TY - JOUR
T1 - Comparison of SpectraCell RA typing and multilocus sequence typing for extended-spectrum-β-lactamase-producing Escherichia coli
AU - Overdevest, I. T.M.A.
AU - Heck, M.
AU - Van Der Zwaluw, K.
AU - Willemsen, I.
AU - Van De Ven, J.
AU - Verhulst, C.
AU - Kluytmans, J. A.J.W.
PY - 2012/12
Y1 - 2012/12
N2 - Multilocus sequence typing (MLST) is one of the most reliable methods for typing of Escherichia coli, including extended-spectrum-β-lactamase- producing E. coli (ESBL-EC). We investigated the performance of a new typing method, SpectraCell RA (River Diagnostics, Madison, WI), in comparison on MLST on a well-defined collection of ESBL-EC isolates obtained from chicken meat and humans. Ninety-two ESBL-EC isolates obtained from meat and 59 ESBL-EC isolates obtained from human rectal swabs and clinical blood cultures were typed using MLST and SpectraCell RA. The sensitivity and specificity of SpectraCell RA were calculated, using MLST as a reference method. Subsequently, the results of SpectraCell RA were used to determine the relatedness of ESBL-EC isolates from chicken and humans. Using MLST as the gold standard, the performance of SpectraCell RA was evaluated for 3 different cutoff values: 0.99975, 0.99955, and 0.99935. Depending on the cutoff value, the sensitivity was mediocre to unacceptably low, with values of 9.4%, 43.9%, and 66.7%, respectively. When sensitivity increased, the specificity decreased rapidly, from 95.6% to 69.8% and 34.4%, respectively. Also, the number of clusters containing both human and meat samples varied from 0 (0.0%) to 14 (38.9%). Our study shows that SpectraCell RA is not a suitable typing method for ESBL-EC when evaluating relationships of ESBL-EC at the population level.
AB - Multilocus sequence typing (MLST) is one of the most reliable methods for typing of Escherichia coli, including extended-spectrum-β-lactamase- producing E. coli (ESBL-EC). We investigated the performance of a new typing method, SpectraCell RA (River Diagnostics, Madison, WI), in comparison on MLST on a well-defined collection of ESBL-EC isolates obtained from chicken meat and humans. Ninety-two ESBL-EC isolates obtained from meat and 59 ESBL-EC isolates obtained from human rectal swabs and clinical blood cultures were typed using MLST and SpectraCell RA. The sensitivity and specificity of SpectraCell RA were calculated, using MLST as a reference method. Subsequently, the results of SpectraCell RA were used to determine the relatedness of ESBL-EC isolates from chicken and humans. Using MLST as the gold standard, the performance of SpectraCell RA was evaluated for 3 different cutoff values: 0.99975, 0.99955, and 0.99935. Depending on the cutoff value, the sensitivity was mediocre to unacceptably low, with values of 9.4%, 43.9%, and 66.7%, respectively. When sensitivity increased, the specificity decreased rapidly, from 95.6% to 69.8% and 34.4%, respectively. Also, the number of clusters containing both human and meat samples varied from 0 (0.0%) to 14 (38.9%). Our study shows that SpectraCell RA is not a suitable typing method for ESBL-EC when evaluating relationships of ESBL-EC at the population level.
UR - http://www.scopus.com/inward/record.url?scp=84869210792&partnerID=8YFLogxK
U2 - 10.1128/JCM.01443-12
DO - 10.1128/JCM.01443-12
M3 - Article
C2 - 23035198
AN - SCOPUS:84869210792
SN - 0095-1137
VL - 50
SP - 3999
EP - 4001
JO - Journal of Clinical Microbiology
JF - Journal of Clinical Microbiology
IS - 12
ER -