Phenotypic and Genotypic Detection of Metallo-Beta-Lactamases among Imipenem Resistant Gram Negative Isolates
Background: Imipenem-resistant gram negative bacteria, resulting from metallo-beta-lactamase (MBLs)-producing strains have been reported to be among the important causes of nosocomial infections and of serious therapeutic problem worldwide. Because of their broad range, potent carbapenemase activi...
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| Format: | Article |
| Language: | English |
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Tehran University of Medical Sciences
2016-12-01
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| Series: | Journal of Medical Bacteriology |
| Subjects: | |
| Online Access: | https://jmb.tums.ac.ir/index.php/jmb/article/view/229 |
| _version_ | 1818483033286639616 |
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| author | Mohammad Mohammadzadeh Mahnaz Tavakoli Abolfazl Mohebi Samad Aghayi |
| author_facet | Mohammad Mohammadzadeh Mahnaz Tavakoli Abolfazl Mohebi Samad Aghayi |
| author_sort | Mohammad Mohammadzadeh |
| collection | DOAJ |
| description | Background: Imipenem-resistant gram negative bacteria, resulting from metallo-beta-lactamase (MBLs)-producing strains have been reported to be among the important causes of nosocomial infections and of serious therapeutic problem worldwide. Because of their broad range, potent carbapenemase activity and resistance to inhibitors, these enzymes can confer resistance to almost all beta-lactams. The prevalence of metallo-beta-lactamase among imipenem-resistant Acinetobacter spp., Pseudomonas spp. and Enerobacteriaceae isolates is determined.
Methods: In this descriptive study 864 clinical isolates of Acinetobacter spp., Pseudomonas spp. and Enterobacteriaceae, were initially tested for imipenem susceptibility. The metallo-beta-lactamase production was detected using combined disk diffusion, double disk synergy test, and Hodge test. Then all imipenem resistant isolates were tested by PCR for imp, vim and ndm genes.
Results: Among 864 isolates, 62 (7.17 %) were imipenem-resistant. Positive phonetypic test for metallo-beta-lactamase was 40 (64.5%), of which 24 (17.1%) and 16 (9.2%) isolates were Acinetobacter spp. and Pseudomonas spp., respectively. By PCR method 30 (48.4%) of imipenem resistant Acinetobacter, and Pseudomonas isolates were positive for MBL-producing genes. None of the Enterobacteriaceae isolates were positive for metallo-beta-lactamase activity.
Conclusion: The results of this study are indicative of the growing number of nosocomial infections associated with multidrug-resistant gram negative bacteria in this region leading to difficulties in antibiotic therapy. Thereby, using of phenotypic methods can be helpful for management of this problem. |
| first_indexed | 2024-12-10T11:54:59Z |
| format | Article |
| id | doaj.art-aaaf421395ed4bad92e09565f546af43 |
| institution | Directory Open Access Journal |
| issn | 2251-8649 2322-2581 |
| language | English |
| last_indexed | 2024-12-10T11:54:59Z |
| publishDate | 2016-12-01 |
| publisher | Tehran University of Medical Sciences |
| record_format | Article |
| series | Journal of Medical Bacteriology |
| spelling | doaj.art-aaaf421395ed4bad92e09565f546af432022-12-22T01:49:49ZengTehran University of Medical SciencesJournal of Medical Bacteriology2251-86492322-25812016-12-0151-2221Phenotypic and Genotypic Detection of Metallo-Beta-Lactamases among Imipenem Resistant Gram Negative IsolatesMohammad Mohammadzadeh0Mahnaz Tavakoli1Abolfazl Mohebi2Samad Aghayi3Department of Microbiology, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran.Department of Microbiology, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran.Department of Microbiology, Faculty of Sciences, Islamic Azad University, Karaj, Iran.Department of Microbiology, Faculty of Sciences, Islamic Azad University, Karaj, Iran.Background: Imipenem-resistant gram negative bacteria, resulting from metallo-beta-lactamase (MBLs)-producing strains have been reported to be among the important causes of nosocomial infections and of serious therapeutic problem worldwide. Because of their broad range, potent carbapenemase activity and resistance to inhibitors, these enzymes can confer resistance to almost all beta-lactams. The prevalence of metallo-beta-lactamase among imipenem-resistant Acinetobacter spp., Pseudomonas spp. and Enerobacteriaceae isolates is determined. Methods: In this descriptive study 864 clinical isolates of Acinetobacter spp., Pseudomonas spp. and Enterobacteriaceae, were initially tested for imipenem susceptibility. The metallo-beta-lactamase production was detected using combined disk diffusion, double disk synergy test, and Hodge test. Then all imipenem resistant isolates were tested by PCR for imp, vim and ndm genes. Results: Among 864 isolates, 62 (7.17 %) were imipenem-resistant. Positive phonetypic test for metallo-beta-lactamase was 40 (64.5%), of which 24 (17.1%) and 16 (9.2%) isolates were Acinetobacter spp. and Pseudomonas spp., respectively. By PCR method 30 (48.4%) of imipenem resistant Acinetobacter, and Pseudomonas isolates were positive for MBL-producing genes. None of the Enterobacteriaceae isolates were positive for metallo-beta-lactamase activity. Conclusion: The results of this study are indicative of the growing number of nosocomial infections associated with multidrug-resistant gram negative bacteria in this region leading to difficulties in antibiotic therapy. Thereby, using of phenotypic methods can be helpful for management of this problem.https://jmb.tums.ac.ir/index.php/jmb/article/view/229Gram negative bacteriaMetallo beta lactamaseImipenem |
| spellingShingle | Mohammad Mohammadzadeh Mahnaz Tavakoli Abolfazl Mohebi Samad Aghayi Phenotypic and Genotypic Detection of Metallo-Beta-Lactamases among Imipenem Resistant Gram Negative Isolates Journal of Medical Bacteriology Gram negative bacteria Metallo beta lactamase Imipenem |
| title | Phenotypic and Genotypic Detection of Metallo-Beta-Lactamases among Imipenem Resistant Gram Negative Isolates |
| title_full | Phenotypic and Genotypic Detection of Metallo-Beta-Lactamases among Imipenem Resistant Gram Negative Isolates |
| title_fullStr | Phenotypic and Genotypic Detection of Metallo-Beta-Lactamases among Imipenem Resistant Gram Negative Isolates |
| title_full_unstemmed | Phenotypic and Genotypic Detection of Metallo-Beta-Lactamases among Imipenem Resistant Gram Negative Isolates |
| title_short | Phenotypic and Genotypic Detection of Metallo-Beta-Lactamases among Imipenem Resistant Gram Negative Isolates |
| title_sort | phenotypic and genotypic detection of metallo beta lactamases among imipenem resistant gram negative isolates |
| topic | Gram negative bacteria Metallo beta lactamase Imipenem |
| url | https://jmb.tums.ac.ir/index.php/jmb/article/view/229 |
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