In vivo selection of resistant E. coli after ingestion of milk with added drug residues.

Antimicrobial resistance represents a major global threat to modern medicine. In vitro studies have shown that very low concentrations of drugs, as frequently identified in the environment, and in foods and water for human and animal consumption, can select for resistant bacteria. However, limited information is currently available on the in vivo impact of ingested drug residues. The objective of our study was to evaluate the effect of feeding preweaned calves milk containing antimicrobial drug residues (below the minimum inhibitory concentration), similar to concentrations detected in milk commonly fed to dairy calves, on selection of resistant fecal E. coli in calves from birth to weaning. At birth, thirty calves were randomly assigned to a controlled feeding trial where: 15 calves were fed raw milk with no drug residues (NR), and 15 calves were fed raw milk with drug residues (DR) by adding ceftiofur, penicillin, ampicillin, and oxytetracycline at final concentrations in the milk of 0.1, 0.005, 0.01, and 0.3 µg/ml, respectively. Fecal samples were rectally collected from each calf once a week starting at birth prior to the first feeding in the trial (pre-treatment) until 6 weeks of age. A significantly greater proportion of E. coli resistant to ampicillin, cefoxitin, ceftiofur, streptomycin and tetracycline was observed in DR calves when compared to NR calves. Additionally, isolates from DR calves had a significant decrease in susceptibility to ceftriaxone and ceftiofur when compared to isolates from NR calves. A greater proportion of E. coli isolates from calves in the DR group were resistant to 3 or more antimicrobial drugs when compared to calves in the ND group. These findings highlight the role that low concentrations of antimicrobial drugs have on the evolution and selection of resistance to multiple antimicrobial drugs in vivo

Ingestion of Milk Containing Very Low Concentration of Antimicrobials: Longitudinal Effect on Fecal Microbiota Composition in Preweaned Calves.

Although antimicrobial drugs are central to combat disease in modern medicine, the use of these drugs can have undesired consequences for human and animal health. One consequence is the post-therapy excretion of pharmacological agents, such as the elimination of drug residues at very low concentrations in the milk of lactating mammals. Limited information is currently available on the impact from the exposure of the gut microbiota to drug residues using in vivo natural models. The objective of our study was to address this knowledge gap and evaluate the effect on the fecal microbiota composition from feeding preweaned dairy calves raw milk with residual concentrations of ampicillin, ceftiofur, penicillin, and oxytetracycline from birth to weaning. At birth, thirty calves were randomly assigned to a controlled feeding trial where: 15 calves were fed raw milk with no drug residues (NR), and 15 calves were fed raw milk with drug residues (DR) by adding ceftiofur, penicillin, ampicillin, and oxytetracycline at final concentrations in the milk of 0.1, 0.005, 0.01, and 0.3 μg/ml, respectively. Fecal samples were rectally collected from each calf once a week starting at birth, prior to the first feeding in the trial (pre-treatment), until 6 weeks of age. Sequencing of the microbial 16S rRNA genes was conducted using the Illumina MiSeq, which provides a high resolution of the microbiota down to the genus level. Discriminant analysis showed that, except for pre-treatment samples, calves fed milk with drug residues and calves fed milk without drug residues easily discriminated at the genus level on their weekly microbial profile. However, analysis comparing the abundance of taxon between NR and DR showed significant differences only at the genus levels, and not at the phylum, class, order or family levels. These results suggest that although drug residues can result in clear discriminate gut microbial communities, they do not result in disruption of taxonomic levels above the genus

In vivo selection of resistant E. coli after ingestion of milk with added drug residues.

Antimicrobial resistance represents a major global threat to modern medicine. In vitro studies have shown that very low concentrations of drugs, as frequently identified in the environment, and in foods and water for human and animal consumption, can select for resistant bacteria. However, limited information is currently available on the in vivo impact of ingested drug residues. The objective of our study was to evaluate the effect of feeding preweaned calves milk containing antimicrobial drug residues (below the minimum inhibitory concentration), similar to concentrations detected in milk commonly fed to dairy calves, on selection of resistant fecal E. coli in calves from birth to weaning. At birth, thirty calves were randomly assigned to a controlled feeding trial where: 15 calves were fed raw milk with no drug residues (NR), and 15 calves were fed raw milk with drug residues (DR) by adding ceftiofur, penicillin, ampicillin, and oxytetracycline at final concentrations in the milk of 0.1, 0.005, 0.01, and 0.3 µg/ml, respectively. Fecal samples were rectally collected from each calf once a week starting at birth prior to the first feeding in the trial (pre-treatment) until 6 weeks of age. A significantly greater proportion of E. coli resistant to ampicillin, cefoxitin, ceftiofur, streptomycin and tetracycline was observed in DR calves when compared to NR calves. Additionally, isolates from DR calves had a significant decrease in susceptibility to ceftriaxone and ceftiofur when compared to isolates from NR calves. A greater proportion of E. coli isolates from calves in the DR group were resistant to 3 or more antimicrobial drugs when compared to calves in the ND group. These findings highlight the role that low concentrations of antimicrobial drugs have on the evolution and selection of resistance to multiple antimicrobial drugs in vivo

The educational space of the circus and the right to itinerant education for circus artists: from the legal system to the reality.

Esta pesquisa discute um tema relevante para as ciências humanas: “O Espaço Educativo do Circo e o Direito à Educação Itinerante para Artistas Circenses: do Ordenamento Jurídico à Realidade”. Concentra-se em investigar as contribuições e problemáticas existentes acerca do tema analisado, buscando compreender a subjetividade de aspectos inerentes à atividade circense no país e ao acesso a políticas públicas e educação de qualidade das crianças circenses. Tem como abordagem metodológica a técnica indutiva, que utiliza de pesquisa monográfica para realização e efetuação das análises estudadas, bem como procedimentos estatísticos para a análise e decomposição dos dados. Constatou-se que o acesso das crianças às unidades de ensino é dotado de uma série de agravantes e lacunas e que o sistema de políticas públicas não contempla as necessidades de maneira real, reduzindo-se apenas a uma série de leis que não possuem efetividade prática.This research discusses about a relevant topic of human sciences: “The Educational Space of the Circus and the Right to the Itinerant Education for Circus‟s Artists: from the Legal Order to the Reality”. It focuses on investigate the contributions and problematics about the analyzed subject, searching understand the subjectivity of circus‟s activity inherent aspects and the circus children‟s public policies and quality education access. The methodological approach is the inductive technique that uses the monographic research to researched analyzes realization and effectuation, as well as the statistical procedures for data analysis and decomposition. It shows that children‟s access to education units have a lot of aggravates and gaps and the public police system doesn‟t really contemplate the needs, reducing to just a lot of laws that haven‟t practical effectiveness

Proportion of <i>E. coli</i> resistant to 3 or more antimicrobial drugs by milk feeding treatment overtime in weeks.

<p>Error bars represent 95% confidence interval of the least square mean. 1. Calves fed raw milk without the addition of sub-MICs of antimicrobial drugs. 2. Calves fed raw milk with the addition of sub-MICs of ceftiofur, penicillin, ampicillin, and oxytetracycline from birth to 6 weeks of age. *Sampling weeks where the the proportion of resistant isolates resistance to 3 or more antimicrobial drugs was significantly different between NR and DR.</p

Ranking of the most common antimicrobial resistant phenotypes (ARP) among 540 <i>E. coli</i> from fecal samples collected from week 1 to week 6.

<p>AMP, Ampicillin; FOX, cefoxitin; TIO, ceftiofur; CHL, chloramphenicol; GEN, gentamicin; NEO, neomycin; STR, streptomycin; COT, trimethoprim sulfamethoxazole; TET, tetracycline.</p><p>1. Ranking or percent of ARP for isolates from calves fed raw milk with the addition of sub-MICs of ceftiofur, penicillin, ampicillin, and oxytetracycline from birth to 6 weeks of age.</p><p>2. Ranking or percent of DRP for isolates from calves fed raw milk without addition of sub-MICs of antimicrobial drugs.</p><p>Ranking of the most common antimicrobial resistant phenotypes (ARP) among 540 <i>E. coli</i> from fecal samples collected from week 1 to week 6.</p

Proportion of resistant <i>E. coli</i> by milk feeding treatment at the calf level over time in weeks.

<p>Error bars represent 95% confidence interval of the least square mean. 1. Calves fed raw milk without the addition of sub-MICs of antimicrobial drugs. 2. Calves fed raw milk with the addition of sub-MICs of ceftiofur, penicillin, ampicillin, and oxytetracycline from birth to 6 weeks of age. *Sampling weeks where the proportion of resistance was significantly different between NR and DR.</p

Proportion of <i>E. coli</i> nonsusceptible to ceftiofur and ceftriaxone by milk feeding treatment at the calf level over time in weeks.

<p>Error bars represent 95% confidence interval of the least square mean. 1. Calves fed raw milk without the addition of sub-MICs of antimicrobial drugs. 2. Calves fed raw milk with the addition of sub-MICs of ceftiofur, penicillin, ampicillin, and oxytetracycline from birth to 6 weeks of age. *Sampling weeks where the proportion of resistance was significantly different between NR and DR.</p

SIR distribution of <i>E. coli</i> and mean disk diffusion zone diameter (ZD) by milk feeding treatment group.

<p>1. Percent distribution by antimicrobial of <i>E. coli</i> from calves fed raw milk without the addition of sub-MICs of antimicrobial drugs.</p><p>2. Percent distribution by antimicrobial of <i>E. coli</i> from calves fed raw milk with the addition of sub-MICs of ceftiofur, penicillin, ampicillin, and oxytetracycline from birth to 6 weeks of age.</p><p>* Trimethoprim-sulfamethoxazole.</p><p>SIR distribution of <i>E. coli</i> and mean disk diffusion zone diameter (ZD) by milk feeding treatment group.</p