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1.
Sheng Wu Gong Cheng Xue Bao ; 36(10): 2206-2215, 2020 Oct 25.
Artículo en Chino | MEDLINE | ID: mdl-33169584

RESUMEN

Dengue virus (DENV) is the most widely transmitted arbovirus in the world. Due to the lack of diagnostic technology to quickly identify the virus serotypes in patients, severe dengue hemorrhagic fever cases caused by repeated infections remain high. To realize the rapid differential diagnosis of different serotypes of DENV infection by immunological methods, in this study, four DENV serotype NS1 proteins were expressed and purified in mammalian cells. Monoclonal antibodies (MAbs) against NS1 protein were obtained by hybridoma technology after immunizing BALB/c mice. Enzyme-linked immunosorbent assay, indirect immunofluorescence assay, dot blotting, and Western blotting were used to confirm the reactivity of MAbs to viral native NS1 and recombinant NS1 protein. These MAbs include not only the universal antibodies that recognize all DENV 1-4 serotype NS1, but also serotype-specific antibodies against DENV-1, DENV-2 and DENV-4. Double antibody sandwich ELISA was established based on these antibodies, which can be used to achieve rapid differential diagnosis of serotypes of DENV infection. Preparation of DENV serotype-specific MAbs and establishment of an ELISA technology for identifying DENV serotypes has laid the foundation for the rapid diagnosis of DENV clinical infection.


Asunto(s)
Anticuerpos Antivirales , Virus del Dengue , Dengue , Animales , Anticuerpos Monoclonales , Anticuerpos Antivirales/clasificación , Anticuerpos Antivirales/genética , Anticuerpos Antivirales/metabolismo , Dengue/diagnóstico , Virus del Dengue/inmunología , Ensayo de Inmunoadsorción Enzimática , Humanos , Ratones , Ratones Endogámicos BALB C , Sensibilidad y Especificidad , Serogrupo , Proteínas no Estructurales Virales/genética , Proteínas no Estructurales Virales/inmunología
2.
Beijing Da Xue Xue Bao Yi Xue Ban ; 52(5): 845-850, 2020 Oct 18.
Artículo en Chino | MEDLINE | ID: mdl-33047717

RESUMEN

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.


Asunto(s)
Dependovirus , Vectores Genéticos , Animales , Dependovirus/genética , Ratones , Ratones Endogámicos C57BL , Retina , Serogrupo , Transducción Genética
3.
BMC Infect Dis ; 20(1): 733, 2020 Oct 07.
Artículo en Inglés | MEDLINE | ID: mdl-33028262

RESUMEN

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.


Asunto(s)
Listeria monocytogenes/aislamiento & purificación , Meningitis Bacterianas/diagnóstico , Neisseria meningitidis/aislamiento & purificación , Streptococcus pneumoniae/aislamiento & purificación , Adulto , Anciano , Anciano de 80 o más Años , Antiinfecciosos/uso terapéutico , Comorbilidad , Femenino , Humanos , Incidencia , Lituania , Masculino , Meningitis Bacterianas/tratamiento farmacológico , Meningitis Bacterianas/microbiología , Persona de Mediana Edad , Estudios Retrospectivos , Factores de Riesgo , Serogrupo , Resultado del Tratamiento , Adulto Joven
4.
PLoS One ; 15(10): e0238609, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-33112881

RESUMEN

INTRODUCTION: Although immune responses to the Japanese Encephalitis virus (JEV), and the dengue viruses (DENV) have a potential to modulate the immune responses to each other, this has been poorly investigated. Therefore, we developed an ELISA to identify JEV specific, DENV non cross-reactive antibody responses by identifying JEV specific, highly conserved regions of the virus and proceeded to investigate if the presence of JEV specific antibodies associate with dengue disease severity. METHODOLOGY AND RESULTS: 22 JEV specific peptides were identified from highly conserved regions of the virus and the immunogenicity and specificity of these peptides were assessed in individuals who were non-immune to JEV and DENV (JEV-DENV-, N = 30), those who were only immune to the JEV and not DENV (JEV+DENV-, N = 30), those who were only immune to DENV(JEV-DENV+, N = 30) and in those who were immune to both viruses (JEV+DENV+, N = 30). 7/22 peptides were found to be highly immunogenic and specific and these 7 peptides were used as a pool to further evaluate JEV-specific responses. All 30/30 JEV+DENV- and 30/30 JEV+DENV+ individuals, and only 3/30 (10%) JEV-DENV+ individuals responded to this pool. We further evaluated this pool of 7 peptides in patients following primary and secondary dengue infection during the convalescent period and found that the JEV-specific peptides, were unlikely to cross react with DENV IgG antibodies. We further compared this in-house ELISA developed with the peptide pool with an existing commercial JEV IgG assay to identify JEV-specific IgG following vaccination, and our in-house ELISA was found to be more sensitive. We then proceeded to investigate if the presence of JEV-specific antibodies were associated with dengue disease severity, and we found that those who had past severe dengue (n = 175) were significantly more likely (p<0.0001) to have JEV-specific antibodies than those with past non-severe dengue (n = 175) (OR 5.3, 95% CI 3.3 to 8.3). CONCLUSIONS: As our data show that this assay is highly sensitive and specific for detection of JEV-specific antibody responses, it would be an important tool to determine how JEV seropositivity modulate dengue immunity and disease severity when undertaking dengue vaccine trials.


Asunto(s)
Anticuerpos Antivirales/sangre , Virus de la Encefalitis Japonesa (Especie)/inmunología , Ensayo de Inmunoadsorción Enzimática/métodos , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Secuencia de Aminoácidos , Especificidad de Anticuerpos , Niño , Secuencia Conservada , Reacciones Cruzadas , Dengue/inmunología , Dengue/virología , Virus del Dengue/clasificación , Virus del Dengue/genética , Virus del Dengue/inmunología , Virus de la Encefalitis Japonesa (Especie)/genética , Encefalitis Japonesa/epidemiología , Encefalitis Japonesa/inmunología , Encefalitis Japonesa/virología , Ensayo de Inmunoadsorción Enzimática/estadística & datos numéricos , Femenino , Voluntarios Sanos , Humanos , Inmunoglobulina G/sangre , Masculino , Persona de Mediana Edad , Fragmentos de Péptidos/genética , Fragmentos de Péptidos/inmunología , Sensibilidad y Especificidad , Estudios Seroepidemiológicos , Serogrupo , Sri Lanka/epidemiología , Vacunación , Proteínas Virales/genética , Proteínas Virales/inmunología , Adulto Joven
5.
Medicine (Baltimore) ; 99(43): e22812, 2020 Oct 23.
Artículo en Inglés | MEDLINE | ID: mdl-33120803

RESUMEN

INTRODUCTION: Legionnaires' disease is caused by Legionella bacteria, and commonly manifests as pneumonia and has a high fatality rate. PATIENT CONCERNS: This case study reports on the fatal incident of a patient, initially diagnosed with pneumonia, and subsequently diagnosed with Legionnaires' disease caused by a new sequence type (ST) of Legionella. DIAGNOSIS: It is speculated that the patient acquired Legionnaires' disease from a contaminated water source. Legionnaires' disease was diagnosed using the Legionella urinary antigen assay and bacterial cultures of respiratory secretions; Legionella pneumophilia Type 1 was also identified through serological testing. Sequence-based typing of the cultured bacterium revealed it to be a previously unidentified species, and it was named ST2345 new-type. INTERVENTIONS: In addition to the treatment of Legionnaires' disease, blood samples taken on the second day of admission showed a co-infection of Candida tropicalis, which was treated with anti-fungal treatment. The patient improved after a week, however, on the seventh day of administration lower respiratory secretions showed the growth of Klebsiella pneumonia, indicative of ventilator-associated pneumonia. OUTCOMES: Despite active treatment, the patient passed away due to multiple organ failure. As this was a fatal case, further research is needed to determine whether the critical condition of this case was related to the virulence of the novel Legionella strain. CONCLUSION: A key finding of this study is that treatment for suspected Legionnaires' disease must be administered rapidly, as infection with Legionella may give rise to secondary pathogenic infections.


Asunto(s)
Legionella pneumophila/genética , Enfermedad de los Legionarios/complicaciones , Insuficiencia Multiorgánica/etiología , Humanos , Enfermedad de los Legionarios/terapia , Masculino , Persona de Mediana Edad , Serogrupo
6.
Wei Sheng Yan Jiu ; 49(5): 823-858, 2020 Sep.
Artículo en Chino | MEDLINE | ID: mdl-33070830

RESUMEN

OBJECTIVE: Multiplex real-time PCR for the identification of 15 Salmonella serovars was developed. METHODS: Through the Salmonella genome comparison, 12 membrane proteins STM4497 gene can be used to identify 15 Salmonella serovars, and these 12 genes were respectively listed as A-L genes. Then primers were designed according to A-L gene conserved sequences, and then multiplex real-time PCR was established assessed with the evaluation of the limit detection, sensitivity, specificity, and repeatability. The 206 Salmonella strains were identified using multiplex real-time PCR with the comparison of the serum slide agglutination assay. RESULTS: The limit detection of multiplex PCR ranged from 1. 1×10~(-3)-1. 2×10~(-3) ng/µL. The target genes were 100% specificity, and the relative standard deviation was lower than 2. 97%. Compared with the serum slide agglutination assay, Kappa ranged 0. 92-1. 00. CONCLUSION: The multiplex real-time PCR can be used to identify 15 Salmonella serovars, which is rapid, accurate and specific.


Asunto(s)
Infecciones por Salmonella , Salmonella , Humanos , Reacción en Cadena de la Polimerasa Multiplex , Reacción en Cadena en Tiempo Real de la Polimerasa , Salmonella/genética , Infecciones por Salmonella/diagnóstico , Serogrupo
7.
Int J Food Microbiol ; 335: 108893, 2020 Dec 16.
Artículo en Inglés | MEDLINE | ID: mdl-33007603

RESUMEN

Food-producing animals are considered a leading source of human Salmonella infections in Korea. However, there is a lack of comprehensive and up-to-date data regarding the diversity and resistance profiles of Salmonella serotypes in these animals. Therefore, this study aimed to determine the distribution and antimicrobial resistance profiles of Salmonella serotypes isolated from cattle, pigs, and chickens in Korea between 2010 and 2018. A total of 3018 Salmonella isolates were obtained from 16 laboratories/centers participating in the Korean Veterinary Antimicrobial Resistance Monitoring System. Salmonella serotypes were identified from the following isolates: 179 cattle (17 serotypes), 959 pig (45 serotypes), and 1880 chicken (64 serotypes). The most frequent serotypes in cattle (Typhimurium, Salmonella 4,[5],12:i:-, and Schwarzengrund), pigs (Typhimurium, Rissen, and S. 4,[5],12:i:-), and chickens (Enteritidis, Albany, Virchow, and Montevideo) accounted for more than 50% of the total serotypes in the respective animal species. To the best of our knowledge, Salmonella 4,[5],12:i:- has not been identified in cattle in Korea to date. More than 80% of the isolates demonstrated resistance to at least one antimicrobial agent. Multidrug-resistance was found in almost half of the serotypes; the highest proportion in cattle (59.2%), followed by pigs (53.4%), and chickens (45.7%). Significant proportions of the serotypes were resistant to ampicillin, streptomycin, and tetracycline. Ceftiofur and ciprofloxacin resistance rates were the highest in Salmonella isolated from chickens (17.1% and 4.1%, respectively) and cattle (10.1% and 3.9%, respectively) compared to that in pigs. Among the frequent serotypes, Albany demonstrated the highest resistance rate (>90%) to five different antimicrobials. Alarmingly, some Salmonella serotypes that are frequently associated with human infections demonstrated a trend of increasing resistance to critically important antibiotics, including 3rd generation cephalosporins and quinolones. Collectively, the presence of antibiotic-resistant Salmonella in food-producing animals poses a potential risk to public health.


Asunto(s)
Antibacterianos/farmacología , Farmacorresistencia Bacteriana , Salmonelosis Animal/microbiología , Salmonella/clasificación , Salmonella/efectos de los fármacos , Animales , Bovinos , Pollos , Farmacorresistencia Bacteriana/efectos de los fármacos , Humanos , Pruebas de Sensibilidad Microbiana , República de Corea/epidemiología , Salmonella/aislamiento & purificación , Salmonelosis Animal/epidemiología , Serogrupo , Porcinos
8.
J Med Microbiol ; 69(10): 1249-1252, 2020 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-32924920

RESUMEN

Erysipelothrix rhusiopathiae is a zoonotic pathogen that causes erysipelas in a variety of animals. In humans, in contrast to the cutaneous form called erysipeloid, which is an occupational disease and common in individuals who handle raw meat and fish, invasive systemic infections are unusual. E. rhusiopathiae expresses an immunogenic surface protein, Spa (surface protective antigen), which is involved in virulence. Among the antigenically different Spa proteins (SpaA, B and C), which are mostly associated with serovars, SpaA is by far the most prevalent in E. rhusiopathiae isolates from diseased animals. However, the Spa type has not been examined for human isolates, and it is unknown whether SpaB- or SpaC-possessing isolates can cause disease in humans. A Gram-positive, rod-shaped bacterium isolated from a case of human pyogenic spondylitis was analysed. The bacterium was identified as E. rhusiopathiae by a routine biochemical test and MS, and ultimately confirmed by an E. rhusiopathiae-specific PCR assay. Spa typing by sequencing revealed the SpaB type, and the serovar of the strain was identified as untypeable by a conventional agar gel precipitation test, but determined to be serovar 6 by a serotyping PCR assay. Sequence analysis of the serovar-defining chromosomal region revealed that the isolate displayed the same gene organization as the serovar 6 reference strain, but the region was disrupted by an insertion sequence element, suggesting that the isolate originated from a serovar 6 strain. These results highlight that unusual, spaB-possessing E. rhusiopathiae strains can potentially pose serious risks to humans.


Asunto(s)
Antígenos de Superficie/inmunología , Infecciones por Erysipelothrix/microbiología , Erysipelothrix/genética , Anciano de 80 o más Años , Antígenos Bacterianos/inmunología , Antígenos Bacterianos/metabolismo , Antígenos de Superficie/metabolismo , Proteínas Bacterianas/inmunología , Proteínas Bacterianas/metabolismo , Erysipelothrix/metabolismo , Erysipelothrix/patogenicidad , Femenino , Humanos , Proteínas de la Membrana/genética , Reacción en Cadena de la Polimerasa/métodos , Serogrupo , Serotipificación , Virulencia
9.
PLoS Negl Trop Dis ; 14(9): e0008676, 2020 09.
Artículo en Inglés | MEDLINE | ID: mdl-32956362

RESUMEN

Dengue virus (DENV)-associated disease is a growing threat to public health across the globe. Co-circulating as four different serotypes, DENV poses a unique challenge for vaccine design as immunity to one serotype predisposes a person to severe and potentially lethal disease upon infection from other serotypes. Recent experimental studies suggest that an effective vaccine against DENV should elicit a strong T cell response against all serotypes, which could be achieved by directing T cell responses toward cross-serotypically conserved epitopes while avoiding serotype-specific ones. Here, we used experimentally-determined DENV T cell epitopes and patient-derived DENV sequences to assess the cross-serotypic variability of the epitopes. We reveal a distinct near-binary pattern of epitope conservation across serotypes for a large number of DENV epitopes. Based on the conservation profile, we identify a set of 55 epitopes that are highly conserved in at least 3 serotypes. Most of the highly conserved epitopes lie in functionally important regions of DENV non-structural proteins. By considering the global distribution of human leukocyte antigen (HLA) alleles associated with these DENV epitopes, we identify a potentially robust subset of HLA class I and class II restricted epitopes that can serve as targets for a universal T cell-based vaccine against DENV while covering ~99% of the global population.


Asunto(s)
Reacciones Cruzadas/inmunología , Vacunas contra el Dengue/inmunología , Epítopos de Linfocito T/inmunología , Linfocitos T/inmunología , Dengue/prevención & control , Vacunas contra el Dengue/genética , Virus del Dengue/inmunología , Antígenos HLA/genética , Antígenos HLA/inmunología , Humanos , Modelos Moleculares , Estructura Terciaria de Proteína , Proteoma , Análisis de Secuencia de Proteína , Serogrupo
10.
PLoS Negl Trop Dis ; 14(9): e0008662, 2020 09.
Artículo en Inglés | MEDLINE | ID: mdl-32986693

RESUMEN

BACKGROUND: Leptospirosis is a widespread zoonosis with global impact, particularly among vulnerable populations in resource-poor settings in tropical countries. Rodents have been considered to be the main reservoir of the disease; however, a wide variety of mammals can act as hosts as well. Here we examine the genetic diversity of Leptospira strains from biological samples of patients and animals in French Polynesia (FP) from 2011 to 2019. METHODOLOGY/PRINCIPAL FINDINGS: From 2011 to 2019, we have collected 444 blood samples from patients diagnosed as having leptospirosis. The limited volume of clinical material and low amount of leptospiral DNA in blood samples led us to develop a nested PCR targeting the secY locus that enabled us to amplify and sequence 244 samples (55%). In addition, 20 Leptospira strains recovered from the blood of patients from 2002 to 2011 were sequenced and fully characterized at the serogroup level and used as reference strains for the association of different phylogenetic branches with respective serogroups. The secY sequences were compared with publicly available sequences from patients and animal reservoirs in FP (n = 79). We identified rats as the main source of infection for L. borgpetersenii serogroup Ballum and L. interrogans serogroup Icterohaemorrhagiae, dogs as the main source of infection for L. interrogans serogroup Australis, and farm pigs as the main source of infection for L. interrogans serogroups Pomona or Canicola. L. interrogans was associated with the most severe infections with 10 and 5 fatal cases due to serogroups Icterohaemorrhagiae and Australis, respectively. Mortality was significantly associated with older age (p-value < 0.001). CONCLUSIONS/SIGNIFICANCE: We described the population dynamics of leptospires circulating among patients in FP, including two patients who were reinfected with unrelated Leptospira genotypes, and clarified the local role of the animal reservoirs in the transmission route of leptospirosis to humans. Routine Leptospira genotyping directly on biological samples should allow the epidemiological follow-up of circulating strains and assess the impact of control interventions on disease transmission.


Asunto(s)
Genotipo , Leptospira/genética , Leptospirosis/epidemiología , Epidemiología Molecular , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Animales , Proteínas Bacterianas/genética , Niño , ADN Bacteriano/sangre , Perros , Femenino , Estudios de Seguimiento , Variación Genética , Humanos , Leptospira/clasificación , Leptospira/aislamiento & purificación , Leptospirosis/microbiología , Leptospirosis/transmisión , Masculino , Persona de Mediana Edad , Tipificación Molecular , Filogenia , Polinesia/epidemiología , Ratas , Análisis de Secuencia de ADN , Serogrupo , Porcinos , Adulto Joven , Zoonosis/epidemiología
11.
PLoS One ; 15(9): e0238190, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32966297

RESUMEN

Salmonella is an important human pathogen and poultry products constitute an important source of human infections. This study investigated prevalence; identified serotypes based on whole genome sequence, described spatial distribution of Salmonella serotypes and predicted risk factors that could influence the prevalence of Salmonella infection in commercial poultry farms in Nigeria. A cross sectional approach was employed to collect 558 pooled shoe socks and dust samples from 165 commercial poultry farms in North West Nigeria. On-farm visitation questionnaires were administered to obtain information on farm management practices in order to assess risk factors for Salmonella prevalence. Salmonella was identified by culture, biotyping, serology and polymerase chain reaction (PCR). PCR confirmed isolates were paired-end Illumina- sequenced. Following de novo genome assembly, draft genomes were used to obtain serotypes by SeqSero2 and SISTR pipeline and sequence types by SISTR and Enterobase. Risk factor analysis was performed using the logit model. A farm prevalence of 47.9% (CI95 [40.3-55.5]) for Salmonella was observed, with a sample level prevalence of 15.9% (CI95 [12.9-18.9]). Twenty-three different serotypes were identified, with S. Kentucky and S. Isangi as the most prevalent (32.9% and 11%). Serotypes showed some geographic variation. Salmonella detection was strongly associated with disposal of poultry waste and with presence of other livestock on the farm. Salmonella was commonly detected on commercial poultry farms in North West Nigeria and S. Kentucky was found to be ubiquitous in the farms.


Asunto(s)
Granjas/estadística & datos numéricos , Aves de Corral/microbiología , Salmonella/aislamiento & purificación , Animales , Nigeria , Prevalencia , Factores de Riesgo , Salmonella/clasificación , Salmonella/inmunología , Serogrupo
12.
BMC Public Health ; 20(1): 1461, 2020 Sep 29.
Artículo en Inglés | MEDLINE | ID: mdl-32993585

RESUMEN

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.


Asunto(s)
Personas con Discapacidad/estadística & datos numéricos , Carga Global de Enfermedades/estadística & datos numéricos , Hepatitis/epidemiología , Anciano , China/epidemiología , Femenino , Humanos , Incidencia , Masculino , Persona de Mediana Edad , Prevalencia , Años de Vida Ajustados por Calidad de Vida , Serogrupo
13.
PLoS One ; 15(9): e0238630, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32911523

RESUMEN

Salmonella enterica serovar Gallinarum (S. Gallinarum) can cause fowl typhoid, a severe systemic disease responsible for considerable economic losses. Chicken pathogenicity test is the traditional method for assessing the virulence of S. Gallinarum. However, this method is limited by several factors, including ethical considerations, costs, and the need for specialized facilities. Hence, we established a chicken embryo lethality assay (ELA) model to determine the virulence of S. Gallinarum. Three virulent and three avirulent representative strains, which were confirmed by the chicken pathogenicity test, were used to perform the ELA. The most significant difference between the virulent and avirulent strains could be observed when 13-day-old embryos were inoculated via the AC route and incubated for 5 days. Based on a 50% embryo lethal dose (ELD50), isolates considered to be virulent had a Log10ELD50 of ≤ 4.0, moderately virulent strains had a Log10ELD50 of 4.0-6.1, and avirulent isolates had a Log10ELD50 of ≥ 6.1. Different abilities to invade the liver of embryos were found between the virulent and avirulent strains by a growth curve experiment in vitro. The maximum colony-forming units (CFU) of the virulent strain was about 10,000 times higher than that of the avirulent strain in the liver at 5 days post infection. The ELA results of 42 field strains showed that thirty-two strains (76.2%) were virulent, nine were moderately virulent (21.4%), and one strain was avirulent (2.4%). In conclusion, these results suggest that the ELA can be used as an alternative method to assess the virulence of S. Gallinarum, which will contribute to the study of virulence genes, virulence evolution, pathogenic mechanisms and vaccine development.


Asunto(s)
Modelos Biológicos , Óvulo/microbiología , Salmonella enterica/patogenicidad , Serogrupo , Animales , Bioensayo , Embrión de Pollo , Salmonella enterica/crecimiento & desarrollo , Virulencia
14.
Nat Commun ; 11(1): 4419, 2020 09 04.
Artículo en Inglés | MEDLINE | ID: mdl-32887892

RESUMEN

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.


Asunto(s)
Anticuerpos Neutralizantes/ultraestructura , Complejo Antígeno-Anticuerpo/ultraestructura , Proteínas de la Cápside/inmunología , Enterovirus Humano B/inmunología , Animales , Anticuerpos Monoclonales/ultraestructura , Antígenos Virales , Antígenos CD55/inmunología , Microscopía por Crioelectrón , Epítopos/ultraestructura , Humanos , Meningitis Aséptica/virología , Ratones , Receptores Fc/inmunología , Serogrupo
15.
PLoS One ; 15(8): e0238479, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32866217

RESUMEN

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.


Asunto(s)
Antígenos Bacterianos/metabolismo , Antígenos Bacterianos/orina , Bioensayo/métodos , Líquido Cefalorraquídeo/microbiología , Legionella pneumophila/aislamiento & purificación , Streptococcus pneumoniae/aislamiento & purificación , Orina/microbiología , Adolescente , Adulto , Niño , Preescolar , Femenino , Humanos , Pruebas Inmunológicas/métodos , Lactante , Enfermedad de los Legionarios/metabolismo , Enfermedad de los Legionarios/microbiología , Enfermedad de los Legionarios/orina , Masculino , Meningitis/metabolismo , Meningitis/microbiología , Meningitis/orina , Neumonía Neumocócica/metabolismo , Neumonía Neumocócica/microbiología , Neumonía Neumocócica/orina , Sensibilidad y Especificidad , Serogrupo , Adulto Joven
16.
PLoS One ; 15(9): e0239457, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32997676

RESUMEN

This study aimed to detect Salmonella from retail meat collected from nine wet markets in Metro Manila, and identify the subtypes of Salmonella isolates using molecular serotyping assays from previously developed primers. Of the 720 collected meat samples, 57.64% were found to be Salmonella-contaminated. The most predominant serogroup was Salmonella O:3, and Salmonella serogroups O:4, O:6,7, O:8, O:9, and undetermined serogroups were also found. Most frequently detected isolates in bovine meat were S. 3:e,h:1,6 (putative identity: S. Anatum) and S: 4:e,h:1,2 (putative identity: S. Saintpaul), in porcine meat was S. 3:e,h:1,6 (putative identity: S. Anatum), and S. 8:i:z6 (putative identity: S. Kentucky) was common in poultry products. This study also demonstrated retail meat samples were contaminated with multiple Salmonella serogroups and serovars. This is the first Philippine study that utilized PCR-based assays to characterize Salmonella isolates down to a serovar level and provides baseline information regarding Salmonella prevalence and serovar distribution in retail meat. Molecular serotyping performed in this study can be used as an alternative approach to traditional serotyping in surveillance of Salmonella in the Philippines since the latter is expensive, time-consuming, and requires skilled technicians.


Asunto(s)
Carne/microbiología , Reacción en Cadena de la Polimerasa , Salmonella/genética , Salmonella/aislamiento & purificación , Animales , Bovinos , Pollos/microbiología , Contaminación de Alimentos , Filipinas , Serogrupo , Serotipificación/métodos , Porcinos/microbiología
17.
Int J Food Microbiol ; 335: 108885, 2020 Dec 16.
Artículo en Inglés | MEDLINE | ID: mdl-32947145

RESUMEN

Worldwide, Listeria monocytogenes is a common foodborne pathogen and serotyping is necessary for traceability and surveillance. Due to high accuracy and speed, PCR is commonly used for serotyping by targeting specific genes, such as lmo1118 and ORF2110 for 1/2c-3c and 4b-4d-4e, respectively. Single nucleotide polymorphisms (SNPs) are single base alterations at specific loci which are associated with various phenomena. In this study, a method was explored to mine specific SNPs from 253 L. monocytogenes genomes with known serotypes by writing Python programming language script. After blasting all the CDS, seventeen candidate genes with specific SNPs were obtained and these genes contained multiple types of SNPs, including lineages I, II, III, 1/2a-3a, 1/2b-3b-7, and 1/2c-3c specific SNPs. The sensitivity and specificity of these candidate SNP sites are higher than 85% in the genomes examined. Combining lineage I-specific, lineage II-specific, 1/2b-3b-7-specific, and 1/2c-3c-specific SNP sites together, using allele-specific multiplex PCR, we could serotype major L. monocytogenes serotypes. This method was used for 60 L. monocytogenes strains isolated from various food samples and the serotyping results were 100% identical to those of the currently accepted method with the reduced primers from ten to eight. Our results indicate that allele-specific multiplex PCR after mining specific SNPs from common genome database can be used for bacterial typing.


Asunto(s)
Microbiología de Alimentos/métodos , Listeria monocytogenes/aislamiento & purificación , Listeriosis/diagnóstico , Polimorfismo de Nucleótido Simple/genética , Serotipificación/métodos , Alelos , Humanos , Listeria monocytogenes/genética , Reacción en Cadena de la Polimerasa Multiplex , Sensibilidad y Especificidad , Serogrupo
18.
Int J Food Microbiol ; 335: 108859, 2020 Dec 16.
Artículo en Inglés | MEDLINE | ID: mdl-32947147

RESUMEN

In this study, 205 Salmonella enterica serovar Corvallis strains were obtained from humans and foods from Guangdong, Guangxi, and Shanghai in China from 2009 to 2017 to assess drug resistance and molecular epidemiology. These isolates displayed high rates of resistance to sulfisoxazole (94.15%) and tetracycline (77.56%). Surprisingly, the rate of resistance to ciprofloxacin reached 21.46%. Moreover, 63.9% of the strains displayed multidrug resistance. Detection of quinolone genes showed that 97.56% of the strains had single mutations (T57S) in parC. The plasmid-mediated quinolone resistance (PMQR) genes qnrS, aac(6')-Ib-cr, and qnrB, were also detected. The extended spectrum ß-lactamase (ESBLS) gene that was most common among the isolates was blaTEM-1 (18.05%). These S. Corvallis isolates are the first to date, that have been reported to possess blaCTX-M-55 or blaNDM-5. Additionally, 95.61% of isolates were biofilm producers. The streptomycin resistance rate was higher in strong biofilm producers (87.50%) than in moderate (37.93%) and weak (26.49%) biofilm producers. Pulsed-field gel electrophoresis (PFGE) showed that some strains from different sources had the same genotype. These isolates may be transmitted to humans through food and therefore the monitoring of these isolates should be strengthened in China.


Asunto(s)
Farmacorresistencia Bacteriana Múltiple/genética , Quinolonas/farmacología , Salmonella enterica/efectos de los fármacos , Salmonella enterica/genética , beta-Lactamasas/genética , Animales , Antibacterianos/farmacología , Biopelículas/crecimiento & desarrollo , Pollos/microbiología , China , Electroforesis en Gel de Campo Pulsado , Microbiología de Alimentos , Humanos , Pruebas de Sensibilidad Microbiana , Plásmidos/genética , Prevalencia , Salmonella enterica/aislamiento & purificación , Serogrupo
19.
Int J Food Microbiol ; 335: 108884, 2020 Dec 16.
Artículo en Inglés | MEDLINE | ID: mdl-32979615

RESUMEN

In recent years, the on-farm prevalence of some poultry-related Salmonella serovars such as S. Kentucky, S. Heidelberg, S. Livingstone and S. Mbandaka has increased significantly, even replacing S. Enteritidis and S. Typhimurium as the most frequently isolated serovars in some production settings and countries. For this reason, the aim of this work was to determine the resistance to several stressing agents and food preservation technologies, in laboratory media and in egg products, of 4 strains of these emerging Salmonella serovars associated to poultry and poultry products and to make comparisons with 4 S. Enteritidis strains. First, the resistance to acid pH, hydrogen peroxide, NaCl, heat, HHP, PEF and UV of the 8 Salmonella strains studied was determined and compared in laboratory media. From this part of the study, it was concluded that variability in resistance to stress among the 8 studied strains varied depending on the investigated agent/technology. However, differences in resistance (2D-values) were always lower than 3.3-fold. Results obtained also indicated that the strains of the emerging serovars studied would display lower acid and NaCl resistance, higher heat resistance and similar oxidative, HHP, PEF and UV resistance than S. Enteritidis. Then, the resistance of these 8 strains was evaluated and compared in egg, egg products and poultry manure. For some agents -including osmotic stresses, UV and PEF- there was a very good correspondence between the results obtained in laboratory media and in real food matrices and poultry manure (r > 0.85; p < 0.01). A significant relationship was also found for acid and HHP resistance (p < 0.05) and a trend for heat resistance (p < 0.10). Therefore, in general terms, conclusions drawn from the study carried out in laboratory media - regarding intraspecific variability and the relative resistance of the different strains - might be extrapolated, although with caution, to real food scenarios. Results obtained in this investigation would help to better understand the physiology and ecology of Salmonella and to design better egg preservation strategies.


Asunto(s)
Aves de Corral/microbiología , Salmonelosis Animal/microbiología , Salmonella/fisiología , Estrés Fisiológico , Animales , Huevos/microbiología , Heces/microbiología , Conservación de Alimentos , Productos Avícolas/microbiología , Salmonella/aislamiento & purificación , Serogrupo
20.
Int J Food Microbiol ; 334: 108801, 2020 Dec 02.
Artículo en Inglés | MEDLINE | ID: mdl-32795712

RESUMEN

In the summer of 2014, a multistate outbreak of listeriosis associated with contaminated stone fruit (peach and nectarine) was reported. A serotype 4b variant Listeria monocytogenes (Lm) strain of singleton Sequence Type (ST) 382 was isolated from clinical samples and stone fruit associated with the outbreak. A serotype 1/2b Lm strain of ST5, Clonal Complex 5 was isolated only from outbreak-associated stone fruit, not from clinical samples. Here we investigated the fate of the serotype 4b and 1/2b strains, at two inoculation levels (high level at 3.7 logCFU/fruit and low level at 2.7 logCFU/fruit), on the surfaces of white peach, yellow peach and yellow nectarine stored at 4 °C for 26 days. After rinsing the fruits, we determined the Lm levels in the rinsates and on the peels. We enumerated Lm using a direct plating method and compared two chromogenic agars. The Lm populations rapidly declined in the first 3 days and then declined more slowly until Day 19/21. The maximum decline was 1.6 logCFU/fruit on yellow peach inoculated with serotype 4b at high level. For fruits inoculated with high-level Lm, the lowest level of Lm (1.7 logCFU/fruit) was observed on for white peach inoculated with serotype 1/2b, and the highest level of Lm (2.6 logCFU/fruit) on Day 19/21 was observed on yellow peach inoculated with the serotype 1/2b strain. For fruits inoculated with low-level Lm, the lowest level of Lm (1.3 logCFU/fruit) was observed on yellow nectarine inoculated with either the serotype 4b or 1/2b strain, and the highest level of Lm (1.7 logCFU/fruit) on Day 19/21 was observed on yellow peach inoculated with ST382. The D-values ranged from 15 days to 28 days. Lm remained viable until the end of storage (Day 26), but the levels were not significantly different from those on Day 19/21. The types of stone fruit and Lm strain did not significantly affect the survival of Lm. These results demonstrate that contaminated stone fruit can carry a potential risk for causing listeriosis in susceptible populations. Comparison of direct plating results using two chromogenic agars showed that RAPID' L. mono and Agar Listeria Ottavani & Agosti performed equivalently for enumerating Lm on stone fruit. The fruit rinsing recovered 80% to 84% of Lm from fruit surfaces.


Asunto(s)
Brotes de Enfermedades , Frutas/microbiología , Listeria monocytogenes/fisiología , Listeriosis/microbiología , Prunus persica/microbiología , Frío , Microbiología de Alimentos , Frutas/clasificación , Humanos , Listeria monocytogenes/genética , Listeria monocytogenes/crecimiento & desarrollo , Listeria monocytogenes/aislamiento & purificación , Listeriosis/epidemiología , Viabilidad Microbiana , Prunus persica/clasificación , Serogrupo
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