ABSTRACT
Abstract INTRODUCTION: Carbapenemase-resistant enterobacteria that produce the bla NDM gene are found worldwide. However, this is the first report of blaNDM in Klebsiella aerogenes in Brazil. METHODS: The identification of bacterial species was performed using anautomated system and confirmed by biochemical tests, 16S rRNA gene sequencing, and detection of resistance genes. RESULTS: The clinical isolate showed minimum inhibitory concentration resistance to meropenem and polymyxin B at 8mg/L and 4mg/L, respectively. Only the blaNDM gene was detected. CONCLUSIONS: The current report of the blaNDM gene in isolated MDR enterobacteria indicates that this gene can spread silently in a hospital setting.
Subject(s)
Enterobacter aerogenes/genetics , Bacterial Proteins , beta-Lactamases/genetics , Brazil , RNA, Ribosomal, 16S , Microbial Sensitivity Tests , Drug Resistance, Multiple, Bacterial/genetics , Enterobacteriaceae , Klebsiella pneumoniae/genetics , Anti-Bacterial Agents/pharmacologyABSTRACT
Abstract INTRODUCTION: The objective of this study was to characterize genes of aminoglycoside modifying enzymes (AMEs) in colonizing and infecting isolates of E. aerogenes harboring bla KPC from patients at a public hospital in Recife-PE, Brazil. METHODS: We analyzed 29 E. aerogenes clinical isolates resistant to aminoglycosides. AMEs genes were investigated by PCR and sequencing. RESULTS: Colonizing and infecting isolates mainly presented the genetic profiles aac(3)-IIa/aph(3')-VI or ant(2")-IIa/aph(3')-VI. This is the first report of aph(3')-VI in E. aerogenes harboring bla KPC in Brazil. CONCLUSIONS: The results highlight the importance in establishing rigorous methods for the surveillance of resistance genes, especially in colonized patients.
Subject(s)
Humans , Enterobacter aerogenes/genetics , Drug Resistance, Bacterial/genetics , Enterobacteriaceae Infections/microbiology , Aminoglycosides/genetics , Anti-Bacterial Agents/pharmacology , Phenotype , Brazil , Microbial Sensitivity Tests , Polymerase Chain Reaction , Enterobacter aerogenes/isolation & purificationABSTRACT
ABSTRACT Enterobacter cloacae and E. aerogenes have been increasingly reported as important opportunistic pathogens. In this study, a high prevalence of multi-drug resistant isolates from Brazil, harboring several β-lactamase encoding genes was found. Several virulence genes were observed in E. aerogenes, contrasting with the E. cloacae isolates which presented none.
Subject(s)
Humans , Male , Female , Adult , Middle Aged , Bacterial Proteins/metabolism , beta-Lactamases/metabolism , Enterobacter cloacae/isolation & purification , Enterobacter aerogenes/isolation & purification , Virulence Factors/metabolism , Enterobacteriaceae Infections/microbiology , Phylogeny , Bacterial Proteins/genetics , Virulence , beta-Lactamases/genetics , Brazil , Microbial Sensitivity Tests , Enterobacter cloacae/classification , Enterobacter cloacae/enzymology , Enterobacter cloacae/genetics , Enterobacter aerogenes/classification , Enterobacter aerogenes/enzymology , Enterobacter aerogenes/genetics , Virulence Factors/genetics , Middle Aged , Anti-Bacterial Agents/pharmacologyABSTRACT
Enterobacter spp. es un patógeno intrahospitalario que presenta múltiples mecanismos de resistencia a los antibióticos b-lactámicos. Se caracterizaron fenotípica y genotípicamente las diferentes b-lactamasas presentes en 27 aislamientos consecutivos e ininterrumpidos de Enterobacter spp. (25 Enterobacter cloacae y 2 Enterobacter aerogenes). También se evaluó la habilidad de diferentes métodos fenotípicos para detectar b-lactamasas de espectro extendido (BLEE) en estos microorganismos. En 15/27 aislamientos (63%) se observó resistencia a las cefalosporinas de tercera generación. En 12 de los aislamientos resistentes se detectó un alto nivel de producción de cefalosporinasa cromosómica, siendo 6 de ellos también productores de PER-2. Dicha resistencia en los 3 aislamientos restantes se debió exclusivamente a la presencia de BLEE, PER-2 en 2 de ellos y CTX-M-2 en un caso. Sólo CTX-M-2 se detectó con todas las cefalosporinas probadas en los ensayos de sinergia, utilizando el método de difusión, mientras que cefepima mejoró la detección de PER-2 en 7/8 aislamientos productores de esta BLEE, 4/8 utilizando la prueba de doble disco y 7/8 comparando discos de cefepima con y sin el agregado de ácido clavulánico. El método de dilución empleado solo detectó 1/9 BLEE al comparar las cefalosporinas con y sin el agregado de inhibidor.
Enterobacter spp. are becoming increasingly frequent nosocomial pathogens with multiple resistance mechanism to b-lactam antibiotics. We carried out the phenotypic and genotypic characterization of beta-lactamases in 27 Enterobacter spp. (25 Enterobacter cloacae y 2 Enterobacter aerogenes), as well as the ability of different extended spectrum b-lactamase (ESBL) screening methods. Resistance to third generation cephalosporins was observed in 15/27 (63%) isolates. Twelve resistant isolates produced high level chromosomal encoded AmpC b-lactamase; 6 of them were also producers of PER-2. Resistance to third generation cephalosporins in the remaining 3 isolates was due to the presence of ESBLs, PER-2 in 2 cases, and CTX-M-2 in the other. Only CTX-M-2 production was detected with all tested cephalosporins using difusion synergy tests, while cefepime improved ESBLs detection in 7/8 PER-2 producers, 4/8 in the inhibitor aproximation test and 7/8 with double disk test using cefepime containing disk with and without clavulanic acid. Dilution method, including cephalosporins with and without the inhibitor detected 1/9 ESBLs producers.