Table 1.
Examples of studies that identified putative uropathogenic E. coli (pUPEC) or extraintestinal pathogenic E. coli (pExPEC) in water samples based on multi-locus sequence typing or the presence of virulence genes17
| Reference | Country | Source of samples | Virulence genes and their function used to identify pUPEC or pExPEC | Findings |
|---|---|---|---|---|
| Müller et al.37 | Switzerland | 207 E. coli from surface waters, freshwater fish, fresh vegetables, retail poultry meat, fecal samples of livestock, healthy humans, and primary care patients | Iron uptake (fyuA, chuA, and yfcv), toxin (vat), pathogenicity island (PAI), and protectins/serum resistance (traT) | Overlaps in E. coli genotypes were found for some pUPEC isolates from water and humans |
| Ahmed et al.42 | Australia | 200 E. coli from 22 rainwater tanks used for potable and non-potable purposes | Adhesins (bmaE, papG allele II, papG allele III, papAH, papEF, and focG), toxins (cdtBa and cvaC), invasins (ibeA), siderophores (iutA), capsule synthesis (kpsMT allele III and kpsMT allele K1), pathogenicity island (PAI), and protectins/serum resistance (traT) | Fifteen of 22 rainwater tanks were positive for pExPEC |
| Hamelin et al.21 | United States | 308 E. coli from surface water collected from two large river systems | P pilus-encoding gene (hlyA); Iron uptake (chuA, fepC, cnf1, irp1, irp2, fyuA, iroN, and usp) | E. coli pathotypes were mostly pExPEC and belonged to phylogenetic groups B2 and D |
| Rayasam et al.20 | India | 104 E. coli from 51 drinking water samples collected from elevated storage reservoirs that are piped to households | STs known to cause UTIs in humans | Nineteen of the E. coli STs (18.3%) belonged to known lineages of human UPEC |
| Amato et al.35 | United States | 337 E. coli from streams draining 15 small watersheds of the Chesapeake Bay | Adhesins (papA, papC, and afaC), siderophores (iutA), and capsule synthesis (kpsMII) | Fifty-six isolates (17%) were pExPEC |
| Sen et al.19 | United States | 134 E. coli from wetlands contaminated by corvids | Siderophores (iutA, iroN, and iutA), capsule synthesis (iss, kpsMTII, and traT), adhesins (papEF, pap A/C, papG, sfa/foc, and afa/dra), toxins and hemolysins (cnf1, stx1, stx2, hlyA, and hlyF), and invasion (ibeA) | Fifteen of 134 isolates (11.2%) were pExPEC |
| Cho et al.22 | United States | 34 Antimicrobial-resistant E. coli identified from a mixed-use watershed | STs known to cause UTIs in humans | Three of the 34 isolates were ST131, which are known lineages of human UPEC |
| Divya et al.43 | India | 300 E. coli from tropical estuarine water | Adhesins (papAH, papC, and sfa/foc), capsule synthesis (kpsMT II), and siderophore (iutA) | Forty-nine isolates (16.3%) were pExPEC, and approximately 34.6% of those isolates had antibiotic-resistant genes |
| Johnson et al.18 | United States | 280 E. coli from seven surface water sites | Type 1 fimbriae (fimA), hemolysin (hlyD), P fimbriae (papAH and papC), S and F1C fimbriae (sfa/focDE), Dr-binding adhesins (afa/draBC), group 2 capsule (kpsM II), and aerobactin system (iutA) | Twenty-six isolates (5%) fulfilled the molecular criteria for pExPEC |
| Gomi et al.40 | Japan | 531 E. coli isolates obtained from Yamato River | STs known to cause UTIs in humans | Among 58 pExPEC isolates, several lineages of human UPEC were found (ST95, ST127, ST12, ST14, and ST131) |
| Franz et al.53 | Netherlands | 170 ESBL-producing E. coli from Dutch wastewater (n = 82) and surface water (n = 88) | Afimbrial adhesion (afa), F1C fimbriae (focG), cytolytic protein toxin (hlyD), iron acquisition system (iutA), group 2 polysaccharide capsule (kpsMII), P fimbriae (papA), and S fimbriae (sfaS) | Fifteen of the ESBL-producing E. coli (8.8%) were pExPEC |
| Diallo et al.45 | France | 1,248 E. coli from effluents of a municipal wastewater treatment plant receiving wastewater from a slaughterhouse | S and F1C fimbriae (sfa/focDE), group 2 capsule (kpsMT K10), hemolysin (hlyA), P fimbriae (papEF), adhesins (afa/draBC), toxins, and hemolysins (clbN, f17A, and cnf) | ExPEC was significantly higher in city wastewater (8.4%) than in slaughterhouse wastewater (1.2%) |
| Anastasi et al.36 | Australia | 264 E. coli isolates collected from 129 receiving water sites in a 20-km radius surrounding sewage treatment plants | P fimbriae (papAH, papEF, and papC), siderophore (iroNE.coli), toxins, and hemolysins (cnf1, hlyA, eltA, estII, eaeA, stx1, and stx2) | ExPEC virulence genes were found in 11% of the 15 most common E. coli types identified |
E. coli = Escherichia coli; ESBL = extended spectrum beta-lactamases; ST = sequence type; UTI = urinary tract infections.