ROBERTA CRISTINA RUEDAS MARTINS
Projetos de Pesquisa
Unidades Organizacionais
LIM/49 - Laboratório de Protozoologia, Hospital das Clínicas, Faculdade de Medicina
36 resultados
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Agora exibindo 1 - 10 de 36
- Synbiotic Supplementation Modulates Gut Microbiota, Regulates beta-Catenin Expression and Prevents Weight Gain in ob/ob Mice: Preliminary Findings(2022) DUARTE, Sebastiao Mauro B.; STEFANO, Jose Tadeu; FRANCO, Lucas A. M.; MARTINS, Roberta C.; MORAES, Bruna D. G. C.; BARBEIRO, Denise Frediani; OLIVEIRA, Nathalia; NERI, Junia Marielle Teixeira Rodrigues; COGLIATI, Bruno; VANNI, Denise Siqueira; SABINO, Ester C.; CARRILHO, Flair J.; OLIVEIRA, Claudia P.Background: Obesity is one of the main health problems in the world today, and dysbiosis seems to be one of the factors involved. The aim of this study was to examine the impact of synbiotic supplementation on obesity and the microbiota in ob/ob mice. Twenty animals were divided into four groups: obese treated (OT), obese control (OC), lean treated (LT) and lean control (LC). All animals received a standard diet for 8 weeks. The treated groups received a synbiotic (Simbioflora-Invictus Farmanutricao Ltd., Sao Paulo, Brazil) in water, while the nontreated groups received only water. After 8 weeks, all animals were sacrificed, and gut tissue and stool samples were collected for mRNA isolation and microbiota analysis, respectively. beta-Catenin, occludin, cadherin and zonulin in the gut tissue were analyzed via RT-qPCR. Microbiome DNA was extracted from stool samples and sequenced using an Ion PGM Torrent platform. Results: Synbiotic supplementation reduced body weight gain in the OT group compared with the OC group (p = 0.0398) and was associated with an increase in Enterobacteriaceae (p = 0.005) and a decrease in Cyanobacteria (p = 0.047), Clostridiaceae (p = 0.026), Turicibacterales (p = 0.005) and Coprococcus (p = 0.047). On the other hand, a significant reduction in Sutterella (p = 0.009) and Turicibacter (p = 0.005) bacteria was observed in the LT group compared to the LC group. Alpha and beta diversities were different among all treated groups. beta-Catenin gene expression was significantly decreased in the gut tissue of the OT group (p <= 0.0001) compared to the other groups. No changes were observed in occludin, cadherin or zonulin gene expression in the gut tissue. Conclusions: Synbiotic supplementation prevents excessive weight gain, modulates the gut microbiota, and reduces beta-catenin expression in ob/ob mice.
- Multidrug-resistant Stenotrophomonas maltophilia: Description of new MLST profiles and resistance and virulence genes using whole-genome sequencing(2018) RIZEK, Camila Fonseca; JONAS, Daniel; PAEZ, Jorge Isaac Garcia; ROSA, Juliana Ferraz; PERDIGAO NETO, Lauro Vieira; MARTINS, Roberta Ruedas; MORENO, Luisa Z.; ROSSI JUNIOR, Alfio; LEVIN, Anna S.; COSTA, Silvia FigueiredoObjectives: Stenotrophomonas maltophilia is an opportunistic pathogen that has high intrinsic and acquired antimicrobial resistance, with great genetic diversity. The aim of this study was to characterise four S. maltophilia clinical isolates displaying different susceptibility profiles using whole-genome sequencing. Methods: The whole genomes of four clinical isolates of S. maltophilia from three patients were sequenced using Ion Torrent (TM) PGM technology. The isolates presented different susceptibilities to trimethoprim/sulfamethoxazole (SXT) and levofloxacin. Results: Three new multilocus sequence typing (MLST) profiles were identified (ST144, ST172 and ST173), differing in virulence and resistance genes. The ST172 isolate had more genes related to toxins than related to motility or adhesion and had different types of efflux pumps than the other isolates. The SXT-resistant strains belonged to ST172 or ST144 and did not harbour the sul1, sul2 or dfrA resistance genes. Strains I and II, from the same patient and belonging to the same ST but differing in resistance to SXT, had all of the resistance genes searched for in common, except for the SmeABC efflux pump complex genes that were only found in the SXT-resistant strain. All strains, including the strain susceptible to levofloxacin, harboured the qnrB gene, which may question the importance of this gene in determining levofloxacin resistance in S. maltophilia. Conclusion: Here we describe three new MLST profiles. Resistance to SXT in these strains appears to be associated with efflux pumps.
- Bordetella trematum infection: case report and review of previous cases(2019) CASTRO, Thais Regina y; MARTINS, Roberta Cristina Ruedas; FORNO, Nara Lucia Frasson Dal; SANTANA, Luciana; ROSSI, Flavia; SCHWARZBOLD, Alexandre Vargas; COSTA, Silvia Figueiredo; TRINDADE, Priscila de ArrudaBackgroundBordetella trematum is an infrequent Gram-negative coccobacillus, with a reservoir, pathogenesis, a life cycle and a virulence level which has been poorly elucidated and understood. Related information is scarce due to the low frequency of isolates, so it is important to add data to the literature about this microorganism.Case presentationWe report a case of a 74-year-old female, who was referred to the hospital, presenting with ulcer and necrosis in both legs. Therapy with piperacillin-tazobactam was started and peripheral artery revascularization was performed. During the surgery, a tissue fragment was collected, where Bordetella trematum, Stenotrophomonas maltophilia, and Enterococcus faecalis were isolated. After surgery, the intubated patient was transferred to the intensive care unit (ICU), using vasoactive drugs through a central venous catheter. Piperacillin-tazobactam was replaced by meropenem, with vancomycin prescribed for 14days. Four days later, levofloxacin was added for 24days, aiming at the isolation of S. maltophilia from the ulcer tissue. The necrotic ulcers evolved without further complications, and the patient's clinical condition improved, leading to temporary withdrawal of vasoactive drugs and extubation. Ultimately, however, the patient's general condition worsened, and she died 58days after hospital admission.ConclusionsDespite being a rare finding, B. trematum is typically associated with the clinical manifestation of disorders that predispose to ulcer development, which can be infected by microorganisms. The combination of antibiotic therapy and surgical debridement plays a key role in preventing systemic infections. Monitoring the appearance of new cases of B. trematum is essential, since it can be an emerging microorganism. Isolating and defining the clinical relevance of unusual bacteria yields a more accurate perspective in the development of new diagnostic tools and allows for assessment of proper antimicrobial therapy.
- Ceftazidime-Avibactam as Salvage Therapy for Infections Caused by Enterobacteriales Coresistant to Carbapenems and Polymyxins(2019) GUIMARAES, Thais; NOUER, Simone A.; MARTINS, Roberta C. R.; V, Lauro Perdigao Neto; MARTINS, Willames M. B. S.; BARBOSA, Ana Clara Narciso; FERREIRA, Adriana L. P.; COSTA, Silvia F.; GALES, Ana C.In this article, we report a case series of patients with infections caused by Enterobacteriales coresistant to carbapenems and polymyxins who were treated with ceftazidime/avibactam (CAZ-AVI) salvage therapy on a compassionate-use protocol. We enrolled 29 adult patients in 3 centers that had an infection due to a resistant microorganism and for whom the treatments available were considered ineffective, treated them with CAZ-AVI, and assessed clinical and microbiological cure at the end of treatment and all-cause mortality at 14 days and 30 days. The antimicrobial susceptibility profile was determined using broth microdilution, and total genomic DNA was sequenced. Twelve (41.4%) patients had bacteremia, and 48.3% (14/29) of the infections were treated with combination therapy. All strains were producers of KPC-2 and were susceptible to CAZ-AVI (MIC90, 1 mu g/ml). Clinical success was high (24/29 [82.7%; 95% confidence interval, 64.2 to 94.2%]), even for the bacteremic cases (75%). The 14-day and 30-day mortality rates were 9/29 (31%) and 15/29 (51.7%), respectively. The 14-day mortality rate for pneumonia was the same as that for bloodstream infections (33.3%) and although not significant, we found that patients with renal impairment that received adjusted doses of CAZ-AVI had high mortality (4/9 (44%); P = 0.22). We concluded that CAZ-AVI is an option for the treatment of severe infections due to difficult-to-treat drug-resistant Enterobacteriales.
- Prevalence of Clostridioides difficile associated diarrhea in hospitalized patients in five Brazilian centers: A multicenter, prospective study(2020) GIRAO, Evelyne Santana; TAVARES, Bruno de Melo; SANTOS, Sania Alves dos; GAMARRA, Gessica Lorena; RIZEK, Camila; MARTINS, Roberta Cristina; NETO, Lauro Vieira Perdigao; DIOGO, Constancia; ORSI, Tatiana D'Annibale; ESPINOZA, Evelyn Patricia Sanchez; MORALES, Hugo Manuel Paz; NOGUEIRA, Keite da Silva; MAESTRI, Adriane Ceshin; BOSZCZOWSKI, Icaro; PIASTRELLI, Filipe; COSTA, Cecilia Leite; COSTA, Daniely Viana; MACIEL, Geovania; ROMAO, Janete; GUIMARAES, Thais; BRITO, Gerly Anne de Castro; COSTA, Silvia FigueiredoEpidemiological data on CD infection (CDI) in Latin American are scarce. CDI prevalence and strains characterization were prospectively evaluated in 5 Brazilian hospitals from different regions. Prevalence rates of CDI were 15%, ranging from 0 to 37%. ST42 was the most common Sequence Type and hyper virulent strains were not identified.
- Identification of Leishmania species by next generation sequencing of hsp70 gene(2022) SOUZA, Regina Maia de; MARTINS, Roberta Cristina Ruedas; FRANCO, Lucas Augusto Moyses; TUON, Felipe Francisco; OLIVEIRA JUNIOR, Isael Gomes de; SILVA, Camila Alves Maia da; IMAMURA, Rui; AMATO, Valdir SabbagaLeishmaniasis is a major public health problem worldwide. Although next generation sequencing technology has been widely used in the diagnosis of infectious diseases, it has been scarcely applied in identification of Leishmania species. The aim of this study was to compare the efficiency of MinIONTM nanopore sequencing and polymerase chain reaction restriction fragment length polymorphism in identifying Leishmania species. Our results showed that the MinIONTM sequencer was able to discriminate reference strains and clinical samples with high sensitivity in a cost and time effective manner without the prior need for culture.
- Comparison of methods for the detection of in vitro synergy in multidrug-resistant gram-negative bacteria(2020) GAUDERETO, Juliana Januario; PERDIGAO NETO, Lauro Vieira; LEITE, Gleice Cristina; SANCHEZ, Evelyn; MARTINS, Roberta Cristina Ruedas; PRADO, Gladys Villas Boas; ROSSI, Flavia; GUIMARAES, Thais; LEVIN, Anna Sara; COSTA, Silvia FigueiredoBackground The use of combined antibiotic therapy has become an option for infections caused by multidrug-resistant (MDR) bacteria. The time-kill (TK) assay is considered the gold standard method for the evaluation of in vitro synergy, but it is a time-consuming and expensive method. The purpose of this study was to evaluate two methods for testing in vitro antimicrobial combinations: the disk diffusion method through disk approximation (DA) and the agar gradient diffusion method via the MIC:MIC ratio. The TK assay was included as the gold standard. MDR Gram-negative clinical isolates (n = 62; 28 Pseudomonas aeruginosa, 20 Acinetobacter baumannii, and 14 Serratia marcescens) were submitted to TK, DA, and MIC:MIC ratio synergy methods. Results Overall, the agreement between the DA and TK assays ranged from 20 to 93%. The isolates of A. baumannii showed variable results of synergism according to TK, and the calculated agreement was statistically significant in this species against fosfomycin with meropenem including colistin-resistant isolates. The MIC:MIC ratiometric agreed from 35 to 71% with TK assays. The kappa test showed good agreement for the combination of colistin with amikacin (K = 0.58; P = 0.04) among the colistin-resistant A. baumannii isolates. Conclusions The DA and MIC:MIC ratiometric methods are easier to perform and might be a more viable tool for clinical microbiology laboratories.
- Alternative drugs against multiresistant Gram-negative bacteria(2020) PERDIGAO NETO, Lauro Vieira; OLIVEIRA, Maura Salaroli; ORSI, Tatiana D'Annibale; PRADO, Gladys Villas Boas do; MARTINS, Roberta Cristina Ruedas; LEITE, Gleice Cristina; MARCHI, Ana Paula; LIRA, Esther Sant'Ana de; CORTES, Marina Farrel; ESPINOZA, Evelyn Patricia Sanchez; CARRILHO, Claudia Maria Dantas de Maio; BOSZCZOWSKI, Icaro; GUIMARAES, Thais; COSTA, Silvia Figueiredo; LEVIN, Anna S.Objectives: Enterobacterales and other non-fermenting Gram-negative bacteria have become a threat worldwide owing to the frequency of multidrug resistance in these pathogens. On the other hand, efficacious therapeutic options are quickly diminishing. The aims of this study were to describe the susceptibility of 50 multiresistant Gram-negative bacteria, mostly pan-resistant, against old and less-used antimicrobial drugs and to investigate the presence of antimicrobial resistance genes. Methods: A total of 50 genetically distinct isolates were included in this study, including 14 Acinetobacter baumannii (belonging to ST79, ST317, ST835 and ST836), 1 Pseudomonas aeruginosa (ST245), 8 Serratia marcescens and 27 Klebsiella pneumoniae (belonging to STII, ST340, ST258, ST16, ST23, ST25, ST101, ST234, ST437 and ST442). The isolates were submitted to antimicrobial susceptibility testing and whole-genome sequencing to evaluate lineages and resistance genes. Results: Our results showed that some strains harboured carbapenemase genes, e.g. bla(K)(PC-)(2) (28/50; 56%) and bla(OXA-23) (11/50; 22%), and other resistance genes encoding aminoglycoside-modifying enzymes (49/50; 98%). Susceptibility rates to tigecycline (96%) in all species (except P. aeruginosa), to minocycline (100%) and doxycycline (93%) in A. baumannii, to ceftazidime/avibactam in S. marcescens (100%) and K. pneumoniae (96%), and to fosfomycin in S. marcescens (88%) were high. Chloramphenicol and quinolones (6% susceptibility each) did not perform well, making their use in an empirical scenario unlikely. Conclusions: This study involving genetically distinct bacteria showed promising results for tigecycline for all Gram-negative bacteria (except P. aeruginosa), and there was good activity of minocycline against A. baumannii, ceftazidime/avibactam against Enterobacterales, and fosfomycin against S. marcescens. (C) 2020 The Author(s).
- Colistin-resistant Klebsiella pneumoniae co-harboring KPC and MCR-1 in a Hematopoietic Stem Cell Transplantation Unit(2019) HIGASHINO, Hermes Ryoiti; MARCHI, Ana Paula; MARTINS, Roberta Cristina Ruedas; BATISTA, Marjorie Vieira; PERDIGAO NETO, Lauro Vieira; LIMA, Victor Augusto Camarinha de Castro; ROSSI, Flavia; GUIMARAES, Thais; LEVIN, Anna Sara; ROCHA, Vanderson; COSTA, Silvia Figueiredo
- Genetic and virulence characterization of colistin-resistant and colistin-sensitive A. baumannii clinical isolates(2019) LEITE, Gleice Cristina; STABLER, Richard A.; NEVES, Patricia; PERDIGAO NETO, Lauro V.; MARTINS, Roberta C. Ruedas; RIZEK, Camila; ROSSI, Flavia; LEVIN, Anna S.; COSTA, Silvia FigueiredoTreatment of infections caused by A. baumannii is becoming a challenge due to the ability to develop multidrug-resistance, virulence, and high mortality. We described the colistin resistance and virulence genes present in sixA. baumannii clinical isolates using WGS, expression by qPCR, and virulence in the Galleria mellonella model. The colistin-resistant isolates were assigned as ST233 and the colistin-susceptible isolates as ST236 and ST407. The colistin-resistant isolates contained mutations within PmrA/PmrB, and the pmrA showed up-regulation in all of them. Only one colistin-resistant isolate indicating virulence in G. mellonella. This particular isolate belonged to a different clone, and it was the only isolate that presented non-synonymous mutations in pmrB. Colistinresistance in A. baumannii isolates seems to be caused by up-regulation of pmrA gene. Only one isolate appeared to be virulent in the G. mellonella model. This finding indicating low virulence in isolates belonging to emerging clones circulating in our hospital.