SEARCH · Search PubMed

Results for “Environment”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

SourceResearch connectionFrom yearThrough year

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

133 records · Page 4Linked to original sources

PubMed2026

Molecular characterization of 16 MAPK genes in silver carp (Hypophthalmichthys molitrix) and the differences of their mRNA expression between Qiandao Lake and Taihu Lake.

Mitogen-activated protein kinase (MAPK), a serine-threonine protein kinase, is involved in a variety of stress-induced responses and also plays an important regulatory role in cell metabolism. In the study the open reading frames (ORFs) of 16 MAPK genes in silver carp (Hypophthalmichthys molitrix) were obtained and verified, with the evaluations of their taxonomy, structures, conserved motifs, and evolutionary linkages. And the expression patterns of these genes in the silver carp from Qiandao Lake and Taihu Lake were explored for better understanding the response of MAPK genes to different water environment. MAPK genes of silver carp were divided into three subfamilies, including extracellular signal-regulated kinase (ERK) subfamily, p38 subfamily and C-Jun N-terminal kinase (JNK) subfamily. All these genes possessed similar structures and conserved motifs of MAPK family. Realtime qPCR revealed that the expression patterns of 10 MAPK genes (ScMAPK1, ScMAPK3, ScMAPK4, ScMAPK7, ScMAPK15, ScMAPK8a, ScMAPK8b, ScMAPK9, ScMAPK10 and ScMAPK11) in head kidney, spleen and gill of silver carp in Taihu Lake and Qiandao Lake were different. These findings provide a basis for further research on the function of MAPK in silver carp.

Animals↗

PubMed2026

Genomic history of the Caucasus: A systematic review and meta-analysis of ancient DNA studies.

The Caucasus region represents a unique natural laboratory for paleogenetic research due to its complex topography, long-standing role as a migratory corridor and glacial refugium, and exceptional preservation conditions for ancient DNA. This review synthesizes recent genome-wide studies to reconstruct the demographic history shaping the distinctive genetic landscape of modern Caucasus populations. The analysis reveals a deep pattern of continuity, isolation, and periodic admixture. Early genetic differentiation emerged in the Neolithic and Chalcolithic, forming distinct steppe and mountain population clusters. The Bronze Age was a pivotal period marked by large-scale gene flow from the Eurasian Steppe, particularly linked to the Yamnaya expansion, and interactions with Iranian and Anatolian-related groups. Despite these influences, many populations demonstrate remarkable genetic continuity from the Bronze Age to the present day. Significant knowledge gaps persist, particularly for the Paleolithic, Mesolithic, and Neolithic of the North Caucasus, as well as for the Late Medieval and Early Modern periods across the entire region. Addressing these gaps through targeted archaeogenomic studies is crucial for understanding the fine-scale processes that formed the hierarchical structure and high linguistic diversity of Caucasus populations, offering a powerful model for studying human adaptation, interaction, and language-genetics dynamics in a mountainous environment.

Humans↗

PubMed2026

Determinants of Meal Satisfaction and Their Association With Childhood Obesity: A Systematic Review.

Meal satisfaction is considered a multidimensional concept that includes sensory enjoyment, cognitive, emotional, and physiological components and relates to contentment with the meal experience as a whole. However, its relevance to eating behavior and body weight remains unclear, especially in children. The present review investigated the potential relationship between meal satisfaction-related constructs and childhood obesity, and whether this relation is shaped by individual factors and the external environment. Seventeen eligible studies from 350 records published between 2008 and 2024 were included. No study directly assessed meal satisfaction; instead, proxy measures were used. Food enjoyment emerged as the proxy most consistently associated with BMI, often clustering with higher food responsiveness, lower satiety responsiveness, and emotional overeating. Parental feeding practices, especially pressure to eat, significantly contributed to variation in children's eating behavior and were associated with lower food enjoyment. Overall, meal satisfaction could be a key aspect to consider in childhood obesity prevention programs. However, to date, the available evidence is heterogeneous and predominantly observational. Future longitudinal and intervention studies are needed, alongside child-appropriate instruments to objectively quantify food satisfaction in children. Research that helps understand the role of contextual eating factors on children's meal satisfaction and eating behavior is also warranted.

Humans↗

PubMed2026

A systematic review of sleep hygiene interventions in physically and operationally demanding occupations.

Workers in physically and operationally demanding (POD) occupations (e.g. military personnel, emergency responders, law enforcement) experience disrupted sleep due to irregular schedules and high-stress work environments. Given the importance of sleep for physical and cognitive performance, interventions to improve sleep in POD occupations are crucial yet remain under-researched. To investigate the effectiveness of sleep hygiene interventions in improving sleep quality and quantity outcomes for POD occupations, a systematic review was conducted across five databases (PubMed, CINAHL, SPORTDiscus, PsycINFO, Web of Science) in September 2024. Eligible studies involved workers in POD occupations where a sleep hygiene intervention was compared against a waitlist or passive control. Ten studies were included, eight randomised controlled trials (RCTs) and two non-randomised controlled trials (NRCTs). Narrative synthesis identified Structured Training Programs (n = 7), Phone Assistance Programs (n = 2), and Single Lecture Interventions (n = 1). Evidence certainty ranged from Very Low to Moderate, converging towards Low quality due to imprecision, risk of bias, and indirectness. Structured Training Programs showed moderate improvements in sleep quality and small-to-moderate effects on sleep duration. Phone Assistance Programs had minimal effects, and Single Lecture Interventions had negligible impact. Higher-quality research is urgently needed to assess sleep hygiene interventions in POD occupations.

Humans↗

PubMed2026

Hydroxyl Radical Inactivation of Vesicle-Cloaked and Free Murine Norovirus: Linking Biomolecular Oxidation to Lifecycle Disruption and Infectivity Loss.

Hydroxyl radicals (•OH) play a central role in inactivating human viruses during advanced oxidation processes for water and wastewater treatment, solar disinfection, and natural attenuation in sunlit aquatic environments. Human norovirus, a leading cause of gastroenteritis, is efficiently transmitted through water and exhibits strong environmental persistence. The recent discovery of vesicle-cloaked virus clusters (viral vesicles) further challenges water treatment and reuse, particularly for norovirus elimination. We investigated •OH inactivation kinetics and mechanisms of murine norovirus 1 (MNV-1), a human norovirus surrogate, in free-virus and vesicle-cloaked forms. •OH rapidly inactivated both MNV-1 vesicles and free MNV-1 with second rate constants of ∼1010 M-1 s-1; however, the vesicle membrane provided a 2.24-fold protective effect to cloaked MNV-1, resulting in slower inactivation kinetics than those of free MNV-1. •OH oxidized viral capsid proteins and genomes together with vesicle proteins and lipids, resulting in impaired CD300lf receptor and cell-based binding, disrupted genome replication, and diminished viral assembly. Despite these biochemical and functional impairments, most vesicle structures remained largely intact following •OH exposure. This study establishes a quantitative framework linking biomolecular damage to viral infectivity loss through functional impairment and lifecycle disruption, providing mechanistic insights into advance water disinfection strategies and public health protection.

Norovirus↗

PubMed2026

The spatial and temporal distribution of Staphylococcus aureus along a tropical Hawaiian watershed.

Staphylococcus aureus is a leading cause of community-acquired skin and soft-tissue infections worldwide. One major route of exposure is recreating in marine waters, but knowledge is limited regarding the drivers of S. aureus in surface waters that discharge into marine environments. This study explores spatial and temporal distributions of S. aureus, including antimicrobial-resistant and virulence genes, using both culture-dependent and molecular techniques across a tropical Hawaiian watershed with a gradient of human influence. Negative binomial generalized linear mixed models revealed that the interaction between spatial and temporal factors was the strongest predictor of S. aureus and associated genes. Cultured S. aureus was highest at mid-watershed sites in summer, which included a popular swimming hole, suggesting human shedding as a significant source. Molecular detection of S. aureus (femA gene) yielded concentrations two orders of magnitude higher than cultured concentrations and peaked at estuarine sites with the greatest nutrients and water residence times. In the winter at upstream sites with no public access, staphylococci antibiotic-resistant (mecA) and S. aureus virulence gene (etb) were elevated, indicating highly pathogenic S. aureus strains in surface waters may originate from zoonotic sources. Our findings indicate that human and zoonotic sources contribute antibiotic-resistant and virulent S. aureus to watersheds, with streams facilitating environmental transmission to marine waters. This watershed-scale assessment enables the prediction of spatial and temporal conditions associated with elevated S. aureus concentrations, thereby reducing exposure and infections.

Staphylococcus aureus↗

PubMed2026

Comparative analysis of genomic variations among different Cdo1 paralogs for salinity-adaptation in oysters.

Under rapid climate change and anthropogenic activities, oysters, a global aquaculture species, are subjected to exacerbated culturing environments, especially for those living in in-shore estuarine species, such as Suminoe oysters Crassostrea ariakensis. This study aims to investigate the molecular mechanisms of salinity adaptation of C. ariakensis. We performed an expression genome-wide association study (eGWAS) to compare genetic regulation among 5 paralogous copies of a key salinity-related gene, cysteine dioxygenase 1 (Cdo1). A total of 40 significant eSNPs with 82 adjacent eGenes were identified in 2 copies (Cdo1_26639 and Cdo1_1666). We identified only trans-eSNPs for Cdo1_26639 and more cis-eSNPs for Cdo1_1666, and different eGenes for these 2 Cdo1 copies, which indicated that the expressional regulation of these paralogs may undergo distinct pathways. We identified 3 eGenes that exhibited identical expression patterns with Cdo1_26639 and Cdo1_1666, including 6-Pgdh, Trapp and tandem copy of Cdo1_27337. The expression correlation between Cdo1 copies and eGenes was enhanced under salinity stresses, suggesting the crucial role of eGenes in regulating Cdo1's expression in response to salinity changes. Our results provide comprehensive identification and comparison of eSNPs across different paralogous copies of one gene, along with insights into the molecular mechanisms underlying salinity tolerance, and genetic markers for breeding salinity-resistant oysters.

Animals↗

PubMed2026

Synchronicity of parent-child sleep and potential mechanisms: A systematic review and meta-analysis.

Existing evidence indicates that parent and child circadian rhythms are associated, but studies have mainly examined factors affecting child sleep health. This systematic review addressed two questions: a) is there a synchronous relationship between parent and offspring sleep? and b) what are the potential mechanisms? PubMed, Embase, PsychINFO, and Scopus were searched from inception to April 2025. Forty-six studies comprising over 100000 parent-child dyads across 16 countries were included. Results showed small-to-moderate parent-child synchronicity in sleep duration (r = 0.18, 95% CI [0.14, 0.23]), sleep efficiency (r = 0.30, 95% CI [0.19, 0.41]), bedtime (r = 0.34, 95% CI [0.20, 0.46]), and wake up time (r = 0.48, 95% CI [0.24, 0.66]), with stronger effects observed in mother-child dyads. Synchronicity in sleep continuity was moderate, whereas associations in sleep satisfaction were small and non-significant. Mechanisms included genetic and hormonal factors, bedtime routines, shared environments, and attachment. These findings are consistent with family systems theory's premise that sleep is a relational phenomenon. Observed synchronicity in sleep timing may partly reflect shared external constraints like work and school schedules. Most studies were cross-sectional, limiting causal or directional conclusions. Future research should adopt standardized methodologies and longitudinal designs to clarify mechanistic pathways.

Humans↗

PubMed2026

Time Heals Some Wounds? Burnout but Not Secondary Traumatic Stress in Critical Care Nurses.

BACKGROUND: Burnout among new nurses has been widely documented. Less is known about how years of professional experience relate to distinct components of professional quality of life, including compassion satisfaction and secondary traumatic stress. Early-career nurses appear particularly vulnerable to occupational strain, warranting examination of how years of experience may influence perceptions of professional well-being. OBJECTIVE: To examine the relationship between years of nursing experience and professional quality of life among critical care nurses. METHODS: A quantitative, cross-sectional pilot study was conducted using the Professional Quality of Life scale. A convenience sample of 55 nurses were recruited and consented from a rural hospital in the western United States. Descriptive statistics and Pearson correlations were used to examine relationships between years of experience and scores on the instrument's subscales. RESULTS: Forty nurses provided complete survey responses. Years of nursing experience correlated positively with compassion satisfaction and negatively with burnout. No significant relationship was found between years of experience and secondary traumatic stress. CONCLUSIONS: Greater professional experience was associated with higher compassion satisfaction and lower burnout but not with secondary traumatic stress. These findings suggest that experience may buffer against cumulative occupational strain, whereas trauma-related stress responses may persist across career stages. Structured mentoring and transition support may help to mitigate burnout among early-career nurses, and trauma-informed leadership approaches may warrant consideration in high-acuity environments.

Humans↗

PubMed2026

A black soybean yoghurt fermented with a reusable probiotic cellulose gel: beneficial effects and metabolic characteristics.

The demand for plant-based yoghurts is continuously increasing. However, achieving stable physicochemical properties and acceptable flavor of the plant-based yoghurts remains challenging. In our previous work, we encapsulated Lactiplantibacillus plantarum (L. plantarum) LCC-605 biofilm into bacterial cellulose (BC), obtaining a LP605@BC gel. LP605@BC gel exhibited excellent harsh-environment resistance abilities and storage stability, and is very suitable as a starter culture. In this work, we used LP605@BC as a starter culture to prepare the fermented plant-based yoghurt (e.g., black soybean yoghurt, BSY-LP605@BC). After fermentation, the inverted nonflowing yoghurt was formed due to the strong interaction between protein and exopolysaccharide (EPS) produced by LCC-605 during fermentation. In addition, the water holding capacity (67.2%) of BSY-LP605@BC was also greatly improved. The viable bacterial counts in BSY-LP605@BC reached 11.2 log CFU/mL after 21 days of storage. BSY-LP605@BC showed increased antioxidant, cholesterol-lowering abilities, and hypoglycemic potential compared with the unfermented black soybean milk. Interestingly, LP605@BC could be reused at least 5 times, demonstrating excellent sustainability. Significant metabolomic differences between BSY-LP605@BC and the black soybean milk were observed via untargeted metabolomic analysis, further proving the beneficial effects of BSY-LP605@BC. Overall, our work developed an effective reusable starter culture for preparing the plant-based yoghurt in a sustainable manner, providing a new design direction and form of starter culture.

Yogurt↗

PubMed2026

Microbial diversity, functional activities, and safety risks in fermented tea: a comprehensive review.

Microbial fermented teas are gaining global popularity due to their unique sensory profiles and health benefits. The quality and safety of these products are governed by complex microbial ecosystems that orchestrate the biotransformation of tea leaf components. This review addresses a critical paradox in the field: the same microbial activities that generate desirable bioactive metabolites, such as theabrownins and organic acids, also create ecological niches for mycotoxigenic fungi, posing significant health risks from contaminants like ochratoxin A, citrinin, and aflatoxins. While extensive research has cataloged the microbial diversity in these systems, a comprehensive framework linking processing environments to microbial community assembly, functional outcomes, and quantifiable safety risks remains elusive. This review systematically bridges this gap by synthesizing current knowledge on the microbial consortia-dominated by Aspergillus, Penicillium, Bacillus, and Lactiplantibacillus species-that drive tea fermentation. We critically analyze their functional roles in enhancing flavor, bioactivity, and potential probiotic activity while simultaneously evaluating the mechanisms of mycotoxin production and accumulation. By integrating microbial ecology, biochemistry, and food safety, we propose a forward-looking perspective focused on transitioning the industry from traditional, spontaneous fermentation to modern, controlled biotechnological processes. This approach, centered on the use of defined starter cultures, predictive modeling, and active biocontrol strategies, provides a roadmap for ensuring the consistent quality and safety of fermented tea products, ultimately unlocking their full potential as high-quality functional foods.

Tea↗

PubMed2026

The global prevalence of horizontal strabismus: A systematic review and meta-analysis with a focus on ethnic variation.

The prevalence of the 2 types of horizontal strabismus, esotropia and exotropia, varies considerably between studies. This variability has been attributed to factors such as geography/environment, research methodology, age of study subjects, and/or ethnicity. Comprehensive estimates of regional and global prevalences of esotropia and exotropia are lacking, making it difficult to recognize true patterns, trends, and etiologies. We compile prevalences and ratios of esotropia to exotropia from 315 population-based studies and 374 clinic-based studies. We analyze data to assess effects of ethnicity, geography, age, and we identify generational changes of horizontal strabismus. Major ethnicities differ in patterns and ratios of esotropia and exotropia prevalence, not only in Caucasians and East Asians, but also Latinos/Hispanics, South Asians, Africans, and Native Americans. Compared to population-based studies, clinic-based studies underestimate exotropia frequency. By weighing prevalences according to the population size of ethnicities, we estimate the worldwide prevalence of horizontal strabismus in the current generation at 1.81% (138.5 million people), comprising 60.0 million people with esotropia (0.67%) and 87.5 million with exotropia (1.14%). In the previous generation, the worldwide prevalence of horizontal strabismus was 1.64% (86.5 million people), comprising 50.5 million with esotropia (0.96%) and 36.0 million with exotropia (0.68%). Esotropia and exotropia prevalences differ between generations within the same ethnicity, indicating that extrinsic factors can modify the underlying intrinsic (genetic) disposition.

Humans↗

PubMed2026

A profile of firearm-related fatalities admitted to the Diepkloof Forensic Pathology Service Soweto medico-legal mortuary during the COVID-19 and post COVID-19 periods.

This retrospective descriptive study examined firearm-related fatalities during (April-December 2020; n = 241) and after (April-December 2023; n = 299) COVID-19 lockdowns using 540 cases from the Diepkloof Forensic Pathology Service, Soweto, South Africa. Data was obtained from autopsy reports, forensic records, police statements, and death scene documentation. Firearm violence affected young adult Black males (22-43 years), with only minor demographic shifts post-pandemic. The overall burden and core patterns of violence remained stable, with criminal activity - primarily robbery and interpersonal violence - persisting as the leading contexts, and homicide the dominant manner of death. Post-COVID-19 findings demonstrated contextual shifts, including increased incidents in public and social environments, reflecting greater mobility and resumption of social activity. A significant rise in mean blood alcohol concentration (0.09 g/100 mL vs 0.14 g/100 mL; p < 0.0001) suggests increased alcohol involvement following easing of restrictions. Unfortunately, persistent information gaps, noted particularly in circumstantial history, incident location, firearm type, highlighting the need for improved data provision and capture systems. While the epidemiology of firearm-related fatalities remained unchanged, the post-COVID-19 period was characterised by increased alcohol involvement, shifts toward public-space violence, and fewer gunshot wounds per victim, suggesting changes in situational and behavioural dynamics rather than underlying drivers of violence.

Humans↗

PubMed2026

An RPA-assisted homogeneous electrochemical DNA sensor for on-site eDNA detection toward early warning of crown-of-thorns starfish outbreaks.

Crown-of-thorns starfish (COTS) outbreaks seriously threaten coral reef ecosystems, while conventional monitoring approaches are time-consuming and often lack sufficient sensitivity for early warning. Existing electrochemical DNA sensors usually require complex electrode-surface immobilization procedures, which can lead to uneven probe distribution, significant steric hindrance, and poor stability. Meanwhile, the low concentration of environmental DNA (eDNA) in marine environments further complicates detection. To overcome these challenges, this study developed a homogeneous electrochemical DNA sensor assisted by recombinase polymerase amplification (RPA) for COTS eDNA detection. Target DNA was first amplified by RPA, and the amplification products were then hybridized in solution with capture probe (CP)-modified magnetic beads (MB) and biotin-labeled signal probe (SP) to form sandwich-structured MB complexes. These complexes were subsequently magnetically enriched and immobilized on the electrode surface for electrochemical signal readout. Under optimized conditions, the sensor displayed a linear response to COTS genomic DNA from 3.77 fg/μL to 1 ng/μL, with an LOD of 2.02 fg/μL and an LOQ of 3.77 fg/μL. The sensor was applied to Xisha Islands samples, and the results agreed with droplet digital PCR (ddPCR) (P > 0.05), demonstrating its potential for sensitive and reliable on-site COTS eDNA detection.

Animals↗

PubMed2025

Uncovering parental exposure risks of TCPP: Impaired development and metabolic homeostasis in zebrafish offspring.

As brominated flame retardants are phased out, tris (1‑chloro-2-propyl) phosphate (TCPP), a phosphorus-based flame retardant, has emerged as a prominent detectable flame retardant in the environment. However, TCPP has been found to exhibit endocrine-disrupting effects on organisms, raising significant safety concerns. In our study, we utilized the zebrafish model to explore the toxic effects of parental TCPP exposure on offspring and uncover its regulatory mechanisms through metabolomics analysis. Moreover, the impact on the nervous system and lipid metabolism was examined through behavioral analysis and specific staining. Our findings demonstrated that both embryonic and parental TCPP exposure induced developmental disorders in larvae, along with decreased locomotor activity and disordered lipid metabolism homeostasis. Parental exposure to TCPP, exhibiting stronger developmental toxicity than direct embryonic exposure, notably led to reductions in crucial energy substrates such as amino acids and carbohydrates. Meanwhile, embryonic TCPP exposure primarily affected the endogenous lipid-related metabolites including phospholipids, lipid-soluble vitamins, steroids and fatty acids, promoting lipid accumulation in larval liver and subcutaneous tissue. What's more, continuously parental and embryonic exposure showed the most pronounced effects on zebrafish development and metabolic regulation. Our study highlights the risk posed by parental exposure to TCPP on offspring zebrafish, underscoring the need for comprehensive consideration of the impact from parental exposure in pollutants regulation.

Animals↗

PubMed2026

Organizational bullying among nursing faculty: A systematic review of consequences, contributing factors, and interventions.

BACKGROUND: Organizational bullying among nursing faculty is a systemic and pervasive issue with profound psychological, professional, and institutional consequences. Despite increasing awareness, the literature remains fragmented, and a comprehensive synthesis is lacking. METHODS: This systematic review followed PRISMA guidelines and examined empirical studies on organizational bullying among nursing faculty, with no date restrictions applied. A structured search across five databases (PubMed, Scopus, Web of Science, CINAHL, and Embase) identified studies that met inclusion criteria related to the consequences, contributing factors, and interventions. The Mixed Methods Appraisal Tool (MMAT) was used to assess study quality. RESULTS: Fifteen studies meeting the quality threshold were included. Organizational bullying was consistently associated with psychological distress (e.g., anxiety, depression, burnout, suicidal ideation), professional disengagement, and intent to leave. Contributing factors were categorized into structural and organizational (e.g., hierarchical power imbalances, toxic workplace culture), managerial and HR-related (e.g., lack of leadership support, poor reporting mechanisms), and individual/social (e.g., gender or ethnic discrimination, early-career vulnerability). Intervention strategies identified included policy reforms, leadership training, supportive reporting systems, and psychological support services, though evidence on their effectiveness remains limited. CONCLUSIONS: Organizational bullying in nursing academia is a serious and multifaceted challenge with detrimental effects on individuals and institutions. Addressing it requires a comprehensive, evidence-based approach that includes structural reforms, leadership development, and psychosocial support systems. Academic institutions must prioritize the creation of safe, inclusive, and respectful environments to retain faculty and sustain the quality of nursing education.

Faculty, Nursing↗

PubMed2026

Viral replication through phase separation: Cytosolic and nuclear condensates.

Replication of many RNA and DNA viruses occurs within specialized intracellular hubs organized as membraneless biomolecular condensates (BCs) driven by liquid-liquid phase separation. As obligate intracellular parasites, viruses depend on the host cell machinery to complete their replication cycles and therefore actively remodel the intracellular environment to favor viral genome replication, transcription, and assembly. Cytosolic and nuclear phase-separated replication compartments (RC) provide concentrated and dynamic platforms that promote efficient interactions between viral genomes and viral or host proteins essential for infection. The formation of viral replication BCs is typically facilitated by viral proteins enriched in intrinsically disordered regions and low-complexity domains, which enable multivalent interactions with viral nucleic acids and cellular factors. These interactions are mediated by diverse biophysical forces, including hydrophobic and π interactions, hydrogen bonding, molecular crowding, and osmotic effects. Throughout infection, viral BCs remain highly dynamic, allowing continuous exchange of components and functional maturation of replication hubs. Their properties and activities are further regulated by post-translational modifications of viral and host proteins, such as phosphorylation, acetylation, and methylation. In this review, we summarize current evidence supporting liquid-liquid phase separation as a central organizing principle of viral RCs. We focus on representative RNA and DNA viruses that replicate in the cytosol or nucleus, highlighting virus-specific strategies, conserved mechanisms, and the consequences of BC formation for viral replication efficiency, host antiviral responses, and therapeutic intervention.

Phase Separation↗

PubMed2026

Genomic characterization and pathogenicity of ruminant Listeria monocytogenes isolates in a murine oral infection model.

Listeria monocytogenes is a major foodborne pathogen; its ruminant isolates display zoonotic characteristics, causing similar clinical signs in humans, including abortion and encephalitis. However, data on whole genome sequencing and pathogenicity of ruminant L. monocytogenes isolates remain sparse. This study aimed to analyze the genotypic characteristics of L. monocytogenes isolates from ruminants with listeriosis. Furthermore, we assessed the in vivo pathogenicity of four ruminant L. monocytogenes isolates, characterized via whole-genome sequencing-based genetic clustering, in orogastrically inoculated mice. The isolate LM18 (serotype 1/2b, ST224, SL6178) had the lowest lethal dose compared to the other three isolates including previous hypervirulence type (serotype 4b, ST1, SL1) and caused secondary bacteremia in lungs, with sustained bacterial loads in the spleen and liver. Genomic (listeria pathogenicity island -1 and -3) and virulence gene (actA and llsX) mutation analyses associated with virulence suggested from well-recognized studies could not elucidate the virulence of the isolates. SSI-1, which only exists in the isolate LM18 (serotype 1/2b, ST224, SL6178), may help L. monocytogenes survive in the gastrointestinal environment, thereby affecting its virulence. Further research should investigate the role of SSI-1 in the pathogenicity of L. monocytogenes. Moreover, additional studies utilizing larger datasets of ruminant isolates are required to validate our genotypic characterization and to obtain a comprehensive picture of further genotypic differences crucial for L. monocytogenes pathogenicity.

Animals↗