A Mycoplasma hominis Nucleic Acid Amplification (NAA) test identifies the presence of Mycoplasma hominis, a bacterium that can reside in the human body. This laboratory method detects the organism’s genetic material.
Understanding Mycoplasma Hominis
Mycoplasma hominis is a unique bacterium that lacks a rigid cell wall. This structural difference makes it naturally resistant to certain antibiotics, such as penicillin, which target bacterial cell walls. It is among the smallest known free-living organisms capable of self-replication.
This bacterium commonly inhabits human genitourinary tracts, where it can exist as part of the normal microbial flora without causing symptoms. However, Mycoplasma hominis is an opportunistic microorganism. This means it can cause an infection when the body’s natural balance is disrupted or the immune system is compromised. Growing this organism in a laboratory setting can be challenging due to its fastidious nutritional requirements, including a need for cholesterol.
The Role of NAA Testing
Nucleic Acid Amplification (NAA) is a molecular diagnostic method preferred for detecting Mycoplasma hominis. This test works by identifying and multiplying minute amounts of the bacterium’s unique genetic material, or DNA, from a patient sample. This amplification process allows for the detection of the organism even when present in very low numbers.
NAA testing is well-suited for Mycoplasma hominis because the bacterium is difficult to grow using traditional laboratory culture methods. Its slow growth and specific environmental needs make culture-based diagnosis time-consuming and less reliable. NAA tests offer high sensitivity, meaning they are very good at detecting the presence of the organism when it is there, and high specificity, meaning they are accurate in identifying Mycoplasma hominis specifically.
Infections and Their Characteristics
Mycoplasma hominis is primarily associated with infections of the genitourinary tract. In women, it can contribute to conditions such as cervicitis, pelvic inflammatory disease (PID), and bacterial vaginosis. It has also been linked to postpartum fever and endometritis following childbirth. Men can develop non-gonococcal urethritis due to this bacterium.
Symptoms associated with these infections can vary but may include vaginal discharge, pelvic pain, urethral inflammation, itching, or penile discharge. Beyond the genitourinary system, Mycoplasma hominis can cause less common but serious infections. These occur particularly in newborns and individuals with weakened immune systems, and can include conjunctivitis, respiratory distress, meningitis, and pneumonia in infants. Post-surgical wound infections have also been reported.
The bacterium is primarily transmitted through sexual contact. Vertical transmission from mother to child during birth is another known mode of spread. Individuals can also carry the bacterium asymptomatically, meaning they have no overt signs of infection.
Diagnosis and Management
Diagnosing an infection caused by Mycoplasma hominis typically begins with a healthcare provider’s evaluation, assessing symptoms and risk factors. Sample collection, such as a cervical or urethral swab, or a urine sample, is then performed. Nucleic Acid Amplification (NAA) testing is the preferred method for detecting Mycoplasma hominis in these samples. A positive NAA test result indicates the presence of the organism’s genetic material, confirming its involvement.
Management of Mycoplasma hominis infections usually involves antibiotic treatment. Due to the bacterium’s lack of a cell wall, it is naturally resistant to antibiotics like penicillin and other beta-lactams. Effective treatment options commonly include antibiotics from the tetracycline class, such as doxycycline, or macrolides, fluoroquinolones, and clindamycin. Treating sexual partners is often important to prevent reinfection and further spread. The emergence of antibiotic resistance is an increasing concern, requiring careful consideration in treatment choices.