ardK | GeneID:4246789 | Escherichia coli

ABG33838   ABG49225   YP_724519  

1. [ ] Gonzalez-Zorn B, et al. (2005) "armA and aminoglycoside resistance in Escherichia coli." Emerg Infect Dis. 11(6):954-956. PMID:15963296

We report armA in an Escherichia coli pig isolate from Spain. The resistance gene was borne by self-transferable IncN plasmid pMUR050. Molecular analysis of the plasmid and of the armA locus confirmed the spread of this resistance determinant.

2. [ ] Gonzalez-Zorn B, et al. (2005) "Genetic basis for dissemination of armA." J Antimicrob Chemother. 56(3):583-585. PMID:16027145

OBJECTIVES AND METHODS: armA is a novel plasmid-borne 16S rRNA methyltransferase that confers high-level resistance to 4,6-disubstituted deoxystreptamines. Recently, we have isolated from a high-level broad-spectrum aminoglycoside-resistant Escherichia coli animal isolate a plasmid, pMUR050, that bore the armA gene. In order to elucidate the genetic basis for the spread of armA, we have determined the complete nucleotide sequence of pMUR050. RESULTS: armA was borne by a complex transposon composite flanked by two direct repeats of IS26. The transposon composite included a class one integron with sul1 for resistance to sulphonamides and ant3''9 conferring resistance to spectinomycin-streptomycin, and a macrolide efflux pump and mefE/mel conferring high-level resistance to erythromycin. We identified in GenBank that another plasmid, pCTX-M3, from a Polish Citrobacter freundii human isolate, bore the same genetic structure, including armA. CONCLUSIONS: armA is present in human and animal isolates within a novel transposon composite. Further spread of armA between bacteria of diverse origin is to be expected.