Modeling Growth Kinetics of and Background Microflora in Hydroponically Grown Lettuce.

Hydroponic cultivation of lettuce is an increasingly popular sustainable agricultural technique. However, , a prevalent bacterium, poses significant concerns for the quality and safety of hydroponically grown lettuce. This study aimed to develop a growth model for and background microflora in hydroponically grown lettuce.

Population Genetic Analyses and Trichothecene Genotype Profiling of Causing Wheat Crown Rot in Henan, China.

In China, has emerged as a major pathogen causing Fusarium crown rot (FCR) and caused significant losses. Studies on the pathogen's properties, especially its mating type and trichothecene chemotypes, are critical with respect to disease epidemiology and food/feed safety. There are currently few available reports on these issues.

Chickpea-Derived Modified Antimicrobial Peptides KTA and KTR Inactivate via Disrupting Cell Membrane and Interfering with Peptidoglycan Synthesis.

The widespread bacterial contamination caused by foodborne pathogens has continuously driven the development of advanced and potent food antimicrobial agents. In this study, two novel antimicrobial peptides (AMPs) named KTA and KTR were obtained by modifying a natural AMP, Leg2, from chickpea storage protein legumin hydrolysates. They were further predicted to be stable hydrophobic cationic AMPs of α-helical structure with no hemolytic toxicity by several online servers.

Transcriptomics of Treated With Olive Leaf Extract.

is a regulated foodborne pathogen that is known to cause listeriosis, a disease associated with high mortality rates in humans. Olive leaf extract (OLE) has been shown to act as a plant antimicrobial and inhibit the growth of pathogens, such as , although its mode of action has not been defined. To help identify the cellular mechanisms important for conveying these beneficial traits, RNA-Seq was used to study the transcriptome of upon exposure to a sublethal level of OLE.

The Possible Transmission and Potential Enterotoxicity of on Lettuce Farms in Five Chinese Provinces.

is a well-characterized human pathogen that produces toxins associated with diarrheal and emetic foodborne diseases. To investigate the possible transmission of on lettuce farms in China and determine its enterotoxicity, (I) a total of 524 samples (lettuce: 332, soil: 69, water: 57, manure: 57, pesticide: 9) were collected from 46 lettuce farms in five Chinese provinces, (II) multilocus sequence typing (MLST) was used to classify isolates and for trace analysis, and (III) the presence of toxin genes and enterotoxins (Hbl and Nhe) was detected in 68 strains. The results showed that one hundred and sixty-one lettuce samples (48.

Evaluation of the Stress Tolerance of with Different Antibiotic Resistance Profiles.

Disease caused by antibiotic-resistant is a serious clinical problem that poses a great threat to public health. The present study is aimed at assessing differences in bacterial kinetics with different antibiotic resistance profiles under environmental stress and at developing microbial tolerance models in lettuce during storage from 4 to 36°C. The drug-resistance phenotypes of 10 Typhimurium (.

A Rapid Method for Detection of in Milk Based on Extraction of mRNA Using Magnetic Capture Probes and RT-qPCR.

Magnetic separation is an efficient method for target enrichment and elimination of inhibitors in the molecular detection systems for foodborne pathogens. In this study, we prepared magnetic capture probes by modifying oligonucleotides complementary to target sequences on the surface of amino-modified silica-coated magnetic nanoparticles and optimized the conditions and parameters of probe synthesis and hybridization. We innovatively put the complexes of magnetic capture probes and target sequences into qPCR without any need for denaturation and purification steps.

A method based on amino-modified magnetic nanoparticles to extract DNA for PCR-based analysis.

DNA extraction using magnetic particles (MPs) is a simple and rapid process. MPs directly combine with DNA, thereby facilitating removal of impurities in complex samples by magnetic attraction. Amino-modified magnetic nanoparticles (AMNPs) have been described as poor substrates for DNA extraction because it was difficult to desorb DNA from the AMNPs for downstream assays.

Effect of sublethal concentrations of ceftriaxone on antibiotic susceptibility of multiple antibiotic-resistant Salmonella strains.

The aim of this study was to determine whether sublethal concentrations of ceftriaxone could alter antibiotic resistance patterns in Salmonella strains. Three multiple antibiotic-resistant Salmonella isolates and the control strain ATCC 13076 were subjected to induction experiments by stepwise increases in sublethal concentrations of ceftriaxone. Sublethal levels of ceftriaxone induced antibiotic resistance but not control Salmonella isolates to ceftriaxone and to other antibiotics.

Enhancement of PCR Sensitivity and Yield Using Thiol-modified Primers.

Various additives can enhance the quality of PCR amplification, but these generally require considerable optimization to achieve peak performance. Here, we demonstrate that the use of thiol-modified primers can enhance both PCR sensitivity and yield. In experiments with V.

Antimicrobial Resistance and Molecular Characterization of Salmonella enterica Serovar Enteritidis from Retail Chicken Products in Shanghai, China.

Salmonella enterica serovar Enteritidis is the leading global cause of salmonellosis. A total of 146 Salmonella Enteritidis isolates obtained from retail chicken products in Shanghai, China were characterized for their antimicrobial susceptibilities, virulence and antibiotic resistance gene profiles, and molecular subtypes using pulsed-field gel electrophoresis (PFGE). Approximately 42% (61/146) of the isolates were susceptible to all 13 antimicrobials tested.

Genetic and Virulent Difference Between Pigmented and Non-pigmented .

Staphyloxanthin (STX), a golden carotenoid pigment produced by , is suggested to act as an important virulence factor due to its antioxidant properties. Restraining biosynthesis of STX was considered as an indicator of virulence decline in pigmented isolates. However, it is not clear whether natural non-pigmented isolates have less virulence than pigmented ones.

Encoding for a Fructose Specific PTS Permease IIA May Be Required for Virulence in Strain F2365.

is a foodborne pathogen that causes listeriosis, which is a major public health concern due to the high fatality rate. , and encode for fructose-specific EIIABC components of phosphotransferase transport system (PTS) permease that is responsible for sugar transport. In previous studies, in-frame deletion mutants of a putative fructose-specific PTS permease (, and ) were constructed and analyzed.

Impact of Sod on the expression of stress-related genes in Listeria monocytogenes 4b G with/without paraquat treatment.

Listeria monocytogenes is a foodborne pathogen that causes listeriosis. Paraquat can generate reactive oxygen species (ROS) in cells, which results in oxidative stress. It was first shown that 1 mM of paraquat inhibited the growth rate of a superoxide dismutase (sod)-deletion mutant (∆sod) generated from L.

Genome sequence and virulence variation-related transcriptome profiles of Curvularia lunata, an important maize pathogenic fungus.

Background: Curvularia lunata is an important maize foliar fungal pathogen that distributes widely in maize growing area in China. Genome sequencing of the pathogen will provide important information for globally understanding its virulence mechanism.

Results: We report the genome sequences of a highly virulent C.

Mutations in gltB and gltC reduce oxidative stress tolerance and biofilm formation in Listeria monocytogenes 4b G.

The foodborne pathogen Listeria monocytogenes has the capability to persist on surfaces in food-processing environments, and the organism is resistant to environmental stresses. In this study, a Tn917 insertion mutant of L. monocytogenes 4b G showing reduced biofilm formation and sensitivity to oxidative stress was identified and characterized.

The expression of superoxide dismutase (SOD) and a putative ABC transporter permease is inversely correlated during biofilm formation in Listeria monocytogenes 4b G.

Little is known about the molecular basis of biofilm formation in Listeria monocytogenes. The superoxide dismutase (SOD) of the deletion mutant of lm.G_1771 gene, which encodes for a putative ABC transporter permease, is highly expressed in biofilm.