Antimicrobial susceptibility of Haemophilus influenzae isolates in Wellington hospital.

103 strains of Haemophilus influenzae isolated during June to October 1980 were tested for susceptibility to seven antimicrobials using the Dynatech MIC 2000 system. Six strains (5.8 percent) were resistant to ampicillin (one type b, five untypable) and all of these produced beta-lactamase. Two of these six strains were isolated from blood; one untypable strain in an adult with pneumonia, and one type b strain in a child with acute epiglottitis. No resistance to the other six antimicrobials was found, except for one strain resistant to tetracycline. All isolates were biotyped, but there were no correlation between biotype and antimicrobial resistance.