Enterobacter spp. Virulence Factors and Biofilm Components: Synthesis, Structure, Function, and Inhibitors

Enterobacter species are multidrug-resistant opportunistic pathogens that produce a variety of virulence factors (VF) to cause disease. They are Gram-negative bacteria widely distributed in the environment, particularly in soil, water, and the gastrointestinal tract of animals and humans. These opportunistic pathogens are considered as ESKAPE pathogens due to their ability to escape the effects of many antimicrobial agents and cause a range of infections that are difficult to treat. The prevalence of Enterobacter-associated infections has increased in recent years in healthcare settings, and many strains of Enterobacter have become resistant to multiple antibiotics, including carbapenems, which are often considered a last resort for treating multidrug-resistant infections. Antibiotic-resistant Enterobacter strains are a major public health issue because they can cause serious infections that are difficult to cure. These organisms produce a variety of VFs, including antibiotic resistance genes, biofilms, and toxins, which enable them to survive in hostile environments and evade host immune defenses. They have a mobile genetic makeup that allows them to acquire and exchange antibiotic resistance genes, which favor antimicrobial resistance. Therefore, understanding the mechanisms by which these bacteria cause disease is essential for the development of effective treatments and prevention strategies. Their synthesis, structure, function, and inhibitors play a significant role in virulence and biofilm formation. One of the VFs of Enterobacter spp. is the production of various enzymes, such as beta-lactamases, that can degrade antibiotics, making the bacteria resistant to treatment. These organisms are also capable of forming biofilms, which provide a protective environment for the bacteria to survive in hostile conditions, during exposure to antibiotics and host immune defenses. These substances form a matrix that surrounds the bacterial cells and protects them from environmental stressors. Enterobacter spp. can produce a variety of extracellular polymeric substances (EPS) components, including cellulose, curli fibers, and fimbriae, which promote biofilm formation and provide structural stability to the matrix. Other VFs include the ability to adhere to host cells, invasion into host tissues, and produce toxins that damage host cells. The bacteria can also evade host immune defenses by modifying their surface structures, such as lipopolysaccharides, to avoid detection by host immune cells. The function of VFs produced by Enterobacter spp. is critical to their pathogenicity. Inhibitors of VFs are potential therapeutics for combating infections caused by these bacteria.