Biofilm-associated heat resistance of Bacillus cereus spores in vitro and in a food model, Cheonggukjang jjigae.

Bacillus cereus, a foodborne pathogen, is capable of forming spores and biofilms as methods to withstand environmental stresses. These bacterial structures are an issue for food safety as they aid the bacteria survive heat sterilisation processes of foods and food contact surfaces. This study was conducted to investigate the role of the biofilm structure in providing an extra layer of protection to spores against heat treatments.

Dissemination mechanisms of NDM genes in hospitalized patients.

Background: NDM-producing Enterobacteriaceae are a major clinical concern worldwide. We characterized NDM-positive pathogens isolated from patients and assessed the dissemination patterns of the genes in a hospital setting.

Methods: Eleven NDM-positive Enterobacteriaceae (three , six and two ) were isolated from nine patients over a 1 year period.

Uterine infusion of bacteria alters the transcriptome of bovine oocytes.

Postpartum uterine infection reduces fertility in dairy cattle; however, the mechanisms of uterine infection-mediated infertility are unknown. Paradoxically, infection-induced infertility persists after the resolution of disease. Oocytes are a finite resource, which are present at various stages of development during uterine infection.

The Role of as a Key Producer and Fermentation Condition as an Influencing Factor in Tyramine Accumulation in .

The study evaluated the role of in tyramine production and its response to fermentation temperature in a traditional Korean fermented soybean paste, . Tyramine content was detected in retail products at high concentrations exceeding the recommended limit up to a factor of 14. All retail products contained spp.

Uterine infection alters the transcriptome of the bovine reproductive tract three months later.

Infection of the postpartum uterus with pathogenic bacteria is associated with infertility months later in dairy cattle. However, it is unclear whether these bacterial infections lead to long-term changes in the reproductive tract that might help explain this infertility. Here we tested the hypothesis that infusion of pathogenic bacteria into the uterus leads to changes in the transcriptome of the reproductive tract 3 months later.

Draft Genome Sequences of Bacteroides pyogenes Strains Isolated from the Uterus of Holstein Dairy Cows with Metritis.

is found in the human and animal gut and is implicated in the pathogenesis of metritis in cows. We report the draft genome sequences of four isolates obtained from the uterus of metritic cows. This will increase the understanding of its pathogenicity, antimicrobial resistance, and differentiation across hosts.

Application of Whole-Genome Sequencing to Transposon Mutants of Salmonella Heidelberg.

Transposons are elements widely dispersed among organisms which are able to move and replicate fragments of genomes. The extensive variability in transposons present in most organisms requires extensive identification and interpretation of the resulting transposon mutants after transposon mutagenesis. However, much of this is reliant on utilizing randomness characteristics of transposon to identify essential genes for the organism of interest.

Draft Genome Sequences of Helcococcus ovis Strains Isolated at Time of Metritis Diagnosis from the Uterus of Holstein Dairy Cows.

is an emerging pathogen implicated in the pathogenesis of metritis in dairy cows. Herein, we report the first draft genome sequences of four isolates from the uterus of dairy cows with metritis. This information will enable a better understanding of the bacterium's pathogenicity and antimicrobial resistance.

Draft Genome Sequences of Two Fusobacterium necrophorum Strains Isolated from the Uterus of Dairy Cows with Metritis.

A commensal in the gastrointestinal tract, is involved in the pathogenicity of abscesses, foot rot, and metritis in cattle. Here, we present the draft genomes of two isolates from the uterus of dairy cows with metritis to allow for future comparative genome studies.

Effects of Calcium and Manganese on Sporulation of Species Involved in Food Poisoning and Spoilage.

Spores are resistant against many extreme conditions including the disinfection and sterilization methods used in the food industry. Selective prevention of sporulation of species is an ongoing challenge for food scientists and fermentation technologists. This study was conducted to evaluate the effects of single and combined supplementation of calcium and manganese on sporulation of common pathogenic and food spoilage species: .

High Prevalence of Cefotaxime Resistant Bacteria in Grazing Beef Cattle: A Cross Sectional Study.

Although the over-use of antibiotics during food animal production is a potential driver of antimicrobial resistant microorganisms (ARMs), a high prevalence of cefotaxime resistant bacteria (CRB) has been observed in grazing animals raised without antibiotic supplementation. In this cross-sectional study, the prevalence and concentration of CRB in beef cattle on grazing farms were investigated. Fecal samples from the recto-anal junction of cattle ( = 840) and environmental samples ( = 258) were collected from 17 farms in North and Central Florida in the United States, and a survey of farm characteristics, animal husbandry practices, and antibiotic usage was conducted.

A model of clinical endometritis in Holstein heifers using pathogenic Escherichia coli and Trueperella pyogenes.

Bacterial infection of the uterus causes clinical endometritis in 15 to 20% of postpartum dairy cows and reduces fertility, even after the resolution of disease. However, it is difficult to disentangle the mechanisms linking reduced fertility with endometritis because cows have multiple confounding postpartum conditions. The aim of the present experiment was to develop an in vivo model of clinical endometritis in Holstein heifers using pathogenic Escherichia coli and Trueperella pyogenes.

Engineering of chitosan-derived nanoparticles to enhance antimicrobial activity against foodborne pathogen Escherichia coli O157:H7.

Chitosan is an abundant and natural polymer derived from chitin, which presents a wide variety of properties, including antimicrobial activity. The raising of antibiotic resistant bacteria has increased the interest in finding alternatives to traditional antibiotics. Many studies have assessed the antimicrobial activity of chitosan itself, but a few have performed comparisons among different chitosan nanoparticle synthesis, which will be of particular interest for further applications.

Simultaneous Detection of Four Foodborne Viruses in Food Samples Using a One-Step Multiplex Reverse Transcription PCR.

A one-step multiplex reverse transcription PCR (RT-PCR) method comprising six primer sets (for the detection of norovirus GI and GII, hepatitis A virus, rotavirus, and astrovirus) was developed to simultaneously detect four kinds of pathogenic viruses. The size of the PCR products for norovirus GI and GII, hepatitis A virus (VP3/VP1 and P2A regions), rotavirus, and astrovirus were 330, 164, 244, 198, 629, and 449 bp, respectively. The RT-PCR with the six primer sets showed specificity for the pathogenic viruses.

Draft Genome Sequences of Strains Isolated at Calving from the Uterus, Vagina, Vulva, and Rectoanal Junction of a Dairy Cow That Later Developed Metritis.

is involved in the pathogenicity of metritis in cows. We report here the genome sequences of strains isolated at calving from the uterus, vagina, vulva, and rectoanal junction of a dairy cow that later developed metritis. The genomic similarities will give an insight into phylogenetic relationships among strains.

Identification and Characterization of Cefotaxime Resistant Bacteria in Beef Cattle.

Third-generation cephalosporins are an important class of antibiotics that are widely used in treatment of serious Gram-negative bacterial infections. In this study, we report the isolation of bacteria resistant to the third-generation cephalosporin cefotaxime from cattle with no previous cefotaxime antibiotic exposure. The prevalence of cefotaxime-resistant bacteria was examined by a combination of culture based and molecular typing methods in beef cattle (n = 1341) from 8 herds located in North Central Florida.

Draft Genome Sequence of an Escherichia coli O8:H19 Sequence Type 708 Strain Isolated from a Holstein Dairy Cow with Metritis.

We present here the genome sequence ofEscherichia coliO8:H19 strain KCJ852, belonging to multilocus sequence type (MLST) 708, isolated from the uterus of a cow with a bovine postpartum uterine infection known as metritis. Genomic investigation of KCJ852 will help us understand its virulence potential.

Complete Genome Sequence of an Escherichia coli O157:H7 Strain Isolated from a Super-Shedder Steer.

We report here the complete genome sequence ofEscherichia coliO157:H7 strain JEONG-1266 isolated from a super- shedder steer in northwest Florida. Cattle are considered a primary reservoir ofE. coliO157:H7, and those cattle that excrete this pathogen in their feces at levels ≥10(4) CFU/g are known as super-shedders.

Colonization of Beef Cattle by Shiga Toxin-Producing Escherichia coli during the First Year of Life: A Cohort Study.

Each year Shiga toxin-producing Escherichia coli (STEC) are responsible for 2.8 million acute illnesses around the world and > 250,000 cases in the US. Lowering the prevalence of this pathogen in animal reservoirs has the potential to reduce STEC outbreaks in humans by controlling its entrance into the food chain.

Spatiotemporal regulation of a Legionella pneumophila T4SS substrate by the metaeffector SidJ.

Modulation of host cell function is vital for intracellular pathogens to survive and replicate within host cells. Most commonly, these pathogens utilize specialized secretion systems to inject substrates (also called effector proteins) that function as toxins within host cells. Since it would be detrimental for an intracellular pathogen to immediately kill its host cell, it is essential that secreted toxins be inactivated or degraded after they have served their purpose.

Novel export control of a Legionella Dot/Icm substrate is mediated by dual, independent signal sequences.

The Legionella pneumophila Dot/Icm T4SS injects ∼ 300 protein effector proteins into host cells. Dot/Icm substrates have been proposed to contain a carboxy-terminal signal sequence that is necessary and sufficient for export, although both traits have been demonstrated for only a small fraction of these proteins. In this study, we discovered that export of the substrate SidJ is mediated by dual signal sequences that include a conventional C-terminal domain and a novel internal motif.

Association between animal age and the prevalence of Shiga toxin-producing Escherichia coli in a cohort of beef cattle.

Even with advancements in pre- and post-harvest food safety, Shiga toxin-producing Escherichia coli (STEC) still present challenges to human health. Since cattle are the primary reservoir for STEC, lowering the prevalence of this pathogen in farm animals may reduce STEC outbreaks in humans. However, because many of the factors that modulate the colonization and persistence of STEC in cattle remain unknown, reducing STEC in this host is challenging.

Underlying mechanism of antimicrobial activity of chitosan microparticles and implications for the treatment of infectious diseases.

The emergence of antibiotic resistant microorganisms is a great public health concern and has triggered an urgent need to develop alternative antibiotics. Chitosan microparticles (CM), derived from chitosan, have been shown to reduce E. coli O157:H7 shedding in a cattle model, indicating potential use as an alternative antimicrobial agent.

Rapid and sensitive detection of Escherichia coli O157:H7 in milk and ground beef using magnetic bead-based immunoassay coupled with tyramide signal amplification.

Escherichia coli O157:H7 is a major foodborne pathogen that has posed serious problems for food safety and public health. Recent outbreaks and recalls associated with various foods contaminated by E. coli O157:H7 clearly indicate its deleterious effect on food safety.

Evaluation of animal genetic and physiological factors that affect the prevalence of Escherichia coli O157 in cattle.

Controlling the prevalence of Escherichia coli O157 in cattle at the pre-harvest level is critical to reduce outbreaks of this pathogen in humans. Multilayers of factors including the environmental and bacterial factors modulate the colonization and persistence of E. coli O157 in cattle that serve as a reservoir of this pathogen.