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.

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.

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.

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 Prevalence of Listeria spp. with PRS Genes in Fresh Vegetables from Traditional Markets

Biomedika ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 123-129
Author(s):  
A. Kaisar Adiwijaya Putra ◽  
Rizalinda Sjahril ◽  
Arif Santoso ◽  
Dianawaty Amiruddin ◽  
Andi Alfian Zainuddin ◽  
...  
Keyword(s):  
Infectious Disease ◽  
Listeria Monocytogenes ◽  
Mortality Rate ◽  
Additional Data ◽  
Traditional Markets ◽  
Vegetable Samples ◽  
Fresh Vegetable ◽  
Listeria Species ◽  
Fresh Vegetables ◽  
Phenotype Analysis

Listeriosis is a foodborne infectious disease caused by Listeria monocytogenes and is considered a serious health problem, due to the severity of symptoms and a high mortality rate in worldwide This study aims to identify and determine the prevalence of Listeria species through prs gene screening of fresh vegetables distributed in several markets of Makassar City. A total of 57 fresh vegetable samples were collected from February to May 2019 in four traditional markets Makassar. The isolates is examines to phenotypically and genotypically Vitek and Multiplex PCR with prs and lmo1030 primer. Phenotype analysis did not show the presence of Listeria species, but the results of genotypic was found 8 positive prs gene samples (14.03%), consisting of 31.2% long beans, 18.2% cabbage, and 9.1% cucumber and. All Listeria species found in this study is Listeria monocytogenes. This study also provide information and additional data that prs genes can be used as screening genotype for identify Listeria species in fresh vegetables.

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.

The Incidence of Listeria Species in Frozen Seafood Products

1988 ◽  
Vol 51 (8) ◽  
pp. 655-657 ◽  
Author(s):  
STEPHEN D. WEAGANT ◽  
PATRICIA N. SADO ◽  
KAREN G. COLBURN ◽  
JAMES D. TORKELSON ◽  
FRED A. STANLEY ◽  
...  
Keyword(s):  
Listeria Monocytogenes ◽  
Drug Administration ◽  
Food And Drug Administration ◽  
Isolation Method ◽  
Listeria Species ◽  
The World ◽  
Seafood Products ◽  
Raw Shrimp ◽  
The U.S

Samples of frozen seafood products from several countries were tested for the presence of Listeria monocytogenes and other Listeria species using the U.S. Food and Drug Administration (FDA) Listeria isolation method. Of 57 samples tested, 35 contained Listeria species and 15 of 57 samples contained L. monocytogenes. Samples found positive included raw shrimp, cooked and peeled shrimp, cooked crabmeat, raw lobster tails, langostinos, scallops, squid and surimi-based imitation seafoods. Positive samples were obtained from nine different countries around the world.

Incidence of Listeria monocytogenes in Cheese Produced in Rio de Janeiro, Brazil

1998 ◽  
Vol 61 (3) ◽  
pp. 354-356 ◽  
Author(s):  
MARIA CRISTINA DELGADO da SILVA ◽  
ERNESTO HOFER ◽  
ANITA TIBANA
Keyword(s):  
Listeria Monocytogenes ◽  
Rio De Janeiro ◽  
Health Protection ◽  
Listeria Innocua ◽  
Retail Stores ◽  
White Cheese ◽  
The World ◽  
Sporadic Cases ◽  
Listeria Welshimeri

The present study evaluated the incidence of Listeria spp. in some Brazilian cheeses obtained from retail stores in Rio de Janeiro. Of 103 samples of various types of cheese examined as recommended in the Listeria isolation protocol of the Health Protection Branch of Canada, 11 (10.68%) were contaminated by Listeria monocytogenes, 13 (12.62%) by Listeria innocua, 6 (5.83%) by Listeria grayi, and 1 (0.97%) by Listeria welshimeri. A higher incidence of L. monocytogenes was observed mainly in the homemade Minas Frescal cheeses (a Brazilian soft white cheese, eaten fresh), 7 of 17 (41.17%), followed by ripened cheeses, 3 of 53 (5.67%), and industrially manufactured Frescal (Minas and Ricotta) cheeses, 1 of 33 (3.03%). Three serotypes (l/2a, l/2b and 4b) were observed among the strains of L. monocytogenes isolated, all of them being frequently involved in outbreaks of foodborne listeriosis and sporadic cases of the disease all over the world.

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.

BIOASSAY CHARACTERISTICS OF INDIVIDUAL URINARY GONADOTROPHIN EXTRACTS

1963 ◽  
Vol 42 (2) ◽  
pp. 214-224
Author(s):  
Raymond C. Mellinger ◽  
Jalileh A. Mansour ◽  
Richmond W. Smith
Keyword(s):  
Reference Material ◽  
Young Women ◽  
Reference Standard ◽  
General Acceptance ◽  
Modifying Factors ◽  
Large Numbers ◽  
The World ◽  
Quantitative Bioassay ◽  
Different Parts ◽  
Age And Sex

ABSTRACT A reference standard is widely sought for use in the quantitative bioassay of pituitary gonadotrophin recovered from urine. The biologic similarity of pooled urinary extracts obtained from large numbers of subjects, utilizing groups of different age and sex, preparing and assaying the materials by varying techniques in different parts of the world, has lead to a general acceptance of such preparations as international gonadotrophin reference standards. In the present study, however, the extract of pooled urine from a small number of young women is shown to produce a significantly different bioassay response from that of the reference materials. Gonadotrophins of individual subjects likewise varied from the multiple subject standards in many instances. The cause of these differences is thought to be due to the modifying influence of non-hormonal substances extracted from urine with the gonadotrophin and not necessarily to variations in the gonadotrophins themselves. Such modifying factors might have similar effects in a comparative assay of pooled extracts contributed by many subjects, but produce significant variations when material from individual subjects is compared. It is concluded that the expression of potency of a gonadotrophic extract in terms of pooled reference material to which it is not essentially similar may diminish rather than enhance the validity of the assay.

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