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1.
Bol. micol. (Valparaiso En linea) ; 36(2): 14-19, dic. 2021.
Article in Spanish | LILACS | ID: biblio-1352557

ABSTRACT

Ha surgido una nueva variante de preocupación de SARS-CoV-2, cuyos efectos en la evolución de la pandemia parecen inciertos. Sin embargo, ha comenzado a surgir evidencia con respecto al comportamiento viral en cuanto a su transmisibilidad, unión a receptor de la célula hospedadora y escape del sistema inmune. Presentamos una revisión actualizada de los datos existentes en la literatura respecto a los aspectos microbiológicos y epidemiológicos que pueden ayudarnos a comprender las futuras investigaciones en esta variante.(AU)


A new variant of concern for SARS-CoV-2 has emerged, the effects of which on the evolution of the pandemic appear uncertain. However, evidence has begun to emerge regarding viral behavior in terms of its transmissibility, receptor binding on the host cell, and escape from the immune system. We present an updated review of the existing data in the literature regarding the microbiological and epidemiological aspects that can help us understand future research on this variant.(AU)


Subject(s)
Evolution, Molecular , SARS-CoV-2/genetics , Virulence , Behavior , SARS-CoV-2/pathogenicity , COVID-19/epidemiology
2.
Rev. psicanal ; 28(1): 1-18, Abril 2021.
Article in Portuguese | LILACS | ID: biblio-1252999

ABSTRACT

O presente trabalho parte da ideia de caracterizar o disruptivo no pensamento freudiano. Como ponto de partida, toma o trabalho de 1914, À guisa de introdução ao narcisismo, por reconhecer nele um momento primeiro de ruptura na teoria pulsional vigente: libido do Eu versus libido objetal. Durante o trajeto, sinaliza marcas desse processo e direciona-se para o disruptivo que se instala em termos metapsicológicos, com maior consistência, com o advento da pulsão de morte. A pulsão de destruição, como agente do disruptivo em sua relação com Eros, desenhará caminhos que permitem vislumbrar destinos tanáticos ou criativos. Com essa concepção metapsicológica como indicador, busca-se refletir a respeito da interação entre o disruptivo da pandemia viral e o disruptivo da virulência do racismo e seus desdobramentos criativos na efetivação, pelo coletivo da humanidade, de posturas antirracistas. Tal contexto alberga uma interrogação pontual: como a pandemia, em seu efeito disruptivo, está relacionada com a percepção em toda a sua sensorialidade, em grande escala, de norte a sul, daquilo que mantinha-se parcialmente silencioso e invisível, o racismo? (AU)


The present article begins from the idea of characterize the disruptive in the freudian's thoughts. Is takes as a starter point the work of 1914, On narcissism: an introduction, for recognize it as a first moment of rupture in the current drive theory: self libido versus object libido. In this path, it signals marks of this process and orientate to the disruptive that develops in metapsychological terms, with great consistency, with the advent of the death drive. The destruction drive, as a disruptive agent, in its relation with Eros, will draw paths that allow glimpse its tanatic fate or criative fate. From this metapsychological conception, as an indicator, seeks to reflect the interaction between the disruptive in the viral pandemic and the disruptive in the racism virulence, and its criatives developments in the effectuation of anti-racist postures, by the humanity collective. Context that holds an punctual interrogation: how the pandemic, with its disruptive effect, is related with the perception in all its sensoriality, in big scale, from north to south, with what was, in part, silence and inivisible: the racism? (AU)


El objetivo inicial del presente trabajo es caracterizar lo disruptivo en el pensamiento freudiano. Se toma como punto de partida el célebre texto de 1914 Introducción del narcisismo por reconocer en él un primer momento de ruptura en la teoría pulsional vigente hasta ese momento, que distinguía la libido del Yo y la libido de objeto. En ese recorrido, se irán señalando marcas de dicho proceso orientándose hacia lo disruptivo, que se instalará con mayor consistencia, en términos metapsicológicos, con el advenimiento de la pulsión de muerte. La pulsión de destrucción, como agente de lo disruptivo, en su relación con Eros, trazará caminos que permiten vislumbrar sus destinos tanáticos o creativos. Tomando esa concepción metapsicológica como indicador, busco reflejar la interacción entre lo disruptivo de la pandemia viral y lo disruptivo de la virulencia del racismo, así como sus desdoblamientos creativos en la adopción de posturas antirracistas por parte del colectivo humano. En este contexto se plantea una interrogación puntual: ¿cómo la pandemia, con su efecto disruptivo, está relacionada con la percepción en toda su sensorialidad, en gran escala, de norte a sur, de aquello que, en parte, se mantenía silencioso e invisible, el racismo?


Subject(s)
Pandemics/prevention & control , Racism/psychology , Rupture/psychology , Virulence , Drive , Narcissism
3.
Infectio ; 25(1): 33-38, ene.-mar. 2021. tab, graf
Article in Spanish | LILACS, COLNAL | ID: biblio-1154399

ABSTRACT

Resumen Objetivo: Aislar STEC en las heces del ganado bovino en el municipio de Ulloa, Valle del Cauca y detectar factores de virulencia asociados con la patogénesis. Materiales y métodos: Se tomaron 21 muestras provenientes de bovinos, las cuales fueron tomadas directamente del recto del animal mediante hisopos. Las muestras se procesaron hasta obtener colonias puras a las cuales se les evaluó la presencia de los genes stx1, stx2, eae, saa y hlyA mediante PCR y posteriormente, se evaluó el efecto citotóxico de las muestras positivas sobre células Vero (ATCC-CCL-81.4). Resultados: De las 21 muestras de heces de bovinos,12 presentaron bacterias con uno o ambos genes stx. Se obtuvieron 106 aislamientos totales de STEC y se observaron diferencias en cuanto a la presencia y ausencia de los genes de virulencia evaluados en los aislamientos de cada bovino, obteniendo cinco combinaciones de genes. 48 aislamientos presentaron únicamente el gen stx2 y 58 presentaron tanto el gen stx1 como el gen stx2; de los 106 aislamientos, se detectaron 44 con el gen hlyA y 57 con el gen saa. Conclusiones: Todos los sobrenadantes de STEC analizados mostraron actividad citotóxica sobre las células Vero, mientras que en ausencia de STEC las células formaron monocapa después de 48 h de incubación. Este trabajo es el primer reporte en Colombia que aporta información sobre la presencia de STEC en el ganado bovino, la presencia de factores de virulencia y el potencial efecto citotóxico que poseen estas cepas nativas.


Abstract Objective: To isolate STEC in stool samples from cattle in Ulloa, Valle del Cauca, and to detect virulence factors associated with its pathogenesis. Materials and methods: We took 21 samples from cattle, which were taken directly from the rectum of the animal using swabs. The samples were processed until obtaining pure colonies and evaluated for the presence of the stx1, stx2, eae, saa and hlyA genes by PCR. Afterward, the cytotoxic effect of positive samples were evaluated on Vero cells (ATCC-CCL- 81.4). Results: We observed that from the 21 stools samples, 12 presented bacteria with one or both stx genes. A total of 106 isolates of STEC were obtained and differences among each other were observed regarding the presence and absence of the virulence genes, obtaining five combinations of genes. We found that 48 isolates presented only stx2 gene and 58 presented both the stx1 and stx2 gene. Regarding the other virulence genes, the hlyA gene was detected in 44 isolates and the saa gene was detected in 57 isolates. Conclusions: All the STEC supernatants showed cytotoxic activity on Vero cells, while in its absence the cells formed monolayer after 48 h of incubation. This work is the first report in Colombia that provides information about the presence of STEC in stool cattle, virulence genes and its potential cytotoxic effect in native strains.


Subject(s)
Animals , Cattle , Shiga Toxin , Escherichia coli , Shiga-Toxigenic Escherichia coli , Feces , Livestock , Bacteria , Virulence , Polymerase Chain Reaction
4.
J. appl. oral sci ; 29: e20200733, 2021. graf
Article in English | LILACS | ID: biblio-1154616

ABSTRACT

Abstract Enterococcus faecalis (E. faecalis), one of the main pathogens responsible for refractory periapical periodontitis and nosocomial infections, exhibits markedly higher pathogenicity in biofilms. Objectives Studies have shown that caseinolytic protease P (ClpP) is involved in biofilm formation. However, to date, few studies have investigated the role of ClpP in the survival of E. faecalis, and in enhancing biofilm formation. Therefore, we investigated the role of ClpP in the formation of E. faecalis biofilms. Methodology In our study, we used homologous recombination to construct clpP deleted and clpP complement strains of E. faecalis ATCC 29212. A viable colony counting method was used to analyze the growth patterns of E. faecalis. Crystal violet staining (CV) and confocal scanning laser microscopy (CLSM) were used to characterize biofilm mass formation and scanning electron microscopy (SEM) was used to observe the biofilm microstructure. Data was statistically analyzed via Student's t-test or one-way analysis of variance (ANOVA). Results The results exhibited altered growth patterns for the clpP deletion strains and depleted polysaccharide matrix, resulting in reduced biofilm formation capacity compared to the standard strains. Moreover, ClpP was observed to increase biofilm formation in E. faecalis. Conclusion Our study shows that ClpP can increase biofilm formation in E. faecalis and emphasizes the importance of ClpP as a potential target against E. faecalis.


Subject(s)
Humans , Enterococcus faecalis , Biofilms , Peptide Hydrolases , Virulence , Microscopy, Electron, Scanning , Microscopy, Confocal , Endopeptidase Clp
5.
Braz. oral res. (Online) ; 35: e062, 2021. tab, graf
Article in English | LILACS, BBO | ID: biblio-1278591

ABSTRACT

Abstract This in vitro study evaluated the impact of TiO2 nanotubes (n-TiO2) incorporated into glass ionomer cement (GIC) on Streptococcus mutans (S. mutans) characteristics at cellular and molecular levels. n-TiO2, synthesized by the alkaline method (20 nm in size), was added to Ketac Molar EasyMix® at 0%, 3%, 5%, and 7% by weight. S. mutans strains were cultured on GIC disks with addition or not of n-TiO2 for 1, 3, and 7 days and the following parameters were assessed: inhibition halo (mm) (n=3/group); cell viability (live/dead) (n=5/group); cell morphology (SEM) (n=3/group); and gene expression by real-time PCR (vicR, covR, gtfB, gtfC, and gtfD) (n=6/group). The data were analyzed by the Kruskal-Wallis test, repeated-measures ANOVA or two-way ANOVA, and Tukey's and Dunn's post-hoc tests (α=0.05). The agar diffusion test showed a higher antibacterial property for 5% n-TiO2 compared with 3% and 7% (p<0.05) with no effect of time (1, 3, and 7 days). The cell number was significantly affected by all n-TiO2 groups, while viability was mostly affected by 3% and 5% n-TiO2, which also affected cell morphology and organization. Real-time PCR demonstrated that n-TiO2 reduced the expression of covR when compared with GIC with no n-TiO2 (p<0.05), with no effect of time, except for 3% n-TiO2 on vicR expression. Within-group and between-group analyses revealed n-TiO2 did not affect mRNA levels of gtfB, gtfC, and gtfD (p>0.05). Incorporation of n-TiO2 at 3% and 5% potentially affected S. mutans viability and the expression of key genes for bacterial survival and growth, improving the anticariogenic properties of GIC.


Subject(s)
Streptococcus mutans , Nanotubes , Titanium , Virulence , Materials Testing , Glass Ionomer Cements/pharmacology
6.
Clinics ; 76: e2052, 2021. tab, graf
Article in English | LILACS | ID: biblio-1153974

ABSTRACT

OBJECTIVES: Single nucleotide variants (SNVs) are the most common type of genetic variation among humans. High-throughput sequencing methods have recently characterized millions of SNVs in several thousand individuals from various populations, most of which are benign polymorphisms. Identifying rare disease-causing SNVs remains challenging, and often requires functional in vitro studies. Prioritizing the most likely pathogenic SNVs is of utmost importance, and several computational methods have been developed for this purpose. However, these methods are based on different assumptions, and often produce discordant results. The aim of the present study was to evaluate the performance of 11 widely used pathogenicity prediction tools, which are freely available for identifying known pathogenic SNVs: Fathmn, Mutation Assessor, Protein Analysis Through Evolutionary Relationships (Phanter), Sorting Intolerant From Tolerant (SIFT), Mutation Taster, Polymorphism Phenotyping v2 (Polyphen-2), Align Grantham Variation Grantham Deviation (Align-GVGD), CAAD, Provean, SNPs&GO, and MutPred. METHODS: We analyzed 40 functionally proven pathogenic SNVs in four different genes associated with differences in sex development (DSD): 17β-hydroxysteroid dehydrogenase 3 (HSD17B3), steroidogenic factor 1 (NR5A1), androgen receptor (AR), and luteinizing hormone/chorionic gonadotropin receptor (LHCGR). To evaluate the false discovery rate of each tool, we analyzed 36 frequent (MAF>0.01) benign SNVs found in the same four DSD genes. The quality of the predictions was analyzed using six parameters: accuracy, precision, negative predictive value (NPV), sensitivity, specificity, and Matthews correlation coefficient (MCC). Overall performance was assessed using a receiver operating characteristic (ROC) curve. RESULTS: Our study found that none of the tools were 100% precise in identifying pathogenic SNVs. The highest specificity, precision, and accuracy were observed for Mutation Assessor, MutPred, SNP, and GO. They also presented the best statistical results based on the ROC curve statistical analysis. Of the 11 tools evaluated, 6 (Mutation Assessor, Phanter, SIFT, Mutation Taster, Polyphen-2, and CAAD) exhibited sensitivity >0.90, but they exhibited lower specificity (0.42-0.67). Performance, based on MCC, ranged from poor (Fathmn=0.04) to reasonably good (MutPred=0.66). CONCLUSION: Computational algorithms are important tools for SNV analysis, but their correlation with functional studies not consistent. In the present analysis, the best performing tools (based on accuracy, precision, and specificity) were Mutation Assessor, MutPred, and SNPs&GO, which presented the best concordance with functional studies.


Subject(s)
Humans , Computational Biology , Mutation, Missense/genetics , Virulence , Polymorphism, Single Nucleotide , Sexual Development , Mutation
7.
Biosci. j. (Online) ; 36(6): 2020-2028, 01-11-2020. ilus, tab, graf
Article in English | LILACS | ID: biblio-1148292

ABSTRACT

Pseudomonas syringae pv. actinidiae is a bacterial pathogen of kiwifruit. Based on the results of the pathogenicity assay, we sequenced the strain Pseudomonas syringae (Psa3) P155 which possesses a series of virulence and resistance genes, CRISPR candidate elements, prophage related sequences, methylation modifications, genomic islands as well as one plasmid. Most importantly, the copper resistance genes copA, copB, copC, copD, and copZ as well as aminoglycoside resistance gene ksgA were identified in strain P155, which would pose a threat to kiwifruit production. The complete sequence we reported here will provide valuable information for a better understanding of the genetic structure and pathogenic characteristics of the genome of P155.


Pseudomonas syringae pv. actinidiae agente causal do cancro bacteriano do kiwi. Com base nos resultados do teste de patogenicidade, foi sequenciado um isolado de Pseudomonas syringae (Psa3) P155, que abriga a uma série de genes de virulência e resistência, elementos candidatos CRISPR, sequências relacionadas a profagos, modificações na metilação, ilhas genômicas, e também um plasmídeo. O mais importante foram os genes de resistência ao cobre, copA, copB, copC, copD e copZ, bem como, o gene de resistência aminoglicosídea ksgA identificados na estirpe P155, os quais representariam uma ameaça à produção de kiwi. A sequência completa relatada fornecerá informações valiosas para uma melhor compreensão da estrutura genética e as características patogênicas do genoma de P155.


Subject(s)
Virulence , Actinidia , Pseudomonas syringae , Whole Genome Sequencing
8.
Acta bioquím. clín. latinoam ; 54(3): 321-331, set. 2020. ilus, graf
Article in Spanish | LILACS | ID: biblio-1130606

ABSTRACT

Los flavivirus transmitidos por mosquitos son una amenaza actual y emergente en todo el mundo. Dentro de este género, el virus Encefalitis San Luis (VESL) causa una forma severa de enfermedad neuroinvasiva donde la respuesta inmune es un componente crucial de la defensa del huésped. En este trabajo se investigó la interacción entre VESL y células de la inmunidad innata, en un modelo de infección in vitro de monocitos humanos (células U937) con cepas de distinta virulencia y condiciones epidemiológicas de aislamiento (CbaAr-4005 y 78V-6507). Se evaluó la capacidad de infectar y replicar del virus, como también el efecto citopático y la cinética de viabilidad de monocitos durante la infección. Los resultados demostraron la susceptibilidad de los monocitos a la infección, replicación y muerte por ambas cepas virales. Sin embargo, se hallaron diferencias significativas entre ellas. La cepa epidémica y de mayor virulencia CbaAr-4005 registró una tasa de infección y replicación superior a la de la cepa endémica y de menor virulencia 78V-6507. Se comprobó también que el VESL indujo la muerte de monocitos humanos, dependiendo del tiempo post-infección (pi) y de la cepa. Así, CbaAr-4005 provocó a partir del día 3 pi el doble de mortalidad celular que 78V-6507. Además, en los monocitos infectados se observaron alteraciones de parámetros morfológicos que podrían relacionarse con el tipo de mecanismo de muerte celular asociado a la infección por VESL.


Mosquitoes borne Flavivirus infections are an actual and emergent worldwide threat to human health. Within this genus, Saint Louis Encephalitis Virus (SLEV) causes a severe neuroinvasive disease where immune response is crucial for host survival. In this study the interaction between SLEV and innate immune cells was evaluated. An in vitro infection model with human monocytes (U937 cells) and strains with variations in virulence and isolation conditions (CbaAr-4005 and 78V-6507) were used. Infection capacity, replication capacity, cytopathic effect and monocyte viability kinetics were measured. The results showed susceptibility to infection and replication to both strains. However, significant differences were found among them. CbaAr-4005, the epidemic and more virulent strain, showed higher infection and replication ratios compared to 78V-6507. SLEV infection that induces cell death of human monocytes was also found in a post-infection time and in a strain dependent manner. Since day 3 post-infection, twice the mortality in CbaAr-4005 infected cells was observed. Furthermore, infected monocytes showed alterations in morphologic parameters that could be related with apoptosis mechanisms associated to SLEV infections.


Os Flavivírus transmitidos por mosquitos são uma ameaça atual e emergente no mundo todo. Nesse gênero, o vírus Encefalite Saint Louis (VESL) causa uma forma grave de doença neuroinvasiva onde a resposta imune é um componente crucial da defesa do hospedeiro. Neste trabalho nos investigamos a interação entre VESL e células de imunidade inata em um modelo de infecção in vitro de monócitos humanos (células U937) com estirpe de diferentes virulências e condições epidemiológicas de isolamento (CbaAr-4005 e 78V-6507). Foi avaliada a capacidade do vírus de infectar e replicar , assim como o efeito citopático e a viabilidade cinética dos monócitos durante a infecção. Os resultados demonstraram a suscetibilidade dos monócitos à infecção, replicação e morte por ambas as estirpes virais. No entanto, foram detectadas diferenças significativas entre eles. A estirpe epidémica e de maior virulenta CbaAr-4005 teve uma maior taxa de infecção e replicação do que a estirpe endémica e menos virulenta 78V-6507. Foi comprovado também que o VESL induziu a morte de monócitos humanos, dependendo do tempo pós-infecção (pi) e da estirpe. Assim, a CbaAr-4005 causou a partir do dia 3 pi o dobro da mortalidade celular o que a 78V- 6507. Além disso, alterações nos parâmetros morfológicos foram observadas nos monócitos infectados que poderiam estar relacionadas ao tipo de mecanismo de morte celular associado à infecção pelo VESL.


Subject(s)
Humans , Male , Female , Virulence , Flavivirus Infections , U937 Cells , Encephalitis , Encephalitis Virus, St. Louis , Encephalitis Viruses/growth & development , Flavivirus , Patient Isolation , Viruses , In Vitro Techniques , Kinetics , Cells , Disease , Incidence , Causality , Mortality , Apoptosis , Reference Parameters , Culicidae
9.
Rev. cuba. invest. bioméd ; 39(3): e868, jul.-set. 2020.
Article in Spanish | LILACS, CUMED | ID: biblio-1138946

ABSTRACT

Introducción: Los coronavirus infectan al ser humano y pueden causar manifestaciones neurológicas en individuos susceptibles. Objetivo: Describir la patogenia de las manifestaciones neurológicas en pacientes con la COVID-19. Estrategia de búsqueda y criterios de selección: Se realizó una revisión bibliográfica empleando la bibliografía nacional e internacional actualizada. Se realizó la búsqueda en Google Académico, se consultaron artículos de libre acceso en las bases de datos Pubmed y SciELO, desde enero de 2014 hasta el 6 de mayo de 2020. Fueron seleccionados 51 artículos (6 en idioma español, 45 en inglés) y un libro de neuroinmunología. Se utilizaron los términos de búsqueda COVID-19, coronavirus, SARS-CoV-2,manifestaciones neurológicas, sistema nervioso, patogénesis, según el descriptor de Ciencias de la Salud (DeCS). Análisis e integración de la información: El SARS-CoV-2 entra al sistema nervioso por la vía linfática, hematógena, transináptica retrógada, por diseminación local a través del etmoides o por disfunción de la barrera hematoencefálica. La patogenia puede ser por la acción directa del virus o inmunomediada. En la pandemia de COVID-19 se reportan pacientes con manifestaciones neurológicas centrales, periféricas y musculoesqueléticas. Los síntomas más frecuentes son los trastornos del gusto, el olfato, cefaleas, mialgias y mareos. En las formas graves se reportan meningitis, encefalitis, síndrome de Guillain-Barré, ictus y encefalopatías. Conclusiones: El SARS-CoV-2 puede afectar al sistema nervioso central y periférico. Causa principalmente manifestaciones leves y transitorias, aunque pueden ocurrir complicaciones neurológicas. Los mecanismos patogénicos principales son el daño citopático directo o mecanismos indirectos debido a una respuesta inflamatoria(AU)


Introduction: Coronaviruses infect humans and may cause neurological manifestations in susceptible individuals. Objective: Describe the pathogenesis of neurological manifestations in patients with COVID-19. Search strategy and selection criteria: A review was conducted of national and international updated bibliography. The search was carried out in Google Scholar and open access papers were consulted in the databases PubMed and SciELO from January 2014 to 6 May 2020. A total 51 papers (6 in Spanish and 45 in English) and a book on neuroimmunology were selected. The search terms used were COVID-19, coronavirus, SARS-CoV-2, neurological manifestations, nervous system and pathogenesis, in compliance with the Health Sciences Descriptors (DeCS). Data analysis and integration: SARS-CoV-2 enters the nervous system by lymphatic, hematogenous, transynaptic, retrograde routes, by local dissemination through the ethmoid, or by dysfunction of the hematoencephalic barrier. Pathogenesis may be due to direct action by the virus or immunomediated. During the COVID-19 pandemic patients have been reported with central, peripheral and musculoskeletal neurological manifestations. The most common symptoms are taste and smell disorders, headache, myalgia and dizziness. Meningitis, encephalitis, Guillain-Barré syndrome, stroke and encephalopathies have been reported in severe forms of the disease. Conclusions: SARS-CoV-2 may affect the central and the peripheral nervous system. It mainly causes mild, transient manifestations, but neurological complications may also occur. The main pathogenic mechanisms are direct cytophatic damage or indirect mechanisms resulting from an inflammatory response(AU)


Subject(s)
Humans , Virulence/immunology , Nervous System Diseases/complications , Coronavirus Infections/transmission
10.
Rev. epidemiol. controle infecç ; 10(3): 1-16, jul.-set. 2020. ilus
Article in English | LILACS | ID: biblio-1247638

ABSTRACT

Justificativa e Objetivos: A candidíase oral tem uma ocorrência comum em pacientes imunocomprometidos. No entanto, outras infecções emergentes tornaram-se cada vez mais habituais. O objetivo deste estudo foi investigar a prevalência, os determinantes de virulência e a suscetibilidade a antifúngicos de leveduras que colonizam a mucosa de pacientes imunocomprometidos na região Nordeste do Brasil. Métodos: A amostra foi composta por 60 pacientes HIV positivos atendidos no Serviço de Atendimento Especializado/Hospital Dia do Hospital Universitário Prof. Alberto Antunes, vinculado à Universidade Federal de Alagoas. As amostras foram coletadas em regiões subgengivais e semeadas em CHROMagar para confirmação presuntiva de Candida spp., seguido por PCR e sequenciamento. Além disso, testamos os determinantes de virulência fosfolipase e protease e avaliamos in vitro a concentração inibitória mínima dos antifúngicos anfotericina B e fluconazol. Este projeto foi aprovado pelo Comitê de ética em pesquisa do Centro de Estudos Superiores de Maceió. Resultados: Aproximadamente 63% dos pacientes foram colonizados por leveduras. A espécie C. albicans foi predominante, enquanto as espécies de Candida não-albicans representaram 49% dos isolados, sendo C. dubliniensis e C. parapsilosis as mais comuns. Entretanto, C. intermedia, Bullera penniseticola e Naganishia liquefaciens também foram encontrados. Os determinantes da virulência protease e/ou fosfolipase também foram produzidos por Candida spp. e alguns isolados oportunistas incomuns como Kodamaea ohmeri, N. liquefaciens e Saitozyma podzolica. Além disso, a maioria dos isolados de Candida spp. e algumas espécies oportunistas incomuns apresentaram altos valores de concentração inibitória mínima. Conclusão: Os resultados obtidos indicam que C. albicans continua a ser a espécie predominante na cavidade oral de pacientes imunodeficientes e, juntamente com outras espécies incomuns, pode apresentar alta resistência aos antifúngicos testados.(AU)


Background and Objectives: Oral candidiasis has a common occurrence in immunocompromised patients. However, other emergent infections have become increasingly common. The aim of this study was to investigate the prevalence, virulence determinants and the antifungal susceptibility of yeast colonizing the mucosa of immunocompromised patients in Northeastern Brazil. Methods: Samples from sixty HIV-positive patients seen at the Specialized Service / Hospital Dia - Hospital Universitário Prof. Alberto Antunes from the Federal University of Alagoas were collected from subgingival sites and seeded on CHROMagar for presumptive confirmation of Candida spp. followed by PCR and sequencing. In addition, we tested virulence determinants, phospholipase and protease and evaluated in vitro the Minimum Inhibitory Concentration of antifungals amphotericin B and fluconazole. This project was approved by the Research Ethics Committee of the Center for Higher Studies in Maceió. Results: Approximately 63% of the patients were colonized by yeasts, with C. albicans as the predominant species, while non-Candida albicans species accounted for 49% of the isolates, with C. dubliniensis and C. parapsilosis being the commonest, but C. intermedia, Bullera penniseticola and Naganishia liquefaciens were also found. The virulence determinants protease and/or phospholipase were also produced by Candida spp. and some uncommon opportunistic isolates such as Kodamaea ohmeri, N. liquefaciens and Saitozyma podzolica. Furthermore, most of Candida spp. strains and some uncommon opportunistic species showed high values of minimal inhibitory concentration. Conclusion: Results obtained indicate that C. albicans continues to be the predominant species in oral cavity of immunodeficient patients and along with other unusual species may present high resistance to the antifungals tested.(AU)


Justificación y Objetivos: La candidiasis oral acomete con frecuencia a pacientes inmunocomprometidos. Sin embargo, otras infecciones emergentes se han vuelto cada vez más comunes. El objetivo de este estudio fue investigar la prevalencia, la producción de determinantes de virulencia y la susceptibilidad a antifúngicos de levaduras que colonizan la mucosa de pacientes inmunocomprometidos en la región Nordeste de Brasil. Métodos: Se colectaron muestras de sesenta pacientes VIH positivos atendidos en el Servicio de Atención Especializado/Hospital Día del Hospital Universitario Prof. Alberto Antunes, vinculado a la Universidad Federal de Alagoas. Se colectaron las muestras en las regiones subgingivales y las sembraron en CHROMagar para la presunta confirmación de Candida spp. seguido de PCR y secuenciación. Además, analizamos los determinantes de virulencia fosfolipasa y proteasa y evaluamos in vitro la concentración mínima inhibitoria de los antifúngicos anfotericina B y fluconazol. Este proyecto fue aprobado por el Comité de Ética en Investigación del Centro de Estudios Superiores de Maceió. Resultados: Aproximadamente el 63% de los pacientes fueron colonizados por levaduras, y la C. albicans fue la especie predominante, mientras que las especies de Candida no-albicans representaron el 49% de los aislamientos, de las cuales la C. dubliniensis y la C. parapsilosis fueron las más comunes. Sin embargo, también se encontraron C. intermedia, Bullera penniseticola y Naganishia liquefaciens. Los determinantes de virulencia de proteasa y/o fosfolipasa también fueron producidos por Candida spp. y algunos aislados oportunistas inusuales como Kodamaea ohmeri, N. liquefaciens y Saitozyma podzolica. Además, la mayoría de los asilados de Candida spp. y algunas especies oportunistas inusuales mostraron valores altos de concentración mínima inhibitoria. Conclusión: Los resultados obtenidos indican que C. albicans continúa siendo la especie predominante en la cavidad oral de pacientes inmunodeprimidos y, junto con otras especies poco comunes, puede presentar una alta resistencia a los antifúngicos evaluados.(AU)


Subject(s)
Humans , Virulence , Yeasts/virology , Candida , Candidiasis, Oral , Virulence Factors , Immunologic Deficiency Syndromes , Antifungal Agents , Prevalence , Acquired Immunodeficiency Syndrome
11.
Arq. bras. med. vet. zootec. (Online) ; 72(4): 1353-1362, July-Aug. 2020. tab, graf
Article in Portuguese | ID: biblio-1131515

ABSTRACT

Objetivou-se avaliar características de virulência, perfil de resistência antimicrobiana e padrão de similaridade genética de 71 cepas de Salmonella Minnesota isoladas na cadeia produtiva de frangos de corte, entre 2009 e 2010, em duas unidades de uma empresa (A e B). Os isolados foram sorotipificados e submetidos ao teste de susceptibilidade antimicrobiana pelo teste de difusão em disco. Utilizando-se PCR, foi avaliada a presença dos genes invA, lpfA, agfA e sefA e os genes de resistência aos betalactâmicos (bla TEM , bla SHV e bla CTX-M ). A relação filogenética foi determinada por RAPD-PCR. Os maiores percentuais de resistência foram para tetraciclina e sulfonamida. Foram reconhecidos oito perfis de resistência aos antimicrobianos entre as cepas isoladas na indústria A, e 11 perfis de resistência na indústria B. Do total de cepas, 100% foram positivas para o gene invA, 98,6% para o gene agfA, 49,3% para o gene lpfA e nenhuma para o gene sefA. Três cepas foram positivas para o gene bla TEM (4,2%) e 11 (15,5%) para o gene bla CTX-M . A avaliação filogenética demonstrou a presença de sete clusters com similaridade superior a 80% e três perfis distintos. Com base no dendrograma, observou-se a disseminação de um mesmo perfil em ambas as empresas.(AU)


The aim of this study was to evaluate virulence characteristics, antimicrobial resistance profile and the pattern of genetic similarity of 71 strains of Salmonella Minnesota isolated in the production chain of broilers between 2009 and 2010, into two units of a company (A and B). Isolates were serotyped and submitted to antimicrobial susceptibility by disk diffusion test. Using PCR, the presence of genes invA, lpfA, agfA and sefA and the genes conferring resistance to beta-lactam (blaTEM, blaSHV and blaCTX-M) were evaluated. The phylogenetic relationship was determined by the RAPD-PCR method. The highest percentages of resistance were to tetracycline and sulfonamide. Eight antimicrobial resistance profiles were recognized among strains isolated in industry A, and 11 resistance profiles in industry B. Of all strains of both industries, 100% were positive for the invA gene, 98.6% to agfA gene, 49.3% for lpfA gene, and no strain showed the sefA gene. Three strains were positive for the gene blaTEM (4.2%), 11 (15.5%) for the blaCTX-M gene. Phylogenetic evaluation showed the presence of seven clusters with similarity greater than 80% and three distinct profiles. Based on the dendrogram we observed the spread with similar profiles in both companies.(AU)


Subject(s)
Humans , Animals , Poultry , Salmonella , Salmonella Infections, Animal/epidemiology , Chickens , Virulence Factors , Virulence , Zoonoses/prevention & control , Polymerase Chain Reaction , Disease Susceptibility
12.
Biosci. j. (Online) ; 36(2): 546-555, 01-03-2020. tab, ilus
Article in English | LILACS | ID: biblio-1146419

ABSTRACT

Campylobacter spp. is an emerging pathogen that causes gastroenteritis in humans and the consumption of dairy food can characterize sources of infection. We aimed to verify the viability and a presence of transcripts associated with characteristics of virulence and adaptation of C. jejuni isolated from Minas Frescal cheeses, produced with contaminated milk and stored under refrigeration for up to ten days. The samples were analyzed for bioindicators, Campylobacter spp., pH, acidity, moisture and sodium chloride. Campylobacter spp. recovered were evaluated for the production of transcripts of: ciaB, dnaJ, p19 and sodB. The results were correlated with the viability of C. jejuni and changes in their transcriptome. Storage at lowtemperatures reduced C. jejuni from the first to the fourth day. The variations in humidity, pH and acidity influenced the decreasing of C. jejuni. There was a reduction in transcripts' production of the four genes, more pronounced on the fourth day, indicating the inability of the microorganism to perform its metabolic activities, due to the conditions of injury. Despite the presence of mechanisms of virulence and adaptation, C. jejuni could not remain viable four days after production. However, consumption of fresh cheese contaminated with Campylobacter jejuni can be a source of infection when consumed up to four days after production.


Campylobacter spp. é um patógeno emergente que causa gastroenterite em seres humanos e o consumo de produtos lácteos pode caracterizar fontes de infecção. O objetivo deste estudo foi verificar a viabilidade e a presença de transcritos associadas a características de virulência e adaptação de C. jejuniisoladas de queijos frescos, produzidos com leite contaminado e mantidos refrigeradas por dez dias. Foram analisados bioindicadores, Campylobacter spp., pH, acidez, umidade e cloreto de sódio. Campylobacter spp. recuperados foram avaliados quanto à produção dos transcritos: ciaB, dnaJ, p19 e sodB. Os resultados foram correlacionados com a viabilidade de C. jejuni e alterações no transcriptoma. O armazenamento em baixas temperaturas reduziu C. jejuni do primeiro ao quarto dia. As variações na umidade, pH e acidez influenciaram a queda de C. jejuni. Houve uma redução na produção de transcritos dos quatro genes, mais pronunciada no quarto dia, indicando a incapacidade do micro-organismo em realizar suas atividades metabólicas, devido às condições de injúria. Apesar da presença de mecanismos de virulência e adaptação, C. jejuni não permaneceu viável quatro dias após a produção. Porém, o consumo de queijo fresco contaminado com Campylobacter jejunipode ser uma fonte de infecção quando consumido até quatro dias após a produção.


Subject(s)
Campylobacter Infections , Cheese , Campylobacter jejuni , Virulence , Dairy Products , Gastroenteritis , Infections , Noxae
13.
Article in English | WPRIM | ID: wpr-829001

ABSTRACT

Objective@#This study aimed to evaluate the genetic diversity, virulence, and antimicrobial resistance of isolates from clinical patients, tap water systems, and food.@*Methods@#Ninety isolates were obtained from Ma'anshan, Anhui province, China, and subjected to multi-locus sequence typing (MLST) with six housekeeping genes. Their taxonomy was investigated using concatenated sequences, while their resistance to 12 antibiotics was evaluated. Ten putative virulence factors and several resistance genes were identified by PCR and sequencing.@*Results@#The 90 isolates were divided into 84 sequence types, 80 of which were novel, indicating high genetic diversity. The isolates were classified into eight different species. PCR assays identified virulence genes in the isolates, with the enterotoxin and hemolysin genes , , , and found in 47 (52.2%), 13 (14.4%), 22 (24.4%), and 12 (13.3%) of the isolates, respectively. The majority of the isolates (≥ 90%) were susceptible to aztreonam, imipenem, cefepime, chloramphenicol, gentamicin, tetracycline, and ciprofloxacin. However, several resistance genes were detected in the isolates, as well as a new variant.@*Conclusions@#Sequence type, virulence properties, and antibiotic resistance vary in isolates from clinical patients, tap water systems, and food.


Subject(s)
Aeromonas , Genetics , Virulence , Anti-Bacterial Agents , Pharmacology , China , Drinking Water , Microbiology , Drug Resistance, Bacterial , Food Microbiology , Genetic Variation , Gram-Negative Bacterial Infections , Microbiology , Species Specificity , Virulence
14.
Article in English | WPRIM | ID: wpr-828967

ABSTRACT

2019-nCoV epidemic was firstly reported at late December of 2019 and has caused a global outbreak of COVID-19 now. Saliva, a biofluid largely generated from salivary glands in oral cavity, has been reported 2019-nCoV nucleic acid positive. Besides lungs, salivary glands and tongue are possibly another hosts of 2019-nCoV due to expression of ACE2. Close contact or short-range transmission of infectious saliva droplets is a primary mode for 2019-nCoV to disseminate as claimed by WHO, while long-distance saliva aerosol transmission is highly environment dependent within indoor space with aerosol-generating procedures such as dental practice. So far, no direct evidence has been found that 2019-nCoV is vital in air flow for long time. Therefore, to prevent formation of infectious saliva droplets, to thoroughly disinfect indoor air and to block acquisition of saliva droplets could slow down 2019-nCoV dissemination. This review summarizes diagnostic value of saliva for 2019-nCoV, possibly direct invasion into oral tissues, and close contact transmission of 2019-nCoV by saliva droplets, expecting to contribute to 2019-nCoV epidemic control.


Subject(s)
Betacoronavirus , Virulence , Clinical Laboratory Techniques , Coronavirus Infections , Diagnosis , Humans , Mouth , Virology , Pandemics , Peptidyl-Dipeptidase A , Metabolism , Pharynx , Virology , Pneumonia, Viral , Diagnosis , SARS Virus , Virulence , Saliva , Virology
15.
Chinese Journal of Biotechnology ; (12): 571-592, 2020.
Article in Chinese | WPRIM | ID: wpr-827010

ABSTRACT

The ongoing outbreak of the coronavirus disease 2019 (COVID-19) as named by the World Health Organization has millions of confirmed cases around the world and has claimed hundreds of thousands of lives. The virus was named SARS-CoV-2 in February by International Committee on Taxonomy of Viruses. COVID-19 presents as fever, dry cough, dyspnea, headache and pneumonia. In a small subset of severe cases, the disease quickly progresses to respiratory failure and even death. Since the 21st century, there have been three major outbreaks caused by human coronaviruses, including the severe acute respiratory syndrome (SARS) that broke out in 2003, the Middle East respiratory syndrome (MERS) in 2012, and the recent pandemic of COVID-19. Since 2003, significant progress has been made in the study of SARS-CoV and MERS-CoV concerning their natural origins, pathogenesis, antiviral development and vaccine design. Since SARS-CoV-2 and SARS-CoV are closely related, previous findings on SARS-CoV are highly relevant to a better understanding as well as diagnosis, treatment, prevention and control of SARS-CoV-2. In this review, we highlight recent progresses in the field; compare the biological characteristics of SARS-CoV and SARS-CoV-2; summarize the urgently-needed diagnostic, treatment, prevention and control options; and provide future perspectives for the outcome of the outbreak and research questions to be answered, including some of the difficulties in vaccine development. Hopefully, our comments and suggestions would prove useful for the control of the SARS-CoV-2 epidemic in China and the world.


Subject(s)
Antiviral Agents , Pharmacology , Therapeutic Uses , Betacoronavirus , Allergy and Immunology , Virulence , Coronavirus Infections , Diagnosis , Therapeutics , Virology , Humans , Middle East Respiratory Syndrome Coronavirus , Allergy and Immunology , Virulence , Pandemics , Pneumonia, Viral , Diagnosis , Therapeutics , Virology , SARS Virus , Allergy and Immunology , Virulence , Severe Acute Respiratory Syndrome , Diagnosis , Therapeutics , Virology , Viral Vaccines
17.
Mem. Inst. Oswaldo Cruz ; 115: e200370, 2020. tab, graf
Article in English | LILACS, SES-SP | ID: biblio-1135225

ABSTRACT

BACKGROUND Bacillus anthracis is the aetiologic agent of anthrax, a re-emerging, septicaemic, haemorrhagic and lethal disease that affects humans, domestic ruminants and wildlife. Plasmids pXO1 and pXO2 are attributes that confer pathogenicity to B. anthracis strains. This bacterium was used as biological weapon in the World Wars and in the biological attack in the United States of America at 2001. B. anthracis is classified as a Tier 1 bioterrorism agent by the Centers for Diseases Control and Prevention. Anthrax is recognised as a re-emerging disease. Several studies concerning the dynamics of B. anthracis cycle in soil revealed that nonpathogenic B. anthracis strains due to lack of pXO2 plasmid are commonly found in some types of soil. OBJECTIVES This study aimed isolation and identification of B. anthracis spores in soil samples of the state of Rio de Janeiro, Brazil. METHODS Phenotypic and genotypic approaches were used to identify isolates including MALDI-TOF/MS, motility test, susceptibility to gamma phage and penicillin, survey for pag and cap genes as surrogates of pXO1 and pXO2 plasmids, respectively, and sequencing of 16SrRNA-encoding gene. Physicochemical analysis of the soil samples were carried out to describe soil characteristics. FINDINGS We observed the presence of one B. anthracis pXO1+ and pXO2- isolated from clay loam soil; one B. anthracis-like strain pXO1+ and pXO2-isolated from loamy sand; and 10 Bacillus spp. strains sensitive to phage-gamma that need better characterisation to define which their species were recovered from loamy sand. MAIN CONCLUSIONS This work showed promising results and it was the first study to report results from an active surveillance for B. anthracis in Brazil.


Subject(s)
Humans , Plasmids/analysis , Soil Microbiology , Spores, Bacterial , Bacillus anthracis/isolation & purification , DNA, Bacterial/genetics , Polymerase Chain Reaction/methods , Virulence Factors/genetics , Plasmids/genetics , Soil , Bacillus anthracis/genetics , Bacillus anthracis/pathogenicity , Bacterial Toxins , Virulence , Brazil , DNA, Bacterial/analysis , Sequence Analysis, DNA , Antigens, Bacterial
18.
Mem. Inst. Oswaldo Cruz ; 115: e200401, 2020. graf
Article in English | LILACS, SES-SP | ID: biblio-1135257

ABSTRACT

BACKGROUND Candida glabrata yeast is the second cause of candidiasis worldwide. Differs from other yeasts since assimilates only glucose and trehalose (a characteristic used in rapid identification tests for this pathogen) by secreting into the medium a highly active acid trehalase encoded by the CgATH1 gene. OBJECTIVE This study aimed to characterise the function of the acid trehalase in the physiopathology of C. glabrata. METHODS Gene deletion was performed to obtain a mutant ath1Δ strain, and the ability of the ath1Δ strain to grow in trehalase, or the presence of trehalase activity in the ath1Δ yeast cells, was verified. We also tested the virulence of the ath1Δ strain in a murine model of infection. FINDINGS The ath1Δ mutant strain grows normally in the presence of glucose, but loses its ability to grow in trehalose. Due to the high acid trehalase activity present in wild-type cells, the cytoplasmic neutral trehalase activity is only detected in the ath1Δ strain. We also observed a significantly lower virulence of the ath1Δ strain in a murine model of infection with either normal or immunocompromised mice. MAIN CONCLUSIONS The acid trehalase is involved in the hydrolysis of external trehalose by C. glabrata, and the enzyme also plays a major virulence role during infectivity.


Subject(s)
Animals , Mice , Trehalase/metabolism , Virulence/genetics , Candida glabrata/genetics , Trehalase/physiology , Trehalase/genetics , Trehalose/analysis , Virulence/physiology , Candidiasis , Gene Deletion , Candida glabrata/physiology , Candida glabrata/metabolism , Candida glabrata/pathogenicity , Genes, Fungal , Hydrolases
19.
Rev. Soc. Bras. Med. Trop ; 53: e20200399, 2020. tab, graf
Article in English | LILACS, ColecionaSUS, SES-SP | ID: biblio-1136908

ABSTRACT

Abstract INTRODUCTION: Pseudomonas aeruginosa is an opportunistic pathogen associated with healthcare-related infections, affecting mainly patients with underlying diseases and immunosuppression. This microorganism has several virulence mechanisms that favour its pathogenesis, including the production of biofilm. This study aimed to analyze the phenotypic production of biofilms, the occurrence of quorum sensing (QS) genes, and the clonal profile of clinical isolates of P. aeruginosa from colonized/infected patients in a tertiary hospital in Recife-PE. METHODS: We obtained 21 isolates that were classified as infection isolates (II), and 10 colonization isolates (CI). The phenotypic analysis for biofilm production was performed quantitatively. The QS genes were detected by specific PCRs, and the clonal profile was assessed using ERIC-PCR. RESULTS: Of the 31 isolates, 58.1 % (18/31) were biofilm producers, of which 70 % (7/10) were CI and classified as weakly adherent; 52.4 % (11/21) of the II produced biofilms, and were classified as weak (38.1 %, (8/21)), moderate (9.5 %, (2/21)), and strongly adherent (4.8 %, (1/21)). All isolates harbored the QS genes analyzed. In the clonal analysis, 26 distinct genetic profiles were identified, highlighting the presence of a clone in four samples, i.e., one infection isolate, and 3 colonization isolates. CONCLUSIONS: The detection of biofilm formation is important in P. aeruginosa in addition to the identification of colonization and infection isolates, especially from complex environments such as ICUs. Further, we define a strategy for monitoring and analyzing P. aeruginosa strains that can potentially cause infections in hospitalized patients.


Subject(s)
Humans , Pseudomonas aeruginosa/genetics , Pseudomonas Infections , Phenotype , Virulence/genetics , Biofilms , Virulence Factors , Quorum Sensing/drug effects , Genotype , Anti-Bacterial Agents/pharmacology
20.
Rev. patol. trop ; 49(2): 94-104, 2020. tab, ilus
Article in English | LILACS | ID: biblio-1118277

ABSTRACT

Vibrio parahaemolyticus is a potentially pathogenic bacterium that occurs naturally in estuarine environments worldwide. This research aimed to investigate the occurrence of V. parahaemolyticus in estuarine environments and determine the virulence profile in an aquaculture environment by molecular techniques and conventional microbiological methods. Sampling was conducted in four estuaries in the State of Ceará (Pacoti, Choró, Pirangi and Jaguaribe), Brazil, between January and April 2009. The analysis included 64 samples of water (n=32) and sediment (n=32) collected from the estuaries. The samples yielded 64 isolates suspected to be V. parahaemolyticus. The isolates were submitted to biochemical identification using a dichotomous key and PCR for the detection of the species-specific tlh gene. Virulence was assessed by testing for urea hydrolysis and ß-hemolysis in erythrocytes (Kanagawa phenomenon) and simultaneous detection of the tdh and trh genes. All but one of the isolates (63/64) were confirmed to be V. parahaemolyticus by genotypic detection of tlh gene. The tdhand trh genes were detected in 57 and 19 isolates, respectively. The Kanagawa test was positive for 51 isolates. Only one isolate was positive for urease. The incidence of tdh/trh-positivity was very high in isolates recovered from the environment. The present study demonstrates the need to increase knowledge of the ecology and pathogeny of V. parahaemolyticus


Subject(s)
Vibrio parahaemolyticus , Virulence
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