Histological and immunocytochemical characterization of Coxiella burnetii-associated lesions in the murine uterus and placenta

Abstract

The fetoplacental units and the postgravid uterus of BALB/cJ (H-2d) mice inoculated intraperitoneally with Coxiella burnetii (Nine Mile isolate, phase I) on day 6 of pregnancy were examined histologically and immunocytochemically at 1 to 160 days postinoculation. Clinically, abortions, stillbirths, and perinatal deaths were observed. Histological lesions in the placenta were characterized by severe necrosis of the decidua basalis and the labyrinth, fibrinoid degeneration of decidual vessels, and microthrombosis. Pyometra and endometritis at the sites of previous placental attachment, characterized by ulceration, central necrosis, and moderate cellular infiltration consisting of neutrophils and macrophages, were observed postpartum. Pups sacrificed at the age of 9 days exhibited interstitial pneumonia with few granulomas and granulomatous hepatitis and splenitis. Immunocytochemically, antigen-bearing cells were first detected in the decidua 9 days postconception, and single immunopositive cells were detected in the fetal placenta 4 days later. Thereafter, until abortion or parturition, abundant accumulation of C. burnetii antigen was observed in the maternal and fetal compartments of the placenta. Up to 28 days postinoculation, many immunopositive cells were demonstrated at the sites of previous placental attachment, whereas the adjacent endometrium contained only a few antigen-positive cells. C. burnetii antigen was demonstrated in decidual cells, trophoblasts, and macrophages and extracellularly within the sinuses of the labyrinth and in the uterine lumen but not in granulated metrial gland cells. Fetuses in utero and aborted, stillborn, or perinatally dying offspring were immunocytochemically negative for C. burnetii antigen; however, pups killed 9 days after birth showed lesion-associated positive immunoreaction in the lung, liver, and spleen. The present study shows that infection with C. burnetii during pregnancy results in uncontrolled growth of the organism in the murine uteroplacental unit and that associated lesions are characterized by necrosis of placental tissues, fibrinoid degeneration of decidual vessels, and microthrombosis.Coxiella burnetii, the etiological agent of Q fever, is an obligate, gram-variable, intracellular pathogen of the family Rickettsiaceae (49). Infection with C. bumetii has been demonstrated in arthropods, numerous free-living and domestic animal species, and humans (1,40). In general, 5232 on August 5, 2020 by guest http://iai.asm.org/ Downloaded from 50. Wiesmann, E., and F. Busrki. 1955. Die veterinar-medizinische Bedeutung der Rickettsia-bumeti-Infektionen bei Ziege, Schaf und Rind in der Schweiz. Schweiz. Arch. Tierheilkd. 97:569-574. 51. Zaht, P. A., and C. Bjerknes. 1943. Induction of deciduaplacental hemorrhage in mice by the endotoxins of certain gram-negative bacteria.

Kinetics of Infection and Effects on Placental Cell Populations in a Murine Model ofChlamydia psittaci-Induced Abortion

“…A very similar occurrence has been observed with Coxiella burnetii, where hepatic lesions have been found in fetus from naturally infected sheep (27); however, Baumgärtner and Bachmann in an extensive immunohistochemical study (4) found no positive immunoreaction or lesions in the fetuses of experimentally infected pregnant mice but found both lesions and positive immunoreaction in surviving 9-day-old offspring, which suggests that fetal infection occurred just before or after birth.…”

Coxiella burnetii penetration into the reproductive system of male mice, promoting sexual transmission of infection

“…The involvement of the epididymis in metastatic dissemination of N. gonorrhoeae to the semen is characteristic of chronic infection (5). C bumetii-associated lesions have been observed in hu-0 0 0 0 0 mans and in experimentally infected female mice (4,17,28,34). In patients with interstitial pneumonitis, researchers have found necrotic foci in the alveolar walls, small granulomas in the spleen and liver, and focal perivascular inflam-_ matory infiltrations in many other organs (28,34).…”

Does Coxiella burnetii Affect Reproduction in Cattle? A Clinical Update

“…It could be that failure of this mechanism determines abortion or stillbirth. Studies performed in mice (Baumga¨rtner and Bachmann 1992) suggest that foetus-placental union resists C. burnetii vertical infection and that the infection of the newborn is established by aerosol inhalation at the moment of parturition. In contrast, if vertical transmission is possible, this could be an indication of persistent infection due to immune tolerance to an early in utero infection, as proposed for other infections such as bovine viral diarrhoea virus (Houe et al 1995) or Mycobacterium avium subsp.…”