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 × 100 and 2 × 101 CFU/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.

Current Demands for Food-Approved Liposome Nanoparticles in Food and Safety Sector

“…The authors further demonstrated the potential of these liposomes in quantifying viral counts using real-time impedance measurements as well as their feasibility as a reliable platform for the determination of viral loads with an ability to detect pathogenic microbes and other bio-fragments ( Damhorst et al, 2013 ). In addition, these liposome-based methods for pathogen detection have been investigated by others ( Shukla et al, 2016a , b ; Song et al, 2016 ). Recently, attempts have been made to develop advanced liposome-based detection methods to achieve multiplexing and gain approval for commercial applications.…”

“…However, since all liposome-based detection methods are based on fluorescence signals that differ according to various pathogenic bacteria, single-step multiple detection is a feasible target. Possible research result formats based on our earlier research were published by Shukla et al (2016a , b ).…”

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“…Cronobacter sakazakii (formerly Enterobacter sakazakii) is one of an opportunistic pathogen that can contaminate a wide range of foods and causes different disease like meningitis, necrotizing enterocolitis and bacteremia in immunocompromised, low weight individuals, neonates and infants with a mortality rate of 40-80% [1][2][3][4][5]. As Almajed and Forsythe [6] indicated in their research Cronobacter sakazakii clinical isolates are able to enough because of microbial cross-contamination like Cronobacter sakazakii [3,14,37,38]. The other contributing factors that lower the rate or early cessation of breastfeeding is that mothers might be informed not to breastfeed or the mother may take medication [34], or infants born from working-class mothers.…”

Survival and Environmental Stress Resistance of Cronobacter sakazakii Exposed to Vacuum or Air Packaging and Stored at Different Temperatures

“…C. sakazakii has been implicated in severe forms of neonatal infection, such as bacteremia, meningitis, and necrotizing enterocolitis, particularly in infants and premature babies; the mortality rates associated with these bacteria range from 50 to 80% (Li et al, 2013). Powdered infant formula (PIF), which is a main source of nutrition for neonates and infants, has been recognized as the major vehicle of transmission of C. sakazakii , and the consumption of contaminated PIF is associated with the majority of C. sakazakii outbreaks (Shukla et al, 2016). Due to the role of trehalose accumulation within its cells, C. sakazakii is remarkably resistant to desiccation (Breeuwer et al, 2010).…”