Research Publications (Food Safety)

Chimeric lysins composed of various combinations of cell wall-lysing (enzymatic) and cell-wall-binding (CWB) domains of endolysins, autolysins, and bacteriocins have been developed as alternatives to or adjuvants of conventional antibiotics. The screening of multiple chimeric lysin candidates for activity via E. coli expression is not cost effective, and we previously reported on a simple cell-free expression system as an alternative.

Methicillin-resistant Staphylococcus aureus (MRSA)-caused infection is difficult to treat because of its resistance to commonly used antibiotic, and poses a significant threat to public health. To develop new anti-bacterial agents to combat MRSA-induced infections, we synthesized novel squaric amide derivatives and evaluated their anti-bacterial activity by determining the minimum inhibitory concentration (MIC).

Wild-type microorganisms have become tolerant to higher antibiotic and antimicrobial agent concentrations due to the global increase in antibiotic consumption. Green-synthesized nanoparticles (NPs) have been proposed as potential antimicrobial agents to overcome the problem. This research prepared cadmium nanoparticles (Cd NPs) using Artemisia persica extract.

Microbially induced carbonate precipitation (MICP), a type of urease-based biomineralization, has been a well-researched technique in recent years for heavy metal immobilization; however, the efficiency of the process remains in question. Poly(amino acids) are known to enhance enzymatic activity.

From a library of compounds, 11 hit antibacterial agents have been identified as potent anti-Gram-positive bacterial agents. These pyrazole derivatives are active against two groups of pathogens, staphylococci and enterococci, with minimum inhibitory concentration (MIC) values as low as 0.78 μg/mL. These potent compounds showed bactericidal action, and some were effective at inhibiting and eradicating Staphylococcus aureus and Enterococcus faecalis biofilms.

At present, foodborne diseases (FBDs) caused by bacteria are gradually increasing every year, and the development of new antibiotics is an urgent necessity for human beings. To find novel antibacterial compounds, three sponge-derived fungal strains (SCSIOS02F40, F46, and F49) were investigated. As a result, Alternaria sp.

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).

Due to industrialization, the contamination of toxic metals in soils is currently one of the major concerns to scientists worldwide. The presence of high concentrations of heavy metals including cadmium in the environment is mainly attributed to human activities. Being a highly toxic metal, cadmium can enter plant cell transporters usually used for the uptake of essential cations, such as iron, calcium, and zinc.

Berberis baluchistanica Ahrendt is a medicinal plant known to have potential for the treatment of various diseases. In the present study, the ethanolic extracts of the bark, leaves, and roots of B. baluchistanica plant were evaluated for in vitro antimicrobial, anti-leishmanial, anticancer, and anti-inflammatory activities. The antibacterial and antifungal activities were determined by agar mix and agar well diffusion method.

A series of oleanolic acid derivatives holding oxo- or 3-N-polyamino-3-deoxy-substituents at C3 as well as carboxamide function at C17 with different long chain polyamines have been synthesized and evaluated for antimicrobial activities. Almost all series presented good to moderate activity against Gram-positive S. aureus, S. faecalis and B. cereus bacteria with minimum inhibitory concentration (MIC) values from 3.125 to 200 µg/mL.

New antibacterial drugs with novel modes of action are urgently needed as antibiotic resistance in bacteria is increasing and spreading throughout the world. In this study, we aimed to explore the possibility of using APIM-peptides targeting the bacterial β-clamp for treatment of skin infections. We selected a lead peptide, named betatide, from five APIM-peptide candidates based on their antibacterial and antimutagenic activities in both G+ and G– bacteria.

Increases in drug-resistant pathogens are becoming a serious detriment to human health. To combat pathogen infections, a new series of amphiphilic coumarin derivatives were designed and synthesized as antimicrobial agents with membrane-targeting action. We herein report a lead compound, 25, that displayed potent antibacterial activity against Gram-positive bacteria, including MRSA.

Eight analogues of the bioherbicides macrocidin A (1) and Z (2) with structural variance in the size of the macrocycle, its para- or meta-cyclophane character, and its functional groups were synthesized on two modular routes and tested for herbicidal, antibiotic, and antibiofilm activities. Apart from the lead compounds 1 and 2, the structurally simplified dihydromacrocidin Z (3) and normacrocidin Z (4) showed high herbicidal activity in either thistles, dandelions or in both.

Efflux pumps are one of the predominant microbial resistant mechanisms leading to the development of multidrug resistance. In Staphylococcus aureus, overexpression of NorA protein enables the efflux of antibiotics belonging to the class of fluoroquinolones and, thus, makes S. aureus resistant. Hence, NorA efflux pumps are being extensively exploited as the potential drug target to evade bacterial resistance and resensitize bacteria to the existing antibiotics.

Antibiotic-resistant ESKAPE pathogens (Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter species) has become a serious threat to public health worldwide. Cationic α-helical antimicrobial peptides (CαAMPs) have attracted much attention as promising solutions in post-antibiotic era. However, strong hemolytic activity and in vivo inefficacy have hindered their pharmaceutical development.

High concentrations of heavy metals in mine soil disturb the interactions between legumes and microorganisms leading to select strains adapted to these specific conditions. In this work, we analyzed the diversity of fifty strains isolated from Trifolium sp. nodules growing on Pb–Zn mine soil, in the Northeastern of Algeria and highlighted their potential symbiotic traits.

New anti-infective approaches are urgently needed to control multidrug-resistant (MDR) pathogens, such as methicillin-resistant Staphylococcus aureus (MRSA). Sortase A (SrtA) is a membrane-bound cysteine transpeptidase that plays an essential role in the catalysis of covalent anchoring of surface proteins to the cell wall of Staphylococcus aureus (S. aureus).

Serious infections caused by multidrug-resistant Staphylococcus aureus clearly urge the development of new antimicrobial agents. Drug repositioning has emerged as an alternative approach that enables us to rapidly identify effective drugs. We first reported a guanidine compound, isopropoxy benzene guanidine, had potent antibacterial activity against S. aureus. Unlike conventional antibiotics, repeated use of isopropoxy benzene guanidine had a lower probability of resistance section.

Multidrug-resistant pathogens pose a serious threat to human health. For decades, the antibiotic vancomycin has been a potent option when treating Gram-positive multidrug-resistant infections. Nonetheless, in recent decades, we have begun to see an increase in vancomycin-resistant bacteria.

The reassessment of known but neglected natural compounds is a vital strategy for providing novel lead structures urgently needed to overcome antimicrobial resistance. Scaffolds with resistance-breaking properties represent the most promising candidates for a successful translation into future therapeutics.

Recent in vitro studies reported the exceptional ability of some bacterial species to form biofilm-like aggregates in human and animal synovial fluids (SF), but evidences from infected clinical samples are still lacking. In this study, we investigated whether this bacterial phenotype was present in infected SFs collected from joint infections and if it was maintained in in vitro settings.

ABSTRACT

The global spread of antibiotic resistance is forcing the scientific community to find new molecular strategies to counteract it. Deep functional profiling of microbiomes provides an alternative source for the discovery of novel antibiotic producers and probiotics. Recently, we implemented this ultrahigh-throughput screening approach for the isolation of Bacillus pumilus strains efficiently producing the ribosome-targeting antibiotic amicoumacin A (Ami).