Jorge Luiz Mello Sampaio

Occurrence of a Multidrug-Resistant Pseudomonas aeruginosa Clone in Different Hospitals in Rio de Janeiro, Brazil

ABSTRACT Multidrug-resistant Pseudomonas aeruginosa nosocomial infections are increasingly recognized worldwide. The existence of metallo-β-lactamase- and extended-spectrum β-lactamase-producing isolates exhibiting resistance to most β-lactam antimicrobial agents greatly complicates the clinical management of patients infected with such isolates. Since 1998, P. aeruginosa isolates resistant to all commercially available antimicrobial agents have been detected at a university-affiliated public hospital in Rio de Janeiro, Brazil. The present study was designed to characterize the antimicrobial resistance profiles and the genetic diversity of the P. aeruginosa strains isolated at this hospital and four private hospitals in Rio de Janeiro. Between April 1999 and March 2000, 200 consecutive isolates were obtained and analyzed for antimicrobial resistance. The genetic diversity of a selected number of them was evaluated by pulsed-field gel electrophoresis and PCR with the ERIC-2 primer. A predominant genotype, designated genotype A, was identified among isolates from four of the five hospitals evaluated. Eighty-four ceftazidime-resistant isolates were evaluated for metallo-β-lactamase production, which was detected in 20 (91%) of 22 genotype A isolates and 11 (18%) of 62 isolates belonging to other genotypes (P < 0.05). Two metallo-β-lactamase-producing genotype A isolates also produced an extended-spectrum β-lactamase. The occurrence of multidrug-resistant P. aeruginosa strains belonging to a unique genotype in different hospitals in Rio de Janeiro underscores the importance of the contribution of a single clone to the increase in the incidence of multidrug-resistant P. aeruginosa nosocomial infections.

The Flagella of an Atypical Enteropathogenic Escherichia coli Strain Are Required for Efficient Interaction with and Stimulation of Interleukin-8 Production by Enterocytes In Vitro

ABSTRACT The ability of some typical enteropathogenic Escherichia coli (EPEC) strains to adhere to, invade, and increase interleukin-8 (IL-8) production in intestinal epithelial cells in vitro has been demonstrated. However, few studies regarding these aspects have been performed with atypical EPEC (aEPEC) strains, which are emerging enteropathogens in Brazil. In this study, we evaluated a selected aEPEC strain (1711-4) of serotype O51:H40, the most prevalent aEPEC serotype in Brazil, in regard to its ability to adhere to and invade Caco-2 and T84 cells and to elicit IL-8 production in Caco-2 cells. The role of flagella in aEPEC 1711-4 adhesion, invasion, and IL-8 production was investigated by performing the same experiments with an isogenic aEPEC mutant unable to produce flagellin (FliC), the flagellum protein subunit. We demonstrated that this mutant (fliC mutant) had a marked decrease in the ability to adhere to T84 cells and invade both T84 and Caco-2 cells in gentamicin protection assays and by transmission electron microscopy. In addition, the aEPEC 1711-4 fliC mutant had a reduced ability to stimulate IL-8 production by Caco-2 cells in early (3-h) but not in late (24-h) infections. Our findings demonstrate that flagella of aEPEC 1711-4 are required for efficient adhesion, invasion, and early but not late IL-8 production in intestinal epithelial cells in vitro.

Detection of OXA-370, an OXA-48-related class D β-lactamase, in Enterobacter hormaechei from Brazil

Jorge L. M. Sampaio, Vanessa B. Ribeiro, Juliana Coutinho Campos, Franciéli P. Rozales, Cibele M. Magagnin, Diego R. Falci, Renato Cassol F. da Silva, Micheline G. Dalarosa, Daniela I. Luz, Fabiane J. Vieira, Laura C. Antochevis, Afonso Luis Barth, Alexandre P. Zavascki Departamento de Análises Clínicas e Toxicológicas—Faculdade de Ciências Farmacêuticas, Universidade de São Paulo, São Paulo, Brazil; Microbiologia—Fleury Medicina e Saúde, São Paulo, Brazil; Laboratório de Pesquisa em Resistência Bacteriana—LABRESIS, Hospital de Clínicas de Porto Alegre, Porto Alegre, Brazil; Programa de PósGraduação em Ciências Farmacêuticas, Faculdade de Farmácia, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil; Infection Control Service, Hospital Nossa Senhora da Conceição, Porto Alegre, Brazil; Infectious Diseases Service, Hospital de Clínicas de Porto Alegre, Porto Alegre, Brazil; Department of Internal Medicine, Medical School, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil

Linezolid Resistance in Brazilian Staphylococcus hominis Strains Is Associated with L3 and 23S rRNA Ribosomal Mutations

Among different clinical staphylococcal strains, linezolid resistance has been mainly mediated by mutations in the central loop of domain V of 23S rRNA, with the G2576T mutation being the most prevalent.…

Cutaneous Mycobacterium haemophilum infection in a kidney transplant recipient after acupuncture treatment

A.N. Castro‐Silva, A.O. Freire, R.S. Grinbaum, M.R. Elmor de Araújo, H. Abensur, M.R.T. Araújo, J.E. Romão Jr, J.L.M. Sampaio, I.L. Noronha. Cutaneous Mycobacterium haemophilum infection in a kidney transplant recipient after acupuncture treatment.
Transpl Infect Dis 2011: 13: 33–37. All rights reserved

Characterization of Tn3000, a Transposon Responsible for blaNDM-1 Dissemination among Enterobacteriaceae in Brazil, Nepal, Morocco, and India

ABSTRACT In Enterobacteriaceae, the blaNDM genes have been found in many different genetic contexts, and a wide diversity of plasmid scaffolds bearing those genes has been found. In August 2013, we identified NDM-1-producing Escherichia coli and Enterobacter hormaechei strains from a single rectal swab sample from a patient hospitalized in Rio de Janeiro, Brazil, who had no history of travel abroad. Complete DNA sequencing using the Illumina platform and annotation of the two plasmids harboring the blaNDM-1 gene, one from each strain, showed that they belonged to incompatibility groups IncFIIK and IncX3 and harbored a novel transposon named Tn3000. Similar genetic structures have been identified among other isolates in Brazil but also on plasmids from other continents. Our findings suggest that the blaNDM-1 gene may be transmitted by Tn3000 in different parts of the world.

Antimicrobial resistance in Enterobacteriaceae in Brazil: focus on β-lactams and polymyxins

During the last 30 years there has been a dissemination of plasmid-mediated β-lactamases in Enterobacteriaceae in Brazil. Extended spectrum β-lactamases (ESBL) are widely disseminated in the hospital setting and are detected in a lower frequency in the community setting. Cefotaximases are the most frequently detected ESBL type and Klebsiella pneumoniae is the predominant species among ESBL producers. Klebsiella pneumoniae carbapenemase-producing Enterobacteriaceae became widely disseminated in Brazil during the last decade and KPC production is currently the most frequent resistance mechanism (96.2%) in carbapenem resistant K. pneumoniae. To date KPC-2 is the only variant reported in Brazil. Polymyxin B resistance in KPC-2-producing K. pneumoniae has come to an alarming rate of 27.1% in 2015 in São Paulo, the largest city in Brazil. New Delhi metallo-β-lactamase was detected in Brazil in 2013, has been reported in different Brazilian states but are not widely disseminated. Antimicrobial resistance in Enterobacteriaceae in Brazil is a very serious problem that needs urgent actions which includes both more strict adherence to infection control measures and more judicious use of antimicrobials.

Detection of blaKPC-2 in a carbapenem-resistant Kluyvera georgiana

Faculdade de Farmacia, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil; Unidade de Microbiologia e Biologia Molecular, Servico de Patologia Clinica, Hospital de Clinicas de Porto Alegre, Porto Alegre, Brazil; Infectious Diseases Service, Hospital de Clinicas de Porto Alegre, Porto Alegre, Brazil; Infection Control Service, Hospital Sao Lucas da Pontificia Universidade Catolica do Rio Grande do Sul, Porto Alegre, Brazil; Faculdade de Ciencias Farmaceuticas, Universidade de Sao Paulo, Sao Paulo, Brazil; Microbiologia—Fleury Medicina e Saude, Sao Paulo, Brazil

Linezolid resistance in vancomycin-resistant Enterococcus faecalis and Enterococcus faecium isolates in a Brazilian hospital.

Linezolid resistance in vancomycin-resistant enterococci (VRE) strains has been rarely reported, with Enterococcus faecium being the species most commonly associated with these few cases ([1][1], [2][2], [3][3]). Here, we report infections due to linezolid- and vancomycin-resistant Enterococcus (

Supramolecular Cationic Assemblies against Multidrug-Resistant Microorganisms: Activity and Mechanism of Action

The growing challenge of antimicrobial resistance to antibiotics requires novel synthetic drugs or new formulations for old drugs. Here, cationic nanostructured particles (NPs) self-assembled from cationic bilayer fragments and polyelectrolytes are tested against four multidrug-resistant (MDR) strains of clinical importance. The non-hemolytic poly(diallyldimethylammonium) chloride (PDDA) polymer as the outer NP layer shows a remarkable activity against these organisms. The mechanism of cell death involves bacterial membrane lysis as determined from the leakage of inner phosphorylated compounds and possibly disassembly of the NP with the appearance of multilayered fibers made of the NP components and the biopolymers withdrawn from the cell wall. The NPs display broad-spectrum activity against MDR microorganisms, including Gram-negative and Gram-positive bacteria and yeast.