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Infection and Immunity Oct 2023Bacteria frequently interfere with the post-translational modifications of host cells to facilitate their survival and growth after invasion. SUMOylation, a reversible... (Review)
Review
Bacteria frequently interfere with the post-translational modifications of host cells to facilitate their survival and growth after invasion. SUMOylation, a reversible post-translational modification process, plays an important role in biological life activities. In addition to being critical to host cell metabolism and survival, SUMOylation also regulates gene expression and cell signal transmission. Moreover, SUMOylation in eukaryotic cells can be used by a variety of bacterial pathogens to advance bacterial invasion. In this minireview, we focused on the role and mechanism of host SUMOylation in the pathogenesis of six important clinical bacterial pathogens (, , Typhimurium, , and ). Taken together, this review provided new insights for understanding the unique pathogen-host interaction based on host SUMOylation and provided a novel perspective on the development of new strategies to combat bacterial infections in the future.
Topics: Humans; Sumoylation; Bacterial Infections; Listeria monocytogenes; Protein Processing, Post-Translational; Salmonella typhimurium
PubMed: 37725062
DOI: 10.1128/iai.00283-23 -
Food Microbiology May 2024The facultative intracellular bacterium Listeria monocytogenes (L. monocytogenes) is the causative agent of listeriosis, a severe invasive illness. This ubiquitous... (Review)
Review
The facultative intracellular bacterium Listeria monocytogenes (L. monocytogenes) is the causative agent of listeriosis, a severe invasive illness. This ubiquitous species is widely distributed in the environment, but infection occurs almost exclusively through ingestion of contaminated food. The pork production sector has been heavily affected by a series of L. monocytogenes-related foodborne outbreaks in the past around the world. Ready-to-eat (RTE) pork products represent one of the main food sources for strong-evidence listeriosis outbreaks. This pathogen is known to be present throughout the entire pig and pork production chain. Some studies hypothesized that the main source of contamination in final pork products was either living pigs or the food-processing environment. A detailed genomic picture of L. monocytogenes can provide a renewed understanding of the routes of contamination from pig farms to the final products. This review provides an overview of the prevalence, the genomic diversity and the genetic background linked to virulence of L. monocytogenes along the entire pig and pork production chain, from farm to fork.
Topics: Animals; Swine; Listeria monocytogenes; Food Microbiology; Pork Meat; Red Meat; Prevalence; Listeriosis; Genomics; Food Contamination
PubMed: 38225039
DOI: 10.1016/j.fm.2023.104430 -
Journal of Food Protection Apr 2024A wide range of drying parameters and methods are used by industry to produce dried apples. To ensure end-product safety and regulatory compliance, it is essential to...
A wide range of drying parameters and methods are used by industry to produce dried apples. To ensure end-product safety and regulatory compliance, it is essential to evaluate the effectiveness of such industrial practices on microbial inactivation. Therefore, the objective of this study was to evaluate the effects of drying air temperature and velocity on Listeria monocytogenes inactivation during drying of apple slices. Apples (cv. Gala) were cored, sliced as rings (∼6 mm thick), and surface-inoculated with broth-grown culture of an 8-strain cocktail of L. monocytogenes to achieve an inoculation level of 8.6 ± 0.3 log CFU/g. Apple rings were dried in batches using dry air in a pilot-scale impingement oven at 60 or 80 °C air temperature and 0.7 or 2.1 m/s air velocity, and sampled every 30 min for bacterial enumeration, water activity (a), and moisture content analysis. L. monocytogenes reduction increased (P < 0.05) with higher air velocity or higher drying air temperature. By the end of drying, in which the standard moisture content for dried apple slices of <24% wet basis was reached, L. monocytogenes was reduced by 1.8 ± 0.3 and 2.8 ± 0.7 log CFU/g at 0.7 and 2.1 m/s air velocity, respectively, after 180 min at 60 °C. When using 80 °C drying temperature, L. monocytogenes reduction was 5.2 ± 0.5 log CFU/g at both air velocities after 150 min. Therefore, process conditions should be considered in the validation of fruit drying processes, instead of solely relying on product endpoint properties, such as moisture content.
Topics: Malus; Temperature; Listeria monocytogenes; Colony Count, Microbial; Fruit; Food Microbiology; Food Handling
PubMed: 38417481
DOI: 10.1016/j.jfp.2024.100253 -
Applied and Environmental Microbiology Jun 2024The foodborne pathogen is differentiated into four distinct lineages which differ in their virulence. It remains unknown, however, whether the four lineages also differ...
The foodborne pathogen is differentiated into four distinct lineages which differ in their virulence. It remains unknown, however, whether the four lineages also differ with respect to their ability to persist in food processing facilities, their resistance to high pressure, a preservation method that is used commercially for control on ready-to-eat meats, and their ability to form biofilms. This study aimed to determine differences in the pressure resistance and biofilm formation of 59 isolates of representing lineages I and II. Furthermore, the genetic similarity of 9 isolates of that were obtained from a meat processing facility over a period of 1 year and of 20 isolates of from food processing facilities was analyzed to assess whether the ability of the lineages of to persist in these facilities differs. Analysis of 386 genomes with respect to the source of isolation revealed that genomes of lineage II are over-represented in meat isolates when compared with clinical isolates. Of the 38 strains of that persisted in food processing facilities (this study or published studies), 31 were assigned to lineage II. Isolates of lineage I were more resistant to treatments at 400 to 600 MPa. The thickness of biofilms did not differ between lineages. In conclusion, strains of lineage II are more likely to persist in food processing facilities while strains of lineage I are more resistant to high pressure.IMPORTANCE substantially contributes to the mortality of foodborne disease in developed countries. The virulence of strains of four lineages of differs, indicating that risks associated with the presence of are lineage specific. Our study extends the current knowledge by documentation that the lineage-level phylogeny of plays a role in the source of isolation, in the persistence in food processing facilities, and in the resistance to pathogen intervention technologies. In short, the control of risks associated with the presence of in food is also lineage specific. Understanding the route of contamination is an important factor to consider when designing improved control measures.
Topics: Listeria monocytogenes; Phylogeny; Food Microbiology; Food Handling; Biofilms; Food-Processing Industry; Meat Products
PubMed: 38809044
DOI: 10.1128/aem.00861-24 -
Infection and Immunity Oct 2023is a remarkably well-adapted facultative intracellular pathogen that can thrive in a wide range of ecological niches. maximizes its ability to generate energy from...
is a remarkably well-adapted facultative intracellular pathogen that can thrive in a wide range of ecological niches. maximizes its ability to generate energy from diverse carbon sources using a respiro-fermentative metabolism that can function under both aerobic and anaerobic conditions. Cellular respiration maintains redox homeostasis by regenerating NAD while also generating a proton motive force. The end products of the menaquinone (MK) biosynthesis pathway are essential to drive both aerobic and anaerobic cellular respirations. We previously demonstrated that intermediates in the MK biosynthesis pathway, notably 1,4-dihydroxy-2-naphthoate (DHNA), are required for the survival and virulence of independent of their role in respiration. Furthermore, we found that restoration of NAD/NADH ratio through expression of water-forming NADH oxidase could rescue phenotypes associated with DHNA deficiency. Here, we extend these findings to demonstrate that endogenous production or direct supplementation of DHNA restored both the cellular redox homeostasis and metabolic output of fermentation in . Furthermore, exogenous supplementation of DHNA rescues the growth and virulence of DHNA-deficient mutants. Finally, we demonstrate that exogenous DHNA restores redox balance in specifically through the recently annotated NADH dehydrogenase Ndh2, independent of its role in the extracellular electron transport pathway. These data suggest that the production of DHNA may represent an additional layer of metabolic adaptability by to drive energy metabolism in the absence of respiration-favorable conditions.
Topics: Listeria monocytogenes; Virulence; NAD; Oxidation-Reduction; Homeostasis
PubMed: 37754681
DOI: 10.1128/iai.00022-23 -
Microorganisms Feb 2024() is a pathogen that is transmitted through contaminated food and causes the illness known as listeriosis. The virulence factor InlA plays a crucial role in the...
() is a pathogen that is transmitted through contaminated food and causes the illness known as listeriosis. The virulence factor InlA plays a crucial role in the invasion of into the human intestinal epithelium. In addition, InlA enhances the pathogenicity of host strains, and different strains of contain varying variations of InlA. Our study analyzed a total of 4393 published genomes from 511 sequence types (STs) of diverse origins. We identified 300 unique InlA protein sequence types (PSTs) and revealed 45 highly mutated amino acid sites. The leucine-rich repeat (LRR) region was found to be the most conserved among the InlA, while the protein A (PA) region experienced the highest mutation rate. Two new types of mutations were identified in the B-repeat region of InlA. Correspondence analysis (CA) was used to analyze correlations between the lineages or 10 most common sequence types (STs) and amino acid (aa) sites. ST8 was strongly correlated with site 192_F, 454_T. ST7 exhibited a strong correlation with site 51_A, 573_E, 648_S, and 664_A, and it was also associated with ST6 and site 544_N, 671_A, 738_B, 739_B, 740_B, and 774_Y. Additionally, a strong correlation between ST1 and site 142_S, 738_N, ST2 and site 2_K, 142_S, 738_N, as well as ST87 and site2_K, 738_N was demonstrated. Our findings contribute significantly to the understanding of the distribution, composition, and conservation of InlA in These findings also suggest a potential role of InlA in supporting molecular epidemiological tracing efforts.
PubMed: 38543536
DOI: 10.3390/microorganisms12030485 -
Journal of Food Protection May 2024Listeria monocytogenes are considered to be the major foodborne pathogen worldwide. To understand the prevalence and potential risk of L. monocytogenes in retail foods,...
Listeria monocytogenes are considered to be the major foodborne pathogen worldwide. To understand the prevalence and potential risk of L. monocytogenes in retail foods, a total of 1243 retail foods in 12 food categories were sampled and screened for L. monocytogenes from 2020 to 2022 in Huzhou, China. A total of 46 out of 1234 samples were confirmed to be L. monocytogenes positive with a total rate of 3.7%. The contamination rate of seasoned raw meat (15.2%) was the highest, followed by raw poultry meat and raw livestock meat (9.9%) and salmon sashimi (9.5%). The L. monocytogenes isolates belonged to four serotypes, 1/2a,1/2b, 1/2c, and 4b, with the most prevalent serotype being 1/2a (47.9%). All isolates were grouped into 15 sequence types (STs) belonging to 14 clonal complexes (CCs) via multilocus sequence typing (MLST). The most prevalent ST was ST9/CC9 (23.9%), followed by ST3/CC3 (19.6%) and ST121/CC121 (17.4%). Notably, 11 STs were detected from ready-to-eat (RTE) foods, some of them have been verified to be strongly associated with clinical origin listeriosis cases, such as ST3, ST2, ST5, ST8, and ST87. Listeria pathogenicity islands 1 (LIPI-1) and LIPI-2 were detected in approximately all L. monocytogenes isolates, whereas the distribution of both LIPI-3 genes and LIPI-4 genes exhibited association with specific ST, with LIPI-3 in ST3 and ST288, and LIPI-4 in ST87. The strains carrying LIPI-3 and LIPI-4 virulence genes in this study were all isolated from RTE foods. Antimicrobial susceptibility tests showed that >90% of isolates were susceptible to PEN, AMP, ERY, CIP, SXT, VAN, CHL, and GEN, indicating the antibiotic treatment might be still efficient for most of the L. monocytogenes strains. However, for the three clinical first-line antibiotics (PEN, AMP, and GEN), we also observed three and four strains showing MIC values greater than the susceptibility standards for PEN and AMP, respectively, and one strain showing resistance to GEN.
PubMed: 38797247
DOI: 10.1016/j.jfp.2024.100307 -
Comprehensive Reviews in Food Science... Sep 2023In 2023, Listeria monocytogenes persistence remains a problem in the food business. A profound understanding of how this pathogen persists may lead to better aimed... (Review)
Review
In 2023, Listeria monocytogenes persistence remains a problem in the food business. A profound understanding of how this pathogen persists may lead to better aimed intervention/prevention strategies. The lack of a uniform definition of persistence makes the comparison between studies complex. Harborage sites offer protection against adverse environmental conditions and form the ideal habitat for the formation of biofilms, one of the major persistence strategies. A retarded growth rate, disinfectant resistance/tolerance, desiccation resistance/tolerance, and protozoan protection complete the list of persistence strategies for Listeria monocytogenes and can occur on themselves or in combination with biofilms. Based on the discussed persistence strategies, intervention strategies are proposed. By enhancing the focus on four precaution principles (cleaning and disinfection, infrastructure/hygienic design, technical maintenance, and work methodology) as mentioned in Regulation (EC) No. 852/2004, the risk of persistence can be decreased. All of the intervention strategies result in obtaining and maintaining a good general hygiene status throughout the establishment at all levels ranging from separate equipment to the entire building.
Topics: Biofilms; Disinfection; Food; Food Microbiology; Listeria monocytogenes
PubMed: 37548605
DOI: 10.1111/1541-4337.13219 -
Revista Argentina de Microbiologia Jun 2024Human listeriosis is an infectious disease caused by Listeria monocytogenes. The invasive form of this disease leads to a high rate of hospitalizations and fatality. The...
Human listeriosis is an infectious disease caused by Listeria monocytogenes. The invasive form of this disease leads to a high rate of hospitalizations and fatality. The main mode of transmission is through contaminated ready-to-eat foods such as dairy, vegetables and meat products. The knowledge of the diversity and population dynamics of isolates collected from human and food sources is essential for the detection of clusters and the identification of common sites of infection. The aim of this study was the molecular characterization of L. monocytogenes isolates in Argentina. We sequenced a total of 63 isolates, 35 from human and 28 from food sources, collected between 2018 and 2023. Our genomic study divided the isolates into two lineages, four serogroups, 17 sequence types and 15 clonal complexes (CCs). The hypervirulent clone CC1 (lineage I; serogroup IVb) predominated in human and food samples. The phylogenomic analysis showed a high and possible epidemiological relationship between isolates from human and/or food sources, suggesting the presence of transmission chains in our country. These findings highlight the need to strengthen genomic surveillance of L. monocytogenes in Argentina. The identification of geographic distribution and characteristics of predominant and emerging clones from human and food sources might help to focus action plans and public health policies better directed at the control and prevention of listeriosis.
PubMed: 38834434
DOI: 10.1016/j.ram.2024.03.002 -
Molecular Microbiology Nov 2023Listeria monocytogenes is a foodborne bacterium that naturally occurs in the soil. Originating from there, it contaminates crops and infects farm animals and their...
Listeria monocytogenes is a foodborne bacterium that naturally occurs in the soil. Originating from there, it contaminates crops and infects farm animals and their consumption by humans may lead to listeriosis, a systemic life-threatening infectious disease. The adaptation of L. monocytogenes to such contrastive habitats is reflected by the presence of virulence genes for host infection and other genes for survival under environmental conditions. Among the latter are ABC transporters for excretion of antibiotics produced by environmental competitors; however, most of these transporters have not been characterized. Here, we generated a collection of promoter-lacZ fusions for genes encoding ABC-type drug transporters of L. monocytogenes and screened this reporter strain collection for induction using a library of natural compounds produced by various environmental microorganisms. We found that the timABR locus (lmo1964-lmo1962) was induced by the macrodiolide antibiotic tartrolon B, which is synthesized by the soil myxobacterium Sorangium cellulosum. Tartrolon B resistance of L. monocytogenes was dependent on timAB, encoding the ATPase and the permease component of a novel ABC transporter. Moreover, transplantation of timAB was sufficient to confer tartrolon B resistance to Bacillus subtilis. Expression of the timABR locus was found to be auto-repressed by the TimR repressor, whose repressing activity was lost in the presence of tartrolon B. We also demonstrate that tartrolon sensitivity was suppressed by high external potassium concentrations, suggesting that tartrolon acts as potassium ionophore. Our results help to map the ecological interactions of an important human pathogen with its co-residing species within their joint natural reservoir.
Topics: Animals; Humans; Listeria monocytogenes; ATP-Binding Cassette Transporters; Membrane Transport Proteins; Listeriosis; Operon; Soil; Bacterial Proteins
PubMed: 37804169
DOI: 10.1111/mmi.15178