Link Between Antibiotic Persistence and Antibiotic Resistance in Bacterial Pathogens

Unveiling the potential of bioslurry and biogenic ZnO nanoparticles formulation as significant bionanofertilizer by ameliorating rhizospheric microbiome of Vigna radiata

Advancements in nanotechnology, particularly the use of bionanofertilizers, show promise for sustainable agriculture by enhancing soil health and reducing reliance on conventional fertilizers. This study explored the impact of a bioslurry and biogenic zinc oxide (ZnO) nanoparticle formulation on microbial diversity in the rhizosphere of Vigna radiata (mung bean) using 16S rRNA sequencing. High-quality reads from both untreated and treated soil samples revealed a dominance of Archaea, though its proportion was reduced in the treated sample (66% in untreated, 58% in treated). The treated soil showed an increased abundance of beneficial bacterial phyla, including Acidobacteria (+ 6%), Actinobacteria (+ 2%), and Firmicutes (+ 2%). Notably, Acidobacteria-6 and Chloroacidobacteria, essential for nutrient cycling, were enriched in treated soil. Alpha diversity (Chao1 and Shannon indices) was lower in treated samples, indicating selective enhancement of beneficial microbes. Functional analyses like Phylogenetic Investigation of Communities by Reconstruction of Unobserved States (PICRUSt) and Statistical Analysis of Taxonomic and Functional Profiles (STAMP) analysis highlighted increased pathways related to motility, chemotaxis, and metabolic processes in the treated soil. These findings suggest that ZnO NPs and bioslurry treatment at 250 ppm improves soil microbial composition and functional attributes, supporting its potential as a bionanofertilizer for soil health restoration and enhanced plant growth.

Unveiling polysaccharides of Houttuynia cordata Thunb.: Extraction, purification, structure, bioactivities, and structure-activity relationships

BACKGROUND

Houttuynia cordata Thunb. is a plant valued for both its culinary and medicinal properties, utilized in the prevention and treatment of various ailments. Houttuynia cordata Thunb. polysaccharides (HCP) exhibit a range of biological activities, including antioxidant, immune modulation, anti-inflammatory, antiviral, maintenance of gut homeostasis, and antibacterial effects, rendering them significant for research in ethnopharmacology.

PURPOSE

This review consolidates recent advancements in the extraction, isolation, purification, structural characteristics, and biological activities of Houttuynia cordata Thunb. polysaccharides, while exploring the structure-activity relationships of HCP and the prospects for future research, thereby providing valuable insights for its drug development.

METHODS

Relevant literature regarding the extraction, isolation, purification, structural analysis, and biological activities of Houttuynia cordata Thunb. polysaccharides was sourced from databases such as PubMed, ScienceDirect, Web of Science, and CNKI.

RESULTS

Houttuynia cordata Thunb. is a perennial herbaceous plant that thrives in shady, humid environments and exhibits a semi-prostrate growth form. As a traditional herb used for heat-clearing and detoxification, it is effective against various conditions, including cholera, dysentery, and hemorrhoids. Houttuynia cordata Thunb. polysaccharides are key active components that can be extracted through various methods, including water extraction, enzymatic extraction, ultrasonic-assisted extraction, acid extraction, and alkali extraction. Structural analyses of the extracted and purified polysaccharides were conducted, focusing on their monosaccharide composition, molecular weight, and glycosidic bond structure. Additionally, pharmacological investigations reveal that Houttuynia cordata Thunb. polysaccharides possess a variety of biological activities, including antioxidant, immune modulation, antiviral, anti-inflammatory, maintenance of gut homeostasis, and antibacterial effects.

CONCLUSIONS

Research on HCP has established a solid foundation regarding its monosaccharide composition, molecular weight, and glycosidic linkages, with substantial documentation of its biological activities, including antioxidant, immune-regulating, and antiviral properties. However, investigations into the structural modification of HCP and the correlation between its structure and biological activity remain relatively underexplored. Additionally, the extraction yield of HCP is significantly affected by the choice of extraction and purification methods, highlighting the necessity for further optimization of extraction protocols.

Changes in the serum phospholipid profile of neuroborreliosis patients, foresters, and patients subjected to long-term therapy according to ILADS methods

The aim of the study was the assessment of changes in the serum phospholipid profile patients with Lyme neuroborreliosis (NB), asymptomatic people after frequent tick bites and patients after long-term multidrug therapy against B.burgdorferi. LC-QTOF-MS/MS platform was used to identify changes in serum phospholipid profile of 37 persons. The results demonstrate differences PL profile among patients with Lyme borreliosis (LB), people frequently exposed to tick bites and patients treated with long-term multidrug therapy compared to healthy subjects. Significant differences in SM, LPC, PI, and PC content of NB patients discriminate this group of patients from the other groups, have potential diagnostic value, and can be used for the development of more effective diagnostic tools. The finding that the phospholipid profile of foresters is similar to healthy people, suggests the existence of adaptive mechanisms that are currently difficult to explain but are interesting from the perspective of future research.

Factors Influencing Antibiotic Prescribing and Antibiotic Resistance Awareness Among Primary Care Physicians in Poland

Introduction: Antibiotic resistance is a major public health problem in Europe. Most antibiotics are sold only by prescription in Poland, and it is mainly up to physicians to decide whether to start antibiotic treatment. Therefore, we analyzed the factors influencing the prescribing of antibiotics for upper respiratory tract infections by primary care physicians in Poland, attitudes toward antibiotic resistance, and knowledge of the principles of antibiotic use. Methods: We conducted a CAWI (Computer-Assisted Web Interview) survey, carried out using a proprietary survey distributed online. Results: A total of 528 doctors participated in the study. The result of the physical examination and additional tests, as well as the recommendations of scientific societies are the most important in deciding whether to start antibiotic therapy. Patient pressure (p < 0.011) and workload (p = 0.021) significantly influenced the decision to prescribe an antibiotic among primary care physicians and physicians in the course of specialization, who fear of legal consequences (p < 0.001). The habits of other physicians (p < 0.001) working at the same facility appeared to be additionally important. Conclusions: The decision to implement antibiotic therapy in upper respiratory tract infections is influenced by several factors that depend on the doctor (including place of work and seniority) and the patient (clinical symptoms, expectation of antibiotic prescription). The physician's level of knowledge contributes to reducing antibiotic prescribing. Considering the factors associated with the level of knowledge and awareness, together with a high prevalence of self-medication with antibiotics in Polish population, there is a strong need to design educational interventions aimed at reducing inappropriate antibiotic prescribing and preventing antibiotic resistance in Poland.

Efficacy of carbonyl cyanide-3-chlorophenylhydrazone in combination with antibiotics against Mycobacterium abscessus

Given the intrinsic resistance of Mycobacterium abscessus to a wide range of conventional antibiotics, it is urgent to explore new therapeutic approaches to manage this infection effectively. Carbonyl cyanide 3-chlorophenylhydrazone (CCCP), a proton pump inhibitor, has shown good bacteriostatic activity against M. abscessus. This study aimed to determine its synergistic antimicrobial effects when combined with commonly used antibiotics. The M. abscessus reference strain and 39 clinical isolates were collected. The minimum inhibitory concentration and fractional inhibitory concentration index were determined for the combined treatment using CCCP with various antibiotics including clarithromycin, amikacin, linezolid, bedaquiline, and clofazimine. A time-killing assay was used to measure the effect of the combined drug regimens quantitatively. The simultaneous use of CCCP with traditional antibiotics shows a synergistic effect across a wide range, significantly boosting the ability to inhibit the growth of M. abscessus throughout its growth phases. When CCCP is used in combination with clarithromycin, amikacin, and linezolid, it produces a synergistic effect on both the standard strain and most clinical isolates. When CCCP is paired with bedaquiline and clofazimine, it exhibits additive effects. Moreover, high levels of CCCP in combination with other antibiotics were found to rapidly eradicate the bacteria. The use of CCCP as a potential treatment for M. abscessus infections shows promising results, especially when combined with other antibiotics to achieve a potent bactericidal effect.IMPORTANCEMycobacterium abscessus poses a significant public health threat due to its intrinsic resistance to a broad spectrum of conventional antibiotics. This resistance necessitates urgently exploring novel therapeutic strategies to effectively combat infections caused by this pathogen. Our previous research has identified carbonyl cyanide-3-chlorophenylhydrazone (CCCP) as a potent direct antimicrobial agent against M. abscessus and as an enhancer of clarithromycin activity. Our results demonstrate that the concurrent administration of CCCP with traditional antibiotics exhibits a synergistic effect across a wide range, which could be crucial for overcoming the challenges posed by M. abscessus infections. Furthermore, the use of high concentrations of CCCP in combination with other antibiotics was found to rapidly eliminate M. abscessus, suggesting a potential therapeutic advantage. These insights not only advance our understanding of antimicrobial synergy but also hold promise for the development of more effective treatment regimens against drug-resistant M. abscessus infections.

CSF-1R blockade to alleviate azithromycin mediated immunosuppression in a mouse model of intracellular infection

Colony Stimulating Factor-1 Receptor (CSF-1R) signalling plays an important role in maturation, differentiation and activation of macrophages. Apposite generation and activation of macrophage phenotypes and subsequent adaptive immune response against any infection is decisive for a positive disease outcome. Antibiotic therapy is imperative for treating bacterial infections however antibiotics have off-target effects on host immune-cells. These effects could either be contextually beneficial or harmful and could potentially aid generation of infection persistence and antimicrobial resistance (AMR) via host immunosuppression. We had recently reported the immunosuppressive-mechanism of azithromycin-induced increased CSF-1R expression on murine-macrophages and bacterial-persistence in Balb/c model of intracellular infection. We further wanted to explore the molecular-mechanism behind these observations and tested GW2580-mediated CSF-1R blockade before azithromycin treatment during S. flexneri induced intracellular infection. In the presented study, we report that the azithromycin alters the protein expression or phosphorylation of transcription-factors ERK1/2, P38, AKT1, STAT3, STAT6, and EGR2 that are involved in macrophage polarisatoin and also take part in CSF-1R signalling pathways. Intrestingly, CSF-1R blockade using GW2580 abrogated or reversed the azithromycin-induced up- or down-regulated expression or phosphorylation of ERK1/2, P38, AKT1, STAT3, STAT6, and EGR2. We further validated our results in Balb/c model of S. flexneri infection. Intrestingly, the CSF-1R blocker and azithromycin treated mice showed batter recovery than the azithromycin alone treated mice and hence we report the aftermath of GW2580 with azithromycin treatment on disease and immunological outcome of an intracellular infection caused by Shigella flexneri.

Dynamic interaction of antibiotic resistance between plant microbiome and organic fertilizers: sources, dissemination, and health risks

Antibiotic resistance is a global health problem driven by the irrational use of antibiotics in different areas (such as agriculture, animal farming, and human healthcare). Sub-lethal concentrations of antibiotic residues impose selective pressure on environmental, plant-associated, and human microbiome leading to the emergence of antibiotic-resistant bacteria (ARB). This review summarizes all sources of antibiotic resistance in agricultural soils (including manure, sewage sludge, wastewater, hospitals/pharmaceutical industry, and bioinoculants). The factors (such as the physicochemical properties of soil, root exudates, concentration of antibiotic exposure, and heavy metals) that facilitate the transmission of resistance in plant microbiomes are discussed. Potential solutions for effective measures and control of antibiotic resistance in the environment are also hypothesized. Manure exhibits the highest antibiotics load, followed by hospital and municipal WW. Chlortetracycline, tetracycline, and sulfadiazine have the highest concentrations in the manure. Antibiotic resistance from organic fertilizers is transmitted to the plant microbiome via horizontal gene transfer (HGT). Plant microbiomes serve as transmission routes of ARB and ARGS to humans. The ingestion of ARB leads to human health risks (such as ineffectiveness of medication, increased morbidity, and mortality).

RBProkCNN: Deep learning on appropriate contextual evolutionary information for RNA binding protein discovery in prokaryotes

RNA-binding proteins (RBPs) are central to key functions such as post-transcriptional regulation, mRNA stability, and adaptation to varied environmental conditions in prokaryotes. While the majority of research has concentrated on eukaryotic RBPs, recent developments underscore the crucial involvement of prokaryotic RBPs. Although computational methods have emerged in recent years to identify RBPs, they have fallen short in accurately identifying prokaryotic RBPs due to their generic nature. To bridge this gap, we introduce RBProkCNN, a novel machine learning-driven computational model meticulously designed for the accurate prediction of prokaryotic RBPs. The prediction process involves the utilization of eight shallow learning algorithms and four deep learning models, incorporating PSSM-based evolutionary features. By leveraging a convolutional neural network (CNN) and evolutionarily significant features selected through extreme gradient boosting variable importance measure, RBProkCNN achieved the highest accuracy in five-fold cross-validation, yielding 98.04% auROC and 98.19% auPRC. Furthermore, RBProkCNN demonstrated robust performance with an independent dataset, showcasing a commendable 95.77% auROC and 95.78% auPRC. Noteworthy is its superior predictive accuracy when compared to several state-of-the-art existing models. RBProkCNN is available as an online prediction tool (https://iasri-sg.icar.gov.in/rbprokcnn/), offering free access to interested users. This tool represents a substantial contribution, enriching the array of resources available for the accurate and efficient prediction of prokaryotic RBPs.

Longitudinal Microbiome Investigations Reveal Core and Growth-Associated Bacteria During Early Life Stages of Scylla paramamosain

In animals, growth and development are strongly correlated with the gut microbiota. The gut of the economically important marine crab (Scylla paramamosain) harbors a diverse microbial community, yet its associations with the surrounding environment, growth performance, and developmental stages remain obscure. In this study, we first characterized stage-specific microbiomes and shifts in the contributions of live feed and water via SourceTracker. We observed decreased microbial diversity and increased priority effects along zoea stages. Psychobacter was identified as the core genus, whereas Lactobacillus was the hub genus connecting different stages. Second, microbial correlations with various stage-specific growth traits were observed under interventions generating enhanced (probiotic mixture enrichment), normal (control), and reduced (antibiotic treatment) microbiomes. By combining machine learning regression and bioinformatics analysis, we identified four candidate growth performance-associated probiotics belonging to Rhodobacterales, Sulfitobacter, Confluentimicrobium, and Lactobacillus, respectively. Our study interpreted the dynamics and origins of the Scylla paramamosain zoea microbiome and underscored the importance of optimizing potential probiotics to increase growth performance during early life stages in marine invertebrates for effective larviculture.

Study on the correlation between abdominal infection and psychological stress in children based on nucleic acid detection

BACKGROUND

Diagnosing and treating abdominal infection in children remains a challenge. Nucleic acid detection, as a rapid and accurate diagnosis tool, has great significance in this field.

AIM

To investigate the diagnosis and treatment of abdominal infection by nucleic acid detection and its possible correlation with psychological stress in children.

METHODS

A total of 50 pediatric patients diagnosed with abdominal infections between September 2020 and July 2021 were included in this study. Intra-abdominal pus samples were collected for pathogen culture, drug susceptibility testing, and broad-spectrum bacterial nucleic acid testing. Psychological stress, anxiety, depression, and coping styles were assessed using the coping with a disease (CODI) scale.

RESULTS

Based on susceptibility testing, a regimen of cefazoxime, piperacillin/tazobactam, and metronidazole or ornidazole achieved 100% effectiveness in treating appendicitis. Psychological assessments revealed a positive correlation between pressure level and both anxiety (r = 0.324, P = 0.001) and depressive disorders (r = 0.325, P < 0.001). Acceptance and distancing as coping strategies were negatively correlated with anxiety and depression, while negative emotional responses were strongly associated with increased anxiety (r = 0.574, P < 0.001) and depression (r = 0.511, P = 0.001). Coping strategies such as illusion and escape showed no significant correlation with emotional outcomes.

CONCLUSION

Nucleic acid testing helps in the diagnosis of abdominal infections in children, and also focuses on children's mental health.

Polysaccharides of natural products alleviate antibiotic-associated diarrhea by regulating gut microbiota: a review

Antibiotic-associated diarrhea (AAD) is diarrhea caused by disturbances in intestinal microbiota and metabolism following inappropriate use of antibiotics. With the over-reliance on antibiotics, the incidence of AAD is increasing worldwide. Recently, the role of probiotics and prebiotic preparations in the prevention and treatment of AAD has received increasing attention. Various prebiotics can not only reduce the incidence of AAD, but also effectively shorten the course of the disease and alleviate the symptoms. Notably, many polysaccharides derived from plants and fungi are a class of biologically active and rich prebiotics with great potential to alleviate AAD. Therefore, this review aims to summarize the latest research on natural product polysaccharides to alleviate antibiotic-associated diarrhea by modulating the gut microbiota. It provides a theoretical basis for exploring the mechanism of natural product modulation of gut microbiota to alleviate AAD, and provides a reference for further development of active prebiotics.

Prussian-Blue-Nanozyme-Enhanced Simultaneous Immunochromatographic Control of Two Relevant Bacterial Pathogens in Milk

Salmonella typhimurium and Listeria monocytogenes are relevant foodborne bacterial pathogens which may cause serious intoxications and infectious diseases in humans. In this study, a sensitive immunochromatographic analysis (ICA) for the simultaneous detection of these two pathogens was developed. For this, test strips containing two test zones with specific monoclonal antibodies (MAb) against lipopolysaccharides of S. typhimurium and L. monocytogenes and one control zone with secondary antibodies were designed, and the double-assay conditions were optimized to ensure high analytical parameters. Prussian blue nanoparticles (PBNPs) were used as nanozyme labels and were conjugated with specific MAbs to perform a sandwich format of the ICA. Peroxidase-mimic properties of PBNPs allowed for the catalytic amplification of the colorimetric signal on test strips, enhancing the assay sensitivity. The limits of detection (LODs) of Salmonella and Listeria cells were 2 × 102 and 7 × 103 cells/mL, respectively. LODs were 100-fold less than those achieved due to the ICA based on the traditional gold label. The developed double ICA was approbated for the detection of bacteria in cow milk samples, which were processed by simple dilution by buffer before the assay. For S. typhimurium and L. monocytogenes, the recoveries from milk were 86.3 ± 9.8 and 118.2 ± 10.5% and correlated well with those estimated by the enzyme-linked immunosorbent assay as a reference method. The proposed approach was characterized by high specificity: no cross-reactivity with other bacteria strains was observed. The assay satisfies the requirements for rapid tests: a full cycle from sample acquisition to result assessment in less than half an hour. The developed ICA has a high application potential for the multiplex detection of other foodborne pathogens.

Assessing pediatric antibiotic knowledge and practices among community pharmacists in Palestine: implications for antibiotic use and resistance

BACKGROUND

Antibiotics are widely used in the pediatric population, and their inappropriate use contributes to antibiotic resistance, which is a growing concern in developing countries. Therefore, this national cross-sectional study aimed to assess community pharmacists' knowledge, attitudes and practices regarding appropriate antibiotic use and dosing in pediatric patients and to explore the barriers to such use in Palestine.

METHODS

A questionnaire-based survey was conducted among community pharmacists on the West Bank, Palestine, from September 2022 to March 2023. The survey assessed the pharmacists' sociodemographic characteristics; knowledge, practices, and attitudes toward antibiotic use; and understanding of antibiotic dosing. The data were analyzed using descriptive statistics, and the factors affecting pharmacists' knowledge were evaluated.

RESULTS

The study included 301 community pharmacists, with an average age of 30.06 years, who were primarily female (75.1%). The majority of the pharmacists (80.1%) correctly believed that antibiotics are effective against bacterial infections. However, 18.3% believed that antibiotics are effective against viruses. While 61.8% knew that antibiotics kill germs, 32.0% were unaware that not all antibiotics require refrigeration. Furthermore, 67.8% were aware that antibiotics do not speed up recovery from diarrhea. Over 99% of the participants recognized that antibiotic resistance developed due to various resistant mechanisms. The majority (78.7%) believed that each infection needed a different antibiotic. Pharmacists demonstrated reasonable knowledge of antibiotic dosing in case scenarios. Knowledge was positively correlated with years of experience (P = 0.001).

CONCLUSIONS

This study revealed that community pharmacy professionals have a good understanding of antibiotic usage in pediatric patients. The findings suggest that professional expertise and quality training improve healthcare services. However, the results may not be universally applicable, as identifying knowledge gaps is necessary to help with the development of focused interventions. Therefore, ongoing educational initiatives, awareness campaigns and antibiotic stewardship programs are recommended.

Decoding Bacterial Persistence: Mechanisms and Strategies for Effective Eradication

The ability of pathogenic bacteria to evade antibiotic treatment is an intricate and multifaceted phenomenon. Over the years, treatment failure among patients due to determinants of antimicrobial resistance (AMR) has been the focal point for the research and development of new therapeutic agents. However, the survival of bacteria by persisting under antibiotic stress has largely been overlooked. Bacterial persisters are a subpopulation of sensitive bacterial cells exhibiting a noninheritable drug-tolerant phenotype. They are linked to the recalcitrance of infections in healthcare settings, in turn giving rise to AMR variants. The importance of bacterial persistence in recurring infections has been firmly recognized. Fundamental work over the past decade has highlighted numerous unique tolerance factors contributing to the persister phenotype in many clinically relevant pathogens. This review summarizes contributing factors that could aid in developing new strategies against bacterial antibiotic persisters.

Ovotransferrin, an alternative and potential protein for diverse food and nutritional applications

Ovotransferrin(OVT)is a protein found in many types of egg white and has a wide range of functional properties. It has 50% homology with human/bovine lactoferrin, and is expected to be one of the most important alternative proteins for use in food and nutritional applications. This paper mainly reviews the structural characteristics and chemical properties of OVT, as well as its extraction and purification methods. It also systematically describes the various biological activities of OVT and its applications in food and medical industries. The challenges and limitations in the research of OVT were suggested. This review recommends some possible methods such as nanoparticle carriers and microencapsulation to improve the bioavailability and stability of OVT. In addition, this review highlights several strategies to overcome the limitations of OVT in terms of preparation and purification. This review systematically summarizes the recent advances in OVT and will provide guidance for the its development for food and nutritional applications.

Cerium Dioxide-Dextran Nanocomposites in the Development of a Medical Product for Wound Healing: Physical, Chemical and Biomedical Characteristics

PURPOSE OF THE STUDY

the creation of a dextran coating on cerium oxide crystals using different ratios of cerium and dextran to synthesize nanocomposites, and the selection of the best nanocomposite to develop a nanodrug that accelerates quality wound healing with a new type of antimicrobial effect.

MATERIALS AND METHODS

Nanocomposites were synthesized using cerium nitrate and dextran polysaccharide (6000 Da) at four different initial ratios of Ce(NO3)3x6H2O to dextran (by weight)-1:0.5 (Ce0.5D); 1:1 (Ce1D); 1:2 (Ce2D); and 1:3 (Ce3D). A series of physicochemical experiments were performed to characterize the created nanocomposites: UV-spectroscopy; X-ray phase analysis; transmission electron microscopy; dynamic light scattering and IR-spectroscopy. The biomedical effects of nanocomposites were studied on human fibroblast cell culture with an evaluation of their effect on the metabolic and proliferative activity of cells using an MTT test and direct cell counting. Antimicrobial activity was studied by mass spectrometry using gas chromatography-mass spectrometry against E. coli after 24 h and 48 h of co-incubation.

RESULTS

According to the physicochemical studies, nanocrystals less than 5 nm in size with diffraction peaks characteristic of cerium dioxide were identified in all synthesized nanocomposites. With increasing polysaccharide concentration, the particle size of cerium dioxide decreased, and the smallest nanoparticles (<2 nm) were in Ce2D and Ce3D composites. The results of cell experiments showed a high level of safety of dextran nanoceria, while the absence of cytotoxicity (100% cell survival rate) was established for Ce2D and C3D sols. At a nanoceria concentration of 10-2 M, the proliferative activity of fibroblasts was statistically significantly enhanced only when co-cultured with Ce2D, but decreased with Ce3D. The metabolic activity of fibroblasts after 72 h of co-cultivation with nano composites increased with increasing dextran concentration, and the highest level was registered in Ce3D; from the dextran group, differences were registered in Ce2D and Ce3D sols. As a result of the microbiological study, the best antimicrobial activity (bacteriostatic effect) was found for Ce0.5D and Ce2D, which significantly inhibited the multiplication of E. coli after 24 h by an average of 22-27%, and after 48 h, all nanocomposites suppressed the multiplication of E. coli by 58-77%, which was the most pronounced for Ce0.5D, Ce1D, and Ce2D.

CONCLUSIONS

The necessary physical characteristics of nanoceria-dextran nanocomposites that provide the best wound healing biological effects were determined. Ce2D at a concentration of 10-3 M, which stimulates cell proliferation and metabolism up to 2.5 times and allows a reduction in the rate of microorganism multiplication by three to four times, was selected for subsequent nanodrug creation.

A bismuth-based double-network hydrogel-mediated synergistic photothermal-chemodynamic therapy for accelerated wound healing

Multidrug-resistant bacterial infections present a significant challenge to wound healing. Non-antibiotic approaches such as photothermal therapy (PTT) and chemodynamic therapy (CDT) are promising but have suboptimal anti-bacterial efficacy. Herein, we developed a green bismuth-based double-network hydrogel (Bi@P-Cu) as a PTT/CDT synergistic platform for accelerated drug-resistant bacteria-infected wound healing. Bismuth (Bi) nanoparticles fabricated using a microwave method were used as a highly efficient and biocompatible PTT agent while the integration of a small amount of CDT agent Cu2+ endowed the hydrogel with excellent mechanical and self-healing properties, markedly increased photothermal efficiency, promoted cell migration ability, and negligible toxicity. Importantly, PTT enhanced the production of hydroxyl radicals in CDT and the destruction of bacterial cell membranes, which in turn enhanced the thermal sensitivity of bacteria. This synergistic anti-bacterial effect, together with the demonstrated capability to promote angiogenesis and anti-inflammation as well as enhanced fibroblast proliferation, led to accelerated wound healing in a full-thickness mouse model of resistant bacterial infection. This study provides an effective and safe strategy to eliminate drug-resistant bacteria and accelerate wound healing through green, non-antibiotic, double-network hydrogel-mediated synergistic PTT and CDT.

Antibacterial agents and the fight against antibiotic resistance: A real-world evidence analysis of consumption and spending by an Italian healthcare company

INTRODUCTION

The escalating bacterial resistance stands as an increasingly pertinent concern, particularly in the post-pandemic era where the use of antibiotics appears to be relentlessly surging, giving rise to profound apprehensions. The substantial utilization of last-generation penicillins and cephalosporins is anticipated to imminently result in the emergence of superbugs for which therapeutic solutions will be scarce.

METHODS

An analysis of antibiotic consumption in the hospital setting has been conducted in an Italian healthcare organization. Querying the internal management system facilitated the calculation of indicators and assessment of prescription trends.

RESULTS

A comparison has been made between the first half of 2023 and the first half of 2022, to highlight the exponential growth in the consumption of beta-lactam antibiotics, with consumption doubling compared to the previous year's semester. Overall, considering the prescription averages, there is a prescribing growth of +29% concerning hospitalization and +28% concerning hospital discharge. However, it should be noted that the consumption of certain antibiotics such as sulphonamides and trimethoprim (-103.00%), tetracyclines (-54.00%), macrolides, lincosamides and streptogramins (-50.00%) and colistin (-13.00%) decreased.

CONCLUSION

This real-world evidence analysis aimed to support the justified and comprehensible global concerns regarding bacterial resistance. The extensive consumption of antibiotics will inevitably lead to the development of increasingly drug-resistant bacteria for which no antibiotic may be efficacious. National programs addressing antibiotic resistance and the awareness of all healthcare personnel must be accorded the utmost priority to enhance consumption data and, consequently, safeguard future human survival.

Expression of Staphylococcus aureus translation elongation factor P is regulated by a stress-inducible promotor

Translation elongation factor P, expressed by the efp gene, is a conserved protein closely related to bacterial virulence and environmental stress regulation responses, however, little is known about the efp gene expression regulations. Here, the strain of Staphylococcus aureus subsp. aureus NCTC 8325 was taken as the research object and cultured under different conditions, including different culture temperatures, pH, and antibiotics, to study the expression of the efp gene in S. aureus by qRT-PCR, the results showed that the expression of the efp gene is upregulated under high temperature (40 °C), acidic (pH 5.4) or alkaline (pH 9.4) culture conditions, but upregulated early and downregulated later under the conditions of 0.5 MIC antibiotics (chloramphenicol at the final concentration of 2 μg/mL and vancomycin at the final concentration of 0.25 μg/mL), indicating that the efp promoter in S. aureus is inducible. The efp promoter sequence and structure in S. aureus were predicted by bioinformatics methods, and the predicted promoter was validated by constructing a promoter-probe vector and a series of promoter mutants, the results showed that the efp promoter sequence in S. aureus, named Pro, located in 1,548,179-1,548,250 of the S. aureus genome (NC_007795.1), and the sequence of - 10 element is CCTTATAGT, - 35 element is TTTACT. The results above could lay a foundation for screening transcription factors involved in the expression of the efp gene and then exploring the transcriptional regulation mechanism of EF-P in S. aureus.

A stochastic approach for modelling the in-vitro effect of osmotic stress on growth dynamics and persistent cell formation in Listeria monocytogenes

Persistent bacteria (or persisters) can be defined as a microbial subpopulation that, exposed to bactericidal treatment, is killed more slowly than the rest of the population they are part of. They stochastically originate in response to environmental stressors or spontaneously without external signals. When transferred into a fresh medium, persisters can resume active replication although they spend more time adapting to the new conditions remaining in the lag phase longer. They were studied for decades for their ability to survive antibiotic treatments while studies on their formation in food and potential impact on their safety are lacking. The most common food preservation techniques may act as stressors that trigger the formation of persistent bacteria able to survive bactericidal treatments and grow later in foods during storage. This study aimed to investigate a possible relationship between exposure to different salt concentrations (osmotic stress) and the amount of persisters triggered in a strain of Listeria monocytogenes. Furthermore, we described this phenomenon from a mathematical perspective through predictive microbiology models commonly used in the food field. The lag time distribution of a L. monocytogenes ATCC 7644 strain grown in broth with additional 2 %, 4 % and 6 % NaCl was evaluated using the software ScanLag. It uses office scanners to automatically record the colony growth on agar plates and evaluate the frequency distribution of their appearance times (lag phase) by automated image analysis. The same broth cultures were diluted to equalize salt concentration and transferred into a fresh broth to evaluate how the previous salt exposure impacted their growth kinetics. The observed growth curves were reproduced using predictive models in which the mean duration of the lag phase of the whole population took into account the occurrence of persisters with a longer lag phase. The models were solved first using a deterministic approach and then a stochastic one introducing a stochastic term that mimics the variability of lag phase duration due to the persisters occurrence. Results showed that the growth of L. monocytogenes in broth with additional NaCl might trigger the formation of persistent cells whose number increased consistently with salt concentrations. The proposed predictive approach reproduced the observed real curves in strong agreement, especially through the stochastic resolution of the models. Persistence is currently a neglected bacterial defence strategy in the food sector but the persisters' formation during production cannot be excluded; therefore, further insights on the topic are certainly desirable.

Effects of Dietary Terminalia chebula Extract on Growth Performance, Immune Function, Antioxidant Capacity, and Intestinal Health of Broilers

Terminalia chebula extract (TCE) has many physiological functions and is potentially helpful in maintaining poultry health, but its specific effect on the growth of broilers is not yet known. This research investigated the effects of dietary Terminalia chebula extract (TCE) supplementation on growth performance, immune function, antioxidant capacity, and intestinal health in yellow-feathered broilers. A total of 288 one-day-old yellow-feathered broilers were divided into four treatment groups (72 broilers/group), each with six replicates of 12 broilers. The broilers were given a basal diet of corn-soybean meal supplemented with 0 (control), 200, 400, and 600 mg/kg TCE for 56 d. The results demonstrated that, compared with the basal diet, the addition of TCE significantly increased (linear and quadratic, p < 0.05) the final body weight and overall weight gain and performance and decreased (linear and quadratic, p < 0.05) the feed-to-gain ratio in the overall period. Dietary TCE increased (linear, p < 0.05) the levels of IgM, IL-4, and IL-10 and decreased (linear and quadratic, p < 0.05) the level of IL-6 in the serum. Dietary TCE increased (linear and quadratic, p < 0.05) the levels of IL-2 and IL-4, decreased (linear and quadratic, p < 0.05) the level of IL-1β, and decreased (linear, p < 0.05) the level of IL-6 in the liver. Dietary TCE increased (linear and quadratic, p < 0.05) the level of IgM and IL-10, increased (linear, p < 0.05) the level of IgG, and decreased (linear and quadratic, p < 0.05) the levels of IL-1β and IL-6 in the spleen. Supplementation with TCE linearly and quadratically increased (p < 0.05) the catalase, superoxide dismutase, glutathione peroxidase, and total antioxidant capacity activities while decreasing (p < 0.05) the malonic dialdehyde concentrations in the serum, liver, and spleen. TCE-containing diets for broilers resulted in a higher (linear and quadratic, p < 0.05) villus height, a higher (linear and quadratic, p < 0.05) ratio of villus height to crypt depth, and a lower (linear and quadratic, p < 0.05) crypt depth compared with the basal diet. TCE significantly increased (linear, p < 0.05) the acetic and butyric acid concentrations and decreased (quadratic, p < 0.05) the isovaleric acid concentration. Bacteroidaceae and Bacteroides, which regulate the richness and diversity of microorganisms, were more abundant and contained when TCE was added to the diet. In conclusion, these findings demonstrate that supplementing broilers with TCE could boost their immune function, antioxidant capacity, and gut health, improving their growth performance; they could also provide a reference for future research on TCE.

Defying the odds: Determinants of the antimicrobial response of Salmonella Typhi and their interplay

Salmonella Typhi, the invasive serovar of S. enterica subspecies enterica, causes typhoid fever in healthy human hosts. The emergence of antibiotic-resistant strains has consistently challenged the successful treatment of typhoid fever with conventional antibiotics. Antimicrobial resistance (AMR) in Salmonella is acquired either by mutations in the genomic DNA or by acquiring extrachromosomal DNA via horizontal gene transfer. In addition, Salmonella can form a subpopulation of antibiotic persistent (AP) cells that can survive at high concentrations of antibiotics. These have reduced the effectiveness of the first and second lines of antibiotics used to treat Salmonella infection. The recurrent and chronic carriage of S. Typhi in human hosts further complicates the treatment process, as a remarkable shift in the immune response from pro-inflammatory Th1 to anti-inflammatory Th2 is observed. Recent studies have also highlighted the overlap between AP, persistent infection (PI) and AMR. These incidents have revealed several areas of research. In this review, we have put forward a timeline for the evolution of antibiotic resistance in Salmonella and discussed the different mechanisms of the same availed by the pathogen at the genotypic and phenotypic levels. Further, we have presented a detailed discussion on Salmonella antibiotic persistence (AP), PI, the host and bacterial virulence factors that can influence PI, and how both AP and PI can lead to AMR.

Comparison and Analysis of Antibiotic Consumption in Two Italian Hospital Settings in Relation to the Fight of Antimicrobial Resistance

Introduction: The emergence and spread of drug-resistant pathogens due to the improper use of antibiotics have become increasingly apparent in recent years. Objective: This retrospective comparative analysis aimed to assess and compare antibiotic prescription trends in Italy across two different regions based on geographic area and healthcare structure. One region represents a large hospital institution, while the other represents a populous local Italian health agency. The study also examined the impact of documented antibiotic stewardship programs and efforts to promote responsible antibiotic use at all levels, in alignment with international goals. Antibiotic consumption data were collected from the Umberto I Polyclinic Hospital and the ASL Napoli 3 South Local Health Agency. Methods: To compare consumption between regions, a standardized comparison using the Defined Daily Dose (DDD) was employed. The internal management system of each healthcare facility records all prescriptions and drug dispensations, and these data were extrapolated for this retrospective study. Results: A comparative assessment between the first half of 2022 and 2023 (January-June) highlighted a significant increase in beta-lactam antibiotic consumption, showing a twofold rise compared to the previous year's term. Regarding prescription averages, there was a noticeable increase of +29.00% in hospitalizations and +28.00% in hospital discharges within the ASL Napoli 3 South. Conversely, at Policlinico Umberto I, there was a marginal increase of +1.60% in hospitalizations and a decrease of -7.40% in hospital discharges. Conclusions: The study offers valuable insights into expenditure patterns and antibiotic consumption, underscoring the need for enhanced prescribing practices and awareness campaigns to address the issue of antibiotic resistance. The findings stress the importance of implementing international guidelines to combat the growing threat of antibiotic resistance and ensure the effective management of infectious diseases.

Synthesis and antibacterial effects of silver nanoparticles (AgNPs) against multi-drug resistant bacteria

BACKGROUND

The emergence of the global problem of multi-drug resistant bacteria (MDR) is closely related to the improper use of antibiotics, which gives birth to an urgent need for antimicrobial innovation in the medical and health field. Silver nanoparticles (AgNPs) show significant antibacterial potential because of their unique physical and chemical properties. By accurately regulating the morphology, size and surface properties of AgNPs, the antibacterial properties of AgNPs can be effectively enhanced and become a next generation antibacterial material with great development potential.

OBJECTIVE

The detection of the inhibitory effect of AgNPs on MDR provides more possibilities for the research and development of new antimicrobial agents.

METHODS

Promote the formation of AgNPs by redox reaction; determine the minimum inhibitory concentration (MIC) of AgNPs to bacteria by broth microdilution method; evaluate the killing efficacy of AgNPs against multi-drug-resistant bacteria by plate counting; evaluate the inhibitory effect of AgNPs on biofilm construction by crystal violet staining; study the drug resistance of bacteria by gradually increasing the concentration of AgNPs; and detect the toxicity of AgNPs to cells by CCK-8 method.

RESULTS

AgNPs has a significant bactericidal effect on a variety of drug-resistant bacteria. After exposure to AgNPs solution for 12 hours, the number of E. coli decreased sharply, and S. aureus was basically eliminated after 16 hours. In particular, AgNPs showed stronger inhibition against Gram-negative bacteria. In addition, AgNPs can effectively hinder the formation of bacterial biofilm, and its inhibitory effect increases with the increase of AgNPs solution concentration. When AgNPs is used for a long time, the development of bacterial resistance to it is slow. From the point of view of safety, AgNPs has no harmful effects on organisms and has biosafety.

CONCLUSION

AgNPs can inhibit MDR, and the bacteriostatic ability of Gram-negative bacteria is higher than that of Gram-positive bacteria. It can also inhibit the formation of bacterial biofilm, avoid drug resistance and reduce cytotoxicity.

Cranberry, but not D-mannose and ibuprofen, prevents against uropathogenic Escherichia coli-induced cell damage and cell death in MDCK cells

Introduction

The main function of the urinary tract is to form an impermeable barrier against urinary solutes and bacteria. However, this barrier can be compromised by urinary tract infections, most commonly caused by uropathogenic Escherichia coli (UPEC). This can result in damage to the epithelial barrier, leading to decreased epithelial thickness, loss of tight junctions, loss of epithelial integrity, and apoptosis. Due to the rise in antimicrobial resistance, there is worldwide interest in exploring non-antibiotic agents as alternative therapy.

Methods

Using the Madin-Darby canine kidney (MDCK) cell line, a widely accepted epithelial cell model for the urinary tract, and the UPEC strain UTI89, this paper aimed to investigate the impact of UPEC on cell integrity, permeability, and barrier functions, and determine whether cranberry, D-mannose and ibuprofen could counteract the effects induced by UPEC. Furthermore, the study examined the protective potential of these agents against UPEC-induced increase in reactive oxygen species (ROS) production and programmed death-ligand 1 (PD-L1) expression.

Results

The results demonstrated that UTI89 caused a marked reduction in cell viability and monolayer integrity. Cranberry (3 mg/mL) was protective against these changes. In addition, cranberry exhibited protective effects against UPEC-induced damage to cell barrier integrity, escalation of oxidative stress, and UPEC/TNFα-triggered PD-L1 expression. However, no effect was observed for D-mannose and ibuprofen in alleviating UPEC-induced cell damage and changes in ROS and PD-L1 levels.

Conclusion

Overall, cranberry, but not D-mannose or ibuprofen, has a protective influence against UPEC associated damage in urinary epithelial cells.

Enhanced Antimicrobial Activity through Synergistic Effects of Cold Atmospheric Plasma and Plant Secondary Metabolites: Opportunities and Challenges

The emergence of antibiotic resistant microorganisms possesses a great threat to human health and the environment. Considering the exponential increase in the spread of antibiotic resistant microorganisms, it would be prudent to consider the use of alternative antimicrobial agents or therapies. Only a sustainable, sustained, determined, and coordinated international effort will provide the solutions needed for the future. Plant secondary metabolites show bactericidal and bacteriostatic activity similar to that of conventional antibiotics. However, to effectively eliminate infection, secondary metabolites may need to be activated by heat treatment or combined with other therapies. Cold atmospheric plasma therapy is yet another novel approach that has proven antimicrobial effects. In this review, we explore the physiochemical mechanisms that may give rise to the improved antimicrobial activity of secondary metabolites when combined with cold atmospheric plasma therapy.

Founding of the culture collection of antibiotic-resistant strains of zoonotic bacteria in the Russian Federation

Background and Aim

The main purpose of a national bioresource center is to standardize, centralize, preserve, and ensure accessibility of microbial bioresources that accumulate there because of state research programs. The establishment of national bioresource centers for antibiotic-resistant microorganisms allows to solve practical problems in the field of veterinary service, as well as to develop effective chemotherapeutic and disinfectant drugs to overcome the mechanisms of resistance. This study aimed to outline the process of forming a national culture collection of antibiotic-resistant strains of zoonotic bacteria in the Russian Federation using two microbial strains.

Materials and Methods

The object of research was isolates of Salmonella spp., Escherichia coli, Enterococcus spp., Campylobacter spp., Listeria monocytogenes, and Staphylococcus spp., all of which were obtained from biomaterials of farm animals, feed samples, bedding, water from livestock buildings, washouts from environmental objects, and food products. The resistance of bacterial isolates was determined using microbiological and molecular-genetic research methods.

Results

During monitoring studies, 1489 bacterial isolates were isolated. In total, 408 bacterial isolates were tested for sensitivity to antimicrobial agents, including E. coli (47.6%), Salmonella spp. (30.4%), Enterococcus spp. (11.3%), and Campylobacter spp. (10.8%). For genetic characterization, 95 isolates of Salmonella enterica, E. coli, Campylobacter spp., L. monocytogenes, Staphylococcus spp., Enterococcus spp. were chosen from the research collection, which was formed as part of the monitoring program for antibiotic resistance.

Conclusion

Deposited isolates that underwent whole-genome analysis can be used as positive control samples both in the development and use of methods or test systems for the detection of various resistance genes in zoonotic bacteria. In addition, such isolates can also be used for microbiological studies related to determining the sensitivity of microorganisms to antibacterial drugs, for phenotypic studies in the diagnosis of various bacterial infections in animals and birds, and retrospective analysis of strains from numerous collections.

Eradication of Drug-Tolerant Mycobacterium tuberculosis 2022: Where We Stand

The lungs of tuberculosis (TB) patients contain a spectrum of granulomatous lesions, ranging from solid and well-vascularized cellular granulomas to avascular caseous granulomas. In solid granulomas, current therapy kills actively replicating (AR) intracellular bacilli, while in low-vascularized caseous granulomas the low-oxygen tension stimulates aerobic and microaerophilic AR bacilli to transit into non-replicating (NR), drug-tolerant and extracellular stages. These stages, which do not have genetic mutations and are often referred to as persisters, are difficult to eradicate due to low drug penetration inside the caseum and mycobacterial cell walls. The sputum of TB patients also contains viable bacilli called differentially detectable (DD) cells that, unlike persisters, grow in liquid, but not in solid media. This review provides a comprehensive update on drug combinations killing in vitro AR and drug-tolerant bacilli (persisters and DD cells), and sterilizing Mycobacterium tuberculosis-infected BALB/c and caseum-forming C3HeB/FeJ mice. These observations have been important for testing new drug combinations in noninferiority clinical trials, in order to shorten the duration of current regimens against TB. In 2022, the World Health Organization, following the results of one of these trials, supported the use of a 4-month regimen for the treatment of drug-susceptible TB as a possible alternative to the current 6-month regimen.

NIR-induced improvement of catalytic activity and antibacterial performance over AuAg nanorods in Rambutan-like Fe3O4@AgAu@PDA magnetic nanospheres

Pathogenic bacteria and difficult-to-degrade pollutants in water have been serious problems that always plague people. Therefore, finding a "one stone-two birds" method that can quickly catalyze the degradation of pollutants and show effective antibacterial behavior become an urgent requirement. This work reports a facile one-step strategy for fabricating a Rambutan-like Fe₃O₄@AgAu@PDA (Fe₃O₄@AgAu@Polydopamine) core/shell nanosphere with both catalytic and antibacterial activities which can be critically improved by externally applying an NIR laser irradiation (NIR, 808 nm) and a rotating magnetic field. Typically, the Rambutan-like Fe₃O₄@AgAu@PDA nanosphere have a rather rough surface due to the AuAg bimetallic nanorods sandwiched between the Fe₃O₄ core and the PDA shell. Owing to the penetrated PDA shell, AgAu nanorods show high and magnetically recyclable photothermal-enhanced catalytic activity for the reduction of 4-nitrophenol to 4-aminophenol and they can also be applied to initiate TMB oxidation under the help of NIR heating condition. Moreover, Fe₃O₄@AgAu@PDA shows a moderate antibacterial activity due to the weak release of Ag⁺. Under applying a rotating external magnetic field, the rough-surface Fe₃O₄@AgAu@PDA nanospheres produce a controllable magnetolytic force on the bacterial due to their good affinity. As a result, the Fe₃O₄@AgAu@PDA nanospheres show a "magnetolytic-photothermal-Ag⁺" synergistic antibacterial behavior against E. coli and S. aureus.

Intracellular lifestyle of Chlamydia trachomatis and host-pathogen interactions

In recent years, substantial progress has been made in the understanding of the intracellular lifestyle of Chlamydia trachomatis and how the bacteria establish themselves in the human host. As an obligate intracellular pathogenic bacterium with a strongly reduced coding capacity, C. trachomatis depends on the provision of nutrients from the host cell. In this Review, we summarize the current understanding of how C. trachomatis establishes its intracellular replication niche, how its metabolism functions in the host cell, how it can defend itself against the cell autonomous and innate immune response and how it overcomes adverse situations through the transition to a persistent state. In particular, we focus on those processes for which a mechanistic understanding has been achieved.

Alternative strategies for Chlamydia treatment: Promising non-antibiotic approaches

Chlamydia is an obligate intracellular bacterium where most species are pathogenic and infectious, causing various infectious diseases and complications in humans and animals. Antibiotics are often recommended for the clinical treatment of chlamydial infections. However, extensive research has shown that antibiotics may not be sufficient to eliminate or inhibit infection entirely and have some potential risks, including antibiotic resistance. The impact of chlamydial infection and antibiotic misuse should not be underestimated in public health. This study explores the possibility of new therapeutic techniques, including a review of recent studies on preventing and suppressing chlamydial infection by non-antibiotic compounds.

Efficacy of Antimicrobial Photodynamic Therapy Mediated by Photosensitizers Conjugated with Inorganic Nanoparticles: Systematic Review and Meta-Analysis

Antimicrobial photodynamic therapy (aPDT) is a method that does not seem to promote antimicrobial resistance. Photosensitizers (PS) conjugated with inorganic nanoparticles for the drug-delivery system have the purpose of enhancing the efficacy of aPDT. The present study was to perform a systematic review and meta-analysis of the efficacy of aPDT mediated by PS conjugated with inorganic nanoparticles. The PubMed, Scopus, Web of Science, Science Direct, Cochrane Library, SciELO, and Lilacs databases were searched. OHAT Rob toll was used to assess the risk of bias. A random effect model with an odds ratio (OR) and effect measure was used. Fourteen articles were able to be included in the present review. The most frequent microorganisms evaluated were Staphylococcus aureus and Escherichia coli, and metallic and silica nanoparticles were the most common drug-delivery systems associated with PS. Articles showed biases related to blinding. Significant results were found in aPDT mediated by PS conjugated with inorganic nanoparticles for overall reduction of microorganism cultured in suspension (OR = 0.19 [0.07; 0.67]/p-value = 0.0019), E. coli (OR = 0.08 [0.01; 0.52]/p-value = 0.0081), and for Gram-negative bacteria (OR = 0.12 [0.02; 0.56/p-value = 0.0071). This association approach significantly improved the efficacy in the reduction of microbial cells. However, additional blinding studies evaluating the efficacy of this therapy over microorganisms cultured in biofilm are required.

Fluoroquinolones Hybrid Molecules as Promising Antibacterial Agents in the Fight against Antibacterial Resistance

The emergence of bacterial resistance has motivated researchers to discover new antibacterial agents. Nowadays, fluoroquinolones keep their status as one of the essential classes of antibacterial agents. The new generations of fluoroquinolones are valuable therapeutic tools with a spectrum of activity, including Gram-positive, Gram-negative, and atypical bacteria. This review article surveys the design of fluoroquinolone hybrids with other antibacterial agents or active compounds and underlines the new hybrids' antibacterial properties. Antibiotic fluoroquinolone hybrids have several advantages over combined antibiotic therapy. Thus, some challenges related to joining two different molecules are under study. Structurally, the obtained hybrids may contain a cleavable or non-cleavable linker, an essential element for their pharmacokinetic properties and mechanism of action. The design of hybrids seems to provide promising antibacterial agents helpful in the fight against more virulent and resistant strains. These hybrid structures have proven superior antibacterial activity and less susceptibility to bacterial resistance than the component molecules. In addition, fluoroquinolone hybrids have demonstrated other biological effects such as anti-HIV, antifungal, antiplasmodic/antimalarial, and antitumor activity. Many fluoroquinolone hybrids are in various phases of clinical trials, raising hopes that new antibacterial agents will be approved shortly.