did not affect the survival of fibroblasts for 3 days after bioprinting, as cell viability was not affected. Remarkably, the inclusion of rGO did not compromise the printability of the hydrogel, ensuring the successful fabrication of complex constructs. Furthermore, the presence of rGO in the final scaffold continued to provide the benefits of photothermal antimicrobial therapy without detrimentally affecting fibroblast growth. This outcome underscores the potential of rGO-enhanced hydrogels in tissue engineering and regenerative medicine applications. Our findings hold promise for developing game-changer strategies in 4D bioprinting to create smart and functional tissue constructs with high fibroblast proliferation and promising therapeutic capabilities in drug delivery and bactericidal skin-inspired dressings.

Cannabinoids in Integumentary Wound Care: A Systematic Review of Emerging Preclinical and Clinical Evidence

This systematic review critically evaluates preclinical and clinical data on the antibacterial and wound healing properties of cannabinoids in integument wounds. Comprehensive searches were conducted across multiple databases, including CINAHL, Cochrane library, Medline, Embase, PubMed, Web of Science, and LILACS, encompassing records up to May 22, 2024. Eighteen studies met the inclusion criteria. Eleven were animal studies, predominantly utilizing murine models (n = 10) and one equine model, involving 437 animals. The seven human studies ranged from case reports to randomized controlled trials, encompassing 92 participants aged six months to ninety years, with sample sizes varying from 1 to 69 patients. The studies examined the effects of various cannabinoid formulations, including combinations with other plant extracts, crude extracts, and purified and synthetic cannabis-based medications administered topically, intraperitoneally, orally, or sublingually. Four animal and three human studies reported complete wound closure. Hemp fruit oil extract, cannabidiol (CBD), and GP1a resulted in complete wound closure in twenty-three (range: 5-84) days with a healing rate of 66-86% within ten days in animal studies. One human study documented a wound healing rate of 3.3 cm2 over 30 days, while three studies on chronic, non-healing wounds reported an average healing time of 54 (21-150) days for 17 patients by oral oils with tetrahydrocannabinol (THC) and CBD and topical gels with THC, CBD, and terpenes. CBD and tetrahydrocannabidiol demonstrated significant potential in reducing bacterial loads in murine models. However, further high-quality research is imperative to fully elucidate the therapeutic potential of cannabinoids in the treatment of bacterial skin infections and wounds. Additionally, it is crucial to delineate the impact of medicinal cannabis on the various phases of wound healing. This study was registered in PROSPERO (CRD42021255413).

Peptide-based strategies for overcoming biofilm-associated infections: a comprehensive review

Biofilms represent resilient microbial communities responsible for inducing chronic infections in human subjects. Given the escalating challenges associated with antibiotic therapy failures in clinical infections linked to biofilm formation, a peptide-based approach emerges as a promising alternative to effectively combat these notoriously resistant biofilms. Contrary to conventional antimicrobial peptides, which predominantly target cellular membranes, antibiofilm peptides necessitate a multifaceted approach, addressing various "biofilm-specific factors." These factors encompass Extracellular Polymeric Substance (EPS) degradation, membrane targeting, cell signaling, and regulatory mechanisms. Recent research endeavors have been directed toward assessing the potential of peptides as potent antibiofilm agents. However, to translate these peptides into viable clinical applications, several critical considerations must be meticulously evaluated during the peptide design process. This review serves to furnish an all-encompassing summary of the pivotal factors and parameters that necessitate contemplation for the successful development of an efficacious antibiofilm peptide.

Two colistin resistance-producing Aeromonas strains, isolated from coastal waters in Zhejiang, China: characteristics, multi-drug resistance and pathogenicity

Introduction

Aeromonas spp. are ubiquitous inhabitants of ecosystems, and many species are opportunistically pathogenic to humans and animals. Multidrug-resistant (MDR) Aeromonas species have been widely detected in hospitals, urban rivers, livestock, and aquatic animals.

Results

In this study, we identified two Aeromonas isolates, namely Aeromonas veronii 0728Q8Av and Aeromonas caviae 1029Y16Ac, from coastal waters in Zhejiang, China. Both isolates exhibited typical biochemical characteristics and conferred MDR to 11 kinds of antibiotics, remaining susceptible to ceftazidime. Whole-genome sequencing revealed that both isolates harbored multiple antibiotic resistance genes (ARGs) and several mobile genetic elements (MGEs) on the chromosomes, each containing a resistance genomic island (GI), a typical class 1 integron, a transposon, and various insertion sequences (ISs). Most ARGs were situated within the multiple resistance GI, which contained a class 1 integron and a transposon in both Aeromonas isolates. Furthermore, a chromosomal mcr-3.16 gene was identified in A. veronii 0728Q8Av, while a chromosomal mcr-3.3 was found in A. caviae 1029Y16Ac. Both mcr-3 variants were not located within but were distanced from the multidrug resistance GI on the chromosome, flanking by multiple ISs. In addition, a mcr-3-like was found adjacent to mcr-3.16 to form a tandem mcr-3.16-mcr-3-like-dgkA structure; yet, Escherichia coli carrying the recombinants of mcr-3-like did not exhibit resistance to colistin. And an incomplete mcr-3-like was found adjacent to mcr-3.3 in A. caviae 1029Y16Ac, suggesting the possibility that mcr-3 variants originated from Aeromonas species. In vivo bacterial pathogenicity test indicated that A. veronii 0728Q8Av exhibited moderate pathogenicity towards infected ayu, while A. caviae 1029Y16Ac was non-virulent.

Discussion

Thus, both Aeromonas species deserve further attention regarding their antimicrobial resistance and pathogenicity.

Advancements of Porphyrin-Derived Nanomaterials for Antibacterial Photodynamic Therapy and Biofilm Eradication

The threat posed by antibiotic-resistant bacteria and the challenge of biofilm formation has highlighted the inadequacies of conventional antibacterial therapies, leading to increased interest in antibacterial photodynamic therapy (aPDT) in recent years. This approach offers advantages such as minimal invasiveness, low systemic toxicity, and notable effectiveness against drug-resistant bacterial strains. Porphyrins and their derivatives, known for their high molar extinction coefficients and singlet oxygen quantum yields, have emerged as crucial photosensitizers in aPDT. However, their practical application is hindered by challenges such as poor water solubility and aggregation-induced quenching. To address these limitations, extensive research has focused on the development of porphyrin-based nanomaterials for aPDT, enhancing the efficacy of photodynamic sterilization and broadening the range of antimicrobial activity. This review provides an overview of various porphyrin-based nanomaterials utilized in aPDT and biofilm eradication in recent years, including porphyrin-loaded inorganic nanoparticles, porphyrin-based polymer assemblies, supramolecular assemblies, metal-organic frameworks (MOFs), and covalent organic frameworks (COFs). Additionally, insights into the prospects of aPDT is offered, highlighting its potential for practical implementation.

Alanazi M, El Yazidi M. Efficient Synthesis, Structural Characterization, Antibacterial Assessment, ADME-Tox Analysis, Molecular Docking and Molecular Dynamics Simulations of New Functionalized Isoxazoles

This work describes the synthesis, characterization, and in vitro and in silico evaluation of the biological activity of new functionalized isoxazole derivatives. The structures of all new compounds were analyzed by IR and NMR spectroscopy. The structures of 4c and 4f were further confirmed by single crystal X-ray and their compositions unambiguously determined by mass spectrometry (MS). The antibacterial effect of the isoxazoles was assessed in vitro against Escherichia coli, Bacillus subtilis, and Staphylococcusaureus bacterial strains. Isoxazole 4a showed significant activity against E. coli and B. subtilis compared to the reference antibiotic drugs while 4d and 4f also exhibited some antibacterial effects. The molecular docking results indicate that the synthesized compounds exhibit strong interactions with the target proteins. Specifically, 4a displayed a better affinity for E. coli, S. aureus, and B. subtilis in comparison to the reference drugs. The molecular dynamics simulations performed on 4a strongly support the stability of the ligand-receptor complex when interacting with the active sites of proteins from E. coli, S. aureus, and B. subtilis. Lastly, the results of the Absorption, Distribution, Metabolism, Excretion and Toxicity Analysis (ADME-Tox) reveal that the molecules have promising pharmacokinetic properties, suggesting favorable druglike properties and potential therapeutic agents.

Application of Mono and Trinuclear Cyclometalated Iridium (III) Complexes in Differential Bacterial Imaging and Antimicrobial Photodynamic Therapy

The application of transition metal complexes for antimicrobial photodynamic therapy (PDT) has emerged as an attractive alternative in mitigating a broad range of bacterial pathogens, including multidrug-resistant pathogens. In view of their photostability, long excited-state lifetimes, and tunable emission properties, transition metal complexes also contribute as bioimaging agents. In the present work, we designed mono and trinuclear cyclometalated iridium (III) complexes to explore their imaging application and antibacterial potential. For this, we used Methicillin-resistant S. aureus (MRSA), the most prevalent of community-associated (CA) multidrug-resistant (MDR) bacteria (CA MDR) and Lactococcus lactis (L. lactis) as Gram-positive while Campylobacter jejuni (C. jejuni) and E. coli as Gram-negative bacteria. In addition to differential bioimaging of these bacteria, we assessed the antibacterial effects of both mono and trinuclear Ir(III) complexes under exposure to 427 nm LED light. The data presented herein strongly suggest better efficacy of trinuclear Ir(III) complex over the mononuclear complex in imparting photoinduced cell death of MRSA. Based on the safety profile of these complexes, we propose that trinuclear cyclometalated iridium(III) complex holds great promise for selective recognition and targeting MDR bacteria with minimal off-target effect.

In vitro evaluation of two novel Escherichia bacteriophages against multiple drug resistant avian pathogenic Escherichia coli

BACKGROUND

In recent years, there has been a growing interest in phage therapy as an effective therapeutic tool against colibacillosis caused by avian pathogenic Escherichia coli (APEC) which resulted from the increasing number of multidrug resistant (MDR) APEC strains.

METHODS

In the present study, we reported the characterization of a new lytic bacteriophage (Escherichia phage AG- MK-2022. Basu) isolated from poultry slaughterhouse wastewater. In addition, the in vitro bacteriolytic activity of the newly isolated phage (Escherichia phage AG- MK-2022. Basu) and the Escherichia phage VaT-2019a isolate PE17 (GenBank: MK353636.1) were assessed against MDR- APEC strains (n = 100) isolated from broiler chickens with clinical signs of colibacillosis.

RESULTS

Escherichia phage AG- MK-2022. Basu belongs to the Myoviridae family and exhibits a broad host range. Furthermore, the phage showed stability under a wide range of temperatures, pH values and different concentrations of NaCl. Genome analysis of the Escherichia phage AG- MK-2022. Basu revealed that the phage possesses no antibiotic resistance genes (ARGs), mobile genetic elements (MGEs), and any E. coli virulence associated genes. In vitro bacterial challenge tests demonstrated that two phages, the Escherichia phage VaT-2019a isolate PE17 and the Escherichia phage AG- MK-2022. Basu exhibited high bactericidal activity against APEC strains and lysed 95% of the tested APEC strains.

CONCLUSIONS

The current study findings indicate that both phages could be suggested as safe biocontrol agents and alternatives to antibiotics for controlling MDR-APEC strains isolated from broilers.

ARGNet: using deep neural networks for robust identification and classification of antibiotic resistance genes from sequences

BACKGROUND

Emergence of antibiotic resistance in bacteria is an important threat to global health. Antibiotic resistance genes (ARGs) are some of the key components to define bacterial resistance and their spread in different environments. Identification of ARGs, particularly from high-throughput sequencing data of the specimens, is the state-of-the-art method for comprehensively monitoring their spread and evolution. Current computational methods to identify ARGs mainly rely on alignment-based sequence similarities with known ARGs. Such approaches are limited by choice of reference databases and may potentially miss novel ARGs. The similarity thresholds are usually simple and could not accommodate variations across different gene families and regions. It is also difficult to scale up when sequence data are increasing.

RESULTS

In this study, we developed ARGNet, a deep neural network that incorporates an unsupervised learning autoencoder model to identify ARGs and a multiclass classification convolutional neural network to classify ARGs that do not depend on sequence alignment. This approach enables a more efficient discovery of both known and novel ARGs. ARGNet accepts both amino acid and nucleotide sequences of variable lengths, from partial (30-50 aa; 100-150 nt) sequences to full-length protein or genes, allowing its application in both target sequencing and metagenomic sequencing. Our performance evaluation showed that ARGNet outperformed other deep learning models including DeepARG and HMD-ARG in most of the application scenarios especially quasi-negative test and the analysis of prediction consistency with phylogenetic tree. ARGNet has a reduced inference runtime by up to 57% relative to DeepARG.

CONCLUSIONS

ARGNet is flexible, efficient, and accurate at predicting a broad range of ARGs from the sequencing data. ARGNet is freely available at https://github.com/id-bioinfo/ARGNet , with an online service provided at https://ARGNet.hku.hk . Video Abstract.

Antimicrobials from endophytes as novel therapeutics to counter drug-resistant pathogens

The rapid increase in antimicrobial resistance (AMR) projects a "global emergency" and necessitates a need to discover alternative resources for combating drug-resistant pathogens or "superbugs." One of the key themes in "One Health Concept" is based on the fact that the interconnected network of humans, the environment, and animal habitats majorly contribute to the rapid selection and spread of AMR. Moreover, the injudicious and overuse of antibiotics in healthcare, the environment, and associated disciplines, further aggravates the concern. The prevalence and persistence of AMR contribute to the global economic burden and are constantly witnessing an upsurge due to fewer therapeutic options, rising mortality statistics, and expensive healthcare. The present decade has witnessed the extensive exploration and utilization of bio-based resources in harnessing antibiotics of potential efficacies. The discovery and characterization of diverse chemical entities from endophytes as potent antimicrobials define an important yet less-explored area in natural product-mediated drug discovery. Endophytes-produced antimicrobials show potent efficacies in targeting microbial pathogens and synthetic biology (SB) mediated engineering of endophytes for yield enhancement, forms a prospective area of research. In keeping with the urgent requirements for new/novel antibiotics and growing concerns about pathogenic microbes and AMR, this paper comprehensively reviews emerging trends, prospects, and challenges of antimicrobials from endophytes and their effective production via SB. This literature review would serve as the platform for further exploration of novel bioactive entities from biological organisms as "novel therapeutics" to address AMR.

Toxicological assessment of photoactivated tetra-cationic porphyrin molecules under white light exposure in a Caenorhabditis elegans model

Photodynamic therapy (PDT) utilizes the potential of photosensitizing substances to absorb light energy and produce reactive oxygen species. Tetra-cationic porphyrins, which have organic or coordination compounds attached to their periphery, are heterocyclic derivatives with well-described antimicrobial and antitumoral properties. This is due to their ability to produce reactive oxygen species and their photobiological properties in solution. Consequently, these molecules are promising candidates as new and more effective photosensitizers with biomedical, environmental, and other biomedical applications. Prior to human exposure, it is essential to establish the toxicological profile of these molecules using in vivo models. In this study, we used Caenorhabditis elegans, a small free-living nematode, as a model for assessing toxic effects and predicting toxicity in preclinical research. We evaluated the toxic effects of porphyrins (neutral and tetra-cationic) on nematodes under dark/light conditions. Our findings demonstrate that tetra-methylated porphyrins (3TMeP and 4TMeP) at a concentration of 3.3 µg/mL (1.36 and 0.93 µM) exhibit high toxicity (as evidenced by reduced survival, development, and locomotion) under dark conditions. Moreover, photoactivated tetra-methylated porphyrins induce higher ROS levels compared to neutral (3TPyP and 4TPyP), tetra-palladated (3PdTPyP and 4PdTPyP), and tetra-platinated (3PtTPyP and 4PtTPyP) porphyrins, which may be responsible for the observed toxic effects.

Rational molecular design converting fascaplysin derivatives to potent broad-spectrum inhibitors against bacterial pathogens via targeting FtsZ

The filamentous temperature-sensitive mutant Z protein (FtsZ), a key player in bacterial cell division machinery, emerges as an attractive target to tackle the plight posed by the ever growing antibiotic resistance over the world. Therefore in this regard, agents with scaffold diversities and broad-spectrum antibacterial activity against Gram-positive and Gram-negative pathogens are highly needed. In this study, a new class of marine-derived fascaplysin derivatives has been designed and synthesized by Suzuki-Miyaura cross-coupling. Some compounds exhibited potent bactericidal activities against a panel of Gram-positive (MIC = 0.024-6.25 μg/mL) and Gram-negative (MIC = 1.56-12.5 μg/mL) bacteria including methicillin-resistant S. aureus (MRSA). They exerted their effects by dual action mechanism via disrupting the integrity of the bacterial cell membrane and targeting FtsZ protein. These compounds stimulated polymerization of FtsZ monomers and bundling of the polymers, and stabilized the resulting polymer network, thus leading to the dysfunction of FtsZ in cell division. In addition, these agents showed negligible hemolytic activity and low cytotoxicity to mammalian cells. The studies on docking and molecular dynamics simulations suggest that these inhibitors bind to the hydrophilic inter-domain cleft of FtsZ protein and the insights obtained in this study would facilitate the development of potential drugs with broad-spectrum bioactivities.

Prevalence of multidrug-resistant bacterial infections in diabetic foot ulcers: A meta-analysis

Multidrug-resistant (MDR) bacterial infections have become increasingly common in recent years due to the increased prevalence of diabetic foot ulcers (DFUs). We carried out a meta-analysis aimed at investigating the prevalence of MDR bacteria isolated from DFUs and analysing the risk factors for MDR bacterial infection in patients with DFUs. The PubMed/Medline, Web of Science, Embase, Cochrane Library, Ovid, Scopus, and ProQuest databases were searched for studies published up to November 2023 on the clinical outcomes of MDR bacteria in DFUs. The main outcome was the prevalence of MDR bacteria in DFUs. A total of 21 studies were included, representing 4885 patients from which 2633 MDR bacterial isolates were obtained. The prevalence of MDR bacteria in DFUs was 50.86% (95% confidence interval (CI): 41.92%-59.78%). The prevalence of MDR gram-positive bacteria (GPB) in DFUs was 19.81% (95% CI: 14.35%-25.91%), and the prevalence of MDR gram-negative bacteria (GNB) in DFUs was 32.84% (95% CI: 26.40%-39.62%). MDR Staphylococcus aureus (12.13% (95% CI: 8.79%-15.91%)) and MDR Enterococcus spp. (3.33% (95% CI: 1.92%-5.07%)) were the main MDR-GPB in DFUs. MDR Escherichia coli, MDR Pseudomonas aeruginosa, MDR Enterobacter spp., MDR Klebsiella pneumoniae, and MDR Proteus mirabilis were the main MDR-GNB in DFUs. The prevalence rates were 6.93% (95% CI: 5.15%-8.95%), 6.01% (95% CI: 4.03%-8.33%), 3.59% (95% CI: 0.42%-9.30%), 3.50% (95% CI: 2.31%-4.91%), and 3.27% (95% CI: 1.74%-5.21%), respectively. The clinical variables of diabetic foot ulcer patients infected with MDR bacteria and non-MDR bacteria in the included studies were analysed. The results showed that peripheral vascular disease, peripheral neuropathy, nephropathy, osteomyelitis, Wagner's grade, previous hospitalization and previous use of antibacterial drugs were significantly different between the MDR bacterial group and the non-MDR bacterial group. We concluded that there is a high prevalence of MDR bacterial infections in DFUs. The prevalence of MDR-GNB was greater than that of MDR-GPB in DFUs. MDR S. aureus was the main MDR-GPB in DFUs, and MDR E. coli was the main MDR-GNB in DFUs. Our study also indicated that peripheral vascular disease, peripheral neuropathy, nephropathy, osteomyelitis, Wagner's grade, previous hospitalization, and previous use of antibacterial drugs were associated with MDR bacterial infections in patients with DFUs.

Preventing biofilm formation and eradicating pathogenic bacteria by Zn doped histidine derived carbon quantum dots

Bacterial infections are of major medical concern due to antibiotic resistance. Carbon quantum dots (CDs) have emerged as potentially excellent biomaterials for multifunctional applications due to their low toxicity, outstanding water solubility, high fluorescence, and high biocompatibility. All of these properties allow CDs to be exceptional biomaterials for inhibiting the growth of bacteria and stopping biofilm formation due to their strong binding affinity, cell wall penetration, and solubilizing biofilm in water. Here, we describe a strategy for one-pot synthesis of histidine-derived zinc-doped N-doped CDs (Zn-NCDs) by a hydrothermal method for inhibiting the growth of both Gram-positive and Gram-negative bacteria without harming mammalian cells. The NCDs and Zn-NCDs showed uniform sizes (∼6 nm), crystallinity, good photostability, high quantum yield (76%), and long decay time (∼5 ns). We also studied their utilization for live cell bio-imaging and the antimicrobial properties towards the Gram-positive Staphylococcus aureus and the Gram-negative Pseudomonas aeruginosa. Importantly, the Zn-NCDs could penetrate the biofilm and bacterial cell wall to effectively inhibit the growth of bacteria and subsequently inhibit biofilm formation. Thus, the structure, chemical composition, and low toxicity properties of the newly-developed Zn-NCDs exemplify a promising novel method for the preparation of nano-level antibacterial drugs.

Nanomaterial-based methods for sepsis management

Sepsis is a serious disease caused by an impaired host immune response to infection, resulting in organ dysfunction, tissue damage and is responsible for high in-hospital mortality (approximately 20%). Recently, WHO documented sepsis as a global health priority. Nevertheless, there is still no effective and specific therapy for clinically detecting sepsis. Nanomaterial-based approaches have appeared as promising tools for identifying bacterial infections. In this review, recent biosensors are introduced and summarized as nanomaterial-based platforms for sepsis management and severe complications. Biosensors can be used as tools for the diagnosis and treatment of sepsis and as nanocarriers for drug delivery. In general, diagnostic methods for sepsis-associated bacteria, biosensors developed for this purpose are presented in detail, and their strengths and weaknesses are discussed. In other words, readers of this article will gain a comprehensive understanding of biosensors and their applications in sepsis management.

Characterization of young infants with fecal carriage of multidrug-resistant Escherichia coli in Southern Taiwan

BACKGROUND

The accelerating prevalence of extended-spectrum β-lactamase (ESBL)-producing and multidrug-resistance (MDR) Escherichia coli(E. coli) become a public health challenge worldwide. This study aimed to discuss the prevalence of drug-resistant E. coli colonization and analyze its risk factors and clinical characteristics among young infants in Southern Taiwan.

METHODS

Stool samples were collected from young infants, aged less than three months, within three days of their hospitalization from September to December 2019 in a tertiary hospital. A questionnaire was designed for parents to complete. E. coli colonies were selected and analyzed for antimicrobial susceptibility. PCR-based multilocus sequence typing was to detect the presence of sequence type ST131 and blaCTX-M genes.

RESULTS

Among 100 enrolled infants, 36% had fecal carriage of E. coli isolates, of which twenty nine (80.5%) were MDR, thirteen (36.1%) were ESBL-producing isolates and five (13.8%) and ten (27.7%) were ST131 and strains carrying CTX-M-14 gene, respectively. Compared to non-ST131 and non-CTX-M-14 gene carrier, isolates of ST131 and CTX-M-14 gene carrier showed a significantly higher resistance rate to cefixime, ceftriaxone, and gentamycin, with p value all <0.05.

CONCLUSION

The prevalence of ESBL-producing and MDR E. coli fecal carriage were both high in young infants. The most common sequence type is ST131, of which all are strains carrying CTX-M-14. Further surveillance and investigation to control for the high prevalence of antimicrobial-resistant E. coli fecal carriage among infants in Taiwan are warranted.

Antimicrobial potential of Streptomyces coeruleofuscus SCJ isolated from microbiologically unexplored garden soil in Northwest Morocco

Research on microorganisms in various biotopes is required to identify new, natural potent molecules. These molecules are essential to control the development of multi-drug resistance (MDR). In the present study, a Streptomyces sp., namely SCJ, was isolated from a soil sample collected from a Moroccan garden. SCJ isolate was identified on the basis of a polyphasic approach, which included cultural, micro-morphological, biochemical, and physiological characteristics. The sequence of the 16S rRNA gene of the SCJ strain showed 99.78% similarity to strains of Streptomyces coeruleofuscus YR-T (KY753282.1). The preliminary screening indicated that the SCJ isolate exhibited activity against Candida albicans ATCC 60,193, Escherichia coli ATCC 25,922, Staphylococcus aureus CECT 976, Staphylococcus aureus ATCC 25,923, Bacillus cereus ATCC 14,579, Pseudomonas aeruginosa ATCC 27,853, as well as various other clinical MDR bacteria and five phytopathogenic fungi. The ethyl acetate extract of the isolated strain demonstrated highly significant (p < 0.05) antimicrobial activity against multi-resistant bacteria and phytopathogenic fungi. The absorption spectral analysis of the ethyl acetate extract of the SCJ isolate obtained showed no absorption peaks characteristic of polyene molecules. Moreover, no hemolytic activity against erythrocytes was observed in this extract. GC-MS analysis of the ethyl acetate extract of the SCJ isolate revealed the presence of 9 volatile compounds including 3,5-Dimethylpyrazole, and pyrrolizidine derivatives (Pyrrolo[1,2-a]pyrazine 1,4-dione, hexahydro-3-(2-methylpropyl)), which could potentially explain the antimicrobial activity demonstrated in this study.

Mapping pathogenic bacteria resistance against common antibiotics and their potential susceptibility to methylated white kidney bean protein

As antibiotics cannot inhibit multidrug-resistant bacteria (MDR), continuous research is mandatory to find other antibacterials from natural resources. Native legume proteins and their modified forms exhibited broad spectra of high antimicrobial activities. Sixteen bacterial isolates were mapped for antibiotic resistance, showing resistance in the range of (58-92%) and (42-92%) in the case of the Gram-negative and Gram-positive bacteria, respectively. White native Phaseolus vulgaris protein (NPP) was isolated from the seeds and methylated (MPP). The MIC range of MPP against 7 MDR bacteria was 10-25 times lower than NPP and could (1 MIC) considerably inhibit their 24 h liquid growth. MPP showed higher antibacterial effectiveness than Gentamycin, the most effective antibiotic against Gram-positive bacteria and the second most effective against Gram-negative bacteria. However, MPP recorded MICs against the seven studied MDR bacteria in the 1-20 µg/mL range, the same for Gentamycin. The combination of Gentamycin and MPP produced synergistic effects against the seven bacteria studied, as confirmed by the Transmission Electron Microscopic images. The antimicrobial activity of MPP against the seven MDR bacteria remained stable after two years of cold storage at 8-10 °C as contrasted to Gentamycin, which lost 20-72% of its antimicrobial effectiveness.

Synthesis and in vitro evaluation of antibacterial and antibiofilm activities of novel triphenylphosphonium-functionalized substituted pyrimidines

The increase in the prevalence of antibiotic-resistant pathogens leads to a decrease in the number of antimicrobial agents for the treatment of infections and prompts researchers to search for new effective antimicrobial drugs. This study reports the synthesis of novel triphenylphosphonium-functionalized substituted pyrimidines and in vitro evaluation of their antibacterial and antibiofilm activity. Most of the synthesized derivatives showed high antibacterial activity (MIC = 0.39-1.56 μg/mL) against the methicillin-resistant strain of S. aureus 222. Compounds 2a and 11 exhibited a high level of antibiofilm activity against S. aureus 222 and E. coli 311. The triphenylphosphonium-containing pyrimidines 11 and 2a reduced S. aureus 222 biofilm formation by 99.1% and 95.8%, respectively. In addition, compound 2a was the most active against E. coli 311 biofilm formation (the biomass decreased by 98.4%).

Dual-mode colorimetric and fluorescence biosensors for the detection of foodborne bacteria

Due to the growing demand for detection technologies, there has been significant interest in the development of integrated dual-modal sensing technologies, which involve combining two signal transduction channels into a single technique, particularly in the context of food safety. The integration of two detection signals not only improves diagnostic performance by reducing assumptions, but also enhances diagnostic functions with increased application flexibility, improved accuracy, and a wider detection linear range. The top two output signals for emerging dual-modal probes are fluorescent and colorimetric, due to their exceptional advantages for real-time sensitive sensing and point-of-care applications. With the rapid progress of nanotechnology and material chemistry, the integrated colorimetric/fluorimetric dual-mode systems show immense potential in sensing foodborne pathogenic bacteria. In this comprehensive review, we present a detailed summary of various colorimetric and fluorimetric dual-modal sensing methods, with a focus on their application in detecting foodborne bacteria. We thoroughly examine the sensing methodologies and the underlying principles of the signal transduction systems, and also discuss the challenges and future prospects for advancing research in this field.

Potential of Flavonoids as Promising Phytotherapeutic Agents to Combat Multidrug-Resistant Infections

BACKGROUND

Considering the limited number of current effective treatments, Multidrug- Resistant (MDR) illnesses have grown to be a serious concern to public health. It has become necessary to look for new antimicrobial drugs because of the emergence of resistance to numerous kinds of antibiotics. The use of flavonoids is one phytotherapeutic strategy that has been researched as a potential remedy for this issue. Secondary plant compounds called flavonoids have been found to have an antibacterial effect against resistant microorganisms.

OBJECTIVE

This review seeks to give readers a glimpse into contemporary studies on flavonoids' potential to fight MDR infections.

METHODS

A systematic search was conducted on electronic databases (PubMed, Scopus, and Google Scholar) using relevant keywords such as flavonoids, MDR infections, antimicrobial activity, and resistance microbes. Studies that investigated the antimicrobial activity of flavonoids against resistant microbes were included in this review.

RESULTS

Most research found that flavonoids have antibacterial efficacy against resistant microorganisms, and some also showed that they have synergistic benefits with traditional antibiotics. The flavonoids quercetin, kaempferol, apigenin, and luteolin were the most often investigated ones. According to research, flavonoids affect microbial gene expression, inhibit microbial enzymes, and disrupt the integrity of microbial cell membranes. Additionally, a few studies have noted the flavonoids' low toxicity and safety.

CONCLUSION

For the treatment of infections that are resistant to many drugs, flavonoids constitute a promising class of phytotherapeutic agents. To develop flavonoid-based treatment methods for treating MDR illnesses and assess the potential of flavonoids as adjuvants to conventional antimicrobial drugs, more study is required.

Discovery of novel tetrahydrobenzothiophene derivatives as MSBA inhibitors for antimicrobial agents

The incidence of infections caused by drug-resistant bacteria has been one of the most serious health threats in the past and is substantially increasing in an alarming rate. Therefore, the development of new antimicrobial agents to combat bacterial resistance effectively is urgent. This study focused on the design and synthesis of 40 novel tetrahydrobenzothiophene amide/sulfonamide derivatives and their antibacterial activities were evaluated. Compounds 2p, 6p, and 6 s exhibited significant inhibitory effects on the growth of bacteria. To assess their safety, the cytotoxicity of the compounds was assessed using human normal liver cells, revealing that compound 6p has lower cytotoxicity. A mouse wound healing experiment demonstrated that compound 6p effectively improved wound infection induced by trauma and accelerated the healing process. Compound 6p holds promise as a potential therapeutic agent for combating bacterial infections.

The current state of phage therapy in livestock and companion animals

In a global context, bacterial diseases caused by pathogenic bacteria have inflicted sustained damage on both humans and animals. Although antibiotics initially appeared to offer an easy treatment for most bacterial infections, the recent rise of multidrug-resistant bacteria, stemming from antibiotic misuse, has prompted regulatory measures to control antibiotic usage. Consequently, various alternatives to antibiotics are being explored, with a particular focus on bacteriophage (phage) therapy for treating bacterial diseases in animals. Animals are broadly categorized into livestock, closely associated with human dietary habits, and companion animals, which have attracted increasing attention. This study highlights phage therapy cases targeting prominent bacterial strains in various animals. In recent years, research on bacteriophages has gained considerable attention, suggesting a promising avenue for developing alternative substances to antibiotics, particularly crucial for addressing challenging bacterial diseases in the future.

In Silico and In Vitro Identification of 1,8-Dihydroxy-4,5-dinitroanthraquinone as a New Antibacterial Agent against Staphylococcus aureus and Enterococcus faecalis

Increasing rates of bacterial resistance to antibiotics are a growing concern worldwide. The search for potential new antibiotics has included several natural products such as anthraquinones. However, comparatively less attention has been given to anthraquinones that exhibit functional groups that are uncommon in nature. In this work, 114 anthraquinones were evaluated using in silico methods to identify inhibitors of the enzyme phosphopantetheine adenylyltransferase (PPAT) of Staphylococcus aureus, Enterococcus faecalis, and Escherichia coli. Virtual screenings based on molecular docking and the pharmacophore model, molecular dynamics simulations, and free energy calculations pointed to 1,8-dihydroxy-4,5-dinitroanthraquinone (DHDNA) as the most promising inhibitor. In addition, these analyses highlighted the contribution of the nitro group to the affinity of this anthraquinone for the nucleotide-binding site of PPAT. Furthermore, DHDNA was active in vitro towards Gram-positive bacteria with minimum inhibitory concentration (MIC) values of 31.25 µg/mL for S. aureus and 62.5 µg/mL for E. faecalis against both antibiotic-resistant isolates and reference strains but was ineffective against E. coli. Experiments on kill-time kinetics indicated that, at the tested concentrations, DHDNA produced bacteriostatic effects on both Gram-positive bacteria. Overall, our results present DHDNA as a potential PPAT inhibitor, showing antibacterial activity against antibiotic-resistant isolates of S. aureus and E. faecalis, findings that point to nitro groups as key to explaining these results.

Targeting bacterial transcription factors for infection control: opportunities and challenges

The rising threat of antibiotic resistance in pathogenic bacteria emphasizes the need for new therapeutic strategies. This review focuses on bacterial transcription factors (TFs), which play crucial roles in bacterial pathogenesis. We discuss the regulatory roles of these factors through examples, and we outline potential therapeutic strategies targeting bacterial TFs. Specifically, we discuss the use of small molecules to interfere with TF function and the development of transcription factor decoys, oligonucleotides that compete with promoters for TF binding. We also cover peptides that target the interaction between the bacterial TF and other factors, such as RNA polymerase, and the targeting of sigma factors. These strategies, while promising, come with challenges, from identifying targets to designing interventions, managing side effects, and accounting for changing bacterial resistance patterns. We also delve into how Artificial Intelligence contributes to these efforts and how it may be exploited in the future, and we touch on the roles of multidisciplinary collaboration and policy to advance this research domain.Abbreviations: AI, artificial intelligence; CNN, convolutional neural networks; DTI: drug-target interaction; HTH, helix-turn-helix; IHF, integration host factor; LTTRs, LysR-type transcriptional regulators; MarR, multiple antibiotic resistance regulator; MRSA, methicillin resistant Staphylococcus aureus; MSA: multiple sequence alignment; NAP, nucleoid-associated protein; PROTACs, proteolysis targeting chimeras; RNAP, RNA polymerase; TF, transcription factor; TFD, transcription factor decoying; TFTRs, TetR-family transcriptional regulators; wHTH, winged helix-turn-helix.

Photochemical outcomes triggered by gold shell-isolated nanorods on bioinspired nanoarchitectonics for bacterial membranes

Boosted by the indiscriminate use of antibiotics, multidrug-resistance (MDR) demands new strategies to combat bacterial infections, such as photothermal therapy (PTT) based on plasmonic nanostructures. PTT efficiency relies on photoinduced damage caused to the bacterial machinery, for which nanostructure incorporation into the cell envelope is key. Herein, we shall unveil the binding and photochemical mechanisms of gold shell-isolated nanorods (AuSHINRs) on bioinspired bacterial membranes assembled as Langmuir and Langmuir-Schaefer (LS) monolayers of DOPE, Lysyl-PG, DOPG and CL. AuSHINRs incorporation expanded the isotherms, with stronger effect on the anionic DOPG and CL. Indeed, FTIR of LS films revealed more modifications for DOPG and CL owing to stronger attractive electrostatic interactions between anionic phosphates and the positively charged AuSHINRs, while electrostatic repulsions with the cationic ethanolamine (DOPE) and lysyl (Lysyl-PG) polar groups might have weakened their interactions with AuSHINRs. No statistical difference was observed in the surface area of irradiated DOPE and Lysyl-PG monolayers on AuSHINRs, which is evidence of the restricted nanostructures insertion. In contrast, irradiated DOPG monolayer on AuSHINRs decreased 4.0 % in surface area, while irradiated CL monolayer increased 3.7 %. Such results agree with oxidative reactions prompted by ROS generated by AuSHINRs photoactivation. The deepest AuSHINRs insertion into DOPG may have favored chain cleavage while hydroperoxidation is the mostly like outcome in CL, where AuSHINRs are surrounding the polar groups. Furthermore, preliminary experiments on Escherichia coli culture demonstrated that the electrostatic interactions with AuSHINRs do not inhibit bacterial growth, but the photoinduced effects are highly toxic, resulting in microbial inactivation.

Prevalence and Characterization of Staphylococcus aureus Isolated from Retail Raw Milk Samples in Chennai, India

Milk is an important source of food, and it is also a nutrient-rich medium, which can harbor multiple microorganisms. Staphylococcus aureus is an important foodborne pathogen in food-producing animals, and there have been many reports on its infection and antimicrobial resistance (AMR), which has significant global public health concerns. This study was designed to isolate, characterize, and analyze the AMR pattern of S. aureus from milk samples collected in Chennai, India. A total of 259 raw milk samples from 3 groups: dairy farms, local vendors, and retail outlets were analyzed, and it was found that 34% (89/259) were positive for S. aureus. Positive isolates were further characterized by pulsed-field gel electrophoresis and isolates recovered from different sources, study areas, and locations showed high genetic diversity with no similarity. The presence of AMR has been further assessed by phenotypic methods as per CLSI-M100 performance standards, and all the isolates were susceptible to ampicillin/sulbactam, mupirocin, and tylosin. Additionally, all of the isolates were resistant to ampicillin. There were 28 isolates categorized as multidrug-resistant, which showed resistance to more than 2-3 classes of antimicrobials. This is the first report of inducible clindamycin resistance and mupirocin sensitivity pattern from S. aureus isolates recovered from milk. This study established the occurrence varied with genetic diversity in the isolates prevalent in the study area and divergence pattern of AMR S. aureus. The AMR in these isolates and with methicillin-resistant S. aureus could pose a serious threat to food safety and economic implications.

The evolution of resistance to synergistic multi-drug combinations is more complex than evolving resistance to each individual drug component

Multidrug antibiotic resistance is an urgent public health concern. Multiple strategies have been suggested to alleviate this problem, including the use of antibiotic combinations and cyclic therapies. We examine how adaptation to (1) combinations of drugs affects resistance to individual drugs, and to (2) individual drugs alters responses to drug combinations. To evaluate this, we evolved multiple strains of drug resistant Staphylococcus epidermidis in the lab. We show that evolving resistance to four highly synergistic combinations does not result in cross-resistance to all of their components. Likewise, prior resistance to one antibiotic in a combination does not guarantee survival when exposed to the combination. We also identify four 3-step and four 2-step treatments that inhibit bacterial growth and confer collateral sensitivity with each step, impeding the development of multidrug resistance. This study highlights the importance of considering higher-order drug combinations in sequential therapies and how antibiotic interactions can influence the evolutionary trajectory of bacterial populations.

Dual cross-linked gellan gum/gelatin-based multifunctional nanocomposite hydrogel scaffold for full-thickness wound healing

Biological macromolecules are excellent materials for wound dressing owing to their similar structure to the extracellular matrix and adjustable physicochemical properties. This research focuses on fabricating biological macromolecule-based hydrogel with desirable antibacterial, antioxidant, controlled drug release, cytocompatibility, and wound healing properties. Herein, different concentrations of nanoceria (NC) and flurbiprofen (FLU) drug-loaded gellan gum/gelatin (GG/Ge) based dual crosslinked (Ionic and EDC/NHS coupling) hydrogels were engineered. All fabricated hydrogels were hydrophilic, biodegradable, good strength, porous, antioxidant, hemocompatible and cytocompatible. Among all, hydrogel loaded with 500 μg/ml NC (GG/Ge/NC@FLU) exhibited desirable antioxidant, antibacterial (killed Staphylococcus aureus and Escherichia coli within 12 h), hemocompatible, cytocompatible, supports oxidative-stressed L929 cell growth and acted as a controlled release matrix for FLU, following Fickian diffusion, Peppas Sahlin and Korsmeyer-Peppas drug release models. Furthermore, nanocomposite hydrogel (GG/Ge/NC@FLU)-treated wounds of rats on day 14 demonstrated significantly higher collagen synthesis, nearly 100 % wound contractions, and efficiently decreased the expression of TNF-α and IL-1 while increasing the production of IL-10 and TNF-ß3, indicating antiinflammatory activity, and effectively reduced the expression of VEGF gene indicating effective angiogenesis than all other controls. In conclusion, the fabricated multifunctional GG/Ge/NC@FLU nanocomposite hydrogel shows promising potential for effectively treating full-thickness wound healing in a rat model.

Multidrug-resistant Escherichia coli isolated from patients and surrounding hospital environments in Bangladesh: A molecular approach for the determination of pathogenicity and resistance

Extended spectrum β-lactamase producing Escherichia coli (ESBL E. coli) is a primary concern for hospital and community healthcare settings, often linked to an increased incidence of nosocomial infections. This study investigated the characteristics of ESBL E. coli isolated from hospital environments and clinical samples. In total, 117 ESBL E. coli isolates were obtained. The isolates were subjected to molecular analysis for the presence of resistance and virulence genes, antibiotic susceptibility testing, quantitative adherence assay, ERIC-PCR for phylogenetic analysis and whole genome sequencing of four highly drug resistant isolates. Out of the 117 isolates, 68.4% were positive for blaCTX-M, 39.3% for blaTEM, 30.8% for blaNDM-1, 13.7% for blaOXA and 1.7% for blaSHV gene. Upon screening for diarrheagenic genes, no isolates were found to harbour any of the tested genes. In the case of extraintestinal pathogenic E. coli (ExPEC) virulence factors, 7.6%, 11%, 5.9%, 4.3% and 21.2% of isolates harbored the focG, kpsMII, sfaS, afa and iutA genes, respectively. At a temperature of 25°C, 14.5% of isolates exhibited strong biofilm formation with 21.4% and 28.2% exhibiting moderate and weak biofilm formation respectively, whereas 35.9% were non-biofilm formers. On the other hand at 37°C, 2.6% of isolates showed strong biofilm formation with 3.4% and 31.6% showing moderate and weak biofilm formation respectively, whereas, 62.4% were non-biofilm formers. Regarding antibiotic susceptibility testing, all isolates were found to be multidrug-resistant (MDR), with 30 isolates being highly drug resistant. ERIC-PCR resulted in 12 clusters, with cluster E-10 containing the maximum number of isolates. Hierarchical clustering and correlation analysis revealed associations between environmental and clinical isolates, indicating likely transmission and dissemination from the hospital environment to the patients. The whole genome sequencing of four highly drug resistant ExPEC isolates showed the presence of various antimicrobial resistance genes, virulence factors and mobile genetic elements, with isolates harbouring the plasmid incompatibility group IncF (FII, FIB, FIA). The sequenced isolates were identified as human pathogens with a 93.3% average score. This study suggests that ESBL producing E. coli are prevalent in the healthcare settings of Bangladesh, acting as a potential reservoir for AMR bacteria. This information may have a profound effect on treatment, and improvements in public healthcare policies are a necessity to combat the increased incidences of hospital-acquired infections in the country.

Establishment and Validation of Models for the Risk of Multi-Drug Resistant Bacteria Infection and Prognosis in Elderly Patients with Pulmonary Infection: A Multicenter Retrospective Study

Purpose

The aim of this study was to establish risk prediction and prognosis models for multidrug-resistant bacterial infections (MDRB) in elderly patients with pulmonary infections in a multicenter setting.

Patients and Methods

This study is a retrospective cohort analysis in Anhui province of China. Data dimension reduction and feature selection were performed using the lasso regression model. Multifactorial regression analysis to identify risk factors associated with MDRB infection and prognosis. The relevant risks of each patient in the prognostic training cohort were scored based on prognostic independent risk factors. Subsequently, patients were classified into high-risk and low-risk groups, and survival differences were compared between them. Finally, models were established based on independent risk factors for infection, risk groups, and independent prognostic factors, and were presented on nomograms. The predictive accuracy of the model was assessed using corresponding external validation set data.

Results

The study cohort comprised 994 elderly patients with pulmonary infection. Multivariate analysis revealed that endotracheal intubation, previous antibiotic use beyond 2 weeks, and concurrent respiratory failure or cerebrovascular disease were independent risk factors associated with the incidence of MDRB infection. Cox regression analysis identified respiratory failure, malnutrition, an APACHE II score of at least 20, and higher blood creatinine levels as independent prognostic risk factors. The models were validated using an external validation dataset from multiple centers, which demonstrated good diagnostic ability and a good fit with a fair benefit.

Conclusion

In conclusion, our study provides an appropriate and generalisable assessment of risk factors affecting infection and prognosis in patients with MDRB, contributing to improved early identification of patients at higher risk of infection and death, and appropriately guiding clinical management.

Natural nanogels crosslinked with S-benzyl-L-cysteine exhibit potent antibacterial activity

Biofilm-forming bacteria E. coli and P. aeruginosa have both exhibited resistance against multiple antibiotics in clinical settings. To find a solution, researchers have turned to antibacterial structurally modified from natural materials that are harmless to the human body. Among these is DNA, a natural polymer composed of deoxyribose that when treated with HCl exposes its aldehyde groups and produces DNA-HCl. Here, we crosslinked these aldehyde groups with the primary amines in S-benzyl-L-cysteine (SBLC) using a Schiff reaction to obtain DNA-HCl-SBLC. We additionally treated alginate acid (AA) with EDAC, obtaining AA-EDAC, and substituting it with SBLC to produce AA-SBLC. We incorporated the above reactions with an emulsification process to produce nanogels (NGs) that were verified to be spherical and possessing benzene rings successfully grafted onto DNA-HCl and AA-EDAC. These natural NGs were proven to be negatively charged through zeta potential analysis and presented low cytotoxicity toward normal cells in cell organoid viability assays. These SBLC-modified polymers provided better inhibition of bacterial growth than those without modification. Moreover, after incubation with SBLC-modified NGs, bacteria expressed intracellular recA or pvdA in a dose-dependent manner, which was consistent with SEM data from damaged bacteria. Out of four tested NGs, DNA-HCl-SBLC NGs suppressed P. aeruginosa-induced sepsis most effectively and extended the lifespan of C. elegans. This study provides an alternative clinical solution to antibiotics-resistant biofilm strains.

Antibiotic resistance in periodontitis patients: A systematic scoping review of randomized clinical trials

OBJECTIVES

The objective of the study was to evaluate the prevalence and proportions of antibiotic-resistant species in periodontitis patients.

METHODS

A systematic scoping review of randomized clinical trials (RCTs) was conducted using the PRISMA extension for scoping reviews involving different databases. MeSH terms and keywords were provided to examine only RCTs with antibiotic-resistant results that included at least 3 months of follow-up of systematically healthy patients diagnosed with periodontitis and treated with systemic or local antibiotics adjunctive to subgingival debridement. RCTs that managed participants surgically, duplicate publications, and investigations implemented on animals were discarded.

RESULTS

Six RCTs were chosen. These studies included 465 patients. Most investigations observed that while Aggregatibacter actinomycetemcomitans, Tannerella forsythia, and Porphyromonas gingivalis had low resistance to amoxicillin, microorganisms in many sites showed resistance to tetracycline, metronidazole, and azithromycin pretreatment. A. actinomycetemcomitans showed high resistance to tetracycline pre- and post-therapy. The proportion of antibiotic-resistant samples augmented rapidly after the prescription of antibiotics in all test groups. The percentage of antibiotic-resistant microorganisms decreased over time; at the end of the follow-up period, resistance levels were close to baseline levels.

CONCLUSIONS

Adjunctive local and systemic antibiotic treatment temporarily increased the antibiotic resistance of subgingival microorganisms; nonetheless, many bacteria remained susceptible to antibiotics during their administration.

Comparative De Novo and Pan-Genome Analysis of MDR Nosocomial Bacteria Isolated from Hospitals in Jeddah, Saudi Arabia

Multidrug-resistant (MDR) bacteria are one of the most serious threats to public health, and one of the most important types of MDR bacteria are those that are acquired in a hospital, known as nosocomial. This study aimed to isolate and identify MDR bacteria from selected hospitals in Jeddah and analyze their antibiotic-resistant genes. Bacteria were collected from different sources and wards of hospitals in Jeddah City. Phoenix BD was used to identify the strains and perform susceptibility testing. Identification of selected isolates showing MDR to more than three classes on antibiotics was based on 16S rRNA gene and whole genome sequencing. Genes conferring resistance were characterized using de novo and pan-genome analyses. In total, we isolated 108 bacterial strains, of which 75 (69.44%) were found to be MDR. Taxonomic identification revealed that 24 (32%) isolates were identified as Escherichia coli, 19 (25.3%) corresponded to Klebsiella pneumoniae, and 17 (22.67%) were methicillin-resistant Staphylococcus aureus (MRSA). Among the Gram-negative bacteria, K. pneumoniae isolates showed the highest resistance levels to most antibiotics. Of the Gram-positive bacteria, S. aureus (MRSA) strains were noticed to exhibit the uppermost degree of resistance to the tested antibiotics, which is higher than that observed for K. pneumoniae isolates. Taken together, our results illustrated that MDR Gram-negative bacteria are the most common cause of nosocomial infections, while MDR Gram-positive bacteria are characterized by a wider antibiotic resistance spectrum. Whole genome sequencing found the appearance of antibiotic resistance genes, including SHV, OXA, CTX-M, TEM-1, NDM-1, VIM-1, ere(A), ermA, ermB, ermC, msrA, qacA, qacB, and qacC.

The functional repertoire of AmpR in the AmpC β-lactamase high expression and decreasing β-lactam and aminoglycosides resistance in ESBL Citrobacter freundii

Citrobacter freundii is characterized by AmpC β-lactamases that develop resistance to β-lactam antibiotics. The production of extended-spectrum β-lactamase (ESBL) is substantially high in Escherichia coli, C. freundii, Enterobacter cloacae, and Serratia marcescens, but infrequently explored in C. freundii. The present investigation characterized the ESBL C. freundii and delineated the genes involved in decrease in antibiotics resistance. We used the VITEK-2 system and Analytical Profile Index (API) kit to characterize and identify the Citrobacter isolates. The mRNA level of AmpC and AmpR was determined by RT-qPCR, and gel-shift assay was performed to evaluate protein-DNA binding. Here, a total of 26 Citrobacter strains were isolated from COVID-19 patients that showed varying degrees of antibiotic resistance. We examined and characterized the multidrug resistant C. freundii that showed ESBL production. The RT-qPCR analysis revealed that the AmpC mRNA expression is significantly high followed by a high level of AmpR. We sequenced the AmpC and AmpR genes that revealed the AmpR has four novel mutations in comparison to the reference genome namely; Thr64Ile, Arg86Ser, Asp135Val, and Ile183Leu while AmpC remained intact. The ΔAmpR mutant analysis revealed that the AmpR positively regulates oxidative stress response and decreases β-lactam and aminoglycosides resistance. The AmpC and AmpR high expression was associated with resistance to tazobactam, ampicillin, gentamicin, nitrofurantoin, and cephalosporins whereas AmpR deletion reduced β-lactam and aminoglycosides resistance. We conclude that AmpR is a positive regulator of AmpC that stimulates β-lactamases which inactivate multiple antibiotics.

Antibody-Functionalized Polymer Nanoparticles for Targeted Antibiotic Delivery in Models of Pathogenic Bacteria Infecting Human Macrophages

The efficacy of antibody-functionalized poly(d,l-lactide-co-glycolide) (PLGA) nanoparticles (NPs), prepared by nanoprecipitation, carrying rifampicin (RIF) against planktonic, sessile, and intracellular Staphylococcus aureus and Escherichia coli is reported here. A biotinylated anti-S. aureus polyclonal antibody, which binds to structural antigens of the whole bacterium, was functionalized on the surface of RIF-loaded PLGA-based NPs by using the high-affinity avidin-biotin complex. This general strategy allows the binding of commercially available biotinylated antibodies. Coculture models of S. aureus ATCC 25923 and Escherichia coli S17 were used to demonstrate the preferential selectivity of the antibody-functionalized NPs against the Gram-positive bacterium only. At 0.2 μg/mL, complete S. aureus eradication was observed for the antibody-functionalized RIF-loaded NPs, whereas only a 5-log reduction was observed for the nontargeted RIF-loaded NPs. S. aureus is a commensal facultative pathogen having part of its live cycle intracellularly in both phagocytic and nonphagocytic cells. Those intracellular bacterial persisters, named small colony variants, have been postulated as reservoirs of relapsed episodes of infection and consequent treatment failure. At 0.5 μg/mL, the RIF-loaded NPs reduced in 2-log intracellular S. aureus-infecting human macrophages. The ability of those antibody-functionalized nanoparticles to prevent biofilm formation or to reduce the bacterial burden in already-formed mature biofilms is also reported here using S. aureus and E. coli single and cocultured biofilms. In the prevention of S. aureus biofilm formation, the antibody-functionalized NPs exerted a superior inhibition of bacterial growth (up to 2 logs) compared to the nonfunctionalized ones. This study demonstrates the selectivity of the synthesized immunonanoparticles and their antimicrobial efficacy in different scenarios, including planktonic cultures, sessile conditions, and even against intracellular infective pathogens.

Natural Product as an Inner Responsive Molecule Inhibits Antimicrobial-Resistant Staphylococcus aureus via Synergism

Multidrug-resistant Staphylococcus aureus, a Gram-positive bacterium that causes several difficult-to-treat human infections, is a considerable threat to global healthcare. We hypothesize that there exist inner responsive molecules (IRMs) which can function synergistically with antibiotics to restore the sensitivity of resistant bacteria to existing antibiotics without inducing new antibiotic resistance. An investigation of the extracts of the Chinese medicinal herb Piper betle L. led to the isolation of six benzoate esters, BO-1-BO-6. Among these, BO-1 as a distinct IRM displayed considerable synergism by potentiating antibacterial activity against five antibiotic-resistant S. aureus strains. Mechanistic studies demonstrated that BO-1 acted as a suppressing drug resistance IRM via inhibiting efflux activity. A combination of BO-1 with ciprofloxacin significantly inhibited resistance to this antibiotic and reversed its resistance in the S. aureus strain. Furthermore, BO-1 effectively enhanced the activity of ciprofloxacin against the efflux fluoroquinolone-resistant S. aureus strain SA1199B that caused infection in two animal models and significantly decreased the inflammatory factors IL-6 and C-reactive protein of the infected mice, thereby showing the practice utility of this approach.

Current Status of Probiotics in European Sea Bass Aquaculture as One Important Mediterranean and Atlantic Commercial Species: A Review

European sea bass production has increased in recent decades. This increase is associated with an annually rising demand for sea bass, which encourages the aquaculture industries to increase their production to meet that demand. However, this intensification has repercussions on the animals, causing stress that is usually accompanied by dysbiosis, low feed-conversion rates, and immunodepression, among other factors. Therefore, the appearance of pathogenic diseases is common in these industries after immunodepression. Seeking to enhance animal welfare, researchers have focused on alternative approaches such as probiotic application. The use of probiotics in European sea bass production is presented as an ecological, safe, and viable alternative in addition to enhancing different host parameters such as growth performance, feed utilization, immunity, disease resistance, and fish survival against different pathogens through inclusion in fish diets through vectors and/or in water columns. Accordingly, the aim of this review is to present recent research findings on the application of probiotics in European sea bass aquaculture and their effect on growth performance, microbial diversity, enzyme production, immunity, disease resistance, and survival in order to help future research.

Synthetic Pathways to Non-Psychotropic Phytocannabinoids as Promising Molecules to Develop Novel Antibiotics: A Review

Due to the rapid emergence of multi drug resistant (MDR) pathogens against which current antibiotics are no longer functioning, severe infections are becoming practically untreatable. Consequently, the discovery of new classes of effective antimicrobial agents with novel mechanism of action is becoming increasingly urgent. The bioactivity of Cannabis sativa, an herbaceous plant used for millennia for medicinal and recreational purposes, is mainly due to its content in phytocannabinoids (PCs). Among the 180 PCs detected, cannabidiol (CBD), Δ⁸ and Δ⁹-tetrahydrocannabinols (Δ⁸-THC and Δ⁹-THC), cannabichromene (CBC), cannabigerol (CBG), cannabinol (CBN) and some of their acidic precursors have demonstrated from moderate to potent antibacterial effects against Gram-positive bacteria (MICs 0.5-8 µg/mL), including methicillin-resistant Staphylococcus aureus (MRSA), epidemic MRSA (EMRSA), as well as fluoroquinolone and tetracycline-resistant strains. Particularly, the non-psychotropic CBG was also capable to inhibit MRSA biofilm formation, to eradicate even mature biofilms, and to rapidly eliminate MRSA persiter cells. In this scenario, CBG, as well as other minor non-psychotropic PCs, such as CBD, and CBC could represent promising compounds for developing novel antibiotics with high therapeutic potential. Anyway, further studies are necessary, needing abundant quantities of such PCs, scarcely provided naturally by Cannabis plants. Here, after an extensive overture on cannabinoids including their reported antimicrobial effects, aiming at easing the synthetic production of the necessary amounts of CBG, CBC and CBD for further studies, we have, for the first time, systematically reviewed the synthetic pathways utilized for their synthesis, reporting both reaction schemes and experimental details.

Epidemiology of pathogens and antimicrobial resistance of nosocomial urinary tract infections in patients with spinal cord injuries in China: A systematic review and meta-analysis

CONTEXT

Despite a high urinary tract infection (UTI) rate in spinal cord injured patents in China, there is limited evidence on the epidemiological character of that.

OBJECTIVE

The purpose of our article was to characterize the distribution of pathogens of UTI patients with spinal cord injuries (SCI) and the resistance profile of pathogens.

METHODS

A literature search of six electronic databases was carried out to identify the incidence, pathogen distribution, and drug resistance of UTI after SCI based on our inclusion and exclusion criteria. Meta-analysis was carried out using R 4.0.2 software; a subgroup analysis was performed by the year 2012.

RESULTS

We screened 1110 eligible studies, 33 were included in our final review. A total of 7271 bacterial species were included in our studies; 6092 were gram-negative (81.13% [76.83-85.11]) and 1003 were gram-positive (14.89% [11.70-18.38]). Before 2012, E. coli (45.43%) was the predominant isolated pathogen, followed by Klebsiella (7.49%) and Enterococcus (6.01%). After 2012, E. coli (50.23%) was the main pathogen, followed by Klebsiella (12.47%) and Proteus (6.88%). E. coli was more likely to be resistant to Levofloxacin, Amikacin, sulfonamides, 4th-generation cephalosporins and Nitrofurantoin before 2012 (81.8% vs. 62.9%, 32.0% vs. 7.6%, 81.3% vs. 61.6%, 81.8% vs. 24.1%, 33.5% vs. 5.1%), whereas E. coli was more frequently resistant to Inhibitor-resistant β-lactamas after 2012 (56.3% vs. 34.0%). K. pneumoniae was more likely to be resistant to Aztreonam, Amikacin before 2012 (80.0% vs. 39.8%, 48.1% vs. 19.0%). P. aeruginosa presented a high resistance to Levofloxacin, Inhibitor-resistant β-lactamas after 2012 (61.8% vs. 35.6%, 59.1% vs. 5.7%).

CONCLUSIONS

UTI in patients with SCI in China were mainly caused by gram-negative bacteria. We observed a remarkable modification in resistance profiles of pathogen distribution before 2012 and after 2012, which suggests reasonable control of the use of antibiotics has a positive effectiveness on resistance profiles.

Current State of Knowledge Regarding WHO High Priority Pathogens-Resistance Mechanisms and Proposed Solutions through Candidates Such as Essential Oils: A Systematic Review

Combating antimicrobial resistance (AMR) is among the 10 global health issues identified by the World Health Organization (WHO) in 2021. While AMR is a naturally occurring process, the inappropriate use of antibiotics in different settings and legislative gaps has led to its rapid progression. As a result, AMR has grown into a serious global menace that impacts not only humans but also animals and, ultimately, the entire environment. Thus, effective prophylactic measures, as well as more potent and non-toxic antimicrobial agents, are pressingly needed. The antimicrobial activity of essential oils (EOs) is supported by consistent research in the field. Although EOs have been used for centuries, they are newcomers when it comes to managing infections in clinical settings; it is mainly because methodological settings are largely non-overlapping and there are insufficient data regarding EOs' in vivo activity and toxicity. This review considers the concept of AMR and its main determinants, the modality by which the issue has been globally addressed and the potential of EOs as alternative or auxiliary therapy. The focus is shifted towards the pathogenesis, mechanism of resistance and activity of several EOs against the six high priority pathogens listed by WHO in 2017, for which new therapeutic solutions are pressingly required.

Efflux pumps and microbial biofilm formation

Biofilm-related infections are resistant forms of pathogens that are regarded as a medical problem, particularly due to the spread of multiple drug resistance. One of the factors associated with biofilm drug resistance is the presence of various types of efflux pumps in bacteria. Efflux pumps also play a role in biofilm formation by influencing Physical-chemical interactions, mobility, gene regulation, quorum sensing (QS), extracellular polymeric substances (EPS), and toxic compound extrusion. According to the findings of studies based on efflux pump expression analysis, their role in the anatomical position within the biofilm will differ depending on the biofilm formation stage, encoding gene expression level, the type and concentration of substrate. In some cases, the function of the efflux pumps can overlap with each other, so it seems necessary to accurate identify the efflux pumps of biofilm-forming bacteria along with their function in this process. Such studies will help to choose treatment strategy, at least in combination with antibiotics. Furthermore, if the goal of treatment is an efflux pump manipulation, we should not limit it to inhibition.

Cinnamon Oil-Loaded Nanoliposomes with Potent Antibacterial and Antibiofilm Activities

Despite recent scientific advances, the global load of bacterial disease remains high and has been established against a backdrop of increasing antimicrobial resistance. Therefore, there is a pressing need for highly effective and natural antibacterial agents. In the present work, the antibiofilm effect provided by essential oils was evaluated. Of these, cinnamon oil extract showed potent antibacterial and antibiofilm activities against Staphylococcus aureus at an MBEC of 75.0 µg/mL. It was revealed that benzyl alcohol, 2-propenal-3-phenyl, hexadecenoic acid, and oleic acid were the major components of the tested cinnamon oil extract. In addition, the interaction between the cinnamon oil and colistin showed a synergistic effect against S. aureus. Cinnamon oil that had been combined with colistin was encapsulated by liposomes to enhance the essential oil's chemical stability, demonstrating a particle size of 91.67 nm, a PDI of 0.143, a zeta potential of -0.129 mV, and an MBEC of 50.0 µg/mL against Staphylococcus aureus. Scanning electron microscopy was employed to observe the morphological changes in the Staphylococcus aureus biofilm that was treated with the encapsulated cinnamon oil extract/colistin. As a natural and safe option, cinnamon oil exhibited satisfactory antibacterial and antibiofilm performance. The application of liposomes further improved the stability of the antibacterial agents and extended the essential oil release profile.

Morphological, biological, and genomic characterization of Klebsiella pneumoniae phage vB_Kpn_ZC2

BACKGROUND

Bacteriophages (phages) are one of the most promising alternatives to traditional antibiotic therapies, especially against multidrug-resistant bacteria. Klebsiella pneumoniae is considered to be an opportunistic pathogen that can cause life-threatening infections. Thus, this study aims at the characterization of a novel isolated phage vB_Kpn_ZC2 (ZCKP2, for short).

METHODS

The phage ZCKP2 was isolated from sewage water by using the clinical isolate KP/08 as a host strain. The isolated bacteriophage was purified and amplified, followed by testing of its molecular weight using Pulse-Field Gel Electrophoresis (PFGE), transmission electron microscopy, antibacterial activity against a panel of other Klebsiella pneumoniae hosts, stability studies, and whole genome sequencing.

RESULTS

Phage ZCKP2 belongs morphologically to siphoviruses as indicated from the Transmission Electron Microscopy microgram. The Pulsed Field Gel Electrophoresis and the phage sequencing estimated the phage genome size of 48.2 kbp. Moreover, the absence of lysogeny-related genes, antibiotic resistance genes, and virulence genes in the annotated genome suggests that phage ZCKP2 is safe for therapeutic use. Genome-based taxonomic analysis indicates that phage ZCKP2 represents a new family that has not been formally rated yet. In addition, phage ZCKP2 preserved high stability at different temperatures and pH values (-20 - 70 °C and pH 4 - 9). For the antibacterial activity, phage ZCKP2 maintained consistent clear zones on KP/08 bacteria along with other hosts, in addition to effective bacterial killing over time at different MOIs (0.1, 1, and 10). Also, the genome annotation predicted antibacterial lytic enzymes. Furthermore, the topology of class II holins was predicted in some putative proteins with dual transmembrane domains that contribute significantly to antibacterial activity. Phage ZCKP2 characterization demonstrates safety and efficiency against multidrug-resistant K. pneumoniae, hence ZCKP2 is a good candidate for further in vivo and phage therapy clinical applications.