Antibiotic Resistance Patterns and a Survey of Metallo-beta-Lactamase Genes Including bla-(IMP) and bla-(VIM) Types in Acinetobacter baumannii Isolated from Hospital Patients in Tehran

作者：Aghamiri Samira; Amirmozafari Nour^*; Mehrabadi Jalil Fallah; Fouladtan Babak; Abdar Mojtaba Hanafi

来源：Chemotherapy, 2015, 61(5): 275-280.

DOI：10.1159/000443825

• Acinetobacter baumannii
• Metallo-beta-lactamase
• bla-(IMP)
• bla-(VIM)
• Antibiotic resistance
• PCR

Background: Metallo-beta-lactamases (MBLs) producing strains of Acinetobacter baumannii are serious etiological agents of hospital infections worldwide. Among the beta-lactams, carbapenems are the most effective antibiotics used against A. baumannii. However, resistance to these drugs among clinical strains of A. baumannii has been increasing in recent years. In this study, the antimicrobial sensitivity patterns of A. baumannii strains isolated from eleven different hospitals in Tehran, Iran, and the prevalence of MBL genes (bla-(VIM) and bla-(IMP)) were determined. Method: During a period of 5 months, 176 isolates of A. baumannii were collected from different clinical specimens from hospitalized patients in Tehran. All isolates were confirmed by biochemical methods. The isolates were tested for antibiotic sensitivity by the Kirby-Bauer disk diffusion method. Following minimum inhibitory concentration determination, imipenem-resistant isolates were further tested for MBL production by the double disk synergy test (DDST) method. PCR assays were performed for the detection of the MBL genes bla-(IMP) and bla-(VIM). Results: The DDST phenotypic method indicated that among the 169 imipenem-resistant isolates, 165 strains were MBL positive. The PCR assays revealed that 63 of the overall isolates (36%) carried the bla-(VIM) gene and 70 strains (40%) harbored bla-(IMP). Conclusions: It is obvious that nosocomial infections associated with multidrug-resistant Acinetobacter spp. are on the rise. Therefore, the determination of antibiotic sensitivity patterns and screening for MBL production among A. baumannii isolates is important for controlling clinical Acinetobacter infections.

• 出版日期2015