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1.
BMC Genomics ; 17(1): 960, 2016 11 22.
Artículo en Inglés | MEDLINE | ID: mdl-27875980

RESUMEN

BACKGROUND: Avian pathogenic Escherichia coli (APEC) causes colibacillosis, which results in significant economic losses to the poultry industry worldwide. However, the diversity between isolates remains poorly understood. Here, a total of 272 APEC isolates collected from the United Kingdom (UK), Italy and Germany were characterised using multiplex polymerase chain reactions (PCRs) targeting 22 equally weighted factors covering virulence genes, R-type and phylogroup. Following these analysis, 95 of the selected strains were further analysed using Whole Genome Sequencing (WGS). RESULTS: The most prevalent phylogroups were B2 (47%) and A1 (22%), although there were national differences with Germany presenting group B2 (35.3%), Italy presenting group A1 (53.3%) and UK presenting group B2 (56.1%) as the most prevalent. R-type R1 was the most frequent type (55%) among APEC, but multiple R-types were also frequent (26.8%). Following compilation of all the PCR data which covered a total of 15 virulence genes, it was possible to build a similarity tree using each PCR result unweighted to produce 9 distinct groups. The average number of virulence genes was 6-8 per isolate, but no positive association was found between phylogroup and number or type of virulence genes. A total of 95 isolates representing each of these 9 groupings were genome sequenced and analysed for in silico serotype, Multilocus Sequence Typing (MLST), and antimicrobial resistance (AMR). The UK isolates showed the greatest variability in terms of serotype and MLST compared with German and Italian isolates, whereas the lowest prevalence of AMR was found for German isolates. Similarity trees were compiled using sequencing data and notably single nucleotide polymorphism data generated ten distinct geno-groups. The frequency of geno-groups across Europe comprised 26.3% belonging to Group 8 representing serogroups O2, O4, O18 and MLST types ST95, ST140, ST141, ST428, ST1618 and others, 18.9% belonging to Group 1 (serogroups O78 and MLST types ST23, ST2230), 15.8% belonging to Group 10 (serogroups O8, O45, O91, O125ab and variable MLST types), 14.7% belonging to Group 7 (serogroups O4, O24, O35, O53, O161 and MLST type ST117) and 13.7% belonging to Group 9 (serogroups O1, O16, O181 and others and MLST types ST10, ST48 and others). The other groups (2, 3, 4, 5 and 6) each contained relatively few strains. However, for some of the genogroups (e.g. groups 6 and 7) partial overlap with SNPs grouping and PCR grouping (matching PCR groups 8 (13 isolates on 22) and 1 (14 isolates on 16) were observable). However, it was not possible to obtain a clear correlation between genogroups and unweighted PCR groupings. This may be due to the genome plasticity of E. coli that enables strains to carry the same virulence factors even if the overall genotype is substantially different. CONCLUSIONS: The conclusion to be drawn from the lack of correlations is that firstly, APEC are very diverse and secondly, it is not possible to rely on any one or more basic molecular or phenotypic tests to define APEC with clarity, reaffirming the need for whole genome analysis approaches which we describe here. This study highlights the presence of previously unreported serotypes and MLSTs for APEC in Europe. Moreover, it is a first step on a cautious reconsideration of the merits of classical identification criteria such as R typing, phylogrouping and serotyping.


Asunto(s)
Infecciones por Escherichia coli/veterinaria , Escherichia coli/genética , Genoma Bacteriano , Genómica , Enfermedades de las Aves de Corral/microbiología , Animales , Análisis por Conglomerados , Biología Computacional/métodos , Minería de Datos , Farmacorresistencia Bacteriana , Escherichia coli/clasificación , Escherichia coli/efectos de los fármacos , Genómica/métodos , Secuenciación de Nucleótidos de Alto Rendimiento , Aprendizaje Automático , Tipificación de Secuencias Multilocus , Filogenia , Polimorfismo de Nucleótido Simple , Serotipificación , Factores de Virulencia/genética
2.
mSystems ; 8(1): e0085222, 2023 02 23.
Artículo en Inglés | MEDLINE | ID: mdl-36629432

RESUMEN

Pigs infected with Salmonella may excrete large amounts of Salmonella, increasing the risk of spread of this pathogen in the food chain. Identifying Salmonella high shedder pigs is therefore required to mitigate this risk. We analyzed immune-associated markers and composition of the gut microbiota in specific-pathogen-free pigs presenting different shedding levels after an oral infection with Salmonella. Immune response was studied through total blood cell counts, production of anti-Salmonella antibodies and cytokines, and gene expression quantification. Total Salmonella shedding for each pig was estimated and hierarchical clustering was used to cluster pigs into high, intermediate, and low shedders. Gut microbiota compositions were assessed using 16S rRNA microbial community profiling. Comparisons were made between control and inoculated pigs, then between high and low shedders pigs. Prior to infection, high shedders had similar immunological profiles compared to low shedders. As soon as 1 day postinoculation (dpi), significant differences on the cytokine production level and on the expression level of several host genes related to a proinflammatory response were observed between high and low shedders. Infection with Salmonella induced an early and profound remodeling of the immune response in all pigs, but the intensity of the response was stronger in high shedders. In contrast, low shedders seroconverted earlier than high shedders. Just after induction of the proinflammatory response (at 2 dpi), some taxa of the fecal microbiota were specific to the shedding phenotypes. This was related to the enrichment of several functional pathways related to anaerobic respiration in high shedders. In conclusion, our data show that the immune response to Salmonella modifies the fecal microbiota and subsequently could be responsible for shedding phenotypes. Influencing the gut microbiota and reducing intestinal inflammation could be a strategy for preventing Salmonella high shedding in livestock. IMPORTANCE Salmonellosis remains the most frequent human foodborne zoonosis after campylobacteriosis and pork meat is considered one of the major sources of human foodborne infections. At the farm, host heterogeneity in pig infection is problematic. High Salmonella shedders contribute more significantly to the spread of this foodborne pathogen in the food chain. The identification of predictive biomarkers for high shedders could help to control Salmonella in pigs. The purpose of the present study was to investigate why some pigs become super shedders and others low shedders. We thus investigated the differences in the fecal microbial composition and the immune response in orally infected pigs presenting different Salmonella shedding patterns. Our data show that the proinflammatory response induced by S. Typhimurium at 1 dpi could be responsible for the modification of the fecal microbiota composition and functions observed mainly at 2 and 3 dpi and to the low and super shedder phenotypes.


Asunto(s)
Microbiota , Salmonella typhimurium , Porcinos , Animales , Humanos , Salmonella typhimurium/genética , ARN Ribosómico 16S/genética , Heces , Fenotipo
3.
Front Mol Biosci ; 10: 1144001, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37842636

RESUMEN

Introduction: Accurate and rapid diagnostics paired with effective tracking and tracing systems are key to halting the spread of infectious diseases, limiting the emergence of new variants and to monitor vaccine efficacy. The current gold standard test (RT-qPCR) for COVID-19 is highly accurate and sensitive, but is time-consuming, and requires expensive specialised, lab-based equipment. Methods: Herein, we report on the development of a SARS-CoV-2 (COVID-19) rapid and inexpensive diagnostic platform that relies on a reverse-transcription loop-mediated isothermal amplification (RT-LAMP) assay and a portable smart diagnostic device. Automated image acquisition and an Artificial Intelligence (AI) deep learning model embedded in the Virus Hunter 6 (VH6) device allow to remove any subjectivity in the interpretation of results. The VH6 device is also linked to a smartphone companion application that registers patients for swab collection and manages the entire process, thus ensuring tests are traced and data securely stored. Results: Our designed AI-implemented diagnostic platform recognises the nucleocapsid protein gene of SARS-CoV-2 with high analytical sensitivity and specificity. A total of 752 NHS patient samples, 367 confirmed positives for coronavirus disease (COVID-19) and 385 negatives, were used for the development and validation of the test and the AI-assisted platform. The smart diagnostic platform was then used to test 150 positive clinical samples covering a dynamic range of clinically meaningful viral loads and 250 negative samples. When compared to RT-qPCR, our AI-assisted diagnostics platform was shown to be reliable, highly specific (100%) and sensitive (98-100% depending on viral load) with a limit of detection of 1.4 copies of RNA per µL in 30 min. Using this data, our CE-IVD and MHRA approved test and associated diagnostic platform has been approved for medical use in the United Kingdom under the UK Health Security Agency's Medical Devices (Coronavirus Test Device Approvals, CTDA) Regulations 2022. Laboratory and in-silico data presented here also indicates that the VIDIIA diagnostic platform is able to detect the main variants of concern in the United Kingdom (September 2023). Discussion: This system could provide an efficient, time and cost-effective platform to diagnose SARS-CoV-2 and other infectious diseases in resource-limited settings.

5.
J Gen Virol ; 91(Pt 10): 2524-30, 2010 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-20519455

RESUMEN

Complete genome sequences were determined for two distinct strains of slow bee paralysis virus (SBPV) of honeybees (Apis mellifera). The SBPV genome is approximately 9.5 kb long and contains a single ORF flanked by 5'- and 3'-UTRs and a naturally polyadenylated 3' tail, with a genome organization typical of members of the family Iflaviridae. The two strains, labelled 'Rothamsted' and 'Harpenden', are 83% identical at the nucleotide level (94% identical at the amino acid level), although this variation is distributed unevenly over the genome. The two strains were found to co-exist at different proportions in two independently propagated SBPV preparations. The natural prevalence of SBPV for 847 colonies in 162 apiaries across five European countries was <2%, with positive samples found only in England and Switzerland, in colonies with variable degrees of Varroa infestation.


Asunto(s)
Abejas/virología , Genoma Viral , Virus ARN/genética , Virus ARN/aislamiento & purificación , ARN Viral/genética , Regiones no Traducidas 3' , Regiones no Traducidas 5' , Animales , Análisis por Conglomerados , Europa (Continente) , Datos de Secuencia Molecular , Sistemas de Lectura Abierta , Filogenia , ARN Mensajero/genética , Análisis de Secuencia de ADN , Homología de Secuencia de Aminoácido , Homología de Secuencia de Ácido Nucleico
6.
J Invertebr Pathol ; 103 Suppl 1: S30-47, 2010 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-19909972

RESUMEN

Acute bee paralysis virus (ABPV), Kashmir bee virus (KBV) and Israeli acute paralysis virus (IAPV) are part of a complex of closely related viruses from the Family Dicistroviridae. These viruses have a widespread prevalence in honey bee (Apis mellifera) colonies and a predominantly sub-clinical etiology that contrasts sharply with the extremely virulent pathology encountered at elevated titres, either artificially induced or encountered naturally. These viruses are frequently implicated in honey bee colony losses, especially when the colonies are infested with the parasitic mite Varroa destructor. Here we review the historical and recent literature of this virus complex, covering history and origins; the geographic, host and tissue distribution; pathology and transmission; genetics and variation; diagnostics, and discuss these within the context of the molecular and biological similarities and differences between the viruses. We also briefly discuss three recent developments relating specifically to IAPV, concerning its association with Colony Collapse Disorder, treatment of IAPV infection with siRNA and possible honey bee resistance to IAPV.


Asunto(s)
Abejas/parasitología , Abejas/virología , Dicistroviridae/patogenicidad , Infestaciones por Ácaros/veterinaria , Infecciones por Picornaviridae/veterinaria , Secuencia de Aminoácidos , Animales , Apicultura , Cartilla de ADN , Dicistroviridae/genética , Brotes de Enfermedades/veterinaria , Genoma , Interacciones Huésped-Parásitos , Interacciones Huésped-Patógeno , Mapas como Asunto , Infestaciones por Ácaros/virología , Datos de Secuencia Molecular , Parálisis/veterinaria , Filogenia , Infecciones por Picornaviridae/patología , Infecciones por Picornaviridae/terapia , Infecciones por Picornaviridae/transmisión , ARN Interferente Pequeño/uso terapéutico , Varroidae/fisiología , Varroidae/virología
7.
J Invertebr Pathol ; 104(2): 153-6, 2010 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-20219470

RESUMEN

Ugandan honey bees (Apis mellifera L.) produce honey, and are key pollinators within commercial crops and natural ecosystems. Real-time RT-PCR was used to screen immature and adult bees collected from 63 beekeeping sites across Uganda for seven viral pathogens. No samples tested positive for Chronic bee paralysis virus, Sacbrood virus, Deformed wing virus, Acute bee paralysis virus, Apis iridescent virus or Israeli acute paralysis virus. However, Black queen cell virus (BQCV) was found in 35.6% of samples. It occurred in adults and larvae, and was most prevalent in the Western highlands, accounting for over 40% of positive results nationally.


Asunto(s)
Abejas/virología , Virus de Insectos/aislamiento & purificación , Virosis/veterinaria , Animales , Virus de Insectos/clasificación , Virus de Insectos/genética , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Uganda , Virosis/virología
8.
Genes (Basel) ; 11(12)2020 12 11.
Artículo en Inglés | MEDLINE | ID: mdl-33322364

RESUMEN

To reconstruct aspects of human demographic history, linguistics and genetics complement each other, reciprocally suggesting testable hypotheses on population relationships and interactions. Relying on a linguistic comparative method based on syntactic data, here we focus on the non-straightforward relation of genes and languages among Finno-Ugric (FU) speakers, in comparison to their Indo-European (IE) and Altaic (AL) neighbors. Syntactic analysis, in agreement with the indications of more traditional linguistic levels, supports at least three distinct clusters, corresponding to these three Eurasian families; yet, the outliers of the FU group show linguistic convergence with their geographical neighbors. By analyzing genome-wide data in both ancient and contemporary populations, we uncovered remarkably matching patterns, with north-western FU speakers linguistically and genetically closer in parallel degrees to their IE-speaking neighbors, and eastern FU speakers to AL speakers. Therefore, our analysis indicates that plausible cross-family linguistic interference effects were accompanied, and possibly caused, by recognizable demographic processes. In particular, based on the comparison of modern and ancient genomes, our study identified the Pontic-Caspian steppes as the possible origin of the demographic processes that led to the expansion of FU languages into Europe.


Asunto(s)
Variación Genética , Genoma Humano , Migración Humana , Lenguaje , Población Blanca , Europa (Continente)/etnología , Historia Antigua , Humanos , Población Blanca/etnología , Población Blanca/genética , Población Blanca/historia
9.
Sci Rep ; 6: 26589, 2016 05 25.
Artículo en Inglés | MEDLINE | ID: mdl-27220895

RESUMEN

This study assessed the prevalence and zoonotic potential of Shiga toxin-producing Escherichia coli (STEC) sampled from 104 dairy units in the central region of Zambia and compared these with isolates from patients presenting with diarrhoea in the same region. A subset of 297 E. coli strains were sequenced allowing in silico analyses of phylo- and sero-groups. The majority of the bovine strains clustered in the B1 'commensal' phylogroup (67%) and included a diverse array of serogroups. 11% (41/371) of the isolates from Zambian dairy cattle contained Shiga toxin genes (stx) while none (0/73) of the human isolates were positive. While the toxicity of a subset of these isolates was demonstrated, none of the randomly selected STEC belonged to key serogroups associated with human disease and none encoded a type 3 secretion system synonymous with typical enterohaemorrhagic strains. Positive selection for E. coli O157:H7 across the farms identified only one positive isolate again indicating this serotype is rare in these animals. In summary, while Stx-encoding E. coli strains are common in this dairy population, the majority of these strains are unlikely to cause disease in humans. However, the threat remains of the emergence of strains virulent to humans from this reservoir.


Asunto(s)
Enfermedades de los Bovinos , Infecciones por Escherichia coli/genética , Filogenia , Escherichia coli Shiga-Toxigénica , Zoonosis , Animales , Bovinos , Enfermedades de los Bovinos/genética , Enfermedades de los Bovinos/microbiología , Humanos , Escherichia coli Shiga-Toxigénica/genética , Escherichia coli Shiga-Toxigénica/aislamiento & purificación , Escherichia coli Shiga-Toxigénica/patogenicidad , Zambia , Zoonosis/genética , Zoonosis/microbiología
10.
Res Vet Sci ; 102: 162-6, 2015 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-26412537

RESUMEN

Strangles is one of the most common equine infectious diseases with serious health, welfare and socio-economic impact. However, the detection of Streptococcus equi subspecies equi can be challenging and persistently infected carriers are common. Furthermore, the use of classical microbiology can result in an underestimation of the prevalence of the disease. The difficulties associated with the slow diagnosis of Strangles can result in rapid spread of the disease. Therefore, rapid and economical diagnostic tests are urgently required. Here, two multiplex assays, were developed and validated for the detection of S. equi and S. equi subspecies zooepidemicus, the most common differential diagnosis. Using 59 S. equi and 59 S. zooepidemicus strains collected from various geographical areas, the PCR tests demonstrated a sensitivity of 95% and a specificity of 98%. Furthermore, the assay can be performed directly from clinical swabs. Thus, the assays designed here provide a rapid, reliable and economical solution for the diagnosis of Strangles.


Asunto(s)
Enfermedades de los Caballos/diagnóstico , Reacción en Cadena de la Polimerasa/veterinaria , Infecciones Estreptocócicas/veterinaria , Streptococcus equi/aislamiento & purificación , Animales , Enfermedades de los Caballos/microbiología , Caballos , Sensibilidad y Especificidad , Infecciones Estreptocócicas/diagnóstico , Factores de Tiempo
11.
Vet Ital ; 43(3): 431-6, 2007.
Artículo en Inglés | MEDLINE | ID: mdl-20422519

RESUMEN

Bee-keeping in the Marche region of Italy is an ancient tradition. Besides the production of honey and other products of the apiary (wax, propolis, royal jelly, bee bread and venom), bees also play a fundamental role in the pollination of cultivated and natural plants. For these reasons, and to update information on the status of apiculture in the Territorial Zone 7 (TZ 7) of the Marche Region of Italy, a survey was conducted in 2005 using geographic information system (GIS) technology. A CD-Rom was developed in html; this tool enables the visualisation of data using any operating system and browser. We collected information on the health status of 57 apiaries out of 169 for a total of 1 570 hives. Samples of honey were tested for the presence of antibiotics and pesticides. The data collected on American foulbrood showed that this disease is endemic in the area and the extent of spread appears to be largely under-estimated. No antibiotics were detected in any of the honey samples tested using the bacterial growth inhibition method. Similarly, high performance liquid chromatography did not detect any pesticide residues. Further research will be conducted by geo-referencing all apiaries in the same area and in apiaries located in other territorial zones of the Marche region.

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