Extraintestinal Pathogenic Escherichia coli: Virulence Factors and Antibiotic Resistance

Abstract

The One Health approach emphasizes the importance of antimicrobial resistance (AMR) as a major concern both in public health and in food animal production systems. As a general classification, E. coli can be distinguished based on the ability to cause infection of the gastrointestinal system (IPEC) or outside of it (ExPEC). Among the different pathogens, E. coli are becoming of great importance, and it has been suggested that ExPEC may harbor resistance genes that may be transferred to pathogenic or opportunistic bacteria. ExPEC strains are versatile bacteria that can cause urinary tract, bloodstream, prostate, and other infections at non-intestinal sites. In this context of rapidly increasing multidrug-resistance worldwide and a diminishingly effective antimicrobial arsenal to tackle resistant strains. ExPEC infections are now a serious public health threat worldwide. However, the clinical and economic impact of these infections and their optimal management are challenging, and consequently, there is an increasing awareness of the importance of ExPECs amongst healthcare professionals and the general public alike. This review aims to describe pathotype characteristics of ExPEC to increase our knowledge of these bacteria and, consequently, to increase our chances to control them and reduce the risk for AMR, following a One Health approach.

The Molecular Characterization and Risk Factors of ST131 and Non-ST131 Escherichia coli in Healthy Fecal Carriers in Tehran, Iran

“…Escherichia coli, a member of Enterobacteriaceae and a prevalent gut normal microflora in the human body, causes intestinal and extraintestinal infections (ie, intestinal pathogenic E. coli [IPEC] and extraintestinal pathogenic E. coli [ExPEC]) (1). The isolates of E. coli are classified into distinct pathotypes mainly characterized by their specific virulence determinants, disease clinical symptoms, and phylogenetic background (2).…”

Pathogenome comparison and global phylogeny of Escherichia coli ST1485 strains

“…They are classified into pathotypes based on their virulence characteristics and the symptoms they produce 1 , 2 . Escherichia coli strains termed extraintestinal pathogenic E. coli (ExPEC) exhibit a broad range of genes that encode virulence factors involved in colonization, adherence, invasion, persistence, and/or toxin production in the host, causing illnesses such as urinary tract infections, neonatal meningitis, pneumonia, and septicemia 3 , 4 . It is still unclear what differentiates ExPEC from commensal E. coli 1 , 2 , 5 .…”

“…It is still unclear what differentiates ExPEC from commensal E. coli 1 , 2 , 5 . ExPEC strains mainly include uropathogenic E. col (UPEC), neonatal meningitis-causing E. coli (NMEC), avian pathogenic E. coli (APEC), sepsis-associated E. coli (SEPEC) and mammary pathogenic E. coli (MPEC) 4 , 6 , 7 .…”

Comparative Characteristics and Pathogenic Potential of Escherichia coli Isolates Originating from Poultry Farms, Retail Meat, and Human Urinary Tract Infection

“…The ExPEC pathotype differs from commensals by the presence of functional genes which enable the colonization of a specific host organism. Within the pathogenicity islands present in the ExPEC reference strains (serotypes: O6: K2: H1, O6: K15: H31, O18: K1: H7, OR: K5: H, and O1: K1: H7), various iron uptake systems are coded, the most often mentioned being: ent (enterobactin), iro (salmochelin), chu (hemin uptake system), sie (iron and manganese transport), iutA (aerobactin), fyuA (yersiniabactin), adhesins: fimbriae fim (type 1), pap (P), sfa (S), foc (F1C), or toxins: hly (α-haemolysin), CNF1 (cytotoxic necrosis factor), vat (vacuolating autotransporter toxin), or sat (autotransporter), but the spectrum of virulence genes detected for these isolates is much wider and varies with the isolate [ 7 , 8 , 9 ]. In turn, the most common APEC virulence genes determine the production of colicins ( cva ), aerobactin ( iut ), hemagglutinin ( tsh ), envelope antigens ( kps ), the irp2 gene associated with iron transport genes, the pap operon encoding P-type fimbria, and the Iss protein associated with bactericidal resistance to the serum, encoded by the iss gene located within the plasmid pColV-I-K94 [ 10 , 11 , 12 ].…”