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1.
Anaerobe ; 71: 102410, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34174401

RESUMO

A novel Loop-mediated isothermal amplification (LAMP) assay, HiberGene's CD was evaluated with 82 unformed stools from patients suspected of C. difficile infection (CDI). Compared to glutamate dehydrogenase (GDH) toxins A/B test (C.diff Quik Chek®), HiberGene's LAMP showed 100% of sensitivity and 95,8% of specificity; and compared to FilmArray™ GI panel ® (BioFire), a sensitivity of 81,2% and a specificity of 100%, with 96.38% of agreement.


Assuntos
Clostridioides difficile/genética , Infecções por Clostridium/diagnóstico , Infecções por Clostridium/microbiologia , Testes Diagnósticos de Rotina/métodos , Técnicas de Diagnóstico Molecular/métodos , Técnicas de Amplificação de Ácido Nucleico/métodos , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Proteínas de Bactérias/genética , Toxinas Bacterianas/genética , Criança , Clostridioides difficile/isolamento & purificação , Fezes/microbiologia , Feminino , Glutamato Desidrogenase/genética , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Sensibilidade e Especificidade , Adulto Jovem
2.
COPD ; 18(1): 53-61, 2021 02.
Artigo em Inglês | MEDLINE | ID: mdl-33353408

RESUMO

Patients with chronic obstructive pulmonary disease (COPD) exhibit frequent acute exacerbations (AE). The objectives of this study were first to evaluate the prevalence of pathogens associated to these episodes by combining conventional bacteriology and multiplex viral and bacterial PCR assays in sputum specimens, and second to determine whether C-reactive protein (CRP) value and clinical outcome could be influenced by the type of microbial agent(s) recovered from these samples. A cohort of 84 Tunisian patients hospitalized at the emergency room for AECOPD was investigated prospectively for the semi-quantitative detection of bacteria by conventional culture (the threshold of positivity was of 107 CFU/ml) and for the detection of viral genome and DNA of atypical bacteria by quantitative PCR using two commercial multiplex respiratory kits (Seegene and Fast-track). The two kits exhibited very similar performances although the Seegene assay was a bit more sensitive. A large number and variety of pathogens were recovered from the sputum samples of these 84 patients, including 15 conventional bacteria, one Chlamydia pneumoniae and 63 respiratory viruses, the most prevalent being rhinoviruses (n = 33) and influenza viruses (n = 13). From complete results available for 74 patients, the presence of bacteria was significantly associated with risk of recurrence at 6 and 12 months post-infection. The combination of these different markers appears useful for delineating correctly the antimicrobial treatment and for initiating a long-term surveillance in those patients with high risk of recurrent exacerbation episodes. A prospective study is required for confirming the benefits of this strategy aimed at improving the stewardship of antibiotics.


Assuntos
Doença Pulmonar Obstrutiva Crônica , Viroses , Antibacterianos/uso terapêutico , Anti-Infecciosos , Bactérias , Humanos , Doença Pulmonar Obstrutiva Crônica/complicações , Doença Pulmonar Obstrutiva Crônica/tratamento farmacológico , Escarro , Viroses/complicações , Viroses/tratamento farmacológico , Viroses/epidemiologia
3.
Clin Infect Dis ; 70(5): 875-883, 2020 02 14.
Artigo em Inglês | MEDLINE | ID: mdl-31556939

RESUMO

BACKGROUND: Improving knowledge regarding Streptococcus pneumoniae distribution in pneumonia cases is important to better target preventive and curative measures. The objective was to describe S. pneumoniae serotypes in children with or without pneumonia. METHODS: It was a case-control study carried out in 8 developing and emerging countries between 2010 and 2014. Cases were children aged <5 years admitted to the hospital for pneumonia. Controls were children admitted for surgery or routine outpatient care. RESULTS: In nasopharyngeal samples, S. pneumoniae were detected in 68.2% of the cases and 47.5% of the controls (P < .001). Nasopharyngeal carriage was associated with a higher risk of being a case in 6/8 study sites (adjusted odds ratio ranged from 0.71 [95% confidence interval [CI], .39-1.29; P = .26] in India [Pune/Vadu] to 11.86 [95% CI, 5.77-24.41; P < .001] in Mongolia). The 13-valent pneumococcal conjugate vaccine (PCV13) serotypes were more frequently detected in cases with nasopharyngeal carriage (67.1%) than in controls with nasopharyngeal carriage (54.6%), P < .001. Streptococcus pneumoniae was detected in blood by polymerase chain reaction in 8.3% of the cases. Of 34 cases with an S. pneumoniae serotype detected in blood, 27 (79%) had the same serotype in the nasopharyngeal sample. CONCLUSIONS: The results confirm the assumption that the isolate carrying or causing disease in an individual is of the same serotype. Most serotypes independently associated with nasopharyngeal carriage or pneumonia are covered by PCV13, suggesting that increased PCV coverage would reduce the burden of S. pneumoniae-related pneumonia.


Assuntos
Infecções Pneumocócicas , Pneumonia , Idoso , Portador Sadio/epidemiologia , Estudos de Casos e Controles , Criança , Pré-Escolar , Humanos , Índia , Lactente , Mongólia , Nasofaringe , Infecções Pneumocócicas/epidemiologia , Vacinas Pneumocócicas , Sorogrupo , Streptococcus pneumoniae , Vacinas Conjugadas
4.
PLoS Pathog ; 13(9): e1006610, 2017 09.
Artigo em Inglês | MEDLINE | ID: mdl-28957419

RESUMO

IFITMs are broad antiviral factors that block incoming virions in endosomal vesicles, protecting target cells from infection. In the case of HIV-1, we and others reported the existence of an additional antiviral mechanism through which IFITMs lead to the production of virions of reduced infectivity. However, whether this second mechanism of inhibition is unique to HIV or extends to other viruses is currently unknown. To address this question, we have analyzed the susceptibility of a broad spectrum of viruses to the negative imprinting of the virion particles infectivity by IFITMs. The results we have gathered indicate that this second antiviral property of IFITMs extends well beyond HIV and we were able to identify viruses susceptible to the three IFITMs altogether (HIV-1, SIV, MLV, MPMV, VSV, MeV, EBOV, WNV), as well as viruses that displayed a member-specific susceptibility (EBV, DUGV), or were resistant to all IFITMs (HCV, RVFV, MOPV, AAV). The swapping of genetic elements between resistant and susceptible viruses allowed us to point to specificities in the viral mode of assembly, rather than glycoproteins as dominant factors of susceptibility. However, we also show that, contrarily to X4-, R5-tropic HIV-1 envelopes confer resistance against IFITM3, suggesting that viral receptors add an additional layer of complexity in the IFITMs-HIV interplay. Lastly, we show that the overall antiviral effects ascribed to IFITMs during spreading infections, are the result of a bimodal inhibition in which IFITMs act both by protecting target cells from incoming viruses and in driving the production of virions of reduced infectivity. Overall, our study reports for the first time that the negative imprinting of the virion particles infectivity is a conserved antiviral property of IFITMs and establishes IFITMs as a paradigm of restriction factor capable of interfering with two distinct phases of a virus life cycle.


Assuntos
Antígenos de Diferenciação/metabolismo , Vírion , Replicação Viral , Linhagem Celular , HIV-1/fisiologia , Interações Hospedeiro-Patógeno , Humanos , Internalização do Vírus
5.
BMC Infect Dis ; 19(1): 851, 2019 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-31615439

RESUMO

BACKGROUND: In Lao People's Democratic Republic (PDR), tuberculosis (TB) prevalence was estimated at 540/100,000 in 2011. Nevertheless, little is known about the genetic characteristics and anti-TB drug resistance of the Mycobacterium tuberculosis population. The main objective of this work was to study the genetic characteristics and drug resistance of M. tuberculosis population collected during the first National TB Prevalence Survey (TBPS) of Lao PDR (2010-2011). METHODS: Two hundred and twenty two isolates collected during TBPS (2010-2011) were analyzed with the GenoType MTBDRplus test for M. tuberculosis identification and drug resistance detection. Then, 206 of the 222 isolates were characterized by spoligotyping and MIRU-VNTR typing. RESULTS: Among the 222 M. tuberculosis isolates, 11 were mono-resistant to isoniazid and 2 were resistant to isoniazid and rifampicin (MDR-TB), using the GenoType MTBDRplus test. Among the 202 genetically characterized isolates, the East African-Indian (EAI) family was predominant (76.7%) followed by the Beijing (14.4%) and T (5.5%) families. EAI isolates came from all the country provinces, whereas Beijing isolates were found mainly in the northern and central provinces. A higher proportion of Beijing isolates was observed in people younger than 35 years compared to EAI. Moreover, the percentage of drug resistance was higher among Beijing (17.2%) than EAI (5.2%) isolates, and the two MDR-TB isolates belonged to the Beijing family. Combined analysis of the MIRU-VNTR and spoligotyping results (n = 202 isolates) revealed an estimated clustering rate of 11% and the occurrence of mini-outbreaks of drug-resistant TB caused by Beijing genotypes. CONCLUSIONS: The EAI family, the ancient and endemic family in Asia, is predominant in Lao PDR whereas the prevalence of Beijing, the most harmful M. tuberculosis family for humans, is still low, differently from neighboring countries. However, its association with drug resistance, its presence in young patients and its potential association with recent transmission suggest that the Beijing family could change TB epidemiological pattern in Lao PDR. Therefore, efficient TB control and surveillance systems must be maintained and reinforced to prevent the emergence of highly transmissible and drug-resistant strains in Lao PDR, as observed in neighboring countries.


Assuntos
Mycobacterium tuberculosis/genética , Tuberculose Resistente a Múltiplos Medicamentos/diagnóstico , Adolescente , Adulto , Antituberculosos/farmacologia , Antituberculosos/uso terapêutico , Análise por Conglomerados , Farmacorresistência Bacteriana Múltipla/efeitos dos fármacos , Feminino , Genótipo , Humanos , Isoniazida/farmacologia , Isoniazida/uso terapêutico , Laos/epidemiologia , Masculino , Pessoa de Meia-Idade , Mycobacterium tuberculosis/classificação , Mycobacterium tuberculosis/isolamento & purificação , Filogenia , Prevalência , Rifampina/farmacologia , Rifampina/uso terapêutico , Tuberculose Resistente a Múltiplos Medicamentos/tratamento farmacológico , Tuberculose Resistente a Múltiplos Medicamentos/epidemiologia , Adulto Jovem
6.
J Gen Virol ; 99(4): 489-500, 2018 04.
Artigo em Inglês | MEDLINE | ID: mdl-29504924

RESUMO

The interplay between respiratory syncytial virus (RSV) and the p53 pathway has only been reported in a limited number of studies, yet the underlying abrogation mechanisms of p53 activity during the time course of infection, possibly involving viral proteins, remained unclear. Here, we demonstrate that RSV infection impairs global p53 transcriptional activity, notably via its proteasome-dependent degradation at late stages of infection. We also demonstrate that NS1 and NS2 contribute to the abrogation of p53 activity, and used different experimental strategies (e.g. siRNA, small molecules) to underline the antiviral contribution of p53 in the context of RSV infection. Notably, our study highlights a strong RSV-induced disequilibrium of the p53/NF-κB functional balance, which appears to contribute to the up-regulation of the expression of several proinflammatory cytokines and chemokines.


Assuntos
Citocinas/imunologia , NF-kappa B/metabolismo , Infecções por Vírus Respiratório Sincicial/imunologia , Vírus Sincicial Respiratório Humano/fisiologia , Proteína Supressora de Tumor p53/metabolismo , Citocinas/genética , Humanos , NF-kappa B/genética , Fosfatidilinositol 3-Quinases/genética , Fosfatidilinositol 3-Quinases/metabolismo , Complexo de Endopeptidases do Proteassoma/genética , Complexo de Endopeptidases do Proteassoma/metabolismo , Proteínas Proto-Oncogênicas c-akt/genética , Proteínas Proto-Oncogênicas c-akt/metabolismo , Infecções por Vírus Respiratório Sincicial/genética , Infecções por Vírus Respiratório Sincicial/metabolismo , Infecções por Vírus Respiratório Sincicial/virologia , Vírus Sincicial Respiratório Humano/genética , Transdução de Sinais , Proteína Supressora de Tumor p53/genética , Proteínas não Estruturais Virais/genética , Proteínas não Estruturais Virais/metabolismo
7.
Clin Infect Dis ; 65(4): 604-612, 2017 08 15.
Artigo em Inglês | MEDLINE | ID: mdl-28605562

RESUMO

Background: Pneumonia, the leading infectious cause of child mortality globally, mainly afflicts developing countries. This prospective observational study aimed to assess the microorganisms associated with pneumonia in children aged <5 years in developing and emerging countries. Methods: A multicenter, case-control study by the GABRIEL (Global Approach to Biological Research, Infectious diseases and Epidemics in Low-income countries) network was conducted between 2010 and 2014 in Cambodia, China, Haiti, India (2 sites), Madagascar, Mali, Mongolia, and Paraguay. Cases were hospitalized children with radiologically confirmed pneumonia; controls were children from the same setting without any features suggestive of pneumonia. Nasopharyngeal swabs were collected from all subjects; 19 viruses and 5 bacteria were identified by reverse-transcription polymerase chain reaction. Associations between microorganisms and pneumonia were quantified by calculating the adjusted population attributable fraction (aPAF) after multivariate logistic regression analysis adjusted for sex, age, time period, other pathogens, and site. Results: Overall, 888 cases and 870 controls were analyzed; ≥1 microorganism was detected in respiratory samples in 93.0% of cases and 74.4% of controls (P < .001). Streptococcus pneumoniae, Mycoplasma pneumoniae, human metapneumovirus, rhinovirus, respiratory syncytial virus (RSV), parainfluenza virus 1, 3, and 4, and influenza virus A and B were independently associated with pneumonia; aPAF was 42.2% (95% confidence interval [CI], 35.5%-48.2%) for S. pneumoniae, 18.2% (95% CI, 17.4%-19.0%) for RSV, and 11.2% (95% CI, 7.5%-14.7%) for rhinovirus. Conclusions: Streptococcus pneumoniae, RSV, and rhinovirus may be the major microorganisms associated with pneumonia infections in children <5 years of age from developing and emerging countries. Increasing S. pneumoniae vaccination coverage may substantially reduce the burden of pneumonia among children in developing countries.


Assuntos
Pneumonia Bacteriana/epidemiologia , Pneumonia Bacteriana/microbiologia , Ásia/epidemiologia , Estudos de Casos e Controles , Pré-Escolar , Países em Desenvolvimento , Feminino , Haiti/epidemiologia , Humanos , Lactente , Masculino , Mali/epidemiologia , Estudos Prospectivos
8.
J Clin Microbiol ; 55(1): 302-312, 2017 01.
Artigo em Inglês | MEDLINE | ID: mdl-27847374

RESUMO

A serotype-specific urinary antigen detection (UAD) assay for 13 serotypes included in the pneumococcal conjugate vaccine (PCV13) was recently reported as a useful diagnostic tool for pneumococcal pneumonia. We aimed to assess the diagnostic accuracy of the UAD in HIV-infected South African adults. Urine specimens from a well-defined cohort of HIV-infected South African adults with pneumonia were evaluated retrospectively in the UAD assay. Pneumonia was considered pneumococcal if either sputum Gram stain, sputum culture, blood culture, or the immunochromatographic (ICT) BinaxNow S. pneumoniae test (composite diagnostic) was positive. Among 235 enrolled pneumonia patients, the UAD assay was more frequently positive (104 [44.3%]) than the composite diagnostic (71 [30.2%]; P < 0.001) and increased the pneumococcal etiology from 30.2% by an additional 22.6% to 52.8%. The UAD assay detected more pneumococcal etiologies (45.0%) than the serotype-independent ICT (23.4%, P < 0.001). UAD identified 6/7 patients with PCV13 serotype bacteremia without misclassification of bacteremia episodes due to non-PCV13 serotypes. UAD was positive for 5.1% of asymptomatic HIV-infected persons, with higher rates among those with nasopharyngeal carriage. Concordance between serotypes identified by UAD and by Quellung reaction and PCR serotyping was 70/86 (81.4%). UAD identified the dominant serotype in multiple serotype carriage. This study confirms the utility of the UAD assay for HIV-infected adults comparing favorably with other diagnostic tests. A highly valent UAD may become a new standard for detection of pneumococcal pneumonia in adults. Prior to PCV introduction, at least 53% of pneumonia cases were due to pneumococci in HIV-infected South African adults.


Assuntos
Antígenos de Bactérias/urina , Infecções por HIV/complicações , Imunoensaio/métodos , Pneumonia Pneumocócica/diagnóstico , Streptococcus pneumoniae/imunologia , Adulto , Humanos , Estudos Retrospectivos , Sorogrupo , África do Sul
9.
Int J Mol Sci ; 18(12)2017 Dec 07.
Artigo em Inglês | MEDLINE | ID: mdl-29215596

RESUMO

Respiratory syncytial virus (RSV), a major etiologic agent of acute lower respiratory infection constitutes the most important cause of death in young children worldwide. Viral/bacterial mixed infections are related to severity of respiratory inflammatory diseases, but the underlying mechanisms remain poorly understood. We have previously investigated the intracellular mechanisms that mediate the immune response in the context of influenza virus/Streptococcus pneumoniae (Sp) co-infection using a model of human monocyte-derived macrophages (MDMs). Here, we set up and characterized a similar model of MDMs to investigate different scenarios of RSV infection and co-infection with Sp. Our results suggest that Sp contributes to a faster and possibly higher level of CXCL10/IP-10 expression induced by RSV infection in human MDMs.


Assuntos
Quimiocina CXCL10/metabolismo , Coinfecção/imunologia , Macrófagos/imunologia , Infecções Pneumocócicas/imunologia , Infecções por Vírus Respiratório Sincicial/imunologia , Linhagem Celular Tumoral , Células Cultivadas , Quimiocina CXCL10/genética , Humanos , Macrófagos/microbiologia , Macrófagos/virologia
10.
J Clin Microbiol ; 53(2): 498-503, 2015 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-25428144

RESUMO

The emergence of drug-resistant forms of tuberculosis (TB) represents a major public health concern. Understanding the transmission routes of the disease is a key factor for its control and for the implementation of efficient interventions. Mycobacterial interspersed repetitive-unit-variable-number tandem-repeat (MIRU-VNTR) marker typing is a well-described method for lineage identification and transmission tracking. However, the conventional manual genotyping technique is cumbersome and time-consuming and entails many risks for errors, thus hindering its implementation and dissemination. We describe here a new approach using the QIAxcel system, an automated high-throughput capillary electrophoresis system that also carries out allele calling. This automated method was assessed on 1,824 amplicons from 82 TB isolates and tested with sets of markers of 15 or 24 loci. Overall allele-calling concordance between the methods from 140 to 1,317 bp was 98.9%. DNA concentrations and repeatability and reproducibility performances showed no biases in allele calling. Furthermore, turnaround time using this automated system was reduced by 81% compared to the conventional manual agarose gel method. In sum, this new automated method facilitates MIRU-VNTR genotyping and provides reliable results. Therefore, it is well suited for field genotyping. The implementation of this method will help to achieve accurate and cost-effective epidemiological studies, especially in countries with a high prevalence of TB, where the high number of strains complicates the surveillance of circulating lineages and requires efficient interventions to be carried out in an urgent manner.


Assuntos
Técnicas de Genotipagem , Repetições Minissatélites , Tipagem Molecular/métodos , Mycobacterium tuberculosis/classificação , Mycobacterium tuberculosis/genética , Tuberculose/microbiologia , Automação Laboratorial/métodos , Ensaios de Triagem em Larga Escala , Humanos , Epidemiologia Molecular/métodos , Reprodutibilidade dos Testes , Fatores de Tempo , Tuberculose/epidemiologia
11.
BMC Infect Dis ; 15: 518, 2015 Nov 14.
Artigo em Inglês | MEDLINE | ID: mdl-26572220

RESUMO

BACKGROUND: Dengue is the most widespread mosquito-borne viral disease of public health concern. In some patients, endothelial cell and platelet dysfunction lead to life-threatening hemorrhagic dengue fever or dengue shock syndrome. Prognostication of disease severity is urgently required to improve patient management. The pathogenesis of severe dengue has not been fully elucidated, and the role of host proteins associated with viral particles has received little exploration. METHODS: The proteomes of virion-enriched fractions purified from plasma pools of patients with dengue fever or severe dengue were compared. Virions were purified by ultracentrifugation combined with a water-insoluble polyelectrolyte-based technique. Following in-gel hydrolysis, peptides were analyzed by nano-liquid chromatography coupled to ion trap mass spectrometry and identified using data libraries. RESULTS: Both dengue fever and severe dengue viral-enriched fractions contained identifiable viral envelope proteins and host cellular proteins. Canonical pathway analysis revealed the identified host proteins are mainly involved in the coagulation cascade, complement pathway or acute phase response signaling pathway. Some host proteins were over- or under-represented in plasma from patients with severe dengue compared to patients with dengue fever. ELISAs were used to validate differential expression of a selection of identified host proteins in individual plasma samples of patients with dengue fever compared to patients with severe dengue. Among 22 host proteins tested, two could differentiate between dengue fever and severe dengue in two independent cohorts (olfactomedin-4: area under the curve (AUC), 0.958; and platelet factor-4: AUC, 0.836). CONCLUSION: A novel technique of virion-enrichment from plasma has allowed to identify two host proteins that have prognostic value for classifying patients with acute dengue who are more likely to develop a severe dengue. The impact of these host proteins on pathogenicity and disease outcome are discussed.


Assuntos
Vírus da Dengue/patogenicidade , Dengue/sangue , Interações Hospedeiro-Patógeno , Plasma/virologia , Proteômica/métodos , Reação de Fase Aguda , Adulto , Dengue/virologia , Vírus da Dengue/genética , Vírus da Dengue/metabolismo , Ensaio de Imunoadsorção Enzimática , Feminino , Fator Estimulador de Colônias de Granulócitos/sangue , Humanos , Masculino , Fator Plaquetário 4/sangue , Dengue Grave/sangue , Dengue Grave/virologia , Espectrometria de Massas em Tandem/métodos , Proteínas do Envelope Viral/análise , Proteínas do Envelope Viral/metabolismo , Vírion/química
12.
J Clin Microbiol ; 52(12): 4224-9, 2014 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-25253798

RESUMO

Quantitative lytA real-time PCR (rtPCR) results from nasopharyngeal (NP) swabs distinguish community-acquired pneumococcal pneumonia (CAP) from asymptomatic colonization. The use of an optimized cutoff value improved pneumococcal etiology determination compared to that of traditional diagnostic methods. Here, we compare the utility of lytA rtPCR from induced sputum and from NP swabs. Pneumococcus was considered the cause of CAP in HIV-infected South African adults if blood culture, induced-sputum culture or Gram stain, urine antigen test, or whole-blood lytA rtPCR revealed pneumococcus or if lytA rtPCR from NP swabs gave a result of >8,000 copies/ml. lytA rtPCR was also performed on induced sputum. Pneumococcus was detected by lytA rtPCR from sputum in 149 (67.1%) of 222 patients with available induced sputum, whereas the results of either Gram stain or culture of sputum were positive in 105 of 229 patients (45.9%; P < 0.001). The mean copy numbers from sputum were higher when the sputum cultures were positive than when the sputum cultures were negative (7.9 versus 5.6 log10 copies/ml; P < 0.001). Against the composite diagnostic standard, a cutoff value of 10,000 copies/ml for good-quality sputum lytA rtPCR had a sensitivity of 78.1% and a specificity of 80.0%. This cutoff value performed similarly to the previously identified cutoff value of 8,000 copies/ml for NP swab lytA rtPCR (area under the curve receiver operating characteristic [AUC-ROC], 80.4% for sputum of any quality versus 79.6% for NP swabs). The AUC-ROC for good-quality sputum was 83.2%. Overall, lytA rtPCR performs similarly well on induced sputum as on NP swabs for most patients but performs slightly better if good-quality sputum can be obtained. Due to the ease of specimen collection, NP swabs may be preferable for the diagnosis of pneumococcal pneumonia.


Assuntos
Carga Bacteriana/métodos , Infecções por HIV/complicações , Técnicas de Diagnóstico Molecular/métodos , Pneumonia Pneumocócica/diagnóstico , Reação em Cadeia da Polimerase em Tempo Real/métodos , Streptococcus pneumoniae/isolamento & purificação , Adulto , DNA Bacteriano/genética , Humanos , Nasofaringe/microbiologia , Pneumonia Pneumocócica/microbiologia , Sensibilidade e Especificidade , Escarro/microbiologia , Streptococcus pneumoniae/genética
13.
BMC Infect Dis ; 14: 635, 2014 Dec 10.
Artigo em Inglês | MEDLINE | ID: mdl-25927410

RESUMO

BACKGROUND: Data on the etiologies of pneumonia among children are inadequate, especially in developing countries. The principal objective is to undertake a multicenter incident case-control study of <5-year-old children hospitalized with pneumonia in developing and emerging countries, aiming to identify the causative agents involved in pneumonia while assessing individual and microbial factors associated with the risk of severe pneumonia. METHODS/DESIGN: A multicenter case-control study, based on the GABRIEL network, is ongoing. Ten study sites are located in 9 countries over 3 continents: Brazil, Cambodia, China, Haiti, India, Madagascar, Mali, Mongolia, and Paraguay. At least 1,000 incident cases and 1,000 controls will be enrolled and matched for age and date. Cases are hospitalized children <5 years with radiologically confirmed pneumonia, and the controls are children without any features suggestive of pneumonia. Respiratory specimens are collected from all enrolled subjects to identify 19 viruses and 5 bacteria. Whole blood from pneumonia cases is being tested for 3 major bacteria. S. pneumoniae-positive specimens are serotyped. Urine samples from cases only are tested for detection of antimicrobial activity. The association between procalcitonin, C-reactive protein and pathogens is being evaluated. A discovery platform will enable pathogen identification in undiagnosed samples. DISCUSSION: This multicenter study will provide descriptive results for better understanding of pathogens responsible for pneumonia among children in developing countries. The identification of determinants related to microorganisms associated with pneumonia and its severity should facilitate treatment and prevention.


Assuntos
Protocolos Clínicos , Países em Desenvolvimento , Pneumonia/etiologia , Antibacterianos/urina , Bactérias/isolamento & purificação , Brasil , Proteína C-Reativa/metabolismo , Calcitonina/sangue , Peptídeo Relacionado com Gene de Calcitonina , Camboja , Estudos de Casos e Controles , Pré-Escolar , China , Feminino , Haiti , Humanos , Índia , Lactente , Madagáscar , Masculino , Mali , Mongólia , Paraguai , Derrame Pleural/microbiologia , Pneumonia/sangue , Pneumonia/metabolismo , Pneumonia/urina , Precursores de Proteínas/sangue , Vírus/isolamento & purificação
14.
Virologie (Montrouge) ; 18(2): 59-74, 2014 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-33065876

RESUMO

Dengue is an endemic viral disease present in inter-tropical countries. If dengue is usually benign, more severe forms (severe dengue [SD]) may lead to serious complications. The prognosis of SD is currently unreliable. To improve the prognosis, it could be necessary to know the key elements of the pathogenicity of the SD. Many hypotheses have been developed to explain a higher pathogenicity in SD patients. Numerous studies have highlighted the role of the host immune response and of the infecting virus strain. The development of these hypothesis allows to have a better understanding of the pathogenesis and consequently, to provide prognostic candidate-markers of SD, these markers being either associated with the host or with the virus. The present review proposes to paint a non-exhaustive picture of the most important hypothesis of dengue pathogenicity as well as potential prognostic markers of severe forms of dengue.

16.
Eur Respir J ; 42(2): 470-9, 2013 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-23060626

RESUMO

An unexplained increase in the incidence of parapneumonic empyema (PPE) in pneumonia cases has been reported in recent years. The present study investigated the genetic and biological specifications of new isolates of torque teno mini virus (TTMV) detected in pleural effusion samples from children hospitalised for severe pneumonia with PPE. A pathogen discovery protocol was applied in undiagnosed pleural effusion samples and led to the identification of three new isolates of TTMV (TTMV-LY). Isolated TTMV-LY genomes were transfected into A549 and human embryonic kidney 293T cells and viral replication was assessed by quantitative real-time PCR and full-length genome amplification. A549 cells were further infected with released TTMV-LY virions and the induced-innate immune response was measured by multiplex immunoassays. Genetic analyses of the three TTMV-LY genomes revealed a classic genomic organisation but a weak identity (<64%) with known sequences. We demonstrated the in vitro replication of TTMV-LY in alveolar epithelial cells and the effective release of infectious viral particles. We also showed a selective production of inflammatory mediators in response to TTMV infection. This study reports the description of replicative TTMV-LY isolated from parapneumonic effusions of children hospitalised with PPE, suggesting a potential role of the virus in the pathogenesis of pneumonia.


Assuntos
Empiema/virologia , Pneumonia Viral/virologia , Torque teno virus/isolamento & purificação , Adolescente , Sequência de Bases , Linhagem Celular Tumoral , Quimiocinas/metabolismo , Criança , Pré-Escolar , Citocinas/metabolismo , DNA Viral/análise , Feminino , Células HEK293 , Humanos , Imunoensaio , Lactente , Masculino , Dados de Sequência Molecular , Conformação de Ácido Nucleico , Fases de Leitura Aberta , Filogenia , Derrame Pleural , Pneumonia Viral/fisiopatologia , Prevalência , Estudos Prospectivos
17.
J Med Virol ; 85(2): 348-53, 2013 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-23192884

RESUMO

Respiratory syncytial virus (RSV) is a leading cause of respiratory tract illnesses worldwide. Although the prevalence and clinical manifestations of the two subtypes, RSV-A and RSV-B, have been studied in some detail in infants and young children, they have not been determined in adults. To evaluate the prevalence of the RSV subtypes and disease severity between RSV-A and RSV-B infections in adults, nasal and throat swabs that were collected from patients ≥15 years old who sought medical care for acute respiratory infections at the Fever Clinic of the Peking Union Medical College Hospital in Beijing, China between May 2005 and April 2010. The samples were tested for RSV infection using PCR and sequencing analysis. RSV was detected in 95 (1%) of the adult patients, of whom 53 (55.8%) were positive for RSV-A and 42 (44.2%) for RSV-B. The incidence of RSV infections increased with age (χ(2) = 37.17, P = 1.66E-07). Demographic data and clinical manifestations of RSV-A were similar to those of RSV-B. Although RSV-A and RSV-B co-circulated during the 2005-2006 and 2008-2009 seasons, RSV-A was predominant in the 2006-2008 seasons, whereas RSV-B was predominant in the 2009-2010 season. Upper respiratory tract infections were diagnosed in most RSV-infected patients (n = 80, 84.2%), and three patients suffered from pulmonary infection. This is the first study to provide data on the prevalence and clinical manifestations of RSV subgroups among Chinese adults with fever and acute illness, over five successive epidemic seasons.


Assuntos
Infecções por Vírus Respiratório Sincicial/epidemiologia , Infecções por Vírus Respiratório Sincicial/patologia , Vírus Sincicial Respiratório Humano/classificação , Infecções Respiratórias/epidemiologia , Infecções Respiratórias/patologia , Adolescente , Adulto , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , China/epidemiologia , DNA Viral/química , DNA Viral/genética , Feminino , Humanos , Incidência , Masculino , Pessoa de Meia-Idade , Nariz/virologia , Faringe/virologia , Reação em Cadeia da Polimerase , Prevalência , Infecções por Vírus Respiratório Sincicial/virologia , Vírus Sincicial Respiratório Humano/genética , Vírus Sincicial Respiratório Humano/isolamento & purificação , Infecções Respiratórias/virologia , Análise de Sequência de DNA , Adulto Jovem
18.
Virol J ; 10: 295, 2013 Sep 28.
Artigo em Inglês | MEDLINE | ID: mdl-24073713

RESUMO

BACKGROUND: CTL escape mutations have been described during acute hepatitis C in patients who developed chronic disease later on. Our aim was to investigate the mutual relationship between HCV specific CD8+ T cells and evolution of the viral sequence during early acute HCV infection. RESULTS: We sequenced multiple clones of NS3 1406 epitope in 4 HLA-A*02 patients with acute hepatitis C genotype 1b infection. Pentamers specific for the variants were used to monitor the corresponding CD8+ T cell response. We observed outgrowth of mutations, which induced only a weak and thus potentially insufficient CD8+ T cell response. In one patient we observed outgrowth of variant epitopes with similarities to a different genotype rather than de novo mutations most probably due to a lack of responsiveness to these likely pre-existing variants. We could show that in acute hepatitis C CTL escape mutations occur much earlier than demonstrated in previous studies. CONCLUSIONS: The adaption of the virus to a new host is characterized by a high and rapid variability in epitopes under CD8+ T cell immune pressure. This adaption takes place during the very early phase of acute infection and strikingly some sequences were reduced below the limit of detection at some time points but were detected at high frequency again at later time points. Independent of the observed variability, HCV-specific CD8+ T cell responses decline and no adaption to different or new antigens during the course of infection could be detected.


Assuntos
Linfócitos T CD8-Positivos/imunologia , Hepacivirus/genética , Hepacivirus/imunologia , Hepatite C/imunologia , Hepatite C/virologia , Evasão da Resposta Imune , Adaptação Biológica , Adulto , Antígenos Virais/genética , Antígenos Virais/imunologia , Análise Mutacional de DNA , Feminino , Hepacivirus/isolamento & purificação , Humanos , Masculino , Pessoa de Meia-Idade , Mutação , Análise de Sequência de DNA
19.
Diagnostics (Basel) ; 13(13)2023 Jul 07.
Artigo em Inglês | MEDLINE | ID: mdl-37443699

RESUMO

Chikungunya (CHIK) is a debilitating mosquito-borne disease with an epidemiology and early clinical symptoms similar to those of other arboviruses-triggered diseases such as dengue or Zika. Accurate and rapid diagnosis of CHIK virus (CHIKV) infection is therefore challenging. This international study evaluated the performance of the automated VIDAS® anti-CHIKV IgM and IgG assays compared to that of manual competitor IgM and IgG ELISA for the detection of anti-CHIKV IgM and IgG antibodies in 660 patients with suspected CHIKV infection. Positive and negative agreements of the VIDAS® CHIKV assays with ELISA ranged from 97.5% to 100.0%. The sensitivity of the VIDAS® CHIKV assays evaluated in patients with a proven CHIKV infection confirmed reported kinetics of anti-CHIKV IgM and IgG response, with a positive detection of 88.2-100.0% for IgM ≥ 5 days post symptom onset and of 100.0% for IgG ≥ 11 days post symptom onset. Our study also demonstrated the superiority of ELISA and VIDAS® assays over rapid diagnostic IgM/IgG tests. The analytical performance of VIDAS® anti-CHIKV IgM and IgG assays was excellent, with a high precision (coefficients of variation ≤ 7.4%) and high specificity (cross-reactivity rate ≤ 2.9%). This study demonstrates the suitability of the automated VIDAS® anti-CHIKV IgM and IgG assays to diagnose CHIKV infections and supports its applicability for epidemiological surveillance and differential diagnosis in regions endemic for CHIKV.

20.
PLoS Negl Trop Dis ; 17(1): e0011037, 2023 01.
Artigo em Inglês | MEDLINE | ID: mdl-36608155

RESUMO

BACKGROUND: Chikungunya-fever (CHIKF) remains a public health major issue. It is clinically divided into three phases: acute, post-acute and chronic. Chronic cases correspond to 25-40% individuals and, though most of them are characterized by long-lasting arthralgia alone, many of them exhibit persistent or recurrent inflammatory signs that define post-Chikungunya chronic inflammatory joint disease (pCHIKV-CIJD). We aimed to identify early clinical markers of evolution to pCHIKV-CIJD during acute and post-acute phases. METHODOLOGY/PRINCIPAL FINDINGS: We studied a prospective cohort of CHIKF-confirmed volunteers with longitudinal clinical data collection from symptoms onset up to 90 days, including a 21-day visit (D21). Of 169 patients with CHIKF, 86 (50.9%) completed the follow-up, from whom 39 met clinical criteria for pCHIKV-CIJD (45.3%). The relative risk of chronification was higher in women compared to men (RR = 1.52; 95% CI = 1.15-1.99; FDR = 0.03). None of the symptoms or signs presented at D0 behaved as an early predictor of pCHIKV-CIJD, while being symptomatic at D21 was a risk factor for chronification (RR = 1.31; 95% CI = 1.09-1.55; FDR = 0.03). Significance was also observed for joint pain (RR = 1.35; 95% CI = 1.12-1.61; FDR = 0.02), reported edema (RR = 3.61; 95% CI = 1.44-9.06; FDR = 0.03), reported hand and/or feet small joints edema (RR = 4.22; 95% CI = 1.51-11.78; FDR = 0.02), and peri-articular edema observed during physical examination (RR = 2.89; 95% CI = 1.58-5.28; FDR = 0.002). Furthermore, patients with no findings in physical examination at D21 were at lower risk of chronic evolution (RR = 0.41, 95% CI = 0.24-0.70, FDR = 0.01). Twenty-nine pCHIKV-CIJD patients had abnormal articular ultrasonography (90.6% of the examined). The most common findings were synovitis (65.5%) and joint effusion (58.6%). CONCLUSION: This cohort has provided important insights into the prognostic evaluation of CHIKF. Symptomatic sub-acute disease is a relevant predictor of evolution to chronic arthritis with synovitis, drawing attention to joint pain, edema, multiple articular involvement including small hand and feet joints as risk factors for chronification beyond three months, especially in women. Future studies are needed to accomplish the identification of accurate and early biomarkers of poor clinical prognosis, which would allow better understanding of the disease's evolution and improve patients' management, modifying CHIKF burden on global public health.


Assuntos
Artrite , Febre de Chikungunya , Sinovite , Masculino , Humanos , Feminino , Febre de Chikungunya/complicações , Febre de Chikungunya/diagnóstico , Febre de Chikungunya/epidemiologia , Estudos Prospectivos , Brasil/epidemiologia , Artralgia/epidemiologia , Artralgia/etiologia , Biomarcadores , Doença Crônica
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