Virulence potential of Listeria monocytogenes strains recovered from pigs in Spain

2020 ◽  
Vol 187 (11) ◽  
pp. e101-e101
Author(s):  
Jaime Gómez-Laguna ◽  
Fernando Cardoso-Toset ◽  
Jazmín Meza-Torres ◽  
Javier Pizarro-Cerdá ◽  
Juan J Quereda
Keyword(s):  
Listeria Monocytogenes ◽  
Virulence Factors ◽  
Bacterial Pathogen ◽  
Listeriolysin O ◽  
Actin Assembly ◽  
Virulence Potential ◽  
Serotype 1 ◽  
Internalin B ◽  
Meat Samples ◽  
Internalin A

BackgroundListeria monocytogenes is a foodborne bacterial pathogen that causes listeriosis, an infectious disease in animals and people, with pigs acting as asymptomatic reservoirs. In August 2019 an outbreak associated with the consumption of pork meat caused 222 human cases of listeriosis in Spain. Determining the diversity as well as the virulence potential of strains from pigs is important to public health.MethodsThe behaviour of 23 L monocytogenes strains recovered from pig tonsils, meat and skin was compared by studying (1) internalin A, internalin B, listeriolysin O, actin assembly-inducing protein and PrfA expression levels, and (2) their invasion and intracellular growth in eukaryotic cells.ResultsMarked differences were found in the expression of the selected virulence factors and the invasion and intracellular replication phenotypes of L monocytogenes strains. Strains obtained from meat samples and belonging to serotype 1/2a did not have internalin A anchored to the peptidoglycan. Some strains expressed higher levels of the studied virulence factors and invaded and replicated intracellularly more efficiently than an epidemic L monocytogenes reference strain (F2365).ConclusionThis study demonstrates the presence of virulent L monocytogenes strains with virulent potential in pigs, with valuable implications in veterinary medicine and food safety.

scholarly journals Lactiplantibacillus plantarum subsp. plantarum and Fructooligosaccharides Combination Inhibits the Growth, Adhesion, Invasion, and Virulence of Listeria monocytogenes

Foods ◽  
2022 ◽  
Vol 11 (2) ◽  
pp. 170
Author(s):  
Qingli Dong ◽  
Xinxin Lu ◽  
Binru Gao ◽  
Yangtai Liu ◽  
Muhammad Zohaib Aslam ◽  
...  
Keyword(s):  
Listeria Monocytogenes ◽  
Incubation Temperature ◽  
Foodborne Pathogen ◽  
Untreated Group ◽  
Listeriolysin O ◽  
Regulatory Factor ◽  
Gene Expressions ◽  
Internalin B ◽  
Serotype 4B ◽  
Internalin A

Listeria monocytogenes is a foodborne pathogen responsible for many food outbreaks worldwide. This study aimed to investigate the single and combined effect of fructooligosaccharides (FOS) and Lactiplantibacillus plantarum subsp. plantarum CICC 6257 (L. plantarum) on the growth, adhesion, invasion, and virulence of gene expressions of Listeria monocytogenes 19112 serotype 4b (L. monocytogenes). Results showed that L. plantarum combined with 2% and 4% (w/v) FOS significantly (p < 0.05) inhibited the growth of L. monocytogenes (3–3.5 log10 CFU/mL reduction) at the incubation temperature of 10 °C and 25 °C. Under the same combination condition, the invasion rates of L. monocytogenes to Caco-2 and BeWo cells were reduced more than 90% compared to the result of the untreated group. After L. plantarum was combined with the 2% and 4% (w/v) FOS treatment, the gene expression of actin-based motility, sigma factor, internalin A, internalin B, positive regulatory factor A, and listeriolysin O significantly (p < 0.05) were reduced over 91%, 77%, 92%, 89%, 79%, and 79% compared to the result of the untreated group, respectively. The inhibition level of the L. plantarum and FOS combination against L. monocytogenes was higher than that of FOS or L. plantarum alone. Overall, these results indicated that the L. plantarum and FOS combination might be an effective formula against L. monocytogenes.

scholarly journals The Listeria monocytogenes hemolysin has an acidic pH optimum to compartmentalize activity and prevent damage to infected host cells

2002 ◽  
Vol 156 (6) ◽  
pp. 1029-1038 ◽  
Author(s):  
Ian J. Glomski ◽  
Margaret M. Gedde ◽  
Albert W. Tsang ◽  
Joel A. Swanson ◽  
Daniel A. Portnoy
Keyword(s):  
Listeria Monocytogenes ◽  
Bacterial Pathogen ◽  
Cytolytic Activity ◽  
Host Cells ◽  
Adaptive Mutation ◽  
Acidic Ph ◽  
Listeriolysin O ◽  
Lysosomal Hydrolases ◽  
Ph Optimum ◽  
Neutral Ph

Listeria monocytogenes is a facultative intracellular bacterial pathogen that escapes from a phagosome and grows in the host cell cytosol. The pore-forming cholesterol-dependent cytolysin, listeriolysin O (LLO), mediates bacterial escape from vesicles and is ∼10-fold more active at an acidic than neutral pH. By swapping dissimilar residues from a pH-insensitive orthologue, perfringolysin O (PFO), we identified leucine 461 as unique to pathogenic Listeria and responsible for the acidic pH optimum of LLO. Conversion of leucine 461 to the threonine present in PFO increased the hemolytic activity of LLO almost 10-fold at a neutral pH. L. monocytogenes synthesizing LLO L461T, expressed from its endogenous site on the bacterial chromosome, resulted in a 100-fold virulence defect in the mouse listeriosis model. These bacteria escaped from acidic phagosomes and initially grew normally in cells and spread cell to cell, but prematurely permeabilized the host membrane and killed the cell. These data show that the acidic pH optimum of LLO results from an adaptive mutation that acts to limit cytolytic activity to acidic vesicles and prevent damage in the host cytosol, a strategy also used by host cells to compartmentalize lysosomal hydrolases.

scholarly journals Pathogenic Biohacking: Induction, Modulation and Subversion of Host Transcriptional Responses by Listeria monocytogenes

Toxins ◽  
2020 ◽  
Vol 12 (5) ◽  
pp. 294
Author(s):  
Matthew J. G. Eldridge ◽  
Pascale Cossart ◽  
Mélanie A. Hamon
Keyword(s):  
Gene Expression ◽  
Listeria Monocytogenes ◽  
Virulence Factors ◽  
Bacterial Pathogen ◽  
Typical Feature ◽  
Host Gene ◽  
Host Cells ◽  
Host Gene Expression ◽  
Transcriptional Responses ◽  
The Impact

During infection, the foodborne bacterial pathogen Listeria monocytogenes dynamically influences the gene expression profile of host cells. Infection-induced transcriptional changes are a typical feature of the host-response to bacteria and contribute to the activation of protective genes such as inflammatory cytokines. However, by using specialized virulence factors, bacterial pathogens can target signaling pathways, transcription factors, and epigenetic mechanisms to alter host gene expression, thereby reprogramming the response to infection. Therefore, the transcriptional profile that is established in the host is delicately balanced between antibacterial responses and pathogenesis, where any change in host gene expression might significantly influence the outcome of infection. In this review, we discuss the known transcriptional and epigenetic processes that are engaged during Listeria monocytogenes infection, the virulence factors that can remodel them, and the impact these processes have on the outcome of infection.

Incidence and Characterization of Listeria monocytogenes from Domestic and Imported Foods in Korea

2000 ◽  
Vol 63 (2) ◽  
pp. 186-189 ◽  
Author(s):  
SUN-YOUNG BAEK ◽  
SOON-YOUNG LIM ◽  
DONG-HA LEE ◽  
KYUNG-HEE MIN ◽  
CHANG-MIN KIM
Keyword(s):  
Listeria Monocytogenes ◽  
Raw Milk ◽  
Listeriolysin O ◽  
Department Of Agriculture ◽  
Saltwater Fish ◽  
Serotype 1 ◽  
Imported Food ◽  
Polymerase Chain ◽  
Imported Foods

A total of 1,537 domestic and imported food products were examined for the incidence of Listeria monocytogenes between 1993 and 1997 in Korea. L. monocytogenes was detected using the U.S. Department of Agriculture isolation method. Isolated L. monocytogenes was confirmed by polymerase chain reaction with hly1 and hly2 primers designed from the listeriolysin O. Overall, 122 samples (7.9%) contained L. monocytogenes. The rate of isolation was 4.3% for beef, 19.1% for pork, 30.2% for chicken, 1.2% for shellfish, 4.4% for raw milk, 4.4% for frozen smoked mussels, and 6.1% for ice cream. No L. monocytogenes was found in pasteurized milk, pasteurized processed cheese, saltwater fish, dried seafoods, or ham. The overall incidence was lower than that reported in previous studies from other countries. Most isolates were serotype 1/2b except for chicken, in which serotype 1/2a was predominant. The serotyping results might imply the presence of food or geography-specific L. monocytogenes strains.

scholarly journals Listeria monocytogenes Phospholipase C-Dependent Calcium Signaling Modulates Bacterial Entry into J774 Macrophage-Like Cells

1999 ◽  
Vol 67 (4) ◽  
pp. 1770-1778 ◽  
Author(s):  
Sandra J. Wadsworth ◽  
Howard Goldfine
Keyword(s):  
Listeria Monocytogenes ◽  
Calcium Signaling ◽  
Phospholipase C ◽  
Virulence Factors ◽  
Intracellular Signaling ◽  
Lethal Dose ◽  
Listeriolysin O ◽  
Wild Type ◽  
J774 Macrophage ◽  
Kinetics Of

ABSTRACT Listeria monocytogenes secretes several proteins that have been shown to contribute to virulence. Among these is listeriolysin O (LLO), a pore-forming hemolysin that is absolutely required for virulence. Two other virulence factors are phospholipases: a phosphatidylinositol-specific phospholipase C (PI-PLC [plcA]) and a broad-range PLC (plcB). Although mutations in plcA or plcB resulted in small increases in mouse 50% lethal dose (LD50), deletions in both genes resulted in a 500-fold increase in LD50. We have examined the role of these secreted proteins in host intracellular signaling in the J774 macrophage-like cell line. Measurements of cytosolic free calcium ([Ca2+]i) have revealed a rapid spike upon exposure of these cells to wild-typeL. monocytogenes. This is followed by a second peak at 5 min and a third prolonged peak with a maximal [Ca2+]i of 800 to 1,000 nM. The pattern of calcium changes was greatly altered by deletion of any of the three virulence factors. An LLO mutant produced none of these elevations in [Ca2+]i; however, a transient elevation was observed whenever these bacteria entered the cell. A PI-PLC mutant produced a diminished single elevation in [Ca2+]i at 15 to 30 min. A broad-range PLC mutant produced only the first calcium spike. Studies with inhibitors suggested that the first elevation arises from influx of calcium from the extracellular medium through plasma membrane channels and that the second and third elevations come from release of Ca2+ from intracellular stores. We observed that internalization of wild-type bacteria and the broad-range PLC mutant was delayed for 5 to 10 min, but the LLO and PI-PLC mutants were internalized rapidly upon infection. Inhibitors that affected calcium signaling changed the kinetics of association of wild-type bacteria with J774 cells, the kinetics of entry, and the efficiency of escape from the primary phagosome.

Prediction of Persistence of Listeria monocytogenes ST451 in a Rabbit Meat Processing Plant in the Czech Republic

2019 ◽  
Vol 82 (8) ◽  
pp. 1350-1356
Author(s):  
TEREZA GELBÍČOVÁ ◽  
MARTINA FLORIANOVÁ ◽  
ZUZANA TOMÁŠTÍKOVÁ ◽  
LUCIE POSPÍŠILOVÁ ◽  
IVANA KOLÁČKOVÁ ◽  
...  
Keyword(s):  
Listeria Monocytogenes ◽  
Core Genome ◽  
Sequence Type ◽  
Processing Plant ◽  
Meat Processing ◽  
Sequencing Method ◽  
Serotype 1 ◽  
Rabbit Meat ◽  
Meat Samples

ABSTRACT This study was focused on characterization of the genetic diversity of Listeria monocytogenes isolated from packed fresh rabbit meat obtained from one producer via retail outlets. The partial aim was to compare the characteristics of a suspect persistent strain with strains from human cases. The occurrence of L. monocytogenes in vacuum-packed rabbit meat was monitored during 2013 to 2016. All strains were characterized by serotyping, pulsed-field gel electrophoresis, and multilocus sequence typing (MLST). Selected strains, which represented each year, were analyzed using the whole genome sequencing method. L. monocytogenes was detected in 21 (38%) of 56 originally packed rabbit meat samples from one food producer during the whole monitored period. All strains showed the identical serotype (1/2a), AscI/ApaI pulsotype (735/2), and sequence type (ST451). The clonal similarity of strains from rabbit meat was also confirmed on the basis of core genome MLST (on 1,701 loci). This fact suggests the occurrence of a suspect persistent strain in the meat processing plant. Results of core genome MLST enabled us to unambiguously exclude rabbit meat as a source of listeriosis in humans caused by the indistinguishable AscI/ApaI pulsotype and sequence type, although all strains carried all genes important for the virulence of L. monocytogenes. No specific genes that may be associated with its persistence in the food processing environment were detected among the tested strains of ST451. HIGHLIGHTS

Occurrence of Zoonotic Bacteria in Retail Game Meat in Japan with Special Reference to Erysipelothrix

1997 ◽  
Vol 60 (3) ◽  
pp. 328-331 ◽  
Author(s):  
YOKO KANAI ◽  
HIDEKI HAYASHIDANI ◽  
KEN-ICHI KANEKO ◽  
MASUO OGAWA ◽  
TOSHIO TAKAHASHI ◽  
...  
Keyword(s):  
Listeria Monocytogenes ◽  
Wild Boar ◽  
Yersinia Enterocolitica ◽  
The Other ◽  
Salmonella Spp ◽  
Serotype 1 ◽  
Meat Samples ◽  
Zoonotic Bacteria ◽  
Highly Virulent ◽  
Campylobacter Spp

From December 1993 to March 1994, a total of 93 wild boar and 30 deer meat samples were purchased from 13 retail shops and examined for the presence of species of Erysipelothrix, Yersinia, Listeria, Salmonella and Campylobacter. Erysipelothrix spp. were isolated from 41 wild boar and 15 deer samples. These isolates were identified as 13 serotypes. Serotypes 6 and 2 were the most predominant. Of 17 isolates examined, 14 isolates were highly virulent for mice. The bacteria of the same serotype were isolated repeatedly from the samples purchased in 4 of the shops. Yersinia enterocolitica was isolated from 36 wild boar and 10 deer samples; however, all isolates of Y. enterocolitica did not have pathogenic properties. Listeria monocytogenes was isolated from 5 wild boar samples. The isolates were identified as serotype 1/2c and 4b. Salmonella spp. were isolated from 2 wild boar samples; one isolate was identified as S. typhimurium and the other was untypable. Campylobacter spp. were not detected.

scholarly journals Listeria monocytogenes Isolated from Illegally Imported Food Products into the European Union Harbor Different Virulence Factor Variants

Genes ◽  
2018 ◽  
Vol 9 (9) ◽  
pp. 428 ◽  
Author(s):  
Kathrin Rychli ◽  
Beatrix Stessl ◽  
Kati Szakmary-Brändle ◽  
Anja Strauß ◽  
Martin Wagner ◽  
...  
Keyword(s):  
European Union ◽  
Listeria Monocytogenes ◽  
Virulence Factors ◽  
Food Samples ◽  
Pathogen Transmission ◽  
Listeriolysin O ◽  
The European Union ◽  
Genetic Fingerprint ◽  
Genotype Diversity ◽  
Imported Food

Unregulated international flow of foods poses a danger to human health, as it may be contaminated with pathogens. Recent studies have investigated neglected routes of pathogen transmission and reported the occurrence of Listeria monocytogenes in food illegally imported into the European Union (EU), either confiscated at four international airports or sold illegally on the Romanian black market. In this study we investigated the genotype diversity and the amino acid sequence variability of three main virulence factors of 57 L. monocytogenes isolates. These isolates were derived from 1474 food samples illegally imported into the EU and originated from 17 different countries. Multilocus sequence typing revealed 16 different sequence types (STs) indicating moderate genotype diversity. The most prevalent STs were ST2, ST9, and ST121. The pulsed-field gel electrophoresis (PFGE) analysis resulted in 34 unique pulsotypes. PFGE types assigned to the most prevalent STs (ST2, ST9, and ST121) were highly related in their genetic fingerprint. Internalin A (InlA) was present in 20 variants, including six truncated InlA variants, all harbored by isolates of ST9 and ST121. We detected eight ST-specific listeriolysin O (LLO) variants, and among them, one truncated form. The actin-assembly-inducing protein ActA was present in 15 different ST-specific variants, including four ActA variants with an internal truncation. In conclusion, this study shows that L. monocytogenes, isolated from illegally imported food, have moderate genotype diversity, but diverse virulence factors variants, mainly of InlA.

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