Research Publications (Food Safety)

Osteomyelitis is a Staphylococcus aureus-caused bone infection. In this study, the effects of miR-146a on osteomyelitis were evaluated. Using the osteoblast cell model and S. aureus-induced osteomyelitis mice model, we monitored the miR-146 expression and explored the effects of miR-146a on cell proliferation of osteoblasts, bone remodeling, osteoclastogenesis, inflammatory cytokine production, and bacterial burden. Upregulated miR-146a was found in mice with S. aureus-induced osteomyelitis.

The balance of microbial species in the intestine must be maintained to prevent inflammation and disease. Healthy bacteria suppress infection by pathogens and prevent disorders such as inflammatory bowel diseases (IBDs). The role of mucus in the relation between pathogens and the intestinal microbiota is poorly understood.

Infections of Toxoplasma gondii can cause severe and sometimes fatal diseases in immunocompromised individuals. The de novo heme biosynthesis pathway is required for intracellular growth and pathogenesis, making it an appealing therapeutic target. We synthesized a small library of derivatives of the herbicide oxadiazon, a known inhibitor of the penultimate reaction within the heme biosynthesis pathway in plants, catalyzed by protoporphyrinogen oxidase (PPO).

Cerebral malaria (CM) is a serious central nervous system dysfunction caused by Plasmodium falciparum infection. In this study, we investigated the effect of Listeria monocytogenes (Lm) inoculation on experimental cerebral malaria (ECM) using Plasmodium berghei ANKA (PbA)-infected C57BL/6 mice. Live Lm inoculation inhibited the parasitemia and alleviated ECM symptoms.

Daptomycin is an important antibiotic used for treating serious infections caused by Gram-positive bacteria including methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant enterococci. Establishing structure–activity relationships of daptomycin is important for developing new daptomycin-based antibiotics with expanded clinical applications and for tackling the ever-increasing problem of antimicrobial resistance.

Synthetic and naturally occurring siderophores and their conjugates provide access to the bacterial cytoplasm via active membrane transport. Previously, we displaced iron with the radioactive isotope 67Ga to quantify and track in vitro and in vivo uptake and distribution of siderophore Trojan Horse antibiotic conjugates. Here, we introduce a multi-isotope tagging strategy to individually elucidate the fate of metal cargo and the ligand construct with radioisotopes 67Ga and 124I.

The antinoroviral effect of copper ions is well known, yet most of this work has previously been conducted in copper and copper alloy surfaces, not copper ions in solution. In this work, we characterized the effects that Cu ions have on human norovirus capsids’ and surrogates’ integrity to explain empirical data, indicating virus inactivation by copper alloy surfaces, and as means of developing novel metal ion-based virucides.

Drug-resistant bacterial pathogens still cause high levels of mortality annually despite the availability of many antibiotics. Methicillin-resistant Staphylococcus aureus (MRSA) is especially problematic, and the rise in resistance to front-line treatments like vancomycin and linezolid calls for new chemical modalities to treat chronic and relapsing MRSA infections.

Antimicrobial drug resistance is a major health issue plaguing healthcare worldwide and leading to hundreds of thousands of deaths globally each year. Tackling this problem requires discovery and development of new antibacterial agents.

Salmonella enterica subsp. enterica serovar Enteritidis (S. Enteritidis) in poultry is most often transmitted by the fecal–oral route, which can be attributed to high population density. Upon encountering the innate immune response in a host, the pathogen triggers a stress response and virulence factors to help it survive in the host.

Given the importance of epigenetic modification, pathogens have found a variety of ways to alter chromatin and affect host gene expression. The apicomplexan parasite Toxoplasma gondii expresses two nuclear targeted secreted effectors TgIST and TgNSM that target the activity of host histone deacetylase regulating corepressor complexes NuRD and NCoR/SMRT, respectively.

The N-acetylneuraminic acid−α(2–3)-galactose epitope is often located at the nonreducing terminal ends of glycans on the envelopes of many pathogens, and it is believed that this structure mimics a host’s oligosaccharide so as to circumvent and/or counteract the host’s immune responses.

An immunochemical strategy to detect and quantify AIP-IV, the quorum sensing (QS) signaling molecule produced by Staphylococcus aureusagr type IV, is reported here for the first time. Theoretical calculations and molecular modeling studies have assisted on the design and synthesis of a suitable peptide hapten (AIPIVS), allowing to obtain high avidity and specific antibodies toward this peptide despite its low molecular weight.

Human milk N-glycome was previously identified to have strong antipathogenic activities. This study is aimed to characterize the detailed antibacterial properties and the potential function mechanism of human milk N-glycome against Staphylococcus aureus.

Natural products provide a rich source of potential antimicrobials for treating infectious diseases for which drug resistance has emerged. Foremost among these diseases is tuberculosis.

During infection, bacteria use an arsenal of resistance mechanisms to negate antibiotic therapies. In addition, pathogenic bacteria form surface-attached biofilms bearing enriched populations of metabolically dormant persister cells. Bacteria develop resistance in response to antibiotic insults; however, nonreplicating biofilms are innately tolerant to all classes of antibiotics. As such, molecules that can eradicate antibiotic-resistant and antibiotic-tolerant bacteria are of importance.

Quaternary ammonium compounds (QACs) serve as mainstays in the formulation of disinfectants and antiseptics. However, an over-reliance and misuse of our limited QAC arsenal has driven the development and spread of resistance to these compounds, as well as co-resistance to common antibiotics.

Mycobacterium abscessus (Mab) has emerged as a challenging threat to individuals with cystic fibrosis. Infections caused by this pathogen are often impossible to treat due to the intrinsic antibiotic resistance leading to lung malfunction and eventually death. Therefore, there is an urgent need to develop new drugs against novel targets in Mab to overcome drug resistance and subsequent treatment failure.

Staphylococcus aureus-induced infective endocarditis (IE) is a life-threatening disease. Differences in virulence between distinct S. aureus strains, which are partly based on the molecular mechanisms during bacterial adhesion, are not fully understood. Yet, distinct molecular or elemental patterns, occurring during specific steps in the adhesion process, may help to identify novel targets for accelerated diagnosis or improved treatment.

Currently, no specific therapeutics are available for foodborne Shiga toxin-producing Escherichia coli (STEC) infections that cause severe gastroenteritis and life-threatening complications of hemolytic uremic syndrome (HUS). As STEC attachment to intestinal epithelium might increase the host absorption of Shiga toxins and severity of the disease, we were inspired to develop a bispecific neutralizer capable of blocking its Shiga toxin and adhesin intimin simultaneously.

Currently, no specific therapeutics are available for foodborne Shiga toxin-producing Escherichia coli (STEC) infections that cause severe gastroenteritis and life-threatening complications of hemolytic uremic syndrome (HUS). As STEC attachment to intestinal epithelium might increase the host absorption of Shiga toxins and severity of the disease, we were inspired to develop a bispecific neutralizer capable of blocking its Shiga toxin and adhesin intimin simultaneously.

In vitro experimental evolution of pathogens to antibiotics is commonly used for the identification of clinical biomarkers associated with antibiotic resistance. Microdroplet emulsions allow exquisite control of spatial structure, species complexity, and selection microenvironments for such studies. We investigated the use of monodisperse microdroplets in experimental evolution.

Fungal fatty acid (FA) synthase and desaturase enzymes are essential for the growth and virulence of human fungal pathogens. These enzymes are structurally distinct from their mammalian counterparts, making them attractive targets for antifungal development. However, there has been little progress in identifying chemotypes that target fungal FA biosynthesis. To accomplish this, we applied a whole-cell-based method known as Target Abundance-based FItness Screening using Candida albicans.

Hookworm infections affect millions of people worldwide and are responsible for impaired mental and physical growth in children, and anemias. There is no vaccine, and increasing anthelmintic drug resistance in nematodes of domestic animals, and reduced drug cure rates in nematode infections of humans is alarming.

With the acquirement of antibiotic resistance, Shigella has resulted in multiple epidemics of shigellosis, an infectious diarrheal disease, causing thousands of deaths per year. Unfortunately, there are no licensed vaccines, primarily due to low or serotype-specific immunogenicity. Thus, conserved subunit vaccines utilizing recombinant invasion plasmid antigens (Ipa) have been explored as cross-protective vaccine candidates.