ABSTRACT
An investigation was carried out into the genetic mechanisms responsible for multidrug resistance in nine carbapenem-resistant Pseudomonas aeruginosaisolates from different hospitals in Recife, Brazil. Susceptibility to antimicrobial agents was determined by broth microdilution. Polymerase chain reaction (PCR) was employed to detect the presence of genes encoding β-lactamases, aminoglycoside-modifying enzymes (AMEs), 16S rRNA methylases, integron-related genes and OprD. Expression of genes coding for efflux pumps and AmpC cephalosporinase were assessed by quantitative PCR. The outer membrane proteins were separated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The blaSPM-1, blaKPC-2 and blaGES-1 genes were detected in P. aeruginosaisolates in addition to different AME genes. The loss of OprD in nine isolates was mainly due to frameshift mutations, premature stop codons and point mutations. An association of loss of OprD with the overexpression of MexAB-OprM and MexXY-OprM was observed in most isolates. Hyper-production of AmpC was also observed in three isolates. Clonal relationship of the isolates was determined by repetitive element palindromic-PCR and multilocus sequence typing. Our results show that the loss of OprD along with overexpression of efflux pumps and β-lactamase production were responsible for the multidrug resistance in the isolates analysed.
Subject(s)
Humans , Carbapenems/metabolism , Drug Resistance, Multiple, Bacterial/genetics , Mutation , Pseudomonas aeruginosa/drug effects , Pseudomonas aeruginosa/genetics , beta-Lactam Resistance/genetics , beta-Lactamases/metabolism , Aminoglycosides/metabolism , Amphotericin B/analogs & derivatives , Amphotericin B/metabolism , Antifungal Agents/metabolism , Brazil , Cephalosporinase/classification , Cephalosporinase/metabolism , Codon, Nonsense/metabolism , Enzyme Activation/genetics , Frameshift Mutation/genetics , Gene Expression Regulation, Bacterial/genetics , Membrane Transport Proteins/metabolism , Methyltransferases/metabolism , Nucleotidyltransferases/metabolism , Point Mutation/genetics , Porins/metabolism , Pseudomonas aeruginosa/enzymology , Pseudomonas aeruginosa/isolation & purification , Repetitive Sequences, Nucleic Acid , beta-Lactamases/geneticsABSTRACT
Os autores relataram nove casos de dermatite verrucosa cromoparasitária (cromomicose) diagnósticados e pacientes do sexo masculino, trabalhadores rurais, residentes no interior e no litoral do Estado do Espiríto Santo. Os fungos isolados de oito dos pacientes foram: Fonsecaea pedrosoi (cinco casos); F. pedrosoi var. cladosporióides (dois casos) e Pbialophora verrucosa (um caso) que apresentaram susceptibilidade in vitro ao sulfato de cobre e ao tiabendazol, sendo resistente a anfotericina B