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Biomedical subjects

M C Gutiérrez

Publications and source records attributed to M C Gutiérrez.

At least 19 recordsLinked to original sources
PubMed2006

Decolourisation of simulated reactive dyebath effluents by electrochemical oxidation assisted by UV light.

This study is focused on the optimisation of the electrochemical decolourisation of textile effluents containing reactive dyes with the aim of making feasible-technically and economically-this method at industrial scale. Coloured waters were treated in continuous at low current density, to reduce the electrical consumption. Ti/PtO(x) electrodes were used to oxidize simulated dyebaths prepared with an azo/dichlorotriazine reactive dye (C.I. Reactive Orange 4). The decolourisation yield was dependent on the dyeing electrolyte (NaCl or Na(2)SO(4)). Dyeing effluents which contained from 0.5 to 20 gl(-1) of NaCl reached a high decolourisation yield, depending on the current density, immediately after the electrochemical process. These results were improved when the effluents were stored for several hours under solar light. After the electrochemical treatment the effluents were stored in a tank and exposed under different lighting conditions: UV light, solar light and darkness. The evolution of the decolourisation versus the time of storage was reported and kinetic constants were calculated. The time of storage was significantly reduced by the application of UV light. A dye mineralization study was also carried out on a concentrated dyebath. A TOC removal of 81% was obtained when high current density was applied for a prolonged treatment with recirculation. This treatment required a high electrical consumption.

Coloring Agents↗
PubMed2006

Halovivax asiaticus gen. nov., sp. nov., a novel extremely halophilic archaeon isolated from Inner Mongolia, China.

Strain EJ-46T, a novel pleomorphic, aerobic, extremely halophilic member of the Archaea was isolated from sediment of the saline Lake Ejinor, in Inner Mongolia, China. This organism was neutrophilic and required at least 15 % (2.5 M) NaCl for growth. MgCl2 was not required. The isolate was able to grow at pH 6.0-9.0. Optimum growth occurred in media containing 20 % (3.4 M) NaCl at pH 7.0-7.5. Polar lipid analysis revealed the presence of phosphatidylglycerol and phosphatidylglycerol phosphate methyl ester, derived from both C20C20 and C20C25 glycerol diethers. Four glycolipids were detected, one of which may be novel. The DNA G+C content was 60.3 mol%. 16S rRNA gene analysis revealed that strain EJ-46T was a member of the phylogenetic group defined by the family Halobacteriaceae, and the highest 16S rRNA gene similarity values of 94.9 and 94.8 % were obtained with the haloalkaliphilic species of the genus Natronococcus, Natronococcus occultus and Natronococcus amylolyticus, respectively. Based on the phenotypic, genotypic and phylogenetic analyses, it is proposed that the novel isolate should be classified as representing a new genus and species, for which the name Halovivax asiaticus gen. nov., sp. nov. is proposed. The type strain is EJ-46T (=CGMCC 1.4248T = CECT 7098T).

China↗
PubMed2006

Halostagnicola larsenii gen. nov., sp. nov., an extremely halophilic archaeon from a saline lake in Inner Mongolia, China.

Strain XH-48(T) was isolated from the sediment of Lake Xilinhot, a saline lake in Inner Mongolia (China). The organism is pleomorphic, neutrophilic and requires at least 2.5 M (15 %) NaCl, but not MgCl(2), for growth; it exhibits optimal growth at 3.4 M (20 %) NaCl. The G+C content of its DNA is 61 mol%. 16S rRNA gene sequence analysis revealed that strain XH-48(T) is a member of the family Halobacteriaceae, but there were low levels of similarity with other members of this family. The highest sequence similarity values (94.5 and 93.3 %) were obtained with the 16S rRNA genes of Natrialba aegyptiaca and Natrialba asiatica, respectively. Polar lipid analyses revealed that strain XH-48(T) contains phosphatidylglycerol and phosphatidylglyceromethylphosphate, derived from both C(20)C(20) and C(20)C(25) glycerol diethers, and two unidentified glycolipids. On the basis of the data obtained, the novel isolate cannot be classified within any recognized genus. Strain XH-48(T) should be placed within a novel genus and species within the family Halobacteriaceae, order Halobacteriales, for which the name Halostagnicola larsenii gen. nov., sp. nov. is proposed. The type strain of Halostagnicola larsenii is strain XH-48(T) (=DSM 17691(T)=CGMCC 1.5338(T)=JCM 13463(T)=CECT 7116(T)).

Aerobiosis↗
PubMed2006

Halorubrum orientale sp. nov., a halophilic archaeon isolated from Lake Ejinor, Inner Mongolia, China.

A motile, pleomorphic, red-pigmented archaeon, strain EJ-52T, was isolated from water from Lake Ejinor, a saline lake in Inner Mongolia, China. Analysis of the almost-complete 16S rRNA gene sequence showed that the isolate was phylogenetically related to species of the genus Halorubrum, being most closely related to Halorubrum saccharovorum ATCC 29252T (96.1% sequence similarity), Halorubrum lacusprofundi JCM 8891T (95.9%), Halorubrum tibetense AS 1.3239T (95.2%), Halorubrum alcaliphilum AS 1.3528T (95.2%) and Halorubrum vacuolatum JCM 9060T (95.1%). The polar lipids of strain EJ-52T were C20C20 derivatives of phosphatidylglycerol phosphate and phosphatidylglycerol phosphate methyl ester and a sulfated diglycosyl diether. Strain EJ-52T requires at least 2.5 M NaCl for growth and grows optimally at 3.4 M NaCl. The strain grows at 25-50 degrees C, with optimal growth occurring at 35-45 degrees C. Mg2+ is not required. The DNA G+C content is 64.2 mol%. On the basis of the data obtained in this study, strain EJ52T represents a novel species, for which the name Halorubrum orientale sp. nov. is proposed. The type strain is EJ-52T (=CECT 7145T=JCM 13889T=CGMCC 1.6295T).

Base Composition↗
PubMed2006

Natrinema ejinorense sp. nov., isolated from a saline lake in Inner Mongolia, China.

A Gram-negative, non-motile, neutrophilic, pleomorphic and extremely halophilic archaeon, strain EJ-57T, was isolated from saline Lake Ejinor in Inner Mongolia, China. Strain EJ-57T was able to grow at 25-50 degrees C, required at least 1.8 M NaCl for growth (optimum at 3.4 M NaCl) and grew over a pH range from 6.0 to 8.5 (optimum at pH 7.0). Hypotonic treatment with less than 1.5 M NaCl caused cell lysis. Analysis of the almost complete 16S rRNA gene sequence indicated that the isolate represented a member of the genus Natrinema in the family Halobacteriaceae. Strain EJ-57T was most closely related to Natrinema versiforme JCM 10478T (96.2% sequence similarity), Natrinema pallidum NCIMB 777T (95.9% sequence similarity), Natrinema altunense JCM 12890T (95.8% sequence similarity) and Natrinema pellirubrum NCIMB 786T (95.5 % sequence similarity). However, DNA-DNA hybridization experiments showed that strain EJ-57T was not related to these species, with levels of DNA-DNA relatedness equal to or below 39%. The major polar lipids of the isolate were C20C20 and C20C25 derivatives of phosphatidylglycerol, phosphatidylglycerol phosphate methyl ester and the disulfated glycolipid S2-DGA-1. The G+C content of the genomic DNA was 64.7 mol%. Comparative analysis of phenotypic characteristics between strain EJ-57T and recognized Natrinema species supported the conclusion that EJ-57T represents a novel species within this genus, for which the name Natrinema ejinorense sp. nov. is proposed. The type strain is EJ-57T (=CECT 7144T=JCM 13890T=CGMCC 1.6202T).

Base Composition↗
PubMed2005

Solid surface mapping by inverse gas chromatography.

Inverse gas chromatography (IGC) at infinite dilution, is a technique for characterising solid surfaces. Current practice is the injection of n-alkane homologous series to obtain the free energy of adsorption of the CH2 group, from which the London component of the solid surface free energy, gamma(d)s, is calculated. A value around 40 mJ/m2 is obtained for poly(ethylene), and 30 mJ/m2 for a clean glass fibre, while the potential surface interactivity of a glass fibre is far greater than that of poly(ethylene). A specific component of the surface, in mJ/m2, should be calculated in order to obtain significant parameters. As applied up to date, when calculating the specific component of the surface energy, the fact that W(sp)a energy values are in a totally different scale than AN or DN values is a major drawback. Consequently, Ka and Kb values obtained are in arbitrary energy units, different from those of the London component measured by injecting the n-alkane series. This paper proposes a method to obtain Ka and Kb values of the surface in the same energetic scale than the London component. The method enables us to correct the traditional London component of a solid, obtaining a new value, where the amount of WaCH2 accounting for Debye interactions with polar sites, is excluded. As a result, an approach to surface mapping is performed in several different substrate materials. We show results obtained on different solid surfaces: poly(ethylene), clean glass fibre, glass beads, chemically modified glass beads and carbon fibre.

Chromatography, Gas↗
PubMed2005

IS6110 restriction fragment length polymorphism of Mycobacterium tuberculosis isolates from an area of Casablanca, Morocco.

Using IS6110 RFLP, 61 isolates recovered from new cases of pulmonary tuberculosis (TB) were compared from September to December 1999 in Casablanca, Morocco, a city with a high incidence of TB. The majority of the isolates (92%) harboured 6-14 copies of IS6110. The minimal fraction of patients in groups of recently acquired infection is 13.1%. This preliminary study showed that IS6110 RFLP is a suitable method for finger-printing Mycobacterium tuberculosis in Casablanca. The unexpectedly low level of recent transmission of TB found in this study deserves further studies involving higher numbers of isolates recovered during a longer recruitment period.

Humans↗
PubMed2001

Biotransformation of 4beta-hydroxyeudesmane-1,6-dione by Gliocladium roseum and Exserohilum halodes.

Biotransformation of sesquiterpene 4beta-hydroxyeudesmane-1,6-dione by the filamentous fungi Gliocladium roseum and Exserohilum halodes was achieved. With Exserohilum halodes, only one metabolite was obtained, as a result of the regio- and stereoselective reduction of the keto group at C-1, which is difficult to achieve by chemical means. Five metabolites were produced with Gliocladium roseum, three of which, the 7alpha-hydroxylated, the 7alpha,11- and the 1alpha,8alpha-dihydroxylated derivatives, have not previously been reported. The hydroxylation at C-11 is the main action of this microorganism. These 11-hydroxylated compounds can be chemically transformed into 6beta,12-eudesmanolides.

Ascomycota↗
PubMed2000

Taxonomic analysis of extremely halophilic archaea isolated from 56-years-old dead sea brine samples.

A taxonomic study comprising both phenotypic and genotypic characterization, has been carried out on a total of 158 extremely halophilic aerobic archaeal strains. These strains were isolated from enrichments prepared from Dead Sea water samples dating from 1936 that were collected by B. E. Volcani for the demonstration of microbial life in the Dead Sea. The isolates were examined for 126 morphological, physiological, biochemical and nutritional tests. Numerical analysis of the data, by using the S(J) coefficient and UPGMA clustering method, showed that the isolates clustered into six phenons. Twenty-two out of the 158 strains used in this study were characterized previously (ARAHAL et al., 1996) and were placed into five phenotypic groups. The genotypic study included both the determination of the guanineplus-cytosine content of the DNA and DNA-DNA hybridization studies. For this purpose, representative strains from the six phenons were chosen. These groups were found to represent some members of three different genera - Haloarcula (phenons A, B, and C), Haloferax (phenons D and E) and Halobacterium (phenon F) - of the family Halobacteriaceae, some of them never reported to occur in the Dead Sea, such as Haloarcula hispanica, while Haloferax volcanii (phenons D and E) was described in the Dead Sea by studies carried out several decades later than Volcani's work.

Archives↗
PubMed1999

Proposal to transfer Halococcus turkmenicus, Halobacterium trapanicum JCM 9743 and strain GSL-11 to Haloterrigena turkmenica gen. nov., comb. nov.

The 16S rRNA gene sequences of Halococcus saccharolyticus and Halococcus salifodinae were closely related (94.5-94.7% similarity) to that of Halococcus morrhuae, the type species of the genus Halococcus. However, Halococcus turkmenicus was distinct from the other members of this genus, with low 16S rRNA similarities when compared to Halococcus morrhuae (88.7%). On the basis of phylogenetic tree reconstruction, detection of signature bases and DNA-DNA hybridization data, it is proposed to transfer Halococcus turkmenicus to a novel genus, Haloterrigena, as Haloterrigena turkmenica gen. nov., comb. nov., and to accommodate Halobacterium trapanicum JCM 9743 and strain GSL-11 in the same species. On the basis of morphological, cultural and 16S rRNA sequence data, it is also proposed that the culture collection strains of Halobacterium trapanicum NCIMB 767, ATCC 43102 and JCM 8979 should be renamed as Halococcus sp.

Base Composition↗
PubMed1999

Haloarcula quadrata sp. nov., a square, motile archaeon isolated from a brine pool in Sinai (Egypt).

The motile, predominantly square-shaped, red archaeon strain 801030/1T, isolated from a brine pool in the Sinai peninsula (Egypt), was characterized taxonomically. On the basis of its polar lipid composition, the nucleotide sequences of its two 16S rRNA genes, the DNA G+C content (60.1 mol%) and its growth characteristics, the isolate could be assigned to the genus Haloarcula. However, phylogenetic analysis of the two 16S rRNA genes detected in this organism and low DNA-DNA hybridization values with related Haloarcula species showed that strain 801030/1T is sufficiently different from the recognized Haloarcula species to warrant its designation as a new species. A new species, Haloarcula quadrata, is therefore proposed, with strain 801030/1T (= DSM 11927T) as the type strain.

Base Composition↗
PubMed1999

Molecular markers demonstrate that the first described multidrug-resistant Mycobacterium bovis outbreak was due to Mycobacterium tuberculosis.

We genetically characterized multidrug-resistant Mycobacterium tuberculosis complex strains which caused a nosocomial outbreak of tuberculosis affecting six human immunodeficiency virus (HIV)-positive patients and one HIV-negative staff member (E. Bouvet, E. Casalino, G. Mendoza-Sassi, S. Lariven, E. Vallée, M. Pernet, S. Gottot, and F. Vachon, AIDS 7:1453-1460, 1993). The strains showed all the phenotypic characteristics of Mycobacterium bovis. They presented a high copy number of IS6110, the spacers 40 to 43 in the direct repeat locus, and the mtp40 fragment. They lacked the G-A mutation at position 285 in the oxyR gene and the C-G mutation at position 169 in the pncA gene. These genetic characteristics revealed that these were dysgonic, slow-growing M. tuberculosis strains mimicking the M. bovis phenotype, probably as a consequence of cellular alterations associated with the multidrug resistance. Spoligotyping and IS6110 restriction fragment length polymorphism (RFLP) analysis confirmed that the outbreak was due to a single strain. However, the IS6110 RFLP pattern of the strain isolated from the last patient, diagnosed three years after the index case, differed slightly from the patterns of the other six strains. A model of a possible genetic event is presented to explain this divergence. This study stresses the value of using several independent molecular markers to identify multidrug-resistant tubercle bacilli.

AIDS-Related Opportunistic Infections↗
PubMed1998

Molecular fingerprinting of Mycobacterium tuberculosis and risk factors for tuberculosis transmission in Paris, France, and surrounding area.

Forty-three percent of the tuberculosis cases reported in France are from the Ile de France region. The incidence of tuberculosis in this region is 33 cases per 100,000 inhabitants, twice the national average. A restriction fragment length polymorphism (RFLP) analysis was performed with clinical isolates of Mycobacterium tuberculosis isolated during 1995 in 10 hospitals in Paris and surrounding areas to detect tuberculosis transmission and define the factors associated with clustering in this population. The molecular markers used were the insertion sequence IS6110 and the direct repeat (DR) sequence. Social, demographic, and clinical data were collected from the patients' medical files. Ten patients with isolates with a single copy of IS6110 were excluded from further analysis. Twenty-four patients with false-positive cultures due to laboratory contamination (based on RFLP analysis with IS6110 and examination of patient data) were also excluded. The study was then conducted with 272 strains isolated from 272 patients. Further fingerprinting was performed by using the DR element with strains with patterns by RFLP analysis with IS6110 that differed by one band only and strains with identical patterns by RFLP analysis with IS6110 and with low numbers of copies of IS6110. The combined use of both markers identified unique patterns for 177 strains and clustered 95 (35.7%) strains in 26 groups, each containing isolates from 2 to 12 patients. The clustering was strongly associated with homelessness and the male sex. It was not associated with age, birth in a foreign country, human immunodeficiency virus positivity, or residence in hostels or prison. Isolates from homeless people were often included in large clusters, and homeless people could be the source of tuberculosis transmission for more than 50% of the clustered patients. These results suggest that homeless people play a key role in the spread of M. tuberculosis in the community and that poor socioeconomic conditions are the main risk factors associated with active tuberculosis transmission.

AIDS-Related Opportunistic Infections↗
PubMed1995

DNA relatedness among Aeromonas allosaccharophila strains and DNA hybridization groups of the genus Aeromonas.

The genomic relatedness among three Aeromonas allosaccharophila strains, including the type strain, and other Aeromonas type and reference strains that were assigned to DNA hybridization groups was estimated by DNA-DNA hybridization (competition procedure using a membrane method). All A. allosaccharophila strains were highly related (70 to 100%) to strains 289T (= CECT 4199T) and ATCC 35942. Type strains of other validated Aeromonas species, reference strains of DNA groups 8 and 11, and the Aeromonas sp. strain ATCC 43946 (enteric group 501) were 0 to 41% related to A. allosaccharophila 289T and ATCC 35942. The G+Cs content of A. allosaccharophila strains were in the range 55.9 to 57.3 mol%. The G+C content of the type strain of this species was 56.9 mol%, a value somewhat lower than that reported in the original description.

Aeromonas↗
PubMed1995

Aeromonas encheleia sp. nov., isolated from European eels.

Four strains isolated from European eels in Valencia, Spain, were found to constitute a DNA relatedness group which is 0 to 50% related to the 13 species and DNA group 11 of the genus Aeromonas. Phenotypically, these strains have all of the properties that define the genus Aeromonas. However, they differ from the previously described Aeromonas species by three or more properties. The strains are positive for motility, growth at 37 degrees C, indole production, and arginine dihydrolase activity. They exhibit negative reactions in tests for growth at 42 degrees C and in thiosulfate-citrate-bile salts-sucrose medium (Oxoid), Simmons citrate tests, and tests for lysine and ornithine decarboxylase activities. They produce acid from salicin but not from L-arabinose, D-cellobiose, or lactose. All four strains hydrolyze esculin and arbutin but not elastin. They use L-serine as a sole carbon and energy source but cannot utilize L-arabinose, L-arginine, D-gluconate, or L-glutamine. The strains are resistant to ampicillin. The guanine-plus-cytosine content of the DNA is 59.4 to 60.8 mol%. The name Aeromonas encheleia sp. nov. is proposed for these strains; strain S181 (= CECT 4342) is the type strain. This new species is generally not pathogenic for eels or mice.

Aeromonas↗
PubMed1992

Identification and partial purification of an Entamoeba histolytica membrane protein that binds fibronectin.

A 37 kDa protein has been described as a putative receptor for fibronectin (Fn) on E. histolytica trophozoites (1). We have now identified a membrane protein that binds biotinylated fibronectin (BFn) with an apparent molecular weight of 140 kDa. Using BFn we were able to follow this protein during partial purification through DEAE-cellulose and Fn-Sepharose chromatography. Antisera prepared against a peptide corresponding to the deduced amino acid sequence for the putative receptor binding site for human Fn (2) recognized a protein with the same molecular weight. The purified protein was also recognized by this sera. We propose that this protein may function as a Fn receptor and will explore the possibility for it being an integrin.

Amino Acid Sequence↗