Borrelia burgdorferi

Abstract: Borrelia burgdorferi is difficult to detect in routine biopsy material from patients with skin lesions of borreliosis. In this study, a new immunohistochemical method, focus floating microscopy (FFM), was developed to detect B burgdorferi in tissue sections and was compared with polymerase chain reaction (PCR). By using standard histologic equipment, tissue sections stained with a polyclonal B burgdorferi antibody were simultaneously scanned through 2 planes: horizontally in serpentines and vertically by focusing through the thickness of the section. Borrelia were detected in 47 of 71 ticks, 34 of 66 tick bites, 30 of 32 erythema chronicum migrans cases, 41 of 43 borrelial lymphocytomas, and 50 of 51 acrodermatitis chronica atrophicans cases. FFM proved to be more sensitive than PCR (96.0% vs 45.2%) and nearly equally specific (99.4% vs 100%). All 169 control cases, except 1 false-positive case of secondary syphilis, were negative with FFM. FFM is an easy, quick, and inexpensive method to reliably detect Borrelia in cutaneous tissue sections.

Abstract: We compared epidemiological and clinical characteristics of patients with erythema migrans (EM) caused by Borrelia afzelii and Borrelia garinii 200 consecutive adult patients with B afzelii isolated from the skin lesion and 53 consecutive adult patients with EM caused by B garinii qualified for the present study Comparison of the two groups revealed several distinctions Patients with EM caused by B garinii were older, had their skin lesions more often located on the trunk but less often on extremities, had shorter incubation and faster evolution of EM, more often reported associated local and certain systemic symptoms, had abnormal liver function test results more often and were more frequently seropositive Early localized Lyme borreliosis caused by B afzelii and B garinii has distinct epidemiological and clinical characteristics Clinical features of EM depend upon the genospecies of Borrelia burgdorferi sensu lato causing the illness

Abstract: Borrelia burgdorferi has developed efficient mechanisms for evading the innate immune response during mammalian infection and has been shown to be resistant to the complement-mediated bactericidal activity of human serum. It is well recognized that B. burgdorferi expresses multiple lipoproteins on its surface that bind the human complement inhibitors factor H and factor H-like protein 1 (FH/FHL-1). The binding of FH/FHL-1 on the surface of B. burgdorferi is thought to enhance its ability to evade serum-mediated killing during the acute phase of infection. One of the key B. burgdorferi FH/FHL-1 binding proteins identified thus far was designated CspA. While it is known that CspA binds FH/FHL-1, it is unclear how the interaction between CspA and FH/FHL-1 specifically enhances serum resistance. To better understand how CspA mediates serum resistance in B. burgdorferi, we inactivated cspA in a virulent strain of B. burgdorferi. An affinity ligand blot immunoassay and indirect immunofluorescence revealed that the CspA mutant does not efficiently bind human FH to its surface. Consistent with the lack of FH binding, the CspA mutant was also highly sensitive to killing by human serum. Additionally, the deposition of complement components C3, C6, and C5b-9 was enhanced on the surface of the CspA mutant compared to that of the wild-type strain. The combined data lead us to conclude that the CspA-mediated binding of human FH confers serum resistance by directly inhibiting complement deposition on the surface of B. burgdorferi.

Abstract: Lyme disease recently has been recognized in Wisconsin. Trapping studies were conducted at four geographically separate and ecologically distinct regions in Wisconsin to elucidate the distribution and host preferences of Ixodes dammini on small and medium sized mammals, and the occurrence of antibodies to Borrelia burgdorferi in these wild mammals. Peak I. dammini larval activity occurred from June–September. Nymphs were most active from May–August. White-footed mice (Peromyscus leucopus) and chipmunks (Tamias striatus) were important hosts for immature ticks. Mean numbers of I. dammini per mouse were highest in regions of high prevalence of Lyme disease. Antibody to B. burgdorferi was detected in sera of 60/371 (16%) white-footed mice, 5/104 (5%) chipmunks, 3/5 (60%) gray squirrels (Sciurus carolinensis), 0/8 raccoons (Procyon lotor), and 0/12 opossum (Didelphis virginiana); antibody prevalence correlated positively with I. dammini occurrence, and seropositive animals were not detected in areas where I. dammini were not found. Two of 15 recaptured P. leucopus had ≥4-fold changes in antibody titer. B. burgdorferi was cultured from blood of a P. leucopus captured in west-central Wisconsin, and was observed by direct immunofluorescence in 9/23 (39%) I. dammini nymphs. In Wisconsin, I. dammini has increased in numbers and has significantly expanded its range since its first recognition in 1968.