Key Laboratory of Animal Disease and Human Health of Sichuan Province, Avian Disease Research Center, Institute of Preventive Veterinary Medicine, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu/Ya'an , Sichuan, China.
Front Cell Infect Microbiol. 2013 Oct 18;3:60. doi: 10.3389/fcimb.2013.00060. eCollection 2013.
Bartonella are hemotropic bacteria responsible for emerging zoonoses. Most Bartonella species appear to share a natural cycle that involves an arthropod transmission, followed by exploitation of a mammalian host in which they cause long-lasting intra-erythrocytic bacteremia. Persistence in erythrocytes is considered an adaptation to transmission by bloodsucking arthropod vectors and a strategy to obtain heme required for Bartonella growth. Bartonella genomes do not encode for siderophore biosynthesis or a complete iron Fe(3+) transport system. Only genes, sharing strong homology with all components of a Fe(2+) transport system, are present in Bartonella genomes. Also, Bartonella genomes encode for a complete heme transport system. Bartonella must face various environments in their hosts and vectors. In mammals, free heme and iron are rare and oxygen concentration is low. In arthropod vectors, toxic heme levels are found in the gut where oxygen concentration is high. Bartonella genomes encode for 3-5 heme-binding proteins. In Bartonella henselae heme-binding proteins were shown to be involved in heme uptake process, oxidative stress response, and survival inside endothelial cells and in the flea. In this report, we discuss the use of the heme uptake and storage system of B. henselae during its infection cycle. Also, we establish a comparison with the iron and heme uptake systems of Yersinia pestis used during its infection cycle.
巴尔通体属是引起新兴人畜共患病的血源性病原体。大多数巴尔通体物种似乎共享一个自然循环，包括节肢动物传播，然后利用哺乳动物宿主，在哺乳动物宿主中引起持久的红细胞内菌血症。在红细胞中的持续存在被认为是适应吸血节肢动物媒介的传播，并是获得巴尔通体生长所需血红素的策略。巴尔通体基因组不编码铁载体生物合成或完整的铁 Fe(3+)转运系统。仅存在与 Fe(2+)转运系统的所有成分具有强同源性的基因。此外，巴尔通体基因组编码完整的血红素转运系统。巴尔通体在其宿主和媒介中必须面对各种环境。在哺乳动物中，游离血红素和铁很少，氧浓度也很低。在节肢动物媒介中，肠道中存在高浓度的有毒血红素，氧浓度很高。巴尔通体基因组编码 3-5 种血红素结合蛋白。在汉塞巴尔通体中，血红素结合蛋白被证明参与血红素摄取过程、氧化应激反应以及在内皮细胞和跳蚤内的存活。在本报告中，我们讨论了汉塞巴尔通体在其感染周期中血红素摄取和储存系统的利用。此外，我们还与鼠疫耶尔森菌在感染周期中使用的铁和血红素摄取系统进行了比较。
