Detection of viable Salmonella using microelectrode-based capacitance measurement coupled with immunomagnetic separation

被引:74
作者
Yang, LJ [1 ]
Li, YB [1 ]
机构
[1] Univ Arkansas, Dept Biol & Agr Engn, Ctr Excellence Poultry Sci, Fayetteville, AR 72701 USA
关键词
impedance; interdigitated microelectrode; magnetic separation; Salmonella typhimurium;
D O I
10.1016/j.mimet.2005.04.022
中图分类号
Q5 [生物化学];
学科分类号
071010 ; 081704 ;
摘要
In this study, we demonstrated the use of a general medium-brain heart infusion (BHI) broth that is not specifically formulated for impedance measurement, to achieve detectable impedance signals by using an interdigitated microclectrode (IME) with capacitance measurement at low frequencies. Anti-Salmonella antibody coated immunomagnetic beads were used to separate S. typhimurium from samples to provide the selectivity to this method. From analysis based on the equivalent circuit of the IME system, we found that the impedance change in BHI broth resulting from the growth of Salmonella was indeed the change in the double layer capacitance and could be monitored at 10 Hz using the IME. The results indicated that medium modification to improve impedance signal is not necessary with this IME system. However, effective immunological separation for the target organism is required for the selectivity when non-selective media are used. This finding provides a more flexible option of medium in impedance methods, which may provide opportunities to test those species of bacteria that have no suitable conductance growth medium. The detection time, t(d), was obtained from the impedance growth curve (impedance against bacterial growth time) at 10 Hz at the point where the impedance started to change. A linear relationship between the detection time and the logarithmic value of the initial cell number (N) was found in the Salmonella cell number ranging from 10(1) to 10(6) cfu/ml. The regression equation was t(d) = - 1.22Log N + 8.90, with R-2 = 0.95. The detection times for the initial cell number of 10(1) CFU/ml and 10(6) CFU/ml are 8 It and 1.5 h, respectively. This method is more sensitive than impedance methods using conventional electrodes. (c) 2005 Elsevier B.V. All rights reserved.
引用
收藏
页码:9 / 16
页数:8
相关论文
共 23 条
[1]  
[Anonymous], 1980, ELECTROCHEMICAL METH
[2]   The isolation and detection of Escherichia coli O157 by use of immunomagnetic separation and immunoassay procedures [J].
Bennett, AR ;
MacPhee, S ;
Betts, RP .
LETTERS IN APPLIED MICROBIOLOGY, 1996, 22 (03) :237-243
[3]  
Che YH, 1999, J RAPID METH AUT MIC, V7, P47
[4]   Impedance microbiology: quantification of bacterial content in milk by means of capacitance growth curves [J].
Felice, CJ ;
Madrid, RE ;
Olivera, JM ;
Rotger, VI ;
Valentinuzzi, ME .
JOURNAL OF MICROBIOLOGICAL METHODS, 1999, 35 (01) :37-42
[5]  
FUTSCHIK K, 1988, INT M CHEM ENG BIOT, P88
[6]   Enzyme-linked immunomagnetic electrochemical detection of Salmonella typhimurium [J].
Gehring, AG ;
Crawford, CG ;
Mazenko, RS ;
VanHouten, LJ ;
Brewster, JD .
JOURNAL OF IMMUNOLOGICAL METHODS, 1996, 195 (1-2) :15-25
[7]   SOME MODIFICATION TO THE MEDIA FOR RAPID AUTOMATED DETECTION OF SALMONELLAS BY CONDUCTANCE MEASUREMENT [J].
GIBSON, DM .
JOURNAL OF APPLIED BACTERIOLOGY, 1987, 63 (04) :299-304
[8]   Evaluation of a selective broth for detection of Staphylococcus aureus using impedance microbiology [J].
Glassmoyer, KE ;
Russell, SM .
JOURNAL OF FOOD PROTECTION, 2001, 64 (01) :44-50
[9]   Microfluidic Biochip for Impedance Spectroscopy of Biological Species [J].
Gomez, R. ;
Bashir, R. ;
Sarikaya, A. ;
Ladisch, M. R. ;
Sturgis, J. ;
Robinson, J. P. ;
Geng, T. ;
Bhunia, A. K. ;
Apple, H. L. ;
Wereley, S. .
BIOMEDICAL MICRODEVICES, 2001, 3 (03) :201-209
[10]   Nanoscaled interdigitated titanium electrodes for impedimetric biosensing [J].
Laureyn, W ;
Nelis, D ;
Van Gerwen, P ;
Baert, K ;
Hermans, L ;
Magnée, R ;
Pireaux, JJ ;
Maes, G .
SENSORS AND ACTUATORS B-CHEMICAL, 2000, 68 (1-3) :360-370