探究稀释液温度对金黄色葡萄球菌定量检测的影响

目的通过单因子变量实验分析探究稀释液温度对金黄色葡萄球菌热损伤的影响。方法根据GB4789.10-2016《食品安全国家标准食品微生物学检验金黄色葡萄球菌检验第二法金黄色葡萄球菌平板计数法》,对不同温度稀释液下的金黄色葡萄球菌进行计数。结果使用50℃的稀释液的金黄色葡萄球菌计数实验结果偏低。结论 50℃的稀释液会对金黄色葡萄球菌造成热损伤,影响实验结果。     

食品快速检测方法在国内外的应用与管理比较

食品快速检测因其简便、价格低廉等特点广泛用于食品的快速筛查和现场检测,是基层食品安全监管的技术支撑。本研究整理了食品快速检测方法的发布情况,对比分析了食品快速检测方法在国内外食品安全监管中的应用现状与管理模式,并对现阶段存在的主要问题进行了深入剖析,并提出建议。     

2015~2018年成都市包装饮用水中铜绿假单胞菌污染情况分析

目的 掌握GB 19298-2014《食品安全国家标准 包装饮用水》实施以来成都市内生产和销售的包装饮用水中铜绿假单胞菌的污染情况。方法 统计2015~2018年成都市包装饮用水中铜绿假单胞菌检测情况, 按照瓶装饮用水和桶装饮用水、饮用水的类型(纯净水、矿泉水、其他饮用水)、生产季节及厂址地域进行分析。结果 共计994批次, 检出率为8.8%; 瓶装饮用水检出率0.6%, 桶装饮用水检出率达12.9%; 各类型桶装水均有检出, 纯净水、矿泉水及其他饮用水的检出率分别为2.0%、5.4%、15.5%; 分季节统计, 第三季度的检出率最高, 高达22.1%; 检出铜绿假单胞菌的包装饮用水厂址地域主要分布在成都市西北(属于邛崃山脉)。结论 桶装饮用水中铜绿假单胞菌污染非常严重(尤其是桶装其他饮用水); 三季度污染情况最严重; 地域主要集中在邛崃山脉一带。     

生物可降解Mg-2Zn-0.2Mn合金的体外生物相容性

采用真空铸造技术制备了Mg-2Zn-0.2Mn三元镁合金,并对该合金体外生物生物相容性能进行了研究。采用血小板粘附、溶血率评价镁合金的血液相容性,采用细胞增殖实验(CCK-8)、细胞凋亡实验(AO/PI)评价镁合金的细胞相容性。结果表明:血小板粘附实验表明,与常用的AZ31B镁合金和316L不锈钢样品相比较,Mg-2Zn0.2Mn镁合金表面粘附的血小板数量少,且激活和团聚较轻微;溶血实验的结果表明Mg-2Zn0.2Mn的溶血率为4.7%,远小于AZ31B的80.9%溶血率。血小板黏附和溶血实验说明Mg-2Zn0.2Mn镁合金具有优异的血液相容性。细胞增殖和凋亡实验结果也表明,较AZ31B样品,Mg-2Zn0.2Mn样品表面显示了更好的内皮细胞粘附和增殖能力,说明Mg-2Zn0.2Mn镁合金具有很好的血液相容性和内皮细胞相容性,有望作为今后可降解血管支架的候选材料。     

新型国家药品服务体系建设的构想

我国现有药品服务体系可初步满足医疗卫生的基本需求,但在研发、生产、销售及使用的各领域中均存在一些突出问题。本研究通过文献检索、数据查询、专家咨询及专题讨论,对我国药品服务体系的现状进行调研,找准存在的问题,并提出建设新型国家药品服务体系的构想,旨在为我国人民提供质量优良、疗效可靠、价格合理、使用方便的药品,保障临床用药的有效性、安全性、可及性及合理性;同时,促进制药产业结构转型发展,推动我国从制药大国向制药强国的转变。     

Tribological performance of ultra-high-molecular-weight polyethylene sliding against DLC-coated and nitrogen ion implanted CoCrMo alloy measured in a hip joint simulator

The influence on the tribological properties in a modified metal‐on‐polymer (CoCrMo/UHMWPE) articulation should be tested with DLC coated or N⁺ ion implanted into artificial hip joint heads. For this a diamond like carbon (DLC) film was deposited on a CoCrMo artificial hip joint head by filtered cathodic vacuum arc technique (FCVA) with a thickness of approximately 600 nm. Alternatively nitrogen ions were implanted into the CoCrMo artificial hip joint head by plasma immersion ion implantation (PIII) technology. Before wear tests, the surface morphology and topography of unmodified, DLC coated and N⁺ implanted CoCrMo heads were investigated by optical microscopy (OM) and stylus profilometry. Then a MTS hip joint simulator was used to characterize the tribological properties of the artificial hip joint implants. The wear loss of UHMWPE cup and wear morphology of both the CoCrMo head and UHMWPE cup were investigated after hip joint simulator wear tests. The results showed that the DLC film deposited on the CoCrMo joint head by FCVA method had excellent tribological properties and didn't fail during two million wear cycles while the N⁺ implanted layer formed on the CoCrMo head was damaged during the wear test. Compared with sliding against unmodified CoCrMo head, the UHMWPE cup had a higher wear rate when sliding against DLC coated or N⁺ implanted CoCrMo head. In our opinion, only applying the surface modification (DLC film or N⁺ implantation) on the CoCrMo head could not improve the wear resistance of metal‐on‐polymer (CoCrMo/UHMWPE) articulation for artificial hip joint implant.     

Prevalence and quantification of Campylobacter contamination on raw chicken carcasses for retail sale in China

The quantitative contamination load of Campylobacter on raw chicken carcasses at retail outlets in seven provinces and cities of China was determined. A total of 1587 carcasses over 12 consecutive months were sampled. The overall Campylobacter contamination rate was 45.1% and 19.8% of contaminated carcasses was higher in the load than 3.0 log₁₀CFU/g. The median load was 2.1 log₁₀CFU/g with 1.4 log₁₀CFU/g as the 25th percentile and 2.9 log₁₀CFU/g as the 75th percentile, respectively. Using logistic regression, it observed the significant provincial and monthly variations in prevalence, freshly slaughtered chicken carcasses (63.1%) were found to be 2.3 times higher compared to chilled carcasses (32.9%), while no statistical significance was observed in prevalence among chicken carcasses that had various packaging solution (P = 0.370) nor from different market types (P = 0.680) suggesting that possible cross-contamination had occurred during processing and transportation. The present study found that 52.1%, 59.9%, 2.9%, 8.8% and 8.3% of carcasses were contaminated with C. jejuni, C. coli, C. lari, C. fetus, and C. upsaliensis, respectively. A higher proportion of C. coli (45.4%) than C. jejuni (39.5%) were cultured from the contaminated carcasses and this finding was suggestive of a high degree of cross-contamination occurred not just among poultry products, but also with pork products before/at retail points in China. This study provided quantitative data suitable for a risk assessment model designed to evaluate useful intervention methods to facilitate a reduction in the risk of campylobacteriosis arising from the consumption of contaminated domestically produced chicken meat in China.     

Serovar diversity and antimicrobial resistance of non-typhoidal Salmonella enterica recovered from retail chicken carcasses for sale in different regions of China

Non-typhoidal Salmonella enterica (NTS), the etiological agents in foodborne salmonellosis, is a major public health concern. This study describes the serovar diversity and antimicrobial resistance phenotypes identified in NTS isolates from retail whole chicken carcasses across six provinces of China. From food samples tested, a total of 2210 Salmonella isolates were recovered and these were serotyped by conventional and molecular serotyping methods and tested for their susceptibility to a panel of antimicrobial compounds. Sixteen serogroups and 52 serovars were identified, with serogroups B, D1 and C1 common among Enteritidis, Indiana and Infantis isolates. The serovar distribution varied both geographically and seasonally. Most (80.18%) of these isolates were found to be resistant to at least one antimicrobial compound and 54.6% were multi-drug resistant (MDR). Resistance to nalidixic acid (NAL) was common (70.6%) among the 11 tested compounds and no isolate was found to be resistant to carbapenems. There were 119 antimicrobial resistance profiles identified in the study collection. Two-hundred eighty-four isolates, including 99 Salmonella enterica serovar Indiana (S. Indiana), were resistant to seven or eight classes of antimicrobial compound. One-hundred eighty-three S. Indiana isolates were found to be co-resistant to ciprofloxacin and cefotaxime and 179 of these were confirmed as extended-spectrum β-lactamase producers. These data begin to describe the serovar diversity and antimicrobial resistance of NTS isolates recovered from retail chicken carcasses in parts of China. The findings highlight the emergence of ciprofloxacin and cefotaxime co-resistant S. Indiana, a feature displaying serious antimicrobial resistance but not commonly reported in human infections of Salmonella until recently. The food safety implications of these findings are discussed.     

气相色谱法测定陈皮中丙溴磷的残留量

目的建立气相色谱法测定陈皮中丙溴磷残留量的分析方法。方法样品经乙腈提取,经过滤,QuECHERS净化,浓缩后,用丙酮定容,采用气相色谱法测定、外标法定量。结果丙溴磷在0.005～1.000μg/mL范围内线性良好,相关系数r~2达到0.999;方法检出限为0.008 mg/kg;平均回收率为89.9%～110.8%,相对标准偏差(relative standard deviation,RSD)为2.2%～3.3%(n=6)。结论本方法操作简便、灵敏度高、准确度好,适用于陈皮中丙溴磷残留量测定。     

铜绿假单胞菌检测能力验证结果与分析

目的 分析实验室对饮用水中铜绿假单胞菌检测能力验证结果。方法 依据能力验证作业指导书幵参照GB4789.2-2016对样品进行稀释,根据GB8538-2016进行检测,同时对可疑菌落使用API20NE与VITEK2进行辅助鉴定。结果 样品18-N361、18-U838能力验证结果为满意。结论 通过此次能力验证,解决了饮用水样品的稀释问题,验证了API 20NE与VITEK2对可疑菌落进行辅助鉴定的准确性。VITEK2能缩短检验时间。