Urogenital mycoplasmas (Mycoplasma hominis, Mycoplasma genitalium, Ureaplasma parvum and Ureaplasma urealyticum): diagnostic interest by PCR

 

Information 22-04-2014.

 

Four species of mycoplasmas (Mycoplasma hominis, Mycoplasma genitalium, Ureaplasma urealyticum and Ureaplasma parvum) (Family Mycoplasmataceae, genera Mycoplasma and Ureaplasma) may be involved in different types of urogenital infections.

     

Mycoplasma genitalium

 

Mycoplasma genitalium was isolated in 1980 from urethral samples from two patients with non - gonococcal urethritis-is transmitted through sexual contact, but their share of genital infections is not fully elucidated. In males, it has been associated with arthritis and urethritis (or reactive arthritis); in both sexes, with the presence of exudate and dysuria; and in women with vaginal pruritus, dyspareunia, bacterial vaginosis and pelvic inflammatory disease (PID: Pelvis Inflammatory Disease).

 

Mycoplasma hominis

 

Mycoplasma hominis is commonly found as part of the flora of the urogenital tract, especially in women and sexually active adult males. It has been linked with various infections as postabortal fever, postpartum fever, salpingitis, bacterial vaginosis and pelvic inflammatory disease. In addition, it has been found in extragenital infections in immunocompromised patients. It has also been linked to meningitis, pneumonia, abscesses in the newborn. However, it is also considered normal microflora present in 20% of men and 40% of women.

 

Mycoplasma hominis, has also been linked to cases of female infertility, premature birth, ectopic pregnancy and low birth weight. In addition, it has been isolated from cases of pharyngitis and respiratory disease, septic arthritis, infection of the central nervous system, and infertility in women.

 

Bacterial vaginosis is overgrowth of bacteria in the reproductive tract of women, and although it may appear any woman, is more related to sexually active women. Vaginosis occurs when the normal vaginal pH is altered, when decrease defenses, with Douching with placing some contraceptive devices, vaginal diaphragm, or buffers, or with the administration of some antibiotics that kill bacteria normal vaginal flora (Mobiluncus spp., Peptostreptococcus spp., Gardnerella vaginalis and Bacteroides spp.), Mycoplasma hominis leaving dominant and causing an imbalance of the normal flora. Symptoms include itching vaginosis and vaginal irritation, along with the elevation of vaginal pH, and the presence of vaginal discharge fishy gray or dark.

 

Ureaplasma urealyticum parvum and Ureaplasma (formerly Ureaplasma urealyticum biovar 1, being 1, 3, 6, 14.)

 

Ureaplasma urealyticum and Ureaplasma parvum (Mycoplasmataceae Family, Genus Ureaplasma), genital part of normal flora of men and women, and are found in 70% of sexually active people. It has been linked to human diseases following: non-gonococcal urethritis (unspecific), infertility, chorioamnionitis, premature birth, and in the prenatal period pneumonia, bronchopulmonary dysplasia and meningitis. In some of these situations, their significance is doubtful. Some isolated considered Ureaplasma urealyticum, actually correspond to Ureaplasma parvum.

 

Ureaplasma urealyticum, Ureaplasma parvum and Mycoplasma hominis have been isolated from amniotic fluid without having been a previous rupture of membranes, even at 16-20 weeks of gestation. Ureaplasma urealyticum / parvum Ureaplasma may cause chronic chorioamnionitis silent and infants. Ureaplasma urealyticum, Mycoplasma hominis Ureaplasma parvum and can cause chronic infections of the CNS. In infants with very low weight, Ureaplasma urealyticum / parvum Ureaplasma, can cause chronic lung disease.

 

Treatment of urogenital mycoplasma infections

 

Mycoplasmas lack cell wall peptidoglycan and also PBPs (penicillin binding proteins) on the cytoplasmic membrane, so that they are resistant to all active antimicrobial agents against cell wall, ?-lactam like. They are also resistant to rifampicin by having an RNA polymerase different, polymyxins, nalidixic acid, sulfonamides and trimethoprim.

 

Useful antimicrobials are those belonging to the group of tetracyclines, macrolides and related (lincosamides, streptogramins, ketolides), aminoglycosides and fluoroquinolones. These antimicrobials also obtained good intracellular concentrations, so are of interest as some species of mycoplasma, such as Mycoplasma hominis, Mycoplasma genitalium, and are located within the cells survive.

 

It has been found Mycoplasma hominis resistance to tetracyclines (3 to 30% of cases), by acquiring the tetM gene. However, the new derivatives of tetracyclines as Glycylcycline, are active against resistant strains to tetracyclines. Mycoplasma hominis is resistant to erythromycin and other macrolides 14 atoms (roxithromycin, clarithromycin, dirithromycin) and to 15 atoms (azithromycin). However, it is sensitive to macrolide 16 atoms (josamycin).

 

By macrolide resistance, the two groups of drugs of choice are the fluoroquinolones and tetracyclines. Some of the infections can be treated with a single antibiotic, such as non-gonococcal urethritis acute. The combined therapy is indicated for polymicrobial infections such as pelvic inflammatory disease (PID). It is also indicated in combination of antimicrobial infections in immunosuppressed serious combining doxycycline and clindamycin, and doxycycline or a fluoroquinolone. In some serious infections in which the diffusion of the antimicrobial is important, as in the central nervous system, to be used despite the risks, chloramphenicol, thiamphenicol or derivative.

 

Treatment of some specific situations:

 

Gonococcal urethritis-: targeted therapy should be administered to all pathogens involved in gonococcal urethritis-(Mycoplasma hominis, Mycoplasma genitalium, Chlamydia trachomatis, Ureaplasma urealyticum, Ureaplasma parvum and). Mycoplasma being resistant to macrolides of 14-atoms and 15-atoms hominis, a tetracycline be used, such as doxycycline (100 mg oral bid for 7 days), or a fluoroquinolone.

 

Urogenital infections in women (pelvic inflammatory disease) when PID (PDI) polymicrobial entity therapy should be active against Chlamydia trachomatis, Neisseria gonorhoeae, Mycoplasma hominis, gram - negative aerobes and anaerobes. Combinations including an active antimicrobial against Mycoplasma hominis (doxycycline 100 mg, bid-twice a day), ofloxacin (200-400 mg bid-twice a day), or clindamycin (300-450 mg qid- used four times a day), taking into account possible adverse reactions or contraindications such as pregnancy. Therapy should be reevaluated initiated 72 hours and administered for 14 days. In cases postpartum fever, which may resolve itself, only treat mycoplasmas thinking when the fever persists despite antibiotic treatment ?-lactam, or Mycoplasma hominis has been isolated. Doxycycline is the antibiotic of choice, and a macrolide of 16 atoms, or a fluoroquinolone, when resistance is suspected to tetracyclines, since these strains are resistant.

 

Extragenital infections (wound infections, joint, endocarditis, meningitis) may be administered antimicrobial doxycycline, clindamycin, ofloxacin, ciprofloxacin, for 2 weeks. Joint or bone infections require prolonged treatment with doxycycline or clindamycin. Mycoplasma hominis arthritis require between 2 weeks and 7 months of treatment. For infections of prosthetic valve endocarditis or doxycycline is the drug of choice. For meningitis, chloramphenicol and fluoroquinolones penetrate well into cerebral spinal fluid may be used.

 

Newborn infections: should not be used tetracyclines or fluoroquinolones or chloramphenicol. In severe infections such as meningitis Mycoplasma hominis, doxycycline (2-4 mg / kg / d for 14 days) may be used. There injectable macrolide 16 atoms, so an alternative is thiamphenicol (30-50 mg / kg / d) or ciprofloxacin (30 mg / kg / d).

 

Diagnosis of urogenital mycoplasma infections

 

Diagnosis of urogenital Mycoplasma infections can be by culture methods or molecular methods.

 

  • Cultivation: cultivation is well achieved for some species that can be isolated easily and quickly as Mycoplasma hominis, Ureaplasma parvum and Ureaplasma urealyticum, allowing quantitative results and have isolated for testing antimicrobial susceptibility. However, culture is not well developed for highly problematic species like Mycoplasma genitalium.
  • PCR: is well achieved to detect all species in clinical samples. This method has been replaced in many laboratories cultivation.
  • Serology: is not indicated for the diagnosis of urogenital mycoplasma infections.

Tests in IVAMI:

 

  • Mycoplasma hominis culture of Ureaplasma urealyticum and Ureaplasma parvum.
  • PCR detection of Mycoplasma hominis, Mycoplasma genitalium, Ureaplasma urealyticum and Ureaplasma parvum.

Recommended sample:

 

  • Urethritis: Urethral exudate taken Swab Dacron / rayon rod aluminum or plastic, rubbing on the mucosa to ensure obtaining cells, inserting between 1 to 3 cm into the urethra, and rotating 360, introduced in liquid medium Stuart or Amies, or a universal transport medium.
  • Cervicitis: cervical swab exudate taken Dacron / rayon rod aluminum or plastic, rubbing on the mucosa to ensure obtaining cells, introduced in liquid medium Stuart or Amies, or a universal transport medium.
  • Vaginitis / vaginosis: vaginal swab taken Dacron swab / rayon rod aluminum or plastic, rubbing on the mucosa to ensure obtaining cells, introduced in liquid medium Stuart or Amies, or a universal transport medium.
  • Amnionitis (amniotic fluid): depositing 1 to 2 mL of liquid sample in a tube or in a sterile container, preferably polypropylene to prevent breakage, containing 3 mL of a universal transport medium.
  • Prostatitis (prostate secretion) deposit 1 to 2 mL of liquid sample in a tube or in a sterile container, preferably polypropylene to prevent breakage, containing 3 mL of a universal transport medium.
  • Infertility (sperm) deposit 1 to 2 mL of liquid sample in a tube or in a sterile container, preferably polypropylene to prevent breakage, containing 3 mL of a universal transport medium.
  • Arthritis (synovial fluid): depositing 1 to 2 mL of liquid sample in a tube or in a sterile container, preferably polypropylene to prevent breakage, containing 3 mL of a universal transport medium.
  • PID (pelvic exudate): depositing 1 to 2 mL of liquid sample in a tube or in a sterile container, preferably polypropylene to prevent breakage, containing 3 mL of a universal transport medium.
  • Uterine or tubal drainage: depositing 1 to 2 mL of liquid sample in a tube or in a sterile container, preferably polypropylene to prevent breakage, containing 3 mL of a universal transport medium.
  • Respiratory infections of the newborn (lower respiratory secretions) deposit 1 to 2 mL of liquid sample in a tube or in a sterile container, preferably polypropylene to prevent breakage, containing 3 mL of a universal transport medium.
  • UTI (urine): depositing 10 mL in a sterile container.
  • Urinary calculi: depositing the complete calculation into a sterile container.
  • Placenta: depositing fragment 5 mm in a sterile container.
  • Abortions: depositing fragment 5 mm in a sterile container.

 

Sample preservation:

 

  • Refrigerated (preferred) for less than 2 days.
  • Frozen more than 48 hours.

 

Shipment to the laboratory:

 

  • Refrigerated.

 

Delivery term:

 

  • Crops: 96 hours.
  • PCR: 48 hours.

 

Cost of testing:

 

Consult ivami@ivami.com