Isolation and characterization of autolysin-defective mutants of Staphylococcus aureus that form cell packets.
Staphylococcus aureus produces multiple bacteriolytic enzymes (autolysins) and grows usually as a mixture of single cells, pairs, short chains, and irregular clusters. Autolysin-defective mutants that form cubic cell packets (Pa4A and PaH13) or grape-like clusters (Cu9S and CuD10) were isolated from S. aureus FDA 209P after mutagenesis with N-methyl-N'-nitro-N-nitrosoguanidine. The Pa4A mutant grown in nutrient broth formed cell packets consisting of 8-64 cells that appeared regularly arranged in three dimensions. Thin-section electron micrographs revealed that the packet cells were encased in an orderly manner within a thick peripheral wall and that their septa failed to split. Zymographic analysis of enzyme extracts from mutant Pa4A showed that it lacked the 33-kDa autolytic enzyme band present in the parent strain. Another mutant, Cu9S, formed grape-like clusters and showed a single autolytic enzyme band (33-kDa). The possibility that the 33-kDa autolytic enzyme is involved in splitting of the septum prior to cell separation inS. aureus is discussed.
Kaneda
S
S
Faculty of Pharmaceutical Science, Hokuriku University, Kanagawa-machi, Kanazawa 920-11, Japan.
D008769:Methylnitronitrosoguanidine; D016296:Mutagenesis; D009154:Mutation; D009238:N-Acetylmuramoyl-L-alanine Amidase / Q000235:genetics*; D013211:Staphylococcus aureus / Q000166:cytology* / Q000235:genetics* / Q000254:growth & development
D008769:Methylnitronitrosoguanidine; D009238:N-Acetylmuramoyl-L-alanine Amidase