Pseudomonas fluorescens

Question

Is intravenous antibiotic therapy necessary when Pseudomonas fluorescens is found in sputum of a CF patient? Is this type of Pseudomonas dangerous? Is the patient considered as colonised by pseudomonas? Thank you for your reply.

Answer

Dear questioner,
Pseudomonas fluorescens is a microb which is rather often found in the population. However, according to our long-term experience, it is rarely found in CF-patients. In contrast to Pseudomonas aeruginosa, there is no patient in whom this bacterium could be detected for a long period of time. In the case that the patient has no clinical signs of respiratory tract infection e.g. coughing and the presence of ps. fluorescens is detected only by cultivation, antibiotic treatment is not necessary. When there are clinical signs of infection, v.s. oral - not i.v. - antibiotic treatment is indicated. There is no specific evidence in the scientific literature for a pathogenic role of Pseudomonas fluorescens. We would not consider patient with this type of infection as colonised and wouldn´t separate him among Pseudomonas aeruginosa chronically infected patients.

However, it can not be excluded that actually P. aeruginosa had been misclassified as P. flourescens as mistaking of both germs happen during microbiological analysis. Therefore, it is advisable to control the sputum finding of P. fluorescens soon or repeatedly (e.g 2-4 weeks after the first finding) in order to be able to react immediately to a possible positive finding of P. aeruginosa.

Best regards
Věra Vávrová

04.01.2009