43 research outputs found
NopC is a rhizobium-specific type 3 secretion system effector secreted by sinorhizobium (ensifer) fredii HH103
Sinorhizobium (Ensifer) fredii HH103 is a broad host-range nitrogen-fixing bacterium able to nodulate many legumes, including soybean. In several rhizobia, root nodulation is influenced by proteins secreted through the type 3 secretion system (T3SS). This specialized secretion apparatus is a common virulence mechanism of many plant and animal pathogenic bacteria that delivers proteins, called effectors, directly into the eukaryotic host cells where they interfere with signal transduction pathways and promote infection by suppressing host defenses. In rhizobia, secreted proteins, called nodulation outer proteins (Nops), are involved in hostrange determination and symbiotic efficiency. S. fredii HH103 secretes at least eight Nops through the T3SS. Interestingly, there are Rhizobium-specific Nops, such as NopC, which do not have homologues in pathogenic bacteria. In this work we studied the S. fredii HH103 nopC gene and confirmed that its expression was regulated in a flavonoid-, NodD1-and TtsI-dependent manner. Besides, in vivo bioluminescent studies indicated that the S. fredii HH103 T3SS was expressed in young soybean nodules and adenylate cyclase assays confirmed that NopC was delivered directly into soybean root cells by means of the T3SS machinery. Finally, nodulation assays showed that NopC exerted a positive effect on symbiosis with Glycine max cv. Williams 82 and Vigna unguiculata. All these results indicate that NopC can be considered a Rhizobium-specific effector secreted by S. fredii HH103Junta de Andalucía P11-CVI-7050Ministerio de Economía y Competitividad AGL2012-38831Universidad de Sevill
Canine Leishmaniasis in Southeastern Spain
To examine prevalence changes and risk factors for canine leishmaniasis, we conducted a cross-sectional seroprevalence study and a survey during April–June 2006. Seroprevalence had increased at the meso-Mediterranean bioclimatic level over 22 years. Risk was highest for dogs that were older, large, lived outside, and lived at the meso-Mediterranean level
Leishmaniasis vectors in the environment of treated leishmaniasis cases in Spain
Transmission of leishmaniasis in endemic areas is characterized by microfocality related to the presence of the vector. Most entomological studies in southwestern Europe have focused on sylvatic areas and town outskirts, very few have sampled town or urban centres, and no survey has investigated inside households. The aim of this study was to determine the sand fly species diversity and vector density in the surroundings of human leishmaniasis cases compared with environments in which there was no association. Sand flies were captured in 26 households associated with recently treated leishmaniasis patients, 15 neighbouring houses without associated cases, and in others environments. Overall 7495 sand flies belonging to six species were captured. The highest sand fly density was found in farmhouses where there is a great availability of blood sources and breeding sites. In the environment of human leishmaniasis cases, Sergentomyia minuta was the most prevalent species followed by Phlebotomus perniciosus. Nevertheless, lower Leishmania infantum infection rates and lower intensity of infection were detected in S. minuta sand flies than in P. perniciosus. The density of P. perniciosus in households with recently treated leishmaniasis patients varies between 0 and 108 sand flies per light trap/night, with the maximum values corresponding to farmhouses. This species appears to be adapted to both indoors and outdoors domestic biotopes, including urban households
The Rhizobial Type 3 Secretion System: The Dr. Jekyll and Mr. Hyde in the Rhizobium–Legume Symbiosis
Rhizobia are soil bacteria that can establish a symbiotic association with legumes. As a result, plant nodules are formed on the roots of the host plants where rhizobia differentiate to bacteroids capable of fixing atmospheric nitrogen into ammonia. This ammonia is transferred to the plant in exchange of a carbon source and an appropriate environment for bacterial survival. This process is subjected to a tight regulation with several checkpoints to allow the progression of the infection or its restriction. The type 3 secretion system (T3SS) is a secretory system that injects proteins, called effectors (T3E), directly into the cytoplasm of the host cell, altering host pathways or suppressing host defense responses. This secretion system is not present in all rhizobia but its role in symbiosis is crucial for some symbiotic associations, showing two possible faces as Dr. Jekyll and Mr. Hyde: it can be completely necessary for the formation of nodules, or it can block nodulation in different legume species/cultivars. In this review, we compile all the information currently available about the effects of different rhizobial effectors on plant symbiotic phenotypes. These phenotypes are diverse and highlight the importance of the T3SS in certain rhizobium–legume symbioses.Ministerio de Ciencia e Innovación PID2019-107634RB-I00Junta de Andalucía P20_00185Universidad de Sevilla FEDER-US 1259948, FEDER-US 125054
Adecuación de la prescripción de soporte nutricional a las guías de práctica clínica en pacientes con anorexia nerviosa
Background: nutritional support (NS) is a core element in the treatment of underweight patients with anorexia nervosa (AN).
Objective: to analyze the adherence of NS prescriptions to clinical practice guidelines (CPGs) for AN patients and to compare the effectiveness,
safety, and cost of NS according to adherence.
Methods: this retrospective observational study included AN patients admitted to an Eating Disorders Unit between January 2006 and December
2009 and followed until December 2014. NS prescriptions were compared with guidelines published by the American Psychiatric Association
(APA), the National Institute for Clinical Excellence (NICE), and the Spanish Ministry of Health and Consumption (SMHC). Adherence was defined
as percentage of hospitalizations that followed all recommendations.
Results: adherence to APA and NICE/SMHC was observed in 10.2% and 73.4%, respectively, of the total of 177 hospitalizations. Body weight
and body mass index were higher at admission in the NICE/SMHC adherence versus non-adherence group (p < 0.001). Weight gain rate during
hospitalization was higher (p = 0.009) in “APA adherence” (135.5 g/day) versus “non-adherence” (92.1 g/day) group. Hospital stay was significantly
shorter (p = 0.025) in “NICE/SMHC adherence” (39.5 days) versus “non-adherence” group (50.0 days). NICE/SMHC adherence was
associated with lower costs (p = 0.006).
Conclusions: NS prescriptions for anorexic patients more frequently followed NICE/SMHC than APA recommendations. Over the short-term, APA
adherence was associated with improved weight gain. Patients adhering to NICE/SMHC recommendations had shorter hospital stay and reduced
costs, likely due to their more favorable nutritional status at admission
Role of wild rabbits as reservoirs of leishmaniasis in a non-epidemic Mediterranean hot spot in Spain
We would like to thank the hunters of the municipality of Montefrio for their support in the study. This study was funded by the Project, Ministry of Economy and Competitiveness, Instituto de Salud Carlos III, Madrid and Feder Funds for Regional Development from the European Union, "One way to make Europe". Funding for open access charge: Universidad de Granada/CBVA.There is limited information regarding the role of wild mammals in the transmission dynamics of Leishmania
infantum. A potential human leishmaniasis hot spot was detected in southern Spain that could not be explained
solely by canine leishmaniasis prevalence. The aim of this work was to analyse the involvement of wild rabbits as
the main factor affecting this Mediterranean hot spot. A survey of wild rabbits, dogs and sand flies was conducted
in the human cases environment. A nearby region without clinical leishmaniasis cases was used as reference
control. 51 wild rabbits shot by hunters were analysed by molecular techniques. 1100 sand flies were captured
and morphologically identified. Blood collected from patients’ relatives/ neighbours (n = 9) and dogs (n = 66)
was used for molecular analysis and serology. In Mediterranean leishmaniasis hot spots such as Montefrío municipality
(average incidence of 16.8 human cases per 100,000 inhabitants/year), wild rabbits (n = 40) support
high L. infantum infection rates (100%) and heavy parasite burdens (average value: 503 parasites/mg) in
apparently normal ear skin directly accessible to sand flies, enabling the existence of heavily parasitized Phlebotomus
perniciosus females (12.5% prevalence). The prevalence of infection and median parasite load were very
low among rabbits captured in Hu´escar (n = 11), a human clinical leishmaniasis-free area for the last 18 years.
P. perniciosus was the most abundant Phlebotomus species in all the domestic/peridomestic microhabitats
sampled, both indoors and outdoors. Accordingly, leishmaniasis is clustering in space and time at this local scale
represented by Montefrío due to the proximity of two competent host reservoirs (dogs and heavily parasitized
wild rabbits) associated with overlapping sylvatic and domestic transmission cycles through the main vector,
P. perniciosus. We highlight the usefulness of determining the prevalence of infection and parasite burden in wild
rabbits as a control leishmaniasis measure with the advantage that the use of the ear offers.Ministry of Economy and Competitiveness, Instituto de Salud Carlos III, MadridFeder Funds for Regional Development from the European Union, "One way to make Europe"Universidad de Granada/CBV
Wild rabbits are Leishmania infantum reservoirs in southeastern Spain
We contribute to the understanding of the transmission dynamics of
Leishmania infantum suggesting the involvement of rabbits as wild reservoirs.
Results: The prevalence of infection was 86.0% (270/314 wild rabbits) ranging from
18.2% to 100% in natural geographical regions. The estimated average parasite load
was 324.8 [CI 95% 95.3–554.3] parasites per mg of ear lobe ranging from 0 to 91,597
parasites/mg per tissue section.
Conclusions: A positive correlation was found between skin parasite load in wild rabbits
and human incidence with evidence of the presence of the same L. infantum genotypes
in rabbits and humans, providing new epidemiological and biological basis for
the consideration of wild rabbits as a relevant L. infantum wild reservoir. Molecular
parasite surveillance reflects the great genotypic variability of the parasite population
in wild rabbits. Most of these genotypes have also been found to infect humans,
dogs and sandflies in the region. Our findings also highlight that direct genotyping of
the parasite in host tissues should be used for molecular surveillance of the parasite
instead of cultured isolates.Ministerio de Ciencia e Innovación, Spain
(MICIU/AEI/10.1339/50110011033)FEDER, UE through the project, Grant/
Award Number: PID2022-142230NB.
100Universidad de Granada/CBU
Morphology does not allow differentiating the species of the Phlebotomus perniciosus complex: Molecular characterization and investigation of their natural infection by Leishmania infantum in Morocco
Morphological and DNA-based
complemented approaches were applied for characterization
of sympatric populations of Phlebotomus longicuspis and Phlebotomus perniciosus
in Morocco. Both sand fly species are generally recorded in sympatry in North
Africa but on few occasions have been molecularly characterized. The diagnostic confusion
of these species has led to errors in their geographical distribution and probably,
in the assignment of their role in the transmission of L. infantum. Sand flies were
caught inside households in El Borouj, central Morocco, in 2014–2015.
For female
sand flies, detection of L. infantum natural infection and blood meal identification were
carried out. According to morphological identification, Phlebotomus longicuspis s.l.
(34.7%) was the second most abundant Phlebotomus species after P. sergenti, followed
by atypical Phlebotomus perniciosus (7.1%); 11.6% of the male specimens of P. longicuspis
s.l. were identified as P. longicuspis LCx according to the number of coxite setae.
The density of Larroussius species was very high (31 Larroussius/light trap/night) in the
peripheral neighbourhood of Oulad Bouchair (p = 0.001) where the first case of cutaneous
leishmaniasis due to Leishmania infantum was detected in 2017. Phylogenetic
trees based on three independent genes highlighted three well-supported
clusters
within P. perniciosus complex that could be interpreted as corresponding to P. perniciosus,
P. longicuspis s.s. and an undescribed species, all coexisting in sympatry. Some
females with typical morphology of P. longicuspis were genetically homologous to P.
perniciosus. The taxa cannot be differentiated by morphological methods but characterized
by a distinctive genetic lineage for which the synapomorphic characters are
described. Leishmania infantum was detected in females of all clusters with a low parasite
load. Population genetics will help to assess the threat of the geographical spreadUniversity of Granada (Centro de
Iniciativas de Cooperación al Desarrollo,
CICODE, 2013)Universidad de Granada/CBU
Effectiveness of an O-Alkyl Hydroxamate in Dogs with Naturally Acquired Canine Leishmaniosis: An Exploratory Clinical Trial
Canine leishmaniosis is a challenge in veterinary medicine and no drug to date has achieved
parasite clearance in dogs. Histone deacetylase inhibitors are a drug class widely used in cancer
chemotherapy. We have successfully used O-alkyl hydroxamates (vorinostat derivatives) in the
treatment of a laboratory model of visceral leishmaniasis without showing toxicity. In order to
test the effectiveness of a particular compound, MTC-305, a parallel-group, randomized, singlecentre,
exploratory study was designed in naturally infected dogs. In this clinical trial, 18 dogs
were allocated into 3 groups and were treated with either meglumine antimoniate (104 mg SbV/kg),
MTC-305 (3.75 mg/kg) or a combination of both using a lower MTC-305 dose (1.5 mg/kg) through
a subcutaneous route for 2 treatment courses of 30 days, separated by a 30-day rest period. After
treatment, a follow-up time of 4 months was established. Parasite burden in bone marrow, lymph
node and peripheral blood were quantified through qPCR. Antibody titres were determined through
an immunofluorescence antibody test, and cytokine expression values were calculated through RTqPCR.
Treatment safety was evaluated through the assessment of haematological and biochemical
parameters in blood, weight, and gastrointestinal alterations. Assessment was carried out before,
between and after treatment series. Treatment with MTC-305 was effective at reducing parasite
burdens and improving the animals’ clinical picture. Dogs treated with this compound did not
present significant toxicity signs. These results were superior to those obtained using the reference
drug, meglumine antimoniate, in monotherapy. These results would support a broader clinical trial,
optimised dosage, and an expanded follow-up stage to confirm the efficacy of this drug.University of GranadaAndalusian GovernmentEuropean Commission B-CTS-270UGR18
P20_0013
Predicting the distribution of canine leishmaniasis in western Europe based on environmental variables.
The domestic dog is the reservoir host of Leishmania infantum, the causative agent of zoonotic visceral leishmaniasis endemic in Mediterranean Europe. Targeted control requires predictive risk maps of canine leishmaniasis (CanL), which are now explored. We databased 2187 published and unpublished surveys of CanL in southern Europe. A total of 947 western surveys met inclusion criteria for analysis, including serological identification of infection (504, 369 dogs tested 1971-2006). Seroprevalence was 23 2% overall (median 10%). Logistic regression models within a GIS framework identified the main environmental predictors of CanL seroprevalence in Portugal, Spain, France and Italy, or in France alone. A 10-fold cross-validation approach determined model capacity to predict point-values of seroprevalence and the correct seroprevalence class (20%). Both the four-country and France-only models performed reasonably well for predicting correctly the 20% seroprevalence classes (AUC >0 70). However, the France-only model performed much better for France than the four-country model. The four-country model adequately predicted regions of CanL emergence in northern Italy (<5% seroprevalence). Both models poorly predicted intermediate point seroprevalences (5-20%) within regional foci, because surveys were biased towards known rural foci and Mediterranean bioclimates. Our recommendations for standardizing surveys would permit higher-resolution risk mapping