title: Novel cassette array in a class 1 integron in clinical isolates of Acinetobacter baumannii from central Iran.
abstract: Antibiotic resistance in Acinetobacter baumannii is a major problem in the hospital and outbreaks caused by this organism have been reported frequently. The present study aimed at determining the antibiotic susceptibility patterns, the prevalence of different classes of integrons and the characterization of integron class 1 gene cassettes in Iranian A. baumannii isolates. A total of 63 non-duplicate A. baumannii isolates were collected from clinical and environmental specimens in the Vali-Asr hospital in the central province of Iran (March to September, 2011). The antimicrobial susceptibility for 15 antibiotics which are used conventionally was determined by disk diffusion. The presence of different integron classes was investigated by PCR and the size of gene cassettes in class 1 integrons was then determined by PCR as well. Moreover, integron cassette arrays of isolates were delineated by RFLP and sequencing amplicons with different lengths. Of 63 isolates 62 (98.4%) carried a class 1 integron. The prevalence of IntI2 was 15.9% and the length of the amplicons ranged from 500 bp to 3 kb. Sequencing of integrons of class 1 revealed the presence of many resistance genes (aadA, aacA, aacC, dfrA, bla(GES) and bla(IMP)). We identified a completely new gene cassette which contained aacA7-qacF-aadA5-bla(IMP), this cassette has not been reported previously in A. baumannii.
authors.affiliation: Student Research Committee, Arak University of Medical Sciences, Arak, Iran; Department of Microbiology and Immunology, Faculty of Medicine, Arak University of Medical Sciences, Arak, Iran.
authors.forename: Alireza
authors.initials: A
authors.lastname: Japoni-Nejad
authors.forename: Shohreh
authors.initials: S
authors.lastname: Farshad
authors.forename: Alex
authors.initials: A
authors.lastname: van Belkum
authors.forename: Ehsanollah
authors.initials: E
authors.lastname: Ghaznavi-Rad
mesh_terms: D000151:Acinetobacter Infections / Q000382:microbiology*; D040981:Acinetobacter baumannii / Q000235:genetics* / Q000302:isolation & purification; D016000:Cluster Analysis; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D004783:Environmental Microbiology; D023061:Gene Order; D005798:Genes, Bacterial; D014644:Genetic Variation; D006761:Hospitals; D006801:Humans; D032023:Integrons; D007492:Iran; D008969:Molecular Sequence Data; D010802:Phylogeny; D016133:Polymerase Chain Reaction; D012150:Polymorphism, Restriction Fragment Length; D017422:Sequence Analysis, DNA
chemical_list: D004269:DNA, Bacterial
keywords: A. baumannii; Antimicrobial resistance; Class 1 integron; Gene cassette array; qacF gene