Volume 20, Number 12—December 2014
Research
Geographic Divergence of Bovine and Human Shiga Toxin–Producing Escherichia coli O157:H7 Genotypes, New Zealand1
Table 1
Virulence profiles and SBI types of Shiga toxin–producing Escherichia coli O157:H7 isolates obtained from humans and fecal samples from slaughterhouse cattle, New Zealand, 2008–2011*
Species, no. isolates | NI | SI | Virulence genes† |
SBI type |
||||||
---|---|---|---|---|---|---|---|---|---|---|
ehxA | eae | stx2 | stx2c | stx1 | Dominant (no., %) | Other (no., %) | ||||
Bovine | ||||||||||
6 | 6 | 0 | + | + | + | − | + | WY12a (6, 100.0) | – | |
10 | 2 | 8 | + | + | + | + | − | ASY2c (7, 70.0), SY2c (2, 20.0) | AS2c (1, 10.0) | |
24 |
24 |
0 |
+ |
+ |
+ |
− |
− |
AY2a (22, 91.7) |
AWY2a (2, 8.3) |
|
Human | ||||||||||
51 | 43 | 9 | + | + | + | – | + | WY12a (49, 96.2) | AWY12a (2, 3.8) | |
1 | 0 | 1 | + | + | + | – | + | WY12a (1, 100.0) | – | |
94 | 54 | 40 | + | + | + | + | − | ASY2c (69, 73.4), SY2c (15, 16.0) | SWY2c (3, 3.2), ASWY2c (2, 2.1), AS2c (2, 2.1), Y2c (2, 2.1), ASY2a2c (1, 1.1) | |
214 | 179 | 35 | + | + | + | − | − | AY2a (210, 98.1) | AWY2a (4, 1.9) | |
3 | 2 | 1 | + | + | + | + | + | ASY12c (2, 66.7) | AS12c (1, 33.3) |
*NI, North Island of New Zealand; SBI, Shiga toxin–encoding bacteriophage insertion; SI, South Island of New Zealand; +, gene present; −, gene absent.
†ehxA gene encodes for enterohemolysin; eae gene encodes for intimin; stx2, primers for detection of this gene did not differentiate between subtypes of Shiga toxin type 2; stx2c gene encodes for Shiga toxin subtype 2c; stx1, primers for detection of this gene did not differentiate between subtypes of Shiga toxin type 1.
1Preliminary results from this study were presented at the New Zealand Veterinary Association Conference; June 16–20, 2014, Hamilton, New Zealand.