Selection of Multidrug-Resistant Enterobacteria in Weaned Pigs and Its Association With In-feed Subtherapeutic Combination of Colistin and Tylosin.

In-feed antibiotics are administered to piglets to improve performance and production efficiency. However, the use of growth promoters in the swine industry can select for multidrug-resistant (MDR) bacteria. Here, we evaluate the resistance profile of enterobacteria isolated from fecal samples of weaned pigs (21-35 days) fed or not with antibiotics (colistin and tylosin) and investigated the piglets gut microbiota in both groups. Six hundred and eighteen bacterial cultures were isolated from the control group (CON; n = 384) and antibiotic-fed pigs (ATB; n = 234). All isolates were tested for resistance to 12 antibiotics belonging to six distinct antibiotic classes. Isolates were highly resistant to ampicillin (90%; n = 553), amoxicillin (85%; n = 525), and tetracycline (81%; n = 498). A significant increase (P < 0.05) in resistance to cephalexin, kanamycin, doxycycline, and colistin was observed for bacteria from the ATB group. Piglets allocated in the ATB and CON groups shared similar intestinal microbiota, as revealed by alpha- and beta-diversity analyses. Our findings demonstrate that colistin and tylosin contribute to select MDR enterobacteria in weaned piglets. The high frequency of antibiotic resistance among isolates from the CON group suggests that environmental sources (e.g., fecal contents, aerosols, soil, water, food) also represent a potential reservoir of multidrug-resistant enterobacteria in pig production systems.

Data standardization of plant-pollinator interactions.

BACKGROUND: Animal pollination is an important ecosystem function and service, ensuring both the integrity of natural systems and human well-being. Although many knowledge shortfalls remain, some high-quality data sets on biological interactions are now available. The development and adoption of standards for biodiversity data and metadata has promoted great advances in biological data sharing and aggregation, supporting large-scale studies and science-based public policies. However, these standards are currently not suitable to fully support interaction data sharing. RESULTS: Here we present a vocabulary of terms and a data model for sharing plant-pollinator interactions data based on the Darwin Core standard. The vocabulary introduces 48 new terms targeting several aspects of plant-pollinator interactions and can be used to capture information from different approaches and scales. Additionally, we provide solutions for data serialization using RDF, XML, and DwC-Archives and recommendations of existing controlled vocabularies for some of the terms. Our contribution supports open access to standardized data on plant-pollinator interactions. CONCLUSIONS: The adoption of the vocabulary would facilitate data sharing to support studies ranging from the spatial and temporal distribution of interactions to the taxonomic, phenological, functional, and phylogenetic aspects of plant-pollinator interactions. We expect to fill data and knowledge gaps, thus further enabling scientific research on the ecology and evolution of plant-pollinator communities, biodiversity conservation, ecosystem services, and the development of public policies. The proposed data model is flexible and can be adapted for sharing other types of interactions data by developing discipline-specific vocabularies of terms.

Retrospective whole-genome comparison of Salmonella enterica serovar Enteritidis from foodborne outbreaks in Southern Brazil.

Salmonella enterica serovar Enteritidis is frequently isolated from animal-source foods associated with human salmonellosis outbreaks. This serovar was spread to animal (mainly poultry) farms worldwide in the 1980s, and it is still detected in foods produced in many countries, including Brazil. The present study reports a retrospective genome-wide comparison of S. Enteritidis from foodborne outbreaks in Southern Brazil in the last two decades. Fifty-two S. Enteritidis isolates were obtained from foodborne outbreaks occurring in different cities of the Brazilian southernmost State, Rio Grande do Sul (RS), from 2003 to 2015. Whole-genome sequences (WGS) from these isolates were obtained and comparatively analyzed with 65 additional genomes from NCBI. Phylogenetic and Bayesian analyses were performed to study temporal evolution. Genes related to antibiotic resistance and virulence were also evaluated. The results demonstrated that all S. Enteritidis isolates from Southern Brazil clustered in the global epidemic clade disseminated worldwide originally in the 1980s. Temporal analysis demonstrated that all Brazilian isolates had a tMRCA (time to most recent common ancestor) in 1986 with an effective population size (Ne) increase soon after until 1992, then becoming constant up to now. In Southern Brazil, there was a significant decrease in the spreading of S. Enteritidis in the last decade. In addition, three antibiotic resistance genes were detected in all isolates: aac(6')-Iaa, mdfA, and tet(34). These results demonstrate the high frequency of one only specific S. Enteritidis lineage (global epidemic clade) in foodborne outbreaks from Southern Brazil in the last two decades.

Leigh syndrome in a patient with a novel C12orf65 pathogenic variant: case report and literature review.

Leigh syndrome is an early onset progressive disorder caused by defects in mitochondrial oxidative phosphorylation. Pathogenic variants in nuclear and mitochondrial genes are associated with the syndrome. Homozygous pathogenic variants in the C12orf65 gene impair the mitochondrial oxidative phosphorylation system. We describe a new case of Leigh syndrome caused by a novel pathogenic variant of the C12orf65 gene resulting in the lack of the Gly-Gly-Gln (GGQ) domain in the predicted protein, and review clinical and molecular data from previously reported patients. Our study supports that the phenotype caused by C12orf65 gene variants is heterogeneous and varies from spastic paraparesis to Leigh syndrome. Loss-of-function variants are more likely to cause the disease, and variants affecting the GGQ domain tend to be associated with more severe phenotypes, reinforcing a possible genotype-phenotype correlation.

Acute effects of moderate-intensity and high-intensity exercise on hemodynamic and autonomic reactivity to the cold pressor test in young adults with excess body weight.

OBJECTIVE: To investigate the effects of a single session of moderate-intensity and high-intensity interval exercise in cardiovascular reactivity to the cold pressor test in young adults with excess body weight. METHODS: Twenty-two subjects with excess body weight (23 ± 2 years; 30.0 ± 3.4 kg·m) performed three sessions: (1) moderate-intensity exercise (30-minute cycling at 50%-60% of heart rate reserve); (2) high-intensity exercise (four series of 3-minute cycling at 80%-90% of heart rate reserve, interspersed by 2-minute recovery) and (3) control (i.e. 30-minute seated). Before and 30 minutes after the interventions, subjects undertook assessments of SBP/DBP and heart rate in response to the cold pressor test (1-minute rest + 1-minute hand immersed in 4°C water). Reactivity was calculated as the absolute response of SBP, DBP and heart rate to cold pressor test and compared between interventions using a two-way analysis of variance (P < 0.05). RESULTS: Neither moderate-intensity exercise or high-intensity interval exercise attenuated SBP/DBP reactivity to cold pressor test compared with control. On the other hand, heart rate reactivity was reduced after moderate-intensity exercise compared with control (1.36 ± 8.35 bpm vs. 5.18 ± 9.45 bpm). Furthermore, moderate-intensity exercise reduced absolute levels of SBP/DBP from pre- to post-intervention. CONCLUSION: A single session of moderate-intensity exercise or high-intensity interval exercise did not reduce the SBP/DBP reactivity to cold pressor test. However, absolute levels of SBP/DBP were lower after moderate-intensity exercise, indicating a hypotensive effect promoted by a single session of moderate-intensity exercise in young adults with excess body weight.

Nutritive value and fermentation quality of palisadegrass and stylo mixed silages.

The nutritive value and fermentation quality of palisadegrass (Brachiaria brizantha cv. Xaraes) and stylo (Stylosanthes capitata × S. macrocephala cv. Campo Grande) mixed silages were evaluated. The experiment was analyzed in a factorial scheme (5 × 2) in a completely randomized design using increasing levels of stylo (0, 25, 50, 75 and 100% on a fresh matter basis) on palisadegrass silages, with and without microbial inoculants (MI). With the increased ratio of stylo in mixed silages, dry matter (DM), crude protein (CP), acid detergent fiber (ADF), and lignin content increased in silages. The presence of MI promoted lower DM content, and higher neutral detergent fiber corrected for ash and protein, ADF and lignin content. The acid detergent insoluble nitrogen content and the lactic acid bacteria populations were not affected by treatments. The in vitroDM digestibility was affected by the interaction of levels of the stylo and MI. The pH, NH3 -N/total nitrogen and butyric acid concentrations decreased with increasing levels of stylo. Better nutritive value and quality of fermentation was found in the silage containing higher proportions of this stylo mixed with palisadegrass. The microbial inoculant evaluated did not alter the nutritive value or quality of the fermentation of the silages in this experiment.

Worldwide Phylogenetic Group Patterns of Escherichia coli from Commensal Human and Wastewater Treatment Plant Isolates.

Escherichia coli is an important microorganism in the gastrointestinal tract of warm-blooded animals. Commensal populations of E. coli consist of stable genetic isolates, which means that each individual has only one phylogenetic group (phylogroup). We evaluated the frequency of human commensal E. coli phylogroups from 116 people and observed that the majority of isolates belonged to group A. We also evaluated the frequency of phylogroups in wastewater samples and found a strong positive correlation between the phylogroup distribution in wastewater and human hosts. In order to find out if some factors, such as geographical location, and climate could influence the worldwide phylogroup distribution, we performed a meta-analysis of 39 different studies and 24 countries, including different climates, living areas, and feeding habits. Unexpectedly, our results showed no substructuring patterns of phylogroups; indicating there was no correlation between phylogroup distribution and geographic location, climate, living area, feeding habits, or date of collection.

Native and Non-Native Supergeneralist Bee Species Have Different Effects on Plant-Bee Networks.

Supergeneralists, defined as species that interact with multiple groups of species in ecological networks, can act as important connectors of otherwise disconnected species subsets. In Brazil, there are two supergeneralist bees: the honeybee Apis mellifera, a non-native species, and Trigona spinipes, a native stingless bee. We compared the role of both species and the effect of geographic and local factors on networks by addressing three questions: 1) Do both species have similar abundance and interaction patterns (degree and strength) in plant-bee networks? 2) Are both species equally influential to the network structure (nestedness, connectance, and plant and bee niche overlap)? 3) How are these species affected by geographic (altitude, temperature, precipitation) and local (natural vs. disturbed habitat) factors? We analyzed 21 plant-bee weighted interaction networks, encompassing most of the main biomes in Brazil. We found no significant difference between both species in abundance, in the number of plant species with which each bee species interacts (degree), and in the sum of their dependencies (strength). Structural equation models revealed the effect of A. mellifera and T. spinipes, respectively, on the interaction network pattern (nestedness) and in the similarity in bee's interactive partners (bee niche overlap). It is most likely that the recent invasion of A. mellifera resulted in its rapid settlement inside the core of species that retain the largest number of interactions, resulting in a strong influence on nestedness. However, the long-term interaction between native T. spinipes and other bees most likely has a more direct effect on their interactive behavior. Moreover, temperature negatively affected A. mellifera bees, whereas disturbed habitats positively affected T. spinipes. Conversely, precipitation showed no effect. Being positively (T. spinipes) or indifferently (A. mellifera) affected by disturbed habitats makes these species prone to pollinate plant species in these areas, which are potentially poor in pollinators.

Layer-by-layer films based on carbon nanotubes and polyaniline for detecting 2-chlorophenol.

Electrochemical sensors made with layer-by-layer (LbL) films of functionalized multi-walled carbon nanotubes (MWCNTs-COO-) and polyaniline (PAni) deposited onto ITO substrates were used to detect 2-chlorophenol. Concentrations down to ppm level could be detected with square wave voltammetry (SWV), owing to synergistic effects between PAni and nanotubes, whose molecular-level interactions in the LbL films were inferred using FTIR and Raman spectroscopy. Significantly, the Raman spectra of MWCNTs-COO-/PAni LbL films indicated that the conducting properties of PAni were preserved upon adsorption on the ITO substrates, with homogeneous nanocomposites being formed according to Scanning Electron Microscopy (SEM) images.