Microbial biosensor for Salmonella using anti-bacterial antibodies isolated from human serum

Abstract

In this work, we present a novel microbial biosensor for Salmonella based on impedance spectrometry by using isolated antibodies against a specific bacterial strain from human serum. Anti-Salmonella (or BL21(DE3)) antibodies were isolated from human serum using S. enteritidis (or BL21(DE3)) and the mutant strain ClearColi. After the purification steps, the purification yield of the antibodies was calculated to be 0.2 %. From the FACS analysis, the isolated anti-Salmonella antibodies were estimated to have more than 6-fold higher binding affinity for S. enteritidis compared to antibodies against other kinds of Gram-negative bacterial strains, including HB101, ClearColi, JM110, DH5α, and BL21(DE3). Finally, the anti-Salmonella antibodies isolated herein were used for bacterial detection using electrochemical biosensors based on impedance spectrometry and the R_ct value of the antibodies was estimated for S. enteritidis from the Nyquist plot. The limit of detection of the isolated anti-Salmonella antibodies was estimated to be 1.0 × 10³ cells/mL for S. enteritidis and 1.0 × 10⁶ cells/mL for BL21(DE3), respectively.

paper information

Enzyme and Microbial Technology  Volume 144, March 2021, 109721

Received 7 July 2020, Revised 24 November 2020, Accepted 26 November 2020, Available online 28 December 2020.

Authors: Jun-HeePark,  Ji-Hong Bong,  Jaeyong Jung, Jeong Soo Sung, Ga-Yeon Lee,  Min-Jung Kang, Jae-Chul Pyun

DOI : https://doi.org/10.1016/j.enzmictec.2020.109721