Volume 13, Number 12—December 2007
Dispatch
Escherichia coli O157:H7 in Feral Swine near Spinach Fields and Cattle, Central California Coast1
, Michael Cooley‡, Diana Carychao‡, Gerald W. Wiscomb§, Richard A. Sweitzer¶, Leta Crawford-Miksza*, Jeff A. Farrar#, David K. Lau**, Janice O’Connell*, Anne Millington#, Roderick V. Asmundson**, Edward R. Atwill, and Robert E. Mandrell‡Table 1
Escherichia coli O157:H7 isolated from environmental samples collected at ranch A, California, September–November 2006
| Sample type | No. tested | No. positive (%) | No. matches* |
|---|---|---|---|
| Cattle feces | 77 | 26 (33.8) | 15 |
| Cattle water trough | 10 | 0 | NA |
| Compost (chicken pellets)† | 1 | 0 | NA |
| Feral swine | |||
| Necropsy | 40 | 2 (5) | 2 |
| Buccal swab | 8 | 0 | NA |
| Colonic feces | 40 | 2 (5) | 2 |
| Rectal-anal swab | 8 | 0 | NA |
| Tonsil | 8 | 0 | NA |
| Feces from ground | 47 | 11 (23.4) | 6 |
| Subtotal | 87 | 13 (14.9) | 8 |
| Other animal specimens‡ | 26 | 0 | NA |
| Surface water§ | 79 | 3 (3.8) | 2 |
| Soil/sediment | 37 | 3 (8.1) | 3 |
| Well/irrigation water¶ | 18 | 0 | NA |
| Total | 335 | 45 (13.4) | 28 |
*No. samples indistinguishable from the major spinach-related outbreak strain by pulsed-field gel electrophoresis (XbaI-BlnI PulseNet profile EXHX01.0124-EXHA26.0015). NA, not applicable.
†Commercial, heat-treated chicken manure.
‡Included feces from coyote (n = 1), deer (n = 4), dog (n = 1), horse (n = 2), sheep/goat (n = 3, composite), waterfowl (n = 2), unknown species (n = 11), and owl (n = 2).
§Surface water (rivers, streams, ponds) was sampled by collection of 100-mL grab samples or placement of a modified Moore swab for 4–5 d.
¶Well water was sampled from 3 wells or sprinkler heads by collection of 100-mL or 1,000-mL grab samples or by concentration of 40,000 mL to 500 mL by using ultrafiltration (7).
