Rees Megan A, Stinear Timothy P, Goode Robert J A, Coppel Ross L, Smith Alexander I, Kleifeld Oded
Coppel Laboratory, Department of Microbiology, Monash University Clayton, VIC, Australia ; Monash Biomedical Proteomics Facility, Department of Biochemistry and Molecular Biology, Monash University Clayton, VIC, Australia.
Stinear Laboratory, Department of Microbiology and Immunology, University of Melbourne Parkville, VIC, Australia.
Front Cell Infect Microbiol. 2015 Oct 14;5:71. doi: 10.3389/fcimb.2015.00071. eCollection 2015.
Bacterial proteomic studies frequently use strains cultured in synthetic liquid media over many generations. It is uncertain whether bacterial proteins expressed under these conditions will be the same as the repertoire found in natural environments, or when bacteria are infecting a host organism. Thus, genomic and proteomic characterization of bacteria derived from the host environment in comparison to reference strains grown in the lab, should aid understanding of pathogenesis. Isolates of Corynebacterium pseudotuberculosis were obtained from the lymph nodes of three naturally infected sheep and compared to a laboratory reference strain using bottom-up proteomics, after whole genome sequencing of each of the field isolates. These comparisons were performed following growth in liquid media that allowed us to reach the required protein amount for proteomic analysis. Over 1350 proteins were identified in the isolated strains, from which unique proteome features were revealed. Several of the identified proteins demonstrated a significant abundance difference in the field isolates compared to the reference strain even though there were no obvious differences in the DNA sequence of the corresponding gene or in nearby non-coding DNA. Higher abundance in the field isolates was observed for proteins related to hypoxia and nutrient deficiency responses as well as to thiopeptide biosynthesis.
细菌蛋白质组学研究经常使用在合成液体培养基中传代培养多代的菌株。目前尚不确定在这些条件下表达的细菌蛋白质是否与在自然环境中发现的蛋白质库相同，或者与细菌感染宿主生物体时的蛋白质库相同。因此，与实验室培养的参考菌株相比，对源自宿主环境的细菌进行基因组和蛋白质组特征分析，应该有助于理解发病机制。从三只自然感染绵羊的淋巴结中获取了假结核棒状杆菌分离株，并在对每个野外分离株进行全基因组测序后，使用自下而上的蛋白质组学方法将其与实验室参考菌株进行比较。这些比较是在液体培养基中培养后进行的，这使我们能够获得蛋白质组分析所需的蛋白质量。在分离菌株中鉴定出了超过1350种蛋白质，从中揭示了独特的蛋白质组特征。尽管相应基因的DNA序列或附近的非编码DNA没有明显差异，但与参考菌株相比，在野外分离株中鉴定出的几种蛋白质显示出显著的丰度差异。在野外分离株中，与缺氧和营养缺乏反应以及硫肽生物合成相关的蛋白质丰度更高。
