Joris Koetsveld, Alexander E. Platonov, Konstantin Kuleshov, Alex Wagemakers, Dieuwertje Hoornstra, Wim Ang, Sandor Szekeres, Gilian L.A. van Duijvendijk, Erol Fikrig, Monica E. Embers, Hein Sprong, Joppe W. Hovius

Borrelia miyamotoi is a relapsing fever Borrelia, transmitted by hard (Ixodes) ticks, which are also the main vector for Borrelia burgdorferi. A widely used test for serodiagnosis of Lyme borreliosis is an EIA based on the C6 peptide of the B. burgdorferi sl VlsE protein. We set out to study C6 reactivity upon infection with B. miyamotoi in a large well-characterized set of Borrelia miyamotoi disease (BMD) patient sera and in experimental murine infection.

Rogovskyy, A. S., Caoili, S. E. C., Ionov, Y., Piontkivska, H., Skums, P., Tsyvina, V., Zelikovsky, A., Waghela, S. D.

Lyme disease (LD), the most prevalent vector-borne illness in the United States and Europe, is caused by Borreliella burgdorferi (Bb). No vaccine is available for humans. Dogmatically, Bb can establish a persistent infection in the mammalian host (e.g., mice) due to a surface antigen, VlsE. This antigenically variable protein allows the spirochete to continually evade borreliacidal antibodies. However, our recent study has shown that the Bb spirochete is effectively cleared by anti-Bb antibodies of New Zealand White rabbits despite the surface expression of VlsE. Besides homologous protection, the rabbit antibodies also cross-protect against heterologous Bb and significantly reduced pathology of LD arthritis in persistently infected mice. Thus, this finding that NZW rabbits develop a unique repertoire of very potent antibodies targeting the protective surface epitopes, despite abundant VlsE, prompted us to identify specificities of the rabbit protective antibodies and their respective targets. By applying subtractive reverse vaccinology, which involved random peptide phage display libraries coupled with the next generation sequencing and our computational algorithms, repertoires of non-protective (early) and protective (late) rabbit antibodies were identified and directly compared. Consequently, putative surface epitopes that are unique to the rabbit protective sera have been mapped. Importantly, the relevance of newly identified protection-associated epitopes for their surface exposure has been strongly supported by prior empirical studies. This study is significant because it now allows us to systematically test the putative epitopes for their protective efficacy with an ultimate goal of selecting the most efficacious targets for development of a long-awaited LD vaccine.…

Susan J. Best, Marlene I. Tschaepe, Kim M. Wilson

by Susan J. Best, Marlene I. Tschaepe, Kim M. Wilson Spirochaetes of the Borrelia burgdorferi sensu lato complex, which includes those that cause Lyme disease, have not been identified in Australia. Nevertheless, Australian patients exist, some of whom have not left the country, who have symptoms consistent with so-called “chronic Lyme disease”. Blood specimens from these individuals may be tested in Australian laboratories and in specialist laboratories outside Australia and sometimes conflicting results are obtained. Such discrepancies cause the patients to question the results from the Australian laboratories and seek assistance from the Australian Government in clarifying why the discrepancies occur. The aim of this study was to determine the level of agreement in results between commonly used B. burgdorferi serology assays in specimens of known status, and between results reported by different laboratories when they use the same serology assay. Five immunoassays and five immunoblots used in Australia and elsewhere were examined for the detection of IgG antibodies to Borrelia burgdorferi sensu lato. Predominantly, archived specimens previously tested for Lyme disease were used for the study and included 639 contributed by seven clinical laboratories located either in Australia or in areas endemic for Lyme disease. Also included were 308 prospectively collected Australian blood donor specimens. All clinical specimens were tested in all 10 assays whereas blood donor specimens were tested in all immunoassays and a subset was tested on immunoblots. With the exception of one immunoblot, the results between the assays agreed with each other in a known positive specimen population ≥ 77% of the time and in a known negative population, 88% of the time or greater. The test results obtained during the study were different from the participating laboratory’s less than 2% of the time when the same assay was used. These findings suggest that discordance in results between laboratories is more likely due to variation in algorithms or in the use of assays with different sensitivities or specificities rather than conflicting results being reported from the same assay in different laboratories. In the known negative population, specificities of the immunoassays ranged between 87.7% and 99.7%. In Australia’s low prevalence population, this would translate to a positive predictive value of < 4%.

Mosel, M. R., Carolan, H. E., Rebman, A. W., Castro, S., Massire, C., Ecker, D. J., Soloski, M. J., Aucott, J. N., Eshoo, M. W.

Borrelia burgdorferi is the etiological agent of Lyme disease. In the current study, we used direct detection PCR and electrospray ionization mass spectrometry to monitor and genotype B. burgdorferi from serially collected whole blood specimens from clinically diagnosed early Lyme disease patients before and during 21 days of antibiotic therapy. B. burgdorferi was detected up to three weeks after the initiation of antibiotic treatment with ratios of co-infecting B. burgdorferi genotypes changing over time.…

Batool, M., Hillhouse, A. E., Ionov, Y., Kochan, K. J., Mohebbi, F., Stoica, G., Threadgill, D. W., Zelikovsky, A., Waghela, S. D., Wiener, D. J., Rogovskyy, A. S.

Borrelia burgdorferi is a tick-borne bacterium responsible for approximately 300,000 annual cases of Lyme disease (LD) in the USA with increasing incidents in other parts of the world. The debilitating nature of LD is mainly attributed to the ability of B. burgdorferi to persist in patients for many years despite strong anti-Borrelia antibody responses. Antimicrobial treatment of persistent infection is challenging. Similar to humans, B. burgdorferi establishes long-term infection in various experimental animal models except in New Zealand White (NZW) rabbits, which clear the spirochete within 4-12 weeks. LD spirochetes have a highly evolved antigenic variation vls system, on the lp28-1 plasmid, where gene conversion results in surface expression of antigenically variable VlsE protein. VlsE is required for B. burgdorferi to establish persistent infection by continually evading otherwise potent antibody. Since the clearance of B. burgdorferi is mediated by humoral immunity in NZW rabbits, the previously published results that LD spirochetes lose lp28-1 during the rabbit infection could potentially explain the failure of B. burgdorferi to persist. However, the present study unequivocally disproves that prior finding by demonstrating that LD spirochetes retain the vls system. Yet, despite the vls system being fully functional, the spirochete fails to evade anti-Borrelia antibody of the NZW rabbit. In addition to being protective against homologous and heterologous challenge, the rabbit antibody significantly ameliorate LD-induced arthritis in persistently infected mice. Overall, the current data indicate that NZW rabbits develop a protective antibody repertoire, whose specificities once defined will identify potential candidates for a much-anticipated LD vaccine.…

Basma El Hamzaoui, Maureen Laroche, Yassina Bechah, Jean Michel Bérenger and Philippe Parola

Abstract. In recent years, bed bugs have reappeared in greater numbers, more frequently, and are biting humans in many new geographic areas. Infestations by these hematophagous insects are rapidly increasing worldwide. Borrelia recurrentis, a spirochete bacterium, is the etiologic agent of louse-borne relapsing fever. The known vectors are body lice, Pediculus humanus humanus. However, previous studies have suggested that bed bugs might also be able to transmit this bacterium. Adult Cimex lectularius were artificially infected with a blood meal mixed with bacterial suspension of B. recurrentis. They were subsequently fed with pathogen-free human blood until the end of the experiment. Bed bugs and feces were collected every 5 days to evaluate the capacity of bed bugs to acquire and excrete viable B. recurrentis using molecular biology, cultures, fluorescein diacetate and immunofluorescence assays. The feces collected on the day 5 and 10 postinfection contained viable bacteria. Immunofluorescence analysis of exposed bed bugs showed the presence of B. recurrentis in the digestive tract, even in bed bugs collected on day 20 after infection. Like human body lice, bed bugs can acquire, maintain, and excrete viable B. recurrentis that might infect humans through skin lesions. This preliminary work suggests that bed bugs might be competent vectors of B. recurrentis. Because bed bugs and body lice may share the same ecological niches, the role of bed bugs in transmitting recurrent fevers deserves further study.…

Hodzic, E., Imai, D. M., Escobar, E.

A basic feature of infection caused by Borrelia burgdorferi, the etiological agent of Lyme borreliosis, is that persistent infection is the rule in its many hosts. The ability to persist and evade host immune clearance poses a challenge to effective antimicrobial treatment. A link between therapy failure and the presence of persister cells has started to emerge. There is growing experimental evidence that viable, but non-cultivable spirochetes persist following treatment with several different antimicrobial agents. The current study utilized the mouse model to evaluate if persistence occurs following antimicrobial treatment in a disease-susceptible (C3H/HeJ) and disease-resistant (C57BL/6) mouse strain infected with B. burgdorferi strains N40 and B31, to confirm the generality of this phenomena as well as to assess the persisters' clinical relevance. The status of infection was evaluated at 12 and 18-months after treatment. The results demonstrated that persistent spirochetes remain viable for up to 18 months following treatment, as well as being non-cultivable. The phenomenon of persistence in disease-susceptible C3H mice is equally evident in disease-resistant B6 mice, and not unique to any particular B. burgdorferi strain. Results also demonstrate that following antimicrobial treatment, both strains of B. burgdorferi, N40 and B31, lose one or more plasmids. The study demonstrated that non-cultivable spirochetes can persist in a host following antimicrobial treatment for a long time but did not demonstrate their clinical relevance in a mouse model of chronic infection. The clinical relevance of persistent spirochetes beyond 18 months following antimicrobial treatment require further studies in other animal models.…

Alice Raffetin, Aurélie Saunier, Kevin Bouiller, Pauline Caraux-Paz, Carole Eldin, Sébastien Gallien, Romain Jouenne, Anna Belkacem, Jérôme Salomon, Olivier Patey, Emilie Talagrand-Reboul, Benoît Jaulhac, Antoine Grillon

Lyme borreliosis (LB) diagnosis currently relies mainly on serological tests and sometimes polymerase chain reaction or culture. However, other biological assays are being developed to try to improve Borrelia-infection diagnosis and/or monitoring.