Mycoplasma genitalium
| Mycoplasma genitalium | ||||||||||||||
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| File:Mycoplasma genitalium.gif | ||||||||||||||
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| Mycoplasma genitalium Tully et al., 1983 |
Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: Dima Nimri, M.D. [2]
Overview
Classification
Historical Perspective
- Mycoplasma genitalium is the 11th Mycoplasma species of human origin.[1]
- In 1980, 13 men were tested for non-gonoccal urethritis (NGU). Mycoplasma genitalium was isolated from 2 of those 13 men.[2][3][4]
- In the early 1990s, polymerase chain reaction (PCR) was developed, which allowed for diagnosis of Mycoplasma genitalium.[2][4][5]
- Since 1993, the role of Mycoplasma genitalium as a cause of non-gonococcal urethritis has appeared in literature following the advances in polymerase chain reaction (PCR).[5]
Pathophysiology
Pathogenesis
Mode of Transmission
- Mycoplasma genitalium is recognized as a sexually transmitted disease (STD) with the mode of transmission being through direct genital-to-genital contact and subsequent inoculation of infected secretions. Transmission of Mycoplasma genitalium has also been implicated in penile-anal intercourse. [2]
- Mycoplasma genitalium is less likely to be transmitted via oro-genital contact, as carriage in the oropharynx is low. [2]
- Whether or not Mycoplasma genitalium is vertically transmitted from mother to newborn is yet to be studied. However, the bacterium has been isolated from the respiratory tract of newborns. [2]
Incubation Period
The incubation period of Mycoplasma genitalium is unknown yet.[6]
Infectious Dose
The infectious dose of Mycoplasma genitalium is unknown yet.[6]
Factors facilitating the pathogenesis of Mycoplasma genitalium
The following virulence factors have been implicated in the pathogenesis of Mycoplasma genitalium: [1][2][7]
- Adhesion molecules: Mycoplasma genitalium has the ability to attach to different types of cells, including red blood cells, respiratory cells, fallopian tube cells, as well as sperm cells. It is believed that the attachment to sperm cells facilitates the spread of Mycoplasma genitalium to the female genital tract. MgPa, a major adhesion in attachment protein complex, facilitates not only adhesion to epithelial cells, but also the motility of Mycoplasma genitalium.
- Intracellular localization: Mycoplasma genitalium is a facultative intracellular organism and this allows for its survival both inside and outside of cells.
- Antigenic variation: Mycoplasma genitalium is able to generate surface lipoprotein with high frequency, which helps it evade the human immune system.
- Toxins: Mycoplasma genitalium has a calcium-dependent membrane associated nuclease known as MG-186. MG-186 is capable of degrading host cell nucleic acid, hence providing a source of nucleotides for the growth and pathogenesis of Mycoplasma genitalium.
- Enzymes: Glyceraldehyde 3-phosphate dehydrogenase (GADPH) acts as a ligand to the receptors mucin and fibronectin, found on vaginal and cervical epithelium.
- Immunological response: Mycoplasma genitalium possesses an immunogenic protein, MG-309, which secretes pro-inflammatory cytokines, such as IL-6 and IL-8. MG-309 exerts its effect via attaching to a toll-like receptor, hence activating nuclear factor kappa B (NF-kB)
Genetics
Associated Conditions
Gross Pathology
Microscopic Pathology
Causes
Differentiating Mycoplasma genitalium infection from other diseases
Epidemiology and Demographics
- The incidence and prevalence of Mycoplasma genitalium is not well established, because more than half of the women who tested positive were asymptomatic.[2]
- In the United States, the prevalence of Mycoplasma genitalium was estimated as follows:[8]
- The prevalence in all females aged 14-70 years old is 16.3%.
- The prevalence in all males aged 18-78 years old is 17.2%.
- Infection in both males and females was more prevalent in those younger than 30 years of age.
- The prevalence of Mycoplasma genitalium infection was higher than Chlamydia Trachomatis and Neisseria Gonorrhea, while in males it was higher than Neisseria Gonorrhea but comparable to that of Chlamydia Trachomatis.
- Between the years 2002-2011, the prevalence of Mycoplasma genitalium worldwide ranged between 4%-42%.[7]
Risk Factors
There several risk factors that have been identified with Mycoplasma genitalium infection. These risk factors include:[2][4][9]
- High risk sexual behavior, defined as having >3 new sexual partners in the past year
- Being engaged in sexual contact with persons with STDs, particularly Mycoplasma genitalium
- Non-white race
- Having a black partner
- Young age (<20 years old)
- Smoking
- Having less than high school education
- Having an annual income of less than $10,000
- Risk factors specific to females includes:
- Frequent douching
- Proliferative phase of the menstrual cycle
- History of spontaneous miscarriage
- Undergoing procedures that breach the cervical barrier
- Use of Depo-Provera for contraception
Screening
There are no recommendations for screening for Mycoplasma genitalium.[10]
Natural history, Complications and Prognosis
History
The presenting symptoms of Mycoplasma genitalium are related to the disease processes it may cause. Presenting symptoms can be divided based on gender:
- Females: 40-75% of women infected with Mycoplasma genitalium are asymptomatic. However, when symptoms are present, they are usually related to the disease process Mycoplasma genitalium resulted. These include:[2][11][12]
- Cervicitis: presents with vaginal discharge, vaginal itching, inter-menstrual, heavy or post-coital bleeding
- PID: presents with pelvic discomfort or lower abdominal pain, painful sexual intercourse (dyspareunia) vaginal discharge and/or bleeding
- Urethritis: presents with pain on urination (dysuria) or urethral discharge
- Males: tend to be more symptomatic than females and present with symptoms of urethritis, which include urethral discharge and dysuria.[2][13][14][15]
Physical Examination
Laboratory Findings
X-Ray
CT
Other Imaging Findings
Other Diagnostic Studies
Medical Therapy
Mycoplasma genitalium is intracellular and hence, eradication of the organism is sometimes challenging. The antibiotic drug of choice and dosing depends on susceptibility of the Mycoplasma genitalium strain, as well as the clinical presentation of the infection, as follows:[2][3][5]
- Doxycycline has poor efficacy for Mycoplasma genitalium.
- For uncomplicated Mycoplasma genitalium infection susceptible to macrolides, azithromycin given as a single 1g dose or 500mg on day 1 followed by 250mg on days 2-5 may be used. Another macrolide that may be used is josamycin 500mg, given 3 times daily for 10 days.
- For uncomplicated macrolide resistant Mycoplasma genitalium infection, moxifloxacin 400mg once daily is given for 7-10 days.
- Pristinamycin 1g 4 times daily is given for 7-10 days when both azithromycin and moxifloxacin fail.
- For complicated Mycoplasma genitalium infection, moxifloxacin 400mg once daily is used for 14 days.
Surgical Therapy
Primary Prevention
Secondary Prevention
References
- ↑ 1.0 1.1 Taylor-Robinson D, Jensen JS (2011). "Mycoplasma genitalium: from Chrysalis to multicolored butterfly". Clin. Microbiol. Rev. 24 (3): 498–514. doi:10.1128/CMR.00006-11. PMC 3131060. PMID 21734246.
- ↑ 2.00 2.01 2.02 2.03 2.04 2.05 2.06 2.07 2.08 2.09 2.10 Jensen JS, Cusini M, Gomberg M, Moi H (2016). "Background review for the 2016 European guideline on Mycoplasma genitalium infections". J Eur Acad Dermatol Venereol. doi:10.1111/jdv.13850. PMID 27605499.
- ↑ 3.0 3.1 "Sexually Transmitted Diseases: Summary of 2015 CDC Treatment Guidelines". J Miss State Med Assoc. 56 (12): 372–5. 2015. PMID 26975162.
- ↑ 4.0 4.1 4.2 Manhart LE, Critchlow CW, Holmes KK, Dutro SM, Eschenbach DA, Stevens CE, Totten PA (2003). "Mucopurulent cervicitis and Mycoplasma genitalium". J. Infect. Dis. 187 (4): 650–7. doi:10.1086/367992. PMID 12599082.
- ↑ 5.0 5.1 5.2 Ross JD, Jensen JS (2006). "Mycoplasma genitalium as a sexually transmitted infection: implications for screening, testing, and treatment". Sex Transm Infect. 82 (4): 269–71. doi:10.1136/sti.2005.017368. PMC 2564705. PMID 16877571.
- ↑ 6.0 6.1 Public Health Agency of Canada http://www.phac-aspc.gc.ca/lab-bio/res/psds-ftss/mycoplasma-genitalium-eng.php Accessed on Oct 6, 2016.
- ↑ 7.0 7.1 Sethi S, Singh G, Samanta P, Sharma M (2012). "Mycoplasma genitalium: an emerging sexually transmitted pathogen". Indian J. Med. Res. 136 (6): 942–55. PMC 3612323. PMID 23391789.
- ↑ Getman D, Jiang A, O'Donnell M, Cohen S (2016). "Mycoplasma genitalium Prevalence, Coinfection, and Macrolide Antibiotic Resistance Frequency in a Multicenter Clinical Study Cohort in the United States". J. Clin. Microbiol. 54 (9): 2278–83. doi:10.1128/JCM.01053-16. PMC 5005488. PMID 27307460.
- ↑ Hancock EB, Manhart LE, Nelson SJ, Kerani R, Wroblewski JK, Totten PA (2010). "Comprehensive assessment of sociodemographic and behavioral risk factors for Mycoplasma genitalium infection in women". Sex Transm Dis. 37 (12): 777–83. doi:10.1097/OLQ.0b013e3181e8087e. PMC 4628821. PMID 20679963.
- ↑ United States Preventive Services Task Force https://www.uspreventiveservicestaskforce.org/BrowseRec/Search?s=mycoplasma+genitalium Accessed on Oct. 6, 2016.
- ↑ Tosh AK, Van Der Pol B, Fortenberry JD, Williams JA, Katz BP, Batteiger BE, Orr DP (2007). "Mycoplasma genitalium among adolescent women and their partners". J Adolesc Health. 40 (5): 412–7. doi:10.1016/j.jadohealth.2006.12.005. PMC 1899169. PMID 17448398.
- ↑ Korte JE, Baseman JB, Cagle MP, Herrera C, Piper JM, Holden AE, Perdue ST, Champion JD, Shain RN (2006). "Cervicitis and genitourinary symptoms in women culture positive for Mycoplasma genitalium". Am. J. Reprod. Immunol. 55 (4): 265–75. doi:10.1111/j.1600-0897.2005.00359.x. PMID 16533338.
- ↑ Falk L, Fredlund H, Jensen JS (2004). "Symptomatic urethritis is more prevalent in men infected with Mycoplasma genitalium than with Chlamydia trachomatis". Sex Transm Infect. 80 (4): 289–93. doi:10.1136/sti.2003.006817. PMC 1744873. PMID 15295128.
- ↑ Jensen JS, Orsum R, Dohn B, Uldum S, Worm AM, Lind K (1993). "Mycoplasma genitalium: a cause of male urethritis?". Genitourin Med. 69 (4): 265–9. PMC 1195084. PMID 7721285.
- ↑ Anagrius C, Loré B, Jensen JS (2005). "Mycoplasma genitalium: prevalence, clinical significance, and transmission". Sex Transm Infect. 81 (6): 458–62. doi:10.1136/sti.2004.012062. PMC 1745067. PMID 16326846.