Susceptibility of the rabbit to an enteropathogenic strain of Escherichia coli 0103: effect of animals' age.

Abstract

Experimental infections with an enteropathogenic strain of Escherichia coli 0103 were studied in SPF rabbits of different ages. Whatever the age, the weight gains in all animals were reduced more or less significantly. However, mortality differed considerably according to the age. Four to 5-week-old rabbits were most susceptible to the infection, with 80-100% mortality associated with diarrhoea, generally of the hemorrhagic type. Peak mortality was observed between 5-10 days post-inoculation. In general, 21-day-old rabbits died from the second week post-inoculation onwards. After the 6th week of age, mortality was rare. Study of the microflora showed that the colonization of the gut by E coli 0103 occurred whatever the age as 10(6)-10(9) bacteria per g of feces of the inoculated strain were recovered. The role of specific receptors has been discussed.