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.

Incidence of Listeria monocytogenes and other Listeria spp. in Ewes' Raw Milk

1994 ◽  
Vol 57 (7) ◽  
pp. 571-575 ◽  
Author(s):  
JOSE L. RODRIGUEZ ◽  
PILAR GAVA ◽  
MARGARITA MEDINA ◽  
MANUEL NUÑEZ
Keyword(s):  
Listeria Monocytogenes ◽  
Sampling Period ◽  
Raw Milk ◽  
Seasonal Influence ◽  
Listeria Ivanovii ◽  
Milk Contamination ◽  
One Year ◽  
The One ◽  
Listeria Seeligeri ◽  
Listeria Welshimeri

Ewes' milk samples from 287 farm bulk tanks and 17 transport tankers were analyzed for Listeria over a one-year period. Listeria monocytogenes and Listeria innocua were detected in 2.19% and 2.00% of 1052 farm samples, and in 18.38% and 11.76% of 136 tanker samples, respectively. Incidence of Listeria grayi, Listeria ivanovii, Listeria seeligeri and Listeria welshimeri was under 0.4% in farm samples and under 1% in tanker samples. Most farms (93.38%) produced milk free from L. monocytogenes throughout the one-year sampling period. No seasonal influence on milk contamination by Listeria was found. However, ewes' milk contamination by L. monocytogenes and other Listeria spp. was significantly higher in farms where cows were also reared than in farms where only ewes were present.

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 Assurance Polyclonal Enzyme Immunoassay for Detection of Listeria monocytogenes and Related Listeria Species in Selected Foods: Collaborative Study

1997 ◽  
Vol 80 (4) ◽  
pp. 775-790 ◽  
Author(s):  
Philip T Feldsine ◽  
Andrew H Lienau ◽  
Robin L Forgey ◽  
Roger D Calhoon ◽  
S Al-Hasani ◽  
...  
Keyword(s):  
Listeria Monocytogenes ◽  
Enzyme Immunoassay ◽  
Collaborative Study ◽  
Culture Method ◽  
The United States ◽  
Food Type ◽  
Green Beans ◽  
Private Industry ◽  
Listeria Species ◽  
Two Samples

Abstract Six foods representing a variety of food products were analyzed by the Assurance Listeria polyclonal enzyme immunoassay (EIA) and by either the Bacteriological Analytical Manual or the U.S. Department of Agriculture culture method for detecting Listeria monocytogenes and related Listeria species. Samples of each food type, at each inoculation level, were analyzed simultaneously by both methods. A total of 19 laboratories representing federal government agencies and private industry in the United States and Canada participated. Food types were inoculated with Listeria species including L. monocytogenes, with the exception of 3 lots of green beans, which were naturally contaminated. During this study, 1764 samples and controls were analyzed and confirmed, of which 492 were positive and 947 were negative by both methods. There were 159 samples that were positive by culture method but negative by the EIA and 188 that were negative by culture method but positive by EIA. Twenty-two samples were negative by EIA and by culture method but confirmed positive when Assurance selective enrichment broths were subcultured to selective agar. The Assurance polyclonal EIA for detecting L. monocytogenes and related Listeria species in foods has been adopted first action by AOAC INTERNATIONAL.

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.

Associations between Bovine, Human, and Raw Milk, and Beef Isolates of Non-O157 Shiga Toxigenic Escherichia coli within a Restricted Geographic Area of the United States

2008 ◽  
Vol 71 (5) ◽  
pp. 1023-1027 ◽  
Author(s):  
R. N. COBBOLD ◽  
M. A. DAVIS ◽  
D. H. RICE ◽  
M. SZYMANSKI ◽  
P. I. TARR ◽  
...  
Keyword(s):  
United States ◽  
Escherichia Coli ◽  
Raw Milk ◽  
Geographic Area ◽  
The United States ◽  
Geographic Region ◽  
Toxin Gene ◽  
Sample Type ◽  
E Coli ◽  
Milk Samples

A survey for Shiga toxigenic Escherichia coli in raw milk and beef was conducted within a defined geographic region of the United States. Prevalence rates based on detection of Shiga toxin gene (stx) were 36% for retail beef, 23% for beef carcasses, and 21% for raw milk samples, which were significantly higher than were Shiga toxigenic E. coli isolation rates of 7.5, 5.8, and 3.2%, respectively. Seasonal prevalence differences were significant for stx positivity among ground beef and milk samples. Distribution of stx subtypes among isolates varied according to sample type, with stx1 predominating in milk, stx2 on carcasses, and the combination of both stx1 and stx2 in beef. Ancillary virulence markers eae and ehx were evident in 23 and 15% of isolates, respectively. Pulsed-field gel electrophoresis demonstrated associations between food isolates and sympatric bovine fecal, and human clinical isolates. These data demonstrate that non-O157 Shiga toxigenic E. coli is present in the food chain in the Pacific Northwest, and its risk to health warrants critical assessment.

Pulsed-field gel electrophoresis applied for comparing Listeria monocytogenes strains involved in outbreaks

1993 ◽  
Vol 39 (4) ◽  
pp. 395-401 ◽  
Author(s):  
C. Buchrieser ◽  
R. Brosch ◽  
B. Catimel ◽  
J. Rocourt
Keyword(s):  
United States ◽  
Listeria Monocytogenes ◽  
Gel Electrophoresis ◽  
The United States ◽  
Pulsed Field Gel Electrophoresis ◽  
Chromosomal Dna ◽  
Restriction Patterns ◽  
Pulsed Field ◽  
Dna Restriction Fragments ◽  
Dna Restriction

Recent food-borne outbreaks of human listeriosis as well as numerous sporadic cases have been mainly caused by Listeria monocytogenes serovar 4b strains. Thus, it was of interest to find out whether a certain clone or a certain few clones were responsible for these cases and especially for outbreaks., We used pulsed-field gel electrophoresis of large chromosomal DNA restriction fragments generated by ApaI, SmaI, or NotI to analyse 75 L. monocytogenes strains isolated during six major and eight smaller recent listeriosis outbreaks. These strains could be divided into 20 different genomic varieties. Thirteen of 14 strains isolated during major epidemics in Switzerland (1983–1987), the United States (California, 1985) and Denmark (1985–1987) demonstrated indistinguishable DNA restriction patterns. In contrast, strains responsible for the outbreaks in Canada (Nova Scotia, 1981), the United States (Massachusetts, 1983), France (Anjou, 1975–1976), New Zealand (1969), and Austria (1986) and some smaller outbreaks in France (1987, 1988, 1989) were each characterized by particular combinations of DNA restriction patterns. Seventy-seven percent of the tested strains could be classified into the previously described ApaI group A (Brosch et al. 1991), demonstrating a very close genomic relatedness. Because 49% of the epidemic strains selected for this study belonged to phagovar 2389/2425/3274/2671/47/108/340 or 2389/47/108/340, fifty-six additional strains of these phagovars, isolated from various origins, were also typed to determine whether differences in DNA restriction profiles between epidemic and randomly selected strains of the same phagovars could be pointed out. Variations in DNA patterns appeared more frequently within randomly selected strains than within epidemic strains.Key words: Listeria monocytogenes, listeriosis, typing, pulsed-field gel electrophoresis, epidemic.

Sign in / Sign up

Export Citation Format

Share Document