@article{PAR00014993,
  title = {{L}yophilization to improve the sensitivity of q{PCR} for bacterial {DNA} detection in serum : the {Q} fever paradigm},
  author = {{E}douard, {S}. and {R}aoult, {D}idier},
  editor = {},
  language = {{ENG}},
  abstract = {{Q}uantitative real-time {PCR} (q{PCR}) on serum provides significant added value to the diagnosis of {Q} fever, mainly at the acute stage of the disease in seronegative patients and in patients with endocarditis. {W}e evaluated the benefits of {C}oxiella burnetii {DNA} concentration in serum by lyophilization to improve q{PCR} sensitivity. {T}he detection limit of q{PCR} was determined by comparing six 10-fold dilutions of serum (calibrated with 10(4) bacteria ml(-1)) with and without lyophilization. {W}e also tested, after lyophilization, 73 sera from patients with acute {Q} fever and 10 sera from patients with endocarditis for which specific q{PCR} for {C}. burnetii performed under our usual conditions remained negative. {L}yophilization of {DNA} was found to improve sensitivity of the q{PCR}; the limit of detection of {C}. burnetii {DNA} by q{PCR} was 100-fold lower in lyophilized sera (1 bacterium ml(-1)) than in non-lyophilized sera (10(2) bacteria ml(-1)). {A}mong the 73 sera from patients with acute {Q} fever, 26 (36%) were positive after lyophilization, demonstrating a sensitivity gain of 44% for early negative sera and 30% for positive sera compared to our usual q{PCR} conditions. {S}ensitivity was also higher in sera from patients with endocarditis for which 8/10 (80%) were positive after lyophilization. {O}ur results serve as a proof of concept that lyophilization increases the sensitivity of q{PCR} in serum by concentrating bacterial {DNA}. {T}his technique may be applied for the earlier diagnosis of other fastidious bacteria or viruses and extended to other clinical samples.},
  keywords = {},
  booktitle = {},
  journal = {{J}ournal of {M}edical {M}icrobiology},
  volume = {65},
  numero = {6},
  pages = {462--467},
  ISSN = {0022-2615},
  year = {2016},
  DOI = {10.1099/jmm.0.000253},
  URL = {https://www.documentation.ird.fr/hor/{PAR}00014993},
}