Ayral Florence, Zilber Anne-Laure, Bicout Dominique J, Kodjo Angeli, Artois Marc, Djelouadji Zoheira
WildTech, USC 1233, Université de Lyon-VetAgro Sup, Marcy L'Etoile, France.
USC 1233, Université de Lyon-VetAgro Sup, Marcy L'Etoile, France.
PLoS One. 2015 Oct 8;10(10):e0139604. doi: 10.1371/journal.pone.0139604. eCollection 2015.
Urban leptospirosis has increasingly been reported in both developing and developed countries. The control of the disease is limited because our understanding of basic aspects of the epidemiology, including the transmission routes of leptospires among rat populations, remains incomplete. Through the ability to distinguish among Leptospira strains in rats, multispacer sequence typing (MST) could provide a modern understanding of Leptospira epidemiology; however, to our knowledge, the distribution of Leptospira strains among urban rat colonies has not been investigated using MST.
The objective of this study was to identify the Leptospira strains present in rats (Rattus norvegicus) in Lyon (France) using MST and to characterize their spatial distribution. Kidneys and urine were collected from rats trapped live in seven locations in the city and in one suburban location. Each location was considered to represent a rat colony. Bacterial cultures and quantitative polymerase chain reaction (qPCR) assays were performed, and the L. interrogans DNA identified was then genotyped using MST. The distributions of Leptospira strains were spatially described.
Among 84 wild rats, MST profiles were obtained in 35 of 37 rats that had a positive result for L. interrogans by bacterial culture and/or qPCR analyses. All of the MST profiles were related to reference strains previously isolated from human patients that belong to the serogroup Icterohaemorrhagiae and the serovars [strain(s)] Copenhageni [Wijinberg or M20] (n = 26), Icterohaemorrhagiae [CHU Réunion] (n = 7), Icterohaemorrhagiae [R1] (n = 1) and Copenhageni [Shibaura 9] (n = 1). Each colony was infected with leptospires having the same MST profile.
This study demonstrated that MST could be used for the purpose of field studies, either on culture isolates or on DNA extracted from kidneys and urine, to distinguish among L. interrogans isolates in rats. MST could thus be used to monitor their distributions in urban rats from the same city, thereby providing new knowledge that could be applied to explore the circulation of L. interrogans infection in rat colonies. Because the strains are related to those previously found in humans, this application of MST could aid in the source tracking of human leptospirosis, and the findings would be relevant for public health purposes according to the One Health principle.
在发展中国家和发达国家，城市钩端螺旋体病的报告日益增多。由于我们对该疾病流行病学的基本方面，包括钩端螺旋体在鼠群中的传播途径的了解仍不完整，疾病控制受到限制。通过区分大鼠体内的钩端螺旋体菌株，多间隔序列分型（MST）可以为钩端螺旋体病流行病学提供现代的理解；然而，据我们所知，尚未使用MST研究城市鼠群中钩端螺旋体菌株的分布。
本研究的目的是使用MST鉴定法国里昂褐家鼠体内存在的钩端螺旋体菌株，并描述其空间分布。从该市七个地点和一个郊区地点活捉的大鼠中收集肾脏和尿液。每个地点被视为代表一个鼠群。进行了细菌培养和定量聚合酶链反应（qPCR）分析，然后使用MST对鉴定出的问号钩端螺旋体DNA进行基因分型。对钩端螺旋体菌株的分布进行了空间描述。
在84只野生大鼠中，通过细菌培养和/或qPCR分析对问号钩端螺旋体检测呈阳性的37只大鼠中的35只获得了MST图谱。所有MST图谱均与先前从人类患者中分离出的参考菌株相关，这些参考菌株属于出血热血清群和血清型哥本哈根型[维金伯格或M20]（n = 26）、出血热型[留尼汪岛株]（n = 7）、出血热型[R1]（n = 1）和哥本哈根型[芝浦9]（n = 1）。每个鼠群感染的钩端螺旋体具有相同的MST图谱。
本研究表明，MST可用于现场研究，无论是对培养分离株还是对从肾脏和尿液中提取的DNA，以区分大鼠体内的问号钩端螺旋体分离株。因此，MST可用于监测同一城市城市大鼠中钩端螺旋体的分布，从而提供可用于探索问号钩端螺旋体感染在鼠群中传播的新知识。由于这些菌株与先前在人类中发现的菌株相关，MST的这种应用有助于追踪人类钩端螺旋体病的来源，根据“同一健康”原则，这些发现将与公共卫生目的相关。
