Direct Isolation of Treponema pallidum from Syphilis Patients

从梅毒患者中直接分离梅毒螺旋体

• 批准号: 10511750
• 负责人: Diane G Edmondson
• 金额: $ 23.4万
• 依托单位: UNIVERSITY OF TEXAS HLTH SCI CTR HOUSTON
• 依托单位国家: 美国
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-06-23 至 2024-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10511750
• 关键词: Adult; Antimicrobial Resistance; Antimicrobial susceptibility; Azithromycin; Bacteria; Biological Availability; Biology; Blood; Body Fluids; Characteristics; Clinical; Coculture Techniques; Collection; Communities; Congenital Syphilis; Development; Disease; Epithelial Cells; Gene Expression Profile; Genetic; Genomics; Globus Pallidus; Goals; Growth; Histopathology; In Vitro; Infant; Infection; Laboratory culture; Latent Syphilis; Lead; Length; Lesion; Methods; Modeling; Modernization; Morphology; Order Spirochaetales; Organism; Oryctolagus cuniculus; Pathogenesis; Patient-Focused Outcomes; Patients; Pattern; Phenotype; Physiological; Placenta; Predisposition; Primary Lesion; Property; Research; Research Personnel; Sampling; Secondary Lesion; Sequence Analysis; Sexually Transmitted Diseases; Specimen; Syphilis; Syphilitic chancre; System; Temperature; Testing; Testis; Tissues; Treponema pallidum; Tube; Umbilical cord structure; Variant; Virulence; antimicrobial drug; clinical research site; experimental study; genetic analysis; human pathogen; in vivo; insight; novel; skin lesion; tissue tropism

Research on Treponema pallidum subspecies pallidum (T. pallidum), the causative agent of syphilis, was impeded for years by inability to cultivate the spirochete in vitro. This limitation also hampered isolation of new T. pallidum strains with the result that most research strains were isolated in the last century and have been propagated in rabbits for many years. In 2018, we developed an in vitro culture system involving co-culture of T. pallidum with Sf1Ep rabbit epithelial cells under microaerobic conditions that has resulted in continuous in vitro cultivation of T. pallidum. Currently, we have maintained cultures in vitro for over three years, and these cultures have retained full virulence in the rabbit model. Here, we propose to use this newly developed in vitro system to isolate novel strains of T. pallidum directly from clinical samples derived from syphilis patients. In the Aim 1, we will attempt to isolate new strains of T. pallidum from patients. Initial experiments will focus on the best approaches to collect samples and maintain T. pallidum viability during transport from clinical sites. After definition of these parameters, we will proceed with isolation of T. pal/idum from patient lesions and from placenta and umbilical cord specimens from infants with suspected congenital syphilis. Our clinical co-investigators will coordinate collection of patient samples and we will use the in vitro culture system to expand those samples in vitro. In Aim 2, the new patient-derived T. pallidum strains will be analyzed for differences in in vitro growth rates and infection properties in the rabbit model (e.g. in vivo growth rates, dissemination, tissue tropism, and histopathology). Antimicrobial susceptibility will also be examined using a well-developed in vitro culture procedure. Lastly, genomic sequencing will be performed to permit analysis of the sequences of the isolated strains for differences related to their physiologic and infection properties, particularly in view of their relationship to the ongoing changes in the distribution of the Nichols and SS14 genetic clusters and of azithromycin susceptibility. It is anticipated that this project will lead to greatly increased efficiency of T. pallidum isolation relative to rabbit inoculation, thereby permitting a much more thorough characterization of strains causing this important sexually transmitted infection. Analyses of variability present in modern syphilis strains can lead to insight into community infection patterns, patient outcomes, and the development of antimicrobial resistance in the community. In addition, successful completion of this project will also allow for the creation of a readily available bank of syphilis strains for research, greatly increasing the number of strains that are available for the physiologic and genetic analysis of this important human pathogen.

梅毒螺旋体（Treponema pallidum， T. pallidum）是梅毒的病原体，由于无法在体外培养螺旋体，对其亚种梅毒螺旋体的研究一直受到阻碍。这一限制也阻碍了新技术的分离