Volume 12, Number 5—May 2006
Shiga-toxigenic Escherichia coli O157 in Agricultural Fair Livestock, United States
|Fair code||Total isolates||PFGE patterns||Unique XbaI patterns (P1–P47) (sample type† - no. isolates)||Simpson D (95% CI)‡|
|SF2||35||25||P1 (F-5, B-2), P2 (B-2), P3 (B-2), P4 (B-2), P5 (B-2), P6–P25§||0.96 (0.92–0.99)|
|CF19||4||2||P26 (B-1, P-1), P27 (E-2)||0.67 (0.49–0.85)|
|CF20||9||5||P28 (P-1, B-1, F-1), P29 (F-3), P30 (D-1),¶ P31 (B-1), P32 (D-1)||0.83 (0.73–0.94)|
|CF22||14||6||P33 (B-5, P-2), P34 (S-3), P30 (D-1),¶ P35 (B-1), P36 (B-1), P37 (B-1)||0.74 (0.59–0.89)|
|CFB||4||4||P38 (Ef-1), P39 (B-1), P40 (B-1), P41 (S-1)||1.00 (NA)|
|CFY||4||4||P42 (B-1), P43 (B-1), P44 (B-1), P45 (S-1),||1.00 (NA)|
|CF16||9||2||P46 (B-8),# P47 (B-1)||0.22 (0.00–0.57)|
*PFGE, pulsed-field gel electrophoresis; STEC, Shiga-toxigenic Escherichia coli.
†F, fly (pooled fly sample collected when livestock were present on fair grounds); B, beef cattle; P, pig; E, environment; D, dairy cattle; S, sheep; Ef, environment fly (pooled fly sample collected when fair grounds were closed to the public and no animals were present).
‡Probability that any 2 randomly selected isolates from a given fair have unique PFGE patterns. CI, confidence interval; NA, not available.
§Twenty isolates from SF2 each with a unique PFGE pattern from the following samples: 16 beef cattle, 2 sheep, 1 pig, and 1 dairy cow.
¶Isolates from dairy samples at CF20 and CF22 were indistinguishable; fairs were geographically close to each other.
#A Stool STEC O157 isolate from a human clinical case-patient (hemorrhagic colitis) who had visited this fair also had this PFGE pattern.