Mesoporous cobalt-manganese layered double hydroxides promote the activation of calcium sulfite for degradation and detoxification of metronidazole

Metronidazole (MNZ), a commonly used antibiotic, poses risks to water bodies and human health due to its potential carcinogenic, mutagenic, and genotoxic effects. In this study, mesoporous cobalt-manganese layered double hydroxides (CoxMny-LDH) with abundant oxygen vacancies (Ov) were successfully synthesized using the co-precipitation method and used to activate calcium sulfite (CaSO3) with slight soluble in water for MNZ degradation. The characterization results revealed that Co2Mn-LDH had higher specific areas and exhibited good crystallinity. Co2Mn-LDH/CaSO3 exhibited the best catalytic performance under optimal conditions, achieving a remarkable MNZ degradation efficiency of up to 98.1 % in only 8 min. Quenching experiments and electron paramagnetic resonance (EPR) tests showed that SO4•- and 1O2 played pivotal roles in the MNZ degradation process by activated CaSO3, while the redox cycles of Co2+/Co3+ and Mn3+/Mn4+ on the catalyst surface accelerated electron transfer, promoting radical generation. Three MNZ degradation routes were put forward based on the density functional theory (DFT) and liquid chromatography-mass spectrometer (LC-MS) analysis. Meanwhile, the toxicity analysis result demonstrated that the toxicity of intermediates post-catalytic reaction was decreased. Furthermore, the Co2Mn-LDH/CaSO3 system displayed excellent stability, reusability, and anti-interference capability, and achieved a comparably high removal efficiency across various organic pollutant water bodies. This study provides valuable insights into the development and optimization of effective heterogeneous catalysts for treating antibiotic-contaminated wastewater.

Deep eutectic solvent-based ferrofluid for highly efficient preconcentration and determination of metronidazole by vortex-assisted liquid-phase microextraction under experimental design optimization

To determine metronidazole in water samples, we developed an environmentally friendly, efficient, and straightforward ferrofluid-based liquid-liquid microextraction sample pretreatment technique. It is coupled with a high-performance liquid chromatography-ultraviolet analytical technique known for its sensitivity, speed, and precision. The magnetic separation of metronidazole-containing ferrofluid from the matrix was effortlessly achieved through the application of an external magnetic field, eliminating the need for centrifugation. Response surface optimization was employed to systematically determine the key experimental parameters influencing extraction efficiency, including pH, NaCl concentration, ferrofluid volume, and vortex duration. With a low detection limit (0.116 ng mL-1), a broad linear range between 0.5 and 700 ng mL-1 was achieved at optimal conditions. Additionally, acceptable spiking recoveries (94.3-97.3 %) and RSD values (≤3.7 %) for intra- and inter-day precision were attained in water samples. In conclusion, the effectiveness of the vortex and ferrofluid combination, along with the convenience of collection and elimination of the need for centrifugation, bestows a highly valuable technique for determining metronidazole in water samples.

Near-infrared light responsive gold nanoparticles coating endows polyetheretherketone with enhanced osseointegration and antibacterial properties

Polyetheretherketone (PEEK) is considered as a promising dental implant material owing to its excellent physicochemical and mechanical properties. However, its wide range of applications is limited by its biologically inert nature. In this study, a near-infrared (NIR) light responsive bioactive coating with gold nanoparticles (AuNPs) and metronidazole adhered to the PEEK surface via dopamine polymerization. Compared to pure PEEK, the hydrophilicity of the treated PEEK surface was significantly improved. In addition, under NIR light, the surface coating exhibited photothermal conversion effect, and gold nanoparticles and the antibiotic can be released from the coating. This improved the antibacterial properties of PEEK materials. Moreover, the coating was more conducive to the early adhesion of bone mesenchymal stem cells. The results of in vitro and in vivo osteogenic activity studies showed that the developed coating promoted osseointegration of PEEK implants, and NIR light irradiation further improved the antibacterial ability and osteogenic activity of PEEK implants. Through RNA sequencing, the potential underlying mechanism of promoting bone formation of the AuNPs coating combined metronidazole was interpreted. In summary, the developed coating is a potential surface treatment strategy that endows PEEK with enhanced osseointegration and antibacterial properties.

Amebic liver abscess: An update

Amebic liver abscess (ALA) is still a common problem in the tropical world, where it affects over three-quarters of patients with liver abscess. It is caused by an anaerobic protozoan Entamoeba hystolytica, which primarily colonises the cecum. It is a non-suppurative infection of the liver consisting primarily of dead hepatocytes and cellular debris. People of the male gender, during their reproductive years, are most prone to ALA, and this appears to be due to a poorly mounted immune response linked to serum testosterone levels. ALA is more common in the right lobe of the liver, is strongly associated with alcohol consumption, and can heal without the need for drainage. While majority of ALA patients have an uncomplicated course, a number of complications have been described, including rupture into abdomino-thoracic structures, biliary fistula, vascular thrombosis, bilio-vascular compression, and secondary bacterial infection. Based on clinico-radiological findings, a classification system for ALA has emerged recently, which can assist clinicians in making treatment decisions. Recent research has revealed the role of venous thrombosis-related ischemia in the severity of ALA. Recent years have seen the development and refinement of newer molecular diagnostic techniques that can greatly aid in overcoming the diagnostic challenge in endemic area where serology-based tests have limited accuracy. Metronidazole has been the drug of choice for ALA patients for many years. However, concerns over the resistance and adverse effects necessitate the creation of new, safe, and potent antiamebic medications. Although the indication of the drainage of uncomplicated ALA has become more clear, high-quality randomised trials are still necessary for robust conclusions. Percutaneous drainage appears to be a viable option for patients with ruptured ALA and diffuse peritonitis, for whom surgery represents a significant risk of mortality. With regard to all of the aforementioned issues, this article intends to present an updated review of ALA.

Development of New PCR Protocols to Detect Genetic Diversity in the Metronidazole Metabolism Genes in Susceptible and Refractory Clinical Samples of Giardia duodenalis

PURPOSE

Investigating the genetic variation in thioredoxin reductase (TrxR) and nitroreductase (NR) genes in both treatment-resistant and -sensitive Giardia duodenalis isolates can provide valuable information in identifying potential markers of resistance to metronidazole. The rapid increase in metronidazole treatment failures suggests the presence of genetic resistance mechanisms. By analyzing these genes, researchers can gain insights into the efficacy of metronidazole against G. duodenalis and potentially develop alternative treatment strategies. In this regard, four G. duodenalis isolates (two clinically sensitive and two clinically resistant to metronidazole) were collected from various hospitals of Shiraz, southwestern Iran.

METHODS

Parasitological methods including sucrose flotation and microscopy were employed for the primary confirmation of G. duodenalis cysts in stool samples. Microscopy-positive samples were approved by SSU-PCR amplification of the parasite DNA. All four positive G. duodenalis specimens at SSU-PCR were afterward analyzed utilizing designed primers based on important metronidazole metabolism genes including TrxR, NR1, and NR2.

RESULTS

Unlike TrxR gene, the results of NR1 and NR2 genes showed that there are non-synonymous variations between sequences of treatment-sensitive and -resistant samples compared to reference sequences. Furthermore, the outcomes of molecular docking revealed that there is an interaction between the protein sequence and spatial shape of treatment-resistant samples and metronidazole in the position of serine amino acid based on the NR1 gene.

CONCLUSION

This issue can be one of the possible factors involved in the resistance of Giardia parasites to metronidazole. To reach more accurate results, a large sample size along with simulation and advanced molecular dynamics investigations are needed.

Association Between First-Time Neurologic Events and Metronidazole Treatment: A Case-Time Control Study

PURPOSE

Metronidazole, a widely used antimicrobial medication, has been linked to neurologic adverse drug reactions. This study investigates the association between metronidazole use and first-time neurologic events.

METHODS

We conducted a case-time-control study using data from the Danish National Patient Register and the National Prescription Register in years 2013 to 2021. Patients with a first-time diagnosis of encephalopathy, cerebellar dysfunction, or peripheral neuropathy were included. Conditional logistic regression analyses were performed to estimate the risk of neurologic events associated with metronidazole use.

FINDINGS

Out of 476,066 first-time metronidazole prescriptions, the 100-day cumulative incidence of peripheral neuropathy was 0.016%, and 0.002% for cerebellar dysfunction or encephalopathy. In the case-time control study, we identified 17,667 persons with a first-time neurologic event and were included for the analysis. The estimated odds ratio for the combined neurologic events was 0.98 (95% CI, 0.59-1.64, P = 0.95) with no statistically significant association across different subgroups and time windows.

IMPLICATIONS

Our findings suggest that metronidazole-induced neurologic events may be rarer than previously described, and we did not find any consistent or statistically significant association between metronidazole exposure. Nonetheless, clinicians should remain vigilant to potential neurologic risks in patients receiving metronidazole, to ensure its safe and effective use.

Effective treatment of Clostridioides difficile infection improves survival and affects graft-versus-host disease: a multicenter study by the Polish Adult Leukemia Group

Clostridioides difficile infection (CDI) is the most common cause of infectious diarrhea after allogeneic hematopoietic cell transplantation (allo-HCT). The impact of CDI and its treatment on allo-HCT outcomes and graft-versus-host disease (GVHD), including gastrointestinal GVHD (GI-GVHD) is not well established. This multicenter study assessed real-life data on the first-line treatment of CDI and its impact on allo-HCT outcomes. Retrospective and prospective data of patients with CDI after allo-HCT were assessed. We noted statistically significant increase in the incidence of acute GVHD and acute GI-GVHD after CDI (P = 0.005 and P = 0.016, respectively). The first-line treatment for CDI included metronidazole in 34 patients, vancomycin in 64, and combination therapy in 10. Treatment failure was more common with metronidazole than vancomycin (38.2% vs. 6.2%; P < 0.001). The need to administer second-line treatment was associated with the occurrence or exacerbation of GVHD (P < 0.05) and GI-GVHD (P < 0.001) and reduced overall survival (P < 0.05). In the multivariate analysis, the risk of death was associated with acute GVHD presence before CDI (hazard ratio [HR], 3.19; P = 0.009) and the need to switch to second-line treatment (HR, 4.83; P < 0.001). The efficacy of the initial CDI treatment affects survival and occurrence of immune-mediated GI-GVHD after allo-HCT. Therefore, agents with higher efficacy than metronidazole (vancomycin or fidaxomicin) should be administered as the first-line treatment.

Application of artificial intelligence for the optimization of advanced oxidation processes to improve the water quality polluted with pharmaceutical compounds

Sulfamethoxazole and metronidazole are emerging pollutants commonly found in surface water and wastewater. These compounds have a significant environmental impact, being necessary in the design of technologies for their removal. Recently, the advanced oxidation process has been proven successful in the elimination of this kind of compounds. In this sense, the present work discusses the application of UV/H2O2 and ozonation for the degradation of both molecules in single and binary systems. Experimental kinetic data from O3 and UV/H2O2 process were adequately described by a first and second kinetic model, respectively. From the ANOVA analysis, it was determined that the most statistically significant variables were the initial concentration of the drugs (0.03 mmol L-1) and the pH = 8 for UV/H2O2 system, and only the pH (optimal value of 6) was significant for degradation with O3. Results showed that both molecules were eliminated with high degradation efficiencies (88-94% for UV/H2O2 and 79-98% for O3) in short reaction times (around 30-90 min). The modeling was performed using a quadratic regression model through response surface methodology representing adequately 90 % of the experimental data. On the other hand, an artificial neural network was used to evaluate a non-linear multi-variable system, a 98% of fit between the model and experimental data was obtained. The identification of degradation byproducts was performed by high-performance liquid chromatography coupled to a time mass detector. After each process, at least four to five stable byproducts were found in the treated water, reducing the mineralization percentage to 20% for both molecules.

Composite of a thiacalix[4]arene-copper(I) metal-organic framework and mesoporous carbon for efficient electrochemical detection of antibiotics

Abundant use of nitrofurantoin (NFT) and metronidazole (MTZ) antibiotics has led to excessive residues in the environments and humans, resulting in serious damage to the human body and ecosystem. Therefore, effective detection of NFT and MTZ is exceedingly necessary. In this regard, metal-organic frameworks (MOFs) are promising materials as electrochemical sensors. Herein, we synthesized a new two-dimensional thiacalix [4]arene-copper (I) MOF (Cu-TC4A-M). This MOF was mixed with mesoporous carbon (MC) to a give Cu-TC4A-M@MC composite. In addition, the sensors of Cu-TC4A-M@MC(2:1)/GCE and Cu-TC4A-M@MC(1:2)/GCE were achieved (GCE = glassy carbon electrode), and then were applied for effectively detecting NFT and MTZ, respectively. Markedly, the two sensors exhibited satisfactory linear detection range, anti-interference, reproducibility and stability. When they were utilized in the real samples, such as human serum, urine, tap water and lake water, satisfactory recoveries were attained. The relative standard deviations (RSDs) were in the range of 1.16 % ∼ 1.92 % for NFT and 0.95 % ∼ 2.33 % for MTZ. This work provided a new application prospect for the thiacalix [4]arene-based MOFs as promising candidate materials for NFT and MTZ detection.

On the use of intravenous metronidazole for severe and complicated Clostridioides difficile infection: a review and meta-analysis

The European Society of Clinical Microbiology and Infectious Disease (ESCMID) has advised against the use of metronidazole for fulminant Clostridioides difficile (C. difficile) infection (CDI) in their latest guidelines. They suggest using oral vancomycin alone instead. This recommendation is based on a few retrospective studies, which have multiple biases. We evaluated the three studies that led ESCMID to advise against intravenous metronidazole for fulminant CDI and performed a meta-analysis. The meta-analysis revealed a mild (2.7%), not statistically significant (p=0.8) difference in mortality between the two groups. The high heterogeneity (I2= 89%) should also be noted. The decision to add or remove metronidazole should be discussed in the near future. In the meantime, combination therapy could be a cautious treatment for fulminant CDI.

Metronidazole promotes oxidative stress and DNA fragmentation-mediated myocardial injury in albino mice

The purpose of the present study was to investigate the cardiotoxic effects of Metronidazole (Mtz) in albino mice. The mice were divided into four experimental groups: Gp.I (control group): saline, Gp.II:125 mg/kg b.w Mtz, Gp.III:250 mg/kg b.w, Gp.IV:500 mg/kg b.w Mtz. Heart weight ratio, markers of cardiac injury, markers of oxidative stress, histopathological examinations, DNA fragmentation and spectral analysis were used to determine cardiotoxicity. Administration of 125-500 mg/kg Mtz caused an increase in heart weight and a decrease in body weight. Administration of 500 mg/kg Mtz increased heart weight by 35.5% and decreased body weight by 21.9% compared with control. Mtz-treated mice showed a significant increase in cardiac injury biomarkers and serious alterations in cardiac oxidative stress markers. Histopathological changes of cardiac tissues observed in mice treated with Mtz include myocardial hypertrophy, fibrosis, myocarditis, separation of the muscle fibers, congestion-narrowing in vessels, necrosis, myocardium-vacuolation, myocytolysis, myocyte degeneration, nuclear aggregation, cytoplasmic fragmentation and prevalent nuclei. Mtz treatment already resulted in a significant decrease in the percentage of head DNA and an increase in the percentage of tail DNA. The most striking tail formation among the Mtz-treated groups was observed in the group receiving 500 mg/kg Mtz. In the presence of Mtz, there was a hypochromic shift in the absorption spectrum of DNA, and the potential DNA-Mtz interaction was found to occur in the intercalation mode. These results show that Mtz used against anaerobic bacteria and protozoa in gastrointestinal infections can cause severe cardiotoxic findings in albino mice and cause fragmentation in DNA.

Zein and hydroxypropyl methylcellulose acetate succinate microfibers combined with metronidazole benzoate and/or metronidazole-incorporated cellulose nanofibrils for potential periodontal treatment

The development of flexible and porous materials to control antibacterial delivery is a pivotal endeavor in medical science. In this study, we aimed to produce long and defect-free fibers made of zein and hydroxypropyl methylcellulose acetate succinate (HPMCAS) to be used as a platform for the release of metronidazole (MDZ) and metronidazole benzoate (BMDZ) to be potentially used in periodontal treatment. Microfibers prepared via electrospinning under a 2:3 (w/w) zein to HPMCAS ratio, containing 0.5 % (w/w) poly(ethylene oxide) (PEO) and 1 % (w/w) cellulose nanofibril (CNF) were loaded with 40 % (w/w) MDZ, 40 % (w/w) BMDZ, or a combination of 20 % (w/w) of each drug. The addition of CNF improved the electrospinning process, resulting in long fibers with reduced MDZ and BMDZ surface crystallization. MDZ- and BMDZ-incorporated fibers were semicrystalline and displayed commendable compatibility among drugs, nanocellulose and polymeric chains. Release tests showed that zein/HPMCAS/PEO fibers without CNF and with 20 % (w/w) MDZ/ 20 % (w/w) BMDZ released the drug at a slower and more sustained rate compared to other samples over extended periods (up to 5 days), which is a favorable aspect concerning periodontitis treatment.

Metal-free carbon-based anode for electrochemical degradation of tetracycline and metronidazole in wastewater

Degradation of antibiotics through electrocatalytic oxidation has recently been comprehended as a promising strategy in wastewater treatment. Herein, nitrogen and sulphur doped graphene oxide (N,S-rGO) nanosheets were synthesized and employed as metal-free anodic material for electrochemical degradation of antibiotics, viz. metronidazole (MNZ) and tetracycline (TC). The synthesized anodic material was characterized using various spectral techniques and further the electrochemical behaviour of N,S-rGO was thoroughly examined. Thereafter, the N,S-rGO material was then employed as the anode material towards the electrocatalytic degradation of antibiotics. Parameters such as initial concentration of the antibiotics and current densities were varied and their effect towards the degradation of MNZ and TC were probed. Notably, the N,S-rGO based anode has shown impressive removal efficiency of 99% and 98.5%, after 120 min of reaction time for MNZ and TC, respectively, under optimized conditions. The obtained results including the kinetic parameters, removal efficiency and electrical efficiency ensure that the prepared anodic material has huge prospective towards real-time application for removal of antibiotics from water.

Statistical computational optimization approach for photocatalytic-ozonation decontamination of metronidazole in aqueous media using CuFe2O4/SiO2/ZnO nanocomposite

The increasing use of pharmaceuticals and the ongoing release of drug residues into the environment have resulted in significant threats to environmental sustainability and water safety. In this sense, developing a robust and easy-recovered magnetic nanocomposite with eminent photocatalytic activity is very imperative for detoxifying pharmaceutical compounds. Herein, a systematic study was conducted to investigate the photocatalytic ozonation for eliminating metronidazole (MET) from aqueous media utilizing the CuFe2O4/SiO2/ZnO heterojunction under simulated sunlight irradiation. The composite material was fabricated by a facile hydrothermal method and diagnosed by multiple advanced analytical techniques. Modelling and optimization of MET decontamination by adopting the central composite design (CCD) revealed that 90 % of MET decontamination can be achieved within 120 min of operating time at the optimized circumstance (photocatalyst dose: 1.17 g/L, MET dose: 33.20 mg/L, ozone concentration: 3.99 mg/min and pH: 8.99). In an attempt to scrutinize the practical application of the CuFe2O4/SiO2/ZnO/xenon/O3 system, roughly 56.18% TOC and 73% COD were removed under the optimized operational circumstances during 120 min of degradation time. According to the radical quenching experiments, hydroxyl radicals (HO•) were the major oxidative species responsible for the elimination of MET. The MET degradation rate maintained at 83% after seven consecutive runs, manifesting the efficiency of CuFe2O4/SiO2/ZnO material in the MET removal. Ultimately, the photocatalytic ozonation mechanism over the CuFe2O4/SiO2/ZnO heterojunction of the fabricated nanocomposites was rationally proposed for MET elimination. In extension, the results drawn in this work indicate that integrating photocatalyst and ozonation processes by the CuFe2O4/SiO2/ZnO material can be applied as an efficient and promising method to eliminate tenacious and non-biodegradable contaminants from aqueous environments.

Efficacy of antimicrobial and nutraceutical treatment for canine acute diarrhoea: A systematic review and meta-analysis for European Network for Optimization of Antimicrobial Therapy (ENOVAT) guidelines

Systemic antimicrobial treatments are commonly prescribed to dogs with acute diarrhoea, while nutraceuticals (prebiotics, probiotics, and synbiotics) are frequently administered as an alternative treatment. The aim of this systematic review and meta-analysis was to assess the effectiveness of antimicrobials and nutraceutical preparations for treatment of canine acute diarrhoea (CAD). The results of this study will be used to create evidence-based treatment guidelines. PICOs (population, intervention, comparator, and outcome) were generated by a multidisciplinary expert panel taking into account opinions from stakeholders (general practitioners and dog owners). The Grading of Recommendations Assessment, Development and Evaluation (GRADE) methodology was used to evaluate the certainty of the evidence. The systematic search yielded six randomised controlled trials (RCT) for antimicrobial treatment and six RCTs for nutraceutical treatment meeting the eligibility criteria. Categories of disease severity (mild, moderate, and severe) were created based on the presence of systemic signs and response to fluid therapy. Outcomes included duration of diarrhoea, duration of hospitalization, progression of disease, mortality, and adverse effects. High certainty evidence showed that antimicrobial treatment did not have a clinically relevant effect on any outcome in dogs with mild or moderate disease. Certainty of evidence was low for dogs with severe disease. Nutraceutical products did not show a clinically significant effect in shortening the duration of diarrhoea (based on very low to moderate certainty evidence). No adverse effects were reported in any of the studies.

Dual stimuli-responsive delivery system for self-regulated colon-targeted delivery of poorly water-soluble drugs

Inflammatory bowel disease (IBD) are chronic inflammatory conditions which cause significant patient morbidity. Local drug delivery to the colon can improve treatment efficacy and reduce side effects associated with IBD treatment. Smart drug delivery systems are designed to regulate the release of therapeutic agents at the desired site of action. pH-responsive drug carriers have been previously utilised for improved oral drug delivery beyond stomach harsh conditions. Additionally, the colon possesses a diverse microbiome secreting bioactive molecules e.g., enzymes, that can be exploited for targeted drug delivery. We herein synthesised and characterised a 2-hydroxyethyl methacrylate and methacrylic acid copolymer, crosslinked with an azobenzyl crosslinker, that displayed pH- and enzyme-responsive properties. The swelling and drug release from hydrogel were analysed in pH 1.2, 6.5 and 7.4 buffers, and in the presence of rat caecal matter using metronidazole and mesalamine as model BCS Class I and IV drugs, respectively. Swelling studies displayed pH-responsive swelling behaviour, where swelling was maximum at pH 7.4 and minimum at pH 1.2 (69 % versus 32 %). Consequently, drug release was limited in gastric and small intestinal conditions but increased significantly when exposed to colonic conditions containing caecal matter. This system displays promising capacity for achieving colon-targeted drug delivery with enhanced dissolution of poorly water-soluble drugs for local treatment of IBD and other colon-targeted therapies.

Efficacy of a 2-week therapy with levofloxacin concomitant versus a levofloxacin sequential regimen for Helicobacter pylori infection in the Syrian population: a study protocol for randomized controlled trial

BACKGROUND

Treating Helicobacter pylori is becoming increasingly difficult with the development of bacterial resistance to many established treatment regimens. As a result, researchers are constantly looking for novel and effective treatments. This trial aims to establish the efficacy of levofloxacin-based sequential treatment regimen and concomitant levofloxacin-based regimen as empirical first-line therapy in the Syrian population.

METHOD

This is an open-label, prospective, single-center, parallel, active-controlled, superiority, randomized clinical trial. The recruitment will target Helicobacter pylori-positive males and females between the ages of 18 and 65 to evaluate the efficacy of empirical first-line therapy in the Syrian population. We are planning to recruit up to 300 patients which is twice the required sample size. One hundred fifty individuals will be randomly assigned to undergo either a sequential levofloxacin-based treatment regimen or a concomitant levofloxacin-based regimen. High-dose dual therapy (proton-pump inhibitor and amoxicillin) will be the rescue therapy in the event of first-line failure. The first-line eradication rate in both groups is the primary outcome, and one of the secondary outcomes is the overall eradication rate of high-dose dual therapy in the event of first-line treatment protocol failure. Intention-to-treat analysis and per-protocol analysis will be used to evaluate the eradication rates of Helicobacter pylori for first-line treatment protocols.

DISCUSSION

For the first time in the Syrian population, this randomized controlled trial will provide objective and accurate evidence about the efficacy of a sequential levofloxacin-based treatment regimen.

TRIAL REGISTRATION

ClinicalTrials.gov NCT06065267 . Registered on October 3, 2023. Prospective registered. Enrollment of the first participant has not started yet.

Bandgap engineering approach for synthesising photoactive novel Ag/HAp/SnS2 for removing toxic anti-fungal pharmaceutical from aqueous environment

The present work shed light on synthesising a novel ternary Z-scheme Ag/HAp/SnS2 (AHS) nano photocatalyst to degrade metronidazole (MTZ) in wastewater through H2O2-assisted AOP under natural sunlight. HAp extracted from the fish scales of rohu fish through alkaline treatment was decorated with Ag nanoparticles using ascorbic acid as a bio-reductant. Tin disulphide (SnS2) was anchored over Ag/HAp to prevent agglomeration and enhance photocatalytic activity by delaying the electron-hole recombination rate. After 45 min of irradiation, a degradation efficiency of 98.85 ± 1.86% for 15 ppm MTZ could be achieved. The performance of the prepared photocatalyst in real wastewater was investigated by introducing several metal cations and anions in the photodegradation process. The degradation products were identified by HRLCMS analysis, and the breakdown mechanism of MTZ was proposed. The present study enlightens the importance of SnS2-based photocatalysts for organic pollutant degradation under natural sunlight through an advanced oxidation process. The characterization results showed that the enhanced photodegradation efficiency of AHS is attributed to the formation of an all-solid-state Z-scheme heterojunction with Ag nanoparticles acting as charge transfer medium and as electron accumulators helping in delaying charge recombination.

The effect of antibiotic therapy for Clostridioides difficile infection on mortality and other patient-relevant outcomes: a systematic review and meta-analysis

BACKGROUND

Current practice guidelines favour fidaxomicin over vancomycin and exclude metronidazole from the recommended standard regimen for Clostridioides difficile infection (CDI), based on lower recurrence rates with fidaxomicin, giving little weight to mortality or the clinical implications of recurrences.

OBJECTIVES

To compile the effects of metronidazole, glycopeptides (vancomycin or teicoplanin), and fidaxomicin for CDI on mortality and other patient-relevant outcomes.

DATA SOURCES

PubMed, the Cochrane Library, ClinicalTrials.gov, conference proceedings, and Google Scholar, until August 2023.

STUDY ELIGIBILITY CRITERIA

Randomized controlled trials (RCTs).

PARTICIPANTS

Adult patients experiencing primary or recurrent CDI.

INTERVENTIONS

Glycopeptides versus fidaxomicin or metronidazole (comparators).

ASSESSMENT OF RISK OF BIAS

We used the Risk of Bias 2 (RoB 2) tool for randomized trials, focusing on the outcome of all-cause mortality.

METHODS OF DATA SYNTHESIS

Random effects meta-analyses were performed for dichotomous outcomes. Outcomes were summarized preferentially for all randomly assigned patients.

RESULTS

Thirteen trials were included. There was no significant difference in all-cause mortality (risk ratio [RR] < 1 favouring the comparator) between vancomycin and fidaxomicin (RR 0.86, 95% CI 0.64-1.14, 8 RCTs, 1951 patients) or metronidazole (RR 0.78, 95% CI 0.46-1.32, 4 RCTs, 808 patients), with low and very low certainty of evidence, respectively. No significant difference in initial treatment failure between fidaxomicin and vancomycin was found, however, initial treatment failure was higher with metronidazole (RR 1.58, 95% CI 1.10-2.27, 5 RCTs, 843 patients). No study reported on symptomatic recurrence necessitating re-treatment among all randomly assigned patients. Among initially cured patients, symptomatic recurrence necessitating re-treatment was lower with fidaxomicin than with vancomycin (RR 0.54, 95% CI 0.42-0.71, 6 RCTs, 1617 patients). None of the studies reported on other CDI complications or the burden of infection on daily activities.

CONCLUSIONS

Setting patient-relevant outcomes for CDI independently of the RCT definitions and results might lead to less confidence in the guidance for CDI management.

Selective Cell Ablation Using an Improved Prodrug-Converting Nitroreductase

Selective cell ablation is an invaluable tool to investigate the function of cell types, the regeneration of cells, and the modeling of diseases associated with cell loss. The nitroreductase (NTR)-mediated cell ablation system is a simple method enabling the elimination of targeted cells through the expression of a nitroreductase enzyme and the application of a prodrug (such as metronidazole). The prodrug is reduced to a cytotoxic product by nitroreductase, thereby leading to DNA damage-induced cell death. In species with elevated regenerative capacity such as zebrafish, removing the prodrug allows endogenous tissue to replace the lost cells. Herein, we describe a method for the use of a markedly improved nitroreductase enzyme for spatially and temporally controlled targeted cell ablation in the zebrafish. Recently, we identified an NTR variant (NTR 2.0) that achieves effective targeted cell ablation at concentrations of metronidazole well below those causing toxic side effects. NTR 2.0 thereby enables the ablation of "resistant" cell types and novel cell ablation paradigms. These advances simplify investigations of cell function, enable interrogations of the effects of chronic inflammation on regenerative processes and facilitate modeling of degenerative diseases associated with chronic cell loss. Techniques for transgenic nitroreductase expression and prodrug application are discussed.

Metronidazole-induced encephalopathy in a patient with cirrhosis

Metronidazole is a commonly used antibiotic with anaerobic bacterial, protozoal, and microaerophilic bacterial coverage. Encephalopathy and peripheral neurotoxicity are rare but known adverse events with prolonged metronidazole use, which can be difficult to distinguish from other causes of delirium in acutely ill patients. Definitive diagnosis can be made by brain magnetic resonance imaging (MRI), which often reveals symmetric bilateral hypersignal demyelination lesions typically involving the dentate nuclei, splenium of the corpus collosum, midbrain, dorsal medulla, and pons. This case report describes a 72-year-old male presenting with altered mental status and neurological deficits after prolonged metronidazole use for bacteremia with spondylodiscitis, with full clinical and neuroradiological resolution upon appropriate diagnosis and drug cessation. Neuroradiologists play an indispensable role in recognizing this rare and poorly understood manifestation.

A prospective, single-centre, randomized, double-blind controlled study protocol to study whether long-term oral metronidazole can effectively reduce the incidence of postoperative liver metastasis in patients with colorectal cancer

INTRODUCTION

Fifteen to 25% of patients with colorectal cancer have combined liver metastases at the time of diagnosis, whereas an additional 15 to 25% will develop liver metastases after curative resection of primary colorectal cancer, with the vast majority (80-90%) of liver metastases unresponsive to curative resection at first. Colorectal cancer liver metastasis is also the leading cause of death in patients with colorectal cancer. In recent years, several studies have demonstrated that intestinal flora, especially Fusobacterium nucleatum, plays a crucial role in the development of colorectal cancer liver metastasis, so we hypothesized that long-term metronidazole use could effectively reduce the incidence of postoperative liver metastasis in colorectal cancer patients.

METHODS/DESIGN

This study is a prospective, single-centre, randomized, double-blind controlled study in which 300 patients will be randomly assigned to the test group or the control group in a 1:1 allocation ratio. The aim of this trial is to demonstrate that long-term oral antibiotics can effectively reduce the incidence of postoperative liver metastasis in patients with colorectal cancer.

ETHICS AND DISSEMINATION

Ethics approval was obtained from the Ethics Committee at the Chinese Ethics Committee of Registering Clinical Trials (ChiECRCT20210229). The results of this study will be disseminated at several research conferences and as published articles in peer-reviewed journals.

TRIAL REGISTRATION

Chinese Clinical Trial Registry ChiCTR2100046201. Registered on July 05, 2021.

Ecofriendly single-step HPLC and TLC methods for concurrent analysis of ternary antifungal mixture in their pharmaceutical products

Two accurate, sensitive, and selective methods for simultaneous determination of miconazole nitrate (MIC), nystatin (NYS), and metronidazole (MET) in pure state or drug product were established and verified. First, RP-HPLC-DAD was designed. Separation was accomplished using a ZOBRAX Eclipse Plus RP-C8 column that was running under an isocratic elution of methanol: 0.05% aqueous solution of sodium dodecyl sulphate (40: 60 v/v), with a flow rate that was regulated at 0.8 mL/min. The column temperature was adjusted at 25 °C and diode array detector was monitored at 220 nm. The linearity range of the proposed method was achieved at the concentration of 5-50, 4-50, and 4-40 µg/mL and the attained retention time for the studied drugs was 2.52, 3.52 and 4.99 min for MIC, NYS, and MET, correspondingly. Second, a TLC-densitometric approach was used to resolve the three compounds. Resolution of the three cited drugs was carried out using TLC aluminum plates pre-coated with 0.25 mm silica gel 60 F254. A developing solvent comprised ethyl acetate: toluene: methanol: triethyl amine: formic acid (3: 1: 7: 0.3: 0.1 by volume) (pH = 5.5) was utilized and scanning of the resolved bands at 215 nm. Linearity of the developed TLC method was evaluated and evident to be 0.4-2, 0.4-2.2, and 0.4-2 μg/band for MIC, NYS, and MET, in that order. The suggested chromatographic methods were verified according to ICH directives. The findings of the developed chromatographic procedures were statistically compared with the results of the reported ones using student's t-test and F-test. Furthermore, two green assessment tools evaluated the indicated methods' level of greenness (GAPI and AGREE).

Performance evaluation of PdO/ CuO TiO2 photocatalytic membrane on ceramic support for removing pharmaceutical compounds from water

This study investigated photocatalytic degradation of pharmaceutical compound using CuO or PdO-TiO2 membrane. The synthesized membranes were characterized by some techniques including X-ray powder diffraction (XRD), dynamic light scattering (DLS), scanning electron microscopy (SEM), and Fourier-transform infrared spectroscopy (FT-IR). The structural properties confirmed that the photocatalytic membranes were successfully prepared on ceramic supports. The PdO-TiO2 and CuO-TiO2 membranes were employed as photocatalytic membranes to degrade metronidazole (MNZ) and diphenhydramine (DPH) in aqueous solutions, respectively. Some parameters affecting the photocatalytic reaction such as pH, initial concentration, and light source were also investigated. The maximum degradation for both pharmaceutical compounds was obtained at basic pH (pH = 10), low initial concentration (C0 = 10 ppm) under UV irradiation. At high transmembrane pressure (ΔP = 3 bar), the flow rate across the membrane increased up 0.0078 and 0.0082 cc/s.cm2 for CuO-TiO2 and PdO-TiO2 photocatalytic membrane respectively while not affected on degradation efficiency (DE). At the same condition operation (C0 = 10 ppm, pH = 10, ΔP = 2 bar under UV irradiation), the MNZ and DPH degradation of the PdO-TiO2 membrane was 94 and 95% respectively that relatively higher than the CuO-TiO2 membrane. It is probably due to the lower energy band gap of PdO-TiO2 (2.5 eV) than CuO-TiO2 (2.7 eV). The membrane stability tests confirmed the high performance of the prepared membranes.

Production of all-male non-transgenic zebrafish by conditional primordial germ cell ablation

Many fish species exhibit remarkable sexual dimorphism, with males possessing numerous advantageous traits for commercial production by aquaculture such as faster growth rate, more efficient food energy utilization for muscle development, and better breeding performance. Several studies have shown that a decrease in the number of primordial germ cells (PGCs) during early development leads predominantly to male progeny. In this study, we developed a method to obtain all-male zebrafish (Danio rerio) by targeted PGC ablation using the nitroreductase/metronidazole (NTR/Mtz) system. Embryos generated by female heterozygous Tg(nanos3:nfsB-mCherry-nanos3 3'UTR) and male wild-types (WTs) were treated with vehicle or Mtz. Compared to vehicle-treated controls, 5.0 and 10.0 mM Mtz treatment for 24 h significantly reduced the number of PGCs and yielded an exclusively male phenotype in adulthood. The gonads of offspring treated with 5.0 mM Mtz exhibited relatively normal morphology and histological characteristics. Furthermore, these males were able to chase females, spawn, and produce viable offspring, while about 20.0% of males treated with 10.0 mM Mtz were unable to produce viable offspring. The 5.0 mM Mtz treatment protocol may thus be suitable for large-scale production of fertile male offspring. Moreover, about half of these males were WT as evidenced by the absence of nfsB gene expression. It may thus be possible to breed an all-male WT fish population by Mtz-mediated PGC ablation.

Pleural penetration of amoxicillin and metronidazole during pleural infection: An ambispective cohort study

OBJECTIVES

The pharmacokinetics of antibiotics in pleural fluid during pleural infections has been poorly described. This study aimed to explore amoxicillin and metronidazole diffusion into the pleural space.

METHODS

This was an ambispective, single-centre study that included patients with complicated parapneumonic effusion or pleural empyema managed with repeated therapeutic thoracentesis as first-line treatment between 2014 and 2022. Pleural steady-state or trough concentrations of amoxicillin and metronidazole were measured, with a lower limit of quantification of 5 mg/L.

RESULTS

Seventy paired blood and pleural samples were analysed from 40 patients. The median (interquartile range) patient age was 55 years (45-67 years) and 88% were male. The median patient weight was 65.8 kg (57.3-82 kg) and median plasma albumin concentration was 29.7 g/L (23.7-33.9 g/L). Median creatinine clearance was 106 mL/min (95-117 mL/min). Median amoxicillin pleural concentrations in patients treated with oral, bolus and continuous intravenous administrations (6 g/day) were, respectively, 5.2 (<5-6.4), 9.4 (8-13.1) and 10.8 (7.1-13.1) mg/L. Pleural concentrations were <5 mg/L in 5/11 samples (45%) with oral treatment and 6/59 (10%) with intravenous treatment. Median metronidazole pleural concentrations were 18.4 (15.7-22.8) mg/L, with all patients being treated orally (1.5 g/day).

CONCLUSIONS

Oral metronidazole (1.5 g/day) and intravenous amoxicillin (6 g/day) achieved therapeutic targets in pleural fluid in most cases, but oral amoxicillin did not.

Bimetal-oxide (Fe/Co) modified bagasse-waste carbon coated on lead oxide-battery electrode for metronidazole removal

Current study covers the preparation and application of a commercial modified lead oxide battery electrode (LBE) in electrochemical oxidation (ECO) of metronidazole (MNZ) in an aqueous phase. Modified electrode is prepared by doping of bimetal-oxide (Fe and Zn) nanoparticles (NPs) & single metal-oxide (Fe/Zn) on bagasse-waste carbon (bwc) which is further coated on LBE. The modified LBE electrode surface was examined for metal-oxide NPs through X-ray diffraction analysis (XRD). Different electrodes are prepared by varying combinations of two metal-oxide based on molar ratio and tested for electrochemical characterization and MNZ removal test. Based on large oxygen evolution potential in a linear sweep volumetry (LSV) analysis and high MNZ removal rate, the best electrode has been represented as Fe1:Co2-bwc/LBE which contains Fe & Co molar ratio of 1:2. Moreover, equilibrium attained at faster rate in degradation process of MNZ, where pseudo first order kinetics of 2.29 × 10-2 min-1 was obtained under optimized condition of (MNZ:100 mg/L, pH:7, CD: 30 mA/cm2 and electrolyte: 0.05 M Na2SO4). Maximum MNZ removal, total organic carbon removal (TOC), mineralization current efficiency (MCE) & energy consumption (EC) of 98.7%, 85.3%, 62.2% & 96.143 kW h/kg-TOC removed are found in 180 min of treatment time for Fe1:Co2-bwc/LBE electrode. Accelerated service life test confirms that the stability of modified electrode is enhanced by 1.5 times compared to pristine LBE. Repeatability test confirms that modified LBE (Fe1:Co2-bwc/LBE) can be utilized up to 3 times.

Relationship between antibiotic resistance and the cagA and vacA genotypes among Helicobacter pylori strain isolates from patients in Xi'an

The issue of drug resistance of Helicobacter pylori is becoming increasingly serious. To analyze the correlation between the cagA and vacA genotypes of H. pylori strains and their resistance to metronidazole, levofloxacin, and clarithromycin in patients in Xi'an, we studied 117 H. pylori strains isolated from patients in Xi'an. Antibiotic susceptibility testing of H. pylori was performed. The cagA and vacA genotypes were investigated using PCR. Among 117 strains of H. pylori, the rate of detection of cagA was 91.45% (107/117), among which the detection rate of East Asian-type cagA was 85.05% (91/107) and that of Western-type cagA was 14.95% (16/107). There were only two genotypes of vacA: s1m1 and s1m2. The detection rate of vacAs1m1 was 47.01% (55/117) and that of vacAs1m2 was 52.99% (62/117). The dominant strains in Xi'an were cagA + vacAs1m2 strains. The metronidazole resistance rate of vacAs1m2 H. pylori strains was significantly higher than that of vacAs1m1 H. pylori strains (91.94% vs. 69.09%, P = 0.002). The levofloxacin resistance rate of Western-type cagA strains was significantly higher than that of East Asian-type cagA strains (56.25% vs. 20.88%, P = 0.004). The metronidazole resistance rate of cagA + vacAs1m2 H. pylori strains was significantly higher than that of cagA + vacAs1m1 H. pylori strains (91.23% vs. 66.00%, P = 0.001). Our results showed that Western-type cagA strains were more likely to develop levofloxacin resistance than East Asian-type cagA strains. VacAs1m2 strains were more prone to metronidazole resistance than vacAs1m1 strains.

Role of autophagy in stress and drug-responsive cell death in Entamoeba histolytica and its cross-talk with apoptosis-inducing factor

Cell death in unicellular protozoan parasite Entamoeba histolytica is not yet reported though it displays several features of autophagic cell death. Autophagic cell death was reported to take place in ancient protozoans under several stresses. Here we report the occurrence of autophagic cell death in the Entamoeba histolytica trophozoites under oxidative stress as well as by the treatment with metronidazole, the most-widely-used drug for amoebiasis treatment and was shown to generate oxidative stress in the trophozoites. The autophagic flux increases during nutrient deprivation and metronidazole treatment and decreases upon oxidative stress. During oxidative stress the autophagy leads to nucleophagy that is ultimately destined to be digested within the lysosomal chamber. The formation of nucleophagosome depends on the apoptosis-inducing factor (AIF) that translocates to the nucleus from cytoplasm upon oxidative stress. It was experimentally proved that ATG8 (Autophagy-related protein 8) binds with the AIF in the nucleus of the trophozoites and helps in ATG8 recruitment and autophagy initiation overall suggesting that oxidative stress-driven AIF translocation to nucleus results in binding with ATG8 and initiates nucleophagy leading to cell death.

Ertapenem combined with metronidazole for treatment of complex abdominal infections: Efficacy and impact on serum inflammatory indicators and T lymphocyte subsets

BACKGROUND

Complex intra-abdominal infections (cIAIs), often associated with abdominal trauma, have a complex etiology, are acute and severe, and have a high risk. They are an important cause of death in patients with abdominal trauma. Safe and effective treatment strategies are the factors affecting the prognosis of such patients.

AIM

To investigate the efficacy and safey of ertapenem combined with metronidazole in the treatment of cIAIs as well as the impact on serum inflammatory markers and T lymphocyte subsets, recovery status, and treatment costs.

METHODS

A total of 92 patients with cIAIs treated at our hospital from June 2021 to January 2023 were randomly divided into a control group and a study group, with 46 cases in each group. After admission, both groups received puncture drainage, continuous double-cannula irrigation, anti-infection therapy, organ function support, nutritional support, and other treatments. On this basis, the control group was treated with piperacillin/tazobactam combined with metronidazole, while the study group was treated with ertapenem combined with metronidazole. The therapeutic effects, recovery conditions, treatment costs, serum inflammatory indicators [procalcitonin (PCT), Toll-like receptor 4 (TLR-4), tumor necrosis factor-α (TNF-α), and C-reactive protein (CRP)], T lymphocyte subsets (CD3⁺, CD4⁺, and CD4⁺/CD8⁺ ratio), acute physiology and chronic health evaluation Ⅱ (APACHE Ⅱ) score, sequential organ failure assessment (SOFA) score, adverse reactions, and bacterial culture results were compared between the two groups.

RESULTS

The total effective rate of the study group was 93.48%, significantly higher than that of the control group (78.26%; P < 0.05). After 3 d and 7 d of treatment, the levels of serum PCT, TLR-4, TNF-α, and CRP in the study group were significantly lower and the levels of serum CD3⁺ and CD4⁺ T lymphocytes and CD4⁺/CD8⁺ ratio were significantly higher than those of the control group (P < 0.05). The APACHEⅡ score and SOFA score of the study group were significantly lower than those of the control group after 3 d and 7 d of treatment (P < 0.05). The time to fever resolution, ICU stay duration, and hospital stay in the study group were significantly shorter than those of the control group, and the costs of drugs and other resources were less than those of the control group (P < 0.05). The incidence of adverse reactions in the study group was 4.35%, significantly lower than that of the control group (17.39%; P < 0.05). There was no significant difference in the distribution of pathogenic bacteria between the two groups before and after treatment (P > 0.05).

CONCLUSION

Ertapenem combined with metronidazole is effective in the treatment of cIAIs, which can reduce inflammation, improve immune function, control disease progression, reduce the risk of organ failure, reduce the economic burden of patients, and improve treatment safety.

Metronidazole for Prevention of Pelvic Cellulitis and Abscess after Laparoscopic Hysterectomy: A Triple-blinded, Randomized, Placebo-controlled Clinical Trial

STUDY OBJECTIVE

To determine whether a postoperative 5-day treatment schedule with vaginal metronidazole added to conventional antibiotic prophylaxis with 2 g cefazolin modifies the risk of pelvic cellulitis (PC) and pelvic abscess (PA) after total laparoscopic hysterectomy (TLH).

DESIGN

A randomized, controlled, triple-blind, multicenter clinical trial.

SETTING

Two centers dedicated to minimally invasive gynecologic surgery in Colombia.

PATIENTS

A total of 574 patients were taken to TLH because of benign diseases.

INTERVENTION

Patients taken to TLH were divided into 2 groups (treatment group, cefazolin 2 g intravenous single dose before surgery + metronidazole vaginal ovules for 5 days postoperatively, control group: cefazolin 2 g intravenous single dose + placebo vaginal ovules for 5 days postoperatively).

MEASUREMENTS AND MAIN RESULTS

The absolute frequency (AF) of PC and PA and their relationship with the presence of bacterial vaginosis (BV) were measured. There was no difference in AF of PC (AF, 2/285 [0.7%] vs 5/284 [1.7%] in the treatment and placebo groups, respectively; risk ratio, 1.75; 95% confidence interval, 0.54-5.65; p = .261), nor for PA (AF, 0/285 [0%] vs 2/289 [0.7%]; p = .159, in the treatment and placebo groups, respectively). The incidence of BV was higher in the metronidazole group than the placebo group (42.5% vs 33.4%, p = .026).

CONCLUSION

The use of vaginal metronidazole ovules during the first 5 days in postoperative TLH added to conventional cefazolin prophylaxis does not prevent the development of PC or PA, regardless of the patient's diagnosis of BV.

Rapid degradation and detoxification of metronidazole using calcium sulfite activated by CoCu two-dimensional layered bimetallic hydroxides: Performance, mechanism, and degradation pathway

In this study, cobalt copper-layered double hydroxides (CoCu-LDHs) were prepared by coprecipitation as catalysts to activate CaSO3 for metronidazole (MNZ) degradation. This is the first report on layered double hydroxides activating sulfite for the degradation of organic pollutants. Meanwhile, to address the issue of self-quenching reactions readily occurring in conventional sulfite advanced oxidation systems and resulting in low oxidant efficiency, CaSO3 with slightly soluble in water was used instead of commonly used Na2SO3, to improve the limitations of traditional systems. The results showed that in the CoCu-LDHs/CaSO3 system, the degradation rate of MNZ reached 98.7% within 5 min, representing a 23.0% increase compared to the CoCu-LDHs/Na2SO3 system. Owing to the excellent catalytic performance exhibited by CoCu-LDHs, characterizations including XRD, FTIR, SEM, TEM, BET and XPS were carried out to investigate this further. The results confirmed the successful synthesis of CoCu-LDH, and the activation mechanism study revealed that Co and Cu were considered to the main elements in activating CaSO3, demonstrating good synergistic effects. In addition, the oxygen vacancies on the catalyst surface also played a positive role in generating radicals and promoting electron transfer. Subsequently, the effects of Co/Cu ratio, catalyst dosage, oxidant concentration, pollutant concentration, pH and coexisting substances on MNZ degradation were investigated. Additionally, based on the LC-MS analysis of degradation products and toxicity tests, MNZ was transformed into different intermediates with low toxicity through four pathways, eventually mineralizing into inorganic small molecules. After six cycles, the MNZ degradation rate still reached 82.1%, exhibiting excellent stability and recyclability. In general, this study provides new ideas for activating sulfite, while providing theoretical support for subsequent research on sulfite advanced oxidation system.

Combination of Bifidobacterium breve and antibiotics against Clostridioides difficile: effect of the time interval of combination on antagonistic activity

Co-administration of probiotics and antibiotics has been used to prevent or treat primary Clostridioides difficile (pCDI), and the closer the interval between the combination, the more effective it is, but the reason behind this is unknown. In this study, the cell-free culture supernatant (CFCS) of Bifidobacterium breve YH68 was used in combination with vancomycin (VAN) and metronidazole (MTR) to treat C. difficile cells. The growth and biofilm production of C. difficile under different co-administration time interval treatments were determined by optical density and crystalline violet staining, respectively. The toxin production of C. difficile was determined by enzyme immunoassay, and the relative expressions of C. difficile virulence genes tcdA and tcdB were determined by real-time qPCR method. Meanwhile, the types and contents of organic acids in YH68-CFCS were investigated by LC-MS/MS. The results showed that YH68-CFCS in combination with VAN or MTR significantly inhibited the growth, biofilm production, and toxin production of C. difficile in the effective time interval range (0-12 h) but did not affect the expression level of C. difficile virulence genes. In addition, the effective antibacterial component of YH68-CFCS is lactic acid (LA).

Molecular imprinted polymer-based potentiometric approach for the assay of the co-formulated tetracycline HCl, metronidazole and bismuth subcitrate in capsules and spiked human plasma

BACKGROUND

An anti-H-pylori co-formulated mixture of tetracycline HCl (TET), metronidazole (MET), and bismuth subcitrate (BSC) is recently available. Only two chromatographic and spectrophotometric methods are reported for determining those drugs simultaneously where the effect of impurities that could be present as well as the biological fluids matrix influence do not be taken into consideration. There is a need to develop an easy-to-use potentiometric technique for analysis of TET, MET, and BSC in their co-formulated capsules, in presence of some official impurities and in spiked human plasma.

RESULTS

Three carbon paste electrodes (CPEs) were fabricated for this purpose. Being a solid contact ion-selective electrode, CPE suffers from the creation of a water layer affecting its stability and reproducibility. Besides, it has a common problem in differentiation between two drugs carrying the same charge (positively charged TET and MET). Water layer formation was prevented through inserting polyaniline nanoparticles (≈10.0 nm diameter) between solid contact and ion-sensing membrane in the three proposed sensors. TET and MET interference was overcome by synthesizing a corresponding molecular imprinted polymer (MIP) for each drug. The synthesized MIPs were inserted in equivalent sensing membranes and characterized using several techniques. The suggested MIPs have a noticeable enhanced sensitivity in potentiometric determination. The obtained LODs were 5.88 × 10-8, 5.19 × 10-7, and 1.73 × 10-6 M for TET, MET and BSC proposed CPEs, respectively, with corresponding slopes of 57.37, 56.20, and -57.40 mV decade-1.

SIGNIFICANCE

The proposed potentiometric method makes the detection of the three cited drugs simple, fast, and feasible. This approach is the first for determining three drugs potentiometrically in one combined formulation. The obtained results were compared favorably with previously reported potentiometric methods.

Different methods for resolving overlapping UV spectra of combination medicinal dose forms of ciprofloxacin and metronidazole

Four simple, specific, easy, precise and accurate spectrophotometric methods were developed for the first time to examine ciprofloxacin and metronidazole in combination, without having been separated beforehand by the developed methods. Ciprofloxacin and metronidazole were determined by utilizing advanced absorbance subtraction (AAS), spectrum subtraction, bivariate and ratio difference methods. Precision, repeatability, robustness, and accuracy were all determined to be within acceptable levels after each of these procedures underwent validation in accordance with ICH recommendations. Each method's benefits and drawbacks are illustrated, and the proposed and reported methodologies were statistically compared.

The mechanisms of metronidazole resistance of Helicobacter pylori: A transcriptomic and biochemical study

Helicobacter pylori (H. pylori) is a bacterial pathogen in the stomach, causing gastritis, gastric ulcer, duodenal ulcer and even gastric cancer. The triple therapy containing one bismuth-containing compound or a proton-pump inhibitor with two antibiotics was the cornerstone of the treatment of H. pylori infections. However the drug resistance of Helicobacter pylori is more and more common, which leads to the continued decline in the radical cure rate. The purpose of this study was to investigate the mechanism of metronidazole resistance of H. pylori through transcriptomics and biochemical characterizations. In this study, a 128-time-higher metronidazole-resistant H. pylori strain compared to the sensitive strain was domesticated, and 374 significantly differential genes were identified by transcriptomic sequencing as compared to the metronidazole-sensitive strain. Through GO and KEGG enrichment analysis, antibiotic-resistance pathways were found to be mainly involved in redox, biofilm formation and ABC transportation, and the results were verified by qRT-PCR. The subsequent biochemical analysis found that the urease activity of the drug-resistant strain decreased, and whereas the capabilities of bacterial energy production, membrane production and diffusion ability increased. The work here will drop hints for the mechanisms of antibiotic-resistance of H. pylori and provide promising biomarkers for the further development of new-kind drugs to treat metronidazole-resistant H. pylori.

Association of antimicrobial perioperative prophylaxis with cefuroxime plus metronidazole or amoxicillin/clavulanic acid and surgical site infections in colorectal surgery

OBJECTIVE

To compare intravenous (IV) amoxicillin/clavulanic acid (A/CA) to IV cefuroxime plus metronidazole (C + M) for preventing surgical site infections (SSI) in colorectal surgery.

BACKGROUND

Given their spectra that include most Enterobacterales and anaerobes, C + M is commonly recommended as prophylaxis of SSI in colorectal surgery. A/CA offers good coverage of Enterobacterales and anaerobes as well, but, in contrast to C + M, it also includes Enterococcus faecalis which is also isolated from patients with SSI and could trigger anastomotic leakage.

METHODS

Data from a Swiss SSI surveillance program were used to compare SSI rates after class II (clean contaminated) colorectal surgery between patients who received C + M and those who received A/CA. We employed multivariable logistic regression to adjust for potential confounders, along with propensity score matching to adjust for group imbalance.

RESULTS

From 2009 to 2018, 27,922 patients from 127 hospitals were included. SSI was diagnosed in 3132 (11.2%): 278/1835 (15.1%) in those who received A/CA and 2854/26,087 (10.9%) in those who received C + M (p < 0.001). The crude OR for SSI in the A/CA group as compared to C + M was 1.45 [CI 95% 1.21-1.75]. The adjusted OR was 1.49 [1.24-1.78]. This finding persisted in a 1:1 propensity score matched cohort of 1835 patients pairs with an OR of 1.60 [1.28-2.00]. Other factors independently associated with SSI were an ASA score > 2, a longer duration of operation, and a reoperation for a non-infectious complication. Protective factors were female sex, older age, antibiotic prophylaxis received 60 to 30 min before surgery, elective operation, and endoscopic approach.

CONCLUSIONS

Despite its activity against enterococci, A/CA was less effective than C + M for preventing SSI, suggesting that it should not be a first choice antibiotic prophylaxis for colorectal surgery.

Can vitamin B6 alleviate the adverse reactions of quadruple anti-Helicobacter pylori regimen? : randomized controlled trial

BACKGROUND

Vitamin B6 is an essential water-soluble vitamin for humans. It is often used to prevent a variety of neuropathies, relieve vomiting, and relieve symptoms such as hand and foot neuritis.

AIM

To evaluate whether vitamin B6 can alleviate the adverse reactions caused by the quadruple anti-Helicobacter pylori treatment regimen containing minocycline and metronidazole.

METHODS

In this randomized controlled trial, 280 patients with H. pylori infection were randomly placed into one of two treatment groups-the conventional treatment group and the vitamin B6 supplement treatment group-for 2 weeks. The primary endpoint was the total incidence of adverse reactions up to 2 weeks after treatment initiation. The study was designed according to CONSORT Medicinal Interventions. And it was registered with Chinese Clinical Trial Registry under the number ChiCTR2100053833.

RESULTS

In terms of efficacy, vitamin B6 does not affect the efficacy of conventional regimen. In the vitamin B6 supplement treatment group, the incidence of adverse reactions was 56.92%, which was significantly lower than the 74.62% observed in the conventional treatment group. In addition, the severity of adverse reactions was also significantly reduced. The proportion of moderate to severe central nervous system symptoms decreased from 58.7 to 14.63%. And, the proportion of moderate to severe gastrointestinal reactions decreased from 33.33 to 0%. We speculate that the mechanism of vitamin B6 of reducing adverse reaction may be related to the production of GABA in the brain.

CONCLUSIONS

Vitamin B6 can alleviate adverse reactions of the quadruple anti-H. pylori regimen containing minocycline and metronidazole.

Antibiotic prescriptions among dentists across Norway and the impact of COVID-19 pandemic

BACKGROUND

The prescription of antibiotics in dental practice contributes significantly to the total use of antibiotics in primary healthcare. This study aimed to evaluate antibiotic prescription in dental practice during the years 2016-2021 in Norway and their relative contribution to national outpatient consumption and to investigate the influence of age, gender, geographic region, and COVID-19. A further aim was to review differences in prescribing patterns to verify effect of governmental strategies to reduce over-prescribing of antibiotics.

METHODS

This register study investigated the national antibiotic prescription between 2016 and 2021. Data was obtained from the Norwegian prescription register, the Norwegian Institute of Public Health and Statistics Norway. The consumption of 12 common antibiotics was measured using WHO defined daily doses (DDDs), DDD per 1000 inhabitants per day (DIDs 1000).

RESULTS

A total of 6,049,445 antibiotic prescriptions of the 12 investigated compounds were issued in primary care during the study period. Dentists accounted for 942,350 prescriptions corresponding to 15.6% of the total. An overall decrease in the number of prescriptions by health professions other than dentists during the 5 years (IRR = 0.92, 95% CI:0.92-0.93, p < 0.001) was observed. For dentists a slight increase in the number of prescriptions (IRR = 1.01, 95% CI: 1.01-1.01, p < 0.001) was seen over the study period. The increase of antibiotic prescriptions in dentistry was more pronounced during the COVID-19 pandemic. The 4 most prescribed type of antibiotics based on average number of DDDs of the total period 2016-2021 were in descending order; phenoxymethylpenicillin (1,109,150) followed by amoxicillin (126,244), clindamycin (72,565), and metronidazole (64,599). An unexpected finding was that the prescription of the combination compound amoxicillin/clavulanic acid had significantly increased in dentistry during the last 5 years. Geographic, gender, and age differences in the rates of prescriptions were also seen. The data revealed that there are seasonal variations in dental prescriptions.

CONCLUSIONS

Noticeable differences exist in prescribing patterns of antibiotics in the last 5 years. Restricted access to dental care due to COVID-19 may have resulted in increased antibiotic prescribing in dentistry as opposed to an otherwise downward trend. Despite national guidelines there is still a need for improvement of antibiotic stewardship in dentistry and to define effective methods to disseminate information.

Development of double crosslinked sodium alginate/chitosan based hydrogels for controlled release of metronidazole and its antibacterial activity

Double network sodium alginate/chitosan hydrogels were prepared using calcium chloride (CaCl2) and glutaraldehyde as the crosslinking agents by the ionotropic interaction method for controlled metronidazole release. The effect of polymer ratios and CaCl2 amount is investigated by the developing porosity, gel fraction, and extent of swelling in simulated physiological fluids. Interaction between the polymers with the formation of crosslinked structures, good stability, phase nature, and morphology of the hydrogels is revealed by Fourier-transform infrared spectroscopy, thermogravimetric analysis, X-ray diffraction, and scanning electron microscopy. A sodium alginate/chitosan hydrogel (weight ratio of 75:25) crosslinked with two percent CaCl2 is chosen for the in-situ loading of 200 mg of metronidazole. The drug release kinetics using different models show that the best-fit Korsmeyer-Peppas model suggests metronidazole release from the matrix follows diffusion and swelling-controlled time-dependent non-Fickian transport related to hydrogel erosion. This composition displays enhanced antimicrobial activity against Staphylococcus aureus and Escherichia coli.

Treatment of Dientamoeba fragilis: A retrospective Finnish analysis of faecal clearance and clinical cure comparing four antiprotozoal drugs

Background

Dientamoeba fragilis (DF), the most common intestinal protozoal pathogen in affluent countries, causes asymptomatic or symptomatic infections with severity ranging from mild to disabling. Currently, many studies of treatment options only have small sample sizes and report results that are partly contradictory.

Methods

Investigating data retrieved from Helsinki University Hospital and Helsinki City patient records, we searched for the most effective antiprotozoal in treating DF infections. To study microbiological clearance of DF, we collected laboratory results of control samples from patients given one of four commonly used antiprotozoals: doxycycline, metronidazole, paromomycin, or secnidazole. For patients symptomatic prior to antiprotozoal treatment, we also retrieved data on clinical outcomes. Furthermore, we explored factors associated with faecal clearance and clinical cure.

Results

A total of 369 patients (median age 38) and 492 treatment episodes were included. Paromomycin (n ​= ​297) proved effective (clearance rate 83%), showing strong association with faecal clearance (aOR 18.08 [7.24-45.16], p ​< ​0.001). For metronidazole the rate was 42% (n ​= ​84), for secnidazole 37% (n ​= ​79), and doxycycline 22% (n ​= ​32). In pairwise comparisons, paromomycin outdid the three other regimens (p ​< ​0.001, χ2 test). Faecal clearance was associated with clinical cure (aOR 5.85 [3.02-11.32], p ​< ​0.001).

Conclusions

Faecal clearance, strongly associated with clinical cure, is most effectively achieved with a course of paromomycin, followed by metronidazole, secnidazole and doxycycline. Our findings will be useful in devising treatment guidelines for adults with symptomatic D. fragilis infection.

Controlled drug delivery from metronidazole-containing bioactive endodontic cements

OBJECTIVES

This study aims to formulate metronidazole liquid nanocapsules (MTZLNC) and evaluate their effect on the physicochemical and biological properties of calcium silicate-based bioactive endodontic cements, in vitro.

METHODS

A MTZLNC suspension was formulated by deposition of the preformed polymer and characterized by laser diffraction and high-performance liquid chromatography (HPLC). Calcium silicate (CS) was mixed with a radiopaque agent (calcium tungstate - CaWO4), at 10 wt%, to produce the cement powder. Cements liquids were used with two concentrations of MTZLNC suspension: 0.3 mg/ml and 0.15 mg/ml. Cements prepared with distilled water were used as the control. The radiopacity, setting time, and flow were evaluated following ISO 6876:2012. The compressive strength analysis was conducted according to ISO 9917:2007. pH and mineral deposition were evaluated after immersion in simulated body fluid (SBF). Cell behavior was evaluated by the viability of pre-osteoblastic cells and pulp fibroblasts by SRB and MTT and the antibacterial activity against Enterococcus faecalis was analyzed immediately and after nine months of water storage.

RESULTS

MTZLNCs were formulated with a median diameter of 148 nm and 83.44 % load efficiency. Increased flow and reduced strength were observed for both MTZLNCs concentrations. The incorporation of MTZLNCs maintained the ability of cements to increase pH media and promote mineral deposition over the samples, without promoting cytotoxicity. A 2 log10 reduction in E. faecalis CFU was observed immediately and after nine months in water storage.

CONCLUSION

The formulation of MTZLNCs allowed the development of antibacterial calcium silicate-based-cements with suitable physicochemical properties and bioactivity, with a reduction in mechanical strength. The 0.3 mg/ml concentration in cements liquid promoted effective and sustainable antibacterial activity.

Surveillance of Helicobacter pylori resistance over 22 Years (2000-2021) in Northern Spain

OBJECTIVES

Helicobacter pylori gastritis is considered an infectious disease, regardless of symptoms and stage of disease. Most consensus documents recommend empirical therapy based on local antimicrobial susceptibility patterns. We aimed to provide clinically useful information about primary and secondary antimicrobial resistance to antimicrobials commonly prescribed for H. pylori.

METHODS

Overall, 31,406 gastroduodenal biopsies and 2,641 string tests from patients over 15 years of age were plated on selective media, isolating H. pylori in 36.7% of biopsies and 50.7% of string tests. Susceptibility testing could be performed in 96.6% (12,399/12,835) of H. pylori isolates. Polymerase chain reaction (PCR) was also used to detect H. pylori and its resistance to clarithromycin, providing susceptibility data for 112 patients with negative culture results.

RESULTS

Resistance to amoxicillin and tetracycline was unusual (0.6% and 0.2%, respectively). Rates of primary resistance to clarithromycin and metronidazole remained steady over the 22-year study period, at around 14% for clarithromycin and 30% for metronidazole, while primary resistance to levofloxacin tripled (from 7.6% in 2000 to 21.7% in 2021, P < 0.001) and increased with patient age. Notably, 1.8% of isolates were multiresistant to clarithromycin, metronidazole, and levofloxacin. Overall, secondary resistance rates were higher (P < 0.0001) than primary resistance rates for clarithromycin (42.5% vs 14.1%), metronidazole (40.9% vs 32%), and levofloxacin (21.5% vs 17.1%).

CONCLUSION

Determination of susceptibility for H. pylori by culture and/or PCR in patients undergoing endoscopy could facilitate the implementation of tailored therapy and guide the choice of empirical therapy when susceptibility testing cannot be performed, potentially helping limit the emergence of antimicrobial resistance.

The use of metronidazole in acute diarrhea in dogs: a narrative review

Acute diarrhea is a common reason for non-wellness veterinary visits in dogs. Treatment for acute diarrhea usually consists of supportive care with nutritional intervention, fluid therapy, anthelmintics, and often an antibiotic - commonly metronidazole in North America. The empirical use of metronidazole for acute diarrhea in dogs has been a common practice in veterinary medicine for many decades; however, recent studies evaluating its use suggest it may be inappropriately utilized in many cases. Herein, we review the evidence evaluating the use of metronidazole and other antibiotics in acute diarrhea in the human and veterinary literature. Recommendations on the use of metronidazole and other antibiotics as well as other therapeutic considerations in the treatment of acute diarrhea are also provided.

Emergency contraceptive use of Metronidazole among University female students in Dodoma region of Tanzania: a descriptive cross-sectional study

BACKGROUND

Metronidazole is known for its therapeutic effect as antibacterial and anti-parasitic. However, its toxicity on the reproductive system remains unclear. Metronidazole use in rodents is associates with toxic effects on the reproductive system, including hormonal alterations, reduced number of fertile cells and reduced sites for implantation, size of the placental disc area, constituent elements of the labyrinth, and spongiotrophoblast layers. Its use at a therapeutic dose among humans has been associated with an increased risk of spontaneous abortion. The effects on the reproductive system in humans may result in misconceptions about contraceptive effects hence sexually active individuals like students who, for any reason, fail to access safe contraceptive services use any possible methods to protect them from conception. This study aims to investigate the unofficial (un-prescribed) use of Metronidazole as an emergency contraceptive and some of its associated factors.

METHODS

This quantitative cross-sectional study involved 470 participants where stratified random sampling technique was used to obtain the sample from three educational institutions in the Dodoma Municipal, Dodoma region. Collected data were analyzed using SPSS version 25, descriptive statistical analysis was done to determine frequencies, percentages, and association, p < 0.05 was used to determine statistical significance. Further analysis using Multivariate binary logistic regression was done to determine the nature of the association between the study variables.

RESULTS

The finding shows that 169(62.4%) use Metronidazole as an emergency contraceptive. Notably, 345(73.4%) stated that they had ever heard someone use Metronidazole for contraception, especially their peers. Furthermore, an increase in the year of study was significantly associated with reduced use of Metronidazole as an emergency contraceptive (B = [-0.45], p = [0.02]). Furthermore, an increase in age, studying in non-medical college/university, the experience of using contraceptive methods, and hearing someone ever used Metronidazole was found to be positively associated with its use as an emergency contraceptive, although not statistically significant.

CONCLUSION

Metronidazole was found to be used as an emergency contraceptive in high doses, different factors associated with its use, and reasons influencing its use. Further research may be done to explore the toxicological effect of high doses of Metronidazole as a contraception and compare the efficiency of Metronidazole over other emergency contraceptives.

An inducible model of chronic hyperglycemia

Transgene driven expression of Escherichia coli nitroreductase (NTR1.0) renders animal cells susceptible to the antibiotic metronidazole (MTZ). Many NTR1.0/MTZ ablation tools have been reported in zebrafish, which have significantly impacted regeneration studies. However, NTR1.0-based tools are not appropriate for modeling chronic cell loss as prolonged application of the required MTZ dose (10 mM) is deleterious to zebrafish health. We established that this dose corresponds to the median lethal dose (LD50) of MTZ in larval and adult zebrafish and that it induced intestinal pathology. NTR2.0 is a more active nitroreductase engineered from Vibrio vulnificus NfsB that requires substantially less MTZ to induce cell ablation. Here, we report on the generation of two new NTR2.0-based zebrafish lines in which acute β-cell ablation can be achieved without MTZ-associated intestinal pathology. For the first time, we were able to sustain β-cell loss and maintain elevated glucose levels (chronic hyperglycemia) in larvae and adults. Adult fish showed significant weight loss, consistent with the induction of a diabetic state, indicating that this paradigm will allow the modeling of diabetes and associated pathologies.

Analysis of a clinical guideline for treatment and early discharge in complicated acute appendicitis

OBJECTIVE

The objective of this study was to assess the results of a clinical guideline for the treatment and early discharge of patients with complicated acute appendicitis in terms of infectious complications and hospital stay.

MATERIALS AND METHODS

A guideline for appendicitis treatment according to severity was created. Complicated appendicitis cases were treated with ceftriaxone-metronidazole for 48h, with discharge being approved if certain clinical and blood test criteria were met. A retrospective analytical study comparing the incidence of postoperative intra-abdominal abscess (IAA) and surgical site infection (SSI) in patients under 14 years of age to whom the new guideline was applied (Group A) vs. the historical cohort (Group B, treated with gentamicin-metronidazole for 5 days) was carried out. A prospective cohort study to assess which antibiotic therapy (amoxicillin-clavulanic acid or cefuroxime-metronidazole) proved more effective in patients meeting early discharge criteria was also conducted.

RESULTS

205 patients under 14 years of age were included in Group A, whereas 109 patients were included in Group B. IAA was present in 14.3% of patients from Group A vs. 13.8% from Group B (p= 0.83), while SSI was present in 1.9% of patients from Group A vs. 8.25% from Group B (p= 0.008). Early discharge criteria were met by 62.7% of patients from Group A. Median hospital stay decreased from 6 to 3 days. At discharge, 57% of patients received amoxicillin-clavulanic acid, whereas 43% received cefuroxime-metronidazole, with no differences being found in terms of SSI (p= 0.24) or IAA (p= 0.12).

CONCLUSIONS

Early discharge reduces hospital stay without increasing the risk of postoperative infectious complications. Amoxicillin-clavulanic acid is a safe option for at-home oral antibiotic therapy.

Ten-day tegoprazan-based concomitant therapy as a first-line treatment for Helicobacter pylori eradication

Background/Aims

Tegoprazan, a novel potassium-competitive acid blocker, has shown rapid action and gastric acid inhibition. In this study, we evaluated the efficacy of a tegoprazan-based, nonbismuth-containing quadruple (concomitant) therapy for the primary eradication of Helicobacter pylori.

Methods

We conducted a prospective, single-arm, single-center, primitive study to verify the efficacy of a 10-day tegoprazan- based (50-mg dose) concomitant therapy, including amoxicillin (1,000-mg dose), clarithromycin (CLA; 500-mg dose), and metronidazole (MET; 500-mg dose) twice daily as a first-line treatment for H. pylori eradication.

Results

We tested consecutive cultures for antibiotic susceptibility and minimum inhibitory concentrations. We enrolled 84 participants; 79 (94.0%) completed first-line therapy. The overall intention-to-treat and per-protocol eradication rates were 90.5% (95% confidence interval [CI], 82.1-95.8) and 96.2% (95% CI, 83.4-97.6), respectively. Of the 73 participants evaluated for antibiotic resistance, 19 (26.0%), 32 (42.5%), and 8 (11.0%) exhibited CLA, MET, and CLA and MET dual resistance, respectively. Of these, 39 participants (66.1%) exhibited successful eradication after the therapeutic regimen despite antibiotic resistance.

Conclusions

The 10-day tegoprazan-based concomitant therapy may be an effective first-line treatment for eradicating H. pylori.