Final answer:
If Brucella enters the placenta, the placenta becomes infected and poses a serious risk to the fetus due to the bacterium's ability to survive within host cells and form granulomas.
Step-by-step explanation:
If Brucella enters the placenta, the placenta becomes infected. Like Listeria monocytogenes, the bacterium responsible for listeriosis which is known to cross the blood-placental barrier and can lead to fetal infection, Brucella is also capable of infecting the placenta. Pregnant women's immune systems are somewhat downregulated, which makes them more susceptible to infections, including those that can be transmitted via the placenta. Brucella, a facultative intracellular bacteria, can survive inside host cells like phagocytes and result in the formation of granulomas in various tissues. During pregnancy, an infection of the placenta by pathogens like Brucella can pose a serious risk to the fetus.