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首页> 外文期刊>Infection and immunity >Induction of L-Variants in Human Diploid Cells Infected by Group A Streptococci
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Induction of L-Variants in Human Diploid Cells Infected by Group A Streptococci

机译：A组链球菌感染人二倍体细胞中L变异的诱导

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Human diploid cells in culture, infected with a balanced amount of living group A streptococci, were able to survive the infection and could be divided and propagated normally thereafter. The streptococci were rapidly phagocytized by the tissue culture cells. At the beginning, they kept their typical appearance, as well as their ability to fix dyes and group-specific immunoglobulins. After 1 to 2 days, the number of detectable streptococci decreased and they underwent important morphological changes. After some subsequent divisions of the cell line, streptococci persisted in cells only as large, isolated, swollen cocci, and no longer grew on suitable media. After six to eight divisions, a noticeable percentage of the tissue culture cells were very similar in appearance to the same cell line experimentally infected with “stable” L-variants. Cultures on L-phase media of supernatant fraction and cells, made 24 to 48 hr after inoculation, showed typical L-colonies. These grew well on media without antibiotics, as well as on media containing penicillin or vancomycin. They could be propagated on media with penicillin for months and were able to revert to group A streptococci after several subcultures on antibiotic-free media. Controls of uninoculated tissue culture cells never showed the presence of any microorganism. Group A streptococci inoculated into Eagle's basal medium, which was used for the tissue cultures, did not grow and never gave rise to L-colonies, even though the medium contained penicillin. Previous data suggest a biochemical explanation for this conversion, which otherwise is an occasional phenomenon.
机译：培养中的人类二倍体细胞感染了均衡数量的A组活链球菌，能够在感染中幸存，此后可以分裂并正常繁殖。链球菌被组织培养细胞迅速吞噬。最初，它们保持了典型的外观以及固定染料和特定于组的免疫球蛋白的能力。 1至2天后，可检测到的链球菌数量减少，并且发生了重要的形态变化。在随后的细胞系分裂后，链球菌仅以大的，分离的，肿胀的球菌形式存在于细胞中，并且不再在合适的培养基上生长。经过六到八次分裂，明显百分比的组织培养细胞的外观与实验上感染“稳定” L变体的同一细胞系非常相似。接种后24至48小时，在上清液级分和细胞的L相培养基上进行培养，显示出典型的L克隆。这些在不含抗生素的培养基以及含有青霉素或万古霉素的培养基上生长良好。它们可以在含有青霉素的培养基上繁殖数月，并且在无抗生素培养基上进行几次传代培养后能够恢复为A组链球菌。未接种的组织培养细胞的对照从未显示出任何微生物的存在。接种到Eagle基础培养基中的A组链球菌被用于组织培养，即使该培养基含有青霉素，该菌也没有生长并且从不产生L菌落。以前的数据建议对此转化进行生化解释，否则为偶然现象。

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