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Microorganisms Jan 2024is a Gram-positive pathogenic bacterium which can be found in soil or water. Infection with the microorganism can occur after ingestion of contaminated food products.... (Review)
Review
is a Gram-positive pathogenic bacterium which can be found in soil or water. Infection with the microorganism can occur after ingestion of contaminated food products. Small and large outbreaks of listeriosis have been described in the past. can cause a number of different clinical syndromes, most frequently sepsis, meningitis, and rhombencephalitis, particularly in immunocompromised hosts. systemic infections can develop following tissue penetration across the gastrointestinal tract or to hematogenous spread to sterile sites, possibly evolving towards bacteremia. only rarely causes bone or joint infections, usually in the context of prosthetic material that can provide a site for bacterial seeding. We describe here the clinical findings of invasive listeriosis, mainly focusing on the diagnosis, clinical management, and treatment of bone and vertebral infections occurring in the context of invasive listeriosis.
PubMed: 38258004
DOI: 10.3390/microorganisms12010178 -
Foodborne Pathogens and Disease Jan 2024is a foodborne pathogen that has variable subtypes associated with human listeriosis and occurs in food and processing environments. This study was conducted to provide...
is a foodborne pathogen that has variable subtypes associated with human listeriosis and occurs in food and processing environments. This study was conducted to provide the genetic and phenotypic characterization of in pig carcasses and environments of slaughterhouses in Korea. A total of 22 were isolated from eight of 26 pig slaughterhouses between 2020 and 2022, and the most common serotype was 1/2c (40.9%), followed by serotypes 1/2b (31.8%) and 1/2a (27.3%). The isolates showed a significantly high prevalence of virulence genes located in pathogenicity island-1 (LIPI-1) and internalins (90.9-100%; < 0.05). However, the prevalence rates of , , and stress survival islet-1 (SSI-1) located in LIPI-3, LIPI-4, and SSI were only 9.1%, 22.7%, and 31.8%, respectively. In addition, among the epidemic clones (EC), ECI, ECII, ECIII, and ECV, only one isolate was represented as ECV. Isolates identified from the same slaughterhouses were divided into two or more pulsotypes, except for two slaughterhouses. Furthermore, the seven STs were classified into seven clonal complexes (CCs) (CC8, CC9, CC37, CC87, CC121, CC155, and CC288), and all CCs belonged to lineages I (31.8%) and II (68.1%). Interestingly, the isolates showed a high prevalence of oxacillin resistance (59.1%), and most isolates of the serotypes 1/2a and 1/2b exhibited oxacillin resistance, whereas only one of nine serotype 1/2c isolates exhibited oxacillin resistance. These results provide the genetic diversity of in pig carcasses and environments of slaughterhouses, and continuous monitoring will be helpful in predicting food safety risks.
Topics: Animals; Swine; Humans; Listeria monocytogenes; Abattoirs; Listeriosis; Oxacillin; Republic of Korea; Food Microbiology
PubMed: 37819680
DOI: 10.1089/fpd.2023.0053 -
Microorganisms Sep 2023The prevalence of in 30 samples of poultry was determined using culture-dependent (isolation on OCLA and confirmation by conventional polymerase chain reaction -PCR-,...
The prevalence of in 30 samples of poultry was determined using culture-dependent (isolation on OCLA and confirmation by conventional polymerase chain reaction -PCR-, OCLA&PCR) and culture-independent (real-time polymerase chain reaction, q-PCR) methods. was detected in 15 samples (50.0%) by OCLA&PCR and in 20 (66.7%) by q-PCR. The concentrations (log cfu/g) of (q-PCR) ranged from 2.40 to 5.22 (total cells) and from <2.15 to 3.93 (viable cells). The two methods, q-PCR using a viability marker (v-PCR) and OCLA&PCR (gold standard), were compared for their capacity to detect viable cells of , with the potential to cause human disease. The values for sensitivity, specificity and efficiency of the v-PCR were 100%, 66.7% and 83.3%, respectively. The agreement between the two methods (kappa coefficient) was 0.67. The presence of nine virulence genes (, , , , , , , and ) was studied in 45 isolates (three from each positive sample) using PCR. All the strains harbored between six and nine virulence genes. Fifteen isolates (33.3% of the total) did not show the potential to form biofilm on a polystyrene surface, as determined by a crystal violet assay. The remaining strains were classified as weak (23 isolates, 51.1% of the total), moderate (one isolate, 2.2%) or strong (six isolates, 13.3%) biofilm producers. The strains were tested for susceptibility to a panel of 15 antibiotics. An average of 5.11 ± 1.30 resistances per isolate was observed. When the values for resistance and for reduced susceptibility were taken jointly, this figure rose to 6.91 ± 1.59. There was a prevalence of resistance or reduced susceptibility of more than 50.0% for oxacillin, cefoxitin, cefotaxime, cefepime ciprofloxacin, enrofloxacin and nitrofurantoin. For the remaining antibiotics tested, the corresponding values ranged from 0.0% for chloramphenicol to 48.9% for rifampicin. The high prevalence and level of with numerous virulence factors in poultry underline how crucial it is to follow correct hygiene procedures during the processing of this foodstuff in order to reduce the risk of human listeriosis.
PubMed: 37764076
DOI: 10.3390/microorganisms11092232 -
Foods (Basel, Switzerland) Feb 2024is a foodborne pathogen that causes listeriosis, a group of human illnesses that appear more frequently in countries with better-developed food supply systems. This... (Review)
Review
is a foodborne pathogen that causes listeriosis, a group of human illnesses that appear more frequently in countries with better-developed food supply systems. This review discusses the efficacy of actual biocontrol methods combined with the main types of food involved in illnesses. Comments on bacteriophages, lactic acid bacteria, bacteriocins, essential oils, and endolysins and derivatives, as main biological antilisterial agents, are made bearing in mind that, using them, food processors can intervene to protect consumers. Both commercially available antilisterial products and solutions presented in scientific papers for mitigating the risk of contamination are emphasized. Potential combinations between different types of antilisterial agents are highlighted for their synergic effects (bacteriocins and essential oils, phages and bacteriocins, lactic acid bacteria with natural or synthetic preservatives, etc.). The possibility to use various antilisterial biological agents in active packaging is also presented to reveal the diversity of means that food processors may adopt to assure the safety of their products. Integrating biocontrol solutions into food processing practices can proactively prevent outbreaks and reduce the occurrences of -related illnesses.
PubMed: 38472848
DOI: 10.3390/foods13050734 -
Veterinary Immunology and... Jul 2023Sheep have been used as a large animal experimental model for studying infectious diseases. However, due to a lack of staining antibodies and reagents, immunological...
Sheep have been used as a large animal experimental model for studying infectious diseases. However, due to a lack of staining antibodies and reagents, immunological studies on sheep have not progressed. The immunoinhibitory receptor programmed death-1 (PD-1) is expressed on T lymphocytes. The interaction of PD-1 with its ligand PD-ligand 1 (PD-L1) delivers inhibitory signals and impairs proliferation, cytokine production, and cytotoxicity of T cells. We previously reported that the PD-1/PD-L1 pathway was closely associated with T-cell exhaustion and disease progression in bovine chronic infections using anti-bovine PD-L1 monoclonal antibodies (mAbs). Furthermore, we found that blocking antibodies against PD-1 and PD-L1 restore T-cell functions and could be used in immunotherapy of cattle. However, the immunological role of the PD-1/PD-L1 pathway in chronic diseases of sheep remains unknown. In this study, we identified cDNA sequences of ovine PD-1 and PD-L1 and examined the cross-activity of anti-bovine PD-L1 mAbs against ovine PD-L1 as well as the expression of PD-L1 in ovine listeriosis. The amino acid sequences of ovine PD-1 and PD-L1 share a high degree of identity and similarity with homologs from ruminants and other mammalian species. Anti-bovine PD-L1 mAb recognized ovine PD-L1 on lymphocytes in the flow cytometric assay. Furthermore, an immunohistochemical staining confirmed the PD-L1 expression on macrophages in the brain lesions of ovine listeriosis. These findings indicated that our anti-PD-L1 mAb would be useful for analyzing the ovine PD-1/PD-L1 pathway. Further research is needed to determine the immunological role of PD-1/PD-L1 in chronic diseases such as BLV infection through experimental infection of sheep.
Topics: Cattle; Animals; Sheep; Programmed Cell Death 1 Receptor; Ligands; T-Lymphocytes; Amino Acid Sequence; Antibodies, Monoclonal; B7-H1 Antigen; Mammals
PubMed: 37201379
DOI: 10.1016/j.vetimm.2023.110609 -
The Veterinary Record Mar 2024
Topics: Animals; Sheep; Female; Listeriosis; Animal Husbandry; Sheep Diseases
PubMed: 38488587
DOI: 10.1002/vetr.4067 -
Journal of Food Protection Nov 2023Listeria monocytogenes (Lm) is a Gram-positive bacterium that causes invasive listeriosis, an illness with high mortality and hospitalization rates. Due to the severity...
Listeria monocytogenes (Lm) is a Gram-positive bacterium that causes invasive listeriosis, an illness with high mortality and hospitalization rates. Due to the severity of illness associated with Lm, rapid identification and characterization of isolates from foods and the food-processing environment are critical to properly identify and track the pathogen and quickly remove adulterated foods from the market. Prior methods can rely on time-consuming biochemical or sera-agglutination assays to perform these tasks. Development of a high-throughput method that would rapidly perform these tasks is critical to improve response to contamination events. Previously, a single laboratory validation of a qPCR-based method was presented that could rapidly verify Lm isolates and characterize them into six molecular serogroups. In the current study, a multi-laboratory validation (MLV) was performed to evaluate the reliability of the qPCR method for identification and serogrouping of Lm isolates. Sixteen collaborating laboratories independently analyzed a panel of 43 blinded isolates plus three control strains using the qPCR method. This panel was comprised of representatives for non-Listeria (n = 7), Listeria sp. (n = 8), and Lm (n = 28) strains. The Lm isolates contained representatives of the six serogroups: 2A, 2B, 2C, 4B, NT, and 4bV/IVb-v1, with five strains for each serogroup except 4bV/IVb-v1 (n = 3). The results generated by 16 laboratories showed high sensitivity, specificity, and accuracy, generally ≥97%, for both the genus-species and serogrouping qPCRs. Results from one laboratory lowered the sensitivity of the non-Listeria group to 93%. These results indicated the method was highly reliable. However, only the previously evaluated serogroups were tested within the MLV panel, though there is the potential for other serogroup results. Sequence Read Archive (SRA) files for Lm isolates were evaluated to determine the frequency of other potential serogroup profiles. This effort identified a low percentage of isolates with atypical qPCR serogroups (0.30%) that are consistent with Lm and were generally associated with lineage II and the natural environment. In summary, the results indicate that the proposed qPCR method is reliable and has a high degree of sensitivity, accuracy, and specificity, while also decreasing hands-on analysis time and increasing throughput of the analysis.
Topics: Humans; Listeria monocytogenes; Serotyping; Reproducibility of Results; Food Microbiology; Listeriosis; Serogroup
PubMed: 37806351
DOI: 10.1016/j.jfp.2023.100178 -
Innate Immunity Aug 2023The study of cellular immune responses in animal disease models demands detailed knowledge of development, function, and regulation of immune cells, including natural... (Review)
Review
The study of cellular immune responses in animal disease models demands detailed knowledge of development, function, and regulation of immune cells, including natural killer (NK) cells. () bacterium has been explored in a large area of research fields, including the host pathogen interaction. Although the importance role of NK cells in controlling the first phase of burden has been investigated, the interaction between NK cells and infected cells in details are far from being comprehended. From and experiments, we can drive several important pieces of knowledge that hopefully contribute to illuminating the intercommunication between infected cells and NK cells. Experimental studies performed in rats revealed that certain NK cell ligands are influenced in infected cells. These ligands include both classical- and non-classical MHC class I molecules and C-type lectin related (Clr) molecules that are ligands for Ly49- and NKR-P1 receptors respectively. Interaction between these receptors:ligands during infection, demonstrated stimulation of rat NK cells. Hence, these studies provided additional knowledge to the mechanisms NK cells utilise to recognise and respond to infection outlined in the current review.
Topics: Rats; Animals; Listeria monocytogenes; Ligands; Killer Cells, Natural; Listeriosis; Histocompatibility Antigens Class I; Lectins, C-Type
PubMed: 37285590
DOI: 10.1177/17534259231178223 -
Foods (Basel, Switzerland) Dec 2023Cold-smoked salmon are ready-to-eat products that may support the growth of pathogenic during their long shelf-life. Consumption of such contaminated products can cause...
Cold-smoked salmon are ready-to-eat products that may support the growth of pathogenic during their long shelf-life. Consumption of such contaminated products can cause fatal listeriosis infections. Another challenge and potential risk associated with CS salmon is their high levels of sodium salt. Excess dietary intake is associated with serious health complications. In the present study, anti-listerial bacteriocin (nisin), P100 bacteriophages (Phageguard L, PGL) and fermentates (Verdad N6, P-NDV) were evaluated as commercial bio-preservation strategies for increased control of in standard (with NaCl) and sodium-reduced (NaCl partially replaced with KCl) CS salmon. Treatments of CS salmon with nisin (1 ppm) and PGL (5 × 10 pfu/cm) separately yielded significant initial reductions in (up to 0.7 log) compared to untreated samples. Enhanced additive reductions were achieved through the combined treatments of nisin and PGL. Fermentates in the CS salmon inhibited the growth of Listeria but did not lead to its eradication. The lowest levels of during storage were observed in nisin- and PGL-treated CS salmon containing preservative fermentates and stored at 4 °C, while enhanced growth was observed during storage at an abusive temperature of 8 °C. Evaluation of industry-processed standard and sodium-replaced CS salmon confirmed significant effects with up to 1.7 log reductions in levels after 34 days of storage of PGL- and nisin-treated CS salmon-containing fermentates. No differences in total aerobic plate counts were observed between treated (PGL and nisin) or non-treated standard and sodium-reduced CS salmon at the end of storage. The microbiota was dominated by but with a shift showing dominance of spp. and spp. in fermentate-containing samples. Similar and robust reductions in can be achieved in both standard and sodium-replaced CS salmon using the bio-preservation strategies of nisin, PGL and fermentates under various and relevant processing and storage conditions.
PubMed: 38137194
DOI: 10.3390/foods12244391 -
The Science of the Total Environment Jan 2024Fish and seafood products are one of the most common causes of listeriosis in humans. A systematic review and meta-analysis were conducted using scientific literature to... (Meta-Analysis)
Meta-Analysis Review
Fish and seafood products are one of the most common causes of listeriosis in humans. A systematic review and meta-analysis were conducted using scientific literature to summarize available data on the prevalence of Listeria monocytogenes and Listeria sp. in fish, fish products and fish processing environment. Meta-analysis models were used to estimate the mean prevalence of the pathogen and to compare prevalence among the most popular fishes. Data from a total of 14,496 samples were analysed. Pooled prevalence of L. monocytogenes and Listeria sp. in raw fish was 5.8 % (95 % CI: 4.7-6.9) and 12.2 % (95 % CI: 8.9-15.5) respectively. Significantly higher results were observed for ready-to-eat products, occurrence of L. monocytogenes and Listeria sp. was 14.5 % (95 % CI: 11.1-18.0) and 21.7 % (95 % CI: 11.8-31.6) respectively. Moreover, meta-regression was performed to investigate changes in L. monocytogenes and Listeria sp. occurrence over the years and it shows a downward trend for both raw fish and RTE products. The results of the present study provide useful epidemiological information about the contamination level and distribution of Listeria sp. and L. monocytogenes among raw fish, fish products and fish processing environment.
Topics: Humans; Animals; Listeria monocytogenes; Listeria; Food Microbiology; Food Contamination; Prevalence; Fish Products; Fishes
PubMed: 37866612
DOI: 10.1016/j.scitotenv.2023.167912