Escobar M M, Carbonell G V, Beriam L O, Siqueira W J, Yano T
Departamento de Microbiología e Imunologia, Universidade Estadual de Campinas, SP, Brasil.
Rev Latinoam Microbiol. 2001 Oct-Dec;43(4):165-70.
In this work, culture filtrates of entomopathogenic and phytopathogenic Serratia marcescens strains induced cytotoxic effects on CHO, Vero and HEp-2 cell lines. Morphological changes on sensitive cells were characterized by cell rounding and detachment as soon as 30 min of incubation, culminating in cell death after 24 h. The cytotoxic effect was completely neutralized by specific antiserum indicating that occur antigenic similarity among cytotoxins produced by these strains. The toxicity assays on plants showed that the culture supernatants did not provoke any visible morphological change and did not affect their growth. By contrast, the plants treated with bacterial suspension showed disease symptom, such as shriveling and decay of stores bulbus in onion and lettuce plantlets. In conclusion, this study show that phytopathogenic and entomopathogenic S. marcescens may produce a cytototoxin similar to that produced by clinical isolates and it is toxic to different mammalian cell lines. These results are especially important for studies involving this bacterium as biological control agent.
在本研究中，昆虫致病性和植物致病性粘质沙雷氏菌菌株的培养滤液对CHO、Vero和HEp-2细胞系产生了细胞毒性作用。敏感细胞的形态变化表现为孵育30分钟后细胞变圆并脱离，24小时后最终导致细胞死亡。细胞毒性作用被特异性抗血清完全中和，表明这些菌株产生的细胞毒素之间存在抗原相似性。对植物的毒性试验表明，培养上清液未引起任何可见的形态变化，也未影响其生长。相比之下，用细菌悬液处理的植物出现了病害症状，如洋葱和生菜幼苗贮藏鳞茎的枯萎和腐烂。总之，本研究表明，植物致病性和昆虫致病性粘质沙雷氏菌可能产生与临床分离株产生的细胞毒素相似的细胞毒素，并且对不同的哺乳动物细胞系有毒性。这些结果对于涉及该细菌作为生物防治剂的研究尤为重要。
