[Spheroplast formation in clinical isolates of gram-negative bacteria by beta-lactam antibiotic in the presence of Ca2+ or Mg2+].
Induction to cell wall-deficient bacteria has been suggested to be a cause of intractable and opportunistic infection after chemotherapy. Spheroplast formation by beta-lactam antibiotic in not so high osmotic pressure was investigated in six species of gram-negative bacteria. Some species of gram-negative bacteria were induced to form spheroplast at a high rate by 1:10 concentration of ceftizoxime in the presence of Ca2+ or Mg2+. Especially in 38% of Proteus mirabilis and P. vulgaris, more than 40% of the original cells were induced to form spheroplast by ceftizoxime in a medium supplemented with 40 mM Ca2+. The same formation rate was also found in 22% of Serratia marcescens. Formation rates in the drug sensitive strains of S. marcescens were enhanced as the drug concentration increased. Ca2+ was more effective in spheroplast formation than Mg2+.
Tada
Y
Y
Department of Bacteriology, Kinki University School of Medicine.
Yamaguchi
J
J
D002118:Calcium / Q000494:pharmacology*; D015296:Ceftizoxime / Q000494:pharmacology*; D002473:Cell Wall / Q000187:drug effects; D006090:Gram-Negative Bacteria / Q000166:cytology / Q000187:drug effects*; D008274:Magnesium / Q000494:pharmacology*; D008826:Microbial Sensitivity Tests
D015296:Ceftizoxime; D008274:Magnesium; D002118:Calcium