The Charles T. Campbell Ophthalmic Microbiology Laboratory, University of Pittsburgh Medical Center, Pittsburgh, PA 15213, USA.
J Ocul Pharmacol Ther. 2012 Feb;28(1):12-6. doi: 10.1089/jop.2011.0107. Epub 2011 Oct 20.
Staphylococcus aureus (SA) endophthalmitis is generally a postsurgical infection with an undefined source of entry. Hospital-acquired (HA) SA infections are associated with multi-antibiotic resistance and absence of the Panton-Valentine Leukocidin (PVL) toxin. Community-acquired (CA) SA infections are not associated with multi-antibiotic resistance and possess the PVL toxin. We hypothesize that CA infection is more common than HA for SA endophthalmitis.
Twenty de-identified SA isolates, collected from the vitreous and/or aqueous of clinical endophthalmitis, were tested for the presence of PVL toxin and antibiotic susceptibility. PVL testing was performed using a kit to detect the Staphylococcal toxin by reversed passive latex agglutination (PVL-RPLA "Seiken," Denka Seiken Co., LTD). SA isolates were tested for antibiotic susceptibility using disk diffusion at the time of isolation. Multi-antibiotic resistance was defined as resistance to at least 3 classes of antibiotics.
Of the 20 isolates, 15 were multi-antibiotic resistant and PVL-negative consistent with HA, and 1 was not multi-antibiotic resistant and PVL-positive, consistent with CA. Two isolates tested positive for PVL with one demonstrating both methicillin and fluoroquinolone (FQ) resistance. Of the 18 PVL-negative SA isolates, 15 (83%) were multi-antibiotic resistant (12 methicillin-resistant SA, 14 FQ resistant).
Our results reject the hypothesis that SA isolated from endophthalmitis is consistent with CA sources due to the lack of the PVL toxin and multiple resistant patterns of the SA. PVL does not appear to be a key virulence factor for the development of SA endophthalmitis.
金黄色葡萄球菌 (SA) 眼内炎通常是一种术后感染，其来源不明。医院获得性 (HA) SA 感染与多药耐药和缺乏 Panton-Valentine 白细胞毒素 (PVL) 有关。社区获得性 (CA) SA 感染与多药耐药无关，且具有 PVL 毒素。我们假设 CA 感染比 HA 更常见于 SA 眼内炎。
从临床眼内炎的玻璃体和/或房水中收集了 20 株去鉴定的 SA 分离株，用于检测 PVL 毒素和抗生素敏感性。使用试剂盒通过反向被动乳胶凝集法 (PVL-RPLA“Seiken”，Denka Seiken Co.，LTD) 检测 Staphylococcal 毒素来进行 PVL 检测。在分离时使用圆盘扩散法测试 SA 分离株对抗生素的敏感性。多药耐药性定义为对至少 3 类抗生素的耐药性。
在 20 株分离株中，15 株为多药耐药且 PVL 阴性，与 HA 一致，1 株非多药耐药且 PVL 阳性，与 CA 一致。2 株分离株对 PVL 呈阳性，其中 1 株对甲氧西林和氟喹诺酮 (FQ) 均耐药。在 18 株 PVL 阴性的 SA 分离株中，15 株（83%）为多药耐药（12 株耐甲氧西林的 SA，14 株 FQ 耐药）。
由于缺乏 PVL 毒素和 SA 的多种耐药模式，我们的结果否定了从眼内炎中分离出的 SA 与 CA 来源一致的假设。PVL 似乎不是 SA 眼内炎发展的关键毒力因素。
