Study On The Pathogenicity Of Ureaplasma Urealyticu Serotype 3 And 8 In Female Rabbits's Reproductive Tract

Objective:To study the pathogenicity of Ureaplasma urealyticum serotype3(Uu3) and 8(Uu8) with the same concentration in Female Rabbits's Reproductive tract.Method:52 oestradiol-treated adult female rabbits were randomly divided into 4 groups, including groupA, B, C and D. Ureaplasma urealyticum serotype 3,8,3 and 8, with the same concentration of 106copy/g were inoculated intravaginally into all 16 rabbits of every experimental group, group A was inoculated intravaginally with Ureaplasma urealyticum serotype 3, group B serotype 8 and group C serotype 3 and 8, while 4 rabbits of control group (groupD) inoculated sterile medium.They were detect Uu from cervical secretions by fluorescent quantitative polymerase chain reaction (FQ-PCR) at 1,3,7, 14,21,35,49,63,77,91,105 days. They were necropsied at 14,105 days of postinoculation randomly to observing tissues of cervix, endometria, fallopian tube by light microscope and cervical mucosa by scanning electron microscope.,Result:(1)The total positive rabbits of Uu in three experimental groups show a significant difference(P<0.05), which were 27.3% (25/88),55.7%(49/88),69.3%(61/88). But before 35 days,the positive rate of the three experimental groups at the same time point in all of Female rabbits infected cervical secretions does not show a statistically significant (P> 0.05), after 35 days the infection rate of group A was 0, while the group B and group C was not not statistical difference (P> 0.05).And the positive rate descended as the days of postinoculation lasting. The highest positive rates of three experimental groups were 87.5%(7/8),100.0%(8/8),100.0%(8/8) at 1d after inoculation, but the conlisation didn't persist at 105d. All rabbits of control group were negtive. (2)There was not statistical difference in the quantity of Uu among experimental groups(P>0.05). Their peak level were 3.64×106copy/g,4.01×106copy/g,4.93×106copy/g, reached at 1d, but the FQ-PCR values reduced as the days of postinoculation lasting.In the same experimental group at different time points,the concentrations was a significant difference(P<0.05),(3)The total pathogenicity rates of three groups were significant different (P=0.015),which were 31.3%(5/16), 62.5%(10/16),81.3%(13/16),. But there were not statistical difference among experimental groups at 14 days (P> 0.05), but 105 days later the pathogenicity rates of three groups were significant different (P=0.041).. None of control group was positive.Conclusion:(1)In Female Rabbits's Reproductive tract, the pathogenicity of each experimental group was shown when inoculatin Uu with FQ-PCR value is 106copy/g. the pathogenicity rates of three groups were significant different. the pathogenicity of the mixed group (groupC) was the highest and Uu3 group(groupA) the lowest,Uu8 group(groupB) was the Second.(2)In Female Rabbits's Reproductive tract, the infectivity and quantatitive value were significant different among experimental groups, the infectivity and quantatitive value of the mixed group (groupC) was the highest and Uu3 group(groupA) the lowest,Uu8 group(groupB) was the Second when inoculating Uu with the same concentration.(3) The pathogenic concentration of Uu3 and Uu8 may differ, Uu8 may be≥104copy/g, so further research is needed confirm it.