No evidence of Borrelia mayonii in an endemic area for Lyme borreliosis in France

The Impact of Telemedicine in the Diagnosis of Erythema Migrans during the COVID Pandemic: A Comparison with In-Person Diagnosis in the Pre-COVID Era

Background: Erythema migrans (EM) is the hallmark manifestation of the Lyme borreliosis (LB), and therefore its presence and recognition are sufficient to make a diagnosis and to start proper antibiotic treatment to attempt to eradicate the infection. Methods: In this study we compared the clinical data of 439 patients who presented an EM either according to the diagnostic modality through physical assessment or through telemedicine. Conclusions: Our data clearly show that telemedicine for EM diagnosis is useful as it enables prompt administration of appropriate antibiotic therapy, which is critical to avoid complications, especially for neurologic and articular entities. Therefore, telemedicine is a tool that could be adopted for the diagnosis of Lyme disease both by specialized centers but also by general practitioners.

When to Think About Other Borreliae:: Hard Tick Relapsing Fever (Borrelia miyamotoi), Borrelia mayonii, and Beyond

In North America, several hard tick-transmitted Borrelia species other than Borrelia burgdorferi cause human disease, including Borrelia miyamotoi, Borrelia mayonii, and possibly Borrelia bissettii. Due to overlapping clinical syndromes, nonspecific tickborne disease (TBD) testing strategies, and shared treatment approaches, infections with these lesser known Borrelia are likely under-reported. In this article, we describe the epidemiology, clinical manifestations, diagnosis, and treatment of these less common Borrelia pathogens.

Elucidating the Immune Evasion Mechanisms of Borrelia mayonii, the Causative Agent of Lyme Disease

Borrelia (B.) mayonii sp. nov. has recently been reported as a novel human pathogenic spirochete causing Lyme disease (LD) in North America. Previous data reveal a higher spirochaetemia in the blood compared to patients infected by LD spirochetes belonging to the B. burgdorferi sensu lato complex, suggesting that this novel genospecies must exploit strategies to overcome innate immunity, in particular complement. To elucidate the molecular mechanisms of immune evasion, we utilized various methodologies to phenotypically characterize B. mayonii and to identify determinants involved in the interaction with complement. Employing serum bactericidal assays, we demonstrated that B. mayonii resists complement-mediated killing. To further elucidate the role of the key regulators of the alternative pathway (AP), factor H (FH), and FH-like protein 1 (FHL-1) in immune evasion of B. mayonii, serum adsorption experiments were conducted. The data revealed that viable spirochetes recruit both regulators from human serum and FH retained its factor I-mediated C3b-inactivating activity when bound to the bacterial cells. In addition, two prominent FH-binding proteins of approximately 30 and 18 kDa were detected in B. mayonii strain MN14-1420. Bioinformatics identified a gene, exhibiting 60% identity at the DNA level to the cspA encoding gene of B. burgdorferi. Following PCR amplification, the gene product was produced as a His-tagged protein. The CspA-orthologous protein of B. mayonii interacted with FH and FHL-1, and both bound regulators promoted inactivation of C3b in the presence of factor I. Additionally, the CspA ortholog counteracted complement activation by inhibiting the alternative and terminal but not the classical and Lectin pathways, respectively. Increasing concentrations of CspA of B. mayonii also strongly affected C9 polymerization, terminating the formation of the membrane attack complex. To assess the role of CspA of B. mayonii in facilitating serum resistance, a gain-of-function strain was generated, harboring a shuttle vector allowing expression of the CspA encoding gene under its native promotor. Spirochetes producing the native protein on the cell surface overcame complement-mediated killing, indicating that CspA facilitates serum resistance of B. mayonii. In conclusion, here we describe the molecular mechanism utilized by B. mayonii to resists complement-mediated killing by capturing human immune regulators.

[Epidemiology of Lyme borreliosis in France - both certainties and uncertainties]

Epidemiological evidence for tick-borne infections, particularly those related to Lyme borreliosis, is heterogeneous. Lyme borreliosis is a tick-born zoonosis transmitted by ticks of the genus Ixodes ricinus. After tick bite, the risk of transmission of an infectious agent remains low, most often represented by Borrelia burgdorferi sensu lato; co-infections in Humans by several different infectious agents (bacterial, viral or parasitic) are possible but a priori rare. In addition, besides well-known tick-borne pathogens, new species or gender of micro-organisms are regularly described in ticks but their pathogenicity in human pathology is not described or not yet established. The clinical presentation of Lyme borreliosis is varied, with localized and disseminated forms occurring long ago after tick bite, making diagnosis sometimes difficult. The natural course of Lyme borreliosis is insufficiently known because of recommendations of antibiotherapy in case of illness; however, some historical studies seem reassuring with possible spontaneous healing and seemingly minor sequelae. The diagnosis of disseminated forms requires paraclinical examinations, in first place serology, whose sensitivity increases with time of evolution of borreliosis; this is all the more interesting as the disseminated forms are of more difficult clinical diagnosis. After antibiotherapy, the clinical course is good, the sequelae remain possible especially in case of late diagnosis or late disseminated form; however, their frequency remains unknown.

Assessment of MALDI-TOF MS biotyping for Borrelia burgdorferi sl detection in Ixodes ricinus

Matrix Assisted Laser Desorption/Ionization Time-of-Flight Mass Spectrometry (MALDI-TOF MS) has been demonstrated to be useful for tick identification at the species level. More recently, this tool has been successfully applied for the detection of bacterial pathogens directly in tick vectors. The present work has assessed the detection of Borrelia burgdorferi sensu lato in Ixodes ricinus tick vector by MALDI-TOF MS. To this aim, experimental infection model of I. ricinus ticks by B. afzelii was carried out and specimens collected in the field were also included in the study. Borrelia infectious status of I. ricinus ticks was molecularly controlled using half-idiosome to classify specimens. Among the 39 ticks engorged on infected mice, 14 were confirmed to be infected by B. afzelii. For field collection, 14.8% (n = 12/81) I. ricinus ticks were validated molecularly as infected by B. burgdorferi sl. To determine the body part allowing the detection of MS protein profile changes between non-infected and B. afzelii infected specimens, ticks were dissected in three compartments (i.e. 4 legs, capitulum and half-idiosome) prior to MS analysis. Highly reproducible MS spectra were obtained for I. ricinus ticks according to the compartment tested and their infectious status. However, no MS profile change was found when paired body part comparison between non-infected and B. afzelii infected specimens was made. Statistical analyses did not succeed to discover, per body part, specific MS peaks distinguishing Borrelia-infected from non-infected ticks whatever their origins, laboratory reared or field collected. Despite the unsuccessful of MALDI-TOF MS to classify tick specimens according to their B. afzelii infectious status, this proteomic tool remains a promising method for rapid, economic and accurate identification of tick species. Moreover, the singularity of MS spectra between legs and half-idiosome of I. ricinus could be used to reinforce this proteomic identification by submission of both these compartments to MS.