Table 1 Virulence genes of ExPEC encoding adhesins, toxins and siderophores
Description | Virulence genes | Function | ExPEC pathotype |
|---|---|---|---|
Adhesins | |||
Type 1 fimbriae | fim | Factor of colonization in extraintestinal infections, biofilm formation | UPEC, NMEC, SEPEC, APEC |
Afimbrial adhesin | afa | The non-fibrous adhesin binds to the DAF receptor on the cell surface epithelium, hemagglutination capacity | UPEC |
Dr fimbriae | dra | Binding to the DAF receptor on the surface epithelial cells and mediation of internalization bacteria to the host cells | UPEC |
P fimbriae | pap | Stimulate the production of cytokines by T lymphocytes, colonization factor in extraintestinal infections | UPEC, SEPEC, APEC |
S fimbriae | sfa | Adhesion to intestinal epithelial cells, kidney, lower urinary tract cells; facilitate the penetration of bacteria into the tissues | UPEC, NMEC |
F1C fimbriae | foc | Adhesion to renal epithelial cells and endothelial cells of the bladder and kidneys | UPEC |
Iha | iha | Iron‐regulated‐gene‐homologue adhesion | UPEC |
Mat | mat | Meningitis associated and temperature regulated fimbriae | NMEC |
Curli fiber gene | crl, csg | Enable biofilm formation and promote pathogenicity | UPEC, SEPEC, APEC |
Antigen43 | agn43(flu) | Protein of autotransporter family, adhesion and biofilm development | UPEC |
Invasine | |||
Ibe ABC | ibeA,B,C | Cell invasion into the host tissues | NMEC, SEPEC, APEC |
Iron uptake | |||
Aerobactin | iuc,aer | Siderophore, acquisition of Fe2 + / 3 + in the host system | UPEC, APEC |
Iron repressible protein | irp | Yersiniabactin synthesis | NMEC |
Salmochelin | iroN | Siderophore receptor, use of Fe ions obtained from the body host | UPEC, NMEC, SEPEC APEC |
ChuA, Hma | chu, hma | Enable using of Fe from hemoglobin in the host system | UPEC, SEPEC |
SitABC | sitA,B,C | Transportation of Fe, Mn | UPEC, APEC |
Protectins/serum resistance | |||
Transfer protein | traT | Inhibition of the classical pathway of complement activity | NMEC, SEPEC APEC |
Capsula antigens | KpsMI-neuA, KpsMII | The protection factor against phagocytosis and the spreading factor | NMEC, SEPEC |
Outer membrane protein | omp | Enable intracellular survival, evasion from the body’s defense. | UPEC, NMEC |
Increased serum survival | iss | The protection factor against phagocytosis | NMEC, SEPEC, APEC |
ColV, CvaC | colV, cvaC | Factor facilitating colonization | NMEC, SEPEC, APEC |
Toxins | |||
Serin protease autotransporter | pic | Degrades mucins, facilitates colonization epithelium, damages of the cell membrane | UPEC |
Secreted autotransporter toxin | sat | Proteolytic toxin, effect cytotoxic—influences on cell vacuolization | UPEC |
Vacuolating autotransporter toxin | vat | Proteolytic toxin, induces host cell vacuolization | UPEC, APEC |
Hemolysin A | hlyA | Creating of pores in membranes of host cells (cell lysis) | UPEC |
Cytotoxic necrotizing factor | cnf | Engaging in cell necrosis | UPEC, SEPEC |
Cytolethal distending toxin | cdt | Cytolethal distending factor | SEPEC |