Research Publications (Food Safety)

Author(s): Felix Schottroff, Katja Johnson, Nicholas B. Johnson, Matthieu F. Bédard, Henry Jaeger

This study provides phenotypic and molecular analyses of the antibiotic resistance of Ensifer adhaerens strain YX1 (CICC 11008s), a strain that was identified using a polyphasic taxonomy approach. The antibiotic resistance profile of E. adhaerens YX1 was assessed using the Clinical & Laboratory Standards Inst. (CLSI) method.

As reported by European Food Safety Authority, the identification of a meat product obtained from mechanically separated meat (MSM) has significance from a point of view both of food quality and safety. As a consequence, it recommended the development of innovative methods for identifying a MSM. The electron spin resonance (ESR) spectroscopy is a useful tool for identifying previously irradiated meat products containing bone.

Food irradiation is used to preserve food from pathogenic microorganisms, deterioration and to extend shelf life. The EU legislation states that any irradiated food or food ingredients must be labeled with the word “irradiated”. The ESR spectroscopy is a powerful tool to enhance official checks; hence, it has been used to detect irradiated hazelnuts. The results from the ESR studies on hazelnuts before and after X-ray irradiation are reported.

A growing concern exists over water contamination by veterinary pharmaceuticals from small pig farms in Yucatan, Mexico, where the anaerobic digesters installed as the wastewater treatment system are not operated properly. Therefore, considerable interest exists to develop analytical methods to detect these compounds and characterize their fate in the environment.

Livestock and poultry manure containing high levels of copper and zinc have led to contamination of farmland and products which could have an impact on human health. Biochar is an inexpensive and efficient heavy metal absorbent. In the present study, we have used biochar to mitigate the effects of heavy metals on the growth of wheat seedlings. The study showed that the effects of heavy metals on wheat seedlings growth were mitigated by increasing exposure to biochar.

Lactic acid bacteria (LAB) are indigenous microorganisms that have been involved in food fermentations throughout history to preserve food and also to give special characteristics to them. The traditional fermented foods that are still being elaborated in indigenous populations around the world are a potential source of LAB with important biotechnological properties and/or beneficial to health.

by Aung B. Bo, Jae D. Kim, Young S. Kim, Hun T. Sin, Hye J. Kim, Botir Khaitov, Young K. Ko, Kee W. Park, Jung S. Choi

Cyclic di-GMP (c-di-GMP) is a bacterial second messenger molecule that is important in the biology of Vibrio cholerae, but the molecular mechanisms by which this molecule regulates downstream phenotypes have not been fully characterized. We have previously shown that the Vc2 c-di-GMP-binding riboswitch, encoded upstream of the gene tfoY, functions as an off-switch in response to c-di-GMP. However, the mechanism by which c-di-GMP controls expression of tfoY has not been fully elucidated.

Colicin U is a protein produced by the bacterium Shigella boydii (serovars 1 and 8). It exerts antibacterial activity against strains of the enterobacterial genera Shigella and Escherichia. Here we report that colicin U forms voltage-dependent pores in planar lipid membranes; its single-pore conductance was found to be about 22 pS in 1M KCl, at pH 6 under 80 mV in asolectin bilayers.

Type VI secretion systems (T6SSs) are highly conserved and complex protein secretion systems that deliver effector proteins into eukaryotic hosts or other bacteria. T6SSs are regulated precisely by a variety of regulatory systems, which enables bacteria to adapt to varied environments.

Bacteria synthesize amino acids according to their availability in the environment or, in the case of pathogens, within the host. We explored the regulation of the biosynthesis of branched-chain amino acids (BCAAs) (l-leucine, l-valine, and l-isoleucine) in Vibrio alginolyticus, a marine fish and shellfish pathogen and an emerging opportunistic human pathogen. In this species, the ilvGMEDA operon encodes the main pathway for biosynthesis of BCAAs.

Carbapenem-hydrolyzing class D carbapenemases (CHDLs) are enzymes that produce resistance to the last-resort carbapenem antibiotics, severely compromising the available therapeutic options for the treatment of life-threatening infections. A broad variety of CHDLs, including OXA-23, OXA-24/40, and OXA-58, circulate in Acinetobacter baumannii, while the OXA-48 CHDL is predominant in Enterobacteriaceae. Extensive structural studies of A.

Salmonella enterica serovar Goldcoast infection was rare in Taiwan; it was not detected in routine surveillance from 2004 to 2013. This serovar was first identified in 2014, but the frequency of infection remained low until 2017. From 2014 to 2016, all but one isolate was pan-susceptible. S. Goldcoast infections abruptly increased in 2018, and all isolates were multidrug-resistant (MDR).

Glutamate amidation, a secondary modification of the peptidoglycan, was first identified in Staphylococcus aureus. It is catalyzed by the protein products of the murT and gatD genes, which are conserved and colocalized in the genomes of most sequenced Gram-positive bacterial species. The MurT-GatD complex is required for cell viability, full resistance to β-lactam antibiotics, and resistance to human lysozyme and is recognized as an attractive target for new antimicrobials.

A pan-susceptible Salmonella enterica serovar Worthington isolate was detected in the stool of a man returning from Sri Lanka. Under ceftriaxone treatment, a third-generation cephalosporin (3GC)-resistant Salmonella Worthington was isolated after 8 days. Molecular analyses indicated that the two isolates were identical. However, the latter strain acquired a blaDHA-1-carrying IncFII plasmid probably from a Citrobacter amalonaticus isolate colonizing the gut.

Oral candidiasis (OC) caused by the fungal pathogen Candida albicans is the most common opportunistic infection in immunocompromised populations. The dramatic increase in resistance to common antifungal agents has emphasized the importance of identifying alternative therapeutic options.

Carbapenem-resistant Enterobacteriaceae (CRE) can be mechanistically classified into carbapenemase-producing Enterobacteriaceae (CPE) and non-carbapenemase-producing carbapenem nonsusceptible Enterobacteriaceae (NCPCRE). We sought to investigate the effect of antecedent carbapenem exposure as a risk factor for NCPCRE versus CPE. Among all patients with CRE colonization and infection, we conducted a case-control study comparing patients with NCPCRE (cases) and patients with CPE (controls).

The mortality rate associated with Vibrio vulnificus sepsis remains high. An in vitro time-kill assay revealed synergism between tigecycline and ciprofloxacin. The survival rate was significantly higher in mice treated with tigecycline plus ciprofloxacin than in mice treated with cefotaxime plus minocycline. Thus, combination treatment with tigecycline-ciprofloxacin may be an effective novel antibiotic regimen for V. vulnificus sepsis.

Author(s): Herbert Musarurwa, Luke Chimuka, Vusumzi Emmanuel Pakade, Nikita Tawanda Tavengwa

Author(s): Du Guo, Shuo Wang, Jiahui Li, Fangting Bai, Yanpeng Yang, Yunfeng Xu, Sen Liang, Xiaodong Xia, Xin Wang, Chao Shi

Author(s): Anas A. Al-Nabulsi, Tareq M. Osaili, Amin N. Olaimat, Weam E. Almasri, Mutamed Ayyash, Murad A. Al-Holy, Ziad W. Jaradat, Reyad S. Obaid, Richard A. Holley

Author(s): Dandan Xu, Peng Wang, Xin Zhang, Jian Zhang, Yong Sun, Lihua Gao, Wenping Wang

Author(s): Xiaoye Shen, Yi-Cheng Su, Chengchu Liu, Tom Oscar, Angelo DePaola

Author(s): Lanlan Peng, Jiwang Chen, Lu Chen, Jie Cai, Wenping Ding, Yonggui Gao, Yongning Wu, Shuiyuan Cheng