RESUMO
Tetracyclines and polyether ionophores are veterinary drugs frequently used in animals reared for food production. Despite the benefits, residues can be harmful for human health if levels are higher than those considered safe. The aim of this study was to evaluate, by LC-MS/MS, tetracyclines residues in pasteurised milk samples marketed in São Paulo state, Brazil and estimate the exposure of the adult/adolescent/children population. Within the eight antibiotics monitored two were detected, tetracycline and 4-epitetracycline, found in 22.5% and 12.5% of the samples, respectively. Since the same samples had been previously tested for polyether ionophore residues, risk assessment based on dietary exposure to tetracyclines when considered individually and in combination with the ionophores was performed. The daily intakes were below the acceptable daily intake (ADI) for tetracycline. Considering the levels of monensin reported in a previous study, the combined exposure with tetracycline and 4-epi-tetracycline also indicated low potential health concerns.
Assuntos
Resíduos de Drogas , Tetraciclinas , Criança , Adulto , Adolescente , Animais , Humanos , Tetraciclinas/análise , Ionóforos/análise , Cromatografia Líquida , Tetraciclina/análise , Leite/química , Brasil , Espectrometria de Massas em Tandem , Contaminação de Alimentos/análise , Antibacterianos/análise , Medição de Risco , Resíduos de Drogas/análiseRESUMO
Adding ionophores to ruminant diets is a strategy to manipulate ruminal fermentation and improve milk yield. This study evaluates the effects of narasin supply to lactating ewes on dry matter intake (DMI), milk yield and composition, and performance of the lambs. Thirty lactating Santa Inês and Santa Inês × Dorper ewes fed a basal diet containing 50 % coastcross hay and 50 % concentrate were randomly assigned to two treatments: control (CON; without ionophores) or NAR (addition of 13 mg narasin kg-1 DM). From the 2nd to 10th week of lactation, DMI of ewes was determined, and once a week, their milk production and composition was measured over a 3-h interval. At the 10th week of lactation, lambs were weaned and their average daily gain (ADG) and starter DMI continued to be evaluated for two more weeks. Narasin supply did not affect weight and DMI of ewes. Ewes fed NAR had greater feed efficiency for milk production and displayed tendency for higher milk yield. Narasin supply reduced milk protein levels, but it did not affect other milk component levels. Ewes fed NAR had greater production of milk urea nitrogen and showed tendency for higher production of fat and total solids. Starter DMI of lambs was not affected by treatments; however, there was a tendency for greater weaning weight for NAR lambs. At the end of experiment, no differences were observed in the performance of lambs. The supply of 13 mg narasin kg-1 to lactating ewes improved milk yield efficiency and tended to increase the weaning weight of their lambs.(AU)
Assuntos
Animais , Feminino , Ovinos/fisiologia , Coccidiostáticos/química , Leite/fisiologia , Animais Lactentes/fisiologia , Lactação , Ionóforos/análiseRESUMO
This paper aimed to survey the occurrence of six polyether ionophores (lasalocid, maduramycin, monensin, narasin, salinomycin and semduramycin) in pasteurized milk using a validated method by liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS). For that, 40 samples of pasteurized milk, from seven brands, collected in six locations (supermarkets, grocery stores and greengrocers) in the metropolitan region of São Paulo and Campinas, São Paulo State, Brazil, were evaluated. Sampling included whole (18), skimmed (8) and semi-skimmed (10) milk as well as lactose-free (4) products. Only monensin antibiotic residues were found in the analyzed samples. This ionophore was confirmed in 45% of the samples and quantified in 32.5% at concentrations ranging from 0.1 to 0.27 µg kg-1. The positive samples were whole or semi-skimmed milk. Considering the levels of monensin reported in the present study and data on milk consumption in Brazil, an exposure assessment indicated that the intake of this antibiotic does not represent a risk to health.
Assuntos
Leite , Espectrometria de Massas em Tandem , Animais , Brasil , Cromatografia Líquida , Ionóforos/análise , Leite/químicaRESUMO
An analytical method was developed and validated for the determination of three polyether ionophores (monensin, lasalocid, and salinomycin) in 60 samples of Brazilian Minas Frescal cheese by UHPLC-MS/MS. Linearity ranged from 1 to 8 µg kg-1 for monensin and salinomycin, and from 0.50 to 4 µg kg-1 for lasalocid. Limits of detection and quantitation were 0.50 µg kg-1 and 1 µg kg-1, respectively, for both monensin and salinomycin, and 0.25 µg kg-1 and 0.50 µg kg-1, respectively, for lasalocid. Recoveries were between 69% and 84% with coefficients of variation up to 16.28% for repeatability and 13.79% for intermediate precision. A total of 60 samples of Minas Frescal cheese were analysed and only monensin residues were found. Monensin was detected in 55% of the samples and quantified in 5 of them at mean levels varying from 1.00 to 1.73 µg kg-1. The proposed method demonstrated the suitability for monitoring these substances in cheese.
Assuntos
Queijo/análise , Contaminação de Alimentos/análise , Ionóforos/análise , Brasil , Cromatografia Líquida de Alta Pressão , Lasalocida/análise , Monensin/análise , Piranos/análise , Espectrometria de Massas em TandemRESUMO
Ionophores are the second top selling class of antimicrobials used in food-producing animals in the United States. In chickens, ionophores are used as feed additives to control coccidiosis; up to 80% of administered ionophores are excreted in the litter. Because poultry litter is commonly used to fertilize agricultural fields, ionophore residues in litter have become contaminants of emerging concern. This study aims to develop a liquid chromatography with tandem mass spectrometry (LC-MS/MS) method to quantify ionophores, and identify their transformation products (TPs) in poultry litter after on-farm pilot-scale composting. The validation parameters of the optimized method showed good accuracy, ranging from 71 to 119% recovery and relative standard deviation (precision) of ≤19% at three different concentration levels (10, 50 and 100 µg/kg). Monensin, salinomycin and narasin, were detected in the poultry litter samples prior to composting at 290.0 ± 40, 426 ± 46, and 3113 ± 318 µg kg(-1), respectively. This study also aims to investigate the effect of different composting conditions on the removal of ionophores, such as the effect of turning or aeration. Results revealed a 13-68% reduction in ionophore concentrations after 150 d of composting, depending on whether the compost was aerated, turned, or subjected to a combination of both aeration and turning. Three transformation products and one metabolite of ionophores were identified in the composted litter using high-resolution liquid chromatography with quadrupole time-of-flight mass spectrometry (LC-QToF/MS).
Assuntos
Antibacterianos/análise , Fezes/química , Ionóforos/análise , Esterco/análise , Poluentes do Solo/análise , Solo/química , Drogas Veterinárias/análise , Animais , Antibacterianos/metabolismo , Galinhas , Cromatografia Líquida de Alta Pressão/veterinária , Cromatografia Líquida/métodos , Coccidiose , Ionóforos/química , Ionóforos/metabolismo , Aves Domésticas , Poluentes do Solo/química , Extração em Fase Sólida , Espectrometria de Massas em Tandem/métodos , Espectrometria de Massas em Tandem/veterinária , Estados Unidos , Drogas Veterinárias/químicaRESUMO
BACKGROUND/AIMS: Cystic Fibrosis (CF) is caused by mutations in the CFTR gene, encoding a cAMP-activated chloride (Cl-) channel. We have previously demonstrated that the expression of several genes can be modulated by the CFTR activity; among them, SRC, MTND4, CISD1, and IL1B. However, the CFTR signalling mechanism involved in the expression of CFTR-dependent genes is unknown. The aim of this work was to determine if intracellular chloride (Cl-)i might function as a second messenger modulating the expression of specific genes. METHODS: Differential display (DD) was applied to IB3-1 cells (CF cells), cultured under conditions that produce different intracellular Cl- concentrations ([Cl-]i), to analyse their expression profile. RESULTS: Several differentially expressed gene products were observed by using DD, suggesting the presence of chloride-dependent gene expression. Two cDNA fragments, derived from differentially expressed mRNAs and showing opposed response to Cl-' were isolated, cloned, sequenced and its Cl- dependency validated by reverse transcription quantitative-PCR (RT-qPCR). We identified the gene RPS27, which encodes the multifunctional ribosomal protein RPS27, also known as metallopanstimulin-1 (MPS-1), and the gene GLRX5, encoding glutaredoxin-related protein 5, as chloride-dependent genes. RPS27 was negatively regulated with increased [Cl-]i, approximately from 25-75 mM Cl- (EC50 = 46 ± 7 mM), and positively regulated from 75-125 mM Cl- (EC50 = 110 ± 11 mM) (biphasic response). In contrast, GLRX5 was positively modulated by [Cl-]i, showing a typical sigmoidal dose-response curve from 0-50 mM Cl-, reaching a plateau after 50 mM Cl- (EC50 â¼ 34 mM). CONCLUSION: The results suggest the existence of chloride-dependent genes. The Cl- anion, therefore, might act as a second messenger for channels or receptors able to modulate the intracellular Cl- concentration, regulating in turn the expression of specific genes.
Assuntos
Cloretos/farmacologia , Expressão Gênica/efeitos dos fármacos , Glutarredoxinas/metabolismo , Metaloproteínas/metabolismo , Proteínas Nucleares/metabolismo , Proteínas de Ligação a RNA/metabolismo , Proteínas Ribossômicas/metabolismo , Sistemas do Segundo Mensageiro/efeitos dos fármacos , Sequência de Aminoácidos , Ânions/química , Sequência de Bases , Sítios de Ligação , Linhagem Celular , Fibrose Cística/metabolismo , Fibrose Cística/patologia , Glutarredoxinas/genética , Humanos , Ionóforos/análise , Ionóforos/química , Metaloproteínas/genética , Simulação de Dinâmica Molecular , Dados de Sequência Molecular , Proteínas Nucleares/genética , Estrutura Terciária de Proteína , RNA Mensageiro/metabolismo , Proteínas de Ligação a RNA/genética , Reação em Cadeia da Polimerase em Tempo Real , Proteínas Ribossômicas/genética , Alinhamento de SequênciaRESUMO
The objective of the present study was to evaluate the effects of the inclusion of sodium monensin on the starter concentrate of lactating heifers on weight gain, chest girth, withers height, hip height and body length. Twelve heifers were divided into two experimental groups according to date of birth: a control group without supplementation and a daily supplemented group with 0.4 mg of sodium monensin per kg of body weight. The animals were observed from thirty days of age until 86 days of age. Production parameters as body weight, chest girth, withers height, hip height and body length were weekly evaluated. These parameters did not show variation depending on supplementation with monensin, the lowest yield observed in the supplemented group may have been due to lower consumption. The supplementation of monensin had no effect on weight gain of dairy calves in early weaning system.(AU)
O estudo teve como objetivo avaliar o efeito da inclusão de monensina sódica no concentrado inicial de bezerras lactantes, sobre o ganho de peso, perímetro torácico, altura de cernelha, altura de garupa e comprimento corporal. Foram utilizadas 12 bezerras divididas em dois grupos experimentais de acordo com a data de nascimento. Foram avaliados os tratamentos controle (sem suplementação com monensina) e suplementação diária com 0,4 mg de monensina/kg de peso corporal, a dosagem de monensina iniciou em 0,2 mg/kg peso vivo, para adaptação dos animais, sendo os animais acompanhados a partir dos 30 dias até os 86 dias de idade. Os parâmetros avaliados semanalmente foram peso corporal, perímetro torácico, altura de cernelha, altura da garupa e comprimento corporal. Tais parâmetros não apresentaram variação em função da suplementação com monensina, o menor rendimento observado para o grupo suplementado pode ter sido decorrente da diminuição do consumo. A suplementação de monensina não apresentou efeito sobre desempenho ponderal de bezerras leiteiras em sistema de desaleitamento precoce.(AU)
Assuntos
Animais , Bovinos , Peso-Estatura , Dieta/veterinária , Suplementos Nutricionais/análise , Desmame , Ionóforos/análise , Pesos e Medidas Corporais/veterináriaRESUMO
A liquid chromatography-electrospray ionization tandem mass spectrometric (LC-ESI-MS/MS) method was developed and validated for the determination of residues of 6 polyether ionophores (lasalocid, maduramicin, monensin, narasin, salinomycin, semduramicin), 3 macrolides (erythromycin, tylosin, clarithromycin) and 1 lincosamide (lincomycin) in eggs. Nigericin was used as qualitative internal standard. Samples were deproteinizated/extracted with acetonitrile without pH adjustments. Aliquots of the extracts were evaporated and reconstituted for injection in the instrument operated in positive multiple reaction monitoring (MRM) mode. The stability of the antibiotics and the intensity of the formed ions were considered in order to select a suitable solvent for the reconstitution of the obtained dry extracts. No clean-up steps were required and matrix effects were controlled by sample dilution, selection of appropriate chromatographic conditions and reduced injection volume. Good within-laboratory reproducibility was obtained, with relative standard deviations (RSD(R)) from 4.0 (semduramicin at 5 µgkg(-1)) to 18.6 (erythromycin at 25 µgkg(-1)) for the ionophores and macrolides. Lincomycin showed the least precise results, with a maximum RSD(R) of 20.2% at 75 µgkg(-1)). Satisfactory decision limits (CCα) and detection capabilities (CCß) were also attained. Method limits of detection (LODs) from 0.04 (salinomycin) to 1.6 µgkg(-1) (lincomycin) were achieved. Method limits of quantification (LOQs) were from 0.14 to 5.3 µgkg(-1) for the same drugs, respectively. All the LOQs, except that obtained for maduramicin were remarkably below the lowest validation level. The proposed method is suitable for routine application in commercial egg samples.
Assuntos
Antibacterianos/análise , Ovos/análise , Ionóforos/análise , Lincosamidas/análise , Macrolídeos/análise , Espectrometria de Massas por Ionização por Electrospray/métodos , Animais , Calibragem , Galinhas , Cromatografia Líquida/métodos , Limite de Detecção , Reprodutibilidade dos TestesRESUMO
A liquid chromatography-tandem mass spectrometry (LC-MS/MS) method, which has recently been developed and validated, was used for the identification and quantification of polyether ionophore, macrolide and lincosamide residues in commercial eggs sold in the metropolitan area of Rio de Janeiro, Brazil. The method was applied to 100 samples and the results showed a high incidence of polyether ionophore residues (25%). Salinomycin was detected in 21% of samples, but only two non-compliant results (5.3 and 53 µg kg(-1)) were found if maximum limits (tolerances) established by European Union were adopted in Brazil and if a method decision limit (CCα) of 3.4 µg kg(-1) was considered. In 8% of analyzed samples, more than one studied coccidiostat was found. The lincosamide, lincomycin, and the macrolide, tylosin, were detected at trace levels in 4 and 1% of the samples, respectively. Lasalocid, clarithromycin and erythromycin were not found.
Assuntos
Ovos/análise , Éteres/análise , Ionóforos/análise , Lincosamidas/análise , Macrolídeos/análise , Resíduos de Praguicidas/análise , Animais , Antibacterianos/análise , Brasil , Galinhas , Cromatografia Líquida de Alta Pressão , Cromatografia Líquida/métodos , Coccidiostáticos/análise , União Europeia , Contaminação de Alimentos/análise , Humanos , Concentração Máxima Permitida , Espectrometria de Massas em Tandem/métodosRESUMO
Rações comerciais para frangos de corte geralmente contêm coccidiostáticos na sua fórmula. Um deles, a Monensina, é amplamente utilizado, e quando administrado em doses tóxicas pode levar a lesões nas musculaturas cardíaca e esquelética. A Roxarsona muitas vezes é adicionada à Monensina para potencializá-la, causando lesões em nervos periféricos de aves submetidas ao estresse. Os objetivos desse estudo foram conhecer os efeitos tóxicos da associação das drogas Monensina e Roxarsona em frangos de corte e desenvolver um modelo experimental que permita estudo das lesões macro e microscópicas das musculaturas esquelética e cardíaca e de nervos periféricos. Frangos de corte, pelo seu rápido crescimento e desenvolvimento, foram os animais de escolha. Para tanto, 360 frangos de corte foram divididos em seis grupos experimentais, com três repetições. Diferentes grupos foram tratados com doses crescentes de Monensina, associada ou não à Roxarsona, durante 35 dias. Após esse período as aves foram abatidas e foram colhidos fragmentos das musculaturas cardíaca e esquelética e também nervos periféricos para exame histopatológico. Músculos e nervos de animais tratados com ambas as drogas apresentaram lesões inflamatórias e degenerativas. A intoxicação por Monensina e Roxarsona mostrou ser eficaz como modelo experimental para lesões musculares e nervosas.
Anticoccidial agents are commonly used in the poultry industry. One of them, Monensin, is widely used, and in toxic levels can induce lesions in cardiac and skeletal muscle. Roxarsone can be used in addition to Monensin, increasing its efficacy. Peripheral neuropathy has been shown in chickens that were fed roxarsone supplemented diets and subjected to stress. This paper shows the effects of Monensin in association with Roxarsone in broiler chicken to develop an experimental model that concerns gross and microscopic study of lesions in peripheral nerves and cardiac and skeletal muscle. Broiler chickens are select due to fast growing and developing. 360 chickens distribute in six grups (three repetitions) were fed either with Monensin and/or Roxarsona for a period of thirty five days. The groups were Monensin Oppm/Roxarsone Oppm, Monensin Oppm/Roxarsone 80ppm, Monensin 150ppm/Roxarsone Oppm, Monensin 150ppm Roxarsone 80ppm, Monensin 300ppm/Roxarsone Oppm, Monensin 300ppm /Roxarsone 80ppm. Clinical signs were observed and recorded. After this period, birds were euthanatized and muscles and nerves were removed and submitted to microscopic examination. No gross lesions were observed. The histopathologic findings showed necrosis and myodegeneration in cardiac and skeletal muscle, and macrophages between the fibers. Microscopic lesions were observed in peripheral nerves and cardiac and skeletal muscles consisting in degeneration of and infiltration of inflammatory cells. The use of the association of these drugs in broilers showed to be adequate as a model for nerve and muscle lesions.