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Wang D.,China Agricultural University | Wang D.,Xinjiang Academy of Animal Science | Wang Z.,Xinjiang Academy of Animal Science | Yan Z.,Lanzhou Institute of Husbandry and Pharmaceutical science of CAAS | And 5 more authors.
Infection, Genetics and Evolution

The aim of present study was to detect new trends of methicillin-resistant Staphylococcus aureus (MRSA) and methicillin-sensitive Staphylococcus aureus (MSSA) towards antibiotic susceptibility, resistance genes and molecular typing by methods of disc diffusion, multiplex PCR assay and multilocus sequence typing (MLST). A total of 219 S. aureus strains were isolated from bovine mastitis cases from six provinces of China, including 34 MRSA strains. The results revealed that more than 70% isolated strains showed resistance to various antibiotics, and multiple-drugs resistance to more than five categories of antibiotics was found more common. The ermC was the most prevalent resistance gene, followed by other genes; however, ermA was the least frequently detected gene. Twenty-eight mecA-negative MRSA and six mecA-positive MRSA strains were detected, and in which three strains were ST97-MRSA-IV, others were ST965-MRSA-IV, ST6-MRSA-IV and ST9-MRSA-SCC. mec-NT. The mecA-negative MRSA strains were found resistant to most of the antibiotics, and harbored aac(6')/. aph(2''), aph(3')-III and tetM genes higher than MSSA strains. The resistance to most of the antibiotics was significantly higher in MRSA than in MSSA strains. The MLST profiles showed that these strains mainly belonged to CC5, CC398, CC121 and CC50 lineage, especially within ST97 and ST398, while some novel sequence types (ST2154, ST2165 and ST2166) were identified and deposited in the MLST database. This indicates that the resistance of S. aureus is becoming more complicated by changes in multi-drug resistance mechanism and appearance of mecA-negative MRSA isolates, and importantly, MRSA-IV strains in different MLST types are emerging. © 2015 Elsevier B.V. Source

Liu Z.-K.,Hunan Agricultural University | Liu Z.-K.,National and Provincial Union Engineering Research Center for the Veterinary Herbal medicine resources and initiative | Li J.-Y.,Lanzhou Institute of Husbandry and Pharmaceutical science of CAAS | Pan H.,Lanzhou Institute of Animal science and Pharmaceutics of CAAS
Preventive Veterinary Medicine

Little information is available about the seroprevalence of Toxoplasma gondii and Neospora caninum infections in sheep and goats in China. In the present investigation, the seroprevalence of T. gondii and N. caninum infections in sheep and goats were investigated in Qinghai province, China between January 2012 and June 2013. A total of 1250 serum samples (600 sheep and 650 goats) collected from 8 administrative regions of Qinghai province, China were evaluated by enzyme-linked immunosorbent assay for the detection of specific antibodies, and sera positive were subsequently confirmed with indirect fluorescent antibody test. Specific IgG against T. gondii were detected in 21.33% (95% confidence interval [CI]: 18.06-24.61%) (128/600) and 29.54% (95% CI: 26.03-33.05%) (192/650) and against N. caninum in 10.33% (95% CI: 7.9-12.77%) (62/600) and 7.23% (95% CI: 5.24-9.22%) (47/650) of the sheep and goats, respectively. The risk factors significantly associated with T. gondii and N. caninum seroprevalence were the presence of cats and dogs, the pasturing system, the herd size, the hygiene in the farms. The results of the present survey indicate that T. gondii and N. caninum infections are highly prevalent in sheep and goats in Qinghai province, China. This is the first time that antibodies to N. caninum have been detected in sheep and goats in China. © 2015 Elsevier B.V. Source

Liu S.,Shijiazhuang University | Shang R.,Lanzhou Institute of Husbandry and Pharmaceutical science of CAAS | Shi L.,Shijiazhuang University | Wan D.C.-C.,Chinese University of Hong Kong | Lin H.,Chinese University of Hong Kong
European Journal of Medicinal Chemistry

A series of 7H-thiazolo[3,2-b]-1,2,4-triazin-7-one derivatives 7a-i were synthesized and evaluated as novel acetylcholinesterase (AChE) inhibitors. All target compounds were evaluated in vitro for the inhibitory activities against AChE via Ellman colorimetric assay. Compound 7c showed an excellent (89.82%) inhibitory activity. The molecular docking studies revealed that 7c, 7d and 7g, with the lateral chain in the para position of the phenyl ring, possessed an optimal docking pose and can perfectly fit into the catalytic active site (CAS) and peripheral anionic site (PAS), simultaneously, and, consequently, exhibited higher inhibitory potency than 7b that bears the same lateral chain as 7g, but in the ortho position of the phenyl ring. © 2014 Elsevier Masson SAS. All rights reserved. Source

Wang R.,CAS Lanzhou Institute of Chemical Physics | Li J.-Y.,Lanzhou Institute of Husbandry and Pharmaceutical science of CAAS | Qi H.-Y.,CAS Lanzhou Institute of Chemical Physics | Shi Y.-P.,CAS Lanzhou Institute of Chemical Physics
Journal of Asian Natural Products Research

The phytochemical investigation of the flower buds of Daphne genkwa yielded four highly oxygenated tigliane diterpene esters (1-4), including two new phorbol derivatives, 12-O-(2′E,4′E-decadienoyl)-7-oxo-5-ene-phorbol- 13-acetate (1) and 12- O-neodecanoyl-7-oxo-5-ene-phorbol-13-acetate (2). The molecular structures of the isolated compounds were elucidated on the basis of extensive spectroscopic analysis, including 1D and 2D NMR. © 2013 Taylor & Francis. Source

Shang R.,Lanzhou Institute of Husbandry and Pharmaceutical science of CAAS | Pu X.,Lanzhou University of Technology | Xu X.,Guiyang Medical University | Xin Z.,CAS Lanzhou Institute of Modern Physics | And 4 more authors.
Journal of Medicinal Chemistry

A series of novel pleuromutilin derivatives possessing thiadiazole moieties were synthesized via acylation reactions under mild conditions. The in vitro antibacterial activities of the derivatives against methicillin-resistant Staphylococcus aureus, methicillin-resistant Staphylococcus epidermidis, Escherichia coli, and Streptococcus agalactiae were tested by the agar dilution method and Oxford cup assay. The majority of the tested compounds displayed moderate antibacterial activities. Importantly, the three compounds with amino or tertiary amine groups in their side chains, 11, 13b, and 15c, were the most active antibacterial agents. Docking experiments carried out on the peptidyl transferase center (PTC) of 23S rRNA proved that there is a reasonable direct correlation between the binding free energy (ΔGb, kcal/mol) and the antibacterial activity. Moreover, the pharmacokinetic profiles of 11 and 15c in rat were characterized by moderate clearance and oral bioavailability. © 2014 American Chemical Society. Source

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