Heterogeneous activation of self-generated H2O2 by Pd@UiO-66(Zr) for trimethoprim degradation: Efficiency and mechanism.

The Fenton reaction is recognized as an effective technique for degrading persistent organic pollutants, such as the emerging pollutant trimethoprim (TMP). Recently, due to the excellent reducibility of active hydrogen ([H]), Pd-H2 has been preferred for Fenton-like reactions and the specific H2 activation of Pd-based catalysts. Herein, a heterogeneous Fenton catalyst named the hydrogen-accelerated oxygen reduction Fenton (MHORF@UiO-66(Zr)) system was prepared through the strategy of building ships in the bottle. The [H] has been used for the acceleration of the reduction of Fe(III) and self-generate H2O2. The systematic characterization demonstrated that the nano Pd0 particle was highly dispersed into the UiO-66(Zr). The results found that 20 mg L-1 of TMP was thoroughly degraded within 90 min in the MHORF@UiO-66(Zr) system under conditions of initial pH 3, 30 mL min-1 H2, 2 g L-1 Pd@UiO-66(Zr) and 25 µM Fe2+. The hydroxyl radical as well as the singlet oxygen were evidenced to be the main reactive oxygen species by scavenging experiments and electron spin resonance. In addition, both reducing Fe(III) and self-generating H2O2 could be achieved due to the strong metal-support interaction (SMSI) between the nano Pd0 particles and UiO-66(Zr) confirmed by the correlation results of XPS and calculation of density functional theory. Finally, the working mechanism of the MHORF@UiO-66(Zr) system and the possible degradation pathway of the TMP have been proposed. The novel system exhibited excellent reusability and stability after six cyclic reaction processes.

Trimethoprim-Based multicomponent solid Systems: Mechanochemical Screening, characterization and antibacterial activity assessment.

In this work, multicomponent trimethoprim-based pharmaceutical solid systems were developed by mechanochemistry, using coformers from the GRAS list and other active pharmaceutical ingredients. The choice of coformers took into account their potential to increase the aqueous solubility/dissolution rate of TMP or its antibacterial activity. All the binary systems were characterized by thermal analysis, powder X-ray diffraction and infrared spectroscopy, and 3 equimolar systems with FTIR pointing to salts, and 4 eutectic mixtures were identified. The intrinsic dissolution rate of TMP in combination with nicotinic acid (a salt) and with paracetamol (eutectic mixture) were 25% and 5% higher than for pure TMP, respectively. For both Gram-positive and -negative strains, the antibacterial activity of TMP with some of the coformers was improved, since the dosage used was lower than the TMP control. A significant increase in antibacterial activity against E. coli was found for the eutectic mixture with curcumin, with the best results being obtained for the eutectic and equimolar mixtures with ciprofloxacin. Combining trimethoprim with coformers offers an interesting alternative to using trimethoprim alone: multicomponent forms with enhanced TMP dissolution rates were identified, as well as combinations showing enhanced antibacterial activity relatively to the pure drug.

Proteomic analysis in the brain and liver of sea bream (Sparus aurata) exposed to the antibiotics ciprofloxacin, sulfadiazine, and trimethoprim.

Antibiotics, frequently detected in aquatic ecosystems, can negatively impact the health of resident organisms. Although the study on the possible effects of antibiotics on these organisms has been increasing, there is still little information available on the molecular effects on exposed non-target organisms. In our study we used a label free proteomic approach and sea bream, Sparus aurata, to evaluate the effects of exposure to environmentally relevant concentrations of the antibiotic compounds ciprofloxacin (CIP), sulfadiazine (SULF) and trimethoprim (TRIM) produced at the protein level. Individuals of sea bream were exposed to single compounds at 5.2 ± 2.1 µg L-1 of CIP, 3.8 ± 2.7 µg L-1 of SULF and 25.7 ± 10.8 µg L-1 of TRIM for 21 days. After exposure, the number of differentially expressed proteins in the liver was 39, 73 and 4 for CIP, SULF and TRIM respectively. In the brain, there was no alteration of proteins after CIP and TRIM treatment, while 9 proteins were impacted after SULF treatment. The differentially expressed proteins were involved in cellular biological, metabolic, developmental, growth and biological regulatory processes. Overall, our study evidences the vulnerability of Sparus aurata, after exposure to environmentally relevant concentrations of the major antibiotics CIP, SULF and TRIM and that their chronic exposure could lead to a stress situation, altering the proteomic profile of key organs such as brain and liver.

Effect of ultra-high-density polyethylene microplastic on the sorption and biodegradation of organic micropollutants.

Microplastics and organic micropollutants are two emerging contaminants that interact with each other in environmental and engineered systems. Sorption of organic micropollutants, such as pharmaceuticals, pesticides and industrial compounds, to microplastics can modify their bioavailability and biodegradation. The present study investigated the capacity of ultra-high density polyethylene particles (125 µm in diameter), before and after aging, to sorb 21 organic micropollutants at different environmentally relevant concentration. Furthermore, the biodegradation of these organic micropollutants by a biofilm microbial community growing on the microplastic surface was compared with the biodegradation by a microbial community originating from activated sludge. Among all tested organic micropollutants, propranolol (70%), trimethoprim (25%) and sotalol (15%) were sorbed in the presence of polyethylene particles. Growth of a biofilm on the polyethylene particles had a beneficial effect on the sorption of bromoxynil, caffeine and chloridazon and on the biodegradation of irbesartan, atenolol and benzotriazole. On the other hand, the biofilm limited the sorption of trimethoprim, propranolol, sotalol and benzotriazole and the biodegradation of 2,4-D. These results showed that ultra-high density polyethylene particles can affect both in a positive and negative way for the abiotic and biotic removal of organic micropollutants in wastewater. This project highlights the need for further investigation regarding the interaction between microplastics and organic micropollutants in the aquatic environment.

Effects of sulfamonomethoxine and trimethoprim co-exposures at different environmentally relevant concentrations on microalgal growth and nutrient assimilation.

In aquaculture around the world, sulfamonomethoxine (SMM), a long-acting antibiotic that harms microalgae, is widely employed in combination with trimethoprim (TMP), a synergist. However, their combined toxicity to microalgae under long-term exposures at environmentally relevant concentrations remains poorly understood. Therefore, we studied the effects of SMM single-exposures and co-exposures (SMM:TMP=5:1) at concentrations of 5 µg/L and 500 µg/L on Chlorella pyrenoidosa within one aquacultural drainage cycle (15 days). Photosynthetic activity and N assimilating enzyme activities were employed to evaluate microalgal nutrient assimilation. Oxidative stress and flow cytometry analysis for microalgal proliferation and death jointly revealed mechanisms of inhibition and subsequent self-adaptation. Results showed that exposures at 5 µg/L significantly inhibited microalgal nutrient assimilation and induced oxidative stress on day 7, with a recovery to levels comparable to the control by day 15. This self-adaptation and over 95 % removal of antibiotics jointly contributed to promoting microalgal growth and proliferation while reducing membrane-damaged cells. Under 500 µg/L SMM single-exposure, microalgae self-adapted to interferences on nutrient assimilation, maintaining unaffected growth and proliferation. However, over 60 % of SMM remained, leading to sustained oxidative stress and apoptosis. Remarkably, under 500 µg/L SMM-TMP co-exposure, the synergistic toxicity of SMM and TMP significantly impaired microalgal nutrient assimilation, reducing the degradation efficiency of SMM to about 20 %. Consequently, microalgal growth and proliferation were markedly inhibited, with rates of 9.15 % and 17.7 %, respectively, and a 1.36-fold increase in the proportion of cells with damaged membranes was observed. Sustained and severe oxidative stress was identified as the primary cause of these adverse effects. These findings shed light on the potential impacts of antibiotic mixtures at environmental concentrations on microalgae, facilitating responsible evaluation of the ecological risks of antibiotics in aquaculture ponds.

Serotype diversity and antimicrobial susceptibility profiles of Actinobacillus pleuropneumoniae isolated in Italian pig farms from 2015 to 2022.

Actinobacillus pleuropneumoniae (APP) is a bacterium frequently associated with porcine pleuropneumonia. The acute form of the disease is highly contagious and often fatal, resulting in significant economic losses for pig farmers. Serotype diversity and antimicrobial resistance (AMR) of APP strains circulating in north Italian farms from 2015 to 2022 were evaluated retrospectively to investigate APP epidemiology in the area. A total of 572 strains isolated from outbreaks occurring in 337 different swine farms were analysed. The majority of isolates belonged to serotypes 9/11 (39.2%) and 2 (28.1%) and serotype diversity increased during the study period, up to nine different serotypes isolated in 2022. The most common resistances were against tetracycline (53% of isolates) and ampicillin (33%), followed by enrofloxacin, florfenicol and trimethoprim/sulfamethoxazole (23% each). Multidrug resistance (MDR) was common, with a third of isolates showing resistance to more than three antimicrobial classes. Resistance to the different classes and MDR varied significantly depending on the serotype. In particular, the widespread serotype 9/11 was strongly associated with florfenicol and enrofloxacin resistance and showed the highest proportion of MDR isolates. Serotype 5, although less common, showed instead a concerning proportion of trimethoprim/sulfamethoxazole resistance. Our results highlight how the typing of circulating serotypes and the analysis of their antimicrobial susceptibility profile are crucial to effectively manage APP infection and improve antimicrobial stewardship.

Enhancing trimethoprim pollutant removal from wastewater using magnetic metal-organic framework encapsulated with poly (itaconic acid)-grafted crosslinked chitosan composite sponge: Optimization through Box-Behnken design and thermodynamics of adsorption parameters.

Trimethoprim (TMP), an antibiotic contaminant, can be effectively removed from water by using the innovative magnetic metal-organic framework (MOF) composite sponge Fe3O4@Rh-MOF@PIC, which is shown in this study. The composite is made up of magnetite (Fe3O4) nanoparticles and a rhodium MOF embedded in a poly(itaconic acid) grafted chitosan matrix. The structure and characteristics of the synthesized material were confirmed by thorough characterization employing SEM, FTIR, XPS, XRD, and BET techniques. Notably, the composite shows a high magnetic saturation of 64 emu g-1, which makes magnetic separation easier, according to vibrating sample magnetometry. Moreover, BET analysis revealed that the Fe3O4@Rh-MOF@PIC sponge had an incredibly high surface area of 1236.48 m2/g. Its outstanding efficacy was confirmed by batch adsorption tests, which produced a maximum adsorption capacity of 391.9 mg/g for the elimination of TMP. Due to its high porosity, magnetic characteristics, and superior trimethoprim uptake, this magnetic MOF composite sponge is a promising adsorbent for effective removal of antibiotics from contaminated water sources. An adsorption energy of 24.5 kJ/mol was found by batch investigations on the Fe3O4@Rh-MOF@PIC composite sponge for trimethoprim (TMP) adsorption. The fact that this value was up 8 kJ/mol suggests that the main mechanism controlling TMP absorption onto the sponge adsorbent is chemisorption. Chemisorption requires creating strong chemical interactions between adsorbate and adsorbent surface groups, unlike weaker physisorption. The magnetic composite sponge exhibited strong removal capabilities and high adsorption capacities for the antibiotic pollutant. The Fe3O4@Rh-MOF@PIC composite sponge also showed magnetism, which allowed for easy magnetic separation after adsorption. Over the course of 6 cycles, it showed outstanding reusability, and XRD confirmed that its composition was stable. The high surface area MOF's pore filling, hydrogen bonding, π-π stacking, and electrostatic interactions were the main trimethoprim adsorption mechanisms. This magnetic composite is feasible and effective for removing antibiotics from water because of its separability, reusability, and synergistic adsorption mechanisms via electrostatics, H-bonding, and π-interactions. The adsorption results were optimized using Box Behnken-design (BBD).

Migration and transformation behaviors of antibiotics in water-sediment system under simulated light and wind waves.

Antibiotics can generally be detected in the water-sediment systems of lakes. However, research on the migration and transformation of antibiotics in water-sediment systems based on the influences of light and wind waves is minimal. To address this research gap, we investigated the specific impacts of light and wind waves on the migration and transformation of three antibiotics, norfloxacin (NOR), trimethoprim (TMP), and sulfamethoxazole (SMX), under simulated light and wind waves disturbance conditions in a water-sediment system from Taihu Lake, China. In the overlying water, NOR was removed the fastest, followed by TMP and SMX. Compared to the no wind waves groups, the disturbance of big wind waves reduced the proportion of antibiotics in the overlying water. The contributions of light and wind waves to TMP and SMX degradation were greater than those of microbial degradation. However, the non-biological and biological contributions of NOR to degradation were almost equal. Wind waves had a significant impact on the microbial community changes in the sediment, especially in Methylophylaceae. These results verified the influence of light and wind waves on the migration and transformation of antibiotics, and provide assistance for the risk of antibiotic occurrence in water and sediments.

Paediatric Escherichia coli urinary tract infection: susceptibility trends and clinical management-a retrospective analysis of a 10-year period.

BACKGROUND: Escherichia coli is the predominant urinary pathogen in children. Irish and international studies have demonstrated increasing antimicrobial resistance (AMR) to antibiotics such as co-amoxiclav. AIMS: We aimed to (1) examine the AMR patterns of paediatric urinary E. coli isolates, from both hospital and community sources, over a 10-year period; (2) assess the effectiveness of Children's Health Ireland (CHI) antimicrobial guidance given local susceptibility data; and (3) review the clinical management of an admitted patient sub-set over a 6-year period. METHODS: Pure growth of urinary E. coli from patients aged ≤ 14 from 2012 to 2021 were analysed for AMR. Differences in susceptibility rates were assessed. A retrospective chart review conducted on inpatients aged ≥ 2 months to ≤ 14 years, 2016-2021. RESULTS: E. coli accounted for 70.8% of likely significant positive pure growth cultures (9314 isolates). Susceptibility to co-amoxiclav significantly increased over time, from 66.7% to 80.4% (2016-2021, p < 0.001). Nitrofurantoin and cefalexin had significantly higher susceptibility rates than trimethoprim (< 70% annually). 85.1% of isolates were susceptible to the combination of co-amoxiclav and gentamicin, recommended for those > 2months and systemically unwell. The additional gain in empiric susceptibility provided by gentamicin above that provided by co-amoxiclav alone has fallen from 16.4% to 6.7% (2016-2021). The 222 clinical cases reviewed showed improved antimicrobial guideline compliance over time. CONCLUSIONS: This study provides important regional AMR data. Co-amoxiclav susceptibility increased significantly over time, contrasting with previous studies. This was temporally associated with stewardship measures reducing co-amoxiclav prescribing. Decreasing utility of gentamicin supports recent CHI guideline updates reducing gentamicin use.

Development of an Open Droplet Microchannel-Based Magnetosensor for Immunofluorometric Assay of Trimethoprim in Chicken and Pork Samples with a Wide Linear Range.

Trimethoprim (TMP), functioning as a synergistic antibacterial agent, is utilized in diagnosing and treating diseases affecting livestock and poultry. Human consumption of the medication indirectly may lead to its drug accumulation in the body and increase drug resistance due to its prolonged metabolic duration in livestock and poultry, presenting significant health hazards. Most reported immunoassay techniques, such as ELISA and immunochromatographic assay (ICA), find it challenging to achieve the dual advantages of high sensitivity, simplicity of operation, and a wide detection range. Consequently, an open droplet microchannel-based magnetosensor for immunofluorometric assay (OMM-IFA) of trimethoprim was created, featuring a gel imager to provide a signal output derived from the highly specific antibody (Ab) targeting trimethoprim. The method exhibited high sensitivity in chicken and pork samples, with LODs of 0.300 and 0.017 ng/mL, respectively, and a wide linear range, covering trimethoprim's total maximum residue limits (MRLs). Additionally, the spiked recoveries in chicken and pork specimens varied between 81.6% and 107.9%, maintaining an acceptable variation coefficient below 15%, aligning well with the findings from the ultraperformance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) technique. The developed method achieved a much wider linear range of about 5 orders of magnitude of 10-2-103 levels with grayscale signals as the output signal, which exhibited high sensitivity, excellent applicability and simple operability based on magnetic automation.

Efficacy of a Novel Antibiotic Drug Combination Toward Multidrug-Resistant Ocular Pathogens.

PURPOSE: Antimicrobial resistance is a global health threat, compounded by the reduction in the discovery of new antibiotics. A repurposed drugs-based approach could provide a viable alternative for the treatment of multidrug-resistant (MDR) bacterial infections. In this study, we sought to evaluate the in vitro efficacy of a novel drug combination, polymyxin B/trimethoprim (PT) + rifampin on MDR isolates from patients with bacterial keratitis in India. METHODS: Forty-three isolates, which included 20 Staphylococcus aureus , 19 Pseudomonas aeruginosa , 3 Pseudomonas stutzeri , and 1 Acinetobacter baumannii , were evaluated for their antibiotic resistance by minimum inhibitory concentration (MIC). Fractional Inhibitory Concentration Index (FICI) testing was performed to measure the antimicrobial impact of PT + rifampin in combination. RESULTS: Among S. aureus isolates, 100% were resistant to at least 1 antibiotic class, 12 (60%) were MDR, and 14 (70%) were classified as methicillin-resistant. Among the gram-negative isolates, >90% were classified as MDR. Fractional Inhibitory Concentration (FIC) testing revealed that PT + rifampin was effective in completely inhibiting growth of all isolates while also displaying additive or synergistic activity in approximately 70% of the strains. Mean FICI values were 0.753 ± 0.311 and 0.791 ± 0.369 for S. aureus and gram-negative isolates, respectively, and a >2-fold reduction in MIC was measured for both PT and rifampin when tested in combination versus alone. CONCLUSIONS: Our data demonstrate the ability of PT + rifampin to eliminate all isolates tested, even those conferring MDR, highlighting the promise of this drug combination for the treatment of bacterial keratitis.

Trimethoprim-sulfonamide: a valid antimicrobial treatment in foals?

Trimethoprim-sulfonamide (TMPS) combinations are widely used to treat a range of infectious diseases in horses, but some equine practitioners are reluctant to use them for treatment of both neonatal and older foals. Considering the emergence of increased antimicrobial resistance, the use of protected antimicrobials commonly prescribed to foals should be avoided and alternative first-line therapy considered, where appropriate. This review examines the characteristics and pharmacokinetics of TMPS and its suitability for treatment of foals. Data regarding dosage and route of administration are reported on the basis of recent publications in foals. The review intends to share significant information about the common infections that are most likely responsive to TMPS treatment in foals and, as such, where TMPS might be considered a suitable first-line therapeutic option.

Antibiotic Combination to Effectively Postpone or Inhibit the In Vitro Induction and Selection of Levofloxacin-Resistant Mutants in Elizabethkingia anophelis.

Fluoroquinolones are potentially active against Elizabethkingia anophelis. Rapidly increased minimum inhibitory concentrations (MICs) and emerging point mutations in the quinolone resistance-determining regions (QRDRs) following exposure to fluoroquinolones have been reported in E. anophelis. We aimed to investigate point mutations in QRDRs through exposure to levofloxacin (1 × MIC) combinations with different concentrations (0.5× and 1 × MIC) of minocycline, rifampin, cefoperazone/sulbactam, or sulfamethoxazole/trimethoprim in comparison with exposure to levofloxacin alone. Of the four E. anophelis isolates that were clinically collected, lower MICs of levofloxacin were disclosed in cycle 2 and 3 of induction and selection in all levofloxacin combination groups other than levofloxacin alone (all p = 0.04). Overall, no mutations were discovered in parC and parE throughout the multicycles inducted by levofloxacin and all its combinations. Regarding the vastly increased MICs, the second point mutations in gyrA and/or gyrB in one isolate (strain no. 1) occurred in cycle 2 following exposure to levofloxacin plus 0.5 × MIC minocycline, but they were delayed appearing in cycle 5 following exposure to levofloxacin plus 1 × MIC minocycline. Similarly, the second point mutation in gyrA and/or gyrB occurred in another isolate (strain no. 3) in cycle 4 following exposure to levofloxacin plus 0.5 × MIC sulfamethoxazole/trimethoprim, but no mutation following exposure to levofloxacin plus 1 × MIC sulfamethoxazole/trimethoprim was disclosed. In conclusion, the rapid selection of E. anophelis mutants with high MICs after levofloxacin exposure could be effectively delayed or postponed by antimicrobial combination with other in vitro active antibiotics.

Is the reliability of wastewater-based epidemiology affected by season? Comparative analysis with pharmaceuticals prescriptions.

Wastewater-based epidemiology (WBE) has been already proposed by several authors for estimating the consumption of drugs, mainly the illicit ones. However, not much information is available about the actual reliability of this tool given the absence of comparison with the actual consumption. This work aims to evaluate the reliability of the WBE as a tool for estimating the consumption of pharmaceuticals in urban area. Measured consumption back-calculated with a WBE approach was compared with prescription of pharmaceutical products as "control." Moreover, seasonal influence on (i) pharmaceutical consumption, (ii) load of pharmaceutical products in the sewer system, and (iii) reliability of WBE was evaluated. Ciprofloxacin, sulfamethoxazole, metoprolol, carbamazepine, and citalopram were estimated by WBE with a difference respect to the "control" value lower than 0.2 order of magnitude while only trimethoprim and sotalol exceeded the 0.5 order of magnitude of difference but below the 1 order of magnitude. Sedatives were the best represented by WBE (on average 0.15 order of magnitude of difference compared to prescription data). However, further studies are suggested to fully estimate the influence of the type of APs on the reliability of the WBE. Seasonal patterns were found for the load of ciprofloxacin in the sewer and for the consumption of sulfamethoxazole and trimethoprim by population but seasonal changes did not have a significant impact (p > 0.05) on the reliability of WBE. Despite some gaps remained to optimize the reliability of the tool, WBE can be considered a valid method to estimate the consumption of prescribed drugs from the analysis of the sewer system.

Insights into the efficient mineralization of antibiotic trimethoprim in aqueous media by Fe2+ catalytically enhanced vacuum-UV irradiation: Kinetics, mechanisms, and toxicity evaluation.

The widespread existence of antibiotics in the environment has attracted growing concerns regarding the potential adverse effects on aquatic organisms, ecosystems, and human health even at low concentrations. Extensive efforts have been devoted to developing new methods for effective elimination of antibiotics from wastewater. Herein, a novel process of Fe2+ catalytically enhanced vacuum ultraviolet (VUV) irradiation was proposed as a promising approach for the removal of antibiotic trimethoprim (TMP) in water. Compared with UVC photolysis, VUV photolysis, and UVC/Fe2+, VUV/Fe2+ could increase the pseudo-first-order reaction rate constant of TMP removal by 6.6-38.4 times and the mineralization rate by 36.5%-59.9%. The excellent performance might originate from the synergistic effect of VUV and Fe2+, i.e., VUV irradiation could effectively split water and largely accelerate the Fe3+/Fe2+ cycle to generate more reactive oxygen species (ROS). EPR results indicated that •OH and O2•- were identified as the main ROS in the UVC/Fe2+ and VUV/Fe2+ processes, while •OH, O2•-, and 1O2 were involved in the VUV process. The operating parameters, such as Fe2+ dosage and initial TMP contents, were evaluated and optimized. Up to 8 aromatic intermediates derived from hydroxylation, demethylation, carbonylation, and methylene group cleavage were identified by UPLC-QTOF-MS/MS technique, the possible pathways of TMP degradation were proposed. Finally, the acute and chronic toxicity of intermediates formed during TMP degradation in the VUV/Fe2+ process were also evaluated.

Regulation of overexpressed efflux pump encoding genes by cinnamon oil and trimethoprim to abolish carbapenem-resistant Acinetobacter baumannii clinical strains.

Resistance mechanisms are a shelter for Acinetobacter baumannii to adapt to our environment which causes difficulty for the infections to be treated and WHO declares this organism on the top of pathogens priority for new drug development. The most common mechanism that develops drug resistance is the overexpression of the efflux pump, especially Resistance-nodulation-cell division (RND) family, to almost most antibiotics. The study is designed to detect RND efflux pump genes in A. baumannii, and its correlation to multidrug resistance, in particular, the carbapenems resistance Acinetobacter baumannii (CRAB), and using different inhibitors that restore the antibiotic susceptibility of imipenem. Clinical A. baumannii isolates were recovered from different Egyptian hospitals in Intensive care unit (ICU). The expression of genes in two strains was analyzed using RT-PCR before and after inhibitor treatment. About 100 clinical A. baumannii isolates were recovered and identified and recorded as MDR strains with 75% strains resistant to imipenem. adeB, adeC, adeK, and adeJ were detected in thirty- seven the carbapenems resistance Acinetobacter baumannii (CRAB) strains. Cinnamomum verum oil, Trimethoprim, and Omeprazole was promising inhibitor against 90% of the carbapenems resistance Acinetobacter baumannii (CRAB) strains with a 2-6-fold decrease in imipenem MIC. Downregulation of four genes was associated with the addition of those inhibitors to imipenem for two the carbapenems resistance Acinetobacter baumannii (CRAB) (ACN15 and ACN99) strains, and the effect was confirmed in 24 h killing kinetics. Our investigation points to the carbapenems resistance Acinetobacter baumannii (CRAB) strain's prevalence in Egyptian hospitals with the idea to revive the imipenem activity using natural and chemical drugs as inhibitors that possessed high synergistic activity.

Synergistic Control of Trimethoprim and the Antimicrobial Resistome in Electrogenic Microbial Communities.

Synergistic control of the risks posed by emerging antimicrobials and antibiotic resistance genes (ARGs) is crucial for ensuring ecological safety. Although electrogenic respiration can enhance the biodegradation of several antimicrobials and reduce ARGs accumulation, the association mechanisms of antimicrobial biodegradation (trimethoprim, TMP) with the fate of the antimicrobial resistome remain unclear. Here, the biotransformation pathway of TMP, microbial associations, and functional gene profiles (e.g., degradation, antimicrobial resistance, and electron transfer) were analyzed. The results showed that the microbial electrogenic respiration significantly enhanced the biodegradation of TMP, especially with a cosubstrate sodium acetate supply. Electroactive bacteria enriched in the electrode biofilm positively correlated with potential TMP degraders dominated in the planktonic communities. These cross-niche microbial associations may contribute to the accelerated catabolism of TMP and extracellular electron transfer. Importantly, the evolution and dissemination of overall ARGs and mobile genetic elements (MGEs) were significantly weakened due to the enhanced cometabolic biodegradation of TMP. This study provides a promising strategy for the synergistic control of the water ecological risks of antimicrobials and their resistome, while also highlighting new insights into the association of antimicrobial biodegradation with the evolution of the resistome in an electrically integrated biological process.

Development and validation of an UPLC-MS/MS assay for the simultaneous quantification of seven commonly used antibiotics in human plasma and its application in therapeutic drug monitoring.

OBJECTIVE: To develop and validate an UPLC-MS/MS assay for simultaneous determination of the total concentration of ceftazidime, ciprofloxacin, flucloxacillin, piperacillin, tazobactam, sulfamethoxazole, N-acetyl sulfamethoxazole and trimethoprim, and the protein-unbound concentration of flucloxacillin, in human plasma to be used for research and clinical practice. METHODS: Sample pretreatment included protein precipitation with methanol. For the measurement of protein-unbound flucloxacillin, ultrafiltration was performed at physiological temperature. For all compounds, a stable isotopically labelled internal standard was used. Reliability of the results was assessed by participation in an international quality control programme. RESULTS: The assay was successfully validated according to the EMA guidelines over a concentration range of 0.5-100 mg/L for ceftazidime, 0.05-10 mg/L for ciprofloxacin, 0.4-125 mg/L for flucloxacillin, 0.2-60 mg/L for piperacillin, 0.15-30 mg/L for tazobactam, 1-200 mg/L for sulfamethoxazole and N-acetyl sulfamethoxazole, 0.05-10 mg/L for trimethoprim and 0.10-50 mg/L for unbound flucloxacillin. For measurement of total concentrations, the within- and between-day accuracy ranged from 90.0% to 109%, and 93.4% to 108%, respectively. Within- and between-day precision (variation coefficients, CVs) ranged from 1.70% to 11.2%, and 0.290% to 5.30%, respectively. For unbound flucloxacillin, within-day accuracy ranged from 103% to 106% and between-day accuracy from 102% to 105%. The within- and between-day CVs ranged from 1.92% to 7.11%. Results of the international quality control programme showed that the assay is reliable. CONCLUSIONS: The method provided reliable, precise and accurate measurement of seven commonly prescribed antibiotics, including the unbound concentration of flucloxacillin. This method is now routinely applied in research and clinical practice.

Protecting the Achilles heel: three FolE_I-type GTP-cyclohydrolases needed for full growth of metal-resistant Cupriavidus metallidurans under a variety of conditions.

In Cupriavidus metallidurans and other bacteria, biosynthesis of the essential biochemical cofactor tetrahydrofolate (THF) initiates from guanosine triphosphate (GTP). This step is catalyzed by FolE_I-type GTP cyclohydrolases, which are either zinc-dependent FolE_IA-type or metal-promiscuous FolE_IB-type enzymes. As THF is also essential for GTP biosynthesis, GTP and THF synthesis form a cooperative cycle, which may be influenced by the cellular homeostasis of zinc and other metal cations. Metal-resistant C. metallidurans harbors one FolE_IA-type and two FolE_IB-type enzymes. All three proteins were produced in Escherichia coli. FolE_IA was indeed zinc dependent and the two FolE_IB enzymes metal-promiscuous GTP cyclohydrolases in vitro, the latter, for example, functioning with iron, manganese, or cobalt. Single and double mutants of C. metallidurans with deletions in the folE_I genes were constructed to analyze the contribution of the individual FolE_I-type enzymes under various conditions. FolE_IA was required in the presence of cadmium, hydrogen peroxide, metal chelators, and under general metal starvation conditions. FolE_IB1 was important when zinc uptake was impaired in cells without the zinc importer ZupT (ZIP family) and in the presence of trimethoprim, an inhibitor of THF biosynthesis. FolE_IB2 was needed under conditions of low zinc and cobalt but high magnesium availability. Together, these data demonstrate that C. metallidurans requires all three enzymes to allow efficient growth under a variety of conditions.IMPORTANCETetrahydrofolate (THF) is an important cofactor in microbial biochemistry. This "Achilles heel" of metabolism has been exploited by anti-metabolites and antibiotics such as sulfonamide and trimethoprim. Since THF is essential for the synthesis of guanosine triphosphate (GTP) and THF biosynthesis starts from GTP, synthesis of both compounds forms a cooperative cycle. The first step of THF synthesis by GTP cyclohydrolases (FolEs) is metal dependent and catalyzed by zinc- or metal-promiscuous enzymes, so that the cooperative THF and GTP synthesis cycle may be influenced by the homeostasis of several metal cations, especially that of zinc. The metal-resistant bacterium C. metallidurans needs three FolEs to grow in environments with both high and low zinc and cadmium content. Consequently, bacterial metal homeostasis is required to guarantee THF biosynthesis.

Clarification of adverse drug reactions by a pharmacovigilance team results in increased antibiotic re-prescribing at a freestanding United States children's hospital.

Documentation of adverse drug reactions (ADRs) is a key factor in guiding future prescribing. However, incomplete documentation is common and often fails to distinguish implicated drugs as true allergies. This in turn leads to unnecessary avoidance of implicated drug classes and may result in sub-optimal prescribing. Pharmacovigilance (PV) programs utilize a systematic approach to clarify ADR documentation and are known to improve patient safety. Yet it remains unclear if PV alters prescribing. Or, if the existence of the ADR documentation itself continues to prompt avoidance of implicated drugs. To address this, our work presents a retrospective cohort study assessing if clarification of antibiotic ADRs by a hospital-wide PV team was associated with future, safe, re-prescribing at a freestanding pediatric hospital in the midwestern United States. First, we compared the likelihood of future prescribing in an antibiotic class with an active ADR, as compared to alternative drug classes, between PV-clarified and non-clarified patients. Second, we assessed differences in adverse event rates 30-days after future prescribing based on PV clarification status. For robustness, analyses were performed on patients with ADRs in four antibiotic classes: penicillin-based beta-lactams (n = 45,642), sulfonamides/trimethoprim (n = 5,329), macrolides (n = 3,959), and glycopeptides (n = 622). Results illustrate that clarification of an ADR by PV was associated with an increased odds of future prescribing in the same drug class (Odds Ratio [95%-CI]): penicillin-based beta-lactams (1.59 [1.36-1.89]), sulfonamides/trimethoprim (2.29 [0.89-4.91]), macrolides (0.77 [0.33-1.61]), and glycopeptide (1.85 [1.12-3.20]). Notably, patients clarified by PV experienced no increase in the rate of adverse events within 30-days following the prescribing of antibiotics in the same class as an active ADR. Overall, this study provides strong evidence that PV reviews safely increase the rate of re-prescribing antibiotics even in the presence of an existing implicated drug ADR.