Detection of extended-spectrum beta-lactamase typePER1 in Acinetobacter baumannii species isolated from bloodstream infections and investigation of clonal relationship
Abstract number: O441
Cosar M., Tuncer I., Arslan U., Mansur A., Otlu B., Durmaz R., Findik D.
Objective:Acinetobacter baumannii is an important nosocomial pathogen with wide intrinsic resistance. However, due to the dissemination of the acquired resistance mechanisms; such as extended-spectrum beta-lactamase (ESBL) and metallo betalactamase (MBL) production, multidrug resistant strains have been isolated more often. PER-1 was first detected in Turkey and was found to be widespread among Acinetobacter spp. and P. aeruginosa. Since then, PER-1 has been discovered in other countries, and most recently found in northern Italy and in Korea. In this study, the presence of PER-1 type ESBL was investigated in caftazidime resistant A. baumannii strains isolated from bloodstream infections by PCR and also the clonal relatedness of the isolates were investigated by Random Amplified Polymorphic DNA (RAPD) and Pulsed Field Gel Electrophoresis (PFGE) in all PER-1 producing A. baumannii strains.
Methods:A. baumannii strains isolated from bloodstream infections was included in this study. The isolates were identified as A. baumannii by conventional methods and Phoenix 100 BD automated System system (Becton Dickinson Diagnostic Systems, Sparks). Ceftazidime resistance was determined by E-test. PER-1 genes were screened by PCR. The clonal relationship of PER producing A. baumannii isolates were analyzed by RAPD and PFGE. Data analyses were performed using Gel Compar II (Applied Maths, Sint-Martens-Latem, Belgium).
Results: Of the 100 A. baumannii isolates; 78 (78%) were determined as ceftazidime-resistant by E-test. Among the 78 ceftazidime-resistant A. baumannii isolates the PER-1 gene was identified in 18 (23%). The similarity of the bands were calculated according to "dice smilarity coefficients" and all PER-1 positive isolates were found as clonally related.
Conclusion: In our study the prevalence of PER-1 was lower than the previous studies. But the presence of high ceftazidime resistance rates among these isolates may indicate the presence of other beta-lactamases. DNA analysis by PFGE and RAPD revealed an outbreak caused by a unique clone. Detection of clonal related isolates among different services may be because of the treatment of these patients at the same services before and this may explain the spread of PER-1 positive strains.
|Session name:||19th European Congress of Clinical Microbiology and Infectious Diseases|
|Location:||Helsinki, Finland, 16 - 19 May 2009|
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