Saturday 26
FREQUENCY OF E.
COLI K ANTIGENS IN
URINARY-TRACT INFECTIONS IN CHILDREN B.
KAIJSER U. JODAL J.
L. A. HANSON G. LIDIN-JANSON B. ROBBINS
Institute of Medical Microbiology, University of Göteborg, Sweden, and Division of Bacterial Products, Bureau of Biologics, Food and Drug Administration, Bethesda, Maryland 20014, U.S.A.
The
somatic (O) and capsular (K) antigens of Escherichia coli from the urine of patients with acute pyelonephritis, acute cystitis, and asymptomatic bacteriuria, and in the fæces of healthy schoolchildren have been investigated. Typing antisera for sixteen capsular acidic polysaccharide K antigens were used, and five (numbers 1, 2, 3, 12, and 13) accounted for 70% of isolates from patients with acute pyelonephritis. These five K antigens were found to a lesser extent in the three other study groups. Thus, only a few K polysaccharides are associated with virulent properties of E. coli for the upper urinary tract. This finding is similar to the association of only some capsular types of pneumococci, meningococci, and Hœmophilus influenzœ with invasiveness. The identifi-
Summary
cation of virulence markers for E. coli associated with upper-urinary-tract disease may permit more successful control with reference to preventive immunisation.
Introduction Escherichia coli is the aetiological agent for at least 90% of primary urinary-tract infections (u.T.i.) in children.’-3 Capsular polysaccharide K antigens have been related to invasiveness of E. coli for upper u.T.I.4-10 which might be because of their suggested comparative resistance to antibody-mediated complement-dependent activities.8 Kaijser found a relationship FREQUENCY
(%)
CYSTITIS I
March 1977
between the amount of capsular polysaccharide per bacterial cell and the invasiveness of Kl strains for upper V.T.I.9 The Kl antigen was also found to be a virulence factor for E. coli causing neonatal meningitis." For these reasons, we have compared the distribution of K capsular polysaccharide antigens in urine isolates from children with acute pyelonephritis, acute cystitis, and asymptomatic bacteriuria, and in fxces of healthy children ; similarly we have compared the distribution of the corresponding 0 antigens, also suggested to be related to pathogenicity. 12-11 We have found that some K antigens are more frequently associated with invasive upper V.T.I. Patients and Methods 346 patients, age 3 months to 15 years, treated for U.T.i. at the Children’s Hospital, Goteborg, Sweden, were studied (see accompanying table). Acute pyelonephritis (N=118), acute cystitis (N=108), or asymptomatic bacteriuria (N=120) were diagnosed according to criteria already established.’ All acute infections were the patients’ first known attacks of U.T.I. Strains were isolated from ixcal samples of 100 healthy schoolchildren from two schools in Goteborg, Sweden.16 Urine from all of these control children was cultivated to exclude U.T.I. Bacterial strains, obtained from the W.H.O. Escherichia Centre, Statens Seruminstitut, Copenhagen, Denmark, were used for antiserum production corresponding to sixteen different K antigens and sixty-nine different 0 antigens,.’6 K antisera were available for Kl, 2, 3, 6, 7, 12, 13, 14, 13, 51, 32, 53, 54, 92, 95, and 100-i.e., acidic polysaccharide K antigens with high electrophoretic mobility. Antisera to E. coli 0 as well as K antigens were prepared as described previously. 17 18 Kantiserum was also produced by immunisation of a horse with formalin-treated meningococcal group-B strain B-11, since there is immunochemical similarity between the meningococcal groups B and E. coli K1capsular polysaccharides. 19 20 For identification and quantitation all bacteria were cultivated on blood agar as well as on Drigalski plates according to Kauffmann.2’ The quantitation of bacteria in urine samples was done using calibrated loops for cultivation. K-typing was done with cultivations in antiserum-agar plates containing
OF E. COLI K ANTIGENS IN URINARY ISOLATES FROM CHILDREN WITH ACUTE PYELONEPHRITIS
(C), OR ASYMPTOMATIC
BACTERIURIA
(A.B.U.) AND IN
I
I
—————————————.————————————————————!—————————!—————————!————————!————————!————————t———
K antigens mentioned
in
Methods,
(P), ACUTE (N)
STOOL ISOLATES FROM HEALTHY CHILDREN
not
shown
in
table
were not
detected.
8013 ©
664 0-73% glucose.22 O-grouping of the strains was done by agglutination in buffered saline as previously described. 16
The X2 test or the conditional used for statistical analysis.23
test
described
by
Lehman
was
Results
70% of the acute pyelonephritis strains (table) were classified serologically with only five K antigens, numbers 1, 2, 3, 12, and 13. There were significantly more K-typable strains from patients with pyelonephritis (70%) than from those with
cystitis (53%) or asymptomatic bacteriuria (42%) or from faeces of healthy children (55%). Kl was the most frequent K antigen in all groups. Two of the K antigens, Kl and K12, were found more often in strains causing pyelonephritis (pyelonephritis compared with cystitis for Kl, p
FREQUENCY OF E.
COLI K ANTIGENS IN
URINARY-TRACT INFECTIONS IN CHILDREN B.
KAIJSER U. JODAL J.
L. A. HANSON G. LIDIN-JANSON B. ROBBINS
Institute of Medical Microbiology, University of Göteborg, Sweden, and Division of Bacterial Products, Bureau of Biologics, Food and Drug Administration, Bethesda, Maryland 20014, U.S.A.
The
somatic (O) and capsular (K) antigens of Escherichia coli from the urine of patients with acute pyelonephritis, acute cystitis, and asymptomatic bacteriuria, and in the fæces of healthy schoolchildren have been investigated. Typing antisera for sixteen capsular acidic polysaccharide K antigens were used, and five (numbers 1, 2, 3, 12, and 13) accounted for 70% of isolates from patients with acute pyelonephritis. These five K antigens were found to a lesser extent in the three other study groups. Thus, only a few K polysaccharides are associated with virulent properties of E. coli for the upper urinary tract. This finding is similar to the association of only some capsular types of pneumococci, meningococci, and Hœmophilus influenzœ with invasiveness. The identifi-
Summary
cation of virulence markers for E. coli associated with upper-urinary-tract disease may permit more successful control with reference to preventive immunisation.
Introduction Escherichia coli is the aetiological agent for at least 90% of primary urinary-tract infections (u.T.i.) in children.’-3 Capsular polysaccharide K antigens have been related to invasiveness of E. coli for upper u.T.I.4-10 which might be because of their suggested comparative resistance to antibody-mediated complement-dependent activities.8 Kaijser found a relationship FREQUENCY
(%)
CYSTITIS I
March 1977
between the amount of capsular polysaccharide per bacterial cell and the invasiveness of Kl strains for upper V.T.I.9 The Kl antigen was also found to be a virulence factor for E. coli causing neonatal meningitis." For these reasons, we have compared the distribution of K capsular polysaccharide antigens in urine isolates from children with acute pyelonephritis, acute cystitis, and asymptomatic bacteriuria, and in fxces of healthy children ; similarly we have compared the distribution of the corresponding 0 antigens, also suggested to be related to pathogenicity. 12-11 We have found that some K antigens are more frequently associated with invasive upper V.T.I. Patients and Methods 346 patients, age 3 months to 15 years, treated for U.T.i. at the Children’s Hospital, Goteborg, Sweden, were studied (see accompanying table). Acute pyelonephritis (N=118), acute cystitis (N=108), or asymptomatic bacteriuria (N=120) were diagnosed according to criteria already established.’ All acute infections were the patients’ first known attacks of U.T.I. Strains were isolated from ixcal samples of 100 healthy schoolchildren from two schools in Goteborg, Sweden.16 Urine from all of these control children was cultivated to exclude U.T.I. Bacterial strains, obtained from the W.H.O. Escherichia Centre, Statens Seruminstitut, Copenhagen, Denmark, were used for antiserum production corresponding to sixteen different K antigens and sixty-nine different 0 antigens,.’6 K antisera were available for Kl, 2, 3, 6, 7, 12, 13, 14, 13, 51, 32, 53, 54, 92, 95, and 100-i.e., acidic polysaccharide K antigens with high electrophoretic mobility. Antisera to E. coli 0 as well as K antigens were prepared as described previously. 17 18 Kantiserum was also produced by immunisation of a horse with formalin-treated meningococcal group-B strain B-11, since there is immunochemical similarity between the meningococcal groups B and E. coli K1capsular polysaccharides. 19 20 For identification and quantitation all bacteria were cultivated on blood agar as well as on Drigalski plates according to Kauffmann.2’ The quantitation of bacteria in urine samples was done using calibrated loops for cultivation. K-typing was done with cultivations in antiserum-agar plates containing
OF E. COLI K ANTIGENS IN URINARY ISOLATES FROM CHILDREN WITH ACUTE PYELONEPHRITIS
(C), OR ASYMPTOMATIC
BACTERIURIA
(A.B.U.) AND IN
I
I
—————————————.————————————————————!—————————!—————————!————————!————————!————————t———
K antigens mentioned
in
Methods,
(P), ACUTE (N)
STOOL ISOLATES FROM HEALTHY CHILDREN
not
shown
in
table
were not
detected.
8013 ©
664 0-73% glucose.22 O-grouping of the strains was done by agglutination in buffered saline as previously described. 16
The X2 test or the conditional used for statistical analysis.23
test
described
by
Lehman
was
Results
70% of the acute pyelonephritis strains (table) were classified serologically with only five K antigens, numbers 1, 2, 3, 12, and 13. There were significantly more K-typable strains from patients with pyelonephritis (70%) than from those with
cystitis (53%) or asymptomatic bacteriuria (42%) or from faeces of healthy children (55%). Kl was the most frequent K antigen in all groups. Two of the K antigens, Kl and K12, were found more often in strains causing pyelonephritis (pyelonephritis compared with cystitis for Kl, p
