title: Detection of Cronobacter sakazakii in powdered infant formula using an immunoliposome-based immunomagnetic concentration and separation assay.
abstract: This study aimed to optimize the applicability of an immunoliposome-based immunomagnetic concentration and separation assay to facilitate rapid detection of Cronobacter sakazakii in powdered infant formula (PIF). To determine the detection limit, specificity, and pre-enrichment incubation time (0, 4, 6, and 8 h), assay tests were performed with different cell numbers of C. sakazakii (2 × 100and 2 × 101CFU/ml) inoculated in 10 g of PIF. The assay was able to detect as few as 2 cells of C. sakazakii/10 g of PIF sample after 6 h of pre-enrichment incubation with an assay time of 2 h 30 min. The assay was assessed for cross-reactivity with other bacterial strains and exhibited strong specificity to C. sakazakii. Moreover, the assay method was applied to the detection of C. sakazakii in PIF without pre-enrichment steps, and the results were compared with INC-ELISA and RT-PCR. The developed method was able to detect C. sakazakii in spiked PIF without pre-enrichment, whereas INC-ELISA failed to detect C. sakazakii. In addition, when compared with the results obtained with RT-PCR, our developed assay required lesser detection time. The developed assay was also not susceptible to any effect of the food matrix or background contaminant microflora.
authors.affiliation: Department of Food Science and Technology, Yeungnam University, 280 Daehak-ro, Gyeongsan-si, Gyeongsangbuk-do 38541, Republic of Korea.
authors.forename: Shruti
authors.initials: S
authors.lastname: Shukla
authors.affiliation: Department of Food Science and Technology, Yeungnam University, 280 Daehak-ro, Gyeongsan-si, Gyeongsangbuk-do 38541, Republic of Korea.
authors.forename: Gibaek
authors.initials: G
authors.lastname: Lee
authors.affiliation: Department of Food Science and Technology, Yeungnam University, 280 Daehak-ro, Gyeongsan-si, Gyeongsangbuk-do 38541, Republic of Korea.
authors.forename: Xinjie
authors.initials: X
authors.lastname: Song
authors.affiliation: Department of Food Science and Technology, Yeungnam University, 280 Daehak-ro, Gyeongsan-si, Gyeongsangbuk-do 38541, Republic of Korea.
authors.forename: Jung Hyun
authors.initials: JH
authors.lastname: Park
authors.affiliation: Experiment and Research Institute, National Agricultural Products Quality Management Service, Gimcheon-si 39660, Republic of Korea.
authors.forename: Hyunjeong
authors.initials: H
authors.lastname: Cho
authors.affiliation: Department of Medical Biotechnology, Yeungnam University, 280 Daehak-ro, Gyeongsan-si, Gyeongsangbuk-do 38541, Republic of Korea.
authors.forename: Eun Ju
authors.initials: EJ
authors.lastname: Lee
authors.affiliation: Department of Food Science and Technology, Yeungnam University, 280 Daehak-ro, Gyeongsan-si, Gyeongsangbuk-do 38541, Republic of Korea.
authors.forename: Myunghee
authors.initials: M
authors.lastname: Kim
mesh_terms: D000907:Antibodies, Bacterial / Q000378:metabolism*; D044083:Cronobacter sakazakii / Q000276:immunology / Q000302:isolation & purification*; D004797:Enzyme-Linked Immunosorbent Assay; D005506:Food Contamination / Q000032:analysis; D005516:Food Microbiology; D006801:Humans; D018189:Immunomagnetic Separation / Q000379:methods*; D007223:Infant; D041943:Infant Formula / Q000382:microbiology*; D057230:Limit of Detection; D008081:Liposomes / Q000276:immunology*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013045:Species Specificity; D013997:Time Factors
chemical_list: D000907:Antibodies, Bacterial; D008081:Liposomes