Research Publications (Food Safety)

The quorum sensing (QS) and c‐di‐GMP signaling pathways are intricately intertwined to control swarming in Vibrio parahaemolyticus strain RIMD 2210633. The QS signals which inhibit LuxOvp phosphorylation are essential for V. parahaemolyticus to swarm efficiently on surfaces. And LuxOvp regulates swarming in a mechanism that involves modulating c‐di‐GMP levels, which may be intracellularly compartmentalized in V. parahaemolyticus.

Translation rates of transcripts in the dinoflagellate Fugacium kawagutii were measured every 2 h over a light–dark cycle using ribosome profiling. Several thousand transcripts show increased rates of translation at specific times of day. Abstract Dinoflagellates respond to daily changes in light and dark by changes in cellular metabolism, yet the mechanisms used are still unclear.

Molecular Microbiology, EarlyView. Methicillin-resistant Staphylococcus aureus (MRSA) can be transmitted between pigs and humans on farms. Hence, the reduction of MRSA carriage in pigs could decrease the risk of zoonotic transmission. Recently, straw bedding has been found to significantly reduce MRSA carriage in pigs. The mechanisms behind this effect remain unclear but changes in the nasal microbiome may play a role.

Molecular Microbiology, Accepted Article. The marine pathogen Vibrio vulnificus senses and responds to environmental stimuli via two chemosensory systems and 42-53 chemoreceptors. Here we present an analysis of the V. vulnificus Aer2 chemoreceptor, VvAer2, which is the first V.

Molecular Microbiology, Accepted Article. Virulence and persistence of the obligate intracellular parasite Toxoplasma gondii involve the secretion of effector proteins belonging to the family of dense granule proteins (GRAs) that act notably as modulators of the host defense mechanisms and participate in cyst wall formation.

Molecular Microbiology, Accepted Article. Salmonella enterica spp. produce siderophores to bind iron with high affinity and can also use three xenosiderophores secreted by other microorganisms, ferrichrome, coprogen, and ferrioxamine. Here we focused on FoxA, a TonB-dependent transporter of ferrioxamines.

Molecular Microbiology, Accepted Article. Listeria monocytogenes (Lm) is a widespread environmental Gram-positive bacterium that can transition into a pathogen following ingestion by a susceptible host. To cross host barriers and establish infection, Lm is dependent upon the regulated secretion and activity of many proteins including PrsA2, a peptidyl-prolyl cis-trans isomerase with foldase activity.

Molecular Microbiology, Accepted Article. Some prokaryotes compartmentalize select metabolic capabilities. Salmonella enterica subspecies enterica serovar Typhimurium LT2 (hereafter S. Typhimurium) catabolizes ethanolamine (EA) within a proteinaceous compartment that we refer to as the ethanolamine utilization (Eut) metabolosome.

Molecular Microbiology, Accepted Article. Teg49 is a S. aureus trans-acting regulatory sRNA derived from cleavage of the sarA P3 transcript. We showed here by RNA-Seq that the 5’ trident-like structure in Teg49 regulates transcriptionally (direct and indirect) 22 genes distinct from sarA.

Molecular Microbiology, Accepted Article. Staphylococcus aureus is a Gram-positive commensal that can also cause a variety of infections in humans. S. aureus virulence factor gene expression is under tight control by a complex regulatory network, which includes, sigma factors, sRNAs, and Two-Component Systems (TCS). Previous work in our lab demonstrated that overexpression of the sRNA tsr37 leads to an increase in bacterial aggregation.

Molecular Microbiology, Accepted Article. The behaviours of infectious bacteria are commonly studied in bulk. This is effective to define general properties of a given isolate, but insufficient to resolve subpopulations and unique single-microbe behaviours within the bacterial pool.

Molecular Microbiology, Accepted Article. Biofilm formation of staphylococci has been an emerging field of research for many years. However, the underlying molecular mechanisms are still not fully understood, and vary widely between species and strains. The aim of this study was to identify new effectors impacting biofilm formation of two Staphylococcus (S.) xylosus strains.

Molecular Microbiology, Accepted Article. Desulfovibrio fructosovorans, a sulfate-reducing bacterium, possesses six gene clusters encoding six hydrogenases catalyzing the reversible oxidation of H2 into protons and electrons. Among them, Hnd is an electron-bifurcating hydrogenase, coupling the exergonic reduction of NAD+ to the endergonic reduction of a ferredoxin with electrons derived from H2.

Molecular Microbiology, Accepted Article. YscX was discovered as an essential part of the Yersinia type III secretion system about 20 years ago. It is required for substrate secretion and is exported itself. Despite this central role, its precise function and mode of action remains unknown. In order to address this knowledge gap, this present study refocused attention on YscX to build on the recent advances in the understanding of YscX function.

Molecular Microbiology, Volume 116, Issue 6, Page 1407-1419, December 2021.

Molecular Microbiology, Volume 116, Issue 6, Page 1464-1475, December 2021. Invasion of the intestinal epithelium is an essential but energetically expensive survival strategy and is, therefore, tightly regulated by using specific cues from the environment. The enteric pathogen Salmonella controls its invasion machinery through the elegant coordination of three AraC-type transcription activators, HilD, HilC, and RtsA.

Molecular Microbiology, Volume 116, Issue 6, Page 1533-1551, December 2021. The SGI1-family elements that are specifically mobilized by the IncA- and IncC-family plasmids are important vehicles of antibiotic resistance among enteric bacteria. Although SGI1 exploits many plasmid-derived conjugation and regulatory functions, the basic mobilization module of the island is unrelated to that of IncC plasmids.

Molecular Microbiology, EarlyView. Anti-bacterial autophagy, known as xenophagy, is a host innate immune response that targets invading pathogens for degradation. Some intracellular bacteria, such as the enteric pathogen Salmonella enterica serovar Typhimurium (S. Typhimurium), utilize effector proteins to interfere with autophagy.

Molecular Microbiology, EarlyView. Salmonella is a major foodborne pathogen and is responsible for a range of diseases. Not all Salmonella contributes to severe health outcomes as there is a large degree of genetic heterogeneity among the 2,600 serovars within the genus. This variability across Salmonella serovars is linked to numerous genetic elements that dictate virulence.

Molecular Microbiology, Accepted Article. Listeria monocytogenes is a food-borne bacterium that causes gastroenteritis, meningitis, or abortion. L. monocytogenes induces its internalization (entry) into human cells and either spreads laterally in tissues or transcytoses to traverse anatomical barriers. In this review, we discuss mechanisms by which five structurally related proteins of the ‘internalin’ family of L.

Molecular Microbiology, Accepted Article. Cyclic-di-GMP plays crucial roles in the cell cycle regulation of the α-Proteobacterium Caulobacter crescentus. Here we investigated its role in the α-Proteobacterium Brucella abortus, a zoonotic intracellular pathogen. Surprisingly, deletion of all predicted cyclic-di-GMP synthesizing or degrading enzymes did not drastically impair the growth of B. abortus, nor its ability to grow inside cell lines. As other Rhizobiales, B.

Molecular Microbiology, Accepted Article. Shigella flexneri is a gram-negative bacterial pathogen that causes dysentery. Critical for disease is the ability of Shigella to use an actin-based motility (ABM) process to spread between cells of the colonic epithelium. ABM transports bacteria to the periphery of host cells, allowing the formation of plasma membrane protrusions that mediate spread to adjacent cells.

Molecular Microbiology, Accepted Article. ABSTRACT

Molecular Microbiology, Accepted Article. Enterohemorrhagic Escherichia coli (EHEC) causes severe human diseases worldwide. The type three secretion system and effector proteins are essential for EHEC infection, and are encoded by the locus of enterocyte effacement (LEE). RNA-binding protein Hfq is essential for small regulatory RNA (sRNA)-mediated regulation at a post-transcriptional level and full virulence of many pathogenic bacteria.

Molecular Microbiology, Accepted Article. Campylobacter jejuni is a microaerophilic zoonotic pathogen with an atypical respiratory Complex I that oxidises a flavodoxin (FldA) instead of NADH. FldA is essential for viability and is reduced via pyruvate and 2‐oxoglutarate oxidoreductases (POR/OOR). Here, we show that FldA can also be reduced by FqrB (Cj0559), an NADPH:flavodoxin reductase. An fqrB deletion mutant was viable but displayed a significant growth defect.