Multilocus Sequence Typing von Borrelia burgdorferi sensu stricto und Borrelia afzelii Stämmen aus Europa und den USA: Populationsstruktur, Pathogenität und Patientensymptomatik

Jungnick, Sabrina (2018): Multilocus Sequence Typing von Borrelia burgdorferi sensu stricto und Borrelia afzelii Stämmen aus Europa und den USA: Populationsstruktur, Pathogenität und Patientensymptomatik. Dissertation, LMU München: Medizinische Fakultät

Abstract

To understand the epidemiological and ecological context of vector borne diseases, precise typing of causative agents is necessary. Multilocus sequence typing (MLST) is a method in molecular biology for the fast, economic and unambiguous characterization of bacteria and other organisms. Lyme borreliosis (LB) is the most common tick borne disease in the Northern hemisphere caused by species of the Borrelia burgdorferi sensu lato complex. To better understand the epidemiological and clinical context of two Borrelia species frequently reported in LB, 133 Borrelia (B.) burgdorferi sensu stricto (s. s.) and Borrelia (B.) afzelii strains from patients and ticks in Europe were typed via MLST. MLST data from additional 744 B. burgdorferi s. s. and B. afzelii strains were downloaded from the MLST data bank. The population structure, clinical manifestations and human pathogenicity of B. afzelii in Europe as well as B. burgdorferi s. s. in Europe and the USA were compared. In addition, the invasiveness of sequence types (ST) and clonal complexes (CC) were analyzed in both species. Special attention was paid to the clinical manifestation of neuroborreliosis. Analysis of the population structure confirmed the hypothesis that B. afzelii shows a greater heterogeneity of ST (98 ST from n = 198 strains) compared to B. burgdorferi s. s. (112 ST from n = 677 strains). Moreover there was a greater prevalence of B. afzelii (ticks: 41.3 %, patients: 52.7 %) than B. burgdorferi s. s. (ticks: 13.2 %, patients: 13.7 %) in Europe. B. burgdorferi s. s. populations from Europe and the USA showed an overlap of two sequence types (ST1 and ST3) in patient isolates while there was no overlap of STs in ticks. Thus, it was hypothesized that the patients in Europe carrying ST1 or ST3 may have acquired their infection in the USA. B. burgdorferi s. s. infections in Europe were found to be more often associated with disseminated symptoms (93 %) and neuroborreliosis (odds ratio: 3.0) than B. afzelii infections (42 %) in Europe and B. burgdorferi s. s. infections in the USA (42 %), respectively it was noticed that some ST and CC might have greater human pathogenity than others (cf. ST1, ST3 and CC4 in Hanincova et al. 2013). Modern typing systems have already generated a huge data base for bacterial analyses. Nevertheless, further studies based on our data would be required to verify the differences of ST and CC in human pathogenicity and to get appropriate statistical data about differences of ST in Europe and the USA. In this context, our data can be relevant for further vaccine development.

• Dokumententyp: Dissertationen (Dissertation, LMU München)
• Keywords: Multilocus Sequence Typing, Borrelia burgdorferi sensu stricto, Borrelia afzelii
• Themengebiete: 600 Technik, Medizin, angewandte Wissenschaften ; 600 Technik, Medizin, angewandte Wissenschaften > 610 Medizin und Gesundheit
• Fakultäten: Medizinische Fakultät
• Sprache der Hochschulschrift: Deutsch
• Datum der mündlichen Prüfung: 26. April 2018
• 1. Bericht­erstatter:in: Sing, Andreas