鸡肉已成为人们日常生活的重要消费品,然而鸡肉及其制品中的一系列食品安全问题制约着其健康发展,其主要的致病菌有沙门氏菌、金黄色葡萄球菌、肠球菌等。目前对致病菌的检测虽有多种方法,但都存在一些问题,因此研究建立更高特异性、高通量、定量、快速的鸡与鸡肉制品中主要致病菌的检测方法显得尤为重要,可以为本地区开展鸡与鸡肉类产品的安全性研究、防控食源性疾病的发生提供技术支持。建立一种高通量、定量、快速检测技术,而定量PCR实现了PCR技术从定性到定量的飞跃,且适合多重反应。根据Gen Bank中已发表的禽源致病性沙门氏菌,金黄色葡萄球菌和肠球菌的基因组序列,采用Primer Express5.0软件分别设计一对特异引物,沙门氏菌扩增片段279bp,金黄色葡萄球菌扩增片段395bp,肠球菌扩增片段445bp,以SYBR Green I为扩增产物荧光染色剂,建立一种具有特异性、敏感性,且能快速检测鸡肉中沙门氏菌与金黄色葡萄球菌和肠球菌的三重SYBR Green I荧光定量PCR检测方法,并进行反应体系的优化、敏感性分析、特异性验证、重复性试验,并用临床组织样本对该方法的特异性进行检测。结果显示研究以临床分离的禽源沙门氏菌,金黄色葡萄球菌和肠球菌为实验株,基于三重SYBR Green I荧光染色的LC-PCR技术,能扩增出特异性的目的片段,无引物二聚体;检测3种致病菌灵敏度达101cfu/m L;重复性熔解曲线趋于一致,且三种菌的Tm值可区分。从不同鸡肉中采集样本的DNA作为模板,经普通PCR方法进行检测,结果显示沙门氏菌扩增出大小约279 bp,金黄色葡萄球菌扩增出大小约395 bp,肠球菌扩增出大小约445 bp。经3重SYBR Green I荧光定量PCR方法进行检测,特异性扩增曲线,走向一致,熔解曲线趋于一致。且CT值与菌落相对应。说明该方法敏感性高、特异性强、重复性好,可用于禽源致病性沙门氏菌,金黄色葡萄球菌与肠球菌的快速和定量检测。
The chemical composition and microstructure of seven uroliths and four urinary sediment samples associated with the feeding of high-level cottonseed meal diet to buffalo calves were examined by chemical qualitative an...
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The chemical composition and microstructure of seven uroliths and four urinary sediment samples associated with the feeding of high-level cottonseed meal diet to buffalo calves were examined by chemical qualitative analyses, scanning electron microscopy ( ), X-ray diffraction, and X-ray energy dispersive spectrometry ( ). Struvite was a major component of kidney stones and of some bladder stones. The kidney stone sample appeared cracked under low power under, aggregated into tiny balls under high power, and as a bladelike structure under even higher power. The bladder stone samples appeared finely granular or granular with various forms of prismatic crystals. The urinary sediments were prismatic crystals, with granules. The newly found prismatic crystals, which were rich in potassium and similar to struvite in crystal structure, were identified as potassium magnesium phosphate (KMgP04·6H2O) in some bladder stones and urinary sediments. However, crystals which contained Mg and P only, which had been used for struvite identification, were not found by examination in urinary sediments from fresh urine samples of buffalo calves fed the high-level cottonseed meal diet.
Objective: The response to intravenous glucose loading in the buffalo using the intravenous glucose tolerance test (IGTT) was investigated to provide a reference for intravenous glucose injection in buffaloes. Method:...
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Objective: The response to intravenous glucose loading in the buffalo using the intravenous glucose tolerance test (IGTT) was investigated to provide a reference for intravenous glucose injection in buffaloes. Method: Twelve healthy, fasted, male swamp buffaloes were divided into three groups. Group I: six buffaloes were given 50% glucose at a dosage of 1 g/kg body weight via the jugular vein. Group II: three buffaloes received normal saline. Group III: three buffaloes were not injected. Blood samples were taken from the opposite vein at 60 and 10 min pre-injection (pre60 and pre10), and at 1, 5, 10, 30, 60, 120, 180, 240, 300, 360 and 420 min post-glucose injection (PGI). Plasma glucose was analyzed by the oxidase method. Insulin and glucagon were soon determined with a human radioimmunoassay kit. The insulin (pmol/l)/glucose (mmol/l) ratios (IGR) were also calculated for each sampling time. Results: Mean plasma glucose, insulin and glucagon concentrations of buffaloes in groups II and III were similar at all the sampling times (p>0.05) and the curves of the IGR for group II and group III were flat throughout. Group I Buffaloes showed an immediate 20 times increase in the mean plasma glucose concentration PGI, over the pre60 and pre10. The peak plasma insulin concentration occurred at 30 min PGI. The mean plasma glucose and insulin concentrations remained above pre-administration levels untill 420 min PGI (p<0.05). However, the mean plasma glucagon concentrations were different only at 1 and 5 min PGI sampling times. The curve of the IGR for group I showed an initial decrease at 1 min PGI, and fluctuated from 10.18 to 25.55 for the remainder of the sampling period. The correlation analysis showed that the mean plasma glucose concentration was positively correlated with insulin level (r=0.73, p<0.005), and significantly negatively correlated with mean plasma glucagon (r=-0.58, p<0.05). The mean plasma insulin level did not show significant correlation with the gluca
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