Rapid label-free identification of mixed bacterial infections by surface plasmon resonance

Abstract

BackgroundEarly detection of mixed aerobic-anaerobic infection has been a challenge in clinical practice due to the phenotypic changes in complex environments. Surface plasmon resonance (SPR) biosensor is widely used to detect DNA-DNA interaction and offers a sensitive and label-free approach in DNA research.MethodsIn this study, we developed a single-stranded DNA (ssDNA) amplification technique and modified the traditional SPR detection system for rapid and simultaneous detection of mixed infections of four pathogenic microorganisms (Pseudomonas aeruginosa, Staphylococcus aureus, Clostridium tetani and Clostridium perfringens).ResultsWe constructed the circulation detection well to increase the sensitivity and the tandem probe arrays to reduce the non-specific hybridization. The use of 16S rDNA universal primers ensured the amplification of four target nucleic acid sequences simultaneously, and further electrophoresis and sequencing confirmed the high efficiency of this amplification method. No significant signals were detected during the single-base mismatch or non-specific probe hybridization (P < 0.05). The calibration curves of amplification products of four bacteria had good linearity from 0.1 nM to 100 nM, with all R2 values of >0.99. The lowest detection limits were 0.03 nM for P. aeruginosa, 0.02 nM for S. aureus, 0.01 nM for C. tetani and 0.02 nM for C. perfringens. The SPR biosensor had the same detection rate as the traditional culture method (P < 0.05). In addition, the quantification of PCR products can be completed within 15 min, and excellent regeneration greatly reduces the cost for detection.ConclusionsOur method can rapidly and accurately identify the mixed aerobic-anaerobic infection, providing a reliable alternative to bacterial culture for rapid bacteria detection.

Nucleic acid detection technologies and marker molecules in bacterial diagnostics

“…Probably the most widely used of these is surface plasmon resonance (SPR), a refractive index-sensitive label-free technology that enables monitoring of nucleic acid hybridization on sensor surface in real time [69,70]. In bacterial diagnostics, conventional SPR and its highly multiplexed variation SPR imaging (SPRi) have been described for detection and quantification of ribosomal DNA [71] and RNA, respectively [72].…”

Label-free optical biosensing: going beyond the limits

“…2 Limit of detection for different plasmonic detection techniques. Data taken: [a], 44 [b], 45 [c], 46 [d], 47 [e], 48 [f], 49 [g], 50 [h], 51 [i], 52 [j], 53 [l], 54 [m], 55 [n], 56 [o], 57 [p], 58 [q], 59 [r], 60 [s], 38 [t], 33 [u], 61 [v], 62 [w], 33 [x], 60 [y], 38 [z]. 61 on biological interaction under study and then transmits this information to a reflected beam which is encoded in amplitude and phase data.…”

Advances in Biosensor Technologies for Acute Kidney Injury

“…Although their development is commonly executed using metals, novel integrative materials such as graphene and its derivations , have also drawn attention . Surface plasmon resonance (SPR), LSPR, and surface enhanced raman spectroscopy (SERS) have been widely applied as optical biosensor systems for disease detection. − The strength of the SPR and LSPR in clinical diagnosis, environmental monitoring, and food safety as biosensing platforms comes from rapid and ultrasensitive detection of the diverse analytes (e.g., viruses, bacteria, and proteins , ) . In addition, SERS promises label-free, sensitive, and selective detection by utilizing amplified localized electric fields on the surface of a plasmonic material through exciting monochromatic light .…”