Table 2.
Distribution of virulence factors among four main sequence types of 82 Escherichia coli causing bovine mastitis
| Gene or marker* | Prevalence by sequence type (n, %) | ||||
| ST10 | ST58 | ST88 | ST1125 | Other | |
| (n=7) | (n=8) | (n=6) | (n=9) | (n=52) | |
| ExPEC-associated genes | |||||
| papAH | – | 2 (25) | 2 (33.3) | – | 3 (5.8) |
| papC | – | 2 (25) | 2 (33.3) | – | 3 (5.8) |
| papEF | – | – | – | – | 1 (1.9) |
| yfcv | – | – | – | – | 2 (3.8) |
| hlyA | – | – | – | 9 (100) | 6 (11.5) |
| vat | – | – | – | – | 3 (5.8) |
| fyuA | 3 (42.9) | 6 (75) | 5 (83.3) | – | 9 (17.3) |
| iutA | – | 5 (62.5) | 4 (66.7) | – | 8 (15.4) |
| KpsMII | – | – | – | – | 2 (3.8) |
| PAI | – | – | – | – | 1 (1.9) |
| traT | 2 (29.6) | 8 (100) | 5 (83.3) | 9 (100) | 35 (67.3) |
| Virulence factor score (median, range) | 1, 0–1 | 3, 1–5 | 3, 0–5 | 2, 2–2 | 1, 0–8 |
| IPEC-associated genes | |||||
| stx1a | – | – | – | – | 2 (3.8) |
| subAB | – | – | – | – | 1 (1.9) |
*aggR, afa, eae, LT, sfa, STh, STp and stx2 genes were not identified in any of the isolates.
–, not detected; ExPEC, extraintestinal pathogenic E. coli;fyuA, ferric yersiniabactin uptake protein; hlyA, haemolysin; IPEC, intestinal pathogenic E. coli; iutA, aerobactin siderophore receptor; KpsMII, group two polysaccharide capsule; PAI, right-hand terminus of pathogenicity island; papAH, pyelonephritis-associated major pilin protein; papC, outer membrane usher protein; papEF, fimbrial protein subunit; stx1a, Shiga toxin subunit; subAB, subtilase cytotoxin; traT, lipoprotein involved in serum resistance; vat, vacuolating autotransporter toxin; yfcv, major subunit of a chaperone-usher fimbria.