scholarly journals Elucidation of Listeria monocytogenesContamination Routes in Cold-Smoked Salmon Processing Plants Detected by DNA-Based Typing Methods

2001 ◽  
Vol 67 (6) ◽  
pp. 2586-2595 ◽  
Author(s):  
Birte Fonnesbech Vogel ◽  
Hans Henrik Huss ◽  
Bente Ojeniyi ◽  
Peter Ahrens ◽  
Lone Gram
Keyword(s):  
Fragment Length Polymorphism ◽  
Random Amplified Polymorphic Dna ◽  
Pulsed Field Gel Electrophoresis ◽  
Processing Equipment ◽  
Smoked Salmon ◽  
Fish Samples ◽  
Processing Plants ◽  
Typing Methods ◽  
Raw Fish ◽  
Contamination Routes

ABSTRACT The contamination routes of Listeria monocytogenes in cold-smoked salmon processing plants were investigated by analyzing 3,585 samples from products (produced in 1995, 1996, 1998, and 1999) and processing environments (samples obtained in 1998 and 1999) of two Danish smokehouses. The level of product contamination in plant I varied from 31 to 85%, and no L. monocytogenes was found on raw fish (30 fish were sampled). In plant II, the levels of both raw fish and product contamination varied from 0 to 25% (16 of 185 raw fish samples and 59 of 1,000 product samples were positive for L. monocytogenes). A total of 429 strains of L. monocytogenes were subsequently compared by random amplified polymorphic DNA (RAPD) profiling, and 55 different RAPD types were found. The RAPD types detected on the products were identical to types found on the processing equipment and in the processing environment, suggesting that contamination of the final product (cold-smoked salmon) in both plants (but primarily in plant I) was due to contamination during processing rather than to contamination from raw fish. However, the possibility that raw fish was an important source of contamination of the processing equipment and environment could not be excluded. Contamination of the product occurred in specific areas (the brining and slicing areas). In plant I, the same RAPD type (RAPD type 12) was found over a 4-year period, indicating that an established in-house flora persisted and was not eliminated by routine hygienic procedures. In plant II, where the prevalence of L. monocytogenes was much lower, no RAPD type persisted over long periods of time, and several differentL. monocytogenes RAPD types were isolated. This indicates that persistent strains may be avoided by rigorous cleaning and sanitation; however, due to the ubiquitous nature of the organism, sporadic contamination occurred. A subset of strains was also typed by using pulsed-field gel electrophoresis and amplified fragment length polymorphism profiling, and these methods confirmed the type division obtained by RAPD profiling.

scholarly journals Raw and Processed Fish Show Identical Listeria monocytogenes Genotypes with Pulsed-Field Gel Electrophoresis

2005 ◽  
Vol 68 (6) ◽  
pp. 1228-1231 ◽  
Author(s):  
ANNUKKA MARKKULA ◽  
TIINA AUTIO ◽  
JANNE LUNDÉN ◽  
HANNU KORKEALA
Keyword(s):  
Listeria Monocytogenes ◽  
Gel Electrophoresis ◽  
Pulsed Field Gel Electrophoresis ◽  
Raw Material ◽  
Processing Plant ◽  
Pulsed Field ◽  
Fish Samples ◽  
Processing Plants ◽  
Fish Product ◽  
Raw Fish

A total of 257 raw fish samples at two different sites were examined for the presence of Listeria monocytogenes. The prevalence of L. monocytogenes was 4%. From 11 positive samples, nine different L. monocytogenes pulsed-field gel electrophoresis genotypes were recovered. From nine pulsotypes recovered from raw fish and 32 pulsotypes shown by 101 fish product isolates, two raw fish and fish product pulsotypes were indistinguishable from each other. Although the prevalence of L. monocytogenes in raw fish is low, the range of L. monocytogenes strains entering the processing plant in large amounts of raw material is wide. This indicates that the raw material is an important initial contamination source of L. monocytogenes in fish processing plants. This postulation is supported by the identical pulsotypes recovered from both raw and processed fish. Some L. monocytogenes strains entering a plant may thus contaminate and persist in the processing environment, causing recurrent contamination of the final products via processing machines.

scholarly journals Sources of Listeria monocytogenes Contamination in a Cold-Smoked Rainbow Trout Processing Plant Detected by Pulsed-Field Gel Electrophoresis Typing

1999 ◽  
Vol 65 (1) ◽  
pp. 150-155 ◽  
Author(s):  
Tiina Autio ◽  
Sebastian Hielm ◽  
Maria Miettinen ◽  
Anna-Maija Sjöberg ◽  
Kaarina Aarnisalo ◽  
...  
Keyword(s):  
Rainbow Trout ◽  
Listeria Monocytogenes ◽  
Gel Electrophoresis ◽  
Pulsed Field Gel Electrophoresis ◽  
Hot Water ◽  
Processing Plant ◽  
Pulsed Field ◽  
Eradication Program ◽  
Fish Samples ◽  
Raw Fish

ABSTRACT Sites of Listeria monocytogenes contamination in a cold-smoked rainbow trout (Oncorhynchus mykiss) processing plant were detected by sampling the production line, environment, and fish at different production stages. Two lots were monitored. The frequency of raw fish samples containing L. monocytogenes was low. During processing, the frequency of fish contaminated with L. monocytogenes clearly rose after brining, and the most contaminated sites of the processing plant were the brining and postbrining areas. A total of 303 isolates from the raw fish, product, and the environment were characterized by pulsed-field gel electrophoresis (PFGE). PFGE yielded nine pulsotypes, which formed four clusters. The predominating L. monocytogenespulsotypes of the final product were associated with brining and slicing, whereas contaminants of raw fish were not detected in the final product. Air-mediated contamination in the plant could not be proved. In accordance with these results, an L. monocytogenes eradication program was planned. The use of hot steam, hot air, and hot water seemed to be useful in eliminatingL. monocytogenes. None of the control samples taken in the 5 months after the eradication program was implemented containedL. monocytogenes.

Campylobacter Contamination during Poultry Slaughter in Belgium

2006 ◽  
Vol 69 (1) ◽  
pp. 27-33 ◽  
Author(s):  
G. RASSCHAERT ◽  
K. HOUF ◽  
J. VAN HENDE ◽  
L. de ZUTTER
Keyword(s):  
Alimentary Tract ◽  
Fragment Length Polymorphism ◽  
Pulsed Field Gel Electrophoresis ◽  
Species Level ◽  
Campylobacter Coli ◽  
Flagellin Gene ◽  
Thermophilic Campylobacter ◽  
Typing Methods ◽  
Campylobacter Species ◽  
Campylobacter Lari

The relation between internal carriage and surface contamination with thermophilic Campylobacter species in broilers was examined by molecular typing methods. Samples from 39 flocks were collected in three Belgian poultry slaughterhouses. From each flock, crop swabs before slaughter and intestines and neck skins during slaughter were collected. A total of 309 isolates were identified at species level and further characterized by flagellin gene A PCR/restriction fragment length polymorphism and pulsed-field gel electrophoresis. Isolates were identified as Campylobacter jejuni (90%), Campylobacter coli (8.7%), and Campylobacter lari (2.2%), and 27 genotypes could be distinguished by combining the two molecular methods. Seventy-two percent of the flocks arriving at the abattoir were colonized with campylobacters. After slaughter, 79% of the flocks had contaminated neck skins. In six flocks, genotypes isolated from the neck skins were also found in the alimentary tract from previously slaughtered flocks. Four of these flocks were initially free of Campylobacter. These four flocks might have had no contaminated carcasses after logistic slaughtering.

scholarly journals Molecular epidemiology of nalidixic acid-resistant campylobacter isolates from humans and poultry by pulsed-field gel electrophoresis and flagellin gene analysis

2002 ◽  
Vol 129 (1) ◽  
pp. 227-231 ◽  
Author(s):  
T. L. WU ◽  
L. H. SU ◽  
J. H. CHIA ◽  
T. M. KAO ◽  
C. H. CHIU ◽  
...  
Keyword(s):  
Nalidixic Acid ◽  
Gel Electrophoresis ◽  
Antimicrobial Agents ◽  
Fragment Length Polymorphism ◽  
Pulsed Field Gel Electrophoresis ◽  
Flagellin Gene ◽  
Pulsed Field ◽  
Poultry Products ◽  
Typing Methods ◽  
Human Infections

To investigate the potential of poultry products as the source of human infections associated with quinolone-resistant campylobacters, 140 human and 75 poultry isolates of nalidixic acid-resistant campylobacters were collected between 1996 and 1998, and analysed by two molecular typing methods. By the analysis of restriction fragment length polymorphism of the flagellin gene, 33 distinct patterns were obtained, with 18 of which shared by both human (89%) and poultry (93%) isolates. By the pulsed-field gel electrophoresis of SmaI-restricted macrofragments, 105 different profiles were obtained, and 11 were found in both human (40%) and poultry (23%) isolates. When the two typing methods were combined, 112 unique genotypes were obtained, 11 of which were shared by both populations, including 53 (38%) human isolates and 14 (19%) poultry isolates. Although domestic poultry products are still important sources of the quinolone-resistant campylobacter infections in humans, there are other factors that might contribute to these increasing infections simultaneously. A more stringent policy in the use of antimicrobial agents in food animals can no longer be ignored.

scholarly journals Application of Different Genotyping Methods forPseudomonas aeruginosa in a Setting of Endemicity in an Intensive Care Unit

1999 ◽  
Vol 37 (11) ◽  
pp. 3654-3661 ◽  
Author(s):  
Han Speijer ◽  
Paul H. M. Savelkoul ◽  
Marc J. Bonten ◽  
Ellen E. Stobberingh ◽  
Jeroen H. T. Tjhie
Keyword(s):  
Intensive Care Unit ◽  
Intensive Care ◽  
Gel Electrophoresis ◽  
Fragment Length Polymorphism ◽  
Rapd Analysis ◽  
Random Amplified Polymorphic Dna ◽  
Pulsed Field Gel Electrophoresis ◽  
Aflp Analysis ◽  
Typing Method ◽  
Strain Differentiation

Colonization with Pseudomonas aeruginosa was studied by taking serial swab specimens from the oropharynges and anuses and tracheal and gastric aspirates from patients in an intensive care unit during a 10-month period in a setting of endemicity. Nineteen (10%) of the 192 patients included in the study were colonized on admission, while another 30 (16%) patients acquired P. aeruginosawhile in the hospital. Typing of 353 isolates was performed by random amplified polymorphic DNA (RAPD) analysis, and 56 strains were selected for further typing by RAPD analysis, pulsed-field gel electrophoresis (PFGE), and amplified fragment length polymorphism (AFLP) analysis. By these methods, 42, 44, and 44 genotypes were found, respectively. Computer-aided cluster analysis indicated that similar groups of related isolates were obtained by each method. By taking admission periods into account, analysis of the typing results suggested cross-acquisition of P. aeruginosa for five patient pairs. The small number of transfers and the large number of genotypes found indicate that most P. aeruginosa strains were derived from the patients themselves. The numbers of observed typing patterns and band differences between related isolates were counted for each typing method. AFLP analysis with primers without a selective base proved to be the most discriminatory method, followed by PFGE, AFLP analysis (with one selective base), and RAPD analysis. On the basis of a comparison with established strain differentiation criteria for PFGE, the criteria for differentiation of P. aeruginosa by AFLP analysis are presented.

scholarly journals Bacteremic Pneumonia Caused by a Single Clone of Streptococcus pneumoniae with Different Optochin Susceptibilities

2000 ◽  
Vol 38 (1) ◽  
pp. 458-459
Author(s):  
Hsiu-Yuan Tsai ◽  
Po-Ren Hsueh ◽  
Lee-Jene Teng ◽  
Ping-Ing Lee ◽  
Li-Min Huang ◽  
...  
Keyword(s):  
Streptococcus Pneumoniae ◽  
Gel Electrophoresis ◽  
Fragment Length Polymorphism ◽  
Random Amplified Polymorphic Dna ◽  
Community Acquired Pneumonia ◽  
Pulsed Field Gel Electrophoresis ◽  
Penicillin Binding Protein ◽  
Single Clone ◽  
Bacteremic Pneumonia ◽  
Arbitrarily Primed Pcr

ABSTRACT Two isolates of Streptococcus pneumoniae having different optochin susceptibilities were recovered from a blood sample of a 2-year-old boy with community-acquired pneumonia. The two isolates were documented to belong to a single clone on the basis of the isolates' identical serotype (23F), antibiograms by the E-test, random amplified polymorphic DNA patterns generated by arbitrarily primed PCR, pulsed-field gel electrophoresis, and restriction fragment length polymorphism of the penicillin-binding protein genes pbp2b and pbp2x .

High-Resolution Genotyping of Listeria monocytogenes by Fluorescent Amplified Fragment Length Polymorphism Analysis Compared to Pulsed-Field Gel Electrophoresis, Random Amplified Polymorphic DNA Analysis, Ribotyping, and PCR–Restriction Fragment Length Polymorphism Analysis

2004 ◽  
Vol 67 (8) ◽  
pp. 1656-1665 ◽  
Author(s):  
BIRTE FONNESBECH VOGEL ◽  
VIVIAN FUSSING ◽  
BENTE OJENIYI ◽  
LONE GRAM ◽  
PETER AHRENS
Keyword(s):  
Length Polymorphism ◽  
Fragment Length ◽  
Gel Electrophoresis ◽  
Dna Analysis ◽  
Fragment Length Polymorphism ◽  
Random Amplified Polymorphic Dna ◽  
Pulsed Field Gel Electrophoresis ◽  
Polymorphism Analysis ◽  
Aflp Fingerprinting ◽  
Main Cluster

The purpose of this study was to evaluate fluorescent amplified fragment length polymorphism (AFLP) analysis for the inter- and intraspecies differentiation of a collection of 96 strains of Listeria monocytogenes and 10 non–L. monocytogenes strains representing six other Listeria species of different origin. The AFLP technique was compared with three other molecular typing methods—ribotyping, random amplified polymorphic DNA analysis (RAPD), and pulsed-field gel electrophoresis (PFGE)—in terms of discriminatory ability. PCR–restriction fragment length polymorphism was included for virulence gene allele characterization. The 96 L. monocytogenes strains were divided into two major clusters by AFLP fingerprinting at a similarity level of 82% in concordance with the results of PFGE, RAPD, and ribotyping. One main cluster consisted of all of the 24 L. monocytogenes hly allele 1 strains, while another main cluster consisted of all of the 72 L. monocytogenes hly allele 2 strains. This indicates the existence of two distinct phylogenetic divisions. Isolates of the remaining Listeria species were not included in the clusters. AFLP, PFGE, and RAPD typing were highly discriminatory methods, with discrimination (D) indices of 0.974, 0.969, and 0.954, respectively, whereas ribotyping had a lower D index of 0.874. AFLP, PFGE, and RAPD typing showed some level of agreement in terms of strain grouping and differentiation. However, all three methods subdivided types of strains grouped by the other methods. Isolates with identical DNA profiles were distributed across the spectrum of origin. It was not possible to associate certain types with specific food sectors or clinical cases, which is indicative of the spread of L. monocytogenes clones across species. Overall, AFLP fingerprinting was suitable for the high-resolution genotyping of L. monocytogenes and had an equally high or higher differentiation power compared to PFGE or RAPD typing.

Tracking of Listeria monocytogenes in Smoked Fish Processing Plants†

2004 ◽  
Vol 67 (2) ◽  
pp. 328-341 ◽  
Author(s):  
JOANNE THIMOTHE ◽  
KENDRA KERR NIGHTINGALE ◽  
KEN GALL ◽  
VIRGINIA N. SCOTT ◽  
MARTIN WIEDMANN
Keyword(s):  
Listeria Monocytogenes ◽  
Environmental Samples ◽  
Control Strategies ◽  
Fish Processing ◽  
Smoked Fish ◽  
Plant Environment ◽  
Fish Samples ◽  
Processing Plants ◽  
Raw Fish ◽  
Contact Surfaces

Four smoked fish processing plants were used as a model system to characterize Listeria monocytogenes contamination patterns in ready-to-eat food production environments. Each of the four plants was sampled monthly for approximately 1 year. At each sampling, four to six raw fish and four to six finished product samples were collected from corresponding lots. In addition, 12 to 14 environmental sponge samples were collected several hours after the start of production at sites selected as being likely contamination sources. A total of 234 raw fish, 233 finished products, and 553 environmental samples were tested. Presumptive Listeria spp. were isolated from 16.7% of the raw fish samples, 9.0% of the finished product samples, and 27.3% of the environmental samples. L. monocytogenes was isolated from 3.8% of the raw fish samples (0 to 10%, depending on the plant), 1.3% of the finished product samples (0 to 3.3%), and 12.8% of the environmental samples (0 to 29.8%). Among the environmental samples, L. monocytogenes was found in 23.7% of the samples taken from drains, 4.8% of the samples taken from food contact surfaces, 10.4% of the samples taken from employee contact surfaces (aprons, hands, and door handles), and 12.3% of the samples taken from other nonfood contact surfaces. Listeria spp. were isolated from environmental samples in each of the four plants, whereas L. monocytogenes was not found in any of the environmental samples from one plant. Overall, the L. monocytogenes prevalence in the plant environment showed a statistically significant (P < 0.0001) positive relationship with the prevalence of this organism in finished product samples. Automated EcoRI ribotyping differentiated 15 ribotypes among the 83 L. monocytogenes isolates. For each of the three plants with L. monocytogenes–positive environmental samples, one or two ribotypes seemed to persist in the plant environment during the study period. In one plant, a specific L. monocytogenes ribotype represented 44% of the L. monocytogenes–positive environmental samples and was also responsible for one of the two finished product positives found in this plant. In another plant, a specific L. monocytogenes ribotype persisted in the raw fish handling area. However, this ribotype was never isolated from the finished product area in this plant, indicating that this operation has achieved effective separation of raw and finished product areas. Molecular subtyping methods can help identify plant-specific L. monocytogenes contamination routes and thus provide the knowledge needed to implement improved L. monocytogenes control strategies.

scholarly journals Commercial Ripening Starter Microorganisms Inoculated into Cheese Milk Do Not Successfully Establish Themselves in the Resident Microbial Ripening Consortia of a South German Red Smear Cheese

2008 ◽  
Vol 74 (7) ◽  
pp. 2210-2217 ◽  
Author(s):  
Stefanie Goerges ◽  
Jérôme Mounier ◽  
Mary C. Rea ◽  
Roberto Gelsomino ◽  
Valeska Heise ◽  
...  
Keyword(s):  
Fragment Length Polymorphism ◽  
Microbial Consortium ◽  
Random Amplified Polymorphic Dna ◽  
Starter Culture ◽  
Debaryomyces Hansenii ◽  
Pulsed Field Gel Electrophoresis ◽  
Microbial Consortia ◽  
Bacterial Isolates ◽  
Low Frequencies ◽  
Dna Restriction

ABSTRACT Production of smear-ripened cheese critically depends on the surface growth of multispecies microbial consortia comprising bacteria and yeasts. These microorganisms often originate from the cheese-making facility and, over many years, have developed into rather stable, dairy-specific associations. While commercial smear starters are frequently used, it is unclear to what degree these are able to establish successfully within the resident microbial consortia. Thus, the fate of the smear starters of a German Limburger cheese subjected to the “old-young” smearing technique was investigated during ripening. The cheese milk was supplemented with a commercial smear starter culture containing Debaryomyces hansenii, Galactomyces geotrichum, Arthrobacter arilaitensis, and Brevibacterium aurantiacum. Additionally, the cheese surface was inoculated with an extremely stable in-house microbial consortium. A total of 1,114 yeast and 1,201 bacterial isolates were identified and differentiated by Fourier transform infrared spectroscopy. Furthermore, mitochondrial DNA restriction fragment length polymorphism, random amplified polymorphic DNA, repetitive PCR, and pulsed field gel electrophoresis analyses were used to type selected isolates below the species level. The D. hansenii starter strain was primarily found early in the ripening process. The G. geotrichum starter strain in particular established itself after relocation to a new ripening room. Otherwise, it occurred at low frequencies. The bacterial smear starters could not be reisolated from the cheese surface at all. It is concluded that none of the smear starter strains were able to compete significantly and in a stable fashion against the resident microbial consortia, a result which might have been linked to the method of application. This finding raises the issue of whether addition of starter microorganisms during production of this type of cheese is actually necessary.

Comparison of serotyping, pulsed field gel electrophoresis and amplified fragment length polymorphism for typing of Streptococcus pneumoniae

2005 ◽  
Vol 54 (5) ◽  
pp. 467-472 ◽  
Author(s):  
Aishath Shaaly ◽  
Marit Gjerde Tellevik ◽  
Nina Langeland ◽  
E Arne Høiby ◽  
Roland Jureen
Keyword(s):  
Streptococcus Pneumoniae ◽  
Gel Electrophoresis ◽  
Fragment Length Polymorphism ◽  
Pulsed Field Gel Electrophoresis ◽  
Discriminatory Power ◽  
Western Norway ◽  
Typing System ◽  
Typing Methods ◽  
Good Concordance

The aim of the present study was to compare serotyping, PFGE and AFLP for typing of Streptococcus pneumoniae with regard to discriminatory power, typeability and typing system concordance. Thirty-four isolates from cerobrospinal fluid and 34 time-matched blood culture isolates collected from in-patients at two hospitals in western Norway during the period from January 1994 to May 2002 were included in the study. The discriminatory powers of serotyping, PFGE and AFLP were 0.93, 0.99 and 0.95, respectively. The typeabilities for serotyping, PFGE and AFLP were 1, 1 and 0.99, respectively. A good concordance was shown between all the typing methods. Serotyping would most probably have a higher discriminatory power if further subtyping had been performed. PFGE was more discriminatory than AFLP, and AFLP grouped more-distantly related isolates together. The two typing methods thus provided different information, and therefore both could be useful adjuncts to serotyping for the characterization of S. pneumoniae.

Sign in / Sign up

Export Citation Format

Share Document