TY - JOUR
T1 - Streptococcus agalactiae strains with chromosomal deletions evade detection with molecular methods
AU - Tickler, Isabella A.
AU - Tenover, Fred C.
AU - Dewell, Scott
AU - Le, Victoria M.
AU - Blackman, Rachel N.
AU - Goering, Richard V.
AU - Rogers, Amy E.
AU - Piwonka, Heather
AU - Jung-Hynes, Brittney D.
AU - Chen, Derrick J.
AU - Loeffelholz, Michael J.
AU - Gnanashanmugam, Devasena
AU - Baron, Ellen Jo
N1 - Publisher Copyright:
© 2018 American Society for Microbiology. All rights reserved.
PY - 2018/4
Y1 - 2018/4
N2 - Surveillance of circulating microbial populations is critical for monitoring the performance of a molecular diagnostic test. In this study, we characterized 31 isolates of Streptococcus agalactiae (group B Streptococcus [GBS]) from several geographic locations in the United States and Ireland that contain deletions in or adjacent to the region of the chromosome that encodes the hemolysin gene cfb, the region targeted by the Xpert GBS and GBS LB assays. PCR-negative, culturepositive isolates were recognized during verification studies of the Xpert GBS assay in 12 laboratories between 2012 and 2018. Whole-genome sequencing of 15 GBS isolates from 11 laboratories revealed four unique deletions of chromosomal DNA ranging from 181 bp to 49 kb. Prospective surveillance studies demonstrated that the prevalence of GBS isolates containing deletions in the convenience sample was <1% in three geographic locations but 7% in a fourth location. Among the 15 isolates with chromosomal deletions, multiple pulsed-field gel electrophoresis types were identified, one of which appears to be broadly dispersed across the United States.
AB - Surveillance of circulating microbial populations is critical for monitoring the performance of a molecular diagnostic test. In this study, we characterized 31 isolates of Streptococcus agalactiae (group B Streptococcus [GBS]) from several geographic locations in the United States and Ireland that contain deletions in or adjacent to the region of the chromosome that encodes the hemolysin gene cfb, the region targeted by the Xpert GBS and GBS LB assays. PCR-negative, culturepositive isolates were recognized during verification studies of the Xpert GBS assay in 12 laboratories between 2012 and 2018. Whole-genome sequencing of 15 GBS isolates from 11 laboratories revealed four unique deletions of chromosomal DNA ranging from 181 bp to 49 kb. Prospective surveillance studies demonstrated that the prevalence of GBS isolates containing deletions in the convenience sample was <1% in three geographic locations but 7% in a fourth location. Among the 15 isolates with chromosomal deletions, multiple pulsed-field gel electrophoresis types were identified, one of which appears to be broadly dispersed across the United States.
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U2 - 10.1128/JCM.02040-18_rfseq1
DO - 10.1128/JCM.02040-18_rfseq1
M3 - Article
AN - SCOPUS:85065491624
VL - 57
JO - Journal of Clinical Microbiology
JF - Journal of Clinical Microbiology
SN - 0095-1137
IS - 4
M1 - e02040-18
ER -