Pathogenic significance of Klebsiella oxytoca in acute respiratory tract infection.

A retrospective study of all Klebsiella isolations from patients admitted to hospital with acute respiratory tract infections over a 27-month period was carried out. Ten of the Klebsiella isolations from sputum and one from a blood culture were identified as Klebsiella oxytoca. The clinical and radiological features of six patients are described. Four of these patients had lobar pneumonia, one bronchopneumonia, and one acute respiratory tract infection superimposed on cryptogenic fibrosing alveolitis. One of the patients with lobar pneumonia had a small-cell carcinoma of the bronchus. We concluded that Klebsiella oxytoca was of definite pathogenic significance in these six patients and of uncertain significance in the remaining five patients. Klebsiella oxytoca has not previously been described as a specific pathogen in the respiratory tract. Close co-operation between clinicians and microbiologists in the management of patients with respiratory infections associated with the Enterobacteriaceae is desirable.