Carbapenem-resistant Acinetobacter baumannii in Taiwan

Acinetobacter baumannii has emerged recently as a major cause of health care-associated infections due to the extent of its antimicrobial resistance and its propensity to cause nosocomial infectious outbreaks. Carbapenems have been used to treat multidrug-resistant A. baumannii infections. However, the incidences of carbapenem-resistant A. baumannii are rising in Taiwan and many other countries. Clonal spread of cabapenem-resistant A. baumannii via intra-hospitals or inter-hospitals has been reported; their resistance phenotype is mainly due to the acquisition of oxacillin-hydrolyzing-β-lactamase (OXA) genes. The rapid emergence and increase of imipenem resistance in A. baumannii in different areas of Taiwan is contributed to by a variety of mechanisms. The finding of different resistant gene determinants could not explain the phenotypic variation in drug susceptibility. More researches would be required to solve the gaps from resistant genes to phenotypic dynamics by functional genomic studies via the products of genome using high throughput analytic technologies.