Human Lyme Borreliosis Research Articles

Molecular cloning and characterization of nlpH, encoding a novel, surface-exposed, polymorphic, plasmid-encoded 33-kilodalton lipoprotein of Borrelia afzelii

Borrelia burgdorferi sensu lato organisms, comprising B. burgdorferi sensu stricto, Borrelia afzelii, and Borrelia garinii, are tick-borne pathogens causing Lyme borreliosis in humans. To identify putative virulence determinants, a B. afzelii DNA library was screened for Congo red dye binding, a property associated with virulence in pathogenic bacteria. One clone was found to carry a 663-nucleotide-long open reading frame encoding a Congo red dye-binding protein with a calculated molecular mass of 25,660 Da. The amino acid sequence deduced from its nucleotide sequence was found to include a consensus bacterial lipidation site present at residues 15 to 18 (Leu-Ser-Gly-Cys). The lipoprotein nature was demonstrated by incorporation of radioactive palmitate; hence, this protein has been termed NlpH, for new lipoprotein H. NlpH is located on the surface of B. afzelii, and the nlpH gene is found on a circular plasmid. The nlpH gene is also found in B. burgdorferi sensu stricto and B. garinii. Immediately upstream of nlpH is located a smaller reading frame encoding a polypeptide containing the casein kinase II phosphorylation recognition sequence, (Ser/Thr)-X-Y-(Glu/Asp), repeated 10 times.

Serological evidence of human granulocytic ehrlichiosis in Norway.

Human granulocytic ehriichoisis was first described in 1994. This tick-transmitted illness is increasingly recognized in the USA as well as in Europe in areas where ixodes ticks and Lyme borreliosis are endemic. Blood samples from 58 Norwegian patients with physician-diagnosed Lyme borreliosis were examined for the presence of antibodies to Ehrlichia equi, a surrogate marker of the agent of human granulocytic ehrlichiosis. The results indicated that 10.2% of the patients may have been co-infected with human granulocytic ehrlichiosis and Lyme borreliosis. Human granulocytic ehrlichiosis appears to be established in southern Norway.

A simple method of transmission risk assessment in enzootic foci of Lyme borreliosis.

The proposed method consists in examining individual host-seeking vector ticks of the Ixodes ricinus complex by microscopy for borreliae and evaluating the proportion of ticks with more than 100 borreliae. The investigations were carried out in a deciduous oak forest habitat in South Moravia, Czech Republic, over four years (1991-1994). In May (i.e., at the peak of seasonal activity of I. ricinus), about 150 nymphal and 200 adult ticks were examined each year. It was found that annual incidence of human Lyme borreliosis in the region correlated better with the proportion of heavily infected ticks than with the overall infection rate of the ticks.

Characterization of a 30-kDa Borrelia burgdorferi substrate-binding protein homologue

A Borrelia burgdorferi chromosomal gene encodes a 30-kDa antigen (P30) that has considerable homology with periplasmic substrate-binding proteins of Gram-negative bacteria, and is recognized by antibodies in sera from a subset of patients with Lyme disease and from B. burgdorferi-infected mice. The p30 gene is 801 nucleotides in length and P30 contains 267 amino acids, with predicted molecular mass of 30 kDa. The P30 amino acid region 36–258 has homology to conserved domains of the oligopeptide permease A of Gram-negative bacteria. Immunofluorescence studies using murine anti-P30 serum suggest that P30 is on the outer surface of B. burgdorferi. P30 expression could be detected in representatives of all 3 subspecies of B. burgdorferi sensu lato, but not in all of the tested strains. Antibodies to P30 were detected in sera of 18 out of 82 patients (22%) with Lyme disease, including individuals with early- or late-stage infection. Although antibodies to P30 are present in the sera of C3H/HeN mice infected with B. burgdorferi for at least 90 days, immunization with recombinant P30 does not protect mice from infection. We conclude that P30 is a putative substrate-binding protein of B. burgdorferi and is immunologically recognized in human and murine Lyme borreliosis.

9 長野県の人体マダニ咬症とライム病

9 長野県の人体マダニ咬症とライム病

Acquisition of Borrelia burgdorferi by Ixodes ricinus ticks fed on the European hedgehog, Erinaceus europaeus L

A hedgehog, Erinaceus europaeus, was found to be heavily infested with larval and nymphal Ixodes ricinus in a forest park in Co. Galway, Ireland. A large proportion of the ticks that engorged and detached were infected with the spirochaete, Borrelia burgdorferi, the causative agent of human Lyme borreliosis. The identity of these spirochaetes was confirmed by immunofluorescent assay with B. burgdorferi-specific monoclonal antibody and by polymerase chain reaction test and they were transmitted from the hedgehog to laboratory-reared ticks and from the ticks obtained from the hedgehog to gerbils (Meriones unguiculatus). The high infection rate of the larvae that fed on the hedgehog in comparison with unfed larvae from the same habitat was interpreted as strong evidence that this host species is reservoir competent. Since hedgehogs can evidently feed adult ticks as well as many immature stages, they may well have an important role in the ecology of Lyme borreliosis in some habitats.

Variability of a bacterial surface protein and disease expression in a possible mouse model of systemic Lyme borreliosis.

During persistent infection of scid mice with Borrelia turicatae, an agent of relapsing fever and neuroborreliosis, there was variation in the surface proteins the bacteria expressed and in disease manifestations over time. Two serotypes, A and B, were isolated from the mice, cloned by limiting dilution, and further characterized. The only discernible difference between the two variants was in the size of the major surface protein they expressed: serotype A had a variable major protein (Vmp) of 23,000, and serotype B had a Vmp of 20,000. When other scid mice were inoculated with clonal populations of A and B, the infections were similar with respect to onset and degree of spirochetemia, involvement of the eye and heart, and occurrence of a peripheral vestibular disorder. However, there were differences between the serotypes in other respects: (a) serotype B but not A caused reddened and significantly enlarged joints, markedly impaired performance on a walking bar, and severe arthritis by histologic examination; (b) serotype A but not B invaded the central nervous system during early infection; and (c) serotype A penetrated monolayers of human umbilical vein endothelial cells more readily than did serotype B. The combination of arthritis, myocarditis, and neurologic disease resembled human Lyme borreliosis. The findings indicate that differences in disease expression are determined by variable surface proteins of the bacterium and that scid mouse infections with B. turicatae provide a model for the study of the pathogenesis of Lyme borreliosis and other persistent spirochetal diseases.

Facial palsy and infection: the unfolding story.

While it is now universally accepted that Ramsay Hunt syndrome is caused by varicella-zoster virus, Bell's palsy continues to be labeled "idiopathic." We review the literature associating Bell's palsy with various infectious agents as well as with Kawasaki disease, a condition in which an infectious etiology is suspected. Good evidence--mostly serological--exists for an etiologic role for the herpes group of viruses, mumps virus, and rubella virus. In addition, recent evidence has focused on Bell's palsy in human immunodeficiency virus infection and Lyme borreliosis. In view of the multiplicity of implicated agents, it is likely that the immunologic response associated with infection triggers a cranial or generalized polyneuropathy culminating in facial nerve compression, degeneration, and paralysis. The mounting interest in Bell's palsy, coupled with the increasing availability of more sensitive and specific tests, is likely to augment the available evidence for an infectious etiology and to clarify the role of other, previously unsuspected infectious agents.

Reactivity of human Lyme borreliosis sera with a 39-kilodalton antigen specific to Borrelia burgdorferi

Borrelia burgdorferi is the causative agent of Lyme borreliosis, a spirochetal illness with a variety of acute clinical manifestations that may lead to debilitating neurological and arthritic complications. Diagnosis is difficult because symptoms mimic a variety of unrelated clinical conditions, spirochetes cannot always be isolated from infected patients, and current serological tests are frequently inconclusive because of the presence of cross-reacting non-B. burgdorferi antibodies. To identify antigens specific to B. burgdorferi that could be used in the serodiagnosis of Lyme borreliosis, we screened a Borrelia DNA expression library in Escherichia coli for antigens reactive with human Lyme borreliosis sera. One clone carried a 6.3-kilobase EcoRI chromosomal fragment (pSPR33), which encoded two species-specific antigens with molecular masses of 28 (P28) and 39 (P39) kilodaltons (kDa). These two antigens were immunologically distinct from OspA, OspB, and the 41-kDa flagellin. Ninety-four serum specimens from patients having Lyme borreliosis were tested for reactivity with P39. All of 33 the serum specimens with immunofluorescence assay titers of greater than or equal to 1:256, 13 of 17 serum specimens with titers of 1:128, and 14 of 44 serum specimens with titers of less than or equal to 1:64 reacted with P39. Notably, many sera reactive to P39 did not appear to react with the 41-kDa flagellin. Therefore, antibody to P39 could be mistaken for antibody to the 41-kDa flagellin in tests of human sera by Western blot (immunoblot). Twenty-five control serum specimens, which included sera from syphilitic, relapsing fever, and amyotrophic lateral sclerosis patients as well as from 10 normal individuals, did not react to P39. Our data suggest that P39 may be a useful antigen for the serological confirmation of Lyme borreliosis.

Histopathology of Clinical Phases of Human Lyme Disease

Acute, subacute, or chronic persistent human Lyme borreliosis is an inflammatory disorder composed pathologically of lymphocytes, plasma cells, macrophages, and mast cells. The lymphoplasmocellular infiltrates can at times be seen in the skin, subcutaneous tissues, lymph nodes, spleen, liver, myocardium, brain, autonomic ganglia, and peripheral nerves. The joints in arthritic cases have proliferative synovitis, fibrinaceous deposits, lymphoplasmocellular aggregates, and mast cells. Varying degrees of vascular damage does occur in these sites; however, usually only in late, chronic disease. Spirochetes are present in most sites, in an extracellular location, but are sparse.