长甲牌百消丹辐射灭菌剂量设定的研究

采用活菌计数法和D_(10)值测定对长甲牌百消丹辐射灭菌剂量进行设定。结果,3批长甲牌百消丹初始染菌数平均值分别为2620 cfu/g、15630 cfu/g和4900 cfu/g,3批平均总菌数为7717 cfu/g,污染菌数范围为1700～28000 cfu/g。测得D_(10)值为1.75kGy,计算出最低灭菌剂量为17.70kGy。结论,~(60)钴辐照对长甲牌百消丹辐射灭菌剂量为17.70 kGy,确定灭菌保证水平为10~(-3)。     

确定电离辐射灭菌剂量方法的比较

对一次性使用的注射器和针头作了初始污染菌数和分离出的17种污染菌对辐射敏感性的测定。以初始污染菌数的最大值,最抗辐射菌的D_(10)值和灭菌保证水平按公式计算出的辐射灭菌剂量接近于按AAMIB_1法确定值。     

问题解答

<正> 问:在贵刊文章中,常见以D_(10)值作为杀菌指标,请问D_(10)值是什么意思?实际应用时如何计算? (河南读者原寒文) 答:在消毒学中,D_(10)值是指在某种消毒因子作用下,杀灭90％活存微生物个体或使活存微生物数降低到十分之一所需要的时间。在国外有关文献中,亦称之为DRT(decimal reduction time)。其度量衡单位多为min(分钟)。但在电离辐射灭菌中,D_(10)值则是指杀灭90％活存微生物个体所需要的辐射剂量,其度量衡单位为Mrad(百万拉德)或kGy(千戈瑞)。通常,可将D_(10)值简写为D值。同杀灭率等一样,D_(10)值亦是衡量消毒     

医用手术台罩辐射灭菌初始污染菌数量的动态观察

目的了解一次性医用手术台罩初始污染菌量的动态变化,以确定单一辐照剂量25 kGy辐射灭菌的安全性,为厂家的GMP生产提供参考。方法依据ISO11737-1推荐的方法进行初始污染菌数量的检测和产品洗脱菌回收率检测。结果对某企业随机抽取的40个样品检出初始污染菌数量范围为998~1774 cfu/件,校正因子为1.28~1.46。结论该企业现采用25KGy辐照剂量照射法对于医用手术台罩灭菌不具备可靠的安全性;提示在辐射灭菌剂量确定后,应进行持续有效的定期审核。     

电离辐射灭菌指示菌D_(10)值的研究

<正> 指示菌及其它细菌对射线抵抗力D_(10)值,在电离辐射灭菌中对照射剂量的估算占有重要地位。今特将短小芽胞杆菌E601及某些细菌和真菌的D_10值测定结果报告如下,以为灭博照射剂景的确定提供依据。     

医疗用品电离辐射灭菌剂量的测定

对无纺布、输液器、羊肠线等产品进行了初始污染菌调查,以及短小芽胞杆菌(E601)D_(10)值的测定。根据结果计算出上述产品的电离辐射灭菌剂量,并在灭菌处理中进行了验证。     

感染的预防与控制(29)

消毒灭菌方法(三) (三)光照(辐射)消毒灭菌法: 1.非电离辐射: (1)紫外线灯消毒法: 紫外线是一种低能量的电子辐射,因其在光谱中位于紫色可见光之外,所以叫紫外线。紫外线可分为长波段和短波段:     

鲍曼不动杆菌、铜绿假单胞菌qacEΔ1基因检测及消毒剂抗性研究

目的研究临床分离鲍曼不动杆菌和铜绿假单胞菌携带qac EΔ1耐消毒剂基因及对3种常用消毒剂抗性情况。方法选择我院2012年1月至2014年12月临床分离的鲍曼不动杆菌及铜绿假单胞菌各30株,采用PCR法检测所有菌株携带qac EΔ1耐消毒剂基因情况,采用定量杀菌试验检测qac EΔ1基因阳性菌株对3种临床常用消毒剂抗性的变化,对检测结果进行统计学分析。结果在30株鲍曼不动杆菌中,有22株携带qac EΔ1基因,阳性率为73.3%(22/30)。在30株铜绿假单胞菌中,有18株携带qac EΔ1基因,阳性率为60.0%(18/30)。标准菌株大肠埃希菌ATCC 25922和铜绿假单胞菌ATCC 27853的qac EΔ1基因检测均为阴性。有效碘、有效氯及快速手消毒剂对鲍曼不动杆菌、铜绿假单胞菌及质控菌株的灭菌率均随时间和剂量的提高而提高,呈现明显的量-效关系和时-效关系。在灭菌1 min时,除300 mg/L有效碘对鲍曼不动杆菌、铜绿假单胞菌qac EΔ1基因阳性菌株灭菌率均低于基因阴性菌株,且差异均有统计学意义(P均0.05)外,其他浓度下有效碘对鲍曼不动杆菌、铜绿假单胞菌qac EΔ1基因阳性菌株与阴性菌株灭菌率差异均无统计学意义(P均0.05)。其他作用时间下不同浓度有效碘对鲍曼不动杆菌和铜绿假单胞菌qac EΔ1基因阳性菌株的灭菌率均低于qac EΔ1基因阴性菌株,且差异均有统计学意义(P均0.05)。不同浓度的有效氯在作用5 min、7min时对鲍曼不动杆菌及铜绿假单胞菌qac EΔ1基因阳性菌株灭菌率均低于基因阴性菌株,且差异均有统计学意义(P均0.05);作用1 min时,500 mg/L有效氯对鲍曼不动杆菌qac EΔ1基因阳性菌株灭菌率均低于阴性菌株,且差异有统计学意义(P0.05),但对铜绿假单胞菌qac EΔ1基因阳性与阴性菌株灭菌率差异无统计学意义(P0.05)。快速手消毒剂在作用1 min、5 min和7 min时对鲍曼不动杆菌及铜绿假单胞菌qac EΔ1基因阳性菌株灭菌率均低于基因阴性菌株,且差异均有统计学意义(P均0.05)。结论我院分离的鲍曼不动杆菌和铜绿假单胞菌携带qac EΔ1耐消毒剂基因比例较高,qac EΔ1基因阳性菌株对临床常用的3种消毒剂的抗力高于阴性菌株和标准菌株。     

^(60)Co和电子束辐照对金黄色葡萄球菌消毒效果的研究

目的研究^(60)Co和电子束辐照对金黄色葡萄球菌的消毒效果。方法以金黄色葡萄球菌为指示微生物,用2、5和10 kGy 3个辐照强度的^(60)Co和电子束射线对聚四氟乙烯片、牛皮纸片、玻璃片和不锈钢金属片4种染菌载体进行辐照,计算杀灭率;根据试验结果选用合适剂量对4种染菌载体进行模拟现场试验,评价其消毒效果。结果^(60)Co和电子束辐照剂量为2 kGy时,4种染菌载体的平均杀灭率均<99.99%;辐照剂量达到5和10 kGy时,4种染菌载体的平均杀灭率均≥99.99%。模拟现场试验的^(60)Co辐照剂量达到5.2~6.3 kGy以及电子束辐照剂量达到5.05~5.42 kGy时,4种染菌载体的平均杀灭率均≥99.99%。结论^(60)Co和电子束对4种染菌载体的最佳辐照剂量为5 kGy,聚四氟乙烯片载体的消毒效果最好,玻璃片和不锈钢金属片消毒效果次之,牛皮纸消毒效果最差。     

微波对医院儿科常用物品的灭菌效果

<正> 为了解家用微波炉(ER-692型)能否对医院儿科常用物品,如乳胶奶嘴、玻璃奶瓶、药杯、毛巾、纱布及棉签等灭菌,我们进行了消毒效果观察。试验中用类炭疽杆菌(8008株)芽胞作为指标菌,选用与被试物品具有相同性质的表面作为染菌载体(1.5×1.5cm~2),以滴染法染菌。回收菌量为2.5×10~6     

医用羊肠线电离辐射灭菌的研究

<正> 医疗用品电离辐射灭菌,目前已遍及世界上40多个国家。国际上最早是美国Ethicon公司用电子束对羊肠线进行灭菌;获得了显著的灭菌效果。由于辐射源的发展,电离辐射灭菌方法也随着发展,所以这种方法愈来愈为人们所关注。它有许多优点,例如:灭菌彻底,均匀,无环境污染;射线     

电子束对医用乳胶手套灭菌效果的研究

实验证明,以电子加速器产生的电子束照射医用乳胶手套,当初始染菌量小于10~3,照射剂量为25 kGy时,可获良好灭菌效果。照射后手套的乳胶质量无明显变化。     

无纺布在灭菌中耐辐射性的研究

试验表明,对维尼纶与涤纶无纺布用25 kGy γ射线照射,其扯断强度、白度与红外光谱无明显改变。用15kGy照射,未检出细菌与真菌。     

人工股骨体辐射灭菌后遗传和血液相容性研究

目的评价人工关节经辐射灭菌后遗传毒性和血液相容性,探讨辐射灭菌在医用高分子生物材料灭菌中的应用。方法采用ISO11137标准方法检测初始污染菌回收率、校正因子,完成辐照灭菌的剂量设定;对灭菌合格的人工股骨体进行遗传和血液相容性评价。结果人工股骨样品上初始染菌量,需氧菌数平均波动在263~303cfu/件之间,真菌数波动在25~43 cfu/件之间;污染菌回收率范围为92.72%~96.15%。辐照灭菌处理的样品各剂量组与阴性对照组间经统计学检验比较均无显著性差异(P>0.05),未显示出遗传性毒性。经辐照灭菌后样品致溶血率为1.38%,在规定允许范围内。结论设定剂量辐照灭菌后的人工关节遗传和血液相容性好,辐照灭菌作为医用高分子生物材料使用具有良好的安全性。     

Gamma irradiation for terminal sterilization of 17beta-estradiol loaded poly-(D,L-lactide-co-glycolide) microparticles.

17beta-Estradiol-loaded microparticles using poly-(D, L-lactide-co-glycolide) polymer (PLG) were prepared by a modified spray-drying method and the effects of gamma-irradiation on drug substance, polymer and microparticles were investigated. Irradiation doses ranging from 5.1 to 26.6 kGy were applied using a 60Co-radiation source. 17beta-Estradiol drug substance showed excellent stability against gamma-irradiation in the investigated dose range, whereas microencapsulated estradiol seems to be converted to conjugation products with PLG, and to a lesser extent to the degradation product 9,11-dehydroestradiol. The weight-average molecular weight of the PLG polymers decreased with increasing irradiation dose while polydispersity indices (M(w)/M(n)) remained nearly unchanged, compatible with a random chain scission mechanism in lactide/glycolide-copolymer degradation. In vitro drug release studies showed accelerated kinetics with increasing irradiation doses due to dose dependent polymer degradation. Microbiological process monitoring showed decreasing bioburden with increasing spraying time, which was successfully further reduced by applying irradiation sterilization. Microencapsulated test spore suspensions of Bacillus pumilus ATCC 27142, the official test specimen for the gamma-sterilization process, revealed effective reduction of bioburden, confirming its published D(10) value. In conclusion, our studies demonstrated efficacy of gamma-irradiation as terminal sterilization method for poly-(D,L-lactide-co-glycolide) polymer-based drug delivery systems. The sterilization conditions need to be carefully adjusted for the final dosage form.     

Microbial bioburden in endoscope reprocessing and an in-use evaluation of the high-level disinfection capabilities of Cidex PA.

Most endoscopy clinics use 2% glutaraldehyde as a high-level disinfectant for reprocessing flexible endoscopes. However, even with contact times greater than 30 minutes, survival of organisms has been documented. We compared the high-level disinfection capabilities of glutaraldehyde (45-minute immersion) with a new peracetic acid germicide (20- to 25-minute immersion). Channels, valve housings, and outer sheaths were sampled to quantify bioburden levels after a patient procedure, after manual cleaning, and after disinfection. Total mean bioburden after clinical use was greater than 6 log10 colony-forming units (CFU). Manual cleaning reduced the bioburden by means of 4.7 log10 CFU (gastroscopes) and 6.2 log10 CFU (colonoscopes). High-level disinfection with the new product was achieved in five of six (product stressed by EPA Reuse Test) and 7 of 10 (product stressed by dilution and organic load) successfully disinfected endoscopes, whereas glutaraldehyde achieved it in 4 of 10 (product stressed by dilution and organic load). We conclude that the new peracetic acid product (20- and 25-minute contact time) is at least as effective as glutaraldehyde (45-minute contact time) for reducing the bioburden of vegetative aerobic organisms in endoscopes.     

猪天然管状SIS人工食管的制备和不同灭菌方式的比较

目的天然管状细胞外基质的制取及灭菌方式的比较。方法以物理方法刮除猪小肠的肌层与粘膜层制取天然管状细胞外基质膜，对比粒子加速器的不同辐照剂量与过氧化氢低温等离子灭菌的效果。结果25KGy辐照剂量与过氧化氢低温等离子的灭菌方法均可达到理想的灭菌效果。结论粒子加速器25KGy辐照剂量的灭菌方式更适合细胞外基质膜灭菌处理。     

Biochemical basis of mupirocin resistance in strains of Staphylococcus aureus.

Twenty one strains of Staphylococcus aureus, of varying resistance to mupirocin, were examined in order to determine the mechanism of resistance to this antibiotic; six of these strains were mupirocin sensitive (MIC 0.12-1.0 mg/L) nine moderately resistant strains (MIC 8-256 mg/L) and six highly resistant strains (MIC > 2048 mg/L). Mupirocin showed a time-dependent inhibition of the target enzyme, isoleucyl-tRNA synthetase (IRS); incubation of the antibiotic with this enzyme before adding the substrates markedly increased inhibition in sensitive strains. The IRS I50 values (the antibiotic concentrations which cause a 50% decrease in enzyme activity) correlated well with the MIC values for each strain (P < 0.01). The mean I50 value for sensitive strains was 3.3 x 10(-2) mg/L, in moderately resistant strains it was 1.3 x 10(-1) mg/L and in highly resistant strains it was 7.5 mg/L. No degradation of mupirocin could be detected during extended incubation of the antibiotic with cell free extracts from four resistant S. aureus strains. We conclude that the production of a modified IRS enzyme is the major cause of mupirocin resistance in the strains studied.