SIGNIFICANCE OF COAGULASE-NEGATIVE STAPHYLOCOCCI IN THE URINARY TRACT
1982 Volume 30 Issue 11 Pages 1319-1336
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1982 Volume 30 Issue 11 Pages 1319-1336
Significance of coagulase-negative staphylococci (CNS) as pathogens of the urinary tract was studied both bacteriologically and clinically. Results were summarized as follows;
1) In the study of acute uncomplicated cystitis in the female, CNS were regarded as pathogens only when isolated with bacterial count of 105 bacteria per ml of urine or more as a single organism with significant pyuria of 10 cells per high power field or more. CNS which agreed with this criteria were isolated from approximately 10% of the patients with acute uncomplicated cystitis and were second commonest cause after Escherichia coli.
2) CNS occured predominantly in younger age group as compared with E. coli and were more frequent in summer than in winter season.
3) Urinary CNS disappeared by adequate treatment simultaneously with the disappearance of pyuria and symptoms. This could be regarded as a strong evidence that CNS had pathogenic role in acute uncomplicated cystitis.
4) Whereas, in most cases with complicated urinary tract infections, CNS were isolated with bacterial count of less than 103 bacteria per ml of urine in polymicrobial infections without significant pyuria. These findings suggested that significance of CNS was rather low at least in complicated urinary tract infections.
5) When CNS were classified by BAIRD-PARKER'S method, Staphylococcus subgroup II was most predominant in acute uncomplicated cystitis, followed by Staphylococcus subgroup IV. But in chronic complicated urinary tract infections, Staphylococcus subgroup II, subgroup V and Micrococcus subgroup 3 were predominant. When KLOOS & SCHLEIFER's classification was employed, S. saprophyticus was most prevalent and S. epidermidis was second in acute cases. Whereas in chronic cases, most strains were classified as S. epidermidis.
6) Most strains of S. saprophyticus were novobiocin resistant but some strains were sensitive, whereas 57% of S. epidermidis strains were novobiocin sensitive and 43% were resistant. Therefore, novobiocin sensitivity test seemed unsuitable for the differentiation of S. saprophyticus from S. epidermidis.
7) Difference of distribution in biovar, species or novobiocin susceptibility between acute and chronic cases suggested that source or mode of CNS infection in acute cases might be different from that of chronic cases.
