A portable immunomagnetic cell capture system to accelerate culture diagnosis of bacterial infections.
Bacterial infections continue to be a major cause of deaths globally, particularly in resource-poor settings. In the absence of rapid and affordable diagnostic solutions, patients are mostly administered broad spectrum antibiotics leading to antibiotics resistance and poor recovery. Culture diagnosis continues to be a gold standard for diagnosis of bacterial infection, despite its long turnaround time of 24 to 48 h. We have developed a portable immunomagnetic cell capture (iMC(2)) system that allows rapid culture diagnosis of bacterial pathogens. Our approach involves the culture growth of the blood samples in broth media for 6 to 8 h, followed by immunomagnetic enrichment of the target cells using the iMC(2) device. The device comprises a disposable capture chip that has two chambers of 5 ml and 50 μl volume connected through a channel with a manual valve. Bacterial cells bound to antibody coated magnetic nanoparticles are swept from the 5 ml sample chamber into the 50 μl recovery chamber by moving an external magnetic field with respect to the capture chip using a linear positioner. This enables specific isolation and up to 100× enrichment of the target cells. The presence of bacteria in the recovered sample is confirmed visually using a lateral flow immunoassay. The system is demonstrated in buffer and blood samples spiked with S. typhi. The method has high sensitivity (10 CFU ml(-1)), specificity and a rapid turnaround time of less than 7 h, a significant improvement over conventional methods.
Kusuma School of Biological Sciences, Indian Institute of Technology Delhi, 110016, India.
Saurabh
S
Singh
Kusuma School of Biological Sciences, Indian Institute of Technology Delhi, 110016, India.
Mohita
M
Upadhyay
Department of Biochemical Engineering and Biotechnology, Indian Institute of Technology Delhi, 110016, India. elangovan@dbeb.iitd.ac.in.
Jyoti
J
Sharma
Department of Chemical Engineering, Indian Institute of Technology Delhi, 110016, India.
Shalini
S
Gupta
Kusuma School of Biological Sciences, Indian Institute of Technology Delhi, 110016, India.
Perumal
P
Vivekanandan
Department of Biochemical Engineering and Biotechnology, Indian Institute of Technology Delhi, 110016, India. elangovan@dbeb.iitd.ac.in.
Ravikrishnan
R
Elangovan
D001424:Bacterial Infections / Q000175:diagnosis*; D001769:Blood / Q000382:microbiology*; D003470:Culture Media; D006801:Humans; D007118:Immunoassay; D018189:Immunomagnetic Separation; D058185:Magnetite Nanoparticles; D012485:Salmonella typhi; D012680:Sensitivity and Specificity
D003470:Culture Media; D058185:Magnetite Nanoparticles