Hykin P G, Tobal K, McIntyre G, Matheson M M, Towler H M, Lightman S L
Department of Clinical Science, Institute of Ophthamology, London.
J Med Microbiol. 1994 Jun;40(6):408-15. doi: 10.1099/00222615-40-6-408.
Delayed post-operative endophthalmitis is a complication of modern cataract extraction and posterior chamber lens implantation. Propionibacterium acnes has been isolated in a few such cases but the majority are culture-negative, compounding surgical and medical management decisions. A method of detecting bacterial, and specifically P. acnes, DNA by the polymerase chain reaction (PCR) directed at 16S rDNA is reported. Nested PCR with universal eubacterial primers complimentary to regions of 16S rDNA conserved sequences detected 50 fg of bacterial DNA spike in normal vitreous. Nested PCR with P. acnes primers detected 10 fg of DNA. Vitreous samples from 29 patients undergoing vitrectomy for reasons unrelated to infection and 23 samples from 19 patients with delayed post-operative endophthalmitis were analysed. Four (14%) of 29 normal individuals and 17 (74%) of 23 delayed cases gave positive results with universal eubacterial primers. None of 29 and eight of 23 samples gave positive results with P. acnes primers. The 14% positive rate with universal primers in non-infected cases may limit their use in delayed post-operative endophthalmitis. PCR detection of bacterial DNA with specific primers from vitreous samples may prove a useful means of diagnosing delayed post-operative endophthalmitis and facilitating management decisions when conventional bacterial culture is negative.
术后迟发性眼内炎是现代白内障摘除及后房型人工晶状体植入术的一种并发症。痤疮丙酸杆菌在少数此类病例中被分离出来，但大多数病例培养结果为阴性，这使得手术和药物治疗决策变得更加复杂。本文报道了一种通过针对16S核糖体DNA的聚合酶链反应（PCR）检测细菌，尤其是痤疮丙酸杆菌DNA的方法。使用与16S核糖体DNA保守序列区域互补的通用真细菌引物进行巢式PCR，可检测出正常玻璃体中50飞克的细菌DNA加样。使用痤疮丙酸杆菌引物进行巢式PCR可检测出10飞克的DNA。分析了29例因与感染无关的原因接受玻璃体切除术患者的玻璃体样本，以及19例术后迟发性眼内炎患者的23份样本。29例正常个体中有4例（14%），23例迟发性病例中有17例（74%）使用通用真细菌引物检测结果为阳性。29例样本中无一例，23例样本中有8例使用痤疮丙酸杆菌引物检测结果为阳性。非感染病例中通用引物14%的阳性率可能会限制其在术后迟发性眼内炎中的应用。当传统细菌培养为阴性时，用特异性引物从玻璃体样本中PCR检测细菌DNA可能是诊断术后迟发性眼内炎及辅助治疗决策的一种有用方法。
