scholarly journals Characterization of epidemic clones of Listeria monocytogenes serotype 4b isolated from humans and meat products in Brazil

2015 ◽  
Vol 9 (09) ◽  
pp. 962-969 ◽  
Author(s):  
André Victor Barbosa ◽  
Aloysio de Mello Figueiredo Cerqueira ◽  
Leonardo Alves Rusak ◽  
Cristhiane Moura Falavina Dos Reis ◽  
Nilma Cintra Leal ◽  
...  
Keyword(s):  
Listeria Monocytogenes ◽  
Gel Electrophoresis ◽  
Virulence Genes ◽  
Foodborne Pathogen ◽  
Meat Products ◽  
Human Case ◽  
Pulsed Field Gel Electrophoresis ◽  
Clinical Samples ◽  
Pulsed Field ◽  
Serotype 4B

Introduction: Listeria monocytogenes is an important foodborne pathogen and the 4b serotype is responsible for many cases of human listeriosis reported in Brazil. Several listeriosis outbreaks worldwide have involved a small number of well-defined clonal groups, designated as epidemic clones (ECs). Methodology: We studied 71 strains of serotype 4b, including 25 isolates from human cases of listeriosis and 46 from meat-based foods, collected in Brazil between 1977 and 2010. The presence of ECs (I and II) markers and virulence genes (inlA, inlB, ilnC, inlJ and actA) were evaluated by PCR assay. The genetic relationship of ECs-positive strains was assessed by pulsed field gel electrophoresis. Results: ECI and ECII markers were found both in human and food strains, with 19.7% positive for the ECI marker and 40.8% for ECII. Most strains (97.2%) were positive for the virulence genes that were studied. Nevertheless, the actA gene amplicons showed two distinct sizes, with all ECI positive strains exhibiting a 105bp deletion. Pulsed field gel electrophoresis (PFGE) analysis allowed the recognition of highly related strains, particularly from two outbreaks of neonatal listeriosis in São Paulo State occurred in 1992 and 1997, both ECII-positive; and two ECI strains from a human case (1982) and from bovine meat (2009). Conclusions: The presence of ECs among clinical samples and beef isolates of serotype 4b from some regions of Brazil highlights the need for rigorous control of production procedures. Furthermore, the association of ECII with two nosocomial outbreaks suggests its ability to spread in these settings.

Listeria monocytogenes From Farm to Fork in a Brazilian Pork Production Chain

2020 ◽  
Vol 83 (3) ◽  
pp. 485-490 ◽  
Author(s):  
DANILO A. L. SILVA ◽  
CLARISSE V. BOTELHO ◽  
BRUNA T. F. MARTINS ◽  
RAFAELA M. TAVARES ◽  
ANDERSON C. CAMARGO ◽  
...  
Keyword(s):  
Listeria Monocytogenes ◽  
Gel Electrophoresis ◽  
Virulence Genes ◽  
Pulsed Field Gel Electrophoresis ◽  
Control Measures ◽  
Production Chain ◽  
Pork Production ◽  
Pulsed Field ◽  
Genetic Profiles ◽  
Different Sources

ABSTRACT Listeria monocytogenes contamination was assessed in different steps of a pork production chain. Ten lots of pigs were sampled at termination barns, at slaughter (after bleeding, after buckling, after evisceration, and after final washing), at processing (knives, deboning tables, and employees' hands), and of end products (ribs, shoulder, ham, and sausage). All samples (n = 670) were subjected to L. monocytogenes detection, and the obtained isolates (n = 18, identified as Listeria spp.) were characterized by their biochemical characteristics, serogroups, virulence genes, pulsed-field gel electrophoresis profiles, antibiotic resistances (ampicillin, penicillin, gentamicin, and sulfamethoxazole-trimethoprim), and adhesion abilities. The results revealed the low occurrence of Listeria spp. in the evaluated pork production chain. However, four tested sausage samples (40%) were positive for Listeria spp., with L. monocytogenes identified in two (20%) of these samples. Ten isolates were identified as L. monocytogenes (eight from serogroup 1/2a or 3a and two from serogroup 4b, 4d, or 4e): all isolates were also positive for the virulence-related genes hlyA, iap, plcA, actA, inlA, inlB, inlC, and inlJ and susceptible to the tested antibiotics. One sausage sample was contaminated by both serogroups 1/2a or 3a and 4b, 4d, or 4e. Isolates from serogroup 1/2a or 3a obtained during visits 5 and 6 presented distinct genetic profiles by pulsed-field gel electrophoresis, indicating that contamination may come from different sources. The adhesion potential exhibited by Listeria spp. isolates (n = 18) ranged from weak (serogroup 4b, 4d, or 4e) to moderate (L. innocua and L. monocytogenes serogroup 1/2a or 3a). Despite the low occurrence of L. monocytogenes, pathogenic serogroups were detected in sausages, demanding control measures by the industry. HIGHLIGHTS

scholarly journals Molecular Typing by Pulsed-Field Gel Electrophoresis of Spanish Animal and Human Listeria monocytogenes Isolates

2001 ◽  
Vol 67 (12) ◽  
pp. 5840-5843 ◽  
Author(s):  
A. I. Vela ◽  
J. F. Fernandez-Garayzabal ◽  
J. A. Vazquez ◽  
M. V. Latre ◽  
M. M. Blanco ◽  
...  
Keyword(s):  
Listeria Monocytogenes ◽  
Molecular Typing ◽  
Gel Electrophoresis ◽  
Pulsed Field Gel Electrophoresis ◽  
Clinical Samples ◽  
Pulsed Field ◽  
Clinical Strains ◽  
Great Genetic Diversity ◽  
Different Sources ◽  
Maize Stalks

ABSTRACT A total of 153 strains of Listeria monocytogenesisolated from different sources (72 from sheep, 12 from cattle, 18 from feedstuffs, and 51 from humans) in Spain from 1989 to 2000 were characterized by pulsed-field gel electrophoresis. The strains ofL. monocytogenes displayed 55 pulsotypes. The 84 animal, 51 human, and 18 feedstuff strains displayed 31, 29, and 7 different pulsotypes, respectively, indicating a great genetic diversity among the Spanish L. monocytogenes isolates studied. L. monocytogenes isolates from clinical samples and feedstuffs consumed by the diseased animals were analyzed in 21 flocks. In most cases, clinical strains from different animals of the same flock had identical pulsotypes, confirming the existence of a listeriosis outbreak. L. monocytogenes strains with pulsotypes identical to those of clinical strains were isolated from silage, potatoes, and maize stalks. This is the first study wherein potatoes and maize stalks are epidemiologically linked with clinical listeriosis.

Use of Pulsed-Field Gel Electrophoresis To Monitor a Five-Strain Mixture of Listeria monocytogenes in Frankfurter Packages†

2003 ◽  
Vol 66 (8) ◽  
pp. 1465-1468 ◽  
Author(s):  
ANNA C. S. PORTO ◽  
LAURA WONDERLING ◽  
JEFFREY E. CALL ◽  
JOHN B. LUCHANSKY
Keyword(s):  
Listeria Monocytogenes ◽  
Gel Electrophoresis ◽  
Pulsed Field Gel Electrophoresis ◽  
Processing Plant ◽  
Refrigerated Storage ◽  
Pork Sausage ◽  
Pulsed Field ◽  
Potassium Lactate ◽  
Serotype 1 ◽  
Serotype 4B

In a previous study, the viability of a five-strain mixture of Listeria monocytogenes (including Scott A [serotype 4b, clinical isolate], 101M [serotype 4b, beef-pork sausage isolate], F6854 [serotype 1/2a, turkey frankfurter isolate], H7776 [serotype 4b, frankfurter isolate], and MFS-2 [serotype 1/2a, pork plant isolate]) was monitored during refrigerated storage of frankfurters prepared with and without 3.0% added potassium lactate. Throughout a 90-day period of storage at 4°C, the initial inoculum level of 20 CFU per package remained relatively constant in packages containing frankfurters prepared with potassium lactate, but pathogen counts increased to 4.6 log10 CFU in packages containing frankfurters prepared without added potassium lactate. To determine which of the five strains persisted under these conditions, randomly selected colonies obtained after 28 and 90 days of refrigerated storage of frankfurters were analyzed by pulsed-field gel electrophoresis (PFGE) with the restriction enzyme SmaI to generate distinct banding patterns for each of the five strains. Then, with the use of PFGE as a tool for identification, the percentages of the strains on days 28 and 90 of the growth study were compared. In the absence of any added potassium lactate in the product, 43% of the 58 isolates recovered on day 28 were identified as strain Scott A, 12% were identified as strain 101M, 22% were identified as strain F6854, 10% were identified as strain H7776, and 12% were identified as strain MFS-2. However, by day 90, an appreciable number (83%) of the 60 isolates analyzed were identified as strain MFS-2. In packages containing frankfurters formulated with 3.0% potassium lactate, all five strains were present at frequencies of 5 to 36% among the 19 isolates tested on day 28; however, by day 90, strain MFS-2 made up the statistical majority (63%) of the 27 isolates tested. The results of this study indicate that strain MFS-2, a serotype 1/2a isolate recovered from a pork processing plant, was more persistent than strains Scott A, 101M, F6854, or H7776 during the extended refrigerated storage of frankfurters.

Analysis of Listeria monocytogenes Strain Distribution in a Pork Slaughter and Cutting Plant in the Province of Quebec

2014 ◽  
Vol 77 (12) ◽  
pp. 2121-2128 ◽  
Author(s):  
GUILLAUME LARIVIÉRE-GAUTHIER ◽  
ANN LETELLIER ◽  
ANNAËLLE KÉROUANTON ◽  
SADJIA BEKAL ◽  
SYLVAIN QUESSY ◽  
...  
Keyword(s):  
Listeria Monocytogenes ◽  
Gel Electrophoresis ◽  
Food Production ◽  
Control Strategies ◽  
Meat Products ◽  
Pulsed Field Gel Electrophoresis ◽  
Public Health Perspective ◽  
Pulsed Field ◽  
Plant Environment ◽  
Production Stages

Following the 2008 Canadian listeriosis outbreak associated with ready-to-eat (RTE) meat products, regulations on the presence of Listeria monocytogenes in RTE food production facilities were modified by Health Canada, confirming the need to control this pathogen, not only in the final product but also in the plant environment. Information on the occurrence of this microorganism during the early steps of production, such as the slaughtering process and in the cutting area, is scarce in Canada. In this study, we sampled different production steps in a slaughtering and cutting plant in the province of Quebec over a 2-year period. The lairage pens, representative areas of the slaughter line, and cutting zones were targeted after their respective cleaning procedures. A total of 874 samples were analyzed for the presence of L. monocytogenes. Characterization was done by first genoserogrouping the isolates using multiplex PCR and then using a pulsed-field gel electrophoresis approach. L. monocytogenes was detected throughout all production stages. The 108 positive samples found were analyzed further, and we established that there were 4 different serogroups, with serogroup IIb being the most prevalent. The results of pulsed-field gel electrophoresis analysis showed a significant decrease in the diversity of strains from the first areas of the plant to the cutting room (10 pulsotypes in 13 positive samples in lairage and 9 in 86 positive samples in cutting) and also showed the overrepresentation of a single predominant strain in the cutting room environment (type 1, representing 96.1% of the isolates). Biofilm formation analysis of the strains cannot exclusively explain the transitions we observed. A strong genotypic similarity between strains isolated in the early production areas and some strains in the cutting room was shown. These results support the need for better surveillance of L. monocytogenes prior to RTE food production in order to design control strategies that are better adapted from a public health perspective.

scholarly journals Relatedness of Listeria monocytogenes Isolates Recovered from Selected Ready-To-Eat Foods and Listeriosis Patients in the United States

2005 ◽  
Vol 71 (12) ◽  
pp. 8115-8122 ◽  
Author(s):  
Stefanie Evans Gilbreth ◽  
Jeff E. Call ◽  
F. Morgan Wallace ◽  
Virginia N. Scott ◽  
Yuhuan Chen ◽  
...  
Keyword(s):  
United States ◽  
Listeria Monocytogenes ◽  
Gel Electrophoresis ◽  
Food Products ◽  
The United States ◽  
Pulsed Field Gel Electrophoresis ◽  
Clinical Isolates ◽  
Pulsed Field ◽  
Serotype 1 ◽  
Serotype 4B

ABSTRACT Pulsed-field gel electrophoresis and serotyping were performed for 544 isolates of Listeria monocytogenes, including 502 isolates recovered from contaminated samples from 31,705 retail ready-to-eat (RTE) food products and 42 isolates recovered from human cases of listeriosis. The isolates were from Maryland (294 isolates) and California (250 isolates) and were collected in 2000 and 2001. The isolates were placed into 16 AscI pulsogroups (level of relatedness within each group, ≥66%), 139 AscI pulsotypes (levels of relatedness, ≥25% to 100%), and eight serotypes (serotypes 1/2a, 1/2b, 1/2c, 3a, 3b, 4b, 4c, and 4d). The most frequently found pulsotypes belonged to either pulsogroup A (150 food isolates plus 4 clinical isolates) or pulsogroup B (104 food isolates plus 5 clinical isolates). The majority of the 502 food isolates were either serotype 1/2a (298 isolates) or serotype 1/2b (133 isolates), whereas the majority of the 42 clinical isolates were either serotype 1/2a (19 isolates) or serotype 4b (15 isolates). Additionally, 13 clinical isolates displayed pulsotypes also found in food isolates, whereas the remaining 29 clinical isolates displayed 24 unique pulsotypes. These data indicate that most (86%) of the L. monocytogenes subtypes found in the RTE foods sampled belonged to only two serotypes and that 90% of the isolates displayed 73 pulsotypes, with 107 isolates displaying pulsotype 1. These data should help define the distribution and relatedness of isolates found in RTE foods in comparison with isolates that cause listeriosis.

Multiplex PCR Assay Simplifies Serotyping and Sequence Typing of Listeria monocytogenes Associated with Human Outbreaks

2005 ◽  
Vol 68 (9) ◽  
pp. 1907-1910 ◽  
Author(s):  
WEI ZHANG ◽  
STEPHEN J. KNABEL
Keyword(s):  
Listeria Monocytogenes ◽  
Multiplex Pcr ◽  
Gel Electrophoresis ◽  
Virulence Genes ◽  
Rapid Identification ◽  
Pulsed Field Gel Electrophoresis ◽  
Pcr Assay ◽  
Pulsed Field ◽  
Typing Scheme ◽  
Multiplex Pcr Assay

Listeria monocytogenes serotypes 1/2a and 4b are responsible for the majority of cases of human listeriosis worldwide. In this study, a multiplex PCR assay was developed to allow rapid identification and easily interpretable differentiation of serotypes 1/2a and 4b from other serotypes of L. monocytogenes by simultaneously targeting two virulence genes (inlB and inlC) and two serotype-specific genes (ORF2372 and lmo0171). A subsequent gel extraction and sequence typing analysis of the highly polymorphic intragenic regions in inlB and inlC simplified a previously developed multi–virulence-locus sequence typing scheme and provided discriminatory power for subtyping L. monocytogenes similar to pulsed-field gel electrophoresis analysis.

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.

Low Potential Virulence Associated with Mutations in the inlA and prfA Genes in Listeria monocytogenes Isolated from Raw Retail Poultry Meat

2013 ◽  
Vol 76 (1) ◽  
pp. 129-132 ◽  
Author(s):  
VICTORIA LÓPEZ ◽  
JAIME NAVAS ◽  
JOAQUÍN V. MARTÍNEZ-SUÁREZ
Keyword(s):  
Listeria Monocytogenes ◽  
Gel Electrophoresis ◽  
Virulence Genes ◽  
Pulsed Field Gel Electrophoresis ◽  
Poultry Meat ◽  
Pathogenic Potential ◽  
Molecular Serotyping ◽  
Potential Source ◽  
Raw Foods ◽  
Over Time

Packaged raw foods can represent a potential source of Listeria monocytogenes contamination when opened at home, and listeriosis is associated with the consumption of undercooked raw foods. The aim of this study was to characterize a group of L. monocytogenes strains isolated from 56 packages of raw chicken meat from a single brand in order to determine the diversity of the strains that dominate in a particular food over time, as well as their pathogenic potential. Forty (71%) samples were found to be positive for L. monocytogenes, and three isolates per sample were subjected to PCR molecular serotyping. Subtyping of 45 isolates from different manufacturing dates (n = 40) or different molecular serotype within the same sample (n = 5) identified 11 different L. monocytogenes subtypes as defined by pulsed-field gel electrophoresis and sequencing of virulence genes actA and inlA. Two of the subtypes accounted for 51% of the isolates. About 40% of isolates (three subtypes) were found to potentially present attenuated virulence because of the presence of mutations in the prfA and inlA genes.

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