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1.
Bull Environ Contam Toxicol ; 106(5): 866-872, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-33768336

RESUMO

Orthogonal experiments were used to simulate the enrofloxacin (ENR) elimination dynamic in deeper water of aquaculture. Two factors at values common in fishery water (temperature of 20°C, 25°C, and 30°C; pH of 5, 7, and 9) were studied. The degradation of ENR in the nine treatment groups ranged from 44.7 to 80.1%. Variance analysis indicated that pH had a strong impact on the elimination of ENR, while temperature changes showed little effect. The ENR removal rate was highest at a combination of 25°C and pH 5. The optimal conditions of eliminating ENR were performed for exploring the generation of ciprofloxacin (CIP), which indicated that higher ENR concentrations led to the production of greater amounts of CIP. The half-time of ENR was increased 2.02-times in the ENR concentrations increasing from 20 to 2000 ng/mL. This study could increase our understanding of the behaviors of ENR and CIP during the aquaculture process.


Assuntos
Fluoroquinolonas , Água , Antibacterianos , Aquicultura , Enrofloxacina , Concentração de Íons de Hidrogênio , Temperatura
2.
J Environ Manage ; 287: 112354, 2021 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-33735681

RESUMO

In this work batch-type experiments were used to study the adsorption of the antibiotics doxycycline (DC), enrofloxacin (ENR), and sulfamethoxypyridazine (SMP) in cultivation soils, before and after the removal of soil organic matter. Organic matter removal by calcination resulted not only in C and N removal, but also in increased soil pH, exchangeable basic cations and surface area values. The results indicate a very different behavior depending on the type of antibiotic, showing the adsorption sequence DC > ENR > SMP. Specifically, DC adsorption was very high in untreated soil samples (with organic matter), and was still high (although decreased) after the removal of soil organic matter. Furthermore, the adsorption behavior of DC was clearly dependent on the pH of the medium. Regarding ENR, it also showed high adsorption, although to a lesser extent than DC. However, when soil organic matter was removed, ENR adsorption significantly decreased in all soil samples. As regards SMP, it was adsorbed to a much lesser extent, and the removal of soil organic matter caused an additional drastic decrease in adsorption, reaching negligible values in some samples. Desorption followed the reverse sequence of adsorption, specifically in the order DC < ENR < SMP. In the case of DC, desorption was negligible, both in samples with and without organic matter, while for ENR and SMP, desorption clearly increased for soil samples where organic matter was removed. These results may be of relevance as regards environmental quality and public health, especially to facilitate a correct use of soils and organic amendments in areas that receive the application of substances containing the investigated antibiotics.


Assuntos
Poluentes do Solo , Sulfametoxipiridazina , Adsorção , Doxiciclina , Enrofloxacina , Solo , Poluentes do Solo/análise
3.
J Environ Sci (China) ; 103: 93-107, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-33743922

RESUMO

In order to enhance the removal performance of graphitic carbon nitride (g-C3N4) on organic pollutant, a simultaneous process of adsorption and photocatalysis was achieved via the compounding of biochar and g-C3N4. In this study, g-C3N4 was obtained by a condensation reaction of melamine at 550°C. Then the g-C3N4/biochar composites were synthesized by ball milling biochar and g-C3N4 together, which was considered as a simple, economical, and green strategy. The characterization of resulting g-C3N4/biochar suggested that biochar and g-C3N4 achieved effective linkage. The adsorption and photocatalytic performance of the composites were evaluated with enrofloxacin (EFA) as a model pollutant. The result showed that all the g-C3N4/biochar composites displayed higher adsorption and photocatalytic performance to EFA than that of pure g-C3N4. The 50% g-C3N4/biochar performed best and removed 45.2% and 81.1% of EFA (10 mg/L) under darkness and light with a dosage of 1 mg/mL, while g-C3N4 were 19.0% and 27.3%, respectively. Besides, 50% g-C3N4/biochar showed the highest total organic carbon (TOC) removal efficiency (65.9%). Radical trapping experiments suggested that superoxide radical (•O2-) and hole (h+) were the main active species in the photocatalytic process. After 4 cycles, the composite still exhibited activity for catalytic removal of EFA.


Assuntos
Luz , Adsorção , Carvão Vegetal , Enrofloxacina , Grafite , Compostos de Nitrogênio
4.
Chemosphere ; 270: 129791, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-33556815

RESUMO

Enrofloxacin (ENR) belongs to the fluoroquinolone (FQ) antibiotics family, which are contaminants of emerging concern frequently found in effluents. Although many works studying photo-Fenton process for FQ degradation have been reported, there are no reports analysing in deep the effect of iron complexation, as well as other metals, towards FQs' photolysis, which, evidently, also contributes in the overall degradation of the pollutant. Therefore, in this work, we report a comparative study between the photochemical fate of ENR and its complex with Fe(III) under simulated sunlight irradiation. In addition, the effect of dissolved oxygen, self-sensitization process, and H2O2 addition on the studied photochemical systems are also investigated. Results indicate that, for free and iron-complexed ENR, singlet oxygen (1O2) is generated from the interaction of its triplet state with ground state oxygen. Half-life time (t1/2) of ENR under sun simulated conditions is estimated to be around 22 min, while complexation with iron enhances its photostability, leading to a t1/2 of 2.1 h. Such finding indicates that at least the presence of iron, might notably increase the residence time of these pollutants in the environment. Eventually, only with the addition of H2O2, the FQ-iron complex is efficiently degraded due to photo-Fenton process even at circumneutral pH values due to the high stability of the formed complex. Finally, after LC/FT-ICR MS analysis, 39 photoproducts are detected, of which the 14 most abundant ones are identified. Results indicate that photoproducts formation is pH and iron dependent.


Assuntos
Ferro , Poluentes Químicos da Água , Enrofloxacina , Peróxido de Hidrogênio , Fotólise
5.
Food Chem ; 351: 129279, 2021 Jul 30.
Artigo em Inglês | MEDLINE | ID: mdl-33631615

RESUMO

The use of the antibiotic enrofloxacin (ENR) in poultry is controversial. A high-performance liquid chromatography coupled to fast-scanning fluorescence detection (HPLC-FSFD) method for the determination of ENR in egg white, egg yolk, and lyophilized samples was developed. In a first analysis, the long-term administration of ENR (100 days) to laying hens was carried out to determine its presence in egg white, yolk, or both. The predominance of ENR was observed in egg white and variations in the weight of egg white and eggshell was evidenced, showing a potential problem in the industry. Eventually, the presence of ENR was confirmed in commercial lyophilized egg white samples in concentration values around 350 µg kg-1. The consumer exposure assessment was estimated for children, adolescents, and adults. The result displayed that, in an intake of lyophilized egg white with food-producing animals, the %ADI exceeds 100%, showing toxicological levels.


Assuntos
Antibacterianos/análise , Ovos/análise , Enrofloxacina/análise , Contaminação de Alimentos/análise , Adolescente , Adulto , Animais , Galinhas , Criança , Cromatografia Líquida de Alta Pressão , Clara de Ovo/química , Gema de Ovo/química , Humanos , Espectrometria de Massas em Tandem
6.
Int J Food Microbiol ; 340: 109046, 2021 Feb 16.
Artigo em Inglês | MEDLINE | ID: mdl-33445066

RESUMO

Campylobacteriosis is a zoonosis and the most frequent cause of food-borne bacterial enteritis in humans. C. jejuni and C. coli are the most common species implicated in campylobacteriosis. Broilers and their products are considered the most important food sources of human infections. The aim of the present study was to evaluate the presence of thermotolerant Campylobacter in different reservoirs at the farm, and the permanence of this pathogen during four consecutive rearing periods. The samples were taken from the same house farm in the downtime period and during the last week of broiler rearing, prior to their slaughter during four consecutive cycles. Different reservoirs as potential sources of Campylobacter were analysed. The prevalence of Campylobacter in vectors was 23% in A. diaperinus larvae, 20% in wild birds, 13% in A. diaperinus adults, and 9% in flies; as regards fomites, the prevalence was 50% in workers' boots, 27% in litter, and 21% in feed, while in broilers it was 80%. Campylobacter jejuni was the most detected species (51%) in the samples analysed. In addition, some Campylobacter genotypes persisted in the house farm throughout consecutive rearing periods, indicating that those strains remain during downtime periods. However, our study could not identify the Campylobacter sources in the downtime periods because all the samples were negative for Campylobacter isolation. In addition, a remarkable finding was the effect of the use of enrofloxacin (as a necessary clinical intervention for flock health) in cycle 3 on the Campylobacter population. No Campylobacter could be isolated after that clinic treatment. Afterwards, we found a greater proportion of C. coli isolates, and the genotypes of those isolates were different from the genotypes found in the previous rearing periods. In conclusion, the effect of the use of enrofloxacin during the rearing period changed the Campylobacter species proportion, and this finding is particularly interesting for further evaluation. Furthermore, more studies should be conducted with the aim of detecting the Campylobacter sources between rearing periods.


Assuntos
Antibacterianos/uso terapêutico , Infecções por Campylobacter/veterinária , Campylobacter/isolamento & purificação , Galinhas , Reservatórios de Doenças , Enrofloxacina/uso terapêutico , Fazendas , Animais , Animais Selvagens/microbiologia , Campylobacter/fisiologia , Infecções por Campylobacter/tratamento farmacológico , Infecções por Campylobacter/microbiologia , Campylobacter jejuni/genética , Galinhas/microbiologia , Genótipo , Doenças das Aves Domésticas/tratamento farmacológico , Doenças das Aves Domésticas/microbiologia , Prevalência , Termotolerância
7.
Chemosphere ; 268: 129208, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33352514

RESUMO

Antibiotics are detected in association with heavy metals in the soil. However, interactions between antibiotics and heavy metals on soil enzyme activity have yet to been studied thoroughly. In this study, soil enzyme activity (urease, sucrase, phosphatase, and Rubisco) were measured after exposure to soils dosed with copper (Cu) and/or enrofloxacin (ENR) over 28 days. Enzyme responses to ENR only treatments varied, but Cu exhibited a strong negative response from all soil enzymes except Rubisco. An interaction between the effects of the two pollutants on soil enzymes was observed in the combined contamination treatments. Greater comprehensive toxicity to soil enzyme activity was observed in combined treatment groups compared to other groups. We anticipate our studies can provide a scientific theoretical basis for the combined pollution of antibiotics and heavy metals in soil.


Assuntos
Metais Pesados , Poluentes do Solo , Cobre/análise , Cobre/toxicidade , Enrofloxacina , Metais Pesados/análise , Solo , Poluentes do Solo/análise , Poluentes do Solo/toxicidade
8.
Carbohydr Polym ; 252: 117162, 2021 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-33183613

RESUMO

In order to overcome treatment difficulty of S. aureus infections, a pH/hyaluronidase dual responsive enrofloxacin-cyclodextrin (ß-CD) inclusion complexes (IC) containing hyaluronic acid/chitosan (HA/CS) self-assemble composite nanosystems covered by poloxamer 188 (F68) was firstly explored for targeted "on-demand" delivery. The FTIR, DSC and PXRD showed that enrofloxacin was embedded into IC and then distributed into F68 coating nanogels formulated by electrostatic interaction between CS and HA. The optimal nanosystems of 118.8 ± 30.7 nm showed excellent stability and responsive release in the acid medium, hyaluronidase containing medium, and LB broth medium where S. aureus present. The nanosystems displayed strong surface adsorption on S. aureus and enhanced activity against S. aureus. It had stronger sustained release than the polymeric nanoparticles formulated by entrapping of IC into F68 and the single HA/CS nanogels. This study provides a promising multi-functionalized nanosystems to overcome the treatment challenge of S. aureus and other bacterial infections.


Assuntos
Antibacterianos/farmacologia , Ciclodextrinas/farmacologia , Enrofloxacina/farmacologia , Nanogéis/química , Staphylococcus aureus/efeitos dos fármacos , Quitosana/química , Quitosana/uso terapêutico , Portadores de Fármacos , Liberação Controlada de Fármacos , Ácido Hialurônico/química , Ácido Hialurônico/uso terapêutico , Hialuronoglucosaminidase/metabolismo , Concentração de Íons de Hidrogênio , Nanogéis/uso terapêutico , Poloxâmero/química , Poloxâmero/uso terapêutico , Infecções Estafilocócicas/tratamento farmacológico
9.
ACS Appl Mater Interfaces ; 12(52): 58191-58200, 2020 Dec 30.
Artigo em Inglês | MEDLINE | ID: mdl-33319977

RESUMO

Purification of antibodies has become a critical factor in antibody production. A high-purity specific antibody against antigens, especially small molecules, seems to be difficult to obtain, even with the help of a protein A affinity column, which is a conventional and broadly used ligand for the separation of antibody and non-antibody proteins. Therefore, it is urgent to develop a cheap, simple, efficient, and stable method to separate the specific antibody from other antibodies. In this study, to improve the sensitivity and accuracy of immunoassay results, enrofloxacin (ENR) was grafted onto polyethylenimine (PEI) by the abundant amino groups and then the whole ligand (ENR-PEI) was conjugated to CNBr-Sepharose 4B to prepare the affinity column for the purification of the specific antibody against ENR from polyclonal antibodies. Scanning electron microscopy and Fourier transform infrared spectroscopy verification showed that Sepharose 4B was successfully modified by ENR-PEI with excellent uniformity. The capacity of the prepared column could reach to 6.15 mg of specific antibody with high purity per milliliter resin due to the high coupling ratio (49.3:1) of ENR on PEI, and the IC50 value of the antibody after purification was 47.58 ng/mL with a lowest limit of detection (IC10) of 1.099 ng/mL-18 times lower than those of the antibody purified through the protein A column. All the results showed that this new kind of resin could be used as the potential ligand in the purification of the trace-specific antibody against antigens in complex mixtures with high efficiency and specificity.


Assuntos
Anticorpos/imunologia , Anticorpos/isolamento & purificação , Especificidade de Anticorpos , Haptenos/química , Haptenos/imunologia , Imunoensaio/métodos , Polietilenoimina/química , Enrofloxacina/química , Ligantes
10.
Anim Sci J ; 91(1): e13475, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33078490

RESUMO

Growth performance of pigs has been associated with healthy gut microbiota. To improve production, pigs are usually treated with antimicrobials. Nonetheless, while antimicrobials harm the gut-indigenous microbiota, probiotic supplementation seems to help keep it healthy. Here, using antimicrobials, we artificially induced dysbiosis in pigs and evaluated a possible preventive effect of probiotic supplementation. Three 6-week-old piglets were given a basal feed, and 3 more the feed supplemented with 2.0 × 106  CFU of Bacillus subtilis QST713/g of feed. After 14 days, antimicrobial enrofloxacin (5 mg/kg B.W.) was injected intramuscularly to all pigs on days 14-16. Feces were collected on days 14, 17, 19, 21, and 23. Total bacteria count was unaffected by enrofloxacin or QST713. However, Lactobacillus spp. and, in particular, Escherichia coli were affected by enrofloxacin, the latter not being observed in the feces on days 17 and 19. Interestingly, a reciprocal increase in E. coli was observed in control pigs on days 21 and 23, although in QST713-supplemented piglets, this increase was attenuated. While the gut microbiota composition did not return to initial levels in antimicrobial-administered piglets, it did in QST713-supplemented piglets. QST713 supplementation was likely crucial to keep the microbiota of piglets healthy.


Assuntos
Antibacterianos/efeitos adversos , Bacillus subtilis , Suplementos Nutricionais , Disbiose/prevenção & controle , Disbiose/veterinária , Enrofloxacina/efeitos adversos , Probióticos/administração & dosagem , Doenças dos Suínos/prevenção & controle , Animais , Antibacterianos/administração & dosagem , Disbiose/induzido quimicamente , Disbiose/microbiologia , Enrofloxacina/administração & dosagem , Fezes/microbiologia , Microbioma Gastrointestinal , Injeções Intramusculares , Suínos , Doenças dos Suínos/induzido quimicamente , Doenças dos Suínos/microbiologia
11.
Ecotoxicol Environ Saf ; 203: 111025, 2020 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-32888593

RESUMO

We investigated individual and combined effects of environmentally representative concentrations of amoxicillin (AMX; 2 µg l-1), enrofloxacin (ENR; 2 µg l-1), and oxytetracycline (OXY; 1 µg l-1) on the aquatic macrophyte Lemna minor. While the concentrations of AMX and ENR tested were not toxic, OXY decreased plant growth and cell division. OXY induced hydrogen peroxide (H2O2) accumulation and related oxidative stress through its interference with the activities of mitochondria electron transport chain enzymes, although those deleterious effects could be ameliorated by the presence of AMX and/or ENR, which prevented the overaccumulation of ROS by increasing catalase enzyme activity. L. minor plants accumulated significant quantities of AMX, ENR and OXY from the media, although competitive uptakes were observed when plants were submitted to binary or tertiary mixtures of those antibiotics. Our results therefore indicate L. minor as a candidate for phytoremediation of service waters contaminated by AMX, ENR, and/or OXY.


Assuntos
Amoxicilina/toxicidade , Araceae/efeitos dos fármacos , Enrofloxacina/toxicidade , Oxitetraciclina/toxicidade , Fotossíntese/efeitos dos fármacos , Poluentes Químicos da Água/toxicidade , Amoxicilina/análise , Amoxicilina/metabolismo , Araceae/crescimento & desenvolvimento , Araceae/metabolismo , Biodegradação Ambiental , Catalase/metabolismo , Relação Dose-Resposta a Droga , Interações Medicamentosas , Enrofloxacina/análise , Enrofloxacina/metabolismo , Peróxido de Hidrogênio/metabolismo , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Oxitetraciclina/análise , Oxitetraciclina/metabolismo , Poluentes Químicos da Água/análise
12.
Exp Parasitol ; 217: 107958, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32730769

RESUMO

Anaplasma marginale is the causative agent of the severe bovine anaplasmosis. The tick Rhipicephalus microplus is one of the main vectors of A. marginale in tropical and subtropical regions of the world. After the tick bite, the bacterium invades and proliferates within the bovine erythrocytes leading to anemia, impairment of milk production and weight loss. In addition, infection can cause abortion and high mortality in areas of enzootic instability. Immunization with live and inactivated vaccines are employed to control acute bovine anaplasmosis. However, they do not prevent persistent infection. Consequently, infected animals, even if immunized, are still reservoirs of the bacterium and contribute to its dissemination. Antimicrobials are largely employed for the prophylaxis of bovine anaplasmosis. However, they are often used in sublethal doses which may select pre-existing resistant bacteria and induce genetic or phenotypic variations. Therefore, we propose a new standardized in vitro assay to evaluate the susceptibility of A. marginale strains to different antimicrobials. This tool will help health professionals to choose the more adequate treatment for each herd which will prevent the selection and spread of resistant strains. For that, we initially evaluated the antimicrobial susceptibility of two field isolates of A. marginale (Jaboticabal and Palmeira) infecting bovines. The least susceptible strain (Jaboticabal) was used for the standardization of an antimicrobial assay using a culture of Ixodes scapularis-derived tick cell line, ISE6. Results showed that enrofloxacin (ENRO) at 0.25, 1 or 4 µg/mL and oxytetracycline (OTC) at 4 or 16 µg/mL are the most efficient treatments, followed by OTC at 1 µg/mL and imidocarb dipropionate (IMD) at 1 or 4 µg/mL. In addition, this proposed tool has technical advantages compared to the previously established bovine erythrocyte culture. Thereby, it may be used to guide cattle farmers to the correct use of antimicrobials. The choice of the most suitable antimicrobial is essential to eliminate persistent infections, prevent the spread of resistant strains and help controlling of bovine anaplasmosis.


Assuntos
Anaplasma marginale/efeitos dos fármacos , Anaplasmose/prevenção & controle , Antibacterianos/farmacologia , Vetores Aracnídeos/citologia , Doenças dos Bovinos/prevenção & controle , Rhipicephalus/citologia , Anaplasmose/tratamento farmacológico , Anaplasmose/microbiologia , Animais , Antibacterianos/uso terapêutico , Vetores Aracnídeos/parasitologia , Brasil , Bovinos , Doenças dos Bovinos/tratamento farmacológico , Doenças dos Bovinos/microbiologia , Linhagem Celular , Enrofloxacina/farmacologia , Eritrócitos/microbiologia , Imidocarbo/análogos & derivados , Imidocarbo/farmacologia , Imidocarbo/uso terapêutico , Masculino , Testes de Sensibilidade Microbiana , Oxitetraciclina/farmacologia , Oxitetraciclina/uso terapêutico , Reação em Cadeia da Polimerase em Tempo Real , Rhipicephalus/parasitologia
13.
PLoS One ; 15(7): e0236758, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32730301

RESUMO

Chlamydiosis is the most significant infectious disease of koalas (Phascolarctos cinereus). It is primarily a systemic sexually transmitted disease caused by Chlamydia pecorum and was responsible for 46% of the 2348 koala admissions to Australia Zoo Wildlife Hospital between 2013 and 2017. Treatment of chlamydiosis in koalas is complicated by three major factors. Firstly, koalas rely on bacterial fermentation of their high fibre diet making antibiotic therapy a risk. Secondly, they possess efficient metabolic pathways for the excretion of plant toxins and potentially of therapeutic agents. Thirdly, wild koalas, often present to rehabilitation facilities with chronic and severe disease. Traditional anti-chlamydial antibiotics used in other species may cause fatal dysbiosis in koalas or be excreted before they can be effective. We compared five anti-chlamydial antibiotics, azithromycin, chloramphenicol, doxycycline, enrofloxacin and florfenicol, which were used to treat 86 wild koalas with chlamydiosis presented to Australia Zoo Wildlife Hospital under consistent conditions of nutrition, housing, husbandry and climate. Response to treatment was assessed by recovery from clinical signs, and clearance of detectable Chlamydia via quantitative PCR. Doxycycline was the most effective anti-chlamydial antibiotic of the five, producing a 97% cure rate, followed by chloramphenicol (81%), enrofloxacin (75%), florfenicol (66%) and azithromycin (25%). The long-acting injectable preparation of doxycycline was well tolerated by koalas when administered via the subcutaneous route, and the weekly dosing requirement is a major advantage when treating wild animals. These findings indicate that doxycycline is the current drug of choice for the treatment of chlamydiosis in koalas, with chloramphenicol being the best alternative.


Assuntos
Antibacterianos/farmacologia , Infecções por Chlamydia/tratamento farmacológico , Chlamydia/efeitos dos fármacos , Phascolarctidae/microbiologia , Animais , Austrália , Azitromicina/farmacologia , Infecções por Chlamydia/microbiologia , Infecções por Chlamydia/patologia , Cloranfenicol/farmacologia , Doxiciclina/farmacologia , Enrofloxacina/farmacologia , Feminino , Masculino , Tianfenicol/análogos & derivados , Tianfenicol/farmacologia
14.
Huan Jing Ke Xue ; 41(6): 2688-2697, 2020 Jun 08.
Artigo em Chinês | MEDLINE | ID: mdl-32608784

RESUMO

Enrofloxacin (ENR), a fluoroquinolones antibiotic, is widely used in the medical and aquaculture fields. Its residues in surface waters in China are high. However, few studies have evaluated both its toxicity to phytoplankton and the degradation or removal by microalgae. In this study, the growth, photosynthetic activity, and exopolysaccharides (EPS) of freshwater micro-green algae Dictyosphaerium sp. and the dynamics of ENR concentrations (0, 5, 25, 50, and 100 mg·L-1) were studied through an exposure experiment for 12 days. Results showed that the biomass and photosynthetic pigment content of Dictyosphaerium sp. increased with increasing exposure time in each treatment; however, it showed a significant inhibitory effect on the growth and pigment accumulation of Dictyosphaerium sp. compared with the control group (P<0.01). The LC50 of ENR to Dictyosphaerium sp. was (241.29±7.33) mg·L-1 after 96-h exposure, indicating that Dictyosphaerium sp. could adapt to the stress conditions of high concentration ENR. Meanwhile, when the concentration of enrofloxacin was<5 mg·L-1, it was found to promote the maximum photosynthetic rate (Fv/Fm) of Dictyosphaerium sp. On the contrary, when the concentration of enrofloxacin was>5 mg·L-1, photosynthetic inhibition was observed (P<0.01). The actual photosynthetic rate (Yield) and the maximum electron transfer rate (ETRmax) showed a trend of initially decreasing and then increasing in 12 days. It can gradually adapt to the stress conditions and recover certain photosynthetic activity after 6 days' exposure. In addition, ENR can also stimulate the EPS (RPS and CPS) release. At the end of the experiment, the removal rates of ENR in the four control groups (no algae addition groups) (5, 25, 50, and 100 mg·L-1ENR) were 7.27%, 5.56%, 5.30%, and 4.88%, respectively, while the removal rates of the treatment groups were 3.21, 3.01, 2.69, and 2.83 times of the no algae groups, indicating that Dictyosphaerium sp. had a significant promoting effect on the removal of ENR (P<0.01). Overall, our results can provide new insights for the understanding of the ecological toxicity of fluoroquinolone antibiotics to primary producers in the aquatic system and also provide new ideas for the ecological removal of antibiotic residues in water bodies and the biological resource utilization of freshwater microalgae.


Assuntos
Clorófitas , Poluentes Químicos da Água/análise , China , Enrofloxacina , Fluoroquinolonas/análise , Água Doce
15.
Chemosphere ; 258: 127266, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32535443

RESUMO

Copper oxide nanoparticles (CuO-NPs) have been suggested as effective catalysts to degrade many persistent organic contaminants. In parallel, CuO-NPs are considered toxic to soil microorganisms, plants and human cells, possibly because they induce oxidative stress and generation of reactive oxygen species (ROS). However, the mechanism of the catalytic process and the generated ROS are poorly understood. Here we discuss the reaction mechanism of CuO-NPs during the catalytic degradation of enrofloxacin - an antibiotic pharmaceutical used in this study as a representative persistent organic compound. The degradation of an aqueous solution of the enrofloxacin exposed to CuO-NPs and hydrogen peroxide was studied showing fast removal of the enrofloxacin at ambient conditionsns. ROS production was identified by electron spin resonance and a spin trapping technique. The distribution of the free radical species indicated production of a high percentage of superoxide (O2-.) radicals as well as hydroxyl radicals; this production is similar to the "radical production" activity of the superoxide dismutase (SOD) enzyme in the presence of hydrogen peroxide. This activity was also tested in the opposite direction, to examine if CuO-NPs show reactivity that potentially mimics the classical SOD enzymatic activity. The CuO-NPs were found to catalyze the dismutation of superoxide to hydrogen peroxide and oxygen in a set of laboratory experiments.


Assuntos
Cobre/química , Enrofloxacina/análise , Nanopartículas/química , Espécies Reativas de Oxigênio/química , Poluentes Químicos da Água/análise , Purificação da Água/métodos , Catálise , Enrofloxacina/química , Humanos , Peróxido de Hidrogênio/química , Modelos Teóricos , Oxirredução , Superóxido Dismutase/química , Poluentes Químicos da Água/química
16.
Arq. bras. med. vet. zootec. (Online) ; 72(3): 931-935, May-June, 2020. tab, graf
Artigo em Inglês | LILACS, VETINDEX | ID: biblio-1129612

RESUMO

Bacterial resistance is a reality in both human and veterinary health, it limits the therapeutic arsenal and raises the costs of the patient's treatment. A dog with signs of cystitis received treatment with 5mg/kg enrofloxacin at three consecutive times, with low effectiveness. The presence of urethral uroliths was identified and urohydropulsion was done. The animal presented a new obstruction, for which a cystotomy was performed, but continued with signs of infection. Uroculture and antimicrobial susceptibility test were then performed. Escherichia coli was identified, which was resistant to 13 antibiotics, being sensitive only to piperacillin-tazobactam and amikacin. In the screening test for ß-lactamase, the production of ESßL was detected. The qPCR indicated the presence of the bla CTXm, bla DHA, bla OXA, bla IMP, bla TEM, bla GIM, bla SIM, bla SPM and bla SME genes, which may lead to a phenotypic resistance profile for ampicillin, amoxicillin-clavulanate, aztreonam, cefepime cefoxitin, cefuroxime, ceftazidime, ceftriaxone, imipenem, and piperacillin-tazobactam. This case reaffirms the value that laboratory analysis adds to the diagnosis and treatment of cystitis and urolithiasis, which can define the direction of evolution of the prognosis and the speed at which the patient's health will be restored.(AU)


A resistência bacteriana aos antibióticos é uma realidade, tanto na saúde humana quanto veterinária, limita o arsenal terapêutico e eleva os custos relacionados ao tratamento do paciente. Um cão, com sinais de cistite, recebeu tratamento com enrofloxacina, na dose de 5mg/kg, em três momentos seguidos, com baixa efetividade. Identificou-se presença de urólitos uretrais e foi feita uro-hidropropulsão. O animal apresentou nova obstrução, para a qual foi realizada uma cistotomia, mas continuou com sinais de infecção. Realizou-se, então, urocultura e teste de antibiograma. Foi identificada Escherichia coli, que se mostrou resistente a 13 antibióticos, sendo sensível somente à piperacilina-tazobactam e amicacina. No teste de triagem para ß-lactamase, detectou-se a produção de ESßL. A qPCR indicou presença dos genes blaCTXm, blaDHA, blaOXA, blaIMP, blaTEM, blaGIM, blaSIM, blaSPM e blaSME, que podem conduzir um perfil fenotípico de resistência para ampicilina, amoxicilina-ácido clavulânico, aztreonam, cefepima, cefoxitina, cefuroxima, ceftazidima, ceftriaxona, imipenem, piperacilina-tazobactam. Este caso reafirma o valor que a análise laboratorial agrega ao diagnóstico e tratamento da cistite e da urolitíase, podendo definir o sentido de evolução do prognóstico e a velocidade em que a saúde do paciente será restabelecia.(AU)


Assuntos
Animais , Cães , Cistite/veterinária , Farmacorresistência Bacteriana Múltipla , Escherichia coli/isolamento & purificação , Urolitíase , Cistotomia/veterinária , Enrofloxacina
17.
Environ Sci Pollut Res Int ; 27(22): 28198-28208, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32415445

RESUMO

The degradation and metabolic pathways of sulfamethazine (SMZ) and enrofloxacin (ENR) via microalgal treatment systems were investigated in this study. SMZ and ENR applied at 1-25 mg L-1 did not significantly inhibit the growth of Chlorella vulgaris or Scenedesmus obliquus. SMZ and ENR exposure did not significantly alter the maximum quantum efficiencies of C. vulgaris and S. obliquus. When cultured at light intensities of 45-50 µmol photon m-2 s-1, the C. vulgaris and S. obliquus treatment systems achieved 24% and 11% degradation, respectively. The greatest removal of ENR was 52% and 43.3%, for C. vulgaris and S. obliquus treatment systems, respectively, after 15 days. The results indicated that the degradation of SMZ and ENR occurred by a combination of biodegradation and photolysis. Kinetic investigations revealed that the removal of SMZ and ENR (5 mg L-1) followed a first-order model, with apparent rate constants (k) ranging from 0.0141 to 0.0048 day-1 and 0.0132 to 0.0086 day-1, respectively. Fifteen metabolites of SMZ and five intermediates of ENR were identified by UPLC-MS, and degradation pathways for SMZ and ENR were proposed. SMZ transformation reactions included ring cleavage, hydroxylation, methylation, and oxidation, whereas ENR was degraded by dealkylation, decarboxylation, and defluorination. Graphical abstract.


Assuntos
Chlorella vulgaris , Scenedesmus , Cromatografia Líquida , Enrofloxacina , Redes e Vias Metabólicas , Sulfametazina , Espectrometria de Massas em Tandem
18.
Bioresour Technol ; 312: 123567, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32470826

RESUMO

It is worth to reveal the long-term responses of antibiotic resistance genes (ARGs) in aerobic granular sludge (AGS) system exposed to high level enrofloxacin (ENR), sulfadiazine (SDZ) and triclosan (TCS). In present study, ppm level ENR, SDZ and TCS were added into three AGS reactors, respectively. ARGs in ENR and SDZ systems showed trends of increasing first and then decreasing, which were contrary to that in TCS system. 80%, 56% and 40% ARGs in ENR, SDZ and TCS systems, respectively, were enriched after loading, but several ARGs still kept high enrichment values after the withdrawn of loadings. The dominant bacteria in ENR (Flavobacterium), SDZ (Candidatus_Competibacter and Defluviicoccus) and TCS (Defluviicoccus) systems might contribute to the reductions of ARGs. IntI1 altered the overall ARGs profiles through horizontal gene transfer. The interactions of bacterial communities and environmental factors might be responsible for the different ARGs patterns in ENR, SDZ and TCS systems.


Assuntos
Triclosan , Antibacterianos , Resistência Microbiana a Medicamentos , Enrofloxacina , Genes Bacterianos , Esgotos , Sulfadiazina
19.
Water Environ Res ; 92(11): 1935-1947, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32319707

RESUMO

A novel sorbent based on a mixture of magnetic functionalized graphene oxide and MOFs was developed to remove enrofloxacin (EFX) from water samples. The prepared sorbent was characterized using Fourier transform infrared spectra, scanning electron microscope images, and X-ray powder diffraction pattern. The sorbent compositions were optimized by the mixture experimental design. Under the optimal condition, the percentages of each sorbent component, including triethylene tetramine-functionalized graphene oxide (FGO), Fe3 O4 , and MOF-5, were 40%, 21%, and 39%, respectively. Besides, the intraparticle diffusion and pseudo-second-order kinetic models can describe the EFX adsorption procedure because of two adsorption mechanisms of EFX on FGO and MOF-5. A positive standard enthalpy of 49.80 kJ/mol indicated the EFX adsorption is endothermic with a chemisorption process. The negative values of ΔGo obtained in the range of -8.979 to -3.431 kJ/mol at all studied temperatures showed that the adsorption process was also spontaneous. The Langmuir and Freundlich isotherm models were analyzed with the partition coefficient to reduce bias in the isotherm model evaluation. The maximum adsorption capacity of 344.83 mg/g and a high partition coefficient of 17.42 g/L in an initial EFX concentration of 10 mg/L were obtained for the EFX removal. PRACTITIONER POINTS: Magnetic functionalized graphene oxide @MOF-5 as a sorbent for the enrofloxacin removal is synthesized. The percentage amount of each component of the sorbent is optimized using the D-optimal mixture design. Adsorption mechanisms of enrofloxacin on magnetic functionalized graphene oxide @MOF-5 are discussed. Thermodynamic parameters for the enrofloxacin adsorption with the sorbents are determined. Isotherm model for the enrofloxacin removal with the sorbent is investigated.


Assuntos
Grafite , Estruturas Metalorgânicas , Poluentes Químicos da Água , Adsorção , Enrofloxacina , Cinética , Fenômenos Magnéticos , Projetos de Pesquisa
20.
Sci Total Environ ; 724: 138280, 2020 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-32247984

RESUMO

g-C3N4 makes good prospects in photocatalytic field due to its two-dimensional (2D) structure and visible-light activity. How to improve its photocatalytic activity by minimizing the unexpected recombination of photo-induced charge carries on g-C3N4 motivates our research. Herein, mesoporous TiO2/g-C3N4 composites are fabricated with 2D TiO2(B) nanosheets regulating thermal condensation process of g-C3N4 nanosheets. FT-IR and XPS results suggest that the formation of O-Ti-N chemical bond increases the percentage of N-(C)3 in the conjugated system, accelerating the transportation of photo-induced electrons. The optical property and PL results illustrate that the formed interface heterojunction with chemical bond facilitates the separation and transfer of photo-induced charge carriers. Hence, the removal constant of TiO2/g-C3N4 composites is 46.3 times higher than that of g-C3N4. This study opens up a new insight into the development of composite materials in the field of organic pollutant treatment.


Assuntos
Enrofloxacina , Titânio , Catálise , Fotólise , Espectroscopia de Infravermelho com Transformada de Fourier
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