Comparative genomic analysis of plasmids encoding metallo-ß-lactamase NDM-5 in Enterobacterales Korean isolates from companion dogs.

Carbapenems are broad-spectrum antibiotics widely used for the treatment of human infections caused by multidrug-resistant (MDR) Gram-negative bacteria. However, emerging carbapenemase-producing Enterobacterales (CPE) are rising as a public threat to human and animal health. We screened clinical bacterial isolates from 241 dogs and 18 cats hospitalized at Veterinary Medical Teaching Hospital, Seoul National University, from 2018 to 2020 for carbapenemase production. In our study, 5 strains of metallo-ß-lactamase NDM-5-producing Escherichia coli and Klebsiella pneumoniae were isolated from 4 different dogs. Multilocus sequence typing (MLST) results showed that all E. coli strains were ST410 and all K. pneumoniae strains were ST378. Whole genome analysis of the plasmid showed that blaNDM-5 is carried on a IncX3 plasmid, showing a high concordance rate with plasmids detected worldwide in human and animal isolates. The blaNDM gene was associated with the bleMBL gene and the ISAba125 element, truncated with the IS5 element. The results of this study show that CPE has already become as a threat to both animals and humans in our society, posing the necessity to solve it in terms of "One Health". Therefore, preventive strategies should be developed to prevent the spread of CPE in animal and human societies.

MicroRNA profiling in bovine serum according to the stage of Mycobacterium avium subsp. paratuberculosis infection.

Mycobacterium avium subsp. paratuberculosis (MAP) is the causative agent of Johne's disease (JD), and it causes diarrhea and weakness in cattle. During a long subclinical stage, infected animals without clinical signs shed pathogens through feces. For this reason, the diagnosis of JD during the subclinical stage is very important. Circulating miRNAs are attracting attention as useful biomarkers in various veterinary diseases because of their expression changes depending on the state of the disease. Based on current knowledge, circulating miRNAs extracted from bovine serum were used to develop a diagnostic tool for JD. In this study, the animals were divided into 4 groups according to fecal shedding, the presence of antibodies, and clinical signs. Gene expression was analyzed by performing miRNA sequencing for each group, and it was identified that the miRNA expression changed more as the MAP infection progressed. The eight miRNAs that were differentially expressed in all infected groups were selected as biomarker candidates based on their significant differences compared to the control group. These biomarker candidates were validated by qRT-PCR. Considering the sequencing data, two upregulated miRNAs and two downregulated miRNAs showed the same trend in the validation results. Network analysis was also conducted and the results showed that mRNAs (IL-10, TGF-ß1) associated with regulatory T cells were predicted to be activated in the subclinical stage. Taken together, our data suggest that two miRNAs (bta-miR-374b, bta-miR-2887) may play major roles in the immune response to MAP infection during the subclinical stage.

Genome-wide association study and genomic predictions for exterior traits in Yorkshire pigs1.

The objectives of this study were to identify informative genomic regions that affect the exterior traits of purebred Korean Yorkshire pigs and to investigate and compare the accuracy of genomic prediction for response variables. Phenotypic data on body height (BH), body length (BL), and total teat number (TTN) from 2,432 Yorkshire pigs were used to obtain breeding values including as response variable the estimated breeding value (EBV) and 2 types of deregressed EBVs-one including the parent average (DEBVincPA) and the other excluding it (DEBVexcPA). A final genotype panel comprising 46,199 SNP markers was retained for analysis after quality control for common SNPs. The BayesB and BayesC methods-with various π and weighted response variables (EBV, DEBVincPA, or DEBVexcPA)-were used to estimate SNP effects, through the genome-wide association study. The significance of genomic windows (1 Mb) was obtained at 1.0% additive genetic variance and was subsequently used to identify informative genomic regions. Furthermore, SNPs with a high model frequency (≥0.90) were considered informative. The accuracy of genomic prediction was estimated using a 5-fold cross-validation with the K-means clustering method. Genomic accuracy was measured as the genomic correlation between the molecular breeding value and the individual weighted response variables (EBV, DEBVincPA, or DEBVexcPA). The number of identified informative windows (1 Mb) for BH, BL, and TTN was 4, 3, and 4, respectively. The number of significant SNPs for BH, BL, and TTN was 6, 4, and 5, respectively. Diversity π did not influence the accuracy of genomic prediction. The BayesB method showed slightly higher genomic accuracy for exterior traits than BayesC method in this study. In addition, the genomic accuracy using DEBVincPA as response variable was higher than that using other response variables. Therefore, the genomic accuracy using BayesB (π = 0.90) with DEBVinPA as a response variable was the most effective in this study. The genomic accuracy values for BH, BL, and TTN were calculated to be 0.52, 0.60, and 0.51, respectively.

Molecular Characterization of Fluoroquinolone Resistance Mechanisms of Campylobacter Isolates from Duck Meats.

The purpose of this study was to identify the molecular basis of quinolone resistance of Campylobacter isolates recovered from duck meats. Sixty-one isolates from duck meat samples were studied using sequence analysis of the gyrA gene, and PCR assays were used to identify the presence of the CmeABC efflux pump and its restored sensitivity in the presence of efflux-pump inhibitors. High-level resistance to nalidixic acid and ciprofloxacin was attributed to amino acid substitutions Thr-86-Ile in some isolates. The PCR assay confirmed the presence of the cmeB gene in 29 (47.5%) of the 61 Campylobacter isolates. Phenylalanine arginine ß-naphthylamide reduced the MICs of ciprofloxacin and nalidixic acid in 16 (55.2%) and 26 (89.7%) isolates, respectively. The Thr-86-Ile substitution in the gyrA was the primary contributor to the high-level quinolone resistance in Campylobacter isolates from duck meats.

Novel (bisarylmethoxy)butylpiperidine analogues as neurotransmitter transporter inhibitors with activity at dopamine receptor sites.

A series of (bisarylmethoxy)butylpiperidine derivatives was prepared and evaluated in vitro and in vivo to determine the structural requirements necessary for dual activity at the DAT and DA/5-HT receptor sites. These hybrid ligands, constructed by combining pharmacophores specific for the DAT and DA/5-HT receptors, could be useful drugs for treating cocaine addiction by assisting cocaine addicts in maintaining abstinence. The series was evaluated in vitro for DAT and DA/5-HT receptor activity and then selected compounds were tested in vivo for their effects on cocaine-induced hyperlocomotor activity (LMA). The majority of the new compounds demonstrated high to moderate affinity (4-191 nM) for the DAT with 4-hydroxy-4-phenylpiperidine analogues 14 and 15 possessing the greatest affinity. Compounds 15 and 22 exhibited the highest ratio of reuptake inhibition-to-binding (discrimination ratio, DR), 111 and 323, respectively. These derivatives had modest affinity and antagonistic activity for dopamine D(2)/D(3) receptors. Compounds 9 and 15 (DR=0.9 and 111, respectively) stimulated locomotor activity, whereas the other compounds suppressed this response. All compounds tested except for 17 and 21 attenuated cocaine-induced hyperlocomotion.