Editorial: Developments in Campylobacter, Helicobacter & Related Organisms Research – CHRO 2019

Publication history: Accepted - 14 December 2020; Published - 8 January 2021

Foodborne Pathogen Campylobacter

Publication history: Accepted - 3 June 2021; Published online - 8 June 2021

Prevalence and persistence of Listeria monocytogenes in premises and products of small food business operators in Northern Ireland

peer-reviewedListeriosis is a foodborne disease, with a high mortality rate, that predominantly affects the elderly. Under European Union legislation, EC 2073/2005, food business operators are encouraged to undertake sampling to ensure that the food processing environment, and required to ensure that food products, are free of Listeria monocytogenes. To determine the prevalence of L. monocytogenes in smaller food processing facilities in Northern Ireland, 24 companies submitted six processing environment swabs and two food samples every two months for eighteen months (July 2015 to November 2016) for L. monocytogenes examination. The prevalence of L. monocytogenes was 4.6% in food samples, and 6.3% in processing environment swabs. Over the duration of the study, 96 isolates of L. monocytogenes were obtained, one from each positive sample, except for two meat samples that had >100 cfu/g, where two isolates were obtained from each sample. No seasonality in occurrence of L. monocytogenes was seen for food isolates but significantly higher numbers of positive processing environment swabs were found in the warmer months of May, July and September (p = .007). Pulsed Field Gel Electrophoresis (PFGE) analysis revealed the presence of 27 pulsotypes; 9 pulsotypes were shared between different facilities and 9 were persistent. Based on a Combase predictive growth model, 77.5% (n = 130) of the foods tested were predicted to support the growth of L. monocytogenes. All of the isolates carried the pathogenicity genes inlA and actA and 71.4% carried qacH, which confers resistance to quaternary ammonium compounds which are frequently used in sanitizers. Whole genome sequencing of the isolates allowed multi-locus sequence typing to be undertaken. The data indicated that the sequence types identified included those with disease-causing ability, highlighting the disease-causing potential of the isolates

Corrigendum: Bioinformatic Analysis of the Campylobacter jejuni Type VI Secretion System and Effector Prediction.

[This corrects the article DOI: 10.3389/fmicb.2021.694824.]

Geraniol and Linalool Loaded Nanoemulsions and Their Antimicrobial Activity

Geraniol and linalool have been found to be effective against foodborne microorganisms in vitro. However, due to their hydrophobic nature, it is difficult to achieve an even dispersion in foods with high water content resulting in dramatic loss of activity. The aim of the study was to fabricate geraniol or linalool nanoemulsions and investigate their effect against Escherichia coli K12, Listeria innocua and Pseudomonas lundensis in a meat simulation medium. The agar diffusion assay revealed that both geraniol and linalool had a potent antimicrobial activity against all bacteria. Dynamic light scattering showed that geraniol and linalool nanoemulsions had a mean diameter of 68.22±2.46 and 173.59±4.15 nm, respectively. Killing assay results showed that both nanoemulsions were able to significantly reduce E. coli and L. innocua counts by approx. 3 log CFU/ml. Ps. lundensis proved to be more resistant to both nanoemulsions showing a reduction of approx. 1.2 log CFU/ml,. Overall, this study showed that nanoemulsions loaded with geraniol or linalool represent a promising antimicrobial system to improve food preservation and food safety

THE EMERGENCE OF ΒETA - LACTAMASE PRODUCING Escherichia coli AND THE PROBLEMS IN ASSESSING THEIR POTENTIAL CONTRIBUTION TO FOODBORNE ILLNESS: A REVIEW

Antimicrobial agents have been in use for therapeutic purposes for over a century, with most of the development occurring in the latter half of the twentieth century. Penicillin was the first of the naturally occurring antimicrobials to be used in medicine and its structure includes a beta-lactam ring. Further compounds, such as the cephalosporins, were discovered and these also included beta-lactam structures. Subsequently bacteria which were resistant to these compounds were found, and their resistance was due to their production of enzymes, beta-lactamases, which hydrolysed the beta-lactam ring. Synthetic derivatives of the beta-lactam antimicrobials were developed to render them recalcitrant to beta-lactamases but enzymes with a broader substrate range evolved, and were categorised as extended substrate beta-lactamases (ESBL). Since the antimicrobials had a significant role to play in human medicine the emergence of ESBL caused significant concerns. Further, similar antimicrobials were used by veterinarians, raising the prospect that bacteria in the commensal flora of livestock could acquire ESBL resistance properties and exchange them via genetic exchange. Thus, pathogenic bacteria present in livestock could become resistant to antimicrobials with adverse consequences should zoonotic infections occur. In this review we consider the emergence of ESBL, the problems involved in detecting and reporting such properties, and consider the consequences for consumers of potentially contaminated food product

Bioinformatic Analysis of the Campylobacter jejuni Type VI Secretion System and Effector Prediction

Publication history: Accepted - 7 June 2021; Published online - 29 June 2021.The Type VI Secretion System (T6SS) has important roles relating to bacterial antagonism, subversion of host cells, and niche colonisation. Campylobacter jejuni is one of the leading bacterial causes of human gastroenteritis worldwide and is a commensal coloniser of birds. Although recently discovered, the T6SS biological functions and identities of its effectors are still poorly defined in C. jejuni. Here, we perform a comprehensive bioinformatic analysis of the C. jejuni T6SS by investigating the prevalence and genetic architecture of the T6SS in 513 publicly available genomes using C. jejuni 488 strain as reference. A unique and conserved T6SS cluster associated with the Campylobacter jejuni Integrated Element 3 (CJIE3) was identified in the genomes of 117 strains. Analyses of the T6SS-positive 488 strain against the T6SS-negative C. jejuni RM1221 strain and the T6SS-positive plasmid pCJDM202 carried by C. jejuni WP2-202 strain defined the “T6SS-containing CJIE3” as a pathogenicity island, thus renamed as Campylobacter jejuni Pathogenicity Island-1 (CJPI-1). Analysis of CJPI-1 revealed two canonical VgrG homologues, CJ488_0978 and CJ488_0998, harbouring distinct C-termini in a genetically variable region downstream of the T6SS operon. CJPI-1 was also found to carry a putative DinJ-YafQ Type II toxin-antitoxin (TA) module, conserved across pCJDM202 and the genomic island CJIE3, as well as several open reading frames functionally predicted to encode for nucleases, lipases, and peptidoglycan hydrolases. This comprehensive in silico study provides a framework for experimental characterisation of T6SS-related effectors and TA modules in C. jejun

Effects of phenolic acids and IgY immunoglobulins on aspects of rumen fermentation, in vitro.

Publication history: Accepted – 4 January 2019; Published – 2019.The current study was carried out in order to determine the effects of simple phenols and of specific anti-methanogen IgY antibodies on ruminal gas production, methane emissions, volatile fatty acids (VFA) profile and pH in in vitro ruminal cultures. Caffeic and p-Coumaric acids and IgY antibodies were added anaerobically to ruminal batch cultures. Ruminal parameters were measured after 24, 48 and 72 hours of incubation. The results showed that addition ofboth phenolic acids and IgY antibodies significantly (P <0.05) decreased methane production at 24 and 48 hours of incubation. At 24 and 48 hours of incubation some significant differences were observed in volatile fatty acids profile, while the pH was not affected by simple phenols and IgY antibodies addition. Simple phenols and IgY avian antibodies can be further tested in order to achieve the purpose of methane mitigation strategies, but the ideal way to inhibit the methanogenesis process in rumen would reduce methane production without altering the other ruminal parameters, such as VFAs, total gas production or pH.DBU (Deutsche BundesstiftungUmwelt) scholarship program at Helmholtz Centre for Environmental Research, Leipzig, Germany