Features of virulence factors of the Enterobacteriaceae involved in the necrotizing enterocolitis development

Necrotizing enterocolitis is a severe, multifactorial disease manifests by transmural necrosis of the intestinal wall. Recent studies propose new concepts regarding the etiology and pathogenesis of necrotizing enterocolitis. There are numerous risk factors for the development of this condition, including the immaturity of the immune system in premature neonates, impaired colonization of the gut microbiota, underdeveloped intestinal barrier functions, and reduced tolerance to enteral nutrition. Both risk factors and the etiological microbial agent plays an equally important role in the development of this disease. The most commonly isolated bacteria that damage the intestinal wall in children include Escherichia coli, Klebsiella pneumoniae, Cronobacter spp., Staphylococcus aureus, Enterococcus spp., Clostridium perfringens, Pseudomonas aeruginosa, and Proteus mirabilis. In infants under one month of age with immunodeficiency of various etiologies who are receiving antimicrobial therapy, Candida species are identified as causative agents. Viral agents, such as Coronaviruses, Rotaviruses, and Coxsackieviruses, also play a role in the development of necrotizing enterocolitis. However, the disease most commonly results from the damaging action of bacterial agents. Each bacterial strain has its own genetic determinants, which influence the pathogenicity of the agent and the severity and duration of the disease. This review summarizes data from both domestic and international publications on the virulence factors of the Enterobacteriaceae, such as Cronobacter spp., Klebsiella spp., and Enterobacter spp., which are primary causative agents of necrotizing enterocolitis. Enterobacteriaceae bacteria possess a variety of virulence factors, including adhesive activity, invasiveness, survival within macrophages, exotoxin production, and biofilm formation.

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