RT Journal Article SR Electronic(1) A1 TAGUCHI, HARUHIKO A1 TAKAHASHI, MOTOMICHI A1 YAMAGUCHI, HIROYUKI A1 OSAKI, TAKAKO A1 KOMATSU, AKIO A1 FUJIOKA, YASUNORI A1 KAMIYA, SHIGERUYR 2002 T1 Experimental infection of germ-free mice with hyper-toxigenic enterohaemorrhagic Escherichia coli O157:H7, strain 6 JF Journal of Medical Microbiology, VO 51 IS 4 SP 336 OP 343 DO https://doi.org/10.1099/0022-1317-51-4-336 PB Microbiology Society, SN 1473-5644, AB A mouse enterohaemorrhagic Escherichia coli (EHEC) infection model was developed with a combination of germ-free (GF) mice and hyper-toxigenic EHEC (HT-EHEC) O157:H7 strain 6. The HT-EHEC strain 6 produced both Shiga-like toxin (SLT)-1 1.0 μg/ml and SLT-2 8.2 μg/ml in vitro. Eight-week-old germ-free mice were inoculated intragastrically with 5.0×107 cfu of HT-EHEC strain 6. All GF mice challenged with the HT-EHEC developed ruffled fur and convulsion of limbs or hindleg weakness within 3 days after the challenge, culminating in death within 5 days. The HT-EHEC colonised well at a level of 108−−109 cfu/g of faeces 5 days after the challenge. Both SLT-1 and SLT-2 were demonstrated in the faeces of the mice for 5 days after challenge. Histological examination of the colons of the infected mice showed congestion of the lamina propria mucosa, mild inflammatory cell infiltration and goblet cell depletion. In proximal tubules of the renal cortex, epithelial swelling with scattered necrotic cells was recognised. Endothelial swelling and mononuclear cell infiltration were also observed in the glomeruli. The brain showed acute neuronal necrosis in the cerebrum and slight loss of Purkinje cells in the cerebellum. Passive immunisation with anti-SLT antisera prolonged the life of the mice without any neural symptoms. Microscopically, all tissue specimens from the passively immunised mice were not remarkable. These results indicate that the infection of GF mice with HT-EHEC is a useful animal model to study the pathogenicity of SLT-producing E. coli and the toxins., UL https://www.microbiologyresearch.org/content/journal/jmm/10.1099/0022-1317-51-4-336