Biofilm Formation and Antibiotic Resistance Profiles in Carbapenemase-Producing Gram-Negative Rods-A Comparative...

Area of Science:

• Microbiology
• Infectious Diseases
• Antimicrobial Resistance

Background:

• Carbapenem-resistant (CR) bacteria present a major global health threat due to resistance to beta-lactam antibiotics.
• CR bacteria can form biofilms, which are crucial for persistent infections and treatment evasion.
• Understanding factors influencing CR bacterial biofilm formation is vital for effective control strategies.

Purpose of the Study:

• To investigate the biofilm-forming capacity of CR clinical isolates.
• To assess the impact of serum on CR bacterial biofilm formation.
• To evaluate the resistance profiles and genetic markers associated with carbapenemase production in clinical isolates.

Main Methods:

• Collected CR bacterial isolates from clinical samples (pharyngeal, rectal, respiratory).
• Assessed biofilm formation in vitro with and without fetal bovine serum.
• Detected carbapenemase genes (blaKPC, blaOXA-48-like, blaNDM) using PCR and phenotypic methods.

Main Results:

• CR bacteria were detected in 4.25% of pharyngeal and 6.38% of rectal swabs; Acinetobacter baumannii and Klebsiella pneumoniae were most common.
• Clinical isolates exhibited higher biofilm production compared to standard strains.
• Serum stimulated biofilm formation in Acinetobacter spp. but not Klebsiella spp.; carbapenemase genes were present but not always the primary resistance driver.

Conclusions:

• Biofilm formation in CR clinical isolates is variable and influenced by bacterial species and environmental factors like serum.
• Differences exist in biofilm formation between carriage and infection isolates.
• Findings are critical for developing targeted treatments and infection control measures against CR bacteria.