scholarly journals Listeria monocytogenes and other Listeria species in raw milk and sausage in East Algeria

2019 ◽  
Author(s):  
L. Benhalima ◽  
T. Merad ◽  
M. Bensouilah ◽  
R. Ouzrou
Keyword(s):  
Listeria Monocytogenes ◽  
Raw Milk ◽  
Food Samples ◽  
Pathogenic Bacterium ◽  
Listeria Species

Listeria monocytogenes is a pathogenic bacterium that can cause Listeriosis in humans. The aim of this study is to isolate and enumerate L. monocytogenes and other Listeria species from raw milk and sausage samples collected in East Algeria. A total of 87 food samples were analyzed according to ISO 11290-1 and ISO 11290-2 methods. Of the samples examined, 10.34% were found to be positive for Listeria spp. Three species of Listeria were detected, in which L. innocua was the most commonly recovered species (66.67%) followed by L. seeligeri (22.22%) and L. monocytogenes (11.11%).The count for L. innocua ranged from 1.95 to 3.13 log10 (CFU g-1 or CFU ml-1), against 1.65 to 2.48 log10 (CFU g-1 or CFU ml-1) for L. seeligeri. L. monocytogenes contaminated sausage sample had enumeration results of 1.65 log10 (CFU g-1). The presence of Listeria in milk and sausage samples reflects the no control of hygienic practices.

scholarly journals Prevalence and Characterization of Listeria Species from Raw Milk and Dairy Products from Çanakkale Province

2018 ◽  
Vol 6 (1) ◽  
pp. 61 ◽  
Author(s):  
Pınar Şanlıbaba ◽  
Başar Uymaz Tezel
Keyword(s):  
Listeria Monocytogenes ◽  
Raw Milk ◽  
Common Species ◽  
Food Samples ◽  
Pasteurized Milk ◽  
Listeria Species ◽  
Test Kit ◽  
White Cheese ◽  
Listeria Welshimeri

The objective of this study was to determine the prevalence of Listeria species, specifically Listeria monocytogenes, in raw milk, pasteurized milk, white cheese, and homemade cheese. A total of 200 food samples were collected and analyzed to examine the presence of Listeria spp. The EN ISO 11290-1 method was used for isolation of Listeria. API Listeria test kit was used for biochemically characterization. Listeria spp. were isolated in 25 of the 200 samples (12.5%). The largest number of Listeria spp. was detected in homemade cheese (24%), followed by raw milk (18%), and white cheese (8%). Listeria spp. were not isolated from the pasteurized milk. The most common species isolated were Listeria innocua (5.5%); the remaining Listeria isolates were Listeria ivanovi (3.5%), Listeria welshimeri (3%), and Listeria monocytogenes (0.5%). Listeria monocytogenes was detected in only raw milk.

Listeria monocytogenes in Raw Milk: Detection, Incidence, and Pathogenicity

1987 ◽  
Vol 50 (3) ◽  
pp. 188-192 ◽  
Author(s):  
J. LOVETT ◽  
D. W. FRANCIS ◽  
J. M. HUNT
Keyword(s):  
United States ◽  
Listeria Monocytogenes ◽  
Sampling Period ◽  
Raw Milk ◽  
The United States ◽  
Isolation Method ◽  
Listeria Species ◽  
Adult Mice ◽  
Listeria Ivanovii

To determine the incidence of Listeria monocytogenes in raw milk, an isolation method was evaluated and used to analyze milk from three areas of the United States. The incidence varied by area from 0% in California to 7% in Massachusetts, with an overall incidence of 4.2%. The highest incidence found in any area during a single sampling period was 12% in Massachusetts in March 1985. During that same sampling, the incidence for all Listeria species was 26%. Of the 27 L. monocytogenes strains isolated during the survey, 25 were pathogenic in adult mice. One of three Listeria ivanovii isolated was pathogenic. No other isolates demonstrated pathogenicity.

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.

Occurrence of Listeria monocytogenes in Milk and Dairy Products Produced or Imported Into Morocco

1993 ◽  
Vol 56 (3) ◽  
pp. 256-259 ◽  
Author(s):  
A. EL MARRAKCHI ◽  
A. HAMAMA ◽  
F. EL OTHMANI
Keyword(s):  
Listeria Monocytogenes ◽  
Dairy Products ◽  
Raw Milk ◽  
Listeria Innocua ◽  
Pasteurized Milk ◽  
Listeria Species ◽  
Fresh Cheese ◽  
Milk And Dairy Products

Examination of 227 samples of milk and dairy products for Listeria monocytogenes showed that raw milk and some Moroccan traditionally made dairy products such as Iben and raib (fermented milks) and jben (fresh cheese) were contaminated with this pathogen. L. monocytogenes was the only Listeria species isolated except in one case in which it was associated with Listeria innocua. Pasteurized milk, fresh cream, and fresh and ripened cheeses (industrially made) were free from L. monocytogenes.

Occurrence of Listeria monocytogenes in Raw Milk in Nebraska

1988 ◽  
Vol 51 (11) ◽  
pp. 840-841 ◽  
Author(s):  
MICHAEL B. LIEWEN ◽  
MARK W. PLAUTZ
Keyword(s):  
Listeria Monocytogenes ◽  
Dairy Farms ◽  
Raw Milk ◽  
Storage Tanks ◽  
Biochemical Tests ◽  
Bulk Storage ◽  
Milk Samples ◽  
Listeria Species ◽  
Enrichment Procedure

Raw milk samples were obtained from bulk storage tanks of individual dairy farms in eastern Nebraska during February and July of 1986. One hundred different farms were tested during each period. One-tenth ml of each sample was plated directly onto McBride's Listeria Agar (MLA) and 30 ml was subjected to a four-week cold enrichment procedure. Suspect colonies from MLA were subjected to biochemical tests to confirm identity. Nine percent of all raw milk samples examined were determined to be positive for Listeria species after the cold enrichment procedure. Four percent contained L. monocytogenes and five percent contained L. innocua. Six percent and two percent of samples were found to contain L. monocytogenes in February and July respectively.

scholarly journals Rapid detection of Listeria monocytogenes in raw milk and soft cheese by a redox potential measurement based method combined with real-time PCR

2014 ◽  
Vol 62 (3) ◽  
pp. 304-316 ◽  
Author(s):  
Orsolya Erdősi ◽  
Katalin Szakmár ◽  
Olivér Reichart ◽  
Zsuzsanna Szili ◽  
Noémi László ◽  
...  
Keyword(s):  
Listeria Monocytogenes ◽  
Redox Potential ◽  
Real Time ◽  
Real Time Pcr ◽  
Rapid Detection ◽  
Raw Milk ◽  
Food Samples ◽  
Potential Measurement ◽  
Effective Manner ◽  
Soft Cheese

The incidence of outbreaks of foodborne listeriosis has indicated the need for a reliable and rapid detection of the microbe in different foodstuffs. A method combining redox potential measurement and real-time polymerase chain reaction (PCR) was developed to detectListeria monocytogenesin artificially contaminated raw milk and soft cheese. Food samples of 25 g or 25 ml were homogenised in 225 ml of Listeria Enrichment Broth (LEB) with Oxford supplement, and the redox potential measurement technique was applied. ForListeriaspecies the measuring time was maximum 34 h. The absence ofL. monocytogenescould reliably be proven by the redox potential measurement method, butListeria innocuaandBacillus subtiliscould not be differentiated fromL. monocytogeneson the basis of the redox curves. The presence ofL. monocytogeneshad to be confirmed by real-time PCR. The combination of these two methods proved to detect < 10 cfu/g ofL. monocytogenesin a cost- and time-effective manner. This method can potentially be used as an alternative to the standard nutrient method for the rapid detection ofL. monocytogenesin food.

scholarly journals Isolation and Identification of Listeria Monocytogenes in Bangalore City from Various Food Samples

2021 ◽  
Vol 14 (4) ◽  
pp. 2271-2276
Author(s):  
Vedavati Goudar ◽  
Kanthesh B M ◽  
Nagalambika Prasad
Keyword(s):  
Listeria Monocytogenes ◽  
Ice Cream ◽  
Raw Milk ◽  
Food Samples ◽  
Selective Medium ◽  
Chicken Meat ◽  
Isolation And Identification ◽  
Fresh Milk ◽  
Biochemical Identification ◽  
Raw Fish

The current research emphasis on the isolation and differentiation of Listeria monocytogenes from different food samples most frequently infected with Listeriosis outbreaks. Crude chicken meat, raw milk, pasteurized cheese, ice cream and raw fish are samples from the city of Bangalore. The selective medium mainly used for the isolation of Listeria is oxford agar. Using isolated L. monocytogenes from food samples, morphologic and biochemical identification was carried out. 2 samples (fresh milk and Ice cream) were positive out of 5 samples; 3 samples (raw chicken meat, raw fish, and pasteurized cheese) were negative. The results conferred during this study indicate the contamination of Ice- cream and Raw Milk samples with L. monocytogenes.

scholarly journals Prevalence, Antibiogram and Genetic Characterization of Listeria monocytogenes from Food Products in Egypt

Foods ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 1381
Author(s):  
Eman E. Abdeen ◽  
Walid S. Mousa ◽  
Ola. H. Harb ◽  
Gehad A. Fath-Elbab ◽  
Mohammed Nooruzzaman ◽  
...  
Keyword(s):  
Listeria Monocytogenes ◽  
Genetic Characterization ◽  
Food Products ◽  
Raw Milk ◽  
Food Samples ◽  
World Health ◽  
Fish Fillet ◽  
Minced Meat ◽  
The Impact

World Health Organization classified Listeria monocytogenes as a major notable foodborne pathogen associated with high mortality and hospitalization. The study reports the prevalence, antibiogram, virulence determination and genetic characterization of L. monocytogenes from different food products. A total of 250 food samples, fifty samples each from raw milk, ice cream, minced meat, fish fillet and sausage were collected from the Menoufiya governorate in Egypt. L. monocytogenes was detected in 17 (6.8%) of the tested food samples including minced meat (14%), fish fillet (8%), sausage (6%) and raw milk (6%). The antimicrobial susceptibility assay of 17 L. monocytogenes isolates against seventeen antibiotics belonging to eight antibiotics classes revealed a high susceptibility to norfloxacin (82.3%), amoxicillin-clavulanic acid (76.4%), cefotaxime (70.5%), erythromycin (64.6%), amoxicillin (64.6%), gentamicin (58.7%) and vancomycin (58.7%). While, high resistance was observed against oxytetracycline (76.4%), trimethoprim-sulfamethoxazole (76.4%), chloramphenicol (70.5%), doxycycline (64.6%), levofloxacin (41.2%) and azithromycin (41.2%). Of note, all L. monocytogenes isolates were multidrug-resistant. The multiplex PCR successfully amplified L. monocytogenes in all tested isolates. Screening of the five virulence-related genes revealed the hlyA and iap as the most prevalent genes followed by actA gene, however, the inlA and prfA genes were not detected in any of the studied isolates. The partial 16S rRNA gene sequencing of three L. monocytogenes isolates showed a high nucleotide similarity (99.1–99.8%) between the study isolates and various global clones, and phylogenetic analysis clustered these L. monocytogenes strains with other Listeria species including L. welshimeri, L. seeligeri and L. innocua. This study demonstrates the impact of L. monocytogenes as a major contaminant of various food products and suggests more attention to the awareness and hygienic measures in the food industry.

Assessment of Listeria sp. Interference Using a Molecular Assay To Detect Listeria monocytogenes in Food

2016 ◽  
Vol 79 (1) ◽  
pp. 138-143 ◽  
Author(s):  
SANDRA I. ZITTERMANN ◽  
BRENDA STANGHINI ◽  
RYAN SOO SEE ◽  
ROBERTO G. MELANO ◽  
PETER BOLESZCZUK ◽  
...  
Keyword(s):  
Listeria Monocytogenes ◽  
Real Time ◽  
Real Time Pcr ◽  
False Negative ◽  
Reference Method ◽  
Food Samples ◽  
Pcr Assay ◽  
The Real ◽  
Current Reference ◽  
Listeria Species

ABSTRACT Detection of Listeria monocytogenes in food is currently based on enrichment methods. When L. monocytogenes is present with other Listeria species in food, the species compete during the enrichment process. Overgrowth competition of the nonpathogenic Listeria species might result in false-negative results obtained with the current reference methods. This potential issue was noted when 50 food samples artificially spiked with L. monocytogenes were tested with a real-time PCR assay and Canada's current reference method, MFHPB-30. Eleven of the samples studied were from foods naturally contaminated with Listeria species other than those used for spiking. The real-time PCR assay detected L. monocytogenes in all 11 of these samples; however, only 6 of these samples were positive by the MFHPB-30 method. To determine whether L. monocytogenes detection can be affected by other species of the same genus due to competition, an L. monocytogenes strain and a Listeria innocua strain with a faster rate of growth in the enrichment broth were artificially coinoculated at different ratios into ground pork meat samples and cultured according to the MFHPB-30 method. L. monocytogenes was detected only by the MFHPB-30 method when L. monocytogenes/L. innocua ratios were 6.0 or higher. In contrast, using the same enrichments, the real-time PCR assay detected L. monocytogenes at ratios as low as 0.6. Taken together, these findings support the hypothesis that L. monocytogenes can be outcompeted by L. innocua during the MFHPB-30 enrichment phase. However, more reliable detection of L. monocytogenes in this situation can be achieved by a PCR-based method mainly because of its sensitivity.

Incidence and Polymerase Chain Reaction Assay of Listeria monocytogenes from Raw Milk in Gyeongnam Province of Korea

2002 ◽  
Vol 65 (1) ◽  
pp. 111-115 ◽  
Author(s):  
KWANG-SOO HA ◽  
SEON-JA PARK ◽  
SOOK-JAE SEO ◽  
JUNG-HYUN PARK ◽  
DUCK-HWA CHUNG
Keyword(s):  
Polymerase Chain Reaction ◽  
Listeria Monocytogenes ◽  
Raw Milk ◽  
Food Samples ◽  
Chain Reaction ◽  
Pcr Assay ◽  
Biochemical Tests ◽  
Milk Samples ◽  
Polymerase Chain ◽  
Pcr Assays

A total of 50 raw milk samples from Gyeongnam Province of Korea were examined for the incidence of Listeria monocytogenes between July 1998 and August 1998. L. monocytogenes isolated by biochemical test was confirmed by polymerase chain reaction (PCR) with two sets of primers designed from the invasion-associated protein (iap) gene. After standard PCR with external primers, the amplified DNA was confirmed by a second round of PCR with internal primers (nested PCR). Both the external and internal primers generated 468-bp and 287-bp products, respectively. Only one (G9 strain) of the three suspect samples that tested positive in biochemical tests for L. monocytogenes from 50 raw milk samples was also PCR positive. Following this procedure, PCR-positive G9 strain was confirmed by Southern blot using the 287-bp internal iap probe again. The detection limit of G9 strain by standard PCR assay was as few as 102 cells, equivalent to approximately 1 pg of L. monocytogenes DNA. These PCR assays may be useful for novel detection as well as rapid confirmation for L. monocytogenes from food samples and the field.

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