Publicaciones científicas 1999

Cloning and analysis of the L-lactate utilization genes from Streptococcus iniae

Applied And Environmental Microbiology 65(10):4346-50.

     The presence of lactate oxidase was examined in eight Streptococcus species and some related species of bacteria. A clone (pGR002) was isolated from a genomic library of Streptococcus iniae generated in Escherichia coli, containing a DNA fragment spanning two genes designated lctO and lctP. We show that these genes are likely to be involved in the L-lactic acid aerobic metabolism of this organism. This DNA fragment has been sequenced and characterized. A comparison of the deduced amino acid sequence of LctP protein demonstrated that the protein had significant homology with the L-lactate permeases of other bacteria. The amino acid sequence of the LctO protein of S. iniae also showed a strong homology to L-lactate oxidase from Aerococcus vir… Leer más

Gibello A., Collins MD., Dominguez L., Fernandez-Garayzabal JF. y Richardson PT.

Helcococcus ovis sp. nov., a gram-positive organism from sheep

International Journal Of Systematic Bacteriology 49(Pt 4):1429-32.

     Two strains of a hitherto undescribed Gram-positive, catalase-negative, facultatively anaerobic coccus isolated from sheep were characterized by phenotypic and molecular taxonomic methods. Comparative 16S rRNA gene sequencing studies demonstrated that the unknown strains were genealogically highly related and constitute a new line close to, but distinct from, Helcococcus kunzii. The unknown bacterium was readily distinguished from H. kunzii by biochemical tests and electrophoretic analysis of whole-cell proteins. Based on phylogenetic and phenotypic evidence, it is proposed that the unknown bacterium be classified as Helcococcus ovis sp. nov. The type strain of Helcococcus ovis is CCUG 37441T… Leer más

Collins MD., Falsen E., Foster G., Monasterio LR., Dominguez L. y Fernandez-Garayzabal JF..

Rapid detection of specific polyclonal and monoclonal antibodies against bovine leukemia virus

Journal Of Virological Methods 82(2):129-36.

     ELISA and Western blot have been used for detecting specific antibodies or antigens for routine diagnostic laboratory tests and experimental protocols, as well as for screening hybridomas secreting antibodies. Although these techniques are sensitive, some slow growing hybridomas are identified as positive only when they are grown slowly long time. We standardized the dot-ELISA, a more sensitive technique, for the detection of antibodies against BLV. The main advantages of the dot-ELISA described in this study are (a) its sensitivity, detecting hybridomas which would otherwise be considered negative and discarded from the results of indirect ELISA and/or Western blot; and (b) the possibility of economizing reagents using as little as 1 micro… Leer más

Llames L., Goyache J., Domenech A., de Avila A., Suarez G. y Gomez-Lucia E.

Field evaluation of the single intradermal cervical tuberculin test and the interferon-gamma assay for detection and eradication of bovine tuberculosis in Spain

Veterinary Microbiology 70(1-2):55-66.

     A field comparison of the interferon-gamma (IFN-gamma) assay and the single intradermal cervical tuberculin (SICT) test for the diagnosis of bovine tuberculosis was conducted. A total of 1136 cattle belonging to 85 herds placed in `Castilla y León` (northwestern Spain) were chosen, and 21 of these herds were subjected to the diagnostic assays two or three times at intervals of at least 4 months. All the animals positive to any of the tests were slaughtered and tuberculosis was confirmed by culture isolation method (CIM) and further identification by means of PCR. Only 10.6% of cattle reacted with the bovine PPD in the SICT test, a percentage that increased to 12.8% in the IFN-gamma assay. The sensitivity of the IFN-gamma assay compared to C… Leer más

Gonzalez-Llamazares O., Gutierrez CB., Alvarez D., de la Puente VA., Dominguez L. y Rodriguez-Ferri E.

Comparison of different methods for diagnosis of bovine tuberculosis from tuberculin- or interferon-gamma-reacting cattle in Spain

Journal Of Applied Microbiology 87(4):465-71.

     Of 1479 cattle from herds in Northwestern Spain previously diagnosed as tuberculosis (TB) positive, 218 animals which gave a positive tuberculin or interferon-gamma reaction were examined at the slaughterhouse. Medial retropharyngeal and caudal mediastinal lymph nodes, and any tissues containing lesions suspected to be tuberculous, were removed and submitted to the laboratory. Three techniques for diagnosis of TB were used: post mortem examination (PME), smear staining by means of auramine O method (AOM), and culture isolation in Coletsos and Lowenstein-Jensen media followed by confirmation of M. tuberculosis complex organisms using PCR (CIM-PCR). Only 123 (29.9%) of the 412 samples collected showed typical tuberculous lesions. Confirmed M.… Leer más

Gonzalez-Llamazares O., Gutierrez CB., Aranaz A., Liebana E., Dominguez L. y Rodriguez-Ferri E.

The smcL gene of Listeria ivanovii encodes a sphingomyelinase C that mediates bacterial escape from the phagocytic vacuole

Molecular Microbiology 33(3):510-23.

     The ruminant pathogen Listeria ivanovii differs from Listeria monocytogenes in that it causes strong, bizonal haemolysis and a characteristic shovel-shaped co-operative haemolytic (`CAMP-like`) reaction with Rhodococcus equi. We cloned the gene responsible for the differential haemolytic properties of L. ivanovii, smcL. It encodes a sphingomyelinase C (SMase) highly similar (> 50% identity) to the SMases from Staphylococcus aureus (beta-toxin), Bacillus cereus and Leptospira interrogans. smcL was transcribed monocistronically and was expressed independently of PrfA. Low-stringency Southern blots demonstrated that, within the genus Listeria, smcL was present only in L. ivanovii. We constructed an smcL knock-out mutant. Its phenotype on blood… Leer más

Gonzalez-Zorn B., Dominguez-Bernal G., Suarez M., Ripio MT., Vega Y., Novella S. y Vazquez-Boland JA.

Outbreak of acute ovine mastitis associated with Pseudomonas aeruginosa infection

The Veterinary Record 145:111-112.

Las Heras A., Dominguez L., Lopez I. y Fernandez-Garayzabal JF..

Repeated oral dosing with Listeria monocytogenes in mice as a model of central nervous system listeriosis in man

Journal Of Comparative Pathology 121:117-123.

     Human1999 W.B. Saunders Company Ltdlisteriosis is a food-borne disease of immunosuppressed or previously healthy adults. The repeated oral administration of a sublethal dose (5×109colony-forming units) ofCopyright Listeria monocytogenesfor 7 or 10 consecutive days led to the development of severe central nervous system (CNS) lesions in 25% of experimental mice. Histopathological examination of the brain revealed rhombencephalitis and ventriculitis as two distinct inflammatory patterns, resembling those seen in human listeriosis. This model would seem to be potentially useful for research on pathogenesis, predisposing factors and therapy in CNS listeriosis in man.1999 W.B. Saunders and Company Ltd.… Leer más

Altimira J., Prats N., Lopez S., Domingo M., Briones V., Dominguez L. y Marco A.

Mycobacterium tuberculosis subsp. caprae subsp. nov.: a taxonomic study of a new member of the Mycobacterium tuberculosis complex isolated from goats in Spain

International Journal Of Systematic Bacteriology 49(Pt 3):1263-73.

     Isolates from the Mycobacterium tuberculosis complex cultured from caprine pathological tissue samples were biochemically and genetically characterized. The isolates were negative for nitrate reduction and niacin accumulation, they weakly hydrolysed Tween 80, were sensitive to pyrazinamide (50 micrograms ml-1) and were resistant to 1 and 2 micrograms tiophene-2-carboxylic acid hydrazide ml-1 but not to 5 or 10 micrograms tiophene-2-carboxylic acid hydrazide ml-1. Sequencing of the pncA gene revealed a polymorphism characteristic of M. tuberculosis, whereas oxyR, katG and gyrA sequences were characteristic of Mycobacterium bovis. The fingerprinting patterns obtained with IS6110, direct repeats and polymorphic G+C-rich sequence-associated RFL… Leer más

Aranaz A., Liebana E., Gomez-Mampaso E., Galan JC., Cousins DV., Ortega A., Blazquez J., Baquero F., Mateos A., Suarez G. y Dominguez L..

Prevalence and aetiology of subclinical mastitis in dairy ewes of the Madrid region

Small Ruminant Research 32:21-29.

     A bacteriological survey for studying the prevalence and aetiology of subclinical mastitis was carried out in 22 dairy sheep flocks of the Madrid region. A total of 1128 milk samples were collected from 564 ewes. 17 Manchega flocks (5 flocks had mechanical milking and 12 flocks had hand milking) and 5 Assaf flocks (all had mechanical milking) were included in the study. Prevalence of subclinical mastitis in the different flocks ranged from 4.5-67% of the glands and 9-83% of the animals, with an average of 21 and 34.%, respectively. Prevalence of subclinical mastitis in Manchega flocks with mechanical milking was lower than those with hand milking (P<0.05). Assaf flocks had higher prevalence rates than Manchega flocks with mechanical milking… Leer más

Las Heras A., Dominguez L. y Fernandez-Garayzabal JF..

Association of Pseudomonas anguilliseptica infection with Winter Disease in sea-bream

Journal Of Fish Diseases 22:69-71.

Domenech A., Fernandez-Garayzabal JF., Garcia JA., Cutuli MT., Blanco MM., Gibello A., Moreno MA. y Dominguez L..

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

Applied And Environmental Microbiology 65(1):346-50.

     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… Leer más

Gibello A., Blanco MM., Moreno MA., Cutuli MT., Domenech A., Dominguez L. y Fernandez-Garayzabal JF..