烧伤病区病原菌分布及其耐药性调查

目的了解烧伤病区病原菌分布特点及其耐药情况，为临床治疗提供参考。方法回顾性分析笔者单位烧伤病区348例住院患者的创面、血液、静脉导管、痰液、尿液及脓液等标本分离而得的菌株，统计其病原菌分布情况及耐药性。结果共检出464株病原菌，其中革兰阴性杆菌244株占52、6％、革兰阳性球菌188株占40．5％、真菌32株占6．9％。主要检出菌株为金黄色葡萄球菌、铜绿假单胞菌、鲍氏不动杆菌、大肠埃希菌。甲氧西林耐药金黄色葡萄球菌（MRSA）对环丙沙星、青霉素G、苯唑西林等的耐药率已达100、0％，只对万古霉素敏感。铜绿假单胞菌对头孢哌酮／舒巴坦、亚胺培南、头孢吡肟的耐药率分别为15、8％、36、8％、33、3％。结论金黄色葡萄球菌、铜绿假单胞菌、鲍氏不动杆菌、大肠埃希菌是烧伤病区感染的主要病原菌；金黄色葡萄球菌、鲍氏不动杆菌对抗生素的耐药率较高。     

烧伤患者2748株病原菌分布特点及耐药性分析

目的 提供近年烧伤患者病原菌分布及耐药性状况的流行病学资料,以指导临床合理使用抗生素. 方法 选择2003年3月-2011年6月西南医院全军烧伤研究所478例患者1977份临床标本(血液、导管、创面分泌物等),共分离出病原菌2748株.用API细菌鉴定板条鉴定菌株;采用K-B纸片扩散法,选择庆大霉素、妥布霉素、哌拉西林、阿米卡星等55种常用抗生素进行药物敏感试验.采用WHONET 5.3软件统计分析如下项目:各年度不同类型、不同标本来源的病原菌分布情况,主要革兰阴性杆菌、革兰阳性球菌、真菌对多种抗生素的耐药率变化情况,铜绿假单胞菌、金黄色葡萄球菌、鲍氏不动杆菌、白色念珠菌对多种抗生素的敏感率变化情况. 结果 2748株病原菌中,革兰阴性杆菌1879株占68.38％、革兰阳性球菌628株占22.85％、真菌241株占8.77％.创面分泌物标本病原菌检出率最高(1022株占37.19％),其次是呼吸道(995株占36.21％)和血液(421株占15.32％),其他类型标本检出率较低.铜绿假单胞菌检出率最高,共996株占36.24％,其次是金黄色葡萄球菌和鲍氏不动杆菌,依次为495株占18.01％、395株占14.37％.鲍氏不动杆菌检出率呈逐年增加趋势,金黄色葡萄球菌呈逐年下降趋势,铜绿假单胞菌检出率较稳定.检出的葡萄球菌中以甲氧西林耐药金黄色葡萄球菌为主,共484株占17.61％.铜绿假单胞菌和鲍氏不动杆菌对多黏菌素E、多黏菌素B的耐药率低于30.00％,鲍氏不动杆菌对米诺环素的耐药率仅为39.68％,除此之外,这2种细菌对其他抗生素如第三代头孢菌素、β内酰胺类、氨基糖苷类、喹诺酮类等抗生素呈多药耐药,耐药率为57.91％～100.00％.2004-2011年,铜绿假单胞菌对喹诺酮类抗生素敏感率呈逐年增加趋势,鲍氏不动杆菌对米诺环素、奈替米星、亚胺培南、美罗培南、妥布霉素和头孢哌酮/舒巴坦敏感率呈逐年下降趋势.粪肠球菌、屎肠球菌和金黄色葡萄球菌对替考拉宁和利奈唑胺的耐药率低于10.00％.金黄色葡萄球菌、表皮葡萄球菌和屎肠球菌对万古霉素的耐药率均为0.金黄色葡萄球菌对奎奴普丁/达福普汀、米诺环素、夫西地酸和复方磺胺甲(晤)唑的耐药率较低,分别为0.82％、9.35％、2.21％和31.85％;该菌对红霉素、克林霉素、复方磺胺甲(恶)唑、四环素和米诺环素的敏感率呈逐年增加趋势.真菌感染率很低,且对药物的耐药率不高;白色念珠菌对5种抗生素的耐药率均低于15.00％,除对5-氟胞嘧啶的敏感率略呈下降趋势外,对其他4种抗生素的敏感率均呈逐年上升趋势. 结论 近年引发西南医院烧伤研究所患者感染的病原菌中,居前3位的依次为铜绿假单胞菌、金黄色葡萄球菌和鲍氏不动杆菌.所有分离菌株中铜绿假单胞菌和鲍氏不动杆菌的多药耐药性尤为突出,鲍氏不动杆菌将可能取代铜绿假单胞菌成为烧伤感染死亡的主要致病菌.     

2004-2006年瑞金医院烧伤病房病原菌分布及分子流行病学分析

目的 了解瑞金医院烧伤病房院内感染病原菌的分布、耐药性和流行情况.方法 2004年1月-2006年12月,从瑞金医院烧伤住院患者创面分泌物、静脉导管、血液、尿液、大便等标本中分离获得甲氧西林耐药金黄色葡萄球菌(MRSA)17株,铜绿假单胞菌52株,鲍氏不动杆菌11株.分析3年间该烧伤病房病原菌的分布和药物敏感试验情况;采用随机扩增多态DNA(RAPD)对院内感染病原菌进行同源性分析.结果 金黄色葡萄球菌、铜绿假单胞菌和鲍氏不动杆菌是瑞金医院烧伤病房近年来的3种主要病原菌,金黄色葡萄球菌占首位,而3年间MRSA在金黄色葡萄球菌中的比例分别为77%(63/82)、85%(63/74)、75%(74/99).3年中MRSA的主要耐药模式为阿米卡星/庆大霉素/红霉素/克林霉素/左氧氟沙星;铜绿假单胞菌的耐药模式为阿米卡星/庆大霉素/哌拉西林/头孢他啶/头孢哌酮/氨曲南/亚胺培南;鲍氏不动杆菌的耐药模式为阿米卡星/庆大霉素/哌拉西林/头孢他啶/亚胺培南/环丙沙星.3种细菌行RAPD同源性分析均为同一型别.结论 笔者医院烧伤病房存在多种院内感染病原菌,细菌耐药情况严重,对这些细菌流行的控制应成为院内感染防治的重点.     

烧伤病房728株感染病原菌的分布特点及耐药性分析

目的了解笔者单位近5年烧伤感染病原菌的分布特点及耐药情况。方法收集2001-2006年笔者单位306例烧伤患者创面分泌物等标本中分离的病原菌，对其菌种分布特点及耐药性进行分析。结果革兰阳性菌378株，其中金黄色葡萄球菌的菌株数居首位，尤以甲氧西林耐药金黄色葡萄球菌居多，表皮葡萄球菌和粪肠球菌的菌株数分别位居第2、3位。革兰阴性杆菌338株，其中鲍氏不动杆菌的菌株数居首位，阴沟肠杆菌和铜绿假单胞菌的菌株数分别位居第2、3位。检出真菌12株。结论笔者单位病原菌的分布情况，可能与甲氧西林耐药葡萄球菌呈多重耐药性以及鲍氏不动杆菌产生各种类型的β内酰胺酶有关。     

热带海岛地区某医院烧伤感染病原菌分布及耐药性调查

目的 了解热带海岛地区烧伤感染病原菌分布及耐药情况。方法 回顾性调查分析2000-2005年笔者单位烧伤病区392例住院患者的病原菌分布情况及其耐药性特点。结果 （1）共检出671株病原菌，其中铜绿假单胞菌、金黄色葡萄球菌、阴沟肠杆菌、不动杆菌是主要菌种。最常见的铜绿假单胞菌检出率为27．7％，较20世纪90年代（33．6％）有下降趋势。（2）铜绿假单胞菌对亚胺培南／西司他丁及头孢吡肟的耐药率分别为32．2％和36．7％，对其余10种常用抗生素的耐药率均在80．0％以上。（3）141株金黄色葡萄球菌中，共检出89株甲氧西林耐药金黄色葡萄球菌，检出率为63．1％；未检出对万古霉素耐药的金黄色葡萄球菌。结论 铜绿假单胞菌、金黄色葡萄球菌、阴沟肠杆菌、不动杆菌等是热带海岛地区烧伤感染的主要病原菌；前两者的抗生素耐药率较高。     

烧伤临床鲍氏不动杆菌分离株生物膜内菌aba Ⅰ基因表达的变化

目的 了解烧伤临床鲍氏不动杆菌分离株生物膜形成过程中,密度感应基因aba Ⅰ表达变化及其对生物膜ECM和细菌耐药性的影响. 方法 2011年1-10月,收集上海交通大学医学院附属瑞金医院烧伤住院患者创面、血液和静脉导管来源的鲍氏不动杆菌耐药菌6株、敏感菌5株.以鲍氏不动杆菌标准菌株ATCC 19606为参照.(1)临床分离株和标准菌株体外常规培养10、24、48 h后,经碘化丙啶染色,用激光扫描共聚焦显微镜观察生物膜厚度.(2)采用试管培养法,将临床分离株和标准菌株振摇培养10、24、48 h,培养液内漂浮细菌为游离菌,黏附于试管壁的生物膜内细菌为膜内菌.采用实时荧光定量PCR技术检测各菌株中aba Ⅰ基因及pgaB基因的相对表达量(标准菌株基因表达丰度设为1).对实验数据进行方差分析. 结果 (1)鲍氏不动杆菌临床分离株体外培养10、24、48 h,生物膜厚度均超过标准菌株,其中耐药菌株生物膜厚度分别为(28.8±0.6)、(31.7±1.1)、(38.1±3.1)μm,明显高于敏感菌株[(17.1±0.4)、(20.1±1.6)、(25.8±1.7)μm,F值分别为1274.38、206.60、61.73,P值均小于0.05].(2)膜内菌:体外培养10、24、48 h,耐药菌株aba Ⅰ表达量分别为6.6±1.7、25.7±3.5、9.8±3.6,均高于敏感菌株(2.7±1.0、15.0±3.5、4.7±3.2,F值分别为21.82、25.24、6.22,P值均小于0.05);耐药菌株pgaB的表达量分别为37.4±1.1、44.5±3.6、33.1±11.5,明显高于敏感菌株(14.6±0.8、20.0±6.9、18.7±6.8,F值分别为1488.44、57.26、6.01,P值均小于0.05).(3)游离菌:体外培养10、24、48 h,耐药菌株aba Ⅰ表达量均与敏感菌株接近(F值分别为0.24、2.33、0.11,P值均大于0.05);耐药菌株pgaB表达量分别为13.8±3.8、12.5±2.9、23.7±2.1,明显高于敏感菌株(7.0±5.9、5.0±1.3、15.6±6.7,F值分别为5.44、28.42、7.76,P值均小于0.05).(4)膜内菌与游离菌的耐药菌株比较:膜内菌各时相点aba Ⅰ表达量均多于游离菌(F值分别为43.69、286.61、9.98,P值均小于0.05),膜内菌pgaB表达量在10、24 h多于游离菌(F值分别为214.26、283.20,P值均小于0.05).(5)膜内菌与游离菌的敏感菌株比较:膜内菌abaⅠ表达量在培养24 h多于游离菌(F=70.28,P＜0.05),pgaB表达量在10、24 h多于游离菌(F值分别为8.03、22.62,P值均小于0.05). 结论 烧伤临床鲍氏不动杆菌分离株生物膜形成过程中,耐药菌株的密度感应基因aba Ⅰ表达明显增多,可能引起pgaB基因表达上调,导致细菌ECM及生物膜形成增加、耐药性增强.     

烧伤病区细菌培养及耐药性的分析

目的探讨临床合理用药依据,提高烧伤感染的治愈率。方法从1999年至2004年烧伤住院患者血培养及创面分离出的细菌,用纸片琼脂扩散法进行药敏试验。结果共分离病原菌379株,G 125株,G-241株其中烧伤病区感染病原体以革兰氏阴性杆菌为主,常见感染病原体依次为铜绿假单胞菌(19.8%),金黄色葡萄球菌(18.5%),大肠埃希氏菌(7.7%),不动杆菌(7.4%),肺炎克雷伯氏菌(6.6%)。其中仅万古霉素对金黄色葡萄球菌有效;头胞噻肟钠对肺炎克雷伯氏菌较有效;大肠埃希氏菌对10种抗菌药物的耐药性>68%。烧伤病区耐药菌株以耐5种以上抗菌药物的菌株为主,占全院多重耐药菌株的50.8%。结论医院感染的耐药问题较严重,加强对细菌耐药性的监测,有助于临床合理应用抗菌药物。     

2014-2015年烧伤科细菌耐药情况及临床对策分析

目的:分析2014-2015年湖南省浏阳市人民医院烧伤科细菌流行变迁及耐药的相关因素,从而指导临床合理用药.方法:对2014年1月-2015年12月于湖南省浏阳市人民医院住院治疗的烧伤患者创面培养病原菌(943株)以及药敏试验结果进行分析比较.结果:2014年铜绿假单胞菌为绝对优势菌,2015年优势菌群不明显,但鲍曼不动杆菌所占构成比增加.鲍曼不动杆菌对碳青酶烯类耐药率并没有随着药物用量下降而下降;铜绿假单胞菌随着碳青酶烯类抗生素使用量的下降,耐药率在下降;头孢哌酮/舒巴坦、碳青酶烯类抗生素对阴沟肠杆菌依然敏感,头孢类、半合成青霉素、喹诺酮耐药率在上升;头孢哌酮/舒巴坦、碳青酶烯类抗生素对肺炎克雷伯菌依然敏感,头孢类变化不大,喹诺酮耐药率在下降;头孢哌酮/舒巴坦、碳青酶烯类抗生素对大肠埃希菌依然敏感.结论:2014年耐药菌以铜绿假单胞菌、金黄色葡萄球菌、鲍曼不动杆菌、肺炎克雷伯菌等为主,2015年耐药菌以鲍曼不动杆菌、肺炎克雷伯杆菌,金黄色葡萄球菌等菌分布为主.鲍曼不动杆菌、阴沟肠杆菌、肺炎克雷伯菌对阿米卡星耐药率有差异,铜绿假单胞菌对大部分抗生素耐药率有差异,大肠埃希菌对大部分抗生素耐药无明显差异.2015年较2014年治愈好转率高.     

烧伤患者难愈性创面多重耐药菌回顾性分析

目的分析烧伤外科病房难愈性创面多重耐药菌（MDRO）定植感染情况，为临床感染防控提供依据。 方法对2012年1月至2017年12月中国人民解放军海军第九〇五医院烧伤外科住院患者难愈性创面的细菌学资料进行调查，回顾性分析MDRO的分布、检出率及特殊耐药情况。 结果难愈性创面分离出270株MDRO，其中革兰阳性菌128株（47.41%），革兰阴性菌142株（52.59%）。居前5位的MDRO依次为金黄色葡萄球菌（125株）、铜绿假单胞菌（56株）、大肠埃希菌（30株）、肺炎克雷伯菌（19株）和鲍曼不动杆菌（18株）。MDRO平均检出率为77.14%，以上前5位MDRO检出率分别为88.65%、65.12%、90.91%、100.00%和90.00%。特殊耐药菌株中，耐甲氧西林金黄色葡萄球菌共118株，碳青霉烯类耐药的铜绿假单胞菌、鲍曼不动杆菌和肺炎克雷伯菌分别为42株、12株和5株。 结论烧伤外科病房难愈性创面MDRO分布广泛、检出率高，应采取有效的感染防控措施。     

烧伤创面感染细菌1116株分析

对１９８９－１９９１年５３６例烧伤病人创面分离的各种细菌，真菌共３９种１１６株进行分析，结果表明：金黄色葡萄球菌２１７株，检出率为１９．４％，居第一位；铜绿假单胞菌２０８株，检出率为１８．６％，居第二位；乙酸钙不动杆菌１１９株，检出率为１０．６％，居第三倍。同时于创面及烧伤病房环境中分离出了蜡样芽胞杆菌，绿色气球菌，曲霉菌等机会致病菌，且创面分离数量较多的菌在环境中几种均可检出。我们还对分离数量较     

烧伤患者鲍氏不动杆菌pgaABC基因簇表达及生物膜表型变化

目的 观察并探讨烧伤患者鲍氏不动杆菌pgaABC基因簇转录表达水平及生物膜形成过程中表型变化.方法收集2009年1月-2010年10月笔者单位住院烧伤患者创面、血液和静脉导管分离的鲍氏不动杆菌24株,以其标准菌株ATCC 19606为对照.采用实时荧光定量RT-PCR技术检测各菌株pgaABC基因簇表达;分别采用改良微孔法及试管法在静置(静态)和摇菌(动态)状态下体外培养各菌株16 h,进行细菌生物膜半定量检测;各菌株体外培养48 h后荧光染色,激光扫描共聚焦显微镜观察并测定生物膜厚度.对数据行t检验.结果 (1)鲍氏不动杆菌临床菌株pgaB基因转录相对表达量为27.91±7.93,明显高于设定基准为1.00的标准菌株(t=5.77,P＜0.05);pgaA和pgaC的表达量分别为1.01±0.28、1.15±0.38,与标准菌株比较差异无统计学意义(t值分别为0.04、0.64,P值均大于0.05).(2)静态培养16 h,鲍氏不动杆菌临床菌株与标准菌株的生物膜半定量结晶紫染色吸光度值相近;而临床菌株动态培养16 h,生物膜半定量结晶紫染色形成明显的紫色环,吸光度值为1.25±0.31,显著高于标准菌株(0.76±0.03,t=2.67,P＜0.05).(3)体外培养48 h,临床菌株ECM中绿色荧光强度及分布均多于标准菌株,临床菌株生物膜厚度为(27.3±9.4)μm,明显大于标准菌株的(15.6±1.7)μm,t=2.09,P＜0.05.结论烧伤患者鲍氏不动杆菌pgaABC基因簇中pgaB转录水平增高,从而导致细菌ECM增多,这可能与鲍氏不动杆菌临床菌株生物膜形成能力和厚度增加有关.

Abstract：

Objective To observe expressions of pgaABC gene clusters and changes in biofilm (BF) phenotype in Acinetobacter baumannii (AB) isolated from burn patients. Methods From January 2009 to October 2010, 24 strains of AB isolated from burn patients hospitalized in our burn wards were collected for the study, while the standard strain ATCC 19606 was used as control. Expressions of pgaABC gene clusters were detected by real time fluorescence quantitative RT-PCR. All strains were cultured for 16 hours in vitro, BF with semi-quantitative detection was respectively evaluated by modified microtiter-plate test under stable condition and tube test under shaking condition for expression of absorbance value. All strains were cultured for 48 hours in vitro, then stained with fluorescent agent and collected for measurement of BF thickness with confocal laser scanning microscopy ( CLSM ). Data were processed with t test. Results ( 1 ) The expression of pgaB gene (27.91 ± 7.93 ) in clinical AB strains was much higher than that of standard strain ATCC 19606 (1.00, t = 5.77, P ＜ 0.05 ). There was no statistical difference in expression of pgaA and pagC genes between standard strain ATCC 19606 (1.00) and clinical AB strains (1.01 ± 0.28,1.15 ±0.38, with t value respectively 0.04, 0.64, P values all above 0.05). (2) After being cultured for 16 hours, BF of clinical AB strains cultured under shaking condition formed distinct "purple circle" , and its absorbance value ( 1.25 ±0.31 ) was higher than that in standard strain ATCC 19606 (0.76 ± 0.03, t =2.67, P ＜ 0.05 ). There was no obvious difference in absorbance value between clinical AB strains and standard strain ATCC19606 cultured under stable condition. (3) After being culture for 48 hours, green fluorescence intensity and distribution in extracellular matrix of clinical AB strains were stronger as compared with those of standard strain ATCC 19606, and BF thickness in clinical AB strains [(27.3 ± 9.4) μm] was thicker than that in standard strain ATCC 19606 [( 15.6 ± 1.7) μm, t = 2.09, P ＜ 0. 05]. Conclusions The high expression of pgaB gene in AB strains isolated from burn patients can induce production of extracellular matrix, which may be related to increase in the ability and thickness of BF formation.     

A prospective analysis of 1400 pulmonary artery catheterizations in patients undergoing cardiac surgery

During 1983 and 1984, 1305 patients underwent 1,400 pulmonary artery (PA) catheterizations. Successful placement was achieved in 1397 (99.6%) of 1,403 attempts. The catheters were inserted via the right internal jugular vein on 1364 occasions. The median duration of monitoring was 28 h with a range from 3 to 220 h. Central venous puncture complications included carotid artery puncture in 67 instances (4.8%) and pneumothorax in one patient. Insertion of the catheters was associated with supraventricular arrhythmias on 11 occasions, ventricular arrhythmias on 930 (66.4%), right bundle branch block on two and a total heart block on one occasion. Eighteen (2.3%) of the 794 cultured catheter tips were positive. An in situ time of more than 72 h was associated with a significantly higher percentage (7.2%) of positive tip cultures compared with an in situ time of less than 72 h (P less than 0.01). Repeated PA catheterization was not associated with significantly more complications than the initial catheterization. The results show that monitoring with a PA catheter in cardiac surgical patients is associated with a low incidence of morbidity.     

Risk factor analysis for long-term tunneled dialysis catheter-related bacteremias

Infection, mainly related to vascular access, is one of the main causes of morbidity and a preventable cause of death in hemodialysis patients. From January 1994 to April 1998 we conducted a prospective study to assess the incidence and risk factors of catheter-related bacteremia. One hundred and twenty-nine tunneled dual-lumen hemodialysis catheters were inserted percutaneously into the internal jugular vein in 89 patients. Bacteremia (n = 56) occurred at least once with 37 (29%) of the catheters (an incidence of 1.1/1,000 catheter-days); local infection (n = 45, 1/1,000 catheter-days) was associated with bacteremia in 18 cases. Death in 1 case was directly related to Staphylococcus aureus (SA) septic shock, and septicemia contributed to deaths in 2 additional cases. Catheters were removed in 48% of the bacteremic episodes. Treatment comprised intravenous double antimicrobial therapy for 15-20 days. Bacteriological data of bacteremia showed 55% involvement of SA. Nasal carriage of SA was observed in 35% of the patients with catheters. Bacteremic catheters were more frequently observed in patients with diabetes mellitus (p = 0.03), peripheral atherosclerosis (p = 0.001), a previous history of bacteremia (p = 0.05), nasal carriage of SA (p = 0.0001), longer catheter survival time (p = 0.001), higher total intravenous iron dose (p = 0.001), more frequent urokinase catheter infusion (p < 0.01), and local infection (p < 0.001) compared with non-bacteremic catheters. Monovariate survival analysis showed that significant initial risk factors for bacteremia were nasal carriage of SA (p = 0.00001), previous bacteremia (p = 0.0001), peripheral atherosclerosis (p = 0.005), and diabetes (p = 0.04). This study confirms the relatively high incidence of bacteremia with tunneled double-lumen silicone catheters and its potential complications. Possible preventive actions are discussed according to the risk factors.     

武汉市第三医院烧伤重症监护病房三年间鲍氏不动杆菌分布及耐药性变化

目的 了解烧伤ICU鲍氏不动杆菌临床分布特征及耐药性变化,寻找与其感染相关的危险因素,为制定防治该菌株感染的策略提供参考. 方法 2006年1月-2008年12月,收集笔者单位烧伤ICU 156例患者的血液、静脉导管、痰液、创面分泌物及咽拭标本,行细菌培养.分析3年间细菌分布情况,检测细菌耐药性,行鲍氏不动杆菌感染相关危险因素分析.用WHONET 5.3软件处理细菌耐药率数据,对其他数据行x2检验与Logistic回归分析. 结果 3年间共检出鲍氏不动杆菌92株,在2006、2007、2008年各年度检出总菌株数中比例分别为23.1%(30/130)、27.5%(25/91)、28.2%(37/131).菌株来源:来自创面分泌物41株占44.6%,咽拭、痰液标本均检出14株各占15.2%,血液标本检出13株占14.1%,静脉导管10株占10.9%.除头孢哌酮/舒巴坦和亚胺培南外,所获鲍氏不动杆菌菌株对临床常用的10种抗生素平均耐药率均达50.0%以上.烧伤总面积(x2=24.374,P=0.000)、机械通气(x2=8.968,P=0.003)、抗生素使用时间(x2=3.981,P=0.046)、深静脉置管(x2=9.170,P=0.002)是引起烧伤ICU鲍氏不动杆菌感染的危险因素,前二者为独立危险因素. 结论 笔者单位烧伤ICU鲍氏不动杆菌广泛耐药且检出率呈逐年增加趋势.严格执行无菌操作及隔离措施,规范性使用抗生素,避免气管切开及深静脉置管等侵入性操作或缩短其时间,对预防和控制鲍氏不动杆菌感染有重要意义.     

Burn wound assessment in porcine skin using indocyanine green fluorescence.

BACKGROUND: An accurate assessment of deep dermal burns within the first week after burn is still an unresolved clinical problem. Infrared-excited fluorescence of indocyanine green was examined as a method of early determination of burn depth. METHODS: Burns of varying depths were placed on the paraspinal region, flank, and abdomen of swine using a heated brass block. Fluorescence images of the burns were recorded 1, 24, 48, and 72 hours later. RESULTS: The ratio of fluorescence in 64 burn wounds relative to adjacent normal tissue identified wounds that healed and did not heal within 21 days with an accuracy of 100%, after accounting for the age of the burn. Higher fluorescence ratios were observed in newly placed burns relative to older burns having comparable depths. CONCLUSION: Deep partial-thickness burns were differentiated from deep dermal full-thickness burns in a porcine skin burn model independent of body location. Diagnosis was possible between 1 and 72 hours after injury.     

Dexamethasone does not alter in vitro antibacterial efficacy of gentamicin.

OBJECTIVES: Aminoglycoside ototoxicity may be mitigated by administration of dexamethasone; however, dexamethasone could theoretically impair its antibacterial properties. The purpose of this experiment was to determine if dexamethasone decreases the antibacterial activity of gentamicin against Pseudomonas aeruginosa (PA) and Staphylococcus aureus (SA). STUDY DESIGN: In vitro microbiological assay. METHODS: Four separate trials of minimum inhibitory concentration (MIC) testing were performed for gentamicin against five PA strains and six SA strains, with and without the addition of high and low concentrations of dexamethasone. RESULTS: MICs were not changed by more than one dilution with the addition of either high or low concentrations of dexamethasone for any of the PA and SA strains. CONCLUSION: Dexamethasone does not impair the antibacterial efficacy of gentamicin for PA and SA. This supports the role of dexamethasone as an oto-protectant with aminoglycoside therapy.     

Outcomes of tunneled femoral hemodialysis catheters: comparison with internal jugular vein catheters

BACKGROUND: Tunneled femoral vein dialysis catheters are used as a last resort when all other options for a permanent vascular access or thoracic central vein catheter have been exhausted. There is little published literature on the complications or outcomes of tunneled femoral catheters. METHODS: Using a prospective, computerized vascular access database, we identified all tunneled femoral dialysis catheters placed at the University of Alabama at Birmingham during a five-year period. The clinical features, catheter patency, and complications in these patients were compared to those observed in a group of sex-, age-, and date-matched control patients with tunneled internal jugular vein dialysis catheters. RESULTS: During the study period, 27 patients received a tunneled femoral dialysis catheter, accounting for 1.9% of all tunneled catheters placed. Only 7 patients (26%) were able to convert to a new permanent dialysis access. The primary catheter patency (time from placement to exchange) was substantially shorter for femoral catheters than for internal jugular dialysis catheters (median survival, 59 vs. >300 days, P < 0.0001). Infection-free survival was similar for both groups (P= 0.66). Seven patients with femoral catheters (or 26%) developed an ipsilateral deep vein thrombosis, but catheter use was possible with anticoagulation. CONCLUSION: Tunneled femoral dialysis catheters have a substantially shorter primary patency, but a similar risk of catheter-related bacteremia, as compared with internal jugular vein catheters. An ipsilateral lower extremity deep vein thrombosis occurs commonly after placement of a femoral dialysis catheter, but does not preclude continued catheter use.     

烧伤病房鲍氏不动杆菌耐药性趋势和同源性分析

目的 监测烧伤病房鲍氏不动杆菌耐药性趋势和同源性情况.方法收集2008年11月-2009年2月、2010年6-9月笔者单位住院烧伤患者创面、血液和静脉导管分离的鲍氏不动杆菌26株,采用K-B纸片扩散法检测该菌对阿米卡星、庆大霉素等13种临床常用抗生素的耐药性,用重复序列PCR法检测基因分型.对细菌耐药率数据进行x2检验.结果 (1)26株鲍氏不动杆菌中多药耐药菌株16株、泛耐药菌株9株,菌株对庆大霉素、哌拉西林、哌拉西林/他唑巴坦、头孢呋辛、头孢噻肟、头孢他啶、头孢吡肟、环丙沙星、亚胺培南和美罗培南的耐药率均高达90.00%以上;对头孢哌酮/舒巴坦的耐药率最低,为42.31%(11/26).26株鲍氏不动杆菌对13种抗生素的耐药率比较,差异有统计学意义(42.31%～100.00%,x2=97.371,P＜0.05).(2)26株鲍氏不动杆菌共分为7个基因型:A型17株,B型3株,C型2株,D、E、F、G型各1株.17株A型菌株中,2008、2009年各1株,2010年15株;创面来源11株、血液和静脉导管来源共6株.结论笔者单位烧伤病房近年来存在鲍氏不动杆菌同一克隆株A型的流行,对临床常用抗生素呈多药耐药或泛耐药趋势.目前头孢哌酮/舒巴坦是治疗烧伤患者鲍氏不动杆菌感染的首选药物.

Abstract：

Objective To monitor genotypes and drug-resistance trend of Acinetobacter baumannii (AB) isolated from burn wards. Methods Twenty-six strains of AB isolated from wound secretion, venous catheter, and blood were collected from burn patients hospitalized in our burn wards from November 2008 to February 2009, and June to September 2010. Homogeneous genotype analysis was performed with repetitive extragenic palindromic PCR, and drug-resistance rate to 13 antibiotics including amikacin, gentamicin, etc. , which were commonly used in clinic, was tested by K-B paper disk diffusion. The data of drugresistance rate were processed with chi-square test. Results ( 1 ) Sixteen AB strains were multi-drug resistant (MDR), 9 AB strains were pan-drug resistant (PDR). Among all strains, the resistance rate to gentamicin, piperacillin, piperacillin/tazobactam, cefuroxime, cefotaxime, ceftazidime, cefepime, ciprofloxacin, imipenem, and meropenem was respectively higher than 90.00%; the resistance rate against cefoperazone/sulbactam was the lowest (11/26, 42.31% ). There were obvious difference among the drug-resistance rates of AB strains to 13 antibiotics (with rates from 42.31% to 100.00% , x 2 = 97. 371, P ＜ 0.05 ). (2)There were 7 genotypes among 26 AB strains, respectively type A ( 17), type B (3), type C (2) , type D (1), type E (1), typeF (1), and typeG (1). Out of the 17 AB strains inAgenotype, 1 strain was from 2008, 1 strain was from 2009, 15 strains were from 2010, and among them 11 strains were collected from wound secretion and 6 strains were obtained from blood and venous catheter. Conclusions AB strains in A genotype are dominant in our burn wards in recent years, which are MDR or PDR to commonly used antibiotics. Cefoperazone/sulbactam is the drug of choice for burn patients with AB infection.     

热损伤角质形成细胞培养上清液对成纤维细胞生物学行为的影响

目的 了解KC热损伤后培养上清液对真皮Fb生物学行为的影响.方法 分离培养人真皮Fb,另建立KC(选用HaCaT细胞)热损伤模型.收集正常堵养及热损伤后12 h的KC培养上清液,用无血清DMEM以1:1体积比稀释,分别制成正常KC和热损伤KC 2种条件培养液.将Fb分别用无血清DMEM和2种条件培养液培养:(1)于培养12、24、36、48 h时,采用噻唑蓝法检测Fb增殖活性;(2)于培养12 h时,用流式细胞术检测Fb的凋亡情况(Fb预先致热损伤,并增设Fb伤后无处理对照);(3)培养24 h时,用免疫荧光法检测Fb胞质α平滑肌肌动蛋白(α-SMA)的表达情况,并用实时定量PCR法测定Fb α-SMA mRNA的表达.对实验结果进行单因素方差分析,用LSD-t检验行组间两两比较.结果 (1)Fb增殖活性:Fb经热损伤KC条件培养液培养12、24、36、48 h时,其吸光度值均高于同时相点用无血清DMEM培养的Fb(t值分别为1.89、2.35、2.02、1.94,P值均小于0.01);其中12、24、48 h时与用正常KC条件培养液培养的Fb比较,差异有统计学意义(12 h时t=1.83,P<0.01;24 h时t=2.91,P<0.05;48 h时t=1.83,P<0.05).(2)Fb凋亡检测:热损伤KC条件培养液培养的Fb与正常KC条件培养液培养以及伤后无处理的Fb比较,凋亡率均明显下降(t=3.31,P<0.05;t=1.47,P<0.01).(3)Fb胞质α-SMA表达:荧光显微镜下可见,用无血清DMEM或正常KC条件培养液培养的Fb中,α-SMA阳性表达(红色荧光)细胞较少;热损伤KC条件培养液培养的Fb中,α-SMA阳性表达细胞明显增多.(4)α-SMA mRNA表达:热损伤KC条件培养液培养的Fb α-SMA mRNA相对表达量为1.32±0.06,高于正常KC条件培养液培养的Fb(1.14±0.07,t=2.51,P<0.05)和无血清DMEM培养的Fb(1.00±0.09,t=1.77,P<0.05).结论 KC热损伤后12 h培养上清液可明显促进Fb增殖、抑制Fb凋亡、促进Fb向肌成纤维细胞转分化.