Boulouis H J, Barrat F, Bermond D, Bernex F, Thibault D, Heller R, Fontaine J J, Piémont Y, Chomel B B
UMR 956 INRA-AFSSA-ENVA/IIAC, 94704 Maisons-Alfort, France.
Infect Immun. 2001 Sep;69(9):5313-7. doi: 10.1128/IAI.69.9.5313-5317.2001.
The kinetics of infection and the pathogenic effects on the reproductive function of laboratory mice infected with Bartonella birtlesii recovered from an Apodemus species are described. B. birtlesii infection, as determined by bacteremia, occurred in BALB/c mice inoculated intravenously. Inoculation with a low-dose inoculum (1.5 x 10(3) CFU) induced bacteremia in only 75% of the mice compared to all of the mice inoculated with higher doses (> or =1.5 x 10(4)). Mice became bacteremic for at least 5 weeks (range, 5 to 8 weeks) with a peak ranging from 2 x 10(3) to 10(5) CFU/ml of blood. The bacteremia level was significantly higher in virgin females than in males but the duration of bacteremia was similar. In mice infected before pregnancy (n = 20), fetal loss was evaluated by enumerating resorption and fetal death on day 18 of gestation. The fetal death and resorption percentage of infected mice was 36.3% versus 14.5% for controls (P < 0.0001). Fetal suffering was evaluated by weighing viable fetuses. The weight of viable fetuses was significantly lower for infected mice than for uninfected mice (P < 0.0002). Transplacental transmission of Bartonella was demonstrated since 76% of the fetal resorptions tested was culture positive for B. birtlesii. The histopathological analysis of the placentas of infected mice showed vascular lesions in the maternal placenta, which could explain the reproductive disorders observed. BALB/c mice appeared to be a useful model for studying Bartonella infection. This study provides the first evidence of reproductive disorders in mice experimentally infected with a Bartonella strain originating from a wild rodent.
描述了从姬鼠属物种分离出的伯氏巴尔通体感染实验小鼠的感染动力学及其对生殖功能的致病作用。通过菌血症确定,静脉接种的BALB/c小鼠发生了伯氏巴尔通体感染。与所有接种高剂量(≥1.5×10⁴)的小鼠相比,接种低剂量接种物(1.5×10³CFU)仅在75%的小鼠中诱导出菌血症。小鼠菌血症至少持续5周(范围为5至8周),峰值范围为每毫升血液2×10³至10⁵CFU。未孕雌性小鼠的菌血症水平显著高于雄性,但菌血症持续时间相似。在怀孕前感染的小鼠(n = 20)中,通过在妊娠第18天清点吸收和胎儿死亡情况来评估胎儿丢失。感染小鼠的胎儿死亡和吸收百分比为36.3%,而对照组为14.5%(P < 0.0001)。通过称量存活胎儿来评估胎儿发育情况。感染小鼠的存活胎儿体重显著低于未感染小鼠(P < 0.0002)。由于76%的测试胎儿吸收物伯氏巴尔通体培养呈阳性,证明了巴尔通体的胎盘传播。感染小鼠胎盘的组织病理学分析显示母体胎盘有血管病变,这可以解释观察到的生殖障碍。BALB/c小鼠似乎是研究巴尔通体感染的有用模型。本研究首次提供了实验感染源自野生啮齿动物的巴尔通体菌株的小鼠出现生殖障碍的证据。