What is Mycoplasma hominis?

From the Guidelines

Mycoplasma hominis is considered an etiologic agent of pelvic inflammatory disease (PID), along with other sexually transmitted organisms, and should be treated accordingly. Mycoplasma hominis is a type of bacteria that lacks a cell wall and can cause various infections in humans, including PID, which comprises a spectrum of inflammatory disorders of the upper genital tract among women 1. It commonly colonizes the urogenital tract and can be transmitted sexually. Infections caused by Mycoplasma hominis include pelvic inflammatory disease, postpartum fever, urinary tract infections, and in rare cases, systemic infections in immunocompromised patients.

Key Points to Consider

• Mycoplasma hominis can cause PID, as well as other infections, and should be treated with effective antibiotics 1.
• The lack of a cell wall in Mycoplasma hominis makes it naturally resistant to antibiotics that target cell wall synthesis, such as beta-lactams (penicillins and cephalosporins).
• Treatment options for Mycoplasma hominis infections typically include tetracyclines, fluoroquinolones, or clindamycin, but the most effective treatment should be chosen based on the specific case and patient factors 1.
• Testing for Mycoplasma hominis infection typically involves PCR or culture methods, as the organism is difficult to detect through conventional methods.

Treatment Considerations

• Tetracyclines like doxycycline may be considered for treatment, but the specific dosage and duration should be determined based on the individual case and current guidelines.
• Alternative treatments, such as fluoroquinolones or clindamycin, may also be effective, but the choice of antibiotic should be guided by the most recent and highest-quality evidence 1.
• Macrolides like azithromycin are not effective against Mycoplasma hominis due to natural resistance, and should not be used as a first-line treatment.

From the Research

Mycoplasma Hominis Overview

• Mycoplasma hominis is a type of bacteria that can cause infections in humans, particularly in the genital and extragenital areas 2, 3, 4.
• It is often associated with sexually transmitted diseases, infertility, and risky sexual behavior 2.
• The bacteria can be resistant to certain antibiotics, making treatment challenging 2, 3, 4.

Antibiotic Susceptibility and Treatment

• Mycoplasma hominis is susceptible to tetracyclines, such as doxycycline, and macrolides, such as azithromycin 2, 3, 4.
• However, resistance to these antibiotics is common, and alternative treatments may be necessary 2, 3, 4.
• Clindamycin is an alternative to tetracyclines, and moxifloxacin can be used as a second-line treatment 3, 5.
• The optimal duration of antibiotic therapy for Mycoplasma hominis infections is not established, but 10-14 days is suggested 4.

Extragenital Infections

• Mycoplasma hominis can cause extragenital infections, such as bloodstream invasion, central nervous system infections, and joint infections 4.
• These infections require effective antibiotic treatment, and tetracyclines are generally the drug of choice 4.
• In contrast, M. hominis bacteremia in women with febrile abortion and postpartum fever is often transient and self-limiting, and does not generally require treatment 4.

Resistance and Treatment Guidelines

• Resistance-guided therapy using doxycycline-moxifloxacin and doxycycline-2.5 g azithromycin is effective for treating Mycoplasma genitalium infections, which can inform treatment for Mycoplasma hominis 5.
• The inclusion of moxifloxacin in resistance-guided strategies and the use of 2.5 g azithromycin are supported by current guidelines 5.