Abstract：
Although tissue culture is the gold standard for diagnosing infection, histologic examination of surgically resected tissue can be a critical component in the diagnosis of tissue infection. The goal of this brief report is to alert surgical pathologists that Pseudomonas species can appear strikingly filamentous histologically and may somewhat mimic the appearance of filamentous bacteria, such Actinomyces or Nocardia, or thin fungal hyphae. A secondary aim is to raise awareness that Pseudomonas can sometimes only be identified histologically through the use of a modified silver impregnation method (Steiner stain). Five cases of filamentous Pseudomonas were encountered in three different surgical pathology subspecialities (ophthalmic pathology, cardiovascular pathology, and dermatopathology) over a 1-year period. All cases were of formalin-fixed, paraffin-embedded tissue, stained using hematoxylin & eosin (H&E) and multiple histochemical stains. Four cases grew Pseudomonas aeruginosa in culture and, in the fifth case, a nonaeruginosa species was detected using polymerase chain reaction-based methods. The markedly filamentous-appearing Pseudomonas organisms were identified in five different tissue sites: vascular graft, enucleation (whole eye) specimen, scleral biopsy, soft-tissue excision, and skin punch biopsy. In one of the five cases the organisms were seen on H&E, and in only two of the five were the organisms seen on Brown-Hopps stain. In all five cases, the organisms were identified on Steiner stain. It is therefore important to recognize that Pseudomonas can appear markedly filamentous, Pseudomonas or other bacterial infection is suspected, the surgical pathologist would be advised to employ the Steiner stain to most consistently detect the organisms.
摘要：
虽然组织培养是诊断感染的金标准,手术切除组织的组织学检查可能是诊断组织感染的关键组成部分。这份简短报告的目的是提醒外科病理学家，假单胞菌在组织学上可能出现惊人的丝状，并且可能在某种程度上模仿丝状细菌的外观。放线菌或诺卡氏菌，或薄的真菌菌丝。次要目的是提高人们的认识，即假单胞菌有时只能通过使用改良的银浸渍方法（Steiner染色法）在组织学上进行鉴定。在三个不同的手术病理亚科（眼科病理，心血管病理学，和皮肤病理学）超过1年。所有病例都是福尔马林固定的，石蜡包埋组织，使用苏木精和伊红(H&E)和多种组织化学染色。4例铜绿假单胞菌培养，在第五种情况下，使用基于聚合酶链反应的方法检测了非铜绿假单胞菌。在五个不同的组织部位中发现了明显的丝状假单胞菌生物：血管移植物，摘除（全眼）标本，巩膜活检,软组织切除,还有皮肤穿刺活检.在五个案例中的一个中，在H&E上看到了这些生物，五个中只有两个是在布朗-霍普斯染色上看到的生物。在所有五个案例中，这些生物是在斯坦纳染色上被鉴定出来的。因此，重要的是要认识到假单胞菌可以出现明显的丝状，怀疑假单胞菌或其他细菌感染，外科病理学家将被建议使用Steiner染色剂来最一致地检测生物体。
