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Foods (Basel, Switzerland) Apr 2024A review of quantitative risk assessment (QRA) models of in produce was carried out, with the objective of appraising and contrasting the effectiveness of the control... (Review)
Review
A review of quantitative risk assessment (QRA) models of in produce was carried out, with the objective of appraising and contrasting the effectiveness of the control strategies placed along the food chains. Despite nine of the thirteen QRA models recovered being focused on fresh or RTE leafy greens, none of them represented important factors or sources of contamination in the primary production, such as the type of cultivation, water, fertilisers or irrigation method/practices. Cross-contamination at processing and during consumer's handling was modelled using transfer rates, which were shown to moderately drive the final risk of listeriosis, therefore highlighting the importance of accurately representing the transfer coefficient parameters. Many QRA models coincided in the fact that temperature fluctuations at retail or temperature abuse at home were key factors contributing to increasing the risk of listeriosis. In addition to a primary module that could help assess current on-farm practices and potential control measures, future QRA models for minimally processed produce should also contain a refined sanitisation module able to estimate the effectiveness of various sanitisers as a function of type, concentration and exposure time. Finally, growth in the products down the supply chain should be estimated by using realistic time-temperature trajectories, and validated microbial kinetic parameters, both of them currently available in the literature.
PubMed: 38611415
DOI: 10.3390/foods13071111 -
BMC Infectious Diseases Jul 2023The clinical presentation of adult-onset immunodeficiency with anti-interferon (IFN)-γ autoantibodies with intracellular pathogens can be highly variable, which can...
BACKGROUND
The clinical presentation of adult-onset immunodeficiency with anti-interferon (IFN)-γ autoantibodies with intracellular pathogens can be highly variable, which can lead to misdiagnosis during the early stage of disease.
CASE PRESENTATION
We report a complex case of a 54-year-old Chinese male who was human immunodeficiency virus-negative. He had a presence of anti-IFN-γ autoantibodies and suffered from various intracellular pathogenic infections. The patient was admitted to our hospital for the first time in July 2016 with severe pneumonia, and he experienced multiple pneumonia infections between 2017 and 2019. In March 2019, the patient was hospitalized due to pulmonary lesions and multiple-bone destruction. During hospitalization, the patient was confirmed to have disseminated Talaromyces marneffei infection and was successfully treated with antifungal therapy for 1 year. In June 2021, Mycobacterium kansasii infection was detected by positive culture and progressive bone destruction. A high concentration of anti-IFN-γ antibodies was observed in the patient's serum. In addition, Listeria monocytogenes was isolated by blood culture, and the presence of L. monocytogenes in cerebrospinal fluid was confirmed by next-generation sequencing. Following anti-non-tuberculous mycobacteria (NTM) therapy and anti-bacterial therapy, the patient's symptoms, pulmonary lesions, and bone destruction gradually improved.
CONCLUSIONS
Although the clinical presentation of adult-onset immunodeficiency with anti-IFN-γ autoantibodies can be highly variable, the diagnosis should be considered if patients suffer from unexplained repeated bacterial or opportunistic infections. Conventional and advanced molecular testing should be used, as needed, for microbiological diagnoses among this special immunodeficient population.
Topics: Humans; Male; Middle Aged; Autoantibodies; HIV; Immunologic Deficiency Syndromes; Interferon-gamma; Mycobacterium Infections, Nontuberculous; Nontuberculous Mycobacteria
PubMed: 37495965
DOI: 10.1186/s12879-023-08404-8 -
Biomedicine & Pharmacotherapy =... Feb 2024Listeria monocytogenes (Lm), a foodborne bacterium, can infect people and has a high fatality rate in immunocompromised individuals. Listeriolysin O (LLO), the primary... (Review)
Review
Listeria monocytogenes (Lm), a foodborne bacterium, can infect people and has a high fatality rate in immunocompromised individuals. Listeriolysin O (LLO), the primary virulence factor of Lm, is critical in regulating the pathogenicity of Lm. This review concludes that LLO may either directly or indirectly activate a number of host cell viral pathophysiology processes, such as apoptosis, pyroptosis, autophagy, necrosis and necroptosis. We describe the invasion of host cells by Lm and the subsequent removal of Lm by CD8 T cells and CD4 T cells upon receipt of the LLO epitopes from major histocompatibility complex class I (MHC-I) and major histocompatibility complex class II (MHC-II). The development of several LLO-based vaccines that make use of the pore-forming capabilities of LLO and the immune response of the host cells is then described. Finally, we conclude by outlining the several natural substances that have been shown to alter the three-dimensional conformation of LLO by binding to particular amino acid residues of LLO, which reduces LLO pathogenicity and may be a possible pharmacological treatment for Lm.
Topics: Humans; Bacterial Toxins; Listeriosis; CD8-Positive T-Lymphocytes; Immunity; Listeria monocytogenes; Heat-Shock Proteins; Hemolysin Proteins
PubMed: 38194738
DOI: 10.1016/j.biopha.2024.116129 -
Using participatory epidemiology to investigate the causes of cattle abortion in Southwest Ethiopia.Heliyon Feb 2024Cattle abortion, stemming from both infectious and non-infectious causes, lead to notable financial setbacks in the cattle industry. Between October 2020 and October...
Cattle abortion, stemming from both infectious and non-infectious causes, lead to notable financial setbacks in the cattle industry. Between October 2020 and October 2021, an epidemiological investigation took place in Southwest Ethiopia. The objective was to determine the magnitude and seasonal occurrence of the presumed causes of cattle abortion. Information for this research was collected through 30 group discussions, each involving 8-12 participants. Various participatory epidemiological tools, including semi-structured interviews, pairwise ranking, matrix scoring, proportional piling, and seasonal calendars, were employed in the designated areas. By employing the pairwise ranking approach, the relative significance of presumed causes contributing to cattle abortion was established. The identified major presumed causes of cattle abortion, listed in increasing order of importance, were blackleg, foot-and-mouth disease, pasteurellosis, lumpy skin disease, listeriosis, trypanosomosis, Q fever, leptospirosis, and brucellosis. Participants identified brucellosis (6.1%), leptospirosis (6.0%), and Q-fever (5.7%) as the primary presumed causes of abortion, determined through proportional piling. Matrix scoring analysis indicated a robust agreement (W = 0.464-0.989; P < 0.001) among different informant groups regarding both the presumed causes of abortion and the associated clinical signs. Brucellosis and Q-fever were perceived to be more prevalent during the dry season, while leptospirosis, listeriosis, and lumpy skin disease were associated with the wet, hot, and rainy seasons. However, Pasteurellosis, blackleg, and physical/mechanical factors were deemed to be consistently encountered causes of abortion throughout the year. The patterns of seasonal occurrence of suspected abortion causes were widely acknowledged across informant groups (W = 0.977-0.863; P < 0.001). Local practices involving herbal remedies and traditional methods were employed by participants to manage cattle abortion. Moreover, the results underscore the necessity for additional laboratory research to pinpoint the exact causes of abortion in the study areas.
PubMed: 38390138
DOI: 10.1016/j.heliyon.2024.e25726 -
MBio Oct 2023Folic acid and its derivatives are required for the synthesis of purines, pyrimidines, and some amino acids. Antifolate antibiotics that target the folic acid metabolism...
Folic acid and its derivatives are required for the synthesis of purines, pyrimidines, and some amino acids. Antifolate antibiotics that target the folic acid metabolism pathway are commonly used for the treatment of listeriosis caused by the intracellular pathogen (). In recent work in , Feng et al. sought to understand the role of folic acid metabolism in virulence (Y. Feng, S. Chang, D. A. Portnoy, 2023, mBio https://doi.org/10.1128/mbio.01074-23). The authors discovered that N-formylmethionine, an amino acid utilized by bacteria to initiate protein synthesis, is crucial for intracellular growth and pathogenesis. Surprisingly, purines and thymidine were found to be dispensable for infection. Together these results demonstrate that while can obtain many essential nutrients from the host cytosol, including purines and most amino acids, it requires N-formylmethionine biosynthesis to properly regulate translation initiation during infection.
Topics: Humans; Listeria monocytogenes; Listeriosis; Amino Acids; Folic Acid; Purines
PubMed: 37706879
DOI: 10.1128/mbio.01385-23 -
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 -
European Journal of Cell Biology Feb 2024The facultative intracellular bacterium Listeria (L.) monocytogenes may cause severe diseases in humans and animals. The control of listeriosis/L. monocytogenes requires...
The facultative intracellular bacterium Listeria (L.) monocytogenes may cause severe diseases in humans and animals. The control of listeriosis/L. monocytogenes requires the concerted action of cells of the innate and adaptive immune systems. In this regard, cell-intrinsic immunity of infected cells, activated by the immune responses, is crucial for the control and elimination intracellular L. monocytogenes. Both the immune response against L. monocytogenes and cell intrinsic pathogen control are critically regulated by post-translational modifications exerted by the host ubiquitin system and ubiquitin-like modifiers (Ubls). In this review, we discuss our current understanding of the role of the ubiquitin system and Ubls in listeriosis, as well as future directions of research.
PubMed: 38442571
DOI: 10.1016/j.ejcb.2024.151401 -
International Journal of Food... Jan 2024Listeria (L.) monocytogenes is of global concern for food safety as the listeriosis-causing pathogen is widely distributed in the food processing environments, where it...
Listeria (L.) monocytogenes is of global concern for food safety as the listeriosis-causing pathogen is widely distributed in the food processing environments, where it can survive for a long time. Frozen vegetables contaminated with L. monocytogenes were recently identified as the source of two large listeriosis outbreaks in the EU and US. So far, only a few studies have investigated the occurrence and behavior of Listeria in frozen vegetables and the associated processing environment. This study investigates the occurrence of L. monocytogenes and other Listeria spp. in a frozen vegetable processing environment and in frozen vegetable products. Using whole genome sequencing (WGS), the distribution of sequence types (MLST-STs) and core genome sequence types (cgMLST-CT) of L. monocytogenes were assessed, and in-house clones were identified. Comparative genomic analyses and phenotypical characterization of the different MLST-STs and isolates were performed, including growth ability under low temperatures, as well as survival of freeze-thaw cycles. Listeria were widely disseminated in the processing environment and five in-house clones namely ST451-CT4117, ST20-CT3737, ST8-CT1349, ST8-CT6243, ST224-CT5623 were identified among L. monocytogenes isolates present in environmental swab samples. Subsequently, the identified in-house clones were also detected in product samples. Conveyor belts were a major source of contamination in the processing environment. A wide repertoire of stress resistance markers supported the colonization and survival of L. monocytogenes in the frozen vegetable processing facility. The presence of ArgB was significantly associated with in-house clones. Significant differences were also observed in the growth rate between different MLST-STs at low temperatures (4 °C and 10 °C), but not between in-house and non-in-house isolates. All isolates harbored major virulence genes such as full length InlA and InlB and LIPI-1, yet there were differences between MLST-STs in the genomic content. The results of this study demonstrate that WGS is a strong tool for tracing contamination sources and transmission routes, and for identifying in-house clones. Further research targeting the co-occurring microbiota and the presence of biofilms is needed to fully understand the mechanism of colonization and persistence in a food processing environment.
Topics: Listeria monocytogenes; Vegetables; Multilocus Sequence Typing; Food Microbiology; Listeriosis; Listeria
PubMed: 37977080
DOI: 10.1016/j.ijfoodmicro.2023.110479 -
Nucleic Acids Research Dec 2023Cell autonomous responses to intracellular bacteria largely depend on reorganization of gene expression. To gain isoform-level resolution of these modes of regulation,...
Cell autonomous responses to intracellular bacteria largely depend on reorganization of gene expression. To gain isoform-level resolution of these modes of regulation, we combined long- and short-read transcriptomic analyses of the response of intestinal epithelial cells to infection by the foodborne pathogen Listeria monocytogenes. Among the most striking isoform-based types of regulation, expression of the cellular stress response regulator CIRBP (cold-inducible RNA-binding protein) and of several SRSFs (serine/arginine-rich splicing factors) switched from canonical transcripts to nonsense-mediated decay-sensitive isoforms by inclusion of 'poison exons'. We showed that damage to host cell membranes caused by bacterial pore-forming toxins (listeriolysin O, perfringolysin, streptolysin or aerolysin) led to the dephosphorylation of SRSFs via the inhibition of the kinase activity of CLK1, thereby driving CIRBP alternative splicing. CIRBP isoform usage was found to have consequences on infection, since selective repression of canonical CIRBP reduced intracellular bacterial load while that of the poison exon-containing isoform exacerbated it. Consistently, CIRBP-bound mRNAs were shifted towards stress-relevant transcripts in infected cells, with increased mRNA levels or reduced translation efficiency for some targets. Our results thus generalize the alternative splicing of CIRBP and SRSFs as a common response to biotic or abiotic stresses by extending its relevance to the context of bacterial infection.
Topics: Humans; Alternative Splicing; Listeriosis; Protein Isoforms; RNA-Binding Proteins; Listeria monocytogenes
PubMed: 37941135
DOI: 10.1093/nar/gkad1033 -
Frontiers in Immunology 2024Previous studies have demonstrated an association between lymphatic vessels and diseases caused by bacterial infections. (LM) bacterial infection can affect multiple...
Previous studies have demonstrated an association between lymphatic vessels and diseases caused by bacterial infections. (LM) bacterial infection can affect multiple organs, including the intestine, brain, liver and spleen, which can be fatal. However, the impacts of LM infection on morphological and functional changes of lymphatic vessels remain unexplored. In this study, we found that LM infection not only induces meningeal and mesenteric lymphangiogenesis in mice, but also impairs meningeal lymphatic vessels (MLVs)-mediated macromolecules drainage. Interestingly, we found that the genes associated with lymphatic vessel development and function, such as and , were downregulated, suggesting that LM infection may affect cellular polarization and valve development. On the other hand, photodynamic ablation of MLVs exacerbated inflammation and bacterial load in the brain of mice with LM infection. Overall, our findings indicate that LM infection induces lymphangiogenesis and may affect cell polarization, cavity formation, and valve development during lymphangiogenesis, ultimately impairing MLVs drainage.
Topics: Animals; Mice; Listeria monocytogenes; Listeriosis; Lymphatic Vessels; Lymphangiogenesis; Meninges
PubMed: 38638427
DOI: 10.3389/fimmu.2024.1382971