Table 1.

Genotypes of PBP3-mediated resistance in Haemophilus influenzae

Genotype designations a			PBP3 substitutions b
			SSN	KTG
Category c	Level	Group	S385	R517	N526
rPBP3	High	IIId	T		K
		III-likee	T	H
	Low	II			K
		I		H
sPBP3	NA	NA

^aAccording to Ubukata et al.[7], Hasegawa et al.[8], Garcia-Cobos et al.[9], Hotomi et al.[10] and this study. NA, not applicable.

^bEssential amino acid substitutions in PBP3 (transpeptidase domain, 338–573) with the amino acid sequence of H. influenzae Rd KW20 [GenBank:U32793] as reference. SSN, Ser-Ser-Asn motif; KTG, Lys-Thr-Gly motif.

^crPBP3, isolates with PBP3 sequences conferring resistance to beta-lactams (isolates assigned to groups I, II, III-like and III); sPBP3, isolates with PBP3 sequences conferring wild-type susceptibility to beta-lactams (remaining isolates).

^dOriginally reserved for isolates with the additional substitutions M377I and L389F by Ubukata et al.[7], modification proposed by Hotomi et al.[10].

^eOriginally categorized as group I by Ubukata et al.[7], new group assignment proposed by Garcia-Cobos et al.[9].