Comparison of antimicrobial resistance of Campylobacter jejuni isolated from humans, chickens, raw milk, and environmental water in Québec

This study compares the occurrence of antimicrobial resistance to erythromycin, ciprofloxacin, and tetracycline among 384 Campylobacter jejuni isolates from humans (245), fresh whole retail chickens (56), raw milk (33), and environmental water (41) collected between 2000 and 2003 in Québec, Canada. Resistance to ciprofloxacin was significantly more frequent in human isolates acquired abroad than in those acquired locally (50 versus 5.9%; P < 0.001); ciprofloxacin resistance was almost absent in water, chicken, and raw milk isolates. In contrast, resistance to erythromycin was significantly more common in chicken than in locally acquired human isolates (16 versus 3.0%, respectively; P < 0.001); no erythromycin resistance was found among water, raw milk, and human isolates acquired abroad. Resistance to tetracycline was significantly more common in chicken and human isolates acquired locally (58.9 and 45.8%, respectively) than in raw milk and water isolates (9.1 and 7.3%, respectively, P < 0.001). Tetracycline resistance was also observed in 44.4% of human isolates acquired abroad. No human isolate was resistant to both ciprofloxacin and erythromycin, but one chicken isolate was resistant to all three antimicrobial agents. Our results suggest that from 2000 to 2003 in Québec, antimicrobial resistance remained stable among locally acquired C. jejuni human clinical isolates and might even have decreased. However, the high erythromycin resistance rate observed among chicken isolates is concerning because of the risk of transmission of such isolates to humans. Additional studies are needed to monitor trends in antimicrobial resistance among food, environment, and human C. jejuni isolates as well as antibiotic use in animals.     

Campylobacter jejuni infection during pregnancy: long-term consequences of associated bacteremia, Guillain-Barré syndrome, and reactive arthritist

Campylobacter jejuni infections are the main cause of foodborne gastroenteritis in the United States and other developed countries. Generally, C. jejuni infections are self-limiting and treatment is not necessary; however, infections caused by this organism can lead to potentially dangerous long-term consequences for some individuals. Bacteremia, Guillain-Barré syndrome (GBS; an acute flaccid paralytic disease), and reactive arthritis (ReA) are the most serious of the long-term consequences of C. jejuni infections. During pregnancy, foodborne infections may be hazardous to both the woman and the fetus. C. jejuni-induced bacteremia during pregnancy may lead to intrauterine infection of the fetus, abortion, stillbirth, or early neonatal death. Infection of a newborn by the mother during the birth process or shortly after birth may lead to neonatal enteritis, bacteremia, and/or meningitis. C. jejuni enteritis is the inducing antecedent infection in approximately 30% of cases of GBS. Thus, pregnant women infected with C. jejuni may contract GBS. GBS during pregnancy does not affect fetal or infant development and does not increase spontaneous abortion or fetal death; however, it may induce spontaneous delivery during the third trimester in severe cases. Reactive arthritis occurs in approximately 2% of C. jejuni enteritis cases and leads to the impaired movement of various joints. Pregnant women with C. jejuni-induced reactive arthritis can be expected to deliver a normal infant. A pregnant patient with GBS or ReA may be unable to care for a newborn infant because of the physical impairment induced by these diseases. Since C. jejuni infections put both fetuses and pregnant women at risk, pregnant women must take special care in food handling and preparation to prevent such infections.     

Mites in spice and medicinal dehydrated plants stored in bulk in the metropolitan area of São Paulo

Mites can occur in large numbers in storage units, causing serious economic damage to stored products, as well as health problems such as asthma, diarrhea, acute enteritis, and allergic reactions. In Brazil, spice and medicinal dehydrated plants are widely sold in bulk, but almost nothing is known about mite infestations. Thus, the objective of this research was to evaluate the diversity and relative abundance of mites in samples of Coriandrum sativum L., Pimpinella anisum L., Petroselinum sativum Hoffm., Matricaria chamomilla L., Baccharis trimera (Less) DC, Bixa orellana L., Senna alexandrina Mill., Origanum vulgare L., Ocimum basilicum L., Melissa officinalis L., Mentha piperita L., Rosmarinus officinalis L., Peumus boldus Molina, Salvia officinalis L., Thymus vulgaris L., Laurus nobilis L., Hibiscus sabdariffa L., Myristica fragans Houtt., Capsicum annuum L., and Curcuma longa L., collected from food retailers in the metropolitan area of São Paulo, Brazil, from October 2015 to March 2016. A total of 2584 mites, distributed into 13 families, were found in the samples of these dehydrated plants. The most abundant mite species (families) were: Tyrophagus putrescentiae (Schrank) (Acaridae) (84.6%), Cheyletus malaccensis Oudemans (Cheyletidae) (5.4%), Blattisocius tarsalis (Berlese) (Blattisociidae) (4.6%), Suidasia sp. (Astigmata: Suidasiidae) (3.2%), and Typhlodromus transvaalensis (Nesbitt) (Phytoseiidae) (1.4%). Other families (Glycyfagidae, Ameroseiidae, Bdellidae, Iolinidae, Raphignatidae, Stigmaeidae, Tydeidae) together represented less than 1.0% of the mites. T. transvaalensis is recorded for the first time in stored products in Brazil. Differences among the plant species in terms of diversity, frequency and abundance of mites were observed. Although there is a regulatory standard for good food production and service practices, the results of this study demonstrate that the bulk retail market for dehydrated plants has failed to control hygiene and quality, considering the relatively high mite infestations in most of the evaluated plant species.     

Determination of ochratoxin A in traditional Chinese medicinal plants by HPLC–FLD

Traditional Chinese medicinal plants (TCMPs), commonly used as spices, additives or foods, are also widely used in China to prevent and cure human disease. Due to their provenance, TCMPs may be contaminated by various fungal species, including ochratoxigenic fungi, during growth, collection, transportation and, especially, storage. A reliable method for the determination of ochratoxin A (OTA) in TCMPs of different origins was developed to monitor OTA levels in China. Analyses involved the extraction of OTA by methanol/water, immunoaffinity column (IAC) clean-up and HPLC quantification with fluorescence detection (FLD). Positive results were further confirmed by LC–ESI–MS/MS. The limit of detection (LOD) was 0.3 µg kg^?1, based on a signal-to-noise ratio of 3 : 1. Among the total of 57 TCMPs samples collected from six different areas, 31 were visibly moldy due to inappropriate storage; 26 sample, purchased from local TCMPs markets, were not visibly moldy. The results showed that 23 of the visibly moldy samples and two of the not visibly moldy were contaminated with OTA at levels ranging 1.2–158.7 and 2.5–5.6 µg kg^?1, respectively. This is the first report of the natural occurrence of OTA in TCMPs.     

N‐Carboxymethylchitosan: Uptake and effect on chlorophyll production,water potential and biomass in tomato plants

Uptake and effects of water solutions of N‐carboxymethylchitosan (NCMC) were determined in tomato plants under greenhouse conditions. Rapid uptake of NCMC occurred during the initial 12 hours of treatment and there was an increase of chlorophyl content in leaves of NCMC‐treated plants. However, neither the water potential nor the biomass of test plants was influenced by NCMC treatments.     

Carotenoid composition and retinol equivalent in plants of nutritional and medicinal importance: Efficacy of β-carotene from Chenopodiumalbum in retinol-deficient rats

This study aimed to (1) quantify carotenoids in leafy vegetables and plants of nutritional and medicinal importance, (2) evaluate retinol equivalent (RE) of provitamin-A carotenoids and (3) determine efficacy of β-carotene from Chenopodium album and to compare with retinol formed on feeding to retinol-deficient rats for 3 weeks. β-Carotene and lutein contents (mg/100 g dry weight) ranged from 1.5 to 120 and 11.7 to 185 (leafy greens) and 0.4 to 34.7 and 11.8 to 679 (medicinal plants) whereas, α-carotene ranged from 0.3 to 35.6 (leafy greens) and 0.1 to 15.7 (medicinal plants). RE values (mg%) ranged from 0.4 to 20 and 0.42 to 5.8 in leafy greens and medicinal plants. Efficacy of β-carotene (2400 μg/kg diet) from C. album in retinol-deficient rats revealed a 93.6% rise in plasma retinol levels from 0.53 to 8.4 μM. The plants analysed are a good source of retinol precursors and biologically active lutein; therefore can be exploited to meet carotenoid requirements.     

Volatile trans-2-hexenal, a soybean aldehyde, inhibits Aspergillus flavus growth and aflatoxin production in corn

Abstract: Trans‐2‐hexenal, a volatile aldehyde, is produced by soybean (Glycine max [L.] Merr) and other plants via the lipoxygenase pathway. In vitro tests showed it significantly (P < 0.001) reduced Aspergillus flavus germinating conidial viability at 10 μM, with approximately 95% viability reduction observed at 20 μM. The viability of nongerminated conidia was not reduced. To test the effectiveness of this volatile to prevent fungal growth in stored corn, trans‐2‐hexenal was pumped intermittently into glass jars containing corn. Experiments were performed to determine the ability of 2 different pump cycle time‐courses to prevent A. flavus growth on sterile corn (23% moisture). Intermittently (30‐min pumping period) over 7 d, this volatile was pumped through 350 g of corn kernels inoculated with 1 mL of 3 × 10⁴ conidia of A. flavus. Controls consisted of (1) sterile corn, (2) corn inoculated with A. flavus with no pumped air, and (3) corn inoculated with A. flavus with intermittently pumped air. Aflatoxin B₁ (AFB₁), viability counts, and aldehyde concentration in the headspace were performed in each experiment. To determine whether an increased time period between volatile pumping would prevent A. flavus growth, a 2nd series of experiments were performed that were similar to the 1st series except that trans‐2‐hexenal (only) was pumped for a 30‐min period every 12 h. Experiments were performed 3 times for each time course. Both experiments showed that intermittent pumping of volatile trans‐2‐hexenal significantly (P < 0.001) prevented A. flavus growth and aflatoxin B₁ production over a 7‐d period. Practical Application: Results from this study indicate that intermittent pumping of volatile trans‐2‐hexenal could be used to protect stored corn from A. flavus growth and aflatoxin contamination.     

Can plant phenolic compounds reduce Fusarium growth and mycotoxin production in cereals?

ABSTRACT

To assess the in vitro activity of three phenolic acids (ferulic acid, p-hydroxybenzoic acid, vanillic acid) and two flavonols (quercetin, rutin) on mycelial growth and mycotoxin accumulation of Fusarium graminearum (FG), F. langsethiae (FL) and F. poae (FP), two different approaches were chosen. First, grains from oat varieties were inoculated with a suspension of three FL isolates to determine the influence of phenolic compounds on the accumulation of mycotoxins. The oat variety Zorro showed a tendency for lower accumulation of T-2/HT-2, diacetoxyscirpenol and neosolaniol. Second, a mycelium growth assay was conducted to follow FG, FL and FP growth on cereal based media supplemented with phenolic compounds. Increasing concentrations of ferulic acid substantially inhibited growth of FG and FL, while FP growth was reduced to 57%. In contrast, p-hydroxybenzoic acid, vanillic acid, quercetin, and rutin slightly stimulated mycelium growth. Results about mycotoxin production in cereal based media were less conclusive.     

Saccharomyces cerevisiae strains and the reduction of Aspergillus parasiticus growth and aflatoxin B1 production at different interacting environmental conditions,in vitro

The effect of Saccharomyces cerevisiae RC008 and RC016, previously selected based on their aflatoxin B₁ binding ability and beneficial properties, against Aspergillus parasiticus under different interacting environmental conditions was evaluated. Studies concerning the lag phase, growth rate and aflatoxin B₁ production were carried out in vitro under different regimes of a _w (0.95 and 0.99), pH (4 and 6), temperature (25 and 37°C), and oxygen availability (normal and reduced). Both yeast strains showed great antagonistic activity at pH 4, decreasing growth rate compared with the control. The RC008 strain showed the greatest inhibitory activity at all assayed conditions. A. parasiticus produced large amounts of AFB₁ in vitro. A significant decrease of AFB₁ levels in comparison with the control were observed with yeast interaction. Differences between control and treatment values ranged from 130 to 5400?ng?ml^?1. S. cerevisiae RC008 and RC016 could be considered as effective agents in reducing growth and AFB₁ production at different interacting environmental conditions, related to that found in stored feedstuff. The importance of the present work lies in the search for live strains with both probiotic and biocontrol properties able to prolong the safe storage of feedstuff and exert beneficial properties after animal consumption and which could be included in a novel product for animal feed.     

Water vapor permeability,mechanical, and structural properties of edible β-casein films

Edible films were made using glycerol and β-casein that had been stored for 16 months at −29 and +22.5°C. Water vapor permeability at 22.5°C was determined for two relative humidity gradients. Stress–strain curves for mechanical property evaluation were obtained by dynamic mechanical analysis. Film structure was observed by scanning electron microscopy and Fourier transform infrared spectroscopy. Protein storage temperature did not significantly affect water vapor permeability, elongation, or observed structure; however, differences in yield strength, modulus of elasticity, and tensile strength were detected.     

Comparative study on the levels of carotenoids lutein,zeaxanthin and β-carotene in Indian spices of nutritional and medicinal importance

The carotenoid levels in Indian spices of nutritional and medicinal importance were determined using high performance liquid chromatography. Lutein (L) and zeaxanthin (Z) levels (mg/100 g dry wt) in curry leaves (27.34), spearmint (18.0), green chilli (13.74), coriander leaves (9.92) and mustard seeds (1.2) were higher (2–22-fold) than mace, anise seeds, onion, fenugreek seeds and carum seeds (0.62 and 0.85) whilst their levels in cumin seeds, black pepper, green cardamom and coriander seeds were in the range of 0.32–0.47. β-Carotene (mg/100 g dry wt) was higher in coriander leaves (67.5), green chilli (9.06), curry leaves (8.95) and spearmint (7.5) than black cardamom (0.22) and coriander seeds (0.22), respectively. Neoxanthin, violaxanthin and α-carotene levels were also discussed. Spices analysed are a better source of L + Z than β-carotene (except for coriander leaves). Usage of spices as an adjuvant in food preparations also provides L + Z as antioxidants.     

Statistical optimization,partial purification,and characterization of coffee pulp β-glucosidase and its application in ethanol production

Extracellular β-glucosidase was produced using coffee pulp as a sole carbon source by Penicillium verrucosum by solid state fermentation and 897.36±59 U/g enzyme activity was obtained. Increase in 2.21-fold of enzyme activity on optimizing the bioprocess parameters by response surface methodology based on central composite rotatable design is illustrated. Maximum production level of 1,991.17 U/g was obtained with optimum values of pH 4.2, moisture 66.8%, and fermentation duration of 56 h. The enzyme was partially purified and the enzyme activity was optimum at 50°C temperature and at pH 6. The metal ions such as Mg²⁺, Zn²⁺, Ca²⁺, K⁺, detergents, and chelator such as EDTA were effective and further increased the β-glucosidase activity. On application of β-glucosidase for simultaneous saccharifiation and fermentation, 3.3% ethanol was obtained. Thus, this study provides insight on exploitation of P. verrucosum for synthesis of of β-glucosidase using coffee pulp which is available abundantly in coffee processing industries.

     

Associations between immune competence,stress responsiveness,and production in Holstein-Friesian and Holstein-Friesian × Jersey heifers reared in a pasture-based production system in Australia

The objectives of this study were to assess antibody and cellular immune responses in first-lactation dairy heifers reared under a pasture-based production system and to investigate associations between immune competence and stress responsiveness, health, and productivity. A commercial vaccine was used to induce antibody and cellular immune responses and, based on measured responses, animals were classified as above average, average, and below average for each trait independently and in combination (overall immune competence). Overall immune competence phenotypic rankings were generated by combining standardized residual values for antibody and cellular responses measured in individual heifers. Cortisol responses to handling and yarding were used to assess stress responsiveness, worm egg counts were used to assess internal parasite burden, somatic cell counts to assess udder health and estimates of total daily milk volume, and milk fat and milk protein contents to assess productivity. A total of 393 Holstein-Friesian and Holstein-Friesian × Jersey crossbred heifers from 2 herds practicing seasonal calving in a pasture-fed production system were enrolled in the study. The immune competence phenotypes of individual heifers were assessed before their first mating and their subsequent performance during their first lactation was monitored. Animals with below-average antibody and cellular immune competence had higher serum cortisol concentrations compared with their counterparts following handling, suggesting they had a reduced ability to cope with management-induced stress. Furthermore, a significant negative (favorable) correlation was observed between antibody responses and stress responsiveness. Similarly, correlations between antibody responses and internal parasite burden were significant and negative (favorable). No correlations were observed between overall immune competence and milk yield, milk fat, and milk protein content.     

Saccharomyces cerevisiae strains and the reduction of Aspergillus parasiticus growth and aflatoxin B(1) production at different interacting environmental conditions, in vitro

The effect of Saccharomyces cerevisiae RC008 and RC016, previously selected based on their aflatoxin B(1) binding ability and beneficial properties, against Aspergillus parasiticus under different interacting environmental conditions was evaluated. Studies concerning the lag phase, growth rate and aflatoxin B(1) production were carried out in?vitro under different regimes of a (w) (0.95 and 0.99), pH (4 and 6), temperature (25 and 37°C), and oxygen availability (normal and reduced). Both yeast strains showed great antagonistic activity at pH 4, decreasing growth rate compared with the control. The RC008 strain showed the greatest inhibitory activity at all assayed conditions. A. parasiticus produced large amounts of AFB(1) in?vitro. A significant decrease of AFB(1) levels in comparison with the control were observed with yeast interaction. Differences between control and treatment values ranged from 130 to 5400?ng?ml(-1). S. cerevisiae RC008 and RC016 could be considered as effective agents in reducing growth and AFB(1) production at different interacting environmental conditions, related to that found in stored feedstuff. The importance of the present work lies in the search for live strains with both probiotic and biocontrol properties able to prolong the safe storage of feedstuff and exert beneficial properties after animal consumption and which could be included in a novel product for animal feed.     

Synergistic effect of fruit–seed mixed juice on inhibition of angiotensin I-converting enzyme and activation of NO production in EA.hy926 cells

Food Science and Biotechnology - Commonly consumed fruit juices possess low inhibitory activity of angiotensin I-converting enzyme (ACE), which plays central role in elevation of blood pressure....     

Effect of alternative C2 carbon sources on the growth, lipid, and γ-linolenic acid production of spirulina (Arthrospira platensis)

The influence of different organic carbon sources (glucose, ethanol, and acetic acid) at different concentrations (0.1, 0.5, and 1.0 g/L for batch and 1.0, 2.0, and 3.0 g/L for fed-batch) were studied in the mixotrophic production (using both light and carbon source) of γ-linolenic acid (GLnA) by spirulina (Arthrospira platensis). The obtained spirulina was analyzed in terms of biomass, lipid, and GLnA production. In the batch media, increasing the concentrations of glucose, ethanol, and acetic acid led to an increase in the biomass, lipid, and GLnA production. However, carbon sources at concentrations greater than 1.0 g/L in fed-batch media appeared to have no significant effects on the above parameters. It was also demonstrated that biomass, lipid, and GLnA production using ethanol and acetic acid could be as good as those achieved with the classic glucose-based culture media.     

Purification, characterization, and production of β-mannanase from Bacillus subtilis TJ-102 and its application in gluco-mannooligosaccharides preparation

A novel β-mannanase-producing strain, Bacillus subtilis TJ-102, was identified and characterized. Response surface method was applied to improving and enhancing the enzyme production. The optimized media components were obtained: 45.25 g/L konjac, 9.29 g/L Na₂HPO₄·12H₂O, 2.60 g/L CaCO₃, 1.0 g/L (NH₄)₂SO₄, 0.3 g/L KH₂PO₄, 1.0 g/L NaCl, 1.0 g/L MgCl₂·6H₂O, and 0.01 g/L FeSO₄. Under these conditions, the β-mannanase activity could achieve 205.3 U/mL in a 7-L fermentor. Then, β-mannanase was 7.39-fold purified by salting out, ultrafiltration, anion-exchange, and size-exclusion preparative chromatography with a recovery of 21.41 % and a specificity of 125.36 U/mg proteins. β-Mannanase was stable below 65 °C and pH 5.0–8.0, which exhibited excellently enzymatic efficiency in the preparation of gluco-mannooligosaccharides (GMOS) by hydrolyzing konjac flour. The GMOS yield of 57.76 % has been achieved with 8.71 % of mannose and 14.49 % of glucose, demonstrating the potential use of β-mannanase in food industry.     

Effect of milk protein composition and amount of β-casein on growth performance,gut hormones,and inflammatory cytokines in an in vivo piglet model

The objective of this work was to better understand the effect of differences in milk protein composition, and specifically, a change in β-casein to total casein in a milk-based matrix, on growth performance and metabolic and inflammatory responses using a piglet model. Three formulas were optimized for piglets, with similar metabolizable energy, total protein content, and other essential nutrients. Only the protein type and ratio varied between the treatments: the protein fraction of the control diet contained only whey proteins, whereas 2 other matrices contained a whey protein to casein ratio of 60:40, and differed in the amount of β-casein (12.5 and 17.1% of total protein). Piglets fed formula containing whey proteins and caseins, regardless of the concentration of β-casein, showed a significantly higher average daily gain, average daily feed intake, and feed efficiency compared with piglets consuming the formula with only whey protein. Consumption of the formula containing only whey protein showed higher levels of plasma glucagon-like peptide-1 and ghrelin compared with the consumption of formula containing casein and whey protein. A positive correlation was observed between postprandial time and glucagon-like peptide-1 response. The intestinal pro-inflammatory cytokine tumor necrosis factor α increased significantly in piglets fed the whey protein/casein diet compared with those fed whey protein formula. All formula-fed piglets showed a lower level of IL-6 cytokine compared with the ad libitum sow-fed piglets, regardless of composition. No significant differences in the anti-inflammatory IL-10 concentration were observed between treatment groups. Milk protein composition contributed to the regulation of piglets‘ metabolic and physiological responses, with whey protein/casein formula promoting growth performance and a different immune regulatory balance compared with a formula containing only whey protein. Results indicated no differences between treatments containing different levels of β-casein.