Kokkayil P, Dhawan B
Department of Microbiology, All India Institute of Medical Sciences, New Delhi, India.
Indian J Med Microbiol. 2015 Apr-Jun;33(2):205-14. doi: 10.4103/0255-0857.154850.
Ureaplasma species are the most prevalent genital Mycoplasma isolated from the urogenital tract of both men and women. Ureaplasma has 14 known serotypes and is divided into two biovars- Ureaplasma parvum and Ureaplasma urealyticum. The organism has several genes coding for surface proteins, the most important being the gene encoding the Multiple Banded Antigen (MBA). The C-terminal domain of MBA is antigenic and elicits a host antibody response. Other virulence factors include phospholipases A and C, IgA protease and urease. Besides genital tract infections and infertility, Ureaplasma is also associated with adverse pregnancy outcomes and diseases in the newborn (chronic lung disease and retinopathy of prematurity). Infection produces cytokines in the amniotic fluid which initiates preterm labour. They have also been reported from renal stone and suppurative arthritis. Genital infections have also been reported with an increasing frequency in HIV-infected patients. Ureaplasma may be a candidate 'co factor' in the pathogenesis of AIDS. Culture and polymerase chain reaction (PCR) are the mainstay of diagnosis. Commercial assays are available with improved turnaround time. Micro broth dilution is routinely used to test antimicrobial susceptibility of isolates. The organisms are tested against azithromycin, josamycin, ofloxacin and doxycycline. Resistance to macrolides, tetracyclines and fluoroquinolones have been reported. The susceptibility pattern also varies among the biovars with biovar 2 maintaining higher sensitivity rates. Prompt diagnosis and initiation of appropriate antibiotic therapy is essential to prevent long term complications of Ureaplasma infections. After surveying PubMed literature using the terms 'Ureaplasma', 'Ureaplasma urealyticum' and 'Ureaplasma parvum', relevant literature were selected to provide a concise review on the recent developments.
脲原体属是从男性和女性泌尿生殖道分离出的最常见的生殖支原体。脲原体有14种已知血清型,分为两个生物变种——微小脲原体和解脲脲原体。该生物体有几个编码表面蛋白的基因,其中最重要的是编码多带抗原(MBA)的基因。MBA的C端结构域具有抗原性,可引发宿主抗体反应。其他毒力因子包括磷脂酶A和C、IgA蛋白酶和脲酶。除了生殖道感染和不孕症外,脲原体还与不良妊娠结局及新生儿疾病(慢性肺病和早产儿视网膜病变)有关。感染会在羊水中产生细胞因子,从而引发早产。在肾结石和化脓性关节炎中也有脲原体的报道。在HIV感染患者中,生殖道感染的报告频率也在增加。脲原体可能是艾滋病发病机制中的候选“辅助因子”。培养和聚合酶链反应(PCR)是诊断的主要方法。有商业化检测方法,周转时间有所改善。微量肉汤稀释法常规用于检测分离株的抗菌药敏性。对分离出的脲原体进行阿奇霉素、交沙霉素、氧氟沙星和多西环素的药敏测试。已有对大环内酯类、四环素类和氟喹诺酮类耐药的报道。药敏模式在生物变种之间也有所不同,生物变种2的敏感率更高。及时诊断并开始适当的抗生素治疗对于预防脲原体感染的长期并发症至关重要。在使用“脲原体”、“解脲脲原体”和“微小脲原体”等术语检索PubMed文献后,挑选了相关文献以对近期进展进行简要综述。