[Determination of biotypes of the genus Haemophilus and study of the sensitivity to ampicillin in hospital practice. Study of 500 strains].

The authors use a biologic micromethod to identify five hundred species and biotypes of Haemophilus strains isolated from clinical specimens. The relation between biotypes and infection is studied. A rapid and highly accurate test to search for beta-lactamase production is done to determined the actual ampicillin resistance in Haemophilus for different biotypes. 6.9 p. cent of Haemophilus influenzae and 17.5 p. cent of Haemophilus para-influenzae were found resistant to ampicillin.