TY - JOUR
T1 - The O4 specific antigen moiety of lipopolysaccharide but not the K54 group 2 capsule is important for urovirulence of an extraintestinal isolate of Escherichia coli
AU - Russo, Thomas A.
AU - Brown, Jennifer J.
AU - Jodush, Stephen T.
AU - Johnson, James R.
PY - 1996/6
Y1 - 1996/6
N2 - Group 2 capsules and lipopolysaccharides are regarded as important virulence factors in extraintestinal isolates of Escherichia coli, but their specific contributions to bladder and renal infections, if any, are unknown. Proven isogenic derivatives deficient in the K54 antigen alone (CP9.137), the 04 antigen alone (CP921), or both the K54 and 04 antigens (CP923) were compared with their wild-type parent (CP9 [O4/K54/H5]) for growth in human urine in vitro and for virulence in vivo in a mouse model of ascending urinary tract infection (UTI). Growth of CP9.137 and CP921 was equivalent to that of CP9 in human urine. CP923 demonstrated a small but reproducible decrease in log-phase growth but achieved the same plateau density. In the mouse model of UTI, the isogenic mutant deficient in the O4 antigen alone (CP921) and, to a greater degree, the derivative deficient in both the K54 and O4 antigens (CP923) were significantly less virulent in nearly all parameters measured. In contrast, the K54 knockout derivative was as virulent as its parent, CP9, in causing bladder infection and nearly as virulent in causing renal infection. These results demonstrate an important role for the O4 antigen moiety of lipopolysaccharide in the pathogenesis of UTI. The possibility that the K54 antigen also plays a minor role cannot be excluded.
AB - Group 2 capsules and lipopolysaccharides are regarded as important virulence factors in extraintestinal isolates of Escherichia coli, but their specific contributions to bladder and renal infections, if any, are unknown. Proven isogenic derivatives deficient in the K54 antigen alone (CP9.137), the 04 antigen alone (CP921), or both the K54 and 04 antigens (CP923) were compared with their wild-type parent (CP9 [O4/K54/H5]) for growth in human urine in vitro and for virulence in vivo in a mouse model of ascending urinary tract infection (UTI). Growth of CP9.137 and CP921 was equivalent to that of CP9 in human urine. CP923 demonstrated a small but reproducible decrease in log-phase growth but achieved the same plateau density. In the mouse model of UTI, the isogenic mutant deficient in the O4 antigen alone (CP921) and, to a greater degree, the derivative deficient in both the K54 and O4 antigens (CP923) were significantly less virulent in nearly all parameters measured. In contrast, the K54 knockout derivative was as virulent as its parent, CP9, in causing bladder infection and nearly as virulent in causing renal infection. These results demonstrate an important role for the O4 antigen moiety of lipopolysaccharide in the pathogenesis of UTI. The possibility that the K54 antigen also plays a minor role cannot be excluded.
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U2 - 10.1128/iai.64.6.2343-2348.1996
DO - 10.1128/iai.64.6.2343-2348.1996
M3 - Article
C2 - 8675348
AN - SCOPUS:0030004189
SN - 0019-9567
VL - 64
SP - 2343
EP - 2348
JO - Infection and immunity
JF - Infection and immunity
IS - 6
ER -