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Category: Clinical Microbiology
Borrelia * , Page 1 of 2
< Previous page | Next page > /docserver/preview/fulltext/10.1128/9781555816728/9781555814632_Chap56-1.gif /docserver/preview/fulltext/10.1128/9781555816728/9781555814632_Chap56-2.gifAbstract:
Borreliosis, in the form of louse-borne relapsing fever (LBRF), has been the cause of massive epidemics as recently as the early 1900s. Tick-borne relapsing fever (TBRF) and Lyme borreliosis (LB) are caused by over a dozen Borrelia species and were first described about 100 years ago. There is a high prevalence of B.afzelii among human skin isolates from Europe, whereas isolates from cerebrospinal fluid (CSF) in Europe are most often B.garinii. A few studies have reported the detection of Borrelia species (B.valaisiana, B.spielmanii, and B. lusitaniae) in patient samples in Europe. The genomes of the borreliae are unusual among prokaryotes in having a small linear chromosome of approximately 1,000 kb and both linear and circular plasmids. Two colinear plasmids (lp54 and cp26) seem to belong to the basic genome inventory of the Borrelia species that causes Lyme disease. The ecological components that maintain Borrelia species in nature are quite diverse and are spread throughout the world. This chapter talks about collection, transport, and storage of specimens. Direct microscopic visualization of borreliae in clinical samples is applicable only to cases of relapsing fever. The chapter describes molecular techniques and immunological techniques for identifying Borrelia species, and explains about the serologic test. The antimicrobial susceptibility of Borrelia species has been studied intensively in vitro. Standard methods for the determination of the minimal bactericidal concentration have not been established. Clinical criteria (case history and clinical findings) are decisive factors in the diagnosis and ordering of microbiological laboratory testing.
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Two genera of ticks are vectors for relapsing fever and LB: Ornithodoros (a) and Ixodes (b).
Two genera of ticks are vectors for relapsing fever and LB: Ornithodoros (a) and Ixodes (b).
Scanning electron micrograph of B. burgdorferi (provided by Gerhard Wanner, Munich, Germany).
Scanning electron micrograph of B. burgdorferi (provided by Gerhard Wanner, Munich, Germany).
Borrelia spirochetes. (A) B. hermsii in a thin smear of patient blood (bright-field microscopy, Giemsa stain); (B) B. burgdorferi culture (dark-field microscopy).
Borrelia spirochetes. (A) B. hermsii in a thin smear of patient blood (bright-field microscopy, Giemsa stain); (B) B. burgdorferi culture (dark-field microscopy).
Two-step approach for serodiagnosis.
Two-step approach for serodiagnosis.
Whole-cell immunoblot for identification of diagnostic bands with MAbs. The antigen used is B. afzelii strain PKo. Lanes: G, IgG blot from a patient with late disease; M, IgM blot from a patient with early disease; 1 to 11, different MAbs against the respective reactive proteins. (Modified from reference 53. )
Whole-cell immunoblot for identification of diagnostic bands with MAbs. The antigen used is B. afzelii strain PKo. Lanes: G, IgG blot from a patient with late disease; M, IgM blot from a patient with early disease; 1 to 11, different MAbs against the respective reactive proteins. (Modified from reference 53. )
Characteristics of arthropod-borne borreliae a
a Modified from reference 132 .
Characteristics of arthropod-borne borreliae a
a Modified from reference 132 .
Distribution of species of B. burgdorferi sensu lato in European isolates from CSF, skin, and synovial fluid specimens a
a Data from references 38 , 104 , and 119 .
b B. burgdorferi sensu lato species identifications from CSF and skin are based on culture; species identification from synovial fluid samples is based on ospA PCR results. Culture isolates from synovial fluid are too few to estimate Borrelia species distribution.
Distribution of species of B. burgdorferi sensu lato in European isolates from CSF, skin, and synovial fluid specimens a
a Data from references 38 , 104 , and 119 .
b B. burgdorferi sensu lato species identifications from CSF and skin are based on culture; species identification from synovial fluid samples is based on ospA PCR results. Culture isolates from synovial fluid are too few to estimate Borrelia species distribution.
Specimen types used for the diagnosis of LB
a From the same day for AI determination.
Specimen types used for the diagnosis of LB
a From the same day for AI determination.
Sensitivity of methods for pathogen detection (PCR and culture) in LB
a Up to 50% in patients with disease duration of less than 2 weeks compared with only 13% in patients for whom the illness duration was greater than 2 weeks.
b Higher sensitivity of direct pathogen detection from synovial biopsy specimen.
Sensitivity of methods for pathogen detection (PCR and culture) in LB
a Up to 50% in patients with disease duration of less than 2 weeks compared with only 13% in patients for whom the illness duration was greater than 2 weeks.
b Higher sensitivity of direct pathogen detection from synovial biopsy specimen.
Sensitivity of antibody detection methods in the diagnosis of Lyme disease
a Negative only for patients with a very short duration of symptoms.
Sensitivity of antibody detection methods in the diagnosis of Lyme disease
a Negative only for patients with a very short duration of symptoms.