Culture‐Independent Rapid Detection Methods for Bacterial Pathogens and Toxins in Food Matrices

Wang, Yun; Salazar, Joelle K.

doi:10.1111/1541-4337.12175

Cited by 233 publications

(162 citation statements)

References 203 publications

(266 reference statements)

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“…The decrease in the number of samples needed to achieve a given probability of detection is another factor that favors concentration through membrane microfiltration of low levels of microbial cells in large volumes . The probability of detecting 10 living cells in a 1 L of buffer is 1,000× lower than if the same 10 cells were suspended in 1 mL of fluid.…”

Section: Introductionmentioning

confidence: 99%

Microfiltration of enzyme treated egg whites for accelerated detection of viable Salmonella

Ximenes

Kreke

et al. 2016

Biotechnology Progress

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We report detection of <13 CFU of Salmonella per 25 g egg white within 7 h by concentrating the bacteria using microfiltration through 0.2-μm cutoff polyethersulfone hollow fiber membranes. A combination of enzyme treatment, controlled cross-flow on both sides of the hollow fibers, and media selection were key to controlling membrane fouling so that rapid concentration and the subsequent detection of low numbers of microbial cells were achieved. We leveraged the protective effect of egg white proteins and peptone so that the proteolytic enzymes did not attack the living cells while hydrolyzing the egg white proteins responsible for fouling. The molecular weight of egg white proteins was reduced from about 70 kDa to 15 kDa during hydrolysis. This enabled a 50-fold concentration of the cells when a volume of 525 mL of peptone and egg white, containing 13 CFU of Salmonella, was decreased to a 10 mL volume in 50 min. A 10-min microcentrifugation step further concentrated the viable Salmonella cells by 10×. The final cell recovery exceeded 100%, indicating that microbial growth occurred during the 3-h processing time. The experiments leading to rapid concentration, recovery, and detection provided further insights on the nature of membrane fouling enabling fouling effects to be mitigated. Unlike most membrane processes where protein recovery is the goal, recovery of viable microorganisms for pathogen detection is the key measure of success, with modification of cell-free proteins being both acceptable and required to achieve rapid microfiltration of viable microorganisms. © 2016 American Institute of Chemical Engineers Biotechnol. Prog., 32:1464-1471, 2016.

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Section: Introductionmentioning

confidence: 99%

Microfiltration of enzyme treated egg whites for accelerated detection of viable Salmonella

Ximenes

Kreke

et al. 2016

Biotechnology Progress

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“…While biosensor‐based screening technologies offer rapid and inexpensive methods for bacterial pathogen detection and identification (Jasson et al . ; Gehring and Tu ; Bhunia ; Wang and Salazar ).…”

Section: Discussionmentioning

confidence: 99%

Simultaneous detection ofSalmonella enterica,Escherichia coliandListeria monocytogenesin food using a light scattering sensor

2019

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Aim To investigate the use of a light scattering sensor, BActerial Rapid Detection using Optical scattering Technology (BARDOT) coupled with a multipathogen selective medium, Salmonella, Escherichia and Listeria (SEL), for concurrent detection of the three major foodborne pathogens in a single assay. Methods and Results BARDOT was used to detect and distinguish the three major pathogens, Salmonella enterica, Shiga toxin‐producing Escherichia coli (STEC) and Listeria monocytogenes from food based on colony scatter signature patterns on SEL agar (SELA). Multiple strains of three test pathogens were grown on SELA, and BARDOT was used to generate colony scatter image libraries for inclusive (SEL Library) and exclusive (non‐SEL Library) bacterial group. These pathogens were further differentiated using the SEL scatter image library. Raw chicken and hotdog samples were artificially inoculated with pathogens (100 CFU per 25 g each), and enriched in SEL broth at 37°C for 18 h and colonies were grown on SELA for 11–22 h before screening with BARDOT. The BARDOT sensor successfully detected and differentiated Salmonella, STEC and Listeria on SELA with high classification accuracy 92–98%, 91–98% and 83–98% positive predictive values (PPV) respectively; whereas the nontarget strains showed only 0–13% PPV. BARDOT‐identified colonies were further confirmed by multiplex PCR targeting inlB gene of L. monocytogenes, stx2 of STEC and sefA of S. enterica serovar Enteritidis. Conclusions The results show that BARDOT coupled with SELA can efficiently screen for the presence of three major pathogens simultaneously in a test sample within 29–40 h. Significance and Impact of the Study This innovative SELA‐BARDOT detection platform can reduce turnaround time and economic burden on food industries by offering a label‐free, noninvasive on‐plate multipathogen screening technology for reducing microbial food safety and public health concerns.

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“…Since the advent of the modern diet with the promotion of consumption of vegetables, lettuce, sprouts, and seeds, an increase in the number of STEC has been associated with the intake of these products (Hou and others ). In addition, food products can be exposed to STEC contamination in several ways, such as through contaminated water, air, soil, fertilizers, and during the processing stages of slaughter, from the raw material up to final consumption (Wang and Salazar ). The STEC group is considered a serious public health problem in many developed countries (Majowicz and others ).…”

Section: Stec Occurrence and Foodborne Outbreaksmentioning

confidence: 99%

Shiga‐toxin Producing Escherichia coli: Pathogenicity, Supershedding, Diagnostic Methods, Occurrence, and Foodborne Outbreaks

Castro

Carvalho

Conté-Júnior

et al. 2017

Comp Rev Food Sci Food Safe

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Historically, Escherichia coli is among the most studied organisms and serves as the basis for understanding many fundamental biochemical and genetic concepts. In addition, it displays 9 pathogenesis groups, with the Shiga toxin-producing (STEC) group being the main representative regarding foodborne pathogenesis. Its typical characteristic is the presence of 2 distinct toxins and variants: stx1 (stx1a, stx1c, and stx1d), and stx2 (stx2a, stx2b, stx2c, stx2d, stx2e, stx2f, and stx2g). The main challenge regarding the study of E. coli is the standardization of a high sensitivity method including all pathotypes, that allows for enrichment of STEC cells and a decrease of background microbiota. The ability of some E. coli cells belonging to other pathogenic groups, such as O104:H4, to acquire genes unique to the STEC group, increases the pathogenic power and the risk of new outbreaks related to these bacteria. In addition, animals with a high concentration of pathogenic E. coli cells present in feces (above 10 4 CFU/g), designated as supershedding animals, may be the primary transmission factor among ruminants. Therefore, the purpose of this review is to address pathogenicity factors and the importance of supershedding animals in the transmission of this pathogen, discussing the main methods currently applied, to focus on the occurrence of STEC in beef.

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Culture‐Independent Rapid Detection Methods for Bacterial Pathogens and Toxins in Food Matrices

Cited by 233 publications

References 203 publications

Microfiltration of enzyme treated egg whites for accelerated detection of viable Salmonella

Microfiltration of enzyme treated egg whites for accelerated detection of viable Salmonella

Simultaneous detection ofSalmonella enterica,Escherichia coliandListeria monocytogenesin food using a light scattering sensor

Shiga‐toxin Producing Escherichia coli: Pathogenicity, Supershedding, Diagnostic Methods, Occurrence, and Foodborne Outbreaks

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