Pathomorphology, immunohistochemical, and molecular detection of an atypical porcine dermatitis and nephropathy syndrome (PDNS) due to PCV-2d-2 in naturally affected grower pigs of India
Pathomorphology, immunohistochemical, and molecular detection of an atypical porcine dermatitis and nephropathy syndrome (PDNS) due to PCV-2d-2 in naturally affected grower pigs of India
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DOI：
10.1016/j.micpath.2022.105738
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发表时间：
2022-10-01
影响因子：
3.8
通讯作者：
Sahoo, Nihar Ranjan
中科院分区：
文献类型：
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作者：
Sahoo, Monalisa;Pathak, Mamta;Sahoo, Nihar Ranjan
猪圆环病毒2型(PCV-2)对全球养猪业具有重要的经济意义。PCV-2变异株和基因型别在世界范围内交替变化，是引起猪皮炎和肾病综合征(PDNS)、断奶后多系统衰竭综合征(PMWS)等多种临床症状的病原体。本研究报告了12头3~4.5月龄的生长猪的非典型PDNS表现，不分性别，死于该病，以肾病为主要病变，皮肤无明显临床病变。猪的尸检显示肾脏和右耳心脏肌肉组织有瘀点到瘀斑的出血。肾脏HE切片的显微镜病变表现为急性肾小球肾炎、间质性肾炎和血管炎，但与文献中描述的PDNS的病理性病变相比，皮肤的形态和结构没有改变。这些病例中与PDNS相关的其他症状包括心肌炎、间质性肺炎、淋巴组织衰竭、扁桃体炎、肠炎和脑膜脑炎。在肾、心、肺、脾、淋巴结、肠和脑的双重石蜡切片中，皮损部位显示PCV-2抗原位于细胞质中，免疫组化染色呈强阳性。以ORF2基因为靶点，对PCV-2阳性组织进行了再鉴定，扩增出481bp的产物。系统发育分析表明，481bp的产物与数据库中属于PCV2d-2基因的序列有94%的相似性。本报告可能第一次确认了印度自然感染的养殖户猪中因PCV2d-2基因导致的非典型PDNS病例。
Porcine circovirus type 2 (PCV-2) is of great economic significance to porcine industry worldwide. PCV-2 variants and genotypes, alternating world over, are the etiological agent of several clinical syndromes such as porcine dermatitis and nephropathy syndrome (PDNS), post-weaning multi-systemic wasting syndrome (PMWS) and others in pigs. This study is reporting an atypical manifestation of PDNS in twelve grower pigs, 3- to - 4.5 months age and either sex, died of the disease, with predominant lesions of nephropathy and no obvious clinical lesions in skin. Necropsy examination of pigs showed lesions of petechial -to- ecchymotic hemorrhages in the kidneys and in the right auricular musculature of the hearts. Microscopic lesions in H & E sections of the kidneys showed acute glomerulonephritis, interstitial nephritis, and vasculitis, but the skin morphology and architecture remained unaltered in contrast to the pathognomonic lesions of PDNS described in the literature. Other syndromic associations of PDNS in these cases included-perimyocarditis, interstitial pneumonia, depleted lymphoid tissues, tonsillitis, enteritis, and meningo-encephalitis. The lesional sites in duplicate paraffin tissue sections of kidneys, heart, lungs, spleen, lymph nodes, intestine, and brain demonstrated PCV-2 antigen in the cytoplasm of cells as highlighted by the intense immunolabeling on IHC staining. The PCV-2 positive organs reconfirmed by PCR, targeting ORF2 gene, which yielded 481bp size of products. The sequencing results of 481bp products on phylogenetic analysis showed 94% similarity with that of PCV-2 sequences in the database that grouped into PCV2d-2 genotype. The present report confirms, probably for the first time, the atypical PDNS cases due to PCV2d-2 genotype in naturally affected grower pigs of India.