Defunctionalization Enabled by Intramolecular Radical Aromatic Substitution.

A chemoselective and regioselective copper-promoted defunctionalization procedure has been developed, enabling the rapid construction of various -polyheterocycles. Initial mechanistic studies reveal that a single-electron transfer radical process is potentially involved.

Contrasting demographic history and mutational load in three threatened whitebark pines (Pinus subsect. Gerardianae): implications for conservation.

Demographic history and mutational load are of paramount importance for the adaptation of the endangered species. However, the effects of population evolutionary history and genetic load on the adaptive potential in endangered conifers remain unclear. Here, using population transcriptome sequencing, whole chloroplast genomes and mitochondrial DNA markers, combined with niche analysis, we determined the demographic history and mutational load for three threatened whitebark pines having different endangered statuses, Pinus bungeana, P.

Structural basis of DNA recognition of the CosR regulator.

Unlabelled: is a foodborne pathogen commonly found in the intestinal tracts of animals. This pathogen is a leading cause of gastroenteritis in humans. Besides its highly infectious nature, is increasingly resistant to a number of clinically administrated antibiotics.

A Longitudinal Study on in Conventionally Reared Commercial Broiler Flocks in the United States: Prevalence and Genetic Diversity.

Poultry meat contaminated with , a major bacterial cause of foodborne gastroenteritis worldwide, is considered the primary source of human campylobacteriosis. Thus, reduction or elimination of in poultry production will have a significant impact on food safety and public health. Despite the significant progress made over the last decades, many puzzles remain about the epidemiology of on poultry farms, hampering the development of an effective control strategy.

Nonparametric bootstrap methods for interval estimation of the area under the ROC curve with correlated diagnostic test data: application to whole-virus ELISA testing in swine.

Developing and evaluating novel diagnostic assays are crucial components of contemporary diagnostic research. The receiver operating characteristic (ROC) curve and the area under the ROC curve (AUC) are frequently used to evaluate diagnostic assays' performance. The variation in AUC estimation can be quantified nonparametrically using resampling methods, such as bootstrapping, and then used to construct interval estimation for the AUC.

Fecal Microbiota Transplantation Reduces Colonization in Young Broiler Chickens Challenged by Oral Gavage but Not by Seeder Birds.

spp., particularly and , are major food safety concerns, transmitted to humans mainly via contaminated poultry meat. In a previous study, we found that some commercial broiler farms consistently produced -free flocks while others consistently reared -colonized flocks, and significant differences in the gut microbiota compositions between the two types of farm categories were revealed.

[A novel CRISPR/Cas9-hLacI donor adapting system for dsDNA-templated gene editing].

During the gene editing process mediated by CRISPR/Cas9, precise genome editing and gene knock-in can be achieved by the homologous recombination of double-stranded DNA (dsDNA) donor template. However, the low-efficiency of homologous recombination in eukaryotic cells hampers the development and application of this gene editing strategy. Here, we developed a novel CRISPR/Cas9-hLacI donor adapting system (DAS) to enhance the dsDNA-templated gene editing, taking the advantage of the specific binding of the LacI repressor protein and the LacO operator sequence derived for the lactose operon.

Deciphering the Association between Colonization and Microbiota Composition in the Intestine of Commercial Broilers.

is a major food safety concern and is transmitted mainly via poultry meat. We previously found that some commercial broiler farms consistently produced -negative flocks while others were consistently -positive for consecutive production cycles although the farms operated under similar management practices. We hypothesized that this difference in colonization might be associated with the gut microbiota composition.

Direct interaction of small non-coding RNAs CjNC140 and CjNC110 optimizes expression of key pathogenic phenotypes of .

Small non-coding RNAs (sRNAs) are important players in modulating gene expression in bacterial pathogens, but their functions are largely undetermined in , an important cause of foodborne gastroenteritis in humans. In this study, we elucidated the functions of sRNA CjNC140 and its interaction with CjNC110, a previously characterized sRNA involved in the regulation of several virulence phenotypes of . Inactivation of CjNC140 increased motility, autoagglutination, L-methionine concentration, autoinducer-2 production, hydrogen peroxide resistance, and early chicken colonization, indicating a primarily inhibitory role of CjNC140 for these phenotypes.

Cryo-Electron Microscopy Structures of a Campylobacter Multidrug Efflux Pump Reveal a Novel Mechanism of Drug Recognition and Resistance.

Campylobacter jejuni is a bacterium that is commonly present in the intestinal tracts of animals. It is also a major foodborne pathogen that causes gastroenteritis in humans. The most predominant and clinically important multidrug efflux system in C.

Growth kinetics and fitness of fluoroquinolone resistant and susceptible strains of cattle origin.

Human enterocolitis is frequently caused by the Gram-negative microaerobic bacterium . Macrolides (e.g.

Recent advances in the chemistry of aryltriazene.

Triazene is one of the most versatile building blocks in organic synthesis. Generally, it is viewed as a safe equivalent of diazonium salt, thus immediately finding numerous applications in preparative chemistry and medicinal chemistry. Besides, it can be used as a removable directing group in C-H functionalization or play a smart role as a precursor for aryl cation/radical generation.

Influence of Single Dose Enrofloxacin Injection on Development of Fluoroquinolone Resistance in in Calves.

Fluoroquinolone (FQ) resistance in a major foodborne bacterial pathogen, , derived from cattle has recently become prevalent and poses a significant public health concern. However, the underlying factors for this increase are not entirely clear. To evaluate the effect of enrofloxacin treatment on FQ-resistance development in , 35 commercial calves were equally divided into five groups (Groups 1-5) and were orally inoculated with FQ-susceptible (FQ-S) .

Redox-Neutral Generation of Iminyl Radicals by -Heterocyclic Carbene Catalysis: Rapid Access to Phenanthridines from Vinyl Azides.

An -heterocyclic carbene-catalyzed oxidant-, metal- and light-free iminyl radical generation pathway stemming from the reaction of vinyl azide and α-bromo ester is uncovered. This newly developed methodology is successfully applied to the redox-neutral construction of a number of diversified phenanthridine derivatives with nice functional group compatibility. Insights from the mechanism study reveal that this NHC-catalyzed transformation potentially proceeds through an alkyl radical addition-initiated HAS process, with the iminyl radical as an active intermediate.

PS-216 Spores Supplemented in Broiler Chicken Drinking Water Reduce Colonization and Increases Weight Gain.

is the leading cause of bacterial gastroenteritis, or campylobacteriosis, in humans worldwide, and poultry serves as a major source of infection. To reduce the risk associated with transmission via poultry meat, effective interventions during poultry production are needed, and the use of probiotics is a promising approach. In this study, 15 strains were initially screened for their anti- activities.

Construction of -Polyheterocycles by -Heterocyclic Carbene Catalysis via a Regioselective Intramolecular Radical Addition/Cyclization Cascade.

-Polyheterocycles are rapidly accessed by -heterocyclic carbene (NHC) catalysis through regioselective sequential radical addition/cyclization in the absence of any metals or oxidants. The transformation occurs under mild conditions and enjoys a wide substrate scope with excellent functional group compatibility. Furthermore, a gram-scale synthesis is also conducted.

Nrf2 Activation Protects Against Organic Dust and Hydrogen Sulfide Exposure Induced Epithelial Barrier Loss and Invasion.

Agriculture workers report various respiratory symptoms owing to occupational exposure to organic dust (OD) and various gases. Previously, we demonstrated that pre-exposure to hydrogen sulfide (HS) alters the host response to OD and induces oxidative stress. Nrf2 is a master-regulator of host antioxidant response and exposures to toxicants is known to reduce Nrf2 activity.

Effect of Danofloxacin Treatment on the Development of Fluoroquinolone Resistance in in Calves.

is a leading cause of foodborne gastroenteritis. Recent studies have indicated a rise in fluoroquinolone-resistant (FQ-R) in cattle, where FQ is used to control bovine respiratory disease (BRD). To assess the effect of danofloxacin treatment on the development of FQ-resistance in , 30 commercial calves were divided into Group 1, Group 2, and Group 3 ( = 10), and were all inoculated orally with FQ-susceptible (FQ-S) ; seven days later, Group 3 was challenged with transtracheal , and one week later, Group 2 and Group 3 were injected subcutaneously with danofloxacin.

Dual C-H activation: Rh(iii)-catalyzed cascade π-extended annulation of 2-arylindole with benzoquinone.

A rhodium-catalyzed, N-H free indole directed cyclization reaction of benzoquinone a dual C-H activation strategy is disclosed. This protocol has a good functional group tolerance and affords useful indole-fused heterocylces. Besides, it is insensitive to moisture, commercially available solvent can be directly used and work quite well for this transformation.

Comparisons of plasma and fecal pharmacokinetics of danofloxacin and enrofloxacin in healthy and Mannheimia haemolytica infected calves.

Danofloxacin and enrofloxacin are fluoroquinolones (FQs) used to treat and control bovine respiratory disease (BRD) complex. While low toxicity, high bactericidal activity, and availability in single and multiple dosing regimens make them preferable, the increasing incidence of FQ-resistance in foodborne pathogens and effects on gut microbiota necessitate evaluating their pharmacokinetics (PKs). The objective of this study was to determine the exposure level of gut microbiota to subcutaneously administered FQs and compare their PKs between plasma and feces in healthy and Mannheimia haemolytica infected calves.

Enrofloxacin Alters Fecal Microbiota and Resistome Irrespective of Its Dose in Calves.

Enrofloxacin is a fluoroquinolone drug used to prevent and control bovine respiratory disease (BRD) complex in multiple or single doses, ranging from 7.5 to 12.5 mg/kg body weight.

Danofloxacin Treatment Alters the Diversity and Resistome Profile of Gut Microbiota in Calves.

Fluoroquinolones, such as danofloxacin, are used to control bovine respiratory disease complex in beef cattle; however, little is known about their effects on gut microbiota and resistome. The objectives were to evaluate the effect of subcutaneously administered danofloxacin on gut microbiota and resistome, and the composition of in calves. Twenty calves were injected with a single dose of danofloxacin, and ten calves were kept as a control.

Campylobacter jejuni genotypes are associated with post-infection irritable bowel syndrome in humans.

Campylobacter enterocolitis may lead to post-infection irritable bowel syndrome (PI-IBS) and while some C. jejuni strains are more likely than others to cause human disease, genomic and virulence characteristics promoting PI-IBS development remain uncharacterized. We combined pangenome-wide association studies and phenotypic assays to compare C.