Correlation of teichoic acid D-alanyl esterification with the expression of methicillin resistance in Staphylococcus aureus.
Methicillin-susceptible and -resistant isolates of Staphylococcus aureus, including a teichoic acid-deficient mutant, were examined under varying physiological conditions for their degree of teichoic acid and lipoteichoic acid D-alanyl esterification. Methicillin-resistant strains grown in the presence of methicillin and NaCl possessed significantly decreased amounts of D-alanyl ester when compared with methicillin-susceptible isolates. These strains also exhibited reduced autolysis. An autoradiographic procedure was used to detect mutants, isolated by Tn917 and nitrosoguanidine mutagenesis of methicillin-susceptible strains, which were defective in D-alanyl ester formation. The quantitative uptake of D-[14C]alanine in these mutants was determined and the effect of methicillin on the growth and viability of each mutant was compared with the wild-type strain. S. aureus mutant strains, defective in the uptake and incorporation of D-alanine, were shown to exhibit slightly reduced autolysis and an enhanced expression of methicillin resistance.
Department of Biological Sciences, Northern Illinois University, DeKalb 60115, USA.
M J
MJ
O'Brien
S A
SA
Kuhl
M J
MJ
Starzyk
D000409:Alanine / Q000032:analysis / Q000378:metabolism*; D000596:Amino Acids / Q000032:analysis; D002473:Cell Wall / Q000737:chemistry / Q000378:metabolism; D004951:Esterification; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D008712:Methicillin / Q000494:pharmacology*; D016106:Methicillin Resistance / Q000235:genetics; D008826:Microbial Sensitivity Tests; D016296:Mutagenesis; D009604:Nitrosoguanidines / Q000494:pharmacology; D010068:Oxacillin / Q000494:pharmacology; D010406:Penicillins / Q000494:pharmacology; D012965:Sodium Chloride / Q000494:pharmacology; D013211:Staphylococcus aureus / Q000187:drug effects* / Q000235:genetics / Q000378:metabolism; D013682:Teichoic Acids / Q000378:metabolism*; D013696:Temperature; D001618:beta-Lactamases / Q000378:metabolism
D000596:Amino Acids; D009604:Nitrosoguanidines; D010406:Penicillins; D013682:Teichoic Acids; D012965:Sodium Chloride; D001618:beta-Lactamases; D000409:Alanine; D008712:Methicillin; D010068:Oxacillin