Related Experiment Videos
Urethral infection in male chimpanzees produced experimentally by Mycoplasma genitalium
Abstract:
Four young male chimpanzees were inoculated intra-urethrally with a strain (G37) of Mycoplasma genitalium which had been isolated from the urethra of a patient with non-gonococcal urethritis. Two of the chimpanzees became infected as indicated by persistent recovery of the organisms from the urethra for 13 weeks and by an antibody response measured by both metabolism inhibition and micro-immunofluorescence techniques. The numbers of organisms isolated from both animals increased about 4 weeks after inoculation and antibody development was first detected 1 week later. The infected animals developed a minimal and inconsistently detected urethral polymorphonuclear leucocyte response which was not seen in those that were uninfected, nor in a chimpanzee that had been given medium only. The organisms were not isolated and the cellular response was not observed after treatment of the infected chimpanzees with oxytetracycline. One of the animals that had been infected was re-inoculated with strain G37 six months after successful treatment, but although the titre of serum antibody had diminished to its original level urethral recolonization did not occur. The organisms in the inoculum were not attenuated, however, because they infected another chimpanzee that had not had previous experience of M. genitalium. The results are discussed in relation to the potential of this mycoplasma to produce urethritis in man.
Insights
Mycoplasma genitalium caused urethritis in two of four chimpanzees, showing infection via persistent organism recovery and antibody response. Treatment with oxytetracycline eliminated the infection, and re-inoculation did not lead to recolonization.
Area of Science:
- Urogenital Microbiology
- Infectious Diseases
- Primate Models
Background:
- Mycoplasma genitalium is a pathogen associated with non-gonococcal urethritis in humans.
- Understanding the pathogenesis of Mycoplasma genitalium requires suitable animal models.
Purpose of the Study:
- To investigate the infectivity and pathogenicity of Mycoplasma genitalium (strain G37) in a chimpanzee model.
- To evaluate the host response and the efficacy of oxytetracycline treatment.
Main Methods:
- Intra-urethral inoculation of four young male chimpanzees with Mycoplasma genitalium (strain G37).
- Monitoring organism recovery from urethral swabs for 13 weeks.
- Assessing host immune response using metabolism inhibition and micro-immunofluorescence antibody tests.
- Evaluating urethral polymorphonuclear leucocyte response.
- Administering oxytetracycline treatment to infected animals.
- Conducting a re-inoculation study after treatment.
Main Results:
- Two of four chimpanzees became infected, confirmed by persistent Mycoplasma genitalium recovery and seroconversion.
- Increased organism load observed around 4 weeks post-inoculation, with antibody response detected one week later.
- Minimal and inconsistent urethral polymorphonuclear leucocyte response in infected chimpanzees.
- Oxytetracycline treatment successfully eradicated the organisms and resolved the cellular response.
- Re-inoculation of a treated chimpanzee did not result in urethral recolonization, despite diminished antibody titers.
Conclusions:
- Mycoplasma genitalium can establish urethral infection in chimpanzees, mimicking aspects of human non-gonococcal urethritis.
- The chimpanzee model is useful for studying Mycoplasma genitalium pathogenesis and evaluating treatment strategies.
- Immunity following infection and treatment may confer some protection against subsequent urethral colonization.