Isolation and cultivation of Borrelia lusitaniae from the blood of a patient with multiple erythema migrans.

Introduction: The region of Serbia is characterised by a high prevalence and diversity of Borrelia species, with Borrelia lusitaniae dominating, followed by Borrelia afzelii. Before this report, there were no data on Borrelia species causing Lyme borreliosis (LB) in Serbia.

Case presentation: We report the case of a 10-year-old boy with a clinical presentation of disseminated erythema migrans (EM). His results showed IgM antibodies at 6.27 (negative ˂ 0.20; positive ˃ 0.32) against Borrelia burgdorferi sensu lato, which was confirmed via ELFA. Except for skin lesions, the patient did not show any other clinical signs of systemic infection. His blood was taken to isolate and cultivate spirochetes and for molecular analysis. Antimicrobial therapy was prescribed according to the recommended treatment for patients with LB. A follow-up examination was conducted after nine days. The EMs on the skin had disappeared, and antibiotic therapy was continued for 14 days. A second follow-up was conducted one month after the end of therapy. The boy's health condition was normal. After 16 days of incubation in BSK-H medium, viable, motile, and spiral-shaped spirochetes were observed in the culture tube, and cultivation was prolonged for 29 days. PCR and sequencing were successful in both the blood sample and the culture and confirmed the presence of B. lusitaniae.

Conclusions: The results presented here is the first Borrelia isolate from the blood of a patient with the clinical manifestation of LB-disseminated EM. The presented results confirm the potential of B. lusitaniae for dissemination via the hematogenous route.