Integrons: Genetic Dynamic Elements in <i>Aeromonas</i>
<p id="p1">Integrons are genetic elements able to incorporate, express, and exchange cassettes. Cassette exchanges are mediated by an integrase that excises and reinserts them <em><italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:xsi="http://www....
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| Main Authors: | , , |
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| Format: | Book Chapter |
| Language: | English |
| Published: |
IntechOpen
2024
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| Subjects: | |
| Online Access: | https://www.intechopen.com/chapters/1183014 |
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| Summary: | <p id="p1">Integrons are genetic elements able to incorporate, express, and exchange cassettes. Cassette exchanges are mediated by an integrase that excises and reinserts them <em><italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">via</italic></em> site-specific recombination between flanking <em><italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">att</italic></em> sequences. Cassettes lack for the most part a promoter, and their excision and reinsertion at the <em><italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">att</italic></em>I site, downstream a Pc promoter, render them transcriptionally active. This work documents the occurrence of complete integrons or parts of them in <em><italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">Aeromonas</italic></em> and examines the dynamics of these elements. Class 1 integrons linked to antibiotic-resistant cassettes were the most abundant in strains isolated from environmental and clinical samples. Detection of class 2 and 3 integrons was infrequent. Only one report of a class 4-like integron in <em><italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">Aeromonas</italic></em> sp. genomospecies <em><italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">paramedia</italic></em> was found, but a search of these integrons in <em><italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">Aeromonas</italic></em> genomes revealed that class 4-like integrons were the second most abundant after those belonging to class 1. In addition to complete integrons, clusters of <em><italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">att</italic></em>C sites lacking a neighboring integron-integrase (CALINs), single <em><italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">att</italic></em>C sites lacking integron-integrase (SALINs), and orphan integrase genes were found in chromosomes, and a low percentage in <em><italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">Aeromonas</italic></em> plasmids. Concerning the integron behavior, it is known to be regulated by SOS response and could be also controlled by host specific factors.</p> |
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| ISBN: | 978-0-85466-548-8 |
| DOI: | 10.5772/intechopen.1005503 |