Detection and Genotyping of Leuconostoc spp. in a Sausage Processing Plant

Some Leuconostoc spp. have the ability to produce slime and undesirable compounds in cooked sausage. The objectives of this research were to identify Leuconostoc sources in a Vienna-type sausage processing plant and to evaluate the genetic diversity of the isolated strains. Three hundred and two samples of sausage batter, sausages during processing, spoiled sausage, equipment surfaces, chilling brine, workers' gloves and aprons, and used casings were collected (March to November 2008 and February to April 2010) from a sausage processing plant. Lactic acid bacteria (LAB) were quantified, and Leuconostoc were detected using PCR. Strains were isolated and identified in Leuconostoc-positive samples. Leuconostoc strains were genotyped using randomly amplified polymorphic DNA and pulsed-field gel electrophoresis. LAB content of nonspoiled and spoiled sausage ranged from <0.8 to 4.4 log CFU/g and from 4.9 to 8.3 log CFU/g, respectively. LAB levels on equipment surfaces ranged from <1.3 to 4.8 log CFU/100 cm2. Leuconostoc was detected in 35% of the samples, and 88 Leuconostoc spp. strains were isolated and genotyped. The main Leuconostoc spp. isolated were L. mesenteroides (37 genotypes), L. fallax (29 genotypes), and L. lactis (6 genotypes). Some strains of Leuconostoc isolated from equipment surfaces and sausages showed the same genotype. One L. lactis genotype included strains isolated from spoiled sausages analyzed in April 2008 and March to April 2010. Equipment and conveyor belts constitute Leuconostoc contamination sources. Leuconostoc persistence in the sausage processing environment and in the final product suggests the existence of microbial reservoirs, possibly on equipment surfaces.

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Polyphasic study of the genetic diversity of lactobacilli associated with 'Almagro' eggplants spontaneous fermentation, based on combined numerical analysis of randomly amplified polymorphic DNA and pulsed-field gel electrophoresis patterns

Journal of Applied Microbiology ◽

10.1111/j.1365-2672.2004.02324.x ◽

2004 ◽

Vol 97 (2) ◽

pp. 446-458 ◽

Cited By ~ 38

Author(s):

I. Sanchez ◽

S. Sesena ◽

L.L. Palop

Keyword(s):

Genetic Diversity ◽

Numerical Analysis ◽

Gel Electrophoresis ◽

Pulsed Field Gel Electrophoresis ◽

Randomly Amplified Polymorphic Dna ◽

Spontaneous Fermentation ◽

Pulsed Field

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Monitoring lactic acid bacteria strains during ‘Cacioricotta’ cheese production by restriction endonuclease analysis and pulsed-field gel electrophoresis

Journal of Dairy Research ◽

10.1017/s0022029900004672 ◽

2001 ◽

Vol 68 (1) ◽

pp. 139-144 ◽

Cited By ~ 14

Author(s):

GIUSEPPE BLAIOTTA ◽

GIANCARLO MOSCHETTI ◽

ERMENEGILDA SIMEOLI ◽

ROSAMARIA ANDOLFI ◽

FRANCESCO VILLANI ◽

...

Keyword(s):

Lactic Acid ◽

Lactic Acid Bacteria ◽

Restriction Endonuclease ◽

Gel Electrophoresis ◽

Water Buffalo ◽

Restriction Endonuclease Analysis ◽

Buffalo Milk ◽

Pulsed Field Gel Electrophoresis ◽

Pulsed Field ◽

Endonuclease Analysis

Lactic acid bacteria (LAB) play an important role in food fermentation, as the products obtained with their aid are characterized by hygienic safety, storage stability and attractive sensory properties. A major aim of the research in this field is the selection of LAB strains that could be used. Hence it is very important to be able to apply a reliable method to distinguish a particular strain specifically and unambiguously, which allows studies of population dynamics of mixed cultures and monitoring starter strains during fermentation (Ramos & Harlander, 1990).Molecular methods are a powerful alternative to the traditional differentiation of bacteria. A highly reproducible method for characterizing and distinguishing closely related strains, is represented by REA-PFGE (restriction endonuclease analysis by pulsed-field gel electrophoresis) performed by infrequently cutting endonucleases. Genetic differentiation of strains in several species of LAB has been successfully performed by this technique (Moschetti et al. 1997; Villani et al. 1997) obtaining very clear and reproducible restriction patterns (Moschetti et al. 1998).In this study selected inoculated strains (lactococci or lactobacilli) were monitored by REA-PFGE during the whole process of water-buffalo ‘cacioricotta’ cheese-making. This product is a typical and traditional cheese in southern Italy produced from cow, goat, ewe or water-buffalo milk. The original technology of this preparation permits the recovery of whey proteins due to the high heat treatment of whole milk employed, allowing interesting yields to be achieved in terms of cheese. The use of starters is not common in traditional technology but low acid protection of the final product suggested the use of LAB as starter (Emaldi et al. 1987).

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Differentiation ofLactobacillus sanfranciscensisstrains by randomly amplified polymorphic DNA and pulsed-field gel electrophoresis

FEMS Microbiology Letters ◽

10.1111/j.1574-6968.1998.tb13908.x ◽

1998 ◽

Vol 166 (2) ◽

pp. 325-332 ◽

Cited By ~ 63

Author(s):

Giacomo Zapparoli ◽

Sandra Torriani ◽

Franco Dellaglio

Keyword(s):

Gel Electrophoresis ◽

Pulsed Field Gel Electrophoresis ◽

Randomly Amplified Polymorphic Dna ◽

Pulsed Field

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

Applied and Environmental Microbiology ◽

10.1128/aem.65.1.150-155.1999 ◽

1999 ◽

Vol 65 (1) ◽

pp. 150-155 ◽

Cited By ~ 203

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.

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Prevalence of Listeria monocytogenes in Broilers at the Abattoir, Processing Plant, and Retail Level

Journal of Food Protection ◽

10.4315/0362-028x-64.7.994 ◽

2001 ◽

Vol 64 (7) ◽

pp. 994-999 ◽

Cited By ~ 54

Author(s):

MARIA K. MIETTINEN ◽

LIISA PALMU ◽

K. JOHANNA BJÖRKROTH ◽

HANNU KORKEALA

Keyword(s):

Listeria Monocytogenes ◽

Gel Electrophoresis ◽

Conveyor Belt ◽

Pulsed Field Gel Electrophoresis ◽

Contamination Level ◽

Contamination Rate ◽

Processing Plant ◽

Broiler Meat ◽

Pulsed Field ◽

Processing Plants

The environment and products from two broiler abattoirs and processing plants and raw broiler pieces at the retail level were sampled for Listeria monocytogenes in order to evaluate the contamination level of the broiler carcasses and products. Sampling started in the slaughtering process and finished with raw broiler meat or ready-to-eat cooked product. Sampling sites positive for L. monocytogenes at the broiler abattoir were the air chiller, the skin-removing machine, and the conveyor belt leading to the packaging area. The L. monocytogenes contamination rate varied from 1 to 19% between the two plants studied. Furthermore, 62% (38 of 61) of the raw broiler pieces, bought from retail stores, were positive for L. monocytogenes. Altogether, 136 L. monocytogenes isolates were obtained for serotyping and pulsed-field gel electrophoresis(PFGE) characterization performed with two rare-cutting enzymes (ApaI and AscI). Altogether three serotypes (1/2a, 1/2c, and 4b) and 14 different PFGE types were obtained using information provided from both ApaI and AscI patterns for discrimination basis. The two broiler abattoirs studied did not share the same PFGE types. However, the same PFGE types found in the raw broiler pieces at the retail level were also found in the broiler abattoirs where the broilers had been slaughtered.

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