TABLE 1.

Hybrids of aadA1 and aadA2 gene cassettes

GenBank accession no.	Namea	Original name	Order	Crossover positionb	Change(s) from standard cassettec		Cassette array	Species	Reference or source
					aadA2d	aadA1d
AF047479	aadA3	aadA3	2/1	758-760		C759T	aadA3-aacA1/orfG-orfsH to M-catB3
AF326210e	aadA8	aadA8	2/1	550-600		C759T + 4f	Unknown	Klebsiella pneumoniae	12
AY139603	aadA8b	aadA8	2/1	602-647	A402Gg	C759T	aadA8b	Uncultured	15
AY852272	aadA8b		2/1	602-647	T17A C216T		dfrA12-orfF-aadA8b	Mixed culture	This work
AY232671	aadA1	aadA1	2/1	88-101	T17A	C759T	aadA2/1-blaP1	Pasteurella multocida	16
AY171244e	aadA21	aadA21	2/1	148-159		GC634-635CGg	aadA21	Salmonella enterica serovar Typhimurium	2
AY550883	aadA21	aadA22	2/1	148-159		G790Ag	aadA21	Salmonella enterica serovar Choleraesuis
AJ809407	aadA21	aadA23	2/1	148-159		G444Ag	aadA21	Salmonella enterica serovar Agona
AB189176	aadA21	aadA23b	2/1	148-159		A529Gg	aadA21	Escherichia coli
						G790Ag
AY665771h	aadA12	aadA12	2/1/2	148-159			Unknown	Escherichia coli
				550-600
AB107663	aadA1	aadA1	1/2	783-786		G732C C759T	aadA1/2	Vibrio cholerae

^aCassettes with high identity (>98%) to aadA1 or aadA21 are named aadA1 or aadA21, respectively.

^bFor boundary x-y, the last base identifiable as matching only the “front” cassette is x − 1, and the first base identifiable as matching only the “back” cassette is y + 1.

^cUnless otherwise indicated, these differences are found in a number of other variants of the relevant cassette.

^dThe standard cassettes used for comparison are found in GenBank accession no. X12870 for aadA1, variants of which commonly have C759T, and X68227 for aadA2.

^eThe first 9 nucleotides of the cassette sequence are missing from AF326210, and the last 28 bp of the cassette sequence are missing from AY171244.

^fThe four additional changes are C609A, A612G, G773A (also found in the aadA1 cassette variant in AY139597), and the unique change C599T.

^gThe changes indicated have not been seen in any other variant of the relevant cassette.

^hThe sequence of the aadA12 gene only is present in AY665771.