Evaluation of a new culture medium for Borrelia burgdorferi

Persistent Symptoms After Treatment of Lyme Disease

Most patients with Lyme disease will fully recover with recommended antibiotic therapy. However, some patients report persisting nonspecific symptoms after treatment, referred to as posttreatment Lyme disease symptoms (PTLDs) or syndrome (PTLDS), depending on the degree to which the individual's symptoms impact their quality of life. PTLDs occur in a portion of patients diagnosed with chronic Lyme disease (CLD), a controversial term describing different patient populations, diagnosed based on unvalidated tests and criteria. Practitioners should review the evidence for the Lyme disease diagnosis and not overlook unrelated conditions. Current evidence shows that prolonged antibiotic therapy provides little benefit and carries significant risk. Further research to elucidate the mechanisms underlying persistent symptoms after Lyme disease and to understand CLD is needed.

The Platelet Fraction Is a Novel Reservoir to Detect Lyme Borrelia in Blood

Simple Summary

To diagnose Lyme disease, a patient’s blood is tested for antibodies that develop as part of the immune response. This can lead to cases being missed or inadequately treated. An ideal test would directly detect the Lyme disease bacteria, Borrelia, to provide better clinical guidance. In this study, we aimed to improve the methods currently used to find Borrelia in human blood, and identified two opportunities for optimization. We demonstrate that the container most commonly used to collect blood (EDTA) decreases Borrelia’s ability to grow, and we identify a superior alternative (citrate). Additionally, using experimentally infected blood, we show that Borrelia is highly concentrated in the platelet fraction, making it an ideal candidate for direct detection. These results lay the foundation for diagnostic test development, which could improve patient outcomes in Lyme disease.

Abstract

Serological diagnosis of Lyme disease suffers from considerable limitations. Yet, the technique cannot currently be replaced by direct detection methods, such as bacterial culture or molecular analysis, due to their inadequate sensitivity. The low bacterial burden in vasculature and lack of consensus around blood-based isolation of the causative pathogen, Borrelia burgdorferi, are central to this challenge. We therefore addressed methodological optimization of Borrelia recovery from blood, first by analyzing existing protocols, and then by using experimentally infected human blood to identify the processing conditions and fractions that increase Borrelia yield. In this proof-of-concept study, we now report two opportunities to improve recovery and detection of Borrelia from clinical samples. To enhance pathogen viability and cultivability during whole blood collection, citrate anticoagulant is superior to more commonly used EDTA. Despite the widespread reliance on serum and plasma as analytes, we found that the platelet fraction of blood concentrates Borrelia, providing an enriched resource for direct pathogen detection by microscopy, laboratory culture, Western blot, and PCR. The potential for platelets to serve as a reservoir for Borrelia and its diagnostic targets may transform direct clinical detection of this pathogen.

Identifying Vancomycin as an Effective Antibiotic for Killing Borrelia burgdorferi

Borrelia burgdorferi is the causative agent of Lyme borreliosis. Antibiotic therapy of early acute infection is effective for most patients, but 10 to 20% go on to develop posttreatment Lyme disease syndrome (PTLDS). The nature of PTLDS remains unknown, but currently approved antibiotics for the treatment of Lyme disease do not appear to impact these symptoms after they have developed. We reason that minimizing the time the pathogen interacts with the host will diminish the probability of developing PTLDS, irrespective of its nature. This calls for an efficient eradication of the pathogen during acute infection. In search of a superior killing antibiotic, we examined approved antibiotics for their ability to kill B. burgdorferi Vancomycin proved more effective in killing the pathogen in vitro than ceftriaxone, the standard of care for disseminated B. burgdorferi infection. Both compounds were also the most effective in killing stationary-phase cells. This is surprising, given that inhibitors of cell wall biosynthesis are known to only kill growing bacteria. We found that peptidoglycan synthesis continues in stationary-phase cells of B. burgdorferi, explaining this paradox. A combination of vancomycin and gemifloxacin sterilized a stationary-phase culture of B. burgdorferi Examination of the action of antibiotics in severe combined immunodeficient (SCID) mice showed that doxycycline, a standard of care for uncomplicated acute infection, did not clear the pathogen. In contrast, both ceftriaxone and vancomycin cleared the infection. A trial examining the early use of more potent antibiotics on the development of PTLDS may be warranted.

Studies that report unexpected positive blood cultures for Lyme borrelia - are they valid?

Positive blood cultures for Lyme borrelia have been well documented in untreated patients with early Lyme disease. In this report we review the validity of three studies that reported the recovery of Borrelia burgdorferi sensu lato from the blood of a high proportion of patients for whom no evidence was presented, and no claim was made, that the patients had untreated early Lyme disease. In two of the studies the patients had been treated extensively with antibiotics for Lyme disease before the cultures were obtained. Critical evaluation of the three reports suggests that they are invalid. Indeed, two subsequently published studies could not reproduce the results of one of the reports. In a published analysis of another of the reports, investigators from the Centers for Disease Control and Prevention concluded that the cultures were likely to have been contaminated. When the biologic plausibility of recovering borrelia from blood is extremely low, the level of scientific rigor required of a study that claims a positive result should be particularly high.

The Accuracy of Diagnostic Tests for Lyme Disease in Humans, A Systematic Review and Meta-Analysis of North American Research

There has been an increasing incidence of Lyme disease (LD) in Canada and the United States corresponding to the expanding range of the Ixodes tick vector and Lyme disease agent (Borrelia burgdorferi sensu stricto). There are many diagnostic tests for LD available in North America, all of which have some performance issues, and physicians are concerned about the appropriate use and interpretation of these tests. The objective of this systematic review is to summarize the North American evidence on the accuracy of diagnostic tests and test regimes at various stages of LD. Included in the review are 48 studies on diagnostic tests used in North America published since 1995. Thirteen studies examined a two-tier serological test protocol vs. clinical diagnosis, 24 studies examined single assays vs. clinical diagnosis, 9 studies examined single immunoblot vs. clinical diagnosis, 7 studies compared culture or PCR direct detection methods vs. clinical diagnosis, 22 studies compared two or more tests with each other and 8 studies compared a two-tiered serological test protocol to another test. Recent studies examining the sensitivity and specificity of various test protocols noted that the Immunetics® C6 B. burgdorferi ELISA™ and the two tier approach have superior specificity compared to proposed replacements, and the CDC recommended western blot algorithm has equivalent or superior specificity over other proposed test algorithms. There is a dramatic increase in test sensitivity with progression of B. burgdorferi infection from early to late LD. Direct detection methods, culture and PCR of tissue or blood samples were not as sensitive or timely compared to serological testing. It was also noted that there are a large number of both commercial (n = 42) and in-house developed tests used by private laboratories which have not been evaluated in the primary literature.

Chronic Lyme disease

Chronic Lyme disease is a poorly defined diagnosis that is usually given to patients with prolonged, unexplained symptoms or with alternative medical diagnoses. Data do not support the proposition that chronic, treatment-refractory infection with Borrelia burgdorferi is responsible for the many conditions that get labeled as chronic Lyme disease. Prolonged symptoms after successful treatment of Lyme disease are uncommon, but in rare cases may be severe. Prolonged courses of antibiotics neither prevent nor ameliorate these symptoms and are associated with considerable harm.

Laboratory diagnosis of Lyme disease: advances and challenges

The majority of laboratory tests performed for the diagnosis of Lyme disease are based on detection of the antibody responses against B burgdorferi in serum. The sensitivity of antibody-based tests increases with the duration of the infection. Patients early in their illness are more likely to have a negative result. There is a need to simplify the testing algorithm for Lyme disease, improving sensitivity in early disease while still maintaining high specificity and providing information about the stage of infection. The development of a point of care assay and biomarkers for active infection would be major advances for the field.

Current and past strategies for bacterial culture in clinical microbiology

A pure bacterial culture remains essential for the study of its virulence, its antibiotic susceptibility, and its genome sequence in order to facilitate the understanding and treatment of caused diseases. The first culture conditions empirically varied incubation time, nutrients, atmosphere, and temperature; culture was then gradually abandoned in favor of molecular methods. The rebirth of culture in clinical microbiology was prompted by microbiologists specializing in intracellular bacteria. The shell vial procedure allowed the culture of new species of Rickettsia. The design of axenic media for growing fastidious bacteria such as Tropheryma whipplei and Coxiella burnetii and the ability of amoebal coculture to discover new bacteria constituted major advances. Strong efforts associating optimized culture media, detection methods, and a microaerophilic atmosphere allowed a dramatic decrease of the time of Mycobacterium tuberculosis culture. The use of a new versatile medium allowed an extension of the repertoire of archaea. Finally, to optimize the culture of anaerobes in routine bacteriology laboratories, the addition of antioxidants in culture media under an aerobic atmosphere allowed the growth of strictly anaerobic species. Nevertheless, among usual bacterial pathogens, the development of axenic media for the culture of Treponema pallidum or Mycobacterium leprae remains an important challenge that the patience and innovations of cultivators will enable them to overcome.

Update on persistent symptoms associated with Lyme disease

PURPOSE OF REVIEW

Lyme disease, caused by Borrelia burgdorferi, is the most common vector-borne illness in the United States. The pathogenesis, ecology, and epidemiology of Lyme disease have been well described, and antimicrobial treatment is very effective. There has been controversy about whether infection can persist and cause chronic symptoms despite treatment with antimicrobials. This review summarizes recent studies that have addressed this issue.

RECENT FINDINGS

The pathogenesis of persistent nonspecific symptoms in patients who were treated for Lyme disease is poorly understood, and the validity of results of attempts to demonstrate persistent infection with B. burgdorferi has not been established. One study attempted to use xenodiagnosis to detect B. burgdorferi in patients who have been treated for Lyme disease. Another study assessed whether repeated episodes of erythema migrans were due to the same or different strains of B. burgdorferi. A possible cause of persistent arthritis in some treated patients is slow clearance of nonviable organisms that may lead to prolonged inflammation. The results of all of these studies continue to provide evidence that viable B. burgdorferi do not persist in patients who receive conventional antimicrobial treatment for Lyme disease.

SUMMARY

Patients with persistent symptoms possibly associated with Lyme disease often provide a challenge for clinicians. Recent studies have provided additional evidence that viable B. burgdorferi do not persist after conventional treatment with antimicrobials, indicating that ongoing symptoms in patients who received conventional treatment for Lyme disease should not be attributed to persistent active infection.

Repeat or persistent Lyme disease: persistence, recrudescence or reinfection with Borrelia Burgdorferi?

Whether or not Borrelia burgdorferi can persist after conventional treatment with antimicrobials has been a very controversial issue. Two recent studies took different approaches to try to answer this question. In one, investigators showed that, in each of 22 instances in 17 patients with two consecutive episodes of culture-proved erythema migrans, the strains of B. burgdorferi were different based on their genotypes. This indicated that the repeat episodes were due to new infections rather than recrudescence of the original infection. In another study, in which persistence of B. burgdorferi was assessed by using xenodiagnosis, no viable B. burgdorferi were cultured from ticks fed on any of the patients. There continues to be no evidence that viable B. burgdorferi persist in humans after conventional treatment with antimicrobials.

Antiscience and ethical concerns associated with advocacy of Lyme disease

Advocacy for Lyme disease has become an increasingly important part of an antiscience movement that denies both the viral cause of AIDS and the benefits of vaccines and that supports unproven (sometimes dangerous) alternative medical treatments. Some activists portray Lyme disease, a geographically limited tick-borne infection, as a disease that is insidious, ubiquitous, difficult to diagnose, and almost incurable; they also propose that the disease causes mainly non-specific symptoms that can be treated only with long-term antibiotics and other unorthodox and unvalidated treatments. Similar to other antiscience groups, these advocates have created a pseudoscientific and alternative selection of practitioners, research, and publications and have coordinated public protests, accused opponents of both corruption and conspiracy, and spurred legislative efforts to subvert evidence-based medicine and peer-reviewed science. The relations and actions of some activists, medical practitioners, and commercial bodies involved in Lyme disease advocacy pose a threat to public health.

Chronic Lyme disease: a survey of Connecticut primary care physicians

OBJECTIVE

To determine how frequently Connecticut primary care physicians are diagnosing and treating patients with chronic Lyme disease.

STUDY DESIGN

A survey was mailed to a random 33% sample of primary care physicians in Connecticut, which asked how many cases of Lyme disease and chronic Lyme disease they diagnosed and treated in the last 3 years.

RESULTS

The survey had a response rate of 39.1%. Physician respondents (n = 285) fit in one of 3 groups. Group 1 included 6 of 285 (2.1%) physicians who diagnose and treat patients with chronic Lyme disease. Group 2 included 137 of 285 (48.1%) physicians who are undecided on the existence of chronic Lyme disease, but did not diagnose or treat any patients with chronic Lyme disease. Group 3 included 142 of 285 (49.8%) physicians who do not believe in the existence of chronic Lyme disease.

CONCLUSION

A small percentage (2.1%) of primary care physicians diagnose and treat patients for presumed chronic Lyme disease.

Chronic Lyme disease: a review

Studies have shown that most patients diagnosed with chronic Lyme disease either have no objective evidence of previous or current infection with Borrelia burgdorferi or are patients who should be classified as having post-Lyme disease syndrome, which is defined as continuing or relapsing nonspecific symptoms (such as fatigue, musculoskeletal pain, and cognitive complaints) in a patient previously treated for Lyme disease. Despite extensive study, there is currently no clear evidence that post-Lyme disease syndrome is caused by persistent infection with B burgdorferi. Four randomized placebo-controlled studies have shown that antibiotic therapy offers no sustained benefit to patients who have post-Lyme disease syndrome. These studies also showed a substantial placebo effect and a significant risk of treatment-related adverse events. Further research to elucidate the mechanisms underlying persistent symptoms after Lyme disease and controlled trials of new approaches to the treatment and management of these patients are needed.

Lyme disease: laboratory issues

This article describes the laboratory modalities available to confirm the diagnosis of Lyme borreliosis. Use and limitations of these methods are discussed. Current guidelines for the use of recommended serologic methods and discussion of newer methods also are provided.

Evaluation of a modified culture medium for Borrelia burgdorferi sensu lato

The aim of the present study was to assess the possible use of a modified medium, prepared in the laboratory using the constituents of Barbour-Stonner-Kelly (BSK) medium and medium 199 as base, for the culture of Borrelia strains, comparing the growth of individual strains in this medium and in the BSK-H medium, and the protein profile and antigenic characteristics of Borrelia proteins expressed in these media. A qualitative evaluation of growth of Borrelia species was made with acceptable results (morphology and motility), but during a quantitative evaluation using the three main genospecies of Borrelia, the better results were obtained with a B. burgdorferi sensu stricto strain. The modified medium did not enable the growth of a B. afzelii strain. The protein profile and antigenic characteristic of the expressed proteins in the modified medium were studied with satisfactory results. These results suggest the modified medium as an alternative for the cultivation of Borrelia strains, with some limitations, in poorly-resourced laboratories.

Place des méthodes biologiques dans le diagnostic des manifestations de la borréliose de Lyme

Lyme borreliosis (LB) is a multisystemic infection transmitted by ticks. Its diagnosis is based on clinical and biological criteria. These criteria could be different in Europe than in the USA, because of the existence of multiples strains of borrelia in Europe. In primary stage of LB, the diagnosis is often clinical. In the secondary stage, LB diagnosis is established with an Elisa serology confirmed by a Western blot. The interpretation criteria of these laboratory tests should follow European recommendations (EUCALB). LB with neurological involvement should be confirmed by screening for intrathecal synthesis of borrelia antibodies in CSF. LB with rheumatologic expression could be confirmed by screening for borrelia in joint fluid by PCR. There is no strong marker of activity of the disease. Follow-up for LB is difficult, because antibodies may persist for years and LB does not confer immunization.

The clinical assessment, treatment, and prevention of lyme disease, human granulocytic anaplasmosis, and babesiosis: clinical practice guidelines by the Infectious Diseases Society of America

Evidence-based guidelines for the management of patients with Lyme disease, human granulocytic anaplasmosis (formerly known as human granulocytic ehrlichiosis), and babesiosis were prepared by an expert panel of the Infectious Diseases Society of America. These updated guidelines replace the previous treatment guidelines published in 2000 (Clin Infect Dis 2000; 31[Suppl 1]:1-14). The guidelines are intended for use by health care providers who care for patients who either have these infections or may be at risk for them. For each of these Ixodes tickborne infections, information is provided about prevention, epidemiology, clinical manifestations, diagnosis, and treatment. Tables list the doses and durations of antimicrobial therapy recommended for treatment and prevention of Lyme disease and provide a partial list of therapies to be avoided. A definition of post-Lyme disease syndrome is proposed.

Diagnosis of lyme borreliosis

A large amount of knowledge has been acquired since the original descriptions of Lyme borreliosis (LB) and of its causative agent, Borrelia burgdorferi sensu stricto. The complexity of the organism and the variations in the clinical manifestations of LB caused by the different B. burgdorferi sensu lato species were not then anticipated. Considerable improvement has been achieved in detection of B. burgdorferi sensu lato by culture, particularly of blood specimens during early stages of disease. Culturing plasma and increasing the volume of material cultured have accomplished this. Further improvements might be obtained if molecular methods are used for detection of growth in culture and if culture methods are automated. Unfortunately, culture is insensitive in extracutaneous manifestations of LB. PCR and culture have high sensitivity on skin samples of patients with EM whose diagnosis is based mostly on clinical recognition of the lesion. PCR on material obtained from extracutaneous sites is in general of low sensitivity, with the exception of synovial fluid. PCR on synovial fluid has shown a sensitivity of up to >90% (when using four different primer sets) in patients with untreated or partially treated Lyme arthritis, making it a helpful confirmatory test in these patients. Currently, the best use of PCR is for confirmation of the clinical diagnosis of suspected Lyme arthritis in patients who are IgG immunoblot positive. PCR should not be used as the sole laboratory modality to support a clinical diagnosis of extracutaneous LB. PCR positivity in seronegative patients suspected of having late manifestations of LB most likely represents a false-positive result. Because of difficulties in direct methods of detection, laboratory tests currently in use are mainly those detecting antibodies to B. burgdorferi sensu lato. Tests used to detect antibodies to B. burgdorferi sensu lato have evolved from the initial formats as more knowledge on the immunodominant antigens has been collected. The recommendation for two-tier testing was an attempt to standardize testing and improve specificity in the United States. First-tier assays using whole-cell sonicates of B. burgdorferi sensu lato need to be standardized in terms of antigen composition and detection threshold of specific immunoglobulin classes. The search for improved serologic tests has stimulated the development of recombinant protein antigens and the synthesis of specific peptides from immunodominant antigens. The use of these materials alone or in combination as the source of antigen in a single-tier immunoassay may someday replace the currently recommended two-tier testing strategy. Evaluation of these assays is currently being done, and there is evidence that certain of these antigens may be broadly cross-reactive with the B. burgdorferi sensu lato species causing LB in Europe.

Evaluation of different media and a BGM cell culture assay for isolation of Borrelia burgdorferi sensu lato from ticks and dogs

A co-culture assay for isolation of Borrelia burgdorferi sensu lato (sl.) from naturally infected ticks and dogs suspected of Lyme borreliosis (LB) was evaluated using buffalo-green-monkey (BGM) cells as the mammalian component. Four different media were tested for their ability to provide sufficient growth conditions for spirochetes and BGM cells. A total of 176 Ixodes ricinus ticks and 268 specimens from 98 dogs were used to compare cell-free culture with the BGM co-culture. A 1:1 mixture of Barbour-Stoenner-Kelly medium (BSK) and Eagle's minimum essential medium (EMEM) supported the growth of the two test strains, B. burgdorferi sensu stricto B31 and B. valaisiana VS116 to the same extent as BSK medium and the growth as well as the viability of BGM cells in this medium were the same as in EMEM. Using the 1:1 mixture of BSK and EMEM, borrelial growth measured in co-culture with BGM cells did not differ significantly from corresponding values obtained in cell-free cultures. In cell-free culture the isolation rate of B. burgdorferi sl. from ticks was significantly higher in BSK/EMEM 1:1 than in BSK medium (P < 0.01). Co-culture with BGM cells had no significant influence on the isolation rate of borreliae from ticks. However, a significant amount of isolates were obtained by one of the procedures only. Analysing canine specimens accordingly, spirochetes were grown from the blood of one dog after four weeks in BGM cell co-culture. The isolate was classified as B. afzelii by PCR-coupled restriction fragment length polymorphism analysis.

Modulation of Borrelia burgdorferi stringent response and gene expression during extracellular growth with tick cells

Borrelia burgdorferi N40 multiplied extracellularly when it was cocultured with tick cells in L15BS medium, a medium which by itself did not support B. burgdorferi N40 growth. Growth of B. burgdorferi N40 in the presence of tick cells was associated with decreased production of (p)ppGpp, the stringent response global regulator, a fourfold decrease in relA/spoT mRNA, an eightfold net decrease in bmpD mRNA, and a fourfold increase in rpsL-bmpD mRNA compared to growth of B. burgdorferi in BSK-H medium. As a result, the polycistronic rpsL-bmpD mRNA level increased from 3 to 100% of the total bmpD message. These observations demonstrate that there are reciprocal interactions between B. burgdorferi and tick cells in vitro and indicate that the starvation-associated stringent response mediated by (p)ppGpp present in B. burgdorferi growing in BSK-H medium is ameliorated in B. burgdorferi growing in coculture with tick cell lines. These results suggest that this system can provide a useful model for identifying genes controlling interactions of B. burgdorferi with tick cells in vitro when it is coupled with genetic methods to isolate and complement B. burgdorferi mutants.

Laboratory testing for suspected Lyme disease

Laboratory testing for B. burgdorferi infection is intended to substantiate a physician's clinical judgment of whether a patient has Lyme disease or not. Cultivation of B. burgdorferi from a patient's skin or blood is the gold standard for demonstration of active infection, but it is expensive and lacks clinical sensitivity. Detection of spirochetal DNA in clinical samples by PCR has better sensitivity, but PCR for B. burgdorferi has not yet been standardized for more routine diagnostic testing. Detection of antibodies to B. burgdorferi is the most practical and common approach for laboratory work-up of a case of suspected Lyme disease. Serologic assays fall short of 100% sensitivity and specificity, however, and examination of a single specimen in time does not discriminate between previous and ongoing infection. Because of a background false positivity even among healthy populations of nonendemic regions, serologic testing is recommended only when there is at least a one in five chance, in the physician's estimation, that the patient has active Lyme disease. The pretest likelihood of the disease is determined by the physician in the context of epidemiologic and clinical facts of the case. This estimate can serve to reassure patients who are at low risk of B. burgdorferi infection but are seeking a Lyme test for complaints of a more nonspecific nature. Although new subunit serologic assays based on recombinant proteins are becoming available commercially, the longstanding two-test approach, in which a positive or indeterminate result with a standardized, sensitive ELISA test is followed by verification with a more specific Western blot assay, still provides the physician with a reasonably accurate and reliable assessment of the presence of antibodies to B. burgdorferi. More recent challenges for serologic testing are seropositivity in the population as the result of immunization with the Lyme disease vaccine and the emergence of new Borrelia species that cause Lyme disease-like illnesses.

Lyme disease: an update

Lyme disease is a multisystem illness caused by the spirochete Borrelia burgdorferi, and it is the most common vector-borne illness in the United States. Lyme disease is also endemic in Europe and Asia. There have been major advances in the field since the disease was first described, including the sequencing of the B. burgdorferi genome; an increase in understanding of the interactions among the spirochete, the tick, and the mammalian host; new and improved laboratory tests; and a vaccine for prevention of the disease. Still, the diagnosis of Lyme disease remains based on history and clinical findings, supplemented by careful use of laboratory tests, and requires that the physician be familiar with the disease's clinical manifestations and the shortcomings of the available diagnostic tests.