Infectious Chikungunya Virus in the Saliva of Mice,Monkeys and Humans

Chikungunya virus (CHIKV) is a reemerging, ordinarily mosquito-transmitted, alphavirus that occasionally produces hemorrhagic manifestations, such as nose bleed and bleeding gums, in human patients. Interferon response factor 3 and 7 deficient (IRF3/7^-/-) mice, which are deficient for interferon α/β responses, reliably develop hemorrhagic manifestations after CHIKV infection. Here we show that infectious virus was present in the oral cavity of CHIKV infected IRF3/7^-/- mice, likely due to hemorrhagic lesions in the olfactory epithelium that allow egress of infected blood into the nasal, and subsequently, oral cavities. In addition, IRF3/7^-/- mice were more susceptible to infection with CHIKV via intranasal and oral routes, with IRF3/7^-/- mice also able to transmit virus mouse-to-mouse without an arthropod vector. Cynomolgus macaques often show bleeding gums after CHIKV infection, and analysis of saliva from several infected monkeys also revealed the presence of viral RNA and infectious virus. Furthermore, saliva samples collected from several acute CHIKV patients with hemorrhagic manifestations were found to contain viral RNA and infectious virus. Oral fluids can therefore be infectious during acute CHIKV infections, likely due to hemorrhagic manifestations in the oral/nasal cavities.     

Antifungal properties of selected lactic acid bacteria and application in the biological control of ochratoxin A producing fungi during cocoa fermentation

Thirteen Lactic acid bacteria strains isolated from fermenting cocoa and seven reference strains were used in order to assess their antifungal properties towards three ochratoxin A (OTA) producing fungi (Aspergillus carbonarius, Aspergillus niger and Aspergillus ochraceus). Furthermore, two of the isolates strains (A19 and A21) identified as belonging to the genus of Pediococcus as well as Lactobacillus plantarum B4496, Lactobacillus brevis 207 and Lactobacillus sanfranciscensis BB12 showed interesting in vitro broad antifungal activities towards the three ochratoxin-producing fungi with inhibition percentages ranging from 15% to 66.7%. Treatment of cell-free supernatant at 100°C affected antifungal activity suggesting that the main compounds responsible for this activity were of proteic nature, and hence could be bacteriocins. Application of isolate A19 in cocoa fermentation as starter inhibited the growth of each of the OTA-producing species. At the end of fermentation in boxes inoculated with A19, A. niger was not detectable while A. carbonarius concentration was found to be 2 Log CFU/g of wet beans. The assessment of the ochratoxin produced during fermentation of cocoa inoculated with A. carbonarius indicated that the use of isolate A19 as starter could reduce their level of growth so as to have only a toxin production of 0.0012 ± 0.0005 μg/kg after 40 days of storage, while this was 2.45 ± 0.35 μg/kg of fermented and dried cocoa beans in the absence of A19. This work is a contribution for the application of biological control of OTA-producing fungi during cocoa production.     

Association Between Haptoglobin 2-2 Genotype and Coronary Artery Disease and Its Severity in a Tunisian Population

Haptoglobin (Hp) polymorphism generates three common human genotypes (Hp1-1, Hp2-1, and Hp2-2), having functional differences, related to the risk of development of cardiovascular diseases. These functions are a consequence of hemoglobin binding that leads to the synthesis of an antioxidant like ferritin. We explored the association of Hp polymorphism with significant coronary stenosis (SCS) and its severity within 400 Tunisian patients, using genotyping, biochemical parameters, and the Gensini score. After adjustments for age and gender, Hp2-2 was associated with the highest ferritin but the lowest Hp concentrations. After adjustments for confounding parameters, the OR of SCS associated with Hp2-2 was 1.74 (95% CI 1.18–2.58; p = 0.005). This effect was enhanced within diabetics (OR 1.90, 95% CI 1.11–3.24; p = 0.018), obese subjects (OR 1.98, 95% CI 1.10–4.86; p = 0.034), and smokers (OR 4.17, 95% CI 1.54–1.29; p = 0.005). The Hp2-2 genotype is associated with an increase in SCS especially in diabetics, the obese, and smokers.     

Inhibition of beet molasses alcoholic fermentation by lactobacilli

Summary Alcohol production rate decreases as the concentration of bacterial contaminants increases. In complex medium, such as beet molasses, an alternative mechanism can be used by homofermentative lactic bacteria (Lactobacillus casei). Lactic acid and associated products, especially acetic acid, are liberated into the medium. The inhibition induced by these metabolites was reinforced by the presence of viable lactobacilli. Offprint requests to: P. Villa     

Increased hexose transport in the roots of tomato plants submitted to prolonged hypoxia

We investigated the effects of prolonged hypoxia on the sugar uptake in tomato (Solanum lycopersicum L. var. MP-1) roots. Hydroponic cultures of whole tomato plants were submitted to hypoxic treatment for 1 week, and the roots were analyzed for sugar concentrations, hexose uptake and hexose transporter expression level. Contrary to what has been observed after anoxic shock or short-term hypoxic treatment, we show that sugar concentrations increase and hexose uptake is up-regulated in the roots after 1 week of hypoxic treatment. Increased hexose transport is concomitant with the induction of the hexose transporter gene LeHT2. These responses may be due either to a direct effect of low O₂ supply, or to a secondary effect associated with the increase in sugar concentrations, which, typically, develops in most hypoxic plants.     

Association of three polymorphisms of scavenger receptor class BI gene (exon8, exon1, intron5) with coronary stenosis in a coronary Tunisian population

Background

The potential role of scavenger receptor class BI (gene name SCARB1) in the regulation of lipoproteins metabolism and atherosclerosis has attracted considerable interest. We tested the relationship of SCARB1 polymorphisms with significant coronary stenosis (SCS) and lipid profile in a coronary Tunisian population.

Methods

Three SCARB1 polymorphisms (exon8 (C/T), exon1 (G/A), intron5 (C/T)) were studied in 316 Tunisian patients undergoing coronary angiography. SCS was defined as a luminal narrowing of ≥ 50% in at least one major coronary artery. Lipid profile was measured. Genotyping was performed using PCR–RFLP.

Results

Individuals with TT genotypes of exon8 were associated with higher concentrations of plasma HDL-C and ApoAI in the group without SCS. Carriers of T allele of exon8 were associated with 41% lower risk of SCS. This protective effect seemed to be particularly significant in women, nondiabetics and nonsmokers. Subjects homozygous for the variant allele of intron5 were significantly associated with an increased risk of SCS, particularly in smokers. AA genotype of exon1 was associated with an increased risk of SCS in diabetics and in patients with metabolic syndrome. The (CAT) haplotype was associated with increase in the risk of SCS compared to the wild haplotype and had a 4-fold greater risk of SCS than patients with haplotype (TGC) which seems to be the most protective against SCS.

Conclusion

Carriers of T allele of exon8 in SCARB1 seemed to increase HDL-C and ApoAI concentrations and reduce the risk of SCS. The intron5, exon1 and (CAT) haplotype seemed to have an atherogenic effect.     

Effect of hexokinase activity on tomato root metabolism during prolonged hypoxia

Hypoxically induced tolerance to anoxia in roots of tomato (Solanum lycopersicum) was previously shown to depend on sucrose and the induction of sucrose synthase. In contrast to maize, root hexokinase (HXK) activities did not increase during hypoxia and glucose was unable to sustain glycolytic flux under anoxia. In this paper, we asked whether hypoxic metabolism in roots would be altered in transgenic tomato plants overexpressing either a plant (Arabidopsis) or a yeast (Saccharomyces cerevisiae) HXK and whether such modifications could be related to improved energy metabolism and consequently root tolerance under anoxia. Tomato plants grown hydroponically with shoots always maintained in air were submitted to a 7 d hypoxic treatment applied by stopping air bubbling. A combination of techniques including (1)H-nuclear magnetic resonance spectroscopy, RT-PCR and enzyme analyses was used to obtain a broad picture of hypoxic root metabolism. In normoxic conditions, HXK overexpression resulted in higher ADP and AMP levels only in roots of AtHXK1 transgenic plants. During hypoxic treatment, oxygen levels in the hydroponic tank decreased rapidly to 5 kPa within the first 2 d and then remained at 5 kPa throughout the 7 d experiment. Oxygen levels were similar at 5 and 20 cm below the water surface. A decline of the adenylate energy status was observed after 2 d of hypoxic treatment, with a further decrease by 7 d in roots of non-transgenic (WT) and ScHXK2, but not in AtHXK1 transgenic plants. Sucrose synthase activity increased to comparably higher levels at 7 d of hypoxic treatment in WT and ScHXK2 compared with AtHXK1 roots. Differences between WT and the transgenic plants are discussed with respect to the metabolic response to low (hypoxia) but not zero (anoxia) oxygen.     

Alcoholic Fermentation of beet molasses: study on stillage recycle

Summary Stillage recycle in beet molasses alcoholic fermentation can be lower the production costs by a decrease of energy requirements for waste water treatment but it becomes necessary to optimise, separately, the sugar and non sugar contents of the wort. It is shown that the increase of the wort osmolality, linked to stillage recycle disturbs yeast metabolism above 1,5 osmol. The observed inhibition which is dependent on both sugar and non sugar concentrations leads to an apparent link between yeast behaviour and the dry matter percent of the worts.     

Transmission of elk and deer prions to transgenic mice

Chronic wasting disease (CWD) is a fatal prion disease in deer and elk. Unique among the prion diseases, it is transmitted among captive and free-ranging animals. To facilitate studies of the biology of CWD prions, we generated five lines of transgenic (Tg) mice expressing prion protein (PrP) from Rocky Mountain elk (Cervus elaphus nelsoni), denoted Tg(ElkPrP), and two lines of Tg mice expressing PrP common to white-tailed deer (Odocoileus virginianus) and mule deer (Odocoileus hemionus), denoted Tg(DePrP). None of the Tg(ElkPrP) or Tg(DePrP) mice exhibited spontaneous neurologic dysfunction at more than 600 days of age. Brain samples from CWD-positive elk, white-tailed deer, and mule deer produced disease in Tg(ElkPrP) mice between 180 and 200 days after inoculation and in Tg(DePrP) mice between 300 and 400 days. One of eight cervid brain inocula transmitted disease to Tg(MoPrP)4053 mice overexpressing wild-type mouse PrP-A in approximately 540 days. Neuropathologic analysis revealed abundant PrP amyloid plaques in the brains of ill mice. Brain homogenates from symptomatic Tg(ElkPrP) mice produced disease in 120 to 190 days in Tg(ElkPrP) mice. In contrast to the Tg(ElkPrP) and Tg(DePrP) mice, Tg mice overexpressing human, bovine, or ovine PrP did not develop prion disease after inoculation with CWD prions from among nine different isolates after >500 days. These findings suggest that CWD prions from elk, mule deer, and white-tailed deer can be readily transmitted among these three cervid species.     

Six lipoprotein lipase gene polymorphisms, lipid profile and coronary stenosis in a Tunisian population

Lipoprotein lipase (LPL) is the rate-limiting enzyme in the hydrolysis of triglyceride-rich lipoprotein particles (Chylomicrons and very-low-density lipoprotein). LPL polymorphisms' effects on lipids and coronary artery disease are controversial among studies and populations. Our aim was to study the association between six polymorphisms, haplotypes and significant coronary stenosis (SCS), disease severity and lipid parameters in Tunisian patients. LPL PvuII, 93 T/G, 188 G/E, HindIII, N291S and D9N polymorphisms were analyzed in 316 patients who underwent coronary angiography. Assessment of coronary angiograms identified SCS as the presence of stenosis >50?% in at least one major coronary artery. The stenosis severity was determined by using Gensini score and vessels number. A significant association of SCS with TT of the HindIII polymorphism was showed (odds ratio (OR): 2.84, 95?% CI, 1.19-7.40, p?=?0.017) and TG (OR: 1.77, 95?% CI, 1.99-2.82, p?=?0.033). The mutated HindIII genotype was significantly associated with increased TG and ApoB/ApoA-I ratio and with decreased HDL-C. Haplotype analysis showed that OR of SCS associated with the CTGTAG haplotype was 2.12 (95?% CI 1.05-4.25, p?=?0.032) and with CGGGAA was 0.71 (95?% CI 0.26-1.95, p?=?0.022) compared to the CTGTAA. Significant difference in Gensini score was observed among HindIII genotype and haplotypes. A significant association between the mutated genotype of HindIII polymorphism and decreased HDL-C level and increased ApoB/ApoA-I ratio and TG level was showed. Our results suggest that HindIII and D9N polymorphisms and CTGTAG haplotype seem to be considered as marker of predisposition to coronary stenosis. In another hand, HindIII and haplotypes were related to stenosis severity.