Natural Mutation of PrfA K10N/T151A Enhances Serotype 4h Virulence.

PrfA is a key virulence regulator for (Lm) responding to host environment. Here we report that the natural mutation in PrfA enhanced the pathogenicity of hypervirulent serotype 4h . We characterized the phylogenetic tree of PrfA, and found that PrfA prevalently distributed in all serotype 4h isolates.

Microbiological safety assessment of restaurants and HACCP-certified kitchens in hotels: A study in eastern China.

The Hazard Analysis and Critical Control Point (HACCP) system plays a crucial role in ensuring food safety within food service establishments, effectively reducing the risk of foodborne diseases. This study focused on assessing the risk of microbe contamination in poultry-based cook-served food during meal preparation in four restaurants and five selected HACCP-certified hotels in eastern China. We examined samples collected from 26 poultry-based cooked dishes, 248 food contact surfaces, 252 non-food contact surfaces, and 121 hand swabs.

Invited review: Role of Bacillus licheniformis in the dairy industry-Friends or foes?

Bacillus licheniformis is one of the major spore-forming bacteria with great genotypic diversity in raw milk, dairy ingredients, and final dairy products; it is found throughout the dairy-processing continuum. Although being widely used as a probiotic strain, this species also serves as a potential risk in the dairy industry based on its roles in foodborne illness and dairy spoilage. Biofilm formation of B.

Development and evaluation of rapid and accurate one-tube RPA-CRISPR-Cas12b-based detection of mcr-1 and tet(X4).

The emergence and quick spread of the plasmid-mediated tigecycline resistance gene tet(X4) and colistin resistance gene mcr-1 have posed a great threat to public health and raised global concerns. It is imperative to develop rapid and accurate detection systems for the onsite surveillance of mcr-1 and tet(X4). In this study, we developed one-tube recombinase polymerase amplification (RPA) and CRISPR-Cas12b integrated mcr-1 and tet(X4) detection systems.

The haemagglutinin-neuraminidase protein of velogenic Newcastle disease virus enhances viral infection through NF-κB-mediated programmed cell death.

The haemagglutinin-neuraminidase (HN) protein, a vital membrane glycoprotein, plays a pivotal role in the pathogenesis of Newcastle disease virus (NDV). Previously, we demonstrated that a mutation in the HN protein is essential for the enhanced virulence of JS/7/05/Ch, a velogenic variant NDV strain originating from the mesogenic vaccine strain Mukteswar. Here, we explored the effects of the HN protein during viral infection in vitro using three viruses: JS/7/05/Ch, Mukteswar, and an HN-replacement chimeric NDV, JS/MukHN.

Characterization of Probiotic Properties and Whole-Genome Analysis of N5 and N7 Isolated from Swine.

In our previous microbiome profiling analysis, () was suggested to contribute to resistance against chronic heat stress-induced diarrhea in weaned piglets. Forty-nine strains were isolated from these heat stress-resistant piglets, and their probiotic properties were assessed. Strains N5 and N7 exhibited a high survival rate in acidic and bile environments, along with an antagonistic effect against .

Mobile Colistin Resistance and Plasmid-Mediated Quinolone Resistance Genes in from China, 1993-2019.

Plasmid-mediated quinolone resistance (PMQR) genes and mobile colistin resistance (MCR) genes in () have been widely identified, which is considered a global threat to public health. In the present study, we conducted an analysis of MCR genes (, , , , and ) and PMQR genes [, , , , , , , , , and ] in from China, 1993-2019. From the 3,663 isolates examined, 1,613 (44.

Unraveling the significance of calcium as a biofilm promotion signal for Bacillus licheniformis strains isolated from dairy products.

Bacillus licheniformis, a quick and strong biofilm former, is served as a persistent microbial contamination in the dairy industry. Its biofilm formation process is usually regulated by environmental factors including the divalent cation Ca. This work aims to investigate how different concentrations of Ca change biofilm-related phenotypes (bacterial motility, biofilm-forming capacity, biofilm structures, and EPS production) of dairy B.

Genotype-phenotype evaluation of the heterogeneity in biofilm formation by diverse Bacillus licheniformis strains isolated from dairy products.

The spoilage bacterium Bacillus licheniformis has been identified as a quick and strong biofilm former in the dairy industry. In our previous study, intra-species variation in bacterial biofilms has been observed in diverse B. licheniformis strains from different genetic backgrounds; however, the mechanisms driving the observed heterogeneity of biofilms remain to be determined.

Activation dynamics of antigen presenting cells in vivo against Mycobacterium bovis BCG in different immunized route.

Background: Control of Tuberculosis (TB) infection is mainly the result of productive teamwork between T-cell populations and antigen presenting cells (APCs). However, APCs activation at the site of initiating cellular immune response during BCG early infection is not completely understood.

Methods: In this study, we injected C57BL/6 mice in intravenous (i.

Efficient screening of adsorbed receptors for phage LP31 and identification of receptor-binding protein.

The adsorption process is the first step in the lifecycle of phages and plays a decisive role in the entire infection process. Identifying the adsorption mechanism of phages not only makes phage therapy more precise and efficient but also enables the exploration of other potential applications and modifications of phages. Phage LP31 can lyse multiple serotypes, efficiently clearing biofilms formed by serovar Enteritidis (.

Evaluation of Hygiene Practice for Reducing Contamination on Cutting Boards and Risks Associated with Chicken Handling in Kitchen Environment.

Cutting boards can serve as potential carriers for the cross-contamination of pathogens from chicken to other surfaces. This study aimed to assess chefs' handling practices of cutting boards across five provinces in China and identify the key factors contributing to unsafe cutting board usage, including cleaning methods and handling practices. Handling practices associated with cutting boards were examined through a web-based survey (N = 154), while kitchen environment tests were conducted to investigate the splashing or survival of , inoculated in chicken or on cutting boards, to mimic the practices of chefs.

Assessment of beneficial effects and identification of host adaptation-associated genes of Ligilactobacillus salivarius isolated from badgers.

Background: Ligilactobacillus salivarius has been frequently isolated from the gut microbiota of humans and domesticated animals and has been studied as a candidate probiotic. Badger (Meles meles) is known as a "generalist" species that consumes complex foods and exhibits tolerance and resistance to certain pathogens, which can be partly attributed to the beneficial microbes such as L. salivarius in the gut microbiota.

Emergence of a new designated clade 16 with significant antigenic drift in hemagglutinin gene of H9N2 subtype avian influenza virus in eastern China.

H9N2 avian influenza viruses (AIVs) pose an increasing threat to the poultry industry worldwide and have pandemic potential. Vaccination has been principal prevention strategy to control H9N2 in China since 1998, but vaccine effectiveness is persistently challenged by the emergence of the genetic and/or antigenic variants. Here, we analysed the genetic and antigenic characteristics of H9N2 viruses in China, including 70 HA sequences of H9N2 isolates from poultry, 7358 from online databases during 2010-2020, and 15 from the early reference strains.

[Characterization of the cellular immune response induced by Rv2626c].

Nearly a quarter of the world's population is infected with and remains long-term asymptomatic infection. Rv2626c is a latent infection-related protein regulated by DosR of . In this study, the Rv2626c protein was prokaryotically expressed and purified, and its immunobiological characteristics were analyzed using RAW264.

Multi-omics reveals the increased biofilm formation of Salmonella Typhimurium M3 by the induction of tetracycline at sub-inhibitory concentrations.

Exposure to sub-inhibitory concentrations (sub-MICs) of antibiotics could induce the biofilm formation of microorganisms, but its underlying mechanisms still remain elusive. In the present work, biofilm formation by Salmonella Typhimurium M3 was increased when in the presence of tetracycline at sub-MIC, and the highest induction was observed with tetracycline at 1/8 MIC. The integration of RNA-sequencing and untargeted metabolomics was applied in order to further decipher the potential mechanisms for this observation.

LygA retention on the surface of Listeria monocytogenes via its interaction with wall teichoic acid modulates bacterial homeostasis and virulence.

Wall teichoic acid (WTA) is the abundant cell wall-associated glycopolymer in Gram-positive bacteria, playing crucial roles in surface proteins retention, bacterial homeostasis, and virulence. The WTA glycosylation of Listeria monocytogenes is essential for surface anchoring of virulence factors, whereas the nature and function of the noncovalent interactions between cell wall-associated proteins and WTA are less unknown. In this study, we found that galactosylated WTA (Gal-WTA) of serovar (SV) 4h L.

First Detection of -Haboring IncHI2 Plasmid in Strain Isolated from Goose in China.

Carbapenem-resistant Enterobacteriaceae infections are among the most serious threats to human and animal health worldwide. Of the 1013 strains of isolated and identified in 14 regions of China from 2007 to 2018, seven strains were resistant to meropenem and all were positive for . The seven New Delhi metallo-β-lactamase (NDM)-positive strains belonged to five different sequence types, indicating that most of the NDM-positive strains were nonclonal.

A live attenuated DIVA vaccine affords protection against Listeria monocytogenes challenge in sheep.

Listeria monocytogenes (Lm) is a deadly foodborne pathogen that comprises 14 serotypes, among which, serotype 4b Lm is the primary cause of listeriosis outbreaks in humans and animals. Here, we evaluated the safety, immunogenicity, and protective efficacy of a serotype 4b vaccine candidate Lm NTSNΔactA/plcB/orfX in sheep. The infection dynamics, clinical features, and pathological observation verified that the triple genes deletion strain has adequate safety for sheep.

Characterization and comparative genomic analysis of novel lytic bacteriophages targeting Cronobacter sakazakii.

Cronobacter sakazakii, a foodborne pathogen, can contaminate powdered infant formula (PIF) and cause life-threatening meningitis, necrotizing colitis and meningoencephalitis in infants. Bacteriophages are increasingly considered an efficient approach to target pathogenic microorganisms. In the current study, four virulent phages that can infect C.

Environmental factors and gut microbiota: Toward better conservation of deer species.

Thousands of microbial species inhabiting the animal gut, collectively known as the gut microbiota, play many specific roles related to host nutrient metabolism and absorption, immune regulation, and protection from pathogenic bacteria. Gut microbiota composition is affected by several internal and external factors, such as the host genotype, dietary intake, breeding environment, and antibiotic exposure. As deer species are important members for maintaining ecosystem balance, understanding the effects of multiple factors on the gut microbiota of deer species, particularly endangered ones, is crucial.

[Development of a flow cytometry method for detection of bovine multi-cytokines].

This study aims to develop a method to detect bovine multi-cytokines based on flow cytometry. Previously we have prepared and screened monoclonal antibodies against bovine cytokines IFN-γ, IL-2, TNF-α, IP-10 and MCP-1. These bovine cytokine monoclonal antibodies were fluorescently labeled, and the combination of antibody and cell surface molecules were used to develop the method for detecting bovine multi-cytokines.

Isolation and genomic characterization of Vmp-1 using Vibrio mimicus as the host: A novel virulent bacteriophage capable of cross-species lysis against three Vibrio spp.

Vibrio mimicus is a zoonotic pathogen that is widely distributed in aquatic habitats/environments (marine coastal water, estuaries, etc). The development of biocontrol agents for V. mimicus is imperative for the prevention and control of aquatic animal diseases and human food-borne infections.