Determination of Sulphonamide Antibiotics and Trimethoprim in Wastewater and Sludge Using Liquid Chromatography with Diode-Array Detection

This paper investigates the occurrence of sulphonamide and diaminopyrimidine antibiotics in wastewater and sludge from wastewater treatment plants. In our experiment, they were isolated from wastewater using the solid phase extraction method. In the case of sludge, pressurized solvent extraction techniques were used followed by solid phase extraction. The solid phase extraction method was used for purification and concentration. Sulphonamide and diaminopyrimidine antibiotics were determined using high performance liquid chromatography with diode-array detection. The selected antibiotics were determined in real sludge samples collected from the wastewater treatment plant in Brno-Mod^ice and in real wastewater samples collected from the wastewater treatment plant located on the grounds of the University of Veterinary and Pharmaceutical Sciences in Brno, using the developed and optimized method. Analyses showed that real samples of wastewater contained sulphathiazole 11.82μg/L at the inflow （7.1 μg/L at the outflow）, sulphapyridine 18.57 I.tg/L （12.2 μg/L）, sulphamethazine 13.52 μg/L （8.44 μg/L）, sulphamethoxazole 14.06 lag/L （9.34 Ixg/L） and trimethoprim 521.4 lag/L （422.29 μg/L）. Here it is demonstrated that drugs are removed through the wastewater treatment procedure only partially.

Prescription of Antibiotics in Oral-Dental Practice: Case of the Dental Practice at the Coyah Prefectoral Hospital in the Republic of Guinea 2019-2020

Introduction: Antibiotics are medications that have the property of destroying bacteria or preventing their proliferation. The aim of this study is to evaluate antibiotic prescriptions in oral practice: case of the dental office of the Coyah prefectural hospital. Methods: This is a descriptive cross-sectional study which took place from August 2019 to January 2020 inclusive, i.e. a duration of six (6) months, during which 400 patients were identified. Results: Our results revealed a frequency of 70% of antibiotic prescriptions. The 16 - 25-year-old age group was the most dismayed, at 47.25% and with an average age of 27.78 years. Men represent 55% compared to 45% of women, i.e. sex ratio of 1.22. Pulp gangrene was the most common pathology in 55% of cases. The most prescribed family was Betalactamine or 61.71% and the most represented molecules were Amoxicillin with 56.10% followed by Metronidazole or 34.16%. And the favorable prognosis was observed in 99% of cases. Conclusion: Prescription should always be based on the benefit-risk ratio. This prescription by practitioners aims to prevent or eradicate infections and pain in order to obtain a good therapeutic result.

Antimicrobial Activity of Some Commercial Toothpastes and Antibiotics on Two Oral Pathogenic Bacteria—An in-Vitro Study

Oral health problems such as periodontal diseases, dental caries, and endodontic infections have a significant negative impact on oral health and impose a substantial financial burden on the global population. The prevalence of these issues is increasing due to the buildup of bacterial plaque and the growing resistance of bacteria to antimicrobial treatments. The aims of this study to evaluate the anti-bacterial activity of four types of antibiotics (Amoxicillin, Augmentin, Azithromycin and Metronidazole) and four types of toothpastes (Sensodyne, ipana, denta and cariax Gingival Kin) on two oral pathogenic bacteria (Streptococcus mutans and Staphylococcus epidermidis). Bacterial samples of previously isolated Streptococcus mutans and Staphylococcusepidermidis were used as test organisms and the Kirby-Bauer disc diffusion method was employed to assess the antibacterial efficacy of various antibiotics and evaluate the impact of different toothpastes using a filter paper disc agar measurement technique. Each filter disc was saturated with toothpaste solution in a test tube for approximately 30 to 40 seconds, after which they were placed on Mueller-Hinton broth bacterial cultures in petri dishes. These Petri dishes were then incubated at 37°C for 24 hours, and the clear zone’s diameter (inhibition zone in mm) was subsequently measured and the results were recorded. The results demonstrated that Sensodyne toothpaste and Metronidazole antibiotic were ineffective against both types of bacteria, while Augmentin and Amoxicillin were effective by high diameter inhibition zones of growth against S. mutans and Azithromycine against S. epidermidis. Also Ipana, Denta, and Cariax Gingival Kin toothpastes exhibited a moderate effect against the two bacteria. This study suggests that certain antibiotics and toothpastes can effectively inhibit the growth of harmful oral bacteria, but not all of them are effective.

Simultaneous Degradation, Dehalogenation, and Detoxification of Halogenated Antibiotics by Carbon Dioxide Radical Anions

Despite the extensive application of advanced oxidation processes(AOPs)in water treatment,the efficiency of AOPs in eliminating various emerging contaminants such as halogenated antibiotics is constrained by a number of factors.Halogen moieties exhibit strong resistance to oxidative radicals,affecting the dehalogenation and detoxification efficiencies.To address these limitations of AOPs,advanced reduction processes(ARPs)have been proposed.Herein,a novel nucleophilic reductant—namely,the carbon dioxide radical anion(CO_(2)^(·-))—is introduced for the simultaneous degradation,dehalogenation,and detoxification of florfenicol(FF),a typical halogenated antibiotic.The results demonstrate that FF is completely eliminated by CO_(2)^(·-),with approximately 100%of Cland 46%of Freleased after 120 min of treatment.Simultaneous detoxification is observed,which exhibits a linear response to the release of free inorganic halogen ions(R^(2)=0.97,p<0.01).The formation of halogen-free products is the primary reason for the superior detoxification performance of this method,in comparison with conventional hydroxyl-radical-based AOPs.Products identification and density functional theory(DFT)calculations reveal the underlying dehalogenation mechanism,in which the chlorine moiety of FF is more susceptible than other moieties to nucleophilic attack by CO_(2)^(·-).Moreover,CO_(2)^(·-)-based ARPs exhibit superior dehalogenation efficiencies(>75%)in degrading a series of halogenated antibiotics,including chloramphenicol(CAP),thiamphenicol(THA),diclofenac(DLF),triclosan(TCS),and ciprofloxacin(CIP).The system shows high tolerance to the pH of the solution and the presence of natural water constituents,and demonstrates an excellent degradation performance in actual groundwater,indicating the strong application potential of CO_(2)^(·-)-based ARPs in real life.Overall,this study elucidates the feasibility of CO_(2)^(·-)for the simultaneous degradation,dehalogenation,and detoxification of halogenated antibiotics and provides a promising method for their regulation during water or wastewater treatment.

A novel Ag/ZnO core-shell structure for efficient sterilization synergizing antibiotics and subsequently removing residuals

The massive use of antibiotics has led to the aggravation of bacterial resistance and also brought environmental pollution problems.This poses a great threat to human health.If the dosage of antibiotics is reduced by increasing its bactericidal performance,the emergence of drug resistance is certainly delayed,so that there's not enough time for developing drug resistance during treatment.Therefore,we selected typical representative materials of metal Ag and semiconductor ZnO nano-bactericides to design and synthesize Ag/ZnO hollow core-shell structures(AZ for short).Antibiotics are grafted on the surface of AZ through rational modification to form a composite sterilization system.The research results show that the antibacterial efficiency of the composite system is significantly increased,from the sum(34.7%+22.8%-57.5%)of the antibacterial efficiency of AZ and gentamicin to 80.2%,net synergizes 22.7%,which fully reflects the effect of 1+1>2.Therefore,the dosage of antibiotics can be drastically reduced in this way,which makes both the possibility of bacterial resistance and medical expenses remarkably decrease.Subsequently,residual antibiotics can be degraded under simple illumination using AZ-self as a photocatalyst,which cuts off the path of environmental pollution.In short,such an innovative route has guiding significance for drug resistance.

Indication of conservative treatment by antibiotics for uncomplicated and complicated acute appendicitis

BACKGROUND Acute appendicitis is one of the most common emergency abdominal disease,and recent studies have evaluated conservative treatment using antibiotics for uncomplicated appendicitis.Although the efficacy of conservative treatment for uncomplicated appendicitis is known,its efficacy for complicated appendicitis remains unknown,so are risk factors for the conservative treatment of appendi-citis.In our institution,conservative treatment has long been the first choice for most appendicitis cases,except for perforation.Therefore,this novel study inves-tigated the outcomes of conservative treatment for uncomplicated and compli-cated acute appendicitis and the risk factors associated with conservative treat-ment.treatment.The significant and independent predictors of resistance to conservative treatment were body temperature≥37.3℃,appendicolith and Douglas sinus fluid visible on computed tomography(CT).The rate of resistance to conservative treatment was 66.7%(6/9)for patients with the above three factors,22.9%(8/35)for patients with two factors(appendicolith and body temperature≥37.3℃),16.7%(2/12)for patients with two factors(Douglas sinus fluid and appendicolith)and 11.1%(1/9)for patients with two factors(Douglas sinus fluid and body temperature≥37.3℃).CONCLUSION A temperature≥37.3℃,appendicolith and Douglas sinus fluid on CT might be clinical risk factors of resistance to conservative treatment for acute appendicitis.

Removal of Dye Using Lignin-Based Biochar/Poly(ester amide urethane)Nanocomposites from Contaminated Wastewater

The pursuit of incorporating eco-friendly reinforcing agents in polymer composites has accentuated the exploration of various natural biomass-derived materials.The burgeoning environmental crisis spurred by the discharge of synthetic dyes into wastewater has catalyzed the search for effective and sustainable treatment technologies.Among the various sorbent materials explored,biochar,being renewable,has gained prominence due to its excellent adsorption properties and environmental sustainability.It has also emerged as a focal point for its potential to replace other conventional reinforcing agents,viz.,fumed silica,aluminum oxide,treated clays,etc.This study introduces a novel class of polymer nanocomposites comprising of lignin-based biochar particles and poly(ester amide urethane)matrix via a feasible method.The structural evaluation of these nanocomposites was accomplished using Fourier-transform infrared spectroscopy,X-ray photoelectron spectroscopy,and powder X-ray diffraction.The polymer nanocomposites exhibited superior mechanical properties with an increment in tensile strength factor by 45%in comparison to its pristine matrix,along with an excellent toughness value of 90.22 MJm^(−3)at a low loading amount of only 1 wt%.The composites showed excellent improvement in thermal properties with a sharp rise in the glass transition temperature(Tg)value from−28.15℃to 84℃,while also championing sustainability through inherent biodegradability attributes.Beyond their structural prowess,these polymer nanocomposites demonstrated excellent potential as adsorbents,displaying efficient removal of malachite green and tartrazine dyes from aqueous systems with a removal efficiency of 87.25%and 73.98%,respectively.The kinetics study revealed the pseudo second order model to be the precision tool to assess the dye removal study.Complementing this,the Langmuir adsorption isotherm provided a framework to assess the sorption features of the polymer nanocomposites.Overall,these renewable biochar integrated polymer matrices boast remarkable recovery capabilities up to seven cycles of usage with an excellent dye recovery percentage of 95.21%for the last cycle,thereby defining sustainability as well as economic feasibility.

Early clinical outcomes of two regimens of prophylactic antibiotics in cardiac surgical patients with delayed sternal closure

BACKGROUND Delayed sternal closure(DSC)can be a lifesaving approach for certain patients who have undergone cardiac surgery.The value of the type of prophylactic antibiotics in DSC is still debatable.AIM To investigate clinical outcomes of different prophylactic antibiotic regimens in patients who had DSC after cardiac surgery.METHODS This was a retrospective observational single-center study.Fifty-three consecutive patients who underwent cardiac surgery and had an indication for DSC were included.Patients were subjected to two regimens of antibiotics:Narrow-spectrum and broad-spectrum regimens.RESULTS The main outcome measures were length of hospital and intensive care unit(ICU)stay,duration of mechanical ventilation,and mortality.Of the 53 patients,12(22.6%)received narrow-spectrum antibiotics,and 41(77.4%)received broad-spectrum antibiotics.The mean age was 59.0±12.1 years,without significant differences between the groups.The mean duration of antibiotic use was significantly longer in the broad-spectrum than the narrowspectrum group(11.9±8.7 vs 3.4±2.0 d,P<0.001).The median duration of open chest was 3.0(2.0-5.0)d for all patients,with no difference between groups(P=0.146).The median duration of mechanical ventilation was significantly longer in the broad-spectrum group[60.0(Δinterquartile range(IQR)170.0)h vs 50.0(ΔIQR 113.0)h,P=0.047].Similarly,the median length of stay for both ICU and hospital were significantly longer in the broadspectrum group[7.5(ΔIQR 10.0)d vs 5.0(ΔIQR 5.0)d,P=0.008]and[27.0(ΔIQR 30.0)d vs 19.0(ΔIQR 21.0)d,P=0.031].Five(9.8%)patients were readmitted to the ICU and 18(34.6%)patients died without a difference between groups.CONCLUSION Prophylactic broad-spectrum antibiotics did not improve clinical outcomes in patients with DSC post-cardiac surgery but was associated with longer ventilation duration,length of ICU and hospital stays vs narrow-spectrum antibiotics.

Current trends in nanomaterials-mediated biosensing platforms and signal amplification strategies for antibiotics detection in dairy products

Dairy products have become one of the most prevalent daily foods worldwide,but safety concerns are rising.In dairy farming,unscrupulous traders misuse antibiotics to treat some diseases such as mastitis in cows,leading to antibiotic residues in dairy products.Rapid,sensitive,and simple detection methods for antibiotic residues are particularly important for food safety in dairy products.Traditional detection technology can effectively detect antibiotics,but there are defects such as complicated pre-treatment and high cost.Biosensors are widely used in food safety due to fast detection speed,low detection cost,strong anti-interference ability,and suitability for the field application.Nevertheless,these sensors often fail to trigger the signal conversion output due to low target concentration.To cope with this issue,some high-efficiency signal amplification systems can be introduced to improve the detection sensitivity and linear range of biosensors.In this review,we focused on:(i)Sources and toxicity of major antibiotics in animal-derived foods.(ii)Nanomaterial-mediated biosensors for real-time detection of target antibiotics in animal-derived foods.(iii)Signal amplification techniques to increase the sensitivity of biosensors.Finally,future prospects and challenges in this research field are discussed.

Research Progress of Ketolide Antibiotics

Macrolide antibiotics have been widely used in clinic due to their good antibacterial effects and high safety, but the drug-resistant bacteria appear constantly. To solve the problem of drug resistance in pathogens, scholars obtain the third generation of macrolide antibiotics, ketolide antibiotics, which are developed by modifying the structure of macrolide antibiotics, thereby efficiently solving the problem. Ketolide antibiotics are a type of erythromycin derivatives with macrolide structure, and the typical drugs mainly include telithromycin, cethromycin and solithromycin, etc . This paper briefly introduced the recent progress of ketolide antibiotics, with an attempt to provide help to the research and development of new macrolide antibiotics.

Removal of sulfonamide antibiotics from wastewater by gamma irradiation in presence of iron ions

The presence of sulfonamide antibiotics in aquatic environments has received increasing attention in recent years.Sulfadiazine(SD),a widely used heterocyclic sulfonamide pharmaceutical,has entered into the receiving water body.In this paper,gamma rays are used to irradiate samples of sulfadiazine antibiotics-containing wastewater.The results demonstrate that SD can be effectively degraded by irradiation,but the mineralization degree of SD(in terms of TOC) is not as efficient as the SD degradation.The addition of Fe^(2+) can significantly enhance the SD degradation and mineralization through the generation of hydroxyl radical by catalytic decomposition of H_2O_2 from water radiolysis.Ion chromatography analysis indicates that sulfate ions(SO_4^(2-)) and formate(HCOO^-) are the main intermediate products.Gamma irradiation is a promising technology for removing low-concentration antibiotics from water and wastewater.

Resistance Profile of Urogenital Mycoplasmas to Antibiotics: Comparative Study between the Mycoplasma IST2 and Mycoplasma IST3

Acquired resistance of mycoplasmas to antibiotics constitutes a major health problem in the world in general and in Africa in particular. Despite the diversity of kits marketed, several of them evaluating the sensitivity of mycoplasmas to antibiotics continue to present resistance, in this case, the Mycoplasma IST2. In order to overcome this resistance, a new kit (Mycoplasma IST3) has been developed in accordance with the new Clinical and Laboratory Standard Institute (CLSI) recommendations. The objective of the study was to determine the resistance profile of urogenital Mycoplasmas to antibiotics using this new kit and to highlight cases of co-infections in comparison with the Mycoplasma IST2. Over a period of four mo nths, one hundred and one (101) samples of urogenital secretions were collected (from sexually active men and women) and analyzed. Culture and antibiotic susceptibility testing were performed in a liquid medium using the Mycoplasma IST2 and Mycoplasma IST3 Tests according to the manufacturer’s recommendations. Among the different samples analyzed, we noted a mycoplasma positivity rate of 71.29% with a predominance of infection in women, i.e. 86.12% compared to men 13.88%. Ureaplasma spp was the most encountered germ with a rate of 62.50% followed by cases of co-infections at 33.33% (Uspp/Mh) and the least encountered was Mycoplasma hominis with a rate of 2.79%. We analyzed 25 samples, among which we had 4 co-infections, simultaneously using the two kits in the same patients. The distribution of cases between the two kits was equivalent. We noted a significant rate of resistance to erythromycin 100% using Mycoplasma IST2. However, no resistance was observed in erythromycin with Mycoplasma IST3. Mycoplasma IST2 also showed resistance to fluoroquinolones, which was not the case for Mycoplasma IST3 which did not show any resistance to fluoroquinolones. Both kits showed resistance to tetracycline. The antibiotic sensitivity test using the Mycoplasma IST3 revealed a high rate of resistance to tetracycline, i.e. 57.14% and 91.67% for Ureaplasma spp and Mycoplasma hominis respectively. Resistance rates to other antibiotics were less than 25%. This study was able to demonstrate that Mycoplasma IST3 constitutes a better therapeutic choice compared to its predecessor Mycoplasma IST2, because it eliminated the biggest shortcoming of its predecessor.

In Situ Raman Monitoring of Trace Antibiotics in Different Harsh Water Environments

In situ surface-enhanced Raman scattering(SERS)is a widely used operando analytical technique,while facing numerous complex factors in applications under aqueous environment,such as low detection sensitivity,poor anti-interference capability,etc.,resulting in unreliable detectability.To address these issues,herein a new hydrophobic SERS strategy has been attempted.By comprehensively designing and researching a SERS-active structure of superhydrophobic ZnO/Ag nanowires,we demonstrate that hydrophobicity can not only draw analytes from water onto substrate,but also adjust"hottest spot"from the bottom of the nanowires to the top.As a result,the structure can simultaneously concentrate the dispersed molecules in water and the enhanced electric field in structure into a same zone,while perfecting its own anti-interference ability.The underwater in situ analytical enhancement factor of this platform is as high as 1.67×10^(11),and the operando limited of detection for metronidazole(MNZ)reaches to 10^(-9)M.Most importantly,we also successfully generalized this structure to various real in situ detection scenarios,including on-site detection of MNZ in corrosive urine,real-time warning of wrong dose of MNZ during intravenous therapy,in situ monitoring of MNZ in flowing wastewater with particulate interference,etc.,demonstrating the great application potential of this hydrophobic platform.This work realizes a synergistic promotion for in situ SERS performance under aqueous environment,and also provides a novel view for improving other in situ analytical techniques.

Single flow treatment degradation of antibiotics in water using falling-film dielectric barrier discharge

The environmental contamination caused by antibiotics is increasingly conspicuous due to their widespread manufacture and misuse. Plasma has been employed in recent years for the remediation of antibiotic pollution in the environment. In this work, a falling-film dielectric barrier discharge was used to degrade the antibiotic tetracycline(TC) in water. The reactor combined the gas-liquid discharge and active gas bubbling to improve the TC degradation performance. The discharge characteristics, chemical species’ concentration, and degradation rates at different parameters were systematically studied. Under the optimized conditions(working gas was pure oxygen, liquid flow rate was 100 mL/min, gas flow rate was 1 L/min,voltage was 20 kV, single treatment), TC was removed beyond 70% in a single flow treatment with an energy efficiency of 145 mg/(kW·h). The reactor design facilitated gas and liquid flow in the plasma area to produce more ozone in bubbles after a single flow under pure oxygen conditions, affording fast TC degradation. Furthermore, long-term stationary experiment indicated that long-lived active species can sustain the degradation of TC. Compared with other plasma treatment systems, this work offers a fast and efficient degradation method, showing significant potential in practical industrial applications.

Screening for Streptomyces Hygroscopicus Strains with High Production of Agricultural Antibiotics by Streptomycin Resistance

[Objective] The research aimed to screen Streptomyces hygroscopicus strains with high production of agricultural antibiotics. [ Method] A strain of S. hygroscopicus was screened from the soil of Hainan Island. After natural screening and consecutive ultraviolet induced mutation twice, S6-7 strain was obtained as the original strain then treated by UV irradiation and streptomycin resistance screening, and finally rescreened through shake-flask fermentation. [Result] 7 better strains were selected by primary screening from 62 single colonies which were picked out randomly. After 3 generations of consecutive cultivation on slant media and rescreening, 5 strains presented obvious forward mutation. The forward mutation rate reached 8.06%, and the largest production increasing rate came up to 25.11%. [Conclusion] By combining streptomycin resistance screening and conventional ultraviolet induced mutation, both the antibiotic-producing capacity and forward mutation screening efficiency of the original strain were greatly enhanced.

Gel Filtration Chromatography Combined with Bradford Method for Determination of Total Residual Protein in Ferment Antibiotics

Aim A novel method has been developed for evaluation of the levels of total residual protein in antibiotics produced by fermentation using gel filtration chromatography (GFC) combined with Bradford assay based on determination of residual protein in lincomycin hydrochloride. Methods The chromatographic conditions were SuperdexTM peptide column, 0.01 mol*L-1 phosphate buffer solution as mobile phase, and flow rate of 1 mL·min-1. Five hundred microliters of lincomycin hydrochloride solution (3 g of lincomycin hydrochloride dissolved in 10 mL of mobile phase) was injected into the chromatograph and the eluted solution was collected between 6 min and 14.5 min (protein eluted from column within this period), and the residual content of total protein in the eluted solution was assayed using Bradford assay method. Results The average recovery was more than 90% for bovine serum albumin, the calibration equation for the range of 0-12 μg·mL-1 of protein was y=-0.002 4x2+0.064 2x+0.002 9, r2=0.999 9, RSD=0.1%-0.9%, and the LOD and LOQ were 3 and 10 ng·mL-1 of protein, respectively. Conclusion The novel method for determining the residual protein in ferment antibio-tics is simple, rapid, and precise.

抗生素领域研究热点分析——基于《中国抗生素杂志》和《Jounal of Antibiotics》(日本)近5年载文知识图谱计量分析

目的探索对比中、外抗生素领域近5年研究热点和前沿。方法运用文献计量可视化软件Citespace,对比分析《中国抗生素杂志》与《Jounal of Antibiotics》(日本)(下文简称《J Antibiotics》)两刊近5年刊载文量、影响因子、文献关键词知识图谱,探索抗生素领域中、外文文献关注热点和前沿,寻找国内刊物与国际刊物载文区别以及探索《中国抗生素杂志》的发展之路。结果两刊载文量均处于呈逐年下降并趋于稳定;《中国抗生素杂志》近5年影响因子逐步提升,《J Antibiotics》相对稳定;关键词共现和聚类分析显示两刊共同关注热点是“耐药性”,《中国抗生素杂志》载文热点是抗生素药物研究成果与临床研究成果相结合,及中药在感染性疾病上的应用以及国内抗生素药物的质量控制;《J Antibiotics》则以抗生素类新药剂、天然产物药物研发等基础研究论文为主。结论抗生素领域发展前沿主要是耐药性的探究以及应对此问题的新药及新的治疗方法的研发。在保持现有载文特色的基础上,《中国抗生素杂志》期待能够更多地报道抗生素和天然产物药物领域的基础研究成果。

In situ Detection of Amide A Bands of Proteins in Water by Raman Ratio Spectrum

The amide A band of protein is sensitive to the hydrogen bands of amide groups of proteins. However, it is hard to distinguish the amide A band of aqueous protein in situ directly, since it overlaps with O-H stretching vibration of water. In this work, we presented a new analytical method of Raman ratio spectrum, which can extract the amide A band of proteins in water. To obtain the Raman ratio spectrum, the Raman spectrum of aqueous protein was divided by that of pure water. A mathematical simulation was employed to examine whether Raman ratio spectrum is effective. Two kinds of protein, lysozyme and （^-chymotrypsin were employed. The amide A bands of them in water were extracted from Raman ratio spectra. Additionally, the process of thermal denaturation of lysozyme was detected from Raman ratio spectrum. These results demonstrated the Raman ratio spectra could be employed to study the amide A modes of proteins in water.

Role of prophylactic antibiotics in cirrhotic patients with variceal bleeding

Bacterial infections are common in cirrhotic patients with acute variceal bleeding,occurring in 20%within48 h.Outcomes including early rebleeding and failure to control bleeding are strongly associated with bacterial infection.However,mortality from variceal bleeding is largely determined by the severity of liver disease.Besides a higher Child-Pugh score,patients with hepatocellular carcinoma are particularly susceptible to infections.Despite several hypotheses that include increased use of instruments,greater risk of aspiration pneumonia and higher bacterial translocation,it remains debatable whether variceal bleeding results in infection or vice versa but studies suggest that antibiotic prophylaxis prior to endoscopy and up to 8 h is useful in reducing bacteremia and spontaneous bacterial peritonitis.Aerobic gram negative bacilli of enteric origin are most commonly isolated from cultures,but more recently,gram positives and quinolone-resistant organisms are increasingly seen,even though their clinical significance is unclear.Fluoroquinolones(including ciprofloxacin and norfloxacin)used for short term(7 d)have the most robust evidence and are recommended in most expert guidelines.Short term intravenous cephalosporin(especially ceftriaxone),given in a hospital setting with prevalent quinolone-resistant organisms,has been shown in studies to be beneficial,particularly in high risk patients with advanced cirrhosis.

Recent developments in visible-light photocatalytic degradation of antibiotics

With the significant discharge of antibiotic wastewater into the aquatic and terrestrial ecosystems, antibiotic pollution has become a serious problem and presents a hazardous risk to the environment. To address such issues, various investigations on the removal of antibiotics have been undertaken. Photocatalysis has received tremendous attention owing to its great potential in removing antibiotics from aqueous solutions via a green, economic, and effective process. However, such a technology employing traditional photocatalysts suffers from major drawbacks such as light absorption being restricted to the UV spectrum only and fast charge recombination. To overcome these issues, considerable effort has been directed towards the development of advanced visible light-driven photocatalysts. This mini review summarises recent research progress in the state-of-the-art design and fabrication of photocatalysts with visible-light response for photocatalytic degradation of antibiotic wastewater. Such design strategies involve the doping of metal and non-metal into ultraviolet light-driven photocatalysts, development of new semiconductor photocatalysts, construction of heterojunction photocatalysts, and fabrication of surface plasmon resonance-enhanced photocatalytic systems. Additionally, some perspectives on the challenges and future developments in the area of photocatalytic degradation of antibiotics are provided.