Research Publications (Food Safety)

The effects of global warming are not limited to rising global temperatures and have set in motion a complex chain of events contributing to climate change. A consequence of global warming and the resultant climate change is the rise in cyanobacterial harmful algal blooms (cyano-HABs) across the world, which pose a threat to public health, aquatic biodiversity, and the livelihood of communities that depend on these water systems, such as farmers and fishers.

Lecithin-dependent thermolabile hemolysin (LDH) is a virulence factor excreted by Vibrio parahaemolyticus, a marine bacterium that causes important losses in shrimp farming. In this study, the function of LDH was investigated through its inhibition by metal ions (Mg2+, Ca2+, Mn2+, Co2+, Ni2+ and Cu2+) and chemical modification reagents: β-mercaptoethanol (βME), phenylmethylsulfonyl fluoride (PMSF) and diethyl pyrocarbonate (DEPC).

Orobanche cumana is an obligate holoparasitic plant with noxious effects in sunflower crops. Bellardia trixago is a facultative hemiparasitic plant that infects ruderal plants without noxious significance in agriculture and is known to produce a wide spectrum of bioactive metabolites. The objective of this study was to evaluate the allelopathic effects of B. trixago on the growth of O. cumana seedlings.

Biocides based on chemical synthetic compounds have been commonly used to counteract damages caused by microorganisms on stone cultural heritage. However, in the last few years, the use of commercial and traditional biocides has been banned and/or limited due to their dangerous profile for the environment, as well as human and animal health.

PirAB toxins secreted by Vibrio parahaemolyticus (Vp) harbor the pVA1 virulence plasmid, which causes acute hepatopancreatic necrosis disease (AHPND), an emerging disease in Penaeid shrimp that can cause 70–100% mortality and that has resulted in great economic losses since its first appearance. The cytotoxic effect of PirABVp on the epithelial cells of the shrimp hepatopancreas (Hp) has been extensively documented.

Vibrio cholerae uses cholera toxin (CT) to cause cholera, a severe diarrheal disease in humans that can lead to death within hours of the onset of symptoms.

Immunoglobulin-like (Ig-like) fold domains are abundant on the surface of bacteria, where they are required for cell-to-cell recognition, adhesion, biofilm formation, and conjugative transfer. Fibrillar adhesins are proteins with Ig-like fold(s) that have filamentous structures at the cell surface, being thinner and more flexible than pili.

Foodborne diseases affect an estimated 600 million people worldwide annually, with the majority of these illnesses caused by Norovirus, Vibrio, Listeria, Campylobacter, Salmonella, and Escherichia coli. To elicit infections in humans, bacterial pathogens express a combination of virulence factors and toxins.

Glutathione S-transferases are a family of detoxifying enzymes that catalyze the conjugation of reduced glutathione (GSH) with different xenobiotic compounds using either Ser, Tyr, or Cys as a primary catalytic residue. We identified a novel GST in the genome of the shrimp pathogen V. parahaemolyticus FIM- S1708+, a bacterial strain associated with Acute Hepatopancreatic Necrosis Disease (AHPND)/Early Mortality Syndrome (EMS) in cultured shrimp. This new GST class was named Gtt2.

Pathogenic microorganisms produce various virulence factors, e.g., enzymes, cytotoxins, effectors, which trigger development of pathologies in infectious diseases. Cholera toxin (CT) produced by O1 and O139 serotypes of Vibrio cholerae (V. cholerae) is a major cytotoxin causing severe diarrhea. Cholix cytotoxin (Cholix) was identified as a novel eukaryotic elongation factor 2 (eEF2) adenosine-diphosphate (ADP)-ribosyltransferase produced mainly in non-O1/non-O139 V. cholerae.

Mycotoxins are important food contaminants that commonly co-occur with modified mycotoxins such as mycotoxin-glucosides in contaminated cereal grains. These masked mycotoxins are less toxic, but their breakdown and release of unconjugated mycotoxins has been shown by mixed gut microbiota of humans and animals.

Cholera toxin B subunit (CTB), a non-toxic homopentameric component of Vibrio cholerae holotoxin, is an oral cholera vaccine antigen that induces an anti-toxin antibody response. Recently, we demonstrated that a recombinant CTB variant with a Lys-Asp-Glu-Leu (KDEL) endoplasmic reticulum retention motif (CTB-KDEL) exhibits colon mucosal healing effects that have therapeutic implications for inflammatory bowel disease (IBD).

Toxins, Vol. 11, Pages 233: Structural Insights to the Heterotetrameric Interaction between the Vibrio parahaemolyticus PirAvp and PirBvp Toxins and Activation of the Cry-Like Pore-Forming Domain

Toxins doi: 10.3390/toxins11040233

Authors:
Shin-Jen Lin
Yi-Fan Chen
Kai-Cheng Hsu
Yun-Ling Chen
Tzu-Ping Ko
Chu-Fang Lo
Han-Ching Wang
Hao-Ching Wang

Toxins, Vol. 11, Pages 207: Cholera Toxin Encapsulated within Several Vibrio cholerae O1 Serotype Inaba Outer Membrane Vesicles Lacks a Functional B-Subunit

Toxins doi: 10.3390/toxins11040207

Authors:
Elnaz S. Rasti
Angela C. Brown

Toxins, Vol. 9, Pages 335: Rapid Assessment of the Toxicity of Fungal Compounds Using Luminescent Vibrio qinghaiensis sp. Q67

Toxins doi: 10.3390/toxins9100335

Authors:
Qijie Jian
Liang Gong
Taotao Li
Yong Wang
Yu Wu
Feng Chen
Hongxia Qu
Xuewu Duan
Yueming Jiang

The multifactorial etiology of massive Crassostrea gigas summer mortalities results from complex interactions between oysters, opportunistic pathogens and environmental factors. In a field survey conducted in 2014 in the Mediterranean Thau Lagoon (France), we evidenced that the development of the toxic dinoflagellate Alexandrium catenella, which produces paralytic shellfish toxins (PSTs), was concomitant with the accumulation of PSTs in oyster flesh and the occurrence of C.

Most pathogenic, non-O1/non-O139 serogroup Vibrio cholerae strains cause diarrheal disease in the absence of cholera toxin. Instead, many use Type 3 Secretion System (T3SS) mediated mechanisms to disrupt host cell homeostasis. We identified a T3SS effector protein, VopX, which is translocated into mammalian cells during in vitro co-culture. In a S.

Pore-forming toxins (PFTs) are a distinct class of membrane-damaging cytolytic proteins that contribute significantly towards the virulence processes employed by various pathogenic bacteria. Vibrio cholerae cytolysin (VCC) is a prominent member of the beta-barrel PFT (beta-PFT) family. It is secreted by most of the pathogenic strains of the intestinal pathogen V. cholerae. Owing to its potent membrane-damaging cell-killing activity, VCC is believed to play critical roles in V.

Tetrodotoxin (TTX) is a potent neurotoxin found in the tissues of many taxonomically diverse organisms. Its origin has been the topic of much debate, with suggestions including endogenous production, acquisition through diet, and symbiotic bacterial synthesis. Bacterial production of TTX has been reported in isolates from marine biota, but at lower than expected concentrations. In this study, 102 strains were isolated from Pleurobranchaea maculata (Opisthobranchia) and Stylochoplana sp.