Isolation of spheroplastic forms of Haemophilus influenzae from sputum in conventionally treated chronic bronchial sepsis using selective medium supplemented with N-acetyl-D-glucosamine: possible reservoir for re-emergence of infection.Br Med J (Clin Res Ed) 1984; 289 doi: https://doi.org/10.1136/bmj.289.6456.1409 (Published 24 November 1984) Cite this as: Br Med J (Clin Res Ed) 1984;289:1409
- D Roberts,
- E Higgs,
- A Rutman,
- P Cole
The isolation rate of Haemophilus influenzae from patients with persistent production of purulent sputum has been increased by the routine use of a selective medium. Nevertheless, some purulent sputum still fails to yield a pathogen. The selective medium was supplemented with N-acetyl-D-glucosamine to encourage primary isolation of colony forming, spheroplastic H influenzae, which reverted to normal forms on subculture. On the basis of in vitro experiments it is postulated that these spheroplastic forms of H influenzae may be induced by inadequate antimicrobial chemotherapy and may be responsible for re-emergence of symptoms in these patients during or shortly after stopping chemotherapy.