Direct Molecular Detection and Genotyping of Borrelia burgdorferi Sensu Lato in Cerebrospinal Fluid of Children with Lyme Neuroborreliosis

Molecular diagnostics in cerebrospinal fluid for the diagnosis of central nervous system infections

SUMMARYCentral nervous system (CNS) infections can be caused by various pathogens, including bacteria, viruses, fungi, and parasites. Molecular diagnostic methods are pivotal for identifying the different causative pathogens of these infections in clinical settings. The efficacy and specificity of these methods can vary per pathogen involved, and in a substantial part of patients, no pathogen is identified in the cerebrospinal fluid (CSF). Over recent decades, various molecular methodologies have been developed and applied to patients with CNS infections. This review provides an overview of the accuracy of nucleic acid amplification methods in CSF for a diverse range of pathogens, examines the potential value of multiplex PCR panels, and explores the broad-range bacterial and fungal PCR/sequencing panels. In addition, it evaluates innovative molecular approaches to enhance the diagnosis of CNS infections.

Antibody responses to immunoevasion proteins BBK32 and OspE constitute part of the serological footprint in neuroborreliosis but are insufficient to prevent the disease

Lyme borreliosis, caused by Borrelia burgdorferi sensu lato, is the most common tickborne disease. Its neuronal form, neuroborreliosis, comprises 3 to 38% of borreliosis cases in Europe. Borrelia outer surface proteins and virulence factors, OspE and BBK32, have been previously reported to help cause infection by promoting attachment to human host epithelial cells and evading complement attack. We assessed the serological responses to BBK32 and OspE in 19 individuals diagnosed with neuroborreliosis to see whether antibodies that could both target the bacteria and neutralize the virulence mechanisms on the microbial surface emerge. Results evaluate levels of total protein, IgG and the chemokine CXCL13, a determinant for B-cell recruitment during neuroinflammation, in patients' cerebrospinal fluid samples. Antibody levels against BBK32 and OspE correlated with those against VlsE, a well-characterized diagnostic serological marker of the disease. A dual serological profile of the patients was observed. K-means clustering split the cohort into two discrete groups presenting distinct serological and CNS responses. One group contained young patients with low levels of anti-BBK32 and OspE antibodies. The other group showed stronger responses, possibly following prolonged infections or reinfections. Additionally, we assessed anti-ganglioside antibodies that could cause autoimmunity or complement dysregulation but observed that they did not correlate with neuroborreliosis in our patient cohort. The dual nature of antibody responses against the virulence factors BBK32 and OspE in neuroborreliosis patients may suggest the necessity of repeated exposures for efficient immune responses. Better protection could be achieved if the virulence factors were formulated into vaccines.

Detection of Borrelia burgdorferi sensu lato DNA in cerebrospinal fluid samples following pre-enrichment culture

Molecular methods for diagnosing Lyme neuroborreliosis (LNB) have shown suboptimal diagnostic sensitivities. The objective of this study was to improve the clinical sensitivity of PCR detection of Borrelia burgdorferi sensu lato spirochetes by inoculating cerebrospinal fluid (CSF) from patients suspected of LNB directly into culture medium at the time of lumbar puncture, with this pursuing enrichment of Borrelia spirochetes before PCR analysis. Adult patients with symptoms suggestive of LNB were prospectively enrolled at two hospitals in the Region of Southern Denmark. The CSF-culture samples were incubated for at least eight weeks. During this period, culture sample aliquots were analysed for the presence of Borrelia DNA by separate PCR protocols in two independent clinical laboratories. The included patients were diagnosed with definite (n=12) or possible (n=2) LNB, and non-LNB (n=171) based on clinical and paraclinical findings. Patients in the LNB and the non-LNB group had a median duration from symptom onset to lumbar puncture of 40 days (IQR [23-90] days) and 120 days (IQR [32-365] days), respectively. Pre-enrichment growth of Borrelia spirochetes was accomplished from three patients (21 %) in the LNB group. The positive culture samples were confirmed by both the digital droplet PCR and the real-time PCR methods employed. All CSF samples were PCR negative in the non-LNB group. The results of this study do not support the use of Borrelia-specific PCR as a general routine diagnostic tool in adults. Still, they suggest it may prove of additional value in selected patients with a limited time from symptom onset to sample collection.

Clinical manifestations of Lyme neuroborreliosis in children: a review

Lyme neuroborreliosis (LNB) is a manifestation of Lyme disease involving the central and peripheral nervous system. It is caused by the spirochete Borrelia burgdorferi, transmitted by tick bites to a human host. Clinical signs of LNB develop after the dissemination of the pathogen to the nervous system. The infection occurs in children and adults, but the clinical manifestations differ. In adults, painful meningoradicultis is the most common manifestation of LNB, while children often present with facial nerve palsy and/or subacute meningitis. Subacute headache can be the only manifestation of LNB in children, especially during the summer months in Lyme disease-endemic regions. Non-specific symptoms, such as loss of appetite, fatigue or mood changes, may also occur, especially in young children. A high level of suspicion and early recognition of the various clinical manifestations presented by children with LNB is essential to minimize delay in diagnosis and optimize management. This review provides an overview of the spectrum of clinical manifestations, and discusses diagnosis, antibiotic treatment, and clinical outcome of LNB in children.

Establishment of a digital PCR method for detection of Borrelia burgdorferi sensu lato complex DNA in cerebrospinal fluid

Direct detection of Borrelia burgdorferi sensu lato bacteria in patient samples for diagnosis of Lyme neuroborreliosis (LNB) is hampered by low diagnostic sensitivity, due to few bacteria in cerebrospinal fluids (CSF) samples. Evaluation of novel molecular methods, including digital PCR (dPCR), as future tools in diagnostics of LNB is desirable. This study aimed to establish a dPCR assay and validate pre-PCR procedures for detection of Borrelia in CSF. Synthetic DNA fragments and cultured Borrelia reference strains were used during optimisation experiments. In addition, 59 CSF specimens from patients examined for LNB were included for clinical validation. The results showed that the pre-PCR parameters with the highest impact on Borrelia-specific dPCR method performance were incubation of the PCR-plate at 4 °C for stabilization of droplets, centrifugation for target concentration, quick-spin for dPCR rain reduction, and PCR inhibition by matrix components. Borrelia DNA in CSF was detected in one out of nine patients with LNB. Diagnostic sensitivity was determined to be 11.1% and specificity 100%. In conclusion, this study reports an optimized Borrelia-specific dPCR method for direct detection of Borrelia in CSF samples. The present study does not support the use of Borrelia-specific dPCR as a routine method for diagnosing LNB.

Hyperacute treatment of childhood stroke in Lyme neuroborreliosis: report of two cases and systematic review of the literature

The safety and efficacy of hyperacute reperfusion therapies in childhood stroke due to focal cerebral arteriopathy (FCA) with an infectious and inflammatory component is unknown. Lyme neuroborreliosis (LNB) is reported as a rare cause of childhood stroke. Intravenous thrombolysis (IVT) and endovascular therapy (EVT) have not been reported in LNB-associated stroke in children. We report two children with acute stroke associated with LNB who underwent hyperacute stroke treatment. A systematic review of the literature was performed to identify case reports of LNB-associated childhood stroke over the last 20 years. Patient 1 received IVT within 73 min after onset of acute hemiparesis and dysarthria; medulla oblongata infarctions were diagnosed on magnetic resonance imaging (MRI). Patient 2 received successful EVT 6.5 hr after onset of progressive tetraparesis, coma, and decerebrate posturing caused by basilar artery occlusion with bilateral pontomesencephalic infarctions. Both patients exhibited a lymphocytic cerebrospinal fluid (CSF) pleocytosis and elevated antibody index (AI) to Borrelia burgdorferi. Antibiotic treatment, steroids, and platelet inhibitors including tirofiban infusion in patient 2 were administered. No side effects were observed. On follow-up, patient 1 showed good recovery and patient 2 was asymptomatic. In the literature, 12 cases of LNB-associated childhood stroke were reported. LNB-associated infectious and inflammatory FCA is not a medical contraindication for reperfusion therapies in acute childhood stroke. Steroids are discussed controversially in inflammatory FCA due to LNB. Intensified antiplatelet regimes may be considered; secondary prophylaxis with acetyl-salicylic acid (ASA) is recommended because of a high risk of early stroke recurrence.

Diagnosis of Lyme Borreliosis With a Novel, Seminested Real-Time Polymerase Chain Reaction Targeting the 5S-23S Intergenic Spacer Region: Clinical Features, Histopathology, and Immunophenotype in 44 Patients

ABSTRACT

Lyme borreliosis (LB) is the most common tick-borne infection in Europe and North America. Polymerase chain reaction (PCR) is an important tool to confirm the diagnosis, but not always successful, especially when organisms are sparse. We developed a novel, seminested real-time PCR assay [target: 5S-23S intergenic spacer region (IGS)] and compared it with 3 well-established conventional PCR assays (IGS/OspA/real-time IGS) on 596 formalin-fixed, paraffin-embedded routine skin biopsies. The seminested real-time assay identified 46 cases of borreliosis while 25, 27, and 38 were identified by the 3 other assays, respectively (P 0.01, P 0.02, and P 0.42; significance P < 0.05). Clinicopathologic and immunophenotypic analysis of PCR-positive cases revealed 38 erythema migrans (EM), 6 Borrelia lymphocytomas, and 2 acrodermatitis chronica atrophicans (ACA). In the 44 PCR-confirmed cases, plasma cells were present in only a third of EM cases. By contrast, CD123-positive plasmacytoid dendritic cells were common (74%) and therefore are unlikely to be helpful in the differential diagnosis between EM and tumid lupus erythematosus. A loss of CD34 in a third of all LB specimens limits its diagnostic value in the differential diagnosis with morphea. Interstitial macrophages were common in cutaneous LB (42/43) forming interstitial granulomas in a third of all cases, and 3/38 EM, 3/6 Borrelia lymphocytomas, and 1/2 ACA were only identified by the new seminested real-time assay, suggesting that it is especially helpful in confirming the diagnosis of Borrelia lymphocytoma.

Molecular Detection of Borrelia Bacteria in Cerebrospinal Fluid-Optimisation of Pre-Analytical Sample Handling for Increased Analytical Sensitivity

The main tools for clinical diagnostics of Lyme neuroborreliosis (LNB) are based on serology, i.e., detection of antibodies in cerebrospinal fluid (CSF). In some cases, PCR may be used as a supplement, e.g., on CSF from patients with early LNB. Standardisation of the molecular methods and systematic evaluation of the pre-analytical handling is lacking. To increase the analytical sensitivity for detection of Borrelia bacteria in CSF by PCR targeting the 16S rRNA gene, parameters were systematically evaluated on CSF samples spiked with a known amount of cultured Borrelia bacteria. The results showed that the parameters such as centrifugation time and speed, the use of complementary DNA as a template (in combination with primers and a probe aiming at target gene 16S rRNA), and the absence of inhibitors (e.g., erythrocytes) had the highest impact on the analytical sensitivity. Based on these results, a protocol for optimised handling of CSF samples before molecular analysis was proposed. However, no clinical evaluation of the proposed protocol has been done so far, and further investigations of the diagnostic sensitivity need to be performed on well-characterised clinical samples from patients with LNB.

Development of a capture sequencing assay for enhanced detection and genotyping of tick-borne pathogens

Inadequate sensitivity has been the primary limitation for implementing high-throughput sequencing for studies of tick-borne agents. Here we describe the development of TBDCapSeq, a sequencing assay that uses hybridization capture probes that cover the complete genomes of the eleven most common tick-borne agents found in the United States. The probes are used for solution-based capture and enrichment of pathogen nucleic acid followed by high-throughput sequencing. We evaluated the performance of TBDCapSeq to surveil samples that included human whole blood, mouse tissues, and field-collected ticks. For Borrelia burgdorferi and Babesia microti, the sensitivity of TBDCapSeq was comparable and occasionally exceeded the performance of agent-specific quantitative PCR and resulted in 25 to > 10,000-fold increase in pathogen reads when compared to standard unbiased sequencing. TBDCapSeq also enabled genome analyses directly within vertebrate and tick hosts. The implementation of TBDCapSeq could have major impact in studies of tick-borne pathogens by improving detection and facilitating genomic research that was previously unachievable with standard sequencing approaches.

Are other tick-borne infections overlooked in patients investigated for Lyme neuroborreliosis? A large retrospective study from South-eastern Sweden

In Europe, the hard tick Ixodes ricinus is considered the most important vector of human zoonotic diseases. Human pathogenic agents spread by I. ricinus in Sweden include Borrelia burgdorferi sensu lato (s.l.), Anaplasma phagocytophilum, Rickettsia helvetica, the recently described Neoehrlichia mikurensis, Borrelia miyamotoi, tick-borne encephalitis virus (TBEV), and Babesia spp. (Babesia microti, Babesia venatorum and Babesia divergens). Since these pathogens share the same vector, co-infections with more than one tick-borne pathogen may occur and thus complicate the diagnosis and clinical management of the patient due to possibly altered symptomatology. Borrelia burgdorferi s.l., TBEV and B. miyamotoi are well-known to cause infections of the central nervous system (CNS), whereas the abilities of other tick-borne pathogens to invade the CNS are largely unknown. The aim of this study was to investigate the presence and clinical impact of tick-borne pathogens other than B. burgdorferi s.l. in the cerebrospinal fluid (CSF) and serum samples of patients who were under investigation for Lyme neuroborreliosis (LNB) in a tick-endemic region of South-eastern Sweden. CSF and serum samples from 600 patients, recruited from the Regions of Östergötland County, Jönköping County and Kalmar County in South-eastern Sweden and investigated for LNB during the period of 2009-2013, were retrospectively collected for analysis. The samples were analysed by real-time PCR for the presence of nucleic acid from B. burgdorferi s.l., B. miyamotoi, A. phagocytophilum, Rickettsia spp., N. mikurensis, TBEV and Babesia spp. Serological analyses were conducted in CSF and serum samples for all patients regarding B. burgdorferi s.l., and for the patients with CSF mononuclear pleocytosis, analyses of antibodies to B. miyamotoi, A. phagocytophilum, spotted fever group (SFG) rickettsiae, TBEV and B. microti in serum were performed. The medical charts of all the patients with CSF mononuclear pleocytosis and patients with positive PCR findings were reviewed. Of the 600 patients, 55 (9%) presented with CSF mononuclear pleocytosis, 13 (2%) of whom had Borrelia-specific antibodies in the CSF. One patient was PCR-positive for N. mikurensis, and another one was PCR-positive for Borrelia spp. in serum. No pathogens were detected by PCR in the CSF samples. Four patients had serum antibodies to B. miyamotoi, four patients to A. phagocytophilum, five patients to SFG rickettsiae, and six patients to TBEV. One patient, with antibodies to SFG rickettsiae, had both clinical and laboratory signs suggestive of a current infection. Nine patients had serum antibodies to more than one pathogen, although none of these was assessed as a current co-infection. We can conclude from this study that tick-borne co-infections are uncommon in patients who are being investigated for suspected LNB in South-eastern Sweden, an area endemic for borreliosis and TBE.

Lyme neuroborreliosis in Swedish children-PCR as a complementary diagnostic method for detection of Borrelia burgdorferi sensu lato in cerebrospinal fluid

The aim of this study was to evaluate polymerase chain reaction (PCR) as a diagnostic method for the detection of Borrelia burgdorferi s.l. in CSF of Swedish children with LNB. This study was performed retrospectively on CSF and serum samples collected from children evaluated for LNB (n = 233) and controls with other specific neurological disorders (n = 59) in a Swedish Lyme endemic area. For anti-Borrelia antibody index, the IDEIA Lyme Neuroborreliosis kit (Oxoid) was used. Two in-house real-time PCR assays targeting the 16S rRNA gene were evaluated (TaqMan® and LUX™). Among patients classified as LNB cases (n = 102), five children (5%) were Borrelia PCR-positive in CSF with the TaqMan® assay. In the Non-LNB group (n = 131), one patient was Borrelia PCR positive with the TaqMan® assay. Among controls (n = 59), all CSF samples were PCR negative. When amplifying and sequencing ospA, we found B. garinii (n = 2), B. afzelii (n = 2), B. bavariensis (n = 1), and one untypable (n = 1). With the LUX™ technology, all CSF samples were PCR negative. The TaqMan® assay could detect only few cases (n = 6) of B. burgdorferi s.l. in CSF among children with LNB and the sensitivity was very low (5%). However, using larger CSF volumes and centrifugation of samples, the PCR technique could still be useful as a complementary diagnostic method when evaluating LNB. Furthermore, detection of spirochete DNA in clinical matrices, including CSF, is the method of choice for studying epidemiological aspects of LNB, a tick-borne emerging disease.

Cerebrospinal fluid cytokines and chemokines in children with Lyme neuroborreliosis; pattern and diagnostic utility

BACKGROUND

Lyme neuroborreliosis (LNB) is characterized by cerebrospinal fluid (CSF) inflammation with several cytokines/chemokines and B-lymphocytes. Clinically, LNB in children may be difficult to discriminate from non-Lyme aseptic meningitis (NLAM). We aimed to identify CSF cytokine/chemokine patterns in children with LNB, NLAM and controls and elucidate the diagnostic value of these cytokines/chemokines alone or in combination to discriminate between LNB and NLAM.

METHODS

Children with symptoms suggestive of LNB were included prospectively and categorized as LNB, NLAM or controls (no pleocytosis). Cytokines/chemokines in CSF were measured by multiplex bead assays and levels were compared between the three groups by nonparametric statistical tests. Previous results from the same children on the established biomarker, CXCL13, were included in the statistical analyses. The diagnostic properties of cytokines/chemokines to discriminate between LNB and NLAM were determined by receiver operating characteristic curve analyses with estimates of area under curve (AUC). To explore diagnostic properties of combinations of cytokines/chemokines, prediction models based on logistic regression were used.

RESULTS

We included 195 children with LNB (n = 77), NLAM (n = 12) and controls (n = 106). Children with LNB had higher CSF levels of CCL19, CCL22 and CXCL13 compared to NLAM and controls, whereas INFγ was higher in NLAM than in LNB and controls. CXCL13 was the superior single cytokine/chemokine to discriminate LNB from NLAM (AUC 0.978). The combination CXCL13/CCL19 (AUC 0.992) may possibly improve the specificity for LNB, especially for children with moderate CXCL13 levels.

CONCLUSIONS

The intrathecal immune reaction in LNB is characterized by B cell associated chemokines. Whether the combination CXCL13/CCL19 further improves discrimination between LNB and NLAM beyond the diagnostic improvements by CXCL13 alone needs to be tested in new studies.

The Lyme Disease Polymerase Chain Reaction Test Has Low Sensitivity

Background: The Lyme PCR is a direct detection test, but has not been rigorously evaluated in children undergoing evaluation for acute Lyme disease. Methods: We performed a six-center prospective cohort study of children aged 1 to 21 years undergoing acute evaluation for Lyme disease. For this planned secondary analysis, we limited our cohort to children undergoing evaluation for Lyme disease who had any Lyme PCR test obtained by a treating clinician (blood, synovial fluid, or cerebrospinal fluid). We defined a case of Lyme disease with a positive two-tier Lyme disease serology: a positive or equivocal enzyme immunoassay followed by a positive supplemental immunoblot interpreted using standard criteria. We report the test characteristics of Lyme PCR for the diagnosis of Lyme disease. Results: We identified 124 children of whom 54 (43.5%) had Lyme disease. Overall, 23 had a positive PCR test (sensitivity 41.8%; 95% confidence interval [CI] 29.7-55.0; specificity 100%, 95% CI: 94.2-100). All children with a positive Lyme PCR also had a positive two-tiered Lyme disease serology. Conclusions: The Lyme disease PCR test did not improve the diagnosis of children undergoing evaluation for acute Lyme disease. Given the additional costs of this low utility test, clinicians should not order Lyme PCR testing in the acute care setting.

Lyme Neuroborreliosis in Children: Etiology and Comparison of Clinical Findings of Lyme Neuroborreliosis Caused by Borrelia garinii and Borrelia afzelii

BACKGROUND

Information on the etiology of Lyme neuroborreliosis (LNB) in children in Europe and the influence of Borrelia burgdorferi sensu lato species isolated from cerebrospinal fluid (CSF) on clinical presentation of LNB in children are limited.

METHODS

The study was monocentric. During its 17-year period, children younger than 15 years with presentation suggestive of LNB or confirmed Lyme borreliosis that had B. burgdorferi sensu lato isolated from CSF and had species of B. burgdorferi sensu lato identified by pulsed-field gel electrophoresis were included. Demographic and medical data were compared for children infected with Borrelia garinii to those infected with Borrelia afzelii.

RESULTS

One hundred and fifty-three children had B. burgdorferi sensu lato isolated from CSF. In 71/113 (62.8%) and 42/113 (37.2%) patients, B. garinii and B. afzelii, respectively, were identified. Patients infected with B. garinii did not report symptoms suggestive of central nervous system (CNS) involvement or any other symptoms more often than patients infected with B. afzelii. Compared with children infected with B. afzelii, children infected with B. garinii had erythema migrans less often (18.3% vs. 45.2%) but had positive meningeal signs (69.0% vs. 38.1%), CSF lymphocytic predominance (97.1% vs. 75.0%), and elevated albumin CSF/serum quotient (80.6% vs. 50.0%) more often.

CONCLUSIONS

In Slovenia, LNB in children is more often caused by B. garinii, followed by B. afzelii. The clinical picture of LNB in children caused by B. garinii is not more often suggestive of CNS involvement, but CNS inflammation is more pronounced in children infected with B. garinii, compared with children infected with B. afzelii.

The B-lymphocyte chemokine CXCL13 in the cerebrospinal fluid of children with Lyme neuroborreliosis: associations with clinical and laboratory variables

Background: The B-lymphocyte chemokine CXCL13 is increasingly considered as a useful early phase diagnostic marker of Lyme neuroborreliosis (LNB). However, the large variation in level of CXCL13 in the cerebrospinal fluid (CSF) observed in LNB patients is still unexplained. We aimed to identify factors associated with the level of CXCL13 in children with LNB, possibly improving the interpretation of CXCL13 as a diagnostic marker of LNB. Methods: Children with confirmed and probable LNB were included in a prospective study on CXCL13 in CSF as a diagnostic marker of LNB. The variables age, sex, facial nerve palsy, generalized inflammation symptoms (fever, headache, neck-stiffness and/or fatigue), duration of symptoms, Borrelia antibodies in CSF, Borrelia antibody index (AI), CSF white blood cells (WBC), CSF protein and detection of the genospecies Borrelia garinii by PCR were included in simple and multivariable regression analyses to study the associations with the CXCL13 level. Results: We included 53 children with confirmed and 17 children with probable LNB. CXCL13 levels in CSF were positively associated with WBC, protein and Borrelia antibodies in CSF in both simple and multivariable analyses. We did not find any associations between CXCL13 and age, sex, clinical symptoms, duration of symptoms, AI or the detection of Borrelia garinii. Conclusions: High levels of CSF CXCL13 are present in the early phase of LNB and correlate with the level of CSF WBC and protein. Our results indicate that CSF CXCL13 in children evaluated for LNB can be interpreted independently of clinical features or duration of symptoms.

Lyme neuroborreliosis and bird populations in northern Europe

Many vector-borne diseases are transmitted through complex pathogen-vector-host networks, which makes it challenging to identify the role of specific host groups in disease emergence. Lyme borreliosis in humans is now the most common vector-borne zoonosis in the Northern Hemisphere. The disease is caused by multiple genospecies of Borrelia burgdorferi sensu lato bacteria transmitted by ixodid (hard) ticks, and the major host groups transmit Borrelia genospecies with different pathogenicity, causing variable clinical symptoms in humans. The health impact of a given host group is a function of the number of ticks it infects as well as the pathogenicity of the genospecies it carries. Borrelia afzelii, with mainly small mammals as reservoirs, is the most common pathogen causing Lyme borreliosis, and it is often responsible for the largest proportion of infected host-seeking tick nymphs in Europe. The bird-borne Borrelia garinii, though less prevalent in nymphal ticks, is more likely to cause Lyme neuroborreliosis, but whether B. garinii causes disseminated disease more frequently has not been documented. Based on extensive data of annual disease incidence across Norway from 1995 to 2017, we show here that 69% of disseminated Lyme borreliosis cases were neuroborreliosis, which is three times higher than predicted from the infection prevalence of B. garinii in host-seeking ticks (21%). The population estimate of migratory birds, mainly of thrushes, explained part of the annual variation in cases of neuroborreliosis, with a one-year time lag. We highlight the important role of the genospecies' pathogenicity and the host associations for understanding the epidemiology of disseminated Lyme borreliosis.

The Emerging Role of Microbial Biofilm in Lyme Neuroborreliosis

Lyme borreliosis (LB) is the most common tick-borne disease caused by the spirochete Borrelia burgdorferi in North America and Borrelia afzelii or Borrelia garinii in Europe and Asia, respectively. The infection affects multiple organ systems, including the skin, joints, and the nervous system. Lyme neuroborreliosis (LNB) is the most dangerous manifestation of Lyme disease, occurring in 10-15% of infected individuals. During the course of the infection, bacteria migrate through the host tissues altering the coagulation and fibrinolysis pathways and the immune response, reaching the central nervous system (CNS) within 2 weeks after the bite of an infected tick. The early treatment with oral antimicrobials is effective in the majority of patients with LNB. Nevertheless, persistent forms of LNB are relatively common, despite targeted antibiotic therapy. It has been observed that the antibiotic resistance and the reoccurrence of Lyme disease are associated with biofilm-like aggregates in B. burgdorferi, B. afzelii, and B. garinii, both in vitro and in vivo, allowing Borrelia spp. to resist to adverse environmental conditions. Indeed, the increased tolerance to antibiotics described in the persisting forms of Borrelia spp., is strongly reminiscent of biofilm growing bacteria, suggesting a possible role of biofilm aggregates in the development of the different manifestations of Lyme disease including LNB.