Research Publications (Food Safety)

Author(s): Yuting Shang, Qinghua Ye, Shuzhen Cai, Qingping Wu, Rui Pang, Shuanghong Yang, Xinran Xiang, Chufang Wang, Fei Zha, Yu Ding, Yinzhi Zhang, Jiasheng Wang, Xiulan Sun, Jumei Zhang

Profiles of symbiotic microbial communities (“microbiomes”) can provide insight into the natural history and ecology of their hosts. Using high throughput DNA sequencing of the 16S rRNA V4 region, microbiomes of five shark species in South Florida (nurse, lemon, sandbar, Caribbean reef, and tiger) have been characterized for the first time. The microbiomes show species specific microbiome composition, distinct from surrounding seawater.

Plasmids play a major role in bacterial adaptation to environmental stress and often contribute to antibiotic resistance and disease virulence. Although the complete sequence of each plasmid is essential for studying plasmid biology, most antibiotic resistance and virulence plasmids in Salmonella are present only in a low copy number, making extraction and sequencing difficult. Long read sequencing technologies require higher concentrations of DNA to provide optimal results.

Within Ethiopia, there is a lack of information on the genetic relatedness of Salmonella from cattle, beef, and diarrheic patients and its potential transmission from cattle to humans through consumption of contaminated beef.

A recent work revealed that egg white (EW) at 45 °C exhibits powerful bactericidal activity against S. enterica serovar Enteritidis, which is surprisingly little affected by removal of the >10 kDa EW proteins. Here, we sought to identify the major EW factors responsible for this bactericidal activity by fractionating EW using ultrafiltration and nanofiltration and by characterizing the physicochemical and antimicrobial properties of the resulting fractions.

Despite extensive monitoring programs and preventative measures, Salmonella spp. continue to cause tens of thousands human infections per year, as well as many regional and international food-borne outbreaks, that are of great importance for public health and cause significant socio-economic costs. In Germany, salmonellosis is the second most common cause of bacterial diarrhea in humans and is associated with high hospitalization rates.

ABSTRACT

S. Irfan et al. We evaluated Salmonella enterica serotype Typhi strains isolated from all body sites in Pakistan during 2013–2018. Despite an increase in overall number of localized, extensively drug-resistant Salmonella Typhi in organ infections during 2018, there was no increase in the proportion of such isolates in comparison with non–extensively drug-resistant isolates.

Salmonella is one of the main causes of foodborne diseases worldwide. Molecular tests such as the polymerase chain reaction (PCR) are rapid and sensitive and are increasingly becoming a preferred method for pathogen detection. However, the presence of PCR inhibiting substances in the analyzed samples could reduce the sensitivity or totally inhibit PCR amplification, which might result in failure of detection of the pathogen.

In this study, a systematic review and a meta-analysis were conducted to analyse recent worldwide information about the prevalence of Salmonella spp. in vegetables and fruits to estimate the effect of the different processes such as washing, cutting or disinfection, and place of sampling. A systematic search was conducted for articles from 2014 to 2020 published to date regarding prevalence of Salmonella spp.

Author(s): Yue Han, Ping Luo, Yuji Chen, Jiali Xu, Jing Sun, Chiyu Guan, Pu Wang, Mianmian Chen, Xian Zhang, Yueyue Zhu, Tingting Zhu, Ruidong Zhai, Changyong Cheng, Houhui Song

Author(s): Songtao Du, I-Hsuan Chen, Alana MacLachlan, Yuzhe Liu, Tung-shi Huang, Zhongyang Cheng, Pengyu Chen, Bryan A. Chin

Author(s): Yingyu Liu, Jindou Jiang, Abdelaziz Ed-Dra, Xiaomeng Li, Xianqi Peng, Lining Xia, Qingyong Guo, Gang Yao, Min Yue

DNA gyrase is an essential type II topoisomerase that is composed of two subunits, GyrA and GyrB and has an A2B2 structure. Although the A and B subunits are required in equal proportions to form DNA gyrase, the gyrA and gyrB genes that encode them in Salmonella (and in many other bacteria) are at separate locations on the chromosome, are under separate transcriptional control, and are present in different copy numbers in rapidly growing bacteria.

Author(s): Annaleise Wilson, P. Scott Chandry, Mark S. Turner, Jodi M. Courtice, Narelle Fegan

Although it has been reported that deletion of the response regulator, CpxR, in the CpxRA system confers sensitivity to aminoglycosides (AGAs) and β-lactams in Salmonella enterica serovar Typhimurium, the regulatory effects of CpxA on multidrug resistance (MDR) are yet to be fully investigated in this organism.

Chicken liver is a highly perishable meat product with a relatively short shelf-life and that can get easily contaminated with pathogenic microorganisms. This study was conducted to evaluate the behavior of spoilage microbiota and of inoculated Salmonella enterica on chicken liver. The feasibility of Fourier-transform infrared spectroscopy (FTIR) to assess chicken liver microbiological quality through the development of a machine learning workflow was also explored.

Campylobacter spp. are the leading global cause of bacterial colon infections in humans. Enteropathogens are subjected to several stress conditions in the host colon, food complexes, and the environment. Species of the genus Campylobacter, in collective interactions with certain enteropathogens, can manage and survive such stress conditions. The stress-adaptation mechanisms of Campylobacter spp.

Salmonella Enteritidis is an important foodborne pathogen with high prevalence of resistance to cephalosporins, imposing a serious threat to public health. Therefore, a total of 162 Salmonella Enteritidis isolates collected from child patients in China from 2007 to 2017 were characterized for their resistance to cephalosporins and investigated the transmission characteristics of cephalosporin resistance gene.

Cyadox has potential use as an antimicrobial agent in animals. However, its pharmacodynamic properties have not been systematically studied yet. In this study, the in vitro antibacterial activities of cyadox were assayed, and the antibacterial efficacy of cyadox against facultative anaerobes was also determined under anaerobic conditions.

Fresh produce has been identified as an important vehicle for the transmission of foodborne pathogens. This study evaluated the behavior of vegetative cells and spores of Bacillus thuringiensis, one of the main biological control agents (BCAs) used in the world, and Salmonella enterica on spinach plants (pre-harvest) and spinach cut leaves (post-harvest) at 12°C, experimentally inoculated as single or co-cultures.

Salmonella enterica is one of the most diverse and successful pathogens, representing a species with >2,600 serovars with a variety of adaptations that enable colonization and infection of a wide range of hosts. Fimbriae, thin hair-like projections that cover the surface of Salmonella, are thought to be the primary organelles that mediate Salmonella’s interaction with, and adherence to, the host intestinal epithelium, representing an important step in the infection process.

Author(s): Rongwei Han, Xinyu Liao, Chunmei Ai, Tian Ding, Jun Wang

Author(s): Hongfei Zhang, Sabrina Peiqi Chen, Hon Luen Seck, Weibiao Zhou

Salmonella enterica serovar Typhimurium, an intracellular pathogen, evades the host immune response mechanisms to cause gastroenteritis in animals and humans. After invading the host cells, the bacteria proliferate in Salmonella-containing vacuole (SCV) and escapes from antimicrobial therapy. Moreover, Salmonella Typhimurium develops resistance to various antimicrobials including, fluoroquinolones.