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The objective of this study was to evaluate the impact of dietary zinc supplementation in pre-weaned dairy calves on the phenotypic antimicrobial resistance (AMR) of fecal commensal bacteria. A repository of fecal specimens from a random sample of calves block-randomized into placebo (n = 39) and zinc sulfate (n = 28) groups collected over a zinc supplementation clinical trial at the onset of calf diarrhea, calf diarrheal cure, and the last day of 14 cumulative days of zinc or placebo treatment were analyzed. Antimicrobial susceptibility testing was conducted for Enterococcus spp. (n = 167) and E. coli (n = 44), with one representative isolate of each commensal bacteria tested per sample. Parametric survival interval regression models were constructed to evaluate the association between zinc treatment and phenotypic AMR, with exponentiated accelerated failure time (AFT) coefficients adapted for MIC instead of time representing the degree of change in AMR (MIC Ratio, MR). Findings from our study indicated that zinc supplementation did not significantly alter the MIC in Enterococcus spp. for 13 drugs: gentamicin, vancomycin, ciprofloxacin, erythromycin, penicillin, nitrofurantoin, linezolid, quinupristin/dalfopristin, tylosin tartrate, streptomycin, daptomycin, chloramphenicol, and tigecycline (MR = 0.96-2.94, p > 0.05). In E. coli, zinc supplementation was not associated with resistance to azithromycin (MR = 0.80, p > 0.05) and ceftriaxone (MR = 0.95, p > 0.05). However, a significant reduction in E. coli MIC values was observed for ciprofloxacin (MR = 0.17, 95% CI 0.03-0.97) and nalidixic acid (MR = 0.28, 95% CI 0.15-0.53) for zinc-treated compared to placebo-treated calves. Alongside predictions of MIC values generated from these 17 AFT models, findings from this study corroborate the influence of age and antimicrobial exposure on phenotypic AMR.

The advanced in situ oxidation polymerization technique was employed to synthesize the SiNWs@PANI composite material, which exhibited a unique hybrid structure displaying remarkable properties. The optimized polyaniline content of 5% significantly enhanced the photocatalytic performance of SiNWs@PANI, surpassing pure SiNWs in degradation efficiency. A comprehensive study explored the photocatalytic mechanisms of SiNWs@PANI, focusing on environmental factors such as catalyst composite content, pollutant nature, and solution pH. The material exhibited exceptional activity in the photocatalytic degradation of ciprofloxacin, achieving a remarkable degradation efficiency of up to 91.54% at a concentration of 10 mg L−1. Our findings revealed a significant dependency of degradation efficiency on solution pH, with alkaline conditions favoring enhanced catalytic activity. A rigorous derivation experiment identified the final degradation product, corroborating the effectiveness of SiNWs@PANI in ciprofloxacin degradation and providing insights into the underlying photocatalytic processes. This work offers a novel perspective and methodology for developing highly efficient and environmentally friendly photocatalytic materials, with promising implications for water treatment and environmental remediation applications. [ABSTRACT FROM AUTHOR]

Novel drug like chloroquinoline‐benzylamine hybrids were synthesized and subjected to comprehensive antibacterial evaluation in the present investigation. The pharmacological evaluation comprises determination of minimum inhibitory concentration (MIC), disk diffusion assay, hemolysis and combination assays against both Gram‐negative (Pseudomonas aeruginosa) and Gram‐positive (Bacillus subtilis, Enterococcus faecalis, and Staphylococcus aureus) bacterial strains. Among all, 7‐chloroquinoline‐benzylamine hybrid bearing p‐bromophenyl substituent (SA11) demonstrated significant antibacterial efficacy (MIC=128μg/mL) against the tested panel of Gram‐positive strains with no sign of toxicity towards human red blood cells (hRBCs). Furthermore, another hybrid with o‐hydroxyphenyl substitution (SA12) exhibited notable activity against the tested isolates with MIC values ranging from 64 to 256μg/mL. Molecular docking studies suggested compound SA11 binds within the active site of the biofilm causing protein (PDB: 7C7U) further supported by the molecular dynamics (MD) simulation studies at 100 ns. Compound SA11 exhibited significant efficacy in inhibiting S. aureus growth in the disk diffusion assay. Moreover, it displayed a synergistic effect when combined with ciprofloxacin (CIP), implying its potential utility in addressing antibiotic‐resistant bacterial strains through combination therapy. The pkCSM‐Pharmacokinetics assessment indicated favourable ADME profiles for SA11, supporting its potential as a viable drug candidate. [ABSTRACT FROM AUTHOR]

Antibiotics are increasingly found in urban lakes, posing significant ecological risks to lake ecosystems. The impact of sponge city facilities on urban flood control is significant; however, their influence on the exposure characteristics and risks associated with antibiotics in urban inland lakes remains unclear. This study investigated the exposure characteristics and evaluated the ecological risks of 15 antibiotics across seven lakes of Fuzhou (as the target of sponge city) in different seasons, in comparison to non-sponge cities. The results revealed that 12 antibiotics were consistently detectable across all lakes, with concentrations ranging from non-detectable (ND) to 20.61 ng/L, with sulfamethoxazole (SMX) emerging as the predominant contaminant. Most antibiotics exhibited higher concentrations in the dry season, attributed to environmental conditions, biological mechanisms, and their physicochemical properties. SMX, tetracycline (TTC), oxytetracycline (OTC), and ciprofloxacin (CIP) posed moderate to high ecological risks, with risk quotient (RQ) values of 0.46, 0.14, 0.17, and 0.61, respectively, while the remaining antibiotics presented lower ecological risks in both seasons. Notably, the RQ values for TTC, OTC, and CIP were elevated during the dry season, whereas SMX displayed a higher RQ value in the wet season, indicating an increased ecological risk during the dry months. In comparison to non-sponge cities, sponge cities exhibited significantly lower concentrations of nearly all antibiotics, particularly during the wet season (p ≤ 0.05). Moreover, over 85% of the antibiotics in non-sponge cities were classified as high risk, contrasted with only 55% in sponge cities, underscoring the heightened ecological risks associated with non-sponge urban designs. This study provides critical insights for controlling antibiotic pollution in the lakes of Fuzhou and serves as a valuable reference for maintaining aquatic ecosystem health through the implementation of sponge city infrastructure. [ABSTRACT FROM AUTHOR]

Objectives Mechanisms of non-typhoidal Salmonella (NTS) resistance to azithromycin have rarely been reported. Here we investigate the epidemiology and genetic features of 10 azithromycin-resistant NTS isolates. Methods A total of 457 NTS isolates were collected from a tertiary hospital in Guangzhou. We performed antimicrobial susceptibility tests, conjugation experiments, efflux pump expression tests, whole-genome sequencing and bioinformatics analysis to conduct the study. Results The results showed that 10 NTS isolates (2.8%) were resistant to azithromycin with minimum inhibitory concentration values ranging from 128 to 512 mg/L and exhibited multidrug resistance. The phylogenetic tree revealed that 5 S. London isolates (AR1–AR5) recognized at different times and departments were closely related [3–74 single-nucleotide polymorphisms (SNPs)] and 2 S. Typhimurium isolates (AR7 and AR8) were clones (<3 SNPs) at 3-month intervals. The azithromycin resistance was conferred by mph (A) gene found on different plasmids, including IncFIB, IncHI2, InFII, IncC and IncI plasmids. Among them, IncFIB, InFII and IncHI2 plasmids carried different IS 26 -class 1 integron (intI1) arrangement patterns that mediated multidrug resistance transmission. Conjugative IncC plasmid encoded resistance to ciprofloxacin, ceftriaxone and azithromycin. Furthermore, phylogenetic analysis demonstrated that mph (A)-positive plasmids closely related to 10 plasmids in this study were mainly discovered from NTS, Escherichia coli , Klebsiella pneumonia and Enterobacter hormaechei. The genetic environment of mph (A) in 10 NTS isolates was IS 26 - mph (A)- mrx (A)- mphR (A)-IS 6100 /IS 26 that co-arranged with intI1 harbour multidrug-resistant (MDR) gene cassettes on diverse plasmids. Conclusions These findings highlighted that the dissemination of these plasmids carrying mph (A) and various intI1 MDR gene cassettes would seriously restrict the availability of essential antimicrobial agents for treating NTS infections. [ABSTRACT FROM AUTHOR]

Background Over the years, reports have associated fluoroquinolones (FQ) with seizures. The incidence and whether FQ compared to non-epileptogenic antibiotic are associated with increased risk of seizures has yet to be examined. Methods A retrospective observational study of hospitalized patients treated with FQ (ofloxacin, ciprofloxacin, levofloxacin, moxifloxacin) or macrolides (MA: azithromycin or roxithromycin) between January 2009 and January 2021 in a large tertiary academic medical centre. The outcome was the occurrence of a seizure during treatment. The Naranjo scale was used to assess causality between FQ treatment and seizures. Comparative analysis was conducted using propensity score matching to correct for possible bias due to non-random selection, followed by inverse probability weighting (IPW) to estimate the difference in seizure risk between FQ and MA. Results Overall, 52 722 patients were treated with FQ during a total of 178 982 days. Mean age was 65 (±19) years and 47% were females. Thirty-three patients (0.06%) experienced a seizure, yielding an incidence of 1:5422 treatment days. Causality was deemed probable and possible among 9/33 and 24/33, respectively. The MA group composed of 8522 patients treated during 17 954 treatment days. Mean age was 65 (±21) years, 49% were females. Six (0.07%) patients experienced each a single seizure. IPW estimated OR for seizures among the FQ versus MA group was 1.44 (95%CI 0.59–3.5, P  = 0.42). Discussion The incidence of FQ associated seizures among hospitalized patients is low and the risk did not significantly exceed that under macrolides. Our results provide evidence for clinicians and decision-makers when balancing fluoroquinolones risks and benefits. [ABSTRACT FROM AUTHOR]

Objectives Klebsiella pneumoniae is a significant pathogen with increasing resistance and high mortality rates. Conventional antibiotic susceptibility testing methods are time-consuming. Next-generation sequencing has shown promise for predicting antimicrobial resistance (AMR). This study aims to develop prediction models using whole-genome sequencing data and assess their feasibility with metagenomic next-generation sequencing data from clinical samples. Methods On the basis of 4170 K. pneumoniae genomes, the main genetic characteristics associated with AMR were identified using a LASSO regression model. Consequently, the prediction model was established, validated and optimized using clinical isolate read simulation sequences. To evaluate the efficacy of the model, clinical specimens were collected. Results Four predictive models for amikacin, ciprofloxacin, levofloxacin, and piperacillin/tazobactam, initially had positive predictive values (PPVs) of 92%, 98%, 99%, 94%, respectively, when they were originally constructed. When applied to clinical specimens, their PPVs were 96%, 96%, 95%, and 100%, respectively. Meanwhile, there were negative predictive values (NPVs) of 100% for ciprofloxacin and levofloxacin, and 'not applicable' (NA) for amikacin and piperacillin/tazobactam. Our method achieved antibacterial phenotype classification accuracy rates of 95.92% for amikacin, 96.15% for ciprofloxacin, 95.31% for levofloxacin and 100% for piperacillin/tazobactam. The sequence-based prediction antibiotic susceptibility testing (AST) reported results in an average time of 19.5 h, compared with the 67.9 h needed for culture-based AST, resulting in a significant reduction of 48.4 h. Conclusions These preliminary results demonstrated that the performance of prediction model for a clinically significant antimicrobial–species pair was comparable to that of phenotypic methods, thereby encouraging the expansion of sequence-based susceptibility prediction and its clinical validation and application. [ABSTRACT FROM AUTHOR]

A phase 1b study was conducted to evaluate the safety and feasibility of ciprofloxacin and etoposide combination treatment in subjects with relapsed and refractory acute myeloid leukemia. Eleven subjects were enrolled in the study. Utilizing the standard '3 + 3' design, escalating ciprofloxacin doses (750 mg, 1000 mg) twice daily on D1-D10 in combination with a fixed dose (200 mg) of etoposide on D2-D8 were administered. Maximum tolerated dose was determined to be 1000 mg of ciprofloxacin in combination with 200 mg of etoposide. Serious adverse events occurred in 54.5% (n = 6) subjects and 91% (n = 10) subjects reported ≥ grade 3 toxicities. Nine subjects completed treatment, one had a dose-limiting toxicity, and one withdrew. One subject achieved complete remission with a duration of 111 days and one subject achieved morphologic leukemia-free state after cycle 1. While the combination demonstrated safety and an acceptable toxicity profile, only modest hematologic and clinical benefits were observed. This trial was registered at as #NCT02773732. [ABSTRACT FROM AUTHOR]

Ternary I-III-VI quantum dots, unlike traditional binary counterparts, offer advantages like low toxicity, cadmium-free composition, tunable electronic properties, and near-infrared light emission, making them increasingly popular for their cost-effectiveness and versatile applications in light emission. In this study, monodispersive, water-soluble, highly emissive CuInS2@ZnS quantum dots were synthesized using cysteine and threonine as ligands by a simple one-pot solution method. By adjusting, the ratio of cysteine to threonine to 1:5 and the heating time during the synthesis process to 40 min, CuInS2@ZnS quantum dots achieved the highest fluorescence intensity. Then, CuInS2@ZnS quantum dots were applied for ciprofloxacin (CIP) detection in food sample, showing a linear range of 2–18 μg/ml and a lowest detection limit of 0.28 μg/ml. The fluorescent probe was successfully established by quenching process as CIP concentration increasing, due to photoinduced electron transfer. Experimental results demonstrated the detection method has high sensitivity and good selectivity. We, then utilized smartphones to visually distinguish CIP concentrations based on the colors emitted by the CuInS2@ZnS quantum dots under UV light. The method was finally effectively to detect residual CIP in porcine kidneys, with recoveries of 92%–98%. This approach has promising potential for enhancing food safety testing. [ABSTRACT FROM AUTHOR]

Bacterial persisters avoid antibiotic-mediated death by entering a dormant state and are considered a major cause of antibiotic treatment failure. Antimicrobial peptides (AMPs) with membrane-disrupting activity are promising drugs to eradicate persister cells. In this study, carbonyl cyanide m-chlorophenylhydrazone (CCCP), ciprofloxacin (CIP), and rifampicin (RFP) were applied to induce the formation of multidrug-resistant Pseudomonas aeruginosa (MRPA0108) persisters, and the antibacterial activity and mechanisms of I1W and L12W (two Trp-containing peptides designed in our lab) against MRPA0108 persisters were investigated. The results showed that I1W and L12W displayed potent antibacterial activity against MRPA0108 persisters. Both Trp-containing peptides disturbed the inner and outer membrane of MRPA0108 persisters. In addition, I1W and L12W revealed novel antibacterial mechanisms by decreasing the enzymatic activities of superoxide dismutase (SOD) and catalase (CAT), increasing reactive oxygen species (ROS) and malondialdehyde (MDA) levels, consequently leading to oxidative stress. The transcriptome profile of I1W-treated MRPA0108 persisters revealed that the genes involved in carbon metabolism, biosynthesis of amino acids, and the TCA cycle were downregulated, indicating that I1W interfered with metabolism and energy synthesis processes. Furthermore, both Trp-containing peptides displayed synergistic activities with antibiotic tobramycin and showed additive activities with cefepime or ciprofloxacin, which revealed a potential therapeutic strategy for the eradication of MRPA0108 persisters. [Display omitted] • I1W and L12W, two Trp-containing peptides, exhibited high antibacterial activity against MRPA0108 persisters. • I1W and L12W killed MRPA0108 persisters by disturbing cell membrane and inducing substantial oxidative stress. • I1W and L12W displayed synergistic activities with tobramycin and additive activities with cefepime or ciprofloxacin. [ABSTRACT FROM AUTHOR]

Between 2016 and 2019, the proportion of Escherichia coli bloodstream infection (BSI) with resistance to at least one antibiotic increased nationally. Public health interventions implemented in response to the COVID-19 pandemic changed population contact patterns and healthcare systems, with consequent effects on epidemiological trends of numerous pathogens. We investigated the impact of COVID-19 restrictions on epidemiological trends of E. coli BSI antimicrobial resistance (AMR) across South West England. We undertook a retrospective ecological analysis utilizing routine surveillance data of E. coli BSI cases reported to the UK Health Security Agency between 2016 and 2021. We analysed AMR trends for antimicrobial agents including amoxicillin–clavulanate, ciprofloxacin, piperacillin–tazobactam, gentamicin, third-generation cephalosporins and carbapenems before and after the implementation of COVID-19 restrictions (23 March 2020) using Bayesian segmented regression. We identified 19 055 cases. A total of 50.2% were male. Median age was 76 (interquartile range, 65–85 years). Piperacillin–tazobactam (–2.90% [95% highest density interval {HDI} –4.51%, –0.48%]) and ciprofloxacin (–2.40% [95% HDI –4.35%, 0.48%]) resistance demonstrated immediate step changes at the implementation of COVID-19 restrictions. Gentamicin (odds ratio [OR] 0.92 [95% HDI 0.76, 1.12]) and third-generation cephalosporins (OR 0.95 [95% HDI 0.80, 1.14]) exhibited decreasing annual resistance trends after the implementation of COVID-19 restrictions, with moderate evidence for a lower OR after restrictions as compared to the period before (gentamicin Bayes Factor = 5.10, third-generation cephalosporins Bayes Factor = 6.67). COVID-19 restrictions led to abrupt and longer term changes to E.coli BSI AMR. The immediate effects suggest altered transmission, whereas changes to resistant E. coli reservoirs may explain trend effects. [ABSTRACT FROM AUTHOR]

Some pharmaceutical and personal care products, including endocrine disruptors, are polluting ecosystems, thus requiring advanced materials and methods for detection and remediation. Here we review carbon nanotubes for detection and remediation of pharmaceutical and personal care products, with focus on green synthesis of hybrid carbon nanotubes, removal of pollutants, and deep learning networks to predicts adsorption. Pollutants include bisphenol, phthalates, tetracycline, and ciprofloxacin. We found that magnetic carbon nanotubes are easily recovered from water with a relatively low production cost. Functionalized carbon dots/carbon nanotube hybrids can detect ciprofloxacin contamination at 0.001 mg/L. Some studies report the adsorption of 95% or the photocatalytic degradation of 100% of pollutants using magnetic carbon nanotubes. [ABSTRACT FROM AUTHOR]

Cerium‐containing titania nano‐octahedra (CeTNOh) are obtained by ultrasonication‐hydrothermal synthesis of Ce‐containing titanate nanowires (0.35, 0.46, and 0.70 Ce mol %) from commercial TiO2 (Degussa P25). CeTNOh are tested as photocatalysts to degrade a target pollutant (ciprofloxacin) under simulated solar light and at mild conditions. CeTNOh are anatase polymorphs with increasing crystallite size as Ce content increases. Hydrothermal treatments enhance the specific surface area (SSA) compared to P25, although Ce addition slightly reduces SSA while increasing crystallite size. Electron Microscopy confirms the morphology, although higher Ce levels hinder a full transformation. X‐ray photoemission spectroscopy (XPS) shows the presence of Ce3+/Ce4+ redox pair, promoting electron mobility and Ti‐Ce interactions. Optical and electronic spectroscopy reveals that Ce loading reduces the bandgap from 3.20 to 2.74 eV, extending light absorption into the visible range, thus enhancing the photocatalytic activity. The best sample, CeTNOh0.35, achieved 83% degradation of ciprofloxacin after 360 minutes under solar irradiation, with poor adsorption in the dark period. Higher Ce loadings negatively affect photoactivity by partially covering titania active sites. Reusability tests confirm the stability and efficiency of CeTNOh0.35 over three cycles, highlighting the importance of octahedral morphology in Ce‐containing systems to boost the final photoactivity for water remediation. [ABSTRACT FROM AUTHOR]

One of the procedures that helps remove pharmaceuticals (Phs) from wastewater in Constructed Wetlands (CWs) is phytoremediation. Using Ruellia simplex, the main emphasis of this study is on the function of plants and substrates in the removal mechanism independently from aqueous solution. Even in an aqueous solution containing high concentrations of antibiotics, the plant could thrive, and lighting further promoted growth. For the removal of amoxicillin (AMX) and ciprofloxacin (CIP) at a concentration of 25 mg/L, six reactors are used: hydroponic planted reactors, sand rectors, chicken manure -- wood shavings (CM-WS) rectors, rhizobacterial-inoculated unplanted reactors, unplanted control reactors, and unplanted dark control reactors to study the roles of phytoremediation, adsorption, biodegradation, photodegradation and hydrolysis process in reduction of AMX and CIP. Additionally, the plant's weight is determined for each sample collected and compared to the initial weight of the experiment to monitor plant growth. The possible fates of AMX and CIP were explored using hydroponic tests, whereby 43%, 26% and 19%, respectively, of the total removal of AMX had been accounted for by plant uptake, adsorption by CM-WS and biodegradation after 21 days of exposure, also these process contributed well in CIP removal, where the proportions were 39%, 32% and 18%, respectively of the total CIP reduction at the same intervals. [ABSTRACT FROM AUTHOR]

In this study, the sol–gel synthesis of Ni-doped cadmium zinc aluminum ferrite Ni-doped NixCd0.8−XZn0.2Al0.3Fe1.7O4 (X = 0,0.4) nanoparticles and their photocatalytic activity for ciprofloxacin degradation under visible-light irradiation were investigated. The nanoparticles were characterized using XRD, FTIR, SEM, EDX, and BET analyses. XRD revealed cubic spinel structures with crystallite sizes of 39 (undoped) and 30 nm (Ni-doped). FTIR spectra showed peak shifts upon Ni doping, indicating Ni2+ ion substitution in the spinel lattice. SEM images showed that the nickel-free sample was porous and had larger, loosely packed grains, whereas the nickel-doped sample was denser and featured smaller, uniformly distributed grains. The Ni-doped sample exhibited a higher BET surface area (37.85 m2/g) and pore volume (1.836 cm3/g) than those of the undoped sample. The photocatalytic degradation of ciprofloxacin was significantly enhanced by Ni doping, achieving 97.88% in 60 min under visible light, which was attributed to the narrowed bandgap (2.1 eV), improved visible light absorption, and increased charge separation. Scavenger studies have identified hydroxyl radicals as primary reactive species. The addition of H2O2 (up to 6 mM) enhanced the degradation rate, but higher concentrations decreased the rate. The catalyst exhibited gradual deactivation upon reuse, with the degradation efficiency decreasing from 97.88 (first cycle) to 90.93% (fifth cycle), owing to loss, deactivation, and fouling. [ABSTRACT FROM AUTHOR]

Reactive chlorine species (RCS) like sodium hypochlorite (NaOCl) are potent oxidizing agents and widely used biocides in surface disinfection, water treatment, and biofilm elimination. Moreover, RCS are also produced by the human immune system to kill invading pathogens. However, bacteria have developed mechanisms to survive the damage caused by RCS. Using the comprehensive Pseudomonas aeruginosa PA14 transposon mutant library in a genetic screen, we identified a total of 28 P. aeruginosa PA14 mutants whose biofilms showed increased susceptibility to NaOCl in comparison to PA14 WT biofilms. Of these, ten PA14 mutants with a disrupted apaH, PA0793, acsA, PA1506, PA1547, PA3728, yajC, queA, PA3869, or PA14_32840 gene presented a 4-fold increase in NaOCl susceptibility compared to wild-type biofilms. While none of these mutants showed a defect in biofilm formation or attenuated susceptibility of biofilms toward the oxidant hydrogen peroxide (H2O2), all but PA14_32840 also exhibited a 2–4-fold increase in susceptibility toward the antibiotic ciprofloxacin. Further analyses revealed attenuated levels of intracellular ROS and catalase activity only for the apaH and PA1547 mutant, providing insights into the oxidative stress response in P. aeruginosa biofilms. The findings of this paper highlight the complexity of biofilm resistance and the intricate interplay between different mechanisms to survive oxidative stress. Understanding resistance strategies adopted by biofilms is crucial for developing more effective ways to fight resistant bacteria, ultimately contributing to better management of bacterial growth and resistance in clinical and environmental settings. [ABSTRACT FROM AUTHOR]

Candida albicans invasive candidiasis is considered a global health problem. In such cases, biofilm formation on implanted devices represents a therapeutic challenge and the presence of metabolically inactive persistent cells (PCs) in these communities increases their tolerance to fungicidal drugs. This study investigated the influence of amoxicillin, AMX; cefepime, CEF; gentamicin, GEN; amikacin, AMK; vancomycin, VAN; and ciprofloxacin, CIP; on the production of PCs in biofilms of C. albicans bloodstream isolates. 48 h-mature biofilms (n = 6) grown in RPMI-1640 supplemented with antibiotics were treated with 100 μg ml−1 amphotericin B and then evaluated for PCs. Biofilms grown in the presence of antibiotics produced more PCs, up to 10×, when exposed to AMX and CIP; 5 × to CEF; and 6 × to GEN and VAN. The results indicate that antibiotics can modulate PC production in C. albicans biofilms. This scenario may have clinical repercussions in immunocompromised patients under broad-spectrum antibiotic therapy. LAY SUMMARY: Biofilms are microbial communities tolerant to antifungals. Our research showed that antibiotics stimulate the formation of persistent cells within Candida albicans biofilms. These are dormant, metabolically silent cells that resist to therapy and can be related to metastatic and recalcitrant infections. [ABSTRACT FROM AUTHOR]

Ciprofloxacin has been used to replace tryptophan at positions 3 and 6 in the antimicrobial peptide (AMP) Bac8c. Bac8c(Cip3,6) showed comparable antimicrobial activity but increased selectivity toward some Gram-negative bacteria with MIC values of ≤6.25 μM. Bac8c(Cip3,6) was also non-cytotoxic to cultured HepG2 cells at antimicrobial concentrations, with a CC50 >300 μM. [ABSTRACT FROM AUTHOR]

AbstractExposure to biosolids in human waste handling occupations is associated with a risk for illness due to microbial infections. Although several years of exposure to biosolids might be hypothesized to be a prophylaxis against infection, the risks associated with infections from antibiotic-resistant organisms can also be a potential concern. Therefore, this study aimed to conduct a screening level risk assessment by deriving occupational exposure limits (OELs) characterizing the risks of adverse health effects among workers in human waste handling occupations with a focus on exposure to two pharmaceuticals commonly found in biosolids: ciprofloxacin (CIP) and azithromycin (AZ). Epidemiological and exposure studies of workers exposed to biosolids were identified through searches of major scientific databases. Screening OELs (sOELs) for these antibiotics were derived using a standardized methodology. The airborne concentrations of CIP and AZ antibiotics were determined using an exposure factors approach. The health-based exposure limits (i.e., sOELs) and the acceptable daily exposure (ADE) values for both of these antibiotics were derived as 80 μg/m3 and 12 μg/kg-day, respectively. An exposure factor approach suggested that inhalation route exposures to CIP and AZ are well below the sOELs and ADE daily doses, and likely too low to cause direct adverse health effects through antibiotic inhalation. A critical review of epidemiological studies on different occupations handling biosolids showed that the workers in industries with potential biosolids exposure have experienced an increased incidence of microbial-exposure-related illness. The health effects seen in the workers have been attributed to bacterial, viral, and protozoan infections. To the extent that bacteria are the pathogen of concern, it is not clear whether these bacteria are resistant to antibiotics commonly found in biosolids. It is also unclear whether the presence of antibiotics or antibiotic-resistant bacteria increases the susceptibility of these workers. Additional studies will provide more definitive estimates of inhalation and dermal exposures to CIP and AZ and could verify the exposure estimates in this study based on the literature and common exposure factors. [ABSTRACT FROM AUTHOR]

Thermotolerant Campylobacter is an important zoonotic pathogen known for causing gastroenteritis in humans, with poultry as its primary reservoir. A total of 468 samples were collected, of which 335 were chicken carcass samples (representing the food component), and 133 were chicken caeca samples (representing the animal component). These samples underwent culture, with colonies examined under a microscope. Species identification was achieved through multiplex PCR. Additionally, antimicrobial susceptibility profiles were determined using the Kirby-Bauer method, testing for sensitivity to gentamicin, ciprofloxacin, tetracycline, and erythromycin. Additionally, 55 C. jejuni (62.5%) and 33 C. coli (37.5%) isolates were selected for whole genome sequencing (WGS). A High prevalence of Campylobacter was observed, with rates of 95.5% (n = 127, CI95%: 92.5% - 98.5%) in the animal component and 72.5% (n = 243, CI95%: 69.9% - 75.1%) in the food component. Specifically, C. jejuni was detected in 33.1% (n = 42) of poultry farms and 38.3% (n = 93) of chicken carcasses, while C. coli was found in 64.6% (n = 82) of poultry farms and 60.5% (n = 147) of chicken carcasses. Antimicrobials with the highest rates of resistance (67%-100%) were ciprofloxacin and tetracycline, in both animal and food component isolates. Erythromycin resistance was notable, ranging from 22% to 33%, with only two C. jejuni isolates from retail were resistant to gentamicin. Furthermore, multidrug resistance was identified in 23% (20 isolates) of the Campylobacter isolates. Genetic analysis revealed the presence of fourteen resistance genes in both C. jejuni and C. coli isolates, including tet(O), blaOXA-460, blaOXA-184, blaOXA-489, blaOXA-193, blaOXA-784, blaOXA-603, aph(3')-IIIa, aad9, aph(2")-If, aadE-Cc, sat4, and ant(6)-Ia. Additionally, twenty-five plasmids were detected in the 88 Campylobacter isolates examined. Interestingly, most isolates also harbored genes encoding putative virulence factors associated with pathogenicity, invasion, adherence, and production of cytolethal distending toxin (cdt): cheV, cheA, cheW, cheY, flaA, flgR, flaC, flaD, flgB, flgC, ciaB, ciaC. The WGS analysis showed the presence of several cgSTs in both animal and food components, with nine of them widely disseminated between components. Moreover, C. coli and C. jejuni isolates from different sources presented less than 11 single nucleotide polymorphisms (SNPs), suggesting clonality (16 isolates). Further analysis using SNP tree demonstrated widespread distribution of certain C. jejuni and C. coli clones across multiple farms and retail stores. This study presents, for the first-time, insights into the clonality, plasmid diversity, virulence, and antimicrobial resistance (AMR) of thermotolerant Campylobacter strains originating from the Ecuadorian poultry industry. The identification of AMR genes associated with the main antibiotics used in the treatment of campylobacteriosis in humans, highlights the importance of the prudent use of antimicrobials in the poultry industry. Additionally, this research remarks the need for regional studies to understand the epidemiology of this pathogen. [ABSTRACT FROM AUTHOR]

A novel and highly efficient photocatalyst of a AgBiO3/BiOCl heterojunction has been developed via a facile water bath and in situ precipitation method. The photocatalytic activities of the catalysts were investigated by the degradation of ciprofloxacin (CIP) under visible-light irradiation (>420 nm). The experiment results revealed that the photocatalytic performance of the optimized AgBiO3/BiOCl heterojunction was much higher than pure AgBiO3 and BiOCl. The degradation efficiency of the as-prepared AgBiO3/BiOCl heterojunction (ABC-30) for CIP could reach 88% within 160 min, with 2.89 and 3.76 times higher activity than pure AgBiO3 and BiOCl, respectively. The improved photocatalytic performance of AgBiO3/BiOCl was attributed to the synergistic effect of the enhanced light absorption range and effective separation and transfer of the photo-induced charge carrier. The optimized heterojunction showed broad-spectrum catalytic activities towards various organic contaminants. The degradation efficiencies varied with the nature of the pollutant and decreased in the following order: Lanasol Red 5B (100%) > methyl orange (99%) > methylene blue (98%) > tetracycline (92%) > ciprofloxacin (88%) > ofloxacin (85%) > norfloxacin (78%) > rhodamine B (59%) > metronidazole (43%) > phenol (40%) > carbamazepine (20%). Furthermore, the trapping experiments and ESR indicated that superoxide radicals and holes were the main reactive species. [ABSTRACT FROM AUTHOR]

Herein, a novel UV spectrophotometric method coupled with chemometric tools was developed for the simultaneous determination of three fluoroquinolone antibiotics: ciprofloxacin, lomefloxacin, and enrofloxacin. Such integration of UV spectroscopy and chemometric analysis proved to be a simple, rapid, and cost-effective approach for the quantification of these clinically important pharmaceutical compounds and aid in their quality control analysis. The method employed firefly algorithm for variable selection and partial least squares (PLS) regression for model calibration. The developed method was validated by independent test set in addition the accuracy, intra and inter-day precision as per ICH guidelines which showed a satisfactory performance with mean recovery ranged between 98.18 and 101.83 with %RSD < 2. Besides, the developed method displayed ultrasensitive levels with LODs (0.0803, 0.1125, 0.1309 µg/mL) and LOQs (0.2434, 0.3409, 0.3968 µg/mL) for ciprofloxacin, lomefloxacin, and enrofloxacin, respectively. The greenness and blueness of the developed method were also evaluated using the recently proposed Analytical GREEnness metric approach (AGREE) and Blue applicability grade index (BAGI) tools, which showed a high AGREE score of 0.79 and a BAGI score of 77.5. These results indicate that the developed method provides an environmentally friendly alternative to the traditionally used chromatographic techniques, while maintaining high analytical practicability. Finally, the application of the developed methodology was demonstrated on real pharmaceutical and tap water samples, and the results were in good agreement with those obtained by the reference HPLC method indicating the reliability and suitability of the proposed spectrophotometric method for routine analysis of fluoroquinolone antibiotics. [ABSTRACT FROM AUTHOR]

The increase in life expectancy has led to a concerning decline in the body's functional capacity, particularly in bone health, where decreased resistance and increased fracture susceptibility pose significant challenges in orthopedics. While traditional bone grafting methods have drawbacks, synthetic materials, particularly hydroxyapatite (HA), offer promising alternatives due to their biocompatibility and osteoconductive properties. However, HA's mechanical limitations necessitate reinforcement, with boron nitride nanostructures emerging as a particularly effective option, enhancing fracture resistance and combining HA with collagen, further mimicking natural bone composition, offering several benefits. Moreover, crosslinking agents like tannic acid (TA) improve collagen's stability and introduce therapeutic benefits. Therefore, the present work aimed to synthesize an innovative nanocomposite formed by hydroxyapatite, boron nitride nanostructures, collagen, and tannic acid. The nanocomposites obtained were characterized using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), thermogravimetry (TGA), elemental analysis of carbon, hydrogen, and nitrogen (CHN), and scanning electron microscopy (SEM). Mechanical tests of Vickers hardness, nanoindentation, tensile, and DMA demonstrated an increase in the mechanical resistance of the nanocomposites, thus corroborating their promising character. A controlled drug release test showed that the system could be used for antibiotic (ciprofloxacin) delivery, further expanding its function. Biological cell viability assays reported that the system is not toxic to healthy cells and is harmful to tumor cells, thus demonstrating the antitumor nature of TA. Therefore, integrating HA, BN nanostructures, collagen, and TA into a multifunctional nanocomposite, a novel approach in orthopedic biomaterial design is offered as a promising solution to address various bone-related challenges. [ABSTRACT FROM AUTHOR]

Well-dispersed MIL-100(Fe) nanoparticles were synthesized under mild conditions and used to construct a photo-Fenton system (VMH system) with the assistance of visible-light irradiation and hydrogen peroxide. In such a VMH system, the MIL-100(Fe) has a high specific surface area and provides numerous Fe3+ active sites, thus accelerating the reaction of Fe3+ with photo-generated electrons under visible-light irradiation and generates Fe2+, and then the acquired Fe2+ can activate H2O2 to generate ⋅OH, accompanying with the oxidation of Fe2+ to Fe3+. Hence, the in-situ recycling of Fe2+/Fe3+ promotes the generation of ·OH, thus making the VMH system exhibits promising photocatalytic activity. The removal rate of ciprofloxacin in the VMH system is as high as 95.2% within 120 min photo-Fenton reaction, which is about 26 times higher than that of the Visible light/MIL-100(Fe) system. Moreover, the VMH system also exhibits strong degradation ability to other typical antibiotics, such as tetracycline, norfloxacin and cephalexin, and maintains high cyclic stability, revealing great practical application potential in the purification of antibiotic wastewater. [ABSTRACT FROM AUTHOR]

Antibiotics have several negative effects on aquatic ecosystems and are difficult to degrade using traditional water/wastewater treatment methods. As a result, new treatment techniques must be employed to eliminate these contaminants from aquatic environments. Research on the relationship between the decomposing process of antibiotics and different factors by new technologies is scarce. This research focuses on the capability of ozone micro-nano bubbles (OzMNBs) to eliminate the antibiotics ciprofloxacin (CIPR) and levofloxacin (LEVO) in aqueous solutions. We studied the CIPR and LEVO decomposition to different variables through the central composite design method. The main variables included pH, ozonation time, and initial antibiotic concentration. The correlation coefficients of the quadratic model obtained by using the software, Design Expert version 13.0.1. Analysis of variances proved the significance of models and main factors. Verification tests also confirmed that the final optimum conditions of the antibiotics decomposition were: pH 9, ozonation for 40 min and, initial antibiotic concentration of 5 mg/L. In optimum conditions, removal rate of about 97% and 100% was obtained for CIPR and LEVO, respectively. The order of influence of various factors on CIPR and LEVO decomposition were obtained and the interactions between the main factors were also investigated. At the last stage of the research, the efficiency of OzMNBs in the removal of total organic carbon and mineralization of the solutions containing CIPR and LEVO under optimum conditions was examined. [ABSTRACT FROM AUTHOR]

The adsorbent muscovite mineral clay was used to remove the antibiotic ciprofloxacin (CPx) from the aqueous media. X-ray photoelectron spectroscopy (XPS), X-ray diffractometry (XRD), cation exchange capacity (CEC), Fourier-transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), X-ray energy dispersion spectrometer (EDX), and surface charge were some of the methods used to characterize the clay (pHpzc). The Box-Behnken design (BBD), a potent tool in this process, was used to find the stationary points of the three primary independent parameters, adsorbent mass, time, and pH. The model's significance and sufficiency were analyzed using analysis of variance (ANOVA). According to the statistics, these settings resulted in a pH of 3.4, an adsorbent mass of 0.09942 g, and an optimum dye removal rate of 90.16%. To assess the kinetic research, three models were used: pseudo-first-order (PFO), pseudo-second-order (PSO), and intraparticle diffusion. The PFO and PSO kinetic models agree with the stated kinetics. As a result, the isotherms Langmuir, Freundlich, and Temkin presented an excellent fit to the data from the adsorption equilibrium. The three main elements of a thermodynamic analysis (ΔG°, ΔH°, and ΔS°) provided additional proof that the adsorption of CPx onto Musc-MC was a spontaneous endothermic reaction. [ABSTRACT FROM AUTHOR]

Antibacterial resistance requires an advanced strategy to increase the efficacy of current therapeutics in addition to the synthesis of new generations of antibiotics. In this study, copper oxide nanoparticles (CuO-NPs) were green synthesized using Moringa oleifera root extract. CuO-NPs fabricated into a form of aspartic acid-ciprofloxacin-polyethylene glycol coated copper oxide-nanotherapeutics (CIP-PEG-CuO) to improve the antibacterial activity of NPs and the efficacy of the drug with controlled cytotoxicity. These NPs were charachterized by Fourier transform infrared spectroscopy (FTIR), x-rays diffraction spectroscopy (XRD), scanning electron microscopy (SEM) and energy-dispersive spectroscopy (EDS). Antibacterial screening and bacterial chemotaxis investigations demonstrated that CIP-PEG-CuO NPs show enhanced antibacterial potential against Gram-positive and Gram-negative clinically isolated pathogenic bacterial strains as compared to CuO-NPs. In ex-vivo cytotoxicity CIP-PEG-CuO-nano-formulates revealed 88% viability of Baby Hamster Kidney 21 cell lines and 90% RBCs remained intact with nano-formulations during hemolysis assay. An in-vivo studies on animal models show that Staphylococcus aureus were eradicated by this newly developed formulate from the infected skin and showed wound-healing properties. By using specially designed nanoparticles that are engineered to precisely transport antimicrobial agents, these efficient nano-drug delivery systems can target localized infections, ensure targeted delivery, enhance efficacy through increased drug penetration through physical barriers, and reduce systemic side effects for more effective treatment. [ABSTRACT FROM AUTHOR]

Background: Pythium insidiosum (P. insidiosum) is the causative agent of pythiosis, an infectious disease with a high morbidity and fatality rate. Pythiosis cases have increased dramatically during the past ten years, particularly in tropical and subtropical areas. Sadly, microbiologists and medical professionals know very little about pythiosis, and the disease is frequently challenging to identify. It is frequently misdiagnosed as a fungal infection. Methods: We report two cases of pythiosis, one was Pythium keratitis, the other was cutaneous pythiosis. The patient with corneal infection had no underlying disease, while the patient with cutaneous pythiosis had a history of liver cirrhosis, diabetes, and psoriasis. The corneal sample and subcutaneous pus were sent for metagenomic Next-Generation Sequencing (mNGS). To further diagnose the isolated strain, P. insidiosum zoospores were induced to produce by coincubation with sterile grass leaves in sterile pond water. Their zoospores were used as an inoculum for drug susceptibility testing by disk diffusion and broth microdilution method. Results: The mNGS of two cases were reported as P. insidiosum. Zoospores were produced after incubation 48h. The zoospores were collected for drug susceptibility assay. All antifungal drugs, antibacterial drugs of β-Lactams, vancomycin, levofloxacin, ciprofloxacin, gentamicin, trimethoprim-sulfamethoxazole, clindamycin have no inhibitory activity against P. insidiosum in vitro. Minocycline, tigecycline, linezolid, erythromycin and azithromycin have significant in vitro activity against P. insidiosum. Based on the susceptibility results, the drug was changed from itraconazole to linezolid and minocycline, along with multiple debridements and drainage for cutaneous pythiosis. The patient was discharged after 24 days of treatment. Conclusions: Early and accurate identification, combined with aggressive surgical debridement and appropriate drug therapy, can greatly improve patient managements. Conventional culture and zoospore induction remain gold standard for diagnosis; however, DNA-based method should be performed simultaneously. The drug susceptibility testing provides profound effects on proper drug selection against P. insidiosum. [ABSTRACT FROM AUTHOR]