scholarly journals Optimization of a Viability PCR Method for the Detection of Listeria monocytogenes in Food Samples

2018 ◽  
Vol 75 (6) ◽  
pp. 779-785 ◽  
Author(s):  
Gemma Agustí ◽  
Mariana Fittipaldi ◽  
Francesc Codony
Keyword(s):  
Listeria Monocytogenes ◽  
Food Samples ◽  
Pcr Method

scholarly journals A new method for rapid detection of Listeria monocytogenes in food

2000 ◽  
Vol 18 (No. 3) ◽  
pp. 103-109 ◽  
Author(s):  
K. Zdeňková ◽  
K. Demnerová ◽  
G. Jeníková ◽  
J. Pazlarová
Keyword(s):  
Listeria Monocytogenes ◽  
Pcr Primers ◽  
Immunomagnetic Separation ◽  
Food Samples ◽  
Special Importance ◽  
Ground Meat ◽  
Specific Detection ◽  
Gene Encoding ◽  
Pcr Method

Listeria monocytogenes represents serious danger for human health. Thus detection of this pathogen in food, which represents its main means of entry into the organism, is a topic of special importance. The original classic methods for the determination of Listeria monocytogenes are in general laborious and time-consuming procedures. In order to address this issue we developed a new rapid method for specific detection of Listeria monocytogenes in food samples. The method consists of three steps: i) enrichment of food microflora (16 h), ii) selective isolation of Listeria sp. exploiting immunomagnetic separation (2–3 h) followed by iii) precise identification of Listeria sp. and Listeria monocytogenes using duplex PCR. PCR primers specific to part of 16S rRNA were used in order to identify the members of Listeria genus. The specific identification of Listeria monocytogenes was accomplished exploiting a pair of primers specific to gene encoding invasion-associated protein – iap (4–5 h). Amplification products, 1003 bp and 593 bp respectively, were separated by electrophoresis and visualized by UV detection. The optimized IMS-PCR method was used to test the presence of Listeria sp. and Listeria monocytogenes in food samples (ground meat, low-fat milk and cheese [olomoucké tvarůžky]). A comparison of the efficiency of the bacteria enrichment step by IMS and centrifugation was also performed. The analysis time including enrichment is less than 24 h. The detection limit for Listeria monocytogenes was found between 101–102 cfu per 25 g of food sample.

Combination of Immunomagnetic Separation and Polymerase Chain Reaction for the Simultaneous Detection of Listeria monocytogenes and Salmonella spp. in Food Samples

2001 ◽  
Vol 64 (11) ◽  
pp. 1744-1750 ◽  
Author(s):  
HSIEN-YEE HSIH ◽  
HAU-YANG TSEN
Keyword(s):  
Polymerase Chain Reaction ◽  
Listeria Monocytogenes ◽  
Simultaneous Detection ◽  
Meat Products ◽  
Immunomagnetic Separation ◽  
Food Samples ◽  
Chain Reaction ◽  
Salmonella Spp ◽  
Pcr Method ◽  
Polymerase Chain

A method that combined the immunomagnetic separation (IMS) technique and the multiplex polymerase chain reaction (PCR) method (i.e., the IMS-mPCR method) was developed for simultaneous detection of Listeria monocytogenes and Salmonella spp. in food samples. When only the multiplex PCR method was used, it was found that if cell numbers of each of the two target organisms (L. monocytogenes and Salmonella spp.) were above the detection limit, but differed by more than 2 logs—e.g., n × 107 to n × 104 or n × 106 to n × 103—the organism presenting the lower numbers might go undetected. Following the enrichment step with universal preenrichment (UP) broth, if an IMS method using equal quantities of anti-Listeria and anti-Salmonella immunomagnetic beads was performed prior to PCR, both pathogens could be detected unambiguously. Such results could be obtained for target organisms in food samples, such as milk, dairy, and meat products, if similar enrichment and IMS steps were performed prior to PCR.

scholarly journals Clonogrouping, a Rapid Multiplex PCR Method for Identification of Major Clones of Listeria monocytogenes

2015 ◽  
Vol 53 (10) ◽  
pp. 3355-3358 ◽  
Author(s):  
Viviane Chenal-Francisque ◽  
Mylène M. Maury ◽  
Morgane Lavina ◽  
Marie Touchon ◽  
Alexandre Leclercq ◽  
...  
Keyword(s):  
Listeria Monocytogenes ◽  
Multiplex Pcr ◽  
Multilocus Sequence Typing ◽  
Food Samples ◽  
Content Type ◽  
Efficient Alternative ◽  
Pcr Method ◽  
Pcr Assays

Three multiplex PCR assays were developed to identify the 11 most commonListeria monocytogenesclones in clinical and food samples; 270 (95.7%) of 282 strains of serogroups IVb, IIb, IIa, and IIc were identified accurately. This novel tool is a rapid and efficient alternative to multilocus sequence typing for identification ofL. monocytogenesclones.

A filtration-based real-time PCR method for the quantitative detection of viable Salmonella enterica and Listeria monocytogenes in food samples

2009 ◽  
Vol 26 (3) ◽  
pp. 311-316 ◽  
Author(s):  
Oscar Fernando D'Urso ◽  
Palmiro Poltronieri ◽  
Santo Marsigliante ◽  
Carlo Storelli ◽  
Marta Hernández ◽  
...  
Keyword(s):  
Listeria Monocytogenes ◽  
Real Time ◽  
Real Time Pcr ◽  
Salmonella Enterica ◽  
Food Samples ◽  
Quantitative Detection ◽  
Pcr Method

PCR Detection of Alternaria spp. in Processed Foods, Based on the Internal Transcribed Spacer Genetic Marker

2011 ◽  
Vol 74 (2) ◽  
pp. 240-247 ◽  
Author(s):  
MIGUELÁNGEL PAVÓN ◽  
ISABEL GONZÁLEZ ◽  
MARÍA ROJAS ◽  
NICOLETTE PEGELS ◽  
ROSARIO MARTÍN ◽  
...  
Keyword(s):  
Food Processing ◽  
Internal Transcribed Spacer ◽  
Rapid Identification ◽  
Food Samples ◽  
Pcr Analysis ◽  
Infant Food ◽  
Rrna Gene ◽  
Tomato Pulp ◽  
Pcr Method ◽  
Fungal Contaminants

The genus Alternaria is considered one of the most important fungal contaminants of vegetables, fruits, and cereals, producing several mycotoxins that can withstand food processing methods. Conventional methods for Alternaria identification and enumeration are laborious and time-consuming, and they might not detect toxigenic molds inactivated by food processing. In this study, a PCR method has been developed for the rapid identification of Alternaria spp. DNA in foodstuffs, based on oligonucleotide primers targeting the internal transcribed spacer (ITS) 1 and ITS2 regions of the rRNA gene. The specificity of the Alternaria-specific primer pair designed (Dir1ITSAlt–Inv1ITSAlt) was verified by PCR analysis of DNA from various Alternaria spp., and also from several fungal, bacterial, yeast, animal, and plant species. The detection limit of the method was 102 CFU/ml in viable culture, heated culture, or experimentally inoculated tomato pulp. The applicability of the method for detection of Alternaria spp. DNA in foodstuffs was assessed by testing several commercial samples. Alternaria DNA was detected in 100% of spoiled tomato samples, 8% of tomato products, and 36.4% of cereal-based infant food samples analyzed.

The overgrowth of Listeria monocytogenes by other Listeria spp. in food samples undergoing enrichment cultivation has a nutritional basis

2010 ◽  
Vol 136 (3) ◽  
pp. 345-351 ◽  
Author(s):  
Nathalie Gnanou Besse ◽  
Lena Barre ◽  
Colin Buhariwalla ◽  
Marie Léone Vignaud ◽  
Elissa Khamissi ◽  
...  
Keyword(s):  
Listeria Monocytogenes ◽  
Food Samples

scholarly journals Listeria monocytogenes: An emerging food-borne pathogen and its public health implications

2016 ◽  
Vol 10 (02) ◽  
pp. 149-154 ◽  
Author(s):  
Waffa W Reda ◽  
Khaled Abdel-Moein ◽  
Ahmed Hegazi ◽  
Yasmin Mohamed ◽  
Khaled Abdel-Razik
Keyword(s):  
Listeria Monocytogenes ◽  
Raw Milk ◽  
Food Samples ◽  
Food Borne ◽  
Contaminated Food ◽  
Luncheon Meat ◽  
Stool Specimens ◽  
Polymerase Chain ◽  
Minced Meat

Introduction: Listeria monocytogenes is considered one of the most important food-borne pathogens transmitted to humans via contaminated food. The aim of the present study was to demonstrate the importance of L. monocytogenes as a food-borne pathogen. Methodology: A total of 340 samples were collected from different localities in El Giza Governorate, Egypt, to check the occurrence of L. monocytogenes in that area. The collected samples comprised 250 food samples, 40 swabs from food refrigerators, and 50 stool specimens from diarrheic children. L. monocytogenes was isolated from the examined samples according to the International Organization for Standardization. The isolates were tested biochemically using Listeria Microbact 12L and confirmed by polymerase chain reaction. Results: The isolation rates of L. monocytogenes were 8% in beef burger, 4% in minced meat, 4% in luncheon meat, while sausage samples were all negative. Eight percent of raw milk samples were positive for L. monocytogenes, whereas cheese samples and refrigerator swabs were negative. Only Listeria grayi was isolated from human stools (2.5%). Conclusion: The high isolation rates of L. monocytogenes among the examined food stuffs highlight the crucial role of food as an important vehicle for this pathogen. More efforts should be made to ensure safe handling and processing of these foods to reduce the transmission of L. monocytogenes to humans.

Listeriolysin O-Based Latex Agglutination Test for the Rapid Detection of Listeria monocytogenes in Foods

1997 ◽  
Vol 60 (9) ◽  
pp. 1038-1040 ◽  
Author(s):  
GHASSAN M. MATAR ◽  
PEGGY S. HAYES ◽  
WILLIAM F. BIBB ◽  
BALA SWAMINATHAN
Keyword(s):  
Monoclonal Antibody ◽  
Listeria Monocytogenes ◽  
Rapid Detection ◽  
Rapid Test ◽  
Food Samples ◽  
Cross Reactivity ◽  
Latex Agglutination ◽  
Listeriolysin O ◽  
Agglutination Assay ◽  
Latex Beads

A latex agglutination-based test for the rapid detection of Listeria monocytogenes in foods was developed. An antilisteriolysin O (LLO) monoclonal antibody (HID5E12D7; IgG2b) covalently bound to polystyrene amidine-modified latex beads was used in a slide agglutination assay. The latex reagent detected 0.1 ng/ml of LLO in phosphate-buffered saline plus bovine serum albumin. It reacted with culture supernatants of L. monocytogenes but not with other Listeria species or Streptococcus groups A through G. The listeriolysin O latex agglutination assay (LLOLAT) was applied to 24-h and 48-h USDA primary enrichment cultures of 208 food samples obtained from refrigerators of listeriosis patients enrolled in a study to determine the role of foods in sporadic listeriosis. Of 19 samples positive by cultural techniques, 17 were positive by the LLOLAT. Cultures with low (<0.3 CFU/g) levels of L. monocytogenes were positive in the LLOLAT. No cross-reactivity occurred when using a heterogeneous monoclonal antibody. The LLOLAT is a sensitive, specific and rapid test and may be useful for screening foods for L. monocytogenes.

Prevalence and Numbers of Listeria monocytogenes in Various Ready-to-Eat Foods over a 5-Year Period in Estonia

2019 ◽  
Vol 82 (4) ◽  
pp. 597-604 ◽  
Author(s):  
JULIA KOSKAR ◽  
TOOMAS KRAMARENKO ◽  
KADRIN MEREMÄE ◽  
MAIU KUNINGAS ◽  
JELENA SÕGEL ◽  
...  
Keyword(s):  
Listeria Monocytogenes ◽  
Risk Groups ◽  
Food Samples ◽  
Safety Criterion ◽  
Fish Products ◽  
Product Categories ◽  
Salted Fish ◽  
Smoked Fish ◽  
High Prevalence ◽  
Fish Product

ABSTRACT The prevalence and numbers of Listeria monocytogenes in various categories of ready-to-eat (RTE) food products taken from retail outlets and food industries over a 5-year period are presented. A total of 30,016 RTE food samples were analyzed for L. monocytogenes prevalence, and 3.6% were found to be positive. The highest prevalence was found for RTE fish and fish products (11.6%), especially for lightly salted and cold-smoked fish products. The overall prevalence of L. monocytogenes in other food categories was low, within the range of 0 to 3.9%. In addition, 14,342 RTE food samples were analyzed to determine the numbers of L. monocytogenes. A food safety criterion of 100 CFU/g was exceeded for 0.3% of RTE food samples. Samples most often exceeding the legal safety limit were from the RTE salted and cold-smoked fish product categories. High prevalence, 28.6 and 26.5%, respectively, and high numbers of L. monocytogenes among salted fish and cold-smoked fish products indicate a risk of listeriosis, especially for susceptible risk groups. The results of the current study can be used at both the national and the international levels to update the perception of the L. monocytogenes risk deriving from RTE foods. HIGHLIGHTS

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