Incidence of tick-borne disease in the United States doubled between 2004 and 2016, and continues to rise inthe United States and in many geographic regions around the world.^1,2 Novel methods are needed to improve diagnostic assays and species-level identification, advance surveillance and epidemiological efforts and facilitate drug development of these neglected human pathogens.

The most common bacterial pathogens transmitted by ticks belong to the genus Borrelia and are the causative agents of Lyme borreliosis (Lyme disease) and relapsing fever. Borrelia spp. can be divided into two major groups affecting human health: Borrelia burgdorferi sensu lato complex containing the agents of Lyme borreliosis and Borrelia species associated with human relapsing fever.

Tick-borne relapsing fever (TBRF) occurs worldwide, often in periodic outbreaks, with specific geographic distribution in North America, Europe, Africa and Asia. While most TBRF is transmitted by soft ticks of the Argasidae family, certain species like Borrelia miyamotoi are found in hard Ixodes ticks.³ Louse-borne relapsing fever (LBRF), caused by Borrelia recurrentis, is mainly limited to endemic areas within the Horn of Africa.⁴ Introduction of LBRF intoindustrialized countries via migration underscores the importance of having effective surveillance, diagnostic and treatment tools available.⁵

The availability of different Borrelia species to researchers supports development of necessary tools to minimize the effects of the increasing incidence of tick-borne diseases. Recent additions to the BEI Resources catalog include four species of Borrelia from Dr. Gabriele Margos and Dr. Volker Fingerle of the German National Reference Center for Borrelia (NRZ). This deposit includes four species new to the BEI Resources catalog: Borrelia afzelli, Borrelia hispanica, Borrelia miyamotoi and three Borrelia recurrentis (LBRF) strains.

In vitro adaption and growth of Borrelia spirochetes can be challenging. Optimized growth conditions are detailed on the BEI Resources product information sheet for each isolate and customers are encouraged to follow these growth recommendations to ensure success of the culture and recovery from the freezing process.

References:

1. Rosenberg, R., et al. “Vital Signs: Trends in Reported Vectorborne Disease Cases – United States and Territories, 2004-2016.” MMWR Morb. Mortal. Wkly. Rep. 67 (2018): 496-501. PubMed: 29723166.
2. Chikeka, I. and J. S. Dumler. “Neglected Bacterial Zoonoses.” Clin. Microbiol. Infect. 21 (2015): 404-415. PubMed: 25964152.
3. Talagrand-Reboul, E., et al. “Relapsing Fevers: Neglected Tick-Borne Diseases.” Front. Cell. Infect. Microbiol. 8 (2018): 98. PubMed: 29670860.
4. Warrell, D. A. “Louse-Borne Relapsing Fever (Borrelia recurrentis Infection).” Epidemiol. Infect. 147 (2019): e106. PubMed: 30869050.
5. Marosevic, D., et al. “First Insights in the Variability of Borrelia recurrentis Genomes.” PLoS Negl. Trop. Dis. 11 (2017): e0005865. PubMed: 28902847.
6. Fukunaga, M., et al. “Genetic and Phenotypic Analysis of Borrelia miyamotoi sp. nov., Isolated from the Ixodid Tick Ixodes persulcatus, the Vector of Lyme Disease in Japan.” Int. J. Syst. Bacteriol. 45 (1995): 804-810. PubMed: 7547303.
7. Glöckner, G., et al. “Comparative Genome Analysis: Selection Pressure on the Borrelia VLS Cassettes is Essential for Infectivity.” BMC Genomics 7 (2006): 211. PubMed: 16914037.

Image:  Fluorescence microscopy of Borrelia hispanica, NR-51677 (BEI Resources)