Expression Level of the mip, pmp18D, and ompA Genes in Chlamydia abortus Isolated from Aborted Ewes

Abstract

In this manuscript, we report the proteins macrophage infectivity potentiator (mip, CAB080), major outer membrane protein (momp, CAB048), and polymorphic outer membrane protein (pmp18D, CAB776) that are expressed in different times of pregnancy in mice infected with Chlamydia abortus. Enzootic abortion of ewes (EAE) by C. abortus, an obligate intracellular pathogen, is a critical zoonotic disease-causing significant economic loss to livestock farming globally. This study was carried out for the detection and characterization of macrophage infectivity potentiator (mip, CAB080), major outer membrane protein (momp, CAB048), and polymorphic outer membrane protein (pmp18D, CAB776) using RT-qPCR. These proteins are believed to be expressed as virulence factors in C. abortus isolated from aborted ewes. BALB/c mice (pregnant and nonpregnant) were used as an animal model to be injected intraperitoneally with C. abortus culture in Vero cells since the endometrial lymphoid tissues of these animals resembles that of ewes. Also, the short duration of pregnancy in mice makes them a suitable animal model for obstetric studies. Tissue samples were taken from the mice after 10, 15, and 20 days of pregnancy to compare the expression of the genes mip, pmp18D, and ompA. Transcription level was quantified using RT-qPCR, the GAPDH transcription quantification, as a normalization signal. Abortion occurred in pregnant mice, and apparent differences between the transcriptional levels of the mip, pmp18D, and ompA genes in the samples taken during different time intervals of pregnancy were not observed (p > 0.05). The result indicated that the three bacterial genes, mip, pmp18D, and ompA, play a role as virulence factors in abortion and are differentially expressed in pregnant and nonpregnant animals. Inactivation of the genes is suggested to confirm the hypothesis.