PubMed Health⌕ Search

Biomedical subjects

D Mora

Publications and source records attributed to D Mora.

30 records · Page 2Linked to original sources

Development of molecular RAPD marker for the identification of Pediococcus acidilactici strains.

A RAPD analysis performed using a single primer targeted to the pediocin AcH/PA-1 gene was carried out on several P. acidilactici strains and on some related species of lactic acid bacteria. The high degree of genetic variability detected in P. acidilactici strains did not allow the selection of a common RAPD fragment that could be chosen as a potential species-specific DNA marker. Nevertheless a 700 bp fragment, that was found to be peculiar of all potential pediocin producer strains analyzed, was cloned and sequenced with the aim to develop a species specific PCR marker. Sequence analysis of the cloned 700 bp fragment showed one putative small open reading frame (ORF1), with no significant homology with known genes, and a partial putative second coding region (ORF2) with a high degree of similarity with several methionyl tRNA synthesis (metS) genes. The two coding regions were separated by a short spacer region. Primers targeted to ORF2 plus part of the spacer region and primers designed for the amplification of the entire cloned RAPD fragment were found to be species-specific for the detection of P. acidilactici strains. Furthermore primers designed on the ORF1 sequence allowed the amplification of a 439 bp fragment only in some P. acidilactici strains, including pediocin producing strains.

Amino Acid Sequence↗

Bacillus thermodenitrificans sp. nov., nom. rev.

A polyphasic study was performed on 10 soil isolates of thermophilic denitrifying Bacillus strains from different geographical areas. The presence of two main characteristic bands following amplification of the internal transcribed spacer (ITS) region of rrn operons suggests a close relatedness to 'Bacillus thermodenitrificans'. The isolates cluster around two strains of 'B. thermodenitrificans' in riboprint and fatty acid analyses, though differences occur at the strain level. Subsequent DNA-DNA reassociation studies including the 10 isolates, 'B. thermodenitrificans' DSM 465T and DSM 466, and Bacillus stearothermophilus ATCC 12980T and Bacillus thermoleovorans ATCC 43513T revealed such a high level of genomic relatedness between the isolates and the DSM strains (> 73% similarity) that they must be considered strains of the same taxon. The degree of DNA-DNA similarity between the 12 strains of 'B. thermodenitrificans' and the type strains of the other two phylogenetically neighbouring Bacillus species was significantly lower (21-43% similarity). Based upon phylogenetic, chemotaxonomic and phenotypic evidence, the designation of B. thermodenitrificans sp. nov., nom. rev. is proposed. The type strain of B. thermodenitrificans is DSM 465T.

Bacillus↗

16S-23S rRNA internal transcribed spacers as molecular markers for the species of the 16S rRNA group I of the genus Bacillus.

The internal transcribed spacers between the 16S and the 23S ribosomal RNA genes were used to discriminate species of the 16S rRNA group I of the genus Bacillus by PCR. The spacer-PCR fingerprints clearly discriminated the different species, except those closely related like the members of the 'B. cereus group' (B. cereus, B. thuringiensis and B. mycoides) and the species of the 'B. subtilis group' (B. amyloliquefaciens and B. licheniformis). Examining in more detail the shortest internal transcribed spacers, B. subtilis group species were distinguished by single-strand conformation polymorphism analysis, whereas B. mycoides was differentiated from B. cereus/B. thuringiensis by restriction analysis.

Animals↗

Discrimination among Pediocin AcH/PA-1 producer strains by comparison of pedB and pedD amplified genes and by multiplex PCR assay.

Pediococcus acidilactici, Pediococcus parvulus and Lactobacillus plantarum pediocin AcH/PA-1 produces strains were studied with the aim to investigate their common genetic pediocin determinant using pedA, pedB, pedC and pedD gene-targeted PCR assay. Single Strand Conformation Polymorphism and restriction analysis of pedA and pedC amplified fragments from the three different species did not show any differences in sequence while these analysis carried out on pedB and pedD amplified fragments highlighted differences related to the three species analyzed harboring these plasmid encoded genes. Furthermore different multiplex PCR assay using IdhD, pedA and pedD as target genes were developed to clearly identify the pediocin AcH/PA-1 producer strains and to obtain the simultaneous identification of the P. acidilactici strains.

Bacteriocins↗

Comparative study of bacteremias caused by Enterococcus spp. with and without high-level resistance to gentamicin. The Grupo Andaluz para el estudio de las Enfermedades Infecciosas.

A prospective, multicenter study was carried out over a period of 10 months. All patients with clinically significant bacteremia caused by Enterococcus spp. were included. The epidemiological, microbiological, clinical, and prognostic features and the relationship of these features to the presence of high-level resistance to gentamicin (HLRG) were studied. Ninety-three patients with enterococcal bacteremia were included, and 31 of these cases were caused by HLRG (33%). The multivariate analysis selected chronic renal failure, intensive care unit stay, previous use of antimicrobial agents, and Enterococcus faecalis species as the independent risk factors that influenced the development of HLRG. The strains with HLRG showed lower levels of susceptibility to penicillin and ciprofloxacin. Clinical features (except for chronic renal failure) were similar in both groups of patients. HLRG did not influence the prognosis for patients with enterococcal bacteremia in terms of either the crude mortality rate (29% for patients with bacteremia caused by enterococci with HLRG and 28% for patients not infected with strains with HLRG) or the hospital stay after the acquisition of enterococcal bacteremia. Hemodynamic compromise, inappropriate antimicrobial therapy, and mechanical ventilation were revealed in the multivariate analysis to be the independent risk factors for mortality. Prolonged hospitalization was associated with the nosocomial acquisition of bacteremia and polymicrobial infections.

Adult↗

Effects of nebulized salbutamol on respiratory mechanics in adult respiratory distress syndrome.

OBJECTIVE: To determine whether nebulized salbutamol improves the respiratory mechanics of patients with adult respiratory distress syndrome (ARDS). We also assessed the mechanisms that contribute to high respiratory system resistances during this disease. PATIENTS AND SETTING: Eleven consecutive patients with ARDS without clinical evidence of chronic obstructive pulmonary disease, admitted to a polivalent intensive care unit, and mechanically ventilated with Siemens Elema Servo C ventilator at constant inspiratory flow. METHOD: Peak airway pressure (Ppeak), airway pressure immediately after end inspiratory occlusion (P1), plateau pressure (P2) and intrinsic positive end-expiratory pressure (PEEPi) were measured at baseline condition and then 5, 15, and 30 min after 1 mg of salbutamol had been administered via a nebulizer through the endotracheal tube. Partial pressure of arterial oxygen (PaO2), heart rate (HR) and mean blood pressure (BP) were monitored and minimal respiratory system resistances (Rrs, m), additional resistances (DRrs) and static compliance (Cst) were computed. RESULTS: Between baseline and post-salbutamol, we observed changes in Ppeak, P1, P2, PEEPi and Rrs, m. As there were no significant differences between values at the different intervals during post administration, the results are described comparing baseline and 15 min post-salbutamol administration values. We found a significant decrease in Ppeak (4.9 +/- 0.8 cmH2O). P1 (3 +/- 0.6 cmH2O). P2 (2.1 +/- 0.6 cmH2O), PEEPi (1.9 +/- 0.5 cmH2O) and Rrs, m (1.9 +/- 0.3 cmH2O/1 s-1); DR, rs decreased in five patients, did not change in four and increased in two. HR, PaO2 and BP did not change. CONCLUSIONS: a) Salbutamol administered through the endotracheal tube by a nebulizer device lessens respiratory system resistances and airway and alveolar pressures, and therefore could decrease the risk of barotrauma and alveolar damage; b) high respiratory system resistances in ARDS have an increased smooth muscle tone component that can be reversible with salbutamol.

Adult↗

[Spread pattern of HIV-2 in patients at risk. Evaluation of serologic markers].

The aim of this paper is to ascertain the spread pattern of HIV-2 in patients at risk in an area of frequent contact with sub-Saharan Africa and evaluate the seric marker of HIV-2 infection. 606 serum samples from 524 patients were analysed. 445 patients were intravenous drug users (IDU), 17 used inhaled drugs, 26 had HIV-2 (+)partner, and others 36 high-risk practice. The ser were analysed for HIV-1 and HIV-2, using ELISA, Western blot (LAVBLOT 1, LAVBLOT 2) and specific synthetic peptides such as gp 41 and gp 36 (PEPTI-LAV 1-2). 245 out of 524 (47%) patients were HIV-1 (+). 65 out of 524 (12.4%) were Elavia-2 and HIV-1 (+). All samples tests using Western blot 1, confirmed the results of the ELISA (2 protein of the membrane). The Western blot of HIV-2 Elavia-2 (+) in 2/53 showed two proteins of the membrane and 26/53 one protein of the membrane and several of the core. The PEPTIL-LAV 1-2 was HIV-1 positive in 77/77 HIV-1 serum samples and in 10 HIV-2 positive, however, in all cases the HIV-2 reactivity was lower than HIV-1, allowing the orientation of the diagnosis towards the HIV-1 positive serum. In spite of the frequent contact with Africa, the spread of HIV-2 in the south of Spain is still quite insignificant. The Western blot of HIV-2 gives a high proportion of double reactivity, including those cases with restrictive criteria to be positive. PEPTI-LAV 1-2 has proved most useful in the diagnosis orientation in the cases of crossed reactivity between HIV-1 and HIV-2.

Adult↗

Genotypic characterization of thermophilic bacilli: a study on new soil isolates and several reference strains.

A genotypic study using amplified ribosomal DNA restriction analysis (ARDRA), random amplified polymorphic DNA fingerprinting (RAPD) and ribosomal spacer analysis (RSA) in comparison with DNA-DNA reassociation experiments was carried out with 85 thermophilic Bacillus isolates from uncultivated soil of 14 different geographical areas and seventeen reference strains representing defined thermophilic Bacillus species. This approach permitted the attribution of 51% of the new isolates to the Bacillus thermoleovorans group and the identification of 40% of the new isolates as B. "thermodenitrificans". Moreover, 2 strains were assigned to B. pallidus species and 1 isolate to B. thermosphaericus species. The remaining 6% of our thermophilic isolates from soil, constituting 2 DNA-DNA homology groups, are still unidentified. A detailed genotypic characterization of the heterogeneous species of B. thermoleovorans and B. stearothermophilus was also presented.

Bacillus↗