PMID- 16161677
OWN - NLM
STAT- MEDLINE
DCOM- 20051006
LR  - 20230307
IS  - 0362-028X (Print)
IS  - 0362-028X (Linking)
VI  - 68
IP  - 9
DP  - 2005 Sep
TI  - Magnetic nanoparticle-antibody conjugates for the separation of Escherichia coli 
      O157:H7 in ground beef.
PG  - 1804-11
AB  - The immunomagnetic separation with magnetic nanoparticle-antibody conjugates 
      (MNCs) was investigated and evaluated for the detection of Escherichia coli 
      O157:H7 in ground beef samples. MNCs were prepared by immobilizing biotin-labeled 
      polyclonal goat anti-E. coli antibodies onto streptavidin-coated magnetic 
      nanoparticles. For bacterial separation, MNCs were mixed with inoculated ground 
      beef samples, then nanoparticle-antibody-E. coli O157:H7 complexes were separated 
      from food matrix with a magnet, washed, and surface plated for microbial 
      enumeration. The capture efficiency was determined by plating cells bound to 
      nanoparticles and unbound cells in the supernatant onto sorbitol MacConkey agar. 
      Key parameters, including the amount of nanoparticles and immunoreaction time, 
      were optimized with different concentrations of E. coli O157:H7 in 
      phosphate-buffered saline. MNCs presented a minimum capture efficiency of 94% for 
      E. coli O157:H7 ranging from 1.6 x 10(1) to 7.2 x 10(7) CFU/ml with an 
      immunoreaction time of 15 min without any enrichment. Capture of E. coli O157:H7 
      by MNCs did not interfere with other bacteria, including Salmonella enteritidis, 
      Citrobacter freundii, and Listeria monocytogenes. The capture efficiency values 
      of MNCs increased from 69 to 94.5% as E. coli O157:H7 decreased from 3.4 x 10(7) 
      to 8.0 x 10(0) CFU/ml in the ground beef samples prepared with minimal steps 
      (without filtration and centrifugation). An enrichment of 6 h was done for 8.0 x 
      10(0) and 8.0 x 10(1) CFU/ml of E. coli O157:H7 in ground beef to increase the 
      number of cells in the sample to a detectable level. The results also indicated 
      that capture efficiencies of MNCs for E. coli O157:H7 with and without mechanical 
      mixing during immunoreaction were not significantly different (P > 0.05). 
      Compared with microbeads based immunomagnetic separation, the magnetic 
      nanoparticles showed their advantages in terms of higher capture efficiency, no 
      need for mechanical mixing, and minimal sample preparation.
FAU - Varshney, Madhukar
AU  - Varshney M
AD  - Department of Biological and Agricultural Engineering, University of Arkansas, 
      Fayetteville, Arkansas 72701, USA.
FAU - Yang, Liju
AU  - Yang L
FAU - Su, Xiao-Li
AU  - Su XL
FAU - Li, Yanbin
AU  - Li Y
LA  - eng
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
PL  - United States
TA  - J Food Prot
JT  - Journal of food protection
JID - 7703944
RN  - 0 (Antibodies, Bacterial)
SB  - IM
MH  - Animals
MH  - Antibodies, Bacterial/*analysis
MH  - Cattle
MH  - Colony Count, Microbial
MH  - Escherichia coli O157/*immunology/isolation & purification
MH  - Food Contamination/*analysis
MH  - Food Microbiology
MH  - Immunomagnetic Separation/*methods
MH  - Meat Products/*microbiology
MH  - Sensitivity and Specificity
MH  - Time Factors
EDAT- 2005/09/16 09:00
MHDA- 2005/10/07 09:00
CRDT- 2005/09/16 09:00
PHST- 2005/09/16 09:00 [pubmed]
PHST- 2005/10/07 09:00 [medline]
PHST- 2005/09/16 09:00 [entrez]
AID - S0362-028X(22)01149-8 [pii]
AID - 10.4315/0362-028x-68.9.1804 [doi]
PST - ppublish
SO  - J Food Prot. 2005 Sep;68(9):1804-11. doi: 10.4315/0362-028x-68.9.1804.