Mycoplasma hominis

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Record number: 
Adverse Occurrence type: 
MPHO Type: 
Estimated frequency: 
Extremely uncommonly reported - unclear whether transmissions rarely occur or are rarely recognized. When reported, often occurs in immunocompromised individuals.
Time to detection: 
Days 3 - 19 after transplant
Alerting signals, symptoms, evidence of occurrence: 
Development of pneumonia (+/- arthritis) in three lung transplant recipients soon after transplant procedure, associated with high WBC counts (>20,000).
Demonstration of imputability or root cause: 
Both strains form donor and patient (referred as 1) were identical by whole-genome sequencing.
Imputability grade: 
3 Definite/Certain/Proven
Suggest new keywords: 
Mycoplasma hominis
lung transplant recipient
whole-genome sequencing
Suggest references: 
- Smibert OC, et al. Donor-Derived Mycoplasma hominis and an Apparent Cluster of M. hominis Cases in Solid Organ Transplant Recipients. Clin Infect Dis. 2017 Oct 16;65(9):1504-1508 - Spiller OB. Emerging Pathogenic Respiratory Mycoplasma hominis Infections in Lung Transplant Patients: Time to Reassesses it's Role as a Pathogen? EBioMedicine. 2017 May;19:8-9. doi: 10.1016/j.ebiom.2017.05.002. Epub 2017 May 3. PMID: 28506624; PMCID: PMC5440618. - Isabelle Moneke, Daniel Hornuss, Annerose Serr, Winfried V Kern, Bernward Passlick, Oemer Senbaklavaci, Lung Abscess and Recurrent Empyema After Infection With Mycoplasma hominis: A Case Report and Review of the Literature, Open Forum Infectious Diseases, Volume 9, Issue 1, January 2022, ofab406, - Gass R, Fisher J, Badesch D, Zamora M, Weinberg A, Melsness H, Grover F, Tully JG, Fang FC. Donor-to-host transmission of Mycoplasma hominis in lung allograft recipients. Clin Infect Dis. 1996 Mar;22(3):567-8. doi: 10.1093/clinids/22.3.567. PMID: 8852981.
The link to the Smibert pdf (CID 2017) isn't working, please repair it. - Done (EP) The extra papers were used in creating this record, so please do include them in the reference list - Done (EP)
Expert comments for publication: 
M hominis infection should be considered as a possibility when transplant recipients are affected with pneumonia, and Gram stains and cultures from sputum are negative but with high neutrophil count. High peripheral leukocytosis in a patient who doesn't appear seriously ill can be a diagnostic clue. The manuscript describes the presentation of Mycoplasma hominis infection in three lung transplant recipients who develop pneumonia and/or arthritis soon after transplantation. The authors confirmed by molecular analysis that strains from one donor and one recipient were closely related. However, the other two reports were caused by different strains even though occurring closely in time. Interestingly, there were no other infections in the other organ recipients from the infected donor. Unfortunately, they could not study samples from the other two donors. Altogether raises suspicion that this cluster of Mycoplasma hominis could have been acquired in the setting of the ICU where all donor and recipients were cared for. Possible routes of transmission are person-to-person or environmental exposure, although fomite transmission of m hominis is not reported. As discussed in the Spiller and Moneke manuscripts, M hominis is likely an under-recognized pathogen, is not covered in typical antibiotic regimens for pneumonia (and is indeed resistant to many antibiotics), and is a fastidious organism with tiny colonies that take 48-72 hours to emerge, and because small the colonies are often overlooked even when present.