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Experience with the new genetic variant of Chlamydia trachomatis in Orebro county, Sweden - proportion, characteristics and effective diagnostic solution in an emergent situation.

Unemo, M.; Olcen, P.; Agne-Stadling, I.; Feldt, A.; Jurstrand, M.; Herrmann, B.; Persson, Kenneth LU ; Nilsson, P.; Ripa, T. and Fredlund, H. (2007) In Eurosurveillance 12(4). p.5-5
Abstract
A Chlamydia trachomatis variant that contains a 377 bp deletion in the cryptic plasmid was recently reported in Sweden. This deletion includes the targets for Cobas Amplicor, Cobas TaqMan48, and Abbott m2000. We examined the proportion and characteristics of this variant in Örebro county, Sweden and developed an effective diagnostic solution. In total, 2,401 consecutive C. trachomatis culture samples and 536 PCR samples from symptomatic and asymptomatic patients and screened females were included. Culture, Cobas Amplicor, and LightMix 480HT were used for diagnosis. A mutant-specific PCR, plasmid sequencing, omp1 sequencing and multilocus sequence typing (MLST) were used to identify and characterise mutants. In total, 162 (6.7%) of the... (More)
A Chlamydia trachomatis variant that contains a 377 bp deletion in the cryptic plasmid was recently reported in Sweden. This deletion includes the targets for Cobas Amplicor, Cobas TaqMan48, and Abbott m2000. We examined the proportion and characteristics of this variant in Örebro county, Sweden and developed an effective diagnostic solution. In total, 2,401 consecutive C. trachomatis culture samples and 536 PCR samples from symptomatic and asymptomatic patients and screened females were included. Culture, Cobas Amplicor, and LightMix 480HT were used for diagnosis. A mutant-specific PCR, plasmid sequencing, omp1 sequencing and multilocus sequence typing (MLST) were used to identify and characterise mutants. In total, 162 (6.7%) of the cultured samples were positive for C. trachomatis. However, 61 (38%) of those were negative when using Cobas Amplicor, and 60 of these were subsequently confirmed as the new variant. 13 of these mutant isolates were further characterised genetically, and all were of identical genotype E and the unique MLST sequence type: 21, 19, 1, 2, 1. Of all culture-positive samples, 161 of 162 were positive in the LightMix 480HT assay. The single negative sample was only weakly positive in culture, and negative in all PCRs. Of the 536 PCR samples, 37 were positive in both Cobas Amplicor and LightMix 480HT, 13 were only positive in LightMix 480HT (mutants), and two were only positive in Cobas Amplicor. Mutated C. trachomatis were prevalent in Örebro county in the period from October 2006 to February 2007, and it appeared to be a single clone. LightMix 480HT seemed sensitive, specific, and enabled high throughput diagnostics. However, rare low positive samples may be false-negative. Frequent surveillance and evaluations of diagnostic methods worldwide are crucial. (Less)
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published
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in
Eurosurveillance
volume
12
issue
4
pages
5 - 5
publisher
European Centre for Disease Prevention and Control (ECDC)
external identifiers
  • scopus:34547753033
ISSN
1560-7917
language
English
LU publication?
yes
id
da5a4f16-1c5d-4824-b3d3-63b879232fad (old id 1143665)
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http://www.eurosurveillance.org/ViewArticle.aspx?ArticleId=699
date added to LUP
2008-07-29 12:37:30
date last changed
2017-10-01 03:47:03
@article{da5a4f16-1c5d-4824-b3d3-63b879232fad,
  abstract     = {A Chlamydia trachomatis variant that contains a 377 bp deletion in the cryptic plasmid was recently reported in Sweden. This deletion includes the targets for Cobas Amplicor, Cobas TaqMan48, and Abbott m2000. We examined the proportion and characteristics of this variant in Örebro county, Sweden and developed an effective diagnostic solution. In total, 2,401 consecutive C. trachomatis culture samples and 536 PCR samples from symptomatic and asymptomatic patients and screened females were included. Culture, Cobas Amplicor, and LightMix 480HT were used for diagnosis. A mutant-specific PCR, plasmid sequencing, omp1 sequencing and multilocus sequence typing (MLST) were used to identify and characterise mutants. In total, 162 (6.7%) of the cultured samples were positive for C. trachomatis. However, 61 (38%) of those were negative when using Cobas Amplicor, and 60 of these were subsequently confirmed as the new variant. 13 of these mutant isolates were further characterised genetically, and all were of identical genotype E and the unique MLST sequence type: 21, 19, 1, 2, 1. Of all culture-positive samples, 161 of 162 were positive in the LightMix 480HT assay. The single negative sample was only weakly positive in culture, and negative in all PCRs. Of the 536 PCR samples, 37 were positive in both Cobas Amplicor and LightMix 480HT, 13 were only positive in LightMix 480HT (mutants), and two were only positive in Cobas Amplicor. Mutated C. trachomatis were prevalent in Örebro county in the period from October 2006 to February 2007, and it appeared to be a single clone. LightMix 480HT seemed sensitive, specific, and enabled high throughput diagnostics. However, rare low positive samples may be false-negative. Frequent surveillance and evaluations of diagnostic methods worldwide are crucial.},
  author       = {Unemo, M. and Olcen, P. and Agne-Stadling, I. and Feldt, A. and Jurstrand, M. and Herrmann, B. and Persson, Kenneth and Nilsson, P. and Ripa, T. and Fredlund, H.},
  issn         = {1560-7917},
  language     = {eng},
  number       = {4},
  pages        = {5--5},
  publisher    = {European Centre for Disease Prevention and Control (ECDC)},
  series       = {Eurosurveillance},
  title        = {Experience with the new genetic variant of Chlamydia trachomatis in Orebro county, Sweden - proportion, characteristics and effective diagnostic solution in an emergent situation.},
  volume       = {12},
  year         = {2007},
}