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Category: Microbial Genetics and Molecular Biology
Antibiotic Resistance Plasmids, Page 1 of 2
< Previous page | Next page > /docserver/preview/fulltext/10.1128/9781555817732/9781555812652_Chap23-1.gif /docserver/preview/fulltext/10.1128/9781555817732/9781555812652_Chap23-2.gifAbstract:
This chapter provides an overview of plasmid classification systems and then describes the various mechanisms of plasmid-mediated resistance to antibacterial agents. The major pathways for the evolution of bacterial resistance plasmids are discussed. In general, plasmid-mediated resistance to antibacterials is a result of three major mechanisms: (i) destruction or modification of the antibacterial agents, (ii) prevention of the antibacterial agent from reaching its target in the bacterial cell, and (iii) production of an altered bacterial target. Resistance to tetracyclines, macrolides, glycopeptides, and quinolones are examples of this type of resistance. The majority of the approximately 60 known gene cassettes code for antibiotic resistance determinants. Genes in integrons have been found to encode resistance to a wide variety of antibiotics, including aminoglycosides, chloramphenicol, erythromycin, and the β-lactams. The aadA1 gene cassette (encoding spectinomycin resistance), carried by Tn21, is one of the most widespread resistance genes. Although the epidemiology of integrons has only recently been investigated, several reports have emphasized the importance of integrons in the dissemination of antibiotic resistance. IncHI1 plasmids are representative of antibiotic resistance plasmids that play a central role in the emergence and reemergence of bacterial pathogens. The chapter highlights the dynamic processes involved in plasmid evolution to acquire resistance markers. Transposons, integrons, conjugation, and other mechanisms of resistance spread are all employed by pathogens to respond to continued antibiotic usage in the clinic and in the environment.
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Plasmid incompatibility groups in Enterobacteriaceae
Plasmid incompatibility groups in Enterobacteriaceae
Plasmid incompatibility groups in P. aeruginosa
Plasmid incompatibility groups in P. aeruginosa
Plasmid incompatibility groups in S. aureus
Plasmid incompatibility groups in S. aureus
Completely sequenced resistance plasmids from gram-positive and gram-negative bacteria
Completely sequenced resistance plasmids from gram-positive and gram-negative bacteria
Completely sequenced broad-host-range resistance plasmids
Completely sequenced broad-host-range resistance plasmids