title: Evaluation of real-time PCR and pyrosequencing for screening incubating blood culture bottles from adults with suspected bloodstream infection.
abstract: Several molecular platforms can identify bacteria associated with bloodstream infections but require positive culture bottles as starting material. Here, we describe results of screening 1140 blood cultures at 8h postinoculation, from 918 eligible adults being evaluated for bloodstream infection. DNA was extracted and analyzed by 16S and/or 23S rRNA real-time PCR/pyrosequencing. Compared to culture, PCR/pyrosequencing displayed 90.9% sensitivity, 99.6% specificity, 95.7% positive predictive value, and 99.1% negative predictive value. Overall concordance rate was 98.9% (1127/1140). In 4 cases with molecular-positive/culture-negative results, medical chart reviews provided evidence of identical bacteria from subsequent blood or concomitant urine/sputum cultures. Nine culture-positive/molecular-negative cases were associated with either polymicrobial growth, grew only in the anaerobic bottle of the clinical pair, and/or were detected by PCR/pyrosequencing after 8h. In summary, this approach accurately detected and identified bacteria in ~91% of culture-confirmed cases significantly sooner than the phenotypic identification was available, having the potential to improve antibiotic stewardship.
authors.affiliation: Department of Epidemiology and Biostatistics, Milken Institute School of Public Health, The George Washington University, Washington, DC, USA.
authors.forename: Chase D
authors.initials: CD
authors.lastname: McCann
authors.affiliation: Department of Epidemiology and Biostatistics, Milken Institute School of Public Health, The George Washington University, Washington, DC, USA.
authors.forename: Miranda S
authors.initials: MS
authors.lastname: Moore
authors.affiliation: Department of Emergency Medicine, The George Washington University Medical Faculty Associates, Washington, DC, USA.
authors.forename: Larissa S
authors.initials: LS
authors.lastname: May
authors.affiliation: Department of Epidemiology and Biostatistics, Milken Institute School of Public Health, The George Washington University, Washington, DC, USA.
authors.forename: Matthew G
authors.initials: MG
authors.lastname: McCarroll
authors.affiliation: Department of Epidemiology and Biostatistics, Milken Institute School of Public Health, The George Washington University, Washington, DC, USA. Electronic address: jajordan@gwu.edu.
authors.forename: Jeanne A
authors.initials: JA
authors.lastname: Jordan
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001419:Bacteria / Q000145:classification / Q000235:genetics / Q000302:isolation & purification*; D001769:Blood / Q000382:microbiology*; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D004275:DNA, Ribosomal / Q000737:chemistry / Q000235:genetics; D005260:Female; D006801:Humans; D008297:Male; D008403:Mass Screening / Q000379:methods*; D008875:Middle Aged; D011446:Prospective Studies; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D012338:RNA, Ribosomal, 23S / Q000235:genetics; D060888:Real-Time Polymerase Chain Reaction / Q000379:methods*; D018805:Sepsis / Q000175:diagnosis* / Q000382:microbiology*; D017422:Sequence Analysis, DNA / Q000379:methods*; D055815:Young Adult
chemical_list: D004269:DNA, Bacterial; D004275:DNA, Ribosomal; D012336:RNA, Ribosomal, 16S; D012338:RNA, Ribosomal, 23S
keywords: Bloodstream infections; ED and ICU patients; Molecular diagnosis; PCR/pyrosequencing methods used to more rapidly detect and identify bacteria compared to phenotypic identification; Screening incubating blood culture bottles for bacteria using a molecular approach