Research Publications (Food Safety)

Enterobacteriales have evolved a specialized outer membrane polysaccharide [Enterobacterial Common Antigen (ECA)] which allows them to persist in various environmental niches. Biosynthesis of ECA initiates on the cytoplasmic leaflet of the inner membrane (IM) where glycosyltransferases assemble ECA repeat units (RUs). Complete RUs are then translocated across the IM and assembled into polymers by ECA-specific homologues of the Wzy-dependent pathway.

Iron acquisition and modulation of its intracellular concentration are critical for the development of all living organisms. So far, several proteins have been described to be involved in iron homeostasis. Among them, ferritins act as the major iron storage proteins, sequestering internalized iron and modulating its concentration inside bacterial cells.

The bacterial flagellar stator is a unique ion-conducting membrane protein complex composed of two kinds of proteins, the A subunit and the B subunit. The stator couples the ion-motive force across the membrane into rotational force. The stator becomes active only when it is incorporated into the flagellar motor. The periplasmic region of the B subunit positions the stator by using the peptidoglycan-binding (PGB) motif in its periplasmic C-terminal domain to attach to the cell wall.

The detection of thermotolerant Campylobacter in food may be difficult due to the growth of extended-spectrum β-lactamase (ESBL)-producing Enterobacteriaceae during enrichment, resulting in false-negative samples. Therefore, the ISO protocol (ISO 10272-1:2017) suggests that, next to Bolton broth (BB), Preston broth (PB) is used as an enrichment broth to inhibit competitive flora in samples with suspected high levels of background microorganisms, such as ESBL-producing bacteria.

Background

Chronic hepatitis B virus (HBV) infection remains a major public health problem worldwide. Immune checkpoint molecules expressed on CD4+ T cells play critical roles in chronic HBV infection. However, their roles in chronic asymptomatic HBV carriers (ASCs) with hepatitis B e antigen (HBeAg)-negative remain unclear. In this study, we explored the role of immune checkpoint molecules expressed on CD4+ T cell subsets in chronic ASCs with HBeAg-negative.

Methods

Background Host-microbiota crosstalk has been implicated in multiple host metabolic pathway axes that regulate intestinal barrier function.

Staphylococcus aureus has been recognized as an important human pathogen and poses a serious health threat worldwide. With the advent of antibiotic resistance, such as the increased number of methicillin-resistant Staphylococcus aureus (MRSA), there is an urgent need to develop new therapeutical agents.

Background Cytolethal distending toxin (CDT) is a critical virulence factor of Campylobacter jejuni, and it induces cell death and regulates inflammation response in human epithelial cells.

The commensal microbes of the gut microbiota make important contributions to host defense against gastrointestinal pathogens, including Vibrio cholerae, the etiologic agent of cholera. As interindividual microbiota variation drives individual differences in infection susceptibility, we examined both host and V.

Local antibiotic therapy is increasingly being recognised for its role in preventing and treating orthopaedic device-related infection (ODRI). A bioresorbable, injectable gentamicin-loaded hydrogel has been developed to deliver local antibiotics at the time of surgery with potential for both prevention and treatment of ODRI.

Frog metamorphosis, the development of an air-breathing froglet from an aquatic tadpole, is controlled by thyroid hormone (TH) and glucocorticoids (GC). Metamorphosis is susceptible to disruption by 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), an aryl hydrocarbon receptor (AHR) agonist. Krüppel-like factor 9 (klf9), an immediate early gene in the endocrine-controlled cascade of expression changes governing metamorphosis, can be synergistically induced by both hormones.

Chaetomium fungi produce a diversity of bioactive compounds. Chaetomium cochliodes SD-280 possesses 91 secondary metabolite gene clusters and exhibits strong antibacterial activity. One of the active compounds responsible for that activity, chetomin, has a minimum inhibitory concentration (MIC) for anti-methicillin-resistant Staphylococcus aureus (MRSA) of 0.05 μg/mL (vancomycin: 0.625 μg/mL).

A fluorescence immunochromatographic strip using quantum dot nanobeads (QDNBs)-monoclonal antibody (McAb) conjugates was developed to rapidly detecting okadaic acid (OA) in shellfish. Under optimal conditions, the linear working range was 0.62–20 ng·mL−1, and the full competitive limit of detection (LOD) was 20 ng·mL−1, corresponding to 160 μg·kg−1 per shellfish, meeting the regulatory limit of European Conformity (EC).

Acute stunting in children, liver cancer, and death often occur due to human exposure to aflatoxins in food. The severity of aflatoxin contamination depends on the type of Aspergillus fungus infecting the crops. In this study, Aspergillus species were isolated from households’ staple foods and were characterized for different aflatoxin chemotypes. The non-aflatoxigenic chemotypes were evaluated for their ability to reduce aflatoxin levels produced by aflatoxigenic A.

This study reports on the effects of long-term exposure to the metals arsenic (As), cadmium (Cd) and the polycyclic aromatic hydrocarbon fluoranthene on the survival, growth, development and DNA methylation status of the earthworm Lumbricus rubellus. Exposures to the three chemicals were conducted over their whole juvenile developmental period from egg to adult. Significant effects on one or more measured endpoints were found for all three chemicals.

Journal of Food Science, EarlyView. Bacteriocins inhibit various foodborne bacteria in planktonic and biofilm forms. However, bacteriocins with antibacterial and antibiofilm activity against Staphylococcus argenteus, a pathogen that can cause food poisoning, are still poorly known.

Background The increasing emergence of multidrug-resistant Gram-positive bacterial infections necessitates new antibacterial agents with novel mechanisms of action that can be used to treat these infections. Lomitapide has been approved by FDA for years in reducing levels of low-density lipoprotein (LDL) in cases of familial hypercholesterolemia, whereas the antibacterial effect of lomitapide remains elusive.

Background Vibrio cholerae O1/O139 were the predominant circulating serogroups exhibiting multi-drug resistance (MDR) during the cholera outbreak which led to cholera treatment failures. Objective This meta-analysis aimed to evaluate the weighted pooled resistance (WPR) rates in V.

by Ravinder Polapally, Manasa Mansani, Karthik Rajkumar, Sandeepta Burgula, Bee Hameeda, Alaa Alhazmi, Farkad Bantun, Atiah H. Almalki, Shafiul Haque, Hesham Ali El Enshasy, R. Z. Sayyed The present study reveals the production of dark, extracellular melanin pigment (386 mg/L) on peptone yeast extract iron agar medium by Streptomyces puniceus RHPR9 using the gravimetric method.

Mollusks have recently received increasing attention because of their unique immune systems. Mollusks such as Amphioctopus fangsiao are economically important cephalopods, and the effects of their egg-protecting behavior on the larval immune response are unclear.

Dinoflagellates of the family Symbiodiniaceae are predominantly essential symbionts of corals and other marine organisms. Recent research reveals extensive genome sequence divergence among Symbiodiniaceae taxa and high phylogenetic diversity hidden behind subtly different cell morphologies. Using an alignment-free phylogenetic approach based on sub-sequences of fixed length k (i.e.

Heat stress induced by global warming has damaged the well-being of aquatic animals. The skin tissue plays a crucial role as a defense barrier to protect organism, however, little is known about the effect of heat stress on fish skin, particularly in cold-water fish species. Here, we investigated the effects of mild heat stress (24°C, MS) and high heat stress (28°C, HS) on Siberian sturgeon skin using RNA-seq, histological observation, and microbial diversity analysis.

In this study, a multi-metal-tolerant natural bacterial isolate Providencia rettgeri strain KDM3 from an industrial effluent in Mumbai, India, showed high cadmium (Cd) tolerance. Providencia rettgeri grew in the presence of more than 100 ppm (880 μM) Cd (LD50 = 100 ppm) and accumulated Cd intracellularly. Following Cd exposure, a comparative proteome analysis revealed molecular mechanisms underlying Cd tolerance.

Bacteriocins are antimicrobial peptides with relevance in the modulation of human and animal microbiota that have gained interest in biomedical and biotechnological applications.

In Streptococcus mutans, we find that the histidine kinase WalK possesses the longest C-terminal tail (CTT) among all 14 TCSs, and this tail plays a key role in the interaction of WalK with its response regulator WalR. We demonstrate that the intrinsically disordered CTT is characterized by a conserved tryptophan residue surrounded by acidic amino acids.