Research Unit in Biology of Microorganisms, Narilis, University of Namur, Namur, Belgium.
Mol Microbiol. 2022 Sep;118(3):145-154. doi: 10.1111/mmi.14956. Epub 2022 Jul 6.
The pathogenic bacterium Brucella abortus invades and multiplies inside host cells. To grow inside host cells, B. abortus requires a functional histidine biosynthesis pathway. Here, we show that a B. abortus histidine auxotroph mutant also displays an unexpected chaining phenotype. The intensity of this phenotype varies according to the culture medium and is exacerbated inside host cells. Chains of bacteria consist of contiguous peptidoglycan, and likely result from the defective cleavage of peptidoglycan at septa. Genetic suppression of the chaining phenotype unearthed two essential genes with a role in B. abortus cell division: dipM and cdlP. Loss of function of dipM and cdlP generates swelling at the division site. While DipM is strictly localized at the division site, CdlP is localized at the growth pole and the division site. Altogether, the unexpected chaining phenotype of a hisB mutant allowed the discovery of new crucial actors in cell division in B. abortus.
流产布鲁氏菌属病原体在宿主细胞内入侵和繁殖。为了在宿主细胞内生长，流产布鲁氏菌需要一个功能正常的组氨酸生物合成途径。在这里，我们表明，流产布鲁氏菌属组氨酸营养缺陷型突变体也表现出一种意想不到的链状表型。这种表型的强度根据培养基而变化，并在宿主细胞内加剧。细菌链由连续的肽聚糖组成，可能是由于隔膜处肽聚糖的切割缺陷所致。对链状表型的遗传抑制揭示了两个在流产布鲁氏菌细胞分裂中起作用的必需基因：dipM 和 cdlP。dipM 和 cdlP 的功能丧失会导致分裂部位肿胀。虽然 DipM 严格定位于分裂部位，但 CdlP 定位于生长极和分裂部位。总之，hisB 突变体的意外链状表型揭示了流产布鲁氏菌细胞分裂中一些新的关键因子。
