scholarly journals Development and Validation of a LC-MS/MS Method for Determination of Multi-Class Antibiotic Residues in Aquaculture and River Waters, and Photocatalytic Degradation of Antibiotics by TiO2 Nanomaterials

Catalysts ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 356 ◽  
Author(s):  
Tho Chau Minh Vinh Do ◽  
Duy Quoc Nguyen ◽  
Tuan Duc Nguyen ◽  
Phuoc Huu Le
Keyword(s):  
Anatase Phase ◽  
Mekong Delta ◽  
Average Concentration ◽  
Nanotube Arrays ◽  
Antibiotic Residues ◽  
Beta Lactam ◽  
Tio2 Nanowires ◽  
River Waters ◽  
Reaction Rate Constants ◽  
Liquid Chromatography Tandem Mass

This study presents a multi-residue method for simultaneous qualitative and quantitative analysis of eight antibiotics from some common classes, including beta-lactam, tetracyclines, lincosamides, glycopeptides, and sulfonamides in 39 aquaculture and river water samples from the Mekong Delta (Vietnam) using liquid chromatography-tandem mass spectrometry (LC-MS/MS). As a result, doxycycline (DXC), oxytetracycline (OTC), lincomycin (LCM), sulfamethoxazole (SMX), and sulfamethazine (SMZ) were detected with high frequency over 65% and an average concentration of 22.6–76.8 ng·mL−1. The result suggests that antibiotic residues in the aquaculture and river waters are considered as an emerging environmental problem of the region. To address this issue, we fabricated the well-defined TiO2 nanotube arrays (TNAs) and nanowires on nanotube arrays (TNWs/TNAs) using the anodization method. The TNAs had an inner tube diameter of ~95 nm and a wall thickness of ~25 nm. Meanwhile, the TNWs/TNAs had a layer of TiO2 nanowires with a length of ~6 µm partially covering the TNAs. In addition, both TNAs and TNWs/TNAs had pure anatase phase TiO2 with (101) and (112) dominant preferred orientations. Moreover, the TNAs and TNWs/TNAs effectively and rapidly degraded the antibiotic residues under UV-VIS irradiation at 120 mW/cm2 and obtained over 95% removal at 20 min. Indeed, the photocatalytic reaction rate constants (k) were in the range of 0.14–0.36 min−1 for TNAs, and 0.15–0.38 min−1 for TNWs/TNAs. Noticeably, the k values of TNWs/TNAs were slightly higher than those of TNAs for LCM, DXC, OTC, SMZ, and SMX that could be attributed to the larger surface area of TNWs/TNAs than TNAs when TNWs/TNAs had an additional ~6μm TNWs top layer.

scholarly journals TiO2 and Au-TiO2 Nanomaterials for Rapid Photocatalytic Degradation of Antibiotic Residues in Aquaculture Wastewater

Materials ◽  
2019 ◽  
Vol 12 (15) ◽  
pp. 2434 ◽  
Author(s):  
Tho Chau Minh Vinh Do ◽  
Duy Quoc Nguyen ◽  
Kien Trung Nguyen ◽  
Phuoc Huu Le
Keyword(s):  
Photocatalytic Activity ◽  
Photocatalytic Degradation ◽  
Synergistic Effects ◽  
Chemical Reduction ◽  
Anatase Phase ◽  
Au Nanoparticle ◽  
Nanotube Arrays ◽  
Antibiotic Residues ◽  
Au Nps ◽  
Aquaculture Wastewater

Antibiotic residues in aquaculture wastewater are considered as an emerging environmental problem, as they are not efficiently removed in wastewater treatment plants. To address this issue, we fabricated TiO2 nanotube arrays (TNAs), TiO2 nanowires on nanotube arrays (TNWs/TNAs), Au nanoparticle (NP)-decorated-TNAs, and TNWs/TNAs, which were applied for assessing the photocatalytic degradation of eight antibiotics, simultaneously. The TNAs and TNWs/TNAs were synthesized by anodization using an aqueous NH4F/ethylene glycol solution. Au NPs were synthesized by chemical reduction method, and used to decorate on TNAs and TNWs/TNAs. All the TiO2 nanostructures exhibited anatase phase and well-defined morphology. The photocatalytic performance of TNAs, TNWs/TNAs, Au-TNAs and Au-TNWs/TNAs was studied by monitoring the degradation of amoxicillin, ampicillin, doxycycline, oxytetracycline, lincomycin, vancomycin, sulfamethazine, and sulfamethoxazole under ultraviolet (UV)-visible (VIS), or VIS illumination by LC-MS/MS method. All the four kinds of nanomaterials degraded the antibiotics effectively and rapidly, in which most antibiotics were removed completely after 20 min treatment. The Au-TNWs/TNAs exhibited the highest photocatalytic activity in degradation of the eight antibiotics. For example, reaction rate constants of Au-TNWs/TNAs for degradation of lincomycin reached 0.26 min−1 and 0.096 min−1 under UV-VIS and VIS irradiation, respectively; and they were even higher for the other antibiotics. The excellent photocatalytic activity of Au-TNWs/TNAs was attributed to the synergistic effects of: (1) The larger surface area of TNWs/TNAs as compared to TNAs, and (2) surface plasmonic effect in Au NPs to enhance the visible light harvesting.

scholarly journals Multi-Mycotoxin Contamination of Maize Silages in Flanders, Belgium: Monitoring Mycotoxin Levels from Seed to Feed

Toxins ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 202
Author(s):  
Jonas Vandicke ◽  
Katrien De Visschere ◽  
Maarten Ameye ◽  
Siska Croubels ◽  
Sarah De Saeger ◽  
...  
Keyword(s):  
Quantitative Polymerase Chain Reaction ◽  
Average Concentration ◽  
Stable Phase ◽  
Maize Silage ◽  
Fusarium Spp ◽  
Mycotoxin Contamination ◽  
Liquid Chromatography Tandem Mass ◽  
Feed Analysis ◽  
Fungal Dna ◽  
Silage Process

Maize silage, which in Europe is the main feed for dairy cattle in winter, can be contaminated by mycotoxins. Mycotoxigenic Fusarium spp. originating from field infections may survive in badly sealed silages or re-infect at the cutting edge during feed-out. In this way, mycotoxins produced in the field may persist during the silage process. In addition, typical silage fungi such as Penicillium spp. and Aspergillus spp. survive in silage conditions and produce mycotoxins. In this research, 56 maize silages in Flanders were sampled over the course of three years (2016–2018). The concentration of 22 different mycotoxins was investigated using a multi-mycotoxin liquid chromatography-tandem mass spectrometry (LC-MS/MS) method, and the presence of DNA of three Fusarium spp. (F. graminearum, F. culmorum and F. verticillioides) was analyzed in a selection of these samples using quantitative polymerase chain reaction (qPCR). Every maize silage contained at least two different mycotoxins. Nivalenol (NIV) and deoxynivalenol (DON) were the most prevalent (both in 97.7% of maize silages), followed by ENN B (88.7%). Concentrations often exceeded the EU recommendations for DON and zearalenone (ZEN), especially in 2017 (21.3% and 27.7% of the maize silages, respectively). No correlations were found between fungal DNA and mycotoxin concentrations. Furthermore, by ensiling maize with a known mycotoxin load in a net bag, the mycotoxin contamination could be monitored from seed to feed. Analysis of these net bag samples revealed that the average concentration of all detected mycotoxins decreased after fermentation. We hypothesize that mycotoxins are eluted, degraded, or adsorbed during fermentation, but certain badly preserved silages are prone to additional mycotoxin production during the stable phase due to oxygen ingression, leading to extremely high toxin levels.

Target site pharmacokinetics of meropenem: Measurement in human explanted lung tissue by bronchoalveolar lavage, microdialysis and homogenized lung tissue

2021 ◽  
Author(s):  
Michael Paal ◽  
Christina Scharf ◽  
Ann Katrin Denninger ◽  
Luis Ilia ◽  
Charlotte Kloft ◽  
...  
Keyword(s):  
Bronchoalveolar Lavage ◽  
Lung Tissue ◽  
Target Site ◽  
Therapeutic Drug ◽  
Beta Lactam ◽  
Blood Concentrations ◽  
Intensive Care Patients ◽  
Beta Lactam Antibiotics ◽  
Liquid Chromatography Tandem Mass ◽  
Risk Patients

Objectives: Pneumonia is one of the most common infections in intensive care patients, and it is often treated with beta-lactam antibiotics. Even if therapeutic drug monitoring in blood is available, it is unclear whether sufficient concentrations are reached at the target site: the lung. The following study was initiated to fill this knowledge gap. Methods: Various compartments from ten patients` explanted lungs were subjected to laboratory analysis. Meropenem was quantified in serum, bronchoalveolar lavage (BAL), microdialysate and homogenized lung tissue with isotope dilution liquid chromatography tandem mass spectrometry (ID-LC-MS/MS). BAL represents diluted epithelial lining fluid (ELF), and microdialysate represents interstitial fluid (IF). Differences between target site and blood concentrations were investigated. Results: The median meropenem concentration in blood, ELF, IF and tissue were 26.8, 18.0, 12.1 and 9.1 mg/L, respectively. A total of 37.5% of the target site ELF and IF meropenem concentrations were below the clinical EUCAST breakpoint of 8 mg/L. The median ELF/serum quotient was 61.8% (IQR: 24.8%, 87.6%), the median IF/serum quotient was 35.4% (IQR: 23.8%, 54.3%), and the median tissue/serum quotient was 34.2% (IQR: 28.3%, 38.2%). We observed a substantial interindividual variability between the blood and the compartments (ELF, IF), whereas the intraindividual variability was relatively low. Conclusions: Target site measurement in different lung compartments was feasible and successfully applied in a clinical setting. A relevant amount of 37.5% of the target site concentrations fell under the clinical EUCAST breakpoint, indicating subtherapeutic dosing in high-risk patients receiving perioperative antibiotic prophylaxis in lung transplantation.

A Study of Campylobacter in Sewage, Sewage Sludge and in River Water

1991 ◽  
Vol 24 (2) ◽  
pp. 117-120 ◽  
Author(s):  
W. Stelzer ◽  
J. Jacob
Keyword(s):  
Sewage Sludge ◽  
Treatment Plant ◽  
Electrophoretic Pattern ◽  
River System ◽  
Average Concentration ◽  
Selective Medium ◽  
Cell Protein ◽  
Oxidation Pond ◽  
River Waters ◽  
Whole Cell Protein

This study is aimed at determining the occurrence of campylobacters in waste water, sewage sludge and in a river system. The selective medium for the isolation of campylobacter consists of blood agar supplemented with the antibiotics vancomycin (10 µg/ml), cephalexin (15 µg/ml), trimethoprim (5 µg/ml), polymycin B (2.5 µg/ml) and rifampicin (5 µg/ml). Raw sewage samples contained about 103 Campylobacter/100 ml while the effluent showed an average concentration of 1.3 × 102/100 ml. Raw sewage from an oxidation pond treatment plant contained an average of 51 Campylobacter/100 ml while none were found in the effluent. No Campylobacter could be found in digested, conditioned sludge. The organism could be detected in 82.1% of river waters examined with the majority showing <10/100 ml. The presence of waterfowl and the faecal contamination from a poultry farm resulted in higher Campylobacter levels. About 50 % of the isolates typed as C. coli were really confirmed as C. jejuni by electrophoretic pattern (whole cell protein profiles).

scholarly journals Evaluation of sensitivity of modified star protocol microbiological method for beta-lactame antibiotics detection in raw cow milk

2013 ◽  
Vol 67 (3-4) ◽  
pp. 163-173
Author(s):  
Branka Borovic ◽  
Danka Spiric ◽  
Branko Velebit ◽  
Vesna Djordjevic ◽  
Brankica Lakicevic ◽  
...  
Keyword(s):  
Cow Milk ◽  
Animal Origin ◽  
Reference Laboratory ◽  
Antibiotic Residues ◽  
Beta Lactam ◽  
Bacterial Strains ◽  
Animal Tissues ◽  
Initial Validation ◽  
Beta Lactam Antibiotics ◽  
Microbiological Methods

Antibiotic residues when present in animal tissues, through food chain, can enter human body, causing allergic reactions or facilitating the development of resistant bacterial strains. In order to determine the presence of antibiotics in animal tissues, it is appropriate to use convenient, reliable and sensitive methods. Microbiological methods applied for the detection of antibiotic residues in primary products of animal origin are based on the sensitivity of specific bacterial strains to a particular group of antibiotics. Regulatives on the amount of pesticides, metals and metalloids and other toxic substances, chemotherapeutics, anabolics and other substances which can be found in food ("Off. Gazette", No. 5/92, 11/92 - corr. and 32/02), state that milk and milk products can be used in commercial purposes only if not contain antibiotics in quantities that can be detected by reference methods. The applied method is modified STAR (Screening test for detection of antibiotics) protocol, regulated by the CRL (Community Reference Laboratory) Fougeres, France, in which the initial validation of the method had been carried out. In accordance with the demands of Regulative Commission EC No657/2002, the sensitivity of modified STAR protocol for beta lactam antibiotics group was examined , that is, there was carried out a contracted validation of the method, which initial validation had been performed at CRL. In a couple of series of experiments, 20 blank samples of raw cow milk originating from animals not treated by antibiotics, had been examined. By the beginning of the experiment samples were stored in a freezer at -20?C. Samples of raw cow milk enriched by working solutions of seven beta-lactam antibiotics, in order to obtain concentrations at the level of 0.5, 1 and 1.5 MRL (Maximmum Residue Limit) for each given antibiotic (Commission Regulation EC No. 37/2010). For detection of beta-lactam antibiotics, there was used Kundrat agar test with previously inoculated G.stearothermophilus ATCC 10149 strain. Aliquots of 30 _l of working solution at 0.5, 1 and 1.5 MRL concentration level, for each antibiotic, were inflicted on two paper disks placed on inoculated Kundrat agar surface. Petri plates with Kundrat agar previously inoculated with G.stearothermophilus , on which the samples were deposited, were incubated for 12-15h at 55oC. The obtained width of microorganisms growth inhibition zone, that is supposed to be at least 2.0 mm, measured from the disc edge, demonstrated the capability to detect all the tested 7 antibiotics from the beta lactam group at a level below the MRLs. Consequently, this proves that use of this method it is possible to meet the demands of Regulative Commission EC No. 37/2010.

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