Ureaplasma urealyticum

Ureaplasma urealyticum is a bacterium belonging to the genus Ureaplasma and the family Mycoplasmataceae^[1] in the order Mycoplasmatales. This family consists of the genera Mycoplasma and Ureaplasma. Its type strain is T960. There are two known biovars of this species; T960 and 27. These strains of bacteria are commonly found as commensals in the urogenital tracts of human beings. Unlike most bacteria, Ureaplasma urealyticum lacks a cell wall making it unique in physiology and medical treatment.

Ureaplasma urealyticum
A number of medium-sized, Ureaplasma urealyticum colonies, otherwise known as T-strain mycoplasma, under magnification of 500×
Scientific classification
Domain:	Bacteria
Kingdom:	Bacillati
Phylum:	Mycoplasmatota
Class:	Mollicutes
Order:	Mycoplasmoidales
Family:	Mycoplasmoidaceae
Genus:	Ureaplasma
Species:	U. urealyticum
Binomial name
Ureaplasma urealyticum Shepard et al. 1974 (Approved Lists 1980)

Classification

The six recognised Ureaplasma species have a GC content of 27 to 30 percent and a genome size ranging from 0.76 to 1.17 million base pairs, and cholesterol is required for growth.^[2] A defining characteristic of the genus is that they perform urea hydrolysis, which creates ammonia as a product. Some strains originally classified as U. urealyticum should be treated as a new species, U. parvum.^[3] Both strains of Ureaplasma urealyticum have had their DNA sequenced, using a PCR amplification and dideoxy termination method.^[4] Their sequences can be accessed through public records and databases. Most of the16S rDNA sequence of the two strains constitute the exact same nucleotides bases (97.3% homology), yet small differences have been acknowledged.^[4] Due to the direct similarity and the increased variation in other species of Ureaplasma, it is thought that the two strains of Ureaplasma urealyticum (T960 and 27) have evolutionary diverged together. In the same study conducted, using the same 16s rDNA aligned sequences, they concluded all the mammalian strains diverged and coevolved with their corresponding species (canine, feline, human, bovine) during the Cretaceous period. It was found that the most closely related species strain of Ureaplasma to Ureaplasma urealyticum was Ureaplasma diversum (isolated from bovine).^[4]

Gram staining

U. urealyticum represents one of the 14 distinct types within the Ureaplasma genus. Classified within the Mollicutes class, Ureaplasma species have undergone significant evolutionary adaptations from their Gram-positive bacterial ancestors, a phenomenon termed degenerative evolutions (Kallapur, Suhas G, et al 2013^[2]). This evolutionary trajectory has resulted in the loss of the peptidoglycan cell wall, a hallmark characteristic of Gram-positive bacteria. Despite this evolutionary divergence, instances have been reported where U. urealyticum, upon gram staining, exhibited the same characteristics as Gram-negative bacteria. Notably, despite such staining outcomes, it is imperative to recognize that the U. urealyticum remains a Gram-Positive bacterium, This discrepancy underscores the importance of discerning between staining outcomes and bacterial classification (“Ureaplasma Urealyticum.” Microbewiki^[5]).

Treatment

As stated previously, since these bacteria are still considered Gram-positive, and lack a cell wall, the most versatile antibiotic that can’t be used is penicillin. Since these antibiotics attack the cell wall of a bacterium, they can not be used for this type of infection. The reason that many individuals get this infection can be damage to the uterus wall lining, causing the bacteria to thrive in a carbon-rich environment.

Unfortunately, it was found from trials that many of the antibiotics that we utilize on a day-to-day basis for urinary tract infections do not affect the bacteria due to lacking a cell wall. Yet, the types of antibiotics that can be used are quinolones, tetracyclines, and macrolides, since they affect a large part of the mycoplasma family of bacteria where U. urealyticum falls under.^{[medical citation needed]}

Yet, it is not recommended to be used a lot because these bacteria can develop resistance to these antibiotics fairly fast. Secondly, other drugs that have β-lactamases are infective to treat infection because of how fast the bacteria's circular genome can mutate (Fan et al. 2023^[6]). However, there are new movements to use Azithromycin to treat these infections. This is a therapeutic that can be taken orally, once ingested our macrophages, which are part of our immune system, take up the antibiotic and deliver it to the sites of infection (Fan et al. 2023^[7]). This helps control the infection where the bacteria grows, additionally, it is also a great alternative to when a mother is pregnant so it does not cause harm to the fetus since It's using our immune system to help defend the fetus and the mother's body.

Clinical relevance

Ureaplasma urealyticum can cause urethritis and may cause bacterial vaginosis. Infection can occur in extragenital sites.^[3] A common symptom associated with these infections is the "fishy" smell that is created due to the production of ammonia by the hydrolysis of urea. Patients should confirm diagnosis with a doctor. The bacterium has high correlations with the Human Papillomavirus (HPV).^{[medical citation needed]} It has also been linked to infertility in both males and females.^{[medical citation needed]} In addition, this pathogen may latently infect the chorionic villi tissues of pregnant women, thereby impacting pregnancy outcome.^{[medical citation needed]} Issues that arise from Ureaplasma urealyticum infections during pregnancy include preterm birth and impacted embryonic development.^{[medical citation needed]} Some patients have given birth to children subjected to bronchopulmonary dysplasia, Intraventricular hemorrhage, and necrotizing enterocolitis.^[8] Patients can evolve resistances to normal antibiotic treatments due to the distinctive physiology of these organisms. In the Western World, approximately 40% of Ureaplasma species are resistant to fluoroquinolones (i.e. ciprofloxacin).^[6] Patients who are pregnant have further limitations on the treatment course of a Ureaplasma urealyticum infection, making it far harder to successfully cure.^{[citation needed]}

See also

• International Organization for Mycoplasmology (IOM)
• Sexually transmitted infection
• Vaginal infection
• Vaginal disease
• Vaginal health
• List of bacterial vaginosis microbiota
• Uterine microbiome
• Mycoplasma