Multiplex PCR Study of Plasmid-Mediated AmpC Beta-Lactamase Genes in Clinical Isolates of Escherichia coli
Background: AmpC β-lactamases are important cephalosporinases chromosomally encoded in many of Enterobacteriaceae and a few other organisms where they mediate resistance to cephalothin, cefazolin, cefoxitin and penicillins. The six different families of plasmid-mediated AmpC β-lactamases have been...
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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 |
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| Online Access: | https://jmb.tums.ac.ir/index.php/jmb/article/view/281 |
| _version_ | 1819028027869233152 |
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| author | Maryam Dehghani AZ Haddadi Mahmoud Shavandi |
| author_facet | Maryam Dehghani AZ Haddadi Mahmoud Shavandi |
| author_sort | Maryam Dehghani |
| collection | DOAJ |
| description | Background: AmpC β-lactamases are important cephalosporinases chromosomally encoded in many of Enterobacteriaceae and a few other organisms where they mediate resistance to cephalothin, cefazolin, cefoxitin and penicillins. The six different families of plasmid-mediated AmpC β-lactamases have been described, but no phenotypic test can discriminate among them. AmpC multiplex PCR has been successfully used to discriminate plasmid-mediated ampC specific families in organisms such as Klebsiella pneumonia and Escherichia coli. The aim of this study was to indicate the prevalence of AmpC β-lactamase genes by specifically designed primers through PCR test.
Methods: 243 total clinical urine samples were collected, and 227 isolates were identified as Escherichia coli based on standard biochemical tests. Subsequently, the isolates were screened by disc diffusion and combined disc test for β-lactamase production. Resistant isolates were evaluated by PCR for ampC family determination.
Results: Antibiotic resistance pattern were observed as follows: cefepime (30%), ceftazidime (36%), ceftriaxone (42%), cefotaxime (47%). The ratio of isolates was detected as ESBLs and AmpC producers were 34% and 5.2%, respectively. PCR performed on 12 selected isolates via phenotypic tests and the results revealed that among 12 isolates, 11 contained blaCMY-42.
Conclusion: Unfortunately, antibiotic resistance has become an increasingly critical problem in many countries like Iran and occurrence of isolates co-expressing AmpC-β-lactamases and ESBLs can create serious problems in the future. As antibiotic options in the treatment of AmpC β-lactamases and ESBLs producing organisms are extremely limited, molecular screening by laboratories is suggested to reduce the risk of therapeutic defeat. |
| first_indexed | 2024-12-21T05:51:50Z |
| format | Article |
| id | doaj.art-564becc5b11d45adac407688c8dce324 |
| institution | Directory Open Access Journal |
| issn | 2251-8649 2322-2581 |
| language | English |
| last_indexed | 2024-12-21T05:51:50Z |
| publishDate | 2016-12-01 |
| publisher | Tehran University of Medical Sciences |
| record_format | Article |
| series | Journal of Medical Bacteriology |
| spelling | doaj.art-564becc5b11d45adac407688c8dce3242022-12-21T19:13:57ZengTehran University of Medical SciencesJournal of Medical Bacteriology2251-86492322-25812016-12-0155-6Multiplex PCR Study of Plasmid-Mediated AmpC Beta-Lactamase Genes in Clinical Isolates of Escherichia coliMaryam Dehghani0AZ Haddadi1Mahmoud Shavandi2Department of Microbiology, Karaj Branch, Islamic Azad University, Karaj, Iran.Department of Microbiology, Karaj Branch, Islamic Azad University, Karaj, Iran.Microbiology and Biotechnology Research Group, Research Institute of Petroleum Industry, Tehran, Iran.Background: AmpC β-lactamases are important cephalosporinases chromosomally encoded in many of Enterobacteriaceae and a few other organisms where they mediate resistance to cephalothin, cefazolin, cefoxitin and penicillins. The six different families of plasmid-mediated AmpC β-lactamases have been described, but no phenotypic test can discriminate among them. AmpC multiplex PCR has been successfully used to discriminate plasmid-mediated ampC specific families in organisms such as Klebsiella pneumonia and Escherichia coli. The aim of this study was to indicate the prevalence of AmpC β-lactamase genes by specifically designed primers through PCR test. Methods: 243 total clinical urine samples were collected, and 227 isolates were identified as Escherichia coli based on standard biochemical tests. Subsequently, the isolates were screened by disc diffusion and combined disc test for β-lactamase production. Resistant isolates were evaluated by PCR for ampC family determination. Results: Antibiotic resistance pattern were observed as follows: cefepime (30%), ceftazidime (36%), ceftriaxone (42%), cefotaxime (47%). The ratio of isolates was detected as ESBLs and AmpC producers were 34% and 5.2%, respectively. PCR performed on 12 selected isolates via phenotypic tests and the results revealed that among 12 isolates, 11 contained blaCMY-42. Conclusion: Unfortunately, antibiotic resistance has become an increasingly critical problem in many countries like Iran and occurrence of isolates co-expressing AmpC-β-lactamases and ESBLs can create serious problems in the future. As antibiotic options in the treatment of AmpC β-lactamases and ESBLs producing organisms are extremely limited, molecular screening by laboratories is suggested to reduce the risk of therapeutic defeat.https://jmb.tums.ac.ir/index.php/jmb/article/view/281Antibiotic ResistanceAmpC β-lactamasesESBLs |
| spellingShingle | Maryam Dehghani AZ Haddadi Mahmoud Shavandi Multiplex PCR Study of Plasmid-Mediated AmpC Beta-Lactamase Genes in Clinical Isolates of Escherichia coli Journal of Medical Bacteriology Antibiotic Resistance AmpC β-lactamases ESBLs |
| title | Multiplex PCR Study of Plasmid-Mediated AmpC Beta-Lactamase Genes in Clinical Isolates of Escherichia coli |
| title_full | Multiplex PCR Study of Plasmid-Mediated AmpC Beta-Lactamase Genes in Clinical Isolates of Escherichia coli |
| title_fullStr | Multiplex PCR Study of Plasmid-Mediated AmpC Beta-Lactamase Genes in Clinical Isolates of Escherichia coli |
| title_full_unstemmed | Multiplex PCR Study of Plasmid-Mediated AmpC Beta-Lactamase Genes in Clinical Isolates of Escherichia coli |
| title_short | Multiplex PCR Study of Plasmid-Mediated AmpC Beta-Lactamase Genes in Clinical Isolates of Escherichia coli |
| title_sort | multiplex pcr study of plasmid mediated ampc beta lactamase genes in clinical isolates of escherichia coli |
| topic | Antibiotic Resistance AmpC β-lactamases ESBLs |
| url | https://jmb.tums.ac.ir/index.php/jmb/article/view/281 |
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