Biofilm Formation Status in ESBL-Producing Bacteria Recovered from Clinical Specimens of Patients: A Systematic Review and Meta-Analysis

Background: Recently, the emergence and spread of extended-spectrum beta-lactamase (ESBL) bacteria have become a global health concern. In addition, the ability to form biofilm due to less impermeability to antibiotics and the horizontal transformation (conjugation) of genes involved in antibiotic resistance have exacerbated the concerns. With a comprehensive meta-analysis, this study evaluated the potential relationship between ESBL and biofilm formation. Methods: A literature search was performed using global databases, such as PubMed and Scopus, up to November 2021. We retrieved all relevant documents and selected eligible articles based on inclusion criteria. Finally, the potential association between the biofilm formation capacity and resistance of ESBL-producing bacteria was measured with an odds ratio and a 95% confidence interval. Results: In the present study, 17 articles, including 2,069 Gram-negative isolates, were considered as eligible. The prevalence of biofilm formation in all clinical isolates of ESBL and non-ESBL pathogens was 72.4% (95% CI: 60.7-81.6) and 40.5% (95% CI: 30.2-51.8), respectively. Our results showed a positive relationship between the ability for biofilm formation and conferring antibiotic resistance in ESBL-producing bacteria (OR: 3.35; 95% CI: 1.67-6.74; p-value: 0.001). Conclusion: In general, we showed the rate of biofilm formation to be significantly higher in ESBLproducing strains. Given the current results, the updated therapeutic guidelines should consider the role of biofilm production for optimal therapy, treatment course, and clinical outcomes rather than the recommendation of antimicrobial agents by focusing on the results of the antibiotic susceptibility test.