Comparison of macromolecular oxidation by reactive oxygen species in three bacterial genera exposed to different...

Area of Science:

• Microbiology
• Biochemistry
• Pharmacology

Background:

• Proteins and lipids are vital macromolecules susceptible to oxidative damage, potentially altering cellular functions.
• Antibiotic-induced oxidative stress is an emerging area of concern in microbial research.

Purpose of the Study:

• To investigate the oxidative effects of four common antibiotics (ceftazidime, piperacillin, chloramphenicol, and ciprofloxacin) on Staphylococcus aureus, Escherichia coli, and Pseudomonas aeruginosa.
• To compare the susceptibility of Gram-positive (S. aureus) and Gram-negative (E. coli, P. aeruginosa) bacteria to antibiotic-induced oxidative stress.

Main Methods:

• Exposure of bacterial cultures (S. aureus, E. coli, P. aeruginosa) to ceftazidime, piperacillin, chloramphenicol, and ciprofloxacin.
• Quantification of lipid peroxidation levels.
• Measurement of protein carbonyl residues.
• Assessment of advanced oxidation protein products (AOPP).

Main Results:

• All tested antibiotics induced lipid peroxidation across the three bacterial genera, with higher levels observed in S. aureus compared to Gram-negative bacteria.
• Ciprofloxacin reduced protein carbonyl residues in S. aureus but increased them in Gram-negative bacteria.
• While ciprofloxacin increased advanced oxidation protein products (AOPP) in all strains, S. aureus exhibited a comparatively smaller increase.

Conclusions:

• The study demonstrates differential susceptibility of bacterial genera to antibiotic-induced oxidative stress.
• S. aureus appears more vulnerable to certain oxidative damage markers induced by the studied antibiotics than E. coli and P. aeruginosa.