ABSTRACT
Background and Objectives: Multidrug-resistant Acinetobacter baumannii (MDR-Ab) reported worldwide has become one of the most difficult nosocomially acquired Gram-negative pathogens to control and treat. The clinical utility of carbapenems is under threat with the emergence of acquired carbapenemases, particularly Ambler class B metallo-lactamases (MBL). Because of the global increase in the occurrence and dissemination of MBLs, early detection is critical. This study was undertaken to detect resistance to carbapenems in clinical isolates of A. baumannii from hospitalized patients by both disk-diffusion and minimum inhibitory concentration (MIC) methods and to assess the rate of carbapenemase and MBL production among the isolates. Materials and Methods : A. baumannii were identified from various clinical samples and antibiotic susceptibility profile was determined by the standard disk-diffusion method. Meropenem-resistant strains were tested further by agar dilution MIC for meropenem. Resistant isolates were screened for carbapenemase production by the modified Hodge test and positive isolates were further checked for metallo-β-lacatmase production by the EDTA disk synergy test. Results : 42 isolates (31.81%) showed resistance to meropenem by the disk diffusion method. 47.6% were carbapenemase positive by the modified Hodge test and 19% were MBL producers phenotypically by the EDTA disc synergy test (EDS). These meropenem-resistant isolates were resistant to most of the other antibiotics tested. These 42 isolates were recovered mostly from patients admitted to intensive care units. Four isolates of the A. baumannii complex were pan drug resistant and showed resistance to even tigecycline and polymyxin B. Conclusion : Carbapenem resistance has been increasingly reported, necessitating their detection. This study reports simple, carbapenemase, and MBL detection method that can be easily incorporated into the daily routine of a clinical laboratory.
Subject(s)
Acinetobacter baumannii/genetics , Acinetobacter baumannii/isolation & purification , Bacterial Proteins/genetics , Bacterial Proteins/immunology , Carbapenems/pharmacokinetics , Drug Resistance, Bacterial/genetics , Humans , Intensive Care Units , Genotyping Techniques , Patients , Phenotype , beta-Lactam Resistance , beta-Lactamases/genetics , beta-Lactamases/pharmacokineticsABSTRACT
Se reportan los primeros casos en que se aisló Enterobacter cloacae y Klebsiella pneumoniae productores de beta lactamasa de efecto expandido(ESBL) en nuestro país. Se comenta la importancia de la multirresistencia a antimicrobianos de estas cepas cada vez más frecuentes en nuestros hospitales, y la metodología de laboratorio que debe usarse en su estudio.
Subject(s)
Penicillinase , beta-Lactamases/pharmacokinetics , Enterobacter cloacae/isolation & purification , Clinical Laboratory Techniques , Klebsiella pneumoniae/isolation & purification , Cross Infection/drug therapy , Laboratories, Hospital , Costa Rica , Cross Infection/diagnosis , Cross Infection/etiologyABSTRACT
Foi realizada uma revisäo crítica da literatura a respeito da estabilidade de fármacos em presença de surfactantes. Os grupos funcionais envolvidos nas reaçöes de decomposiçäo dos fármacos foram usados para o desenvolvimento da discussäo. A análise global desses estudos indicou que o efeito de surfactantes pode ser usado no controle de velocidades e mecanismos de decomposiçäo de fármacos e para obter informaçöes específicas de características da reatividade desses compostos em seus sítios de açäo farmacológica