TABLE 3.

Semiquantitative transcription analysis of selected virulence-associated genes in serotype M49 GAS wild-type or lsp operon mutant bacteria

Group and probe target	Resultsa with:
	Wild type	lsp mutant	ORF2 mutant
Housekeeping gene
recA	S	−−	−−
Surface-expressed virulence factors
emm49	S	O	O
fbp54	ND	ND	ND
has	S	O	O
prtF2	W	−−	O
sof/sfbII	W	−	−
Secreted virulence factors
sagA/pel	S	O	O
ska	W	+	+
slo	W	−	−
speB	S	−	−−
Virulence regulators
csrRS	W	−	−
fasX	S	+	+
mga	S	−−	−−
nra	W	−	−
ropB	S	O	O
Genes of the lsp locus
lsp	W	+	+
ORF2	W	+	+
ORF3	S	+	+

^aSemiquantitative Northern blot hybridizations were performed with total RNA prepared from a mixture of stationary- and early-log-phase bacteria. The total RNA was serially diluted in twofold steps before being subjected to denaturing gel electrophoresis. By visual inspection, hybridization signals from wild-type cells were judged as strong (S), weak (W), or not detectable (ND). The strength of these signals was compared to those from lsp or ORF2 mutant bacteria. The differences were recorded as unchanged (O), one or two dilution steps stronger (+) or weaker (−), or three or more dilution steps weaker (−−) compared to the corresponding wild-type signals. The results represent at least three independent RNA preparations and Northern blot hybridizations for each gene.