Acd. Decastro et al., ALTERATIONS INDUCED BY PENICILLIN IN THE PROTEIN PROFILE AND CELL STRUCTURE OF GROUP G-STREPTOCOCCUS, Current microbiology, 28(5), 1994, pp. 269-273
We investigated the effect of a subminimal concentration of penicillin
on the ultrastructure and protein profile of Group G streptococci. In
cells treated with penicillin (1/3 MIC), the protein content increase
d by 50%, and several protein bands with a molecular mass of 14-70 kDa
were detected. In the hydrophilic phase, carbohydrate-containing prot
eins were detected by PAS staining, and in the hydrophobic phase, a gr
oup of proteins that reacted strongly with homologous antisera were ob
served. In terms of cell structure, Triton X-114 extraction was found
to induce alterations in the cross wall of untreated cells. In bacteri
a treated with penicillin but not extracted with Triton X-114, the cel
l wall was observed to detach itself, and regions with reduced amounts
of cellular material appeared in the cytoplasm. After Triton-X114 ext
raction, these penicillin-treated cells exhibited profound morphologic
al changes, leading in some cases to lysis.