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Fleming D, Cunningham SA, Patel R. Contribution of Uremia to Ureaplasma-Induced Hyperammonemia. Microbiol Spectr 2022; 10:e0194221. [PMID: 35171026 PMCID: PMC8849080 DOI: 10.1128/spectrum.01942-21] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2021] [Accepted: 01/16/2022] [Indexed: 12/14/2022] Open
Abstract
Lung transplant recipients (LTRs) are vulnerable to hyperammonemia syndrome (HS) in the early postoperative period, a condition typically unresponsive to nonantibiotic interventions. HS in LTRs is strongly correlated with Ureaplasma infection of the respiratory tract, although it is not well understood what makes LTRs preferentially susceptible to HS compared to other immunocompromised hosts. Ureaplasma species harbor highly active ureases, and postoperative LTRs commonly experience uremia. We hypothesized that uremia could be a potentiating comorbidity, providing increased substrate for ureaplasmal ureases. Using a novel dialyzed flow system, the ammonia-producing capacities of four isolates of Ureaplasma parvum and six isolates of Ureaplasma urealyticum in media formulations relating to normal and uremic host conditions were tested. For all isolates, growth under simulated uremic conditions resulted in increased ammonia production over 24 h, despite similar endpoint bacterial quantities. Further, transcripts of ureC (from the ureaplasmal urease gene cluster) from U. urealyticum IDRL-10763 and ATCC-27816 rose at similar rates under uremic and nonuremic conditions, with similar endpoint populations under the two conditions (despite markedly increased ammonia concentrations under uremic conditions), indicating that the difference in ammonia production by these isolates is due to increased urease activity, not expression. Lastly, uremic mice infected with an Escherichia coli strain harboring a U. urealyticum serovar 8 gene cluster exhibited higher blood ammonia levels compared to nonuremic mice infected with the same strain. Taken together, these data show that U. urealyticum and U. parvum produce more ammonia under uremic conditions compared to nonuremic conditions. This implies that uremia is a plausible contributing factor to Ureaplasma-induced HS in LTRs. IMPORTANCE Ureaplasma-induced hyperammonemia syndrome is a deadly complication affecting around 4% of lung transplant recipients and, to a lesser extent, other solid organ transplant patients. Understanding the underlying mechanisms will inform patient management, potentially decreasing mortality and morbidity. Here, it is shown that uremia is a plausible contributing factor to the pathophysiology of the condition.
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Affiliation(s)
- Derek Fleming
- Division of Clinical Microbiology, Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, Minnesota, USA
| | - Scott A. Cunningham
- Division of Clinical Microbiology, Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, Minnesota, USA
| | - Robin Patel
- Division of Clinical Microbiology, Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, Minnesota, USA
- Division of Infectious Diseases, Department of Medicine, Mayo Clinic, Rochester, Minnesota, USA
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Fleming D, Karau M, Patel R. A novel bioreactor for the stable growth of Ureaplasma parvum and Ureaplasma urealyticum. J Microbiol Methods 2021; 181:106131. [PMID: 33385441 PMCID: PMC7870580 DOI: 10.1016/j.mimet.2020.106131] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2020] [Revised: 11/20/2020] [Accepted: 12/21/2020] [Indexed: 11/25/2022]
Abstract
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.
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Affiliation(s)
- Derek Fleming
- Division of Clinical Microbiology, Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, MN, United States of America
| | - Melissa Karau
- Division of Clinical Microbiology, Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, MN, United States of America
| | - Robin Patel
- Division of Clinical Microbiology, Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, MN, United States of America; Division of Infectious Diseases, Department of Medicine, Mayo Clinic, Rochester, MN, United States of America.
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Roberts SC, Bharat A, Kurihara C, Tomic R, Ison MG. Impact of Screening and Treatment of Ureaplasma spp on Hyperammonemia Syndrome in Lung Transplant Recipients: A Single Center Experience. Clin Infect Dis 2020; 73:e2531-e2537. [PMID: 33068392 DOI: 10.1093/cid/ciaa1570] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2020] [Indexed: 01/12/2023] Open
Abstract
BACKGROUND Infection with Ureaplasma species (spp) has been linked to fatal hyperammonemia syndrome (HS) in lung transplant recipients. We sought to characterize the epidemiology of Ureaplasma spp in candidates and donors and describe outcomes of antimicrobial therapy in preventing and treating HS. METHODS Candidate testing for Ureaplasma spp was performed with urine culture and PCR pre-transplant. Positive candidates were treated with levofloxacin. Donor testing was performed with bronchoalveolar lavage culture and PCR intraoperatively. From 7/2014-2/2017 patients were treated according to results; from 2/2017-10/2018 recipients received empiric levofloxacin and azithromycin at transplant until testing returned negative. HS was defined as new onset altered mental status after transplant with ammonia > 200 µmol/L. RESULTS 60 patients who underwent lung transplant were included. 80% (n = 48) of patients had negative screening tests in donor and candidate pre-lung transplant, 8.3% (n = 5) of recipients had positive Ureaplasma spp testing in urine pre-transplant, and 13.3% (n = 8) had positive donor BAL testing at the time of lung transplant. 3 patients developed HS a median of 7 days post-transplant; 2 died of HS. Recipients of organs with Ureaplasma spp who received empiric therapy did not develop HS. Donors with Ureaplasma spp were younger and more sexually active. CONCLUSION Donor-derived Ureaplasma spp in lung transplant was associated with HS. Screening lung donors for Ureaplasma spp might allow for targeted therapy to reduce risk for development of HS, but future confirmatory studies are needed.
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Affiliation(s)
- Scott C Roberts
- Division of Infectious Diseases, Northwestern University Feinberg School of Medicine, Chicago, Illinois
| | - Ankit Bharat
- Division of Thoracic Surgery, Northwestern University Feinberg School of Medicine, Chicago, Illinois.,Division of Pulmonary and Critical Care Medicine, Northwestern University Feinberg School of Medicine, Chicago, Illinois
| | - Chitaru Kurihara
- Division of Thoracic Surgery, Northwestern University Feinberg School of Medicine, Chicago, Illinois
| | - Rade Tomic
- Division of Pulmonary and Critical Care Medicine, Northwestern University Feinberg School of Medicine, Chicago, Illinois
| | - Michael G Ison
- Division of Infectious Diseases, Northwestern University Feinberg School of Medicine, Chicago, Illinois.,Division of Organ Transplantation, Northwestern University Feinberg School of Medicine, Chicago, Illinois
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Abstract
Idiopathic hyperammonemia is a rare, poorly understood, and often lethal condition that has been described in immunocompromised patients. This report describes an immunocompromised patient with acute myelogenous leukemia who developed persistent hyperammonemia up to 705 µmol/L (normal, 0 to 47 µmol/L) refractory to multiple different therapies. However, after beginning azithromycin and then doxycycline therapy for Ureaplasma species infection, the patient showed immediate and sustained clinical improvement and resolution of ammonia levels. Recognizing disseminated Ureaplasma species infection as a potential cause of idiopathic hyperammonemia, an unexplained, often fatal condition in immunocompromised patients, and empirically treating for this infection could potentially be lifesaving.
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Beeton ML, Payne MS, Jones L. The Role of Ureaplasma spp. in the Development of Nongonococcal Urethritis and Infertility among Men. Clin Microbiol Rev 2019; 32:e00137-18. [PMID: 31270127 PMCID: PMC6750135 DOI: 10.1128/cmr.00137-18] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Ureaplasma spp. are a genus of bacteria for which two human-associated species exist: Ureaplasma urealyticum and Ureaplasma parvum Their definition as a pathogen in the context of nongonococcal urethritis (NGU) and infertility among males remains highly controversial, largely due to historically high rates of isolation of these bacteria from the urethra of seemingly healthy men. This review summarizes the emerging evidence suggesting a true pathogenic role of these bacteria under specific conditions, which we term risk factors. We examine the historical, clinical, and experimental studies which support a causal role for Ureaplasma spp. in the development of NGU as well as some of the proposed mechanisms behind the association of Ureaplasma spp. and the development of infertility. Finally, we discuss the potential for developing a case-by-case risk-based approach toward the management of men who present with seemingly idiopathic NGU but who are positive for Ureaplasma spp.
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Affiliation(s)
- Michael L Beeton
- Cardiff School of Sport and Health Sciences, Department of Biomedical Science, Cardiff Metropolitan University, Cardiff, United Kingdom
| | - Matthew S Payne
- Division of Obstetrics and Gynaecology, The University of Western Australia, Crawley, Western Australia, Australia
| | - Lucy Jones
- Department of Integrated Sexual Health, Dewi Sant Hospital, Cwm Taf University Health Board, Pontypridd, United Kingdom
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Kendall MC, Alves LJC, Suh EI, McCormick ZL, De Oliveira GS. Regional anesthesia to ameliorate postoperative analgesia outcomes in pediatric surgical patients: an updated systematic review of randomized controlled trials. Local Reg Anesth 2018; 11:91-109. [PMID: 30532585 PMCID: PMC6244583 DOI: 10.2147/lra.s185554] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Regional anesthesia is becoming increasingly popular among anesthesiologists in the management of postoperative analgesia following pediatric surgery. The main objective of this review was to systematically evaluate the last 5 years of randomized controlled trials on the role of regional anesthesia techniques in alleviating postoperative pain associated with various pediatric surgical procedures. Forty studies on 2,408 pediatric patients were evaluated. The majority of the articles published from 2013 to 2017 reported that the use of regional anesthesia minimized postoperative pain and reduced opioid consumption. Only a few surgical procedures (cholecystectomy, inguinal hernia repair, and non-laparoscopic major abdominal surgery) reported no significant difference in the postoperative pain relief compared with the standard anesthetic management. The growing number of randomized controlled trials in the pediatric literature is very promising; however, additional confirmation is needed to reinforce the use of specific regional anesthesia techniques to provide optimal postoperative pain relief for a few surgical procedures (reconstructive ear surgery, chest wall deformity, hypospadias, umbilical hernia, cleft palate repair) in pediatric patients. More randomized controlled trials are needed to establish regional anesthesia as an essential component of postoperative analgesia management in children.
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Affiliation(s)
- Mark C Kendall
- Department of Anesthesiology, Rhode Island Hospital, The Warren Alpert Medical School of Brown University, Providence, RI, USA,
| | | | - Edward I Suh
- Department of Anesthesiology, Rhode Island Hospital, The Warren Alpert Medical School of Brown University, Providence, RI, USA,
| | - Zachary L McCormick
- Division of Physical Medicine and Rehabilitation, University of Utah, Salt Lake City, UT, USA
| | - Gildasio S De Oliveira
- Department of Anesthesiology, Rhode Island Hospital, The Warren Alpert Medical School of Brown University, Providence, RI, USA,
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Antimicrobial Susceptibility and Clonality of Clinical Ureaplasma Isolates in the United States. Antimicrob Agents Chemother 2016; 60:4793-8. [PMID: 27246773 DOI: 10.1128/aac.00671-16] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2016] [Accepted: 05/18/2016] [Indexed: 11/20/2022] Open
Abstract
Ureaplasma urealyticum and Ureaplasma parvum are pathogens involved in urogenital tract and intrauterine infections and also in systemic diseases in newborns and immunosuppressed patients. There is limited information on the antimicrobial susceptibility and clonality of these species. In this study, we report the susceptibility of 250 contemporary isolates of Ureaplasma (202 U. parvum and 48 U. urealyticum isolates) recovered at Mayo Clinic, Rochester, MN. MICs of doxycycline, azithromycin, ciprofloxacin, tetracycline, erythromycin, and levofloxacin were determined by broth microdilution, with MICS of the last three interpreted according to CLSI guidelines. Levofloxacin resistance was found in 6.4% and 5.2% of U. parvum and U. urealyticum isolates, respectively, while 27.2% and 68.8% of isolates, respectively, showed ciprofloxacin MICs of ≥4 μg/ml. The resistance mechanism of levofloxacin-resistant isolates was due to mutations in parC, with the Ser83Leu substitution being most frequent, followed by Glu87Lys. No macrolide resistance was found among the 250 isolates studied; a single U. parvum isolate was tetracycline resistant. tet(M) was found in 10 U. parvum isolates, including the single tetracycline-resistant isolate, as well as in 9 isolates which had low tetracycline and doxycycline MICs. Multilocus sequence typing (MLST) performed on a selection of 46 isolates showed high diversity within the clinical Ureaplasma isolates studied, regardless of antimicrobial susceptibility. The present work extends previous knowledge regarding susceptibility to antimicrobial agents, resistance mechanisms, and clonality of Ureaplasma species in the United States.
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