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1.
Biol Res ; 55(1): 9, 2022 Mar 02.
Article in English | MEDLINE | ID: mdl-35236417

ABSTRACT

BACKGROUND: Listeria monocytogenes is a foodborne pathogen that causes listeriosis in humans. This pathogen activates multiple regulatory mechanisms in response to stress, and cobalamin biosynthesis might have a potential role in bacterial protection. Low temperature is a strategy used in the food industry to control bacteria proliferation; however, L. monocytogenes can grow in cold temperatures and overcome different stress conditions. In this study we selected L. monocytogenes List2-2, a strain with high tolerance to the combination of low temperature + copper, to understand whether the cobalamin biosynthesis pathway is part of the tolerance mechanism to this stress condition. For this, we characterized the transcription level of three cobalamin biosynthesis-related genes (cbiP, cbiB, and cysG) and the eutV gene, a transcriptional regulator encoding gene involved in ethanolamine metabolism, in L. monocytogenes strain List2-2 growing simultaneously under two environmental stressors: low temperature (8 °C) + copper (0.5 mM of CuSO4 × 5H2O). In addition, the gene cbiP, which encodes an essential cobyric acid synthase required in the cobalamin pathway, was deleted by homologous recombination to evaluate the impact of this gene in L. monocytogenes tolerance to a low temperature (8 °C) + different copper concentrations. RESULTS: By analyzing the KEGG pathway database, twenty-two genes were involved in the cobalamin biosynthesis pathway in L. monocytogenes List2-2. The expression of genes cbiP, cbiB, and cysG, and eutV increased 6 h after the exposure to low temperature + copper. The cobalamin cbiP mutant strain List2-2ΔcbiP showed less tolerance to low temperature + copper (3 mM) than the wild-type L. monocytogenes List2-2. The addition of cyanocobalamin (5 nM) to the medium reverted the phenotype observed in List2-2ΔcbiP. CONCLUSION: These results indicate that cobalamin biosynthesis is necessary for L. monocytogenes growth under stress and that the cbiP gene may play a role in the survival and growth of L. monocytogenes List2-2 at low temperature + copper.


Subject(s)
Listeria monocytogenes , Bacterial Proteins/genetics , Bacterial Proteins/metabolism , Cold Temperature , Copper , Humans , Listeria monocytogenes/genetics , Temperature , Vitamin B 12/genetics , Vitamin B 12/metabolism
2.
Biol. Res ; 55: 9-9, 2022. ilus
Article in English | LILACS | ID: biblio-1383913

ABSTRACT

BACKGROUND: Listeria monocytogenes is a foodborne pathogen that causes listeriosis in humans. This pathogen activates multiple regulatory mechanisms in response to stress, and cobalamin biosynthesis might have a potential role in bacterial protection. Low temperature is a strategy used in the food industry to control bacteria proliferation; however, L. monocytogenes can grow in cold temperatures and overcome different stress conditions. In this study we selected L. monocytogenes List2-2, a strain with high tolerance to the combination of low temperature +copper, to understand whether the cobalamin biosynthesis pathway is part of the tolerance mechanism to this stress condition. For this, we characterized the transcription level of three cobalamin biosynthesis related genes ( cbiP , cbiB, and cysG ) and the eutV gene, a transcriptional regulator encoding gene involved in ethanolamine metabolism, in L. monocytogenes strain List2-2 growing simultaneously under two environmental stressors: low temperature (8 °C) +copper (0.5 mM of CuSO4 ×5H2O). In addition, the gene cbiP , which encodes an essential cobyric acid synthase required in the cobalamin pathway, was deleted by homologous recombination to evaluate the impact of this gene in L. monocytogenes tolerance to a low temperature (8 °C) +different copper concentrations. RESULTS: By analyzing the KEGG pathway database, twenty-two genes were involved in the cobalamin biosynthesis pathway in L. monocytogenes List2-2. The expression of genes cbiP , cbiB, and cysG, and eutV increased 6 h after the exposure to low temperature +copper. The cobalamin cbiP mutant strain List2-2Δ cbiP showed less tolerance to low temperature +copper (3 mM) than the wild type L. monocytogenes List2-2. The addition of cyanocobalamin (5 nM) to the medium reverted the phenotype observed in List2-2Δ cbiP . CONCLUSION: These results indicate that cobalamin biosynthesis is necessary for L. monocytogenes growth under stress and that the cbiP gene may play a role in the survival and growth of L. monocytogenes List2-2 at low temperature +copper.


Subject(s)
Humans , Listeria monocytogenes/genetics , Temperature , Bacterial Proteins/genetics , Bacterial Proteins/metabolism , Vitamin B 12/genetics , Vitamin B 12/metabolism , Cold Temperature , Copper
3.
Bol. micol. (Valparaiso En linea) ; 35(1): 17-25, jun. 2020. ilus, graf, tab
Article in Spanish | LILACS | ID: biblio-1437207

ABSTRACT

Tectona grandis L.f. es una especie forestal de madera dura que, a pesar de no ser nativa de América, su plasticidad de adaptación ha permitido que en Ecuador se establezcan plantaciones intensivas con fines de exportación. Una compleja enfermedad con características de marchitez vascular está matando miles de árboles de diferentes edades en el país. Se planteó conocer el agente fitopatógeno causante de la patogénesis y muerte de los árboles. Se aislaron los hongos Fusarium sp. y Ceratocystis fimbriata Ellis & Halst. desde árboles enfermos. A nivel de invernadero se plantearon los postulados de Koch, para el efecto 30 plantas de T. grandis de cuatro meses de edad por cada tratamiento, se inocularon con los microrganismos como se describe a continuación: T1= C. fimbriata, T2 = Fusarium sp., T3 = C. fimbriata + Fusarium sp., T4 = agar-agar (control). Se empleó un diseño completo al azar (DCA) y las plantas se evaluaron a los 45 días después de inoculadas. Los tratamientos C. fimbriata, y C. fimbriata + Fusarium sp., mostraron mayores volúmenes aparentes de necrosis, con 1.52 cm3 y 1.93 cm3, y plantas muertas por la infección durante el tiempo de evaluación, mientras que Fusarium sp. mostró baja o nula patogenicidad y comportamiento similar al control, con 0.27 cm3 y 0.16 cm3 respectivamente. Estos resultados sugieren que el agente causal de la enfermedad de marchitez vascular en T. grandis es C. fimbriata y sería el primer reporte del fitopatógeno atacando teca en Ecuador. (AU)


Tectona grandisL.f. it is a hardwood forest species, which despite not being native to America, its adaptive plasticity has allowed intensive plantations to be established for export purposes in Ecuador. A complex disease with characteristics of vascular wilt is killing thousands of trees of different ages in the country. It was proposed to know the phytopathogenic agent causing the pathogenesis and death of the trees. Fusarium sp. andCeratocystis fimbriata Ellis & Halst. were isolated from diseased trees. At the greenhouselevel, Koch's postulates were proposed, for the effect 30 four month old T. grandisplants for each treatment were inoculated with the microorganisms as described below: T1 = C. fimbriata, T2 = Fusariumsp ., T3 = C. fimbriata+ Fusariumsp., T4 = agar-agar (control). A complete randomized design (DCA) was used and the plants were evaluated 45 days after inoculation. The treatments C. fimbriata, and C. fimbriata+ Fusariumsp. showed higher apparent volumes of necrosis, with 1.52 cm3and 1.93 cm3, and plants killed by the infection during the evaluation time, while Fusariumsp. showed low or no pathogenicity and behavior similar to the control, with 0.27 cm3and 0.16 cm3respectively. These results suggest that the causative agent of vascular wilt disease in T. grandisis C. fimbriataand it would be the first report of phytopathogen attacking teak in Ecuador. (AU)


Subject(s)
Trees/microbiology , Ceratocystis/pathogenicity , Forests , Ecuador , Fusarium/pathogenicity
4.
Sci Total Environ ; 636: 727-736, 2018 Sep 15.
Article in English | MEDLINE | ID: mdl-29727840

ABSTRACT

Woody encroachment has been an ongoing process in the subalpine belt of Mediterranean mountains, after land abandonment, the disappearance of the transhumant system and the decrease of the livestock number. The main objectives of this study were: (i) to identify land use/land cover (LULC) changes from 1956 to 2015, and (ii) to investigate the effects of LULC changes in physical and chemical soil properties and soil organic carbon (SOC) and nitrogen (N) stocks. It is hypothesized that woody encroachment in the subalpine belt may lead to significant changes in soil properties, and will generate an increase in the SOC stocks. A land use gradient was identified in the subalpine belt of the Central Spanish Pyrenees: (i) subalpine grasslands, (ii) shrublands, (iii) young forests, and (iv) old forests. Mineral soil samples were collected every 10 cm, down to 40 cm, at three points per each LULC and a total of 48 samples were analyzed. The results showed that (i) woody encroachment has occurred from 1956 to 2015 due to the expansion of coniferous forests and shrublands (at the expense of grasslands), (ii) land cover and soil depth had significant effects on soil properties (except for pH), being larger in the uppermost 0-10 cm depth, (iii) SOC and N contents and stocks were higher in the grassland sites, and (iv) the woody encroachment process initially produced a decrease in the SOC stocks (shrublands), but no differences were observed considering the complete soil profile between grasslands and young and old forests. Further studies, describing SOC stabilization and quantifying above-ground carbon (shrub and tree biomass) are required.

5.
Clin. transl. oncol. (Print) ; 18(10): 1011-1018, oct. 2016. tab, graf
Article in English | IBECS | ID: ibc-155964

ABSTRACT

Purpose: In the present study we compared three different Stereotactic body radiation therapy (SBRT) treatment delivery techniques in terms of treatment time (TT) and their relation with intrafraction variation (IFV). Besides that, we analyzed if different clinical factors could have an influence on IFV. Finally, we appreciated the soundness of our margins. Materials and methods: Forty-five patients undergoing SBRT for stage I lung cancer or lung metastases up to 5 cm were included in the study. All underwent 4DCT scan to create an internal target volume (ITV) and a 5 mm margin was added to establish the planning target volume (PTV). Cone-beam CTs (CBCTs) were acquired before and after each treatment to quantify the IFV. Three different treatment delivery techniques were employed: fixed fields (FF), dynamically collimated arcs (AA) or a combination of both (FA). We studied if TT was different among these modalities of SBRT and whether TT and IFV were correlated. Clinical data related to patients and tumors were recorded as potential influential factors over the IFV. Results: A total of 52 lesions and 147 fractions were analyzed. Mean IFV for x-, y- and z-axis were 1 ± 1.16 mm, 1.29 ± 1.38 mm and 1.17 ± 1.08 mm, respectively. Displacements were encompassed by the 5 mm margin in 96.1 % of fractions. TT was significantly longer in FF therapy (24.76 ± 5.4 min), when compared with AA (15.30 ± 3.68 min) or FA (17.79 ± 3.52 min) (p < 0.001). Unexpectedly, IFV did not change significantly between them (p = 0.471). Age (p = 0.003) and left vs. right location (p = 0.005) were related to 3D shift ≥2 mm. In the multivariate analysis only age showed a significant impact on the IFV (OR = 1.07, p = 0.007). Conclusions: The choice of AA, FF or FA does not impact on IFV although FF treatment takes significantly longer treatment time. Our immobilization device offers enough accuracy and the 5 mm margin may be considered acceptable as it accounts for more than 95 % of tumor shifts. Age is the only clinical factor that influenced IFV significantly in our analysis


No disponible


Subject(s)
Humans , Radiosurgery/methods , Carcinoma, Non-Small-Cell Lung/radiotherapy , Lung Neoplasms/radiotherapy , Ablation Techniques , Radiation Dosage , Cytokines/radiation effects , Neoplasm Metastasis/radiotherapy
6.
Clin Transl Oncol ; 18(10): 1011-8, 2016 Oct.
Article in English | MEDLINE | ID: mdl-26758718

ABSTRACT

PURPOSE: In the present study we compared three different Stereotactic body radiation therapy (SBRT) treatment delivery techniques in terms of treatment time (TT) and their relation with intrafraction variation (IFV). Besides that, we analyzed if different clinical factors could have an influence on IFV. Finally, we appreciated the soundness of our margins. MATERIALS AND METHODS: Forty-five patients undergoing SBRT for stage I lung cancer or lung metastases up to 5 cm were included in the study. All underwent 4DCT scan to create an internal target volume (ITV) and a 5 mm margin was added to establish the planning target volume (PTV). Cone-beam CTs (CBCTs) were acquired before and after each treatment to quantify the IFV. Three different treatment delivery techniques were employed: fixed fields (FF), dynamically collimated arcs (AA) or a combination of both (FA). We studied if TT was different among these modalities of SBRT and whether TT and IFV were correlated. Clinical data related to patients and tumors were recorded as potential influential factors over the IFV. RESULTS: A total of 52 lesions and 147 fractions were analyzed. Mean IFV for x-, y- and z-axis were 1 ± 1.16 mm, 1.29 ± 1.38 mm and 1.17 ± 1.08 mm, respectively. Displacements were encompassed by the 5 mm margin in 96.1 % of fractions. TT was significantly longer in FF therapy (24.76 ± 5.4 min), when compared with AA (15.30 ± 3.68 min) or FA (17.79 ± 3.52 min) (p < 0.001). Unexpectedly, IFV did not change significantly between them (p = 0.471). Age (p = 0.003) and left vs. right location (p = 0.005) were related to 3D shift ≥2 mm. In the multivariate analysis only age showed a significant impact on the IFV (OR = 1.07, p = 0.007). CONCLUSIONS: The choice of AA, FF or FA does not impact on IFV although FF treatment takes significantly longer treatment time. Our immobilization device offers enough accuracy and the 5 mm margin may be considered acceptable as it accounts for more than 95 % of tumor shifts. Age is the only clinical factor that influenced IFV significantly in our analysis.


Subject(s)
Carcinoma, Non-Small-Cell Lung/surgery , Cone-Beam Computed Tomography/methods , Four-Dimensional Computed Tomography/methods , Lung Neoplasms/surgery , Radiosurgery/methods , Radiotherapy Planning, Computer-Assisted/methods , Radiotherapy, Image-Guided/methods , Aged , Aged, 80 and over , Algorithms , Carcinoma, Non-Small-Cell Lung/diagnostic imaging , Carcinoma, Non-Small-Cell Lung/pathology , Dose Fractionation, Radiation , Female , Follow-Up Studies , Humans , Lung Neoplasms/diagnostic imaging , Lung Neoplasms/pathology , Male , Middle Aged , Neoplasm Staging , Prognosis , Radiotherapy Setup Errors/prevention & control , Tumor Burden
7.
J Phys Chem A ; 117(25): 5354-64, 2013 Jun 27.
Article in English | MEDLINE | ID: mdl-23706045

ABSTRACT

A theoretical investigation using density functional theory (DFT) has been carried out in order to understand the molecular mechanism of dihydrogen activation by means of transition metal dioxides MO2 (M = Ti, Zr, and Hf) according to the following reaction: MO2 + H2 → MO + H2O. B3LYP/6-311++G(2df,2pd)/SDD methodology was employed considering two possible reaction pathways. As the first step hydrogen activation by M═O bonds yields to metal-oxo hydride intermediates O═MH(OH). This process is spontaneous for all metal dioxides, and the stability of the O═MH(OH) species depends on the transition metal center. Subsequently, the reaction mechanism splits into two paths: the first one takes place passing through the M(OH)2 intermediates yielding to products, whereas the second one corresponds to direct formation of the product complex OM(H2O). A two-state reactivity mechanism was found for the TiO2 system, whereas for ZrO2 and HfO2 no spin-crossing processes were observed. This is confirmed by CASSCF/CASPT2 calculations for ZrO2 that lead to the correct ordering of electronic states not found by DFT. The results obtained in the present paper for MO2 molecules are consistent with the observed reactivity on surfaces.

8.
J Comput Chem ; 33(7): 748-56, 2012 Mar 15.
Article in English | MEDLINE | ID: mdl-22183786

ABSTRACT

We analyze the behavior of the energy profile of the ring-closure process for the transformation of (3Z,5Z)-octa-1,3,5,7-tetraene 5 to (1Z,3Z,5Z)-cycloocta-1,3,5-triene 6 through a combination of electron localization function (ELF) and catastrophe theory (CT). From this analysis, concepts such as bond breaking/forming processes, formation/annihilation of lone pairs, and other electron pair rearrangements arise naturally through the reaction progress simply in terms of the different ways of pairing up the electrons. A relationship between the topology and the nature of the bond breaking/forming processes along this rearrangement is reported. The different domains of structural stability of the ELF occurring along the intrinsic reaction path have been identified. The reaction mechanism consists of six steps separated by fold and cusp catastrophes. The transition structure is observed in the third step, d(C1-C8) = 2.342 Å, where all bonds have topological signature of single bonds (C-C). The "new" C1-C8 single bond is not formed in transition state and respective catastrophe of the ELF field (cusp) is localized in the last step, d(C1-C8) ≈ 1.97 Å, where the two monosynaptic nonbonding basins V(C1) and V(C8) are joined into single disynaptic bonding basin V(C1,C8). The V(C1,C8) basin corresponds to classical picture of the C1-C8 bond in the Lewis formula. In cycloocta-1,3,5-triene 6 the single C1-C8 bond is characterized by relatively small basin population 1.72e, which is much smaller than other single bonds with 2.03 and 2.26e.

10.
J Comput Chem ; 31(13): 2493-501, 2010 Oct.
Article in English | MEDLINE | ID: mdl-20652991

ABSTRACT

Density functional theory was used to study the mechanism for the oxidation of methanol to formaldehyde. A vanadium oxide cluster O=V(OH)(3) has been utilized to represent the catalytic system under hydrated conditions, i.e., in the presence of V-OH hydroxyl groups. Two types of methoxy-intermediates have been considered: a penta-coordinate methoxy-intermediate (OH)(4)V(OCH(3)) and a tetrahedral methoxy-intermediate (OH)(2)VO(OCH(3))(H(2)O). The most plausible reaction pathway corresponds to the process involving first the formation of the tetrahedral methoxide, and a subsequent rate-limiting step where hydrogen is transferred from the methoxy groups toward the oxygen atom of the vanadyl V=O site. The reaction mechanism is a typical two-state reactivity process due to a change of the multiplicity (reactive singlet --> product triplet) along the reaction coordinate accompanied by a reduction of the vanadium center from V(V) (d(0)) to V(III) (d(2)). Minimum energy crossing points were localized and possible spin inversion processes are discussed by means of the intrinsic reaction coordinate approach to find the most favorable reaction pathways. The hydration effect is found to be mainly the destabilization of the methoxy intermediates. An alternative reaction pathway with a lower apparent barrier is presented.


Subject(s)
Computer Simulation , Formaldehyde/chemical synthesis , Methanol/chemistry , Vanadium Compounds/chemistry , Catalysis , Formaldehyde/chemistry , Oxidation-Reduction
13.
Microb Ecol ; 57(3): 550-61, 2009 Apr.
Article in English | MEDLINE | ID: mdl-18797955

ABSTRACT

Dominant bacterial microbiota of the gut of juvenile farmed Atlantic salmon was investigated using a combination of molecular approaches. Bacterial community composition from the stomach, the pyloric caeca, and the intestine was assessed by extracting DNA directly from each gut compartment. Temporal temperature gradient gel electrophoresis (TTGE) analysis of 16S ribosomal DNA (rDNA) amplicons showed very similar bacterial compositions throughout the digestive tract. Band sequencing revealed a narrow diversity of species with a dominance of Pseudomonas in the three compartments. However, cloning revealed more diversity among the Pseudomonas sequences. To confirm these results, we analyzed the bacterial community by amplifying the variable 16S-23S rDNA intergenic spacer region (ITS). Similar ITS profiles were observed among gastrointestinal compartments of salmon, confirming the TTGE results. Moreover, the dominant ITS band at 650 bp, identified as Pseudomonas, was observed in the ITS profile from fish collected in two seasons (July 2003 and 2004). In contrast, aerobic culture analysis revealed Shewanella spp. as the most prevalent isolate. This discrepancy was resolved by evaluating 16S rDNA and ITS polymerase chain reaction amplification efficiency from both Shewanella and Pseudomonas isolates. Very similar efficiencies were observed in the two bacteria. Hence, this discrepancy may be explained by preferential cultivation of Shewanella spp. under the experimental conditions. Also, we included analyses of pelleted feed and the water influent to explore environmental influences on the bacterial composition of the gut microbiota. Overall, these results indicate a homogeneous composition of the bacterial community composition along the gastrointestinal tract of reared juvenile salmon. This community is mainly composed of Pseudomonas spp., which could be derived from water influent and may be selectively associated with salmon in this hatchery.


Subject(s)
Gastrointestinal Tract/microbiology , Pseudomonas/genetics , Salmo salar/microbiology , Shewanella/genetics , Animals , Colony Count, Microbial , DNA, Bacterial/genetics , DNA, Intergenic/genetics , Ecosystem , Polymorphism, Restriction Fragment Length , Pseudomonas/classification , Pseudomonas/isolation & purification , RNA, Ribosomal, 16S/genetics , Sequence Analysis, DNA , Shewanella/classification , Shewanella/isolation & purification
14.
Transplant Proc ; 40(9): 2879-80, 2008 Nov.
Article in English | MEDLINE | ID: mdl-19010134

ABSTRACT

Loss of donors as a consequence of a coroner's refusal to authorize is an unusual problem that prevents organs becoming available for transplantation. Of 1123 effective donors, 433 (38.5%) died of accidental death. In these latter, it was therefore necessary to request judicial authorization for donation during the coroner's examination. Organ extraction was not performed because of judicial refusal in 15 of these donors (3.46% of the total number of judicial extractions requested and 1.33% of the total number of donors). Despite the lack of differences in the cause of death profile in the four provinces, large differences were noted between the provinces, with most judicial refusals in Malaga (10 refusals; 6.6% of the total judicial refusals), followed by Granada with five refusals (2.9%), Seville with two refusals (1.7%), and zero in Almería. To minimize these judicial refusals, we propose joint action protocols between transplant coordinators, judges, and coroners for these donors to be examined in the hospital prior to extraction and in the operating room during extraction. Any external lesion of judicial interest can then be examined, photographed, and evaluated.


Subject(s)
Tissue Donors/legislation & jurisprudence , Accidental Falls/statistics & numerical data , Accidents/legislation & jurisprudence , Accidents/statistics & numerical data , Accidents, Traffic/statistics & numerical data , Brain Death/legislation & jurisprudence , Cadaver , Coroners and Medical Examiners/legislation & jurisprudence , Coroners and Medical Examiners/statistics & numerical data , Crime/statistics & numerical data , Drowning/epidemiology , Humans , Spain , Suicide/statistics & numerical data , Tissue Donors/statistics & numerical data
15.
Chem Res Toxicol ; 16(2): 208-15, 2003 Feb.
Article in English | MEDLINE | ID: mdl-12588192

ABSTRACT

A series of C4-substituted 1,4-dihydropyridines (DHP) with either secondary or tertiary nitrogen in the dihydropyridine ring were synthesized. All of these compounds together with some commercial DHP derivatives were tested for potential scavenger effects toward alkyl, alkylperoxyl radicals, and ABTS radical cation in aqueous media at pH 7.4. Kinetic rate constants were assessed either by UV/vis spectroscopy or GC/MS techniques. Tested compounds reacted faster toward alkylperoxyl radicals and ABTS radical cation than alkyl ones. N-Ethyl-substituted DHPs showed the lowest reactivity. Kinetic results were compared with either trolox or nisoldipine. Using deuterium kinetic isotope effect studies, we have proved that the hydrogen of the 1-position of the DHP ring is involved in the proposed mechanism. This fact is mostly noticeable in the case of alkyl radicals. In all cases, the respective pyridine derivative was detected as the main product of the reaction.


Subject(s)
Dihydropyridines/chemistry , Peroxides/chemistry , Sulfonic Acids/chemistry , Benzothiazoles , Cations/chemistry , Chromans/chemistry , Free Radical Scavengers/chemistry , Free Radicals/chemistry , Gas Chromatography-Mass Spectrometry , Hydrogen-Ion Concentration , Kinetics , Nisoldipine/chemistry , Spectrophotometry, Ultraviolet , Vitamin E/analogs & derivatives
16.
Clin Diagn Lab Immunol ; 9(5): 1067-71, 2002 Sep.
Article in English | MEDLINE | ID: mdl-12204961

ABSTRACT

An increasing number of studies support a potential role for coccoid forms in Helicobacter pylori infection. Evidence for this was obtained through scanning microscopy, genetic analysis for virulence traits, examination of the presence and activity of key enzymes, and other methods. We studied the serum immunoglobulin G responses to coccoid H. pylori forms by enzyme-linked immunosorbent assay (ELISA) and immunoblotting and compared them with those of bacillary cells. Sera from a total of 295 infected individuals were studied; these included sera from 100 patients with duodenal ulcers, 98 patients with nonulcer dyspepsia, 11 patients with gastroduodenal cancer, and 86 asymptomatic individuals. Initially, we characterized and selected coccoid and bacillary antigenic preparations by one-dimensional (1-D) and 2-D gel electrophoresis and immunoblotting. Data showed that coccoid and bacillary preparations with comparable protein contents have similar patterns in 1-D and 2-D electrophoresis gels and antigenic recognition at blotting. These results revealed that coccoid and spiral antigens in ELISA can equally recognize specific antibodies to H. pylori in sera from infected individuals. The analysis of the spiral and coccoid preparations by Western blotting showed no major differences in antigen recognition. No specific bands or profiles associated with a single gastric condition were identified.


Subject(s)
Antibodies, Bacterial/blood , Helicobacter Infections/immunology , Helicobacter pylori/immunology , Adult , Antigens, Bacterial/analysis , Blotting, Western , Electrophoresis, Gel, Two-Dimensional , Enzyme-Linked Immunosorbent Assay , Helicobacter Infections/microbiology , Helicobacter pylori/pathogenicity , Helicobacter pylori/ultrastructure , Humans , Immunoglobulin G/blood , Virulence
17.
Avian Dis ; 46(3): 686-90, 2002.
Article in English | MEDLINE | ID: mdl-12243533

ABSTRACT

Ten gram-negative, pleomorphic, rod-shaped isolates from coryza-like, respiratory diseased laying and broiler chickens were identified as Ornithobacterium rhinotracheale. All O. rhinotracheale isolates showed typical biochemical and enzymatic characteristics. Also, all isolates showed hemagglutinating activity with glutaraldehyde-fixed erythrocytes. On the basis of this property, a rabbit-raised antiserum was produced for an isolate. All isolates were identified by antiserum by hemagglutination-inhibition tests. No cross-reactions were observed when O. rhinotracheale isolates were tested with Haemophilus paragallinarum antisera, and vice versa. Mild respiratory signs, including mild nasal discharge, slight rales, and sneezing, were observed in challenged chickens. At postmortem examination, multifocal pneumonia, airsacculitis, and foamy exudate in abdominal cavity were observed. Furthermore, because bacterial adherence is regarded as an essential step in the infection process, in vitro adherence of O. rhinotracheale isolates to chicken tracheal epithelial cells was tested. All isolates showed positive adherence. Obtained results indicate that O. rhinotracheale is a pathogenic agent present in the Mexican poultry.


Subject(s)
Chickens , Gram-Negative Bacteria/isolation & purification , Gram-Negative Bacterial Infections/veterinary , Poultry Diseases/microbiology , Respiratory Tract Infections/veterinary , Animals , Bacterial Adhesion , Cross Reactions , Female , Gram-Negative Bacteria/classification , Gram-Negative Bacteria/pathogenicity , Gram-Negative Bacterial Infections/microbiology , Hemagglutination Inhibition Tests/veterinary , Hemagglutination Tests/veterinary , Male , Mexico , Respiratory Tract Infections/microbiology
18.
Rev. méd. Chile ; 130(8): 859-864, ago. 2002.
Article in Spanish | LILACS | ID: lil-356157

ABSTRACT

BACKGROUND: One of the most common pathogens causing alimentary toxi-infections is Staphylococcus aureus (S aureus). The presence of S aureus in food, indicates flaws during food manipulations. For this reason most sanitary norms require the detection of S aureus carriers. AIM: To determine the carriage rate of enterotoxin producing S aureus strains in food handlers, and to evaluate the antibiotic susceptibility to six antimicrobial agents. MATERIALS AND METHODS: A total of 102 food handlers from 19 restaurants in Santiago, were analyzed. Samples for microbiological analysis were obtained with a swab from the retropharynx. RESULTS: S aureus grew in 35 out of the 102 samples obtained (34 per cent). Further analysis revealed that 19/35 (54 per cent) strains were able to produce enterotoxins. Therefore the corrected carriage rate was 19 per cent (19/102). The most frequently detected enterotoxin was the type A (12/19). All S aureus isolates were resistant to penicillin and susceptible to oxacillin, clindamycin, kanamycin, vancomycin and linezolid. CONCLUSIONS: The carriage rate of S aureus in food handlers in similar to the rate reported in the general population in our country. These results confirm the need for education and training programs in food safety, directed to food handlers.


Subject(s)
Humans , Male , Female , Adolescent , Adult , Middle Aged , Enterotoxins/biosynthesis , Staphylococcal Infections/microbiology , Food Handling , Food Microbiology , Carrier State/microbiology , Staphylococcus aureus/isolation & purification , Chile , Staphylococcus aureus/drug effects
19.
Med. intensiva (Madr., Ed. impr.) ; 26(1): 7-12, ene. 2002. tab
Article in Es | IBECS | ID: ibc-10883

ABSTRACT

Objetivo. Valorar la calidad de la asistencia urgente a los traumatizados graves en tres provincias de Andalucía. Método. Estudio prospectivo, observacional de los traumatizados graves asistidos consecutivamente durante 2 meses del año 2000 en tres hospitales de referencia de Andalucía. Se consideraron traumatismos graves los lesionados con Trauma Score Revisado (TSR) 15 puntos. Para valorar la calidad asistencial se utilizaron 17 filtros auditores del comité de traumatología del Colegio Norteamericano de Cirujanos. Resultados. Se incluyeron 108 enfermos, 85 por TSR 15. La comparación de la distribución de las probabilidades de supervivencia de nuestra serie, con la casuística del Mayor Trauma Outcome Study (MTOS) evidenció diferencias estadísticamente significativas (p < 0,001), por mayor gravedad de los enfermos incluidos en nuestro estudio. Un 58,3 por ciento incumplía algún criterio de calidad, aunque esta circunstancia no influyó negativamente en su evolución. El tipo de criterio mayoritariamente incumplido era diferente para cada hospital. Los traumatizados con asistencia subóptima eran significativamente menos graves (p < 0,01) que el subgrupo con asistencia satisfactoria. La tasa de defunciones alcanzó el 13 por ciento con un porcentaje de muertes evitables del 4,6 por ciento, según TRISS. Conclusiones. La asistencia urgente a los traumatizados graves es frecuentemente subóptima, aunque no se observó repercusión en la mortalidad. La estimación de la supervivencia basada en la casuística de datos MTOS no es aplicable a nuestra muestra, por lo que será necesario establecer nuestros propios estándares en el futuro, con series más amplias (AU)


Subject(s)
Humans , Quality of Health Care , Wounds and Injuries/therapy , Quality of Health Care/statistics & numerical data , Prospective Studies , Severity of Illness Index , Outcome and Process Assessment, Health Care , Longitudinal Studies , Wounds and Injuries/mortality , Spain
20.
Rev Med Chil ; 128(7): 767-71, 2000 Jul.
Article in Spanish | MEDLINE | ID: mdl-11050838

ABSTRACT

BACKGROUND: Bacterial vaginosis (BV) is a common disease in reproductive-age women and is associated to important gynecologic and obstetric complications. AIM: To study the occurrence of BV in apparently healthy women attending family planning clinics, using Amsel and Nugent diagnostic criteria. MATERIAL AND METHODS: Two hundred thirty nine women consulting for symptoms associated to cervicovaginitis, were studied. A sample from the lateral walls of the vagina was obtained with a sterile swab for microscopic analysis, Gram stain and amine test. RESULTS: According to Amsel and Nugent criteria a 31.1% and 31.8% BV prevalence was observed. The sensitivity and specificity of Nugent criteria, compared with Amsel criteria were 83.3% and 92.1%, respectively. CONCLUSIONS: The high prevalence of BV found in this study suggests that this vaginal infection should be diagnosed with standardized methods. Nugent criteria are economic easy to perform and sensitive and we propose that they should be used in local health centers.


Subject(s)
Vaginal Smears/methods , Vaginosis, Bacterial/diagnosis , Chile/epidemiology , Female , Humans , Predictive Value of Tests , Prevalence , Sensitivity and Specificity , Vaginosis, Bacterial/epidemiology , Vaginosis, Bacterial/pathology
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