Little T W, Bosbery R I
Res Vet Sci. 1976 Sep;21(2):155-8.
Two out of 30 strains of Streptococcus agalactiae produced stable L phase variants when passaged on hypertonic agar containing penicillin. Streptococcal L phase variants were inoculated into six quarters of cows. The cows were observed for three months but the L phase was not reisolated and no reversion took place, the cows remaining free from streptococcal infection.
30株无乳链球菌中有2株在含有青霉素的高渗琼脂上传代时产生了稳定的L型变异体。将无乳链球菌L型变异体接种到奶牛的六个乳腺中。对奶牛观察了三个月，但未重新分离到L型，也未发生回复突变，奶牛一直未感染无乳链球菌。
