Gentamicin induces efaA expression and biofilm formation in Enterococcus faecalis

Area of Science:

• Microbiology
• Molecular Biology
• Infectious Diseases

Background:

• Enterococci are leading causes of hospital-acquired infections like bacteremia and urinary tract infections.
• Understanding factors influencing Enterococcus faecalis virulence, such as biofilm formation, is crucial for infection control.

Purpose of the Study:

• To investigate the impact of ampicillin, vancomycin, gentamicin, and ceftizoxime on biofilm formation in Enterococcus faecalis.
• To analyze the effect of these antibiotics on the gene expression of key colonization factors (efaA, asa1, ebpA, esp, ace).

Main Methods:

• Utilized flow system assays and Microtiter plates to evaluate biofilm formation.
• Assessed the expression levels of efaA, asa1, ebpA, esp, and ace genes in response to antibiotic treatment in clinical isolates of E. faecalis.

Main Results:

• Gentamicin induced biofilm formation in 89% of isolates and increased the expression of esp and efaA genes.
• Ampicillin, vancomycin, and ceftizoxime showed varied effects on gene expression, with ampicillin strongly upregulating ace, esp, and ebpA.
• Vancomycin and ceftizoxime also altered the expression of several colonization factor genes.

Conclusions:

• Antibiotics, particularly gentamicin, can play a significant role in the biofilm formation and persistence of enterococci.
• The efaA gene appears to be important in antibiotic-induced biofilm formation, especially with gentamicin exposure.
• Further research involving efaA mutants is recommended to elucidate its precise role in antibiotic-mediated biofilm development.