Research Publications (Food Safety)

Activity-guided fractionation based on in vitro assays was used to identify antibacterial components in the residue wasted in the manufacturing process of aged garlic extract (AGE). Antimicrobial activity of the hexane extract of aged garlic-derived residue (AGR) was evaluated against clinically isolated Gram-positive and -negative bacteria including levofloxacin (LVX)-resistant strains.

The nucleocapsid protein (NC) is a highly conserved protein that plays key roles in HIV-1 replication through its nucleic acid chaperone properties mediated by its two zinc fingers and basic residues. NC is a promising target for antiviral therapy, particularly to control viral strains resistant to currently available drugs.

Protein S-palmitoylation is an important post-translational modification (PTM) in blood stages of the malaria parasite, Plasmodium falciparum. S-palmitoylation refers to reversible covalent modification of cysteine residues of proteins by saturated fatty acids.

ABSTRACT BACKGROUND Residual antibiotics are taken along with food consumed through the food chain is the main cause of the super‐bacteria and may damage organs such as liver and kidney. Therefore, monitoring residual antibiotic levels of products in the food chain is both important and a requirement. Maximum residual limits for kanamycin and neomycin are 150 ng mL‐1 and 500 ng mL‐1 respectively, which are challenging for most sensor platforms.

LpxD, acyl-ACP-dependent N-acyltransferase, is the third enzyme of lipid A biosynthesis in Gram-negative bacteria. A recent probe-based screen identified several compounds, including 6359-0284 (compound 1), that inhibit the enzymatic activity of Escherichia coli (E. coli) LpxD. Here, we use these inhibitors to chemically validate LpxD as an attractive antibacterial target.

Therapeutics targeting Gram-negative bacteria have the challenge of overcoming a formidable outer membrane (OM) barrier. Here, we characterize the action of SPR741, a novel polymyxin B (PMB) analogue shown to potentiate several large-scaffold antibiotics in Gram-negative pathogens. Probing the surface topology of Escherichia coli using atomic force microscopy revealed substantial OM disorder at concentrations of SPR741 that lead to antibiotic potentiation.

Multidrug and toxic compound extrusion (MATE) transporters are ubiquitous ion-coupled antiporters that extrude structurally and chemically dissimilar cytotoxic compounds and have been implicated in conferring multidrug resistance. Here, we integrate double electron–electron resonance (DEER) with functional assays and site-directed mutagenesis of conserved residues to illuminate principles of ligand-dependent alternating access...

Author(s): Picheng Gong, Huiling Liu, Chen Cai, Gang Wang, Yanjun Xin, Xiaohu Dai

The Mycobacterium tuberculosis β-lactamase BlaC is a broad-spectrum β-lactamase that can convert a range of β-lactam antibiotics. Enzymes with low specificity are expected to exhibit active-site flexibility. To probe the motions in BlaC, we studied the dynamic behavior in solution using nuclear magnetic resonance (NMR) spectroscopy. 15N relaxation experiments show that BlaC is mostly rigid on the pico- to nanosecond timescale.

Fluoroquinolones (FQs) present in water environments pose threats to aquatic organisms. The concentration of FQs adsorbed onto sediments is generally higher than that in water. Here, we studied the toxicities of two FQ antibiotics, norfloxacin (NOR) and ofloxacin (OFL), on the snail Bellamya aeruginosa, an adaptable benthic animal.

Mebendazole is an anthelmintic drug used in cattle production. However, residues may occur in produced food and in excretions, jeopardizing population health. A method based on micellar liquid chromatography (MLC) was developed to determine mebendazole in dairy products (milk, cheese, butter, and curd) and nitrogenous waste (urine and dung) from bovine animals.

Food contamination with antibiotic residues has become a worldwide problem due to the heavy and improper use of antibiotics. The development of fast, high-throughput, easy, and economical screening methods for the detection of antibiotic residues is an important requirement as an alternative to the traditional assays. Immunoassays are widespread promising methods that can achieve the conditions of an analytical method in the evaluation of food and environmental protection.

The objective of this study was (i) to analyze antibiotic residues, two which were beta-lactam antibiotics, one tetracycline, and one quinolone in the milk of lactating animals; (ii) to evaluate the interference of the drug ceftiofur which is considered as discard-zero. The SNAPduo™ ST Plus kit was used to evaluate the presence of beta-lactam antibiotics and tetracyclines in natural milk. Medications based on penicillin, ceftiofur, enrofloxacin, and oxytetracycline were used.

By utilizing the coffee‐ring effect and microfluidic paper‐based analytical devices (µPADs), this study improved the sensitivity of the determination of norfloxacin in four different food matrices. Micro‐PADs in this study were fabricated by designing and embedding wax channels onto cellulose‐based filter paper through printing and subjecting the paper to heat to allow the wax to penetrate the paper.

by Rana Adnan Tahir, Afsheen Bashir, Muhammad Noaman Yousaf, Azka Ahmed, Yasmine Dali, Sanaullah Khan, Sheikh Arslan Sehgal

by Sumaira Javaid, Syed Muhammad Saad, Humaira Zafar, Rizwana Malik, Khalid Mohammed Khan, M. Iqbal Choudhary, Atta-ur Rahman

In this study, we aimed to assess the in vitro susceptibility to GSK656 among multiple mycobacterial species and to investigate the correlation between leucyl-tRNA synthetase (LeuRS) sequence variations and in vitro susceptibility to GSK656 among mycobacterial species. A total of 187 mycobacterial isolates, comprising 105 Mycobacterium tuberculosis isolates and 82 nontuberculous mycobacteria (NTM) isolates, were randomly selected for the determination of in vitro susceptibility. For M.

Hepatitis E virus (HEV) has emerged as a global health concern during the last decade. In spite of a high mortality rate in pregnant women with fulminant hepatitis, no antiviral drugs or licensed vaccine is available in India. HEV-protease is a pivotal enzyme responsible for ORF1 polyprotein processing leading to cleavage of the non-structural enzymes involved in virus replication.

Pig manure may contain antibiotic residues, antibiotic-resistant bacteria or pathogens, which may reach the environment upon fertilization. During this study, 69 antibiotic residues belonging to 12 classes were quantified in 89 pig slurry samples. These samples were also studied for the presence of Salmonella and for E. coli resistant to meropenem, colistin, ciprofloxacin, or cefotaxim. The obtained isolates were further tested for antibacterial susceptibility.

Author(s): Yongfeng Wang, Qingke Nie, Baoshan Huang, Huicai Cheng, Liang Wang, Qiang He

Author(s): Ning Xu, Miao Li, Wei-Chun Chou, Zhoumeng Lin

Author(s): Calvin Ho-Fung Lau, Erica N. DeJong, Forest Dussault, Catherine Carrillo, Peter J. Stogios, Alexei Savchenko, Edward Topp

The milk bar is an emerging style of retail business that mainly produces pasteurized milk (PM) and other dairy products on-site in many large cities of the People's Republic of China. To date, no data about veterinary drug residues in PM samples produced from milk bars have been reported.

Author(s): Roghayeh Jalili, Alireza Khataee, Mohammad-Reza Rashidi, Amir Razmjou