[Study of distribution of serovars of Enterococcus faecalis clinical isolates]

Serotyping was conducted of E. faecalis strains isolated from various clinical specimens, and the distribution of the serovars was investigated. To date, 21 serovars of E. faecalis have been identified. The most common serovars in Japanese 770 strains were types 2 (30.6%), 7 (13.9%), 1 (12.2%) and 4 (6.9%), and these four serovars accounted for 63.6% of the total strains. The most common serovars in USA 200 strains were types 1 (22.5%), 4 (14.5%) and 2 (14.0%). The most common serovars in UK 65 strains were types 2 (24.6%), 4 (13.8%) and 9 (7.7%). The distribution of E. faecalis serovars differ as a function of the country of origin. Next, serological classification was performed for E. faecalis strains isolated from various Japanese clinical specimens. For the strains obtained from the urine, the most common serovars were types 2 (32.7%) and 7 (14.6%). Similarly, the most common serovars of the strains isolated from the various other clinical specimens were as follows: types 7 (35.0%) and 2 (15.0%) from pus; types 7 (44.4%) and 2 (33.3%) from sputum; types 2 (22.3%) and 1 (13.1%) from blood; and types 2 (34.9%) and 1 (27.9%) from the vaginal smear. It had no definite pattern for the distribution of serovars. The distribution of serovars varied in accordance with isolated years. Accordingly, the data obtained in these studies revealed that the distributions of E. faecalis serovars differ as a function of the geographical area of origin, the clinical specimen of origin and the year of origin. This approach is useful for serological classification of E. faecalis strains, and it is thought that it will be useful for epidemiological studies of this bacterium.