Link found between donor, infection in heart, lung transplant recipients

May 16, 2017

The way in which heart and lung transplant recipients acquired a specific species of bacteria, Mycoplasma hominis, had been previously undefined, and the bacterium was difficult to test. Originally, this bacterium was considered to reside exclusively in, and be a potential pathogen of, the area of the reproductive and urinary organs - the genitourinary tract.

"This finding could affect how we approach the evaluation of organ donors," says Mark Wylam, M.D., who led the team of Mayo Clinic researchers on this study. "If potential transmission of these harmful bacteria can be identified and addressed, the recipient will face a decreased risk of and its serious complications. This study shows us that surveillance of both donor and recipient are important in recognizing M. hominis and the infection it can cause."

Heart and lung transplant recipient infection caused by M. hominis may present with pleurisy (inflammation of membrane in chest cavity and lungs), surgical site infection and mediastinitis (inflammation of tissue in mid-chest). M. hominis resists most antibiotics, and the three antibiotic treatment recommendations for these infections are neither standard for post-transplant recipient care nor are they standard in therapy regimens for surgical site infections.

The study, published recently in EBioMedicine, investigates Mayo Clinic lung and heart-lung transplants between 1998 and July 2015. Seven previously unreported cases of with M. hominis infection were discovered. In each case, pre-transplant sputum cultures had tested negative for M. hominis. Also, a literature review since 1950 found 15 cases of M. hominis infection in lung, heart or heart-lung transplant recipients. The way the germ spread remained uncertain. Given its normal residence in the genitourinary tract, some speculated that infection arose from urinary catheter placement during the transplant surgery.

Mayo investigators noted two particular cases of M. hominis infection that each had received a single transplant from the same donor, and no other patients in the hospital were infected by M. hominis. The samples of the M. hominis taken from each infected individual were genetically indistinguishable, suggesting the infections had the same source. This finding, in addition to two other observations, supported the likelihood that M. hominis could be passed from transplant donor to recipient.

Common testing methods have proven insufficient in identifying the bacteria, but the use of detection developed by Robin Patel, M.D., director of Mayo Clinic's Infectious Diseases Research Laboratory, offers a more time-sensitive and specific test for the bacteria. With this method, researchers zoom in on a certain portion of DNA and then create multiple copies to amplify the segment. Polymerase chain reaction detection reduces the time to detect M. hominis to a few hours, compared to the two to five days needed for a culture media test.

"The true rate of M. hominis infection may actually be higher than what we've seen reported," says Dr. Wylam. "Better detection methods like PCR tests have given us more insight into how common this bacterium is in the airway, which is especially important in heart or recipients. More research is needed to learn about these bacteria when it's found far from its natural home in the genitourinary tract, and especially when it is transmitted to cardiothoracic transplant recipients."

Explore further: How fecal microbial transplant restores microbial balance

Related Stories

How fecal microbial transplant restores microbial balance

April 12, 2017
When facing a life-threatening infection, the "yuck factor" is a minor concern. Fecal microbiota transplant (FMT for short) has become an accepted treatment for recurrent Clostridium difficile infection, which can cause severe ...

Donor-recipient weight and sex mismatch may contribute to kidney transplant failure

March 30, 2017
A new study indicates that the success of a kidney transplant may rely in part on a kidney donor's weight and sex, factors that are not typically considered when choosing a recipient for a deceased donor kidney. The findings, ...

E. cuniculi can cause febrile illness after transplant

February 19, 2014
(HealthDay)—Solid organ transplant recipients who become febrile weeks after transplantation may have acquired microsporidiosis from Encephalitozoon cuniculi, according to a case series published in the Feb. 18 issue of ...

Viral infection in transplant recipients increases risk of developing damaging antibodies

September 25, 2014
Kidney transplant recipients infected with BK virus are more likely to develop antibodies against their kidney transplants than uninfected patients, according to a study appearing in an upcoming issue of the Journal of the ...

Roundworm infections threaten organ recipients

April 11, 2013
(HealthDay)—Three people who received transplant organs in 2012 from the same 24-year-old donor got more than they bargained for: Each developed a severe roundworm infection, U.S. health officials reported Thursday.

New non-invasive assay may improve surveillance of heart and other solid-organ transplants

October 11, 2016
Patients who have received a solid organ transplant require lifelong immunosuppressive therapy. The threat of transplant rejection due to insufficient drug therapy must be balanced against increased risks of infections and ...

Recommended for you

Study shows electric bandages can fight biofilm infection, antimicrobial resistance

November 6, 2017
Researchers at The Ohio State University Wexner Medical Center have shown - for the first time - that special bandages using weak electric fields to disrupt bacterial biofilm infection can prevent infections, combat antibiotic ...

Obesity increases incidence, severity, costs of knee dislocations

November 3, 2017
A new study of more than 19,000 knee dislocation cases in the U.S. between 2000 and 2012 provides a painful indication of how the nation's obesity epidemic is changing the risk, severity and cost of a traumatic injury.

Defining optimal opioid pain medication prescription length following surgery

September 27, 2017
A new study led by researchers at the Center for Surgery and Public Health at Brigham and Women's Hospital analyzed opioid prescription data from the Department of Defense Military Health System Data Repository, identifying ...

Is older blood OK to use in a transfusion?

September 27, 2017
(HealthDay)—Using older red blood cells to give transfusions to critically ill patients doesn't appear to affect their risk of dying, Australian researchers report.

One weight-loss surgery shows lasting results

September 21, 2017
(HealthDay)—Obesity surgery can have long-lasting effects on weight and the risk of developing type 2 diabetes and high blood pressure, a new study finds.

Hold the phone: An ambulance might lower your chances of surviving some injuries

September 20, 2017
Victims of gunshots and stabbings are significantly less likely to die if they're taken to the trauma center by a private vehicle than ground emergency medical services (EMS), according to results of a new analysis.

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.