scholarly journals INCIDÊNCIA DE Listeria monocytogenes EM QUEIJO DE COALHO REFRIGERADO PRODUZIDO INDUSTRIALMENTE

2003 ◽  
Vol 21 (2) ◽  
Author(s):  
MARIA AURINEIDE DE ABREU CASTELO BRANCO ◽  
EVÂNIA ALTINA TEIXEIRA DE FIGUEIREDO ◽  
MARIA DE FÁTTIMA BORGES ◽  
MARIA CRISTINA DELGADO DA SILVA ◽  
MARIA TEREZA DESTRO
Keyword(s):  
Listeria Monocytogenes ◽  
Water Activity ◽  
Rapid Test ◽  
Listeria Innocua ◽  
Biochemical Tests ◽  
Listeria Species ◽  
Ph Conditions ◽  
Ph Range ◽  
Visual Reading ◽  
The City

Avaliou-se a incidência de Listeria monocytogenes em queijo de coalho, produzido industrialmente e comercializado sob refrigeração na cidade de Fortaleza- CE (Brasil). Também foram avaliadas as condições de pH e de atividade de água nas amostras contaminadas com espécies de Listeria. Foram analisadas 84 amostras de queijo de coalho industrializado de diferentes marcas empregando o TECRA Listeria Visual Immunoassay (LISVIA) modificado. Das 84 amostras, 16 (19%) estavam contaminadas com Listeria monocytogenes, 5 (5,9%) com Listeria innocua e 1 (1,2%) com Listeria grayi. Listeria monocytogenes foi isolada na faixa de pH de 5,75 a 6,37 e em atividade de água entre 0,949 e 0,970. O TECRA LISVIA detectou a presença de Listeria spp. em 9 (10,7%) amostras. Todas as amostras positivas no teste rápido foram confirmadas por testes culturais e bioquímicos e em todas foi detectada a presença de Listeria monocytogenes. O plaqueamento das amostras negativas na leitura visual do teste rápido permitiu o isolamento de Listeria spp. em 8 amostras e em 7 foi detectada a presença de Listeria monocytogenes. INCIDENCE OF Listeria monocytogenes IN INDUSTRIALLY MANUFACTURED REFRIGERATED “COALHO” CHEESE Abstract Incidence of Listeria monocytogenes in “coalho” cheese industrially manufactured and commercialized in refrigerated temperature in the city of Fortaleza, Ceará (Brazil) was evaluated. Water activity and pH conditions in the contaminated samples with Listeria species were also evaluated. Samples (84) of industrialized “coalho” cheese of different brands were analyzed using the modified TECRA Listeria Visual Immunoassay (LISVIA). From 84 samples, 16 (19%) were contaminated with Listeria monocytogenes, 5 (5.9%) with Listeria innocua and 1 (1.2%) with Listeria grayi. Listeria monocytogenes was isolated in the pH range of 5.75 to 6.37 and in water activity between 0.949 e 0.970. The TECRA LISVIA detected the presence of Listeria spp. in 9 (10.7%) samples. All positives samples in the rapid test were confirmed by cultural and biochemical tests and in all samples the presence of Listeria monocytogenes was detected. The negative samples plating in the visual reading of the rapid test allowed the isolation of Listeria spp. in 8 samples and in 7 the presence of Listeria monocytogenes was detected.

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.

Incidence of Listeria monocytogenes in Silage and Its Subsequent Control by Specific and Nonspecific Antagonism

1990 ◽  
Vol 53 (8) ◽  
pp. 642-647 ◽  
Author(s):  
CURTT M. PERRY ◽  
CATHERINE W. DONNELLY
Keyword(s):  
Lactic Acid ◽  
Listeria Monocytogenes ◽  
Lactic Acid Bacteria ◽  
Acid Production ◽  
Lactic Acid Production ◽  
Dairy Farms ◽  
Listeria Innocua ◽  
Listeria Species

Silage samples representing approximately 10% of Vermont's dairy farms were tested for the presence of Listeria species. Listeria innocua was isolated from 15.3% of the silage samples, while Listeria monocytogenes was isolated from 2.9% of the examined samples. As silage pH increased, the incidence of Listeria increased concomitantly. Seventy-eight mesophilic lactic acid bacteria, indigenous to silage, were screened for specific and nonspecific antagonism against four L. monocytogenes indicator strains. Most of the silage isolates demonstrated nonspecific inhibition via lactic acid production against the L. monocytogenes indicator strains. None of the indigenous silage isolates tested in this survey demonstrated specific antagonism via production of bacteriocinogenic compounds.

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.

Prevalence of Listeria monocytogenes in Raw Milk in Guadalajara, Mexico

1995 ◽  
Vol 58 (10) ◽  
pp. 1139-1141 ◽  
Author(s):  
ANGELICA LUISJUAN-MORALES ◽  
RICARDO ALANIZ-DE LA O. ◽  
MARIA E. VÁZQUEZ-SANDOVAL ◽  
BEATRIZ T. ROSAS-BARBOSA
Keyword(s):  
Listeria Monocytogenes ◽  
Raw Milk ◽  
Listeria Innocua ◽  
Retail Stores ◽  
Street Vendors ◽  
Listeria Welshimeri ◽  
The City

The frequency of L. monocytogenes and other species of Listeria was determined in 100 samples of raw milk obtained from street vendors and retail stores located in the city of Guadalajara, Mexico. Listeria innocua and Listeria welshimeri were isolated from 7 and 2 samples, respectively, whereas L. monocytogenes was not isolated from any samples.

Prevalence of Listeria spp. in Feces and Carcasses at a Lamb Packing Plant in Brazil

2003 ◽  
Vol 66 (2) ◽  
pp. 328-330 ◽  
Author(s):  
PAULO CÉSAR ANTONIOLLO ◽  
FERNANDO da SILVA BANDEIRA ◽  
MÁRCIA MONKS JANTZEN ◽  
EDUARDA HALLAL DUVAL ◽  
WLADIMIR PADILHA da SILVA
Keyword(s):  
Listeria Monocytogenes ◽  
Listeria Innocua ◽  
Fecal Samples ◽  
Listeria Species ◽  
Listeria Ivanovii ◽  
Listeria Welshimeri

The objective of this work was to study the occurrence of Listeria species in feces and on dressed and cooled carcasses of lambs at a packing plant in Brazil. Listeria spp. were recovered on Oxford and Palcam agars. The 35 fecal samples yielded Listeria welshimeri (20%) and Listeria innocua (8.6%). The 69 carcass samples yielded L. innocua (34.8%), Listeria monocytogenes (4.3%), and Listeria ivanovii (1.5%). More Listeria spp. were recovered with two selective agars than with either agar alone.

scholarly journals Incidence, Enumeration and Confirmation of Listeria and its Species in Ready-to-eat Street Vended Salads Sold at Various Outlets of Faisalabad City, Pakistan

2021 ◽  
Vol 15 (3) ◽  
pp. 1625-1633
Author(s):  
Adnan Khaliq ◽  
Harris Sajjad ◽  
Muhammad Farhan Jahangir Chughtai ◽  
Samreen Ahsan ◽  
Atif Liaqat ◽  
...  
Keyword(s):  
Listeria Monocytogenes ◽  
Healthy Lifestyle ◽  
Listeria Innocua ◽  
Plate Method ◽  
Safety Concerns ◽  
Fresh Vegetable ◽  
Food Outlets ◽  
Listeria Species ◽  
The World ◽  
Different Parts

The desire for a healthy lifestyle and faster mode of preparation has supported the consumption of ready to eat fresh salad. Street vended salads are recognized as a source of pathogenic transamination in different parts of the world. The present study was designed to evaluate the safety status of fresh vegetable and Russian salads being sold at various food outlets of Faisalabad. Samples of freshly prepared salads were collected from representative selected different areas of Faisalabad city divided into four different zones (zone 1, zone 2, zone 3 and zone 4). Prevalence and enumeration of Listeria was done through microbial testing via the spread plate method. Among samples of vegetable salad, highest prevalence of Listeria was found in the zone 2 (75%) whereas Russian salad samples from zones 1 and 3 exhibited 62% prevalence, the highest among all 4 zones of study. On the whole, the lowest prevalence of Listeria was found in zone 4 (50% vegetable salad and 58% Russian salad). Biochemical conformation of Listeria done through different tests for the identification of various Listeria species, exhibited that Listeria monocytogenes and Listeria innocua were highly prevalent in samples from zones 1 and 3 respectively. The results will help to improve safety concerns associated with street vended foods.

Listeria Species in Raw and Ready-to-Eat Foods from Restaurants

2001 ◽  
Vol 64 (4) ◽  
pp. 551-553 ◽  
Author(s):  
J. M. SORIANO ◽  
H. RICO ◽  
J. C. MOLTÓ ◽  
J. MAÑES
Keyword(s):  
Listeria Monocytogenes ◽  
Listeria Innocua ◽  
Listeria Species ◽  
Listeria Ivanovii ◽  
Listeria Seeligeri ◽  
Listeria Welshimeri

From September 1999 to March 2000, meat (pork, beef, and chicken), fish (salmon, hake, and sole), vegetable (lettuce and spinach), and Spanish potato omelette samples obtained at restaurants were collected and tested for the occurrence of Listeria spp. Listeria monocytogenes was isolated from 3 (2.9%) out of 103 studied samples. Other species isolated were Listeria grayi (13.6%), Listeria innocua (1.9%), Listeria ivanovii (5.8%), Listeria seeligeri (3.9%), and Listeria welshimeri (1.9%). Listeria was neither isolated from beef nor any type of fish.

scholarly journals Postenrichment Population Differentials Using Buffered Listeria Enrichment Broth: Implications of the Presence of Listeria innocua on Listeria monocytogenes in Food Test Samples†

2013 ◽  
Vol 76 (11) ◽  
pp. 1854-1862 ◽  
Author(s):  
ASHLEY L. KEYS ◽  
RACHEL C. DAILEY ◽  
ANTHONY D. HITCHINS ◽  
R. DERIKE SMILEY
Keyword(s):  
Growth Rate ◽  
Listeria Monocytogenes ◽  
Listeria Innocua ◽  
Population Differences ◽  
Enrichment Broth ◽  
Listeria Species ◽  
Plating Method ◽  
Low Levels ◽  
Pathogen Recovery ◽  
Enrichment Step

The recovery of low levels of Listeria monocytogenes from foods is complicated by the presence of competing microorganisms. Nonpathogenic species of Listeria pose a particular problem because variation in growth rate during the enrichment step can produce more colonies of these nontarget cells on selective and/or differential media, resulting in a preferential recovery of nonpathogens, especially Listeria innocua. To gauge the extent of this statistical barrier to pathogen recovery, 10 isolates each of L. monocytogenes and L. innocua were propagated together from approximately equal initial levels using the current U.S. Food and Drug Administration's enrichment procedure. In the 100 isolate pairs, an average 1.3-log decrease was found in the 48-h enrichment L. monocytogenes population when L. innocua was present. In 98 of the 100 isolate pairs, L. innocua reached higher levels at 48 h than did L. monocytogenes, with a difference of 0.2 to 2.4 log CFU/ml. The significance of these population differences was apparent by an increase in the difficulty of isolating L. monocytogenes by the streak plating method. L. monocytogenes went completely undetected in 18 of 30 enrichment cultures even after colony isolation was attempted on Oxoid chromogenic Listeria agar. This finding suggests that although both Listeria species were present on the plate, the population differential between them restricted L. monocytogenes to areas of the plate with confluent growth and that isolated individual colonies were only L. innocua.

scholarly journals Prediction of population behavior of Listeria monocytogenes in food using machine learning and a microbial growth and survival database

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Satoko Hiura ◽  
Shige Koseki ◽  
Kento Koyama
Keyword(s):  
Machine Learning ◽  
Data Mining ◽  
Listeria Monocytogenes ◽  
Water Activity ◽  
Bacterial Population ◽  
Gradient Boosting ◽  
Initial Cell ◽  
Data Mining Approach ◽  
Cell Counts ◽  
Extreme Gradient Boosting

AbstractIn predictive microbiology, statistical models are employed to predict bacterial population behavior in food using environmental factors such as temperature, pH, and water activity. As the amount and complexity of data increase, handling all data with high-dimensional variables becomes a difficult task. We propose a data mining approach to predict bacterial behavior using a database of microbial responses to food environments. Listeria monocytogenes, which is one of pathogens, population growth and inactivation data under 1,007 environmental conditions, including five food categories (beef, culture medium, pork, seafood, and vegetables) and temperatures ranging from 0 to 25 °C, were obtained from the ComBase database (www.combase.cc). We used eXtreme gradient boosting tree, a machine learning algorithm, to predict bacterial population behavior from eight explanatory variables: ‘time’, ‘temperature’, ‘pH’, ‘water activity’, ‘initial cell counts’, ‘whether the viable count is initial cell number’, and two types of categories regarding food. The root mean square error of the observed and predicted values was approximately 1.0 log CFU regardless of food category, and this suggests the possibility of predicting viable bacterial counts in various foods. The data mining approach examined here will enable the prediction of bacterial population behavior in food by identifying hidden patterns within a large amount of data.

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