Shiga toxin-producing E. coli in feces and lymphatic tissue of free-ranging deer in Germany

I sorta cringe, or maybe sigh, every time someone faithfully repeats the dogma that factory-farmed cattle are the source of E. coli O157:H7 and other shiga-toxin producing E. coli (STEC).

All ruminants carry STEC naturally, and there are well-documented and tragic outbreaks involving deer, goats, sheep, elk and others.

German researchers report on the occurrence of STEC in deer in Germany in the current issue of Epidemiology and Infection.

Deer poop has been directly or indirectly linked to several outbreaks:

1 dead and 14 sickened from E. coli O157:H7 from deer feces contaminating strawberries in Oregon in Aug. 2011;

• deer feces were a possible source of E. coli O157 in Oregon hazelnuts that sickened 8 in March 2011;

29 Minnesota high school students sickened with E. coli O103 and E. coli O145 after butchering and processing deer into venison in 2010;

• deer meat was involved in at least two recognized E. coli outbreaks; and,

an E. coli O157:H7 outbreak in Oct. 1996 that killed a 16-month-old and sickened 76 others who drank juice which contained unpasteurized apple cider that was probably contaminated with deer feces.

In the current study, the Germans studied the virulence genes eae, e-hlyA and saa, thestx subtypes, pulsed-field gel electrophoresis (PFGE) patterns and serovars. In total, 120 samples of 60 animals were screened by real-time polymerase chain reaction (PCR). The PCR results showed a high detection rate of stx genes (83%). Mainly faecal samples, but also some lymphatic tissue samples, tested stx-positive. All isolates carried stx2, were eae-negative and carried e-hlyA in 38% and saa in 9% of samples. Serovars (O88:[H8], O174:[H8], O146:H28) associated with human diseases were also identified. In some animals, isolates from lymphatic tissue and faecal samples showed undistinguishable PFGE patterns. The examined deer were shown to be relevant reservoirs of STEC with subtype stx2b predominating.

The complete paper is available at http://journals.cambridge.org/action/displayAbstract?fromPage=online&aid=8501556.