Characterization of non-type B Haemophilus influenzae strains isolated from patients with invasive disease. The HI Study Group.
Forty-one non-type b Haemophilus influenzae isolates from cases of invasive disease were characterized. By PCR capsular genotyping, 33 nonencapsulated strains, 4 type f isolates, and 4 b(-) strains were identified. By pulsed-field gel electrophoresis, the nonencapsulated isolates exhibited great genetic heterogenicity, whereas the type f and the b(-) strains seemed to have a clonal spread. Occurrence of the hifA gene was found by PCR in 18% of the nonencapsulated, 50% of the b(-), and all of the type f strains. Hemagglutinating fimbriae were generally expressed by nonencapsulated isolates when fimbrial gene hifA was present. Two nonencapsulated isolates not susceptible to ampicillin were detected; no strains were positive for beta-lactamase production.
Cerquetti
M
M
Laboratory of Bacteriology and Medical Mycology, Istituto Superiore di Sanità, 00161 Rome, Italy. mcerquet@iss.it
Ciofi degli Atti
M L
ML
Renna
G
G
Tozzi
A E
AE
Garlaschi
M L
ML
Mastrantonio
P
P
D000667:Ampicillin / Q000494:pharmacology; D016667:Bacterial Capsules / Q000235:genetics; D001425:Bacterial Outer Membrane Proteins / Q000235:genetics; D016521:Electrophoresis, Gel, Pulsed-Field; D036781:Fimbriae Proteins; D010861:Fimbriae, Bacterial; D005838:Genotype; D006192:Haemophilus Infections / Q000382:microbiology*; D006193:Haemophilus influenzae / Q000145:classification* / Q000187:drug effects / Q000302:isolation & purification; D006801:Humans; D008826:Microbial Sensitivity Tests; D016133:Polymerase Chain Reaction; D001618:beta-Lactamases / Q000378:metabolism
D001425:Bacterial Outer Membrane Proteins; C090992:HifA protein, Haemophilus influenzae; D036781:Fimbriae Proteins; D000667:Ampicillin; D001618:beta-Lactamases