A magneto-DNA nanoparticle system for the rapid and sensitive diagnosis of enteric fever.
There is currently no widely available optimal assay for diagnosing patients with enteric fever. Here we present a novel assay designed to detect amplified Salmonella nucleic acid (mRNA) using magneto-DNA probes and a miniaturized nuclear magnetic resonance device. We designed primers for genes specific to S. Typhi, S. Paratyphi A, and genes conserved among Salmonella enterica spp. and utilized strongly magnetized nanoparticles to enhance the detection signal. Blood samples spiked with in vitro grown S. Typhi, S. Paratyphi A, S. Typhimurium, and E. coli were used to confirm the specificity of each probe-set, and serial 10-fold dilutions were used to determine the limit of the detection of the assay, 0.01-1.0 CFU/ml. For proof of principle, we applied our assay to 0.5 mL blood samples from 5 patients with culture-confirmed enteric fever from Bangladesh in comparison to 3 healthy controls. We were able to detect amplified target cDNA in all 5 cases of enteric fever; no detectable signal was seen in the healthy controls. Our results suggest that a magneto-DNA nanoparticle system, with an assay time from blood collection of 3.5 hours, may be a promising platform for the rapid and culture-free diagnosis of enteric fever and non-typhoidal Salmonella bacteremia.
Center for Systems Biology, Massachusetts General Hospital, Boston, MA, US.
Ki Soo
KS
Park
Graduate School of Nanoscience and Technology, Korea Advanced Institute of Science and Technology, Daejeon, Korea.
Hyun Jung
HJ
Chung
International Centre for Diarrhoeal Disease Research, Bangladesh (icddr,b), Dhaka, Bangladesh.
Farhana
F
Khanam
Center for Systems Biology, Massachusetts General Hospital, Boston, MA, US.
Hakho
H
Lee
International Centre for Diarrhoeal Disease Research, Bangladesh (icddr,b), Dhaka, Bangladesh.
Rasheduzzaman
R
Rashu
International Centre for Diarrhoeal Disease Research, Bangladesh (icddr,b), Dhaka, Bangladesh.
Md Taufiqur
MT
Bhuiyan
Division of Infectious Diseases, Massachusetts General Hospital, Boston, MA, USA.
Amanda
A
Berger
Division of Infectious Diseases, Massachusetts General Hospital, Boston, MA, USA.|Department of Medicine, Harvard Medical School, Boston, MA, USA.|Department of Pediatrics, Harvard Medical School, Boston, MA, USA.
Jason B
JB
Harris
Division of Infectious Diseases, Massachusetts General Hospital, Boston, MA, USA.|Department of Medicine, Harvard Medical School, Boston, MA, USA.|Department of Microbiology and Immunobiology, Harvard Medical School, Boston, MA, USA.
Stephen B
SB
Calderwood
Division of Infectious Diseases, Massachusetts General Hospital, Boston, MA, USA.|Department of Medicine, Harvard Medical School, Boston, MA, USA.|Department of Immunology and Infectious Diseases, Harvard T. H. Chan School of Public Health, Boston, MA, USA.
Edward T
ET
Ryan
International Centre for Diarrhoeal Disease Research, Bangladesh (icddr,b), Dhaka, Bangladesh.
Firdausi
F
Qadri
Center for Systems Biology, Massachusetts General Hospital, Boston, MA, US.|Department of Medicine, Harvard Medical School, Boston, MA, USA.|Department of Systems Biology, Harvard Medical School, Boston, MA, USA.
Ralph
R
Weissleder
Division of Infectious Diseases, Massachusetts General Hospital, Boston, MA, USA.|Department of Medicine, Harvard Medical School, Boston, MA, USA.
Richelle C
RC
Charles
D015342:DNA Probes / Q000008:administration & dosage / Q000235:genetics*; D004926:Escherichia coli / Q000235:genetics / Q000472:pathogenicity; D006801:Humans; D009682:Magnetic Resonance Spectroscopy; D058185:Magnetite Nanoparticles; D008863:Microspheres; D025202:Molecular Diagnostic Techniques / Q000379:methods*; D016133:Polymerase Chain Reaction; D012333:RNA, Messenger / Q000097:blood; D019779:Salmonella enterica / Q000235:genetics* / Q000472:pathogenicity*; D012482:Salmonella paratyphi A / Q000235:genetics / Q000472:pathogenicity; D012485:Salmonella typhi / Q000235:genetics / Q000472:pathogenicity; D012680:Sensitivity and Specificity; D014435:Typhoid Fever / Q000097:blood / Q000175:diagnosis* / Q000382:microbiology
D015342:DNA Probes; D058185:Magnetite Nanoparticles; D012333:RNA, Messenger