Contribution of membrane-damaging toxins to Bacillus endophthalmitis pathogenesis
Contribution of membrane-damaging toxins to Bacillus endophthalmitis pathogenesis
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DOI：
10.1128/iai.70.10.5381-5389.2002
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发表时间：
2002-10-01
影响因子：
3.1
通讯作者：
Lereclus, D
中科院分区：
文献类型：
--
作者：
Callegan, MC;Cochran, DC;Lereclus, D
膜损伤毒素被认为是负责爆炸性的临床过程中的芽孢杆菌眼内炎。本研究分析了磷脂酰肌醇特异性磷脂酶C（PIPLC）和磷脂酰胆碱特异性磷脂酶C（PC-PLC）在实验性眼内炎发病机制中的作用。通过将lacZ插入苏云金芽孢杆菌（Bacillus thuringiensis）编码PI-PLC（plcA）和PC-PLC（plcB）的基因，构建了等基因突变体。用2log（10）CFU的菌株BT 407（野生型）、PI-PLC突变体（BTplcA：：lacZ）或PC-PLC突变体（BTplcB：：lacZ）玻璃体内注射兔眼。感染同基因突变体的眼睛的视网膜反应降低率与野生型相似，所有感染导致视网膜功能在18小时内消除。菌株BT407在6 h引起视网膜反应的潜伏期显著增加，但菌株BTplcA：：lacZ和BTplcB：：lacZ没有。所有菌株在12 h时均引起显著的炎性细胞流入前房。在组织学上，感染每种菌株的眼睛在整个感染过程中是无法区分的。在该模型中，PI-PLC和PC-PLC对实验性芽孢杆菌眼内炎的过程或严重程度都没有影响。感染早期视网膜反应的改变可能标志着特定感光细胞或神经胶质细胞功能障碍的开始。
Membrane-damaging toxins are thought to be responsible for the explosive clinical course of Bacillus endophthalmitis. This study analyzed the contribution of phosphatidylinositol-specific phospholipase C (PIPLC) and phosphatidylcholine-specific phospholipase C (PC-PLC) to the pathogenesis of experimental Bacillus endophthalmitis. Isogenic mutants were constructed by insertion of lacZ into Bacillus thuringiensis genes encoding PI-PLC (plcA) and PC-PLC (plcB). Rabbit eyes were injected intravitreally with 2 log(10) CFU of strain BT407 (wild type), the PI-PLC mutant (BTplcA::lacZ), or the PC-PLC mutant (BTplcB::lacZ). The rates of decrease in retinal responses of eyes infected with the isogenic mutants were similar to that of wild type, with all infections resulting in elimination of retinal function by 18 h. Strain BT407 caused a significant increase in the latency of retinal responses at 6 h, but strains BTplcA::lacZ and BTplcB::lacZ did not. All strains elicited significant inflammatory cell influx into the anterior chamber by 12 h. Histologically, eyes infected with each strain were indistinguishable throughout the infection course. In this model, neither PI-PLC nor PC-PLC had an effect on the course or severity of experimental Bacillus endophthalmitis. Alterations in retinal responses early in infection may mark the beginnings of specific photoreceptor or glial cell dysfunction.