Biofilm-Producing Ability of Bovine Extraintestinal Pathogenic Escherichia coli and Its Correlation with Attachment Factors

Abstract

Background: Escherichia coli is recognized as a common cause of infection. Long-lasting presence of bacteria on biotic and abiotic surfaces and failure of bacterial eradication are predicted by biofilm production. Some extracellular frills of E. coli can be implicated in productive events, leading to biofilm formation by surface colonization. Objectives: In the present study, correlation of csgA (encoding curli fimbriae) and fimA (encoding a large subunit of type I fimberiae) gene expression with biofilm formation of extraintestinal bovine pathogenic E. coli strains was evaluated in different enrichment media. Methods: The microtiter plate-based crystal violet method was applied to examine the biofilm production of 30 E. coli strains in Luria-Bertani (LB) and Brain-Heart Infusion (BHI) broth with 1% sucrose. PCR assay was performed to determine the presence of the studied genes. Results: According to the results, 100% of isolates contained csgA genes, and 96.7% contained fimA genes. Using the BHI medium with 1% sucrose, 53.3% and 16.6% of strains were average and strong biofilm producers, respectively. On the other hand, by using the LB medium, 66.6% of isolates were poor biofilm producers, whereas none were strong biofilm producers. Conclusions:The BHI medium containing 1% sucrose was better detected in biofilm production, compared to the LB medium. Since the studied genes were present in non-biofilm producing isolates, the correlation of these genes with biofilm-producing ability is questioned.

Biofilm forming potentiality of Escherichia coli isolated from bovine endometritis and their antibiotic resistance profiles

“…The current study reported that 46.6% of the recovered E. coli isolates were phenotypically positive for biofilm formation. Moori Bakhtiari et al [ 29 ] reported that 53.3% and 16.6% of E. coli isolates were moderately and strongly biofilm producers, respectively.…”

Extraintestinal Pathogenic Escherichia coli: Virulence Factors and Antibiotic Resistance

“…Biofilms are dynamic assemblages of microorganisms that adhere to biotic or abiotic surfaces and are characterized by highly specialized interactions between microorganisms. The bacteria are embedded in a matrix of self-produced extracellular polymeric substances (EPS) which allows one to alter phenotypes (e.g., growth rate, gene transcription, and antibiotic resistance) [41,42]. Schematically, a model for the formation of a differentiated and mature bacterial biofilm requires five developmental stages: (i) a reversible attachment of planktonic bacteria to the solid surface; (ii) transition from reversible to irreversible attachment due to production of EPS and/or specific adhesins located on pili and fimbriae, which interact with the surface (e.g., flagella, autotransporter proteins, fimbriae, curli, EPS, and F-type conjugative pilus) [43][44][45]; (iii) early development of biofilm architecture.…”

Probiotics as Therapeutic Tools against Pathogenic Biofilms: Have We Found the Perfect Weapon?

“…Biofilm-forming bacteria are embedded in a matrix of self-produced slime, constituted by extracellular polymeric substances (EPS) [4]. This growing mode can alter bacterial biological and physiological characteristics, such as reproduction, growth, gene transcription rate, and resistance towards antibiotics [5][6][7]. Schematically, the formation of a differentiated biofilm requires five maturation stages: (i) initial attachment of planktonic bacteria (reversible) to a surface; (ii) production and secretion of EPS and/or other means of docking, and specific adhesins (e.g., flagella, autotransporter proteins, fimbriae, curli fibers, and F-type conjugative pilus) that drive the transitional attachment from reversible to irreversible [8][9][10]; (iii) early-maturing of biofilm architecture as a super cellular structure; (iv) late-maturing of micro-colonies and evolution into a mature biofilm; and (v) detachment of cells from the biofilm and dispersion into the surrounding environment (Figure 1).…”