scholarly journals Detection and Pulsed-Field Gel Electrophoresis Typing of Listeria monocytogenes Isolates from Milk Vending Machines in Croatia

Beverages ◽  
2019 ◽  
Vol 5 (3) ◽  
pp. 46
Author(s):  
Nevijo Zdolec ◽  
Dean Jankuloski ◽  
Marta Kiš ◽  
Brigita Hengl ◽  
Nataša Mikulec
Keyword(s):  
Listeria Monocytogenes ◽  
Gel Electrophoresis ◽  
Molecular Detection ◽  
Dna Amplification ◽  
Raw Milk ◽  
Pulsed Field Gel Electrophoresis ◽  
Effective Control ◽  
Pulsed Field ◽  
Milk Samples ◽  
Vending Machines

The aim of the present study was to evaluate the persistence of Listeria monocytogenes in raw milk from vending machines, based on culture and molecular detection of pathogen and Pulsed-Field Gel Electrophoresis typing. From December 2015 to January 2017, a total of 319 milk samples from 36 vending machines were examined for the presence and count of L. monocytogenes by reference methods ISO 11290:1 and ISO 11290:2. Molecular detection of pathogens was performed by loop-mediated isothermal DNA amplification (LAMP) coupled with bioluminescence (Molecular Detection Assay). L. monocytogenes was detected by MDA in 14 milk samples (4.38%) from four farms, compared to eight positive samples (2.5%) retrieved by a reference ISO method. Cultivable L. monocytogenes isolates were subjected to Pulsed-Field Gel Electrophoresis typing and pulsotypes were compared with those obtained during the previous survey in Croatia (2014‒2015). It was found that identical PFGE patterns of L. monocytogenes occur in milk samples of the same producer over a three-year period, indicating the persistence of pathogens in raw milk vending machines. The results obtained support the need for more effective control of milk in the entire food chain.

scholarly journals Characterization of Recurrent and Sporadic Listeria monocytogenes Isolates from Raw Milk and Nondairy Foods by Pulsed-Field Gel Electrophoresis, Monocin Typing, Plasmid Profiling, and Cadmium and Antibiotic Resistance Determination

2001 ◽  
Vol 67 (2) ◽  
pp. 840-847 ◽  
Author(s):  
J. Harvey ◽  
A. Gilmour
Keyword(s):  
Listeria Monocytogenes ◽  
Gel Electrophoresis ◽  
Raw Milk ◽  
Pulsed Field Gel Electrophoresis ◽  
Enzyme Electrophoresis ◽  
Genetic Changes ◽  
Pulsed Field ◽  
Time Period ◽  
Plasmid Profiling

ABSTRACT Following previous surveys to assess the incidence ofListeria monocytogenes in raw milk and nondairy foods processed in Northern Ireland, isolates were characterized as recurrent or sporadic on the basis of multilocus enzyme electrophoresis (MEE) analysis and restriction fragment length polymorphism typing. In the present study, 45 representative recurrent and sporadic electrophoretic types (ETs) previously identified by MEE were subjected to pulsed-field gel electrophoresis (PFGE) of genomic DNA macrorestriction fragments, monocin typing, plasmid profiling, and an examination of resistance to cadmium and nine different antibiotics. Although PFGE proved to be capable of subdividing a number of recurrent and sporadic ETs, the grouping of strains arrived at by PFGE and MEE were in broad agreement, and previous conclusions regarding the designation of L. monocytogenes strains as recurrent or sporadic remained unaltered. It is considered that PFGE was able to detect minor genetic changes in recurrent ETs which occurred during the time period in which food surveys were carried out. Production of type E monocin (Types A to E were found among the 45 strains), plasmid carriage, and resistance to cadmium occurred more frequently in recurrent than in sporadic strains and may be important with regard to the ability of L. monocytogenes to persist in food and food-processing environments. Only 2 of 45 strains showed resistance to any of the nine antibiotics tested: two sporadic strains were resistant to tetracycline (MIC, 64 μg ml−1).

Arcobacter Species and Their Pulsed-Field Gel Electrophoresis Genotypes in Finnish Raw Milk during Summer 2011

2013 ◽  
Vol 76 (9) ◽  
pp. 1630-1632 ◽  
Author(s):  
JOANA REVEZ ◽  
MARIANNE HUUSKONEN ◽  
MARJO RUUSUNEN ◽  
MIIA LINDSTRÖM ◽  
MARJA-LIISA HÄNNINEN
Keyword(s):  
Gel Electrophoresis ◽  
Raw Milk ◽  
Positive Sample ◽  
Pulsed Field Gel Electrophoresis ◽  
Selective Detection ◽  
Potential Hazard ◽  
Pulsed Field ◽  
Milk Samples ◽  
Unpasteurized Milk ◽  
Arcobacter Butzleri

The aim of this study was to investigate the occurrence of Arcobacter species in raw milk in Finland. A total of 177 raw milk samples, each from a separate farm, were examined from June to August 2011. Arcobacter species were isolated using an enrichment and selective detection procedure. Overall, 26 (15%) of the 177 samples yielded Arcobacter spp. Samples from 25 farms were positive for Arcobacter butzleri and from 1 farm for Arcobacter cryaerophilus. Moreover, both Arcobacter butzleri and A. cryaerophilus were recovered from 1 positive sample. To evaluate a possible genetic variability, one strain of A. butzleri from each farm and the A. cryaerophilus sample were analyzed by pulsed-field gel electrophoresis. Genotyping revealed that Arcobacter spp. populations are heterogeneous, and no dominant clone has spread in the investigated samples. Our study is the first report on the isolation of both A. butzleri and A. cryaerophilus in raw milk in Finland. Based on our findings, the presence of Arcobacter species in raw milk may pose a potential hazard for human health, in particular for consumers who prefer drinking unpasteurized milk.

scholarly journals Caracterização molecular de Listeria monocytogenes oriundas de cortes cárneos bovinos e de abatedouros frigoríficos de bovinos localizados no Distrito Federal, Brasil

2016 ◽  
Vol 36 (10) ◽  
pp. 957-964 ◽  
Author(s):  
Joana M. Palma ◽  
◽  
Rodrigo C. Lisboa ◽  
Dália P. Rodrigues ◽  
André F.M. Santos ◽  
...  
Keyword(s):  
Listeria Monocytogenes ◽  
Gel Electrophoresis ◽  
Pulsed Field Gel Electrophoresis ◽  
Pulsed Field ◽  
Distrito Federal

RESUMO: Este trabalho teve como objetivo realizar a detecção de cepas de Listeria monocytogenes de cortes cárneos bovinos bem como no ambiente de abatedouros frigoríficos localizados no Distrito Federal, promover a sorotipificação pela reação em cadeia da polimerase (PCR), realizar antibiograma e submeter às cepas à eletroforese de campo pulsado (Pulsed-field gel electrophoresis - PFGE). Foram analisados um total de 125 cortes cárneos bovinos, 45 amostras de swabs de carcaças e 43 amostras de swabs em que foram detectados 13 cepas de Listeria monocytogenes, sendo 11 em cortes cárneos bovinos e 2 swabs de ambiente em um abatedouro frigorifico. Não foram isoladas cepas de swabs de carcaça. Dentre as 13 cepas de Listeria monocytogenes foram encontradas seis cepas do sorotipo 4b, cinco do sorotipo 1/2c e duas cepas do sorotipo 1/2a. Dentre as 11 cepas de L. monocytogenes encontradas em cortes cárneos bovino, uma (9,1%) cepa apresentou resistência a eritromicina, outra (9,1%) cepa a gentamicina e outra a ciprofloxacina (9,1%) e todas as cepas (100%) apresentaram resistência ao Ác. Nalidíxico. Das duas (2) cepas oriundas de ralos de abatedouro frigorífico, todas (100%) apresentaram resistência ao Ác. Nalidíxico e a sulfonamidas. A análise por eletroforese de campo pulsante (PFGE) demonstrou 13 diferentes pulsotipos, em que foram agrupados em 3 diferentes grupos clonais, que coincidentemente se correlacionavam com os 3 diferentes sorotipos encontrados sugerindo uma ampla disseminação desses perfis no Distrito Federal.

Isolation and Pulsed-Field Gel Electrophoresis Typing of Listeria monocytogenes from Modified Atmosphere Packaged Fresh-Cut Vegetables Collected in Ireland

2006 ◽  
Vol 69 (10) ◽  
pp. 2524-2528 ◽  
Author(s):  
GILLIAN A. FRANCIS ◽  
DAVID O'BEIRNE
Keyword(s):  
Listeria Monocytogenes ◽  
Gel Electrophoresis ◽  
Fruits And Vegetables ◽  
Pulsed Field Gel Electrophoresis ◽  
Leafy Vegetables ◽  
Modified Atmosphere ◽  
Pulsed Field ◽  
Fruit Samples ◽  
Fresh Cut ◽  
Pfge Profiles

The incidence of Listeria monocytogenes in modified atmosphere packaged fresh-cut fruits and vegetables from chill cabinets of a supermarket in Ireland was investigated over a 2-year period. Overall, 9.58% of fresh-cut produce was contaminated with Listeria spp. Various species of Listeria were isolated from samples, including L. monocytogenes, L. seeligeri, L. innocua, L. welshimeri, and L. ivanovii. No fruit samples contained detectable L. monocytogenes. Overall, a total of 21 L. monocytogenes isolates (2.9% of samples) were recovered from a range of products, including dry coleslaw mix (80% shredded cabbage and 20% shredded carrot), bean sprouts, and leafy vegetables such iceberg, romaine, and radicchio lettuce and mixed salad leaves (curly endive, escarole, and radicchio leaves). Dry coleslaw mix appeared to have the highest incidence of Listeria contamination (20%) compared with other products. Listeria contamination was more frequent (P < 0.05) during the summer and autumn months than during the winter and spring months. The 21 L. monocytogenes isolates were subsequently subtyped by genomic macrorestriction techniques using ApaI with pulsed-field gel electrophoresis (PFGE). PFGE of digested DNA produced bands of 79 to 518 kb. Four PFGE profiles were identified, and approximately 50% of the isolates were associated with profile 1. This study indicates that fresh-cut vegetables packaged under a modified atmosphere can support growth of numerous species of Listeria, including L. monocytogenes.

scholarly journals A Nosocomial Outbreak of Community-Associated Methicillin-ResistantStaphylococcus aureusamong Healthy Newborns and Postpartum Mothers

2007 ◽  
Vol 18 (2) ◽  
pp. 128-132 ◽  
Author(s):  
Andrea Saunders ◽  
Linda Panaro ◽  
Allison McGeer ◽  
Alana Rosenthal ◽  
Diane White ◽  
...  
Keyword(s):  
Gel Electrophoresis ◽  
Hospital Setting ◽  
Pulsed Field Gel Electrophoresis ◽  
Effective Control ◽  
Nosocomial Outbreak ◽  
Pulsed Field ◽  
Outbreak Period ◽  
Microbiological Testing ◽  
Unique Strain ◽  
Postpartum Mothers

BACKGROUND: Community-associated methicillin-resistantStaphylococcus aureus(CA-MRSA) has increasingly been isolated from individuals with no predisposing risk factors; however, such strains have rarely been linked to outbreaks in the hospital setting. The present study describes the investigation of an outbreak of CA-MRSA that occurred in the maternal-newborn unit of a large community teaching hospital in Toronto, Ontario.METHODS: Screening and clinical specimens collected from mothers and newborns delivered during the outbreak period, as well as from staff on the affected unit, were submitted for microbiological testing. Computerized delivery logs and nursing notes were reviewed, and a case control study was conducted.RESULTS: Analysis by pulsed-field gel electrophoresis revealed 38 babies and seven mothers with MRSA colonization and/or infection by the same unique strain (Canadian MRSA-10-related) from September to December 2004. Isolates were characterized as having the staphylococcal chromosome cassettemectype IVa and were positive for the Panton-Valentine leukocidin gene. No one health care worker was associated with all cases; however, mothers and newborns exposed to one particular nurse (Nurse A) were almost 23 times (odds ratio 22.7, 95% CI 3.3 to 195.9) more likely to acquire MRSA than those with no such contact. MRSA was successfully isolated from Nurse A and from an environmental swab of a telephone recently used by Nurse A; both isolates matched the pulsed-field gel electrophoresis pattern of the outbreak strain.CONCLUSION: The first nosocomial outbreak of CA-MRSA among healthy newborns and postpartum mothers in Canada is described. Effective control of sustained MRSA transmission within an institution may require prompt identification, treatment and monitoring of colonized and/or infected staff.

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.

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