Mycoplasma hominis as a cause of empyema is rare. We report a case of empyema caused by M. hominis following a caesarean section. A 28-year-old woman at 39 weeks and one day of pregnancy was admitted to our hospital and underwent an emergency caesarean section because of premature rupture of membranes. On postoperative day 2, she developed a fever, and flomoxef was administered. A pleural effusion developed on the right side. A diagnosis of empyema was made, and sulbactam/ampicillin was administered. However, the patient's clinical condition did not improve. Numerous small pinpoint colonies, which did not yield visible bacteria on a Gram stain, were observed on a plate of pleural fluid culture, and M. hominis empyema was suspected. Based on this result, antibiotic therapy was switched to clindamycin, and the patient's clinical condition improved rapidly. M. hominis was detected in the pleural fluid by polymerase chain reaction (PCR) assay. M. hominis should be considered a causative pathogen for empyema following a caesarean section.
Keywords: Bloodstream infection; Mycoplasma hominis; caesarean section; empyema; pregnancy.