PT  - JOURNAL ARTICLE
AU  - W Hansen
AU  - E Schoutens
AU  - E Yourassowsky
TI  - Significance of the detection of beta-galactosidase and of beta-xylosidase in the taxonomic study of the genus Haemophilus.
AID  - 10.1136/jcp.32.10.1058
DP  - 1979 Oct 01
TA  - Journal of Clinical Pathology
PG  - 1058--1060
VI  - 32
IP  - 10
4099  - http://jcp.bmj.com/content/32/10/1058.short
4100  - http://jcp.bmj.com/content/32/10/1058.full
SO  - J Clin Pathol1979 Oct 01; 32
AB  - A total of 314 strains of Haemophilus, isolated from clinical samples, were studied for the production of beta-galactosidase and beta-xylosidase. None of the H. influenzae strains studied (9 beta-lactamase positive strains and 129 beta-lactamase negative strains) possessed these enzymes. Both enzymes were almost constantly observed among strains of H. paraphrophilus (10 strains studied) and of H. paraphrohaemolyticus (9 strains studied). Among the other species (H. parainfluenzae, 55 strains; H. haemolyticus, 5 strains; H. parahaemolyticus, 97 strains), beta-galactosidase was present in about 30% of the strains studied whereas beta-xylosidase was detected occasionally (3% of the strains studied). Detection of these two enzymes could be a valuable test for the taxonomic study of the genus Haemophilus. However, the type of substrate used for the detection of beta-xylosidase is important: use of the para-nitro-phenyl-beta-xylopyranoside yielded more positive results than the use of its ortho-isomer.