Antimicrobial action of calprotectin that does not involve metal withholding.

Calprotectin is a potent antimicrobial that inhibits the growth of pathogens by tightly binding transition metals such as Mn and Zn, thereby preventing their uptake and utilization by invading microbes. At sites of infection, calprotectin is abundantly released from neutrophils, but calprotectin is also present in non-neutrophil cell types that may be relevant to infections. We show here that in patients infected with the Lyme disease pathogen Borreliella (Borrelia) burgdorferi, calprotectin is produced in neutrophil-free regions of the skin, in both epidermal keratinocytes and in immune cells infiltrating the dermis, including CD68 positive macrophages. In culture, B. burgdorferi's growth is inhibited by calprotectin, but surprisingly, the mechanism does not involve the classical withholding of metal nutrients. B. burgdorferi cells exposed to calprotectin cease growth with no reduction in intracellular Mn and no loss in activity of Mn enzymes including the SodA superoxide dismutase. Additionally, there is no obvious loss in intracellular Zn. Rather than metal depletion, we find that calprotectin inhibits B. burgdorferi growth through a mechanism that requires physical association of calprotectin with the bacteria. By comparison, calprotectin inhibited E. coli growth without physically interacting with the microbe, and calprotectin effectively depleted E. coli of intracellular Mn and Zn. Our studies with B. burgdorferi demonstrate that the antimicrobial capacity of calprotectin is complex and extends well beyond simple withholding of metal micronutrients.

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.

Evidence assessments and guideline recommendations in Lyme disease: the clinical management of known tick bites, erythema migrans rashes and persistent disease.

Evidence-based guidelines for the management of patients with Lyme disease were developed by the International Lyme and Associated Diseases Society (ILADS). The guidelines address three clinical questions - the usefulness of antibiotic prophylaxis for known tick bites, the effectiveness of erythema migrans treatment and the role of antibiotic retreatment in patients with persistent manifestations of Lyme disease. Healthcare providers who evaluate and manage patients with Lyme disease are the intended users of the new ILADS guidelines, which replace those issued in 2004 (Exp Rev Anti-infect Ther 2004;2:S1-13). These clinical practice guidelines are intended to assist clinicians by presenting evidence-based treatment recommendations, which follow the Grading of Recommendations Assessment, Development and Evaluation system. ILADS guidelines are not intended to be the sole source of guidance in managing Lyme disease and they should not be viewed as a substitute for clinical judgment nor used to establish treatment protocols.

Xenodiagnosis to detect Borrelia burgdorferi infection: a first-in-human study.

BACKGROUND: Animal studies suggest that Borrelia burgdorferi, the agent of Lyme disease, may persist after antibiotic therapy and can be detected by various means including xenodiagnosis using the natural tick vector (Ixodes scapularis). No convincing evidence exists for the persistence of viable spirochetes after recommended courses of antibiotic therapy in humans. We determined the safety of using I. scapularis larvae for the xenodiagnosis of B. burgdorferi infection in humans. METHODS: Laboratory-reared larval I. scapularis ticks were placed on 36 subjects and allowed to feed to repletion. Ticks were tested for B. burgdorferi by polymerase chain reaction (PCR), culture, and/or isothermal amplification followed by PCR and electrospray ionization mass spectroscopy. In addition, attempts were made to infect immunodeficient mice by tick bite or inoculation of tick contents. Xenodiagnosis was repeated in 7 individuals. RESULTS: Xenodiagnosis was well tolerated with no severe adverse events. The most common adverse event was mild itching at the tick attachment site. Xenodiagnosis was negative in 16 patients with posttreatment Lyme disease syndrome (PTLDS) and/or high C6 antibody levels and in 5 patients after completing antibiotic therapy for erythema migrans. Xenodiagnosis was positive for B. burgdorferi DNA in a patient with erythema migrans early during therapy and in a patient with PTLDS. There is insufficient evidence, however, to conclude that viable spirochetes were present in either patient. CONCLUSIONS: Xenodiagnosis using Ixodes scapularis larvae was safe and well tolerated. Further studies are needed to determine the sensitivity of xenodiagnosis in patients with Lyme disease and the significance of a positive result. Clinical Trials Registration NCT01143558.

Co-infection of Borrelia burgdorferi sensu lato and Rickettsia species in ticks and in an erythema migrans patient.

BACKGROUND: Lyme borreliosis is the most prevalent tick-borne disease in Europe. Ixodes ricinus also carries other pathogenic bacteria, but corresponding human diseases are rarely reported. Here, we compared the exposure to Rickettsia helvetica and Rickettsia monacensis with that to Lyme borreliosis spirochetes. We assumed that their exposure corresponds to their infection rate in questing I. ricinus. FINDINGS: Three Rickettsia species were detected in ticks with a total prevalence of 7.9%, of which the majority was R. helvetica (78%) and R. monacensis (21%). From the same geographic area, skin biopsies of erythema migrans patients were investigated for possible co-infections with Rickettsia spp.. Forty-seven out of 67 skin biopsies were PCR positive for Borrelia burgdorferi s.l. and one sample was positive for R. monacensis. The Borrelia genospecies from the R. monacensis positive patient was identified as Borrelia afzelii. The patient did not show any symptoms associated with rickettsiosis. CONCLUSIONS: Co-infections of I. ricinus with Rickettsia spp. and B. burgdorferi s.l. were as high as expected from the individual prevalence of both pathogens. Co-infection rate in erythema migrans patients corresponded well with tick infection rates. To our knowledge, this is the first reported co-infection of B. afzelii and R. monacensis.

Lyme borreliosis: an update for Canadian dermatologists.

BACKGROUND: Lyme borreliosis is a multisystemic tick-borne spirochetosis, which may result in dermatologic, musculoskeletal, cardiovascular, and neurologic manifestations. OBJECTIVE: Patients with suspected acute Lyme borreliosis infection may be referred for urgent dermatologic review. Canadian dermatologists should be aware of the latest information regarding the diagnosis and management of Lyme borreliosis. METHODS: This review is based on a PubMed database search combining the word "Lyme" with variations of the word "Canada." Data sources included articles from the fields of ecology, epidemiology, laboratory diagnostics, and clinical management. CONCLUSION: In this review, the ecological basis of spirochete transmission by tick vectors is described. The latest available Canadian epidemiologic data are summarized. North American clinical manifestations of Lyme borreliosis are contrasted with European presentations. The Canadian Public Health Laboratory Network's diagnostic guidelines are summarized. Finally, treatment recommendations are outlined.

Clinical characteristics associated with Borrelia burgdorferi sensu lato skin culture results in patients with erythema migrans.

Clinical characteristics associated with isolation of Borrelia burgdorferi sensu lato from skin have not been fully evaluated. To gain insight into predictors for a positive EM skin culture, we compared basic demographic, epidemiologic, and clinical data in 608 culture-proven and 501 culture-negative adult patients with solitary EM. A positive Borrelia spp. skin culture was associated with older age, a time interval of >2 days between tick bite and onset of the skin lesion, EM ≥ 5 cm in diameter, and location of the lesion on the extremities, whereas several other characteristics used as clinical case definition criteria for the diagnosis of EM (such as tick bite at the site of later EM, information on expansion of the skin lesion, central clearing) were not. A patient with a 15-cm EM lesion had almost 3-fold greater odds for a positive skin culture than patients with a 5-cm lesion. Patients with a free time interval between the tick bite and onset of EM had the same probability of a positive skin culture as those who did not recall a tick bite (OR=1.02); however, the two groups had >3-fold greater odds for EM positivity than patients who reported a tick bite with no interval between the bite and onset of the lesion. In conclusion, several yet not all clinical characteristics used in EM case definitions were associated with positive Borrelia spp. skin culture. The findings are limited to European patients with solitary EM caused predominantly by B. afzelii but may not be valid for other situations.

Lyme disease and human granulocytic anaplasmosis coinfection: impact of case definition on coinfection rates and illness severity.

BACKGROUND: Lyme disease is transmitted by the bite of the Ixodes scapularis tick, which can also transmit Anaplasma phagocytophilum, the cause of human granulocytic anaplasmosis (HGA). Conflicting data exist on the frequency of coinfection and on whether Lyme-HGA coinfected patients have more symptoms than patients with Lyme disease alone. METHODS: Blood culture and serology were used to detect HGA infection in patients with early Lyme disease who presented with erythema migrans. The rate of coinfection was determined using different definitions. The clinical and laboratory features of Lyme-HGA coinfection were compared with that of the individual infections. RESULTS: Among 311 patients with erythema migrans, the frequency of coinfection with HGA varied from 2.3% to 10.0%, depending on the definition used (P < .001). Only 1 of 4 groups with presumed coinfection had significantly more symptoms than patients with Lyme disease alone P < .05. High fever and cytopenia were less common in Lyme-HGA coinfection than in patients with HGA alone. CONCLUSION: The results of this study indicate that how HGA is defined in patients with early Lyme disease has an impact on the apparent rate of coinfection and the severity of illness. The findings also suggest that HGA may be less severe than is usually believed, suggesting the existence of referral bias in testing patients preferentially who present with high fever or cytopenia.

Neutrophil extracellular traps entrap and kill Borrelia burgdorferi sensu stricto spirochetes and are not affected by Ixodes ricinus tick saliva.

Lyme disease is caused by spirochetes of the Borrelia burgdorferi sensu lato complex. They are transmitted mainly by Ixodes ricinus ticks. After a few hours of infestation, neutrophils massively infiltrate the bite site. They can kill Borrelia via phagocytosis, oxidative burst, and hydrolytic enzymes. However, factors in tick saliva promote propagation of the bacteria in the host even in the presence of a large number of neutrophils. The neutrophil extracellular trap (NET) consists in the extrusion of the neutrophil's own DNA, forming traps that can retain and kill bacteria. The production of reactive oxygen species is apparently associated with the onset of NETs (NETosis). In this article, we describe NET formation at the tick bite site in vivo in mice. We show that Borrelia burgdorferi sensu stricto spirochetes become trapped and killed by NETs in humans and that the bacteria do not seem to release significant nucleases to evade this process. Saliva from I. ricinus did not affect NET formation by human neutrophils or its stability. However, it greatly decreased neutrophil reactive oxygen species production, suggesting that a strong decrease of hydrogen peroxide does not affect NET formation. Finally, round bodies trapped in NETs were observed, some of them staining as live bacteria. This observation could help contribute to a better understanding of the early steps of Borrelia invasion and erythema migrans formation after tick bite.

Associations of HLA DR and DQ molecules with Lyme borreliosis in Latvian patients.

BACKGROUND: Many autoimmune diseases are associated with variants of HLA genes such as those encoding the MHC complex. This correlation is not absolute, but may help in understanding of the molecular mechanism of disease. The purpose of this study was to determine HLA-DR,-DQ alleles in Latvian patients with Lyme borreliosis and control (healthy) persons. Case patients and control subjects were similar in age, gender and ethnic heritage and differed only as regards the presence of Borrelia burgdorferi infection. The study included 25 patients with clinical stage - erythema migrans and 30 control (healthy) persons. HLA genotyping was performed by PCR with sequence-specific primers. RESULTS: The results show difference in HLA-DRB1 alleles distribution between patients and control subjects. The frequencies of HLA-DRB1 *04 (OR 11.24; p < 0.007) and HLA-DRB1 *17 (03) (OR 8.05; p < 0.033) were increased in the Lyme disease patients. And the frequency of allele DRB1*13 (OR 0.12; p < 0.017) was lower in Borreliosis patients and higher in control group. But, significant differences in frequencies of HLA-DQ alleles we did not detect. CONCLUSIONS: HLA predisposition to Lyme borreliosis appears not to be limited to HLA molecules, but some HLA-DR alleles also have a significant influence, and, may have implications in our understanding of pathogenesis of this disease. In particular, HLA-DRB1*04 and DRB1 *17 (03) may contribute to the Lyme borreliosis development in Latvian population.

Direct molecular detection and genotyping of Borrelia burgdorferi from whole blood of patients with early Lyme disease.

Direct molecular tests in blood for early Lyme disease can be insensitive due to low amount of circulating Borrelia burgdorferi DNA. To address this challenge, we have developed a sensitive strategy to both detect and genotype B. burgdorferi directly from whole blood collected during the initial patient visit. This strategy improved sensitivity by employing 1.25 mL of whole blood, a novel pre-enrichment of the entire specimen extract for Borrelia DNA prior to a multi-locus PCR and electrospray ionization mass spectrometry detection assay. We evaluated the assay on blood collected at the initial presentation from 21 endemic area patients who had both physician-diagnosed erythema migrans (EM) and positive two-tiered serology either at the initial visit or at a follow-up visit after three weeks of antibiotic therapy. Results of this DNA analysis showed detection of B. burgdorferi in 13 of 21 patients (62%). In most cases the new assay also provided the B. burgdorferi genotype. The combined results of our direct detection assay with initial physician visit serology resulted in the detection of early Lyme disease in 19 of 21 (90%) of patients at the initial visit. In 5 of 21 cases we demonstrate the ability to detect B. burgdorferi in early Lyme disease directly from whole blood specimens prior to seroconversion.

Quantitation of cell-associated borrelial DNA in the blood of Lyme disease patients with erythema migrans.

Bloodstream invasion is an important event in the pathogenesis of the more serious manifestations of Lyme disease. The number of spirochetes in the blood of infected patients, however, has not been determined, and, therefore, it is unknown whether the number of spirochetes can be correlated with particular clinical or laboratory features. This study was designed to measure the level of Borrelia burgdorferi in the plasma of Lyme disease patients and correlate these levels with selected clinical and laboratory findings. Nested and quantitative polymerase chain reaction (qPCR) was employed to detect cell-associated flaB gene DNA in the plasma of untreated early Lyme disease patients with erythema migrans (EM). Twenty-nine (45.3%) of 64 patients had evidence of B. burgdorferi in their plasma by at least one of the PCR methods. For the 22 qPCR-positive patients, the mean number of flaB gene copies per mL of plasma was 4,660, with a range of 414 to 56,000. The number of flaB gene copies did not significantly correlate with any of the clinical, demographic, or laboratory variables assessed. For reasons discussed, we suggest caution in extrapolating an estimate of the number of viable Borrelia in plasma from the observed number of flaB copies.

Pregnant women with erythema migrans and isolation of borreliae from blood: course and outcome after treatment with ceftriaxone.

The course and outcome in 7 pregnant European women with erythema migrans and borreliae isolated from blood, treated with intravenous ceftriaxone for 14 days, were uneventful, and the outcome of their pregnancies was good. Spirochetemia was not associated with constitutional symptoms.

Prospective study on the incidence of infection by Borrelia burgdorferi sensu lato after a tick bite in a highly endemic area of Switzerland.

The periurban forest of Neuchâtel (Switzerland) is a high-risk area for Lyme Borreliosis, due to a high density of infected Ixodes ricinus ticks. In this study, we evaluated the risk of subclinical (seroconversion) and clinical infection after a tick bite in Neuchâtel inhabitants from 2003 to 2005. Inhabitants have been invited, through media, to visit a physician after a tick bite. A questionnaire was filled out and two blood samples were taken at 8-week interval. EIA screening tests for IgM and IgG (IMX system, Abbott) were applied for paired sera. In case of a change in antibody titres between both samples, a homemade Western-blot using Borrelia afzelii, B. burgdorferi sensu stricto and B. garinii as antigens was performed. Participants were included into two groups. Group one included asymptomatic participants (n=255). Among them, nine (3.5%) seroconverted with seroconversion rates varying between 6.8% in 2003, 2.1% in 2004 and 2.3% in 2005. Participants who developed clinical symptoms of LB were included into group two (n=14). Erythema migrans (EM) was reported in 5.2% of participants (5.2%), varying between 7.5% in 2003, 5% in 2004 and 3.4% in 2005. Ticks obtained from 186 participants were examined for B. burgdorferi infection by PCR/Reverse Line Blotting, and by Real Time PCR and tick attachment duration was estimated. Among I. ricinus ticks collected from participants, 32.8% were infected by B. burgdorferi sensu lato. B. afzelii predominated among these ticks. Globally, 65.9% of nymphs remained attached for more than 24h whereas only 38.3% of female ticks remained attached for more than 24h. We observed that 6.6% and 2.4% of participants bitten by infected and uninfected ticks, respectively, developed EM.

Borrelia burgdorferi sensu lato bacteremia in Slovenian children with solitary and multiple erythema migrans.

To establish the frequency and characteristics of Borrelia burgdorferi sensu lato bacteremia in Slovenian children with solitary and multiple erythema migrans, 1164 patients were included in this prospective study. Bacteremia was established in 11.4% of all patients, 15.8% of patients with multiple erythema migrans, and in 7.6% of patients with solitary erythema migrans. Bacteremia can be detected in children, with untreated erythema migrans, up to 39 days after the onset of skin rash.

Comparison of erythema migrans caused by Borrelia burgdorferi and Borrelia garinii.

BACKGROUND: A comparison of patients with erythema migrans due to Borrelia garinii versus Borrelia burgdorferi has not been reported. PATIENTS AND METHODS: One hundred nineteen patients from New York State with erythema migrans caused by B. burgdorferi were compared with 116 patients from Slovenia with erythema migrans due to B. garinii infection. RESULTS: Patients with B. garinii infection were older, more often reported a tick bite, and developed larger lesions (median largest diameter: 18 and 14 cm, respectively; p = 0.01) that more often had central clearing (61.2% compared with 35.3%; p < 0.0001). Patients infected with B. burgdorferi, however, more often had systemic symptoms (68.9% vs. 37.1%; p < 0.0001), including fatigue (p < 0.0001), arthralgia (p = 0.0003), myalgia (p < 0.0001), headache (p = 0.0008), fever and/or chills (p < 0.0001), and stiff neck (p < 0.0001), and more often had abnormal physical findings (57.1% compared with 11.2%; p < 0.0001), such as fever (p = 0.0002) or regional lymphadenopathy (p < 0.0001). There was a trend for more patients with B. burgdorferi infection to have multiple erythema migrans skin lesions (13.4% compared with 5.2%; p = 0.051), and among patients with multiple erythema migrans the number of lesions was greater in B. burgdorferi-infected patients (median: 5.5 compared with 2.0; p = 0.006). CONCLUSIONS: The results of the present study indicate that in patients with erythema migrans the clinical features vary according to whether infection is caused by B. garinii or B. burgdorferi.

Burden and viability of Borrelia burgdorferi in skin and joints of patients with erythema migrans or lyme arthritis.

OBJECTIVE: To determine the burden and viability of Borrelia burgdorferi in the skin and joints of patients with Lyme disease. METHODS: Standard and quantitative polymerase chain reaction (PCR) techniques were used to detect B burgdorferi DNA in skin samples from 90 patients with erythema migrans (EM) and in synovial fluid (SF) from 63 patients with Lyme arthritis (LA) and in synovial tissue from 9 patients. Quantitative PCR determinations of B burgdorferi DNA, messenger RNA (mRNA), and ribosomal RNA (rRNA) were made in 10 skin samples from EM patients and 11 SF samples from LA patients. RESULTS: Skin lesions in most patients with EM had positive PCR results for B burgdorferi DNA. In the majority of patients with LA, a late disease manifestation, PCR results in pretreatment SF samples were positive. In patients with antibiotic-refractory arthritis, positive PCR results persisted for as long as 11 months, but positive results in samples taken during the postantibiotic period did not correlate with relapse or with the subsequent duration of arthritis, and at synovectomy, all results of PCR of synovial tissue were negative. B burgdorferi mRNA, a marker of spirochetal viability, was detected in 8 of 10 skin samples from EM patients, but in none of 11 SF samples from LA patients, even when obtained prior to antibiotic administration. Moreover, the median ratio of spirochetal rRNA to DNA, a measure of ribosomal activity, was 160 in the 10 EM skin samples, but only 0.15 in the 3 LA SF samples with positive results. CONCLUSION: B burgdorferi in the skin lesions of EM patients were active and viable, whereas those in the SF of LA patients were moribund or dead at any time point. Thus, detection of B burgdorferi DNA in SF is not a reliable test of active joint infection in Lyme disease.

Comparison of post-Lyme Borreliosis symptoms in erythema migrans patients with positive and negative Borrelia burgdorferi sensu lato skin culture.

PURPOSE: Limited data exist on differences of erythema migrans patients with either positive or negative Borrelia burgdorferi sensu lato skin culture. METHODS: We analyzed 252 adult patients with erythema migrans in whom skin biopsy specimen was cultured for the presence of B. burgdorferi sensu lato. Evaluations of epidemiological, clinical, and microbiological findings were conducted at baseline, 14 days, 2, 6, and 12 months after treatment with either doxycycline or cefuroxime axetil. RESULTS: One hundred fifty-one (59.9%) patients had positive skin culture (86.9% B. afzelii, 8.0% B. garinii, 5.1% B. burgdorferi sensu stricto) and 101 (40.1%) had negative skin culture. Patients in the culture-positive and culture-negative groups were comparable for the basic demographic, epidemiological, clinical, and laboratory characteristics at presentation. Statistically significantly worse selected treatment outcome parameters in the culture-positive group compared with the culture-negative group were established during follow-up. Treatment failure was documented in two patients who were culture positive and in none in the culture-negative group. CONCLUSIONS: Although findings for the pretreatment characteristics were comparable between the erythema migrans skin culture-positive and culture-negative patients, some parameters indicate that borrelia skin culture positivity may predict a less-favorable treatment outcome.

Expression and sequence diversity of the complement regulating outer surface protein E in Borrelia afzelii vs. Borrelia garinii in patients with erythema migrans or neuroborreliosis.

Outer surface protein E (OspE) is a complement factor H-binding virulence factor of borrelial subspecies. It is usually absent from in vitro grown Borrelia garinii, although in vivo B. garinii causes neuroborreliosis (NB). We analyzed the presence and sequence spectrum of the ospE genes in vivo in Borrelia spirochetes. DNA samples from the skin, serum and cerebrospinal fluid (CSF) of patients with infections caused by Borrelia afzelii or B. garinii were studied, and anti-OspE antibodies in the corresponding patient sera were detected by IgG ELISA using recombinant OspE as an antigen. ospE genes were found in 20 of 23 erythema migrans (EM) skin biopsies with B. afzelii, in 2 EM skin biopsies with unknown underlying subspecies, in 5 of 9 EM biopsies with B. garinii, and in 1 of 4 CSF samples of NB patients with B. garinii infection. All OspE sequences from B. garinii samples were identical. In contrast, OspE of B. afzelii origin showed more variation. Anti-OspE antibodies were found in 8/21 (38.0%) sera from patients with B. afzelii-associated EM. In conclusion, our results indicate that all borrelial subspecies, but not necessarily all strains, causing human infections can carry ospE genes to protect themselves against complement attack in vivo.