Phenotypic and genotypic characterization of β-lactam resistance in Klebsiella pneumoniae isolated from swine

Little is known about the antimicrobial resistance mechanisms in Klebsiella pneumoniae from swine in China. Thus, this paper aims to demonstrate the β-lactam resistance phenotypes and genotypes of K. pneumoniae isolates from swine in southwestern China, detect possible new β-lactamase variants, and determine whether or not the variants differ in their antibiotic resistance. Isolates from 58 unrelated diseased swine were collected from 61 pig farms in southwestern China from 2007 to 2009. Among the 58 isolates, 75.8-100% were resistant to β-lactam, 62.0-68.97% to fluoroquinolone, 44.8-46.55% to aminoglycoside, and 8.62-17.24% to β-lactam inhibitors. PCR amplification and DNA sequencing showed that bla(TEM-1) was detected in 100% (n=58) of the isolates, bla(SHV) in 82.76% (n=48), bla(CTX-M) in 39.66% (n=23), and bla(OKP) in 17.24% (n=10). The bla(SHV) types included bla(SHV-1), bla(SHV-11), bla(SHV-12), and bla(SHV-27). None of the isolates harbored bla(KPC), bla(LEN), or bla(GES) gene. Four novel variants (bla(OKP-A-13), bla(OKP-A-14), bla(OKP-A-15), and bla(OKP-A-16)) were identified among the 10 OKP β-lactamase-producing K. pneumoniae isolates resistant to ampicillin, amoxicillin, oxacillin, cefalexin, and cefadroxil. Plasmid analysis and PCR amplification indicated that bla(TEM-1) genes were detected in the total plasmid. Molecular typing by pulsed-field gel electrophoresis revealed the presence of 10 distinct pulsotypes of OKP producer isolates. Plasmid DNA digested with XbaI yielded two to six bands of ca. 0.15-30 kb. Transformants of the 10 OKP producer isolates showed no differences in their antibiotic susceptibility, except for the pulsotype B transformant, which carried bla(CTX-M). In China, β-lactam resistance appeared to be common among K. pneumoniae isolates from swine, suggesting that K. pneumoniae may be a reservoir for the dissemination of β-lactam resistance among Chinese pig farms.     

澳洲坚果物理参数试验研究

对澳洲坚果千粒质量、含水率、果实及果仁三径尺寸、壳厚度、壳仁间隙和出仁率等基本物理参数进行了测定.结果表明:在相同条件下,坚果的外形尺寸呈正态分布,63%的果实分布在24~26mm范围内;不同位置果壳厚度差异较大,果壳底部最厚,中部最薄;壳仁间隙为1.20mm.     

轿车性能分析与优化研究

首先对发动机的外特性和万有特性进行研究并建立相应数学模型.其次结合汽车相关理论,阐述计算整车动力性和经济性的一般方法.以动力性和经济模拟计算为基础,根据变速器传动比优化的思路和方法,结合某款实车进行速比优化的工作.模拟计算结果表明,经过优化整车的动力性和经济性都有一定程度的提高.     

Chemical characterization of a procyanidin-rich extract from sorghum bran and its effect on oxidative stress and tumor inhibition in vivo

The present study was to characterize a procyanidin-rich extract (PARE) from sorghum ( Sorghum bicolor (L.) Moench) bran and assess its biological activities. The procyanidin oligomers were separated and identified by normal-phase HPLC equipped with fluorescence (FLD) and mass spectrometry (MS) detectors. In addition, the effects of PARE on oxidative stress in mice induced by D-galactose as well as tumor inhibition in C57BL/6J mice bearing Lewis lung cancer were investigated. Administration of D-galactose significantly (p < 0.05) lowered the activities of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px). This was accompanied by a significant (p < 0.05) increase in malondialdehyde (MDA) levels in both liver and serum. Administration of PARE (150 mg/kg) significantly (p < 0.05) reversed the d-galactose-induced oxidative stress by enhancing the activities of antioxidant enzymes. Furthermore, PARE administration inhibited tumor growth and metastasis formation by suppressing vascular endothelial growth factor (VEGF) production. The results suggested that PARE had antioxidant and antitumor activities.     

双台河口自然保护区丹顶鹤春季迁徙停歇地生境选择

2009年3月,采用样线法、样点法对辽宁双台河口自然保护区内迁徙停歇的丹顶鹤进行观察监测,确认并用GPS定位其停歇地;通过样方法、因子测定法进行对其停歇生境进行实地测量与分析。结果表明：（1）芦苇沼泽是丹顶鹤主选的停歇生境,占到96.4%;（2）丹顶鹤停歇地与火烧地的距离小于25 m,在火烧地边缘活动,或者停在火烧地中;（3）丹顶鹤一般会选择油井距离大于1 km处作为停歇地（100%）;（4）丹顶鹤距明水面的距离较近,便于获取食物与水等;（5）频繁区对丹顶鹤影响明显。影响丹顶鹤的停歇地选择的因素既有自然因素如植被环境和明水面,也有人为因素如火烧和油井乃至道路。针对不同因素的空间分布,丹顶鹤的迁徙停歇地选择也具有一定的选择性。     

附红细胞体病研究进展

根据国内外文献及临床实践,综述了附红细胞体病的病原学、流行病学、发病机理、临床症状、病理变化、诊断和防治等方面研究现状,为今后的研究提供参考。     

高山牧区人工诱生牛黄试验研究

于高山牧区对43头牛进行了人工诱生牛黄试验。经1年的观察,试验牛(?)情、产犊、泌乳、使役与同群放牧牛不认异常。抽样取黄7头,头头产黄,最多8.4g,最少2.2g,平均每头长黄(干重)4.73g。经用红外光谱和挂甲试验、显色试验、薄层层析试验鉴定,证明诱生牛黄与天然牛黄基本一致。此外,对人工诱生牛黄的有关问题作了讨论。     

STUDY ON THE UTILIZATION OF FAT IN NUTRIA (MYOCASTOR COYPUS) CARCASS

Nutria(Myocastorcoypus)be-longstoCapromyidaeinrodentiaofmammalia-Nutriaisaherbivorousfur-bearinganimalwithsomegoodchar-acteristics:suchasdurablebeautifulfur,highfertility(onefemaleadultmayhave2o-3oyoungsintwoyears),easyraisingandlowcostetc.Itwasoriginallydistrib-utedintheareasofArgentina,ChileandsomewhereinSouthAmerica,butnowithasbeenintroducedandraisedinGermany,Po1and,Czech,Romania'Russian,Korea,Chinaandsoonforsever'altenyears.Manycolornutriashavebeenbred.InDecemberl99O,anutriafurwassol…     

赣中棉花配方施肥试验简报

为了摸索棉花配方施肥最佳方案，作者连续几年在不同土壤类型上进行了各种试验，现将江西省丰城市荣塘镇的试验结果总结如下。