紫外线在杀菌中诱导形成细菌L型的初步观察

PRELIMINARY OBSERVATION OF FORMATION OF L-FORM BACTERIA INDUCED BY ULTRAVIOLET IRRADIATION DURING DISINFECTION TREATMENT

用紫外线对金黄色葡萄球菌和大肠杆菌进行不同时间照射后,未被杀死的细菌可形成L型细菌。在研究中观察与测定了所形成的细菌L型在形态、生化反应与返祖现象等方面的特点。

Staphylococcus aureus and Escherichia coli were exposed to ultraviolet radiation in la- boratory to observe whether they could trasform into L-forms or not. The result indicated that most of the bacteria survived could transform into L-forms of S. aureus and E. coli respectively after exposure to 68μW/cm^2 ultraviolet rays for 30～300min. The colonies of the L-form bacteria formed could be divided morphologically into three forms, namely, filamentous form (light grey), granular form (yellowish or orange) and fried egg form (yellowish). Microscopic examination of the L-form bacteria of S. aureus and E. coli treated with Gram stain revealed gram-negative and gram-positive spheres, filaments and megalospheres. The stained cell wall showed presence of defect. The bacteria from G-form colonies could resume their normal form (atavism) after cultivating for 2～6 generations and those from F-form colonies resumed the characteristics of the original bacteria after cultivating for 4～5 generations, while those from the fried egg form colonies showed no atavism even after 16 passages. The changed biochemical reactions of L-form bacteria returned to normal after atavism.