药品在被少量大肠杆菌污染而造成漏检的有关问题的探讨

目的:探讨药品在被少量大肠杆菌污染后,按中国药典现行方法检验是否存在漏检可能,建立了在该种情况下可行的大肠杆菌检查的方法.方法:对8个品种人为污染少量大肠杆菌后,按中国药典检查.结果:药品在被少量大肠杆菌污染后,按药典法大肠杆菌阳性检出率为0～66%,改进法为100%.结论:药品在被少量大肠杆菌污染后,按中国药典现行方法检验存在漏检可能.     

大肠埃希菌、肺炎克雷伯菌的耐药性变迁

目的了解大肠埃希菌、肺炎克雷伯菌对抗生素耐药性变迁. 方法采用纸片扩散确认试验和双纸片协同试验,药敏试验采用纸片扩散法. 结果 4年中大肠埃希菌、肺炎克雷伯菌超广谱β-内酰氨酶(ESBLs)的发生率呈逐年上升的趋势.从1999～2002年大肠埃希菌、肺炎克雷伯菌总的ESBLs菌的发生率分别为15.9%、14.8%、20.2%、29.6%;产ESBLs菌对氨基糖苷类、喹诺酮类和磺胺类交叉耐药,且呈逐年上升趋势;产ESBLs菌株70%发生于重症监护病房. 结论实验室应尽早开展ESBLs的检测,合理使用抗生素,有效控制ESBLs的传播和流行.     

大肠埃希菌耐药性与头孢菌素类用量变化的相关性分析

目的通过调查医院1994～2002年大肠埃希菌对头孢类抗生素耐药性与该类药物年用量,探讨用药量和耐药性之间的相关性. 方法采用回顾性调查方法,对1994～2002年5种头孢菌素类的年用量与大肠埃希菌对这些药物的敏感性进行分析,计算各药DDDs,并用直线回归对耐药率与DDDs进行相关性分析. 结果9年来大肠埃希菌对5种头孢类抗生素的耐药率全部呈增长态势,其中使用频率较高的头孢唑林(CFZ)和头孢呋辛(CXM)的增长分别为25.9%和23.6%,使大肠埃希菌对这两药的耐药率接近40%;5种头孢类抗生素年用量变化不一,2002年与1994年相比CXM年用量增长了11倍,头孢他啶的年用量增长了3倍,头孢噻肟、头孢哌酮年用量呈波动性下降;耐药率和DDDs相关性分析显示,CXM用量与耐药率的变化呈显著正相关(r=0.768,P<0.05). 结论1994～2002年间大肠埃希菌对头孢类抗生素的耐药率逐年增长,头孢呋辛耐药率的增长与其年用量增加呈显著正相关.     

臭氧·紫外线器械消毒柜消毒效果与影响因素的实验研究

目的探讨臭氧*紫外线消毒柜的机器性能和消毒效果与影响因素. 方法按卫生部<消毒技术规范>测定开机不同时间消毒柜中臭氧浓度、工作环境空气中臭氧浓度和消毒柜中臭氧残留浓度,以及消毒柜对不同微生物的杀灭效果. 结果按消毒柜自动程序开机20min柜内臭氧浓度达253.69mg/m3,柜中平均紫外线照射强度为1 862μW/cm2;消毒柜开机工作35min对不锈钢载体上金黄色葡萄球菌、大肠埃希菌、白色念珠菌杀灭率达100%;开机40min对不锈钢载体上枯草杆菌黑色变种芽胞杀灭率达100%,对染于手术剪和镊子上的金黄色葡萄球菌杀灭率达99.99%,消毒效果可靠而且安全. 结论肯格王牌臭氧*紫外线消毒柜容量大、自动、安全、消毒效果可靠、适用范围广泛的医疗器械消毒产品.     

大肠埃希菌、克雷伯菌产超广谱β-内酰胺酶的检测及耐药性分析

目的研究本院3年中大肠埃希菌、克雷伯菌ESBLs的检出率及对常用抗生素的耐药情况。方法对山西医科大学第二医院2001～2003年分离的837株大肠埃希菌、216株克雷伯菌用标准纸片扩散确证法检测其ESBLs产生率；采用K-B法进行药敏检测。结果大肠埃希菌产ESBLs分离率为2001、2002、2003分别为12．27％、15．90％、30，85％；克雷伯菌产ESBLs分离率为2001、2002、2003分别为23．88％、28．81％、30．00％；产ESBLs株对头孢菌素类、氨基糖苷类、氟喹喏酮类耐药率均高于非产ESBLs菌株；未发现对亚胺培南耐药的菌株。结论近年来大肠埃希菌、克雷伯菌产ESBLs菌株逐年升高，应引起足够的重视，采取有效措施控制产ESBLs菌的感染。     

大肠埃希菌感染的临床分布与耐药性

目的调查医院大肠埃希菌感染的临床分布及耐药,为临床合理使用抗菌药物提供科学依据.方法对358株临床分离的大肠埃希菌对药物敏感试验结果进行回顾性分析.结果大肠埃希菌感染的部位主要见于伤口、泌尿道、呼吸道、血液、引流液等;大肠埃希菌耐药率低的抗菌药物是亚胺培南、阿米卡星、哌拉西林/他唑巴坦,耐药率<10%;对氟喹诺酮类及头孢菌素耐药率较高.结论治疗大肠埃希菌感染时,需根据药敏结果及患者病情选用碳青酶烯类、氨基糖苷类、β-内酰胺类抗生素/β-内酰胺酶抑制剂等.     

Use of complement monoclonal antibody eculizumab in Shiga toxin producing Escherichia coli associated hemolytic uremic syndrome: A review of current evidence

Complement activation plays an important role in the pathogenesis of atypical hemolytic uremic syndrome. Eculizumab is a monoclonal antibody that blocks complement activity and has been approved for use in the treatment of atypical hemolytic uremic syndrome (HUS). Less well appreciated is the role of complement in Shiga toxin‐induced HUS (Shiga toxin producing Escherichia coli [STEC]‐HUS). To a limited extent, eculizumab has been used off label in patients with severe STEC‐HUS with neurological involvement. Through a systematic search of available databases, we identified 16 reports describing the use of eculizumab in STEC‐HUS (eight case reports/series, seven retrospective studies, and one prospective cohort study). All studies described its use in severe STEC‐HUS with neurological or multiorgan dysfunction; none were randomized or blinded. Four studies used the control groups. Although the overall quality of evidence is low, some published studies showed positive clinical improvement after treatment with eculizumab in severe STEC‐HUS with progressive neurological involvement.     

某医院临床分离细菌菌株耐药检测结果与分析

目的 了解该院院内获得病原菌对药物的耐药率和敏感率情况,指导临床用药.方法 收集2010年6月至2011年8月院内患者感染占前5位的病原菌,采用K-B纸片法、ATB药敏试剂盒比色法鉴定对抗菌药物耐药,并进行分析探讨.结果 大肠埃希菌耐药率大于或等于75%的抗菌药物有9种,敏感率大于或等于75%有3种;金黄色葡萄球菌耐药率大于或等于75%的抗菌药物有13种,敏感率50%～74%只有1种;凝固酶阴性葡萄球菌耐药率大于或等于75%的抗菌药物10种,敏感率大于或等于75%只有1种;铜绿假单胞菌耐药率大于或等于75%的抗菌药物有1种,敏感率大于或等于75%有3种;嗜麦芽窄食单胞菌耐药率大于或等于75%的抗菌药物有12种.结论 阿米卡星、美罗培南、亚胺培南对大肠埃希菌保持了较高的抗菌活性;舒普深对凝固酶阴性葡萄球菌保持较高的抗菌活性;阿米卡星、美罗培南、妥布霉素对铜绿假单胞菌保持较高的抗菌活性;复方新诺明对嗜麦芽窄食单胞菌保持较高的抗菌活性,环丙沙星、氨苄西林/舒巴坦对3种细菌耐药率大于或等于75%.     

UV-C radiation induced conformational relaxation of pMTa4 DNA in Escherichia coli may be the cause of single strand breaks

Purpose: The biological consequences of initial physicochemical events following exposure of DNA to germicidal (254 nm) ultraviolet C (UV-C) radiation are not fully understood despite progress that has been made. In particular the cause of UV-C induced single strand breaks is not known. This question has been addressed in the present investigation.

Materials and methods: A plasmid construct, pMTa4, was exposed to UV-C in vitro as well as in vivo after transforming the plasmid into a repair proficient wild type and repair deficient, recF, mutant of E. coli. Following UV exposure in vivo, the plasmid was isolated under repair non-permissive and permissive conditions. The plasmid isolate and the pure super-coiled closed circular (CC) topological form of the plasmid were analyzed by agarose gel electrophoresis. The dependence of UV-C induced damage and conformational changes on the dose of radiation as well as on the duration of post-irradiation repair incubations was observed. The influence of UV-C on hyperchromic change and intercalation of ethidium bromide into plasmid DNA were also recorded.

Results: UV-C exposure of pMTa4 DNA in vitro and in vivo induced dose dependent, but sparsely placed, single strand breaks (SSB). While the wild type (AB1157) E. coli was able to repair SSB nearly completely under repair permissive condition, the recF (JC9239) mutant failed to do so. A dose-dependent relaxation of super-structure of CC form of pMTa4 DNA concomitant with enhanced ethidium bromide intercalation into the plasmid DNA was observed.

Conclusion: It is proposed that the conformational relaxation generated negative super-coiling strain on the DNA backbone of CC form of plasmid as well as exposed chemical bonds for hydrolytic cleavage. This might be the cause of the production of sparsely placed single strand breaks in pMTa4 upon exposure to low doses of UV-C.     

Phenotypic and genotypic characterization of enteroaggregative Escherichia coli isolates from pediatric population in Pakistan

Enteroaggregative Escherichia coli (EAEC) are a leading cause of diarrhea among children. The objective of this study was to define the frequency of EAEC among diarrheal children from flood‐affected areas as well as sporadic cases, determine multidrug resistance, and evaluation of virulence using an in vivo model of pathogenesis. Stool samples were collected from 225 diarrheal children from 2010 to 2011 from flood‐affected areas as well as from sporadic cases in Pakistan. Identified EAEC isolates were characterized by phylogrouping, antibiotic resistance patterns including the extended‐spectrum beta lactamase spectrum, single nucleotide polymorphism detection in gyrA and parC, and virulence potential using wax worm, G. mellonella. A total of 35 (12.5%) confirmed EAEC isolates were identified among 225 E. coli isolates. EAEC isolates displayed high resistance to tetracycline, ampicillin, and cefaclor. A total of 34.28% were ESBL positive. Single nucleotide polymorphism detection revealed 37.14% and 68.57% isolates were positive for SNPs in gyrA (A₆₆₀‐T₆₆₀) and parC (C₃₃₀‐T₃₃₀), respectively. Phylogrouping revealed that B2 phylogroup was more prevalent among all EAEC isolates tested followed by D, A, B1, and non‐typeable (NT). Infection of G. mellonella with EAEC showed that killing infective dose was 100% higher than E. coli DH5 alpha control. EAEC are prevalent among Pakistani children with diarrhea, they are highly resistant to antibiotics, and predominantly fall into B2 phylogroup. Epidemiologic surveillance of EAEC and other E. coli pathotypes is critical to assess not only the role of these pathogens in diarrheal disease but also to determine the extent of multidrug resistance among the population.