676 research outputs found
Exploring Impact of Rare Variation in Systemic Lupus Erythematosus by a Genome Wide Imputation Approach
The importance of low frequency and rare variation in complex disease genetics
is difficult to estimate in patient populations. Genome-wide association studies are
therefore, underpowered to detect rare variation. We have used a combined approach
of genome-wide-based imputation with a highly stringent sequence kernel association
(SKAT) test and a case-control burden test. We identified 98 candidate genes containing
rare variation that in aggregate show association with SLE many of which have
recognized immunological function, but also function and expression related to relevant
tissues such as the joints, skin, blood or central nervous system. In addition we also find
that there is a significant enrichment of genes annotated for disease-causingmutations in
the OMIM database, suggesting that in complex diseases such as SLE, such mutations
may be involved in subtle or combined phenotypes or could accelerate specific organ
abnormalities found in the disease. We here provide an important resource of candidate
genes for SLE
Análisis sobre aspectos logísticos en el comercio electrónico español: plazos, costes, y modalidades de envíos y devoluciones
El surgimiento de Internet ha supuesto una transformación en todos los aspectos de la
vida. De esta manera, ha conseguido revolucionar el comercio de forma que en la
actualidad es posible realizar una compra y que el producto llegue a manos del
consumidor sin necesidad de moverse del domicilio. En este trabajo se estudiará la
importancia que tiene sobre el comercio electrónico la parte de la logística que se
encarga de hacer llegar los productos. Se realizará un estudio empírico sobre una
muestra de 80 empresas, en el que se analizarán las cinco principales variables (costes,
plazos, tipos de envíos, métodos de pago y devoluciones) que condicionan la logística
externa.Universidad de Sevilla. Grado en Administración y Dirección de Empresa
Multiple Genome Sequences of Lactobacillus pentosus Strains Isolated from Biofilms on the Skin of Fermented Green Table Olives
The draft genome sequences of five Lactobacillus pentosus strains isolated
from biofilms on the skin of green table olives are presented here. These genome
sequences will assist in revealing the potential probiotic properties of these
strains, as the intake of fermented olives implicates the passage of millions of Lactobacillus
spp. throughout a consumer’s gastrointestinal tract.This work was funded by the Junta de Andalucía through the P11-AGR-7051 project
and by the Spanish Government through MICIIN projects AGL2013-48300-R/ALI (OliFilm
project: www.olifilm.science.com.es) and BFU2016-77297-P
Gut Microbiota of Great Spotted Cuckoo Nestlings is a Mixture of Those of Their Foster Magpie Siblings and of Cuckoo Adults
Diet and host genetic or evolutionary history are considered the two main factors
determining gut microbiota of animals, although studies are scarce in natural populations. The system
of great spotted cuckoos (Clamator glandarius) parasitizing magpies (Pica pica) is ideal to study both
effects since magpie adults feed cuckoo and magpie nestlings with the same diet and, consequently,
differences in gut microbiota of nestlings of these two species will mainly reflect the importance of
genetic components. Moreover, the diet of adults and of nestling cuckoos drastically differ from each
other and, thus, differences and similarities in their microbiotas would respectively reflect the effect
of environmental and genetic factors. We used next-generation sequencing technologies to analyze
the gut microbiota of cuckoo adults and nestlings and of magpie nestlings. The highest -diversity
estimates appeared in nestling cuckoos and the lowest in nestling magpies. Moreover, despite the
greatest differences in the microbiome composition of magpies and cuckoos of both ages, cuckoo
nestlings harbored a mixture of the Operational Taxonomic Units (OTUs) present in adult cuckoos
and nestling magpies. We identified the bacterial taxa responsible for such results. These results
suggest important phylogenetic components determining gut microbiome of nestlings, and that diet
might be responsible for similarities between gut microbiome of cuckoo and magpie nestlings that
allow cuckoos to digest food provided by magpie adults.This work was supported by the Ministerio de Ciencia, Innovacion y Universidades and European
(FEDER) funds (CGL2017-83103-P)
Characterization of Antimicrobial Substances Produced by Enterococcus faecalis MRR 10-3, Isolated from the Uropygial Gland of the Hoopoe (Upupa epops)
Special structures of hoopoe eggshells enhance the adhesion of symbionts-carrying uropygial secretion to prevent embryo infection
This is the pre-peer-reviewed version of the following article: Martín-Vivaldi, M.; et al. Special structures of hoopoe eggshells enhance the adhesion of symbionts-carrying uropygial secretion to prevent embryo infection. Journal of Animal Ecology, (2014). which has been published in final form at: http://onlinelibrary.wiley.com/doi/10.1111/1365-2656.12243/abstract1. Animals live in a bacterial world, and detecting and exploring adaptations favouring mutualistic relationships with antibiotic-producing bacteria as a strategy to fight pathogens are of prime importance for evolutionary ecologists.
2. Uropygial secretion of European hoopoes (Upupa epops, Linnaeus) contains antimicrobials from mutualistic bacteria that may be used to prevent embryo infection. Here, we investigated the microscopic structure of hoopoe eggshells looking for special features favouring the adhesion of antimicrobial uropygial secretions.
3. We impeded female access to the uropygial gland and compared microscopic characteristics of eggshells, bacterial loads of eggs and of uropygial secretion, and hatching success of experimental and control females. Then, we explored the link between microbiological characteristics of uropygial secretion and these of eggs of hoopoes, as well as possible fitness benefits.
4. The microscopic study revealed special structures in hoopoes' eggshells (crypts). The experimental prevention of females' gland access demonstrated that crypts are filled with uropygial secretion and that symbiotic enterococci bacteria on the eggshells come, at least partially, from those in the female's uropygial gland. Moreover, the experiment resulted in a higher permeability of eggshells by several groups of bacteria and in elimination of the positive relationships detected for control nests between hatching success and density of symbiotic bacteria, either in the uropygial secretion of females or on the eggshell.
5. The findings of specialized crypts on the eggshells of hoopoes, and of video-recorded females smearing secretion containing symbiotic bacteria at a high density onto the eggshells strongly support a link between secretion and bacteria on eggs. Moreover, the detected associations between bacteria and hatching success suggest that crypts enhancing the adhesion of symbiont-carrying uropygial secretion likely protect embryos against infections.Support by funding was provided by Spanish Ministerio de Ciencia e Innovación, European funds (FEDER) (CGL2009-14006, CGL2010-19233-C03-01 and CGL2010-19233-C03-03) and Junta de Andalucía (P09-RNM-4557)
LAB Bacteriocins Controlling the Food Isolated (Drug-Resistant) Staphylococci
Staphylococci are a group of microorganisms that can be often found in processed food
and theymight pose a risk for human health. In this study we have determined the content
of staphylococci in 7 different fresh goat-milk cheeses. These bacteria were present in
all of them, ranging from 103 to 106 CFU/g based on growth on selective media. Thus, a
set of 97 colonies was randomly picked for phenotypic and genotypic identification. They
could be clustered by RAPD-PCR in 10 genotypes, which were assigned by 16S rDNA
sequencing to four Staphylococcus species: Staphylococcus aureus, Staphylococcus
chromogenes, S. simulans, and S. xylosus. Representative strains of these species
(n = 25) were tested for antibiotic sensitivity, and 11 of them were resistant to at
least one of the antibiotics tested, including erythromycin, amoxicillin-clavulanic acid
and oxacillin. We also tested two bacteriocins produced by lactic acid bacteria (LAB),
namely the circular bacteriocin AS-48 and the lantibiotic nisin. These peptides have
different mechanism of action at the membrane level. Nevertheless, both were able
to inhibit staphylococci growth at low concentrations ranging between 0.16–0.73μM
for AS-48 and 0.02–0.23μM for nisin, including the strains that displayed antibiotic
resistance. The combined effect of these bacteriocins were tested and the fractional
inhibitory concentration index (FICI) was calculated. Remarkably, upon combination, they
were active at the low micromolar range with a significant reduction of the minimal
inhibitory concentration. Our data confirms synergistic effect, either total or partial,
between AS-48 and nisin for the control of staphylococci and including antibiotic resistant
strains. Collectively, these results indicate that the combined use of AS-48 and nisin
could help controlling (pathogenic) staphylococci in food processing and preventing
antibiotic-resistant strains reaching the consumer in the final products.This research was funded by the Spanish Ministry of Economy
and Competitiveness (SAF2013-48971-C2-1-R project),
including funds from the European Regional Development
Fundings (ERDF) and the Research Group General (BIO160,
UGR
Environmental Factors Shape the Community of Symbionts in the Hoopoe Uropygial Gland More than Genetic Factors
Seasonal and Sexual Differences in the Microbiota of the Hoopoe Uropygial Secretion
The uropygial gland of hoopoe nestlings and nesting females hosts bacterial symbionts that
cause changes in the characteristics of its secretion, including an increase of its antimicrobial activity.
These changes occur only in nesting individuals during the breeding season, possibly associated
with the high infection risk experienced during the stay in the hole-nests. However, the knowledge
on hoopoes uropygial gland microbial community dynamics is quite limited and based so far on
culture-dependent and molecular fingerprinting studies. In this work, we sampled wild and captive
hoopoes of different sex, age, and reproductive status, and studied their microbiota using quantitative
polymerase chain reaction (qPCR), fluorescence in situ hybridization (FISH) and pyrosequencing.
Surprisingly, we found a complex bacterial community in all individuals (including non-nesting
ones) during the breeding season. Nevertheless, dark secretions from nesting hoopoes harbored
significantly higher bacterial density than white secretions from breeding males and both sexes in
winter. We hypothesize that bacterial proliferation may be host-regulated in phases of high infection
risk (i.e., nesting). We also highlight the importance of specific antimicrobial-producing bacteria
present only in dark secretions that may be key in this defensive symbiosis. Finally, we discuss the
possible role of environmental conditions in shaping the uropygial microbiota, based on differences
found between wild and captive hoopoes.This work was supported by the Spanish Ministry of Economy and Competitiveness and European
(FEDER) funds (CGL2013-48193-C3-1-P/BOS, CGL2013-48193-C3-2-P/BOS, CGL2017-83103-P), and the Junta de
Andalucía (RNM 339, RNM 340). S. M. Rodríguez-Ruano received a grant from the Spanish Ministry of Science
and Innovation (FPI program)
Interspecific variation in deterioration and degradability of avian feathers: the evolutionary role of microorganisms
- …