THAIS GUIMARAES
Projetos de Pesquisa
Unidades Organizacionais
Instituto Central, Hospital das Clínicas, Faculdade de Medicina
LIM/49 - Laboratório de Protozoologia, Hospital das Clínicas, Faculdade de Medicina
LIM/49 - Laboratório de Protozoologia, Hospital das Clínicas, Faculdade de Medicina
16 resultados
Resultados de Busca
Agora exibindo 1 - 10 de 16
- Clinical outcome from hematopoietic cell transplant patients with bloodstream infection caused by carbapenem-resistant P. aeruginosa and the impact of antimicrobial combination in vitro(2022) RAMOS, Jessica Fernandes; LEITE, Gleice; MARTINS, Roberta Cristina Ruedas; RIZEK, Camila; SANABANI, Sabri Saeed Al; ROSSI, Flavia; GUIMARAES, Thais; LEVIN, Anna Sara; ROCHA, Vanderson; COSTA, Silvia FigueiredoBloodstream infection (BSI) caused by carbapenem-resistant P. aeruginosa (CRPA) has high mortality in hematopoietic stem cell transplant (HSCT) recipients. We performed MIC, checkerboard, time-kill assay, PFGE, PCR, and whole genome sequence and described the clinical outcome through Epi Info comparing the antimicrobial combination in vitro. Mortality was higher in BSI caused by CRPA carrying the lasB virulence gene. The isolates were 97% resistant to meropenem displaying synergistic effect to 57% in combination with colistin. Seventy-three percent of the isolates harbored bla(SPM-1) and Tn4371 and belonged to ST277. The synergistic effect in vitro with meropenem with colistin appeared to be a better therapeutic option.
- 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.
- Impact of Discontinuing Levofloxacin Prophylaxis on Bloodstream Infections in Neutropenic Hematopoietic Stem Cell Transplantation Patients(2022) GUIMARAES, Thais; BORGES, Igor Carmo; SPADAO, Fernanda de Souza; MARIANO, Livia; NASCIMENTO, Marina de Mattos; HIGASHINO, Hermes; ROSSI, Flavia; ROCHA, Vanderson; COSTA, Silvia FigueiredoMultidrug-resistant pathogens have emerged worldwide. We have driven the hypothesis that the non-use of fluoroquinolone prophylaxis during neutropenia could reduce antibiotic resistance in Gram-negative bacteria that cause bloodstream infections (BSIs) in hematopoietic stem cell transplantation (HSCT) patients and that this change in resistance pattern could lead to an impact on BSI mortality. This is a quasi-experimental study comparing BSI incidence, resistance patterns of bacteria that cause BSI, and BSI mortality when levofloxacin prophylaxis was routine for neutropenic HSCT patients (2016-2018) to when fluoroquinolone prophylaxis was discontinued in our center (2019). Bivariate comparisons and multivariate logistic regression models were used for analyses. A total of 310 HSCTs (66 (21%) allogeneic and 244 (79%) autologous) were performed during the study period. Sixty (19%) patients had BSIs, 30 in each evaluated period. The discontinuation of levofloxacin prophylaxis was associated with an increase in BSI incidence and a decrease in the resistance rates of causative BSI bacteria and in BSI 30-day mortality. The increase in the rate of resistant bacteria causing BSI and in BSI mortality might outweigh the benefits of a decrease in BSI incidence caused by fluoroquinolone prophylaxis in neutropenic HSCT patients. We suggest that the routine use of fluoroquinolone in this context be revisited.
- 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
- MRSA outbreak in a Neonatal Intensive Care Unit in a developed country: importance of rapid detection of reservoirs and implementation of intervention measures(2022) MOURA, Maria Luisa; RIZEK, Camila Fonseca; AGUIAR, Elisa; BARROS, Ana Natiele da Silva; COSTA, Sibeli; SANTOS, Sania Alves dos; MARCHI, Ana Paula; GIBELLI, Maria Augusta Bento Cicaroni; TRAGANTE, Carla Regina; ARAUJO, Maria Rita Elmor de; ROSSI, Flavia; GUIMARAES, Thais; COSTA, Silvia FigueiredoWe described a MRSA bloodstream infection outbreak that was rapidly identified and controlled in a Neonatal Intensive Care Unit after implementation of a bundle of measures, including PCR-screening and HCW decolonization. We found 35% of healthcare workers(HCW) colonized with S. aureus by PCR, one of them that presented skin lesion positive for MSSA (same clone and spa type than two patients). Our findings raise the hypothesis that the outbreak could be related to HCW colonization.
- Effectiveness of surveillance cultures for high priority multidrug-resistant bacteria in hematopoietic stem cell transplant units(2021) MENDES, Elisa Teixeira; SALOMAO, Matias Chiarastelli; TOMICHI, Lisia Moura; OLIVEIRA, Maura Salaroli; GRACA, Mariana; ROSSI, Flavia; SAPADAO, Fernanda; GUIMARAES, Thais; ROCHA, Vanderson; COSTA, Silvia FigueiredoSurveillance strategies to detect colonization are an important tool to prevent and control the spread of microorganisms in hematopoietic stem cell transplant (HSCT) units. The aim of this study was to evaluate routine surveillance cultures for screening colonization and infection by carbapenem-resistant Enterobacteriaceae (CRE), carbapenem-resistant Pseudomonas aeruginosa (CRPa), and vancomycin-resistant enterococci (VRE). Surveillance cultures were collected (1,323 samples) from 200 patients admitted to an HSCT unit over one year; swabs were taken on admission and then weekly. We compared the positivity of cultures for each site, agent, clinical and epidemiological data according to the colonization status. Infection due to multidrug-resistant organisms (MDROs) occurred in 52 (21.5%) patients, 45 (86.5%) due to blood stream infection; 12 (23%) patients had a positive surveillance culture before the infection. Cultures of 554 (41.8%) samples were performed for CRPa, 413 (31.2%) for VRE and 356 (27%) for CRE. Of these, 179 (13.5%) were positive. Colonization by any MDRO, CRE or CRPa was associated with increased risk of infection (P < 0.05), but not with death. Previous colonization by an MDRO was a significant risk for infection by these pathogens, specially by CRE. Overall, rectal swabs had the highest positivity rate compared with other sites, oropharynx swabs were an option for CRPa, and fecal cultures showed low positivity. Although the impact of the strategy on the mortality of patients undergoing HSCT is not clear, routine VRE surveillance should be questioned with regard to patients undergoing auto-HSCT due to the additional cost and little impact on survival rates.
- Phenotypic and genotypic characteristics of a carbapenem-resistant Serratia marcescens cohort and outbreak: describing an opportunistic pathogen(2022) PRADO, Gladys; MENDES, Elisa Teixeira; MARTINS, Roberta Cristina Ruedas; PERDIGAO-NETO, Lauro Vieira; FREIRE, Maristela Pinheiro; MARCHI, Ana Paula; CORTES, Marina Farrel; LIMA, Victor Augusto Camarinha de Castro; ROSSI, Flavia; GUIMARAES, Thais; LEVIN, Anna Sara; COSTA, Silvia FigueiredoSerratia marcescens is an emerging opportunistic pathogen with high genetic diversity. This article describes the microbiological characteristics of isolates and the risk factors for infections caused by carbapenem-resistant S. marcescens. A retrospective study of patients colonized (n=43) and infected (n= 20) with carbapenem-resistant S. marcescens over a 3-year period was conducted. Polymerase chain reaction for carbapenemase genes and molecular typing of all available strains was performed. Forty-two isolates were analysed, including three environmental samples identified during an outbreak. Thirty-five carbapenem-resistant S. marcescens carried bla KPC-2, one isolate was bla(NDM)-positive and four isolates carried bla(OXA)-101. The genomes were grouped into three clusters with 100% bootstrap; three patterns of mutations on ompC and ompF were found. The strains carried virulence genes related to invasion and haemolysis, and the environmental strains presented fewer mutations on the virulence genes than the clinical strains. Multi-variate analysis showed that previous use of polymyxin (P= 0.008) was an independent risk factor for carbapenem-resistant S. marcescens infection. This study highlighted that bla KPC-2 in association with ompC or ompF mutation was the most common mechanism of resistance in the study hospital, and that previous use of polymyxin was an independent risk factor for carbapenem-resistant S. marcescens. There was a predominant clone, including the environmental isolates, suggesting that crosstransmission was involved in the dissemination of this pathogen.
- Multidrug-resistant Klebsiella pneumoniae: genetic diversity, mechanisms of resistance to polymyxins and clinical outcomes in a tertiary teaching hospital in Brazil(2019) BOSZCZOWSKI, Icaro; SALOMAO, Matias Chiarastelli; MOURA, Maria Luisa; FREIRE, Maristela Pinheiro; GUIMARAES, Thais; CURY, Ana Paula; ROSSI, Flavia; RIZEK, Camila Fonseca; MARTINS, Roberta Cristina Ruedas; COSTA, Silvia FigueiredoIncreased resistance to polymyxin in Klebsiella pneumoniae (ColRKP) has been observed. Molecular epidemiology, as well as the clinical impact of these difficult to treat pathogens need to be better characterized. We present the clinical outcomes of 28 patients infected by ColRKP in a tertiary hospital. Isolates with MIC >2 by Vitek 2 were confirmed by the microdilution broth test. Polymerase chain reaction (PCR) was performed for bla(KPC), bla(NDM), bla(OXA-48), and bla(mcr-1) genes in the isolates, and Whole Genome Sequencing (WGS) was performed in six isolates. Seventeen (61%) patients were female and the mean age was 50 years old. In-hospital and 30-day mortality were 64% (18/28) and 53% (15/28), respectively. Central line-associated bloodstream infection in addition to bacteremia episodes due to other sources were the most frequent (61%). Mean APACHE and Charlson comorbidity index were 16 and 5, respectively. Twenty patients (71%) received at least one active drug and ten (35%) received two drugs: tigecycline 46% (13/28); amikacin 21% (6/28) and fosfomycin 3% (1 case). Twenty-six out of 28 tested cases were positive for bla(KPC) Eight different clusters were identified. Four STs were detected (ST1, ST23, ST340, and ST437). Mutations on pmrA, arnB udg, and yciM genes were present in all six isolates submitted to WGS; /pxMand mgrB mutations were also detected in all but one isolate. In conclusion, we observed resistance to polymyxin in severely ill patients mostly from intensive care units and/or immunosuppressed patients with high mortality rates in whom a diversity of ColRKP clusters was identified and might indicate selective pressure.
- Healthcare Professionals Perception of Mobile Phone Usage and Hand Hygiene Adhesion in Intensive Care Units(2020) SANCHEZ, Evelyn; PERDIGAO-NETO, Lauro; SANTOS, Sania Alves dos; RIZEK, Camila; GOMEZ, Maria Renata; MARTINS, Roberta; OLIVEIRA, Gaspar de; GUIMARAES, Thais; BOSZCZOWSKI, Icaro; ROSSI, Flavia; FREIRE, Maristela; LEVIN, Anna; COSTA, Silvia Figueiredo; FARREL, Marina
- Virulence and resistance pattern of a novel sequence type of linezolid-resistant Enterococcus faecium identified by whole-genome sequencing(2016) PRADO, Gladys Villas Boas do; MARCHI, Ana Paula; MORENO, Luisa Zanolli; RIZEK, Camila; AMIGO, Ulisses; MORENO, Andrea Micke; ROSSI, Flavia; GUIMARAES, Thais; LEVIN, Anna Sara; COSTA, Silvia F.Empirical use of linezolid has been advocated in neutropenic febrile patients colonised by vancomycin-resistant enterococci (VRE) because of the risk of bloodstream infection (BSI). This study aimed to genetically describe a vancomycin-resistant Enterococcus faecium (VREfm) BSI isolate resistant to linezolid (VRLRE) in a patient previously colonised by VREfm and to determine the incidence of colonisation and infection by VREfm in a bone marrow transplant unit over a 10-year period. Data for VREfm colonisation and infection were evaluated. PCR for the vanA and vanB genes, pulsed-field gel electrophoresis (PFGE) and microdilution antimicrobial susceptibility testing (vancomycin, teicoplanin, linezolid and aminoglycosides) were performed. Three isolates, including the VRLRE, were selected for whole-genome sequencing by Ion Torrent (TM), with E. faecium CP006620-Aus0085 used as a reference. Eighty-seven VREfm were analysed; all were linezolid-susceptible and harboured vanA, except for one blood isolate from a febrile neutropenic patient colonised by VREfm who received linezolid for 12 days and developed a BSI by VRLRE (linezolid MIC >= 8 mu g/mL). Linezolid resistance was associated with a G2576T mutation in the 23SrRNA gene. PFGE analysis demonstrated that the 87 isolates belonged to four major clusters; however, the VRLRE presented only 50% similarity. Three sequence types (STs) were identified: ST412 (the predominant clone, which was more virulent compared with the other isolates); ST478 (linezolid-susceptible VREfm); and a novel ST named ST987 (VRLRE). SNP analysis showed a higher similarity between linezolid-susceptible VREfm and the predominant clone compared with VRLRE. VRLRE presented a G2576T mutation and belonged to a novel ST (ST987).