浅黄假单胞菌感染的家猫脓性肉芽肿性脂膜炎 - 宠医帮

Pseudomonas luteola, a pathogen causing disease in humans, has in animals been reported only in rainbow trout and ferrets. This case report describes pyogranulomatous panniculitis in a cat associated with P. luteola infection. Organisms were seen histologically and identified with PCR and sequencing. Lesions resolved after treatment with marbofloxacin.

浅黄假单胞菌是导致人类疾病的病原菌，动物中仅在虹鳟鱼和雪貂中有报告。本病例报告描述了与浅黄假单胞菌感染相关的猫的脓性肉芽肿性脂膜炎。组织学观察到微生物，通过PCR和测序对其进行鉴定。经马波沙星治疗后病变消退。

Pseudomonas spp. are Gram-negative, aerobic, motile bacteria commonly found in soil, water and damp environments. Pseudomonas luteola, formerly known as Chryseomonas luteola, is a rare human pathogen associated with septicaemia, osteomyelitis, meningitis, peritonitis and endocarditis, and noted in patients that underwent surgical procedures. Reports of P. luteola causing disease in domestic animals are sparse. In rainbow trout (Oncorhynchus mykiss), P. luteola was associated with septicaemia, whereas in healthy zebra fish (Danio rerio) it was cultured from the gastrointestinal tract. In domestic animals, the majority of studies published on P. luteola infections involve ferrets (Mustela putorius furo), suggesting a predisposition of ferrets to infection with this bacterium, although the pathogenesis is unclear. Several studies reported an association of P. luteola with pyogranulomatous inflammation in a variety of organs in ferrets including panniculus, pleura, mediastinum, lung and salivary glands. In these studies, diagnosis of P. luteola was confirmed with bacterial culture, transmission electron microscopy and/or molecular analysis with PCR amplification of the 16S rRNA region. This case report describes, to the best of the authors’ knowledge, the first association of P. luteola with panniculitis in a domestic cat.

假单胞菌属是需氧革兰氏阴性菌，常在土壤、水和潮湿环境中发现的运动细菌。浅黄假单胞菌，原名浅黄金色单胞菌，是一种罕见的人类病原菌，与败血症、骨髓炎、脑膜炎、腹膜炎和心内膜炎有关，常出现在接受手术的患者中。关于浅黄假单胞菌引起家畜疾病的报道很少。在虹鳟鱼(虹鳟)中，浅黄假单胞菌与败血症相关，而在健康斑马鱼(斑马鱼)中，能从胃肠道培养而来。在家养动物中，大多数发表的关于浅黄假单胞菌感染的研究涉及雪貂(雪貂)，提示雪貂容易感染这种细菌，但致病机理尚不清楚。几项研究报告了浅黄假单胞菌与雪貂各种器官的脓性肉芽肿炎症的关系，包括脂膜、胸膜、纵隔、肺和唾液腺。在这些研究中，通过细菌培养、透射电镜和/或16S rRNA区域PCR扩增的分子学分析来确诊浅黄假单胞菌。据作者所知，本病例首次报告了一只家猫与浅黄假单胞菌相关的脂膜炎。

An 11-month-old, female spayed, domestic short hair cat was presented to its primary care veterinarian in Florida for evaluation of a raised, ulcerated mass on the left ventral abdomen. The patient was an indoor-only cat with no known history of trauma or signs of systemic illness. The patient had an unknown travel history, and was negative for feline leukaemia virus (FeLV) and feline immunodeficiency virus (FIV). The cat was treated with an injection of cefovicin sodium (Convenia, Zoetis; Parsippany-Troy Hills, NJ, USA) and prednisolone. As a consequence of progression of the lesion, the mass was surgically removed and submitted for histopathological examination. Histopathological findings were consistent with a suppurative and ulcerative dermatitis and panniculitis. Approximately one month later the mass recurred. A fine needle aspirate showed abundant neutrophils, histiocytes and lymphocytes mixed with organisms cautiously interpreted as fungal agents (suspected Cryptococcus sp. Or Sporothrix sp.) (Figure S1). The cat developed pruritus and the mass rapidly increased in size, and thus the cat was referred to the authors. The mass, on the ventral abdomen (Figure 1), was firm, raised, ulcerated, well-demarcated, 2.5 cm in diameter and with cutaneous tracts draining purulent material; it was removed and submitted for histopathological examination. In addition, aerobic, anaerobic, fungal and mycobacterial cultures were performed, which were all negative.

一只11月龄已绝育雌性家养短毛猫，因左腹部腹侧隆起的溃疡性肿物，就诊于佛罗里达的初级护理医院兽医。患猫仅在室内生活，没有已知的外伤病史或全身性疾病症状。患猫无旅行史，猫白血病病毒(FeLV)和猫免疫缺陷病毒(FIV)阴性。患猫治疗史包括注射头孢维星和泼尼松龙。由于病变进一步发展，肿物进行手术切除并提交组织病理学检查。组织病理学检查结果符合化脓性和溃疡性皮炎和脂膜炎。大约一个月后肿物复发。细针抽吸检查显示大量中性粒细胞、组织细胞和淋巴细胞，混合着疑似为真菌元素的微生物(疑似隐球菌属或孢子丝菌属)(图S1)。患猫开始瘙痒，肿物迅速增大，因此患猫被转诊给作者。肿物位于腹部腹侧(图1)，坚硬、隆起、溃疡、边界清晰、直径2.5 cm，皮肤瘘道流出脓性分泌物，切除肿物后进行组织病理学检查。此外也进行需氧、厌氧、真菌、分枝杆菌培养均为阴性。

Histological evaluation of the recurrent mass revealed, within the panniculus and less in the dermis, multifocal-coalescing pyogranulomatous areas of inflammation composed of aggregates of neutrophils, macrophages, scattered multinucleate giant cells, epithelioid macrophages,and fewer lymphocytes and plasma cells (Figure 2). Within the inflammatory infiltrates were many elongate, faintly eosinophilic, 1–2x3 µm organisms with a 2–3 µm thick, clear, round capsule (Figure 3a). The epidermis was multifocally ulcerated. The organism’s capsule stained strongly positive with periodic acid Schiff, whereas the organisms stained weakly positive with Grocott–Gomori’s methenamine silver stain and multifocally stained Gram-negative (Figure 3b–d and Appendix S1). Mayer’s mucicarmine staining was negative. Based on the organism’s morphology and staining results, a fungal infection was given highest consideration, although an unusual bacterial infection could not be excluded.

复发性肿物的组织学评估显示，脂膜层内和真皮层内较少存在多灶性聚结性脓性肉芽肿炎症区域，由中性粒细胞、巨噬细胞、散在多核巨细胞、上皮样巨噬细胞以及较少淋巴细胞和浆细胞聚集组成（图2）。炎性浸润内有许多细长的、微弱嗜酸性的1-2 × 3µm微生物，具有2-3µm厚的透明圆形荚膜（图3a）。表皮层多灶性溃疡。微生物荚膜用高碘酸雪夫染色呈强阳性，而微生物用乌洛托品银染色呈弱阳性，多灶性革兰氏染色呈阴性（图3b–d和附录S1）。Mayer粘蛋白卡红染色阴性。根据微生物的形态和染色结果，最值得考虑真菌感染，但不能排除不寻常的细菌感染。

Panfungal PCR targeting the internally transcribed spacer 2 (ITS-2) region and large subunit region were performed, followed by agarose gel electrophoresis, which were negative for DNA amplification. Because the organisms were multifocally Gram-negative, PCR targeting of the bacterial 16S rRNA region was performed. The positive band was sequenced yielding a 357 bp sequence with a 100% identity match to P. luteola using the basic local alignment search tool (BLAST) from the National Center of Biotechnology Information (NCBI) database. The sequence was deposited in GenBank under accession number MT154074.

进行针对内转录间隔区2(ITS-2)区和大亚基区的泛真菌PCR，然后进行琼脂糖凝胶电泳，DNA扩增均为阴性。由于微生物为多灶性革兰氏阴性，因此进行了细菌16S rRNA区域的靶向PCR。利用美国国家生物技术信息中心(NCBI)数据库的基本局部比对检索工具(BLAST)对阳性条带进行测序，得到357 bp的序列，与浅黄假单胞菌的同源性为100%匹配。该序列保存在GenBank中，登录号为MT154074。

To the best of the authors’ knowledge, this is the first report of a pyogranulomatous dermatitis associated with P. luteola in a cat. Pseudomonas luteola can look similar to fungal organisms and further tests, such as PCR, are needed for definitive diagnosis. Bacterial culture was negative in our case which could be related to bacterial growth inhibition resulting from prior antibiotic treatment. Further studies investigating the growth of P. luteola in culture are warranted to determine which conditions and type of media should be used (Appendix S1). Treatment of P. luteola with fluoroquinolones was reported to be successful in ferrets. Based on follow-up, lesions responded in a similar way to fluoroquinolone therapy in this cat. Clinicians should consider P. luteola among the differential diagnoses for panniculitis in cats.

据作者所知，这是猫中与浅黄假单胞菌相关的脓性肉芽肿性皮炎的首次报告。浅黄假单胞菌可以看起来类似于真菌生物，需要进一步的检测，如PCR来明确诊断。在我们的病例中，细菌培养为阴性，这可能与既往抗生素治疗导致的细菌生长抑制有关。有必要进行进一步研究，以确定应使用哪种条件和培养基类型，研究培养物中浅黄假单胞菌的生长（附录S1）。据报道，用氟喹诺酮类药物治疗浅黄假单胞菌在雪貂中获得成功。基于随访，该猫中病变对氟喹诺酮类药物治疗的反应方式相似。临床医生应考虑将浅黄假单胞菌纳入猫脂膜炎的鉴别诊断中。

(a) Abundant elongate, faintly eosinophilic, 1–2x3 µm organisms (black arrowheads) with a 2–3 µm thick, clear, round, capsule surrounded by large numbers of neutrophils and macrophages. Moderate numbers of organisms with (b) a periodic acid Schiff-positive staining capsule (black arrowheads), (c) weak Gomori’s methenamine silver-positive staining (black arrowheads) and (d) multifocal Gram-negative staining (black arrowheads) (all haematoxylin & eosin, x600).

(a)大量细长、微嗜酸性的1-2x3 μ m生物(黑色箭头)，荚膜厚2-3 μ m，透明、圆形，被大量中性粒细胞和巨噬细胞包围。中等数量的生物具有(b)周期性酸性希夫阳性染色荚膜(黑色箭头)，(c)乌洛托品银染色弱阳性(黑色箭头)和(d)多灶革兰氏染色阴性(黑色箭头)(全部为苏木精和伊红，x600)。