Mycoplasma hominis and Ureaplasma urealyticum infections in the immediate post‐lung transplant period: A case series and literature review

Abstract

Mycoplasma hominis and Ureaplasma species infections in the post‐transplant setting are believed to be donor‐derived and can be associated with poor outcomes. Difficulty in culturing and identifying these organisms is a significant barrier to diagnosis and early intervention. Tetracyclines, macrolides and fluoroquinolones are the mainstay treatments to cure these infections; however, there are increasing reports of antibiotic resistance. In this case series, we report our single‐centre experience with M. hominis and U. urealyticum infection after lung transplantation (9 recipients, all men, mean age 56 years). Delayed diagnosis was common. Young donor age (mean age 23 yrs) and high‐risk donor social history (67%) were repeatedly noted in these cases, and all infections were associated with significant morbidity (anastomosis and sternal wound infection, empyema, mediastinitis, pericarditis). Two patients died; with one directly related to Ureaplasma urealyticum infection. In conclusion post lung transplant M. hominis, and U. urealyticum infections are challenging and carry high morbidity. More prospective studies are required to assess the true prevalence, full spectrum of complications and utility of molecular diagnostics to aid early diagnosis and identify antibiotic susceptibility of Mycoplasma and Ureaplasma infections in the post‐lung transplant setting.

Treatment of Hyperammonemia Syndrome in Lung Transplant Recipients

“…Also, of the 49 cases of hyperammonemia identified in their literature review 18 patients had specimens sent for testing and 16 were positive for Mollicutes [1]. Ureaplasma urealyticum, Mycoplasma hominis, and Ureaplasma parvum are Mollicutes commonly found in the urogenital and sometimes the upper respiratory tract but may be present in other areas of the body in the setting of immunosuppression and broad-spectrum antimicrobials [1][2][3][4]12]. Through different mechanisms, these species are able to generate ammonia.…”

“…The Ureaplasma species require a special medium for growth and can take up to 5 days to produce results, and Mycoplasma hominis grows in pinpoint colonies that are easy to miss. Therefore, polymerase chain reaction (PCR) testing, most commonly done using bronchoalveolar lavage samples, can be done in conjunction [12,13,17]. As these infections can be donor-derived, testing of donors may also be considered [3].…”

“…Tetracyclines and fluoroquinolones are active against both species. Concerns for resistance are present for all active agents and therefore empiric combination therapy can be considered while performing sensitivity testing or identifying resistance-determining gene mutations [4,6,12]. Examples of reported antibiotic regimens include azithromycin 500 mg PO/IV daily, levofloxacin 500 or 750 mg PO/IV daily, which should be renally adjusted, doxycycline 100 mg PO/IV every 12 h, and moxifloxacin 400 mg PO/IV daily [5,16].…”

“…These agents may cause gastrointestinal adverse effects, the QT interval should be monitored with both azithromycin and fluoroquinolones especially in combination with post-transplant medication such as calcineurin inhibitors and azole antifungals, and the risk of Clostridioides difficile infection is increased with clindamycin and fluoroquinolones. Duration of antibiotic treatment varies but ranges from two to four weeks [3,12]. There have been multiple strategies for identifying candidates for antibiotic treatment in the literature given the difficulty and time required to diagnose these infections, but there is no consensus on the optimal method.…”