Wheeler Janice, Freeman Roger, Steward Michael, Henderson Kirstine, Lee Maureen J S, Piggott Nigel H, Eltringham Gary J A, Galloway Angela
Newcastle Regional Public Health Laboratory, Westgate Road, Newcastle upon Tyne NE4 6BE.
Novocastra Laboratories Ltd, Balliol Business Park West, Benton Lane, Newcastle upon Tyne NE 12 8EW.
J Med Microbiol. 1999 Sep;48(9):863-866. doi: 10.1099/00222615-48-9-863.
Western blot detection of the species-specific pneumococcal product, pneumolysin (SPN), was shown to be almost as sensitive as PCR for the non-cultural detection of pneumococci in 27 Streptococcus pneumoniae culture-positive sputa from patients stated to have chest infections. Both techniques were considerably more sensitive than counter-current immuno-electrophoresis for pneumococcal capsular polysaccharide antigens (CPS-CIE) on the same specimens. Sensitivities for PCR, SPN-immunoblotting and CPS-CIE were 100%, 85% and 67%, respectively. In 11 S. pneumoniae culture-negative sputa taken from patients receiving antibiotics, but with proven recent pneumococcal infection, PCR and SPN-blot were positive in six (in two of which CPS-CIE was also positive), PCR alone was positive in one and SPN-blot alone was positive in one. In 11 S. pneumoniae culture-negative samples from patients not receiving antibiotics, all three tests were negative in eight, PCR was positive in three (in one of which CPS-CIE was also positive), but SPN-blot was negative in all 11. In 16 S. pneumoniae culture-negative samples from patients receiving antibiotics and with no known recent pneumococcal infections, one or more non-cultural test was positive in 11. Although further evaluation is required to assess the significance of pneumolysin detection in relation to carriage and infection and to devise a more suitable test format, these preliminary studies suggest that pneumolysin detection is a promising new approach to the non-cultural diagnosis of pneumococcal chest infection.
在27份来自确诊患有胸部感染患者的肺炎链球菌培养阳性痰液中，对种特异性肺炎球菌产物——肺炎溶血素（SPN）进行蛋白质印迹检测，结果显示其对肺炎球菌非培养检测的敏感性几乎与聚合酶链反应（PCR）相同。对于同一标本中的肺炎球菌荚膜多糖抗原（CPS-CIE），这两种技术的敏感性均显著高于对流免疫电泳。PCR、SPN免疫印迹和CPS-CIE的敏感性分别为100%、85%和67%。在11份来自接受抗生素治疗但近期已证实有肺炎球菌感染的患者的肺炎链球菌培养阴性痰液中，PCR和SPN印迹检测有6份呈阳性（其中2份CPS-CIE也呈阳性），仅PCR呈阳性的有1份，仅SPN印迹呈阳性的有1份。在11份来自未接受抗生素治疗患者的肺炎链球菌培养阴性样本中，8份所有三项检测均为阴性，3份PCR呈阳性（其中1份CPS-CIE也呈阳性），但所有11份样本的SPN印迹检测均为阴性。在16份来自接受抗生素治疗且近期无已知肺炎球菌感染患者的肺炎链球菌培养阴性样本中，11份一种或多种非培养检测呈阳性。尽管需要进一步评估以确定肺炎溶血素检测在携带和感染方面的意义，并设计出更合适的检测形式，但这些初步研究表明，肺炎溶血素检测是肺炎球菌性胸部感染非培养诊断的一种有前景的新方法。
