Rapid species identification and biotyping of respiratory isolates of Haemophilus spp

Comparison of three commercial test systems for biotyping Haemophilus influenzae and Haemophilus parainfluenzae

The biotypes of Haemophilus influenzae and Haemophilus parainfluenzae isolates were determined with three commercially available biochemical test kits: the IDS RapID NH system, the Neisseria-Haemophilus identification test (NHI card), and the API NH strip. The API NH strip performed best, correctly classifying the biotypes of 371 of 380 (97.6%) different challenge strains.

Evaluation of four commercial methods for identification and biotyping of genital and neonatal strains of Haemophilus species

Four commercial methods for identification of Haemophilus species were evaluated in comparison to conventional methods using 188 genital and neonatal Haemophilus strains. In the case of discrepancies between results obtained by the different methods, DNA-DNA hybridization was performed. The four commercial systems and conventional methods showed excellent correlation of results in 167 strains (88%). DNA-DNA hybridization was performed in 8 strains with discrepant identification results and 13 strains with discrepant biotyping results. In 15 cases discrepancies could be explained by the fact that the strains belonged to a newly recognised species of Haemophilus.

Comparison of the RIM-H rapid identification kit with conventional tests for the identification of Haemophilus spp

A commercially available system, the RIM-H system (Austin Biological Laboratories, Austin, Tex.), was evaluated for its ability to rapidly and accurately identify various Haemophilus spp. A total of 110 clinical isolates were tested by both the RIM and conventional identification procedures. The RIM agreed with the standard identification for 100% of the Haemophilus influenzae (76 of 76) and 92.0% of the Haemophilus parainfluenzae (23 of 25) isolates tested. The identifications of Haemophilus parahaemolyticus, Haemophilus aphrophilus, and Haemophilus haemolyticus also correlated with those obtained by conventional methods. The RIM was found to be rapid and easy to use and was considered a suitable alternative to conventional identification procedures.

Evaluation of a selective medium for the isolation and differentiation of Haemophilus influenzae and Haemophilus parainfluenzae from the respiratory tract of chronic bronchitics

Respiratory tract specimens from chronic bronchitic patients were cultured for Haemophilus species on conventional chocolate agar and a modified sucrose medium in order to determine the accuracy of the new medium in differentiating Haemophilus influenzae from Haemophilus parainfluenzae strains. Haemophilus influenzae biotypes II and III and Haemophilus parainfluenzae biotypes I and II were found to be the predominant strains isolated from the respiratory tract. The modified sucrose medium was found to be a rapid and reliable means of differentiating Haemophilus influenzae from Haemophilus parainfluenzae by sucrose fermentation, on initial isolation.

Comparison of a new commercially prepared porphyrin test and the conventional satellite test for the identification of Haemophilus species that require the X factor

A test with a commercially developed porphyrin test agar was examined for the identification of Haemophilus spp. The porphyrin test agar method was compared with the conventional paper strip satellite method in tests with 187 isolates and was found to be easier to perform and interpret, giving a sensitivity of 98.7% and specificity of 94.7%.