Prevalence of Ureaplasma species among patients at a tertiary hospital in China: a 10-year retrospective study from 2013 to 2022.

BACKGROUND: Ureaplasma species are common pathogens of the urogenital tract and can cause a range of diseases. Unfortunately, there is still a scarcity of large-scale and cross-sectional studies on the prevalence of Ureaplasma species in China to clarify their epidemic patterns. METHODS: This study retrospectively analyzed the data of 18667 patients who visited Peking Union Medical College Hospital for showing various symptoms of (suspected) Ureaplasma species infection during the period 2013-2022. The overall prevalence of Ureaplasma species was calculated, and subgroup analyses were conducted in view of gender, age, specimen types, and diagnosis in every year within the period studied. Furthermore, previous literature that reported on the prevalence of Ureaplasma species in various regions of China was searched and summarized. RESULTS: The overall positive rate of Ureaplasma species in this study reached 42.1% (7861/18667). Specifically, the prevalence of Ureaplasma species was significantly higher in female patients, while the highest detection rate was found in the 21-50 age group. From 2013 to 2022, there were no significant differences in positive rates of Ureaplasma species among years. However, the detection rate of Ureaplasma species was decreased in COVID-19 period (2020-2022) compared to pre-COVID-19 period (2017-2019). In view of the distribution of patients, outpatients predominated, but the detection rate was lower than inpatients. Urine was the most common specimen type, while cervical swabs had the highest detection rate of Ureaplasma species. When grouped by diagnosis, the highest positive rate of Ureaplasma species was seen in patients with adverse pregnancy outcomes and the lowest rate in patients with prostate disease. The previous literature, although heterogeneous, collectively suggested a high prevalence of Ureaplasma species in China. CONCLUSIONS: Our study has shown that Ureaplasma species have reached a significant prevalence in China and demands adequate attention.

Brain abscess with Ureaplasma parvum in a patient with granulomatosis with polyangiitis.

PURPOSE: Ureaplasma species are associated with urogenital infections, infertility and adverse pregnancy outcomes as well as neonatal infections. Involvement of the central nervous system in adults is extremely rare. We report an unusual case of a brain abscess secondary to otitis media with Ureaplasma parvum in a patient with granulomatosis with polyangiitis (GPA). METHODS: Imaging and laboratory findings, treatment decisions, and outcome of this case are explicated. RESULTS: A young adult with GPA presented with progredient earache after ambulant diagnosis of otitis media. Despite different courses of broad-spectrum antibiotic therapy, she developed meningoencephalitis due to mastoiditis following temporal abscess formation. Mastoidectomy and neurosurgical abscess removal were performed. Standard cultures of cerebrospinal fluid, blood and intracranial abscess material, as well as polymerase chain reaction (PCR) for common bacterial and viral meningitis pathogens remained negative. Only eubacterial PCR of intracranial abscess material returned positive for Ureaplasma parvum. The patient finally improved under antibiotic therapy with moxifloxacin and doxycycline. CONCLUSION: Ureaplasma species are rare causative pathogens in immunocompromised patients. They should be considered in patients with humoral immunodeficiencies with culture-negative infections failing standard therapy. Eubacterial PCR should be performed in early states of infection in these patients for immediate diagnosis and initiation of appropriate treatment to prevent adverse outcomes.

Mycoplasma hominis and Ureaplasma urealyticum infections after knee arthroplasty: A case report.

RATIONALE: Artificial joint infection caused by Mycoplasma hominis and Ureaplasma urealyticum is rare and has not been reported. PATIENTS CONCERNS: A 59-year-old man underwent left total knee arthroplasty for 1 year of pain in the left knee joint. The indwelling urinary catheter was removed after 48 hour of the surgery. On day 8 after the surgery, the patient had fever, increased skin temperature, swelling and redness around the surgical site, and floating patella test (+). According to experience, Vancomycin, Ciprofloxacin and Linezolid were administrated. Evident decrease in C-reactive protein was observed after Linezolid administration, while there was no significant improvement in clinical symptoms. Microbiome sequencing was performed, resulting in diagnosis of positive M hominis and U urealyticum. The patient was then treated with Doxycycline in the following 3 months. During the 11-month outpatient follow-up, there was no evidence of recurrence of infection. DIAGNOSIS: Microbiome sequencing was performed, resulting in diagnosis of positive M hominis and Ureaplasma urealyticum. INTERVENTIONS: The patient recovered following with Doxycycline in the following 3 months. OUTCOMES: During the 11-month outpatient follow-up, there was no evidence of recurrence of infection. LESSONS: M hominis and U urealyticum are common pathogens of the urinary system infections but they are rare in osteoarticular infections. In cases of fever, swelling and heat pain around the surgical site, joint fluid, negative blood culture and being irresponsive to anti-bacterial agents against the cell wall, special bacteria-related infection should be highly suspected.

DnaJ, a promising vaccine candidate against Ureaplasma urealyticum infection.

Ureaplasma urealyticum (U. urealyticum, Uu) is a common sexually transmitted pathogen that is responsible for diseases such as non-gonococcal urethritis, chorioamnionitis, and neonatal respiratory diseases. The rapid emergence of multidrug-resistant bacteria threatens the effective treatment of Uu infections. Considering this, vaccination could be an efficacious medical intervention to prevent Uu infection and disease. As a highly conserved molecular chaperone, DnaJ is expressed and upregulated by pathogens soon after infection. Here, we assessed the vaccine potential of recombinant Uu-DnaJ in a mouse model and dendritic cells. Results showed that intramuscular administration of DnaJ induced robust humoral- and T helper (Th) 1 cell-mediated immune responses and protected against genital tract infection, inflammation, and the pathologic sequelae after Uu infection. Importantly, the DnaJ protein also induced the maturation of mouse bone marrow-derived dendritic cells (BMDCs), ultimately promoting naïve T cell differentiation toward the Th1 phenotype. In addition, adoptive immunization of DnaJ-pulsed BMDCs elicited antigen-specific Immunoglobulin G2 (IgG2) antibodies as well as a Th1-biased cellular response in mice. These results support DnaJ as a promising vaccine candidate to control Uu infections. KEY POINTS: • A novel recombinant vaccine was constructed against U. urealyticum infection. • Antigen-specific humoral and cellular immune responses after DnaJ vaccination. • Dendritic cells are activated by Uu-DnaJ, which results in a Th1-biased immune response.

Metagenomic next-generation sequencing restores the diagnosis of a rare infectious complication of B cell depletion.

A 45-year-old female patient receiving rituximab for B cell non-Hodgkin follicular lymphoma presented unexplained recurrent fever, abdominal discomfort, and pollakiuria. We performed shotgun metagenomic sequencing from peri-kidney collection that identified a co-infection with Mycoplasma hominis and Ureaplasma urealyticum. The patient recovered with sequelae after appropriate antibiotic treatment was given.

[Urogenital Ureaplasma urealyticum can cause invasive infection in immunosuppressed patients]. / Urogenital Ureaplasma gav invasiv infektion hos immunsupprimerad.

Ureaplasma urealyticum (Uu) is a bacterium without a cell wall, which makes it difficult to culture. Uu colonizes the lower genitourinary tract and is transmitted through sexual contact. The presence of Uu is higher in persons with immunosuppressive disease or treatment. Moreover, these persons are at increased risk of developing invasive Uu infections.  We present a case concerning a 47-year-old female with multiple sclerosis treated with Rituximab. She first presented with a urinary tract infection and bartholinitis. Despite treatment with antibiotics and surgical procedures, the infection disseminated and led to intra-abdominal abscesses and empyema. Repeated cultures were negative, which prolonged the time to diagnosis and accurate treatment. Uu was detected with 16S rRNA PCR assays during the course of the disease but was interpreted as non-pathogenic Finally, Uu was suspected as the causing agent, treatment with doxycycline was initiated, and the patient recovered after nine months of disease.

Vaginal Secretion Epithelium Count as a Prognostic Indicator of High Abundance of Ureaplasmas in Women with a Normal Nugent Score.

Genital tract ureaplasma infections are associated with numerous complications, ranging from inflammation, through infertility, to problematic pregnancy. In the course of ureaplasma infection, the risk of human papillomavirus infection increases. Diagnostic tests for urea-plasma infections are not always carried out, especially in women with the normal Nugent test results. The study attempts to check whether it is possible to find a prognostic indicator that could suggest a high abundance of ureaplasmas (≥ 104 CFU/ml) at the stage of the initial examination of vaginal discharge. Such a prognostic factor could qualify women for further tests to detect infections with these atypical bacteria. Six hundred twenty-seven white women with a score of 0-3 on the Nugent scale were tested, including 322 patients with a high abundance of ureaplasmas (≥ 104 CFU/ml) and 305 who tested negative for these bacteria. Ureaplasma infections were detected statistically significant in women who had few or no epithelial cells in the genital swab specimens compared to the results obtained for women with numerous or very numerous epithelial cells (p < 0.001). The risk of the high density of ureaplasmas was 38.7% higher with fewer or no epithelial cells than with high numbers. In patients aged 18-40 years with few or no epithelial cells, a high density of ureaplasmas (≥ 104 CFU/ml) was observed significantly more frequently (p = 0.003). Determining the number of epithelial cells in Gram-stained slides may be the prognostic indicator of ureaplasma infection. Testing for genital ureaplasma infection should be considered, especially in women of childbearing age (18-40 years), even if the Nugent test value is normal and pH ≤ 4.6.

Determination of the prevalence of Mycoplasma hominis and Ureaplasma species in Bacterial vaginosis patients in association with antibiotic resistance profile in Franceville, Gabon.

BACKGROUND: Genital mycoplasma are only considered pathogenic at a certain level and are often associated with other pathological situations such as bacterial vaginosis (BV). They may lead to infertility as well as other gynaeco-obstetrical and neonatal problems. Despite numerous reported resistances, macrolides are required to treat pregnant women while non-pregnant women are managed with tetracyclines and fluoroquinolones. This study aimed to establish the prevalence and resistance rates of Mycoplasma hominis (Mh) and Ureaplasma spp. (Uu) in BV positive (BV+) women. MATERIAL AND METHODS: Vaginal secretions were collected from women aged 14-56 years consulting for a cytobacteriological examination of the vaginal swab associated with a simultaneous search for genital mycoplasma in the medical analysis laboratory of the Research and Medical Analysis Unit (URAM) of CIRMF in Franceville, Gabon. BV was diagnosed using the Nugent score while genital mycoplasma identification and antibiotic susceptibility testing were performed using the Mycoplasma IST 2 kit. RESULTS: Of the 462 women included in this study, 60.18% (278/462, p = 0.00002) were both BV+ and genital mycoplasma carriers, including 5.19% (24/462) pregnant women. Overall mycoplasma carriage was 33.12% (153/462) for Uu, 1.95% for Mh and 25.11% (116/462) for mixed infections (Uu + Mh). The BV + patients most affected by mycoplasma were those whose age varied from 25 to 35 years with 27.49% (127/462, p = 0.980), those not using condoms with 39.40% (182/462, p = 0.014, OR = 2.35), those non-pregnant but capable of bearing children with 53.90% (249/462, p = 0.967, OR = 1.02). In the overall population, 83.66% and 51.63% of Uu strains were highly resistant to Ciprofloxacin and Azithromycin respectively; 100% and 55.56% of Mh strains were resistant to Azithromycin and Tetracycline respectively; while strong resistance has been observed in mixed infections to Ciprofloxacin (97.41%), Azithromycin (81.90%), Ofloxacin (69.83%) and Tetracycline (68.97%). CONCLUSION: The prevalence of genital mycoplasma infections is very high in women with bacterial vaginosis. Given the numerous emerging resistance rates to most classes of antibiotics available for the treatment of genital mycoplasma infections in our study, it would be advisable for therapeutic prescriptions to be made based on laboratory results.

Development of multiplex real-time quantitative PCR for simultaneous detection of Chlamydia trachomatis, Mycoplasma hominis, Ureaplasma urealyticum, and Mycoplasma genitalium in infertile women.

PURPOSE: Sexually Transmitted Diseases (STDs) can cause sterility and many other problems for women planning pregnancy. Currently, almost 340 million people worldwide suffer from Sexually Transmitted Infections (STIs). This study made attempts to quickly identify STDs' most critical infectious agents using dedicated primers and probes. METHODS: The present study was done on the cervical samples of 200 infertile women. After extracting the total DNA of Chlamydia trachomatis, Mycoplasma hominis, Ureaplasma urealyticum, and Mycoplasma genitalium, quantitative methods were employed to determine the rate of target bacteria using multiplex real-time PCR. RESULTS: The multiplex qPCR showed the rates of 47%, 16%, 46%, and 16.5% for Chlamydia trachomatis, Mycoplasma hominis, Ureaplasma urealyticum, and Mycoplasma genitalium in infertile women, respectively. In some patients, there were co-infections with two or three bacteria. The diagnostic approach used in our research could be employed as an alternative detection tool to identify the four most common STD-associated bacterial agents while detecting mixed infections. CONCLUSIONS: Infertile women with no biological problems could have their genital tract checked using this newly designed identification technique and get proper treatment for their infections as quickly as possible.

Antibiotic resistance among clinical Ureaplasma isolates from Cuban individuals between 2013 and 2018.

Introduction. Acquired resistance against the antibiotics that are active against Ureaplasma species has been described.Hypothesis/Gap Statement. Diagnostics combined with antimicrobial sensitivity testing are required for therapeutic guidance.Aim. To report the prevalence of antimicrobial resistance among Cuban Ureaplasma isolates and the related molecular mechanisms of resistance.Methodology. Traditional broth microdilution assays were used for antimicrobial sensitivity testing in 262 clinical Ureaplasma species isolates from Cuban patients between 2013 and 2018, and a subset of samples were investigated in parallel with the commercial MYCO WELL D-ONE rapid culture diagnostic assay. The underlying molecular mechanisms for resistance were determined by PCR and sequencing for all resistant isolates.Results. Among the tested isolates, the tetracycline and erythromycin resistance rates were 1.9 and 1.5%, respectively, while fluoroquinolone resistance was not found. The tet(M) gene was found in all tetracycline-resistant isolates, but also in two tetracycline-susceptible Ureaplasma clinical isolates. We were unable to determine the underlying mechanism of erythromycin resistance. The MYCO WELL D-ONE kit overestimated tetracycline and erythromycin resistance in Ureaplasma spp. isolates.Conclusions. Although low levels of antibiotic resistance were detected in Cuban patients over a 5-year period, continued surveillance of the antibiotic susceptibility of Ureaplasma is necessary to monitor possible changes in resistance patterns.

Ureaplasma parvum alters the immune tolerogenic state in placental tissue and could cause miscarriage.

OBJECTIVE: To study the inflammatory profile and genes involved in the response to bacterial infections in women who developed spontaneous abortion in the presence of Ureaplasma parvum. DESIGN: Cross-sectional study. SETTING: A maternal and child referral center. PATIENT(S): Eighty-nine women with spontaneous abortion and 20 women with normal vaginal delivery (control group) were studied. INTERVENTION(S): Samples of biopsied placental tissue were collected for Mollicutes detection. MAIN OUTCOME MEASURE(S): The samples were subjected to histologic analysis, immunohistochemical evaluation for macrophages and lymphocytes, cytokine quantification, and quantitative polymerase chain reaction array to evaluate the expression of 84 genes related to the innate and adaptive immune responses. RESULT(S): The presence of U. parvum in the abortion group was positively associated with the influx of polymorphonuclear cells in the placental tissue and increased concentrations of interleukin-6 and interleukin-12p70. U. parvum caused downregulation of genes involved in the immune response, such as attraction of immune cells, activation of an inflammatory response, T-helper cell 17 response activation, and activation of the complement system at the beginning and end of pregnancy. CONCLUSION: The direct action of U. parvum on placental tissue altered the gestational tolerogenic state, reducing the immune response against pathogens and activating the extrinsic apoptotic pathway, causing spontaneous abortion.

Perinatal Infections With Ureaplasma.

Ureaplasma species are increasingly recognized as relevant pathogens in prenatal, perinatal and postnatal morbidity. They are commonly found as commensals on the mucous membranes of the lower urogenital tract of pregnant women, but when ascending, they can cause bacterial vaginosis, chorioamnionitis, premature birth and postnatal morbidities such as bronchopulmonary dysplasia, and early-onset neonatal sepsis and meningitis. The detection of Ureaplasma species is challenging and is not covered by routine diagnostics, and current empiric antibiotic treatment in neonates suspected of infection is not directed against Ureaplasma species. The aim of this review is to discuss the pathophysiology of Ureaplasma infections, the clinical consequences and the current difficulties in diagnosis and treatment by providing an overview of the current literature.

Validation of the loop-mediated isothermal amplification method for rapid and sensitive detection of Ureaplasma species in respiratory tracts of preterm infants.

INTRODUCTION: A simple and rapid diagnosis of Ureaplasma spp. is required for the choice of the appropriate antibiotic. However, an ideal detection method has not been available. This study examines the efficacy of the loop-mediated isothermal amplification (LAMP) assay, which provides rapid and sensitive results, to detect Ureaplasma spp. in respiratory tract samples of preterm infants. METHODS: The study included preterm infants born before 32 weeks of gestation admitted Kagoshima City Hospital from June 2018 to March 2020. Nasopharyngeal swabs and/or tracheal aspirates were obtained in the first seven postnatal days. One hundred sixty-seven nasopharyngeal swabs and 101 tracheal aspirates were analyzed by LAMP, culture, and quantitative real-time polymerase chain reaction. RESULTS: All 167 infants had a median (range) gestational age of 28.7 weeks (22.3-30.9) and birthweight 1030g (322-1828). One hundred sixty-seven nasopharyngeal swabs and 101 tracheal aspirates were obtained. In the results of nasopharyngeal swabs, the sensitivity and specificity of LAMP were 73.9% (17/23) and 97.2% (140/144), whereas those of quantitative real-time polymerase chain reaction were 73.9% (17/23) and 95.8% (138/144), compared to culture. In the results of tracheal aspirates, the sensitivity and specificity of LAMP were 89.5% (17/19) and 92.7% (76/82), whereas those of quantitative real-time polymerase chain reaction were 89.5% (17/19) and 93.9% (77/82), compared to culture. CONCLUSIONS: The LAMP assay showed similar sensitivity and specificity with quantitative real-time polymerase chain reaction in the respiratory tracts of preterm infants including extremely preterm infants during the immediate postnatal period. Therefore, the LAMP is a practical alternative for the early detection so that appropriate antibiotics can be administered for preventing BPD.

The use of vaginal wet smear: can we predict Mycoplasmas/Ureaplasmas?

PURPOSE: To evaluate the agreement of wet smear microscopy with Gram stain microscopy and to assess whether it is possible to predict Mycoplasmas/Ureaplasmas when analysing vaginal secretion with Gram stain and wet smear microscopy. METHODS: Women with complaints of the abnormal vaginal discharge were invited to participate. A sample of vaginal secretion was taken for wet smear microscopy and for Gram staining analysis. A sample from the endocervical canal was taken for DNA detection of seven infections: Mycoplasma hominis, Mycoplasma genitalium, Ureaplasma parvum, Ureaplasma urealyticum, Chlamydia trachomatis, Neisseria gonorrhoeae and Trichomonas vaginalis. The percentage agreement between wet smear and Gram stain was determined and the Cohen's Kappa values were calculated. RESULTS: Of 158 consecutive women included, one (or a few) of the infections were detected in 54% of them and the most frequent infection was Ureaplasma parvum (79% of all the cases with infections). The percentage agreement between vaginal wet smear and Gram stain was 73% (Cohen's Kappa value 0.63). A statistically significant association between the DNA detected Mycoplasmas/Ureaplasmas and bacterial vaginosis was found (positive amine test p = 0.046, wet smear p = 0.005 and Gram stain p = 0.03). CONCLUSIONS: There was a statistically significant association between bacterial vaginosis and the DNA detected Mycoplasmas/Ureaplasmas. The agreement of vaginal wet smear with Gram stain was good.

A novel bioreactor for the stable growth of Ureaplasma parvum and Ureaplasma urealyticum.

Ureaplasma species, including Ureaplasma parvum and Ureaplasma urealyticum, are challenging to culture and maintain. Here, we describe a novel bioreactor for growing high-titer liquid Ureaplasma cultures in a stable manner.

Examination of Ureaplasma urealyticum and Mycoplasma hominis in 4082 Chinese patients

The objective of this study was to analyze the infection rate and drug resistance of Ureaplasma urealyticum (UU) and Mycoplasma hominis (MH) in the genitourinary tract of Chinese patients. From December 2018 to June 2019, vaginal secretion or urinary secretion of outpatients in our hospital were selected for culture and drug sensitivity analysis of Ureaplasma urealyticum and Mycoplasma hominis. In 4082 Chinese samples, 1567 Mycoplasma were detected, a detection rate of 38.39%, among which 1366 cases were UU single positive, accounting for 33.47%, 15 cases were MH single positive, accounting for 0.36%, 186 cases were UU and MH mixed positive, accounting for 4.56%. The most affected age groups were 21-30 years and 31-40 years, accounting for 19.09 and 15.05%, respectively. The results of drug sensitivity showed that doxycycline, minocycline, josamycin, clarithromycin, and roxithromycin were more sensitive to mycoplasma infection. The distribution of Ureaplasma urealyticum and Mycoplasma hominis in the human genitourinary system and their sensitivity to antibiotics is different for sex and age groups.

In-vitro activity of lipoic acid against Ureaplasma urealyticum and Ureaplasma parvum isolated from women with infections of the urogenital tract. A pilot study.

Several species of Ureaplasma bacteria are known to be present in the urogenital tract of humans, in both healthy individuals and symptomatic patients. These pathogens are associated with urogenital tract infections, infertility problems and spontaneous abortion in humans. The present study involved 77 strains of Ureaplasma species (Ureaplasma spp.), including 21 Ureaplasma urealyticum (U. urealyticum) strains and 56 Ureaplasma parvum (U. parvum) strains. Lipoic acid (LA) and its reduced form dihydrolipoic acid (DHLA) are synthesized in all prokaryotic and eukaryotic cells. Research of recent years increasingly points to therapeutic properties of exogenously supplemented LA. In our study, we examined for the first time the effect of LA on the bacteria multiplication and its bactericidal activity against U. urealyticum and U. parvum. The LA concentrations used were: 1200 µg/ml, 120 µg/ml, and 12 µg/ml. The titer for each strain of Ureaplasma spp. was estimated using the color changing units (CCU) assay. For CCU measurements, a series of 10-fold dilutions of each cell culture in 0.9% NaCl (titration) was prepared and 1 CCU/ml was defined as the highest dilution of cells at which color change was detected. The strongest bacteriostatic and bactericidal effect of LA was observed at a concentration of 1200 µg/ml. In contrast, at lower LA concentrations, stimulation of the bacteria multiplication was noted for 14% of the total number of strains tested. Taken together, the current data provide novel findings about potential beneficial antimicrobial effects of LA.

Examination of Ureaplasma urealyticum and Mycoplasma hominis in 4082 Chinese patients.

The objective of this study was to analyze the infection rate and drug resistance of Ureaplasma urealyticum (UU) and Mycoplasma hominis (MH) in the genitourinary tract of Chinese patients. From December 2018 to June 2019, vaginal secretion or urinary secretion of outpatients in our hospital were selected for culture and drug sensitivity analysis of Ureaplasma urealyticum and Mycoplasma hominis. In 4082 Chinese samples, 1567 Mycoplasma were detected, a detection rate of 38.39%, among which 1366 cases were UU single positive, accounting for 33.47%, 15 cases were MH single positive, accounting for 0.36%, 186 cases were UU and MH mixed positive, accounting for 4.56%. The most affected age groups were 21-30 years and 31-40 years, accounting for 19.09 and 15.05%, respectively. The results of drug sensitivity showed that doxycycline, minocycline, josamycin, clarithromycin, and roxithromycin were more sensitive to mycoplasma infection. The distribution of Ureaplasma urealyticum and Mycoplasma hominis in the human genitourinary system and their sensitivity to antibiotics is different for sex and age groups.

Septic arthritis of the shoulder due to Ureaplasma urealyticum after emergency caesarean section: a case report.

BACKGROUND: Ureaplasma urealyticum is an intra-cellular bacterium frequently found colonizing the genital tract. Known complications include localized infections, which can result in premature deliveries. Septic arthritis due to U. urealyticum in healthy patients is exceptionally rare, although opportunistic septic arthritis in agammaglobulinemic patients have been reported. However, there are no reports of septic arthritis due to U. urealyticum following caesarean section or in the post-partum period. CASE PRESENTATION: A 38-year-old immunocompetent woman presented with severe right shoulder pain, 1 month following emergency caesarean section at 26 weeks of gestation for pre-eclampsia and spontaneous placental disruption with an uncomplicated post-operative recovery. Our suspicion of septic arthritis was confirmed with abundant pus following arthrotomy by a delto-pectoral approach. Awaiting culture results, empirical antibiotic treatment with intravenous amoxicilline and clavulanic acid was initiated. In spite of sterile cultures, clinical evolution was unfavorable with persistent pain, inflammation and purulent drainage, requiring two additional surgical débridement and lavage procedures. The 16S ribosomal RNA PCR of the purulent liquid was positive for U. urealyticum at 2.95 × 106 copies/ml, specific cultures inoculated a posteriori were positive for U. urealyticum. Levofloxacin and azithromycine antibiotherapy was initiated. Susceptibility testing showed an intermediate sensibility to ciprofloxacin and clarithromycin. The strain was susceptible to doxycycline. Following cessation of breastfeeding, we started antibiotic treatment with doxycycline for 4 weeks. The subsequent course was favorable with an excellent functional and biological outcome. CONCLUSIONS: We report the first case of septic arthritis due to U. urealyticum after caesarean section. We hypothesize that the breach of the genital mucosal barrier during the caesarean section led to hematogenous spread resulting in purulent septic arthritis. The initial beta-lactam based antibiotic treatment, initiated for a purulent arthritis, did not provide coverage for cell wall deficient organisms. Detection of 16S rRNA allowed for a correct microbiological diagnosis in a patient with an unexpected clinical course.