Molecular Genetics, Microbiology and Virology | 2019
Acinetobacter baumannii as Nosocomial Pathogenic Bacteria
Abstract
The Acinetobacter genus has emerged as a nosocomial infection with a wide range of mortality and morbidity in recent years. Although this microorganism which was isolated from clinical samples in the 1970s, still known as an opportunistic bacteria [1]. The bacterial taxonomy is as follow: Bacteria; Proteobacteria; Gammaproteobacteria; Pseudomonadales; Moraxellaceae, Genus: Acinetobacter. The distinguished variant species by Bouvet and Grimont are including as: Acinetobacter baumannii, Acinetobacter calcoaceticus, Acinetobacter haemolyticus, Acinetobacter johnsonii, Acinetobacter jejuni and Acinetobacter lwoffii [2–4]. The Acinetobacter genus consists of A. calcoaceticus, Acinetobacter genomic species 3 and Acinetobacter species TU13. These species are very similar but the phenotypic characterization is extremely difficult. Later on, it was also suggested that these species may be categorized in Acinetobacter-calcoaceticus–Acinetobacter baumannii complex [5]. The other types of this bacterium that are called Acinetobacter parvus, Acinetobacter schindleri, Acinetobacter ursingii were isolated from the human body; and seven other strains, including Acinetobacter baylyi, Acinetobacter bouvetii, Acinetobacter grimontii, Acinetobacter tjernbergiae, Acinetobacter towneri, Acinetobacter tandoii, Acinetobacter gerneri have originated from the mud [6–8]. Currently it has been stated that Acinetobacter baumannii and related species, Acinetobacter nosocomialis and Acinetobacter pittii (Acinetobacter baumannii complex) are regarded as a wide range of clinical infections. Acinetobacter variabilis was discovered recently by Krizova [7]. The genomic species 3 and TU13 were respectively replaced by Acinetobacter nosocomialis and Acinetobacter pittii [8, 9]. A number of the Acinetobacter genus, for example A. johnsonii, A. lwoffii and A. radioresistens are found on the skin normal f lora especially in tropical inhabitants [10]. In contrast, A. baumannii is also isolated from hospitalized patients and environments however, can be colonized about 41 percent in intensive care unit patients [11, 12]. Another group that consists of antibiotic sensitive cluster (A. johnsonii and A. calcoaceticus) is obtained from environmental resources, soil and contaminated waters. According to several studies, the most members of the last two groups have carbapenem resistance genes [13].