Objective To observe the early inflammatory response by animal model with low genital tract Uu infection for investigating the relationship between the serovars and their pathogenicity.

Methods Fifty 8–10-week-old, female BALB/c mice were randomly divided into five groups, namely, control group, serovar 1 group, serovar 3 group, serovar 4 group, and serovar 8 group, and then treated respectively with vaginal inoculation of liquid medium and Uu inoculae of serovars 1, 3, 4 and 8 after subcutaneous injection of oestradiol benzoate. The vulval symptoms and vaginal and cervical swabs were observed weekly after Uu inoculation. Four weeks later, all mice were sacrificed and their cervixes and vaginae were removed for histopathology.

Results There was a significant difference in the inflammation severity of cervical mucosa (p<0.001–0.05) except vaginal mucosa among all groups. The inflammation severity of cervical mucosa in serovar 4 and 8 infection was superior to that in serovar 1 infection (p<0.01–0.05), but there was no statistical difference among other groups (p>0.05).

Conclusions The results suggest that Uu could colonise and infect the cervical columnar epithelium other than vaginal squamous epithelium. Uu-induced inflammation response is different among its serovars. Serovars 4 and 8 are more virulent compared with biovar 1 such as serovar 1.