title: Ultrasensitive Detection of Shigella Species in Blood and Stool.
abstract: A modified immunosensing system with voltage-controlled signal amplification was used to detect Shigella in stool and blood matrixes at the single-digit CFU level. Inactivated Shigella was spiked in these matrixes and detected directly. The detection was completed in 78 min. Detection limits of 21 CFU/mL and 18 CFU/mL were achieved in stool and blood, respectively, corresponding to 2-7 CFUs immobilized on the detecting electrode. The outcome of the detection of extremely low bacterium concentration, i.e., below 100 CFU/mL, blood samples show a random nature. An analysis of the detection probabilities indicates the correlation between the sample volume and the success of detection and suggests that sample volume is critical for ultrasensitive detection of bacteria. The calculated detection limit is qualitatively in agreement with the empirically determined detection limit. The demonstrated ultrasensitive detection of Shigella on the single-digit CFU level suggests the feasibility of the direct detection of the bacterium in the samples without performing a culture.
authors.affiliation: Department of Electrical and Computer Engineering, Cleveland State University , Cleveland, Ohio 44115, United States.
authors.forename: Jieling
authors.initials: J
authors.lastname: Luo
authors.affiliation: Department of Electrical and Computer Engineering, Cleveland State University , Cleveland, Ohio 44115, United States.
authors.forename: Jiapeng
authors.initials: J
authors.lastname: Wang
authors.affiliation: Department of Electrical and Computer Engineering, Cleveland State University , Cleveland, Ohio 44115, United States.
authors.forename: Anup S
authors.initials: AS
authors.lastname: Mathew
authors.affiliation: Department of Electrical and Computer Engineering, Cleveland State University , Cleveland, Ohio 44115, United States.|The Applied Bioengineering Program, Cleveland State University , Cleveland, Ohio 44115, United States.
authors.forename: Siu-Tung
authors.initials: ST
authors.lastname: Yau
mesh_terms: D055910:Antibodies, Immobilized / Q000737:chemistry / Q000276:immunology; D001431:Bacteriological Techniques / Q000379:methods*; D055664:Electrochemical Techniques; D004566:Electrodes; D005243:Feces / Q000382:microbiology*; D006801:Humans; D007118:Immunoassay; D012760:Shigella / Q000276:immunology / Q000302:isolation & purification*
chemical_list: D055910:Antibodies, Immobilized