Research Publications (Food Safety)

Introduction

This study aimed to identify the characteristics of Campylobacter isolated from wild birds (Black-headed gulls Chroicocephalus ridibundus and Great tits Parus major) and collect surface water samples (from rivers, ponds, ornamental lakes, freshwater beaches). Research material included 33 Campylobacter isolates. All the strains were isolated by different monitoring and surveillance plans.

Methods

Shiga toxin-producing Escherichia coli (STEC) O121 is among the top six non-O157 serogroups that are most frequently associated with severe disease in humans. While O121:H19 is predominant, other O121 serotypes have been frequently isolated from environmental samples, but their virulence repertoire is poorly characterized.

Staphylococcus aureus (SA) is a significant and well-recognized causative organism of bacterial osteomyelitis. Osteomyelitis is an inflammatory bone disease characterized by progressive bone destruction and loss. This disease causes significant morbidity and mortality to the patient and poses therapeutic challenges for clinicians.

Microorganisms can adapt quickly to changes in their environment, leading to various phenotypes. The dynamic for phenotypic plasticity caused by environmental variations has not yet been fully investigated. In this study, we analyzed the time-series of phenotypic changes in Staphylococcus cells during adaptive process to antibiotics stresses using flow cytometry and Raman spectroscopy.

Bacterial sphingomyelinases (SMases) hydrolyze sphingomyelin and play an important role in membrane dynamics and the host immune system. While the number of sequenced genomes and metagenomes is increasing, a limited number of experimentally validated SMases have been reported, and the genomic diversity of SMases needs to be elucidated extensively. This study investigated the sequence and structural characteristics of SMases in bacterial genomes and metagenomes.

Despite their clonality, intracellular bacterial pathogens commonly show remarkable physiological heterogeneity during infection of host cells. Physiological heterogeneity results in distinct ultrastructural morphotypes, but the correlation between bacterial physiological state and ultrastructural appearance remains to be established. In this study, we showed that individual cells of Salmonella enterica serovar Typhimurium are heterogeneous in their ultrastructure.

Introduction

Toxoplasma gondii and Neospora caninum are closely related intracellular protozoan parasites of medical and veterinary concern by causing abortions and systemic illness. Limited or ambiguous data on the prevalence of T. gondii and N. caninum in camels triggered us to conduct this study.

Methods

Staphylococcus epidermidis (S. epidermidis) is a clinically important conditioned pathogen that can cause a troublesome chronic implant-related infection once a biofilm is formed. The nitric oxide synthase (NOS) gene, which is responsible for endogenous nitric oxide synthesis, has already been found in the genome of S. epidermidis; however, the specific mechanisms associated with the effects of NOS on S. epidermidis pathogenicity are still unknown.

Salmonella enterica serovar Enteritidis is the most prevalent serotype that causes human infections worldwide. Consumption of S. Enteritidis-contaminated animal foods is a major source of human infections; however, eradicating bacteria from animals remains difficult. Therefore, it is necessary to develop new measures to prevent and control salmonellosis. Here, we used the outer-membrane vesicles (OMVs) of S. Enteritidis and assessed their protective efficacy and immune response in mice.

Toxoplasmosis is an important zoonotic parasitic disease caused by Toxoplasma gondii (T. gondii). However, the functions of circRNAs and miRNAs in response to T. gondii infection in the livers of mice at acute and chronic stages remain unknown. Here, high-throughput RNA sequencing was performed for detecting the expression of circRNAs and miRNAs in livers of mice infected with 20 T.

Shigella, the causative agent of bacillary dysentery, subvert cytoskeletal and trafficking processes to invade and replicate in epithelial cells using an arsenal of bacterial effectors translocated through a type III secretion system. Here, we review the various roles of the type III effector IpgD, initially characterized as phosphatidylinositol 4,5 bisphosphate (PI4,5P2) 4-phosphatase.

Vibrio parahaemolyticus is a common pathogen usually controlled by antibiotics in mariculture. Notably, traditional antibiotic therapy is becoming less effective because of the emergence of bacterial resistance, hence new strategies need to be found to overcome this challenge. Bacteriophages, a class of viruses that lyse bacteria, can help us control drug-resistant bacteria. In this study, a novel Vibrio parahaemolyticus phage phiTY18 isolated from the coastal water of Xiamen was explored.

Shigella sonnei is the most common Shigella spp. in developed areas and the second most common in undeveloped regions. In this study, a multiple cross displacement amplification (MCDA) assay was used in combination with a lateral flow biosensor (LFB) assay to detect virulent S. sonnei strains containing the ipaH and wbgX genes. The multiplex MCDA-LFB assay detected wbgX at ≥1 pg/μL and ipaH at ≥10 fg/μL within 30 min in pure cultures maintained at 63°C.

Giardia duodenalis is a parasitic flagellated protozoan which infects a wide range of mammalian hosts, including humans, and is subdivided into at least eight genetic assemblages commonly thought to represent cryptic species. Molecular studies have shown that G. duodenalis assemblage A, which parasitizes humans and animals, contains several phylogenetically distinct groupings known as sub-assemblages.

The nasogastric enteral feeding tubes (NEFTs) used to feed preterm infants are commonly colonized by bacteria with the ability to form complex biofilms in their inner surfaces. Among them, staphylococci (mainly Staphylococcus epidermidis and Staphylococcus aureus) and some species belonging to the Family Enterobacteriaceae are of special concern since they can cause nosocomial infections in this population.

Hybrid sturgeon is the main species of sturgeon cultured in China, with the advantages of a fast growth rate, early sexual maturity, fertile offspring, and more stable genetic traits. In May 2021, a large number of deaths characterized by superficial hemorrhage and liver damage occurred in a sturgeon farm in Yichang, Hubei Province, which posed a significant risk to hybrid sturgeon captive breeding.

Staphylococcus aureus (Sa) is an opportunistic pathogen capable of causing various infections ranging from superficial skin infections to life-threatening severe diseases including pneumonia and sepsis. Sa produces biofilms readily on biotic and abiotic surfaces. Biofilm cells are embedded in a protective polysaccharide matrix and show an innate resistance to antibiotics, disinfectants, and clearance by host defenses. Additionally, biofilms serve as a source for systemic dissemination.

Salmonella Entertidis (SE) often causes persistent infections and egg contamination in laying ducks. Hcp, the core structural and effector proteins of the Type VI Secretion System (T6SS) in SE, contributes to bacterial invasion, adhesion and virulence. However, little is known about the effect of Hcp on the host’s infection responses and egg contamination incidences in duck.

Humans are exposed to Toxoplasma gondii infection as pet cats gradually become family members and represent an increasing public health risk worldwide. Toxoplasmosis diagnosis constitutes an important measure for disease prevention and control. In this study, real-time fluorescence quantitative loop-mediated isothermal amplification (qLAMP) and visual LAMP detection technologies were established to conduct tests of T.

In order to evaluate the potential and safety of lactic acid bacteria (LAB) isolated from faeces samples of Ganan yak as probiotic for prevention and/or treatment of yak diarrhea, four strains of LAB including Latilactobacillus curvatus (FY1), Weissella cibaria (FY2), Limosilactobacillus mucosae (FY3), and Lactiplantibacillus pentosus (FY4) were isolated and identified in this study.

New therapeutic strategies for clinical Salmonella enterica serovar Typhimurium (S. Typhimurium) infection are urgently needed due to the generation of antibiotic-resistant bacteria. Inhibition of bacterial virulence has been increasingly regarded as a potential and innovative strategy for the development of anti-infection drugs. Salmonella pathogenicity island (SPI)-encoded type III secretion system (T3SS) represents a key virulence factor in S.

Ocular toxoplasmosis (OT) is retinochoroiditis caused by Toxoplasma gondii infection, which poses a huge threat to vision. However, most traditional oral drugs for this disease have multiple side effects and have difficulty crossing the blood-retinal barrier, so the new alternative strategy is required to be developed urgently. Histone deacetylases (HDAC) inhibitors, initially applied to cancer, have attracted considerable attention as potential anti-Toxoplasma gondii drugs.

Free-living amoebae (FLA) are widely distributed protozoa in nature, known to cause severe eye infections and central nervous system disorders. There is growing attention to the potential role that these protozoa could act as reservoirs of pathogenic bacteria and, consequently, to the possibility that, the persistence and spread of the latter may be facilitated, by exploiting internalization into amoebae.

Hepatitis E virus (HEV) is a zoonotic pathogen that causes global hepatitis E. Outbreaks of hepatitis E are directly linked to the consumption of pork liver products. Herein reverse transcription recombinase polymerase amplification assays targeting the ORF2 gene were developed for the rapid detection of HEV by integrating the fluorescence detection platform (qRT-RPA) and the visible lateral flow biosensor by naked eyes (LFB RT-RPA).

Soybean isoflavones (SIs) are widely found in food and herbal medicines. Although the pharmacological activities of SIs have been widely reported, their effects on the intestinal microecology of normal hosts have received little attention. Five-week-old Kunming (KM) mice were administered SIs (10 mg/kg/day) for 15 days. Food intake, body weight, and digestive enzyme activity were measured.