Emergence of Klebsiella pneumoniae carbapenemase-producing Proteus mirabilis in Hangzhou, China

Background Carbapenems are used to treat severe infections caused by multi-drug-resistant organisms, however, the emergence of carbapenem-resistant bacterial isolates is becoming an increasing therapeutic challenge. Since the first Klebsiella （K.） pneumoniae carbapenemase （KPC）-producing K. pneumoniae was reported in 2001, KPC-producing isolates have been found increasingly, specially in Enterobacteriaceae. The aim of this study was to characterize the mechanisms of a carbapenem-resistant Proteus （P.） mirabilis. Methods A carbapenem-resistant P. mirabilis isolate was recovered from pleural drainage fluid of a patient admitted to surgical intensive care unit. Antimicrobial susceptibility testing of the isolate was performed by disk diffusion according to Clinical and Laboratory Standards Institute guidelines, and subsequent minimal inhibitory concentrations were determined with the E-test. Amplification of the blaKPC gene generated a positive band and the PCR products were sequenced subsequently. The plasmid of the isolate was extracted and was successfully transformed into Escherichia （E.） coli DH5a. Results The P. mirabilis isolate was resistant to all detected antimicrobial agents except tigecycline. KPC-2 was confirmed by DNA sequence analysis. The transformant E. coil was resistant to carbapenems. Further study demonstrated that upstream and downstream regions of b/aKPC-2 were identical to that observed in K. pneumoniae submitted to GenBank from China in 2007. Conclusion Carbapenem resistance in the P. mirabilis isolate in this study is mainly due to production of KPC-2.     

肛周脓肿奇异变形杆菌检出及耐药性调查

目的了解肛周脓肿脓液中奇异变形杆菌（PM）的检出情况及耐药性,为临床合理使用抗生素提供参考依据。方法将240例肛周脓肿患者的脓液标本进行细菌培养、耐药酶检测及药敏试验,对其结果进行统计分析。结果所有标本共检出PM菌株31株（12.92%）;31株PM中检出产酶菌株19株（61.29%）,其中产超广谱β内酰胺酶菌株10株（32.26%）,产头孢菌素酶菌株5株（16.13%）,同时产超广谱β内酰胺酶和头孢菌素酶菌株4株（12.90%）。31株PM对亚胺培南、阿米卡星保持着最高的敏感性,对头孢吡肟、哌拉西林/他唑巴坦、头孢他啶、氨曲南亦有较高的敏感性（敏感度≥75%）,但对头孢噻肟、替卡西林、头孢唑啉、头孢西丁、头孢呋辛钠、头孢曲松、环丙沙星、庆大霉素的敏感性降低而耐药性逐渐增强。结论 PM已经成为肛周脓肿的常见致病菌,且容易对临床常用抗生素产生耐药性,但对碳青霉烯类抗生素、阿米卡星及第四代头孢菌素仍具有较高的敏感性。     

基于小波奇异点检测和阈值去噪的眨眼伪迹去除方法

目的眨眼伪迹是脑电中一种常见且影响严重的伪迹。本论文提出一种基于小波奇异点检测和阈值去噪的眨眼伪迹去除方法,无需眼电参考信号,做到自动去除单导脑电信号中的眨眼伪迹。方法首先利用小波奇异点检测特性以检测眨眼伪迹的峰值位置,然后只对眨眼伪迹区域进行小波阈值去噪。结果实验结果表明,本方法能够有效检测眨眼伪迹,避免了普通方法去噪时对非眨眼区域的影响。结论本方法使用的阈值和阈值函数优于典型的阈值和软、硬阈值函数,有效地去除了脑电中的眨眼伪迹。     

一起农村聚餐引发细菌性食物中毒的实验室检测

2014年7月20日,浙江省台州市路桥区横街镇一村民家办喜宴发生食物中毒事件。经现场流行病学调查、实验室检测,从6份患者肛拭/腹泻物、2份剩余可疑食物中检出同源性奇异变形杆菌。证实本次事件是一起因奇异变形杆菌污染食物引起的食物中毒。     

A novel single-trial event-related potential estimation method based on compressed sensing

Cognitive functions are often studied using eventrelated potentials（ERPs）that are usually estimated by an averaging algorithm.Clearly,estimation of single-trial ERPs can provide researchers with many more details of cognitive activity than the averaging algorithm.A novel method to estimate single-trial ERPs is proposed in this paper.This method includes two key ideas.First,singular value decomposition was used to construct a matrix,which mapped singletrial electroencephalographic recordings（EEG）into a low-dimensional vector that contained little information from the spontaneous EEG.Second,we used the theory of compressed sensing to build a procedure to restore single-trial ERPs from this low-dimensional vector.ERPs are sparse or approximately sparse in the frequency domain.This fact allowed us to use the theory of compressed sensing.We verified this method in simulated and real data.Our method and dVCA（differentially variable component analysis）,another method of single-trial ERPs estimation,were both used to estimate single-trial ERPs from the same simulated data.Results demonstrated that our method significantly outperforms dVCA under various conditions of signal-to-noise ratio.Moreover,the single-trial ERPs estimated from the real data by our method are statistically consistent with the theories of cognitive science.     

一株同时携带SGI1和SXT/R391耐药基因岛的奇异变形杆菌

目的分析1株人源奇异变形杆菌CA151922的2个耐药相关基因岛SGI1和SXT/R391的基因结构和耐药基因。方法聚合酶链式反应（PCR）检测SGI1和SXT/R391基因岛特异性整合酶基因,采用二代测序方法测定CA151922基因组。 分别以SGI1和SXT/R391基因岛的参考序列,从基因组序列中提取基因岛片段并组装。 在线预测并注释开放读码框（ORFs）。 基因岛的同源序列通过在线工具BLASTn获得,采用cd-hit获得非冗余的同源基因,利用R语言构建同源基因的聚类进化关系树。 利用微量肉汤稀释法进行耐药表型检测。结果奇异变形杆菌CA151922同时含有SGI1（SGI1-B）和SXT/R391（ICEPmiJpn1）2个耐药相关基因岛。 SGI1-B和ICEPmiJpn1与已知序列相似性分别为97% ~ 99%和96% ~ 99%。 SGI1-B和ICEPmiJpn1携带的耐药基因种类有所差异,但两者携带不同的编码β-内酰胺酶的基因。CA151922为多耐药菌株,耐药达18种,与基因岛耐药基因有关的耐药表型为氨苄西林和磺胺类药物,提示菌株耐药表型不完全由该耐药岛内的耐药基因决定。结论首次在奇异变形杆菌中发现,同时携带SGI1和SXT/R391耐药相关基因岛, 增加了菌株耐药的复杂性和严重性,提示应加强对多耐药菌株耐药相关基因岛的监测。     

奇异变形杆菌致败血症1例

变形杆菌广泛存在于水、土壤腐败的有机物以及人和动物的肠道中,为条件致病菌,多为继发感染,如慢性中耳炎,创伤感染等,也可引起婴儿腹泻,食物中毒,败血症等.变形杆菌属包括普通变形杆菌、奇异变形杆菌、莫根变形杆菌、雷极变形杆菌和无恒变形杆菌.其中以普通变形杆菌和奇异变形杆菌与临床关系较密切.特别是奇异变形杆菌可引起败血症,病死率较高.永德县医院曾收治1例奇异变形杆菌导致的败血症,现报道如下.     

文本分类中一种基于正交变换的特征降维方法

本文讨论了一种基于正交变换的文本特征降维方法.分析了基于特征选择和特征抽取的特征降维方法各自特点,借助矩阵的分解论证了基于Fisher准则函数的特征降维模式的原理与理论基础,讨论了PCA与SVD两种模式的相互关系.实验结果表明这种特征降维模式在文本分类的准确性方面效果较好.     

一起因酒店从业人员带菌引起混合菌污染导致的食物中毒

2003年8月10日下午18至19时，武汉市某大型酒店先后接待3家大型包席，共512人进餐，餐后陆续有28人出现腹痛、腹泻、恶心、呕吐等消化道症状。硚区疾病预防控制中心进行了流行病学调查、临床观察及病原学检验，现将调查结果报告如下。