TABLE 2.

Mutant classifications^a

Category	No. of isolates	K antigen	LPS	Congo red result	Phage sensitivity profile	Complementation group
AK631	NAb	Present	AK631	Salmon	Distinct	NA
rkp-1	3 tested	Absent	AK631	Dark red	Distinct	rkp-1
Class I	5	Absent	AK631	Salmon	Distinct	rkp-3
Class II	6	Absent	Altered	Salmon	Distinct	rkp-2
Class III	1	Absent	Rm41	Dark red	Distinct	Unique
Class IV	1	Absent	AK631	Dark red	Distinct	Unique

^aMutants were characterized with respect to the K antigen and LPS they produced, the sensitivities they displayed to a series of phage strains, their color on Congo red plates, and through tests of complementation to cosmids isolated by Kereszt et al. (7, 8). 

^bNA, not applicable.