Detection of Mycoplasma fermentans in healthy students and patients with congenital immunodeficiency

Objectives: To determine the prevalence of M. fermentans at different anatomical sites in healthy subjects and in patients with congenital immunodeficiency, and to determine whether haematogenous invasion occurs among the latter. Methods: A polymerase chain reaction (PCR) assay was used to detect M. fermentans in throat swabs and urine specimens from healthy students, and from patients with congenital immunodeficiency. Peripheral blood mononuclear cells (PBMCs) from the latter group were also tested. Results: Sixty-two students provided throat swabs, of which 11 (18%) were M. fermentans-positive; 46 provided urine specimens, of which eight (17%) were positive. Of the 45 students who provided both throat and urine specimens, 12 (27%) had M. fermentans-positive samples; four in the throat and urine, four in the throat only and four in the urine only. Nineteen of the 20 patients with congenital immunodeficiency provided throat swabs, of which one (5%) was M. fermentans-positive; 19 also provided urine specimens, of which three (16%) were positive. All of the immunodeficient patients provided a PBMC sample, but none was positive. Conclusion: M. fermentans occurred frequently at mucosal sites in a healthy population and in subjects with congenital immunodeficiency. However, such a deficiency did not lead to overt haematogenous invasion.