Research Publications (Food Safety)

The present study investigated the effects of combined ultrasound (37 kHz, 380 W for 5 min) and peroxyacetic acid (PAA; 50–200 ppm) treatment on the reduction of Salmonella Typhimurium and Campylobacter jejuni on chicken skin. Ultrasound was not sufficient to inactivate S. Typhimurium (0.48 log CFU/g reduction) or C. jejuni (0.25 log CFU/g reduction), whereas PAA significantly (p < .05) reduced S. Typhimurium (0.93–1.59 log CFU/g reduction) and C. jejuni (0.77–1.52 log CFU/g reduction).

by Qinghe Li, Fei Wang, Qiao Wang, Na Zhang, Jumei Zheng, Maiqing Zheng, Ranran Liu, Huanxian Cui, Jie Wen, Guiping Zhao

by Stefan A. Fattinger, Desirée Böck, Maria Letizia Di Martino, Sabrina Deuring, Pilar Samperio Ventayol, Viktor Ek, Markus Furter, Saskia Kreibich, Francesco Bosia, Anna A. Müller-Hauser, Bidong D. Nguyen, Manfred Rohde, Martin Pilhofer, Wolf-Dietrich Hardt, Mikael E. Sellin

Author(s): Samir Subedi, M.S. Roopesh

Salmonella Heidelberg and Salmonella Typhimurium are among the most common serotypes responsible for human salmonellosis in Ontario. Introduction of the Ontario Investigation Tools (OIT) in 2014 allowed for standardized case investigation and reporting. This study compared the risk factors and symptomatology for sporadic S. Heidelberg and S. Typhimurium cases reported in Ontario in 2015, following implementation of the OIT.

Environmental monitoring of bacteria using phage‐based biosensors has been widely developed for many different species. However, there are only a few available methods to detect specific bacteriophages in raw environmental samples. In this work, we developed a simple and efficient assay to rapidly monitor the phage content of a given sample. The assay is based on the bistable expression of the Salmonella enterica opvAB operon.

In livestock production, antibiotics are used to promote animal growth, control infections and thereby increase profitability. This practice has led to the emergence of multi‐resistant bacteria such as Salmonella, of which some serovars are disseminated in the environment. The objective of this study is to evaluate microcin J25 as an inhibitor of Salmonella enterica serovars of various origins including human, livestock and food.

Many Gram-negative bacterial pathogens utilize the type III secretion system (T3SS) to inject virulence factors, named effectors, into host cells. These T3SS effectors manipulate host cellular signaling pathways to facilitate bacterial pathogenesis. Death receptor signaling plays an important role in eukaryotic cell death pathways. NleB from enteropathogenic Escherichia coli (EPEC) and SseK1/3 from Salmonella enterica serovar Typhimurium (S. Typhimurium) are T3SS effectors.

The objective of this study was to determine if immunosuppression through daily dexamethasone (DEX) infusion altered Salmonella translocation from the gastrointestinal tract. Weaned Holstein steers (n = 20; body weight [BW] = 102 ± 2.7 kg) received DEX (n = 10; 0.5 mg/kg BW) or saline (control [CON]; n = 10;) for 4 days (from day −1 to 2) before oral inoculation of naldixic acid-resistant Salmonella enterica Typhimurium (SAL; 3.4 × 106 colony-forming units [CFU]/animal) on day 0.

The aim of this study was to examine whether the process of initial colonization and the formation of mature biofilm structure of foodborne bacterial pathogens Listeria monocytogenes and Salmonella typhimurium can be impeded by active essential oil components β‐caryophyllene, cinnamaldehyde and eugenol at their individual and combined effects.

Highly concentrated sugar solutions are known to be effective anti‐microbial agents. However, it is unknown whether this effect is solely the result of the collective osmotic effect imparted by a mixture of sugars or whether the type of carbohydrate used also has an individual chemical effect on bacterial responses, i.e., inhibition/growth.

Aims To identify a lambda promoter pL mutant that could extend the thermal stability of the thermo‐inducible λcI857‐pR/pL system and to evaluate the effects of the modified system for the controlled expression of lysis gene E during the production of bacterial ghosts (BGs). Methods and Results The promoter pL mutant was identified by random mutagenesis and site‐directed mutagenesis. The results showed that a T→35C mutation in the pL promoter was responsible for the phenotype alteration.

Loop-mediated isothermal amplification (LAMP) had been employed as a powerful tool to facilitate genetic tests for various food pathogens, as it is easy to perform. Recently, various methods of detecting the LAMP amplicon were developed. In this study, we improved two LAMP assays by combining LAMP with chromatographic flow dipstick (LFD) assays for Salmonella (targeting phoP and invA, respectively).

Author(s): Si Hyeon Roh, Yeong Ji Oh, Seung Young Lee, Joo Hyun Kang, Sea C. Min

We studied the antibacterial activity and mechanism of Tetrapleura tetraptera stem extract against Salmonella enteritidis and Salmonella typhimurium and its applications in chicken meat. The extract showed significant antibacterial activity in vitro, minimum inhibitory concentration, and minimum bactericidal concentration on the pathogens was found to be 12.5–50.0 mg/ml. The mechanism of action of the T. tetraptera stem on S. enteritidis and S.

ABSTRACT

Author(s): Mengzhe Li, Hong Lin, Yujie Jing, Jingxue Wang

The rapid emergence of multidrug resistant Salmonella is a global public-health concern as outbreaks in recent years have mostly been caused by multidrug resistant strains. Here, we evaluated an outbreak in China caused by multidrug resistant Salmonella enterica serovar Typhimurium (S. Typhimurium) by employing an epidemiological and laboratory investigation using conventional methods and whole genome sequencing (WGS).

In recent years, protein glycosylation in pathogenic bacteria has attracted more and more attention, and accumulating evidence indicated that this type of posttranslational modification is involved in many physiological processes.

by Matheus O. Costa, Janelle Fouhse, Ana Paula P. Silva, Benjamin Willing, John C. S. Harding

Author(s): Mathieu Gand, Wesley Mattheus, Nancy Roosens, Katelijne Dierick, Kathleen Marchal, Sophie Bertrand, Sigrid C.J. De Keersmaecker

Author(s): Ye Htut Zwe, Seow Fong Chin, Gurjeet Singh Kohli, Kyaw Thu Aung, Liang Yang, Hyun-Gyun Yuk

Salmonellosis is a leading bacterial cause of foodborne illness, and numerous Salmonella enterica serovars have been responsible for foodborne outbreaks. In the United States outbreaks are often linked to poultry and poultry‐related products. The prevalence of Salmonella serovar Infantis has been increasing in poultry processing facilities over the past few years and in 2018 was identified as the causative agent for a large multistate outbreak linked to raw chicken.

Author(s): Liping Gan, Hao Fan, Tahir Mahmood, Yuming Guo

Ultrasound (US) is classified as a nonthermal treatment and it is used in food processing at a frequency range between 20 kHz and 1 MHz. Cavitation bubbles occur when the US strength is high enough to generate rarefaction that exceeds the intermolecular attraction forces in the medium.