Larsson Marie C, Karlsson Ewa, Woksepp Hanna, Frölander Kerstin, Mårtensson Agneta, Rashed Foad, Annika Wistedt, Schön Thomas, Serrander Lena
Division of Clinical Microbiology, Department of Clinical and Experimental Medicine, Linköping University, Linköping, SE 581 85, Sweden.
BMC Infect Dis. 2014 Mar 19;14:146. doi: 10.1186/1471-2334-14-146.
The aim of this study was to evaluate diagnostic tests in order to introduce a diagnostic strategy to identify the most common gram-positive bacteria (pneumococci, enterococci, β-haemolytic streptococci and S. aureus) found in blood cultures within 6 hours after signalling growth.
The tube coagulase test was optimized and several latex agglutination tests were compared and evaluated before a validation period of 11 months was performed on consecutive positive blood culture patient samples from Kalmar County Hospital, Sweden.
During the validation period 150 (91%) of a total of 166 gram-positive cocci (119 in clusters, 45 in chains or pairs and 2 undefined morphology) were correctly identified as S. aureus, CoNS, Pneumococci, Enterococci or group A streptococci (GAS), group B streptococci (GBS), group G streptococci (GGS) within 6 hours with a minimal increase in work-load and costs. The remaining samples (9%) were correctly identified during the next day. No samples were incorrectly grouped with this diagnostic strategy and no patient came to risk by early reporting.
A simple strategy gives reliable and cost-effective reporting of >90% of the most common gram-positive cocci within 6 hours after a blood cultures become positive. The high specificity of the tests used makes preliminary reports reliable. The reports can be used to indicate the focus of infection and not the least, support faster administration of proper antimicrobial treatment for patients with serious bacterial infections.
本研究的目的是评估诊断测试，以便引入一种诊断策略，在血培养显示生长后6小时内识别血培养中最常见的革兰氏阳性菌（肺炎球菌、肠球菌、β-溶血性链球菌和金黄色葡萄球菌）。
优化了试管凝固酶试验，并比较和评估了几种乳胶凝集试验，然后对瑞典卡尔马县医院连续的血培养阳性患者样本进行了11个月的验证期。
在验证期内，总共166株革兰氏阳性球菌中的150株（91%）（119株呈簇状、45株呈链状或成对状，2株形态未定义）在6小时内被正确鉴定为金黄色葡萄球菌、凝固酶阴性葡萄球菌、肺炎球菌、肠球菌或A组链球菌（GAS）、B组链球菌（GBS）、G组链球菌（GGS），工作量和成本增加最小。其余样本（9%）在第二天被正确鉴定。采用这种诊断策略没有样本被错误分组，也没有患者因早期报告而面临风险。
一种简单的策略能够在血培养阳性后6小时内对90%以上最常见的革兰氏阳性球菌进行可靠且具有成本效益的报告。所使用测试的高特异性使得初步报告可靠。这些报告可用于指示感染部位，最重要的是，支持对严重细菌感染患者更快地给予适当的抗菌治疗。
