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M A Moreno

Publications and source records attributed to M A Moreno.

At least 37 records · Page 2Linked to original sources
PubMed2001

Molecular typing by pulsed-field gel electrophoresis of Spanish animal and human Listeria monocytogenes isolates.

A total of 153 strains of Listeria monocytogenes isolated from different sources (72 from sheep, 12 from cattle, 18 from feedstuffs, and 51 from humans) in Spain from 1989 to 2000 were characterized by pulsed-field gel electrophoresis. The strains of L. monocytogenes displayed 55 pulsotypes. The 84 animal, 51 human, and 18 feedstuff strains displayed 31, 29, and 7 different pulsotypes, respectively, indicating a great genetic diversity among the Spanish L. monocytogenes isolates studied. L. monocytogenes isolates from clinical samples and feedstuffs consumed by the diseased animals were analyzed in 21 flocks. In most cases, clinical strains from different animals of the same flock had identical pulsotypes, confirming the existence of a listeriosis outbreak. L. monocytogenes strains with pulsotypes identical to those of clinical strains were isolated from silage, potatoes, and maize stalks. This is the first study wherein potatoes and maize stalks are epidemiologically linked with clinical listeriosis.

Animal Feed↗
PubMed2001

Reduced function of a phenylacetate-oxidizing cytochrome p450 caused strong genetic improvement in early phylogeny of penicillin-producing strains.

The single-copy pahA gene from Penicillium chrysogenum encodes a phenylacetate 2-hydroxylase that catalyzes the first step of phenylacetate catabolism, an oxidative route that decreases the precursor availability for penicillin G biosynthesis. PahA protein is homologous to cytochrome P450 monooxygenases involved in the detoxification of xenobiotic compounds, with 84% identity to the Aspergillus nidulans homologue PhacA. Expression level of pahA displays an inverse correlation with the penicillin productivity of the strain and is subject to induction by phenylacetic acid. Gene expression studies have revealed a reduced oxidative activity of the protein encoded by pahA genes from penicillin-overproducing strains of P. chrysogenum compared to the activity conferred by phacA of A. nidulans. Sequencing and expression of wild-type pahA from P. chrysogenum NRRL 1951 revealed that an L181F mutation was responsible for the reduced function in present industrial strains. The mutation has been tracked down to Wisconsin 49-133, a mutant obtained at the Department of Botany of the University of Wisconsin in 1949, at the beginning of the development of the Wisconsin family of strains.

Aspergillus nidulans↗
PubMed2000

Prevalence of vancomycin-resistant Enterococcus faecium (VREF) in pig faeces from slaughterhouses in Spain.

A study to estimate the prevalence of vancomycin-resistant Enterococcus faecium in faecal samples from pigs at slaughterhouses in Spain was carried out between November 1998 and January 1999 with 900 samples taken from four abattoirs representing 9.7% of all pig slaughtered in 1998. Using a selective enrichment broth with vancomycin (8microg/ml), 64 samples (7.1%; 95% CI: 5.5, 9.0%) had E. faecium vancomycin-resistant strains that showed minimal inhibitory concentrations of 256microg/ml (62 strains) and 512microg/ml (two strains). Results by farm showed that 43 of the 240 pig farms represented in the sampling had at least one faecal sample with vancomycin-resistant E. faecium.

Abattoirs↗
PubMed2000

Risk factors for brucellosis seroprevalence of sheep and goat flocks in Spain.

Risk factors for ovine and caprine brucellosis in the Avila region (center of Spain) were evaluated using data from a cross-sectional study of the most important diseases of small ruminants in this Spanish region between 1996 and 1997. Questionnaire data from 56 herds (35 ovine and 21 caprine) were used. Sixteen (29%) flocks (3 caprine and 13 ovine) were brucellosis-seropositive. Overall, 0.7% of sheep and 0.1% of goats were seropositive. Eleven risk factors were studied at the group level by logistic regression using flock brucellosis-status as outcome, and by linear regression using percentage of brucellosis-seropositivity as outcome. Both final models contained the same variables: contact with sheep and grazing in communal pastures as risk factors, and frequency of disinfecting practices as a protective factor.

Animals↗
PubMed2000

Soil type as a putative risk factor of ovine and caprine paratuberculosis seropositivity in Spain.

Relationships between soil type and ovine and caprine paratuberculosis in the Avila region (central Spain) were evaluated using data from a cross-sectional study of the most-important diseases of small ruminants in this Spanish region between 1996 and 1997. Questionnaire data from 61 herds (38 ovine and 23 caprine) and 1451 serum samples (1041 ovine and 410 caprine) were used. Herd paratuberculosis (herds were scored as positive to paratuberculosis if any of the serum samples was positive in an agar-gel immunodifussion) was the outcome of interest, whereas soil type in the municipality where farms were located was the predictor variable. Other variables related to soil and soil usage, and herd size, replacement, main food production and animal species were also introduced into the multivariable logistic regression. The final model contained only two independent variables: the predictor variable soil type (coded as two dummy variables ST-1 and ST-2) and herd size (dichotomized at the highest quartile). The estimated Odds Ratios were 25.9 (95% CI: 1.6, 411) for ST-1 (entisols as soil type) and 3.5 (95% CI: 0.3, 45) for ST-2 (inceptisols as soil type).

Animals↗
PubMed2000

Large-scale T-DNA mutagenesis in Arabidopsis for functional genomic analysis.

In planta Agrobacterium-mediated transformation combined with a soil-based herbicide selection for transgenic plants was used to recover large numbers of transgenic Arabidopsis plants for functional genomic studies. A tissue-culture-free system for generating transgenic plants was achieved by infiltrating Arabidopsis plants with Agrobacterium tumefaciens harboring a binary T-DNA vector containing the phosphinothricin acetyltransferase gene from Streptomyces hygroscopicus, and by selecting transgenic Arabidopsis growing in soil by foliar application of the herbicide Finale (phosphinothricin). Analysis of herbicide-resistant plants indicated that all were transgenic and that the T-DNA transformation process occurred late during flower development, resulting in a preponderance of independently derived T-DNA insertions. T-DNA insertions were usually integrated in a concatenated, rearranged form, and using linkage analysis, we estimated that T1 plants carried between one and five T-DNA loci. Using pooling strategies, both DNA and seed pools were generated from about 38,000 Arabidopsis plants representing over 115,000 independent T-DNA insertions. We show the utility of these transgenic lines for identifying insertion mutations using gene sequence and PCR-based screening.

Agrobacterium tumefaciens↗
PubMed2000

Antibiotic resistance monitoring: the Spanish programme. The VAV Network. Red de Vigilancia de Resistencias Antibióticas en Bacterias de Origen Veterinario.

Antimicrobial resistance is a problem in modern public health and antimicrobial use and especially misuse, the most important selecting force for bacterial antibiotic resistance. As this resistance must be monitored we have designed the Spanish network 'Red de Vigilancia de Resistencias Antibióticas en Bacterias de Origen Veterinario'. This network covers the three critical points of veterinary responsibility, bacteria from sick animals, bacteria from healthy animals and bacteria from food animals. Key bacteria, antimicrobials and animal species have been defined for each of these groups along with laboratory methods for testing antimicrobial susceptibility and for data analysis and reporting. Surveillance of sick animals was first implemented using Escherichia coli as the sentinel bacterium. Surveillance of E. coli and Enterococcus faecium from healthy pigs was implemented in 1998. In July 1999, data collection on Salmonella spp. was initiated in poultry slaughterhouses. Additionally, the prevalence of vancomycin resistant E. faecium was also monitored. This network has specific topics of interest related to methods of determining resistance, analysis and reporting of data, methods of use for veterinary practitioners and collaboration with public health authorities.

Animals↗
PubMed2000

Epidemiology and ecology of enterococci, with special reference to antibiotic resistant strains, in animals, humans and the environment. Example of an ongoing project within the European research programme.

The objectives of the present study are to generate knowledge of the ecology and epidemiology of enterococci in the food chain by studying the following: (1) the population structure (in measures of abundance, number of vancomycin resistant strains, antibiotic resistance patterns, diversity, and stability) among enterococcal populations in different geographical regions and in different links of the food chain (2) possible transmission of strains through the food chain and between hospital environments and the food chain (3) the association between vancomycin resistance and individual strains of enterococci and (4) the diversity of the drug resistance genes in enterococci. So far, 1578 samples have been collected from different countries within the EU (Sweden, Denmark, UK and Spain), and from different habitats (pig farms, carcasses in slaughter houses, soil, manure, water, sewage, and humans). Total and vancomycin resistant enterococcal populations in each sample have been enumerated and more than 12000 isolates have been characterised by phenotyping. Representative isolates are further species identified and characterised by genotyping and MIC determination and from antibiotic resistant isolates the resistance genes are characterised.

Animals↗
PubMed2000

Surveillance of antimicrobial resistance in Escherichia coli strains isolated from pigs at Spanish slaughterhouses.

Antimicrobial resistance can make the efficient treatment of bacterial infections in humans and animals more difficult. Antimicrobial use in food animals may be one of the factors contributing to resistance. The Spanish surveillance network VAV has established a baseline of antimicrobial resistance in Escherichia coli strains from healthy pigs. Minimum inhibitory concentration and patterns of resistance to antimicrobials used in animals and humans were determined for 205 faecal strains isolated in a sampling frame of four slaughterhouses in Spain from 220 pigs in 1998. Higher levels of resistance were seen against antimicrobial agents authorised for use in food animals especially tetracycline, sulphonamides, trimethoprim and amoxycillin. All isolates were susceptible to antimicrobials employed mainly in humans such as ceftazidime, cefotaxime, imipenem, aztreonam and amikacin.

Abattoirs↗
PubMed2000

Phenotypic and genetic characterization of Lactococcus garvieae isolated in Spain from lactococcosis outbreaks and comparison with isolates of other countries and sources.

The phenotypic and genetic analysis results for 84 isolates of Lactococcus garvieae (including 62 strains from trout with lactococcosis from four different countries, 7 strains from cows and water buffalos with subclinical mastitis, 3 from water, and 10 from human clinical samples) are presented. There was great phenotypic heterogeneity (13 different biotypes) based on the acidification of saccharose, tagatose, mannitol, and cyclodextrin and the presence of the enzymes pyroglutamic acid arylamidase and N-acetyl-beta-glucosaminidase. L. garvieae also exhibited high genetic diversity by pulsed-field gel electrophoresis (PFGE), with 19 different pulsotypes among the isolates of L. garvieae studied. Only epidemiologically related strains, like the Spanish and Italian fish isolates and the cow and water buffalo isolates, displayed a close genetic relationship by PFGE, while the strains isolated from sporadic clinical cases, like the human isolates, were genetically unrelated. Overall, a general correlation between phenotypic and genetic data was observed. Epidemiological analysis of biotype and PFGE results indicated that the trout lactococcosis outbreaks in Spain and Portugal and those in France and Italy were produced by genetically unrelated clones. In Spain, two different clones were detected; the outbreaks diagnosed from 1995 onward were produced by a clone (biotype 2, pulsotype A1) which, although genetically related, was different from the one that was responsible for the outbreaks studied between 1991 and 1994 (biotype 1, pulsotype B). The Portuguese isolate had a biochemical profile identical to that of the Spanish strain isolated from 1995 onward and is also genetically closely related to this strain (pulsotype A2). There was a close relationship between the two pulsotypes (E and F) found in the Italian isolates. The French isolate (biotype 3, pulsotype D) was not genetically related to any other L. garvieae fish isolate. These results suggest the existence of diverse infection sources for the different lactococcosis outbreaks.

Animals↗
PubMed1999

Trace element levels in whole blood samples from residents of the city Badajoz, Spain.

Copper, lead, cadmium, and zinc were determined by anodic stripping voltammetry after sample digestion and potentiometric stripping analysis was used for Pb and Cd determination in original samples. Selenium was determined by cathodic stripping voltammetry or hydride generation AAS. Element levels found in the whole blood sample in a group of 82 people are for Cd: 0.98 +/- 0.94 ng/ml; for Pb: 46.7 +/- 28.6 ng/ml; for Cu: 1.07 +/- 0.12 micrograms/ml; for Zn: 6.95 +/- 1.08 micrograms/ml, and for Se: 116 +/- 25 ng/ml. Analytical data have been correlated to age, sex, smokers or non-smokers, drinking and food habits.

Adult↗
PubMed1999

Comparison of derivative spectrophotometric and liquid chromatographic methods for the determination of omeprazole in aqueous solutions during stability studies.

A first derivative spectrophotometric method was developed for the determination of omeprazole in aqueous solutions during stability studies. The derivative procedure was based on the linear relationship between the omeprazole concentration and the first derivative amplitude at 313 nm. The first derivative spectra was developed between 200 and 400 nm (deltalambda = 8). This method was validated and compared with the official high-performance liquid chromatography (HPLC) method of the USP. It showed good linearity in the range of concentrations studied (10-30 microg ml(-1)), precision (repeatability and inter-day reproducibility), recovery and specificity in stability studies. It also seemed to be 2.59 times more sensitive than the HPLC method. These results allowed to consider this procedure as useful for the rapid analysis of omeprazole in stability studies since there was no interference with its decomposition products.

Anti-Ulcer Agents↗
PubMed1999

Development of a PCR assay for detection of Yersinia ruckeri in tissues of inoculated and naturally infected trout.

A PCR-based method was developed for the specific detection of Yersinia ruckeri in tissues of inoculated trout and naturally infected trout. No amplification products were obtained with other yersiniae, bacterial fish pathogens, or phylogenetically related bacteria (n = 34). The sensitivity of PCR detection was 60 to 65 bacterial cells per PCR tube, which was decreased to 10 to 20 cells by hybridization with a nonradioactive probe. The PCR assay proved to be as reliable as and faster than the conventional culture method for the detection of Y. ruckeri in infected trout tissues.

Animals↗
PubMed1998

Molecular characterization of the phenylacetic acid catabolic pathway in Pseudomonas putida U: the phenylacetyl-CoA catabolon.

Fourteen different genes included in a DNA fragment of 18 kb are involved in the aerobic degradation of phenylacetic acid by Pseudomonas putida U. This catabolic pathway appears to be organized in three contiguous operons that contain the following functional units: (i) a transport system, (ii) a phenylacetic acid activating enzyme, (iii) a ring-hydroxylation complex, (iv) a ring-opening protein, (v) a beta-oxidation-like system, and (vi) two regulatory genes. This pathway constitutes the common part (core) of a complex functional unit (catabolon) integrated by several routes that catalyze the transformation of structurally related molecules into a common intermediate (phenylacetyl-CoA).

Acetyl Coenzyme A↗
PubMed1998

Transcription and weak expression of HLA-DRB6: a gene with anomalies in exon 1 and other regions.

HLA-DRB6 is one of the human major histocompatibility complex (MHC) genes present in DR1, DR2, and DR10 haplotypes (approximately 26% of individuals). It shows several anomalies in human and non-human primates, including exon 2 stop codons (non-randomly grouped between codons 74 and 94) and a promoter region, and an exon 1 coming from an inserted retrovirus. It has been shown that not only chimpanzee but also human Mhc-DRB6 lack the usual 3' untranslated (UT) polyadenylation signal, and in the present work it was found that the human DRB6 gene coming from an HLA-DR2 haplotype is effectively transcribed after transfection in mouse L cells, and that HLA-DRB6 molecules may be expressed on the cell surface. DRB6 transcription level is remarkably lower in human than in chimpanzee. Moreover, their exons 1 (both taken from the 3'LTR region of a mammary tumor retrovirus) are also different; this shows that these viral insertions may be an important mechanism for different evolutionary changes in orthologous genes of different species. The pathways by which DRB6 molecules may be expressed on the membrane are unclear but other examples of truncated protein expression have also been described, even within the human major histocompatibility complex (i. e., in HLA-G). Finally, the presence of mature HLA-DRB6 mRNA molecules supports the notion that splicing may take place even in the absence of a canonical 3'UT polyadenylation signal.

Amino Acid Sequence↗
PubMed1998

The manganese superoxide dismutase from the penicillin producer Penicillium chrysogenum.

The antioxidant enzyme superoxide dismutase has been studied in order to define mechanisms for the influence of oxygen on penicillin production. Manganese-containing SOD activity was purified from penicillin-producing cultures of the filamentous fungus Penicillium chrysogenum and reverse genetics was used to identify full-length cDNA and genomic clones. Sequence analysis revealed a 630-bp ORF containing three exons and two introns with fungal consensus splice-site junctions. The deduced amino-acid sequence (210 amino acids; 23.13 kDa) includes conserved residues required for enzymatic activity and metal binding, and shares significant similarity with Mn- and Fe-containing superoxide dismutases. The sod gene is present as a single copy in the genome of different P. chrysogenum strains and its expression level is not correlated with penicillin-G productivity.

Amino Acid Sequence↗