Investigation published in The Journal of Antimicrobial Chemotherapy

September 1^st, 2005

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

Gonzalez-Zorn B., Catalan A., Escudero JA., Dominguez L., Teshager T., Porrero MC. and Moreno MA.

Genetic basis for dissemination of armA

Genetic basis for dissemination of armA

	Departamento de Sanidad Animal. Facultad de Veterinaria. Universidad Complutense (UCM).
	Servicio de Zoonosis de Transmisión Alimentaria y Resistencia a Antimicrobianos (ZTA). Centro de Vigilancia Sanitaria Veterinaria (VISAVET). Universidad Complutense (UCM).