ABSTRACT
Rapid identification of microorganisms by the clinical microbiology laboratory is of crucial importance for optimal patients management and treatment. In general, bacterial identification by conventional methods requires 18-24 hours for colony isolation and at least 24 additional hours for species identification. New technologies in microbiology have focused on the rapid diagnosis of bloodstream infections, since they are associated with high morbidity and mortality rates.
A rápida identificação de microrganismos no laboratório de microbiologia clínica é de extrema importância para direcionar o manejo e o tratamento de pacientes. Geralmente, a identificação bacteriana por métodos bioquímicos convencionais necessita de 18 a 24 horas para o crescimento e o isolamento da colônia bacteriana e, pelo menos, 24 horas adicionais para a identificação da espécie. Novas tecnologias em microbiologia têm focado no desenvolvimento de métodos relacionados com o diagnóstico rápido das infecções da corrente sanguínea, uma vez que essas infecções são associadas à alta morbimortalidade.
Subject(s)
Clinical Diagnosis , Diagnostic Techniques and Procedures , Bacterial Infections/diagnosis , Bacterial Infections/microbiology , Mass Spectrometry , Spectrometry, Mass, Matrix-Assisted Laser Desorption-IonizationABSTRACT
INTRODUCTION: Pseudomonas aeruginosa is a leading cause of ventilator-associated pneumonia (VAP) and exhibits high rates of resistance to several antimicrobial drugs. The carbapenens are usually the drugs of choice against this microorganism. However, the carbapenem resistance has increased among these strains worldwide. The presence of metallo-ß-lactamases (MBL) has been pointed out as a major mechanism of resistance among these strains. No previous study addressed outcomes of respiratory infections caused by these strains. METHODS: Our group sought to analyze the epidemiology and clinical outcomes of patients with VAP caused by imipenem-resistant P. aeruginosa. A total of 29 clinical isolates of carbapenem-resistant Pseudomonas aeruginosa were screened for metallo-ß-lactamase (MBL) genes. RESULTS: Demographic and clinical variables were similar between the SPM-1-producing and non-SPM-1-producing group. Five (17.2%) isolates were positive for blaSPM-1. No other MBL gene was found. All patients were treated with polymyxin B. The infection-related mortality was 40% and 54.2% for SPM-1-producing and -non-producing isolates, respectively. CONCLUSIONS: There were no differences in epidemiological and clinical outcomes between the two groups.
Subject(s)
Pneumonia, Ventilator-Associated/microbiology , Pseudomonas Infections/microbiology , Pseudomonas aeruginosa/drug effects , beta-Lactam Resistance/genetics , beta-Lactamases/genetics , Anti-Bacterial Agents/pharmacology , Brazil/epidemiology , Female , Humans , Imipenem/pharmacology , Male , Middle Aged , Pneumonia, Ventilator-Associated/epidemiology , Prevalence , Pseudomonas Infections/epidemiology , Pseudomonas aeruginosa/genetics , Pseudomonas aeruginosa/metabolism , beta-Lactamases/biosynthesisABSTRACT
INTRODUCTION: Pseudomonas aeruginosa is a leading cause of ventilator-associated pneumonia (VAP) and exhibits high rates of resistance to several antimicrobial drugs. The carbapenens are usually the drugs of choice against this microorganism. However, the carbapenem resistance has increased among these strains worldwide. The presence of metallo-β-lactamases (MBL) has been pointed out as a major mechanism of resistance among these strains. No previous study addressed outcomes of respiratory infections caused by these strains. METHODS: Our group sought to analyze the epidemiology and clinical outcomes of patients with VAP caused by imipenem-resistant P. aeruginosa. A total of 29 clinical isolates of carbapenem-resistant Pseudomonas aeruginosa were screened for metallo-β-lactamase (MBL) genes. RESULTS: Demographic and clinical variables were similar between the SPM-1-producing and non-SPM-1-producing group. Five (17.2 percent) isolates were positive for blaSPM-1. No other MBL gene was found. All patients were treated with polymyxin B. The infection-related mortality was 40 percent and 54.2 percent for SPM-1-producing and -non-producing isolates, respectively. CONCLUSIONS: There were no differences in epidemiological and clinical outcomes between the two groups.
INTRODUÇÃO: Pseudomonas aeruginosa é uma importante causa de pneumonia associada à ventilação mecânica (PAV) e exibe altas taxas de resistência a vários antimicrobianos. Os carbapenens são usualmente as drogas de escolha para esse microorganismo. Contudo, a resistência a carbapenens tem crescido entre essas amostras em todo o mundo. A presença de metalo- β-lactamase (MBL) tem sido apontado como um importante mecanismo de resistência nessas cepas. Nenhum estudo prévio avaliou desfechos clínicos de infecções respiratórias causadas por essas amostras MÉTODOS: Nosso grupo analisou a epidemiologia e evolução clínica de episódios de PAV causada por P. aeruginosa resistente a imipenem. Um total de vinte e nove isolados clínicos de Pseudomonas aeruginosa resistente a carbapenem foram avaliados quanto à presença de genes para metalo-β-lactamase (MBL). RESULTADOS: Variáveis clínicas e demográficas foram similares entre o grupo produtor de SPM-1 e o não-produtor. Cinco (17,2 por cento) isolados foram positivos para blaSPM-1. Nenhum outro gene para MBL foi encontrado. Todos os pacientes foram tratados com polimixina B. A mortalidade relacionada à infecção foi de 40 por cento e 50 por cento respectivamente para os isolados produtores de SPM-1 e não-produtores de SPM-1. CONCLUSÕES: Nao houve diferença entre os dados epidemiológicos e a evolução clínica entre os dois grupos.
Subject(s)
Female , Humans , Male , Middle Aged , Pneumonia, Ventilator-Associated/microbiology , Pseudomonas Infections/microbiology , Pseudomonas aeruginosa/drug effects , beta-Lactam Resistance/genetics , beta-Lactamases/genetics , Anti-Bacterial Agents/pharmacology , Brazil/epidemiology , Imipenem/pharmacology , Prevalence , Pneumonia, Ventilator-Associated/epidemiology , Pseudomonas Infections/epidemiology , Pseudomonas aeruginosa/genetics , Pseudomonas aeruginosa/metabolism , beta-Lactamases/biosynthesisABSTRACT
Nosocomial pneumonia caused by multidrug-resistant (MDR) Pseudomonas aeruginosa is becoming increasingly prevalent throughout the world. The use of polymyxins to treat these infections has greatly increased. We analysed 74 patients with nosocomial pneumonia caused by MDR P. aeruginosa who were treated with polymyxin B. A favourable outcome was observed in 35 patients (47.3%). A case-control study was performed to assess the variables associated with an unfavourable outcome. The presence of acute respiratory distress syndrome (odds ratio (OR)=11.29, 95% confidence interval (CI) 2.64-48.22; P=0.001) and septic shock (OR=4.81, 95% CI 1.42-16.25; P=0.01) were independently associated with an unfavourable outcome in patients with nosocomial pneumonia due to MDR P. aeruginosa. Our study demonstrated that polymyxin B is a reliable antimicrobial drug, but only as salvage therapy, for nosocomial pneumonia caused by MDR P. aeruginosa.
