Characterization of a clinical isolate of Haemophilus influenzae with a high level of fluoroquinolone resistance

Haemophilus influenzae is one of the bacterial pathogens most likely to be involved in community-acquired respiratory infections in patients with chronic obstructive pulmonary disease. In this species, resistance to fluoroquinolones occurs at very low frequency although in such cases treatment failure has been reported.1 In 2003, a fluoroquinolone-resistant H. influenzae isolate was recovered from the sputum of an 80-year-old male patient with a history of bronchiectasis and residual lesions from old tuberculosis but with no history of treatment with fluoroquinolones. (extract from the letter)