Identification of Beta-Lactamase Enzymes by Isoelectrical Focusing Method in Acinetobacter baumannii
There has been an important resistance problem to various beta-lactam antibiotics in Acinetobacter baumannii strains which cause nosocomial infections. In this study, isoelectric points of beta-lactamase enzymes of 60 strains of A. baumannii isolated from various clinical specimens were investigated...
| Main Authors: | , , , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
Bilimsel Tip Yayinevi
2002-12-01
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| Series: | Flora Infeksiyon Hastalıkları ve Klinik Mikrobiyoloji Dergisi |
| Subjects: | |
| Online Access: | http://www.floradergisi.org/getFileContent.aspx?op=REDPDF&file_name=2002-7-4-233-240.pdf |
| Summary: | There has been an important resistance problem to various beta-lactam antibiotics in Acinetobacter baumannii strains which cause nosocomial infections. In this study, isoelectric points of beta-lactamase enzymes of 60 strains of A. baumannii isolated from various clinical specimens were investigated by polyacrylamid gel electrophoresis (PAGE). Beta-lactamase enzymes of the isolates were estimated by evaluating their susceptibility to beta-lactam group antibiotics and isoelectric points (pI). The presence of beta-lactamase enzymes was detected in all of the A. baumannii species included in the study. Beta-lactamase band was observed in 50 species by IEF method, but couldn’t be shown in the other 10 isolates. However, the presence of betalactamase which shows spreading type around loading space without band formation was detected in all of the strains. Isoelectric points in 29 of the 50 isolates with band formation were 5.4, 8 were 6.3 and 13 were 6.3 and 5.4. According to antibiotic susceptibility and isoelectric points, 6 phenotypes were observed. We suggest that phenotype 1 was either ACE + TEM-1 or PER-1; phenotype 2 was ACE + CARB-5; phenotype 3 was ACE; phenotype 4 was either an over synthesis of ACE or a new beta-lactamase; phenotype 5 was ACE + TEM-1; phenotype 6 was either ACE + TEM-1 or PER-1 + CARB-5. Every phenotype was divided into subgroups according to their resistance to imipenem, except phenotype 5. As well as beta-lactamases, changes in porins and penicillin binding proteins were considered to be responsible for the resistance of A. baumannii strains to beta-lactam antibiotics. |
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| ISSN: | 1300-932X 1300-932X |