Genotypic and phenotypic characterisation of Borrelia burgdorferi sensu lato strains isolated from human blood

Abstract

Lyme borreliosis often presents initially with erythema migrans. Borreliae may disseminate from the primary skin lesion, and different organs and systems could be affected. Borrelia strains were isolated from blood of 70 patients with Lyme borreliosis, including 10 patients from whom borreliae were also isolated from skin. The aim of the present study was to characterise the isolates with regard to their phenotypic and genotypic characteristics. Borreliae were cultivated in MKP medium. Species identification and plasmid profiles were determined by pulsed-field gel electrophoresis (PFGE) and protein profiles by SDS-PAGE. Digestion of Borrelia burgdorferi sensu lato DNA showed 63 (90%) B. afzelii Mla1 and 7 (10%) B. garinii Mlg2. No B. burgdorferi sensu stricto were isolated. Borreliae were isolated from both skin and blood of 10 patients, nine pairs of isolates were identical: seven B. afzelii and two B. garinii. B. afzelii was isolated from the skin and B. garinii from blood of the tenth patient. All but one isolate possessed at least one large plasmid and varying numbers of smaller plasmids. Eight (11.4%) of 70 isolates possessed an unusual plasmid profile (2 of 63 B. afzelii and 6 of 7 B. garinii). Borreliae differed in their protein profiles. OspA and OspB proteins were expressed by all B. afzelii isolates; 85.7% of B. garinii isolates expressed OspA and 71.4% expressed OspB. OspC was expressed by 65% of B. afzelii isolates and all B. garinii isolates. The ratios of B. afzelii and B. garinii isolated from blood and skin were similar. These results do not support the hypothesis that B. garinii has a higher propensity for haematogenous dissemination than B. afzelii. Antigen diversity as well as species and plasmid heterogeneity could play a role in the pathogenesis of the infection, suggesting distinctive strain organotropism.

Comparison of Borrelia burgdorferi Sensu Lato Strains Isolated from Specimens Obtained Simultaneously from Two Different Sites of Infection in Individual Patients

“…Skin and CSF were inoculated into modified Kelly-Pettenkofer medium immediately after they were obtained from patients (33,35). Citrated blood samples were transported to the laboratory where they were processed, and only plasma was inoculated in modified Kelly-Pettenkofer medium (34). All the samples were incubated at 33°C and checked for the presence of borreliae weekly (27).…”

“…), ticks, and reservoir hosts (9,17,25,29,42,49) obtained worldwide have been analyzed by many different phenotypic methods, such as well-established protein profile and serotyping system based on the heterogeneity of OspA and OspC proteins (33)(34)(35)(42)(43)(44)(45), and several genotypic approaches (42). Analysis of borrelial chromosomal or plasmid DNA, as performed by genotypic methods, provides more precise information on the genetic relationships among Borrelia strains (2, 5, 7, 22, 33-35, 42, 47).…”

Evaluation of a modified culture medium for Borrelia burgdorferi sensu lato

“…However, some differences in the region of 20-25 kDa proteins (presumably OspC) were observed. Considerable antigenic variations have been documented for Borrelia strains; besides the adaptive mechanisms of the spirochetes that influence protein expression, each strain has its own potential to express a particular protein (Wilske et al 1996, Ruzic-Sabljic et al 2001). According to these results, the antigen obtained could be used in a Western-blot for the diagnosis of Lyme borreliosis in humans.…”

PCR-Reverse Line Blot Typing Method Underscores the Genomic Heterogeneity of Borrelia valaisiana Species and Suggests Its Potential Involvement in Lyme Disease

“…Molecular analyses such as protein and plasmid profiles, reactivity with monoclonal antibodies, DNA-DNA relatedness, 16 rRNA, flagellin and ospA gene sequence analyses, and finally multilocus enzyme electrophoresis demonstrated that these B. burgdorferi isolates are phenotypically and genotypically divergent (11,12,28,35,38,40). These studies also established that all isolates are gathered in several species and genomic groups that include B. burgdorferi sensu stricto, B. garinii, B. afzelii, B. japonica, B. andersonii, B. valaisiana, B. lusitaniae, B. tanukii, B. turdi, B. bissettii, and B. sinica species (3,13,21,26,33).…”