Stephen L W On

Lincoln University New Zealand · Department of Wine, Food and Molecular Biosciences

We used inter-delta typing (IDT) and MALDI-TOF profiling to characterize the genetic and phenotypic diversity of 45 commercially available winemaking Saccharomyces cerevisiae strains and 60 isolates from an organic winemaker from Waipara, New Zealand, as a stratified approach for predicting the commercial potential of indigenous isolates. A total o...

The peroxidase-like behaviors of gold nanoparticles (AuNPs) have the potential to the development of rapid and sensitive colorimetric assays for specific food ingredients and contaminants. Here, using NaBH4 as a reducing agent, AuNPs with a supramolecular macrocyclic compound β-cyclodextrin (β-CD) capped were synthesized under alkaline conditions....

To assess the possible impact of climatic variation on microbial community composition in organic winemaking, we employed a metabarcoding approach to scrutinize the microbiome in a commercial, organic, Pinot noir wine production system that utilizes autochthonous fermentation. We assessed microbial composition across two vintages (2018 and 2021) us...

Background: Land snails are considered a delicacy in many countries in Europe and sub-Saharan Africa. However, the interaction of microbial pathogens with land snails may present a public health threat when handling and/or consuming snails. This study examines the survival of Escherichia coli in edible land snails in a model system. Methods: Well-s...

Kombucha consumption has grown rapidly worldwide in the last decade, with production at both small- and large scales. The complex fermentation process involves both bacterial and yeast species, but little is known regarding the progression of microbial development during production. We explored the microbial diversity of multiple batches across two...

The naming of prokaryotes is governed by the International Code of Nomenclature of Prokaryotes (ICNP) and partially by the International Code of Nomenclature for Algae, Fungi and Plants (ICN). Such codes must be able to determine names of taxa in a universal and unambiguous manner, thus serving as a common language across different fields and activ...

It has been demonstrated that short-term stress can enhance cellular responses and promote longevity, whereas long-term stress shortens lifespan. Understanding the relationship between short-term and long-term stress could offer new insights into comprehending and modulating age-related diseases. In this study, we investigate this relationship usin...

A special online meeting to discuss contemporaneous issues facing ICSP Subcommittees on Taxonomy.

The potential of using commercial peroxyacetic acid (PAA) for Vibrio parahaemolyticus sanitization was evaluated. Commercial PAA of 0.005 % (v/v, PAA: 2.24 mg/L, hydrogen peroxide: 11.79 mg/L) resulted in a planktonic cell reduction of >7.00 log10 CFU/mL when initial V. parahaemolyticus cells averaged 7.64 log10 CFU/mL. For cells on stainless steel...

The role of microbial diversity in influencing the organoleptic properties of wine and other fermented products is well est ablished, and understanding microbial dynamics within fermentation processes can be critical for quality assurance and product innovation. This is especially true for winemakers using spontaneous fermentation techniques, where...

Vibrio parahaemolyticus biofilms on the seafood processing plant surfaces are a potential source of seafood contamination and subsequent food poisoning. Strains differ in their ability to form biofilm, but little is known about the genetic characteristics responsible for biofilm development. In this study, pangenome and comparative genome analysis...

Background Snail meat is an important source of nutrition in Cameroon, but the food safety risks are poorly understood. We characterized public health risks from snail meat consumption as a social system in Cameroon, by examining local snail practices that expose snail meat handlers and consumers to foodborne pathogens. Methods We used exploratory...

The manuscript investigates and reports for the first time utilizing a non-GMO approach to alter the fermentation process of Pinot Noir wines. We have experimentally demonstrated that certain dietary compounds possess histone deacetylase (HDAC) inhibiting activity and can alter the wine characteristics by potentially altering yeast gene transcripti...

Vibrio parahaemolyticus is a marine oriented pathogen; and biofilm formation enables its survival and persistence on seafood processing plant, complicating the hygienic practice. The objectives of this study are to assess the ability of V. parahaemolyticus isolated from seafood related environments to form biofilms, to determine the effective sodiu...

Epigenetic changes in genomics provide phenotypic modification without DNA sequence alteration. This study shows that benzoic acid, a common food additive and known histone deacetylase inhibitor (HDACi), has an epigenetic effect on Saccharomyces cerevisiae . Benzoic acid stimulated formation of epigenetic histone marks H3K4Me2, H3K27Me2, H3K18ac an...

In tropical countries, land snails are an important food source; however, foodborne disease risks are poorly quantified. We detected Campylobacter spp., Yersinia spp., Listeria spp., Salmonella spp., or Shiga-toxigenic Escherichia coli in 57%–86% of snails in Cameroon. Snail meat is a likely vector for enteric diseases in sub-Saharan African countr...

This paper discusses the methodological challenges in studying health risks that could arise from consuming terrestrial snails infested with pathogenic microorganisms. In Cameroon, snails remain an inexpensive protein source and are collected from free-living environments termed "farms." Our focus has been on understanding health risks due to the h...

Yersinia enterocolitica and Y. pseudotuberculosis are important causes of enteric illness worldwide. Rapid response to suspected foodborne outbreaks is hampered by the widespread use of cold enrichment methods that require incubation periods of 10–21 days. Although these species grow faster at elevated temperatures, part of the rationale for cold e...

As global warming increases the geographical range and frequency of Vibrio parahaemolyticus infections, its formation of biofilms providing bacteria greater resistance to stress and contributing to the persistence of pathogens, is threatening the seafood industry. V. parahaemolyticus has a number of advantages leading to biofilm formation. This stu...

The potential of MALDI-TOF profiling for predicting potential applications of yeast strains in the beverage sector was assessed. A panel of 59 commercial yeasts (47 wine and 12 brewing yeasts) was used to validate the concept whereby 2 culture media (YPD agar and YPD broth), as well as two mass ranges m/z 500–4000 and m/z 2000–20,000, were evaluate...

The prevalence and spread of antimicrobial resistance (AMR) as a result of the persistent use and/or abuse of antimicrobials is a key health problem for health authorities and governments worldwide. A study of contrasting farming systems such as organic versus conventional dairy farming may help to authenticate some factors that may contribute to t...

This paper re-examines the taxonomic positions of recently described Poseidonibacter ( P. parvum and P. antarcticus ), Aliarcobacter (‘ Al. vitoriensis’ ), Halarcobacter (‘ H. arenosus ’) and Arcobacter ( A. caeni , A. lacus ) species, and other species proposed to represent novel genera highly related to the genus Arcobacter . Phylogenomic and sev...

A study on the polyphasic taxonomic classification of an Arcobacter strain, R-73987 T , isolated from the rectal mucus of a porcine intestinal tract, was performed. Phylogenetic analysis based on the 16S rRNA gene sequence revealed that the strain could be assigned to the genus Arcobacter and suggested that strain R-73987 T belongs to a novel undes...

The formation of biofilms is a survival strategy employed by bacteria to help protect them from changing or unfavourable environments. In this research, 319 genes which govern biofilm formation in V. parahaemolyticus, as reported in 1,625 publications, were analysed using protein-protein-interaction (PPI) network analysis. CsrA was identified as a...

Previous studies have shown MALDI-TOF MS to be a powerful tool in wine yeast identification and potential prediction of application. However, it is also established that substrate composition influences protein expression, but the degree to which this may affect MALDI-TOF spectra (and analytical results thereof) has not been fully explored. To furt...

Rapid yeast identification is of particular importance in monitoring wine fermentation and assessing strain application in winemaking. We used MALDI-TOF MS analysis supported by 26 S rRNA gene sequence analysis and Saccharomyces-specific PCR testing to differentiate reference and field strains recovered from organic wine production facilities in Wa...

An increasing number of Arcobacter species (including several regarded as emerging human foodborne pathogens) have been isolated from shellfish, an important food commodity. A method to distinguish these species and render viable isolates for further analysis would benefit epidemiological and ecological studies. We describe a method based on Elasti...

Isolation of the pathogens Yersinia enterocolitica and Yersinia pseudotuberculosis from foods typically rely on slow (10–21 day) “cold enrichment” protocols before confirmed results are obtained. We describe an approach that yields results in 39 h that combines an alternative enrichment method with culture on a non-selective medium, and subsequent...

Although at least two genetically distinct groups, or genomospecies, have been well documented for Campylobacter concisus, no phenotype has yet been identified for their differentiation and thus formal description as separate species. C. concisus has been isolated from a variety of sites in the human body, including saliva and stool samples from bo...

This study isolated lactic acid bacteria from commercially available probiotic foods to determine their capacity to remove aflatoxin B 1 (AFB 1 ) and trichothecene-2 (T-2). The removal rates by original live and heat-treated cells of lactic acid bacteria (LAB) were compared to test the effect of heat treatment on efficacy. LAB is capable to remove...

Strains identified as Campylobacter concisus may belong to one of at least two biochemically indistinguishable, but genomically distinct, groups referred to as “genomospecies” that may differ in their pathogenic and zoonotic potential. Reliable, affordable and available identification methods are required to improve understanding of their significa...

A novel innovative viscoelastic gelling agent (novel gel, NG) has been developed by combining citric acid (CA) and disodium 5-guanylate (DG). NG has the potential to replace other gelling agents such as gelatine, which has been commonly used in foods, dietary supplements, pharmaceutical and cosmetic products including ointments and sprays. NG has u...

Fat-filled milk powders (FMP) are inexpensive milk alternatives predominantly exported to developing countries to satisfy growing demands for dairy proteins. Harsh climatic and sanitary conditions, poor border controls and relatively long periods for distribution and storage enhance the inherent vulnerability of FMP to fraud and stability. Rapid, l...

The gastrointestinal (GI) tract is crucial for food digestion and nutrient absorption in humans. However, the GI tract is usually challenged with oxidative stress that can be induced by various factors, such as exogenous pathogenic microorganisms and dietary alterations. As a part of gut microbiota, Lactobacillus spp. play an important role in modu...

Cows with specialised characteristics and requirements can be aggregated into different herds for targeted nutri-tional management and to facilitate on-farm segregation of raw milk for the production of high-value niche dairy products, offering improved economic returns. Rapid methods for independent verification of product quality and origin are d...

The proposal to restructure the genus Arcobacter into six distinct genera was critically examined using: comparative analyses of up to 80 Epsilonproteobacterial genome sequences (including 26 arcobacters); phylogenetic analyses of three housekeeping genes and also 342 core genes; and phenotypic criteria. Genome sequences were analysed with tools to...

Arcobacter anaerophilus was originally described as the first obligate anaerobe in this genus by Sasi Jyothsna et al. 2013. The complete genome sequence of the type strain of this species was determined and analysed. Genes characteristic for organisms capable of aerobic growth were identified, and the ability of the organism to grow under microaero...

The proliferation of antimicrobial resistance among bacteria is a major public health concern. Staphylococcus aureus is widespread in animals, the environment and humans, in which infections can be fatal. Certain agricultural practices have been linked to the proliferation of antimicrobial resistance traits among S. aureus strains, yet existing iso...

Fat-filled milk powders (FMP) are exported to tropical developing markets as inexpensive milk alternatives. Consequently, FMP are exposed to high temperature and humidity over long distribution and storage times, presenting challenges in preserving product quality and stability. Efficient and cost-effective methods for quality assurance under such...

Although MALDI-TOF mass spectrometric analysis has been applied to the characterization of yeast species important in winemaking, relatively few taxa have so far been examined, and the value of low mass peaks for identification has not, to our knowledge, been previously determined. We describe a modified (pre-mixing) procedure for extraction of low...

Skimmed milk powder can be blended with indigenous vegetable oils to formulate fat-filled milk powder (FMP) to satisfy the growing demand of low-income consumers for dairy proteins in the developing countries where food control systems may be fragmented. Unscrupulous manufacturers may adulterate FMP with melamine or urea to give the false impressio...

A wide range of Arcobacter species have been described from shellfish in various countries but their presence has not been investigated in Australasia, in which shellfish are a popular delicacy. Since several arcobacters are considered to be emerging pathogens, we undertook a small study to evaluate their presence in several different shellfish, in...

Bovine milk lipids can be replaced with cheaper indigenous vegetable oils to produce milk alternatives with healthier saturated/unsaturated fat balance for those in areas where milk supply is poor or even absent. A wide range of vegetable oils can be used, but their impacts when blended with skimmed milk powder to formulate filled milk powder (FMP)...

AIMS: To investigate the presence of Campylobacter spp. in captive kiwi (Apteryx spp.) and compare their genotypic profiles with those of human and animal origin, in order to assess their potential for zoonotic or zooanthroponotic transmission. METHODS: Conventional selective enrichment and filter-based isolation methods were applied to isolate Cam...

Ongoing changes in taxonomic methods, and in the rapid development of the taxonomic structure of species assigned to the Epsilonproteobacteria have lead the International Committee of Systematic Bacteriology Subcommittee on the Taxonomy of Campylobacter and Related Bacteria to discuss significant updates to previous minimal standards for describing...

We report the complete genome sequence of the Campylobacter concisus type strain ATCC 33237 and the draft genome sequences of eight additional well-characterized C. concisus strains. C. concisus has been shown to be a genetically heterogeneous species, and these nine genomes provide valuable information regarding the diversity within this taxon.

Estimates for the burden (number of cases) and cost of diarrhoeal foodborne illness (FBI) per year in Indonesia were calculated. Distinct data sources and models (derived from the World Health Organi-sation, and Indonesian sources) were used to cross-validate results from each analysis. For all cases, estimates of the burdens and costs of the foodb...

Campylobacter species are established as the most frequent bacterial cause of gastroenteritis in the world and are also important causes of other diseases of humans and animals. The taxonomy of the group has undergone remarkable change since inception; the genus currently contains 27 distinct species, many with distinct hosts and traits. This artic...

The emerging pathogen Campylobacter ureolyticus has been isolated from human and animal genital infections, human periodontal disease, domestic and food animals, and from cases of human gastroenteritis. We report the whole-genome sequence of the human clinical isolate RIGS 9880, which is the first closed genome for C. ureolyticus .

Cam.py.lo.bac.ter.a' ce.ae. M.L. masc. n. Campylobacter type genus of the family; suff. -aceae denoting family; M.L. masc. pl. n. Campylobacteraceae, the Campylobacter family. Proteobacteria / Epsilonproteobacteria / Campylobacterales / Campylobacteraceae

He . li . co . bac ' ter. Gr. n. helix a spiral; M.L. masc. n. bacter a staff; M.L. masc. n. Helicobacter a spiral rod. Proteobacteria / Epsilonproteobacteria / Campylobacterales / Helicobacteraceae / Helicobacter Cells may be curved, spiral, or fusiform rods , 0.2–1.2 × 1.5–10.0 µm. Spiral cells may be tightly or loosely wound depending on the spe...

Cam.py' lo.bac.ter . Gr. adj. campylo curved; Gr. n. bacter rod; M.L. masc. n. Campylobacter a curved rod. Proteobacteria / Epsilonproteobacteria / Campylobacterales / Campylobacteraceae / Campylobacter Cells of most species are slender, spirally curved rods , 0.2–0.8 × 0.5–5 µm; cells of some species are predominantly curved or straight rods. The...

Ar' co.bac.ter . L. n. arcus bow; Gr. n. bacter rod; M.L. masc. n. Arcobacter a curved rod. Proteobacteria / Epsilonproteobacteria / Campylobacterales / Campylobacteraceae / Arcobacter Cells are slender, curved rods , 0.2–0.9 × 0.5–3 µm long; S‐shaped or helical cells are often present. Nonsporeforming. Cells in old cultures may form spherical or c...

A proteome map of the foodborne pathogen Campylobacter jejuni NCTC11168 was analyzed using a state-of-the-art gel-free proteomic approach for the first time. A whole cell protein extract was prepared from the C. jejuni strain NCTC11168 grown in brain heart infusion (BHI) broth at 42 o C under microaerobic conditions. A gel-free technique using isob...

The Campylobacteraceae is the largest and most diverse family in the phylogenetically distinct Epsilonproteobacteria, presently comprising the genera Campylobacter (30 taxa), Arcobacter (17 taxa), and Sulfurospirillum (7 taxa). Individual species may be able to grow in microaerobic, anaerobic, and/or aerobic conditions, in temperatures from 25 °C t...

Escherichia coli O157:H7 causes serious foodborne infections warranting the development of effective control measures. One control option is to use bacteriophages (phages), which are regarded as safe to humans and an environmentally friendly alternative to chemical antimicrobials. One of the few remaining safety concerns is the potential for phages...

Campylobacteriosis is the most commonly reported form of human bacterial gastroenteritis in the world. Sound identification of infectious sources requires subtyping, but the most widely used methods have turnaround times measured in days and require specialist equipment and skills. A multiplex ligation-dependent probe amplification-binary typing (M...

A previously described phage infecting Escherichia coli O157:H7 was added to raw and cooked beef pieces at concentrations ranging from 101–108 plaque forming units/cm2 to either low (<100 CFU/cm2) or high (104 CFU/cm2) concentrations of host bacterial cells. Incubation for up to 24 h was performed at 5℃ and 24℃ to simulate refrigerated and room tem...

Campylobacter species are widely regarded as the most frequent bacterial cause of gastroenteritis in humans worldwide. Their main transmission routes are via contaminated food and water. For interventions to be effective, methods for the detection, identification and epidemiological subtyping must be sensitive, accurate and rapid. As yet, methods a...

Amplified Fragment Length Polymorphism (AFLP) profiling was used to evaluate the distribution of phenotypically indistinguishable, but genetically distinct, among Campylobacter concisus strains from South Africa. A Polymerase Chain Reaction (PCR) assay described for identifying strains belonging to Genomospecies 1 and 2 was applied in this study. F...

A PCR-Denaturing Gradient Gel Electrophoresis (PCR-DGGE) method was used to examine 50 stool samples from children in Belgium with gastroenteritis for an extensive range of Epsilonproteobacteria species. During the 3 month study period, Campylobacter concisus was the most common species. Our observations suggest that C. concisus displays similar mi...

We re-examined the sensitivity and specificity of 31 PCR assays (including four commercially available and developed in-house methods) for the identification of Campylobacter species, with particular reference to taxa described since 2004, which are closely related to C. jejuni and C. coli, the pathogenic species of most interest. Each of the assay...

SUMMARY Pulsed-field gel electrophoresis genotypes of Campylobacter isolates from 603 human patients were compared with 485 isolates from retail offal (primarily chicken and lamb) to identify temporal clusters and possible sources of campylobacteriosis. Detailed epidemiological information was collected from 364 of the patients, and when combined w...

The genus Campylobacter contains pathogens causing a wide range of diseases, targeting both humans and animals. Among them, the Campylobacter fetus subspecies fetus and venerealis deserve special attention, as they are the etiological agents of human bacterial gastroenteritis and bovine genital campylobacteriosis, respectively. We compare the whole...

Multilocus sequence typing (MLST) systems have been reported previously for multiple food- and food animal-associated Campylobacter species (e.g., C. jejuni, C. coli, C. lari, and C. fetus) to both differentiate strains and identify clonal lineages. These MLST methods focused primarily on campylobacters of human clinical (e.g., C. jejuni) or veteri...

Campylobacter strains typed in this study.

Using PCR-denaturing gradient gel electrophoresis, we examined 49 fecal samples from healthy volunteers and 128 diarrhea specimens to assess the distribution of Epsilonproteobacteria that might be routinely overlooked. Our results suggest that certain taxa that are not routinely examined for could account for a proportion of diarrhea of previously...

Pulsed-field gel electrophoresis (PFGE) analysis demonstrated that while 76% of patients had only one genotype of campylobacter, 10% carried two different but related genotypes (Dice coefficients > 0.78), and 14% carried at least two unrelated genotypes (Dice coefficients < 0.65). This supports the clustering of Campylobacter isolates with similar...

To study the occurrence and spatial distribution of Shiga toxin-producing Escherichia coli (STEC) O157 in calves less than 1-week-old (bobby calves) born on dairy farms in the North Island of New Zealand, and to determine the association of concentration of IgG in serum, carcass weight, gender and breed with occurrence of E. coli O157 in these calv...

Minute 3. Agenda. The proposed agenda was approved. Minute 4. Minutes of the previous meeting. The minutes of the meeting held in Rotterdam, the Netherlands, in 2007 were approved. Minute 5. Matters arising from the previous meeting. (i) ATCC type strain of Helicobacter cinaedi. Strain ATCC 35683, described as H. cinaedi, was actually Helicobacter...

Shiga toxin-producing Escherichia coli (STEC) is a zoonotic pathogen that causes diarrheal disease in humans and is of public health concern because of its ability to cause outbreaks and severe disease such as hemorrhagic colitis or hemolytic-uremic syndrome. More than 400 serotypes of STEC have been implicated in outbreaks and sporadic human disea...

Background Campylobacter is the most common bacterial cause of gastro-intestinal disease worldwide with consumption of contaminated food or water typically being cited as principal sources of infection. Aims To inform the efforts of the EC-funded MoniQA project team investigating the harmonization and standardization of analytical methods for foods...

In the course of a longitudinal study elucidating the dynamics of Arcobacter populations in pigs, 16 isolates of Gram-reaction-negative, rod-shaped, slightly curved, non-spore-forming bacteria were grouped by amplified fragment length polymorphism analysis into a distinct phenon within the genus Arcobacter. Fragments were generated for all isolates...

To overcome some of the deficiencies with current molecular typing schema for Campylobacter spp., we developed a prototype PCR binary typing (P-BIT) approach. We investigated the distribution of 68 gene targets in 58 Campylobacter jejuni strains, one Campylobacter lari strain, and two Campylobacter coli strains for this purpose. Gene targets were s...

Arcobacter allele numbers and sequence types. List of allele numbers and sequence types for the 374 arcobacters typed in this study. For each strain, the source and geographic origin is provided (if known).

Primers for amplification and sequencing of the seven Arcobacter spp. MLST genes. Primer pairs used for amplifying the MLST loci of A. butzleri, A. cryaerophilus, A. skirrowii, A. cibarius and A. thereius are listed. For each MLST locus, the allele size is given and for each primer pair the expected amplicon size is provided.

Six Gram-stain-negative, spiral-shaped, microaerobic isolates were obtained during a sampling from wild birds in the sub-Antarctic region. Based on initial observations, these isolates were classified as Campylobacter lari-like. The isolates were further characterized by whole-cell protein and amplified fragment length polymorphism (AFLP) analysis,...

Arcobacter spp. are a common contaminant of food and water, and some species, primarily A. butzleri and A. cryaerophilus, have been isolated increasingly from human diarrheal stool samples. Here, we describe the first Arcobacter multilocus sequence typing (MLST) method for A. butzleri, A. cryaerophilus, A. skirrowii, A. cibarius and A. thereius. A...

During a study of the prevalence of Campylobacter jejuni in black-headed gulls (Larus ridibundus) in Sweden, three isolates, strains LMG 24379, LMG 24380T and LMG 24381, were initially identified as Campylobacter lari. Further characterization by both AFLP and whole-cell protein SDS-PAGE analyses revealed that they formed a distinct group in the ge...

During a Danish study on the prevalence of campylobacteria in pig abortions and food of animal origin, eight Gram-negative, slightly curved, rod-shaped, non-spore-forming bacteria were clustered by using amplified fragment length polymorphism analysis in a distinct phenon within the genus Arcobacter. In the present study, numerical analysis of whol...

A polyphasic study was undertaken to clarify the taxonomic position of Campylobacter lari-like strains isolated from shellfish and humans. The diversity within the strain collection was initially screened by means of fluorescent amplified fragment length polymorphism analysis and whole-cell protein electrophoresis, revealing the existence of two cl...