Clinical relevance of three urogenital commensal bacteria, U. urealyticum, U. parvum and M. hominis, as STI’s agents

• Autor(a) principal: Almeida, Inês Gomes Cruz Rito
• Data de Publicação: 2023
• Tipo de documento: Dissertação
• Idioma: eng
• Título da fonte: Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
• Texto Completo: http://hdl.handle.net/10773/40705
• topic: Sexually transmitted infections; Commensal pathogens; Symptoms; Diagnosis; Treatment; Molecular biology; Nulceic acid extraction; Real-time PCR

Sexually Transmitted Infections (STIs), are a worldwide problem with more than 1 million being acquired every day. There are numerous agents, virus, parasites and bacteria, that are responsible for causing STIs, but the most common ones are, Chlamydia trachomatis, Trepanema pallidum, Neisseria Gonorrhoeae and Trichomonas vaginalis, which are curable, and Hepatitis B, Human Immunodeficiency Virus (HIV), Herpes Simplex Virus (HSV), and Human Papillomavirus (HPV), which are incurable. Other microorganisms, including Mycoplasma genitalium, are recognized as STI’s agents. However, within the Mycoplasmataceae family, there are other members such as Mycoplasma hominis, Ureaplasma urealyticum, and Ureaplasma parvum, that are typically commensal urogenital flora organisms, but can also become pathogenic. A total of 432 samples, including urine, urethral, vaginal, anal and oropharyngeal exudates, were examined from 225 individuals. In order to do that, the nucleic acids were extracted and purified, using STARMag 96 x 4 Universal Cartridge Kit. Subsequently, the AllplexTM STI Essential Assay Q was employed to both amplify and detect the target nucleic acids. The qPCR results were subsequently analyzed using the Seegene Viewer software. The AllplexTM STI Essential Assay Q stands out for its capability to identify of 7 pathogens (C. trachomatis, N. gonorrhoeae, U. urealyticum, U.parvum, M. hominis, M. parvum and T. vaginalis) and provides multi-CT values in a single fluorescence channel without melting curve analysis. Additionally, it quantifies U. parvum and M. hominis. Among the infected individuals, men predominated, and the majority of infections were identified in anal swabs. This could be attributed to the increasing practice of unprotected anal intercourse among men, which represents a high-risk group for the transmission of STIs. Regarding U. urealyticum, U. parvum and M. hominis, in general, routine testing and treatment are not recommended in symptomatic or asymptomatic individuals. When they exhibit urogenital symptoms, it is advisable to first exclude “true” STIs and/or bacterial vaginosis or candidiasis. Exceptionally in U. urealyticum case, since it may be responsible for non-goococcal urethritis in males when presented in high bacterial loads, treatment should be considered. This is a topic still under discussion, and it's important to distinguish whether the presence of these microorganisms indicates a STI or if it is related to an imbalance in the urogenital microbiota or if it is considered normal. Thus, it is crucial to establish a cut off value that differentiates infection from colonization, guiding the decision on whether treatment is necessary. This determination may also depend on the specific microorganism, individual health factors, and the presence of associated symptoms.