Panomket Pawana, Wongsana Parichart, Wanram Surasak, Wongratanacheewin Surasakdi
Southeast Asian J Trop Med Public Health. 2017 Jan;48(1):73-82.
Burkholderia pseudomallei is a causative agent of melioidosis. Clinical signs of melioidosis vary from acute septicemia to chronic inflammation or subclinical infection. This study investigated the role of B. pseudomallei biofilm in chronic inflammation in lungs of infected C57BL/6 mice. Low doses of B. pseudomallei H777 and its biofilm defective M10 mutant were fed intra-gastrically to C57BL/6 mice and inflammatory responses were investigated by histopathological techniques. Two hundred colony forming units (CFUs) of B. pseudomallei H777 induced chronic inflammatory responses in mice on day 20 post-infection, with discrete interstitial infiltration by mononuclear inflammatory cells. On day 40 postinfection, there were marked thickening of alveolar septa and congested capillaries, which increased in severity by day 60. On the other hand, mice infected with B. pseudomallei M10 showed less mononuclear infiltration. The results indicate that B. pseudomallei defective in biofilm production gave rise to less severe pathology, resulting a higher rate of survival in infected mice; and pulmonary melioidosis could be developed in C57BL/6 mice by intra-gastric feeding makes it a possible animal model of chronic human melioidosis.
类鼻疽伯克霍尔德菌是类鼻疽的病原体。类鼻疽的临床症状从急性败血症到慢性炎症或亚临床感染不等。本研究调查了类鼻疽伯克霍尔德菌生物膜在感染的C57BL/6小鼠肺部慢性炎症中的作用。将低剂量的类鼻疽伯克霍尔德菌H777及其生物膜缺陷型M10突变体经胃内给予C57BL/6小鼠，并通过组织病理学技术研究炎症反应。类鼻疽伯克霍尔德菌H777的200个菌落形成单位（CFU）在感染后第20天诱导小鼠出现慢性炎症反应，有单核炎性细胞离散性间质浸润。感染后第40天，肺泡间隔明显增厚，毛细血管充血，到第60天严重程度增加。另一方面，感染类鼻疽伯克霍尔德菌M10的小鼠单核浸润较少。结果表明，生物膜产生缺陷的类鼻疽伯克霍尔德菌导致的病理变化较轻，使感染小鼠的存活率更高；通过胃内喂食可在C57BL/6小鼠中引发肺类鼻疽，使其成为慢性人类类鼻疽的一种可能的动物模型。
