A case of Helicobacter cinaedi pleuritis and continuous ambulatory peritoneal dialysis-related peritonitis diagnosed by simultaneous-onset bacteremia.

A 42-year-old man undergoing peritoneal dialysis due to a chronic kidney disease of unknown etiology complained of fever and chills. Oral levofloxacin was started, but the symptoms did not improve. He was admitted, and the levofloxacin was switched to intravenous ciprofloxacin. Without improvement, the antibiotic was changed to intravenous meropenem, and he gradually got afebrile. Blood culture on admission yielded a Gram-negative rod (GNR), which was identified as Helicobacter cinaedi by Matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI TOF-MS). Additionally, after admission, pleural effusion on the left side increased. The pleural effusion was determined as exudative, but the Gram stain and culture were negative. He was diagnosed with H. cinaedi pleuritis and bacteremia. After three-weeks of intravenous meropenem, he was discharged. However, he complained of fever and chills again and was re-admitted. Intravenous meropenem was re-started, and he got afebrile. Ascites test via peritoneal dialysis tube was conducted. The ascitic fluid was turbid, and the white blood cell count was elevated predominantly with neutrophils. Blood culture on re-admission yielded a GNR, identified as H. cinaedi by MALDI TOF-MS. After three-week intravenous meropenem administration, ten-days of intravenous tazobactam/piperacillin plus vancomycin plus oral minocycline, followed by twelve-days of intravenous cefepime plus oral minocycline were administrated due to hospital-acquired pneumonia. This was followed by a two-week oral minocycline intake. H. cinaedi infection did not recur thereafter. To our knowledge, this report is the first case of H. cinaedi pleuritis and continuous ambulatory peritoneal dialysis-related peritonitis diagnosed by simultaneous-onset of bacteremia.