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1.
Le Bars H Le Gall-David S Renoux VM Bonnaure-Mallet M Jolivet-Gougeon A Bousarghin L 《Veterinary microbiology》2012,159(1-2):99-106
In this study, we investigated adherence and motility of the hypermutator Salmonella enterica Heidelberg B182 bovine strain related to a 12bp deletion in mutS. This mutator phenotype was associated with increased adherence to epithelial cells and with high expression of fimA as shown by real-time RT-PCR. Motility studies showed that fliC were up-regulated in the B182 strain, while fljA and fljB were down-regulated. In order to determine if mutated mutS is implicated in this genes expression, isogenic strains, derived from a WT strain, containing the 12bp deletion in mutS (Δ12bpmutS) or an inactivated mutS (ΔmutS) were generated. Δ12bpmutS and ΔmutS strains showed a spontaneous mutation rate similar to the environmental strain B182, but exhibited lower adherence capacity and fimA expression. In contrast to the fimbriae genes, in Δ12bpmutS, fliC expression was up-regulated, but fljA and fljB expression were decreased, as in the B182 strain. Only fljB expression was increased in ΔmutS mutants. Taken together, our data suggest that mutS alteration does not influence fimbriae expression but can impact flagella genes. 相似文献
2.
Oualid Haddad Erwan Guyot Nicolas Marinval Fabien Chevalier Lo?c Maillard Latifa Gadi Christelle Laguillier-Morizot Olivier Oudar Angela Sutton Nathalie Charnaux Hanna Hlawaty 《Marine drugs》2015,13(11):6588-6608
Induction of angiogenesis is a potential treatment for chronic ischemia. Low molecular weight fucoidan (LMWF), the sulfated polysaccharide from brown seaweeds, has been shown to promote revascularization in a rat limb ischemia, increasing angiogenesis in vivo. We investigated the potential role of two heparan sulfate (HS) metabolism enzymes, exostosin-2 (EXT2) and heparanase (HPSE), and of two HS-membrane proteoglycans, syndecan-1 and -4 (SDC-1 and SDC-4), in LMWF induced angiogenesis. Our results showed that LMWF increases human vascular endothelial cell (HUVEC) migration and angiogenesis in vitro. We report that the expression and activity of the HS-degrading HPSE was increased after LMWF treatment. The phenotypic tests of LMWF-treated and EXT2- or HPSE-siRNA-transfected cells indicated that EXT2 or HPSE expression significantly affect the proangiogenic potential of LMWF. In addition, LMWF increased SDC-1, but decreased SDC-4 expressions. The effect of LMWF depends on SDC-4 expression. Silencing EXT2 or HPSE leads to an increased expression of SDC-4, providing the evidence that EXT2 and HPSE regulate the SDC-4 expression. Altogether, these data indicate that EXT2, HPSE, and SDC-4 are involved in the proangiogenic effects of LMWF, suggesting that the HS metabolism changes linked to LMWF-induced angiogenesis offer the opportunity for new therapeutic strategies of ischemic diseases. 相似文献
3.
This study aims to assess the ability of essential oils (EOs) to destroy Eimeria oocyst in vitro using microscopic counting and 273 nm absorbing material release. A screening for the ability of ten EOs to destroy Eimeria oocyst was carried out in liquid medium. Out of these ten, artemisia, tea tree, thyme and clove EOs were identified as being the most effective. The treatment of Eimeria oocyst with these EOs leads to their lysis as shown by the release of substances absorbing at 273 nm. These results were obtained after approximately three hours contact. Four EOs were proven to destroy Eimeria oocysts in a few hours at low concentration. This destructive effect is a consequence of their lysis. This work is a preliminary contribution aiming to develop a new generation of natural efficient agents for destroying Eimeria oocyst to fight coccidiosis in broiler chicken. 相似文献
4.
Chebil L Anthoni J Humeau C Gerardin C Engasser JM Ghoul M 《Journal of agricultural and food chemistry》2007,55(23):9496-9502
The conversion yield at equilibrium, the initial rate, and the regioselectivity of the enzymatic acetylation of aglycone flavonoids (quercetin, naringenin, hesperetin, and chrysin) were investigated and compared to those obtained with a glycosylated one (isoquercitrin). The effects of a wide range of operating conditions were quantified. Fourier transform infrared spectrometry (FT-IR), NMR, and high performance liquid chromatography electrospray ionization mass spectrometry (HPLC-ESI-MS) analyses showed that for glycosylated flavonoids, in the presence of Candida antarctica (CAL-B), the acetylation occurred on the 2'-OH, 3'-OH, and 6'-OH of the glucose part, while with Pseudomonas cepacea lipase (PSL-C) acetylation takes place on 6'-OH of the sugar and 4'-OH of the B-ring. For aglycone flavonoids, the acetylation occurred only with PSL-C on 4'-OH, 3'-OH, and 7-OH hydroxyls. The conversion yield and the number and the relative proportions of the synthesized products were found dependent on the nature of the enzyme, the molar ratio, and the flavonoid structure. The initial rate was affected only by the origin of the enzyme. 相似文献
5.
Chérif N Thiéry R Castric J Biacchesi S Brémont M Thabti F Limem L Hammami S 《Veterinary research communications》2009,33(4):345-353
Viruses belonging to the Nodaviridae family cause disease worldwide among a large number of species of marine fish, and have
been described in all continents. In the present study, a total of 69 farmed Tunisian sea bass (Dicentrarchus labrax) and
24 sea bream (Sparus aurata) samples were tested monthly for the detection of betanodavirus. The virus was identified in both
species using indirect immunofluorescence assays (IFAT) and RT-PCR. In addition sequence analysis of part of the coat protein
gene indicated that both species were infected by highly related, but distinct, strains belonging to the RGNNV genotype. The
sequence of the coat protein gene of several strains was identical but up to 9 different sequences were detected in a single
farm. In addition, viral sequences obtained from fish that were held at lower temperature (<20°C) were distinct from the rest
of the sequences. 相似文献
6.
N. Lassoued M. Rekik S. Khenissi A. Merai 《Journal of animal physiology and animal nutrition》2014,98(4):686-692
This study aimed to investigate monthly changes in oestrus and ovulatory activity of Sicilo‐Sarde sheep. Experimental animals comprised 25 adult and 10 maiden ewes at the start of the experiment. For 12 consecutive months (September–August), the females were exposed to natural photoperiod and permanently kept in presence of seven aproned rams. Oestrus was checked daily and ovarian activity was monitored by monthly endoscopies during the last week of each month. Ovulation rate for a particular month was assessed as the sum of corpora lutea or corpora albicans present on both ovaries at the time of endoscopy. Proportions of ewes observed in oestrus at least once a month were lowest in March (24.3%) and highest in June and October (100%). They tended (p < 0.06) to be different according to age, dropping during summer from a common value of 100% in June to 85.7% and 90% in July and then to 57.1% and 70% in August for, respectively, the Adults and Maiden females. Overall, the experimental period, 92.5% and 83.8% of Adult and Maiden ewes ovulated at least once per month (p < 0.01) respectively. Least proportions ovulating, attained 60% and 30% in April for, respectively, Adult and Maiden ewes before peaking up at 100% again in May (p < 0.05). Mean (±SD) ovulation rate of Sicilo‐Sarde sheep is 1.40 ± 0.503. Adult females had a higher (p < 0.001) ovulation rate than Maiden sheep with respective average values of 1.51 ± 0.516 and 1.16 ± 0.373. It varied little between months and decreased in Adults from a maximum value of 1.95 in October to a minimum value of 1.16 in April. It is concluded that benchmarking seasonal variations of reproductive activity in Sicilo‐Sarde breed would be valuable in designing improved management calendars for this breed. 相似文献
7.
Physicochemical characterization of 82 Algerian honeys, collected between 2005 and 2010, from different botanical and geographical origins were analyzed. The studied parameters were： water content, pH, free acidity （FA）, electrical conductivity （EC）, ash content, hydroxymethylfurfuraldehyde （HMF）, proline content, specific rotatory power and color. Most of the measured parameters had showed values in the range of the international standards, with a particular richness in proline and ash content. Chemometrics-based approach reveals that the discriminated groups were Citrus, Ziziphus and forest even with over represented groups like Eucalyptus. Principle component analysis （PCA） enabled to extract three principal components explaining nearly 65% of total variance, PCj and PC2 were related to botanical origin whereas PC3 to honey age. Analysis of variance showed that the studied variables were almost different depending on botanical, geographical origin and season. The current study also shows the presence of diverse honey varieties in Algeria. The collected data will contribute to the creation of products with protected geographical or/and botanical origins. 相似文献
8.
A reproducible procedure was developed for genetic transformation of Hydrangea macrophylla Ser. cv. Blaumeise by Agrobacterium tumefaciens following the development of an efficient regeneration system using leaf discs excised from 12 to 15 weeks old meristem-derived vitroplants. Explants were cultivated on solid B5 medium complemented with maltose 110 mM, BAP 10 μM and NAA 0.5 μM. A low light regime of 17 μmol m−2 s−1 improved regeneration frequency up to 86%. For transformation, leaf discs were inoculated and co-cultivated with two disarmed A. tumefaciens strains, EHA 101 and LBA 4404, both carrying the binary vector pFAJ3000 which contained the nptII selectable gene and the GUS reporter gene. A pre-culture period of 3 days and a short co-cultivation duration (1 day) improved the efficiency of transformation. Inoculation of only 10 min with agitation including (or not) vacuum infiltration was sufficient. If selection on kanamycin containing medium was applied after a 2 weeks culture period on shoot regeneration medium, the percentage of explants forming kanamycin-resistant shoots increased from 3.3 to 13.3%. Integration and expression of the introduced transgene were confirmed by histochemical GUS assay, PCR and Southern blot analysis. Flowering of transgenic plants in glasshouse occurred 10 months after acclimatization. 相似文献
9.
Emna Ayari-Fakhfakh Abdeljelil Ghram Ali Bouattour Imen Larbi Latifa Griba-Dridi Olivier Kwiatek Michle Bouloy Genevive Libeau Emmanuel Albina Catherine Cêtre-Sossah 《Veterinary journal (London, England : 1997)》2011,187(3):402-404
This study, carried out between September 2006 and January 2007, is the first cross-sectional serological investigation of peste-des-petits-ruminants (PPR) and Rift Valley fever (RVF) in Tunisia. The objective was to assess the potential need to develop a dual, recombinant PPR–RVF vaccine and how such a vaccine might be utilised in Tunisia. An overall PPR seroprevalence of 7.45% was determined, a finding supported by the high specificity (99.4%) and sensitivity (94.5%) of the ELISA used. On assessment of the diversity and density of mosquitoes in the sampling area, four species of RVF-vectors of the genus Aedes and Culex were identified. However, no serological evidence of RVF was found despite the use of a highly sensitive ELISA (99–100%). Larger scale investigations are underway to confirm these findings and the continuation of the emergency vaccination program against these two diseases remains valid. 相似文献