Epps N A, Idziak E S
Appl Microbiol. 1970 Feb;19(2):338-44. doi: 10.1128/am.19.2.338-344.1970.
Salmonellae resistant to gamma irradiation were developed by repeated irradiation and subculturing in a nutrient broth-yeast extract medium. Few differences were noted in the biochemical characteristics of parent and resistant cultures; however, microculture studies revealed variations in morphology and in cell division patterns. A considerable decrease in pathogenicity for day-old chicks was apparent with resistant cultures, but their phenol-water extracts were as toxic as parent material for 10-day chick embryos. Five serial chick passages did not reverse the reduced pathogenicity or aberrant morphology of a resistant Salmonella typhimurium culture. Results of phage typing of both parent and serially irradiated S. typhimurium were inconclusive, whereas the O-1 genus-specific phage lysed all parent serotypes tested but only one of the serially irradiated cultures. Agglutination of parent S. typhimurium cells with their homologous rabbit antiserum was unaffected by prior absorption with resistant strains. The results indicate that radiation recycling altered Salmonella into strains of lesser public health significance.
通过在营养肉汤 - 酵母提取物培养基中反复照射和传代培养，培育出了对伽马辐射具有抗性的沙门氏菌。亲本培养物和抗性培养物的生化特性几乎没有差异；然而，微量培养研究揭示了形态和细胞分裂模式的变化。抗性培养物对一日龄雏鸡的致病性明显降低，但它们的酚 - 水提取物对10日龄鸡胚的毒性与亲本材料相同。连续五次在雏鸡中传代并没有逆转抗性鼠伤寒沙门氏菌培养物降低的致病性或异常形态。亲本和连续照射的鼠伤寒沙门氏菌的噬菌体分型结果尚无定论，而O - 1属特异性噬菌体裂解了所有测试的亲本血清型，但仅裂解了一种连续照射的培养物。亲本鼠伤寒沙门氏菌细胞与同源兔抗血清的凝集不受先用抗性菌株吸收的影响。结果表明，辐射循环将沙门氏菌转变为对公共卫生意义较小的菌株。
