Adaptability to Various Growth Conditions of Biofilm Associated Extended-Spectrum-Beta-Lactamases Producing Bacteria

Abstract

Extended-Spectrum β-Lactamase (ESBL) producing bacteria are becoming increasingly prevalent in biofilmassociated infections. Bacteria form biofilms that allow their survival in hostile environments. The amount of formed biofilm is affected by external environmental factors. This study investigates the effect of specific parameters (media type, incubation condition, and growth stage) on the amount of produced biofilm on antibiotic resistant bacterial strains, Escherichia coli (CTX-M-15, TEM-3, and IMP-type) and Klebsiella pneumoniae (OXA-48, SHV-18, NDM-1, and KPC-3). The amount of biofilm formed was measured at different time points (6, 12, 24 and 48 h) of incubations under static and shaking conditions, using three different types of media (nutrient broth, LB broth, and AB broth). Statistical tests showed that there was a significant difference in biofilm level (p<0.01) for 64 out of 80 tests (80%) when grown under different types of media. Growing under different incubation conditions also showed a statistical difference in biofilm level (p<0.05) for 76 out of 120 tests (63%). Stage of growth of the same species also showed statistical difference, 20 out of 24 tests (83%) for E. coli and 24 out of 24 tests (100%) for K. pneumoniae. These findings suggested that biofilm formation is highly affected by incubation conditions, strains' stage of growth, and media type demonstrating that these conditions may play a role in adaptability of the ESBLs on different environmental conditions and their increased prevalence in biofilm associated infections.

Biofilm and Gene Expression Characteristics of the Carbapenem-Resistant Enterobacterales, Escherichia coli IMP, and Klebsiella pneumoniae NDM-1 Associated with Common Bacterial Infections

“…Bacterial biofilms are recognised as an important cause of many infections as 65-80% of all bacterial infections are related to biofilm formation [10][11][12]. Studies have shown that specific physiological growth conditions and genetic interactions within the biofilms cause a dramatic increase in intolerance to the antimicrobial agents, as well as the association between antibiotic resistance and biofilm formation [13][14][15].…”

“…Although some surveys have shown that different growth conditions influence biofilm formation and, in turn, the association with antibiotic resistance [14], how the growth conditions affect the biofilm-related-gene expression was not well elucidated in CRE. Specifically, how the growth condition influences the expression of the genes responsible for the bacterial cell communication pathways in CRE.…”