Ilam, New Zealand
Ilam, New Zealand

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Fernandez M.,Institute Productos Lacteos Of Asturias | Hudson J.A.,Christchurch Science Center | Hudson J.A.,UK Environment Agency | Korpela R.,University of Helsinki | De Los Reyes-Gavilan C.G.,Institute Productos Lacteos Of Asturias
BioMed Research International | Year: 2015

Fermented dairy products provide nutrients in our diet, some of which are produced by the action of microorganisms during fermentation. These products can be populated by a diverse microbiota that impacts the organoleptic and physicochemical characteristics foods as well as human health. Acidification is carried out by starter lactic acid bacteria (LAB) whereas other LAB, moulds, and yeasts become dominant during ripening and contribute to the development of aroma and texture in dairy products. Probiotics are generally part of the nonstarter microbiota, and their use has been extended in recent years. Fermented dairy products can contain beneficial compounds, which are produced by the metabolic activity of their microbiota (vitamins, conjugated linoleic acid, bioactive peptides, and gamma-aminobutyric acid, among others). Some microorganisms can also release toxic compounds, the most notorious being biogenic amines and aflatoxins. Though generally considered safe, fermented dairy products can be contaminated by pathogens. If proliferation occurs during manufacture or storage, they can cause sporadic cases or outbreaks of disease. This paper provides an overview on the current state of different aspects of the research on microorganisms present in dairy products in the light of their positive or negative impact on human health. © 2015 María Fernández et al.


Ali A.,Federal University of Minas Gerais | Soares S.C.,Federal University of Minas Gerais | Santos A.R.,Federal University of Minas Gerais | Guimaraes L.C.,Federal University of Minas Gerais | And 14 more authors.
Gene | Year: 2012

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 genomes of both subspecies to get insights into genomic architecture, phylogenetic relationships, genome conservation and core virulence factors. Pan-genomic approach was applied to identify the core- and pan-genome for both C. fetus subspecies and members of the genus. The C. fetus subspecies conserved (76%) proteome were then analyzed for their subcellular localization and protein functions in biological processes. Furthermore, with pathogenomic strategies, unique candidate regions in the genomes and several potential core-virulence factors were identified. The potential candidate factors identified for attenuation and/or subunit vaccine development against C. fetus subspecies contain: nucleoside diphosphate kinase (Ndk), type IV secretion systems (T4SS), outer membrane proteins (OMP), substrate binding proteins CjaA and CjaC, surface array proteins, sap gene, and cytolethal distending toxin (CDT). Significantly, many of those genes were found in genomic regions with signals of horizontal gene transfer and, therefore, predicted as putative pathogenicity islands. We found CRISPR loci and dam genes in an island specific for C. fetus subsp. fetus, and T4SS and sap genes in an island specific for C. fetus subsp. venerealis. The genomic variations and potential core and unique virulence factors characterized in this study would lead to better insight into the species virulence and to more efficient use of the candidates for antibiotic, drug and vaccine development. © 2012 Elsevier B.V.


Wardle D.A.,Swedish University of Agricultural Sciences | Wardle D.A.,Landcare Research | Karl B.J.,Landcare Research | Beggs J.R.,University of Auckland | And 3 more authors.
Biological Invasions | Year: 2010

Relatively few studies have considered how aboveground invasive consumers influence decomposer communities. We investigated the potential effects of three types of animals on the decomposer subsystem in a floristically simple New Zealand Nothofagus forest. These animals are the native beech honeydew scale insect (Ultracoelostoma spp.) that secretes large amounts of sugar-rich honeydew that washes to the soil, invasive social wasps (Vespula spp.) that remove honeydew and prevent it from reaching the ground, and invasive rodents (the house mouse (Mus musculus) and ship rat (Rattus rattus)) that are predators of litter invertebrates. We performed a 4 years manipulative experiment involving addition of synthetic honeydew to the soil surface at amounts equal to that washed to the soil both in the absence and presence of wasps. All treatments were subjected to both exclusion and non-exclusion of rodents. Full honeydew addition influenced several components of the belowground community (both positively and negatively), and promoted fungi and fungal feeding fauna at the expense of bacteria and bacterial-feeders. The reduced addition of honeydew (representing effects of wasps) reversed some (but not all) effects of full honeydew addition. Rodents also influenced some belowground organisms, often reversing the effects of honeydew addition. The honeydew levels simulating wasp effects and the presence of rodents both greatly promoted humus carbon and nutrient storage relative to all other treatments, highlighting that invaders can alter soil carbon sequestration and nutrient capital. Our study points to invasive animals modifying the effects of a native animal on multiple components of the decomposer subsystem. © 2009 Springer Science+Business Media B.V.


Hudson J.A.,Christchurch Science Center | Billington C.,Christchurch Science Center | Premaratne A.,Christchurch Science Center | On S.L.W.,Christchurch Science Center
Food Science and Technology International | Year: 2016

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 to facilitate genetic exchange between bacteria so resulting in undesirable mobilisation of genes. UV treatment of phages causes a rapid loss in their ability to replicate, while maintaining their antibacterial activity, and so the use of UV-treated phages could be an alternative to the use of viable phages. Data presented here show the inactivation of E. Coli O157:H7 by UV-treated phages in milk and on the surface of raw and cooked meat. A minimum concentration of approximately 105 PFU cmâ∼'2 (pre-UV treatment titre) of UV-treated phages was required before inactivation of E. Coli O157:H7 on the surface of meat was measurable, and 1-2 log10 CFU cmâ∼'2 reductions were typically obtained at concentrations of around 107 UV-treated phages cmâ∼'2 (pre-UV treatment titre). Inactivation of E. Coli O157:H7 by UV-treated phages was less than that for untreated phages. The production of UV-treated phages was not optimised and it is possible that better reductions in pathogen concentration could be achieved for the same input UV-treated phages concentrations. © 2015 The Author(s).


PubMed | Christchurch Science Center
Type: Comparative Study | Journal: The New Zealand medical journal | Year: 2010

To describe and quantify laboratory testing of faecal samples for enteric pathogens as a component of the reporting pyramid of acute gastrointestinal illness (AGI) in New Zealand.Postal survey of community and hospital laboratories throughout New Zealand conducted in mid-2006, requesting data from the 2005 calendar year.Of the 47 laboratories eligible for the survey, responses were received from 35 (74%, 16 hospital laboratories, 12 community laboratories, five hospital and community laboratories, and two Public Health Laboratories). Based on survey data and extrapolation it was estimated that approximately 250,000 faecal samples were received by New Zealand laboratories in 2005. The majority of these (77%) were requested by primary healthcare providers on people in the community. Routine testing of these samples would include bacteria (Salmonella, Shigella, Campylobacter, Yersinia) and parasites (Cryptosporidium, Giardia) and (depending principally on the age of the patient) rotavirus. Testing for other pathogens was comparatively infrequent. The frequency of detection of a pathogen in community samples was estimated as approximately 20%.The positivity rate of 20% for faecal samples from people in the community is consistent with overseas results. Although there was considerable variation in the testing methods employed by the laboratories the methods were considered appropriate based on consultation with ESR Public Health and Reference Laboratory staff. These data on the number and type of samples, and positivity rate , will assist in the determination of a reporting pyramid for AGI in New Zealand.


PubMed | Christchurch Science Center
Type: Journal Article | Journal: Food science and technology international = Ciencia y tecnologia de los alimentos internacional | Year: 2015

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 to facilitate genetic exchange between bacteria so resulting in undesirable mobilisation of genes. UV treatment of phages causes a rapid loss in their ability to replicate, while maintaining their antibacterial activity, and so the use of UV-treated phages could be an alternative to the use of viable phages. Data presented here show the inactivation of E. coli O157:H7 by UV-treated phages in milk and on the surface of raw and cooked meat. A minimum concentration of approximately 10(5) PFU cm(-2) (pre-UV treatment titre) of UV-treated phages was required before inactivation of E. coli O157:H7 on the surface of meat was measurable, and 1-2 log10 CFUcm(-2) reductions were typically obtained at concentrations of around 10(7) UV-treated phages cm(-2) (pre-UV treatment titre). Inactivation of E. coli O157:H7 by UV-treated phages was less than that for untreated phages. The production of UV-treated phages was not optimised and it is possible that better reductions in pathogen concentration could be achieved for the same input UV-treated phages concentrations.

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