Natural and synthetic plant compounds as anti-biofilm agents against Escherichia coli O157:H7 biofilm

Escherichia coli is a common gram-negative bacterium found in the gut and intestinal tract of warm-blooded animals including humans. An evolved seropathotype E. coli O157:H7 (STEC) came into existence in 1982, since then it has been evolved as a stronger and more robust drug-resistant pathotype of E. coli. This drug resistance is due to horizontal gene transfer, natural gene evolution for survival, and most of the cases due to the ability of STEC to switch to the biofilm growth mode from planktonic lifestyle. During the growth in biofilm mode, Escherichia coli O157:H7 opts more robust ability to grow in adverse environments i.e., in presence of antibiotics and other antimicrobial chemicals. Due to the biofilm matrix, the microbial community acquires drug resistance. This makes the treatment of diseases caused by E. coli O157:H7 a complex challenge. To address the illnesses caused by this biofilm-forming pathogen, there are several possible strategies such as antibiotic therapies, synthetic antimicrobial chemicals, adjunct therapy of synergistic effect of multiple drugs, and more importantly plant originated compounds as a new anti-biofilm candidate. The present review summarizes various phytochemicals and their derivatives reported in the last decade mostly to eliminate the biofilm of STEC. The review will progressively reveal the antibiofilm mechanism of the phytochemicals against STEC and to be a potential candidate for the development of the future antibacterial drugs to STEC induced infections.