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1.
Article in Portuguese | LILACS | ID: biblio-1354573

ABSTRACT

Introdução: Os gliomas representam 80% dos tumores do sistema nervoso central. A Organização Mundial da Saúde (OMS) adicionou, em 2016, critérios moleculares na classificação dos gliomas. A fisiopatologia e os fatores de risco desses tumores ainda não são totalmente conhecidos. Objetivo: Realizar uma análise retrospectiva dos laudos anatomopatológicos e imuno-histoquímicos de gliomas. Método: Estudo transversal, retrospectivo e descritivo, a partir de exames anatomopatológicos e imuno-histoquímicos realizados entre janeiro de 2014 e dezembro de 2018 em um laboratório de anatomia patológica na cidade de Maringá-PR. Dos 234 laudos relacionados com o termo glioma, 204 foram selecionados para este estudo. Resultados: Foram encontrados tumores astrocitários, ependimários e oligodendrogliais, sendo que os astrocitomas corresponderam à maioria (86,8% dos casos encontrados). A média de idade ao diagnóstico foi de 51,8 anos e houve maior prevalência desses tumores no sexo masculino. Também foram analisadas mutações detectáveis por imuno-histoquímica como p53 (mutada em 66,7% dos testados), isocitrato desidrogenase (IDH) (28,6% mutados), X-linked alpha-thalassemia mental retardation (ATRX) (21,0%) e marcadores diagnósticos como o epithelial membrane antigen (EMA) positivo em todos os ependimomas analisados. Conclusão: É inegável a necessidade de novas pesquisas sobre os gliomas tanto no campo epidemiológico, tendo em vista a nova classificação, quanto no escopo fisiopatológico e clínico, com o objetivo de melhorar o entendimento sobre a patologia e o tratamento dos pacientes


Introduction: Gliomas represent 80% of the central nervous system tumors. World Health Organization (WHO) has added, in 2016, molecular features to the classification of gliomas. The pathophysiology and risk factors of these tumors are not yet fully understood. Objective: Perform a retrospective analysis of immunohistochemical and anatomopathological reports of gliomas. Method: Cross-sectional, retrospective and descriptive study carried out from anatomopathological and immunohistochemical exams made between January 2014 and December 2018 in a pathological anatomy laboratory in the city of Maringá-PR. Of the 234 reports related to the term glioma, 204 were selected for this study. Results: Astrocytic, ependymal and oligodendroglial tumors were found, with astrocytomas accounting for the majority (86.8% of the cases found). Mean age at diagnosis was 51.8 years and the prevalence was higher in men. Furthermore, immunohistochemically detectable mutations were analyzed, such as p53 (mutated in 66.7% of those tested), isocitrate dehydrogenase (IDH) (28.6% mutated), X-linked alpha-thalassemia mental retardation (ATRX) (21.0%) and diagnostic markers such as positive epithelial membrane antigen (EMA) in all analyzed ependymomas. Conclusion: The necessity of further researches on gliomas is undeniable , both epidemiologically considering the new classification and within the clinical and pathophysiological scope in order to improve the understanding of the pathology and the treatment for the patients


Introducción: Los gliomas representan 80% de los tumores del sistema nervioso central. La Organización Mundial de la Salud (OMS) agregó, en 2016, criterios moleculares sobre como clasificar los gliomas. La fisiopatología y los factores de riesgo de estos tumores aún no se comprenden completamente. Objetivo: Realizar un análisis retrospectivo de informes inmunohistoquímicos y anatomopatológicos de gliomas. Método: Estudio transversal, retrospectivo y descriptivo con base em pruebas anatomopatológicas e inmunohistoquímicas realizadas entre enero de 2014 y diciembre de 2018 en un laboratorio de anatomía patológica de la ciudad de Maringá-PR. De los 234 informes relacionados con el término glioma, se seleccionaron 204 para este estudio. Resultados: Se encontraron tumores astrocíticos, ependimarios y oligodendrogliales, siendo los astrocitomas la mayoría (86,8% de los casos encontrados). La edad media al diagnóstico fue de 51,8 años y hubo una mayor prevalencia de estos tumores en el sexo masculino. También se analizaron mutaciones detectables inmunohistoquímicamente, como p53 (mutado en 66,7% de los analizados), isocitrato desidrogenase(IDH) (28,6% mutado), X-linked alpha-thalassemia mental retardation (ATRX) (21,0%) y marcadores de diagnóstico como epithelial membrane antigen (EMA) positivo en todos los ependimomas analizados. Conclusión: Es innegable la necesidad de profundizaren las investigaciones sobre los gliomas, tanto en el campo epidemiológico, ante la nueva clasificación, como en el ámbito fisiopatológico y clínico, con el objetivo de mejorar el conocimiento sobre la patología y el tratamiento de los pacientes


Subject(s)
Humans , Male , Female , Astrocytoma , Immunohistochemistry , Molecular Epidemiology , Glioblastoma , Glioma , Glioma/classification , Glioma/immunology
2.
Mem. Inst. Oswaldo Cruz ; 116: e200517, 2021. tab, graf
Article in English | LILACS | ID: biblio-1154877

ABSTRACT

Molecular-typing can help in unraveling epidemiological scenarios and improvement for disease control strategies. A literature review of Mycobacterium tuberculosis transmission in Brazil through genotyping on 56 studies published from 1996-2019 was performed. The clustering rate for mycobacterial interspersed repetitive units - variable tandem repeats (MIRU-VNTR) of 1,613 isolates were: 73%, 33% and 28% based on 12, 15 and 24-loci, respectively; while for RFLP-IS6110 were: 84% among prison population in Rio de Janeiro, 69% among multidrug-resistant isolates in Rio Grande do Sul, and 56.2% in general population in São Paulo. These findings could improve tuberculosis (TB) surveillance and set up a solid basis to build a database of Mycobacterium genomes.


Subject(s)
Humans , Polymorphism, Restriction Fragment Length/genetics , Minisatellite Repeats/genetics , Mycobacterium tuberculosis/genetics , Brazil/epidemiology , Bacterial Typing Techniques , Molecular Epidemiology , Whole Genome Sequencing , Genotype , Mycobacterium tuberculosis/isolation & purification
3.
Braz. j. biol ; 81(2): 351-360, 2021. tab, ilus
Article in English | MEDLINE, LILACS, VETINDEX | ID: biblio-1153372

ABSTRACT

Lower respiratory tract infections (LRTIs) caused by Pseudomonas aeruginosa are the most common infection among hospitalized patients, associated with increased levels of morbidity, mortality and attributable health care costs. Increased resistant Pseudomonas worldwide has been quite meaningful to patients, especially in intensive care unit (ICUs). Different species of Pseudomonas exhibit different genetic profile and varied drug resistance. The present study determines the molecular epidemiology through DNA fingerprinting method and drug resistance of P. aeruginosa isolated from patients with LTRIs admitted in ICU. A total of 79 P. aeruginosa isolated from patients with LRTIs admitted in ICU were characterized by Restriction Fragment Length Polymorphism (RFLP), Random Amplified Polymorphic DNA (RAPD) and Repetitive Extrapalindromic PCR (REP-PCR). Antibiotic resistance was determined by minimum inhibitory concentration (MIC) assay while MDR genes, viz, blaTEM, blaOXA, blaVIM, blaCTX-M-15 were detected by polymerase chain reaction (PCR). Of the 137 Pseudomonas sp isolated from ICU patients, 57.7% of the isolates were reported to be P. aeruginosa. The overall prevalence of P. aeruginosa among the all included patients was 34.5%. The RAPD analysis yielded 45 different patterns with 72 clusters with 57% to 100% similarity level. The RFLP analysis yielded 8 different patterns with 14 clusters with 76% to 100% similarity level. The REP PCR analysis yielded 37 different patterns with 65 clusters with 56% to 100% similarity level. There was no correlation among the different DNA patterns observed between the three different methods. Predominant of the isolates (46.8%) were resistant to amikacin. Of the 79 isolates, 60.8% were positive for blaTEM gene and 39.2% were positive for blaOXA gene. P. aeruginosa was predominantly isolated from patients with LRTIs admitted in ICU. The difference in the similarity level observed between the three DNA fingerprinting methods indicates that there is high inter-strain variability. The high genetic variability and resistance patterns indicates that we should continuously monitor the trend in the prevalence and antibiotic resistance of P. aeruginosa especially in patients with LRTIs admitted in ICU.


Infecções do trato respiratório inferior (ITRIs) são as infecções mais comuns entre pacientes internados em unidade de terapia intensiva (UTI). Pseudomonas aeruginosa é a causa mais comum de ITRIs e está associada ao aumento da mortalidade. Diferentes espécies de Pseudomonas exibem diferentes perfis genéticos e resistência variada as drogas. O presente estudo determina a epidemiologia molecular através do método de fingerprinting de DNA e resistência as drogas de P. aeruginosa isoladas de pacientes com LTRIs internados em UTI. Um total de 79 P. aeruginosa isoladas de pacientes com ITRIs internados em UTI foram caracterizados por Polimorfismo de Comprimento de Fragmentos de Restrição (RFLP), DNA Polimórfico Amplificado ao Acaso (RAPD) e PCR Extrapalindrômico Repetitivo (REP-PCR). A resistência aos antibióticos foram determinadas pelos ensaios de concentrações inibitória mínima (MIC), enquanto os genes MDR, blaTEM, blaOXA, blaVIM, blaCTX-M-15 foram detectados pela reação em cadeia da polimerase (PCR). Das 137 Pseudomonas sp isoladas de pacientes de UTI, 57,7% dos isolados foram relatados como P. aeruginosa. A prevalência geral de P. aeruginosa entre os pacientes incluídos foram de 34,5%. A análise RAPD renderam 45 padrões diferentes com 72 clusters com nível de similaridade de 57% a 100%. A análise RFLP renderam 8 padrões diferentes com 14 clusters com 76% a 100% de similaridade. A análise de PCR do REP produziram 37 padrões diferentes com 65 clusters com nível de similaridade de 56% a 100%. Não houveram correlações entre os diferentes padrões de DNA observados entre os três diferentes métodos. Predominantes dos isolados (46,8%) eram resistentes à amicacina. Dos 79 isolados, 60,8% foram positivos para o gene blaTEM e 39,2% foram positivos para o gene blaOXA. P. aeruginosa foi predominantemente isolado de pacientes com ITRIs internados em UTI. A diferença no nível de similaridade observado entre os três métodos de fingerprinting do DNA indica que há alta variabilidade inter-strain. A alta variabilidade genética e os padrões de resistência indicam que devemos monitorar continuamente a tendência na prevalência e resistência a antibióticos de P. aeruginosa, especialmente em pacientes com ITRIs internados em UTI.


Subject(s)
Humans , Pseudomonas aeruginosa/genetics , Pseudomonas Infections/epidemiology , Respiratory System/microbiology , Microbial Sensitivity Tests , Molecular Epidemiology , Random Amplified Polymorphic DNA Technique , Intensive Care Units
4.
Rev. Soc. Bras. Med. Trop ; 54: e20200087, 2021. tab, graf
Article in English | ColecionaSUS, LILACS, ColecionaSUS, SES-SP | ID: biblio-1136920

ABSTRACT

Abstract INTRODUCTION: In this study, we report a clonal dissemination of carbapenem resistant Acinetobacter baumannii isolates due to the acquisition of blaOXA-23 in a regional hospital located in Brazilian Amazon Region. METHODS: The isolates were identified by MALDI-TOF and the carbapenemase-encoding genes were detected by multiplex-PCR. The genetic similarity was investigated by pulsed-field gel electrophoresis (PFGE). RESULTS: Only 10 (55.6%) isolates harbored the gene bla OXA-23. PFGE analysis revealed that these isolates belong to a single clone. CONCLUSIONS: This dissemination strategy indicates the need for surveillance, adoption of control procedures defined in guidelines, and the careful administration of antimicrobials should be reinforced.


Subject(s)
Humans , Acinetobacter Infections/epidemiology , Acinetobacter baumannii/genetics , Bacterial Proteins/genetics , beta-Lactamases/genetics , Brazil/epidemiology , Drug Resistance , Microbial Sensitivity Tests , Electrophoresis, Gel, Pulsed-Field , Molecular Epidemiology , Hospitals , Anti-Bacterial Agents/pharmacology
5.
Rev. argent. coloproctología ; 31(2): 51-53, jun. 2020.
Article in English, Spanish | LILACS | ID: biblio-1117007

ABSTRACT

Los contenidos de este capítulo se basan en la 3a edición de las Clínicas Quirúrgicas de Cáncer Colorrectal. C. Vaccaro y N. Peralta. del hospital ediciones 2020 (en prensa)


Subject(s)
Colorectal Neoplasms/genetics , Biomarkers, Tumor/genetics , Precision Medicine/trends , Pharmacogenetics/trends , Colorectal Neoplasms/etiology , Colorectal Neoplasms/therapy , Molecular Epidemiology/trends , Mutation , Neoplasm Metastasis/genetics , Neoplasm Metastasis/therapy
6.
Rio de Janeiro; s.n; 2020. xx, 12 p. ilus.
Thesis in Portuguese | LILACS | ID: biblio-1128790

ABSTRACT

Ao longo dos anos vem se observando um declínio do número de casos de infecção pelo vírus da hepatite A (HAV) em crianças, relacionado ao investimento nos programas de vacinação e a melhorias sanitárias. Porém, nota se a mudança desse perfil de infecção, onde indivíduos jovens/adultos vêm sendo mais acometidos. Apesar do vírus ser transmitido principalmente pelo consumo de água e alimentos contaminados, diversos surtos têm ocorrido ao redor do mundo em adultos e sendo relacionados a práticas sexuais. Em nosso país, um aumento no número de casos nos últimos três anos foi observado após um período de declínio de notificações. Assim, este estudo teve como objetivo avaliar os comportamentos de risco e os aspectos moleculares associados à transmissão do HAV em indivíduos atendidos no Ambulatório de Hepatites Virais do Instituto Oswaldo Cruz/FIOCRUZ, Rio de Janeiro, entre os anos de 2017 e 2019. Para tal, foram coletadas amostras de soro e informações socioepidemiológicas de 52 pacientes com anti-HAV IgM reagente, que chegaram ao ambulatório. Posteriormente, essas amostras tiveram o genoma viral extraído e analisado através da técnica de RTPCR. Após detecção, o RNA foi sequenciado e analisado filogeneticamente. Em seguida, foram realizadas análises filogeográficas para obter a rota de dispersão e período de introdução das estirpes virais no país. (AU)


Com a análise dos dados dos prontuários, observou-se que 78,9% (41/52) pacientes eram do sexo masculino, nas faixas etárias 20 a 29 anos (n=24/52) e de 30 a 39 anos (n=20/52) com media 32,1 anos, sendo 63,5% (n=33) dele(a)s homens/mulheres que fazem sexo com homens/mulheres (HSH/MSM), e 89,9% eram residentes na região norte da cidade do Rio de Janeiro. Observou-se uma baixa frequência de exposição a fatores hídricos, alimentares e parenterais na população estudada, sendo 42,3%, 42,3%, 34,7%, respectivamente. Já algumas práticas sexuais apresentaram elevada frequência, destacando o sexo oral (75%) e sexo anal (65,3%). Através das análises filogenéticas, foi identificado um único subgenótipo IA da população estudada. Quatro clados deste subgenótipo foram formados, dos quais, três agruparamse as sequências dos estirpes virais provenientes de surtos Europeus/Asiáticos, e um clado, formado por estirpes virais previamente circulantes no Brasil. Através da filogeografia, foi possível inferir o ano e país de introdução, além da data de origem das estirpes virais no Brasil. A estirpe VRD_521_2016 foi possivelmente introduzida entre 2016-2017 pela Espanha com provável origem em 2013, a RIVM-HAV16-090 europeia/asiática e V16-25801, possivelmente introduzida pela Alemanha, entre 20142015 e 2015-2016 respectivamente, com provável origem em 2000 e 2011. Nossos achados reforçam a necessidade de ampliação do acesso à vacina contra o HAV a grupos adultos de risco e do monitoramento da entrada de novos patógenos no Brasil. Além disso, medidas educativas são úteis para impedir a disseminação do HAV em populações-chave como os HSH. (AU)


Subject(s)
Humans , Molecular Epidemiology , Phylogeography , Hepatitis A
7.
Article in English | WPRIM | ID: wpr-820819

ABSTRACT

OBJECTIVES: We investigated the characteristics of Streptococcus mutans in the national culture collection from Korea. Twenty-nine (dental plaque, n=27; endodontic infections, n=1; blood, n=1) isolates were included in this study.METHODS: Antimicrobial susceptibilities were tested using the disk diffusion test. Multilocus sequence typing (MLST), serotyping, and collagen-binding genes were used for polymerase chain reaction (PCR) and direct sequencing. A collagen-binding (to assess the adhesion properties) assay was performed. S. mutans demonstrated high susceptibility to antimicrobial agents. Differences in collagen-binding abilities of the cnm-positive and -negative groups were compared using the Mann-Whitney U test (P<0.05).RESULTS: MLST analyses revealed 25 sequence types (STs), 17 of which (ST213-ST229) contained new alleles. The strains were classified into four serotypes with the c type encompassing 79.3% of all strains, while the e, f, and k types representing 6.9% each. Analysis of the cnm and cbm genes, which encode the two surface adhesin components of S. mutans, revealed three cnm-positive strains, each displaying greater adhesion ability than those of the cnm-negative strains.CONCLUSIONS: This study highlights the presence of a wide variety of S. mutans genotypes in Korea. These findings may provide useful information regarding the pathogenesis of infectious diseases, such as dental caries.


Subject(s)
Alleles , Anti-Infective Agents , Bacteremia , Communicable Diseases , Dental Caries , Diffusion , Genotype , Inflammation , Korea , Molecular Epidemiology , Multilocus Sequence Typing , Polymerase Chain Reaction , Serogroup , Serotyping , Streptococcus mutans , Streptococcus
8.
Article in English | WPRIM | ID: wpr-878347

ABSTRACT

Objective@#To develop RT-nPCR assays for amplifying partial and complete VP1 genes of human enteroviruses (HEVs) from clinical samples and to contribute to etiological surveillance of HEV-related diseases.@*Methods@#A panel of RT-nPCR assays, consisting of published combined primer pairs for VP1 genes of HEV A-C and in-house designed primers for HEV-D, was established in this study. The sensitivity of each RT-nPCR assay was evaluated with serially diluted virus stocks of five serotypes expressed as CCID @*Results@#The sensitivity of RT-nPCR assays for amplifying partial VP1 gene of HEVs was 0.1 CCID @*Conclusion@#This RT-nPCR system is capable of amplifying the partial and complete VP1 gene of HEV A-D, providing rapid, sensitive, and reliable options for molecular typing and molecular epidemiology of HEVs in clinical specimens.


Subject(s)
Capsid Proteins/genetics , Enterovirus A, Human/genetics , Enterovirus B, Human/genetics , Enterovirus C, Human/genetics , Enterovirus D, Human/genetics , Humans , Molecular Epidemiology/methods , Molecular Typing/methods , Reverse Transcriptase Polymerase Chain Reaction/methods
9.
Braz. j. infect. dis ; 23(6): 427-434, Nov.-Dec. 2019. graf
Article in English | LILACS | ID: biblio-1089313

ABSTRACT

ABSTRACT To investigate the genetic variation and molecular epidemiology characteristics of Human Respiratory Syncytial Virus (HRSV) in Guizhou Province, nasopharyngeal aspirates were collected from patients with acute respiratory infection (ARI) in Guizhou Provincial People's Hospital, from December 2017 to March 2018, and inoculated to Hep-2 cells to isolate HRSV. Cells that showed cytopathic effect (CPE) were then confirmed by indirect immunofluorescence assay and reverse transcription. The sequence of the PCR products was determined for HRSV isolates, and the genetic variation was analyzed. Out of 196 nasopharyngeal aspirate samples, HRSV were isolated in 39. The second hypervariable region at the 3' terminal of glycoprotein gene (HVR2) sequence analysis showed that subgroup A was dominant. Seventy-nine percent of the isolates belonged to subgroup A, ON1 genotype, and 21 % belonged to subgroup B, BA9 genotype, which indicates that the dominant HRSV circulating in Guizhou Province was subgroup A, genotype ON1, co-circulating with a less prevalent subgroup B, genotype BA9.


Subject(s)
Humans , Child, Preschool , Respiratory Tract Infections/virology , Respiratory Syncytial Virus, Human/isolation & purification , Respiratory Syncytial Virus, Human/genetics , Respiratory Syncytial Virus Infections/virology , Phylogeny , Respiratory Tract Infections/epidemiology , China/epidemiology , Polymerase Chain Reaction , Sequence Analysis, DNA , Respiratory Syncytial Virus Infections/epidemiology , Molecular Epidemiology , Genotype , Nasal Cavity/virology
10.
Rev. salud pública Parag ; 9(1): [P73-P80], jun. 2019.
Article in Spanish | LILACS, BDNPAR | ID: biblio-1047036

ABSTRACT

Introducción: Las hepatitis causadas por el virus de la hepatitis C (VHC) se han transformado en uno de los principales problemas de enfermedades infecciosas emergentes, responsables del 80% de las hepatitis crónicas con posible evolución a cirrosis o carcinoma hepatocelular y ocasionando un alto costo para el sistema de salud. Objetivo: Describir el perfil epidemiológico y los genotipos del VHC en pacientes que acudieron al Laboratorio Central de Salud Pública (LCSP). Materiales y métodos: Estudio descriptivo; se incluyeron 162 pacientes con infección por Hepatitis C referidos al LCSP entre el 2013 y 2018, para seguimiento y/o genotipificación. Se les realizó la amplificación del genoma mediante la técnica reacción en cadena de la polimerasa en tiempo real previa transcripción reversa (RT-PCR). A una submuestra con PCR detectable y carga viral >500 UI/ml se determinó el genotipo(n=52). Resultados: La media de edad fue de 44,2 ±15,6 años, el 52,5% eran hombres. El 8,02% presentaron carga viral alta, 32,09 % baja y 59,87 % indetectable. La distribución de genotipos fue la siguiente: 61,5 % genotipo 1 (28,1% 1a, 53,1% 1b y 18,8% genotipo 1 sin subtipificación), 15,4% genotipo 2, 15,4% genotipo 3 y 7,7% genotipo 4. Conclusiones: El presente trabajo muestra la importancia de la implementación de técnicas moleculares aplicadas a la vigilancia epidemiológica de nuestro país de manera a establecer programas de detección temprana y seguimiento adecuado de los pacientes, ya que la caracterización genotípica ayuda a determinar lasestrategias terapéuticas más adecuadas y predecir la respuesta antiviral. Se confirma que el genotipo 1 es el que circula con mayor frecuencia, con alto predominio del subtipo 1b. Palabras Clave: Biología Molecular, Hepatitis C, Genotipo, Epidemiología Molecular, Paraguay.


Introduction: Hepatitis caused by the hepatitis C virus (HCV) has become one of the main problems of emerging infectious diseases, responsible for 80% of chronic hepatitis with possible evolution to cirrhosis or hepatocellular carcinoma and causing a high cost for the health system. Objective: To describe the epidemiological profile and the genotypes of HCV in patients who attended the Central Public Health Laboratory (LCSP). Materials and methods: Descriptive study; included 162 patients with Hepatitis C infection referred to the LCSP between 2013 and 2018, for follow-up and / or genotyping. Genome amplification was performed using the polymerase chain reaction technique in real time prior to reverse transcription (RT-PCR). To a subsample with detectable PCR and viral load> 500 IU / ml, the genotype was determined (n = 52). Results: The mean age was 44.2 ± 15.6 years, 52.5% were men. The 8.02% had high viral load, 32.09% low and 59.87% undetectable. The genotype distribution was as follows: 61.5% genotype 1 (28.1% 1a, 53.1% 1b and 18.8% genotype 1 without subtyping), 15.4% genotype 2, 15.4% genotype 3 and 7.7% genotype 4. Conclusions: The present work shows the importance of the implementation of molecular techniques applied to the epidemiological surveillance of our country in order to establish programs of early detection and adequate monitoring of patients, since genotypic characterization helps to determine the most appropriate therapeutic strategies and predict the antiviral response. It is confirmed that genotype 1 is the one that circulates more frequently, with a high predominance of subtype 1b. Keywords: Molecular Biology, Hepatitis C, Genotype, Molecular Epidemiology, Paraguay.


Subject(s)
Humans , Male , Female , Paraguay/epidemiology , Hepatitis C , Molecular Biology , Molecular Epidemiology , Genotype
11.
Acta bioquím. clín. latinoam ; 53(2): 193-201, jun. 2019. ilus, tab
Article in Spanish | LILACS | ID: biblio-1019253

ABSTRACT

Escherichia coli productora de toxina Shiga (STEC) O157:H7 es el serotipo más frecuentemente identificado como agente causal de colitis hemorrágica y síndrome urémico hemolítico (SUH), aunque se han descripto más de 100 serotipos con potencial patogénico similar. El objetivo del trabajo fue describir casos de enfermedad humana asociados a la infección por STEC O121:H19, atendidos en la ciudad de Mar del Plata y establecer la relación genética de los aislamientos mediante técnicas de epidemiología molecular. Se observó un amplio espectro en la severidad clínica de los ocho casos estudiados: dos fueron asintomáticos (contactos de SUH), un paciente tuvo diarrea sanguinolenta, y cinco presentaron SUH. Uno de los pacientes con SUH falleció. Las cepas O121:H19 portadoras del genotipo stx2a/eae/ehxA fueron sensibles a los antibióticos ensayados y presentaron por electroforesis en gel de campo pulsado (Xbal-PFGE) distintos patrones de macrorrestricción, con similitud del 84,25%. El patrón AREXKX01.0072, detectado en un SUH y en su contacto, es nuevo en la Base de Datos Nacional de STEC no-O157 de la Argentina. La utilización de métodos estandarizados de detección y tipificación de STEC permite a los laboratorios de referencia monitorear la frecuencia temporal y la distribución geográfica de las cepas circulantes para la prevención y control de estos patógenos asociados a enfermedad humana.


Shiga toxin-producing Escherichia coli (STEC) O157:H7 is the most frequent serotype identified as causative agent of sporadic cases and outbreaks of diarrhea with or without blood, hemorrhagic colitis and hemolytic uremic syndrome (HUS), although more than 100 serotypes have been described of similar pathogenic potential. The aim of the study was to describe cases of human disease associated with STEC O121:H19 infections, assisted in Mar del Plata City, and to establish the genetic relationship of the isolates by molecular epidemiology techniques. A wide spectrum was observed in the clinical severity of the eight cases studied: two were asymptomatic (contacts of HUS), one patient had bloody diarrhea, and five cases presented HUS. One HUS case died. All STEC O121:H19 strains carried the stx2a/eae/ehxA genotype, were sensitive to all antibiotics tested and showed different macrorestriction patterns by pulsed-field gel electrophoresis (Xbal-PFGE), with 84.25% similarity. The pattern AREXKX01.0072, detected in a HUS case and in his contact, is new in the Argentine National Database of non-O157 STEC. The use of standardized methods for detection and typing of STEC allows reference laboratories to monitor the temporal frequency and geographical distribution of circulating strains for the prevention and control of these pathogens associated with human diseases.


Escherichia coli produtora de toxina Shiga (STEC) O157:H7 é o sorotipo mais frequentemente identificado como o agente causador de colite hemorrágica e síndrome hemolítica urêmica (SHU), embora tenham sido descritas mais de 100 sorotipos com potencial patogênico semelhantes. O objectivo foi o de descrever os casos de doença humana associadas com a infecção por STEC O121:H19, assistido, na cidade de Mar del Plata e estabelecer relação genética de isolados utilizando epidemiologia molecular. Um amplo espectro foi observado na severidade clínica dos oito casos estudados, dois eram assintomáticos (contacto SHU), uma paciente teve diarreia com sangue, e cinco tiveram SHU. Um caso de SHU faleceu. As cepas O121:H19 portaram o genótipo stx2a/eae/ehxA, foram sensíveis aos antibióticos testados e apresentaram, por eletroforese em gel de campo pulsado (Xbal-PFGE), diferentes padrões de macrorestrição, com similaridade de 84,25%. O padrão AREXKX01.0072 detectado em SHU e em seu contato, é novo para a Base de Dados Nacional de STEC não-O157 na Argentina. O uso de métodos padrão de detecção e tipagem de STEC permite os laboratórios de referência monitorar frequência temporal e distribuição geográfica de estirpes circulantes para a prevenção e controlo destes agentes patogénicos associados com a doença humana.


Subject(s)
Shiga Toxin/analysis , Hemolytic-Uremic Syndrome , Molecular Epidemiology , Shiga Toxin/urine , Escherichia coli/virology , Hemolytic-Uremic Syndrome/ethnology , Microbiology
12.
Rev. Soc. Bras. Med. Trop ; 52: e20190095, 2019. tab, graf
Article in English | LILACS | ID: biblio-1013299

ABSTRACT

Abstract INTRODUCTION Staphylococcus aureus is a major nosocomial pathogen that is associated with high virulence and the rapid development of drug resistance. METHODS We analyzed and compared the antimicrobial resistance, virulence profiles, and molecular epidemiology of 67 S. aureus strains, including 36 methicillin-sensitive (MSSA) and 31 methicillin-resistant (MRSA) strains recovered from a public hospital located in south-eastern Brazil. RESULTS The clones circulating in this hospital presented a great diversity, and the majority of the strains were related to clones responsible for causing worldwide epidemics: these included USA100 (New York/Japan clone), USA300, and USA600. The 31 MRSA (22 SCCmecII and 9 SCCmecIV) and 36 MSSA strains exhibited low resistance against gentamicin and trimethoprim/sulfamethoxazole. No MRSA strain showed resistance to tetracycline. Virulence gene carriage was more diverse and abundant in MSSA than in MRSA. Of the evaluated adhesion-related genes, ebpS was the most prevalent in both MSSA and MRSA strains. The genes bbp and cna showed a strong association with MSSA strains. CONCLUSIONS Our findings reinforce the idea that MSSA and MRSA strains should be carefully monitored, owing to their high pathogenic potential.


Subject(s)
Humans , Staphylococcus aureus/drug effects , Staphylococcus aureus/genetics , Methicillin Resistance , Virulence Factors/genetics , Methicillin-Resistant Staphylococcus aureus/genetics , Anti-Bacterial Agents/pharmacology , Staphylococcal Infections/epidemiology , Staphylococcus aureus/isolation & purification , Staphylococcus aureus/classification , Virulence/genetics , Brazil/epidemiology , Microbial Sensitivity Tests , Molecular Epidemiology , Tertiary Care Centers , Hospitals, Public
13.
Article in English | WPRIM | ID: wpr-786532

ABSTRACT

PURPOSE: This study aimed to investigate the molecular epidemiology of a methicillin-resistant Staphylococcus aureus (MRSA) outbreak at a newborn nursery and neonatal intensive care unit (NICU).METHODS: During the outbreak, from August to September 2017, MRSA isolates collected from neonates and medical staff underwent genotyping and screened for virulence factors. Antibiotic susceptibilities were tested.RESULTS: During the study period, 41 neonates were admitted at the nursery (n=27) and NICU (n=14). Of these, 7 had MRSA infections (skin infection [n=6] and sepsis [n=1]) and 4 were colonized with MRSA. Associated medical staff (n=32) were screened; three were nasal MRSA carriers. Staphylococcal chromosomal cassette mec (SCCmec) type II, sequence type (ST) 89, spa type t375 was found to be the skin infection outbreak causing strain, with multi-drug resistance including low-level mupirocin resistance. SCCmec type IVa, ST 72, and a novel spa type designated t17879, was the cause of MRSA sepsis. Many different types of MRSA were colonized on the neonates; however, SCCmec type IVa, ST 72, spa type t664 was colonized in both neonates and a NICU nurse. All MRSA isolates from colonized infants were positive for the Panton-Valentine leukocidin (PVL) toxin gene.CONCLUSIONS: The strain causing an outbreak of skin infections had multi-drug resistance. Also, MRSA colonized in the neonates were found to carry the PVL toxin gene. Because different strains are present during an outbreak, molecular epidemiologic studies are important to identify the outbreak strain and colonized strains which aid in effective control and prevention of future MRSA outbreaks.


Subject(s)
Colon , Disease Outbreaks , Drug Resistance, Multiple , Epidemiologic Studies , Humans , Infant , Infant, Newborn , Intensive Care, Neonatal , Leukocidins , Medical Staff , Methicillin Resistance , Methicillin-Resistant Staphylococcus aureus , Molecular Epidemiology , Mupirocin , Nurseries, Infant , Sepsis , Skin , Virulence Factors
15.
Article in Chinese | WPRIM | ID: wpr-774114

ABSTRACT

OBJECTIVE@#To investigate the molecular epidemiological characteristics of norovirus (NoV) among children with acute gastroenteritis in Tianjin in 2017.@*METHODS@#A total of 758 stool specimens were collected from the children with acute gastroenteritis possibly caused by viral infection in Tianjin Children's Hospital between January and December, 2017. Quantitative real-time RT-PCR was used for primary screening of NoV, and conventional RT-PCR was used for gene amplification, sequencing and genotype identification of the VP1 region of capsid protein in positive specimens.@*RESULTS@#Among the 758 specimens, 241 (31.8%) were found to have GII NoV. Sequencing of the VP1 region of capsid protein in positive specimens showed that among the 241 specimens with GII NoV, 69 (28.6%) had GII.4 subtype, 51 (21.2%) had GII.3 subtype, 24 (10.0%) had GII.2 subtype, and 18 (7.5%) had other subtypes. There was a significant difference in NoV detection rate between different age groups (P=0.018), and the 1- <4 years group had the highest NoV detection rate (37.3%). There was also a significant difference in NoV detection rate across seasons (P<0.001), and there was a highest NoV detection rate in winter (48.1%). Twenty-seven children (3.6%) had co-infections with NoV and rotavirus.@*CONCLUSIONS@#NoV is one of the major pathogens of the children with acute gastroenteritis from Tianjin in 2017. GII genotype, especially GII.4 subtype, is the prevalent strain. NoV infection is commonly seen in children less than 4 years and reaches the peak in winter. Some children are found to have co-infections with rotavirus.


Subject(s)
Caliciviridae Infections , Child , China , Epidemiology , Feces , Gastroenteritis , Epidemiology , Genotype , Humans , Molecular Epidemiology , Norovirus , Phylogeny , RNA, Viral , Sequence Analysis, DNA
16.
Article in English | WPRIM | ID: wpr-758879

ABSTRACT

Sequence type (ST) 33 of Shiga toxin-producing Escherichia coli (STEC) strain O91:H14 has been proposed as a potential domestic clone of STEC in Korea because of its high prevalence among human patients with mild diarrhea or asymptomatic carriers. Herein, the clonal diversity of 17 STEC O91:H14 isolates of ST33 during 2003 to 2014 was analyzed by pulsed-field gel electrophoresis, including 14 isolates from human patients and 3 from retail meats. Their virulence characteristics, acid resistance, and antimicrobial susceptibility were also determined. Our results showed that all isolates were clustered mainly into three different pulsotypes and were likely low pathogenic without antimicrobial resistance.


Subject(s)
Clone Cells , Diarrhea , Electrophoresis, Gel, Pulsed-Field , Escherichia coli , Humans , Korea , Meat , Molecular Epidemiology , Prevalence , Shiga Toxin , Shiga-Toxigenic Escherichia coli , Virulence
17.
Article in English | WPRIM | ID: wpr-765674

ABSTRACT

Mendelian randomization (MR) in epidemiology is the use of genetic variants as instrumental variables (IVs) in non-experimental design to make causality of a modifiable exposure on an outcome or disease. It assesses the causal effect between risk factor and a clinical outcome. The main reason to approach MR is to avoid the problem of residual confounding. There is no association between the genotype of early pregnancy and the disease, and the genotype of an individual cannot be changed. For this reason, it results with randomly assigned case-control studies can be set by regressing the measurements. IVs in MR are used genetic variants for estimating the causality. Usually an outcome is a disease and an exposure is risk factor, intermediate phenotype which may be a biomarker. The choice of the genetic variable as IV (Z) is essential to a successful in MR analysis. MR is named ‘Mendelian deconfounding’ as it gives to estimate of the causality free from biases due to confounding (C). To estimate unbiased estimation of the causality of the exposure (X) on the clinically relevant outcome (Y), Z has the 3 core assumptions (A1-A3). A1) Z is independent of C; A2) Z is associated with X; and A3) Z is independent of Y given X and C; The purpose of this review provides an overview of the MR analysis and is to explain that using an IV is proposed as an alternative statistical method to estimate causal effect of exposure and outcome under controlling for a confounder.


Subject(s)
Bias , Case-Control Studies , Epidemiology , Genotype , Mendelian Randomization Analysis , Methods , Molecular Epidemiology , Phenotype , Pregnancy , Random Allocation , Risk Factors
18.
Article in English | WPRIM | ID: wpr-761770

ABSTRACT

Cryptosporidium parvum and Giardia duodenalis are the main diarrhea-causing parasitic pathogens; however, their prevalence in Korea is unknown. Here, we conducted a survey to determine the prevalence and genotype distribution of these 2 pathogens causing acute diarrhea in 8,571 patients hospitalized in 17 Regional Institute of Health Environment sites in Korea, during 2013–2016. C. parvum and G. duodenalis were detected and genotyped by nested PCR, and the isolate were molecularly characterized by sequencing the glycoprotein 60 (Gp60) and β-giardin genes, respectively. The overall prevalence of C. parvum and G. duodenalis was 0.37% (n=32) and 0.55% (n=47), respectively, and both pathogens were more prevalent in children under 9 years old. Molecular epidemiological analysis showed that the C. parvum isolates belonged to the IIa family and were subtyped as IIaA13G2R1, IIaA14G2R1, IIaA15G2R1, and IIaA18G3R1. Analysis of the β-giardin gene fragment from G. duodenalis showed that all positive strains belong to assemblage A. This is the first report on the molecular epidemiology and subtyping of C. parvum and G. duodenalis in such a large number of diarrheal patients in Korea. These results highlight the need for continuous monitoring of these zoonotic pathogens and provide a basis for implementing control and prevention strategies. Further, the results might be useful for epidemiological investigation of the source of outbreak.


Subject(s)
Child , Cryptosporidium parvum , Cryptosporidium , Diarrhea , Genotype , Giardia lamblia , Giardia , Glycoproteins , Humans , Korea , Molecular Epidemiology , Polymerase Chain Reaction , Prevalence
19.
Article in English | WPRIM | ID: wpr-719650

ABSTRACT

BACKGROUND: Enterococcus faecalis strains with low-level resistance to linezolid (an oxazolidinone antibiotic) have become common. No large-scale study has examined the underlying mechanisms in linezolid-resistant E. faecalis (LRE) strains. We investigated these mechanisms and molecular characteristics in Chongqing, China. METHODS: A total of 1,120 non-duplicated E. faecalis strains collected from August 2014 to June 2017 underwent drug susceptibility testing. LRE strains were screened for optrA, cfr, and mutations in the 23S rRNA and ribosomal proteins L3 and L4 by PCR amplification and sequencing. Multi-locus sequence typing (MLST) and pulsed-field gel electrophoresis (PFGE) were used for epidemiological analysis. RESULTS: All 43 low-level LRE strains (minimum inhibitory concentration: 8–16 mg/L) harbored optrA; cfr and 23S rRNA mutations were not detected. Novel mutations in the ribosomal proteins L3 and L4—one deletion (Q103del) and four substitutions (S113L, T35A, I98V, and N79D)—were identified. Novel amino acid substitutions at positions E60K, G197D, and T285P of the OptrA protein were observed. MLST revealed 20 types of LRE strains; the most common type was ST16 (32.6%). PFGE showed 14 strains of ST16 with unique banding patterns. Eight novel sequence types (ST823 to ST830) and one allele (gki95) were identified for the first time in China. CONCLUSIONS: optrA plays an important role in linezolid resistance and may serve as a marker for resistance screening. Since the L3 and L4 mutations did not simultaneously occur in the same strain, they play a negligible role in linezolid resistance. Epidemiological investigation suggested that the LRE cases were sporadic.


Subject(s)
Alleles , Amino Acid Substitution , China , Electrophoresis, Gel, Pulsed-Field , Enterococcus faecalis , Enterococcus , Epidemiology , Linezolid , Mass Screening , Molecular Epidemiology , Polymerase Chain Reaction , Ribosomal Proteins
20.
Article in English | SES-SP, LILACS, SES-SP, SESSP-IALPROD, SES-SP, SESSP-IALACERVO | ID: biblio-1021836

ABSTRACT

Diarrhoeagenic Escherichia coli (DEC) is a leading cause of infectious diarrhoea worldwide. In recent years, Escherichia albertii has also been implicated as a cause of human enteric diseases. This study describes the occurrence of E. coli pathotypes and serotypes associated with enteric illness and haemolytic uremic syndrome (HUS) isolated in Brazil from 2011 to 2016. Pathotypes isolated included enteropathogenic E. coli (EPEC), enteroaggregative E. coli (EAEC), enterotoxigenic E. coli (ETEC), enteroinvasive E. coli (EIEC) and Shiga toxinproducing E. coli (STEC). PCR of stool enrichments for DEC pathotypes was employed, and E. albertii was also sought. O:H serotyping was performed on all DEC isolates. A total of 683 DEC and 10 E. albertii strains were isolated from 5047 clinical samples. The frequencies of DEC pathotypes were 52.6% (359/683) for EPEC, 32.5% for EAEC, 6.3% for ETEC, 4.4% for EIEC and 4.2% for STEC. DEC strains occurred in patients from 3 months to 96 years old, but EPEC, EAEC and STEC were most prevalent among children. Both typical and atypical isolates of EPEC and EAEC were recovered and presented great serotype heterogeneity. HUS cases were only associated with STEC serotype O157:H7. Two E. albertii isolates belonged to serogroup O113 and one had the stx2f gene. The higher prevalence of atypical EPEC in relation to EAEC in community-acquired diarrhoea in Brazil suggests a shift in the trend of DEC pathotypes circulation as previously EAEC predominated. This is the first report of E. albertii isolation from active surveillance. These results highlight the need of continuing DEC and E. albertii surveillance, as a mean to detect changes in the pattern of pathotypes and serotypes circulation and provide useful information for intervention and control strategies.


Subject(s)
Bacterial Infections , Molecular Epidemiology , Surveillance , Diarrhea
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