Microbial phosphorylation of the OA-6129 group of carbapenem compounds

Area of Science:

• Microbiology
• Biochemistry
• Pharmacology

Background:

• Carbapenem antibiotics are crucial for treating severe bacterial infections.
• Understanding antibiotic modification and its effects on activity is vital for developing new therapeutic strategies.
• Brevibacterium ammoniagenes possesses enzymes capable of modifying antibiotic structures.

Purpose of the Study:

• To investigate the phosphorylation of OA-6129 carbapenems by Brevibacterium ammoniagenes.
• To determine the impact of this phosphorylation on antimicrobial activity against various bacterial species.
• To assess the altered resistance of phosphorylated carbapenems to dehydropeptidase enzymes.

Main Methods:

• Incubation of OA-6129 carbapenems with ATP and Brevibacterium ammoniagenes.
• Antimicrobial susceptibility testing against Gram-positive and Gram-negative bacteria.
• Enzyme resistance assays using mouse renal and human dehydropeptidase.
• Analysis of susceptibility to A933 acylase and depantothenylation.

Main Results:

• Phosphorylation occurred at the C-3 pantetheinyl side chain of OA-6129 carbapenems.
• Reduced antimicrobial activity against some Gram-positive bacteria was observed.
• Improved activity against certain Gram-negative microbes was noted.
• Increased resistance to mouse renal dehydropeptidase and moderate resistance to human dehydropeptidase.
• Phosphorylated OA-6129A and B2 were resistant to A933 acylase and underwent depantothenylation.

Conclusions:

• Brevibacterium ammoniagenes-mediated phosphorylation significantly alters OA-6129 carbapenem properties.
• The modification impacts spectrum of activity and enzymatic stability, offering insights into carbapenem resistance mechanisms.
• Further research into these modified carbapenems could lead to novel antibiotic development.