Background:

Ralstonia mannitolilytica, an emerging opportunistic pathogen, can infect immunocompromised patients but is a rare cause of severe sepsis and septic shock in kidney transplant recipients (KTRs).
Case presentation:
We present a case of septic shock after renal transplant in a 41-year-old male, which was finally proven to be caused by Ralstonia mannitolilytica through blood cultures and mass spectrometric analysis following the negative result of metagenomic next-generation sequencing (mNGS). He was finally cured after the application of sensitive antibiotics (sulfamethoxazole-trimethoprim, amikacin and piperacillin-tazobactam) based on the drug sensitivity test results. The patient had a satisfactory recovery with no complications during a 6-month follow-up period.
Conclusion:
This study highlights that Ralstonia mannitolilytica is an easily overlooked cause of septic shock in KTRs requiring a detailed inquiry of medical history with inflammatory markers monitored closely. Traditional blood cultures still should be taken seriously. It also provides a cautionary tale that negative results of mNGS have to be interpreted with caution.