RESUMO
INTRODUCTION: Acinetobacter baumannii infections are a growing public-health concern. The bacterium's potentiality to acquire resistance to a number of commonly used antibiotics has turned it into a formidable pathogen. AIMS: Molecular characterization of extensive drug resistant (XDR) typing of A. baumannii clinical isolates by polymerase chain reaction. MATERIALS AND METHODS: Thirty XDR A. baumannii were investigated for the presence of genes encoding carbapenemase resistance, biofilm capacity, autoinducer synthase, virulence and surface motility by polymerase chain reaction (PCR). Later, the isolates were typed by plasmid-based replicon (Rep) (PBRT) and trilocus sequence typing. RESULTS: All 30 XDR A. baumannii strains displayed genes related to surface motility, autoinducer synthase, virulence determinant, biofilm related genes except PER, and bap, the frequency of which was 83.3% and 76.6%, respectively. Analysis of rep genes showed highest frequency of rep6 and rep2 genes, with frequency of 75% and 65%, respectively. All XDR A. baumannii strains belonged to SG I (European clone II) group. CONCLUSIONS: Our results show the extraordinary plasticity of XDR A. baumannii and suggest that the strains have gained endemicity in our hospital, which could be a great concern in the near future.
Assuntos
Infecções por Acinetobacter , Acinetobacter baumannii , Infecções por Acinetobacter/tratamento farmacológico , Infecções por Acinetobacter/epidemiologia , Acinetobacter baumannii/genética , Antibacterianos/farmacologia , Antibacterianos/uso terapêutico , Proteínas de Bactérias/genética , Farmacorresistência Bacteriana Múltipla/genética , Humanos , Testes de Sensibilidade Microbiana , PlasmídeosRESUMO
Acinetobacter baumannii, notorious for causing nosocomial infections especially in patients admitted to intensive care unit (ICU) and burn units, is best at displaying resistance to all existing antibiotic classes. Consequences of high potential for antibiotic resistance has resulted in extensive drug or even pan drug resistant A. baumannii. Carbapenems, mainly imipenem and meropenem, the last resort for the treatment of A. baumannii infections have fallen short due to the emergence of carbapenem resistant A. baumannii (CRAB). Though enzymatic degradation by production of class D ß-lactamases (Oxacillinases) and class B ß-lactamases (Metallo ß-lactamases) is the core mechanism of carbapenem resistance in A. baumannii; however over-expression of efflux pumps such as resistance-nodulation cell division (RND) family and variant form of porin proteins such as CarO have been implicated for CRAB inception. Transduction and outer membrane vesicles-mediated transfer play a role in carbapenemase determinants spread. Colistin, considered as the most promising antibacterial agent, nevertheless faces adverse effects flaws. Cefiderocol, eravacycline, new ß-lactam antibiotics, non-ß-lactam-ß-lactamase inhibitors, polymyxin B-derived molecules and bacteriophages are some other new treatment options streamlined.