Isolation, Characterization and Antibiotic Susceptibility of Mycoplasma hominis and Ureaplasma urealyticum from Infertile and Pregnant Women in Lagos, Nigeria

Background: Mycoplasma hominis and Ureaplasma urealyticum are potentially pathogenic agents, playing aetiologicroles in both genital infections and infertility. In human in-vitro fertilization systems, the presence of U. urealyticum in either semen or female genital tract results in a decline of pregnancy rate per embryo transfer as well as neonatal infections. M. hominis has been associated with bacterial vaginosis, pelvic inflammatory disease, postabortal fever, and a number of gynecological infections.

Aim: The aim of this study is to isolate, characterize and determine the antibiotic susceptibility of M. hominis and U. urealyticum isolates from infertile and pregnant women in Lagos, Nigeria.

Materials and Methods: The samples were collected from Obstetrics and Gynaecology clinics of Lagos University Teaching Hospital and 68 Nigerian Army reference hospital Yaba. A total of 270 specimens of urine and HVS were collected from 135 women attending the clinics for routine consultations. One hundred and eighty HVS and urine specimens were from 90 married infertile women attending the clinics as part of a work-up for fertility investigations after failing to conceive for at least one year of unprotected sexual intercourse. Ninety HVS and urine specimens were from 45 pregnant women attending the clinics for routine antenatal care. None of the subjects expressed any symptom of genitourinary tract infections. All the specimens were inoculated into Mycoplasma broth and subsequently Blood Agar plates, incubated appropriately and identified. Antibiotic susceptibility tests were carried out on the 52 isolates. Polymerase chain reaction (PCR) was used to detect the organisms in all the collected specimens.

Results: Of the 90 HVS specimens collected from infertile women, 9 (10.0%) were positive for M. hominis, while 21 (23.3%) were positive for U. urealyticum. For the pregnant women using HVS specimens, 6 (13.3%) were positive for M. hominis while 5 (11.1%) were positive for U. urealyticum. The first void urine specimens gave lower values in both the infertile and pregnant women. Prevalence of U. urealyticum was higher in infertile women than in pregnant women (p<0.05). The PCR technique gave higher values of 78.5% and 71.1% using HVS specimens for the infertile and pregnant women respectively for Mycoplasma/Urealyticum species. The antibiotic susceptibility test showed that all the isolates of M. hominis (n=18) were sensitive to Tetracycline (100%) and Ciprofloxacin (100%) while all the isolates of U. urealyticum (n=34) were sensitive to Tetracycline (100%) and Erythromycin (100%).

Conclusion: The significantly higher prevalence of U. urealyticum infection in infertile women (23.3%) compared to the lower prevalence in pregnant women (11.1%) may suggest that U. urealyticum can be incriminated in infertility. HVS specimen is preferred over urine specimens for the detection of Mycoplasma and Ureaplasma. Application of the PCR method, where affordable, is recommended for rapid and sensitive detection of Mycoplasma and Ureaplasma in HVS specimens. Tetracycline may be the antibiotic of choice, unless contraindicated, for the treatment of the infections, although the sample size was small.