Research Publications (Food Safety)

Within the species of Salmonella enterica, there is significant diversity represented among the numerous subspecies and serovars. Collectively, these account for microbes with variable host ranges, from common plant and animal colonizers to extremely pathogenic and human-specific serovars. Despite these differences, many Salmonella species find commonality in the ability to form biofilms and the ability to cause acute, latent, or chronic disease.

To the Editor—Symptomatic malaria is predominantly a disease of childhood in areas of higher transmission (ie, much of sub-Saharan Africa). Most cases of severe malaria occur in children aged <5 years. In these regions, both malaria and sepsis are major causes of childhood death, yet the clinical distinction between the 2 is difficult, particularly if there is no obvious focus of infection [1].

by Minho Lee, Minkyung Ryu, Minju Joo, Young-Jin Seo, Jaejin Lee, Hong-Man Kim, Eunkyoung Shin, Ji-Hyun Yeom, Yong-Hak Kim, Jeehyeon Bae, Kangseok Lee

Cashew apple extract (CAE) is a product with intense yellow color obtained from residual fibers of juice processing. Although CAE is known to be rich in carotenoids and anacardic acids, the biological activities of this potential natural food colorant remain unexplored.

Antibacterial adjuvants are of great significance, since they allow the therapeutic dose of conventional antibiotics to be lowered and reduce the insurgence of antibiotic resistance. Herein, we report that an O-acetylserine sulfhydrylase (OASS) inhibitor can be used as a colistin adjuvant to treat infections caused by Gram-positive and Gram-negative pathogens.

Author(s): Yucen Xie, Teng Cheng, Lina Wei, Mei-Jun Zhu, Shyam Sablani, Juming Tang

Fresh produce-borne enteric bacterial pathogens with resistance to antibiotics have posed serious challenges to food safety and public health worldwide.  This study examined the antibiotic resistance profile of Salmonella enterica (n=33), previously isolated from exotic and indigenous leafy green vegetable samples (n=328) collected from 50 vegetable farms in 12 farming areas and 37 vegetable sellers in 4 market centers in Accra, Ghana during the period of March 2016 to March 2017, and de

This study evaluated the potential impact of environmental factors and harvesting practices on microbial load of macadamia nuts. Three farms located in the main macadamia nut production regions including Mbombela (A), Barberton (B) and White River (C) areas in Mpumalanga Province, South Africa were sampled over a ,rtwo-year period. A total of 264, irrigation water (54), soil (30) and macadamia nut (180) samples were collected and evaluated for microbial concentrations.

Since 2008, veterinary authorities in Greece have implemented national control programmes (NSCPs) targeting S. Enteritidis (SE) and S. Typhimurium (ST) in poultry. We assessed the effect of the programs on the reported number of human isolates. Using monthly data for 2006&ndash;2017, we defined two groups (SE, ST) and one control group with serotypes unrelated to poultry or eggs. For SE we also analysed data for 2006&ndash;2015 due to a multi-county SE outbreak in 2016.

Lactoferrin (LF) is a multifunctional protein found in mammals, and it shows broad-spectrum antimicrobial activity. To improve the functional properties of specific probiotics in order to provide both the beneficial characteristics of lactic acid bacteria and the biological activity of LF, cDNAs of bovine LF (BLF), human LF (HLF), or porcine LF (PLF) were cloned into a nisin-inducible plasmid. These were then transformed into the selected eight probiotics, which are LF-resistant hosts.

This study validated a typical batch commercial flour tortilla cooking process against Salmonella contamination. Tortilla dough prepared from flour inoculated with a 7‐serovar Salmonella cocktail was pressed in a dough press (preset at 200 °F [93.3°C]) for 3 s, then heated on a griddle (preheated to 221.1°C [430 °F]) for 30, 45 or 60 s on each side, followed by ~8 min of ambient air cooling. The maximum internal temperature of tortillas during cooking was >97°C for all cooking times.

Salmonella is considered one of the leading causes for foodborne diseases in humans. Pork and its products contaminated with Salmonella are increasingly recognized as an important source of human salmonellosis. The aim of this study was to investigate the antimicrobial resistance and prevalence of integrons in Salmonella isolates from pig farms.

Author(s): Ji-Yeon Kim, Hana Song, Danbi Kim, Sun-Young Lee

Author(s): Phillip Luu, Vijay Singh Chhetri, Marlene E. Janes, Joan M. King, Achyut Adhikari

Unraveling the trends of phage-host versus phage-phage coevolution is critical for avoiding possible undesirable outcomes from the use of phage preparations intended for therapeutic, food safety or environmental safety purposes. We aimed to investigate a phenomenon of intergeneric recombination and its trajectories across the natural populations of phages predominantly linked to foodborne pathogens.

Certain stresses or conditions induce production or import of putrescine and/or cadaverine. Once stress is relieved or conditions change, the polyamines need to be exported via PaeA. Failure to export leads to high polyamine concentrations that are lethal under certain conditions. Abstract Salmonella and E. coli synthesize, import, and export cadaverine, putrescine, and spermidine to maintain physiological levels and provide pH homeostasis.

Salmonella spp. is a leading cause of gastrointestinal enteritis in humans where it is largely contracted via contaminated poultry and pork. Phages can be used to control Salmonella infection in the animals, which could break the cycle of infection before the products are accessible for consumption.

The bacterial cell wall plays a key role in viability and is an important drug target. The cell wall is made of elongated polymers that are cross-linked to one another to form a load-bearing mesh. An alternative cell wall cross-linking mechanism used by the l,d-transpeptidase YcbB has been implicated in the stress-regulated roles of β-lactam resistance, outer membrane defect rescue, and typhoid toxin release.

S. Octavia et al. Global travel has led to intermittent importation of multidrug-resistant-Salmonella enterica serovar Typhi into industrialized countries. We detected azithromycin-resistant Salmonella Typhi in Singapore, of which 2 isolates were likely locally acquired. Ongoing vigilance and surveillance to minimize the public health risk for this serious pathogen is needed.

One objective of this study was to determine overall prevalence of Salmonella in ground pork from U.S. retail stores over three seasons including both case-ready and store-ground packages. Package types collected included: overwrap, chub, modified atmosphere packaging, and other (plastic or wax paper wrapped).

Author(s): Thuan Khanh Nguyen, Hien Thi Bui, Thy Anh Truong, Diep Ngoc Lam, Shunsuke Ikeuchi, Lien Khai Thi Ly, Yukiko Hara-Kudo, Takahide Taniguchi, Hideki Hayashidani

The essential oil (EO) from the roots of Plectranthus barbatus Andr. (Syn. Coleus forskohlii Briq.) was evaluated for quorum sensing (QS) inhibitory activity. P. barbatus EO was screened for inhibition of QS regulated violacein production in Chromobacterium violaceum (ATCC 12472) wild-type strain.

Antimicrobial resistance is a global public health concern, and resistance genes in Salmonella, especially those located on mobile genetic elements, are part of the problem. This study used phenotypic and genomic methods to identify antimicrobial resistance and resistance genes, as well as the plasmids that bear them, in Salmonella isolates obtained from poultry in Nigeria. Seventy-four isolates were tested for susceptibility to eleven commonly used antimicrobials.

Dates are a low moisture ready‐to‐eat fruit which are popular both globally and in the United States. The harvesting and post‐harvest handling of dates could result in the contamination of common produce‐associated foodborne pathogens including E. coli O157:H7, Listeria monocytogenes, and Salmonella spp. In this study, the efficacy of antimicrobial washes for the reduction of foodborne pathogen populations was evaluated as a post‐harvest mitigation step.