CD200 is up-regulated in R6/1 transgenic mouse model of Huntington's disease

In Huntington's disease (HD), striatal medium spiny neurons (MSNs) are particularly sensitive to the presence of a CAG repeat in the huntingtin (HTT) gene. However, there are many evidences that cells from the peripheral immune system and central nervous system (CNS) immune cells, namely microglia, play an important role in the etiology and the progression of HD. However, it remains unclear whether MSNs neurodegeneration is mediated by a non-cell autonomous mechanism. The homeostasis in the healthy CNS is maintained by several mechanisms of interaction between all brain cells. Neurons can control microglia activation through several inhibitory mechanisms, such as the CD200-CD200R1 interaction. Due to the complete lack of knowledge about the CD200-CD200R1 system in HD, we determined the temporal patterns of CD200 and CD200R1 expression in the neocortex, hippocampus and striatum in the HD mouse models R6/1 and HdhQ111/7 from pre-symptomatic to manifest stages. In order to explore any alteration in the peripheral immune system, we also studied the levels of expression of CD200 and CD200R1 in whole blood. Although CD200R1 expression was not altered, we observed and increase in CD200 gene expression and protein levels in the brain parenchyma of all the regions we examined, along with HD pathogenesis in R6/1 mice. Interestingly, the expression of CD200 mRNA was also up-regulated in blood following a similar temporal pattern. These results suggest that canonical neuronal-microglial communication through CD200-CD200R1 interaction is not compromised, and CD200 up-regulation in R6/1 brain parenchyma could represent a neurotrophic signal to sustain or extend neuronal function in the latest stages of HD as pro-survival mechanism

Combined effects of spray‐drying conditions and postdrying storage time and temperature on Salmonella choleraesuis and Salmonella typhimurium survival when inoculated in liquid porcine plasma

The objective of this study was to determine the effectiveness of the spray-drying process on the inactivation of Salmonella choleraesuis and Salmonella typhimurium spiked in liquid porcine plasma and to test the additive effect of immediate postdrying storage. Commercial spray-dried porcine plasma was sterilized by irradiation and then reconstituted (1:9) with sterile water. Aliquots of reconstituted plasma were inoculated with either S. choleraesuis or S. typhimurium, subjected to spray-drying at an inlet temperature of 200°C and an outlet temperature of either 71 or 80°C, and each spray-drying temperature combinations were subjected to either 0, 30 or 60 s of residence time (RT) as a simulation of residence time typical of commercial dryers. Spray-dried samples were stored at either 4·0 ± 3·0°C or 23·0 ± 0·3°C for 15 days. Bacterial counts of each Salmonella spp., were completed for all samples. For both Salmonella spp., spray-drying at both outlet temperatures reduced bacterial counts about 3 logs at RT 0 s, while there was about a 5·5 log reduction at RT 60 s. Storage of all dried samples at either 4·0 ± 3·0°C or 23·0 ± 0·3°C for 15 days eliminate all detectable bacterial counts of both Salmonella spp.info:eu-repo/semantics/publishedVersio

Combined effects of spray-drying conditions and postdrying storage time and temperature on Salmonella choleraesuis and Salmonella typhimurium survival when inoculated in liquid porcine plasma

Altres ajuts: GC/2014DI066The objective of this study was to determine the effectiveness of the spray-drying process on the inactivation of Salmonella choleraesuis and Salmonella typhimurium spiked in liquid porcine plasma and to test the additive effect of immediate postdrying storage. Commercial spray-dried porcine plasma was sterilized by irradiation and then reconstituted (1:9) with sterile water. Aliquots of reconstituted plasma were inoculated with either S. choleraesuis or S. typhimurium, subjected to spray-drying at an inlet temperature of 200°C and an outlet temperature of either 71 or 80°C, and each spray-drying temperature combinations were subjected to either 0, 30 or 60 s of residence time () as a simulation of residence time typical of commercial dryers. Spray-dried samples were stored at either 4·0 ± 3·0°C or 23·0 ± 0·3°C for 15 days. Bacterial counts of each Salmonella spp., were completed for all samples. For both Salmonella spp., spray-drying at both outlet temperatures reduced bacterial counts about 3 logs at 0 s, while there was about a 5·5 log reduction at 60 s. Storage of all dried samples at either 4·0 ± 3·0°C or 23·0 ± 0·3°C for 15 days eliminate all detectable bacterial counts of both Salmonella spp. Safety of raw materials from animal origin like spray-dried porcine plasma (SDPP) may be a concern for the swine industry. Spray-drying process and postdrying storage are good inactivation steps to reduce the bacterial load of Salmonella choleraesuis and Salmonella typhimurium. For both Salmonella spp., spray-drying at 71°C or 80°C outlet temperatures reduced bacterial counts about 3 log at residence time (RT) 0 s, while there was about a 5.5 log reduction at RT 60 s. Storage of all dried samples at either 4.0 ± 3.0°C or 23.0 ± 0.3°C for 15 days was effective for eliminating detectable bacterial counts of both Salmonella spp. Significance and Impact of the Study: Safety of raw materials from animal origin like spray-dried porcine plasma (SDPP) may be a concern for the swine industry. Spray-drying process and postdrying storage are good inactivation steps to reduce the bacterial load of Salmonella choleraesuis and Salmonella typhimurium. For both Salmonella spp., spray-drying at 71°C or 80°C outlet temperatures reduced bacterial counts about 3 log at residence time (RT) 0 s, while there was about a 5.5 log reduction at RT 60 s. Storage of all dried samples at either 4.0 ± 3.0°C or 23.0 ± 0.3°C for 15 days was effective for eliminating detectable bacterial counts of both Salmonella spp

Diversity of Multi-Drug Resistant Avian Pathogenic Escherichia coli (APEC) Causing Outbreaks of Colibacillosis in Broilers during 2012 in Spain

Avian pathogenic Escherichia coli (APEC) are the major cause of colibacillosis in poultry production. In this study, a total of 22 E. coli isolated from colibacillosis field cases and 10 avian faecal E. coli (AFEC) were analysed. All strains were characterised phenotypically by susceptibility testing and molecular typing methods such as pulsed-field gel electrophoresis (PFGE) and multi-locus sequence typing (MLST). The presence of 29 virulence genes associated to APEC and human extraintestinal pathogenic E. coli (ExPEC) was also evaluated. For cephalosporin resistant isolates, cephalosporin resistance genes, plasmid location and replicon typing was assessed. Avian isolates belonged to 26 O:H serotypes and 24 sequence types. Out of 22 APEC isolates, 91% contained the virulence genes predictors of APEC; iutA, hlyF, iss, iroN and ompT. Of all strains, 34% were considered ExPEC. PFGE analysis demonstrated a high degree of genetic polymorphism. All strains were multi-resistant, including those isolated from healthy animals. Eleven strains were resistant to cephalosporins; six contained blaCTX-M-14, two blaSHV-12, two blaCMY-2 and one blaSHV-2. Two strains harboured qnrA, and two qnrA together with aac(6’)-Ib-cr. Additionally, the emergent clone O25b:H4-B2-ST131 was isolated from a healthy animal which harboured blaCMY-2 and qnrS genes. Cephalosporin resistant genes were mainly associated to the presence of IncK replicons. This study demonstrates a very diverse population of multi-drug resistant E. coli containing a high number of virulent genes. The E. coli population among broilers is a reservoir of resistance and virulence-associated genes that could be transmitted into the community through the food chain. More epidemiological studies are necessary to identify clonal groups and resistance mechanisms with potential relevance to public health.This work was partially supported by the grants AGL2011- 28836 and AGL2013-47852-R from the Ministerio de Economía y Competitividad (España) and grants CN2012/303 and EM2014/001 (Consellería de Cultura, Educación e Ordenación Universitaria, Xunta de Galicia and the European Regional Development Fund, ERDF). Work from LMG is supported by the Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA) and the European Social FundS

The role of 'filth flies' in the spread of antimicrobial resistance

'Filth flies' feed and develop in excrement and decaying matter and can transmit enteric pathogens to humans and animals, leading to colonization and infection. Considering these characteristics, 'filth flies' are potential vectors for the spread of antimicrobial resistance (AMR). This review defines the role of flies in the spread of AMR and identifies knowledge gaps. The literature search (original articles, reviews indexed for PubMed) was restricted to the English language. References of identified studies were screened for additional sources. 'Filth flies' are colonized with antimicrobial-resistant bacteria of clinical relevance. This includes extended spectrum beta-lactamase-, carbapenemase-producing and colistin-resistant (mcr-1 positive) bacteria. Resistant bacteria in flies often share the same genotypes with bacteria from humans and animals when their habitat overlap. The risk of transmission is most likely highest for enteric bacteria as they are shed in high concentration in excrements and are easily picked up by flies. 'Filth flies' can 'bio-enhance' the transmission of AMR as bacteria multiply in the digestive tract, mouthparts and regurgitation spots. To better understand the medical importance of AMR in flies, quantitative risk assessment models should be refined and fed with additional data (e.g. vectorial capacity, colonization dose). This requires targeted ecological, epidemiological and in vivo experimental studie

Molecular epidemiology and mechanisms of cephalosporin resistance in escherichia coli of different origins; broilers, flies and white storks

Las bacterias resistentes a antibióticos, y en concreto a betalactamasas de espectro extendido (BLEEs), se han convertido en un problema grave. Su prevalencia ha incrementado rápidamente a nivel mundial debido a una diseminación pandémica de plásmidos y a la introducción de genes de resistencia a BLEEs en clones exitosos (Coque, Baquero et al. 2008, Brolund 2014). Según la Organización Mundial de la Salud (OMS), los antimicrobianos más críticos en sanidad humana y animal son las cefalosporinas de tercera generación, las fluoroquinolonas, los macrólidos y los aminoglicósidos (Collignon, Powers et al. 2009, Collignon, Conly et al. 2016). Por lo tanto, esta tesis se ha centrado en las resistencias a cefalosporinas, y en particular resistencias a BLEEs y betalactamasas tipo AmpC. La mayoría de las investigaciones se han centrado en la epidemiología de las resistencias a antibióticos en medicina humana y veterinaria; sin embargo, en los últimos años ha habido un aumento de los estudios dirigidos a bacterias multiresistentes que circulan en ambientes naturales actuando como reservorios (Allen, Donato et al. 2010). Una vez las bacterias están presentes en el ambiente, pueden transmitirse a los humanos. A través de los estudios incluidos en la actual tesis, hemos investigado la aparición y los mecanismos de diseminación de Escherichia coli resistentes a cefalosporinas de diferentes nichos ecológicos; pollos de engorde como ejemplo de animales de producción, moscas (Musca domestica) como vectores mecánicos y reservorios de genes de resistencia que contribuyen a la diseminación de resistencias en el ambiente de granja; y finalmente, cigüeñas blancas (Ciconia ciconia) como ejemplo de vectores de larga distancia y centinelas de la presión humana. Con este enfoque, intentamos entender la transmisibilidad de las resistencias entre nichos diferentes; e identificar los clones, los genes de resistencia y los plásmidos involucrados.Bacteria resistant to antimicrobials, and specifically to extended-spectrum beta-lactamases (ESBLs), have become of increasing concern. Its prevalence has increased fast worldwide due to a pandemic dissemination of plasmids and the introduction of ESBL resistance genes into successful clones (Coque, Baquero et al. 2008, Brolund 2014). According to the World Health Organization (WHO), the most critical antimicrobials in human and animal health are third-generation cephalosporins, fluoroquinolones, macrolides and aminoglycosides (Collignon, Powers et al. 2009, Collignon, Conly et al. 2016). Therefore, this thesis has focused in resistance to cephalosporins and particularly to ESBLs and AmpC type of resistance. Due to the overuse of antimicrobials in humans and veterinary medicine, the emergence of multi-drug resistance has increased in the last decades. Most of the research has focused on the epidemiology of antibiotic resistance in human and veterinary medicine; however, in the last years it has been an increasing attention on how multiresistant bacteria circulates in natural environments and how these niches can act as reservoirs of resistant traits (Allen, Donato et al. 2010). Once the resistant bacteria are present in the environment, it can easily get in contact with humans. Through the studies compiled in this thesis, we have investigated the occurrence and mechanisms of dissemination of cephalosporin resistance (CR) Escherichia coli from different ecological niches; broilers as an example of food-producing animals, houseflies (Musca domestica) as mechanical vectors and reservoir of resistance genes contributing to the spread of resistance in the farm environment; and finally white storks (Ciconia ciconia) as an example of long-distance vectors and sentinels of human pressure. With this approach, we intend to understand the transmissibility of these resistances among different niches; and identify clones, resistance genes and plasmids involved

Molecular epidemiology and mechanisms of cephalosporin resistance in escherichia coli of different origins; broilers, flies and white storks

Las bacterias resistentes a antibióticos, y en concreto a betalactamasas de espectro extendido (BLEEs), se han convertido en un problema grave. Su prevalencia ha incrementado rápidamente a nivel mundial debido a una diseminación pandémica de plásmidos y a la introducción de genes de resistencia a BLEEs en clones exitosos (Coque, Baquero et al. 2008, Brolund 2014). Según la Organización Mundial de la Salud (OMS), los antimicrobianos más críticos en sanidad humana y animal son las cefalosporinas de tercera generación, las fluoroquinolonas, los macrólidos y los aminoglicósidos (Collignon, Powers et al. 2009, Collignon, Conly et al. 2016). Por lo tanto, esta tesis se ha centrado en las resistencias a cefalosporinas, y en particular resistencias a BLEEs y betalactamasas tipo AmpC. La mayoría de las investigaciones se han centrado en la epidemiología de las resistencias a antibióticos en medicina humana y veterinaria; sin embargo, en los últimos años ha habido un aumento de los estudios dirigidos a bacterias multiresistentes que circulan en ambientes naturales actuando como reservorios (Allen, Donato et al. 2010). Una vez las bacterias están presentes en el ambiente, pueden transmitirse a los humanos. A través de los estudios incluidos en la actual tesis, hemos investigado la aparición y los mecanismos de diseminación de Escherichia coli resistentes a cefalosporinas de diferentes nichos ecológicos; pollos de engorde como ejemplo de animales de producción, moscas (Musca domestica) como vectores mecánicos y reservorios de genes de resistencia que contribuyen a la diseminación de resistencias en el ambiente de granja; y finalmente, cigüeñas blancas (Ciconia ciconia) como ejemplo de vectores de larga distancia y centinelas de la presión humana. Con este enfoque, intentamos entender la transmisibilidad de las resistencias entre nichos diferentes; e identificar los clones, los genes de resistencia y los plásmidos involucrados.Bacteria resistant to antimicrobials, and specifically to extended-spectrum beta-lactamases (ESBLs), have become of increasing concern. Its prevalence has increased fast worldwide due to a pandemic dissemination of plasmids and the introduction of ESBL resistance genes into successful clones (Coque, Baquero et al. 2008, Brolund 2014). According to the World Health Organization (WHO), the most critical antimicrobials in human and animal health are third-generation cephalosporins, fluoroquinolones, macrolides and aminoglycosides (Collignon, Powers et al. 2009, Collignon, Conly et al. 2016). Therefore, this thesis has focused in resistance to cephalosporins and particularly to ESBLs and AmpC type of resistance. Due to the overuse of antimicrobials in humans and veterinary medicine, the emergence of multi-drug resistance has increased in the last decades. Most of the research has focused on the epidemiology of antibiotic resistance in human and veterinary medicine; however, in the last years it has been an increasing attention on how multiresistant bacteria circulates in natural environments and how these niches can act as reservoirs of resistant traits (Allen, Donato et al. 2010). Once the resistant bacteria are present in the environment, it can easily get in contact with humans. Through the studies compiled in this thesis, we have investigated the occurrence and mechanisms of dissemination of cephalosporin resistance (CR) Escherichia coli from different ecological niches; broilers as an example of food-producing animals, houseflies (Musca domestica) as mechanical vectors and reservoir of resistance genes contributing to the spread of resistance in the farm environment; and finally white storks (Ciconia ciconia) as an example of long-distance vectors and sentinels of human pressure. With this approach, we intend to understand the transmissibility of these resistances among different niches; and identify clones, resistance genes and plasmids involved

Molecular epidemiology and mechanisms of cephalosporin resistance in Escherichia coli of different origins : broilers, flies and white storks = Epidemiología molecular y mecanismos de resistencia a cefalosporinas en Escherichia coli de diferentes orígenes : pollos de engorde, moscas y cigüeñas blancas /

Departament responsable de la tesi: Departament de Medicina i Cirurgia Animals.A la portada: CReSA, IRTA.Las bacterias resistentes a antibióticos, y en concreto a betalactamasas de espectro extendido (BLEEs), se han convertido en un problema grave. Su prevalencia ha incrementado rápidamente a nivel mundial debido a una diseminación pandémica de plásmidos y a la introducción de genes de resistencia a BLEEs en clones exitosos (Coque, Baquero et al. 2008, Brolund 2014). Según la Organización Mundial de la Salud (OMS), los antimicrobianos más críticos en sanidad humana y animal son las cefalosporinas de tercera generación, las fluoroquinolonas, los macrólidos y los aminoglicósidos (Collignon, Powers et al. 2009, Collignon, Conly et al. 2016). Por lo tanto, esta tesis se ha centrado en las resistencias a cefalosporinas, y en particular resistencias a BLEEs y betalactamasas tipo AmpC. La mayoría de las investigaciones se han centrado en la epidemiología de las resistencias a antibióticos en medicina humana y veterinaria; sin embargo, en los últimos años ha habido un aumento de los estudios dirigidos a bacterias multiresistentes que circulan en ambientes naturales actuando como reservorios (Allen, Donato et al. 2010). Una vez las bacterias están presentes en el ambiente, pueden transmitirse a los humanos. A través de los estudios incluidos en la actual tesis, hemos investigado la aparición y los mecanismos de diseminación de Escherichia coli resistentes a cefalosporinas de diferentes nichos ecológicos; pollos de engorde como ejemplo de animales de producción, moscas (Musca domestica) como vectores mecánicos y reservorios de genes de resistencia que contribuyen a la diseminación de resistencias en el ambiente de granja; y finalmente, cigüeñas blancas (Ciconia ciconia) como ejemplo de vectores de larga distancia y centinelas de la presión humana. Con este enfoque, intentamos entender la transmisibilidad de las resistencias entre nichos diferentes; e identificar los clones, los genes de resistencia y los plásmidos involucrados.Bacteria resistant to antimicrobials, and specifically to extended-spectrum beta-lactamases (ESBLs), have become of increasing concern. Its prevalence has increased fast worldwide due to a pandemic dissemination of plasmids and the introduction of ESBL resistance genes into successful clones (Coque, Baquero et al. 2008, Brolund 2014). According to the World Health Organization (WHO), the most critical antimicrobials in human and animal health are third-generation cephalosporins, fluoroquinolones, macrolides and aminoglycosides (Collignon, Powers et al. 2009, Collignon, Conly et al. 2016). Therefore, this thesis has focused in resistance to cephalosporins and particularly to ESBLs and AmpC type of resistance. Due to the overuse of antimicrobials in humans and veterinary medicine, the emergence of multi-drug resistance has increased in the last decades. Most of the research has focused on the epidemiology of antibiotic resistance in human and veterinary medicine; however, in the last years it has been an increasing attention on how multiresistant bacteria circulates in natural environments and how these niches can act as reservoirs of resistant traits (Allen, Donato et al. 2010). Once the resistant bacteria are present in the environment, it can easily get in contact with humans. Through the studies compiled in this thesis, we have investigated the occurrence and mechanisms of dissemination of cephalosporin resistance (CR) Escherichia coli from different ecological niches; broilers as an example of food-producing animals, houseflies (Musca domestica) as mechanical vectors and reservoir of resistance genes contributing to the spread of resistance in the farm environment; and finally white storks (Ciconia ciconia) as an example of long-distance vectors and sentinels of human pressure. With this approach, we intend to understand the transmissibility of these resistances among different niches; and identify clones, resistance genes and plasmids involved

Impact of the use of β-lactam antimicrobials on the emergence of Escherichia coli isolates resistant to cephalosporins under standard pig-rearing conditions

The aim of this study was to evaluate if the treatments with ceftiofur and amoxicillin are risk factors for the emergence of cephalosporin resistant (CR) E. coli in a pig farm during the rearing period. One hundred 7-day-old piglets were divided into two groups, a control (n = 50) group and a group parenterally treated with ceftiofur (n = 50). During the fattening period, both groups were subdivided in two. A second treatment with amoxicillin was administered in feed to two of the four groups, as follows: group 1 (untreated, n = 20), group 2 (treated with amoxicillin, n = 26), group 3 (treated with ceftiofur, n = 20), and group 4 (treated with ceftiofur and amoxicillin, n = 26). During treatment with ceftiofur, fecal samples were collected before treatment (day 0) and at days 2, 7, 14, 21, and 42 posttreatment, whereas with amoxicillin, the sampling was extended 73 days posttreatment. CR E. coli bacteria were selected on MacConkey agar with ceftriaxone (1 mg/liter). Pulsed-field gel electrophoresis (PFGE), MICs of 14 antimicrobials, the presence of cephalosporin resistance genes, and replicon typing of plasmids were analyzed. Both treatments generated an increase in the prevalence of CR E. coli, which was statistically significant in the treated groups. Resistance diminished after treatment. A total of 47 CR E. coli isolates were recovered during the study period; of these, 15 contained blaCTX-M-1, 10 contained blaCTX-M-14, 4 contained blaCTX-M-9, 2 contained blaCTX-M-15, and 5 contained blaSHV-12. The treatment with ceftiofur and amoxicillin was associated with the emergence of CR E. coli during the course of the treatment. However, by the time of finishing, CR E. coli bacteria were not recovered from the animals