Moxifloxacin HCl -loaded Cellulose Acetate Butylate In Situ Forming Gel for Periodontitis Treatment.

Periodontitis presents significant treatment challenges due to its complexity and potential complications. In response, an in situ forming gel (ISG) loaded with moxifloxacin HCl (Mx) and cellulose acetate butyrate (CAB) was developed for targeted periodontitis therapy. Mx-loaded 10-45% CAB-based ISGs were developed, and their physicochemical properties such as rheology, viscosity, contact angle, gel morphology and gel formation, interface interaction were investigated. Moreover, the formulation performance studies including drug release and kinetics, in vitro degradation, and antimicrobial activities were also evaluated. The Mx-loaded ISGs containing 25-45% CAB demonstrated rapid matrix formation in both macroscopic and microscopic examinations and presented plastic deformation matrix. Tracking with sodium fluorescein and Nile red fluorescence probes indicated delayed solvent movement owing to CAB matrix formation. Adequate CAB content sustained Mx release for one week, following Peppas-Sahlin model and indicating a predominantly Fickian diffusion mechanism. Higher CAB content likely contributed to a denser matrix structure, leading to a slower in vitro degradation rate. Synchrotron radiation X-ray tomographic and SEM imaging provided insights into the CAB matrix structure and porous network formation. These ISG formulations effectively inhibited Staphylococcus aureus, Escherichia coli, Candida albicans, and Porphyromonas gingivalis. The Mx-loaded 40% CAB-based ISG shows promise as a dosage form for treating periodontitis. Further clinical trials are necessary to ensure the safety of this new ISG formulation, despite existing safety data for other medicinal uses of CAB. HIGHLIGHTS: Moxifloxacin HCl-loaded 10-45% cellulose acetate butyrate (CAB)-based in situ forming gels (ISG) were developed. They were evaluated for physicochemical properties, drug release, in vitro degradation, and antimicrobial activities. ISGs with 25-45% CAB showed swift matrix formation and plastic deformation Adequate CAB content sustained Mx release with Fickian diffusion mechanism They promise for periodontitis treatment because of effective inhibition of related pathogens.

Synergistic oral beta-lactam combinations for treating tuberculosis.

BACKGROUND: The enormous burden of tuberculosis (TB) worldwide is a major challenge to human health, but the costs and risks associated with novel drug discovery have limited treatment options for patients. Repurposing existing antimicrobial drugs offers a promising avenue to expand TB treatment possibilities. This study aimed to explore the activity and synergy of beta-lactams in combination with a beta-lactamase inhibitor, which have been underutilized in TB treatment to date. METHODS: Based on inhibitory concentration, oral bioavailability, and commercial availability, seven beta-lactams (cefadroxil, tebipenem, cephradine, cephalexin, cefdinir, penicillin V, and flucloxacillin), two beta-lactamase inhibitors (avibactam and clavulanate), and three second-line TB drugs (moxifloxacin, levofloxacin, and linezolid) were selected for combination in vitro testing against Mycobacterium tuberculosis H37Rv. Resazurin assays and colony forming unit enumeration were used to quantify drug efficacy, Chou-Talalay calculations were performed to identify drug synergy and Chou-Martin calculations were performed to quantify drug dose reduction index. RESULTS: The order of activity of beta-lactams was cefadroxil > tebipenem > cephradine > cephalexin > cefdinir > penicillin V > flucloxacillin. The addition of clavulanate improved beta-lactam activity to a greater degree than the addition of avibactam. As a result, avibactam was excluded from further investigations, which focused on clavulanate. Synergy was demonstrated for cefdinir/cephradine, cefadroxil/tebipenem, cefadroxil/penicillin V, cefadroxil/cefdinir, cephalexin/tebipenem, cephalexin/penicillin V, cephalexin/cefdinir, cephalexin/cephradine, and cefadroxil/cephalexin, all with clavulanate. However, combining beta-lactams with moxifloxacin, levofloxacin, or linezolid resulted in antagonistic effects, except for the combinations of penicillin V/levofloxacin, penicillin V/moxifloxacin, and cefdinir/moxifloxacin. CONCLUSIONS: Beta-lactam synergy may provide viable combination therapies for the treatment of TB.

Successful treatment of Keratitis caused by Mycobacterium chelonae and an overview of previous cases in Europe.

INTRODUCTION AND PURPOSE: Mycobacterium (M.) chelonae is responsible for a half of relatively rare nontuberculous mycobacteria (NTM) keratitis. We report a case of M. chelonae keratitis in a woman following sclerocorneal suture extraction after cataract surgery. RESULTS: A 70-year-old woman presented with a red eye and corneal infiltration of her left eye six weeks following sclerocorneal suture extraction after an elective cataract surgery in another institute. She complained of a sharp, cutting pain and photophobia. Since initial corneal scrapes and conjunctival swabs proved no pathogen using culture and PCR methods, non-specific antibiotics and antifungal agents were administered. As keratitis was complicated by an inflammation in the anterior chamber and vitreous, samples of the vitreous fluid were sent for microbiologic examination. DNA of Epstein-Barr virus (EBV) was repeatedly detected. Since the intrastromal abscess had formed, corneal re-scrapings were performed and M. chelonae was detected using culture, MALDI-TOF MS and PCR methods. Therapy was changed to a combination of oral and topical clarithromycin, intravitreal, topical and intracameral amikacin, and oral and topical moxifloxacin. The successful therapy led to stabilization. The optical penetrating keratoplasty was performed and no signs of the infection recurrence were found. CONCLUSIONS: The diagnosis of nontuberculous mycobacterial keratitis is difficult and often delayed. An aggressive and prolonged antimicrobial therapy should include systemic and topical antibiotics. Surgical intervention in the form of corneal transplantation may be required in the active and nonresponsive infection. In the presented case this was necessary for visual rehabilitation due to scarring.

A "one-step" approach to heart rate correction and statistical analysis applied to conscious dog QTc studies.

A "one-step" method which combined the heart rate correction and statistical analysis for conscious nonhuman primate (NHP) QTc assessment was recently published. The principles of this method are applicable to other species. In the current analysis, we demonstrate the utility of the technique in conscious dog QTc studies. Two studies in male dogs (n = 8 and n = 7) implanted with telemetry devices were used. In both studies, treatments were randomized and all animals received all treatments. In the primary study, the effect on QTc of moxifloxacin was compared with vehicle. Each treatment (vehicle and moxifloxacin) was given on two separate occasions. In the second study, dogs were given vehicle or dofetilide. Conventional QTc analysis was compared with the "one-step" method. The effect on QTc relative to vehicle was determined along with the median minimal detectable difference. As expected, both moxifloxacin and dofetilide gave QTc increases with a maximum of ~ 20 ms. There was a significant increase in the sensitivity to detect a QTc effect when using the "one-step" method. The minimal detectable difference was 1.6 ms for the "one-step" method compared with 6.2 ms for the conventional method. These analyses are consistent with the increased sensitivity described for the "one-step" method applied to studies in NHP. The increased sensitivity should enhance the ability to support an integrated assessment of the QTc prolongation liability for new drugs.

Risk-stratified treatment for drug-susceptible pulmonary tuberculosis.

The Phase 3 randomized controlled trial, TBTC Study 31/ACTG A5349 (NCT02410772) demonstrated that a 4-month rifapentine-moxifloxacin regimen for drug-susceptible pulmonary tuberculosis was safe and effective. The primary efficacy outcome was 12-month tuberculosis disease free survival, while the primary safety outcome was the proportion of grade 3 or higher adverse events during the treatment period. We conducted an analysis of demographic, clinical, microbiologic, radiographic, and pharmacokinetic data and identified risk factors for unfavorable outcomes and adverse events. Among participants receiving the rifapentine-moxifloxacin regimen, low rifapentine exposure is the strongest driver of tuberculosis-related unfavorable outcomes (HR 0.65 for every 100 µg∙h/mL increase, 95%CI 0.54-0.77). The only other risk factors identified are markers of higher baseline disease severity, namely Xpert MTB/RIF cycle threshold and extent of disease on baseline chest radiography (Xpert: HR 1.43 for every 3-cycle-threshold decrease, 95%CI 1.07-1.91; extensive disease: HR 2.02, 95%CI 1.07-3.82). From these risk factors, we developed a simple risk stratification to classify disease phenotypes as easier-, moderately-harder, or harder-to-treat TB. Notably, high rifapentine exposures are not associated with any predefined adverse safety outcomes. Our results suggest that the easier-to-treat subgroup may be eligible for further treatment shortening while the harder-to-treat subgroup may need higher doses or longer treatment.

Hematological Parameters in Patients with Pulmonary Tuberculosis and its Presentation among Favorable and Unfavorable Treatment Outcomes.

BACKGROUND: Tuberculosis (TB) management continues to be a challenge globally; weakened immunity plays a significant role in the reactivation of TB. There is limited information on hematological parameters in patients with pulmonary TB and its association with outcome. OBJECTIVES: We present hematological parameters of newly diagnosed sputum-positive pulmonary TB patients enrolled in a randomized, clinical trial that assessed the efficacy and safety of 3 and 4 regimens using moxifloxacin. MATERIALS AND METHODS: Blood hematological parameters at baseline, comparison of the baseline and end of treatment values, including the monocytes by lymphocytes ratio (M/L), neutrophil lymphocyte ratio (N/L), and platelet lymphocyte ratio (P/L) between the patients with favorable and unfavorable TB treatment outcome, and among different age group and sex presented in this paper. RESULTS: Among the total 1059 patients, 782 were males, the mean hemoglobin (HB) ± standard deviation (SD) was 11.5 g/dL ± 2.0, the mean white blood cell (WBC) count ± SD was 9800 ± 3009 and the mean platelet count (in lakhs) ± SD was 4.24 ± 1.42 cells/uL. There was an increase from baseline in the mean hemoglobin, eosinophil, and lymphocyte count and a decrease in mean neutrophil, monocyte counts to the end of treatment. There was a decrease in baseline mean total WBC count posttreatment, both in favorable (10,271 cells/uL ± 3007 SD to 6689 cells/uL ± 1837 SD, [P ≤ 0.001]), and unfavorable TB outcome patients. CONCLUSION: An increase in HB, and a decrease in WBC count, M/L, N/L, and P/L ratio is possible at the end of TB treatment and future studies to correlate blood hematology parameters with TB treatment outcome.

Prospectively predicting BPaMZ phase IIb/III trial outcomes using a translational mouse-to-human platform.

Despite known treatments, tuberculosis (TB) remains the world's top infectious killer, highlighting the pressing need for new drug regimens. To prioritize the most efficacious drugs for clinical testing, we previously developed a PK-PD translational platform with bacterial dynamics that reliably predicted short-term monotherapy outcomes in Phase IIa trials from preclinical mouse studies. In this study, we extended our platform to include PK-PD models that account for drug-drug interactions in combination regimens and bacterial regrowth in our bacterial dynamics model to predict cure at the end of treatment and relapse 6 months post-treatment. The Phase III STAND trial testing a new regimen comprised of pretomanid (Pa), moxifloxacin (M), and pyrazinamide (Z) (PaMZ) was suspended after a separate ongoing trial (NC-005) suggested that adding bedaquiline (B) to the PaMZ regimen would improve efficacy. To forecast if the addition of B would, indeed, benefit the PaMZ regimen, we applied an extended translational platform to both regimens. We predicted currently available short- and long-term clinical data well for drug combinations related to BPaMZ. We predicted the addition of B to PaMZ to shorten treatment duration by 2 months and to have similar bacteriological success to standard HRZE treatment (considering only treatment success but not withdrawal from side effects and other adverse events), both at the end of treatment for treatment efficacy and 6 months after treatment has ended in relapse prevention. Using BPaMZ as a case study, we have demonstrated our translational platform can predict Phase II and III outcomes prior to actual trials, allowing us to better prioritize the regimens most likely to succeed.

Relationship Between Fluoroquinolone Resistance and Mutations in the Quinolone Resistance-Determining Region in Corynebacterium macginleyi.

Purpose: The purpose of this study was to investigate the bacterial composition in the conjunctiva and to determine the relationship between fluoroquinolone resistance and mutations in the quinolone resistance-determining region (QRDR) in Corynebacterium macginleyi (C. macginleyi). Methods: Bacteria isolated from conjunctival swabs of patients awaiting ophthalmic surgery or patients with presumed keratoconjunctivitis were included in this study. For C. macginleyi isolates from 49 samples, the minimum inhibitory concentrations (MICs) of second- to fourth-generation fluoroquinolones were determined by broth microdilution. Additionally, we determined the sequence of the QRDR in the gyrA gene of C. macginleyi-positive isolates by direct sequencing and investigated the relationship between the QRDR mutation and the MICs of fluoroquinolones for C. macginleyi. Results: Among 423 eyes of 296 preoperative patients who underwent conjunctival culture testing, 105 eyes of 89 patients were culture-positive, and among 148 eyes of 147 patients with keratoconjunctivitis, 55 eyes of 54 patients were culture-positive. C. macginleyi accounted for the largest proportion of cultured organisms (34.8%). C. macginleyi-positive isolates were found in 45 eyes of 37 preoperative patients and in 4 eyes of 4 patients with keratoconjunctivitis. Direct sequencing revealed that 91.8% of C. macginleyi-positive isolates had amino acid mutations in the QRDR and 95.5% of mutations were found at Ser-87 and Asp-91. Isolates harboring double mutations at Ser-87 and Asp-91 were resistant to second- to fourth-generation fluoroquinolones. One isolate with double mutations at Ser-87 and Ala-88 but no mutation in Asp-91 showed intermediate susceptibility to moxifloxacin, a fourth-generation fluoroquinolone. Conclusions: C. macginleyi isolated from conjunctiva harboring QRDR amino acid mutations were resistant to second- to fourth-generation fluoroquinolones.

Investigating the treatment shortening potential of a combination of bedaquiline, delamanid and moxifloxacin with and without sutezolid, in a murine tuberculosis model with confirmed drug exposures.

BACKGROUND: New and shorter regimens against multi-drug resistant tuberculosis (TB) remain urgently needed. To inform treatment duration in clinical trials, this study aimed to identify human pharmacokinetic equivalent doses, antimycobacterial and sterilizing activity of a novel regimen, containing bedaquiline, delamanid, moxifloxacin and sutezolid (BDMU), in the standard mouse model (BALB/c) of Mycobacterium tuberculosis (Mtb) infection. METHODS: Treatment of mice with B25D0.6M200U200, B25D0.6M200, B25D0.6M200(U2003) or H10R10Z150E100 (isoniazid, rifampicin, pyrazinamide, ethambutol, HRZE), started 3 weeks after Mtb infection. Bactericidal activity was assessed after 1, 2, 3 and 4 months of treatment and relapse rates were assessed 3 months after completing treatment durations of 2, 3 and 4 months. RESULTS: B25D0.6M200U200 generated human equivalent exposures in uninfected BALB/c mice. After 1 month of treatment, a higher bactericidal activity was observed for the B25D0.6M200U200 and the B25D0.6M200 regimen compared to the standard H10R10Z150E100 regimen. Furthermore, 3 months of therapy with both BDM-based regimens resulted in negative lung cultures, whereas all H10R10Z150E100 treated mice were still culture positive. After 3 months of therapy 7% and 13% of mice relapsed receiving B25D0.6M200U200 and B25D0.6M200, respectively, compared to 40% for H10R10Z150E100 treatment showing an increased sterilizing activity of both BDM-based regimens. CONCLUSIONS: BDM-based regimens, with and without sutezolid, have a higher efficacy than the HRZE regimen in the BALB/c model of TB, with some improvement by adding sutezolid. By translating these results to TB patients, this novel BDMU regimen should be able to reduce treatment duration by 25% compared to HRZE therapy.

Clinical Characteristics of Moxifloxacin-Related Arrhythmias and Development of a Predictive Nomogram: A Case Control Study.

This study aimed to analyze the incidence, clinical characteristics, and risk factors of moxifloxacin-related arrhythmias and electrocardiographic alterations in hospitalized patients using real-world data. Concurrently, a nomogram was established and validated to provide a practical tool for prediction. Retrospective automatic monitoring of inpatients using moxifloxacin was performed in a Chinese hospital from January 1, 2017, to December 31, 2021, to obtain the incidence of drug-induced arrhythmias and electrocardiographic alterations. Propensity score matching was conducted to balance confounders and analyze clinical characteristics. Based on the risk and protective factors identified through logistic regression analysis, a prediction nomogram was developed and internally validated using the Bootstrap method. Arrhythmias and electrocardiographic alterations occurred in 265 of 21,711 cases taking moxifloxacin, with an incidence of 1.2%. Independent risk factors included medication duration (odds ratio [OR] 1.211, 95% confidence interval [CI] 1.156-1.270), concomitant use of meropenem (OR 4.977, 95% CI 2.568-9.644), aspartate aminotransferase >40 U/L (OR 3.728, 95% CI 1.800-7.721), glucose >6.1 mmol/L (OR 2.377, 95% CI 1.531-3.690), and abnormally elevated level of amino-terminal brain natriuretic peptide precursor (OR 2.908, 95% CI 1.640-5.156). Concomitant use of cardioprotective drugs (OR 0.430, 95% CI 0.220-0.841) was a protective factor. The nomogram showed good differentiation and calibration, with enhanced clinical benefit. The incidence of moxifloxacin-related arrhythmias and electrocardiographic alterations is in the range of common. The nomogram proves valuable in predicting the risk in the moxifloxacin-administered population, offering significant clinical applications.

A 48-year-old man with fever, nauseous, vomiting, and dizzy: A CARE case report.

RATIONALE: Listeria monocytogenes (LM) is an important foodborne bacterium, and LM meningoencephalitis is rare in clinical practice, with poor prognosis in severe patients. It is prone to misdiagnosis in clinical practice. We first reported a case of severe LM meningoencephalitis with muscle lesions and evaluated the comprehensive condition. PATIENT CONCERNS: A 48-year-old man had a fever and was admitted to the neurology department due to dizziness, nausea, and vomiting for 20 days. DIAGNOSES: LM meningoencephalitis complicated with muscle lesions. INTERVENTIONS: We used moxifloxacin 0.4 g, qd, meropenem 2 g, q8h, and dexamethasone 10 mg, qd to reduce exudation and adhesion. Then due to consideration of side effects, we increased the dose of ampicillin by 2 g, q4h, stopped using meropenem and moxifloxacin, and turned to maintenance treatment with dexamethasone and ampicillin. We comprehensively managed his vital signs and physical organ functions, we also controlled some comorbidities. During the hospitalization period thereafter, we used intravenous anti-infection treatment with moxifloxacin 0.4 g, qd, ampicillin 0.5 g, q4h. OUTCOMES: Half a year later, the reexamination showed only protein elevation in cerebrospinal fluid and hydrocephalus in MRI. Afterward, the symptoms did not recur again. The patient recovered well after discharge. LESSONS: LM meningoencephalitis complicated with lower limb muscle lesions is clinically rare. This report focuses on relevant treatment plans, which provide value for the examination and comprehensive management of patients with LM infection in the future.

A phase I thorough QT/QTc study evaluating therapeutic and supratherapeutic doses of avacopan in healthy participants.

This phase I thorough QTc, double-blind, randomized, placebo- and positive-controlled, parallel group, multiple-dose study evaluated avacopan's effect on cardiac repolarization using concentration-QTc (C-QTc) as the primary analysis. Avacopan 30 mg b.i.d. (therapeutic dose) was administered orally on days 1 through 7 followed by avacopan 100 mg b.i.d. (supratherapeutic dose) on days 8 through 14 in 29 healthy participants. Moxifloxacin 400 mg and placebo were administered on days 1 and 15 in a nested crossover design for assay sensitivity in separate cohorts to 28 participants. Time-matched plasma concentrations and up to 10 replicate ECGs were obtained on prespecified days at baseline and postdose on days 1, 7, 14, and 15. The mean change from baseline on QTcF for avacopan (-5.5 to 3.5 ms) was similar to placebo (-6.9 to 1.4 ms) across days 1, 7, and 14. The mean effect on ΔΔQTcF (90% CI) was estimated as 1.5 ms (-0.17 to 3.09) and 0.8 ms (-2.41 to 4.05) for 30 and 100 mg avacopan b.i.d. treatments, respectively. Based on the C-QTc analysis, avacopan's effect on ΔΔQTcF >10 ms can be excluded within the observed plasma concentration range of up to ~1220 and ~335 ng/mL for avacopan and active major metabolite, M1, respectively. The estimated population slopes showed a shallow relationship, which was not statistically significant. There was no clinically meaningful effect of avacopan on heart rate or cardiac conduction (PR and QRS intervals). Avacopan appeared to be generally well tolerated in this study population.

Determination of bactericidal activity against 3HC-2-Tre-labelled Mycobacterium abscessus (Mycobacteroides abscessus) by automated fluorescence microscopy.

The minimum bactericidal concentration (MBC) of antibiotics is an important parameter for the potency of a drug in eradicating a bacterium as well as an important measure of the potential of a drug candidate in research and development. We have established a fluorescence-based microscopy method for the determination of MBCs against the non-tuberculous mycobacterium Mycobacterium abscessus (Mycobacteroides abscessus) to simplify and accelerate the performance of MBC determination compared to counting colony forming units on agar. Bacteria are labelled with the trehalose-coupled dye 3HC-2-Tre and analysed in a 96-well plate. The results of the new method are consistent with MBC determination by plating on agar. The method was used to evaluate the bactericidality of the antibiotics rifabutin, moxifloxacin, amikacin, clarithromycin and bedaquiline. Bactericidal effects against M. abscessus were observed, which are consistent with literature data.

Drug-impregnated contact lenses via supercritical carbon dioxide: A viable solution for the treatment of bacterial and fungal keratitis.

Keratitis is a corneal infection caused by various bacteria and fungi. Eye drop treatment of keratitis involves significant challenges due to difficulties in administration, inefficiencies in therapeutic dosage, and frequency of drug applications. All these are troublesome and result in unsuccessful treatment, high cost, time loss, development of drug resistance by microorganisms, and a massive burden on human health and the healthcare system. Most of the antibacterial and antifungal medications are non-water-soluble and/or include toxic drug formulations. Here, the aim was to develop drug-loaded contact lenses with therapeutic dosage formulations and extended drug release capability as an alternative to eye drops, by employing supercritical carbon dioxide (ScCO2) as a drug impregnation solvent to overcome inefficient ophthalmic drug use. ScCO2, known as a green solvent, has very low viscosity which provides high mass transfer power and could enhance drug penetration into contact lenses much better with respect to drug loading using other solvents. Here, moxifloxacin (MOX) antibiotic and amphotericin B (AMB) antifungal medicines were separately loaded into commercially available silicone hydrogel contact lenses through 1) drug adsorption from the aqueous solutions and 2) impregnation techniques via ScCO2 and their efficacies were compared. Drug impregnation parameters, i.e., 8-25 MPa pressure, 310-320 K temperature, 2-16-hour impregnation times, and the presence of ethanol as polar co-solvent were investigated for the optimization of the ScCO2 drug impregnation process. The highest drug loading and long-term release kinetic from the contact lenses were obtained at 25 MPa and 313 K with 2.5 h impregnation time by using 1 % ethanol (by volume). Furthermore, antibacterial/antifungal activities of the MOX- and AMB-impregnated contact lenses were effective against in vitro Pseudomonas aeruginosa (ATCC 10145) bacteria and Fusarium solani (ATCC 36031) fungus for up to one week. Consequently, the ScCO2 method can be effectively used to impregnate commercial contact lenses with drugs, and these can then be safely used for the treatment of keratitis. This offers a sustainable delivery system at effective dosage formulations with complete bacterial/fungal inhibition and termination, making it viable for real animal/human applications.

New generation fluoroquinolone sitafloxacin could potentially overcome the majority levofloxacin and moxifloxacin resistance in multidrug-resistant Mycobacterium tuberculosis.

Introduction. Pre-existing fluoroquinolones (FQs) resistance is a major threat in treating multidrug-resistant (MDR) tuberculosis. Sitafloxacin (Sfx) is a new broad-spectrum FQ.Hypothesis. Sfx is more active against drug-resistant Mycobacterium tuberculosis (Mtb) isolates.Aim. To determine whether there is cross-resistance between Sfx and ofloxacin (Ofx), levofloxacin (Lfx) and moxifloxacin (Mfx) in MDR Mtb.Methods. A total of 106 clinical Mtb isolates, including 23 pan-susceptible and 83 MDR strains, were analysed for Sfx, Lfx and Mfx resistance using MIC assay. The isolates were also subjected to whole-genome sequencing to analyse drug-resistant genes.Results. Sfx exhibited the most robust inhibition activity against Mtb clinical isolates, with a MIC50 of 0.0313 µg ml-1 and MIC90 of 0.125 µg ml-1, which was lower than that of Mfx (MIC50 = 0.0625 µg ml-1, MIC90 = 1 µg ml-1) and Lfx (MIC50 = 0.125 µg ml-1, MIC90 = 2 µg ml-1). We determined the tentative epidemiological cut-off values as 0.5 µg ml-1 for Sfx. Also, 8.43% (7/83), 43.37% (36/83), 42.17% (35/83) and 51.81% (43/83) MDR strains were resistant to Sfx, Mfx, Lfx and Ofx, respectively. Cross-resistance between Ofx, Lfx and Mfx was 80.43% (37/46). Only 15.22% (7/46) of the pre-existing FQs resistance isolates were resistant to Sfx. Among the 30 isolates with mutations in gyrA or gyrB, 5 (16.67%) were Sfx resistant. The combination of Sfx and rifampicin could exert partial synergistic effects, and no antagonism between Sfx and six clinically important anti-Mtb antibiotics was evident.Conclusion. Sfx exhibited superior activity against MDR isolates comparing to Lfx and Mfx, and could potentially overcome the majority pre-existing FQs resistance in Mtb strains.

Efficient removal of moxifloxacin through PMS activation by CuFeS2/MXene.

Due to the frequent detection and potential toxicity of moxifloxacin (MOX), its removal technology had attracted attention in recent years. In this research, CuFeS2/MXene was prepared and used to activate peroxymonosulfate (PMS) to remove MOX. The degradation efficiencies, kinetics, influences, and reaction mechanism of MOX by CuFeS2/MXene/PMS were investigated. The synergistic effect of CuFeS2 and MXene significantly enhanced PMS activation, producing SO4•-, HO•, and 1O2 as the main active species. By adding 0.12 g/L CuFeS2/MXene and 0.12 mM PMS, MOX removal efficiency reached 99.1% within 40 min, with a rate constant of 0.1073 min-1. The composite ratios of CuFeS2/MXene impacted PMS activation more significantly than catalyst dosages and PMS concentrations. Acidic conditions were favorable for the degradation of MOX, while HCO3-, HPO42-, Mn2+, and HA had the inhibitory effects. Twelve major products were detected by HPLC-MS, and DFT was used to illustrate possible degradation pathways of MOX, including the removal of nitrogen-containing heterocycle and transformations of quinolone moieties. Toxicity analysis showed that the developmental toxicity, mutagenicity, and acute toxicity of degradation products tended to decrease. CuFeS2/MXene could exhibit excellent reusability, maintaining an average MOX degradation efficiency of 90.8% in the 7-cycle experiments.

Thorough QT/QTc study to evaluate the effect of a single supratherapeutic dose of islatravir on QTc interval prolongation in healthy adults.

Islatravir is a deoxynucleoside analog being developed for the treatment of HIV-1 infection. Clinical studies are being conducted to evaluate islatravir, administered in combination with other antiretroviral therapies, at doses of 0.25 mg once daily and 2 mg once weekly. In multiple previous clinical studies, islatravir was generally well tolerated, with no clear trend in cardiac adverse events. A trial was conducted to evaluate the effect of islatravir on cardiac repolarization. A randomized, double-blind, active- and placebo-controlled phase 1 trial was conducted, in which a single dose of islatravir 0.75 mg, islatravir 240 mg (supratherapeutic dose), moxifloxacin 400 mg (active control), or placebo was administered. Continuous 12-lead electrocardiogram monitoring was performed before dosing through 24 hours after dosing. QT interval measurements were collected, and safety and pharmacokinetics were evaluated. Sixty-three participants were enrolled, and 59 completed the study. Fridericia's QT correction for heart rate was inadequate; therefore, a population-specific correction was applied (QTcP). The placebo-corrected change from baseline in QTcP (ΔΔQTcP) interval at the observed geometric mean maximum plasma concentration associated with islatravir 0.75 mg and islatravir 240 mg was <10 ms at all time points. Assay sensitivity was confirmed because the use of moxifloxacin 400 mg led to a ΔΔQTcP >10 ms. The pharmacokinetic profile of islatravir was consistent with that of previous studies, and islatravir was generally well tolerated. Results from the current trial suggest that single doses of islatravir as high as 240 mg do not lead to QTc interval prolongation.

Drug resistance patterns and treatment outcomes in DR-TB patients at a tertiary care centre in Mumbai.

BACKGROUND: Drug-resistant tuberculosis (DR-TB) is a major health problem and threatens Tuberculosis (TB) control and outcomes globally. India holds one-fourth of global DR-TB burden.1 AIMS: 1- To study drug resistance patterns and outcomes in DR-TB patients under National Tuberculosis Elimination Programme (NTEP) at a tertiary care-centre. 2- To correlate outcome of DR-TB with drug resistance patterns. METHODS: It is a retrospective study of 302 Drug Resistant Tuberculosis patients from Jan 2020 to May 2022. Common mutations of drug resistance, pyrazinamide resistance in DR-TB patients, correlation of High dose Moxifloxacin sensitivity by Line Probe Assay (LPA) and drug sensitivity test (DST), outcome of DR-TB patients with drug resistance patterns and correlation of outcome of DR-TB patients with their initial body-weight were studied. RESULTS: Kat G was the most common mutation in Isoniazid (96%) resistance for MDR TB as well as Isoniazid Mono-resistance TB (p = 0.001). 91% cases with MDR-TB were resistant to pyrazinamide. 51.2% cases had low dose Fluroquinolone resistance. 18.8% cases had low and high dose Fluroquinolone resistance. 8.5% cases had resistance to injectables. 21.7% of cases who were resistant to High dose Moxifloxacin on second line LPA were found to be sensitive on DST. Outcomes were not dependent on the LPA resistance patterns. Body-weight greater than 45 Kg at the time of initiation of treatment was associated with better outcomes (p = 0.007). CONCLUSION: DR-TB patients are resistant to pyrazinamide in nearly all cases; hence pyrazinamide is not suitable for initial replacement sequence. Second line resistance doesn't impact outcome in DR-TB patients.

Pattern and characteristics of mutations conferring resistance to second line drugs in Mycobacterium tuberculosis isolates of pulmonary and extrapulmonary TB samples.

BACKGROUND & OBJECTIVES: The purpose of present study is to analyse the distribution and pattern of genetic mutations in PRE-XDR-TB and extensive drug resistant Mycobacterium tuberculosis (XDR-TB) using second-line line probe assay and to compare them with different parameters. METHOD: Sputum, Lymph node aspirate and cold accesses from patients with rifampicin resistant Tuberculosis were subjected to first line and second line Probe Assay (Genotype MTBDRsl by Hain Life Science, Germany) to assess additional drug resistance to fluroquinolones (Levofloxacin & Moxifloxacin) and Aminoglycosides (Amikacin, Ofloxacin and Kanamycin). The genetic mutation pattern was analysed and compared with demographic, clinical and other parameters. RESULTS: The final study population included 123 fluoroquinolone resistant isolates including 14 isolates with additional second line aminoglycosides drug resistance. The most frequent mutation observed among Gyr A drug resistance mutation was D94G (Gyr A MUT3C, 50/123,40%) corresponding to high level resistance to levofloxacin and moxifloxacin. The most frequent wild type mutant among Gyr A gene locus was WT 3 (85/123,69%). The most common mutation among second line aminoglycoside resistant isolates was at eis WT2 (7/14,50%) followed by rrs MUT 2 (4/14,29%). CONCLUSIONS: GyrA MUT3C (Asp94Gly) was the most common mutation in Gyr A gene locus in M. tuberculosis causing high level levofloxacin and moxifloxacin resistance. Patients with Asp94Gly mutation was significantly associated with underweight body mass index (p = 0.026). This study also observed that history of anti-tuberculosis therapy is a risk factor for FQ drug resistance mutations (p < 0.001).

Agar and agarose used for Staphylococcus aureus biofilm cultivation impact fluoroquinolone tolerance.

AIMS: Staphylococcus aureus is an opportunistic pathogen whose treatment is further complicated by its ability to form biofilms. In this study, we examine the impact of growing S. aureus biofilms on different polymerizing surfaces, specifically agar and agarose, on the pathogen's tolerance to fluoroquinolones. METHODS AND RESULTS: Biofilms of two methicillin-resistant strains of S. aureus were grown on agar or agarose in the presence of the same added nutrients, and their antibiotic susceptibility to two fluoroquinolones, moxifloxacin (MXF) and delafloxacin (DLX), were measured. We also compared the metabolism and extracellular polymeric substances (EPS) production of biofilms that were grown on agar and agarose. CONCLUSIONS: Biofilms that were grown on agarose were consistently more susceptible to antibiotics than those grown on agar. We found that in biofilms that were grown on agar, extracellular protein composition was higher, and adding EPS to agarose-grown biofilms increased their tolerance to DLX to levels that were comparable to agar-grown biofilms.