Open AccessMolecular Subtyping of Treponema pallidum subsp. pallidum in Lisbon, Portugal
Author(s) -
Rogério de Castro,
E. Prieto,
Maria João Águas,
Maria José Manata,
J Botas,
Filomena Pereira
Publication year - 2009
Publication title -
journal of clinical microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.349
H-Index - 255
eISSN - 1070-633X
pISSN - 0095-1137
DOI - 10.1128/jcm.00287-08
Subject(s) - subtyping , treponema , syphilis , biology , typing , polymerase chain reaction , microbiology and biotechnology , sexually transmitted disease , virology , gene , pathology , genetics , medicine , human immunodeficiency virus (hiv) , computer science , programming language
The objectives of this study were to evaluate the reproducibility of a molecular method for the subtyping ofTreponema pallidum subsp.pallidum and to discriminate strains of this microorganism from strains from patients with syphilis. We studied 212 specimens from a total of 82 patients with different stages of syphilis (14 primary, 7 secondary and 61 latent syphilis). The specimens were distributed as follows: genital ulcers (n = 9), skin and mucosal lesions (n = 7), blood (n = 82), plasma (n = 82), and ear lobe scrapings (n = 32). The samples were assayed by a PCR technique to amplify a segment of the polymerase gene I (polA ). Positive samples were typed on the basis of the analysis of two variable genes,tpr andarp . Sixty-two of the 90 samples positive forpolA yielded typeableTreponema pallidum DNA. All skin lesions in whichT. pallidum was identified (six of six [100%]) were found to contain enough DNA for typing of the organism. It was also possible to type DNA from 7/9 (77.7%) genital ulcer samples, 13/22 (59.1%) blood samples, 20/32 (62.5%) plasma samples, and 16/21 (76.2%) ear lobe scrapings. The same subtype was identified in all samples from the same patient. Five molecular subtypes (subtypes 10a, 14a, 14c, 14f, and 14g) were identified, with the most frequently found subtype being subtype 14a and the least frequently found subtype being subtype 10a. In conclusion, the subtyping technique used in this study seems to have good reproducibility. To our knowledge, subtype 10a was identified for the first time. Further studies are needed to explain the presence of this subtype in Portugal, namely, its relationship to theTreponema pallidum strains circulating in the African countries where Portuguese is spoken.