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.

Emergence of Acinetobacter baumannii ST730 carrying the blaOXA-72 gene in Brazil.

Over the last decade, Acinetobacter baumannii resistant to carbapenems has emerged in many medical centres and has been commonly associated with high morbimortality. In Brazil, this resistance is mainly attributed to the spread of OXA-23-producing clones and, to a lesser extent, to OXA-143-producing clones. Here, we describe, for the first time, two OXA-72-producing A.

Antimicrobial susceptibility of Brazilian Clostridium difficile strains determined by agar dilution and disk diffusion.

Clostridium difficile is a leading cause of diarrhea in hospitalized patients worldwide. While metronidazole and vancomycin are the most prescribed antibiotics for the treatment of this infection, teicoplanin, tigecycline and nitazoxanide are alternatives drugs. Knowledge on the antibiotic susceptibility profiles is a basic step to differentiate recurrence from treatment failure due to antimicrobial resistance.

Frequency of BKC-1-Producing Klebsiella Species Isolates.

BKC-1 is a new class A serine carbapenemase that was recently identified in Klebsiella pneumoniae clinical isolates. The principal objective of this study was to evaluate the frequency of blaBKC-1 by testing a collection of Klebsiella isolates. Only 2 of 635 Klebsiella isolates (0.

Frequency of Plasmid-Mediated AmpC β-Lactamases in Escherichia coli Isolates from Urine Samples in São Paulo, Brazil.

Plasmid-mediated AmpC β-lactamases (PMACBLs) in Enterobacteriaceae encode resistance to third-generation cephalosporins, and these can mediate carbapenem resistance when associated with porin loss. However, no standardized phenotypic method is available for detecting these enzymes in the clinical microbiology laboratory. Limited data are available concerning the frequency of PMACBLs in Enterobacteriaceae in Brazil.

fosI Is a New Integron-Associated Gene Cassette Encoding Reduced Susceptibility to Fosfomycin.

In this work, we demonstrate that the fosI gene encodes a predicted small protein with 134 amino acids and determines reduced susceptibility to fosfomycin. It raised the MIC from 0.125 to 6 μg/ml when the pBRA100 plasmid was introduced into Escherichia coli TOP10 and to 16 μg/ml when the gene was cloned into the pBC_SK(-) vector and expressed in E.

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

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.

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.

Rothia aeria endocarditis in a patient with a bicuspid aortic valve: case report.

Rothia aeria is an uncommon pathogen mainly associated with endocarditis in case reports. In previous reports, endocarditis by R. aeria was complicated by central nervous system embolization.

Complete Genome Sequence of an F8-Like Lytic Myovirus ({varphi}SPM-1) That Infects Metallo-β-Lactamase-Producing Pseudomonas aeruginosa.

Pseudomonas aeruginosa is an important cause of infection, especially in immunocompromised patients. In this regard, strains producing carbapenemases, mainly metallo-β-lactamases (MBLs), have become a significant public health concern. Here, we present the complete annotated genome sequence (65.

Complete nucleotide sequences of two blaKPC-2-bearing IncN Plasmids isolated from sequence type 442 Klebsiella pneumoniae clinical strains four years apart.

We sequenced the oldest blaKPC-2-bearing plasmid isolated in Brazil and another plasmid also carried by a Klebsiella pneumoniae strain of sequence type 442 (ST442), isolated 52 months later. Both plasmids present an IncN backbone and few acquired regions. Because the 2005 plasmid presented deletions and a truncated gene within Tn4401b compared to the 2009 plasmid, we can thus infer that IncN blaKPC-2-bearing plasmids pFCF1305 and pFCF3SP had a common ancestor circulating in Brazil prior to May 2005.

Multi-institutional outbreak of Burkholderia cepacia complex associated with contaminated mannitol solution prepared in compounding pharmacy.

Background: Burkholderia cepacia complex (BCC) has been described as a cause of nosocomial outbreaks. We describe an outbreak of and identify risk factors for nosocomial BCC infections associated with intrinsically contaminated mannitol 3% solution.

Methods: Urinary and bloodstream infection caused by BCC were identified in hospitalized patients who underwent urologic surgery and received intraoperative irrigation of 3% mannitol solution in February 2009.

Effect of penicillin G every three weeks on oral microflora by penicillin resistant Viridans Streptococci.

Background: Benzathine penicillin G every 3 weeks is the standard protocol for secondary prophylaxis for recurrent rheumatic fever.

Objective: Assess the effect of Benzathine penicillin G on Streptococcus sanguinis and Streptococcus oralis in patients with cardiac valvular disease due to rheumatic fever receiving secondary prophylaxis.

Methods: Oral streptococci were evaluated before (baseline) and after 7 days (day 7) with Benzathine penicillin G in 100 patients receiving routine secondary rheumatic fever prophylaxis.

Complete sequence of broad-host-range plasmid pRIO-5 harboring the extended-spectrum-β-lactamase gene blaBES₋₁.

Broad-host-range plasmid pRIO-5, harboring the extended-spectrum β-lactamase bla(BES-1) gene in Serratia marcescens, was fully sequenced. Analysis of the 12,957-bp sequence of this IncP6-type plasmid revealed that the bla(BES-1) gene was associated with two copies of the insertion sequence IS26. The promoter responsible for the bla(BES-1) expression was hybrid, made of a -35 box located inside the inverted repeat of IS26 and a -10 box inside a remnant of an insertion sequence.

Distinct Interaction of Two Atypical Enteropathogenic Escherichia coli Strains with Enterocytes In Vitro.

Typical and atypical Enteropathogenic Escherichia coli (EPEC) promote attaching-effacing lesions in intestinal cells but only typical EPEC carry the EPEC adherence factor plasmid. Atypical EPEC (aEPEC) are emerging agents of acute and persistent diarrhea worldwide. We aimed at comparing the ability of two aEPEC strains, 1711-4 (serotype O51:H40) and 3991-1 (serotype O non-typeable:non-motile) to invade, persist inside Caco-2 and T84 cells, and to induce IL-8 production.

Involvement of pmrAB and phoPQ in polymyxin B adaptation and inducible resistance in non-cystic fibrosis clinical isolates of Pseudomonas aeruginosa.

During investigation of susceptibility testing methods for polymyxins, 24 multidrug-resistant clinical isolates of Pseudomonas aeruginosa were observed to have a distinct, reproducible phenotype in which skipped wells were observed during broth microdilution testing for polymyxin B. Possible mechanisms underlying this phenotype were investigated. The effects of various concentrations of polymyxin B on growth, the expression of resistance genes, and outer-membrane permeability were observed.

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.

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.