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The florfenicol/chloramphenicol resistance gene floR was found to be part of the novel 4,284-bp transposon TnfloR from Escherichia coli. TnfloR consists of the gene floR, a putative regulatory gene, and the transposase gene tnpA. A circular form of TnfloR was detected and suggested the potential mobility of this transposon.
The full chromosomal karyotype of six enological Saccharomyces cerevisiae strains used for fermentation and biological ageing of sherry-type wines was studied. A genetic method based on the analysis of segregation frequencies of auxotrophic markers, among random spore progeny of hybrids, constructed between laboratory and industrial wine strains (Bakalinsky and Snow, 1990) was used. This method was combined with the analysis of strains by pulsed-field gel electrophoresis. The results obtained clearly indicate the presence of two, three or four copies of a chromosome in the industrial strains examined, and thus confirm that aneuploidy/polyploidy is not uncommon in these strains. In all strains examined, chromosome XIII polysomy is observed. This chromosome contains the ADH2 and ADH3 loci, that code for the ADHII and ADHIII isoenzymes of alcohol dehydrogenase, which are involved in ethanol oxidative utilization during biological ageing of wines. Tetrad analysis for the 'flor formation' character suggest two possibilities: this character is either regulated by at least a digenic system, or by only one gene present on a chromosome which is, at least, disomic.
Multidrug resistance plasmids carrying the bla(CMY-2) gene have been identified in Salmonella enterica serovars Typhimurium and Newport from the United States. This gene confers decreased susceptibility to ceftriaxone, and is most often found in strains with concomitant resistance to ampicillin, chloramphenicol, streptomycin, sulfamethoxazole and tetracycline. The bla(CMY-2)-carrying plasmids studied here were shown to also carry the florfenicol resistance gene, floR, on a genetic structure previously identified in Escherichia coli plasmids in Europe. These data indicate that the use of different antimicrobial agents, including phenicols, may serve to maintain multidrug resistance plasmids on which extended-spectrum cephalosporin resistance determinants co-exist with other resistance genes in Salmonella.
The French flor sherry wine "Vin jaune" spends 6 years and 3 months in the same barrel under a yeast velum. Because of temperature variations in the cellars, this velum sinks partially into the wine and a deposit of dead yeasts cells accumulates in the bottom of the barrels, favouring the formation of new velum. Growth and autolysis occur simultaneously. This study investigated the evolution of macromolecules released by yeasts during the ageing of "Vin jaune" in a model system closely simulating winemaking. It was observed that the release of macromolecules during the formation of the velums by living yeasts was low but greatly increased when the velums fell and yeast viability decreased. The release of macromolecules was then due to the autolysis of dead cells. Analysis of macromolecules during ageing revealed that they contained 73.3-78.5% neutral sugars and 6-7% proteins according to the ageing stage. Their amino acid composition did not change during ageing. A high content of serine and threonine commonly involved in O-glycosidic linkages present in yeast mannoproteins was observed. Throughout ageing, the mannose and glucose contents of macromolecules increased but the ratio of polymeric mannose to glucose decreased. Size exclusion chromatography showed that mannoproteins released in wine were partially hydrolysed by yeast beta-1,3-glucanases freed in wine.
The effect of periodic aeration on the physiological activity of a strain of Saccharomyces cerevisiae yeast during development of velum (flor) and biological aging of Sherry wine of the Fino type was investigated. L-Proline amino acid was the main nitrogen source for yeasts cells during the biological aging, and its exhaustion may be the cause of the production and consumption of other compounds that are involved in the aroma of wines. Aeration was found to increase adenylate energy charge, growth, and viability of the yeast cells. Also, it affected the intracellular redox equilibrium and the consumption and production of compounds including acetoin, acetaldehyde, higher alcohols, ethanol, glycerol, and acetic acid. Acetaldehyde reached its highest level after the second aeration, which coincided with the exhaustion of the nitrogen source in the medium. The enzyme activity of alcohol dehydrogenases I and II decreased immediately after each aeration, subsequently increasing once all of the dissolved oxygen in the wine had been consumed by yeast cells. Aldehyde dehydrogenase activity was detected only after the first aeration, and it may be related to the production and consumption of acetic acid in the wine.
Urea, ammonium, and free amino acid contents were quantified in a must from Vitis vinifera cv. Pedro Ximenez grapes and in fermented wine and after a short aging of this wine by Saccharomyces cerevisiae race capensis yeast under variable oxygen availability conditions. The previous compounds were also determined in a wine in which the nitrogen source was depleted by the same race of flor yeast (old wine) and also following the addition of ammonium ion, L-glutamic acid, and L-proline. Under specific conditions such as low oxygen level and the absence of some nutrients, the yeasts release some amino acids including L-threonine, L-tryptophan, L-cysteine, and L-methionine to the medium. These amino acids must originate primarily in a de novo synthesis from ethanol that regenerates NAD(P)+. On the basis of these results, the yeasts may be able to use amino acids not only as nitrogen sources but also as redox agents to balance the oxidation-reduction potential under conditions of restricted oxygen, when electron transport along the respiratory chain may be hindered or limited.
Flor yeast Saccharomyces cerevisiae (capensis G1) strain assimilates gluconic acid during the aerobic biological aging process of sherry wines and exerts significant changes on the final volatile compounds of wines, especially a decrease in volatile acidity and butanoic, isobutanoic, 2-methylbutanoic, and 3-methylbutanoic acids. This decrease may have a favorable effect on the quality of sherry wines.
Volatile compounds of sherry wine containing gluconic acid under aging by submerged flor yeast cultures were analyzed. The aroma profile was obtained by grouping the compounds in nine aromatic series. The balsamic, fatty, herbaceous and empyreumatic series increased significantly as consequence of the increase of pantolactone, acids (butanoic, 2-methylbutanoic and 3-methylbutanoic), methionol and gamma-butyrolactone compounds, respectively. The decrease of higher alcohols promoted solvent series diminished. These changes are consistent with those observed in the production of commercial sherry wine using traditional biological aging.
Recently a chromosomal locus possibly specific for Salmonella enterica serovar Typhimurium DT104 has been reported that contains a multiple antibiotic resistance gene cluster. Evidence is provided that Salmonella enterica serovar Agona strains isolated from poultry harbor a similar gene cluster including the newly described floR gene, conferring cross-resistance to chloramphenicol and florfenicol.
The IncC plasmid R55, initially described in the 1970s and isolated from Klebsiella pneumoniae, confers nonenzymatic chloramphenicol resistance. The gene coding for this resistance was cloned and sequenced and shows 95 to 97% nucleotide identity with the recently reported floR gene from Salmonella enterica serovar Typhimurium DT104 and from Escherichia coli animal isolates, respectively, conferring cross-resistance to florfenicol.
The results described indicate that in Saccharomyces sp. the formation of "flor" is under the control of a single Mendelian gene for which is proposed the symbol "Fl."
Essiac (ES) and Flor-Essence (FE) are two herbal teas widely taken by North American cancer patients during chemo- and radiation therapy. In vitro studies on the antiproliferative and differentiation inducing activities of these teas were performed. ES and FE showed negligible antiproliferative activity on Jurkat leukemia cells. Both herbal teas inhibited 50% (IC50) of MCF7 breast cancer cell growth at 1/10 dilution. The IC50 was about 1/40 and 1/10 dilution of FE and ES respectively for MDA-MB-468 human breast cancer cells. The IC50 for HL60 cells was at 1/10 dilution of FE and less than 1/10 dilution of ES. ES at 1/10 dilution induced expression of non-specific esterase in 16% of HL60 cells, compared to about 5% in FE treated cells and untreated controls. ES treatment of HL60 cells induced 47-67% nitroblue tetrazolium positive staining cells compared to 24.6+/-3.1% in cells treated with 1/10 dilution of FE. Flow cytometry analysis showed that both ES and FE treatment between 1/10 and 1/100 dilutions only slightly affected the cell cycle progression of MCF7, MDA-MB-468, Jurkat and HL60 cells. Our data show that both ES and FE herbal teas demonstrated antiproliferative and differentiation inducing properties in vitro only at high concentrations. Further research is needed to elucidate the in vivo activities.
Reduction in cells quantity of thymus, lymphatic nodes, bone marrow and rosette formation cells, decrease in erythrocytes and leucocytes number, suppression of antibody production are seen in experimentally developed acute toxic hepatitis (ATH). Lacto Flor preparation was established to have potential properties to restore different immune and hematological systems disorders observed in mice with ATH.
Essiac (ES) and Flor-Essence (FE) are two herbal teas widely taken by North American cancer patients during chemo- and radiation-therapy. The antioxidant and anti-inflammatory properties of these two herbal teas were assessed in this study. Cell-free Trolox equivalent antioxidant capacity assay shows that at 1/5 dilution, ES and FE have hydroxyl radical scavenging activity equivalent to 10.65 microM and 5.74 microM of Trolox respectively. Treatment with ES at 1/10 and 1/20 dilutions significantly increased nitric oxide (NO) production by murine RAW 264.7 cells, but inhibited NO production in a concentration-dependent manner by lipopolysaccharide (LPS)-stimulated cells. In contrast, FE at 1/10 and 1/20 dilutions did not significantly induce NO production by RAW 264.7 cells, nor did it, at these dilutions, inhibit the NO production by LPS-stimulated RAW 264.7 cells. RT-PCR assay shows that both 1/20 and 1/100 dilutions of ES and FE induced mRNA expression of IL-1beta, inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) pro-inflammatory molecules in RAW 264.7 cells compared to untreated controls. Addition of ES and FE at 1/20 and 1/100 dilutions to LPS-stimulated RAW 264.7 cells did not alter IL-1beta, iNOS and COX-2 mRNA expression in these cells. ES and FE treatment did not affect TNFalpha mRNA expression in non-stimulated or LPS-stimulated RAW 264.7 cells. Our data show that ES but not FE stimulated NO release by non-stimulated and inhibited LPS-stimulated RAW 264.7 cells. There were only minor differences between ES and FE in their induction of mRNA expression of pro-inflammatory molecules. Further research is needed to investigate the differential activities of these two herbal teas in stimulating pro-inflammatory mediators release by RAW 264.7 cells.
A study was conducted en 100 workers from Flor Crombet Contingent in Yateras municipality, province of Guantánamo. Ninety-six men and 4 women out of 100 workers studied had health certificates, most of them made by nurses or physicians, thus sparing the need to go to a polyclinic and saving working hours. When visiting work places, it was observed that workers who did not use protective means were aware of their importance and instructions were imparted that work be carried out in places with lower risk, an order which was fulfilled immediately since there is no lack of promotion, but lack of protective means in the enterprise. One hundred percent of the workers are involved in health education programs.
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Blood samples from 509 Macushi (3 villages) and 623 Wapishana (11 villages) of Northern Brasil and Southern Guyana have been analyzed with respect to the phenotype and gene frequencies at the following 12 polymorphic loci: ABO, Kell-Cellano, MNSs, Rh, P, Duffy, Kidd, Diego, Lewis, Group-specific component, and the immunoglobulin allotypes of the Gm and Inv systems. The data suggest that 5-6% of the Wapishana gene pool is derived from non-Indians but only 1-2% of the Macushi. Inter- and intratribal genetic distances between villages are calculated for these data in an effort to understand gene flow between the tribes and to account for the unusual distribution of a newly-discovered genetic polymorphism of erythrocyte esterase A thus far limited to these 2 tribes (Neel et al., 1977). The data are puzzling and consistent with the possibility that both the Carib-speaking Macushi and the Arawak-speaking Wapishana have derived the esterase A allele in question from some third group now extinct or thus far undiscovered. Intertribal genetic distances based on gene frequencies at 6 loci are derived for 20 Amerindian tribes (including these 2); the "central" position of these 2 tribes can in part be explained by the active migration matrix connecting them.
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