Development and Validation of a Protein Array for Detection of Antibodies against the Tick-Borne Pathogen Borrelia miyamotoi

Current serological tests for the emerging tick-borne pathogen Borrelia miyamotoi lack diagnostic accuracy. To improve serodiagnosis, we investigated a protein array simultaneously screening for IgM and IgG reactivity against multiple recombinant B. miyamotoi antigens. The array included six B. miyamotoi antigens: glycerophosphodiester phosphodiesterase (GlpQ), multiple variable major proteins (Vmps), and flagellin. Sera included samples from cases of PCR-proven Borrelia miyamotoi disease (BMD), multiple potentially cross-reactive control groups (including patients with culture-proven Lyme borreliosis, confirmed Epstein-Barr virus, cytomegalovirus, or other spirochetal infections), and several healthy control groups from regions where Ixodes is endemic and regions where it is nonendemic. Based on receiver operating characteristic (ROC) analyses, the cutoff for reactivity per antigen was set at 5 μg/mL for IgM and IgG. The individual antigens demonstrated high sensitivity but relatively low specificity for both IgM and IgG. The best-performing single antigen (GlpQ) showed a sensitivity of 88.0% (95% confidence interval [CI], 78.9 to 93.5) and a specificity of 94.2% (95% CI, 92.7 to 95.6) for IgM/IgG. Applying the previous published diagnostic algorithm-defining seroreactivity as reactivity against GlpQ and any Vmp-revealed a significantly higher specificity of 98.5% (95% CI, 97.6 to 99.2) but a significantly lower sensitivity of 79.5% (95% CI, 69.3 to 87.0) for IgM/IgG compared to GlpQ alone. Therefore, we propose to define seroreactivity as reactivity against GlpQ and any Vmp or flagellin which resulted in a comparable sensitivity of 84.3% (95% CI, 74.7 to 90.8) and a significantly higher specificity of 97.9% (95% CI, 96.9 to 98.7) for IgM/IgG compared to GlpQ alone. In conclusion, we have developed and validated a novel serological tool to diagnose BMD that could be implemented in clinical practice and epidemiological studies. IMPORTANCE This paper describes the protein array as a novel serological test for the diagnosis of Borrelia miyamotoi disease (BMD), by reporting the methodology, the development of a diagnostic algorithm, and its extensive validation. With rising numbers of ticks and tick bites, tick-borne diseases, such as BMD, urgently deserve further societal and medical attention. B. miyamotoi is prevalent in Ixodes ticks across the northern hemisphere. Humans are exposed to, and infected by, B. miyamotoi and develop BMD in Asia, in North America, and to a lesser extent in Europe. However, the burden of infection and disease remains largely unknown, due to the noncharacteristic clinical presentation, together with the lack of awareness and availability of diagnostic tools. With this paper, we offer a novel diagnostic tool which will assist in assessing the burden of disease and could be implemented in clinical care.

Immunoserological Diagnosis of Human Borrelioses: Current Knowledge and Perspectives

Spirochetes of the genus Borrelia are divided into relapsing fever borreliae and Lyme disease borreliae. Immunoserological assays have been poorly developed for relapsing fever borreliae, where direct detection methods are more adapted to the pathophysiology of these infections presenting with massive bacteraemia. However, emergence of the novel agent of relapsing fever B. miyamotoi has renewed interest in serology in this context. In Lyme disease, because direct detection methods show low sensitivity, serology plays a central role in the diagnostic strategy. This diagnostic strategy is based on a two-tier methodology involving a first test (ELISA) with high sensitivity and acceptable specificity and a second, more specific test (western blot) for diagnostic confirmation. The most frequent limitations and pitfalls of serology are cross reactions, false IgM positivity, a seronegative window period at the early time of the infection, and serologic scars with a suspicion of reinfection. International guidelines have thus been proposed to avoid these difficulties with interpretation. Finally, unconventional diagnostic tests have been developed recently in the context of a highly publicized disease, with widely varying results, some of which have no available evidence-based data. New two-tier testing strategies using two ELISA tests (C6 and WCS for example) to replace immunoblot are currently proposed by some authors and guidelines, and promising new tests such as CXCL-13 in CSF are promising tools for the improvement of the diagnosis of Lyme borreliosis.

Classification and Staging of Morgellons Disease: Lessons from Syphilis

INTRODUCTION

Morgellons disease (MD) is a contested dermopathy that is associated with Borrelia spirochetal infection. A simple classification system was previously established to help validate the disease based on clinical features (classes I-IV).

METHODS

Drawing on historical and pathological parallels with syphilis, we formulated a more detailed staging system based on clinical features as well as severity of skin lesions and corresponding histopathological infection patterns, as determined by anti-Borrelia immunohistochemical staining.

RESULTS

Clinical classes I-IV of MD are further categorized as mild, moderate and severe, or stages A, B and C, respectively, based on histopathological findings. Stage A lesions demonstrated little or no immune infiltrates and little or no disorganization of cells; macrophages were not present, and hemorrhage was negligible. Extracellular isolated spirochetes and intracellular staining of keratinocytes in the lower epidermis was occasionally seen. Stage C lesions demonstrated positive staining of keratinocytes in the stratum basale and stratum spinosum and positive intracellular staining of macrophages for Borrelia. Aggregate Borrelia colonies were frequently encountered, hemorrhage was frequent, and intracellularly stained fibroblasts were occasionally seen. Stage B lesions demonstrated a pattern intermediate between Stages A and C.

CONCLUSION

The enhanced staging system provides objective criteria to assess the severity of dermopathy in MD. Further studies are needed to determine the optimal treatment for MD based on this staging system related to Borrelia infection.

ARGAS (PERSICARGAS) GIGANTEUS SOFT TICK INFECTION WITH RICKETTSIA HOOGSTRAALI AND RELAPSING FEVER BORRELIA ON WILD AVIAN SPECIES OF THE DESERT SOUTHWEST, USA

Changing climatic conditions and the northward expansion of ticks and pathogens are of immense importance to human, animal, and environmental health assessment and risk management. From 2014 through 2015, a wildlife rehabilitation center in south-central Arizona, US noted soft ticks (Argasidae) infesting 23 birds, including Cooper's Hawks (Accipiter cooperii), Gray Hawks (Buteo plagiatus), Harris's Hawks (Parabuteo unicinctus), Red-tailed Hawks (Buteo jamaicensis), Great Horned Owls (Bubo virginianus), Common Ravens (Corvus corax), and a Greater Roadrunner (Geococcyx californianus), during the late summer seasonal rainy seasons. The parasites numbered in the hundreds on individual birds. Infested birds were moribund, obtunded, or paralyzed on presentation, with no prior histories of illness or evidence of trauma. Tick and avian blood samples were collected for vector-borne pathogen analysis focusing on the molecular detection of Rickettsia and Borrelia species. Ticks were identified as the neotropical species of soft tick, Argas (Persicargas) giganteus; their occurrence in the southern US on raptors represented an expansion of host range. Pathogen testing of ticks showed that 41% of 54 ticks were infected with Rickettsia hoogstraalii and 23% of 26 ticks were infected with a relapsing fever Borrelia; both agents are associated with uncertain health consequences. Among the blood samples, one was infected with the same Borrelia spp.; this Red-tailed Hawk also had Borrelia-positive ticks. With supportive therapy, the majority of birds, 74% (17/23), recovered and were released or permanent residents. The management of soft tick-infested birds and mitigation of future disease risk will require additional characterizations of these poorly studied soft ticks and their associated pathogens.

Detection of tick-borne infection in Morgellons disease patients by serological and molecular techniques

Background

Morgellons disease (MD) is a skin condition associated with Lyme disease (LD) and tick-borne illness. Patients with this skin disorder experience ulcerative lesions that contain multicolored filamentous collagen and keratin inclusions. Infection with various species of Borrelia and other tick-borne pathogens has been detected in tissue and body fluid specimens from MD patients. We sought to explore this association further in a cohort of MD patients.

Patients and methods

Sera from 30 patients with MD were tested for antibody reactivity to antigens from the Borrelia burgdorferi (Bb) group and the relapsing fever Borrelia (RFB) group of spirochetes. Tissue and/or body fluid specimens from these patients were also tested for the presence of Bb and RFB infection using PCR technology. In addition, tissue and body fluid specimens were tested for the presence of Bartonella henselae using PCR, and formalin-fixed skin sections from a subset of patients were tested using fluorescent in situ hybridization (FISH) with B. henselae-specific DNA probes.

Results

Seroreactivity to Bb, RFB or both was detected in 63% of the cohort, while positive PCR testing for Bb, RFB or both was detected in 53% of the cohort. Overall, 90% of patients tested positive for exposure and/or infection with Borrelia spirochetes. B. henselae infection was detected by PCR in skin sections or body fluids from 20% of the subjects, and B. henselae FISH testing was positive in 30% of the dermatological specimens submitted for study.

Conclusion

The study demonstrates an association between MD and positive tests for both Bb and RFB spirochetes. In conjunction with previous studies, our study provides corroborative evidence linking MD to Borrelia infection and tick-borne illness.

Relapsing fever Borrelia in California: a pilot serological study

Background

Borrelia spirochetes are tick-borne Gram-negative bacteria that cause disease in humans and animals. Although many studies have focused on Borrelia burgdorferi (Bb), the agent of Lyme disease, recent studies have examined the role of Relapsing Fever Borrelia (RFB) in human disease. In this pilot study, we have evaluated serological reactivity against Bb and RFB in patients residing in California.

Methods

Serological testing for reactivity to Bb and RFB antigens was performed in 543 patients with suspected tick-borne illness using a Western blot technique. Further evaluation of a subset of 321 patients residing in California was obtained. Serum samples were tested for IgM and IgG antibodies reactive with Bb and RFB, and samples were classified by county of residence according to Bb reactivity alone, RFB reactivity alone, and dual reactivity against Bb and RFB. Seroreactivity was ranked in counties with the highest absolute number and the highest prevalence of positive samples.

Results

Of the 543 total serum samples, 32% were positive for Bb, 22% were positive for RFB, and 7% were positive for both Bb and RFB. Of the 321 serum samples from patients residing in California, 33% were positive for Bb, 27% were positive for RFB, and 11% were positive for both Bb and RFB. In the California cohort, the highest rates of positive serological testing for Bb were found in Santa Clara, Alameda, and Contra Costa counties, while the highest rates of positive serological testing for RFB were found in Santa Clara, Alameda, Marin, and San Francisco counties. The highest rates of dual reactivity against Bb and RFB were found in Contra Costa, Alameda, and San Francisco counties. Among the 24 counties with patients who were tested, Bb seropositivity alone was found in four counties, RFB seropositivity alone was found in two counties, and seropositivity for both Bb and RFB was found in 14 counties.

Conclusion

Results of this pilot study suggest that seroreactivity against Bb and RFB is widespread in California, and dual exposure to Bb and RFB may complicate the diagnosis of tick-borne disease. Greater awareness of RFB and broader screening for this tick-borne infection is warranted.

In Vitro Antimicrobial Susceptibility of Clinical Isolates of Borrelia miyamotoi

Borrelia miyamotoi is an emerging relapsing fever (RF) Borrelia species that is reported to cause human disease in regions in which Lyme borreliosis is endemic. We recently showed that B. miyamotoi tick isolates are resistant to amoxicillin in vitro; however, clinical isolates have not been studied. Therefore, our aim was to show the antimicrobial susceptibility of recently obtained clinical isolates of B. miyamotoi A dilution series of various antibiotics was made in modified Kelly-Pettenkofer medium with 10% fetal calf serum. The susceptibilities of different B. miyamotoi clinical, B. miyamotoi tick, RF Borrelia, and Borrelia burgdorferisensu lato isolates were tested by measuring MICs through colorimetric changes and by counting motile spirochetes by dark-field microscopy after 72 h of incubation. The ceftriaxone and azithromycin MIC ranges of the six B. miyamotoi clinical isolates tested were 0.03 to 0.06 mg/liter and 0.0016 to 0.0032 mg/liter, respectively. These values are similar to MICs for RF Borrelia strains and B. miyamotoi tick isolates. All tested RF Borrelia strains were susceptible to doxycycline (microscopic MIC range, 0.0625 to 0.25 mg/liter). In contrast to the MICs of the tested B. burgdorferi sensu lato strains and in line with our previous findings, the amoxicillin MICs (range, 8 to 32 mg/liter) of all RF Borrelia strains, including B. miyamotoi clinical isolates, were above the clinical breakpoint for resistance (≤4 mg/liter). Clinical isolates of B. miyamotoi are highly susceptible to doxycycline, azithromycin, and ceftriaxone in vitro Interestingly, as described previously for tick isolates, amoxicillin shows poor in vitro activity against B. miyamotoi clinical isolates.