Case Report: Comprehensive Management of Pneumocystis Jiroveci Pneumonia (PJP) and Secondary Infections of Multiple-Drug Resistant Enterobacter cloacae complex and Pseudomonas aeruginosa in a Kidney Transplant Recipient with Sulfonamide Allergies

We report a case of pneumocystis jiroveci pneumonia (PJP) in a 46-year-old woman, who previously underwent kidney transplant for chronic renal failure. She did not receive PJP prophylaxis treatment for the history of sulfonamide allergies. Four months after renal transplantation, the patient had cough, chest tightness, and shortness of breath. Procalcitonin (PCT) (0.06 ng/mL) and C-reactive protein (CRP) (5.33 mg/L) were normal, but the level of 1, 3-β-D-glucan test (G test, 193.89 pg/mL) were elevated. Metagenomics next-generation sequencing (mNGS) using bronchoalveolar lavage fluid (BALF) rapidly and accurately identified P. jiroveci. Through sulfonamide desensitization and sulfamethoxazole-trimethoprim (TMP-SMX) combined with caspofungin (CAS) treatment, PJP was controlled. However, the patients' conditions were worsen for the hospital-acquired secondary pulmonary infection. A second BALF mNGS identified Enterobacter cloacae complex and Pseudomonas aeruginosa carrying carbapenem drug resistance genes, which were confirmed by subsequent culture and antimicrobial susceptibility test within 3 days. Finally, symptoms, such as chest tightness, cough, and shortness of breath, were improved and she was discharged after combined treatment with meropenem (MEM), polymyxin B (PMB), CAS, and TMP-SMX. In this case, mNGS, culture, and drug susceptibility testing were combined to monitor pathogenic microbial and adjust medication. At present, there are no case reports of mNGS use and sulfonamide desensitization in a kidney transplant recipient with sulfonamide allergies.