In 2011 a large outbreak of Shiga toxin producing Enterohaemorrhagic Escherichia coli (EHEC) infections occurred in northern Germany which mainly affected adults. 104 out of 3,842 patients experienced a complicated course comprising haemolytic uremic syndrome and neurological complications including cognitive impairment, aphasia, seizures and coma. T2 hyperintensities on Magnet Resonance Imaging (MRI) bilateral in the thalami and in the dorsal pons were found suggestive for a metabolic toxic effect. Five of the 104 patients died due to toxic heart failure. In the present study the post-mortem neuropathological findings of the five EHEC patients are described. Histological investigation of 13 brain regions (frontal-, temporal-, occipital cortex, corpora mamillaria, thalamus, frontal operculum, corona radiata, gyrus angularis, pons, medulla oblongata, cerebellar vermis and cerebellar hemisphere) showed no thrombosis, ischemic changes, or fresh infarctions. Further, no changes were found in electron microscopy. In comparison with 5 age matched controls slightly increased activation of microglia and a higher neuronal expression of interleukin-1β and of Shiga toxin receptor CD77/ globotriaosylceramide 3 was observed. The findings were confirmed by Western blot analyses. It is suggested that CD77/globotriaosylceramide up-regulation may be a consequence to Shiga toxin-exposure whereas increased interleukin-1β expression may point to activation of inflammatory cascades.
