Overview of Side-Effects of Antibacterial Fluoroquinolones: New Drugs versus Old Drugs, a Step Forward in the Safety Profile?

Evaluation of several farnesyloxycarbostyril derivatives as potential 15-LOX-1 inhibitors for prostate cancer treatment

The impact of 15-lipoxygenase-1 (15-LOX-1) in the progression of prostate cancer (PCa) is noteworthy, as it correlates with the Gleason score of the disease. Thus, development of specific 15-LOX-1 inhibitors would be desirable for targeted therapy of PCa. This study focused on evaluating the anti-prostate cancer potency of three farnesyloxycarbostyril derivatives, 6-, 7- and 8-farnesyloxycarbostyril (6-, 7- and 8-FQ), as potential inhibitors of 15-LOX-1 on PCa cells. To this end, the enzymatic activity of 15-LOX was first assessed in PCa and human dermal fibroblast (HDF) cells. Subsequently, the cytotoxic effects and apoptosis-inducing capabilities of the compounds were assessed through MTT assay and FITC-annexin V/PI staining, respectively. Among the compounds, 8-FQ was selected for further assessment in a mouse model bearing xenograft human PCa tumor. The results demonstrated that the most effective compound, 8-FQ, caused an 84-fold and 15.7-fold reduction in 15-LOX activity in PC-3 cells at 30 and 14 μM concentrations, respectively. The MTT assay revealed a dose- and time-dependent toxicity of the compounds on PCa cells, and flow cytometry results indicated that apoptosis served as the dominant mechanism of cell death. Given the upregulation of 15-LOX-1 in human PCa cells, the study concludes that the heightened sensitivity to 8-FQ is likely associated with elevated levels of 15-LOX-1. In vivo experiments using immunosuppressed C57BL/6 mice bearing human PC-3 tumors revealed that 8-FQ, at a dosage of 10 mg/kg, exhibited strong antitumor effects with minimal side effects, indicating its potential as a promising therapeutic agent for PCa following further optimization.

Antibacterial compounds against non-growing and intracellular bacteria

Slow- and non-growing bacterial populations, along with intracellular pathogens, often evade standard antibacterial treatments and are linked to persistent and recurrent infections. This necessitates the development of therapies specifically targeting nonproliferating bacteria. To identify compounds active against non-growing uropathogenic Escherichia coli (UPEC) we performed a drug-repurposing screen of 6454 approved drugs and drug candidates. Using dilution-regrowth assays, we identified 39 compounds that either kill non-growing UPEC or delay its regrowth post-treatment. The hits include fluoroquinolones, macrolides, rifamycins, biguanide disinfectants, a pleuromutilin, and anti-cancer agents. Twenty-nine of the hits have not previously been recognized as active against non-growing bacteria. The hits were further tested against non-growing Pseudomonas aeruginosa and Staphylococcus aureus. Ten compounds - solithromycin, rifabutin, mitomycin C, and seven fluoroquinolones-have strong bactericidal activity against non-growing P. aeruginosa, killing >4 log10 of bacteria at 2.5 µM. Solithromycin, valnemulin, evofosfamide, and satraplatin are unique in their ability to selectively target non-growing bacteria, exhibiting poor efficacy against growing bacteria. Finally, 31 hit compounds inhibit the growth of intracellular Shigella flexneri in a human enterocyte infection model, indicating their ability to permeate the cytoplasm of host cells. The identified compounds hold potential for treating persistent infections, warranting further comparative studies with current standard-of-care antibiotics.

5-Repurposed Drug Candidates Identified in Motor Neurons and Muscle Tissues with Amyotrophic Lateral Sclerosis by Network Biology and Machine Learning Based on Gene Expression

Amyotrophic lateral sclerosis (ALS) is a progressive neurodegenerative disorder that leads to motor neuron degeneration, muscle weakness, and respiratory failure. Despite ongoing research, effective treatments for ALS are limited. This study aimed to apply network biology and machine learning (ML) techniques to identify novel repurposed drug candidates for ALS. In this study, we conducted a meta-analysis using 4 transcriptome data in ALS patients (including motor neuron and muscle tissue) and healthy controls. Through this analysis, we uncovered common shared differentially expressed genes (DEGs) separately for motor neurons and muscle tissue. Using common DEGs as proxies, we identified two distinct clusters of highly clustered differential co-expressed cluster genes: the 'Muscle Tissue Cluster' for muscle tissue and the 'Motor Neuron Cluster' for motor neurons. We then evaluated the performance of the nodes of these two modules to distinguish between diseased and healthy states with ML algorithms: KNN, SVM, and Random Forest. Furthermore, we performed drug repurposing analysis and text-mining analyses, employing the nodes of clusters as drug targets to identify novel drug candidates for ALS. The potential impact of the drug candidates on the expression of cluster genes was predicted using linear regression, SVR, Random Forest, Gradient Boosting, and neural network algorithms. As a result, we identified five novel drug candidates for the treatment of ALS: Nilotinib, Trovafloxacin, Apratoxin A, Carboplatin, and Clinafloxacin. These findings highlight the potential of drug repurposing in ALS treatment and suggest that further validation through experimental studies could lead to new therapeutic avenues.

The future approach for the management of acute bacterial skin and skin structure infections

PURPOSE OF REVIEW

To discuss the new available options for the treatment of acute bacterial skin and skin structure infections (ABSSSIs) and how to implement in the clinical practice innovative approaches for their management.

RECENT FINDINGS

The availability of long-acting antibiotics, including dalbavancin and oritavancin, changed the approach to patients with ABSSSI. Direct discharge from the emergency department and early discharge from the hospital should be considered in patients with ABSSSI. Despite limited data about different bactericidal properties, the choice between dalbavancin and oritavacin is usually based on patients' characteristics and comorbidities. Delafloxacin and omadacycline are other options and have the advantage to be available for both intravenous and oral formulations, allowing a sequential therapy and switch from intravenous to oral treatment in clinically stable patients. Further studies should elucidate the profile of patients who may beneficiate from these drugs.

SUMMARY

Early discharge from the hospital should be considered in patients with ABSSSI at a high risk of methicillin-resistant Staphylococcus aureus and in vulnerable patients for which hospitalization may have detrimental consequences. In elderly individuals, patients with diabetes mellitus, oncological people who need for continuing their healthcare pathway, this approach may reduce complications and costs related to hospitalization.

Cell protective effects of vitamin C against oxidative stress induced by ciprofloxacin on spermatogenesis: involvement of cellular apoptosis

Introduction

Ciprofloxacin (CPFX), a second-generation fluoroquinolone, is widely used as an anti-infective agent for genitourinary tract infections due to its broad-spectrum efficacy against gram-positive and gram-negative organisms. Although CPFX is considered safe at therapeutic doses, recent evidence suggests its potential biological toxicity, particularly affecting testicular histology and function. This study aimed to investigate the effects of CPFX on testicular structure and function and to evaluate the protective role of vitamin C.

Methods

Forty adult male albino rats were divided into four groups: control, CPFX-treated, vitamin C-treated, and CPFX combined with vitamin C-treated. After 60 days of treatment, blood samples were collected for hormonal assays, while testicular and epididymal tissues were analyzed using light and electron microscopy. Oxidative stress markers, including malondialdehyde (MDA), glutathione (GSH), and catalase (CAT) enzyme activity, were assessed. Statistical analyses were conducted using SPSS software.

Results

Confocal microscopy of the CPFX-treated group revealed significant reductions in germ cell populations within seminiferous tubules, accompanied by severe apoptosis and degenerative epithelial changes. Morphometric analysis confirmed a decrease in tubular diameter and epithelial height, degeneration of spermatogenic cells, and detachment of apoptotic cells from the basement membrane. CPFX treatment significantly reduced testosterone levels and induced variable changes in gonadotropin hormones (LH and FSH). Co-administration of vitamin C with CPFX restored normal testicular morphology, preserving seminiferous tubule integrity and maintaining spermatogenic cell populations and spermatozoa within the lumen.

Discussion and Conclusion

Vitamin C supplementation effectively mitigated CPFX-induced oxidative stress by significantly reducing MDA levels and enhancing antioxidant defenses, including increased GSH content and CAT enzyme activity. These findings highlight the therapeutic potential of vitamin C in reversing CPFX-induced testicular toxicity by alleviating oxidative stress and restoring testicular function.

Fluoroquinolone-Mediated Tendinopathy and Tendon Rupture

The fluoroquinolone (FQ) class of antibiotics includes the world's most prescribed antibiotics such as ciprofloxacin, levofloxacin, and ofloxacin that are known for their low bacterial resistance. This is despite their potential to trigger severe side effects, such as myopathy, hearing loss, tendinopathy, and tendon rupture. Thus, healthcare organizations around the world have recommended limiting the prescription of FQs. Tendinopathy is a common name for maladies that cause pain and degeneration in the tendon tissue, which can result in tendon rupture. Whilst there are several identified effects of FQ on tendons, the exact molecular mechanisms behind FQ-mediated tendon rupture are unclear. Previous research studies indicated that FQ-mediated tendinopathy and tendon rupture can be induced by changes in gene expression, metabolism, and function of tendon resident cells, thus leading to alterations in the extracellular matrix. Hence, this review begins with an update on FQs, their mode of action, and their known side effects, as well as summary information on tendon tissue structure and cellular content. Next, how FQs affect the tendon tissue and trigger tendinopathy and tendon rupture is explored in detail. Lastly, possible preventative measures and promising areas for future research are also discussed. Specifically, follow-up studies should focus on understanding the FQ-mediated tendon changes in a more complex manner and integrating in vitro with in vivo models. With respect to in vitro systems, the field should move towards three-dimensional models that reflect the cellular diversity found in the tissue.

Detection of Delafloxacin Resistance Mechanisms in Multidrug-Resistant Klebsiella pneumoniae

Background: In this study, the mechanisms implicated in delafloxacin resistance in Klebsiella pneumoniae strains were investigated. Delafloxacin is a novel, broad-spectrum fluoroquinolone that has been approved for clinical application. Methods: In our study, 43 K. pneumoniae strains were assessed, antimicrobial susceptibility testing was performed via the broth microdilution method, and the minimum inhibitory concentration (MIC) values for ciprofloxacin, delafloxacin, levofloxacin, moxifloxacin, ceftazidime, cefotaxime, and imipenem were determined. Four delafloxacin-resistant K. pneumoniae strains were selected for whole-genome sequencing (WGS). Results: The MIC50 values for the 43 K. pneumoniae strains were as follows: ciprofloxacin 0.5 mg/L, levofloxacin 0.25 mg/L, moxifloxacin 0.5 mg/L, and delafloxacin 0.25 mg/L. All four selected delafloxacin-resistant K. pneumoniae strains showed extended-spectrum beta-lactamase production, and one strain exhibited carbapenem resistance. WGS enabled us to determine the sequence types (STs) of these strains, namely, ST307 (two strains), ST377, and ST147. Multiple mutations in quinolone-resistance-determining regions (QRDRs) were detected in all the delafloxacin-resistant K. pneumoniae strains; specifically, gyrA Ser83Ile and parC Ser80Ile were uniformly present in the strains of ST307 and ST147. However, in the ST377 strain, gyrA Ser83Tyr, Asp87Ala, and parC Ser80Ile, amino acid substitutions were detected. We also identified OqxAB and AcrAB efflux pumps in all delafloxacin-resistant K. pneumoniae strains. The association between beta-lactamase production and delafloxacin resistance was determined; specifically, CTX-M-15 production was detected in the ST147, ST307, and ST377 strains. Moreover, NDM-1 was detected in ST147. Conclusions: We conclude that multiple mutations in QRDRs, in combination with OqxAB and AcrAB efflux pumps, achieved delafloxacin resistance in K. pneumoniae. In our study, we report on NDM-1-producing K. pneumoniae ST147 in Hungary.

Fluid-specific detection of environmental pollutant moxifloxacin hydrochloride utilizing a rare-earth niobate decorated functionalized carbon nanofiber sensor platform

The development of precise and efficient detection methods is essential for the real-time monitoring of antibiotics, especially in environmental and biological matrices. This study aims to address this challenge by introducing a novel electrochemical sensor for the targeted detection of moxifloxacin hydrochloride (MFN), a fourth-generation fluoroquinolone. The sensor is based on a holmium niobate (HNO) and functionalized carbon nanofiber (f-CNF) nanocomposite, synthesized via a hydrothermal approach and subsequently characterized for its structural and electrochemical properties. When deposited onto a glassy carbon electrode (GCE), the HNO/f-CNF nanocomposite demonstrated exceptional electrochemical performance, as assessed using cyclic voltammetry (CV) and differential pulse voltammetry (DPV). The sensor exhibited remarkable sensitivity, with a detection limit of 0.034 μM, a quantification limit of 0.11 μM, and a sensitivity of 0.69 μA μM-1 cm-2. It also achieved a broad linear detection range from 0.001 μM to 1166.11 μM, making it highly effective for MFN detection across various complex matrices, including environmental waters, biological fluids, and artificial saliva, with recovery rates between 98.15% and 101.75%. The novelty of this work lies in the unique combination of HNO's catalytic properties and f-CNF's enhanced electron transport, establishing a highly selective and sensitive platform for MFN detection. This sensor not only advances the field of electrochemical sensing but also offers a promising tool for real-time environmental and pharmaceutical monitoring.

Determining the role of basophil activation testing in reported type 1 allergy to beta-lactam antibiotics

Background

Allergy to beta-lactam antibiotics (BLA), especially to penicillin, is the most commonly reported drug allergy by patients. Alternative antibiotics can yield negative consequences, such as extended hospitalization days due to less efficacy and overall higher costs. The basophil activation test (BAT) is an in vitro assay, in which activation of an individual's own basophils is quantified by flow cytometry. It is an increasingly applied in vitro method in allergy testing that is also gaining traction in drug allergies.

Methods

We correlated 37 BAT results with skin test results. The cohort exclusively included patients with suspected type I BLA allergy. In addition, we examined the concordance of these results with clinical symptoms reported in the BLA patients' medical histories.

Results

BLA-BAT revealed a high specificity of 92.3% [95% confidence interval (CI) 66.7-98.6] but a low sensitivity of only 20.8% (95% CI 9.24-40.47) using BLA-skin tests as a comparator. Negative BLA-BAT in patients with a history of grade I anaphylaxis yielded doubt on the assumption of grading. The exclusion of grade I BLA anaphylaxis increased the sensitivity to 29.4% (95% CI 13.28-53.13) with a still high specificity of 85.7% (95% CI 48.69-97.43). When ImmunoCAP was available, we compared specific IgE and BAT results by using Cohens' kappa (κ) and revealed a moderate level of agreement (κ = 0.538, p = 0.029).

Conclusion

BAT reveals specific positive results exclusively in patients with cephalosporin anaphylaxis. However, these findings could not be generally confirmed in the heterogeneous group of BLA.

"Pleiotropic" Effects of Antibiotics: New Modulators in Human Diseases

Antibiotics, widely used medications that have significantly increased life expectancy, possess a broad range of effects beyond their primary antibacterial activity. While some are recognized as adverse events, others have demonstrated unexpected benefits. These adjunctive effects, which have been defined as "pleiotropic" in the case of other pharmacological classes, include immunomodulatory properties and the modulation of the microbiota. Specifically, macrolides, tetracyclines, and fluoroquinolones have been shown to modulate the immune system in both acute and chronic conditions, including autoimmune disorders (e.g., rheumatoid arthritis, spondyloarthritis) and chronic inflammatory pulmonary diseases (e.g., asthma, chronic obstructive pulmonary disease). Azithromycin, in particular, is recommended for the long-term treatment of chronic inflammatory pulmonary diseases due to its well-established immunomodulatory effects. Furthermore, antibiotics influence the human microbiota. Rifaximin, for example, exerts a eubiotic effect that enhances the balance between the gut microbiota and the host immune cells and epithelial cells. These pleiotropic effects offer new therapeutic opportunities by interacting with human cells, signaling molecules, and bacteria involved in non-infectious diseases like spondyloarthritis and inflammatory bowel diseases. The aim of this review is to explore the pleiotropic potential of antibiotics, from molecular and cellular evidence to their clinical application, in order to optimize their use. Understanding these effects is essential to ensure careful use, particularly in consideration of the threat of antimicrobial resistance.

Antimicrobials in Orthopedic Infections: Overview of Clinical Perspective and Microbial Resistance

Orthopedic infections are challenging pathologies that impose a heavy burden on patients and the healthcare system. Antimicrobial therapy is a critical component of the successful management of orthopedic infections, but its effectiveness depends on patient-, surgery-, drug-, and hospital-related factors. The dramatic increase in the emergence of multidrug-resistant microbial strains necessitates new clinical approaches in order to prevent or limit this phenomenon and to ensure a favorable therapeutic outcome. The present paper reviews the currently available antimicrobial strategies in the management of orthopedic infections, highlighting their clinical use related to the occurrence of microbial resistance. Some approaches for reducing antibiotic resistance emergence in orthopedics are also presented. The use of antibiotics tailored to the microorganism's sensitivity profile, patient factors, and pharmacokinetic profile in terms of monotherapy or combinations, the understanding of microbial pathogenicity and resistance patterns, strict control measures in healthcare facilities, the development of new antimicrobial therapies (drugs, devices, technologies), and patient education for improving compliance and tolerance are some of the most important tools for overcoming microbial resistance.

In Silico Evaluation of Some Computer-Designed Fluoroquinolone-Glutamic Acid Hybrids as Potential Topoisomerase II Inhibitors with Anti-Cancer Effect

Background/Objectives: Fluoroquinolones (FQs) are topoisomerase II inhibitors with antibacterial activity, repositioned recently as anti-cancer agents. Glutamic acid (GLA) is an amino acid that affects human metabolism. Since an anti-cancer mechanism of FQs is human topoisomerase II inhibition, it is expected that FQ-GLA hybrids can act similarly. Methods: We designed 27 hypothetical hybrids of 6 FQs and GLA through amide bonds at the 3- and 7-position groups of FQs or via ethylenediamine/ethanolamine linkers at the carboxyl group of the FQ. Hydroxamic acid derivatives were also theoretically formulated. Computational methods were used to predict their physicochemical, pharmacokinetic, or toxicological properties and their anti-cancer activity. For comparison, etoposide was used as an anti-cancer agent inhibiting topoisomerase II. Molecular docking assessed whether the hybrids could interact with the human topoisomerase II beta in the same binding site and interaction sites as etoposide. Results: All the hybrids acted as potential topoisomerase II inhibitors, demonstrating possible anti-cancer activity on several cancer cell lines. Among all the proposed hybrids, MF-7-GLA would be the ideal candidate as a lead compound. The hybrid OF-3-EDA-GLA and the hydroxamic acid derivatives also stood out. Conclusions: Both FQs and GLA have advantageous structures for obtaining hybrids with favourable properties. Improvements in the hybrids' structure could lead to promising results.

Analysis of molecular mechanisms of delafloxacin resistance in Escherichia coli

In this study delafloxacin resistance mechanisms in Escherichia coli strains were analyzed. Delafloxacin is a new fluoroquinolone, that is approved for clinical application however, resistance against this agent is scarcely reported. In our study 37 E. coli strains were included and antimicrobial susceptibility testing was performed for ciprofloxacin, delafloxacin, levofloxacin, moxifloxacin, ceftazidime, cefotaxime, imipenem. Six delafloxacin resistant E. coli strains were selected for whole-genome sequencing and all of them exhibited resistance to other fluoroquinonlones and showed an extended-spectrum beta-lactamase phenotype. The six delafloxacin resistant E. coli strains belonged to different sequence types (STs) namely, ST131 (2 strains), ST57 (2 strains), ST162 and ST15840. Each delafloxacin resistant strain possessed multiple mutations in quinolone resistance-determining regions (QRDRs). Notably, three mutations in gyrA Ser83Leu, Asp87Asn and parC Ser80Ile were in strains of ST162, ST57 and ST15840. However, the two strains of ST131 carried five combined mutations namely, gyrA Ser83Leu, Asp87Asn, parC Ser80Ile, Glu84Val, parE Ile549Leu. Association of delafloxacin resistance and production of CTX-M-15 in ST131, CMY-2 in ST162 and ST15840 was detected. In this study a new ST, ST15840 of clonal complex 69 was identified. Our results demonstrate, that at least three mutations in QRDRs are required for delafloxacin resistance in E. coli.

Introducing of novel class of pyrano[2,3-c]pyrazole-5-carbonitrile analogs with potent antimicrobial activity, DNA gyrase inhibition, and prominent pharmacokinetic and CNS toxicity profiles supported by molecular dynamic simulation

Microbiological DNA gyrase is recognized as an exceptional microbial target for the innovative development of low-resistant and more effective antimicrobial drugs. Hence, we introduced a one-pot facile synthesis of a novel pyranopyrazole scaffold bearing different functionalities; substituted aryl ring, nitrile, and hydroxyl groups. All new analogs were characterized with full spectroscopic data. The antimicrobial screening for all analogs was assessed against standard strains of Gm + ve and Gm-ve through in vitro considers. The screened compounds displayed very promising MIC/MBC values against some of the bacterial strains with broad or selective antibacterial effects. Of these, 4j biphenyl analog showed 0.5-2/2-8 µg/mL MIC/MBC for suppression and killing of Gm + ve and Gm-ve strains. Moreover, the antimicrobial screening was assessed for the most potent analogs against certain highly resistant microbial strains. Consequently, DNA gyrase supercoiling assay was done for all analogs using ciprofloxacin as reference positive control. Obviously, the results showed a different activity profile with potent analog 4j with IC50 value 6.29 µg/mL better than reference drug 10.2 µg/mL. Additionally, CNS toxicity testing was done using the HiB5 cell line for attenuation of GABA/NMDA expression to both 4j and ciprofloxacin compounds that revealed better neurotransmitter modulation by novel scaffold. Importantly, docking and dynamic simulations were performed for the most active 4j analog to investigate its interaction with DNA binding sites, which supported the in vitro observations and compound stability with binding pocket. Finally, a novel scaffold pyranopyrazole was introduced as a DNA gyrase inhibitor with prominent antibacterial efficacy and low CNS side effect toxicity better than quinolones.Communicated by Ramaswamy H. Sarma.

Occurrence and characterization of plasmid-encoded qnr genes in quinolone-resistant bacteria across diverse aquatic environments in southern Ontario

Antimicrobial resistance is an ever-increasing threat. The widespread usage of ciprofloxacin has led to the manifestation of resistance due to chromosomal mutations or the acquisition of plasmid-mediated quinolone resistance (PMQR) traits. Some particular PMQR traits, qnr genes, have been identified globally in clinical and environmental isolates. This study aimed to determine the prevalence of ciprofloxacin-resistant bacteria in aquatic environments in southern Ontario and investigate the extent of dissemination of ciprofloxacin resistance traits among the bacterial communities. We surveyed the prevalence of plasmid encoding qnr genes using a multiplex PCR assay of associated PMQR genes, qnrA, qnrB, and qnrS, on 202 isolates. Despite the absence of significant impacts on minimum inhibitory concentration levels, the presence of qnr genes correlates with heightened resistance to quinolones and nalidixic acid in some isolates. Taxonomic analysis highlights distinct differences in the composition and diversity of ciprofloxacin-sensitive (CipS) and ciprofloxacin-resistant (CipR) populations, with Proteobacteria dominating both groups. Importantly, CipR populations exhibit lower genetic diversity but higher prevalence of multiple antibiotic resistances, suggesting co-selection mechanisms. Co-occurrence analysis highlights significant associations between ciprofloxacin resistance and other antibiotic resistances, implicating complex genetic linkages. The results of our study signified the critical role of environmental monitoring in public health.

Tetracycline and fluoroquinolone antibiotics contamination in agricultural soils fertilized long-term with chicken litter: Trends and ravages

We investigated the potential accumulation of tetracyclines (TCs) such as chlortetracycline (CTC), oxytetracycline (OTC) and doxycycline (DC), and fluoroquinolones (FQs) like enrofloxacin (ENR) and ciprofloxacin (CIP) in chicken litter and agricultural soils fertilized over short-term to long-term (<1-30 yrs) with chicken litter in a poultry hub for the first time from Tamil Nadu, India. CTC, OTC, DC, CIP, and ENR were detected in 46-92 % of the selected chicken litter samples, with mean levels ranging from 2.90 to 23.30 μg kg-1. Higher concentrations of TCs and FQs were observed in freshly collected chicken litter from poultry sheds than in those stockpiled in cultivated lands. CTC was the prevalent antibiotic in chicken litter. The overall occurrence, as well as the ecological risks of TCs and FQs, changed over a 30-yr period. The accumulation of veterinary antibiotics (VAs) (in μg kg-1) in short-term (>1 yr) to medium-term (1-3 yrs) chicken litter-fertilized soils reached a maximum of 11.60 for CTC, 6.50 for OTC, 0.80 for DC, 3.70 for CIP, and 3.60 for ENR, but decreased in long-term (10-30 yrs) fertilized soils. Ecological risk assessment revealed a Risk Quotient (RQ) of ≤0.10 for CTC, OTC, and DC in all soils, while an average risk (RQ >0.10-<1.0) was evident with CIP and ENR in short-term and medium-term fertilized soils. Antibiotic resistance genes (ARGs), including tetA, tetB, qnrA, qnrB and qnrS were detected in most of the chicken litter samples and litter-fertilized soils. Thus, it is critical to develop and adopt effective mitigation strategies before applying chicken litter in farmlands to decrease VAs and ARGs, reducing their associated risks to public health and ecosystems in India considering 'One Health' approach. Future investigations on the occurrence of other VAs and ARGs in soils fertilized with poultry litter at regional scale are required for effective risk mitigation of the widely used VAs.

Fluoroquinolones and the risk for incidental seizures: a comparative retrospective study

BACKGROUND

Over the years, reports have associated fluoroquinolones (FQ) with seizures. The incidence and whether FQ compared to non-epileptogenic antibiotic are associated with increased risk of seizures has yet to be examined.

METHODS

A retrospective observational study of hospitalized patients treated with FQ (ofloxacin, ciprofloxacin, levofloxacin, moxifloxacin) or macrolides (MA: azithromycin or roxithromycin) between January 2009 and January 2021 in a large tertiary academic medical centre. The outcome was the occurrence of a seizure during treatment. The Naranjo scale was used to assess causality between FQ treatment and seizures. Comparative analysis was conducted using propensity score matching to correct for possible bias due to non-random selection, followed by inverse probability weighting (IPW) to estimate the difference in seizure risk between FQ and MA.

RESULTS

Overall, 52 722 patients were treated with FQ during a total of 178 982 days. Mean age was 65 (±19) years and 47% were females. Thirty-three patients (0.06%) experienced a seizure, yielding an incidence of 1:5422 treatment days. Causality was deemed probable and possible among 9/33 and 24/33, respectively. The MA group composed of 8522 patients treated during 17 954 treatment days. Mean age was 65 (±21) years, 49% were females. Six (0.07%) patients experienced each a single seizure. IPW estimated OR for seizures among the FQ versus MA group was 1.44 (95%CI 0.59-3.5, P = 0.42).

DISCUSSION

The incidence of FQ associated seizures among hospitalized patients is low and the risk did not significantly exceed that under macrolides. Our results provide evidence for clinicians and decision-makers when balancing fluoroquinolones risks and benefits.

Comparative in vitro activity of Delafloxacin and other antimicrobials against isolates from patients with acute bacterial skin, skin-structure infection and osteomyelitis

The aim of this study was to compare the in vitro activity of delafloxacin with other fluoroquinolones against bacterial pathogens recovered from inpatients with osteomyelitis, Acute Bacterial Skin and Skin-Structure Infections (ABSSSI). In total, 100 bacterial isolates (58 % Gram-negative and 42 % Gram-positive) recovered from inpatients between January and April 2021, were reidentified at species level by MALDI-TOF MS. Antimicrobial susceptibility testing was conducted using the broth microdilution method and the detection of biofilm formation was assessed through the microtiter plate assay. The screening for mecA was carried out by PCR, while mutations in the Quinolone Resistance Determining Regions (QRDR), specifically gyrA and parC, were analyzed using PCR followed by Sanger sequencing. Results showed that delafloxacin exhibited greater in vitro potency (at least 64-times) than the other tested fluoroquinolones (levofloxacin and ciprofloxacin) when evaluating Staphylococcus aureus (MIC50 ≤0.008 mg/L) and coagulase-negative Staphylococcus (MIC50 0.06 mg/L). Furthermore, delafloxacin (MIC50 0.25 mg/L) was at least 4 times more potent than other tested fluoroquinolones (MIC50 1 mg/L) against P. aeruginosa. No difference in delafloxacin activity (MIC50 0.03 mg/L) was observed against Enterobacter cloacae when compared with ciprofloxacin (MIC50 0.03 mg/L). Despite presenting low activity against K. pneumoniae isolates (22.2 %), delafloxacin exhibited twice the activity compared to both levofloxacin and ciprofloxacin. Delafloxacin also exhibited a strong activity (71.4 %‒85.7 %.) against biofilm producing bacterial pathogens tested in this study. Interestingly, 82.14 % of the staphylococci tested in this study harbored mecA gene. In addition, the gyrA and parC genes in fluoroquinolone-resistant Gram-negative isolates displayed different mutations (substitutions and deletions). Herein, we showed that delafloxacin was the most active fluoroquinolone against staphylococci (including MRSA) and P. aeruginosa when compared to other fluoroquinolones such as ciprofloxacin and levofloxacin.

Molybdenum disulphide nanoparticles accelerate the transformation of levofloxacin in planting soil upon exposure

The use of nanocatalytic particles for the removal of refractory organics from wastewater is a rapidly growing area of environmental purification. However, little has been done to investigate the effects of nanoparticles on soil-plant systems with antibiotic contamination. This work assessed the effect of molybdenum disulfide (MoS2) on the soil-Phragmites communis system containing levofloxacin (LVX). The results showed that the addition of MoS2 had restoration potential for stressed plant. The MoS2 with catalytic activity promoted the transformation of LVX in rhizosphere soils. The transformation pathways of LVX in the different exposure groups were proposed. The continuous output of radicals in the high MoS2 dosage group facilitated the transformation of LVX to small molecule compounds, which were eventually mineralized. Moreover, the electron-density-difference analysis revealed the easier flow of electrons from the MoS2 surface towards the LVX molecules. This finding provides theoretical support for the application of nanocatalytic particles in ecological environments.

Single and mixture exposure to atrazine and ciprofloxacin on Clarias gariepinus antioxidant defense status, hepatic condition and immune response

Atrazine (ATRA) and ciprofloxacin (CPRO) are widely detected, persistent and co-existing aquatic pollutants. This study investigated effects of 14-day single and joint ATRA and CPRO exposure on juvenile Clarias gariepinus. Standard bioassay methods were used to determine responses of oxidative stress, hepatic condition, and immunological biomarkers on days 7 and 14. Seven groups were used: Control, CPROEC, CPROSubl, ATRAEC, ATRASubl, CPROEC+ATRAEC, and CPROSubl+ATRASubl. The test substances caused decreased activity of superoxide dismutase, catalase, and glutathione peroxidase. Lipid peroxidation was elevated, especially in CPRO-ATRA mixtures. Serum aminotransferases (ALT, and AST), and alkaline phosphatase activity increased significantly. Total protein, albumin, total immunoglobulin, and respiratory burst decreased significantly. Therefore, single and joint exposure to CPRO and ATRA poses adverse consequences on aquatic life.

Long-term toxicity of fluoroquinolones: a comprehensive review

Fluoroquinolones (FQs) are highly potent bactericidal antibiotics with broad-spectrum activity against Gram-negative/positive bacteria. The Food and Drug Administration (FDA) anticipated the presence of a long-lasting incapacity of Fluoroquinolone Associated Toxicity (FQAT), which is not officially documented yet. This review aimed to précis the existing information on FQA long-term toxicity, such as cardiotoxicity, aortic aneurysm, tendon rupture, nephrotoxicity, hepatotoxicity, peripheral neuropathy, vagus nervous dysfunction, reactive oxygen species (ROS), phototoxicity, glucose hemostasis, and central nervous system (CNS) toxicity. We are focused on the CNS toxicity of FQs, either due to the direct action of the FQs on CNS receptors or by other drug co-administration, including nonsteroidal anti-inflammatory disease (NSAIDs) and theophylline. Due to the nature of the R7 side chain, FQs containing unsubstituted 7-piperazine and 7-pyrrolidine have the most significant effect. The gamma-aminobutyric acid-A (GABAA) receptor and CNS effects are inhibited through at least three possible mechanisms. Firstly, by the pharmacological action of the quinolone directly. Secondly, FQ-NSAIDs interact pharmacodynamically in which the interaction between the FQ and a receptor is significantly altered by the presence of another drug that interacts with the same receptor. An example may be the interaction between NSAIDs and some FQs. Thirdly, a pharmacokinetic drug-drug interaction leads to a higher concentration of quinolone or the other drug. An example may be the interaction between theophylline and benzodiazepines with some FQs.

Drug-Drug Interactions in Nosocomial Infections: An Updated Review for Clinicians

Prevention, assessment, and identification of drug-drug interactions (DDIs) represent a challenge for healthcare professionals, especially in nosocomial settings. This narrative review aims to provide a thorough assessment of the most clinically significant DDIs for antibiotics used in healthcare-associated infections. Complex poly-pharmaceutical regimens, targeting multiple pathogens or targeting one pathogen in the presence of another comorbidity, have an increased predisposition to result in life-threatening DDIs. Recognising, assessing, and limiting DDIs in nosocomial infections offers promising opportunities for improving health outcomes. The objective of this review is to provide clinicians with practical advice to prevent or mitigate DDIs, with the aim of increasing the safety and effectiveness of therapy. DDI management is of significant importance for individualising therapy according to the patient, disease status, and associated comorbidities.

Development of Magnetic Porous Polymer Composite for Magnetic Solid Phase Extraction of Three Fluoroquinolones in Milk

In this study, a magnetic porous polymer composite with both hydrophilic and hydrophobic groups was synthesized for magnetic solid phase extraction (MSPE) of milk substrates. Optimization was conducted on various parameters, including adsorption dose, solution pH, adsorption time, and some elution conditions. Coupled with a high-performance liquid chromatography fluorescence detector, a novel MSPE method for determination of norfloxacin (NFX), ciprofloxacin (CIP), and enrofloxacin (ENR) in milk was developed based on magnetic metal organic framework polystyrene polymer (Fe3O4@MOF@PLS) as adsorbent. The Fe3O4@MOF@PLS exhibited significantly improved adsorption performance compared to MOF and PLS. Under optimized experimental conditions, the method exhibited good linearity for the three fluoroquinolones (FQs) in the range of 0.5-1000 μg/kg, with limit of detections (LODs) ranging from 0.21 to 1.33 μg/kg, and limit of quantitations (LOQs) from 0.71 to 4.42 μg/kg. The relative standard deviation (RSD) for the three FQs were 3.4-8.8%. The recoveries of three FQs in milk samples ranged from 84.2% to 106.2%. This method was successfully applied to the detection of three FQs in 20 types of milk, demonstrating its simplicity, speed, and effectiveness in analyte enrichment and separation. The method presented advantages in adsorbent dosage, adsorption time, LODs, and LOQs, making it valuable for the analysis and detection of FQs in milk.

Nitrogen-doped carbon dots: a novel biosensing platform for selective norfloxacin detection and bioimaging

Incomplete metabolism and non-biodegradable nature of norfloxacin (NORx) lead to its persistent residues in the environment and food, potentially fostering the emergence of antibiotic resistance and posing a significant threat to public health. Hence, we developed a norfloxacin sensor employing hydrothermally synthesized N-doped carbon dots (N-Ch-CQDs) from chitosan and PEI demonstrated high sensitivity and specificity towards the antibiotic detection. The quantum yield of excitation-dependent emission of N-Ch-CQDs was effectively tuned from 4.6 to 21.5% by varying the concentration of PEI (5-15%). With the enhanced fluorescence in the presence of norfloxacin, N-Ch-CQDs exhibited a linear detection range of 20-1400 nM with a limit of detection (LoD) of 9.3 nM. The high biocompatibility of N-Ch-CQDs was confirmed in the in vitro and in vivo model and showed the environment-friendly nature of the sensor. Detailed study elucidated the formation of strong hydrogen bonds between N-Ch-CQDs and NORx, leading to fluorescence enhancement. The developed sensor's capability to detect NORx was evaluated in water and milk samples. The recovery rate ranged from 98.5% to 103.5%, demonstrating the sensor's practical applicability. Further, the bioimaging potential of N-Ch-CQDs was demonstrated in both the in vitro (L929 cells) and in vivo model (C. elegans). The synergistic influence of the defecation pattern and functioning of intestinal barrier mitigates the translocation of N-Ch-CQDs into the reproductive organ of nematodes. This study revealed the bioimaging and fluorescent sensing ability of N-Ch-CQDs, which holds significant promise for extensive application in the biomedical field.

Deleterious effects of a combination therapy using fluoroquinolones and tetracyclines for the treatment of Japanese spotted fever: a retrospective cohort study based on a Japanese hospital database

OBJECTIVES

Tetracyclines are the standard treatment for rickettsiosis, including Japanese spotted fever (JSF), a tick-borne rickettsiosis caused by Rickettsia japonica. While some specialists in Japan advocate combining fluoroquinolones with tetracyclines for treating JSF, the negative aspects of combination therapy have not been thoroughly evaluated. Whether fluoroquinolones should be combined with tetracyclines for JSF treatment is controversial. The study aimed to evaluate the disadvantages of fluoroquinolones combined with tetracyclines for JSF treatment.

METHODS

This retrospective cohort study was conducted using a Japanese database comprising claims data from April 2008 to December 2020. The combination therapy group (tetracyclines and fluoroquinolones) was compared with the monotherapy group (tetracycline only) regarding mortality and the incidence of complications.

RESULTS

A total of 797 patients were enrolled: 525 received combination therapy, and 272 received monotherapy. The adjusted odds ratio (OR) for mortality was 2.30 [95% confidence interval (CI): 0.28-18.77] in the combination therapy group with respect to the monotherapy group. According to the subgroup analysis, patients undergoing combination therapy with ciprofloxacin experienced higher mortality rates compared with those receiving monotherapy (adjusted OR = 25.98, 95% CI = 1.71-393.75). Additionally, 27.7% of the combination therapy group received NSAIDs concurrently with fluoroquinolones. The combination therapy with NSAIDs group was significantly more likely to experience convulsions than the monotherapy without NSAIDs group (adjusted OR: 5.44, 95% CI: 1.13-26.30).

CONCLUSIONS

This study found no evidence that combination therapy improves mortality outcomes and instead uncovered its deleterious effects. These findings facilitate a fair assessment of combination therapy that includes consideration of its disadvantages.

General Characteristics and Current State of Antibiotic Resistance in Pediatric Urinary Tract Infection-A Single Center Experience

Urinary tract infection (UTI) represents one of the most common bacterial infections in children, mainly caused by Gram-negative bacteria. Empirical antibiotic treatment is based on international and national guidelines for treating UTIs in children and is individualized with local antibiotic resistance patterns. The aim of this study is to bring a clear view of present-day particularities of UTIs in children.

METHODS

We analyzed 210 positive urine cultures identified in 141 pediatric patients admitted to the hospital over a 6-month period.

RESULTS

The majority of patients were females (57%) with a median age of 5 years (IQR 12), while male patients revealed a median age of 2 (IQR 7). Most patients originated from urban areas (53%). Only 18 patients (12.76%) were identified with underlying Congenital Anomalies of the Kidney and Urinary Tract (CAKUT). Escherichia Coli was the most frequent pathogen. Increased antibiotic resistance was found in commonly-used antibiotics Ampicillin and Trimethoprim/Sulfamethoxazole, and in the case of patients with CAKUT. Suitable antibiotics for treating a Gram-negative UTI are aminoglycosides, Meropenem, third-generation Cephalosporins, and Nitrofurantoin. Vancomycin upholds efficacy in treating a Gram-positive pediatric UTI.

CONCLUSION

Periodical analysis needs to be performed in order to constantly update clinicians on uropathogenic antibiotic resistance and optimal empirical treatment options.

Quinolone Prophylaxis in Conjunction with Bacillus Calmette-Guérin Instillations for Bladder Cancer: Time To Reconsider the Evidence and Open the Quinolone Box?

Adjuvant bacillus Calmette-Guérin (BCG) instillations represent a cornerstone in the treatment of non-muscle-invasive bladder cancer. Instillation schedule and dose modifications have been evaluated in efforts to reduce the incidence of adverse events (AEs), but none so far has the same treatment efficacy as the full-dose recommended schedule. It has been shown that prophylactic quinolone use in conjunction with BCG instillations reduces AE incidence and improves timely completion of instillation regimens and patient survival. However, the European Medicines Agency imposed restrictions on the use of quinolones in 2019 because of side effects. Nevertheless, rational use of quinolone prophylaxis could be considered for selected individuals treated with BCG without risk factors for quinolone-associated side effects in conjunction with patient information about side-effect symptoms. PATIENT SUMMARY: Bladder instillations of BCG (bacillus Calmette-Guérin) are used in the treatment of non-muscle-invasive bladder cancer. Antibiotics from the quinolone class can reduce the adverse effects of BCG and help patients in completing the treatment course; however, these antibiotics have their own side effects. Our mini review suggests that the antibiotics could be used in selective cases if patients are given adequate information on these side effects and their symptoms.

Nanomaterials for Photothermal Antimicrobial Surfaces

Microbial infection diseases are a major threat to human health and have become one of the main causes of mortality. The search for novel antimicrobial strategies is an important challenge for the scientific community, considering also the constant increase of antimicrobial resistance and the rise of new diseases. Among the new strategies to combat microbial infections, the photothermal effect seems to be one of the most promising. Hyperthermia is an effective and broad spectrum strategy for the removal of microbial infections. Among all of the strategies to reduce the diffusion of microbial infections, the preparation of antimicrobial surfaces seems of primary importance. In many cases, in fact, an infection can be diffused through surfaces just by touching them, or by inoculating microbes through an internalizable device, such as an implant, a prosthesis, or a catheter. In this review, we will summarize the recent advances in the preparation of photothermal antibacterial surfaces.

Mechanisms of the Antineoplastic Effects of New Fluoroquinolones in 2D and 3D Human Breast and Bladder Cancer Cell Lines

Antibacterial fluoroquinolones have emerged as potential anticancer drugs, thus prompting the synthesis of novel molecules with improved cytotoxic characteristics. Ciprofloxacin and norfloxacin derivatives, previously synthesized by our group, showed higher anticancer potency than their progenitors. However, no information about their mechanisms of action was reported. In this study, we selected the most active among these promising molecules and evaluated, on a panel of breast (including those triple-negative) and bladder cancer cell lines, their ability to induce cell cycle alterations and apoptotic and necrotic cell death through cytofluorimetric studies. Furthermore, inhibitory effects on cellular migration, metalloproteinase, and/or acetylated histone protein levels were also evaluated by the scratch/wound healing assay and Western blot analyses, respectively. Finally, the DNA relaxation assay was performed to confirm topoisomerase inhibition. Our results indicate that the highest potency previously observed for the derivatives could be related to their ability to induce G2/M cell cycle arrest and apoptotic and/or necrotic cell death. Moreover, they inhibited cellular migration, probably by reducing metalloproteinase levels and histone deacetylases. Finally, topoisomerase inhibition, previously observed in silico, was confirmed. In conclusion, structural modifications of progenitor fluoroquinolones resulted in potent anticancer derivatives possessing multiple mechanisms of action, potentially exploitable for the treatment of aggressive/resistant cancers.

A Review on Fluoroquinolones' Toxicity to Freshwater Organisms and a Risk Assessment

Fluoroquinolones (FQs) have achieved significant success in both human and veterinary medicine. However, regulatory authorities have recommended limiting their use, firstly because they can have disabling side effects; secondly, because of the need to limit the spread of antibiotic resistance. This review addresses another concerning consequence of the excessive use of FQs: the freshwater environments contamination and the impact on non-target organisms. Here, an overview of the highest concentrations found in Europe, Asia, and the USA is provided, the sensitivity of various taxa is presented through a comparison of the lowest EC50s from about a hundred acute toxicity tests, and primary mechanisms of FQ toxicity are described. A risk assessment is conducted based on the estimation of the Predicted No Effect Concentration (PNEC). This is calculated traditionally and, in a more contemporary manner, by constructing a normalized Species Sensitivity Distribution curve. The lowest individual HC5 (6.52 µg L-1) was obtained for levofloxacin, followed by ciprofloxacin (7.51 µg L-1), sarafloxacin and clinafloxacin (12.23 µg L-1), and ofloxacin (17.12 µg L-1). By comparing the calculated PNEC with detected concentrations, it is evident that the risk cannot be denied: the potential impact of FQs on freshwater ecosystems is a further reason to minimize their use.

Exploring the environmental pathways and challenges of fluoroquinolone antibiotics: A state-of-the-art review

Fluoroquinolone (FQ) antibiotics have become a subject of growing concern due to their increasing presence in the environment, particularly in the soil and groundwater. This review provides a comprehensive examination of the attributes, prevalence, ecotoxicity, and remediation approaches associated with FQs in environmental matrices. The paper discusses the physicochemical properties that influence the fate and transport of FQs in soil and groundwater, exploring the factors contributing to their prevalence in these environments. Furthermore, the ecotoxicological implications of FQ contamination in soil and aquatic ecosystems are reviewed, shedding light on the potential risks to environmental and human health. The latter part of the review is dedicated to an extensive analysis of remediation approaches, encompassing both in-situ and ex-situ methods employed to mitigate FQ contamination. The critical evaluation of these remediation strategies provides insights into their efficacy, limitations, and environmental implications. In this investigation, a correlation between FQ antibiotics and climate change is established, underlining its significance in addressing the Sustainable Development Goals (SDGs). The study further identifies and delineates multiple research gaps, proposing them as key areas for future investigational directions. Overall, this review aims to consolidate current knowledge on FQs in soil and groundwater, offering a valuable resource for researchers, policymakers, and practitioners engaged in environmental management and public health.

Effective antibacterial agents in modern wound dressings: a review

Wound infections are a significant concern in healthcare, leading to long healing times. Traditional approaches for managing wound infections rely heavily on systemic antibiotics, which are associated with the emergence of antibiotic-resistant bacteria. Therefore, the development of alternative antibacterial materials for wound care has gained considerable attention. In today's world, new generations of wound dressing are commonly used to heal wounds. These new dressings keep the wound and the area around it moist to improve wound healing. However, this moist environment can also foster an environment that is favorable for the growth of bacteria. Excessive antibiotic use poses a significant threat to human health and causes bacterial resistance, so new-generation wound dressings must be designed and developed to reduce the risk of infection. Wound dressings using antimicrobial compounds minimize wound bacterial colonization, making them the best way to avoid open wound infection. We aim to provide readers with a comprehensive understanding of the latest advancements in antibacterial materials for wound management.

Host-Guest Doping Modulated Afterglow Emission of Fluoroquinolones for Their Separation-Free Detection and Discrimination

Detection and discrimination of fluoroquinolones (FQs) are crucial for food safety but remain a formidable challenge due to their minor differences in molecular structures and the serious interferences from food matrices. Herein, we propose an afterglow assay for the detection and discrimination of FQs through modulating their room-temperature phosphorescence (RTP) and thermally activated delayed fluorescence (TADF) properties by a host-guest doping strategy. FQs were doped into the boric acid host, forming boronic anhydride structures and hydrogen bonds, which prompted the RTP and TADF performance of FQs by stabilizing their excited states, preventing triplet exciton quenching, and reducing the energy gap between singlet and triplet states. The FQs can be quantitatively detected through monitoring the afterglow intensity of host-guest systems, as low as 0.25 μg/mL. The differences in the afterglow intensity and emission lifetime allowed accurate discrimination of 11 types of FQs through pattern recognition methods. Aided by the delayed signal detection model of afterglow emission, the background signal and the interferences from food matrices were effectively eliminated, which endow the detection and discrimination of mixed FQs in commercial meat samples, without multiple-step separation processes.

Safety of fluoroquinolones

Fluoroquinolones (FQs) are one of the most commonly prescribed classes of antibiotics. Although they were initially well tolerated in randomized clinical trials, subsequent epidemiological studies have reported an increased risk of threatening, severe, long-lasting, disabling and irreversible adverse effects (AEs), related to neurotoxicity and collagen degradation, such as tendonitis, Achilles tendon rupture, aortic aneurysm, and retinal detachment. This article reviews the main potentially threatening AEs, the alarms issued by regulatory agencies and therapeutic alternatives.

Bronchiectasis-COPD Overlap Syndrome: A Comprehensive Review of its Pathophysiology and Potential Cardiovascular Implications

Bronchiectasis-Chronic Obstructive Pulmonary Disease Overlap Syndrome (BCOS) is a complex pulmonary condition that merges bronchiectasis and chronic obstructive pulmonary disease (COPD), presenting unique clinical challenges. Patients with BCOS typically exhibit a range of symptoms from both conditions, including a chronic productive cough, reduced lung function, frequent exacerbations, and diminished exercise tolerance. The etiology of BCOS involves multiple factors such as genetic predisposition, respiratory infections, tobacco smoke, air pollutants, and other inflammatory mediators. Accurate diagnosis requires a comprehensive approach, incorporating pulmonary function tests to evaluate airflow limitation, radiographic imaging to identify structural lung abnormalities, and blood eosinophil counts to detect underlying inflammation. Treatment strategies are tailored to individual symptom profiles and severity, potentially including bronchodilators, inhaled corticosteroids, and pulmonary therapy to improve lung function and quality of life. Patients with BCOS are also at an increased risk for cardiovascular complications, such as stroke, ischemic heart disease, and cor pulmonale. Additionally, medications like beta-agonists and muscarinic antagonists used in COPD treatment can further affect cardiac risk by altering heart rate. This paper aims to provide a thorough understanding of BCOS, addressing its development, diagnosis, treatment, and associated cardiovascular complications, to aid healthcare providers in managing this multifaceted condition and improving patient outcomes.

Sitafloxacin- Versus Moxifloxacin-Based Sequential Treatment for Mycoplasma Genitalium Infections: Protocol for a Multicenter, Open-Label Randomized Controlled Trial

BACKGROUND

Mycoplasma genitalium is an emerging sexually transmitted pathogen associated with increasing antibiotic resistance. The current treatment guidelines recommend moxifloxacin-sequential therapy for macrolide-resistant Mgenitalium or strains with unknown resistance profiles. However, it is unclear whether sitafloxacin, a 4th-generation fluoroquinolone antibiotic, is effective against resistant strains.

OBJECTIVE

This study aims to assess and compare the efficacy and safety of sitafloxacin- and moxifloxacin-based treatment regimens for managing Mgenitalium infections.

METHODS

We will conduct this randomized controlled trial at multiple centers in Japan. Eligible participants include adults aged 18 years or older with a confirmed Mgenitalium infection, as determined through the nucleic acid amplification test. Patients will be randomly assigned using a stratified approach based on the treatment facility and infection site. The interventions comprise oral sitafloxacin (200 mg) daily for 7 days (with optional pretreatment of oral doxycycline, 200 mg, daily for up to 7 days), with a control group receiving oral doxycycline (200 mg) daily for 7 days followed by moxifloxacin (400 mg) daily for another 7 days. The primary outcome is the treatment success rate with a superiority margin of 10%, as confirmed through the nucleic acid amplification test. Secondary outcomes encompass changes in the bacterial load at the urogenital or rectal sites and the emergence of posttreatment-resistant mutant strains.

RESULTS

Enrollment commenced in June 2023 and will conclude in December 2024, with findings anticipated by 2025. The expected success rates fall within the range of 80% for sitafloxacin and 42% for moxifloxacin against Mgenitalium carrying the G248T (S83I) mutation, based on previous studies. Accordingly, with a 5% significance level (2-sided) and 80% statistical power, we aim to recruit 50 participants per group, factoring in a 10% expected dropout rate.

CONCLUSIONS

This study will provide valuable insights into the efficacy and safety of sitafloxacin- versus moxifloxacin-based sequential therapy in treating Mgenitalium infections. These findings have the potential to influence clinical guidelines, favoring more effective therapeutic choices. The multicenter approach enhances the robustness of this study. However, a limitation is the potential insufficiency of statistical power to detect posttreatment-resistant mutant strains in each group, rendering posttreatment-resistance mutations a notable concern. In the future, we may need to increase the sample size to enhance power.

TRIAL REGISTRATION

Japan Registry of Clinical Trials (jRCTs031230111); https://jrct.niph.go.jp/en-latest-detail/jRCTs031230111.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

DERR1-10.2196/52565.

The Role of Five-Membered Heterocycles in the Molecular Structure of Antibacterial Drugs Used in Therapy

Five-membered heterocycles are essential structural components in various antibacterial drugs; the physicochemical properties of a five-membered heterocycle can play a crucial role in determining the biological activity of an antibacterial drug. These properties can affect the drug's activity spectrum, potency, and pharmacokinetic and toxicological properties. Using scientific databases, we identified and discussed the antibacterials used in therapy, containing five-membered heterocycles in their molecular structure. The identified five-membered heterocycles used in antibacterial design contain one to four heteroatoms (nitrogen, oxygen, and sulfur). Antibacterials containing five-membered heterocycles were discussed, highlighting the biological properties imprinted by the targeted heterocycle. In some antibacterials, heterocycles with five atoms are pharmacophores responsible for their specific antibacterial activity. As pharmacophores, these heterocycles help design new medicinal molecules, improving their potency and selectivity and comprehending the structure-activity relationship of antibiotics. Unfortunately, particular heterocycles can also affect the drug's potential toxicity. The review extensively presents the most successful five-atom heterocycles used to design antibacterial essential medicines. Understanding and optimizing the intrinsic characteristics of a five-membered heterocycle can help the development of antibacterial drugs with improved activity, pharmacokinetic profile, and safety.

Identification of potential inhibitors against E.coli via novel approaches based on deep learning and quantum mechanics-based atomistic investigations

Currently, drug resistance to commercially available antibiotics is imparting negative consequences to global health, and the development of novel antibiotics in a timely manner is a prime need of the hour. In the current study, an e-pharmacophore model was built using the 3D structure of DNA gyrase in complex with a standard inhibitor. The generated model was subjected to a pharmacophore based virtual screening against 45,257,086 molecules having 223,460,579 conformers available in MCULE database. Pharmacophore based screening retrieved eight molecules as top hit based on pharmacophoric features in comparison to standard inhibitors. Afterward, all eight compounds were subjected molecular docking based on deep learning algorithm. The molecular docking revealed that compound MCULE-6042843173 and MCULE-2362244223 had significant binding orientation inside active pocket of targeted protein with binding affinity of -9.52 and -9.24 kcal/mol respectively. In addition, density functional theory studies (DFT) were performed to evaluate quantum mechanics of top ranked compounds which were investigated through quantum mechanics (QM) computations which strongly assisted the findings of other in-silico investigations. Consequently, the MCULE-6042843173 and MCULE-2362244223 were subjected to MD simulation studies for evaluation of stability, hydrogen bond analysis, van der Waals interactions, and the contact profile of compounds with targeted amino acid residues. Findings of current study suggested MCULE-6042843173 and MCULE-2362244223 as potential and novel inhibitor of DNA Gyrase enzyme.

Benzothiazole Derivatives of Chitosan and Their Derived Nanoparticles: Synthesis and In Vitro and In Vivo Antibacterial Effects

In this work, we focused on synthesizing and assessing novel chitosan-based antibacterial polymers and their nanoparticles by incorporating benzothiazole substituents. The growing resistance to antibiotics has necessitated the search for alternative antimicrobial compounds. This study aimed to synthesize and evaluate chitosan-based polymers and nanoparticles with benzothiazole substituents for their antibacterial properties and toxicity. The benzothiazole derivatives of chitosan and their nanoparticles were synthesized through electrochemical coupling. The in vivo antibacterial efficacy was tested on white rats with induced peritonitis using a microbial suspension containing S. aureus and E. coli. Additionally, in vitro and in vivo toxicity assessments were conducted. The chitosan-based antibacterial systems showed significant in vivo antibacterial activity, surpassing that of unmodified chitosan and commercial antibiotics. Moreover, the toxicity studies revealed low toxicity levels of the synthesized derivatives, which did not differ significantly from native chitosan. The synthesized chitosan-based polymers and nanoparticles demonstrated potent antibacterial activity and low toxicity, highlighting their potential as effective alternatives to traditional antibiotics. Further investigations in pharmacology and preclinical trials are recommended to explore their application in clinical settings.

Updated Review on Clinically-Relevant Properties of Delafloxacin

The extensive use of fluoroquinolones has been consequently accompanied by the emergence of bacterial resistance, which triggers the necessity to discover new compounds. Delafloxacin is a brand-new anionic non-zwitterionic fluoroquinolone with some structural particularities that give it attractive proprieties: high activity under acidic conditions, greater in vitro activity against Gram-positive bacteria-even those showing resistance to currently-used fluoroquinolones-and nearly equivalent affinity for both type-II topoisomerases (i.e., DNA gyrase and topoisomerase IV). During phases II and III clinical trials, delafloxacin showed non-inferiority compared to standard-of-care therapy in the treatment of acute bacterial skin and skin structure infections and community-acquired bacterial pneumonia, which resulted in its approval in 2017 by the Food and Drug Administration for indications. Thanks to its overall good tolerance, its broad-spectrum in vitro activity, and its ease of use, it could represent a promising molecule for the treatment of bacterial infections.

Investigation of Delafloxacin Resistance in Multidrug-Resistant Escherichia coli Strains and the Detection of E. coli ST43 International High-Risk Clone

Delafloxacin is a novel fluoroquinolone agent that is approved for clinical application. In this study, we analyzed the antibacterial efficacy of delafloxacin in a collection of 47 Escherichia coli strains. Antimicrobial susceptibility testing was performed by the broth microdilution method and minimum inhibitory concentration (MIC) values were determined for delafloxacin, ciprofloxacin, levofloxacin, moxifloxacin, ceftazidime, cefotaxime, and imipenem. Two multidrug-resistant E. coli strains, which exhibited delafloxacin and ciprofloxacin resistance as well as extended-spectrum beta-lactamase (ESBL) phenotype, were selected for whole-genome sequencing (WGS). In our study, delafloxacin and ciprofloxacin resistance rates were 47% (22/47) and 51% (24/47), respectively. In the strain collection, 46 E. coli were associated with ESBL production. The MIC50 value for delafloxacin was 0.125 mg/L, while all other fluoroquinolones had an MIC50 value of 0.25 mg/L in our collection. Delafloxacin susceptibility was detected in 20 ESBL positive and ciprofloxacin resistant E. coli strains; by contrast, E. coli strains that exhibited a ciprofloxacin MIC value above 1 mg/L were delafloxacin-resistant. WGS analysis on the two selected E. coli strains (920/1 and 951/2) demonstrated that delafloxacin resistance is mediated by multiple chromosomal mutations, namely, five mutations in E. coli 920/1 (gyrA S83L, D87N, parC S80I, E84V, and parE I529L) and four mutations in E. coli 951/2 (gyrA S83L, D87N, parC S80I, and E84V). Both strains carried an ESBL gene, bla_CTX-M-1 in E. coli 920/1 and bla_CTX-M-15 in E. coli 951/2. Based on multilocus sequence typing, both strains belong to the E. coli sequence type 43 (ST43). In this paper, we report a remarkable high rate (47%) of delafloxacin resistance among multidrug-resistant E. coli as well as the E. coli ST43 international high-risk clone in Hungary.

A Review of the Development of Multitarget Molecules against HIV-TB Coinfection Pathogens

The human immunodeficiency virus (HIV) produces the pathologic basis of acquired immunodeficiency syndrome (AIDS). An increase in the viral load in the body leads to a decline in the number of T lymphocytes, compromising the patient's immune system. Some opportunistic diseases may result, such as tuberculosis (TB), which is the most common in seropositive patients. Long-term treatment is required for HIV-TB coinfection, and cocktails of drugs for both diseases are used concomitantly. The most challenging aspects of treatment are the occurrence of drug interactions, overlapping toxicity, no adherence to treatment and cases of resistance. Recent approaches have involved using molecules that can act synergistically on two or more distinct targets. The development of multitarget molecules could overcome the disadvantages of the therapies used to treat HIV-TB coinfection. This report is the first review on using molecules with activities against HIV and Mycobacterium tuberculosis (MTB) for molecular hybridization and multitarget strategies. Here, we discuss the importance and development of multiple targets as a means of improving adherence to therapy in cases of the coexistence of these pathologies. In this context, several studies on the development of structural entities to treat HIV-TB simultaneously are discussed.

Safety and Efficacy of Nemonoxacin vs Levofloxacin in Patients With Community-Acquired Pneumonia: A Systematic Review and Meta-Analysis of Randomized Control Trials

Community-acquired pneumonia is a leading cause of morbidity and mortality throughout the world, which incurs significant healthcare costs. The aim of his meta-analysis is to assess the clinical efficacy and safety of a novel non-fluorinated quinolone, nemonoxacin, compared with levofloxacin in treating community-acquired pneumonia (CAP). A recursive literature search was conducted using PubMed, Google Scholar, and Scopus up to August 2022. All randomized clinical trials comparing nemonoxacin to levofloxacin for community-acquired pneumonia were included. The patients selected for this study had mild to moderate CAP. Each individual received treatment with either nemonoxacin (500 mg or 750 mg) or levofloxacin (500 mg) for a duration of 3-10 days. Four randomized control trials with a total of 1955 patients were included. Nemonoxacin and levofloxacin were found to have similar clinical cure rates in the treatment of CAP. There were no significant differences reported in the treatment-emergent adverse events between the two drugs (RR=0.95, 95% CI: 0.86, 1.08, I²=0%). However, the most frequent symptoms exhibited were gastrointestinal system-related. Both the dosages (500 mg and 750 mg) of nemonoxacin were found to have similar efficacy as that of levofloxacin. Our meta-analysis indicates that nemonoxacin is a well-tolerated and effective antibiotic therapy for the treatment of community-acquired pneumonia (CAP), with clinical success rates comparable to those of levofloxacin. Furthermore, the adverse effects associated with nemonoxacin are generally mild. Therefore, both the 500 mg and 750 mg dosages of nemonoxacin can be recommended as appropriate antibiotic therapy regimens for the treatment of CAP.