Construction and characterization of bioluminescent Reading outbreak and non-outbreak strains.

Unlabelled: enterica serotype Reading has recently been identified as a significant foodborne pathogen from contaminated poultry products. There is a critical need for close monitoring of this newly emerged pathogen. This study developed bioluminescent strains of Reading for real-time pathogen tracking using bioluminescence imaging.

Innate and adaptive immunity gene expression profiles induced by virulent Aeromonas hydrophila infection in the immune-related organs of channel catfish.

Aeromonas hydrophila causes motile Aeromonas septicemia (MAS) in freshwater fish. In recent years, MAS outbreaks due to virulent Aeromonas hydrophila (vAh) have been responsible for large-scale losses within commercial catfish farms in Mississippi and Alabama. The aim of this study was to evaluate immune gene expression in catfish immune-competent tissues during infection with vAh strain ML09-119.

The RNA chaperone Hfq has a multifaceted role in .

is a Gram-negative, facultative intracellular bacterium that causes enteric septicemia in catfish (ESC). The RNA chaperone Hfq (host factor for phage Qβ replication) facilitates gene regulation via small RNAs (sRNAs) in various pathogenic bacteria. Despite its significance in other bacterial species, the role of in remains unexplored.

Comparative analysis of three plasmids from strain MS-17-188 and their role in antimicrobial resistance.

Background: strain MS-17-188 was isolated from a deceased catfish from East Mississippi and showed resistance to florfenicol, tetracyclines and a sulphonamide. WGS of strain MS-17-188 revealed three plasmids (pPSMS-171881, pPSMS-171882 and pPSMS-171883).

Objectives: To accurately determine the impact of three plasmids found in strain MS-17-188 on the dissemination of antibiotic resistance genes and to provide insights into the molecular structure of these plasmids.

An insight into the role of branched-chain α-keto acid dehydrogenase (BKD) complex in branched-chain fatty acid biosynthesis and virulence of .

is a foodborne bacterial pathogen that causes listeriosis. Positive regulatory factor A (PrfA) is a pleiotropic master activator of virulence genes of that becomes active upon the entry of the bacterium into the cytosol of infected cells. can survive and multiply at low temperatures; this is accomplished through the maintenance of appropriate membrane fluidity via branched-chain fatty acid (BCFA) synthesis.

Catabolite control protein C contributes to virulence and hydrogen peroxide-induced oxidative stress responses in .

causes listeriosis, an infectious and potentially fatal disease of animals and humans. A diverse network of transcriptional regulators, including LysR-type catabolite control protein C (CcpC), is critical for the survival of and its ability to transition into the host environment. In this study, we explored the physiological and genetic consequences of deleting and the effects of such deletion on the ability of to cause disease.

Identification of Protein Biomarkers for Differentiating Genetic Lineage III.

is the causative agent of listeriosis, a severe foodborne illness characterized by septicemia, meningitis, encephalitis, abortions, and occasional death in infants and immunocompromised individuals. is composed of four genetic lineages (I, II, III, and IV) and fourteen serotypes. The aim of the current study was to identify proteins that can serve as biomarkers for detection of genetic lineage III strains based on simple antibody-based methods.

Trans-Cinnamaldehyde Primes More Robust Channel Catfish Immune Responses to Infection.

Infection with a causative agent of enteric septicemia of catfish, threatens profitable catfish production through inventory losses. We previously demonstrated that trans-cinnamaldehyde (TC) enhances the survival of catfish following infection. The present study was conducted to investigate catfish immune responses to TC feeding and infection.

Characterization of Type VI secretion system in Edwardsiella ictaluri.

Edwardsiella ictaluri is a Gram-negative facultative intracellular fish pathogen causing enteric septicemia of catfish (ESC). While various secretion systems contribute to E. ictaluri virulence, the Type VI secretion system (T6SS) remains poorly understood.

Secreted Extracellular Products of as Potential Immunogenic Factors for Protection against Columnaris Disease in Channel Catfish ().

Columnaris disease caused by leads to substantial economic losses in commercially important fish species worldwide. The US channel catfish () industry is particularly vulnerable to this disease. Therefore, there is an urgent need to develop a vaccine to reduce the economic losses caused by this disease.

Development of Bioluminescent Virulent for Understanding Pathogenicity.

Virulent (vAh) strains that cause motile septicemia (MAS) in farmed channel catfish () have been an important problem for more than a decade. However, the routes of infection of vAh in catfish are not well understood. Therefore, it is critical to study the pathogenicity of vAh in catfish.

Characterisation and mobilisation of IncA/C plasmid-mediated antibiotic resistance in Edwardsiella ictaluri.

Objectives: Edwardsiella ictaluri is an important pathogen in farmed raised catfish. Recently, we showed that resistance to tetracycline and florfenicol in the E. ictaluri MS-17-156 strain isolated from channel catfish was facilitated by acquisition of a 135 kb plasmid (named pEIMS-171561).

Serotype-identifying ions in using matrix-associated laser desorption ionization-time of flight mass spectrometry.

is a foodborne pathogen that can cause a potentially life-threatening infection, and almost all cases of human listeriosis are caused by isolates in serotypes 1/2a, 1/2b, 1/2c, and 4b. Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) is a rapid, accurate, and high-throughput tool for clinical diagnosis and microbiological research. In the current study, we examined the potential of MALDI-TOF MS for rapid identification of the foodborne pathogen and to identify high-risk serotypes.

Role of FruR transcriptional regulator in virulence of Listeria monocytogenes and identification of its regulon.

Listeria monocytogenes is a ubiquitous opportunistic foodborne pathogen capable of survival in various adverse environmental conditions. Pathogenesis of L. monocytogenes is tightly controlled by a complex regulatory network of transcriptional regulators that are necessary for survival and adaptations to harsh environmental conditions both inside and outside host cells.

Evaluation of Edwardsiella piscicida basS and basR mutants as vaccine candidates in catfish against edwardsiellosis.

Catfish farming is the largest aquaculture industry in the United States and an important economic driver in several southeastern states. Edwardsiella piscicida is a Gram-negative pathogen associated with significant losses in catfish aquaculture. Several Gram-negative bacteria use the BasS/BasR two-component system (TCS) to adapt to environmental changes and the host immune system.

Pathological and Ultrastructural Characterization of an Edwardsiella ictaluri Triple hemR Mutant.

Enteric septicemia of catfish, which is caused by Edwardsiella ictaluri, is detrimental to farmed Channel Catfish Ictalurus punctatus. The hemin receptor HemR is involved in binding and uptake of heme into bacteria. Here, we explored pathological and ultrastructural changes in catfish fry that were immunized with a triple hemR mutant of E.

Hemolysin Co-regulated Family Proteins Hcp1 and Hcp2 Contribute to Pathogenesis.

is a Gram-negative facultative intracellular pathogen causing enteric septicemia of catfish (ESC), a devastating disease resulting in significant economic losses in the U.S. catfish industry.

Virulence and live vaccine potential of Edwardsiella piscicida phoP and phoQ mutants in catfish against edwardsiellosis.

Edwardsiella piscicida is a Gram-negative facultative intracellular bacterium causing edwardsiellosis in catfish, the largest aquaculture industry in the United States. A safe and effective vaccine is an urgent need to avoid economic losses associated with E. piscicida outbreaks.

Adaptive immune responses in channel catfish exposed to Edwardsiella ictaluri live attenuated vaccine and wild type strains through the specific gene expression profiles.

We extend the previous findings on the differential activity of immune-related genes in the lymphoid organs of channel catfish in the 7 days post-challenge (dpc) with E. ictaluri live attenuated vaccines (LAVs) and wild type (WT) strains by assessing the expression of these genes in the 21 dpc. The expression of T and B cell-specific genes were significantly elevated in the spleen at 14 dpc and in the AK at 21 dpc in catfish treated with E.

Live attenuated Edwardsiella ictaluri vaccines enhance the protective innate immune responses of channel catfish B cells.

Edwardsiella ictaluri causes enteric septicemia of catfish. Our group developed two E. ictaluri live attenuated vaccines (LAVs).

Contributions of a LysR Transcriptional Regulator to Listeria monocytogenes Virulence and Identification of Its Regulons.

The capacity of to adapt to environmental changes is facilitated by a large number of regulatory proteins encoded by its genome. Among these proteins are the uncharacterized LysR-type transcriptional regulators (LTTRs). LTTRs can work as positive and/or negative transcription regulators at both local and global genetic levels.