Research Publications (Food Safety)

The occurrence of multidrug-resistant pathogenic bacteria, such as methicillin-resistant Staphylococcus aureus (MRSA), multidrug-resistant Acinetobacter baumannii (MDRAB), extended-spectrum β-lactamase (ESBL) Escherichia coli, and Pseudomonas aeruginosa, has become a serious problem in animals and public.

Background Additional treatment options for pneumonic plague, the most severe form of infection by Yersinia pestis, are needed, as past US Food and Drug Administration (FDA) approvals were not based on clinical trials that meet today’s standards, and multiple drugs are sought to counter resistance or use in special populations.

Background Ciprofloxacin and levofloxacin, 2 fluoroquinolone antimicrobials, are ≥90% effective for the treatment of inhalational plague when administered within 2–6 hours of fever onset in African green monkeys (AGM). Based on data in the AGM model, these antimicrobials were approved under the Food and Drug Administration’s Animal Efficacy Rule. However, that data did not address the issue of how long treatment with these antimicrobials would remain effective after fever onset.

by Lamyaa Shaban, Giang T. Nguyen, Benjamin D. Mecsas-Faxon, Kenneth D. Swanson, Shumin Tan, Joan Mecsas

Some biological activities of dihydroquercetin (DHQ), including antioxidative, antibacterial and anticancer activities, and the oxidative stability of butter oil supplemented with DHQ were evaluated. The DPPH* radical‐scavenging activity was high for DHQ, with an IC50 of 63.83 ± 3.11 μg/ml, compared to that of Trolox, which had an IC50 of 117.02 ± 5.19 μg/ml, over the concentrations studied (10–100 μg/ml).

Rodents are a large group of mammals that can be carriers of zoonotic pathogens such as Yersinia strains that cause yersiniosis. The prevalence of Yersinia enterocolitica and Yersinia pseudotuberculosis was determined in 214 small wild rodents from south-eastern Poland. Samples were analyzed by precultivation and PCR. Nine (4.2%) Y. enterocolitica and one (0.5%) Y. pseudotuberculosis isolates were received. Most of them (n = 5) were obtained from the common vole (Microtus arvalis). All Y.

Yersinia pestis, Brucella spp., and Bacillus anthracis are pathogens that can cause infectious zoonotic diseases with high mortality rates. An upconverting phosphor-based quantitative immunochromatographic (UPT-LF) assay, a point-of-care testing method suitable for resource-limited areas, was calibrated to quantitatively detect pathogenic bacteria. The bacterial purity or activity were ensured via staining methods and growth curves, respectively.

Brucellosis is a serious zoonosis occurring mainly in developing countries, and its diagnosis is largely dependent on serologic detection and bacterial culture. In this study, we developed the murine monoclonal antibodies (mAbs) against a conserved and major outer membrane protein 25 (Omp25) of Brucella species (B. spp.) for use in clinical diagnosis.

HpaR, a MarR family transcriptional regulator, was first identified in Escherichia coli W for its regulation of the hpa-meta operon. Little else is known regarding its functionality. Here, we report that in Yersinia pseudotuberculosis, HpaR negatively regulates the hpa-meta operon similar to in E. coli W.

Aims of the study The ability of Yersinia enterocolitica strains to form biofilms and the capacity of different alkaloids to inhibit biofilm formation were investigated. Methods and Results The capacity to form biofilm on polystyrene of 31 Y. enterocolitica strains was evaluated. Biofilm and quorum sensing (QS) inhibition of 17 alkaloids were assayed; furthermore, minimum biofilm inhibitory concentration (MBIC) was determined.

Yersinia enterocolitica exhibits a dual lifestyle, existing as both a saprophyte and a pathogen colonizing different niches within a host organism. OmpR has been recognized as a regulator that controls the expression of genes involved in many different cellular processes and the virulence of pathogenic bacteria. Here, we have examined the influence of OmpR and varying temperature (26°C vs. 37°C) on the cytoplasmic proteome of Y. enterocolitica Ye9N (bio-serotype 2/O:9, low pathogenicity).

This study evaluated the efficacy of lactic acid bacteria (LAB) isolated from traditional fermented foods and beverage of Ladakh as biocontrol agents against Yersinia enterocolitica. The antagonistic activities of 46 LAB isolates were screened for their ability to inhibit the growth of Y. enterocolitica at refrigeration temperatures using agar spot tests. On the basis of the 16S rDNA sequences, two selected inhibitory isolates were identified as Lactobacillus sp.

This study evaluated the efficacy of lactic acid bacteria (LAB) isolated from traditional fermented foods and beverage of Ladakh as biocontrol agents against Yersinia enterocolitica. The antagonistic activities of 46 LAB isolates were screened for their ability to inhibit the growth of Y. enterocolitica at refrigeration temperatures using agar spot tests. On the basis of the 16S rDNA sequences, two selected inhibitory isolates were identified as Lactobacillus sp.

While alternating between insects and mammals during its lifecycle, Yersinia pestis, the flea transmitted bacterium that causes plague, regulates its gene expression appropriately to adapt to these two physiologically disparate host environments. In fleas competent to transmit Y. pestis, low GC content genes y3555, y3551 and y3550 are highly transcribed, suggesting that these genes have a highly prioritized role in flea infection.

Oral administration is a preferred model for studying infection by bacterial enteropathogens such as Yersinia spp. In the mouse model, the most frequent method for oral infection consists of oral gavage with a feeding needle directly introduced in the animal stomach via the esophagus. In this study, we compared needle gavage to bread feeding as an alternative mode of bacterial administration.

Yersinia enterocolitica is generally considered an important food-borne pathogen worldwide, especially in the European Union. A lytic Yersinia phage X1 (Viruses; dsDNA viruses, no RNA stage; Caudovirales; and Myoviridae) was isolated. Phage X1 showed a broad host range and could effectively lyse 27/51 Y. enterocolitica strains covering various serotypes that cause yersiniosis in humans and animals (such as serotype O3 and serotype O8). The genome of this phage was sequenced and analyzed.

Fast response to environmental changes plays a key role in the transmission and pathogenesis of Yersinia enterocolitica. Osmoregulated periplasmic glucans (OPGs) are known to be involved in environmental perception of several Enterobacteriaceae pathogens; however, the biological function of OPGs in Y. enterocolitica is still unclear. In this study, we investigated the role of OPGs in Y. enterocolitica by deleting the opgGH operon encoding enzymes responsible for OPGs biosynthesis.

Salmonella enterica, Listeria monocytogenes, Shigella flexneri, Escherichia coli O157:H7, Vibrio parahaemolyticus, Staphylococcus aureus, Vibrio cholerae, Clostridium botulinum type A, Bacillus cereus, Clostridium perfringens Alpha toxin, and Yersinia enterocolitica are 11 common foodborne pathogens. Traditional bacterial culture methods for detecting pathogens are time‐consuming and labor‐intensive.

Poultry meat is one of the most important sources of infection of Yersinia spp. for humans. The aim of the present study was to evaluate the incidence of Yersinia enterocolitica in chicken meat by using culture method on selective medium and confirmation by PCR assay. Also, biochemical methods were used for biotyping. A total of 100 chicken thigh meat samples were collected randomly from retail outlets in Mashhad, Iran.

Author(s): Elisabetta Razzuoli, Walter Vencia, Paola Modesto, Giulia Franzoni, Silvia Dei Giudici, Erica Parisi, Angelo Ferrari, Massimo Amadori

Yersinia enterocolitica, a zoonotic foodborne pathogen, is able to withstand low temperatures. This psychrotrophic ability allows it to multiply in food stored in refrigerators. However, little is known about the Y. enterocolitica cold response. In this study, isolate-specific behavior at 4°C was demonstrated and the cold response was investigated by examining changes in phenotype, gene expression, and the proteome.

by Christian Twittenhoff, Ann Kathrin Heroven, Sabrina Mühlen, Petra Dersch, Franz Narberhaus

by Diana Hooker-Romero, Erin Mettert, Leah Schwiesow, David Balderas, Pablo A. Alvarez, Anadin Kicin, Azuah L. Gonzalez, Gregory V. Plano, Patricia J. Kiley, Victoria Auerbuch

by Zoltán Attila Nagy, Dávid Szakács, Eszter Boros, Dávid Héja, Eszter Vígh, Noémi Sándor, Mihály Józsi, Gábor Oroszlán, József Dobó, Péter Gál, Gábor Pál

Author(s): Erwin M. Berendsen, Evgeni Levin, René Braakman, Andrei Prodan, Hans C. van Leeuwen, Armand Paauw