Gallardo A A, Azevedo V, Malena R, Oppedisano M, Leunda M R, Paolicchi F A
Cátedra de Microbiología Clínica, Departamento de Bioquímica, Facultad de Ciencias Naturales y Ciencias de La Salud, , Universidad Nacional de La Patagonia San Juan Bosco (UNPSJB), Comodoro Rivadavia, Chubut, Argentina.
Departamento de Genética, Ecología E Evolución, Instituto de Ciencias Biológicas, Universidad Federal de Minas Gerais ICB/UFMG, Belo Horizonte, Minas Gerais, Brasil.
Braz J Microbiol. 2025 Sep;56(3):2143-2153. doi: 10.1007/s42770-025-01697-8. Epub 2025 Jun 6.
Caseous lymphadenitis is a contagious disease of chronic evolution affecting mainly sheep, goats, and other domestic animals. The virulence of its etiological agent, Corynebacterium pseudotuberculosis, depends on the activity of enzymes, such as phospholipase D, and its waxy lipid mycolic acid layer, which induces cytotoxicity on the tissue cells of the host. Phospholipase D and mycolic acids contribute to inflammation, edema, and bacterium spread during abscess development. Here, we assessed the adhesion and internalization capacity of six isolates of C. pseudotuberculosis biovar ovis in a non-phagocytic cell lines (Madin-Darb Bovine Kidney (MDBK)) and the cytopathic effects produced in these cells. The interaction of the bacteria strains with MDBK as assessed through scanning electron microscopy and, their cytopathic effects was analyzed by Giemsa staining under light microscopy. Both microscopy assays were monitored after 6, 24, and 72 h of infection. The cytopathic effects evaluated were the formation of cytoplasmic vacuoles, alteration in the nucleus/cytoplasm ratio, and cell lysis. C. pseudotuberculosis biovar ovis was able to adhere and invade MDBK and remained viable for up to 72 h in the cell culture while inducing different levels of cytopathic effects.
干酪性淋巴结炎是一种慢性发展的传染病，主要影响绵羊、山羊和其他家畜。其病原体伪结核棒状杆菌的毒力取决于磷脂酶D等酶的活性及其蜡质脂质分枝菌酸层，该层会对宿主的组织细胞产生细胞毒性。在脓肿形成过程中，磷脂酶D和分枝菌酸会导致炎症、水肿和细菌扩散。在此，我们评估了6株绵羊伪结核棒状杆菌生物变种在非吞噬细胞系（马-达二氏牛肾细胞（MDBK））中的黏附及内化能力，以及这些细胞产生的细胞病变效应。通过扫描电子显微镜评估细菌菌株与MDBK的相互作用，并在光学显微镜下用吉姆萨染色分析其细胞病变效应。在感染6、24和72小时后监测这两种显微镜检测结果。评估的细胞病变效应包括细胞质空泡形成、核质比改变和细胞裂解。绵羊伪结核棒状杆菌生物变种能够黏附并侵入MDBK，在细胞培养中存活长达72小时，同时诱导不同程度的细胞病变效应。
