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1.
Microb Genom ; 9(1)2023 01.
Artigo em Inglês | MEDLINE | ID: mdl-36748435

RESUMO

Human adenovirus F41 causes acute gastroenteritis in children, and has recently been associated with an apparent increase in paediatric hepatitis of unknown aetiology in the UK, with further cases reported in multiple countries. Relatively little is known about the genetic diversity of adenovirus F41 in UK children; and it is unclear what, if any, impact the COVID-19 pandemic has had on viral diversity in the UK. Methods that allow F41 to be sequenced from clinical samples without the need for viral culture are required to provide the genomic data to address these questions. Therefore, we evaluated an overlapping-amplicon method of sequencing adenovirus genomes from clinical samples using Oxford Nanopore technology. We applied this method to a small sample of adenovirus-species-F-positive extracts collected as part of standard care in the East of England region in January-May 2022. This method produced genomes with >75 % coverage in 13/22 samples and >50 % coverage in 19/22 samples. We identified two F41 lineages present in paediatric patients in the East of England in 2022. Where F41 genomes from paediatric hepatitis cases were available (n=2), these genomes fell within the diversity of F41 from the UK and continental Europe sequenced before and after the 2020-2021 phase of the COVID-19 pandemic. Our analyses suggest that overlapping amplicon sequencing is an appropriate method for generating F41 genomic data from high-virus-load clinical samples, and currently circulating F41 viral lineages were present in the UK and Europe before the COVID-19 pandemic.


Assuntos
Infecções por Adenoviridae , COVID-19 , Humanos , Criança , COVID-19/epidemiologia , Pandemias , Análise de Sequência , Adenoviridae/genética , Variação Genética
2.
Gut Pathog ; 14(1): 32, 2022 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-35915480

RESUMO

BACKGROUND: Kenya introduced Rotarix® (GlaxoSmithKline Biologicals, Rixensart, Belgium) vaccination into its national immunization programme beginning July 2014. The impact of this vaccination program on the local epidemiology of various known enteropathogens is not fully understood. METHODS: We used a custom TaqMan Array Card (TAC) to screen for 28 different enteropathogens in 718 stools from children aged less than 13 years admitted to Kilifi County Hospital, coastal Kenya, following presentation with diarrhea in 2013 (before vaccine introduction) and in 2016-2018 (after vaccine introduction). Pathogen positivity rate differences between pre- and post-Rotarix® vaccination introduction were examined using both univariate and multivariable logistic regression models. RESULTS: In 665 specimens (92.6%), one or more enteropathogen was detected, while in 323 specimens (48.6%) three or more enteropathogens were detected. The top six detected enteropathogens were: enteroaggregative Escherichia coli (EAggEC; 42.1%), enteropathogenic Escherichia coli (EPEC; 30.2%), enterovirus (26.9%), rotavirus group A (RVA; 24.8%), parechovirus (16.6%) and norovirus GI/GII (14.4%). Post-rotavirus vaccine introduction, there was a significant increase in the proportion of samples testing positive for EAggEC (35.7% vs. 45.3%, p = 0.014), cytomegalovirus (4.2% vs. 9.9%, p = 0.008), Vibrio cholerae (0.0% vs. 2.3%, p = 0.019), Strongyloides species (0.8% vs. 3.6%, p = 0.048) and Dientamoeba fragilis (2.1% vs. 7.8%, p = 0.004). Although not reaching statistical significance, the positivity rate of adenovirus 40/41 (5.8% vs. 7.3%, p = 0.444), norovirus GI/GII (11.2% vs. 15.9%, p = 0.089), Shigella species (8.7% vs. 13.0%, p = 0.092) and Cryptosporidium spp. (11.6% vs. 14.7%, p = 0.261) appeared to increase post-vaccine introduction. Conversely, the positivity rate of sapovirus decreased significantly post-vaccine introduction (7.8% vs. 4.0%, p = 0.030) while that of RVA appeared not to change (27.4% vs. 23.5%, p = 0.253). More enteropathogen coinfections were detected per child post-vaccine introduction compared to before (mean: 2.7 vs. 2.3; p = 0.0025). CONCLUSIONS: In this rural Coastal Kenya setting, childhood enteropathogen infection burden was high both pre- and post-rotavirus vaccination introduction. Children who had diarrheal admissions post-vaccination showed an increase in coinfections and changes in specific enteropathogen positivity rates. This study highlights the utility of multipathogen detection platforms such as TAC in understanding etiology of childhood acute gastroenteritis in resource-limited regions.

3.
J Clin Microbiol ; 59(1)2020 12 17.
Artigo em Inglês | MEDLINE | ID: mdl-33051242

RESUMO

Nucleic acid amplification for the detection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) RNA in respiratory samples is the standard method for diagnosis. The majority of this testing is centralized and therefore has turnaround times of several days. Point-of-care (POC) testing with rapid turnaround times would allow more effective triage in settings where patient management and infection control decisions need to be made rapidly. The inclusivity and specificity of the Simple AMplification-Based Assay (SAMBA) II SARS-CoV-2 test were determined by both in silico analyses of the primers and probes and wet testing. The SAMBA II SARS-CoV-2 test was evaluated for performance characteristics. Clinical performance was evaluated in residual combined throat/nose swabs and compared to that of the Public Health England real-time PCR assay targeting the RdRp gene. The SAMBA II SARS-CoV-2 test has an analytical sensitivity of 250 copies/ml for detecting two regions of the genome (open reading frame 1ab [ORF1ab] and nucleocapsid protein [N]). The clinical performance was evaluated in 172 residual combined nose/throat swabs provided by the Clinical Microbiology and Public Health Laboratory, Addenbrooke's Hospital, Cambridge (CMPHL), which showed an estimated positive percent agreement of 98.9% (95% confidence interval [CI], 93.83 to 99.97) and negative percent agreement of 96.4% (95% CI, 89.92 to 99.26) compared to testing by the CMPHL. The data show that the SAMBA II SARS-CoV-2 test performs equivalently to the centralized testing methods, but with a shorter turnaround time of 86 to 101 min. Point-of-care tests such as SAMBA should enable rapid patient management and effective implementation of infection control measures.


Assuntos
Teste para COVID-19/métodos , COVID-19/diagnóstico , Proteínas do Nucleocapsídeo de Coronavírus/genética , Técnicas de Amplificação de Ácido Nucleico/métodos , Proteínas Virais/genética , Humanos , Técnicas de Diagnóstico Molecular/métodos , Testes Imediatos , Poliproteínas/genética , RNA Viral/genética , SARS-CoV-2/genética , Sensibilidade e Especificidade
4.
Elife ; 92020 06 19.
Artigo em Inglês | MEDLINE | ID: mdl-32558644

RESUMO

Previously, we showed that 3% (31/1032)of asymptomatic healthcare workers (HCWs) from a large teaching hospital in Cambridge, UK, tested positive for SARS-CoV-2 in April 2020. About 15% (26/169) HCWs with symptoms of coronavirus disease 2019 (COVID-19) also tested positive for SARS-CoV-2 (Rivett et al., 2020). Here, we show that the proportion of both asymptomatic and symptomatic HCWs testing positive for SARS-CoV-2 rapidly declined to near-zero between 25th April and 24th May 2020, corresponding to a decline in patient admissions with COVID-19 during the ongoing UK 'lockdown'. These data demonstrate how infection prevention and control measures including staff testing may help prevent hospitals from becoming independent 'hubs' of SARS-CoV-2 transmission, and illustrate how, with appropriate precautions, organizations in other sectors may be able to resume on-site work safely.


Assuntos
Técnicas de Laboratório Clínico/estatística & dados numéricos , Infecções por Coronavirus/transmissão , Pessoal de Saúde , Programas de Rastreamento/estatística & dados numéricos , Doenças Profissionais/prevenção & controle , Pandemias , Pneumonia Viral/transmissão , Adulto , Doenças Assintomáticas , Betacoronavirus/genética , Betacoronavirus/isolamento & purificação , COVID-19 , Teste para COVID-19 , Infecções Comunitárias Adquiridas/transmissão , Busca de Comunicante , Infecções por Coronavirus/diagnóstico , Infecções por Coronavirus/epidemiologia , Infecções por Coronavirus/prevenção & controle , Transmissão de Doença Infecciosa/prevenção & controle , Inglaterra/epidemiologia , Características da Família , Feminino , Unidades Hospitalares , Hospitais de Ensino/organização & administração , Hospitais de Ensino/estatística & dados numéricos , Hospitais Universitários/organização & administração , Hospitais Universitários/estatística & dados numéricos , Humanos , Controle de Infecções , Transmissão de Doença Infecciosa do Paciente para o Profissional/estatística & dados numéricos , Masculino , Programas de Rastreamento/organização & administração , Pessoa de Meia-Idade , Nasofaringe/virologia , Doenças Profissionais/epidemiologia , Pandemias/prevenção & controle , Admissão do Paciente/estatística & dados numéricos , Pneumonia Viral/diagnóstico , Pneumonia Viral/epidemiologia , Pneumonia Viral/prevenção & controle , Prevalência , Avaliação de Programas e Projetos de Saúde , Reação em Cadeia da Polimerase em Tempo Real , SARS-CoV-2 , Avaliação de Sintomas
5.
BMC Infect Dis ; 20(1): 375, 2020 May 27.
Artigo em Inglês | MEDLINE | ID: mdl-32460721

RESUMO

BACKGROUND: Sexually transmitted infections (STIs) cause a major public health problem that affect both men and women in developing and developed countries. The aim of the study was to estimate the prevalence of 11 STIs among women who voluntarily participated in the study, while seeking gynecological checkup. The existence of an association between the presence of pathogens and symptoms and various sociodemographic risk factors was assessed. METHODS: A total of 505 vaginal and cervical specimens were collected from women above 18 years of age, with or without symptoms related to gynecological infections. Nucleic acid was extracted and samples were tested by real-time PCR for the following pathogens: Chlamydia trachomatis, Neisseria gonorrhoeae, Mycoplasma genitalium, Ureaplasma urealyticum, Urealplasma parvum, Trichomonas vaginalis, Mycoplasma hominis, Mycoplasma girerdii, Gardnerella vaginalis, Candida albicans and Human Papillomavirus (HPV). Positive HPV samples underwent genotyping using a microarray system. RESULTS: Of the 505 samples, 312 (62%) were screened positive for at least one pathogen. Of these, 36% were positive for Gardnerella vaginalis, 35% for Ureaplasma parvum, 8% for Candida albicans, 6.7% for HPV, 4.6% for Ureaplasma urealyticum, 3.6% for Mycoplasma hominis, 2% for Trichomonas vaginalis, 0.8% for Chlamydia trachomatis, 0.4% for Mycoplasma girerdii, 0.2% for Mycoplasma genitalium and 0.2% for Neisseria gonorrhoeae. Lack of symptoms was reported in 187 women (37%), among whom 61% were infected. Thirty-four samples were HPV positive, with 17 high risk HPV genotypes (HR-HPV); the highest rates being recorded for types 16 (38%), 18 (21%) and 51 (18%). Out of the 34 HPV positives, 29 participants had HR-HPV. Association with various risk factors were reported. CONCLUSIONS: This is the first study that presents data about the presence of STIs among women in Lebanon and the MENA region by simultaneous detection of 11 pathogens. In the absence of systematic STI surveillance in Lebanon, concurrent screening for HPV and PAP smear is warranted.


Assuntos
Infecções Sexualmente Transmissíveis/epidemiologia , Adulto , Colo do Útero/microbiologia , Colo do Útero/parasitologia , Colo do Útero/virologia , Chlamydia trachomatis/genética , Chlamydia trachomatis/isolamento & purificação , Estudos Transversais , Feminino , Gardnerella vaginalis/genética , Gardnerella vaginalis/isolamento & purificação , Humanos , Líbano/epidemiologia , Masculino , Epidemiologia Molecular , Infecções por Mycoplasma/epidemiologia , Mycoplasma genitalium/genética , Mycoplasma genitalium/isolamento & purificação , Mycoplasma hominis/genética , Mycoplasma hominis/isolamento & purificação , Neisseria gonorrhoeae/genética , Neisseria gonorrhoeae/isolamento & purificação , Papillomaviridae/genética , Papillomaviridae/isolamento & purificação , Fatores de Risco , Infecções Sexualmente Transmissíveis/microbiologia , Infecções Sexualmente Transmissíveis/parasitologia , Infecções Sexualmente Transmissíveis/virologia , Trichomonas vaginalis/genética , Trichomonas vaginalis/isolamento & purificação , Ureaplasma/genética , Ureaplasma/isolamento & purificação , Vagina/microbiologia , Vagina/parasitologia , Vagina/virologia , Esfregaço Vaginal , Adulto Jovem
6.
Int J Infect Dis ; 69: 1-7, 2018 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-29391246

RESUMO

OBJECTIVE: The aim of this study was to analyze the etiology and clinical consequences of viral respiratory infections in 18 elderly care centers (ECC) in Lisbon, which housed a total of 1022 residents. METHODS: Nasopharyngeal swabs were collected whenever an elderly had symptoms of acute respiratory infections (ARI). PCR and RT-PCR were performed for influenza A/B, human parainfluenza virus 1-4, adenovirus, human metapneumovirus (HMPV), respiratory syncytial virus (RSV), rhinovirus, enterovirus, human coronavirus and human Bocavirus (HBoV). Array cards for atypical bacteria were also used in severe cases. RESULTS: In total, 188 episodes of ARI were reported, being rhinovirus the most frequently detected (n=53), followed by influenza A(H3) (n=19) and HBoV (n=14). Severe infections were reported in 19 patients, 11 of which were fatal, Legionela pneumophila, rhinovirus, HMPV and RSV associated with these fatalities. Nine influenza strains were analyzed, all antigenically dissimilar from vaccine strain 2013/14. "Age", "HMPV" and "Respiratory disease" showed an association with severe infection. CONCLUSIONS: In this study an etiologic agent could be found in 60% of the acute respiratory episodes. These data provides information about the circulating viruses in ECC and highlights the importance of searching both viruses and atypical bacteria in severe ARI.


Assuntos
Instituição de Longa Permanência para Idosos/estatística & dados numéricos , Casas de Saúde/estatística & dados numéricos , Infecções Respiratórias/virologia , Viroses/epidemiologia , Idoso , Idoso de 80 Anos ou mais , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Reação em Cadeia da Polimerase , Portugal/epidemiologia , Infecções Respiratórias/epidemiologia , Estações do Ano , Vacinas
8.
J Med Virol ; 88(11): 1874-81, 2016 11.
Artigo em Inglês | MEDLINE | ID: mdl-27061822

RESUMO

Acute respiratory tract viral infections occur worldwide and are one of the major global burdens of diseases in children. The aim of this study was to determine the viral etiology of respiratory infections in hospitalized children, to understand the viral seasonality in a major Lebanese hospital, and to correlate disease severity and the presence of virus. Over a 1-year period, nasal and throat swabs were collected from 236 pediatric patients, aged 16-year old or less and hospitalized for acute respiratory illness. Samples collected were tested for the presence of 17 respiratory viruses using multiplex real-time RT-PCR. Pathogens were identified in 165 children (70%) and were frequently observed during fall and winter seasons. Co-infection was found in 37% of positive samples. The most frequently detected pathogens were human Rhinovirus (hRV, 23%), Respiratory Syncytial Virus (RSV, 19%), human Bocavirus (hBov, 15%), human Metapneumovirus (hMPV, 10%), and human Adenovirus (hAdV, 10%). A total of 48% of children were diagnosed with bronchiolitis and 25% with pneumonia. While bronchiolitis was often caused by RSV single virus infection and hAdV/hBoV coinfection, pneumonia was significantly associated with hBoV and HP1V1 infections. No significant correlation was observed between a single viral etiology infection and a specific clinical symptom. This study provides relevant facts on the circulatory pattern of respiratory viruses in Lebanon and the importance of using PCR as a useful tool for virus detection. Early diagnosis at the initial time of hospitalization may reduce the spread of the viruses in pediatric units. J. Med. Virol. 88:1874-1881, 2016. © 2016 Wiley Periodicals, Inc.


Assuntos
Pneumonia Viral/epidemiologia , Infecções Respiratórias/epidemiologia , Infecções Respiratórias/virologia , Viroses/epidemiologia , Viroses/virologia , Doença Aguda , Adolescente , Bronquiolite/diagnóstico , Bronquiolite/etiologia , Bronquiolite/virologia , Criança , Pré-Escolar , Coinfecção/virologia , Feminino , Hospitalização , Bocavirus Humano/isolamento & purificação , Bocavirus Humano/patogenicidade , Humanos , Lactente , Líbano/epidemiologia , Masculino , Metapneumovirus/isolamento & purificação , Metapneumovirus/patogenicidade , Reação em Cadeia da Polimerase Multiplex , Pneumonia Viral/virologia , Infecções por Vírus Respiratório Sincicial/diagnóstico , Infecções por Vírus Respiratório Sincicial/epidemiologia , Infecções por Vírus Respiratório Sincicial/virologia , Vírus Sincicial Respiratório Humano/isolamento & purificação , Vírus Sincicial Respiratório Humano/patogenicidade , Infecções Respiratórias/diagnóstico , Rhinovirus/isolamento & purificação , Rhinovirus/patogenicidade , Estações do Ano , Vírus/isolamento & purificação , Vírus/patogenicidade
9.
Am J Gastroenterol ; 110(2): 320-7, 2015 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-25623655

RESUMO

OBJECTIVES: A severe enteropathy of unknown etiology can be associated with common variable immunodeficiency (CVID). METHODS: S tool and archived small intestinal mucosal biopsies from patients with CVID enteropathy were analyzed by PCR for the presence of Norovirus RNA. The PCR products were sequenced to determine the relationship of viral isolates. Stool samples from 10 patients with CVID but no enteropathy served as controls. RESULTS: All eight patients in our CVID cohort with enteropathy showed persistent fecal excretion of Norovirus. Analysis of archived duodenal biopsies revealed a strong association between the presence of Norovirus and villous atrophy over a period of up to 8 years. Analysis of the viral isolates from each patient revealed distinct strains of genogroup II.4. Sequence analysis from consecutive biopsy specimens of one patient demonstrated persistence of the same viral strain over a 6-year period. CVID patients without enteropathy showed no evidence of Norovirus carriage. Viral clearance occurred spontaneously in one patient and followed oral Ribavirin therapy in two further patients, and resulted in complete symptomatic and histological recovery. However, Ribavirin treatment in two further patients was unsuccessful. CONCLUSIONS: Norovirus is an important pathogen for patients with CVID and a cause of CVID enteropathy, as viral clearance, symptom resolution, and histological recovery coincide. Ribavirin requires further evaluation as a potential therapy.


Assuntos
Infecções por Caliciviridae/virologia , Imunodeficiência de Variável Comum/virologia , Duodeno/virologia , Enteropatias/virologia , Norovirus/genética , RNA Viral/análise , Adulto , Idoso , Antivirais/uso terapêutico , Biópsia , Infecções por Caliciviridae/complicações , Infecções por Caliciviridae/tratamento farmacológico , Infecções por Caliciviridae/patologia , Estudos de Casos e Controles , Doença Crônica , Estudos de Coortes , Imunodeficiência de Variável Comum/complicações , Imunodeficiência de Variável Comum/patologia , Duodeno/patologia , Fezes/virologia , Feminino , Humanos , Enteropatias/complicações , Enteropatias/patologia , Intestino Delgado/patologia , Intestino Delgado/virologia , Masculino , Pessoa de Meia-Idade , Ribavirina/uso terapêutico
10.
Eur J Pediatr ; 173(8): 1059-65, 2014 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-24599798

RESUMO

UNLABELLED: Influenza surveillance is usually based on nationally organized sentinel networks of physicians and on hospital reports. This study aimed to test a different report system, based on parents' phone contact to the research team and in home collection of samples by a dedicated team. The identification of influenza and other respiratory viruses in children who attended a Hospital Emergency Department was also recorded. Real-time PCR and reverse transcription PCR were performed for influenza A and B, parainfluenza 1-4, adenovirus, human metapneumovirus, respiratory syncytial virus A and B, rhinovirus, enterovirus, group 1 coronaviruses, group 2 coronaviruses, and human bocavirus. One hundred children were included, 64 from the day care centers and 36 from the Hospital. Overall, 79 samples were positive for at least one respiratory virus. Influenza A (H3) was the virus most frequently detected: 25 cases, 20 of these in children under 5 years of age (ten from day care centers and ten who went to the hospital) which was higher than those reported by the National Influenza Surveillance Programme for this age. CONCLUSION: The results obtained in this study suggest that a surveillance system based on parents' reports could complement the implanted system of the National Influenza Surveillance Programme.


Assuntos
Monitoramento Epidemiológico , Influenza Humana/epidemiologia , Infecções Respiratórias/epidemiologia , Criança , Pré-Escolar , Serviço Hospitalar de Emergência , Feminino , Humanos , Lactente , Influenza Humana/virologia , Masculino , Pais , Portugal/epidemiologia , Reação em Cadeia da Polimerase em Tempo Real , Infecções Respiratórias/virologia , Vírus/isolamento & purificação
11.
Immun Ageing ; 10(1): 35, 2013 Aug 19.
Artigo em Inglês | MEDLINE | ID: mdl-23957956

RESUMO

BACKGROUND: Natural Killer Cells (NK) play an important role in detection and elimination of virus-infected, damaged or cancer cells. NK cell function is guided by expression of Killer Immunoglobulin-like Receptors (KIRs) and contributed to by the cytokine milieu. KIR molecules are grouped on NK cells into stimulatory and inhibitory KIR haplotypes A and B, through which NKs sense and tolerate HLA self-antigens or up-regulate the NK-cytotoxic response to cells with altered HLA self-antigens, damaged by viruses or tumours. We have previously described increased numbers of NK and NK-related subsets in association with sIL-2R cytokine serum levels in BELFAST octo/nonagenarians. We hypothesised that changes in KIR A and B haplotype gene frequencies could explain the increased cytokine profiles and NK compartments previously described in Belfast Elderly Longitudinal Free-living Aging STudy (BELFAST) octo/nonagenarians, who show evidence of ageing well. RESULTS: In the BELFAST study, 24% of octo/nonagenarians carried the KIR A haplotype and 76% KIR B haplotype with no differences for KIR A haplogroup frequency between male or female subjects (23% v 24%; p=0.88) or for KIR B haplogroup (77% v 76%; p=0.99). Octo/nonagenarian KIR A haplotype carriers showed increased NK numbers and percentage compared to Group B KIR subjects (p=0.003; p=0.016 respectively). There were no KIR A/ B haplogroup-associated changes for related CD57+CD8 (high or low) subsets. Using logistic regression, KIR B carriers were predicted to have higher IL-12 cytokine levels compared to KIR A carriers by about 3% (OR 1.03, confidence limits CI 0.99-1.09; p=0.027) and 14% higher levels for TGF-ß (active), a cytokine with an anti-inflammatory role, (OR 1.14, confidence limits CI 0.99-1.09; p=0.002). CONCLUSION: In this observational study, BELFAST octo/nonagenarians carrying KIR A haplotype showed higher NK cell numbers and percentage compared to KIR B carriers. Conversely, KIR B haplotype carriers, with genes encoding for activating KIRs, showed a tendency for higher serum pro-inflammatory cytokines compared to KIR A carriers. While the findings in this study should be considered exploratory they may serve to stimulate debate about the immune signatures of those who appear to age slowly and who represent a model for good quality survivor-hood.

12.
Lancet ; 381(9877): 1551-60, 2013 May 04.
Artigo em Inglês | MEDLINE | ID: mdl-23541540

RESUMO

BACKGROUND: Increasing numbers of individuals with cystic fibrosis are becoming infected with the multidrug-resistant non-tuberculous mycobacterium (NTM) Mycobacterium abscessus, which causes progressive lung damage and is extremely challenging to treat. How this organism is acquired is not currently known, but there is growing concern that person-to-person transmission could occur. We aimed to define the mechanisms of acquisition of M abscessus in individuals with cystic fibrosis. METHOD: Whole genome sequencing and antimicrobial susceptibility testing were done on 168 consecutive isolates of M abscessus from 31 patients attending an adult cystic fibrosis centre in the UK between 2007 and 2011. In parallel, we undertook detailed environmental testing for NTM and defined potential opportunities for transmission between patients both in and out of hospital using epidemiological data and social network analysis. FINDINGS: Phylogenetic analysis revealed two clustered outbreaks of near-identical isolates of the M abscessus subspecies massiliense (from 11 patients), differing by less than ten base pairs. This variation represents less diversity than that seen within isolates from a single individual, strongly indicating between-patient transmission. All patients within these clusters had numerous opportunities for within-hospital transmission from other individuals, while comprehensive environmental sampling, initiated during the outbreak, failed to detect any potential point source of NTM infection. The clusters of M abscessus subspecies massiliense showed evidence of transmission of mutations acquired during infection of an individual to other patients. Thus, isolates with constitutive resistance to amikacin and clarithromycin were isolated from several individuals never previously exposed to long-term macrolides or aminoglycosides, further indicating cross-infection. INTERPRETATION: Whole genome sequencing has revealed frequent transmission of multidrug resistant NTM between patients with cystic fibrosis despite conventional cross-infection measures. Although the exact transmission route is yet to be established, our epidemiological analysis suggests that it could be indirect. FUNDING: The Wellcome Trust, Papworth Hospital, NIHR Cambridge Biomedical Research Centre, UK Health Protection Agency, Medical Research Council, and the UKCRC Translational Infection Research Initiative.


Assuntos
Fibrose Cística/microbiologia , Estudo de Associação Genômica Ampla , Infecções por Mycobacterium não Tuberculosas/genética , Infecções por Mycobacterium não Tuberculosas/transmissão , Micobactérias não Tuberculosas/genética , Estudos de Coortes , Fibrose Cística/complicações , Humanos , Infecções por Mycobacterium não Tuberculosas/microbiologia , Micobactérias não Tuberculosas/isolamento & purificação , Estudos Retrospectivos
13.
Nucleic Acids Res ; 39(17): 7775-90, 2011 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-21693560

RESUMO

Influenza A virus segment 2 mRNA expresses three polypeptides: PB1, PB1-F2 and PB1-N40, from AUGs 1, 4 and 5 respectively. Two short open reading frames (sORFs) initiated by AUGs 2 and 3 are also present. To understand translational regulation in this system, we systematically mutated AUGs 1-4 and monitored polypeptide synthesis from plasmids and recombinant viruses. This identified sORF2 as a key regulatory element with opposing effects on PB1-F2 and PB1-N40 expression. We propose a model in which AUGs 1-4 are accessed by leaky ribosomal scanning, with sORF2 repressing synthesis of downstream PB1-F2. However, sORF2 also up-regulates PB1-N40 expression, most likely by a reinitiation mechanism that permits skipping of AUG4. Surprisingly, we also found that in contrast to plasmid-driven expression, viruses with improved AUG1 initiation contexts produced less PB1 in infected cells and replicated poorly, producing virions with elevated particle:PFU ratios. Analysis of the genome content of virus particles showed reduced packaging of the mutant segment 2 vRNAs. Overall, we conclude that segment 2 mRNA translation is regulated by a combination of leaky ribosomal scanning and reinitiation, and that the sequences surrounding the PB1 AUG codon are multifunctional, containing overlapping signals for translation initiation and for segment-specific packaging.


Assuntos
Regulação Viral da Expressão Gênica , Vírus da Influenza A/genética , Iniciação Traducional da Cadeia Peptídica , RNA Viral/química , Sequências Reguladoras de Ácido Ribonucleico , Proteínas Virais/biossíntese , Montagem de Vírus , Sequência de Aminoácidos , Sequência de Bases , Códon de Iniciação , Códon de Terminação , Células HEK293 , Humanos , Vírus da Influenza A/metabolismo , Vírus da Influenza A/fisiologia , Dados de Sequência Molecular , Mutação , Fases de Leitura Aberta , Biossíntese Peptídica , Peptídeos/genética , RNA Mensageiro/química , RNA Mensageiro/metabolismo , RNA Viral/metabolismo , Proteínas Virais/genética , Vírion/fisiologia
14.
J Hepatol ; 53(2): 252-60, 2010 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-20462651

RESUMO

BACKGROUND & AIMS: Increasing age is associated with impaired immune function and in chronic HCV infection specifically, with progressive fibrosis, liver failure, HCC and impaired responses to antiviral therapy. T-lymphocyte telomere length declines with age. We hypothesised that shorter T-lymphocyte telomere length would be associated with poor clinical outcome in HCV infection. METHODS: Circulating T-lymphocyte telomere length, an objective measure of immune senescence, was measured by flow-FISH in 135 HCV-RNA-positive, treatment-naïve patients and 41 healthy controls in relation to clinical outcome. RESULTS: Shorter CD4+CD45RO+ T-lymphocyte telomeres were associated with severe fibrosis (p=0.003), independent of male sex (p=0.04), CMV positivity (p=0.003), previous HBV infection (p=0.007), and age (p=ns) in viraemic patients compared to controls. There were inverse correlations between CD4+CD45RO+ telomere length and fibrosis stage (p<0.001), portal tract inflammatory grade (p=0.035), prothrombin time (p<0.001) and bilirubin (p=0.001). One hundred and twenty-four viraemic individuals were followed prospectively to a composite endpoint of death, hepatic decompensation or HCC. Independent of age, those with shorter CD4+CD45RO+ telomeres were less likely to be complication free after 2-years than those with longer telomeres (86% versus 96%, p=0.009) with an age-adjusted hazard ratio of 0.93 (0.90-0.96). In addition, CD4+CD45RO+ telomere length predicted successful antiviral therapy (p=0.001) independent of other factors. CONCLUSIONS: CD4+ T-lymphocyte telomere length, independent of age, was related to inflammatory grade, fibrosis stage, laboratory indices of severity, subsequent hepatic decompensation and treatment outcome in patients with chronic HCV infection.


Assuntos
Antivirais/uso terapêutico , Linfócitos T CD4-Positivos/patologia , Hepacivirus , Hepatite C Crônica/tratamento farmacológico , Hepatite C Crônica/patologia , Cirrose Hepática/patologia , Telômero/patologia , Adulto , Biópsia , Estudos de Casos e Controles , Feminino , Hepatite C Crônica/diagnóstico , Humanos , Fígado/patologia , Masculino , Pessoa de Meia-Idade , Fenótipo , Prognóstico , Análise de Regressão , Índice de Gravidade de Doença , Resultado do Tratamento
15.
Vaccine ; 27(45): 6270-5, 2009 Oct 23.
Artigo em Inglês | MEDLINE | ID: mdl-19840659

RESUMO

Influenza A virus vRNA segments contain specific packaging signals at their termini that overlap the coding regions. To further characterise segment 5 packaging signals, we introduced synonymous mutations into the terminal coding regions of the vRNA and characterised the replicative fitness of the resulting viruses. Most mutations tested were well-tolerated, but a virus with alterations to NP codons 464-466, near the 5'-end of the vRNA, produced small plaques and replicated to around one-tenth of the level of wild type virus. The mutant virus supported normal levels of NP and segment 5 vRNA synthesis but packaged reduced levels of both segment 5 and segment 3 into virus particles. This suggests an interaction between segments 3 and 5 during influenza A virus assembly.


Assuntos
Vírus da Influenza A/genética , Vírus da Influenza A/fisiologia , RNA Viral/genética , Replicação Viral , Animais , Linhagem Celular , Códon , Cães , Regulação Viral da Expressão Gênica , Humanos , Mutação , Proteínas do Nucleocapsídeo , Proteínas de Ligação a RNA/genética , Proteínas do Core Viral/genética
17.
Hepatology ; 48(6): 1737-45, 2008 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-18925639

RESUMO

UNLABELLED: It is unclear whether hepatitis C virus (HCV) has been eradicated or persists at a low level in HCV antibody-positive HCV RNA-negative individuals. The natural history and liver histology are not well characterized. One hundred seventy-two HCV antibody-positive, serum HCV RNA-negative patients underwent diagnostic liver biopsy between 1992 and 2000 and were followed a median 7 years (range, 5-12). Patients with any possible cause of liver injury other than HCV were excluded. A single histopathologist scored sections using Ishak criteria. Characterization of the inflammatory infiltrate in selected cases used a novel semiquantitative technique and compared with HCV RNA-positive patients and healthy controls. One hundred two patients were excluded because of a risk factor for liver injury other than HCV. Seventy patients met the study criteria; four (5.7%) became HCV RNA-positive during follow-up. Sixty-six cases remained HCV RNA-negative; five (7.5%) had a normal liver biopsy; 54 (82%) had fibrosis (stage 2 or 3 in 16 (24%)). Nonviremic cases revealed expanded portal tracts (P < 0.05), with fewer CD4+ (P < 0.05) and more CD8+ cells (P < 0.05) than healthy controls, but were indistinguishable from HCV RNA-positive cases for these parameters. Lobular CD4 staining, absent in healthy controls, was noted in both HCV RNA-negative and -positive cases and was more marked in the latter (P < 0.05) with a sinusoidal lining cell distribution. CONCLUSION: Nonviremic HCV antibody-positive patients have a liver biopsy that is usually abnormal. Fibrosis was present in most with similar inflammatory infiltrate to viremic cases. The presence of a CD8+ rich inflammatory infiltrate suggests an ongoing immune response in the liver, supporting the view that HCV may persist in the liver in the majority of HCV RNA-negative cases.


Assuntos
Hepacivirus/genética , Anticorpos Anti-Hepatite C/sangue , Hepatite C/sangue , RNA Viral/sangue , Adulto , Alanina Transaminase/metabolismo , Biópsia , Complexo CD3/metabolismo , Linfócitos T CD8-Positivos/patologia , Estudos de Casos e Controles , Estudos de Coortes , Progressão da Doença , Feminino , Seguimentos , Hepacivirus/imunologia , Hepatite C/diagnóstico , Hepatite C/patologia , Humanos , Fígado/metabolismo , Fígado/patologia , Fígado/virologia , Cirrose Hepática/patologia , Masculino , Pessoa de Meia-Idade , Perforina/metabolismo , Prognóstico , Replicação Viral
18.
Liver Transpl ; 11(12): 1603-7, 2005 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-16315308

RESUMO

Schistosomiasis affects 200 to 250 million people worldwide. Hepatic schistosomiasis is a well-recognized cause of chronic liver disease and portal hypertension. There are no previous reports of schistosomiasis post liver transplantation. We report on 2 cases of schistosomiasis in liver transplant recipients--a case of gastric schistosomiasis and a case of hepatic schistosomiasis. A discussion of the pathology of schistosomal infection and a rationale for screening potential liver transplant recipients from endemic areas follows.


Assuntos
Hepatopatias Parasitárias/etiologia , Transplante de Fígado/efeitos adversos , Esquistossomose mansoni/etiologia , Animais , Anti-Helmínticos/uso terapêutico , Anticorpos Anti-Helmínticos/análise , Biópsia , Diagnóstico Diferencial , Seguimentos , Humanos , Fígado/parasitologia , Fígado/patologia , Hepatopatias Parasitárias/tratamento farmacológico , Hepatopatias Parasitárias/patologia , Masculino , Pessoa de Meia-Idade , Praziquantel/uso terapêutico , Schistosoma/imunologia , Esquistossomose mansoni/tratamento farmacológico , Esquistossomose mansoni/patologia
19.
Hum Immunol ; 65(4): 340-6, 2004 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-15120188

RESUMO

Parkinson's disease (PD) is one of the most prevalent neurodegenerative disorders and is characterized by the progressive loss of dopamine neurons in the substantia nigra. There is increasing evidence to suggest the inflammatory response of the brain contributes to the pathogenesis of PD. This study investigated the frequency of polymorphism located in the critical promoter region of the proinflammatory cytokine genes: interleukin (IL)-2, IL-6, IL-8, and tumor necrosis factor alpha (TNF-alpha) within a cohort of patients with PD in comparison to a group of healthy elderly individuals. No association was observed for single nucleotide polymorphism in the promoter regions of the IL-2, IL-6, and TNF-alpha genes. The single nucleotide polymorphism in the chemokine IL-8 gene was observed to associate with PD and appeared to be independent of age at onset. This association further supports the theory that the proinflammatory response in the brains of patients with PD plays a role in the pathogenesis of the disease and warrants further investigation into the role of chemokines in the brain, and a more detailed analysis of the genetics involved in the immune response of the brain.


Assuntos
Interleucina-8/genética , Doença de Parkinson/genética , Polimorfismo de Nucleotídeo Único , Regiões Promotoras Genéticas/genética , Idoso , Feminino , Humanos , Irlanda , Masculino , Doença de Parkinson/diagnóstico
20.
FASEB J ; 17(13): 1945-7, 2003 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-14519670

RESUMO

Parkinson's disease (PD) and other related disorders are characterized by the accumulation of fibrillar aggregates of alpha-synuclein protein (alpha-syn) inside brain cells. It is likely that the formation of alpha-syn aggregates plays a seminal role in the pathogenesis of at least some of these diseases, because two different mutations in the gene encoding alpha-syn have been found in inherited forms of PD. alpha-Syn is mainly expressed by neuronal cells and is generally considered to exist as a cytoplasmic protein. Here, we report the unexpected identification of alpha-syn in conditioned culture media from untransfected and alpha-syn-transfected human neuroblastoma cells, as well as in human cerebrospinal fluid and blood plasma. The method used was immunocapture by using anti-alpha-syn antibodies coupled to magnetic beads, followed by detection on Western blots. In all cases, alpha-syn was identified as a single 15 kDa band, which co-migrated with a recombinant form of the protein and reacted with five different antibodies to alpha-syn. Our findings suggest that cells normally secrete alpha-syn into their surrounding media, both in vitro and in vivo. The detection of extracellular alpha-syn and/or its modified forms in body fluids, particularly in human plasma, offers new opportunities for the development of diagnostic tests for PD and related diseases.


Assuntos
Proteínas do Tecido Nervoso/análise , Western Blotting , Espaço Extracelular/química , Humanos , Modelos Biológicos , Proteínas do Tecido Nervoso/sangue , Proteínas do Tecido Nervoso/líquido cefalorraquidiano , Neurônios/metabolismo , Doença de Parkinson/etiologia , Sinucleínas , Células Tumorais Cultivadas , alfa-Sinucleína
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