Table 3.

In vitro characterization of 23 S. aureusisolates from CF sputa

Groupd and isolateResult of hemolysisbGTeCcNorthern analysisa
RNAIIIspahla
RS4°Cexpp expexpp expexpp exp
Group I
 9B+++20y++++/−+/−
 10A+++36y+/−++++/−+
 10B+++++++36w+++++++
 11+++++++62w+++++/−+
 13A+++++++48w+/−+++/−+/−+
 17++++17w++++/−
 20+++36w+/−+++/−+
 23+++++++2w+++++++++
 24++++++61w+/−+++++/−+/−+
 25++2w+++++/−+/−
 29++++17y+/−++++/−+
Group II
 7B+1y++++/−
 7C+1w++++
 8B+++2w+++++/−
 9A+20y++++/−+/−
 1219w+++++/−+/−
 18++19w+++/−
 27++1w++++
 32+/−20y+/−+++++
Group III
 8A++++19y++++++/−
 8C+++++++60w++++++/−
 13B++++++63y+++++/−
 14+++++++36w+++/−+/−+
Group IV
 ISP479C++++++w+++++/−+/−++
 DU5723++++++w+++++/−++
 ISP546w+++
  • a For Northern analysis RNA was isolated in exponential (exp) and postexponential (p exp) growth phases and specific transcripts were probed with digoxigenin-labeled gene probes for RNAIII, spa, and hla. Signals were detected by chemiluminescence and characterized as follows: −, none; +/−, weak; +, median; ++, strong; +++, very strong.

  • b Hemolysis was determined on rabbit (R) and sheep (S) blood agar plates and after incubating plates at 4°C. Responses were characterized as follows: −, none; +/−, weak; +, median; ++, strong; +++, very strong.

  • c C, colony appearance, characterized as yellow (y) or white (w) colonies on sheep blood agar plates.

  • d Group I, agr-positive strains; group II, agr-deficient strains; group III,agr-positive strains with inverse spa expression; and group IV, prototypic strains.

  • e GT, genome type.