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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 Apr 2024is a ubiquitous pathogen found both in the environment and food. It can cause listeriosis in a wide range of animals as well as in humans. Investigations on presence,...
is a ubiquitous pathogen found both in the environment and food. It can cause listeriosis in a wide range of animals as well as in humans. Investigations on presence, spread and virulence are still limited to terrestrial and human environments. Embracing the One Health Approach, investigating the presence and spread of in marine ecosystems and among wildlife, would provide us with useful information for human health. This study investigated the presence of and spp. in two species of sea turtles common in the Mediterranean Sea ( and ). A total of one hundred and sixty-four carcasses of sea turtles ( = 161 and = 3) stranded along the Abruzzo, Molise, Campania, and Calabria coasts, were collected. Brain and fecal samples were taken, enriched, and cultured for the detection of spp. From the specimens collected, strains of (brain = 1, brain and feces = 1, multiorgan = 1 and feces = 1), (feces = 1 and brain = 1), and (brain = 1) were isolated. Typical colonies were isolated for Whole Genome Sequencing (WGS). Virulence genes, disinfectants/metal resistance, and antimicrobial resistance were also investigated. , and were detected in , whilst only and in . Notable among the results is the lack of significant differences in gene distribution between human and sea turtle strains. Furthermore, potentially pathogenic strains of were found in sea turtles.
PubMed: 38674761
DOI: 10.3390/microorganisms12040817 -
Journal of Food Protection Mar 2024Thermal inactivation studies were undertaken on Listeria monocytogenes and Salmonella spp. inoculated on the surface of country ham. Hams (average = ca....
Inactivation of Listeria monocytogenes and Salmonella spp. During Cooking of Country Ham and Fate of L. monocytogenes and Staphylococcus aureus During Storage of Country Ham Slices.
Thermal inactivation studies were undertaken on Listeria monocytogenes and Salmonella spp. inoculated on the surface of country ham. Hams (average = ca. 3.4 ± 0.5 kg each; average = ca. ≥18% shrinkage) were used as provided by the processor (i.e., "salted hams"), desalted in tap water (i.e., "desalted hams"), or dried for an additional period (i.e., "extra-dried hams"). Hams were surface inoculated (ca. 9.5 log CFU/ham) with a multistrain cocktail of L. monocytogenes or Salmonella spp. and cooked within a bag ina circulating water bath to an internal temperature of 130°F (54.4°C) instantaneous, 145°F (62.8°C) and held for 4 min, 153°F (67.2°C) and held for 34 s, or 160°F (71.1°C) instantaneous. Regardless of ham type, all four time and temperature combinations tested herein delivered a ≥6.7-log reduction of cells of L. monocytogenes or Salmonella spp. Differences in product pH, moisture content, or a did not have an appreciable impact on the thermal inactivation of L. monocytogenes or Salmonella spp. on country ham. In addition, shelf-life studies were undertaken using slices of "salted" country ham that were surface inoculated (ca. 5.5 log CFU/slice) with a multistrain cocktail of L. monocytogenes or Staphylococcus aureus and then stored at 20°C. Levels of S. aureus increased by ca. ≤1.4 log CFU/slice during storage for 90 days, whereas levels of L. monocytogenes remained relatively unchanged (≤0.2 log CFU/slice increase). Our data validated that cooking parameters elaborated in the U.S. Department of Agriculture's Food Safety and Inspection Service Cooking Guideline for Meat and Poultry Products (Revised Appendix A) are sufficient to deliver significant reductions (ca. ≥6.8 log CFU/ham) in levels of L.monocytogenes and Salmonella spp. on country ham. In addition, in the event of postprocessing contamination, country ham may support the outgrowth of S. aureus or survival of L. monocytogenes during storage at 20°C for 90 days.
Topics: Food Handling; Staphylococcus aureus; Listeria monocytogenes; Colony Count, Microbial; Cooking; Temperature; Salmonella; Water; Food Microbiology; Meat Products
PubMed: 38218339
DOI: 10.1016/j.jfp.2024.100222 -
Microbiology Spectrum Sep 2023is a nuclear transcription factor, and its activity is tightly regulated by the level of available oxygen in cells. Here, we investigated the roles of in the invasion...
is a nuclear transcription factor, and its activity is tightly regulated by the level of available oxygen in cells. Here, we investigated the roles of in the invasion of into tilapia under hypoxic environments. We found that the expression levels of in examined tissues of hypoxic tilapia were significantly upregulated, indicating that the tissue cells have been in hypoxic conditions. After 24-h infection with , we found that bacterial burden counts increased significantly in all examined tissues of hypoxic fish. To explore why the bacterial count increased significantly in the tissues of hypoxic fish, we modulated expression through RNAi technology. The results indicated that expression levels were positively related to expression. Since c-Met is the receptor of InlB that plays critical roles in the adhesion and invasion of , the ∆ strain was used to further explore the reason for the significant increase in bacterial counts in hypoxic fish. As expected, the decrease in the adhesion ability of ∆ suggested that InlB mediates infection in tilapia. After being infected with ∆ strain, we found that the bacterial counts in hypoxic fish were not affected by hypoxic conditions or expression levels. These findings indicate that may promote the internalization of InlB by upregulating expression and therefore contributes to the invasion of into hypoxic tilapia. IMPORTANCE is a zoonotic food-borne bacterial pathogen with a solid pathogenicity for humans. After ingestion of highly contaminated food, is able to cross the intestine invading phagocytic and nonphagocytic cells and causes listeriosis. China is the world's largest supplier of tilapia. The contamination rate of to tilapia products was as high as 2.81%, causing a severe threat to public health. This study revealed the underlying regulatory mechanisms of in the invasion of into tilapia under hypoxic environments. This study will be helpful for better understanding the molecular mechanisms of hypoxic environments in infection to tilapia. More importantly, our data will provide novel insights into the prevention and control of this pathogen in aquaculture.
PubMed: 37681973
DOI: 10.1128/spectrum.01405-23 -
Scientific Reports Aug 2023Listeria outbreaks and food recalls is on the raise globally. Milk particularly is highly susceptible to Listeria as its production and storage adequately support...
Listeria outbreaks and food recalls is on the raise globally. Milk particularly is highly susceptible to Listeria as its production and storage adequately support Listeria growth. The extent of milk contamination with Listeria monocytogenes (Lm) and preventative actions to halt milk associated outbreaks in Africa are unknown. Hence, this study aimed at assessing the national and subregional prevalence of Lm in milk in Africa and identify impacting factors via generalized logistic mixed-effects (GLMEs) and meta-regression modelling. Lm-milk-specific data acquired from primary studies according to standard protocol were fitted using a GLMEs. The GLMEs was subjected to leave-one-study-out-cross-validation (LOSOCV). Factors impacting Lm prevalence in milk were assayed via a 1000-permutation-assisted meta-regression-modelling. The pooled prevalence of Lm in milk in Africa was 4.35% [2.73-6.86] with a prediction interval (PI) of 0.14-59.86% and LOSOCV value of 2.43% [1.62-3.62; PI: 0.32-16.11%]. Western Africa had the highest prevalence [20.13%, 4.13-59.59], then Southern Africa [5.85%, 0.12-75.72], Northern Africa [4.67%, 2.82-7.64], Eastern Africa [1.91%, 0.64-5.55], and there was no record from Central Africa. In term of country, Lm prevalence in milk significantly (p < 0.01) varied from 0.00 to 90.00%. Whereas the Lm prevalence was negligibly different (p = 0.77) by milk type, raw-milk had the highest prevalence [5.26%], followed by fermented-milk [4.76%], boiled-milk [2.90%], pasteurized-milk [1.64%], and powdered-milk [1.58%]. DNA extraction approach did not significantly (p = 0.07) affect Lm prevalence (Boiling [7.82%] versus Kit [7.24%]) as well as Lm detection method (p = 0.10; (ACP [3.64%] vs. CP [8.92%] vs. CS [2.27%] vs. CSP [6.82%]). Though a bivariate/multivariate combination of all tested variables in meta-regression explained 19.68-68.75% (R) variance in Lm prevalence in milk, N, nation, and subregion singly/robustly accounted for 17.61% (F = 7.5994; p = 0.005), 63.89% (F = 4.2028; p = 0.001), and 16.54% (F = 3.4743; p = 0.026), respectively. In conclusion, it is recommended that adequate sample size should be prioritized in monitoring Lm in milk to prevent spuriously high or low prevalence to ensure robust, plausible, and credible estimate. Also, national efforts/interests and commitments to Lm monitoring should be awaken.
Topics: Animals; Listeria monocytogenes; Milk; Food Contamination; Prevalence; Listeria; Africa, Southern; Food Microbiology
PubMed: 37542148
DOI: 10.1038/s41598-023-39955-0 -
Foodborne Pathogens and Disease Aug 2023The objective of this study was to conduct a systematic review to comprehensively understand antimicrobial resistance (AMR) in (LM) isolated from meat and meat... (Meta-Analysis)
Meta-Analysis Review
The objective of this study was to conduct a systematic review to comprehensively understand antimicrobial resistance (AMR) in (LM) isolated from meat and meat products. The study was performed following the guidelines of the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA). Published articles from 2000 to 2022 were collected from six widely used online databases, including AGRICOLA, PubMed, Web of Science (WoS), Scopus, Cochrane Library, and CINAHL-EBSCO. Prevalence rates and AMR of pathogen isolates were analyzed using MedCalc software, including the statistic and Cochrane test for heterogeneity. Sensitivity analysis, subgroup analysis, and meta-regression were conducted to analyze potential sources of heterogeneity at a 95% significance level. The distribution and prevalence of multidrug resistance (MDR) were examined using a random-effect model. The pooled frequency of bacterial MDR was 22.97% (95% confidence interval [CI] = 14.95-32.13). The studies exhibited high heterogeneity ( = 94.82%, 95% CI = 93.74-95.71, < 0.0001). Furthermore, the most prevalent antibiotics resistance found in the majority of included studies were tetracycline, clindamycin, penicillin, ampicillin, and oxacillin ( = 86.66%, 95% CI = 73.20-93.36, < 0.0001). This meta-analysis provides a comprehensive understanding of AMR in LM isolates, and the results indicate that none of the variable factors, including sampling location, sampling size, or methodology, significantly influenced the outcome of LM isolates resistant to multidrug.
Topics: Listeria monocytogenes; Meat Products; Anti-Bacterial Agents; Meat; Ampicillin; Microbial Sensitivity Tests; Prevalence; Drug Resistance, Bacterial
PubMed: 37389828
DOI: 10.1089/fpd.2023.0004 -
Food Microbiology Sep 2023Two specialty mushrooms have recently become novel vectors for foodborne outbreaks in the U.S.: fresh enoki and dried wood ear mushrooms were linked to a listeriosis and...
Two specialty mushrooms have recently become novel vectors for foodborne outbreaks in the U.S.: fresh enoki and dried wood ear mushrooms were linked to a listeriosis and salmonellosis outbreak, respectively. The aim of this study was to evaluate the survival kinetics of Listeria monocytogenes and Salmonella enterica on dehydrated enoki and wood ear mushrooms during long-term storage. Following heat dehydration, mushrooms were inoculated with either L. monocytogenes or S. enterica, allowed to dry for 1 h, and then stored for up to 180 d at 25 °C and 33% relative humidity. Both pathogens were enumerated from the mushrooms at intervals during the storage period. Survival kinetics of both pathogens were modeled using both the Weibull and log-linear with tail models. After inoculation and 1 h drying, both pathogen populations decreased 2.26-2.49 log CFU/g on wood ear mushrooms; no decrease was observed on enoki. Both pathogens survived during storage on both mushroom types. On wood ear mushrooms, a 2-log decrease of both pathogens occurred during storage. On enoki mushrooms, 4-log decreases of both pathogens were modeled to occur after 127.50-156.60 d. The results of this study suggest that L. monocytogenes and S. enterica can persist on dehydrated specialty mushrooms during long-term storage.
Topics: Salmonella enterica; Listeria monocytogenes; Agaricales; Kinetics; Colony Count, Microbial; Food Microbiology; Temperature
PubMed: 37290867
DOI: 10.1016/j.fm.2023.104304 -
Microorganisms Jun 2024is a ubiquitous bacterial pathogen that threatens the food chain and human health. In this study, whole-genome sequencing (WGS) was used for the genomic...
is a ubiquitous bacterial pathogen that threatens the food chain and human health. In this study, whole-genome sequencing (WGS) was used for the genomic characterization of (n = 24) from beef and beef-based products. Multilocus Sequence Type (MLST) analysis revealed that ST204 of CC204 was the most common sequence type (ST). Other sequence types detected included ST1 and ST876 of CC1, ST5 of CC5, ST9 of CC9, ST88 of CC88, ST2 and ST1430 of CC2, and ST321 of CC321. Genes encoding for virulence factors included complete LIPI-1 (-----) from 54% (13/24) of the isolates of ST204, ST321, ST1430, and ST9 and internalin genes that were present in all the STs. All the STs carried four intrinsic/natural resistance genes, , , , and , conferring resistance to fosfomycin, lincosamide, quinolones, and cationic peptides, respectively. Plasmids pLGUG1 and J1776 were the most detected (54% each), followed by pLI100 (13%) and pLM5578 (7%). The prophage profile, vB_LmoS_188, was overrepresented amongst the isolates, followed by LP_101, LmoS_293_028989, LP_030_2_021539, A006, and LP_HM00113468. genomic island 2 (LGI-2) was found to be present in all the isolates, while genomic island 3 (LGI-3) was present in a subset of isolates (25%). The type VII secretion system was found in 42% of the isolates, and sortase A was present in all genomes. Mobile genetic elements and genomic islands did not harbor any virulence, resistance, or environmental adaptation genes that may benefit . All the STs did not carry genes that confer resistance to first-line antibiotics used for the treatment of listeriosis. The characterization of in our study highlighted the environmental resistance and virulence potential of and the risk posed to the public, as this bacterium is frequently found in food and food processing environments.
PubMed: 38930548
DOI: 10.3390/microorganisms12061166 -
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 -
Life (Basel, Switzerland) Nov 2023of the phylogenetic lineage II (PLII) are common in the European environment and are hypovirulent. Despite this, they caused more than a third of the sporadic cases of...
of the phylogenetic lineage II (PLII) are common in the European environment and are hypovirulent. Despite this, they caused more than a third of the sporadic cases of listeriosis and multi-country foodborne outbreaks. ST37 is one of them. During the COVID-19 pandemic, ST37 appeared in clinical cases and ranked second in occurrence among food isolates in the Moscow region. The aim of this study was to describe the genomic features of ST37 isolates from different sources. All clinical cases of ST37 were in the cohort of male patients (age, 48-81 years) with meningitis-septicemia manifestation and COVID-19 or Influenza in the anamnesis. The core genomes of the fish isolates were closely related. The clinical and meat isolates revealed a large diversity. Prophages (2-4/genome) were the source of the unique genes. Two clinical isolates displayed pseudolysogeny, and excided prophages were A006-like. In the absence of plasmids, the assortment of virulence factors and resistance determinants in the chromosome corresponded to the hypovirulent characteristics. However, all clinical isolates caused severe disease, with deaths in four cases. Thus, these studies allow us to speculate that a previous viral infection increases human susceptibility to listeriosis.
PubMed: 38004307
DOI: 10.3390/life13112167