Virulent Brucella abortus Prevents Lysosome Fusion and Is Distributed within Autophagosome-Like Compartments

Virulent and attenuated Brucella abortus strains attach to and penetrate nonprofessional phagocytic HeLa cells. Compared to pathogenic Brucella, the attenuated strain 19 hardly replicates within cells. The majority of the strain 19 bacteria colocalized with the lysosome marker cathepsin D, suggesting that Brucella-containing phagosomes had fused with lysosomes, in which they may have degraded. The virulent bacteria prevented lysosome-phagosome fusion and were found distributed in the perinuclear region within compartments resembling autophagosomes.

强毒力与减毒牛布鲁氏菌（Brucella abortus）菌株可黏附并侵入非专业吞噬细胞海拉（HeLa）细胞。相较于致病性布鲁氏菌，19号减毒株在细胞内几乎无法增殖。19号减毒株的大部分菌体与溶酶体（lysosome）标记物组织蛋白酶D（cathepsin D）共定位，这表明携带布鲁氏菌的吞噬体（phagosome）已与溶酶体发生融合，菌体或可在其中被降解。而强毒力菌株可阻断溶酶体-吞噬体融合过程，其菌体分布于核周区域的类似自噬体（autophagosome）的囊泡中。