Domínguez Bernal, Gustavo Ramón

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First Name
Gustavo Ramón
Last Name
Domínguez Bernal
Universidad Complutense de Madrid
Faculty / Institute
Sanidad Animal
Sanidad Animal
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Now showing 1 - 10 of 11
  • Publication
    Mechanisms of resistance and susceptibility to experimental visceral leishmaniosis: BALB/c mouse versus syrian hamster model
    (2011-02-23) Nieto, Ana; Madrid-Elena, Nadia; Carrión Herrero, Francisco Javier; Domínguez Bernal, Gustavo Ramón; Orden Gutiérrez, José Antonio; Fuente López, Ricardo De La
    Several animal models have been established to study visceral leishmaniosis (VL), a worldwide vector-borne disease affecting humans and domestic animals that constitutes a serious public health problem. BALB/c mice and Syrian hamsters are the most widely used experimental models. In this paper, we summarize the advantages and disadvantages of these two experimental models and discuss the results obtained using these models in different studies of VL. Studies using the BALB/c mouse model have underscored differences between the liver and spleen in the course of VL, indicating that pathological evaluation of the visceral organs is essential for understanding the immune mechanisms induced by Leishmania infantum infection. The main goal of this review is to collate the relevant literature on Leishmania pathogenesis into a sequence of events, providing a schematic view of the main components of adaptive and innate immunity in the liver and spleen after experimental infection with L. infantum or L. donovani. This review also presents several viewpoints and reflections about some controversial aspects of Leishmania research, including the choice of experimental model, route of administration, inoculum size and the relevance of pathology (intimately linked to parasite persistence): a thorough understanding of which is essential for future VL research and the successful development of efficient control strategies for Leishmania spp.
  • Publication
    Engineering of a live Salmonella enterica serovar Choleraesuis negative-marker strain that allows serological differentiation between immunised and infected animals
    (Elsevier, 2016-07-01) Herrero-Gil, Aldara; Carrión Herrero, Francisco Javier; Orden Gutiérrez, José Antonio; Fuente López, Ricardo De La; Domínguez Bernal, Gustavo Ramón
    The usefulness of Salmonella vaccine vehicles is limited by the fact that control programmes relying on Salmonella bacteriology and serology cannot differentiate infected animals from vaccinated ones, an ability referred to as DIVA (differentiating infected from vaccinated animals). As a first step towards Salmonella-based DIVA vaccines, the ompA gene was deleted in live attenuated ΔphoP and ΔrpoS vaccine strains. The ompA gene is present in all Salmonella enterica serovars and it encodes an abundant, highly immunogenic outer membrane protein. The double mutant ΔphoP ΔompA and ΔrpoS ΔompA strains showed similar virulence attenuation, safety and immunogenicity in a mouse model of infection as the parental ΔphoP and ΔrpoS strains. Sera from mice inoculated with the double mutant strains failed to recognise OmpA in Western blots of outer membrane extracts, whereas the protein was recognised by sera from mice inoculated with wild-type Salmonella or a mixture of double mutant and parental strains. These data suggest that OmpA can be a suitable negative marker for DIVA vaccines.
  • Publication
    Characterisation of the ex vivo virulence of Leishmania infantum isolates from Phlebotomus perniciosus from an outbreak of human leishmaniosis in Madrid, Spain
    (BioMed Central Ltd., 2014-11-07) Jiménez, Maribel; Molina, Ricardo; Ordóñez-Gutiérrez, Lara; Carrión Herrero, Francisco Javier; Domínguez Bernal, Gustavo Ramón; Martínez Rodrigo, Abel; Mas Zubiri, Alicia; Cutuli Simón, María Teresa
    Background Since mid 2009, an outbreak of human leishmaniosis in Madrid, Spain, has involved more than 560 clinical cases. Many of the cases occurred in people who live in areas around a newly constructed green park (BosqueSur). This periurban park provides a suitable habitat for sand flies (the vectors of Leishmania infantum). Indeed, studies of blood meals from sand flies captured in the area showed a strong association between the insect vector, hares or rabbits, and humans in the area. Interestingly, up to 70% of cases have been found in immunocompetent patients (aged between 46-60 years). This study was designed to evaluate the ex vivo virulence of the L. infantum isolates from Phlebotomus perniciosus captured in this area of Madrid. Methods Murine macrophages and dendritic cells were infected ex vivo with L. infantum strain BCN150, isolate BOS1FL1, or isolate POL2FL7. At different times after infection, the infection indices, cytokine production (IL-12p40 and IL-10), NO release and arginase activities were evaluated. Results Using an ex vivo model of infection in murine bone marrow-derived cells, we found that infection with isolates BOS1FL1 and POL2FL7 undermined host immune defence mechanisms in multiple ways. The main factors identified were changes in both the balance of iNOS versus arginase activities and the equilibrium between the production of IL-12 and IL-10. Infection with isolates BOS1FL1 and POL2FL7 also resulted in higher infection rates compared to the BCN150 strain. Infection index values at 24 h were as follows: BCN150-infected cells, 110 for infected MØ and 115 for infected DC; BOS1FL1-infected cells, 300 for infected MØ and 247 for infected DC; and POL2FL7-infected cells, 275 for infected MØ and 292 for infected DC. Conclusions Our data indicate that L. infantum isolates captured from this endemic area exhibited high virulence in terms of infection index, cytokine production and enzymatic activities involved in the pathogenesis of visceral leishmaniosis. Altogether, these data provide a starting point for the study of the virulence behaviour of parasites (BOS1FL1 and POL2FL7) isolated from P. perniciosus during the outbreak of human leishmaniosis in Madrid, Spain, and their involvement in infecting immunocompetent hosts.
  • Publication
    Short communication: Isolation frequency of bacteria causing lymphadenitis and abscesses in small ruminants in central Spain
    (Elsevier, 2017-07-10) Heras, Moisés de las; Torrijos, Carlos; Carrión Herrero, Francisco Javier; Fuente López, Ricardo De La; Díez De Tejada Martín, María Paloma; Pérez Sancho, Marta; Orden Gutiérrez, José Antonio; Domínguez Bernal, Gustavo Ramón
    Infectious lymphadenitis in small ruminants caused by Corynebacterium pseudotuberculosis and Staphylococcus aureus subsp. anaerobius are widely distributed throughout the world, and result in significant economic losses. Trueperella pyogenes has also been associated with lymphadenitis in sheep and goats. In order to determinate the isolation frequency of the different agents associated with lymphadenitis and abscesses, 171 pus samples (135 from sheep and 36 from goats) from 46 flocks were investigated. Isolated bacteria were identified by MALDI-TOF method. S. aureus subsp. anaerobius was the most frequently detected agent. It was identified in 76 animals (59 sheep and 17 goats) from 24 of the surveyed flocks. Of these infected animal, 25 (32,9%) were over one year old, confirming that abscess disease may occur in a significant percentage of adult animals. C. pseudotuberculosis was identified in 45 of the sampled animals (36 sheep and 9 goats) from 24 flocks. Only 5 of animals suffering caseous lymphadenitis were under one year old. T. pyogenes was isolated from 17 animals (13 sheep and 4 goats) in 11 flocks. Seven of these samples were taken from subcutaneous abscesses located in not lymph nodes regions. A notable finding of this work is the isolation of Actinomyces hyovaginalis from 5 of the samples analyzed all of them taken from subcutaneous abscesses located in superficial lymph nodes regions. Thus, T. pyogenes and A. hyovaginalis should be included in the differential diagnosis of lymphadenitis in small ruminants. In 19 of the 46 surveyed flocks at least two of the four agents were detected, which underlines the need to analyze samples from several animals to reach an accurate diagnosis in flocks affected by lymphadenitis.
  • Publication
    Subtilase Cytotoxin-Coding Genes in Verotoxin-Producing Escherichia coli Strains from Sheep and Goats Differ from Those from Cattle
    (2011-09-24) Carrión Herrero, Francisco Javier; Orden Gutiérrez, José Antonio; Horcajo Iglesias, María Del Pilar; Fuente López, Ricardo De La; Ruiz Santa Quiteria Serrano De La Cruz, José Antonio; Domínguez Bernal, Gustavo Ramón
    Subtilase cytotoxin (SubAB) from verotoxin (VT)-producing Escherichia coli (VTEC) strains was first described in the 98NK2 strain and has been associated with human disease. However, SubAB has recently been found in two VT-negative E. coli strains (ED 591 and ED 32). SubAB is encoded by two closely linked, cotranscribed genes (subA and subB). In this study, we investigated the presence of subAB genes in 52 VTEC strains isolated from cattle and 209 strains from small ruminants, using PCR. Most (91.9%) VTEC strains from sheep and goats and 25% of the strains from healthy cattle possessed subAB genes. The presence of subAB in a high percentage of the VTEC strains from small ruminants might increase the pathogenicity of these strains for human beings. Some differences in the results of PCRs and in the association with some virulence genes suggested the existence of different variants of subAB. We therefore sequenced the subA gene in 12 strains and showed that the subA gene in most of the subAB-positive VTEC strains from cattle was almost identical (about 99%) to that in the 98NK2 strain, while the subA gene in most of the subAB-positive VTEC strains from small ruminants was almost identical to that in the ED 591 strain. We propose the terms subAB1 to describe the SubAB-coding genes resembling that in the 98NK2 strain and subAB2 to describe those resembling that in the ED 591 strain.
  • Publication
    Differences in virulence gene expression between atypical enteropathogenic Escherichia coli strains isolated from diarrheic and healthy ruminants
    (2012-06-07) Carrión Herrero, Francisco Javier; Horcajo Iglesias, María Del Pilar; Domínguez Bernal, Gustavo Ramón; Fuente López, Ricardo De La; Ruiz Santa Quiteria Serrano De La Cruz, José Antonio; Orden Gutiérrez, José Antonio
    Differences in the pathogenicity of atypical enteropathogenic Escherichia coli (EPEC) strains may be due, at least partially, to different expression patterns of some virulence genes. To investigate this hypothesis, the virulence gene expression patterns of 6 atypical EPEC strains isolated from healthy and diarrheic ruminants were compared using quantitative real-time reverse transcription polymerase chain reaction after growing the bacteria in culture medium alone or after binding it to HeLa epithelial cells. Some virulence genes in strains from diarrheic animals were upregulated relative to their expression in strains from healthy animals. When bacteria were cultured in the presence of HeLa cells, the ehxA and efa1/lifA genes, previously associated with the production of diarrhea, were expressed at higher levels in strains from diarrheic animals than in strains from healthy animals. Thus, the expression levels of some virulence genes may help determine which atypical EPEC strains cause diarrhea in ruminants.
  • Publication
    Ruminants are not a reservoir of enteroaggregative Escherichia coli
    (Universidad Austral de Chile, 2017) Ruiz-Santa-Quiteria, José A.; García, Ángel; Carrión Herrero, Francisco Javier; Orden Gutiérrez, José Antonio; Domínguez Bernal, Gustavo Ramón; Horcajo Iglesias, María Del Pilar
    Enteroaggregative Escherichia coli (EAEC) causes both acute and persistent diarrhoea among children and adults in developing and developed countries. In addition, the large outbreak of food-borne illness in Europe in the summer of 2011 was caused by a verotoxin-producing EAEC O104:H4 strain. The public health threat posed by EAEC makes it important to identify animal reservoirs that might lead to epidemics in humans. Based on only one study in sheep and a few in cattle, researchers have suggested that EAEC are not found in ruminants. To expand the available data on this question, the present study applied polymerase chain reaction to faecal samples from 920 cattle, sheep and goats to detect EAEC. None of the samples tested positive for any of the EAEC genes tested, suggesting that goats, like cattle and sheep, are unlikely to be a significant reservoir of EAEC.
  • Publication
    Subtilase cytotoxin-encoding subAB2 variants in verotoxin-producing Escherichia coli strains isolated from goats and sheep
    (ELSEVIER SCI LTD, 2016-04) Orden Gutiérrez, José Antonio; Domínguez Bernal, Gustavo Ramón; Fuente López, Ricardo De La; Carrión Herrero, Francisco Javier
    Subtilase cytotoxin (SubAB) is a cytotoxin which might contribute to the virulence of verotoxin-producing Escherichia coli (VTEC) strains in humans. Three variants of SubAB encoding genes have been described (subAB1, subAB2-1, and subAB2-2) and it has been suggested that the strains positive for two variants of subAB may be more pathogenic for humans. In this study, 188 subAB2-positive VTEC strains isolated from goats and sheep were investigated for the presence of the subAB2-1 and subAB2-2 variants by PCR. Eighty-one of the 132 (61.4%) caprine strains and 36 of the 56 (64.3%) ovine strains possessed the subAB2-1 variant and all ovine and caprine strains, except one, were positive for the subAB2-2 variant. The results of this study show for first time that the subAB2-1 and subAB2-2 variants are found in caprine subAB2-positive VTEC strains and confirm that both subAB2 variants are detected in ovine subAB2-positive VTEC strains. Since no significant difference in the presence of both subAB2 variants was found among strains belonging to serotypes associated with severe illness in humans and strains not belonging to these serotypes, the occurrence of two subAB2 variants seems not to be associated with a higher risk of severe disease in humans.
  • Publication
    Raccoons (Procyon lotor) in the Madrid region of Spain are carriers of antimicrobial-resistant Escherichia coli and enteropathogenic E. coli
    (Wiley, 2020-11-23) Carrión Herrero, Francisco Javier; Orden Gutiérrez, José Antonio; Fuente López, Ricardo De La; Martínez Rodrigo, Abel; Mas Zubiri, Alicia; Domínguez Bernal, Gustavo Ramón; García‐Meniño, Isidro; Flament‐Simon, Saskia C.; Blanco, Jorge; Francisco Sobrino
    The role of wildlife in the epidemiology of antimicrobial resistance is unclear. Raccoons in North America can carry a variety of enteric bacteria, with associated antimicrobial resistance, that could infect humans and livestock. The potential for raccoons to carry these bacteria in Europe, where they are an invasive species, has not been explored. Our objectives were to determine the prevalence of Escherichia coli with associated antimicrobial resistance in raccoons from the Madrid region of Spain and to determine whether they are carriers of potential human pathogens, including verotoxin-producing E. coli (VTEC) and enteropathogenic E. coli (EPEC). In total, we tested 237 E. coli isolates from the faeces of 83 euthanized raccoons for susceptibility to 14 antimicrobial agents and the presence of VTEC and EPEC. Antimicrobial resistance to at least one antimicrobial was detected in the faeces of 51% (42/83; 95% CI, 40.1–61.1) of the raccoons tested. A high percentage of raccoons carried, in their faeces, E. coli isolates resistant to ampicillin (33%), streptomycin (33%), tetracycline (30%), sulphafurazole (31%) and trimethoprim-sulphamethoxazole (23%). We detected one isolate of extended-spectrum β-lactamase-producing E. coli from the faeces of one raccoon. We detected VTEC in the faeces of one raccoon, and EPEC in the faeces of 12% (10/83) of the raccoons. Of the raccoons that carried EPEC in their faeces, 60% (6/10) carried EPEC isolates that exhibited characteristics associated with pathogenicity in humans. Raccoons in Madrid can carry pathogenic and antimicrobial-resistant E. coli in their faeces and may be a risk to public health because of their potential to contaminate food and the environment with their faeces.
  • Publication
    UCP2 Deficiency Helps to Restrict the Pathogenesis of Experimental Cutaneous and Visceral Leishmaniosis in Mice
    (Public Library of Science (PLOS), 2013-02-21) Carrión Herrero, Francisco Javier; Abengozar, M. Angeles; Fernández-Reyes, María; Sánchez-Martín, Carlos; Rial, Eduardo; Domínguez Bernal, Gustavo Ramón; González-Barroso, M. Mar; Alain Debrabant
    Background: Uncoupling protein 2 (UCP2) is a mitochondrial transporter that has been shown to lower the production of reactive oxygen species (ROS). Intracellular pathogens such as Leishmania upregulate UCP2 and thereby suppress ROS production in infected host tissues, allowing the multiplication of parasites within murine phagocytes. This makes host UCP2 and ROS production potential targets in the development of antileishmanial therapies. Here we explore how UCP2 affects the outcome of cutaneous leishmaniosis (CL) and visceral leishmaniosis (VL) in wild-type (WT) C57BL/6 mice and in C57BL/6 mice lacking the UCP2 gene (UCP2KO). Methodology and Findings: To investigate the effects of host UCP2 deficiency on Leishmania infection, we evaluated parasite loads and cytokine production in target organs. Parasite loads were significantly lower in infected UCP2KO mice than in infected WT mice. We also found that UCP2KO mice produced significantly more interferon-γ (IFN-γ), IL-17 and IL-13 than WT mice (P<0.05), suggesting that UCP2KO mice are resistant to Leishmania infection. Conclusions: In this way, UCP2KO mice were better able than their WT counterparts to overcome L. major and L. infantum infections. These findings suggest that upregulating host ROS levels, perhaps by inhibiting UPC2, may be an effective approach to preventing leishmaniosis.