Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 4.019
Filtrar
1.
Beijing Da Xue Xue Bao Yi Xue Ban ; 52(5): 845-850, 2020 Oct 18.
Artigo em Chinês | MEDLINE | ID: mdl-33047717

RESUMO

OBJECTIVE: To investigate the expression efficiency of exogenous gene mediated by different serotypes of adeno-associated virus (AAV) vectors in retina, and to compare the expression efficiency of AAV vector and two kinds of promoters commonly used in ophthalmology after transfection into mouse retina, so as to provide the basis for selecting appropriate AAV vector and promoter for gene therapy of retinitis pigmentosa. METHODS: AAV2/2, AAV2/5, AAV2/8 and AAV2/9 were prepared. The C57BL/6J mice were injected subretinally with 1 µL purified AAV vectors (1.00×1013 mg/L). Then the mice were killed 2 or 4 weeks after treatment, and the eyes were enucleated for frozen section. The expression of green fluorescent protein (GFP) was observed under the confocal microscope. Two kinds of promoters, CMV and CAG, were selectd, and the expression of AAV2/8-GFP-CMV and AAV2/8-GFP-CAG was observed under confocal microscope. RESULTS: No bacterial infection or immune response were seen in the injected mice. 2 weeks after injection, the GFP green fluorescence of AAV2/8 and AAV2/9 in the mouse retina was obvious, which indicated that the GFP green fluorescence of AAV2/8 and AAV2/9 was high after transfection into the mouse retina. In these two serotypes, GFP green fluorescence of AAV2/8 was mainly concentrated in photoreceptor cells while AAV2/8 was expressed in the whole retina, indicating that AAV2/8 was more specific to photoreceptors. Further experiments on AAV2/8 showed that the GFP green fluorescence of the mouse retina was obvious 4 weeks after injection, indicating that the exogenous gene mediated by AAV2/8 could be stably expressed in vivo. For CMV and CAG promoters, CMV promoter was expressed stronger in retinal pigment epithelium (RPE)cells, while CAG promoter was stronger in photorecepters. In photorecepters, CAG promoter was expressed almost the same as CMV promoter, while CMV promoter was stronger in RPE cells. CONCLUSION: AAV vectors could express transgene robustly in retinal cells; Among several AAV serotypes, AAV2/2 and AAV2/5 showed weaker GFP fluorescence than AAV2/8 and AAV2/9. AAV2/9 showed expression in each layer of the retina including ganglion cells. AAV2/8 was more specific for photoreceptor; CAG promoters had higher specificity for photoreceptors than CMV promoters.


Assuntos
Dependovirus , Vetores Genéticos , Animais , Dependovirus/genética , Camundongos , Camundongos Endogâmicos C57BL , Retina , Sorogrupo , Transdução Genética
2.
BMC Infect Dis ; 20(1): 733, 2020 Oct 07.
Artigo em Inglês | MEDLINE | ID: mdl-33028262

RESUMO

BACKGROUND: The morbidity and mortality in community-acquired bacterial meningitis (CABM) remain substantial, and the etiology, clinical characteristics, treatment outcomes and predictors of poor prognosis must be assessed regularly. The aim of this study was to identify the distribution of etiological agents and their relationship with clinical characteristics, treatment and outcomes in this cohort of patients with CABM. METHODS: Our retrospective chart review analyzed the causative microorganisms, clinical characteristics, laboratory findings, treatment and outcomes of 159 adults with CABM hospitalized in the Infectious Diseases Centre of Vilnius University Hospital from January 1, 2009 to December 31, 2016. A Glasgow Outcome Scale (GOS) score ≤ 3 was defined as unfavorable outcome. Predictors of an unfavorable outcome were identified through logistic regression analysis. RESULTS: The median patient age was 36 (IQR 24-56), and 51.6% were male. Microbiologically confirmed causative agents were identified in 80 (50.3%) patients: N. meningitidis in 55 (34.6%) patients with serotype B accounting for 85% of cases, S. pneumoniae in 15 (9.4%), L. monocytogenes in 5 (3.1%) and other in 5 (3.1%). The clinical triad of fever, neck stiffness and a change in mental status was present in 59.1% of patients. Coexisting conditions and comorbidities were similar in all groups stratified by etiology. Initial antimicrobial treatment consisted of penicillin in 78 patients (49.1%) and ceftriaxone in 72 patients (45.3%). The median time in which antibiotic treatment was started was 40 min (IQR 30.0-90.0). The outcome was unfavorable in 15.7% of episodes and death occurred in 5.7% of cases and did not differ according to the causative agent. Risk factors for an unfavorable outcome were age > 65 years, coexisting pneumonia and a platelet count <150x10e9/l. CONCLUSIONS: The most common causative agent of CABM was N. meningitidis, with serotype B clearly dominant. Causative agents did not influence the disease outcome. The strongest risk factors for an unfavorable outcome were older age, pneumonia and a low platelet count. Since the introduction of routine vaccination against meningococcus B for infants in Lithuania in 2018, the national vaccination policy may hopefully contribute to a decrease in the incidence of serogroup B meningococcal disease in the Lithuanian population.


Assuntos
Listeria monocytogenes/isolamento & purificação , Meningites Bacterianas/diagnóstico , Neisseria meningitidis/isolamento & purificação , Streptococcus pneumoniae/isolamento & purificação , Adulto , Idoso , Idoso de 80 Anos ou mais , Anti-Infecciosos/uso terapêutico , Comorbidade , Feminino , Humanos , Incidência , Lituânia , Masculino , Meningites Bacterianas/tratamento farmacológico , Meningites Bacterianas/microbiologia , Pessoa de Meia-Idade , Estudos Retrospectivos , Fatores de Risco , Sorogrupo , Resultado do Tratamento , Adulto Jovem
3.
PLoS One ; 15(8): e0238479, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32866217

RESUMO

The performances of the ImmuView Streptococcus pneumoniae (Sp) and Legionella pneumophila (Lp) urinary antigen test were compared to that of the BinaxNOW Sp and Lp assays, using frozen urine from 166 patients with Legionnaires' disease (LD) and 59 patients with pneumococcal pneumonia. Thirty Sp-positive or contrived cerebrospinal fluids (CSF) were also tested. Test specimens were collected and tested at different sites, with each site testing unique specimens by technologists blinded to expected results. No significant differences in test concordances were detected for the ImmuView and BinaxNOW assays for the Sp or Lp targets for urine from patients with pneumococcal pneumonia or LD when performance from both sites were combined. At one of two test sites the ImmuView Lp assay was more sensitive than the BinaxNOW assay, with no correlation between test performance and Lp serogroup 1 monoclonal type. Urines from six of seven patients with LD caused by Legionella spp. bacteria other than Lp serogroup 1 were negative in both assays. Both tests had equivalent performance for Sp-positive CSF. The clinical sensitivities for pneumococcal pneumonia were 88.1 and 94.4% for the ImmuView and Binax assays, and 87.6 and 84.2% for the Lp assays, respectively. Test specificities for pneumococcal pneumonia were 96.2 and 97.0% for the ImmuView and Binax assays, and 99.6 and 99.1% for the Lp assays. Both assays were highly specific for Sp in pediatric urines from children with nasopharyngeal colonization by the bacterium. ImmuView and BinaxNOW assay performance was equivalent in these studies.


Assuntos
Antígenos de Bactérias/metabolismo , Antígenos de Bactérias/urina , Bioensaio/métodos , Líquido Cefalorraquidiano/microbiologia , Legionella pneumophila/isolamento & purificação , Streptococcus pneumoniae/isolamento & purificação , Urina/microbiologia , Adolescente , Adulto , Criança , Pré-Escolar , Feminino , Humanos , Testes Imunológicos/métodos , Lactente , Doença dos Legionários/metabolismo , Doença dos Legionários/microbiologia , Doença dos Legionários/urina , Masculino , Meningite/metabolismo , Meningite/microbiologia , Meningite/urina , Pneumonia Pneumocócica/metabolismo , Pneumonia Pneumocócica/microbiologia , Pneumonia Pneumocócica/urina , Sensibilidade e Especificidade , Sorogrupo , Adulto Jovem
4.
BMC Public Health ; 20(1): 1461, 2020 Sep 29.
Artigo em Inglês | MEDLINE | ID: mdl-32993585

RESUMO

BACKGROUND: The aim of this study is to quantify the burden caused by viral hepatitis in China from 1990 to 2016. METHODS: Data from the GBD 2016 study were extracted to calculate incidence, prevalence and disability-adjusted life years (DALYs). Trends in DALYs were assessed in 33 provinces/regions. RESULTS: From 1990 to 2016, the total incidence of hepatitis decreased by 88.5%. However, the prevalence of hepatitis (counts in thousands), increased by 37.6% from 153,856 (95% UI: 136,047-172,319) in 1990 to 211,721 (95% UI: 179,776-240,981) in 2016, with age-standardized prevalence rates changing slightly. The number and age-standardized rates of prevalence increased by 35.9 and 1.6% for hepatitis B, respectively, and by 81.8 and 30.4% for hepatitis C. Guangxi, Guangdong and Hainan had the highest age-standardized prevalence rates (≥16,500 per 100,000). Tibet, Qinghai and Gansu had the highest age-standardized DALYs rates (≥40 per 100,000). The largest absolute number of DALYs was observed in the 15-49 year age group in 2016. The highest rate of DALYs occurred in males aged 50-69 years and in females aged ≧70 years. CONCLUSION: The incidence and DALYs of viral hepatitis decreased dramatically from 1990 to 2016. However, the prevalence still remains at a high level, which may result in heavy burdens in the future.


Assuntos
Pessoas com Deficiência/estatística & dados numéricos , Carga Global da Doença/estatística & dados numéricos , Hepatite/epidemiologia , Idoso , China/epidemiologia , Feminino , Humanos , Incidência , Masculino , Pessoa de Meia-Idade , Prevalência , Anos de Vida Ajustados por Qualidade de Vida , Sorogrupo
5.
Nat Commun ; 11(1): 4419, 2020 09 04.
Artigo em Inglês | MEDLINE | ID: mdl-32887892

RESUMO

Echovirus 30 (E30), a serotype of Enterovirus B (EV-B), recently emerged as a major causative agent of aseptic meningitis worldwide. E30 is particularly devastating in the neonatal population and currently no vaccine or antiviral therapy is available. Here we characterize two highly potent E30-specific monoclonal antibodies, 6C5 and 4B10, which efficiently block binding of the virus to its attachment receptor CD55 and uncoating receptor FcRn. Combinations of 6C5 and 4B10 augment the sum of their individual anti-viral activities. High-resolution structures of E30-6C5-Fab and E30-4B10-Fab define the location and nature of epitopes targeted by the antibodies. 6C5 and 4B10 engage the capsid loci at the north rim of the canyon and in-canyon, respectively. Notably, these regions exhibit antigenic variability across EV-Bs, highlighting challenges in development of broad-spectrum antibodies. Our structures of these neutralizing antibodies of E30 are instructive for development of vaccines and therapeutics against EV-B infections.


Assuntos
Anticorpos Neutralizantes/ultraestrutura , Complexo Antígeno-Anticorpo/ultraestrutura , Proteínas do Capsídeo/imunologia , Enterovirus Humano B/imunologia , Animais , Anticorpos Monoclonais/ultraestrutura , Antígenos Virais , Antígenos CD55/imunologia , Microscopia Crioeletrônica , Epitopos/ultraestrutura , Humanos , Meningite Asséptica/virologia , Camundongos , Receptores Fc/imunologia , Sorogrupo
6.
Zhonghua Liu Xing Bing Xue Za Zhi ; 41(7): 1110-1114, 2020 Jul 10.
Artigo em Chinês | MEDLINE | ID: mdl-32741180

RESUMO

Objective: To understand the etiological characteristics of the patients with fever of unknown origin in Guizhou province through the isolation and identification of Leptospira interrogans and provide evidence for the control, prevention and treatment of human leptospirosis. Methods: Blood and urine samples were collected from patients with fever symptoms in Qiandongnan, an epidemic area, in Guizhou. The suspected Leptospira strains were primarily identified using pathogenic Leptospira specific G1/G2-PCR, and subsequently identified by using Leptospira serogroups specific PCR. The Leptospira strains were then genotyped with multiple locus sequence typing. MLST data based cluster analysis on the isolates and Leptospira reference strains of common serogroups were analyzed by using software NTsys 2.10e. Results: Three suspected strains of Leptospira were isolated from human blood samples, the isolation rate was 8.6%, which were designated as strain 17BX002, 17BX003 and 17AJX008. Strain 17BX002 was further identified as serogroup grippotyphosa by using Leptospira serogroup specific PCR, while the other two strains were negative (excluded as iterohaemorrhagiae, sejroe, canicola, autumnalis, grippotyphosa and hebdomadis). MLST genotyping showed that strain 17BX002 was typed as ST106, most closely clustered with Leptospira grippotyphosa, while strain 17BX003 and 17AJX008 were typed as ST96, the same as serogroup badaviae. Conclusion: There are leptospirosis cases in epidemic area of Guizhou in high incidence season, grippotyphosa and bataviae are the newly discovered serogroups of Leptospira in Guizhou.


Assuntos
Febre de Causa Desconhecida/microbiologia , Leptospira interrogans/genética , Leptospira interrogans/isolamento & purificação , Leptospirose/microbiologia , Técnicas de Tipagem Bacteriana , China/epidemiologia , Humanos , Leptospirose/epidemiologia , Leptospirose/prevenção & controle , Tipagem de Sequências Multilocus , Reação em Cadeia da Polimerase , Sorogrupo
7.
PLoS Negl Trop Dis ; 14(8): e0008544, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32804980

RESUMO

Hand, foot and mouth disease (HFMD) continues to challenge Asia with pandemic potential. In Vietnam, there have been two major outbreaks occurring during 2011-2012 (>200,000 hospitalizations and >200 deaths) and more recently in 2018 (>130,000 hospitalizations and 17 deaths). Given the high burden and the complex epidemic dynamics of HFMD, synthesizing its clinical and epidemiological data remains essential to inform the development of appropriate interventions and design public health measures. We report the results of a hospital-based study conducted during 2015-2018, covering the severe HFMD outbreak recently documented in Vietnam in 2018. The study was conducted at three major hospitals responsible for receiving HFMD patients from southern Vietnam with a population of over 40 million. A total of 19 enterovirus serotypes were detected in 1196 HFMD patients enrolled in the clinical study during 2015-2018, with enterovirus A71 (EV-A71), coxsackievirus A6 (CV-A6), CV-A10 and CV-A16 being the major causes. Despite the emergence of coxsackieviruses, EV-A71 remains the leading cause of severe HFMD in Vietnam. EV-A71 was consistently detected at a higher frequency during the second half of the years. The emergence of EV-A71 subgenogroup C4 in late 2018 was preceded by its low activity during 2017-early 2018. Compared with EV-A71 subgenogroup B5, C4 was more likely to be associated with severe HFMD, representing the first report demonstrating the difference in clinical severity between subgenogroup C4 and B5, the two predominant EV-A71 subgenogroups causing HFMD worldwide. Our data have provided significant insights into important aspects of HFMD over four years (2015-2018) in Vietnam, and emphasize active surveillance for pathogen circulation remains essential to inform the local public health authorities in the development of appropriate intervention strategies to reduce the burden of this emerging infections. Multivalent vaccines are urgently needed to control HFMD.


Assuntos
Doença de Mão, Pé e Boca/diagnóstico , Doença de Mão, Pé e Boca/epidemiologia , Doença de Mão, Pé e Boca/etiologia , Criança , Pré-Escolar , Surtos de Doenças , Enterovirus/isolamento & purificação , Infecções por Enterovirus/diagnóstico , Infecções por Enterovirus/epidemiologia , Infecções por Enterovirus/etiologia , Infecções por Enterovirus/virologia , Feminino , Doença de Mão, Pé e Boca/virologia , Humanos , Lactente , Masculino , Sorogrupo , Vietnã/epidemiologia
8.
PLoS Negl Trop Dis ; 14(8): e0008535, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32813703

RESUMO

Dengue fever occurs worldwide and about 1% of cases progress to severe haemorrhage and shock. Dengue is endemic in Guatemala and its surveillance system could document long term trends. We analysed 17 years of country-wide dengue surveillance data in Guatemala to describe epidemiological trends from 2000 to 2016.Data from the national dengue surveillance database were analysed to describe dengue serotype frequency, seasonality, and outbreaks. We used Poisson regression models to compare the number of cases each year with subsequent years and to estimate incidence ratios within serotype adjusted by age and gender. 91,554 samples were tested. Dengue was confirmed by RT-qPCR, culture or NS1-ELISA in 7097 (7.8%) cases and was IgM ELISA-positive in 19,290 (21.1%) cases. DENV1, DENV2, DENV3, and DENV4 were detected in 2218 (39.5%), 2580 (45.9%), 591 (10.5%), and 230 (4.1%) cases. DENV1 and DENV2 were the predominant serotypes, but all serotypes caused epidemics. The largest outbreak occurred in 2010 with 1080 DENV2 cases reported. The incidence was higher among adults during epidemic years, with significant increases in 2005, 2007, and 2013 DENV1 outbreaks, the 2010 DENV2 and 2003 DENV3 outbreaks. Adults had a lower incidence immediately after epidemics, which is likely linked to increased immunity.


Assuntos
Dengue/diagnóstico , Dengue/epidemiologia , Adolescente , Adulto , Anticorpos Antivirais/imunologia , Criança , Pré-Escolar , Dengue/imunologia , Vírus da Dengue/imunologia , Surtos de Doenças , Ensaio de Imunoadsorção Enzimática , Feminino , Guatemala/epidemiologia , Humanos , Incidência , Lactente , Masculino , Pessoa de Meia-Idade , Reação em Cadeia da Polimerase , Sorogrupo , Sorotipagem/métodos , Adulto Jovem
9.
Arch Virol ; 165(10): 2367-2372, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32757058

RESUMO

Mammalian orthoreoviruses (MRVs) infect almost all mammals, and there are some reports on MRVs in China. In this study, a novel strain was identified, which was designated as HLJYC2017. The results of genetic analysis showed that MRV HLJYC2017 is a reassortant strain. According to biological information analysis, different serotypes of MRV contain specific amino acid insertions and deletions in the σ1 protein. Neutralizing antibody epitope analysis revealed partial cross-protection among MRV1, MRV2, and MRV3 isolates from China. L3 gene recombination in MRV was identified for the first time in this study. The results of this study provide valuable information on MRV reassortment and evolution.


Assuntos
Antígenos Virais/genética , Proteínas do Capsídeo/genética , Orthoreovirus de Mamíferos/genética , Vírus Reordenados/genética , Infecções por Reoviridae/epidemiologia , Infecções por Reoviridae/veterinária , Animais , Anticorpos Neutralizantes/sangue , Anticorpos Antivirais/sangue , Antígenos Virais/imunologia , Proteínas do Capsídeo/imunologia , China/epidemiologia , Quirópteros , Cervos , Fezes/virologia , Expressão Gênica , Mutação INDEL , Camundongos , Epidemiologia Molecular , Orthoreovirus de Mamíferos/classificação , Orthoreovirus de Mamíferos/imunologia , Orthoreovirus de Mamíferos/isolamento & purificação , Filogenia , RNA Viral/genética , Vírus Reordenados/classificação , Vírus Reordenados/imunologia , Vírus Reordenados/isolamento & purificação , Infecções por Reoviridae/imunologia , Infecções por Reoviridae/virologia , Sorogrupo , Suínos
10.
PLoS Negl Trop Dis ; 14(8): e0008573, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32841248

RESUMO

BACKGROUND: Leptospirosis has gained much attention in Sri Lanka since its large outbreak in 2008. However, most of the cases were clinically diagnosed and information on Leptospira genotypes and serotypes currently prevailing in the country is lacking. METHODOLOGY/PRINCIPAL FINDINGS: We retrospectively analyzed 24 Leptospira strains from human patients as well as isolated and characterized three Leptospira strains from black rats using the microscopic agglutination test with antisera for 19 serovars and multilocus sequence typing. The isolates were identified as Leptospira borgpetersenii sequence types (STs) 143 and 144; L. interrogans STs 30, 34, 43, 44, 74, 75, 80, 308, 313, 314, 316, and 317; and L. kirschneri ST318. Six of the 15 STs were identified for the first time in this study. Five serogroups such as Autumnalis, Grippotyphosa, Hebdomadis, Javanica, and Pyrogenes were detected among the isolates. Contrary to previous studies, various genotypes including novel STs were isolated during an outbreak in Southern Province. L. borgpetersenii serogroup Javanica ST143 was isolated both from a human and black rat. CONCLUSIONS/SIGNIFICANCE: This study revealed that genetically diverse Leptospira strains currently circulate in Sri Lanka: some genotypes have been circulating and others have emerged recently, which may explain the recent surge of leptospirosis patients with varying clinical manifestations and frequent outbreaks of leptospirosis. Black rats were identified as the source of infection for humans, but reservoir animals for other genotypes remain unknown.


Assuntos
Genótipo , Leptospira/classificação , Leptospira/genética , Leptospira/isolamento & purificação , Leptospirose/microbiologia , Tipagem de Sequências Multilocus/métodos , Adolescente , Adulto , Idoso , Testes de Aglutinação , Animais , Criança , DNA Bacteriano/análise , Reservatórios de Doenças , Feminino , Humanos , Leptospirose/epidemiologia , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Análise de Sequência de DNA , Sorogrupo , Sorotipagem , Sri Lanka/epidemiologia , Adulto Jovem
11.
PLoS One ; 15(8): e0236807, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32760141

RESUMO

Listeria monocytogenes is the etiological agent of listeriosis, a major foodborne disease and an important public health concern. Contamination of meat with L. monocytogenes occurs frequently at the slaughterhouse. Our aims were; 1) to investigate the distribution of L. monocytogenes in the processing areas of four swine slaughterhouses; 2) to describe the diversity of L. monocytogenes strains by pulsed-field gel electrophoresis; 3) to identify persistent L. monocytogenes strains and describe their distribution; 4) to investigate the associations between persistence of strains and their following characteristics: detection in food isolates, detection in human clinical isolates, and the presence of benzalkonium chloride (BAC) resistance genes. Various operation areas within the four swine slaughterhouses were sampled on four occasions. A total of 2496 samples were analyzed, and L. monocytogenes was successfully isolated from 243 samples. The proportion of positive samples ranged from 32 to 58% in each slaughterhouse and from 24 to 68% in each operation area. Fifty-eight different pulsotypes were identified and eight pulsotypes, present in samples collected during 4 visits, were considered persistent. The persistent pulsotypes were significantly more likely to be detected in food (P < 0.01, exact χ²) and human clinical cases (P < 0.01, exact χ²), respectively. Among pulsotypes harboring the BAC bcrABC resistance cassette or the emrE multidrug transporter gene, 42.8% were persistent compared to 4.5% for pulsotypes without these resistance genes (P < 0.01, exact χ²). Our study highlights the importance of persistent L. monocytogenes strains in the environmental contamination of slaughterhouses, which may lead to repeated contamination of meat products. It also shows that the presence of disinfectants resistance genes is an important contributing factor.


Assuntos
Microbiologia de Alimentos , Listeria monocytogenes/fisiologia , Listeriose/diagnóstico , Carne/microbiologia , Matadouros , Animais , Compostos de Benzalcônio/farmacologia , Farmacorresistência Bacteriana/genética , Eletroforese em Gel de Campo Pulsado , Manipulação de Alimentos , Humanos , Listeria monocytogenes/efeitos dos fármacos , Listeria monocytogenes/isolamento & purificação , Listeriose/microbiologia , Testes de Sensibilidade Microbiana , Sorogrupo , Suínos
12.
Med Sci (Paris) ; 36(8-9): 803-809, 2020.
Artigo em Francês | MEDLINE | ID: mdl-32821055

RESUMO

Jules Bordet came to the Institut Pasteur soon after his MD graduation at the Université libre de Bruxelles, thanks to a grant from the Belgian government. He joined there the laboratory of Elie Metchnikoff, the father of phagocytes and cellular immunity. Amazingly, he will decipher there some of the key mechanisms of humoral immunity initially discovered by the German school against which his mentor was fighting. He described the mechanisms that govern bacteriolysis and hemolysis, following the action of immune sera. Even if he favored the term alexin coined by Hans Buchner, he is indeed one of the founding fathers of the complement system (term coined by Paul Ehrlich). It is for these works that he was awarded in October 1920 the 1919 Nobel Prize. Back in Belgium, he became the director of Institut Pasteur du Brabant and made another landmark discovery, namely the identification of the bacillus of whooping cough, now named Bordetella pertussis.


Assuntos
Bacteriologia , Pessoal de Laboratório , Prêmio Nobel , Bacteriologia/história , Bacteriólise/fisiologia , Bélgica , Bioética , Testes de Hemaglutinação/história , História do Século XIX , História do Século XX , Humanos , Imunidade Celular/fisiologia , Imunidade Humoral/fisiologia , Pessoal de Laboratório/história , Masculino , Sorogrupo , Testes Sorológicos/história
13.
PLoS One ; 15(8): e0237871, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32817720

RESUMO

Streptococcus pneumoniae is a common cause of infectious diseases such as pneumonia and sepsis. Its colonization is thought to be the first step in the development of invasive pneumococcal diseases. This study aimed to investigate pneumococcal colonization patterns in early childhood. A longitudinal birth cohort study was conducted for investigating nasopharyngeal colonized pneumococci at 1, 6, 12, 18, 24, and 36 months of age, particularly focusing on the serotype distribution and antimicrobial susceptibilities. Pneumococcal conjugate vaccine (PCV) effect on nasopharyngeal colonization was also assessed. During 2013-2017, 855 infants were enrolled and a total of 107 isolates were recovered from 95 infants during the first three years of life. In this period, the prevalence of pneumococcal colonization increased, with values ranging from 0.2% (2/834) at 1 month of age to 5.9% (19/323) at 36 months of age. The investigation of serotype revealed that 81.1% (73/90) belonged to the non-PCV13 serotypes-23A, 15A, 15C, and 15B. Moreover, PCV13 serotypes significantly decreased during 2014-2015, when routine PCV13 vaccination was initiated in Taiwan. PCV13 introduction may lead to the reduction in the rates of pneumococcal isolates resistant (R) to penicillin. Under conditional PCV13 vaccination, pneumococcal isolates primarily belonged to non-PCV13 serotypes. This non-PCV13 serotype replacement exhibited lower rates of penicillin R isolates, suggesting that PCV13 administration may reduce the antibiotic-nonsusceptible pneumococcal disease burden and antibiotic use.


Assuntos
Doenças Nasofaríngeas/tratamento farmacológico , Nasofaringe/efeitos dos fármacos , Infecções Pneumocócicas/tratamento farmacológico , Streptococcus pneumoniae/efeitos dos fármacos , Criança , Pré-Escolar , Estudos de Coortes , Feminino , Humanos , Lactente , Masculino , Doenças Nasofaríngeas/imunologia , Doenças Nasofaríngeas/microbiologia , Doenças Nasofaríngeas/patologia , Nasofaringe/microbiologia , Penicilinas/administração & dosagem , Infecções Pneumocócicas/imunologia , Infecções Pneumocócicas/microbiologia , Infecções Pneumocócicas/patologia , Vacinas Pneumocócicas/administração & dosagem , Pneumonia/microbiologia , Pneumonia/prevenção & controle , Sepse/microbiologia , Sepse/prevenção & controle , Sorogrupo , Streptococcus pneumoniae/genética , Streptococcus pneumoniae/patogenicidade , Taiwan , Vacinas Conjugadas/administração & dosagem
14.
Science ; 369(6507): 1123-1128, 2020 08 28.
Artigo em Inglês | MEDLINE | ID: mdl-32855339

RESUMO

The Zika pandemic sparked intense interest in whether immune interactions among dengue virus serotypes 1 to 4 (DENV1 to -4) extend to the closely related Zika virus (ZIKV). We investigated prospective pediatric cohorts in Nicaragua that experienced sequential DENV1 to -3 (2004 to 2015), Zika (2016 to 2017), and DENV2 (2018 to 2020) epidemics. Risk of symptomatic DENV2 infection and severe disease was elevated by one prior ZIKV infection, one prior DENV infection, or one prior DENV infection followed by one ZIKV infection, compared with being flavivirus-naïve. By contrast, multiple prior DENV infections reduced dengue risk. Further, although high preexisting anti-DENV antibody titers protected against DENV1, DENV3, and ZIKV disease, intermediate titers induced by previous ZIKV or DENV infection enhanced future risk of DENV2 disease and severity, as well as DENV3 severity. The observation that prior ZIKV infection can modulate dengue disease severity like a DENV serotype poses challenges to development of dengue and Zika vaccines.


Assuntos
Vírus da Dengue/imunologia , Dengue Grave/epidemiologia , Infecção por Zika virus/epidemiologia , Infecção por Zika virus/imunologia , Zika virus/imunologia , Anticorpos Antivirais/sangue , Vacinas contra Dengue/imunologia , Humanos , Imunogenicidade da Vacina , Nicarágua/epidemiologia , Risco , Sorogrupo
15.
PLoS One ; 15(8): e0237466, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32790762

RESUMO

In the past decade, two leptospirosis outbreaks occurred among strawberry harvesters in Germany, with 13, and 45 reported cases respectively. In both outbreaks, common voles (Microtus arvalis) infected with Leptospira kischneri serovar Grippotyphosa were identified as the most likely outbreak source. In an univariate analysis, eating unwashed strawberries was identified as one of the risk factors associated with Leptospira infection. The aim of this study was to evaluate the survival time of L. kirschneri serovar Grippotyphosa on strawberries under varying conditions. Strawberries were spiked with 5x109 of both a laboratory reference strain (strain Moskva V) and an outbreak field strain (94-6/2007) of L. kirschneri serovar Grippotyphosa sequence type 110. Survival times were investigated in a fully crossed design with three incubation times (2h, 4h, 6h and 8h) and three temperatures (15°C, 21°C and 25°C) with three replicated for each condition. A wash protocol was developed and recovered Leptospira were determined by qPCR, dark field microscopy and culturing. Viable L. kirschneri of both the reference strain and the field strain were identified in all samples at 25°C and an incubation time of 2h, but only 1/9 (11%) and 4/9 (44%) of the samples incubated at 15°C were positive, respectively. Both reference and field strain were viable only in 2/9 (22%) at 25° after 6h. After an 8h incubation, viable Leptospira could not be identified on the surface of the strawberries or within the fruit for any of the tested conditions. Based on these results, the exposure risk of consumers to viable Leptospira spp. through the consumption of strawberries bought at the retail level is most likely very low. However, there is a potential risk of Leptospira infection by consumption of strawberries on pick-your-own farms.


Assuntos
Fragaria/microbiologia , Leptospira/fisiologia , DNA Bacteriano/metabolismo , Frutas/microbiologia , Alemanha/epidemiologia , Humanos , Leptospira/genética , Leptospirose/epidemiologia , Leptospirose/patologia , Microscopia , Reação em Cadeia da Polimerase em Tempo Real , Sorogrupo , Temperatura , Fatores de Tempo
16.
PLoS One ; 15(8): e0237940, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32853255

RESUMO

Acidovorax citrulli, a seedborne bacterium and quarantine pest, causes the devastating bacterial fruit blotch disease in cucurbit plants. Immunological assays such as ELISA are widely used in routine field inspections for this bacterium. However, to the best of our knowledge, none of the currently available monoclonal antibodies (MAbs) can detect all common A. citrulli strains. We therefore aimed to produce a panel of MAbs and to develop an ELISA-based method capable of detecting all A. citrulli strains. We used a high-throughput bead array technique to screen and characterize A. citrulli-specific MAbs produced from hybridoma clones. The hybridoma library was simultaneously screened against five A. citrulli strains (PSA, KK9, SQA, SQB and P) and the closely related bacterium, Delftia acidovorans. Three MAbs exhibiting different binding patterns to A. citrulli were used to develop an ELISA-based method called "double antibody pairs sandwich ELISA" (DAPS-ELISA). DAPS-ELISA employing mixtures of MAbs was able to specifically detect all 16 A. citrulli strains tested without cross-reactivity with other bacteria. By contrast, our previously developed MAb capture-sandwich ELISA (MC-sELISA) and a commercial test kit detected only 15 and 14 of 16 strains, respectively. The sensitivity of the DAPS-ELISA ranged from 5×105 to 1×106 CFU/mL, while those of the MC-sELISA and the commercial test kit ranged from 5×104 to 1×107 CFU/mL and 5×104 to 5×105 CFU/mL, respectively. DAPS-ELISA thus represents an alternative method enabling rapid, accurate, and inexpensive detection of all A. citrulli strains. The method can be applied to seed testing prior to planting as well as to routine field inspections.


Assuntos
Anticorpos Antibacterianos/imunologia , Anticorpos Monoclonais/imunologia , Comamonadaceae/imunologia , Ensaio de Imunoadsorção Enzimática/métodos , Sorogrupo , Hibridomas , Limite de Detecção
17.
MMWR Morb Mortal Wkly Rep ; 69(26): 815-819, 2020 Jul 03.
Artigo em Inglês | MEDLINE | ID: mdl-32614808

RESUMO

In May 2019, the New York City Department of Health and Mental Hygiene (NYCDOHMH) detected an unusual cluster of five salmonellosis patients via automated spatiotemporal analysis of notifiable diseases using free SaTScan software (1). Within 1 day of cluster detection, graduate student interviewers determined that three of the patients had eaten prepared food from the same grocery store (establishment A) located inside the cluster area. NYCDOHMH initiated an investigation to identify additional cases, establish the cause, and provide control recommendations. Overall, 15 New York City (NYC) residents with laboratory-diagnosed salmonellosis who reported eating food from establishment A were identified. The most commonly consumed food item was chicken, reported by 10 patients. All 11 clinical isolates available were serotyped as Salmonella Blockley, sequenced, and analyzed by core genome multilocus sequence typing; isolates had a median difference of zero alleles. Environmental assessments revealed food not held at the proper temperature, food not cooled properly, and potential cross-contamination during chicken preparation. Elevated fecal coliform counts were found in two of four ready-to-eat food samples collected from establishment A, and Bacillus cereus was detected in three. The outbreak strain of Salmonella was isolated from one patient's leftover chicken. Establishing automated spatiotemporal cluster detection analyses for salmonellosis and other reportable diseases could aid in the detection of geographically focused, community-acquired outbreaks even before laboratory subtyping results become available.


Assuntos
Surtos de Doenças , Vigilância em Saúde Pública/métodos , Intoxicação Alimentar por Salmonella/epidemiologia , Análise Espaço-Temporal , Adulto , Automação , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Cidade de Nova Iorque/epidemiologia , Salmonella/genética , Salmonella/isolamento & purificação , Intoxicação Alimentar por Salmonella/diagnóstico , Sorogrupo
18.
PLoS Negl Trop Dis ; 14(7): e0008459, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32667913

RESUMO

Rabies, caused by RNA viruses in the Genus Lyssavirus, is the most fatal of all infectious diseases. This neglected zoonosis remains a major public health problem in developing countries, causing the death of an estimated 25,000-159,000 people each year, with more than half of them in children. The high incidence of human rabies in spite of effective vaccines is mainly linked to the lack of compliance with the complicated administration schedule, inadequacies of the community public health system for local administration by the parenteral route and the overall costs of the vaccine. The goal of our work was the development of a simple, affordable and effective vaccine strategy to prevent human rabies virus infection. This next generation vaccine is based on a replication-defective chimpanzee adenovirus vector belonging to group C, ChAd155-RG, which encodes the rabies glycoprotein (G). We demonstrate here that a single dose of this vaccine induces protective efficacy in a murine model of rabies challenge and elicits strong and durable neutralizing antibody responses in vaccinated non-human primates. Importantly, we demonstrate that one dose of a commercial rabies vaccine effectively boosts the neutralizing antibody responses induced by ChAd155-RG in vaccinated monkeys, showing the compatibility of the novel vectored vaccine with the current post-exposure prophylaxis in the event of rabies virus exposure. Finally, we demonstrate that antibodies induced by ChAd155-RG can also neutralize European bat lyssaviruses 1 and 2 (EBLV-1 and EBLV-2) found in bat reservoirs.


Assuntos
Adenovirus dos Símios/genética , Vacinas Antirrábicas/imunologia , Raiva/prevenção & controle , Animais , Antígenos Virais , Feminino , Vetores Genéticos/genética , Humanos , Macaca fascicularis , Camundongos , Pan troglodytes/virologia , Profilaxia Pós-Exposição , Coelhos , Vírus da Raiva/genética , Vírus da Raiva/imunologia , Sorogrupo , Vacinação , Vacinas Sintéticas/imunologia , Zoonoses
19.
BMC Infect Dis ; 20(1): 472, 2020 Jul 02.
Artigo em Inglês | MEDLINE | ID: mdl-32616018

RESUMO

BACKGROUND: Carbapenem-resistant hypervirulent Klebsiella pneumoniae strains have recently come into existence worldwide; however, researchers in northeast China are not aware of their clinical features and molecular characteristics. METHODS: Here, the molecular and virulent characteristics of 44 carbapenem-resistant K. pneumoniae (CRKP) isolates collected from January 2015 to December 2017 were studied. Multilocus sequence typing (MLST) and pulsed-field gel electrophoresis (PFGE) were carried out to define the clonal relatedness among the isolates. PCR and capsular serotyping of the virulence-associated genes, as well as biofilm formation and serum complement-mediated killing assays, were employed to determine the virulent potential. The genomic features and associated mobile genetic elements of JmsCRE57 were detected by whole genome sequencing. RESULTS: The only positive isolate was JmsCRE57, which belonged to the ST375 serotype K2 that expressed uge, mrkD, fimH, kpn, aerobactin and rmpA virulence-associated genes and showed strong biofilm formation and serum sensitivity. Sequencing results showed that the JmsCRE57 genome mainly consisted of a circular chromosome, three antimicrobial resistant plasmids and a virulent plasmid. The antimicrobial resistant plasmid expressing blaKPC-2, blaCTX-M-15, aph(3″)-Ib, aph(6)-Id, qnrB1, aac(3)-IIa, aac(6')-Ib-cr, blaOXA-1, blaTEM-1B, catB4, sul2, dfrA14 and blaSHV-99. The virulent plasmid belonged to the IncHI1B group, which is mainly composed of mucoid phenotype genes and siderophore-associated genes. The remaining CRKP strains that expressed uge, fimH, mrkD and kpn virulence-associated genes were not successfully typed. CONCLUSION: Our results provide new insights on the epidemiology of carbapenem-resistant K2 hypervirulent K. pneumoniae ST375 and CRKP ST76 strains in northeast China, which may help control their future outbreaks.


Assuntos
Enterobacteriáceas Resistentes a Carbapenêmicos/genética , Enterobacteriáceas Resistentes a Carbapenêmicos/patogenicidade , Surtos de Doenças , Infecções por Klebsiella/epidemiologia , Klebsiella pneumoniae/genética , Klebsiella pneumoniae/patogenicidade , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Antibacterianos/uso terapêutico , Enterobacteriáceas Resistentes a Carbapenêmicos/isolamento & purificação , Carbapenêmicos/uso terapêutico , China/epidemiologia , Eletroforese em Gel de Campo Pulsado , Feminino , Humanos , Infecções por Klebsiella/sangue , Infecções por Klebsiella/tratamento farmacológico , Infecções por Klebsiella/microbiologia , Klebsiella pneumoniae/imunologia , Klebsiella pneumoniae/isolamento & purificação , Masculino , Testes de Sensibilidade Microbiana , Pessoa de Meia-Idade , Tipagem de Sequências Multilocus , Plasmídeos/genética , Sorogrupo , Sorotipagem , Virulência/genética , Sequenciamento Completo do Genoma , Adulto Jovem
20.
MMWR Morb Mortal Wkly Rep ; 69(28): 913-917, 2020 Jul 17.
Artigo em Inglês | MEDLINE | ID: mdl-32673297

RESUMO

Since establishment of the Global Polio Eradication Initiative* in 1988, polio cases have declined >99.9% worldwide; extensive use of live, attenuated oral poliovirus vaccine (OPV) in routine childhood immunization programs and mass campaigns has led to eradication of two of the three wild poliovirus (WPV) serotypes (types 2 and 3) (1). Despite its safety record, OPV can lead to rare emergence of vaccine-derived polioviruses (VDPVs) when there is prolonged circulation or replication of the vaccine virus. In areas with inadequate OPV coverage, circulating VDPVs (cVDPVs) that have reverted to neurovirulence can cause outbreaks of paralytic polio (2). Immunodeficiency-associated VDPVs (iVDPVs) are isolated from persons with primary immunodeficiency (PID). Infection with iVDPV can progress to paralysis or death of patients with PID, and excretion risks seeding cVDPV outbreaks; both risks might be reduced through antiviral treatment, which is currently under development. This report updates previous reports and includes details of iVDPV cases detected during July 2018-December 2019 (3). During this time, 16 new iVDPV cases were reported from five countries (Argentina, Egypt, Iran, Philippines, and Tunisia). Alongside acute flaccid paralysis (AFP) surveillance (4), surveillance for poliovirus infections among patients with PID has identified an increased number of persons excreting iVDPVs (5). Expansion of PID surveillance will facilitate early detection and follow-up of iVDPV excretion among patients with PID to mitigate the risk for iVDPV spread. This will be critical to help identify all poliovirus excretors and thus achieve and maintain eradication of all polioviruses.


Assuntos
Saúde Global/estatística & dados numéricos , Síndromes de Imunodeficiência/complicações , Poliomielite/epidemiologia , Vacina Antipólio Oral/efeitos adversos , Criança , Pré-Escolar , Feminino , Humanos , Lactente , Masculino , Poliomielite/prevenção & controle , Poliovirus/genética , Poliovirus/isolamento & purificação , Vacina Antipólio Oral/administração & dosagem , Sorogrupo
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA