Mycoplasma hominis infections occurring in cardiovascular surgical patients.
BACKGROUND
Postoperative Mycoplasma hominis sternal would or mediastinal infections are uncommon and difficult to diagnose. Atypical growth characteristics in routine bacterial culture, and the inability to demonstrate the organism on Gram stain, lead to delayed diagnosis of M hominis infections and increased morbidity.


METHODS
Postoperative purulent would drainage or acute mediastinitis caused by M hominis developed in 3 cardiovascular surgery patients. These patients were considered along with 9 patients previously reported in the literature.


RESULTS
Operative findings included moderately thick, gray purulent fluid with the degree of tissue necrosis related to duration of infection. Intraoperative Gram stain of wound or mediastinal drainage demonstrated no microorganisms, and initial bacterial cultures did not reveal microbial growth. After an average of 4.5 days of culture, minute translucent colonies of M hominis were identified. The institution of appropriate antimycoplasma therapy (doxycycline and clindamycin) was associated with clinical or microbiological cure in all patients. Sternal wound complications developed in 3 patients, and a chronic infection developed in 1 patient.


CONCLUSIONS
Empiric therapy for M hominis infection should be considered in patients with mediastinitis or a sternal wound infection in which organisms are not observed on Gram stain and are not readily cultured.
Sielaff
T D
TD
Department of Surgery, University of Minnesota Hospital and Clinic, Minneapolis 55455, USA.
Everett
J E
JE
Shumway
S J
SJ
Wahoff
D C
DC
Bolman
R M
RM
Dunn
D L
DL
D000208:Acute Disease; D000368:Aged; D006348:Cardiac Surgical Procedures; D001026:Coronary Artery Bypass; D016027:Heart Transplantation; D006801:Humans; D008297:Male; D008480:Mediastinitis / Q000188:drug therapy / Q000209:etiology / Q000382:microbiology; D008875:Middle Aged; D009175:Mycoplasma Infections / Q000175:diagnosis / Q000188:drug therapy / Q000209:etiology*; D011183:Postoperative Complications / Q000175:diagnosis / Q000188:drug therapy; D013249:Sternum / Q000601:surgery; D013530:Surgical Wound Infection / Q000188:drug therapy