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.

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.

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.

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.

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.

Prevalence and antimicrobial resistance of Listeria species and molecular characterization of Listeria monocytogenes isolated from retail ready-to-eat foods

2020 ◽  
Vol 367 (4) ◽  
Author(s):  
Seza Arslan ◽  
Fatma Özdemir
Keyword(s):  
Antimicrobial Resistance ◽  
Genetic Relatedness ◽  
Fragment Length Polymorphism ◽  
Food Samples ◽  
Diffusion Method ◽  
Consumer Health ◽  
Disk Diffusion Method ◽  
Listeria Species ◽  
Virulence Markers

ABSTRACT A wide variety of foods can be contaminated with Listeria species, especially L. monocytogenes. Ready-to-eat (RTE) foods are predominantly associated with human listeriosis caused by L. monocytogenes. Therefore, this study aimed to assess the presence of Listeria species in RTE foods and to characterize L. monocytogenes isolates by means of detection of virulence markers, serotypes and genetic relatedness. Of the 300 RTE food samples, 59 (19.7%) were positive for Listeria species: L. innocua (13.3%), L. monocytogenes (5%), L. welshimerii (2.3%), L. grayi subsp. murrayi (1.3%), L. grayi (1%), L. ivanovii (1%) and L. ivanovi subsp. londoniensis (0.3%). All L. monocytogenes isolates identified were positive for the actA, iap, inlA, inlB, inlC, inlJ, plcA and prfA virulence genes and biofilm. The isolates were serotyped as 1/2c (33.3%), 4b (26.7%), 1/2a (26.7%), 1/2b (6.7%) and 3c (6.7%) by the multiplex-PCR and agglutination methods. PCR-restriction fragment length polymorphism with AluI and MluCI resulted in three and two profiles, respectively. Pulsed-field gel electrophoresis differentiated the L. monocytogenes isolates into 15 ApaI and 12 AscI patterns. Antimicrobial resistance of all Listeria isolates was determined by the disk diffusion method. Most L. monocytogenes isolates were sensitive to antimicrobials used in the treatment of listeriosis. This study shows the presence of potential pathogenic and antimicrobial-resistant L. monocytogenes in RTE foods that may lead to consumer health risks.

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.

Occurrence and Characterization of Aeromonas Species in Pasteurized Milk and White Cheese in Rio De Janeiro, Brazil

1993 ◽  
Vol 56 (1) ◽  
pp. 62-65 ◽  
Author(s):  
ANGELA CÔRREA FREITAS ◽  
MARLY PAIVA NUNES ◽  
ARLETE MOREIRA MILHOMEM ◽  
ILVAN DELGADO RICCIARDI
Keyword(s):  
Rio De Janeiro ◽  
Foodborne Pathogen ◽  
Food Samples ◽  
High Rate ◽  
Most Probable Number ◽  
Aeromonas Species ◽  
Probable Number ◽  
Pasteurized Milk ◽  
Milk Samples ◽  
White Cheese

A total of 35 samples (1000 ml each) of pasteurized milk and 25 samples (100 g each) of white cheese purchased at supermarkets in Rio de Janeiro were analyzed for the presence of Aeromonas. Strains of Aeromonas were isolated from 28.5% of pasteurized milk and 32% of white cheese samples. Standard Plate counts in the pasteurized milk samples ranged from 7.2 × 10* to 2.5 × 105 CFU/ml. Total and fecal coliform counts in white cheese samples ranged from 1.9 × 10* to 2.4 × 105 most probable number per g and 3.2 × 102 to 1.2 × 105 most probable number per g, respectively. It was possible to identify Aeromonas caviae (58.9%), Aeromonas hydrophila (12.8%), and Aeromonas schubertii (2.5%) among the cultures isolated from pasteurized milk samples. Twenty-five percent of the strains could only be classified as Aeromonas spp. In white cheese samples, unclassified strains were the most frequent isolates (61.5%) followed by A. hydrophila (26.9%), A. caviae (7.6%) and Aeromonas sobria (3.8%). Only strains of A. hydrophila and A. sobria showed high rate of positive results when tested for the production of hemolysin, cytotoxin, and staphylolytic activity. Heat-stable enterotoxin and autoagglutination test did not correlate as virulence factors. The presence of Aeromonas species in refrigerated food samples suggests that this microorganism could be a potential foodborne pathogen, and dairy products may represent an important vehicle of its transmission.

60-Day Aging Requirement Does Not Ensure Safety of Surface-Mold-Ripened Soft Cheeses Manufactured from Raw or Pasteurized Milk When Listeria monocytogenes Is Introduced as a Postprocessing Contaminant

2008 ◽  
Vol 71 (8) ◽  
pp. 1563-1571 ◽  
Author(s):  
DENNIS J. D'AMICO ◽  
MARC J. DRUART ◽  
CATHERINE W. DONNELLY
Keyword(s):  
Listeria Monocytogenes ◽  
Control Strategies ◽  
Raw Milk ◽  
Growth Potential ◽  
Initial Population ◽  
Population Declines ◽  
Pasteurized Milk ◽  
Holding Period ◽  
High Level ◽  
Similar Growth

Because of renewed interest in specialty cheeses, artisan and farmstead producers are manufacturing surface-mold-ripened soft cheeses from raw milk, using the 60-day holding standard (21 CFR 133.182) to achieve safety. This study compared the growth potential of Listeria monocytogenes on cheeses manufactured from raw or pasteurized milk and held for >60 days at 4°C. Final cheeses were within federal standards of identity for soft ripened cheese, with low moisture targets to facilitate the holding period. Wheels were surface inoculated with a five-strain cocktail of L. monocytogenes at approximately 0.2 CFU/cm2 (low level) or 2 CFU/cm2 (high level), ripened, wrapped, and held at 4°C. Listeria populations began to increase by day 28 for all treatments after initial population declines. From the low initial inoculation level, populations in raw and pasteurized milk cheese reached maximums of 2.96 ± 2.79 and 2.33 ± 2.10 log CFU/g, respectively, after 60 days of holding. Similar growth was observed in cheese inoculated at high levels, where populations reached 4.55 ± 4.33 and 5.29 ± 5.11 log CFU/g for raw and pasteurized milk cheeses, respectively. No significant differences (P < 0.05) were observed in pH development, growth rate, or population levels between cheeses made from the different milk types. Independent of the milk type, cheeses held for 60 days supported growth from very low initial levels of L. monocytogenes introduced as a postprocess contaminant. The safety of cheeses of this type must be achieved through control strategies other than aging, and thus revision of current federal regulations is warranted.

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.

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