Isolation of Mycoplasma hominis in critically ill patients with pulmonary infections: clinical and microbiological analysis in an intensive care unit.

Objective: Mycoplasma hominis is a well recognized extragenital pathogen. However, it is an uncommon cause of respiratory infections in critically ill patients admitted to the intensive care unit (ICU).

Design And Setting: Prospective clinical investigation in a 21-bed ICU in a university hospital.

Patients: Seven patients requiring intensive care who developed a ICU-acquired pneumonia in which M. hominis was recovered from bronchoalveolar lavage and pleural fluid cultures.

Interventions: M. hominis was isolated in all patients by use of conventional bacteriological cultures. All strains were identified by 16S rRNA gene sequencing analysis. Patients' charts were reviewed for each case of infection.

Results: Seven strains of M. hominis were isolated during a 4-year period. All of these isolates were recovered from adult men admitted to the ICU and all had clinical signs of pneumonia. In three patients treatment for M. hominis with quinolones was associated with a good clinical response.

Conclusion: Suspicion of M. hominis pneumonia must be heightened particularly in critically ill patients. Therefore an understanding of the microbiology of this organism is essential to successfully treat patients with these infections that are not ordinarily covered with standard antibiotic therapy.