Khurana S, Ganguly N K, Panigrahi D, Khullar M, Walia B N
Department of Experimental Medicine, Postgraduate Institute of Medical Education and Research, Chandigarh, India.
Microbiologica. 1991 Apr;14(2):113-7.
Five strains of Salmonella typhimurium were examined to determine the parameters of virulence. The virulent species significantly resisted the macrophage bactericidal activity (p less than 0.05). The chemiluminescent (CL) response was studied to determine the level of Oxygen-free radicals (OFR) generated and the antioxidant enzymes superoxidase dismutase (SOD), catalase and glutathione peroxidase were assayed to determine the antioxidant mechanism of S. typhimurium to subvert these microbicidal pathways. The levels of the various enzymes were correlated with the virulence (as determined by LD50) and the ability of the microorganisms to induce diarrhoea. Oxygen free radical (OFR) generation elicited by macrophages, in the presence of virulent and avirulent salmonellae was not statistically significant (p greater than 0.05). No correlation was found between the levels of the antioxidant enzymes and the LD50 values. Thus the oxygen-dependent pathways do not appear to play a role in the pathogenesis of salmonellosis, and do not specify the virulence of the microorganism. Immunological and biological assays revealed the virulent strain to be more toxigenic than the avirulent strain. Therefore, the basis of differing virulence in S. typhimurium may be the ability to make and release more toxin in vivo.
对五株鼠伤寒沙门氏菌进行了检测，以确定其毒力参数。有毒菌株对巨噬细胞杀菌活性具有显著抗性（p小于0.05）。研究了化学发光（CL）反应以确定产生的氧自由基（OFR）水平，并测定了抗氧化酶超氧化物歧化酶（SOD）、过氧化氢酶和谷胱甘肽过氧化物酶，以确定鼠伤寒沙门氏菌颠覆这些杀菌途径的抗氧化机制。各种酶的水平与毒力（由半数致死剂量[LD50]确定）以及微生物诱导腹泻的能力相关。在有毒和无毒沙门氏菌存在的情况下，巨噬细胞引发的氧自由基（OFR）生成在统计学上无显著差异（p大于0.05）。未发现抗氧化酶水平与LD50值之间存在相关性。因此，氧依赖性途径似乎在沙门氏菌病的发病机制中不起作用，也不能确定微生物的毒力。免疫学和生物学检测显示，有毒菌株比无毒菌株更具产毒性。因此，鼠伤寒沙门氏菌毒力差异的基础可能是在体内产生和释放更多毒素的能力。
