[Pathohistological changes in guinea pigs experimentally infected with Yersinia enterocolitica serotype 9]

A total of forty-five guinea pigs were injected subcutaneously with 0.1 cu cm carboneum tetracholoratum each and were infected with Yersinia enterocolitica serotype 9. Part of the animals (31) were treated at the 24th hour following infection with omnopon (a morphine preparation). All infected guinea pigs developed an infectious process manifested by dystrophic and inflammatory changes in the liver, intestine, spleen, lymph nodes and lungs. Those treated with omnopon manifested a more acute infectious process. After the 13--20th day of infection the lesions became more weakly expressed. On the 50th day the inflammatory reaction was observed in the lymph nodes and spleen only. The mortality rate in both groups was about 50 per cent.