Network


Latest external collaboration on country level. Dive into details by clicking on the dots.

Hotspot


Dive into the research topics where Karla Rodrigues Miranda is active.

Publication


Featured researches published by Karla Rodrigues Miranda.


Anaerobe | 2010

Detection of resistance genes and susceptibility patterns in Bacteroides and Parabacteroides strains.

Renata F. Boente; L. Ferreira; Laís S. Falcão; Karla Rodrigues Miranda; Priscilla Ls Guimarães; Joaquim dos Santos-Filho; Jéssica Manya B.D. Vieira; David E. Barroso; Jean-Philippe Emond; Eliane de Oliveira Ferreira; Geraldo R Paula; Regina Maria Cavalcanti Pilotto Domingues

Susceptibility to five antimicrobials was determined for Bacteroides spp. (n = 52) and Parabacteroides distasonis (n = 8). All isolates were susceptible to metronidazole. The resistance rates to ampicillin, cefoxitin, tetracycline and clindamycin were 98%, 9.6%, 65.3% and 19.2% of the Bacteroides strains, respectively. The genes cepA, cfiA, cfxA, tetQ, ermF and nim were found in 69.2%, 17.3% 9.6%, 50%, 7.7% and 3.8% for these strains respectively. All P. distasonis strains were resistant to ampicilin. Cefoxitin, tetracycline and clindamycin resistance rates were 75%, 87.5% and 50%, respectively. The ermF and nim genes were absent and 37.5%, 12.5%, 12.5% and 87.5% of this strains possessed cepA, cfiA, cfxA and tetQ genes, respectively. Ten cfiA gene positive strains of Bacteroides and Parabacteroides were submitted to E-test with imipenem and amoxicillin-clavulanate. The resistance rate to imipenem was 4.1% and 8.3% to amoxicillin-clavulanate. This feature is for the first time described in Brazil.


Anaerobe | 2009

Characterization of Clostridium difficile strains isolated from immunosuppressed inpatients in a hospital in Rio de Janeiro, Brazil.

Ilana Teruszkin Balassiano; Karla Rodrigues Miranda; Renata F. Boente; Heidi Pauer; Ivi Cristina Menezes de Oliveira; Joaquim dos Santos-Filho; Efigênia L.T. Amorim; Gerson A. Caniné; Cristina F. Souza; Mariza Z.R. Gomes; Eliane de Oliveira Ferreira; Jon S. Brazier; Regina Maria Cavalcanti Pilotto Domingues

The aim of this work was to identify and characterize Clostridium difficile strains from fecal and hospital environmental samples. C. difficile toxins were detected by ELISA in 28.5% of the analyzed samples. Four strains were isolated from immunosuppressed inpatients presenting antibiotic-associated diarrhea. All strains possessed tcdA and tcdB genes and did not present neither the cdtA and cdtB genes nor any significant deletions in the tcdC gene. PFGE and PCR-ribotyping analysis showed that two strains belonged to the same clonal type (ribotype 014) and the other two were grouped into ribotype 106, in spite of presenting a similar, but not identical genetic fingerprint. This report shows that for the first time ribotype 106 was found outside the United Kingdom. All isolates were equally sensitive to metronidazole. The ribotype 014 isolates were highly resistant to clindamycin, while the ribotype 106 isolates were resistant to all fluoroquinolones tested. This work reveals the spread of C. difficile in the hospital unit studied and the presence of three genetically related types, two of them presenting resistance to fluoroquinolones.


Antonie Van Leeuwenhoek International Journal of General and Molecular Microbiology | 2007

New PCR ribotypes of Clostridium difficile detected in children in Brazil

Ana P. P. Alcides; Jon S. Brazier; Leandro J. F. Pinto; Ilana Teruszkin Balassiano; Renata F. Boente; Geraldo R Paula; Eliane de Oliveira Ferreira; Kátia Eliane Santos Avelar; Karla Rodrigues Miranda; M. Candida S. Ferreira; Regina Maria Cavalcanti Pilotto Domingues

A total of 35 Brazilian isolates of Clostridium difficile from faecal stools and four isolates from hospital environments were analyzed by PCR ribotyping. A whole cell protein profile (as an alternative for serogrouping), in vitro toxin production and susceptibility to vancomycin, metronidazole and clindamycin were also investigated. All strains were typeable by both phenotypic and genotypic methods, and a total of 13 different PCR ribotypes were identified, of which seven (132, 133, 134, 135, 136, 142 and 143) were considered new types and accounted for 78.5% of all samples evaluated (including hospital environments). A non-toxigenic C. difficile PCR ribotype 133 was detected in all children groups examined (inpatients, outpatients and healthy children), whilst toxigenic PCR ribotypes 015, 131, 134 and 135 were associated mostly with symptomatic children. Serogroups G and D were disseminated both in patients from the community and from the pediatric hospital, with group G prevalent among outpatient children. All strains were susceptible to vancomycin and metronidazole but high levels of resistance to clindamycin were found, especially among serogroups G and D. Co-existence of different ribotypes and serogroups in the same individual was observed. The new seven ribotypes found in this investigation may represent strains characteristic of this region of Brazil.


Current Microbiology | 2006

Decreased Susceptibility to Nitroimidazoles Among Bacteroides Species in Brazil

Jéssica Manya B.D. Vieira; Renata F. Boente; Karla Rodrigues Miranda; Kátia Eliane Santos Avelar; Regina Maria Cavalcanti Pilotto Domingues; Maria Candida de Souza Ferreira

In this study, 197 strains of Bacteroides genus from different species and origins were evaluated with regard to their susceptibility to 5-nitroimidazoles (5-Ni)—such as tinidazole, ornidazole, and metronidazole—using the agar dilution method. The presence of nim genes was also investigated by polymerase chain reaction. It was found that 5.6% of Bacteroides strains among all origins showed decreased susceptibility (minimum inhibitory concentrations varying from 4 to 16 μg/ml) to at least one of the imidazoles studied without any known nim gene associate. Also, we detected one strain isolated from a polluted aquatic environment in which one nim gene was found and characterized as nim B using restriction fragment length polymorphism and sequencing. Hence, resistance to 5-Ni should be monitored closely because they constitute, among few drugs, the ones quite effective in treating Bacteroides infections.


Journal of Basic Microbiology | 2014

Production of AI‐2 is mediated by the S‐ribosylhomocystein lyase gene luxS in Bacteroides fragilis and Bacteroides vulgatus

Rafael José Marques Peixoto; Karla Rodrigues Miranda; Eliane de Oliveira Ferreira; Geraldo Renato de Paula; Edson R. Rocha; Leandro Araujo Lobo; Regina Maria Cavalcanti Pilotto Domingues

Quorum sensing is a cell–cell signaling mechanism based on cell density and that involves the production of hormone‐like molecules called autoinducers (AI). One of the most studied AIs has been termed AI‐2, and its biosynthesis requires the enzyme encoded by luxS. We have previously described for the first time that Bacteroides species can produce molecules with AI‐2 activity. In this study, we focus on the detection of luxS and its activity as the AI‐2 synthase in Bacteroides species. The strains Bacteroides fragilis B3b and Bacteroides vulgatus ATCC 8482 were selected based on a positive phenotype for AI‐2 production and the presence of a putative luxS in the genome, respectively. In order to identify the luxS gene, cloning and heterologous expression strategies were utilized. We demonstrate that both strains contain functional luxS orthologs that can complement AI‐2 production in Escherichia coli.


Memorias Do Instituto Oswaldo Cruz | 2008

Enterotoxigenic and nontoxigenic Bacteroides fragilis strains isolated in Brazil.

Karla Rodrigues Miranda; Mariana F Dias; Priscilla Ls Guimarães; Renata F. Boente; Heidi Pauer; Priscila Z Ramos; Laís S. Falcão; Eliane de Oliveira Ferreira; Ilana Teruszkin Balassiano; L. Ferreira; Joaquim dos Santos-Filho; Geraldo Renato de Paula; Eduardo Nf Antunes; Katia Es Avelar; Regina Mcp Domingues

The presence of enterotoxigenic Bacteroides fragilis and nontoxigenic B. fragilis (NTBF) among 109 strains isolated from 1980-2008 in Brazil were investigated by PCR. One strain, representing 0.9% of the total analyzed strains, harbored the bft gene which was identified as bft-1 isoform based on PCR-RFLP and sequencing. Forty-nine strains (44.9%) exhibited the NTBF pattern III which possesses the flanking region required for pathogenicity island acquisition in which the bft gene is codified. These data reinforce the potential of B. fragilis as an emerging enteropathogen in our country.


Anaerobe | 2013

Application of DNA sequence analysis based on five different conserved genes (16S rDNA, rpoB, gdh, est and pgm) for intra-species discrimination of Bacteroides fragilis

Karla Rodrigues Miranda; Felipe Piedade Gonçalves Neves; Joaquim dos Santos-Filho; Geraldo Renato de Paula; Leandro Araujo Lobo; Walter Martin Roland Oelemann; Regina Maria Cavalcanti Pilotto Domingues

In the past few years, many studies revealed a remarkable genetic variability in Bacteroides fragilis species, and the existence of two divisions was proposed according to presence or absence of the cfiA (metallo-β-lactamase/carbapenemase) gene. The aim of this study was to evaluate the use of DNA sequence analysis for glutamate dehydrogenase (gdh), phosphoglucomutase (pgm) and esterase (est) metabolic genes, in comparison to RNA polymerase β subunit (rpoB) and 16S ribosomal RNA (rrs) gene sequencing, to identify the presence of these two groups in seventeen B. fragilis strains. Based on phylogenetic trees, only the est gene sequences generated a classification similar to rrs- and rpoB-genes. On the other hand, the genes pgm and gdh did not allow the discrimination of these divisions. The est gene sequence can be suggested as an additional tool for differentiation of the two groups in B. fragilis, providing highly reproducible and reliable data in B. fragilis taxonomy.


International Immunology | 2018

Probiotic treatment during neonatal age provides optimal protection against experimental asthma through the modulation of microbiota and T cells

Caroline Fraga Cabral Gomes Nunes; Jeane de Souza Nogueira; Pedro Henrique Oliveira Vianna; Bianca Torres Ciambarella; Patrícia Machado Rodrigues; Karla Rodrigues Miranda; Leandro Araujo Lobo; Regina Maria Cavalcanti Pillotto Domingues; Mileane De Souza Busch; Georgia C. Atella; Andre M. Vale; Maria Bellio; Alberto Nobrega; Fábio Barrozo do Canto; Rita Fucs

The incidence of allergic diseases, which increased to epidemic proportions in developed countries over the last few decades, has been correlated with altered gut microbiota colonization. Although probiotics may play a critical role in the restoration of gut homeostasis, their efficiency in the control of allergy is controversial. Here, we aimed to investigate the effects of probiotic treatment initiated at neonatal or adult ages on the suppression of experimental ovalbumin (OVA)-induced asthma. Neonatal or adult mice were orally treated with probiotic bacteria and subjected to OVA-induced allergy. Asthma-like symptoms, microbiota composition and frequencies of the total CD4+ T lymphocytes and CD4+Foxp3+ regulatory T (Treg) cells were evaluated in both groups. Probiotic administration to neonates, but not to adults, was necessary and sufficient for the absolute prevention of experimental allergen-induced sensitization. The neonatally acquired tolerance, transferrable to probiotic-untreated adult recipients by splenic cells from tolerant donors, was associated with modulation of gut bacterial composition, augmented levels of cecum butyrate and selective accumulation of Treg cells in the airways. Our findings reveal that a cross-talk between a healthy microbiota and qualitative features inherent to neonatal T cells, especially in the Treg cell subset, might support the beneficial effect of perinatal exposure to probiotic bacteria on the development of long-term tolerance to allergens.


PLOS ONE | 2018

Impact of violacein from Chromobacterium violaceum on the mammalian gut microbiome

Heidi Pauer; C. C. P. Hardoim; Felipe Lopes Teixeira; Karla Rodrigues Miranda; Davi da Silva Barbirato; Denise P. Carvalho; Luís Antunes; Alvaro C. Leitão; Leandro Araujo Lobo; Regina Maria Cavalcanti Pilotto Domingues

Violacein is a violet pigment produced by Chromobacterium violaceum that possesses several functions such as antibacterial, antiviral, antifungal, and antioxidant activities. The search for potential compounds and therapies that may interfere with and modulate the gut microbial consortia without causing severe damage and increased resistance is important for the treatment of inflammatory, allergic, and metabolic diseases. The aim of the present work was to evaluate the ability of violacein to change microbial patterns in the mammalian gut by favoring certain groups over the others in order to be used as a therapy for diseases associated with changes in the intestinal microflora. To do this, we used male Wistar rats, and administered violacein orally, in low (50 μg/ml) and high (500 μg/ml) doses for a month. Initially, the changes in the microbial diversity were observed by DGGE analyses that showed that the violacein significantly affects the gut microbiota of the rats. Pyrosequencing of 16S rDNA was then employed using a 454 GS Titanium platform, and the results demonstrated that higher taxonomic richness was observed with the low violacein treatment group, followed by the control group and high violacein treatment group. Modulation of the microbiota at the class level was observed in the low violacein dose, where Bacilli and Clostridia (Firmicutes) were found as dominant. For the high violacein dose, Bacilli followed by Clostridia and Actinobacteria were present as the major components. Further analyses are crucial for a better understanding of how violacein affects the gut microbiome and whether this change would be beneficial to the host, providing a framework for the development of alternative treatment strategies for intestinal diseases using this compound.


Anaerobe | 2005

Bacteroides species produce Vibrio harveyi autoinducer 2-related molecules

Luis Caetano Martha Antunes; L. Ferreira; Eliane de Oliveira Ferreira; Karla Rodrigues Miranda; Kátia Eliane Santos Avelar; Regina Maria Cavalcanti Pilotto Domingues; Maria Candida de Souza Ferreira

Collaboration


Dive into the Karla Rodrigues Miranda's collaboration.

Top Co-Authors

Avatar
Top Co-Authors

Avatar

Leandro Araujo Lobo

Federal University of Rio de Janeiro

View shared research outputs
Top Co-Authors

Avatar

Eliane de Oliveira Ferreira

Federal University of Rio de Janeiro

View shared research outputs
Top Co-Authors

Avatar

Renata F. Boente

Federal University of Rio de Janeiro

View shared research outputs
Top Co-Authors

Avatar

Joaquim dos Santos-Filho

Federal University of Rio de Janeiro

View shared research outputs
Top Co-Authors

Avatar
Top Co-Authors

Avatar

Geraldo R Paula

Federal University of Rio de Janeiro

View shared research outputs
Top Co-Authors

Avatar
Top Co-Authors

Avatar

Heidi Pauer

Federal University of Rio de Janeiro

View shared research outputs
Top Co-Authors

Avatar

Kátia Eliane Santos Avelar

Federal University of Rio de Janeiro

View shared research outputs
Researchain Logo
Decentralizing Knowledge