Genç Bahçe Yasemin, Toyran Alparslan, Aksoy Altan
Siirt State Hospital, Medical Microbiology Laboratory, Siirt, Turkey.
Ankara Numune Training and Research Hospital, Medical Microbiology Laboratory, Ankara, Turkey.
Mikrobiyol Bul. 2019 Apr;53(2):119-133. doi: 10.5578/mb.67842.
Bloodstream infections are one of the main causes of morbidity and mortality worldwide. Shortening the turnover time of microbiological analysis leads to a significant reduction of patient morbidity, mortality and medical care expenses. This study aimed to evaluate the performance of Phoenix 100 Instrument (Becton Dickinson, Sparks, MD, USA) system in bacterial identification and the evaluation of antibiotic susceptibility directly taken from positive blood culture bottles in BD BACTEC™ FX (Becton Dickinson, USA) system in patients with the suspicion of bacterial sepsis. In this study, blood culture bottles with a positive signal in BD BACTEC™ FX (Becton Dickinson, USA) system, and in which gram negative bacilli or coccobacilli was observed in Gram staining were evaluated. In our study, direct inoculation to the Phoenix panel from the blood culture bottles giving positive signal was defined as "direct Phoenix method". The blood culture bottles which were taken from hospitalized patients with a suspicion of sepsis, were analyzed comparatively by using BD Phoenix™ (Becton Dickinson, USA) automated microbiology system and "Bruker Biotyper matrix-associated laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS)" (Bruker Daltonics, Germany) in the bottles of patients with the positive signals between August 10, 2015, and December 05, 2015. The effect of the "direct Phoenix method" on the duration of the test and the harmony with conventional methods was demonstrated. A total of 122 gram negative bacteria comprising 95 bacteria in Enterobacteriaceae family, 26 non-fermenting gram negative bacteria (NFGNB) and one Aeromonas spp. were included in the study. In our study, the reporting time of the identification of gram negative bacteria after inoculation with direct Phoenix method ranged from 2.25 hours to 7.84 hours (mean 2.56 hours). When the identification of 122 gram negative bacteria by direct Phoenix method was compared with the identification of Maldi Biotyper (Bruker Daltonics, Germany), an agreement was detected in 96.7% (118/122) of the samples at the genus level and in 86.0% (105/122) of the samples at the species level. Ninety-five bacteria belonging to Enterobacteriaceae family demonstrated an agreement of 95.7% (91/95) and 93.6% (89/95) at the genus and species levels with Maldi Biotyper respectively. Twenty-five NFGNB had an agreement of 96.1% (25/26) and 61.5% (16/26) at genus and species levels with Maldi Biotyper respectively. In our study, the reporting time of antibiotic susceptibility test results of gram negative rods after direct Phoenix method ranged from 7.42 hours to 15.85 hours (mean 12.9 hours). In our study, 2.159 antimicrobial agents were tested for 120 gram negative bacteria (95 strains belonging to Enterobacteriaceae family and 25 NFGNB). Minor error rate was found to be 2.0% with the direct Phoenix method, 1.1% major error rates, and 1.2% very major error rates; making a total of 4.4% (96/2.159). Since error rates in all categories < 10%, very major error rate was < 1.5% and major error rate was < 3%, the direct Phoenix method had an acceptable agreement with the conventional Phoenix method. The direct inoculation of the Phoenix system with culture suspension obtained from positive blood culture bottles decreased reporting time of the identification and determination of the antibiotic susceptibilities for gram negative rods that cause bacteraemia. This result could be important in the clinical benefits for the patients as well as financial savings for the hospital.
血流感染是全球发病和死亡的主要原因之一。缩短微生物分析的周转时间可显著降低患者的发病率、死亡率和医疗费用。本研究旨在评估Phoenix 100仪器(美国马里兰州斯帕克斯市贝克顿·迪金森公司)系统在细菌鉴定方面的性能,以及对疑似细菌性败血症患者直接取自BD BACTEC™ FX(美国贝克顿·迪金森公司)系统阳性血培养瓶的抗生素敏感性进行评估。在本研究中,对在BD BACTEC™ FX(美国贝克顿·迪金森公司)系统中发出阳性信号且在革兰氏染色中观察到革兰氏阴性杆菌或球杆菌的血培养瓶进行了评估。在我们的研究中,将发出阳性信号的血培养瓶直接接种到Phoenix鉴定板上定义为“直接Phoenix法”。对2015年8月10日至2015年12月5日期间有阳性信号的住院疑似败血症患者的血培养瓶,使用BD Phoenix™(美国贝克顿·迪金森公司)自动化微生物系统和“布鲁克微生物鉴定仪基质辅助激光解吸电离飞行时间质谱(MALDI-TOF MS)”(德国布鲁克道尔顿公司)进行了比较分析。证明了“直接Phoenix法”对检测时间的影响以及与传统方法的一致性。本研究共纳入122株革兰氏阴性菌,其中肠杆菌科95株,非发酵革兰氏阴性菌(NFGNB)26株,气单胞菌属1株。在我们的研究中,采用直接Phoenix法接种后革兰氏阴性菌鉴定的报告时间为2.25小时至7.84小时(平均2.56小时)。将直接Phoenix法对122株革兰氏阴性菌的鉴定结果与Maldi Biotyper(德国布鲁克道尔顿公司)的鉴定结果进行比较,在属水平上96.7%(118/122)的样本、在种水平上86.0%(105/122)的样本检测到一致性。属于肠杆菌科的95株菌在属和种水平上与Maldi Biotyper的一致性分别为95.7%(91/95)和93.6%(89/95)。25株NFGNB在属和种水平上与Maldi Biotyper的一致性分别为96.1%(25/26)和61.5%(16/26)。在我们的研究中,直接Phoenix法后革兰氏阴性杆菌抗生素敏感性试验结果的报告时间为7.42小时至15.85小时(平均12.9小时)。在我们的研究中,对120株革兰氏阴性菌(95株肠杆菌科菌株和25株NFGNB)检测了2159种抗菌药物。直接Phoenix法的小错误率为2.0%,主要错误率为1.1%,非常主要错误率为1.2%;总计4.4%(96/2159)。由于所有类别中的错误率<10%,非常主要错误率<1.5%,主要错误率<3%,直接Phoenix法与传统Phoenix法具有可接受的一致性。用从阳性血培养瓶中获得的培养悬液直接接种Phoenix系统,可缩短引起菌血症的革兰氏阴性杆菌鉴定和抗生素敏感性测定的报告时间。这一结果对患者的临床益处以及医院的经济节省可能具有重要意义。