23 research outputs found
Emergence of Multidrug Resistance and Metalloābetaālactamase Producing Acinetobacter baumannii Isolated from Patients in Shiraz, Iran
Background: Metalloābetaālactamase (MĪ²L) enzymes production is one of the most important resistance mechanisms against carbapenems in some bacteria including Acinetobacter baumannii. Aims: This study was aimed to determine the antimicrobial susceptibility and the prevalence of MĪ²L among carbapenemāresistant isolates of A. baumannii. Materials and Methods: In this crossāsectional study from October 2012 to April 2013, 98 isolates were identified as A. baumannii using Microgenā¢ kits and confirmed by molecular method. These isolates were tested for antimicrobial susceptibilities by disk diffusion method according to the Clinical and Laboratory Standards Institute guidelines. Carbapenemāresistant isolates were further detected phenotypically by MĪ²L minimal inhibitory concentration (MIC)ātest strips, and subsequently positive MĪ²L isolates were confirmed by polymerase chain reaction (PCR). Results: Overall, 98% (96/98) of A. baumannii isolates were detected as carbapenemāresistant by MIC test. Highest sensitivity to the tested antibiotic with 42.9% (42/98) was observed to colistin. Of 96 carbapenemāresistant isolates, 43 were phenotypically positive for MĪ²L; out of 43 isolates, 37 were confirmed for the presence of MĪ²L genes by PCR. Conclusion: The frequency of drug resistance among the clinical samples of A. baumannii isolated in our study against most of the antibiotics was very high. Moreover, all MĪ²L producing isolates were multidrug resistance. Therefore, systematic surveillance to detect MĪ²L producing bacteria and rational prescription and use of carbapenems could be helpful to prevent the spread of carbapenem resistance.Keywords: Acinetobacter baumannii, Antibiotic resistance, Carbapenem, Iran, Metalloābetaālactamas