Research Publications (Food Safety)

Ocellatins are peptides produced in the skins of frogs belonging to the genus Leptodactylus that generally display weak antimicrobial activity against Gram-negative bacteria only. Peptidomic analysis of norepinephrine-stimulated skin secretions from Leptodactylus insularum Barbour 1906 and Leptodactylus nesiotus Heyer 1994, collected in the Icacos Peninsula, Trinidad, led to the purification and structural characterization of five ocellatin-related peptides from L.

Upon biofilm formation, production of extracellular matrix components and alteration in physiology and metabolism allows bacteria to build up multicellular communities which can facilitate nutrient acquisition during unfavorable conditions and provide protection toward various forms of environmental stresses to individual cells. Thus, bacterial cells within biofilms become tolerant against antimicrobials and the immune system.

ABSTRACT This study was designed to evaluate the synergistic effect of phage (P22) and antibiotic on the inhibition of Salmonella Typhimurium exposed to ceftriaxone (CEF) and ciprofloxacin (CIP). The effect of phage and antibiotic treatments was evaluated by plaque size, disk diffusion, antibiotic susceptibility and phage multiplication assays.

Aims This study aimed to evaluate the effects of three Bacillus probiotics on Salmonella Typhimurium, and interleukin‐8 (IL‐8) gene expression in the co‐culture of the Bacillus and the pathogen in vitro. Methods and Results Bacillus subtilis, Bacillus indicus, and Bacillus coagulans were initially turned to spore and heat‐inactivated forms. The cellular damages of the probiotics on the HT‐29 cells were investigated individually and in combination with S.

BACKGROUND Animal manure frequently harbors pathogenic microorganisms such as Salmonella spp and diarrheagenic Escherichia coli. A defined microbial consortium such as Effective Microorganisms (EM) can potentially be used as a biocontrol against manure‐borne human pathogens such as Salmonella and pathogenic E. coli. The objective of the study was to investigate the efficacy of EM to decontaminate cattle manure.

Salmonella enterica serovar Typhimurium is a prevalent incitant of enteritis in human beings and nonhuman animals. It has been proposed that host defense responses incited by Salmonella allow the bacterium to overcome colonization resistance. Piglets (n = 24) were orally inoculated with S.

Raw pet food, comprised of raw meat and vegetables, has increased in popularity in recent years. Multiple surveys and frequent recalls indicate that this commodity has a high risk of contamination with Salmonella and other foodborne pathogens. Improved screening methods are needed to meet the growing demand for testing.

Red meat is associated with Salmonella outbreaks resulting in negative impacts for the processing industry. Little work has been reported on the use of dry heat as opposed to moist heat against Salmonella on red meat. We determined the effect of drying at 25°C and dry heat at 70°C with ~10% relative humidity (RH) for 1 h against eleven Salmonella strains of multiple serovars on beef, lamb, goat, and rubber as an inert surface.

The emergence of multidrug resistance (MDR), including colistin resistance, among Enterobacteriaceae recovered from food animals poses a serious public health threat because of the potential transmission of these resistant variants to humans along the food chain. Village chickens or Ayam Kampung are free-range birds and are preferred by a growing number of consumers who consider these chickens to be organic and more wholesome.

The classical bordetellae possess several partially characterized virulence mechanisms that are studied in the context of a complete extracellular life cycle in their mammalian hosts.

The aim of this study was to generate knowledge on the most important milk quality and safety attributes, including somatic cell count (SCC), total bacterial count (TBC), Escherichia coli, Salmonella, and Brucella spp. antibodies and antibiotic residues in milk in the chain from farm to milk collection center (MCC) in Rwanda. In addition, we investigated farm and management factors associated with high TBC, SCC, and Salmonella counts. Raw milk was sampled at the farm and MCC levels.

When a new activity evolves by changes in a pre-existing enzyme this is likely to reduce the original activity, generating a functional trade-off. The properties of this trade-off will affect the continued evolution of both functions. If the trade-off is strong, gene duplication and subsequent divergence would be favored whereas if the trade-off is weak a bi-functional enzyme could evolve that performs both functions.

Post-transcriptional regulation mediated by regulatory small RNAs (sRNAs) has risen as a key player in fine-tuning gene expression in response to environmental stimuli. Here, we show that, in Salmonella enterica, the central metabolic regulator CRP-cAMP differentially regulates the sRNAs CsrB and CsrC in a growth phase-dependent manner.

M. Maes et al. Salmonella enterica serovar Typhi H58, an antimicrobial-resistant lineage, is globally disseminated but has not been reported in Latin America. Genomic analysis revealed 3 independent introductions of Salmonella Typhi H58 with reduced fluoroquinolone susceptibility into Chile. Our findings highlight the utility of enhanced genomic surveillance for typhoid fever in this region.

Author(s): Bruno S. Mendonça, Willian R. de Oliveira, Rhaquel S. Pereira, Luciana R. Santos, Laura B. Rodrigues, Elci L. Dickel, Luciane Daroit, Fernando Pilotto

Author(s): D.V.T. Nair, T.J. Johnson, S.L. Noll, A. Kollanoor Johny

P. hydropiper ethanolic extract: Chlorogenic acid, ferulic acid, rutin, myricetin andquercetin. P. hydropiper essential oil: dodecanal, caryophyllene, caryophyllene oxide, decanal, α‐caryophyllene, citronellol, heptadecanal, linalool and phytol. Ethanolic extract and essential oil of P. hydropiper exhibited antimicrobial activity against three bacteria Staphylococcus aureus 6538P, Escherichia coli ATCC 11229 and Salmonella Typhimurium ATCC 14028 using time‐kill kinetics assay.

Author(s): Lijun Hu, Guojie Cao, Eric W. Brown, Marc W. Allard, Li M. Ma, Ashraf A. Khan, Guodong Zhang

This study aimed to explore the antimicrobial effects of activated lactoferrin (ALF) and rosemary extract (RE) on Escherichia coli O157:H7, Salmonella Enteritidis and Listeria monocytogenes, and to investigate their application potential in the meat storage. Minimum inhibitory concentrations (MICs) of ALF, RE and ALF–RE combinations were determined via microtiter plate assay. MICs of ALF were 1% for E.

In this review, we explore the plasmidome of A. salmonicida. Knowledge has accumulated about this diverse plasmidome, which can be separated into three categories (R‐plasmids, virulence plasmids, and cryptic plasmids). The advance of DNA sequencing technology has played an important role in the elucidation of complete sequences, giving greater clarity to study the roles and importance of plasmids in A. salmonicida.

Carvacrol has been recognized as an efficient growth inhibitor of food pathogens. However, carvacrol oil is poorly water‐soluble and can be oxidized, decomposed or evaporated when exposed to the air, light, or heat. To overcome these limitations, a carvacrol nanoemulsion was developed and its antimicrobial activity against food pathogens evaluated in this study.

Author(s): Shamsun Nahar, Angela Jie-won Ha, Kye-Hwan Byun, Md. Iqbal Hossain, Md. Furkanur Rahaman Mizan, Sang-Do Ha

Author(s): Xiaonan Zhao, Ming Hu, Qing Zhang, Cui Zhao, Yin Zhang, Lulu Li, Jing Qi, Yanbo Luo, Dong Zhou, Yuqing Liu

The loop‐mediated isothermal amplification (LAMP) technique was used to investigate six salmonella‐specific sequences for their suitability to serve as targets for the pathogen identification. Sequences selected for designing LAMP primers were genes invA, bcfD, phoP, siiA, gene62181533 and a region within the ttrRSBCA locus. Primers including single nucleotide polymorphisms were configured as degenerate primers.

HMP‐P synthase (Thi5) is a critical enzyme in the biosynthesis of thiamine pyrophosphate in yeast. A Thi5 homolog from Legionella pneumophila, which contributes to HMP synthesis in its native host, is an enzyme that binds pyridoxal‐5’‐phosphate and releases HMP when the purified protein is incubated with iron. In a heterologous system Thi5 from Saccharomyces cerevisiae and L.