4 689例血培养病原菌的临床分布与种类分析

目的：了解本院血培养病原菌的检出种类及在临床各科的分布。方法：应用Bact/Alert-120全自动血培养仅对4689例血标本进行培养,标本检出病原菌按常规鉴定并分类统计。结果：检出有临床意义病原菌355株,其中肠杆菌科和葡萄球菌属的细菌为主要病原菌（35.5%和27.3%)。以2000年全年标本统计,阳性率12.5%,假阳性率0.4%。以内科,外科,儿科,传染科,血液科,新生儿科等为病区统计,病原菌种类分布有明显不同,此外,病原菌种类不同,其阳性报告时间不同。结论：应用全自动血培养仪可以缩短阳性检出时间,了解病原菌在临床各科的分布特点,有利于医师对败血症诊治,及时准确地选择药物。     

手工和仪器两种血培养结果差异性分析

目的对手工法双相血培养瓶和BACTEC9120全自动血培养仪的阳性率作回顾性分析。方法将血液标本同时接种双相血培养基和BACTEC9120全自动血培养仪配套血瓶中,将阳性结果移种血平板,如为阴性再移种巧克力平板。结果370例血培养,双相血培养瓶阳性25例,阳性率为6．76％（25／370）,树脂需氧（儿童）瓶BACTEC9120报警显示阳性59例,阳性率为15．9％（59／370）,阳性标本移种到血平板及巧克力平板阳性54例,阳性率为14．6％（54／370）,假阳性5例,假阳性率为1．4％（5／370）,共有29例树脂需氧（儿童）瓶阳性,而双相血培养瓶为阴性,P〈0．001。结论BACTEC9120全自动血培养仪提高阳性率,缩短阳性的报告时间优于传统的双相血培养基。     

不同种类微生物血培养阳性报警时间分析

目的分析不同病原菌在Bact/Alert 3D血培养仪中的阳性报警时间。方法收集浙江大学医学院附属第一医院2012年10月到2013年8月血培养阳性报警时间,分析病原菌种类,算出各常见病原菌阳性报警的中位时间。结果总共1 472份阳性标本:革兰阳性菌占55.2%,革兰阴性菌占37.5%,真菌占7.3%。对血培养阳性报警时间进行分析:≤12 h、≤24 h、≤48 h报警的病原菌分别为420株(28.5%)、956株(64.9%)、1290株(87.6%)。血培养阳性病原菌仪器报警中位时间分别为肠杆菌科细菌(10.8 h)、非发酵菌属(13.9 h)、链球菌属(14.6 h)、肠球菌属(14.5 h)、葡萄球菌属(22.3 h)、真菌(43.4 h)。大肠埃希菌(10.1 h)、鲍曼不动杆菌(10.8 h)、阴沟肠杆菌(10.8 h)、肺炎克雷伯杆菌(11.1 h)阳性报警中位时间相近,都≤12 h。结论根据全自动血培养仪对不同种类微生物阳性报警时间的差别,可初步判断病原菌的生长和类型,第一时间指导临床医师准确、合理选择抗菌药物。     

血液或无菌体液培养阳性标本中病原菌检测结果分析

目的：了解血培养（包括血液、无菌体液培养,下同）阳性标本中病原菌的分布及阳性报警时间,为临床及时明确病原菌和正确用药提供参考依据。方法：无菌条件下采集血培养标本注人相应的培养瓶,经仪器扫描后放入血培养仪进行检测,报警后及时进行菌种鉴定和药敏试验。结果：364例阳性报警标本中真阳性标本为176例,其中革兰阳性菌占61．7％,革兰阴性菌占35．0％,真菌占3．3％;188例为假阳性标本,其中革兰阳性菌占54％,革兰阴性菌占41．9％,真菌占4．0％;新生儿科的感染阳性率最高;不同种类病原菌的阳性报警时间多重叠;临床医生经验用药正确或根据药敏结果更换用药的百分比为78．2％。结论：本院引起血液、无菌体液感染的病原菌以革兰阳性细菌为主,病原菌种类较多,存在一定的污染;当新生儿有局部感染时要警惕脓毒血症;单独靠血培养仪报警时间来鉴定区分病原菌与污染菌不一定可靠,及时了解血培养结果及标准药敏结果可以辅助找出感染性疾病的病因,尽早正确合理的使用抗菌药物,从而优化抗菌治疗。     

中山地区小儿血培养病原菌分布及耐药性分析

目的了解中山地区小儿血培养病原菌分布及其常见病原菌对抗生素的耐药情况。方法对2008年至2009年南方医科大学附属中山市博爱医院新生儿科、儿科住院患儿进行血培养,应用BacT/ALERT 3D全自动血培养仪进行检测,阳性菌株用VITEK-32全自动微生物分析仪进行菌株鉴定及药敏试验。结果 4 647例小儿血培养共检出病原菌316株,总阳性率为6.8%;革兰阳性菌258株(81.6%),其中凝固酶阴性葡萄球菌(CNS)209株(66.1%);革兰阴性菌55株(17.4%),以大肠埃希菌14株(4.4%)和肺炎克雷伯菌12株(3.8%)为主。革兰阳性菌对青霉素G耐药率高达93.4%,其次为氨苄西林/舒巴坦(82.9%)、苯唑西林(82.3%),耐药率均在80%以上。耐甲氧西林金黄色葡萄球菌(MRSA)占25%,耐甲氧西林凝固酶阴性葡萄球菌(MRSCN)占82.3%。未检出对万古霉素、利奈唑胺和呋喃妥因耐药的菌株。革兰阴性菌中大肠埃希菌、肺炎克雷伯菌ESBLs的检出率分别为50%和33%,这些菌株对头孢哌酮/舒巴坦、丁胺卡那霉素、左旋氧氟沙星和亚胺培南的敏感率分别为91.7%、100%、92.9%、100%,表现了较低耐药率。结论本地区小儿血培养病原菌以革兰阳性菌为主,且表现为多重耐药。     

2011～2013年血液分离葡萄球菌的临床分布及耐药性分析

目的了解临床各科发热患者（怀疑细菌感染）血培养中葡萄球菌分布及耐药性,为临床治疗提供参考依据。方法血培养采用BaeT／Alert3D全自动血培养仪（梅里埃）培养5d,采用MicroScanWalk—Away-96plus全自动微生物鉴定和药敏分析系统（西门子）进行细菌鉴定和药敏试验。结果血培养共检出葡萄球菌185株,检出最多的科室是ICU,耐甲氧西林金黄色葡萄球菌（methicillin—resistant Staphylococcus aureus,MRSA）检出率为30．4％,而耐甲氧西林凝固酶阴性葡萄球菌（methicillin—resistant coagulase-negative Staphylococci,MRCNS）的检出率高达80．7％。还检出了1株万古霉素中介的凝固酶阴性葡萄球菌。结论通过血培养检出葡萄球菌的耐药性分析发现,凝固酶阴性葡萄球菌对苯唑西林、氨苄西林、青霉素、红霉素的耐药率在70％以上,而对氯霉素、利福平、四环素的耐药率在30％以下,因此这三种药物应为我院应对凝固酶阴性葡萄球菌血流感染的常用首选药物。     

细菌自动培养仪厌氧培养的临床应用

目的 :探讨用细菌自动培养仪作厌氧培养的临床应用价值。方法 :选用 mini VITAL 全自动荧光血培养仪检测常见临床标本 5472份 (其中血液 4869瓶、胸腹水 2 40瓶、脓腔及组织穿刺液 175瓶、脑脊液12 2瓶、骨髓液 2 3瓶、胆汁及其引流液 2 1瓶、其他 2 2瓶 )厌氧培养结果 ,对其阳性检出率、检出细菌种类和时间、假阳性以及药敏结果进行综合分析和评估。结果 :设定收瓶时间为 5d,厌氧培养的阳性检出率为2 5.51% (其中胆汁 76.19% ,脓汁 57.14 % ,血液 2 5.2 8% ,胸腹水 14 .17% ,骨髓 13 .0 4% ,脑脊液 5.74% ) ;共检出各种感染菌 3 3属 77种 ,专性厌氧菌、微需氧菌和兼性厌氧菌的比例为 4.8∶ 1.0∶ 94.2 ;专性厌氧菌的平均检出时间为 (2 6.13± 2 0 .59) h;兼性厌氧菌的检出时间厌氧株比需氧株平均延长 -0 .54～ 4.7h;假阳性率 0 .16% ;药敏结果厌氧株的耐药率普遍较需氧株低。结论 :仪器厌氧培养简便、快速、安全、有效 ,是临床常见标本检测厌氧菌值得推荐使用的方法 ;与需氧培养配对应用可提高培养阳性检出率     

外科血培养标本中病原菌分布及耐药性分析

目的了解中山大学附属第一医院外科血标本中病原菌的菌种分布及常见菌株的耐药性。方法血标本用Bact/A lert-120全自动血培养仪进行血培养,阳性血培养转种后用VITEK-60 AMS细菌鉴定仪鉴定,用K-B法进行药敏试验。结果2002年1月至2005年12月血培养标本中共分离出病原菌256株,阳性率为10.6%。122株(47.7%)为革兰阴性杆菌,其中肠杆菌科细菌占72.1%(88/122),非发酵菌占27.9%(34/122);113株(44.1%)为革兰阳性球菌,其中葡萄球菌属占51.3%(58/113),肠球菌占38.1%(43/113);真菌21株(8.2%)。血培养中的革兰阴性杆菌对亚胺培南、美洛培南治疗敏感;革兰阳性球菌对万古霉素和替考拉宁敏感。结论肠杆菌科细菌和葡萄球菌是外科血培养中的主要病原菌,其耐药现象严重,宜根据药敏结果选用敏感抗菌药物治疗。     

压电体声波阻抗生物传感器技术在血培养中的应用评价

评价全自动压电体声波阻抗生物传感器血液培养系统的应用价值,并与Bactec9120血培养系统相比较。将2005年7~12月临床标本407例分别同时接种于2种不同的血培养系统中进行培养,对其阳性检出率、阳性检出时间、假阳性率及相关因素进行综合性评估。407份标本全自动压电体声波阻抗生物传感器血液培养系统检测出阳性标本58株,阳性率为14.3%,平均检出时间为(11.58±7.62)h;Bactec9120血培养系统培养阳性菌株61株,阳性率为15.0%,平均检出时间为(18.71±12.89)h。经统计学处理,两种检测方法阳性率无显著性差异(χ2=0.089,P>0.5),但检出时间有显著性差异(t=3.64,P<0.001)。全自动压电体声波阻抗生物传感器血液培养系统快速、简单、准确、便宜,可在各医院推广使用。     

2005年至2009年舟山地区血培养病原菌分布及耐药性分析

目的了解舟山地区近5年住院与门诊患者血培养病原菌分布及常见病原菌对抗菌药物的耐药情况,为指导临床诊断及合理用药提供可靠依据。方法对收集的2005年1月至2009年12月10086份血标本采用BACTEC 9120全自动血培养仪进行检测,794株阳性菌株由ATB Expression半自动微生物分析仪进行菌株鉴定及药敏试验。结果 10 086份血培养标本共分离出病原菌794株,总阳性率为7.9%,其中革兰阳性菌424株,占总分离率的53.4%,以表皮葡萄球菌为主,革兰阴性菌328株,占总分离率的41.31%,以大肠埃希菌为主。药敏结果显示表皮葡萄球菌对青霉素耐药最高,未发现对万古霉素、替考拉宁的耐药株,对呋喃妥因耐药率较低,对庆大霉素和左旋氧氟沙星的耐药率逐年明显上升(χ2=11.41,P<0.05;χ2=13.07,P<0.05)。大肠埃希菌未发现亚胺培南和美罗培南的耐药株,对环丙沙星的耐药率逐年明显上升(χ2=12.00,P<0.05)。结论该地血培养病原菌以表皮葡萄球菌和大肠埃希菌为主,药敏结果提示多药耐药,对部分抗生素的耐药率逐年上升应加以重视。     

Evaluation of negative results of BacT/Alert 3D automated blood culture system

Although automated continuous-monitoring blood culture systems are both rapid and sensitive, false-positive and false-negative results still occur. The objective of this study, then, was to evaluate negative results occurring with BacT/Alert 3D blood culture systems. A total of 1032 samples were cultured with the BacT/Alert 3D automated blood culture system, using both aerobic (FA) and anaerobic (FN) [corrected] media, and 128 of these samples yielded positive results. A total of 904 negative blood samples were then subcultured in 5% sheep blood agar, eosin methylene blue, chocolate agar, and sabouraud-dextrose agar. Organisms growing on these subcultures were subsequently identified using both Vitek32 (bioMerieux, Durham, NC) and conventional methods. Twenty four (2.6%) of the 904 subcultures grew on the subculture media. The majority (83.3%) of these were determined to be gram-positive microorganisms. Fourteen (58.3%) were coagulase-negative staphylococci, two (8.3%) were Bacillus spp., one (4.2%) was Staphylococcus aureus, and one (4.2%) was identified as Enterococcus faecium. Streptococcus pneumoniae and Neisseria spp. were isolated together in two (8.3%) vials. Gram-negative microorganisms comprised 12.5% of the subcultures, of which two (8.3%) were found to be Pseudomonas aeruginosa, and one (4.2%) was Pseudomonas fluorescens. The other isolate (4.2%) was identified as Candida albicans. We conclude that the subculture of negative results is valuable in the BacT/Alert 3D system, especially in situations in which only one set of blood cultures is taken.     

Epidemiology of bloodstream infections and time to detection of positive blood cultures: an evaluation of the automated BacT/Alert and BACTEC 9240 systems

Data of 3,097 blood culture sets processed with the BacT/Alert system in 1997 were compared to those of 3,158 blood culture sets processed with BACTEC 9240 in 1999. Agents responsible for bloodstream infections (BSI) were detected in 15.9% and 20.0% of blood cultures in 1997 and 1999, respectively. The incidence of BSI was 9.3 (1997) vs. 11.3 (1999) per 1,000 admissions. In both years, S. aureus was the most frequent isolate, followed by E. coli. Overall, the mean detection time (MDT) obtained with the BACTEC 9240 was significantly shorter than that of the BacT/Alert. Significant MDT differences were found for all organisms, except for Enterobacteriaceae (12.7 vs. 10.6 h). With both systems, over 95% positive samples were detected within 3 days, indicating that a 4-day incubation protocol may disclose most BSI agents. Thus, the added speed of the BACTEC 9240 allowed a particularly fast clinical management of septic patients.     

The rapid evaluation of bacterial growth in blood cultures by selected ion flow tube-mass spectrometry (SIFT-MS) and comparison with the BacT/ALERT automated blood culture system

We compared the performance of the BacT/ALERT automated blood culture system with real-time, quantitative volatile organic compound (VOC) detection by selected ion flow tube-mass spectrometry (SIFT-MS). Blood samples from healthy donors were artificially infected with 5 or 100 CFU of organisms commonly causing bacteremia. Positive results by SIFT-MS analysis of headspace gases were recorded for 53/60 (88.3%) bottles at 8h, and 58/60 (96.6%) bottles at 24 h. We conclude that SIFT-MS is a sensitive method for the detection of microbial VOCs. Furthermore, profiles of the VOCs detected may allow simultaneous identification of infecting organisms.     

革兰阴性菌引起的血培养阳性标本直接细菌鉴定和药敏的应用

目的 评估血培养阳性标本直接细菌鉴定和药敏可行性.方法 将血培养瓶放入Bact/Alert 3D 60血培养系统进行培养筛选.选取78份含革兰阴性杆菌的阳性血培养瓶进行试验.抽取培养液,用BD真空分离管离心血细胞.在收集到足量菌液后,用VITEK-32革兰阴性菌鉴定药敏卡做直接鉴定药敏试验.用标准方法及亚培养后的鉴定药敏试验对直接鉴定药敏试验进行评估.结果 VITEK-32直接鉴定试验,78株中的74株(94.9％)准确鉴定,直接药敏试验标准符合率95.6％.KB法血标本直接药敏试验标准符合率96.2％,但微小错误率高于VITEK-32直接药敏法.结论 Bact/Alert血培养阳性标本直接VITEK-32细菌鉴定和药敏对革兰阴性菌是切实可行的,可大幅度缩短时间,为临床及时修正用药提供依据,具有较高的应用价值.     

Yeast-like fungi as etiologic agents of blood infections in patients hospitalized in 1998-1999

The aim of the study was the analysis of frequency of yeast-like fungi as etiological agents of fungemias in patients hospitalized in operative and conservative wards of Medical Academy Central Clinical Hospital in Warsaw in 1998-1999. Peripheral blood samples and collected from vascular catheters were incubated in BacT/Alert system(Organon Teknika, USA). Positive blood samples were inoculated on Sabouraud medium with chloramphenicol (bioMerieux, France) (the time of cultivation from 48 h to 7 days at 30 C) and on chromogenic medium BBL CHROMagar Candida (Becton Dickinson, USA). Fungal strains were identified by standard mycological procedures using ID 32 C strips (ATB system, bioMerieux, France) and tests of Sanofi Diagnostics Pasteur (France). The total number of positive blood cultures was 1724. Fifty eight fungal strains were isolated from blood samples (3.36%). Strains belonged to 4 genera: Candida (55), Trichosporon (1), Saccharomyces (1) and Pichia (1). Thirty eight fungal strains were isolated from peripheral blood samples. Forty seven fungal strains were cultured from patients hospitalized in operative wards. Among fungi isolated from peripheral blood samples C. albicans (10), C. glabrata (9) and C. parapsilosis (5) strains dominated. From blood samples collected from vascular catheters most often C. albicans (7), C. glabrata (4) and C. parapsilosis (3) were isolated.     

Roadmap to approval: use of an automated sterility test method as a lot release test for Carticel, autologous cultured chondrocytes

BACKGROUND: In February 2004, FDA approved a supplement to our biologics license for Carticel, autologous cultured chondrocytes, to use the BacT/ALERT microbial detection system as an alternative to the compendial sterility test for lot release. This article provides a roadmap to our approval process. The approval represents more than 4 years of development and validation studies comparing the Steritest compact system to the BacT/ALERT microbial detection system. METHODS: For this study, freshly cultured chondrocytes were prepared from a characterized cell bank. Microbial isolates were prepared from either American Type Culture Collection (ATCC) strains or from in-house contaminants. For each test condition, a suspension of chondrocyte cells and test organisms was inoculated into both aerobic media (SA standard adult culture bottles, FA FAN, tryptic soy broth) and anaerobic media (SN standard adult culture bottles, FN FAN, fluid thioglycollate media) and tested for sterility using the Steritest compact system (Millipore, Bedford, MA, USA) and the BacT/ALERT microbial detection system (bioMerieux, Durham, NC, USA). Negative control bottles were inoculated with chondrocytes and no microorganisms. All bottles were incubated for 14 days and read daily. Bacterial growth was determined by either visual examination of Steritest canisters or detection of a positive by the BacT/ALERT system. A gram stain and streak plate were used to confirm positive bottles and negative bottles after 14 days. RESULTS: The detection of a positive by either the Steritest compact system or the BacT/ALERT system was summarized for each organism in each validation study. Data generated from studies reducing the incubation temperature from 35 degrees C to 32 degrees C improved detection times in the automated method compared with the compendial method. Other improvements included the use of FAN aerobic and anaerobic media to absorb the gentamicin contained in the culture media of prepared chondrocyte samples. Chondrocytes alone did not generate positive results in either the compendial method or the automated method. DISCUSSION: Data from validation studies support the use of the BacT/ALERT microbial detection system as an alternative sterility test for Carticel.     

Etiologic agents of fungemia in hospitalized patients]

The aim of performed examinations was the analysis of fungi as etiological agents of blood infections in patients hospitalized in surgical wards, internal medicine wards and intensive care units of the Medical Academy Central Clinical Hospital in Warsaw. Blood samples from patients hospitalized in 1997 were examined. Peripheral blood samples were incubated in BacT/Alert system (Organon Teknika, USA). Positive blood samples were inoculated on Sabouraud medium with chloramphenicol (bioMerieux, France or Oxoid, England). The time of cultivation was from 48 hours to 7 days at 30 degrees C. Fungal strains were identified by standard mycological procedures with the use of chromogenic medium BBL CHROMagar Candida (Becton Dickinson, USA) and biochemical test ID 32 C (bioMerieux, France). Susceptibility of strains to antifungal agents was determined by ATB FUNGUS method (bioMerieux, France). The total number of positive blood cultures in 1997 was 1380. Forty-two fungal strains were isolated from blood samples (3%). Strains belonged to the following species: C. albicans (17 isolates), C. parapsilosis (15), C. glabrata (3), melibiosica (2), C. pelliculosa (2), C. guilliermondii (1), C. tropicalis (1) and T. beigelii (1). Among fungi cultured from patients hospitalized in operative wards dominated C. parapsilosis (11) and C. albicans (10) strains, whereas from patients hospitalized in conservative wards most often C. albicans (6) strains were isolated. Candida strains were mostly susceptible to antifungal agents tested. It was interesting to culture Trichosporon beigelii (T. cutaneum) strain as an etiological agent of fungemia. This strain was multidrug-resistant.