RESUMEN
Kobuviruses have been detected in a wide range of mammals including cats, dogs, pigs, cattle, goats, sheep and bats. Kobuviruses have been detected in symptomatic and asymptomatic animals; however, the clinical significance of infection in animals is still unclear. To date, there is no information regarding kobuvirus prevalence in livestock in Ireland. This study reports the first detection of kobuviruses in pigs, bovines and ovines using quantitative PCR. In this study, mesenteric lymph node was collected from cattle (n = 57), pigs (n = 53) and sheep (n = 50) from farms in Northern Ireland and the Republic of Ireland, from animals which had been submitted by private veterinary practitioners from 2009 to 2011 for routine post mortem and clinico-pathological examination. Kobuviruses were detected in 14 cows (24.5%), 5 pigs (9.4%) and 1 sheep (2%). Phylogenetic analysis of Irish kobuviruses from cattle and pigs revealed that the isolates clustered according to their host species. Interestingly, the sheep kobuvirus clustered with bovine kobuviruses detected in this study and other published kobuvirus strains. The data presented in this study contributes to the understanding of the epidemiology of these viruses in animals and to the genetic diversity that these viruses possess.
Asunto(s)
Enfermedades de los Bovinos/virología , Bovinos/virología , Kobuvirus/genética , Infecciones por Picornaviridae/veterinaria , Enfermedades de las Ovejas/virología , Ovinos/virología , Enfermedades de los Porcinos/virología , Porcinos/virología , Animales , Secuencia de Bases , ADN Viral/genética , Variación Genética , Irlanda/epidemiología , Kobuvirus/clasificación , Kobuvirus/aislamiento & purificación , Ganglios Linfáticos/virología , Mesenterio/virología , Irlanda del Norte/epidemiología , Infecciones por Picornaviridae/epidemiología , Infecciones por Picornaviridae/virología , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Análisis de Secuencia de ADNRESUMEN
Worldwide, Group A Rotavirus (RVA) is recognized as the most common aetiological agent of acute diarrheal disease in children. One hundred and ninety seven positive faecal samples were obtained from patients between 2006 and 2008. Reverse transcriptase polymerase chain reaction (RT-PCR) was used to amplify the VP7 and VP4 gene segments of these samples, and G and P typing was carried out subsequently. The most common strain type was G1P[8], and the emergent global G9-type was identified in both years. RVA strain type G2P[4], previously reported in Ireland in 1999, was also detected. Genotypes G2 and G3 in combination with P[4] were detected in 2006-2007 only. There was also an emergence of strain types including G3P[4], G9P[4], G2P[4 + 8] and G2G4P[8] in this study. Molecular analysis of the VP7 genes revealed G1 strains circulating within lineage Ic as previously reported in Ireland. In addition, new sublineage within lineage I of G1 strains was also identified. Analysis of G4 strain NRVL-Hum-49 revealed similarity with other human G4 viruses in lineage Ib. G9 strain NRVL-Hum-74 clustered with a unique G9 strain, CIT-254, in lineage IIIc. This data supports the observations made that the profile of RVA strains in Ireland appears to be dynamic. This study demonstrates that the circulation of human rotavirus is changing continuously in Ireland, and continued surveillance of the circulating strains is needed to detect the appearance of new strains, or new variants which may lead to vaccine breakthrough.
Asunto(s)
Variación Genética , Genotipo , Infecciones por Rotavirus/epidemiología , Infecciones por Rotavirus/virología , Rotavirus/clasificación , Rotavirus/genética , Antígenos Virales/genética , Proteínas de la Cápside/genética , Niño , Preescolar , Análisis por Conglomerados , Heces/virología , Femenino , Técnicas de Genotipaje , Humanos , Lactante , Recién Nacido , Irlanda/epidemiología , Masculino , Epidemiología Molecular , Filogenia , ARN Viral/genética , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Rotavirus/aislamiento & purificación , Análisis de Secuencia de ADN , Homología de SecuenciaRESUMEN
BACKGROUND: Bovine coronavirus is a primary cause of neonatal calf diarrhea worldwide, and is also associated with acute diarrhea in adult cattle during the winter season. There are no reports on molecular characterization of bovine coronavirus in Ireland, and little data exists apart from serological studies. FINDINGS: In this study, 11 neonatal (mean age 9 days) calf BCoV strains from the south of Ireland were collected over a one year period and characterized using molecular methods. The spike gene which encodes a protein involved in viral entry, infectivity and immune response shows the most variability amongst the isolates and was subsequently selected for in depth analysis. Phylogenetic analysis of the spike gene revealed that the Irish strains clustered with novel BCoV strains from Europe in a unique clade, possibly indicating lineage partitioning. Direct analysis of alignments identified amino acid changes in the spike protein unique to the Irish clade. CONCLUSION: Thus, monitoring of bovine coronavirus in Ireland is important as the current isolates in circulation in the south of Ireland may be diverging from the available vaccine strain, which may have implications regarding future BCoV vaccine efficacy.
RESUMEN
Norovirus (NoV) gastroenteritis occurs in all age groups and is the most common cause of gastroenteritis in the community. However, detection methods and rates vary widely, and few data are available to compare these, particularly in Ireland. Detection of noroviruses through antigen and molecular-based strategies was carried out on 135 suspected NoV-positive samples, collected over the course of three NoV outbreaks, from 2002 to 2006, in the southern region of Ireland. A commercially available ELISA and a panel of six primer sets were evaluated to determine their suitability for NoV detection in Irish clinical samples. The key findings of this study were the detection of both GGI and GGII noroviruses by ELISA, but the detection of only GGII noroviruses by RT-PCR. In addition to this, a variation in the levels of detection from 9.4 % to 17.3 % was observed for conventional PCR assays, while a detection rate of 46.3 % was observed for the real-time PCR assay. A proportion (17.8 %) of samples were found to be negative by all detection strategies, suggesting the possibility of reporting false positives for these samples or low-copy positives that do not often repeat. Sequencing information from selected samples also revealed nucleotide polymorphisms, compromising efficient primer binding in the case of one primer pairing. Phylogenetic analysis of the partial polymerase gene identified NoV GII.4 as the dominant genotype, in accordance with previous NoV studies in Ireland. Investigating the NoV diversity of the circulating strains and the dynamics of strain replacement is important to better assess the efficacy of future NoV vaccines and to facilitate the early detection of changes in circulating NoV strains.
Asunto(s)
Infecciones por Caliciviridae/virología , Brotes de Enfermedades , Ensayo de Inmunoadsorción Enzimática/métodos , Norovirus/genética , Norovirus/aislamiento & purificación , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa/métodos , Secuencia de Bases , Infecciones por Caliciviridae/epidemiología , Cartilla de ADN , Genotipo , Humanos , Irlanda/epidemiología , Datos de Secuencia Molecular , Norovirus/clasificación , Filogenia , Alineación de Secuencia , Factores de TiempoRESUMEN
BACKGROUND: Worldwide, Group A bovine rotavirus (RVA boRV) is one of the main causes of neonatal calf diarrhoea. Currently, limited epidemiological and sequence data exists on the RVA disease in bovines in Southern Ireland only. The aim of the study was to generate epidemiological and sequence data of RVA boRV distributed over a wide geographical area in Ireland. FINDINGS: 272 stool samples were obtained from symptomatic calves and analysed to identify the prevalent G and P genotypes. Viral type combinations including G6P[5], G6P[11] and G10P[11] genotype were the most frequently identified. The G6P[5] combination was predominant throughtout the study, accounting for 70% (n = 191). Sequence analysis of the VP7 gene revealed that Irish G6 strains fell within Lineage IV, similiar to previous reports in Ireland. CONCLUSION: The detection of unusual G and P combinations may have an impact on rotavirus control programmes and current vaccines may need to incorporate new strains, as the current vaccine available may not offer protection against all of these circulating types.
RESUMEN
In this study, the complete genome sequences of seven equine group A rotavirus (RVA) strains (RVA/Horse-tc/GBR/L338/1991/G13P[18], RVA/Horse-wt/IRL/03V04954/2003/G3P[12] and RVA/Horse-wt/IRL/04V2024/2004/G14P[12] from Europe; RVA/Horse-wt/ARG/E30/1993/G3P[12], RVA/Horse-wt/ARG/E403/2006/G14P[12] and RVA/Horse-wt/ARG/E4040/2008/G14P[12] from Argentina; and RVA/Horse-wt/ZAF/EqRV-SA1/2006/G14P[12] from South Africa) were determined. Multiple novel genotypes were identified and genotype numbers were assigned by the Rotavirus Classification Working Group: R9 (VP1), C9 (VP2), N9 (NSP2), T12 (NSP3), E14 (NSP4), and H7 and H11 (NSP5). The genotype constellation of L338 was unique: G13-P[18]-I6-R9-C9-M6-A6-N9-T12-E14-H11. The six remaining equine RVA strains showed a largely conserved genotype constellation: G3/G14-P[12]-I2/I6-R2-C2-M3-A10-N2-T3-E2/E12-H7, which is highly divergent from other known non-equine RVA genotype constellations. Phylogenetic analyses revealed that the sequences of these equine RVA strains are related distantly to non-equine RVA strains, and that at least three lineages exist within equine RVA strains. A small number of reassortment events were observed. Interestingly, the three RVA strains from Argentina possessed the E12 genotype, whereas the three RVA strains from Ireland and South Africa possessed the E2 genotype. The unusual E12 genotype has until now only been described in Argentina among RVA strains collected from guanaco, cattle and horses, suggesting geographical isolation of this NSP4 genotype. This conserved genetic configuration of equine RVA strains could be useful for future vaccine development or improvement of currently used equine RVA vaccines.
Asunto(s)
Secuencia Conservada/genética , Gastroenteritis/veterinaria , Genoma Viral/genética , Enfermedades de los Caballos/virología , Infecciones por Rotavirus/veterinaria , Rotavirus/genética , Animales , Secuencia de Bases , Gastroenteritis/virología , Genes Virales/genética , Genotipo , Caballos/virología , Datos de Secuencia Molecular , Filogenia , Infecciones por Rotavirus/virologíaRESUMEN
Rotavirus is a major cause of gastroenteritis in young children worldwide. There have been several recent reports concerning rotavirus isolation from adults, particularly in the elderly, presenting with gastroenteritis. In this study, the authors report on rotavirus outbreaks in five separate elderly care facilities between April, and June 2011 in Ireland. The following genotypes were detected; G1P[8] (n = 5/11), G2P[4] (n = 2/11), and G9P[8] (n = 2/11). Thus, similarities to previous reports were found in that G1P[8] predominated, G9P[8] was still detected but G2P[4] was detected for the first time in a geriatric population in Ireland. Here also described is the detection of Group 2 lineage IIC rotavirus in Ireland for the first time.
Asunto(s)
Brotes de Enfermedades , Infecciones por Rotavirus/epidemiología , Rotavirus/genética , Rotavirus/aislamiento & purificación , Anciano , Anciano de 80 o más Años , Antígenos Virales/genética , Secuencia de Bases , Proteínas de la Cápside/genética , Femenino , Variación Genética , Genotipo , Humanos , Irlanda/epidemiología , Masculino , Filogenia , ARN Viral/genética , Rotavirus/clasificación , Infecciones por Rotavirus/virología , Alineación de SecuenciaRESUMEN
Community and hospital-acquired cases of human rotavirus are responsible for millions of gastroenteritis cases in children worldwide, chiefly in developing countries, and vaccines are now available. During surveillance activity for human rotavirus infections in Ireland, between 2006 and 2009, a total of 420 rotavirus strains were collected and analysed. Upon either PCR genotyping and sequence analysis, a variety of VP7 (G1-G4 and G9) and VP4 (P[4], P[6], P[8] and P[9]) genotypes were detected. Strains G1P[8] were found to be predominant throughout the period 2006-2008, with slight fluctuations seen in the very limited samples available in 2008-2009. Upon either PCR genotyping and sequence analysis of selected strains, the G1, G3 and G9 viruses were found to contain E1 (Wa-like) NSP4 and I1 VP6 genotypes, while the analysed G2 strains possessed E2 NSP4 and I2 VP6 genotypes, a genetic make-up which is highly conserved in the major human rotavirus genogroups Wa- and Kun-like, respectively. Upon sequence analysis of the most common VP4 genotype, P[8], at least two distinct lineages were identified, both unrelated to P[8] Irish rotaviruses circulating in previous years, and more closely related to recent European humans rotaviruses. Moreover, sequence analysis of the VP7 of G1 rotaviruses revealed the onset of a G1 variant, previously unseen in the Irish population.
Asunto(s)
Antígenos Virales/genética , Proteínas de la Cápside/genética , Gastroenteritis/virología , Infecciones por Rotavirus/virología , Rotavirus/clasificación , Rotavirus/genética , Preescolar , Electroforesis en Gel de Poliacrilamida , Heces/virología , Genotipo , Humanos , Irlanda , Datos de Secuencia Molecular , Filogenia , ARN Viral/genética , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Rotavirus/aislamiento & purificación , Análisis de Secuencia de ADNRESUMEN
Tribolium castaneum (Herbst) has been used as a model organism to develop and test important ecological and evolutionary concepts and is also a major pest of grain and grain products globally. This beetle species is assumed to be a good colonizer of grain storages through anthropogenic movement of grain, and active dispersal by flight is considered unlikely. Studies using T. castaneum have therefore used confined or walking insects. We combine an ecological study of dispersal with an analysis of gene flow using microsatellites to investigate the spatiotemporal dynamics and adult flight of T. castaneum in an ecological landscape in eastern Australia. Flying beetles were caught in traps at grain storages and in fields at least 1 km from the nearest stored grain at regular intervals for an entire year. Significantly more beetles were trapped at storages than in fields, and almost no beetles were caught in native vegetation reserves many kilometres from the nearest stored grain. Genetic differentiation between beetles caught at storages and in fields was low, indicating that although T. castaneum is predominantly aggregated around grain storages, active dispersal takes place to the extent that significant gene flow occurs between them, mitigating founder effects and genetic drift. By combining ecological and molecular techniques, we reveal much higher levels of active dispersal through adult flight in T. castaneum than previously thought. We conclude that the implications of adult flight to previous and future studies on this model organism warrant consideration.
Asunto(s)
Vuelo Animal , Flujo Génico , Variación Genética , Tribolium/genética , Agricultura , Animales , Australia , Ambiente , Femenino , Efecto Fundador , Genotipo , Masculino , Repeticiones de Microsatélite , Estaciones del AñoRESUMEN
Canine parvovirus (CPV) and canine coronavirus (CCoV) are considered the main pathogens responsible for acute gastroenteritis in dogs. From a collection of 250 samples, seven CPV strains and three CCoV strains were identified in symptomatic Irish dogs. Samples were screened for the viruses using polymerase chain reaction (PCR) and typed via DNA sequence analysis. Three CPV strains were characterized as CPV-2a, while four others were characterized as CPV-2b. To date, CPV-2c remains unreported in Ireland. Two CCoV strains were characterized as CCoV-II and one as CCoV-I. In the case of one sample, PH4/09/Ire, a mixed infection with CPV and CCoV was detected.
Asunto(s)
Coronavirus Canino/genética , Coronavirus Canino/aislamiento & purificación , Enfermedades de los Perros/virología , Gastroenteritis/veterinaria , Parvovirus Canino/genética , Parvovirus Canino/aislamiento & purificación , Animales , Análisis por Conglomerados , Coronavirus Canino/clasificación , Perros , Gastroenteritis/virología , Genotipo , Irlanda , Datos de Secuencia Molecular , Parvovirus Canino/clasificación , Reacción en Cadena de la Polimerasa , ARN Viral/genética , Análisis de Secuencia de ADNRESUMEN
As global pig health diseases, porcine respiratory disease complex (PRDC) and porcine circovirus-associated disease (PCVAD) generate substantial economic losses despite pigs been vaccinated against the primary causative virus, highlighting the importance of understanding virome interactions and specifically co-factor infections. Established primary endemic pathogens for PRDC include porcine circovirus 2 (PCV2), porcine reproductive and respiratory syndrome virus (PRRSv) and swine influenza virus (SIV), and PCV2 aetiology in interaction with other co-infecting viruses can result in PCVAD. Porcine parvovirus (PPV) 1 is a well-characterized virus with an available vaccine preventing reproductive failure in sows. However, whilst novel PPV 2 to 7 viruses have been identified since 2001, their viral pathogenic potential in clinical and subclinical disease remains to be determined. Therefore, this study has sought to develop a better understanding of their potential role as associated co-infections in PRDC and PCVAD by examining archival samples for the presence of PCV2 and the novel parvoviruses PPV2-4 from clinically diseased pigs across production age stages. Epidemiologically, the novel PPV2 was found to be the most prevalent within the fattener age group with PPV2-4 statistically associated with pig respiratory disease and enteric ulcers. Additionally, statistical modelling by latent class analysis (LCA) on veterinary pathology scored pigs found a clustering co-factor association between PPV2 and PCV2, suggesting the novel PPV may be involved in PRDC and PCVAD. Phylogenetic analysis of novel PPVs revealed the PPV2 capsid evolution to be diverged from the original strains with a low nucleotide homology of 88%-96% between two distinct clades. These findings determine that novel PPV 2-4 viruses are statistically associated as co-infectors in a diseased pig population, and significantly detected PPV2 clustering co-infection frequency with PCV2 in PRDC and PCVAD diseased pigs through LCA analysis.
Asunto(s)
Infecciones por Circoviridae , Coinfección , Síndrome Respiratorio y de la Reproducción Porcina , Enfermedades de los Porcinos , Animales , Infecciones por Circoviridae/complicaciones , Infecciones por Circoviridae/epidemiología , Infecciones por Circoviridae/veterinaria , Circovirus , Coinfección/veterinaria , Femenino , Parvovirus Porcino/genética , Filogenia , Síndrome Respiratorio y de la Reproducción Porcina/epidemiología , Virus del Síndrome Respiratorio y Reproductivo Porcino , Porcinos , Enfermedades de los Porcinos/epidemiologíaRESUMEN
Porcine group A rotaviruses (GARV) are causative agents of enteritis in piglets and are a large reservoir of genetic material for the diversification of human GARVs. Accumulation of information on the genetic heterogeneity of porcine viruses is pivotal for readily characterising unusual human strains. Screening of 292 fecal samples, collected from 4-5- to 8-9-week-old asymptomatic pigs from four herds in Ireland between 2005 and 2007 resulted in 19 (6.5%) samples testing positive by reverse-transcription PCR (RT-PCR) for GARV. The strains were molecularly characterized to collate data on the VP7 and partial VP4 outer capsid genes. By sequence analysis of the VP7 gene, the Irish strains were identified as G2, G4, G5, G9 and G11 viruses. The G11 strains were closely related to other human and porcine G11 strains, while the G2 strains resembled porcine G2 viruses detected recently in Europe and southern Asia. The G4 strains were distantly related to other G4 human and animal strains, constituting a separate G4 VP7 lineage. Analysis of the G5 strains revealed that they were similar to a selection of G5 human and porcine strains, while the G9 strains resembled other porcine G9 viruses. By sequence analysis of the VP8* fragment of the VP4, the Irish viruses were characterised as P[6], P[7], P[13], P[13]/[22], P[26] and P[32].
Asunto(s)
Infecciones por Rotavirus/veterinaria , Rotavirus/genética , Enfermedades de los Porcinos/virología , Animales , Antígenos Virales/genética , Proteínas de la Cápside/genética , Heces/virología , Genotipo , Irlanda , Datos de Secuencia Molecular , Filogenia , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Rotavirus/clasificación , Rotavirus/aislamiento & purificación , Infecciones por Rotavirus/fisiopatología , Infecciones por Rotavirus/virología , Análisis de Secuencia de ADN , Porcinos/virología , Enfermedades de los Porcinos/fisiopatologíaRESUMEN
Group C rotaviruses are important human enteric pathogens that have also been detected in a variety of mammalian species, including pigs. Group C rotaviruses have been identified in piglets with diarrhea, but their ecology remains to be elucidated. By screening of 292 fecal samples collected from 4- to 5-week-old asymptomatic pigs from four herds in Ireland between 2005 and 2007, 13 (4.4%) samples tested positive by reverse transcription-PCR for group C rotavirus. Group A rotaviruses were also detected in 19 samples but not in conjunction with group C viruses. The gene encoding the major group C neutralization antigen, the outer capsid protein VP7, was sequenced. The majority of the strains were very closely related to each other (>99% amino acid [aa] identity) and were characterized as genogroup G1 since they were genetically related to the prototype porcine strain Cowden (92.6% aa identity). Conversely, two strains (1GA/05/Cork/Ire and 281/07/Dublin/Ire) were characterized as genogroup G6 since they displayed the highest identity (89.2 to 94.0% aa) to porcine G6 strains (43/06-22-like). Unexpectedly, one such G6 strain, 1GA/05/Cork/Ire, lacked the 4-aa insertion in the VP7 variable region VR8 found in all the other G6 group C rotaviruses. This study provides evidence that porcine group C rotavirus may be detected not infrequently in asymptomatic piglets. In addition, it provides evidence that, unlike the human viruses, porcine group C rotaviruses display broad genetic heterogeneity, which may pose a challenge for the development of prophylactic tools.
Asunto(s)
Infecciones por Rotavirus/veterinaria , Rotavirus , Animales , Heces/virología , Irlanda , Datos de Secuencia Molecular , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Rotavirus/genética , Infecciones por Rotavirus/virología , Porcinos/virología , Enfermedades de los Porcinos/virologíaRESUMEN
Group A rotaviruses are important causative agents of severe, acute dehydrating diarrhea in foals. A total of 86 rotavirus-positive fecal samples, collected from diarrheic foals from 11 counties in three of the four provinces of Ireland, were obtained from the Irish Equine Centre in Kildare during a 7-year (1999 to 2005) passive surveillance study and were characterized molecularly to establish the VP7 (G type) and VP4 (P type) antigenic specificities. Fifty-eight samples (67.5%) were found to contain G3 viruses, while in 26 samples (30.2%) the rotaviruses were typed as G14 and in 2 samples (2.3%) there was a mixed infection, G3 plus G14. All samples except for two, which were untypeable, were characterized as P[12]. Fifty-eight percent of the samples were obtained from County Kildare, the center of the Irish horse industry, where an apparent shift from G3P[12] to G14P[12] was observed in 2003. By sequence analysis of the VP7 protein, the G3 Irish strains were shown to resemble viruses of the G3A subtype (H2-like) (97.1 to 100% amino acid [aa] identity), while the G14 Irish strains displayed 93.9 to 97.1% aa identity to other G14 viruses. In the VP8* fragment of the VP4 protein, the P[12] Irish viruses displayed high conservation (92.3 to 100% aa) with other equine P[12] viruses. Worldwide, G3P[12] and G14P[12] are the most prevalent equine rotavirus strains, and G3P[12] vaccines have been developed for prevention of rotavirus-associated diarrhea in foals. Investigations of the VP7/VP4 diversity of the circulating equine viruses and the dynamics of strain replacement are important for better assessing the efficacies of the vaccines.
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Enfermedades de los Caballos/virología , Infecciones por Rotavirus/veterinaria , Rotavirus/clasificación , Rotavirus/aislamiento & purificación , Animales , Antígenos Virales/genética , Antígenos Virales/inmunología , Proteínas de la Cápside/genética , Proteínas de la Cápside/inmunología , Heces/virología , Caballos , Irlanda/epidemiología , Datos de Secuencia Molecular , Filogenia , ARN Viral/genética , Rotavirus/genética , Rotavirus/inmunología , Infecciones por Rotavirus/virología , Análisis de Secuencia de ADN , Homología de Secuencia de Aminoácido , SerotipificaciónRESUMEN
Phosphine, a widely used fumigant for the protection of stored grain from insect pests, kills organisms indirectly by inducing oxidative stress. High levels of heritable resistance to phosphine in the insect pest of stored grain, Rhyzopertha dominica have been detected in Asia, Australia and South America. In order to understand the evolution of phosphine resistance and to isolate the responsible genes, we have undertaken genetic linkage analysis of fully sensitive (QRD14), moderately resistant (QRD369) and highly resistant (QRD569) strains of R. dominica collected in Australia. We previously determined that two loci, rph1 and rph2, confer high-level resistance on strain QRD569, which was collected in 1997. We have now confirmed that rph1 is responsible for the moderate resistance of strain QRD369, which was collected in 1990, and is shared with a highly resistant strain from the same geographical region, QRD569. In contrast, rph2 by itself confers only very weak resistance, either as a heterozygote or as a homozygote and was not discovered in the field until weak resistance (probably due to rph1) had become ubiquitous. Thus, high-level resistance against phosphine has evolved via stepwise acquisition of resistance alleles, first at rph1 and thereafter at rph2. The semi-dominance of rph2 together with the synergistic interaction between rph1 and rph2 would have led to rapid selection for homozygosity. A lack of visible fitness cost associated with alleles at either locus suggests that the resistance phenotype will persist in the field.
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Evolución Biológica , Escarabajos/genética , Epistasis Genética , Resistencia a los Insecticidas/genética , Fosfinas/farmacología , Animales , Ligamiento GenéticoRESUMEN
An FMN-dependent nitroreductase enzyme isolated from Escherichia coli B has been crystallized in a form suitable for high-resolution structural analysis. The crystals belong to the tetragonal space group P4(1)2(1)2 or its enantiomorph P4(3)2(1)2 with cell parameters a = b = 57.74 A, c = 275.51 A and two molecules per asymmetric unit. Diffraction extends to beyond 1.9 A.
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Escherichia coli/enzimología , Nitrorreductasas/química , Cristalización , Cristalografía por Rayos X , Mononucleótido de Flavina , Estructura MolecularRESUMEN
Associated with the development of methods to quantify gastric emptying, there has been an increased understanding of the physiology of gastric emptying in normal subjects and the pathophysiology and pharmacological treatment of gastric emptying disorders. The measurement of gastric emptying, using radionuclide-labeled food markers and a scintillation camera, has widespread clinical and research applications.
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Vaciamiento Gástrico , Gastropatías/diagnóstico por imagen , Sulfato de Bario , Duodeno/fisiología , Vaciamiento Gástrico/efectos de los fármacos , Humanos , Indio , Intubación Gastrointestinal , Métodos , Complicaciones Posoperatorias/fisiopatología , Radiografía , Radioisótopos , Cintigrafía , Células Receptoras Sensoriales/fisiología , Estómago/fisiología , Estómago/cirugía , Gastropatías/etiología , Gastropatías/fisiopatología , Tecnecio , Factores de TiempoRESUMEN
Emergency foodbanks have become an increasingly prominent and controversial feature of austerity in Europe and the USA. In the UK, foodbanks have been called a 'public health emergency'. Despite this, there has been no UK research examining the health of foodbank users. Through an ethnographic study, this paper is the first to explore the health and health perceptions of foodbank users via a case study of Stockton-on-Tees in the North East of England, UK during a period of welfare reform and austerity. Participant observation, field notes and interviews with foodbank users and volunteers were conducted over a seventeen month period (November 2013 to March 2015) inside a Trussell Trust foodbank. Foodbank users were almost exclusively of working age, both men and women, with and without dependent children. All were on very low incomes - from welfare benefits or insecure, poorly paid employment. Many had pre-existing health problems which were exacerbated by their poverty and food insecurity. The latter meant although foodbank users were well aware of the importance and constitution of a healthy diet, they were usually unable to achieve this for financial reasons - constantly having to negotiate their food insecurity. More typically they had to access poor quality, readily available, filling, processed foods. Foodbank users are facing the everyday reality of health inequalities at a time of ongoing austerity in the UK.
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Abastecimiento de Alimentos/estadística & datos numéricos , Estado de Salud , Salud Mental , Pobreza/psicología , Adolescente , Adulto , Antropología Cultural , Femenino , Disparidades en el Estado de Salud , Humanos , Masculino , Persona de Mediana Edad , Factores Socioeconómicos , Reino Unido , Adulto JovenRESUMEN
The human genome sequencing initiative is sure to be an expensive and time-consuming project. To maximize the quality of the initial thrust, it is necessary to concentrate on sequencing those genes that are actively involved in crucial biological processes, both normal and otherwise. To identify the protein products of these genes, we propose the use of two-dimensional acrylamide gel electrophoresis and powerful computer software. The two-dimensional gels can then be scaled to yield sufficient amounts of the protein for direct amino acid sequence analysis. The amino acid sequence then provides the direct link back to the gene.
Asunto(s)
Genoma Humano , Proteínas/genética , Diseño de Software , Programas Informáticos , Secuencia de Aminoácidos , Secuencia de Bases , Electroforesis en Gel Bidimensional , Biblioteca Genómica , Proyecto Genoma Humano , Humanos , Sistemas de InformaciónRESUMEN
Technetium-99m-pyridoxylideneglutamate (99mTc-PG) is a nontoxic radiopharmaceutical that was found to undergo rapid biliary excretion in normal humans. The biliary tree and gallbladder were seen within 10-15 min of injection and by 20 min marked accumulation of radioactivity was noted in the gallbladder and gastrointestinal tract. Of ten "control" volunteers, seven had normal 99mTc-PG-cholescintigrams. In the remaining three, the gallbladder was not visualized. Gallbladder disease was not excluded in these three subjects. Of 24 patients referred for investigation of right upper quadrant abdominal pain, 13 proved to have gallbladder disease. All seven patients with acute cholecystitis and one of four patients with chronic cholecystitis had nonvisualization of the gallbladder on the cholescintigram whereas five patients with chronic cholecystitis or cholesterolosis had normal cholescintigrams. Six of the eight patients with nonvisualization of the gallbladder on cholescintigram had contrast radiologic studies (oral cholecystogram or intravenous cholangiogram or both), and in all six, nonvisualization of the gallbladder was also reported on the contrast study. cholescintigraphy was found to be greatly inferior to contrast radiologic studies in the detection of gallbladder stones. Eleven patients had complete extrahepatic biliary obstruction and this diagnosis was correctly made in all 11 by the cholescintigram. Fourteen patients had incomplete extrahepatic biliary obstruction. The correct diagnosis was made on the cholescintigram in seven but in the remaining seven it was not possible to distinguish between incomplete extrahepatic biliary obstruction and hepatocellular disease. Malignant lesions (carcinomas of head of pancreas, gallbladder, common bile duct or ampulla of Vater) were the cause of obstruction in 10 of the 25 patients with complete or incomplete obstruction and the diagnosis of obstruction due to malignancy was correctly made in 8 of these 10 by means of a scintigraphic equivalent to Courvoisier's sing. Finally, 11 patients had hepatocellular disease and a nonspecific pattern consistent with either imcomplete biliary obstruction or hepatocellular disease was observed on the cholescintigram in all 11. The 99mTc-PG cholescintigram is suggested for a role complementary to that of contrast radiologic studies in the preoperative investigation of patients with possible surgical disease of the biliary tract. Contrast radiologic techniques are advocated as being more appropriate in the nonjaundiced patient with suspected gallbladder disease whereas the 99mTc-PG cholescintigram is advocated as being more appropriate in the patient with jaundice. The value of the 99mTc-PG cholescintigram lies in the confidence with which complete extrahepatic biliary obstruction can be diagnosed. The "scintigraphic Courvoisier's sign" seems a useful indicator of malignant obstruction.