A thermophilic Bacillus isolated from an Eolian shallow hydrothermal vent, able to produce exopolysaccharides.

A thermophilic aerobic microorganism, able to produce two exocellular polysaccharides (EPS1 and EPS2), was isolated from a shallow hydrothermal vent at Vulcano island (Eolian Islands, Italy). EPS1 and EPS2 were based on mannose and glucose although in a different ratio. EPS2 possessed a trisaccharide repeating unit with a manno-pyranoside configuration. New isolate phenotype was studied by physiological and morphological observations, including biochemical and antimicrobial susceptibility tests (134). Previous analyses carried out on 87 field isolates and 8 thermophilic reference bacilli displayed low phenotypic similarity level (S(SM) = 65%) with Bacillus thermodenitrificans DSM 465. Optimal growth occurs at 65 degrees C and pH 7.0. Oxidase and catalase are negative. The guanine-plus-cytosine (G+C) content of DNA is 52.7%. Genotypic investigations demonstrated the diversity of the isolate with fifteen selected thermophilic Bacillus spp. when we compared the restriction patterns of the amplified 16S rDNA. The membrane lipids are based on fatty acids mainly belonging to the iso-family.

Lipid profile: a useful chemotaxonomic marker for classification of a new cyanobacterium in Spirulina genus.

The morphological, physiological and genetic characteristics of an isolate cyanobacterium from hard sand of the lake Venere in the Pantelleria island (Italy) were described. The isolate with a small-size coiled helix shape, growing optimally at pH 9.2-9.5 at 30 degrees C under continuous illumination and aeration, possessed a 61.5 mol% of Guanine + Cytosine content of DNA. The lipid profile showed the presence of mono-, di-glycosyl, sulphoquinovolosyl and phosphatidyl (MGDG, DGDG, SQDG and PG). The fatty acid profile was also studied, characterized by the absence of gamma-linolenic acid and the presence of saturated and monounsaturated C16 and C18. The latter was also present as a dienoic component. The fatty acid composition was affected by growth temperature by increasing the degree of desaturation at a lower temperature and the biosynthesis of shorter acyl chains. The effects of growth conditions other than temperature, physical, nutritional and chemical on lipid composition were also studied. The overall features of the cyanobacterium isolated from Pantelleria clustered it into Spirulina genus.

AIDS-related illness trajectories in Mexico: findings from a qualitative study in two marginalized communities.

This paper describes findings from a recent study examining how people affected directly and indirectly by the HIV/AIDS epidemic cope with HIV-related illness in Mexico. One-hundred-and-thirteen in-depth interviews were conducted with key informants in two contrasting communities: Ciudad Netzahualcóyotl (an economically marginalized community) and the gay community in Mexico City (a sexually marginalized community). This paper describes the AIDS-related wellness/illness careers or trajectories followed by individuals in both communities, and identifies critical points for material and emotional intervention. This career comprises four stages: (1) life before infection; (2) life surrounding the discovery of seropositivity; (3) living as an HIV-positive person; and (4) facing death. Comparisons are drawn between the processes of adjustment and coping found in both communities. In Ciudad Netzahualcóyotl, wellness/illness careers are closely linked to prevailing poverty and oppression, as well as the sense of urgency in which local people live their lives. In the case of the gay community, wellness/illness careers are associated with the intolerance and social repression faced by homosexual men. The paper concludes by suggesting possible interventions to improve the lives of people with HIV/AIDS in Mexico today.

PIP: Characterization of AIDS-related illness trajectories is essential to the design of programs intended to provide support and assistance to HIV-infected persons. These trajectories were investigated through in-depth interviews conducted with 113 HIV-positive persons or their family members from two contrasting communities in Mexico: Ciudad Netza (economically marginalized) and the gay community in Mexico City (sexually stigmatized). This trajectory consisted of 4 basic stages in both settings: 1) life before HIV infection, 2) the discovery of one's HIV seropositivity, 3) living as an HIV-positive person, and 4) facing death. In Ciudad Netza, the daily experience of poverty is so pressing that an HIV diagnosis tends to be viewed as yet another problem to be faced. For many Mexico City gays, HIV infection initiates the need to "come out" both as a homosexual and as an HIV-positive person. In each community, the HIV diagnosis was accompanied by much self-blame and self-recrimination. After diagnosis, many HIV-infected persons who had been living independently stopped working and returned home to live with their families--a step associated with both financial and psychosocial adjustment difficulties. As death approached, financial and health care needs intensified and social stigmatization added to the pain experienced by AIDS patients and their families. Among the needs identified through these interviews are legislation to combat discriminatory employment policies, more sensitive counseling and psychological support at the time of HIV diagnosis, referrals for those who lack family support, and courses for health workers to combat the rejection of patients with AIDS.

[Management strategies in HIV/AIDS at the family level]. / Estrategias de manejo en torno al VIH/SIDA a nivel familiar.

OBJECTIVE: To identify the critical points of the trajectories of the families of persons with AIDS which may serve as a basis to develop educational and support programs. THEORY AND METHODS: A qualitative investigation was conducted in 1995 in Ciudad Netzahualcóyotl, State of Mexico, Mexico. Rapid Assessment Procedures (RAP) were applied to determine the social, economic, demographic and cultural context of persons with HIV/AIDS in the community. Forty-six in-depth interviews were applied to persons with AIDS, their families and people from their social networks. RESULTS: The main aspects of the family response to the HIV/ AIDS are characterized, and it is demonstrated that it is possible to identify critical points in such a response which can be targeted through specific interventions. In Ciudad Netzahualcóyotl, a context of poverty, a migrating tradition, and gender social relations are the basis of the acceptance or rejection of persons with AIDS. The main finding refers to the ambiguos attitude, ranging from rejection to support, displayed by family members of persons with AIDS. This pattern varies according to the history and specific conditions of each family. CONCLUSIONS: Specific health interventions are proposed to support families with one or more persons with AIDS.

[Complementary health care models: a neglected component in the health care systems reform]. / Modelos complementarios de atención: un componente excluido en la reforma de los Sistemas de Salud.

Complementary health care models represent a neglected and scarcely studied area of the health services structure. Within them a myriad of medical therapies of various origins are included. Lately, their importance has grown by means of the increase in demand for such services, both in industrialized and developing countries. It is urgent to reinforce research in the area aiming at understanding the processes through which the population demands these services and the processes through which complementary practitioners are able to maintain their presence in a market environment where the forces of supply and demand are significant. The context created by the health services reform should be used to review the therapeutic value of these models, to promote its regulation, and to amplify the availability of therapeutic options for the population.

The structure of the exopolysaccharide produced by the halophilic Archaeon Haloferax mediterranei strain R4 (ATCC 33500).

The halophilic Archaeon Haloferax mediterranei exudes into the growth medium a high molecular weight sulfated polysaccharide. The structure of the repeating unit of this polymer was determined by a combination of glycose, methylation, and sulfate analysis, periodate oxidation, and 1D and 2D NMR spectroscopic analysis of the native and periodate-oxidised/reduced polysaccharides. The location of the sulfate group was established from the 1H and 13C NMR data. The structure of the repeating unit of the polysaccharide may be written as [formula: see text]

Chemical Composition of Two Exopolysaccharides from Bacillus thermoantarcticus.

The thermophilic bacterium Bacillus thermoantarcticus produces two exocellular polysaccharides (EPS 1 and EPS 2), which can be obtained from the supernatant of liquid cultures by cold-ethanol precipitation, in yields as high as 400 mg liter(sup-1). The EPS fraction was produced with all substrates tested, although a higher yield was obtained with mannose as the carbon and energy source. The EPS content was proportional to the total biomass. On a weight basis, EPS 1 and EPS 2 represented about 27 and 71%, respectively, of the total carbohydrate fraction. EPS 1 is a sulfate heteropolysaccharide containing mannose and glucose in a relative molar proportion of 1.0 and 0.7, respectively. EPS 2 is a sulfate homopolysaccharide containing mannose as the major component. The absolute configurations of hexoses were shown to be d for both EPSs. Nuclear magnetic resonance spectra confirmed the presence of (alpha)-d-mannose and (beta)-d-glucose in EPS 1 and only (alpha)-d-mannose in EPS 2. In addition, (sup1)H nuclear magnetic resonance analysis and chemical analysis indicated the presence of pyruvic acid in EPS 2.

Structural studies of the Escherichia coli O26 O-antigen polysaccharide.

The structure of the O-specific side chain of the E. coli O26 lipopolysaccharide has been investigated. Based on sugar and methylation analyses, and 2D NMR spectroscopy employing HMBC experiments, it is concluded that the polysaccharide is composed of trisaccharide repeating units having the following structure. -->3)-alpha-L-Rhap-(1-->4)-alpha-L-FucpNAc-(1-->3)-beta-D-Gl cpNAc-(1-->

Structural studies of the capsular polysaccharide from Klebsiella type 38: a reinvestigation.

The structure of the capsular polysaccharide from Klebsiella type K38 has been reinvestigated. It is composed of pentasaccharide repeating units of the structure given below. In this structure, Sug stands for a 4-deoxy-threo-hex-4-enopyranosyluronic acid group, most probably having the beta-L configuration. 1H NMR studies further indicate that this group assumes the 1H2 conformation. [formula: see text]

Glycolipids from Thermotoga maritima, a hyperthermophilic microorganism belonging to Bacteria domain.

Two novel glycolipids with a very rare alpha(1-->4) diglucosyl structure have been isolated from the thermophilic bacterium Thermotoga maritima. The structures of these compounds, on the basis of chemical procedures and spectroscopic studies (FAB-MS and NMR), were shown to be: 1(3),2-dipalmitoyl-3(1)-[glucopyranosyl-(6-decanoyl)-alpha-D-(1-->4)- glucopyranosyl-alpha-D]-glycerol (Glycolipid 1) and 1(3),2-dipalmitoyl-3(1)-[glucopyranosyl-alpha-D-(1-->4)-glucopyranosyl- alpha-D]-glycerol (Glycolipid 2).