Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 7 de 7
Filtrar
Mais filtros











Intervalo de ano de publicação
1.
Emerg Infect Dis ; 26(6): 1164-1173, 2020 06.
Artigo em Inglês | MEDLINE | ID: mdl-32441616

RESUMO

Salmonella enterica serovar Paratyphi B variant Java sequence type 28 is prevalent in poultry and poultry meat. We investigated the evolutionary relatedness between sequence type 28 strains from Europe and Latin America using time-resolved phylogeny and principal component analysis. We sequenced isolates from Colombia, Guatemala, Costa Rica, and the Netherlands and complemented them with publicly available genomes from Europe, Africa, and the Middle East. Phylogenetic time trees and effective population sizes (Ne) showed separate clustering of strains from Latin America and Europe. The separation is estimated to have occurred during the 1980s. Ne of strains increased sharply in Europe around 1995 and in Latin America around 2005. Principal component analysis on noncore genes showed a clear distinction between strains from Europe and Latin America, whereas the plasmid gene content was similar. Regardless of the evolutionary separation, similar features of resistance to ß-lactams and quinolones/fluoroquinolones indicated parallel evolution of antimicrobial resistance in both regions.


Assuntos
Salmonella enterica , Salmonella paratyphi B , África , Animais , Antibacterianos/farmacologia , Colômbia , Costa Rica , Farmacorresistência Bacteriana , Farmacorresistência Bacteriana Múltipla , Europa (Continente)/epidemiologia , Guatemala , Indonésia , América Latina/epidemiologia , Oriente Médio , Países Baixos , Filogenia , Aves Domésticas , Salmonella enterica/genética , Salmonella paratyphi B/genética
2.
Vet Microbiol ; 243: 108629, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32273008

RESUMO

INTRODUCTION: The prevalence of Extended-Spectrum Beta-Lactamase (ESBL)-producing Enterobacteriaceae is increasing worldwide and the Agri-Food sector acts as a reservoir of clinically relevant ESBL genes. Our study aimed at detecting and characterizing ESBL-producing Enterobacteriaceae responsible for intestinal colonization of Brazilian bovines. MATERIAL AND METHODS: ESBL-producing E. coli isolates were recovered from fecal samples of healthy cattle in Northwest Brazil. Antimicrobial susceptibility was determined by disk diffusion. Resistance and virulence genes were identified by PCR and amplicons were sequenced, clonality was assessed by PFGE and MLST, and plasmids were characterized by replicon typing, S1-PFGE and Southern blot hybridizations. Transferability of ESBL genes was assessed by conjugation assay. RESULTS: A total of 40 ESBL-producing E. coli were characterized, which originated from 34/191 animals (17.8 %) and 15/22 farms (68.2 %). The blaCTX-M-8 gene was the most frequent ESBL gene (62.5 %), followed by blaSHV-2a (20.0 %), blaCTX-M-2 (10.0 %), and blaCTX-M-15 (7.5 %). The blaCTX-M-8 gene was localized on the IncI1/pST113 plasmid in multiple E. coli sequence types across unrelated animals and farms. DISCUSSION: We report the first characterization and a high prevalence of ESBL-producing E. coli in the beef cattle sector in Brazil, which is mainly supported by the spread of an epidemic IncI1/pST113/blaCTX-M-8 plasmid. Since Brazil is one of the biggest beef meat exporters worldwide, the spread of this ESBL plasmid across other sectors, countries and continents should be considered with attention.


Assuntos
Infecções por Escherichia coli/epidemiologia , Infecções por Escherichia coli/veterinária , Proteínas de Escherichia coli/genética , Escherichia coli/enzimologia , Escherichia coli/genética , Plasmídeos/genética , beta-Lactamases/genética , Animais , Antibacterianos/farmacologia , Brasil/epidemiologia , Bovinos/microbiologia , Doenças dos Bovinos/epidemiologia , Doenças dos Bovinos/microbiologia , Farmacorresistência Bacteriana Múltipla/genética , Escherichia coli/classificação , Fazendas/estatística & dados numéricos , Fezes/microbiologia , Testes de Sensibilidade Microbiana , Tipagem de Sequências Multilocus , Virulência/genética
3.
Microb Drug Resist ; 25(2): 271-276, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30256175

RESUMO

In this study we report the characterization of plasmid-mediated CMY-2-producing Salmonella Heidelberg recovered from food, poultry, and poultry environment in Brazil, between 2014 and 2016. The blaCMY-2 resistance gene was allocated in large (90-148 kb) IncI1 type transferable plasmids. Salmonella Heidelberg isolates were genetically related, indicating the dissemination of closely related isolates among food, poultry, and its environment. This is the first report of IncI1 replicon-types of plasmids encoding the blaCMY-2 resistance gene in Salmonella Heidelberg isolates in Brazil, the world's biggest exporter of chickens.


Assuntos
Plasmídeos/genética , Aves Domésticas/microbiologia , Salmonella/efeitos dos fármacos , Salmonella/genética , beta-Lactamases/genética , Animais , Antibacterianos/farmacologia , Brasil/epidemiologia , Conjugação Genética , Farmacorresistência Bacteriana/genética , Microbiologia de Alimentos , Testes de Sensibilidade Microbiana , Produtos Avícolas/microbiologia
4.
São Paulo; s.n; s.n; 2019. 142 p. tab, graf.
Tese em Português | LILACS | ID: biblio-1361765

RESUMO

Linhagens de Escherichia coli produtoras de ß-lactamase de espectro estendido (ESßL) do tipo CTX-M são endêmicas no Brasil, sendo prevalentes em casos de infecções hospitalares e ambulatoriais. Atualmente, cepas produtoras de CTX-M têm sido recuperadas de ambientes urbanos, animais de companhia ou de produção e de alimentos de origem animal, inclusive afetando o agronegócio, o que aponta uma possível rota de disseminação em diferentes ecossistemas. Recentemente, nesta espécie, foi descoberto um novo gene, chamado de mcr-1, que confere resistência transferível à colistina, um dos últimos antibióticos eficazes para o tratamento de infecções causadas por bactérias produtoras de ESBL e carbapenemases. Deste modo, o presente estudo tem como objetivo elucidar os aspectos sobre a caracterização e a relação de plasmídeos que carregam genes do tipo blaCTX-M-8 e mcr- 1 em cepas de E. coli isoladas de seres humanos, animais, ambiente aquático e alimentos, no Brasil. Neste estudo são apresentados os resultados da análise plasmidial de 25 cepas de E. coli, das quais nove apresentaram o genótipo blaCTX-M-8/IncI1, 11 apresentaram o genótipo mcr-1/IncX4 e cinco apresentaram ambos os genótipos blaCTX-M-8/IncI1 e mcr-1/IncX4. Dos resultados, podemos observar que plasmídeos IncI1 (blaCTX-M-8) e IncX4 (mcr-1) estão circulando no Brasil desde o ano de 2009 entre diferentes clones (STs) de E. coli e em diferentes ambientes e hospedeiros. Os plasmídeos IncI1 foram conjugativos e pertencentes ao ST113, exceto o plasmídeo recuperado de um isolado humano, que foi pertencente ao ST131. Os plasmídeos IncI1 apresentaram sua arquitetura conservada, com a presença de genes de replicação, transferência e estabilidade. A partir do alinhamento, os plasmídeos IncI1 apresentaram 94-99% de similaridade genética entre eles. Dentre os plasmídeos IncX4, independente da fonte de isolamento, todos permaneceram com sua arquitetura altamente conservada. Entretanto, apenas dois plasmídeos (um encontrado em uma cepa de animal e outro encontrado em uma cepa de ambiente aquático) apresentaram uma IS1294, truncando o gene de mobilização. Na análise comparativa, todos os plasmídeos IncX4 apresentaram similaridade genética de 95-99,9% entre eles. No alinhamento de plasmídeos IncX4 brasileiros contra plasmídeos de outras regiões geográficas, foi observada similaridade genética > 99,9%, o que confirma a estabilidade e conservação desses plasmídeos. Neste estudo foram reportados dados inéditos da primeira identificação do gene mcr-1 em diferentes ecossistemas no Brasil, assim como a nova variante mcr-5.3. A análise filogenética dos plasmídeos IncI1 e IncX4, destacam que ambos compartilham uma arquitetura conservada, e a evolução é atribuída à aquisição de genes de resistência. Adicionalmente, um novo vetor de disseminação do gene mcr-1 no Brasil foi identificado - o plasmídeo IncHI2. Os resultados desse estudo demonstram o grave problema da resistência bacteriana dentro do conceito One-health e que, com o avanço de ferramentas moleculares, a identificação e a resolução desse problema poderá estar cada vez mais próxima de ser elucidada


CTX-M-type extended-spectrum-ß-lactamase (ESßL)-producing-Escherichia coli are endemic in Brazil and are prevalent in cases of nosocomial and ambulatory infections. Currently, CTXM-producing strains have been recovered from urban environments, companion/production animals and animal source foods, which indicates a possible route of dissemination in different ecosystems. Recently, in this species, a new gene, called mcr-1, has been discovered, conferring transferable resistance to colistin, one of the last effective antibiotics for the treatment of infections caused by ESBL- and carbapenemases -producing bacteria. Thus, the present study aims to elucidate unknown aspects of the pan-resistome and ancestral relationship of plasmids carrying blaCTX-M-8 and mcr-1 genes in strains of E. coli isolated from humans, animals, aquatic environment and food, in Brazil. In this study, we present results from the plasmidial analysis of 25 E. coli strains, from which nine presented the blaCTX-M-8/IncI1 genotype, 11 presented the mcr-1/IncX4, and five presented both blaCTX-M-8/IncI1 and mcr-1/IncX4 genotypes. Among these results, we can observe that IncI1 (blaCTX-M-8) and IncX4 (mcr-1) plasmids are circulating in Brazil since 2009, between different E. coli clones (STs) and different hosts and environments. IncI1 plasmids were conjugative and assigned to ST113, with exception of a plasmid recovered from a human isolate, which was assigned to ST131. IncI1 plasmids presented conserved architecture, with the presence of genes of replication, transference, and stability. From the alignment analysis, IncI1 plasmids presented 94-99% genetic similarity among them. Among the IncX4 plasmids, regardless the isolation source, their architecture remained highly conserved. However, only two plasmids (one detected in an animal's strain and another detected in an aquatic environment's strain) presented an IS1294, truncating the mobilization gene. In the comparative analysis, all IncX4 plasmids presented 95-99,9% genetic similarity among them. In the alignment of Brazilian IncX4 plasmids against plasmids from other geographic regions, >99.9% genetic similarity was observed, confirming the stability and conservation of these plasmids. In this study, unprecedented data from the first identification of the mcr-1 gene in different ecosystems in Brazil, as well as the new variant, mcr-5.3. Additionally, it was identified a new dissemination vector of the mcr-1 gene in Brazil - the IncHI2 plasmid. Phylogenetic analysis of IncI1and IncX4 plasmids highlight that both share a conserved backbone, and evolution is attributed to the acquisition of clinically relevant antimicrobial resistance genes. The results from this study demonstrate the serious problem of the bacterial resistance within the "One-Health" concept and that, with the advance of molecular tools, identification and resolution of this problem may be increasingly closer to being elucidate


Assuntos
Plasmídeos/análise , Escherichia coli/genética , Colistina/farmacologia , Ambiente Aquático , Meio Ambiente , Alimentos/efeitos adversos , Antibacterianos/administração & dosagem
7.
Diagn Microbiol Infect Dis ; 87(1): 64-67, 2017 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-27773543

RESUMO

This study reports the high-virulence phylogenetic backgrounds of CMY-2- and CTX-M-2-producing avian pathogenic Escherichia coli strains isolated from turkeys sent to slaughter and condemned by airsacculitis in Brazil. Among 300 air sac samples, seven E. coli strains produced plasmid-mediated CMY-2-type AmpC, of which three carried also the blaCTX-M-2 Extended Spectrum Beta-Lactamase encoding gene. Interestingly, the transfer of the blaCMY-2 gene was positive for three E. coli strains, being associated with the presence of IncI1 plasmids. The complete sequence of the representative pJB10 plasmid revealed that the blaCMY-2 gene was within a transposon-like element in the classical genetic environment consisting of tnpA-blaCMY-2-blc-sugE structure. This plasmid with 94-kb belonged to the sequence type (ST) 12 among IncI1 plasmids, which has been associated with the worldwide spread of blaCMY-2 among Salmonella enterica and E. coli. Furthermore, to the best of our knowledge, this is the first complete sequence of a CMY-2-encoding plasmid derived from an Escherichia coli isolated from food-producing animals in Latin America.


Assuntos
Proteínas de Escherichia coli/análise , Escherichia coli/enzimologia , Escherichia coli/patogenicidade , Perus/microbiologia , Fatores de Virulência/análise , beta-Lactamases/análise , Matadouros , Sacos Aéreos/microbiologia , Animais , Brasil , DNA Bacteriano/química , DNA Bacteriano/genética , Escherichia coli/classificação , Escherichia coli/isolamento & purificação , Proteínas de Escherichia coli/genética , Genótipo , Plasmídeos/análise , Plasmídeos/classificação , Análise de Sequência de DNA , Virulência , Fatores de Virulência/genética , beta-Lactamases/genética
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA