Introduction
ExPEC—the spectrum of diseases
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 |
ExPEC—the specific virulence factors
ExPEC pathogenicity-associated islands and ExPEC virulence associated plasmids
Pathogenicity islands or gene | Products |
---|---|
Pathogenicity islands
| |
IICFT073 | P fimbriae, iron-regulated proteins |
I536 | α-Hemolysin, F-17-like fimbriae, CS12-like fimbriae |
II536 | Hek adhesin, P- related fimbriae, α-Hemolysin, hemagglutinin-like adhesion |
III536 | S fimbriae, salmochelin, HmuR-like heme receptor, Sat toxin, Tsh-like hemoglobin protease, antigen 43 |
IV536 | Yersiniabactin siderophore system |
IIJ96 | α-Hemolysin, Prs fimbriae, cytotoxic, necrotizing factor |
Virulence associated genes
| |
malX
| Maltose- and glucose-specific component IIa of a phosphoenolpuryvate-dependent phosphotransferase system |
usp
| Putative bacteriocin |
Plasmid | Size (bp) | Replicon (s) | Key component (s) | GenBank accession no. or source |
---|---|---|---|---|
pAPEC-1 | 103,275 | FIB, FIIA | Aerobactin, sit, hlyF, ompT, ets, iss, salmochelin, CoIV, tsh | CP000836 |
pAPEC-O103-CoIBM | 124,705 | FIB, FIIA | Aerobactin, sit, hlyF, ompT, iss, salmochelin, CoIBM | CP001232 |
pECOS88 | 133,853 | FIB, FIIA | Aerobactin, sit, hlyF, ompT,ets, iss, salmochelin, CoIV | CU928146 |
pVM01 | 151,002 | FIB, FIIA | Aerobactin, sit, hlyF, ompT, iss, ets, salmochelin, CoIBM, tsh | EU330199 |
pAPEC-O1-CoIBM | 174,241 | FIB, FIIA | Aerobactin, sit, hlyF, ompT, iss, ets, salmochelin, CoIBM, tsh | DQ381420 |
pAPEC-O2-CoIV | 184,501 | FIB, FIIA | Aerobactin, sit, hlyF, ompT, ets, iss, salmochelin, CoIV, tsh | AY545598 |
Gene names | Description |
---|---|
Iron uptake systems
| |
iroB
| Putative glucosyltransferase |
iroC
| ATP binding cassette ABC transport homolog |
iroD
| Putative ferric enterochelin esterase |
iroE
| Putative hydrolase |
Iron
| Outer membrane receptor fepA |
iucA
| Aerobactin siderophore biosynthesis protein |
iucB
| N(6)-hydroxylysine acetylase |
iucC
| Aerobactin siderophore biosynthesis protein |
iucD
| l-lysine 6 monooxigenase |
iutA
| Ferric aerobactin receptor precursor |
sitA
| Iron/manganese transport protein, periplasmic-binding protein |
sitB
| Iron/manganese transport protein ATP-binding component |
sitC
| Iron/manganese transport inner membrane component |
sitD
| Iron/manganese transport protein, inner membrane component |
ToxinhlyF
| Hemolysin |
Resistance to innate immunity
| |
ompT
| Outer membrane protease |
Bor
| Bacteriophage lambda bor protein |
The role of surface virulence factors in the development of ExPEC infections
Adhesive properties of ExPEC
Fimbrial adhesins from ExPEC
Afimbrial adhesins from ExPEC
The role of capsules and biofilm in the adhesion of ExPEC strains
Prevalence and transmission of ExPEC strains in different food products
Localization/Country | Origin of food products | E. coli (ExPEC phenotype) with high prevalence of virulence genes | References |
---|---|---|---|
Canada | Frozen poultry meat | fimH, kpsMT KII | Aslam et al. [49] |
Imported to Switzerland from India, Thailand, Vietnam, and the Dominican Republic | Vegetable samples, retail poultry meat |
traT, fyuA, chuA, vat
| Müller et al. [118] |
United States | Chicken meat and egg shells | ompT, iss, traT, fimH, hra, papA, papC i papEF | Mitchell et al. [70] |
Mexico | Unpasteurized cheeses |
fimA-agn43,fyuA
| Guzman-Hernandez et al. [48] |
Egypt | Dairy products: raw milk, Karish cheese, Ras cheese |
hlyA, cnf, vat, fyuA, iroN, iutA
| Ombarak et al. [69] |
China | Pork samples | kpsMII, fimH, papC, sfaS, focG, fimH, afa,iutA,ireA,cnf, | Khan et al. [80] |
Brasil | Poultry |
pap, sfa, usp
| Cunha et al. [81] |