Article Figures & Data
Figures
- Figure.
T2Resistance Panel results compared to simultaneously drawn blood culture results from patients with a possible bloodstream infection.
aNone detected=no target genes were detected with T2R testing.
bBlood culture had 3 bacterial species: Enterococcus faecium (vancomycin resistant); Escherichia coli (ampicillin-sulbactam, amoxicillin-clavulanate, cefazolin, cefepime, and ceftriaxone resistant); and methicillin-resistant Staphylococcus epidermidis (MRSE). T2R Panel results were positive for vanA/B and positive for blaCTX-M-14/15.
cBlood culture had 3 bacterial species: methicillin-resistant Staphylococcus epidermidis, Staphylococcus haemolyticus (oxacillin susceptible), and Staphylococcus capitis (oxacillin resistant). In the T2R Panel results, a mecA/C gene was not detected.
dPatients having a negative simultaneous blood culture but a different positive blood culture collected within 48 hours of the original simultaneous blood culture/T2R sample had their original negative simultaneous blood culture tested with the T2R Panel.
BC, blood culture; E cloacae, Enterobacter cloacae; E coli, Escherichia coli; E faecalis, Enterococcus faecalis; E faecium, Enterococcus faecium; h, hour; K pneumoniae, Klebsiella pneumoniae; MRSA, methicillin-resistant Staphylococcus aureus; MRSE, methicillin-resistant Staphylococcus epidermidis; MSSA, methicillin-susceptible Staphylococcus aureus; MSSE, methicillin-susceptible Staphylococcus epidermidis; neg, negative; P aeruginosa, Pseudomonas aeruginosa; P mirabilis, Proteus mirabilis; P shigelloides, Plesiomonas shigelloides; R ornithinolytica, Raoultella ornithinolytica; S aureus, Staphylococcus aureus; S capitis, Staphylococcus capitis; S cohnii, Staphylococcus cohnii; S haemolyticus; Staphylococcus haemolyticus; T2R, T2Resistance Panel.
Tables
- Table 1.
Blood Cultures Positive With Antimicrobial Susceptibility Testing but Negative With T2Resistance Panel Testing Compared With Next-Generation Sequencing of Bacterial Isolates
Patient No., n=8 Positive Blood Culture Antimicrobial Susceptibility Testing MIC, μg/mL T2R Testing Result Gene Detected With NGS T2R Testing Interpretation 356 Escherichia coli Ampicillin-sulbactam=16 I None detected None detected True negative 482 MRSE Oxacillin >2 R None detected mecA/C False negative 522-1 MRSE Oxacillin >2 R None detected mecA/C False negative 522-2 Staphylococcus capitis Oxacillin >2 R None detected mecA/C False negative 583 Escherichia coli Amoxicillin-clavulanate >16/8 R, ampicillin-sulbactam >16/8 R, cefazolin >16 R None detected None detected True negative 681 MRSE Oxacillin >2 R None detected mecA/C False negative 755 Pseudomonas aeruginosa Cefepime >16 R None detected None detected True negative 756 MRSE Oxacillin >2 R None detected mecA/C False negative 886 Citrobacter spp Amoxicillin-clavulanate=16/8 R, ampicillin-sulbactam=16/8 R, cefazolin >16 R None detected None detected True negative Note: Patient 522 had 2 isolates: methicillin-resistant Staphylococcus epidermidis and Staphylococcus capitis.
I, intermediate; MIC, minimum inhibitory concentration; MRSE, methicillin-resistant Staphylococcus epidermidis; NGS, next-generation sequencing; No., number; R, resistant; T2R, T2Resistance Panel.
- Table 2.
Analysis of Additional Positive Blood Cultures Collected Within ±48 Hours of the Negative Simultaneous (With the T2R Sample) Blood Cultures
Patient No., n=27 Simultaneous Blood Culture Collected With T2R Sample Positive Blood Culture Collected Within ±48 Hours of Simultaneous Blood Culture Time Positive Blood Culture Collected Compared to Simultaneous Blood Culture T2R Testing Result Antimicrobial Susceptibility Testing MIC Interpretation 49 No growth MSSA –48 h None detected Oxacillin S 79 No growth Pseudomonas aeruginosa –48 h None detected All drugs S 199 No growth MSSA Same day None detected Oxacillin S 218 No growth Escherichia coli –24 h None detected All drugs S 229 No growth Enterococcus faecalis –24 h None detected Vancomycin S 231 No growth MSSE –48 h None detected Oxacillin S 322 No growth Enterococcus faecium Same day vanA/B Vancomycin R 340 No growth Escherichia coli –48 h None detected All drugs S 352 No growth Enterococcus faecium –48 h and same day vanA/B Vancomycin R 358 No growth Escherichia coli –48 h None detected Ampicillin-sulbactam R, cefazolin I 363 No growth MSSA –48 h None detected Oxacillin S 426 No growth Acinetobacter baumannii +48 h None detected All drugs S 474 No growth MSSA –24 h, –48 h None detected Oxacillin S 545 No growth Escherichia coli, Vibrio parahaemolyticus –48 h None detected E coli–all drugs S; V parahaemolyticus–cefazolin I 553 No growth MRSA –24 h None detected Oxacillin R 636 No growth MSSA –48 h None detected Oxacillin S 678 No growth Enterococcus faecalis –24 h None detected Vancomycin S 690 No growth Klebsiella pneumoniae –24 h None detected All drugs S 726 No growth Serratia marcescens –48 h None detected Ceftriaxone, piperacillin-tazobactam I 744 No growth Klebsiella oxytoca –24 h None detected Cefazolin R 766 No growth Proteus mirabilis –48 h None detected All drugs S 794 No growth MSSA Same day None detected Oxacillin S 798 No growth Klebsiella pneumoniae –24 h blaCTX-M-14/15 Ceftriaxone, cefazolin, cefepime R 805 No growth Klebsiella pneumoniae –24 h, –48 h None detected Ampicillin-sulbactam, cefazolin R 828 No growth Enterococcus faecalis –24 h None detected Vancomycin S 856 No growth MRSA –24 h None detected Oxacillin R 857 No growth MSSA –48 h None detected Oxacillin S Note: The T2Resistance Panel was tested using the simultaneous blood culture/T2R sample and compared to antimicrobial susceptibility testing for the nonsimultaneous blood culture (collected within ±48 hours of the simultaneous blood culture). Resistance genes detected are identified with bold.
h, hours; I, intermediate; MIC, minimum inhibitory concentration; MRSA, methicillin-resistant Staphylococcus aureus; MSSA, methicillin-susceptible Staphylococcus aureus; MSSE, methicillin-susceptible Staphylococcus epidermidis; No., number; R, resistant; S, susceptible; T2R, T2Resistance Panel.
- Table 3.
Time to Results for Antimicrobial Susceptibility Testing vs the T2Resistance Panel
Test Method Time to Results, hours, mean ± SD Time to Results Range, hours Antimicrobial susceptibility testing (MIC) 70.8 ± 16.6 46.1-117.2 T2Resistance Panel 6.7 ± 1.5 3.6-9.8 Difference 64.1 42.5-107.4 MIC, minimum inhibitory concentration.
- Table 4.
Potential Impact of T2Resistance Panel Testing for Patients with a Positive Blood Culture and Antimicrobial Susceptibility Testing Results
Patient No., n=27 Date and Time Blood Culture/T2R Sample Collected T2R Testing Result; Date and Time Available Positive Blood Culture–AST Result; Date and Time Available Potential Impact of T2R Testing Result on Antibiotic Therapy Impact Level of T2R Testing Resulta 1 1/13/21 at 9:17 None detected; 1/13/21 at 13:12 Escherichia coli–all drugs S; 1/15/21 at 13:02 Vancomycin would not have been administered (1/14/21-1/17/21). Some 82 2/9/21 at 12:50 None detected; 2/9/21 at 19:55 Raoultella ornithinolytica–all drugs S; 2/12/21 at 10:55 On appropriate therapy (cefepime 2/9/21-2/11/21; tobramycin 2/10/21). None 109 2/19/21 at 9:02 mecA/C; 2/19/21 at 12:59 Staphylococcus aureus–oxacillin R; 2/21/21 at 9:33 On appropriate therapy (vancomycin 2/19/21-2/21/21; cefazolin 2/19/21-2/20/21). None 119 2/25/21 at 11:00 None detected; 2/25/21 at 14:29 Enterococcus faecium–vancomycin S; 2/27/21 at 11:37 On appropriate therapy, (vancomycin 2/25/21-2/27/21) but piperacillin-tazobactam (2/25/21-2/27/21) may have been discontinued. None 153 3/2/21 at 12:12 None detected; 3/2/21 at 18:15 Staphylococcus cohnii–oxacillin S; 3/2/21 at 18:15 Vancomycin would not have been administered (3/9/21-3/15/21). Some 288 4/6/21 at 11:35 None detected; 4/6/21 at 17:49 Escherichia coli–all drugs S; 4/8/21 at 11:03 Vancomycin would not have been administered (4/7/21-4/8/21). Some 318 4/8/21 at 12:14 None detected; 4/8/21 at 19:00 Plesiomonas shigelloides–all drugs S; 4/10/21 at 11:44 On appropriate therapy (cefepime 4/8/21-4/9/21), but patient died 4/9/21. None 356 4/19/21 at 11:12 None detected; 4/19/21 at 20:45 Escherichia coli–all drugs S; 4/21/21 at 10:35 On appropriate therapy (ciprofloxacin 4/21/21-5/4/21). None 395 5/14/21 at 9:01 mecA/C; 5/14/21 at 12:48 Staphylococcus epidermidis–oxacillin R; 5/17/21 at 9:59 96 hours faster time to effective therapy (vancomycin). Moderate 427 5/24/21 at 19:53 None detected; 5/24/21 at 19:53 Staphylococcus cohnii–oxacillin S; 5/27/21 at 14:02 Vancomycin would not have been administered (5/25/21-5/26/21). Some 482 6/18/21 at 9:15 vanA/B; 6/18/21 at 16:25 Enterococcus faecium–vancomycin R; Staphylococcus epidermidis–oxacillin R; 6/22/21 at 8:26 79.2 hours faster time to effective therapy (daptomycin). Vancomycin may have been discontinued (6/19/21-6/20/21). Moderate Negative 483 6/17/21 at 9:41 None detected; 6/17/21 at 15:33 Escherichia coli–all drugs S; 6/19/21 at 7:48 On appropriate therapy (ceftriaxone 6/18/21-6/19/21; ciprofloxacin 6/20/21-7/1/21). None 512 6/28/21 at 14:44 None detected; 6/28/21 at 20:59 Staphylococcus epidermidis–oxacillin S; 7/2/21 at 10:42 Vancomycin would not have been administered (6/29/21-7/4/21). Some 521 6/24/21 at 10:38 None detected; 6/24/21 at 14:13 Klebsiella pneumoniae–all drugs S; 6/27/21 at 10:28 Vancomycin may not have been administered (6/25/21). Some 522 6/30/21 at 18:06 None detected; 6/30/21 at 23:20 Staphylococcus epidermidis–oxacillin R; Staphylococcus capitis–oxacillin R; Staphylococcus haemolyticus–oxacillin S; 7/5/21 at 12:04 Vancomycin may not have been administered (7/1/21-7/2/21). Negative 583 7/28/2021 at 11:00 None detected; 7/28/21 at 16:08 Escherichia coli–amoxicillin-clavulanate, ampicillin-sulbactam, cefazolin R; 8/1/21 at 9:17 Vancomycin may not have been administered (7/28/21-7/29/21). Some 615 8/2/21 at 14:32 None detected; 8/2/21 at 21:40 Staphylococcus aureus–oxacillin S; 8/4/21 at 11:17 Vancomycin would not have been administered (8/4/21-8/7/21). Some 647 8/2/21 at 18:13 None detected; 8/3/21 at 2:40 Enterococcus faecalis–vancomycin S; 8/5/21 at 14:15 On appropriate therapy (doxycycline 8/2/21-8/12/21). None 661 8/10/21 at 13:46 None detected; 8/10/21 at 22:31 Enterobacter cloacae–all drugs S; 8/14/21 at 9:10 Vancomycin would not have been administered (8/11/2021). Some 681 8/11/21 at 15:20 None detected; 8/11/21 at 1:07 Staphylococcus epidermidis–oxacillin R; 8/14/21 at 11:18 Vancomycin may not have been administered (8/12/21-8/16/21; 8/18/21). Negative 691 8/12/21 at 11:01 blaCTX-M-14/15; 8/12/21 at 18:24 Klebsiella pneumoniae–ampicillin-sulbactam I; cefazolin and ceftriaxone R; 8/14/2021 at 10:03 Vancomycin would not have been administered (8/17/21; 8/19/21-8/20/2021). 120 hours faster time to effective therapy (meropenem). Some Moderate 724 8/18/21 at 17:07 None detected; 8/18/21 at 2:34 Proteus mirabilis–all drugs S; 8/21/21 at 10:56 Cefepime would not have been administered (8/19/21-8/23/21). Some 755 8/23/21 at 14:16 None detected; 8/23/21 at 22:42 Pseudomonas aeruginosa–cefepime R; 8/26/21 at 11:25 Patient died the same day as treated with cefepime and vancomycin (8/23/21). None 756 8/23/21 at 11:19 None detected; 8/23/21 at 21:06 Staphylococcus epidermidis–oxacillin R; 8/26/21 at 10:07 Vancomycin may not have been administered (8/24/21-8/31/21). Negative 776 8/26/21 at 18:17 None detected; 8/26/21 at 1:46 Klebsiella pneumoniae–ampicillin-sulbactam R; 8/31/21 at 9:00 On appropriate therapy (piperacillin-tazobactam 8/26/21-8/31/21). None 836 9/16/21 at 12:59 None detected; 9/16/21 at 20:35 Escherichia coli–all drugs S; 9/19/21 at 20:35 On appropriate therapy (ceftriaxone 9/17/21-10/5/21; amoxicillin-clavulanate 9/19/21). None 886 10/4/21 at 10:45 None detected; 10/4/21 at 18:06 Citrobacter spp–amoxicillin-clavulanate, ampicillin-sulbactam, and cefazolin R; 10/7/21 at 10:36 On appropriate therapy (piperacillin-tazobactam 10/4/21-10/6/21). None ↵aExplanation of impact levels: None, patients were on appropriate therapy; Some, patients were treated with an effective antimicrobial at the time of the T2R testing result, but the number of administered antibiotics could have been reduced; Moderate, patients were being administered therapy at the time of the T2R testing result but could have been switched to specific directed therapy earlier based on the results of the T2R Panel, which could have reduced the time to effective therapy; Negative, patients with methicillin-resistant coagulase-negative Staphylococcus were being administered vancomycin that may have been discontinued or not administered if T2R testing had not detected a mecA/C gene.
AST, antimicrobial susceptibility testing; I, intermediate; No., number; R, resistant; S, susceptible; T2R, T2Resistance Panel.
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