Integrated Acoustic Separation, Enrichment, and Microchip Polymerase Chain Reaction Detection of Bacteria from Blood for Rapid Sepsis Diagnostics.
This paper describes an integrated microsystem for rapid separation, enrichment, and detection of bacteria from blood, addressing the unmet clinical need for rapid sepsis diagnostics. The blood sample is first processed in an acoustophoresis chip, where red blood cells are focused to the center of the channel by an acoustic standing wave and sequentially removed. The bacteria-containing plasma proceeds to a glass capillary with a localized acoustic standing wave field where the bacteria are trapped onto suspended polystyrene particles. The trapped bacteria are subsequently washed while held in the acoustic trap and released into a polymer microchip containing dried polymerase chain reaction (PCR) reagents, followed by thermocycling for target sequence amplification. The entire process is completed in less than 2 h. Testing with Pseudomonas putida spiked into whole blood revealed a detection limit of 1000 bacteria/mL for this first-generation analysis system. In samples from septic patients, the system was able to detect Escherichia coli in half of the cases identified by blood culture. This indicates that the current system detects bacteria in patient samples in the upper part of the of clinically relevant bacteria concentration range and that a further developed acoustic sample preparation system may open the door for a new and faster automated method to diagnose sepsis.
Department of Biomedical Engineering, Lund University , Box 118, SE-221 00 Lund, Sweden.
Pelle
P
Ohlsson
Department of Biomedical Engineering, Lund University , Box 118, SE-221 00 Lund, Sweden.
Mikael
M
Evander
Department of Biomedical Engineering, Lund University , Box 118, SE-221 00 Lund, Sweden.
Klara
K
Petersson
Stem Cell Center, Lund University , BMC B10, Klinikgatan 24, SE-222 42 Lund, Sweden.
Lisa
L
Mellhammar
Department of Biochemistry/Biotechnology, University of Turku , Tykistökatu 6 A, FI-20520 Turku, Finland.
Ari
A
Lehmusvuori
Department of Biochemistry/Biotechnology, University of Turku , Tykistökatu 6 A, FI-20520 Turku, Finland.
Ulla
U
Karhunen
Department of Biochemistry/Biotechnology, University of Turku , Tykistökatu 6 A, FI-20520 Turku, Finland.
Minna
M
Soikkeli
Department of Biochemistry/Biotechnology, University of Turku , Tykistökatu 6 A, FI-20520 Turku, Finland.
Titta
T
Seppä
Department of Biochemistry/Biotechnology, University of Turku , Tykistökatu 6 A, FI-20520 Turku, Finland.
Emilia
E
Tuunainen
Department of Biochemistry/Biotechnology, University of Turku , Tykistökatu 6 A, FI-20520 Turku, Finland.
Anni
A
Spangar
Abacus Diagnostica Oy, Tykistökatu 4 D, FI-20520 Turku, Finland.
Piia
P
von Lode
Clinical Microbiology, Turku University Hospital , P.O. Box 52, FI-20521 Turku, Finland.
Kaisu
K
Rantakokko-Jalava
Gisela
G
Otto
Stem Cell Center, Lund University , BMC B10, Klinikgatan 24, SE-222 42 Lund, Sweden.
Stefan
S
Scheding
Department of Biochemistry/Biotechnology, University of Turku , Tykistökatu 6 A, FI-20520 Turku, Finland.
Tero
T
Soukka
Department of Biochemistry/Biotechnology, University of Turku , Tykistökatu 6 A, FI-20520 Turku, Finland.
Saara
S
Wittfooth
Department of Biomedical Engineering, Lund University , Box 118, SE-221 00 Lund, Sweden.|Department of Biomedical Engineering, Dongguk University , Seoul, Korea.
Thomas
T
Laurell
D000162:Acoustics; D001769:Blood / Q000382:microbiology*; D000071997:Blood Culture / Q000379:methods*; D004926:Escherichia coli; D006801:Humans; D057230:Limit of Detection; D046208:Microchip Analytical Procedures / Q000379:methods*; D016133:Polymerase Chain Reaction; D016958:Pseudomonas putida; D018805:Sepsis / Q000097:blood* / Q000175:diagnosis*