TY - JOUR
T1 - Advantages and Limitations of Ribosomal RNA PCR and DNA Sequencing for Identification of Bacteria in Cardiac Valves of Danish Patients
AU - Kemp, Michael
AU - Bangsborg, Jette
AU - Kjerulf, Anne
AU - Schmidt, Thomas Andersen
AU - Christensen, John
AU - Irmukhamedov, Akhmadjon 6
AU - Bruun, Niels Eske
AU - Dargis, Rimtas
AU - Andresen, Keld
AU - Christensen, Jens Jørgen
PY - 2013
Y1 - 2013
N2 - Studies on the value of culture-independent molecular identification of bacteria in cardiac valves are mostly restricted to comparing agreement of identification to what is obtained by culture to the number of identified bacteria in culture-negative cases. However, evaluation of the usefulness of direct molecular identification should also address weaknesses, their relevance in the given setting, and possible improvements. In this study cardiac valves from 56 Danish patients referred for surgery for infective endocarditis were analysed by microscopy and culture as well as by PCR targeting part of the bacterial 16S rRNA gene followed by DNA sequencing of the PCR product. PCR and DNA sequencing identified significant bacteria in 49 samples from 43 patients, including five out of 13 culture-negative cases. No rare, exotic, or intracellular bacteria were identified. There was a general agreement between bacterial identity obtained by ribosomal PCR and DNA sequencing from the valves and bacterial isolates from blood culture. However, DNA sequencing of the 16S rRNA gene did not discriminate well among non-haemolytic streptococci, especially within the Streptococcus mitis group. Ribosomal PCR with subsequent DNA sequencing is an efficient and reliable method of identifying the cause of IE, but exact species identification of some of the most common causes, i.e. non-haemolytic streptococci, may be improved with other molecular methods.
AB - Studies on the value of culture-independent molecular identification of bacteria in cardiac valves are mostly restricted to comparing agreement of identification to what is obtained by culture to the number of identified bacteria in culture-negative cases. However, evaluation of the usefulness of direct molecular identification should also address weaknesses, their relevance in the given setting, and possible improvements. In this study cardiac valves from 56 Danish patients referred for surgery for infective endocarditis were analysed by microscopy and culture as well as by PCR targeting part of the bacterial 16S rRNA gene followed by DNA sequencing of the PCR product. PCR and DNA sequencing identified significant bacteria in 49 samples from 43 patients, including five out of 13 culture-negative cases. No rare, exotic, or intracellular bacteria were identified. There was a general agreement between bacterial identity obtained by ribosomal PCR and DNA sequencing from the valves and bacterial isolates from blood culture. However, DNA sequencing of the 16S rRNA gene did not discriminate well among non-haemolytic streptococci, especially within the Streptococcus mitis group. Ribosomal PCR with subsequent DNA sequencing is an efficient and reliable method of identifying the cause of IE, but exact species identification of some of the most common causes, i.e. non-haemolytic streptococci, may be improved with other molecular methods.
U2 - 10.2174/1874285801307010146
DO - 10.2174/1874285801307010146
M3 - Journal article
C2 - 24403979
SN - 1874-2858
VL - 7
SP - 146
EP - 151
JO - The Open Microbiology Journal
JF - The Open Microbiology Journal
ER -