Mycobacterium simiae: A Previously Undescribed Pathogen in Peritoneal Dialysis Peritonitis

[Infections due to Mycobacterium simiae]

Mycobacterium simiae is a slow-growing photochromogenic environmental mycobacterium, first described in 1965. Rarely associated with human infections, possibly due to its limited pathogenicity, it mainly produces lung infection in immunocompetent elderly patients with underlying lung disease, and in disseminated infections in immunosuppressed young patients with AIDS. A microbiological culture is needed to confirm the clinical suspicion, and genetic sequencing techniques are essential to correctly identify the species. Treating M. simiae infections is complicated, owing to the multiple resistance to tuberculous drugs and the lack of correlation between in vitro susceptibility data and in vivo response. Proper treatment is yet to be defined, but must include clarithromycin combined with other antimicrobials such as moxifloxacin and cotrimoxazole. It is possible that M. simiae infections are undiagnosed.

Peritonitis from Mycobacterium wolinskyi in a chronic peritoneal dialysis patient

We report the case of acute peritonitis caused by a rapidly growing mycobacterium in a chronic peritoneal dialysis patient, whose renal failure had been caused by diabetic glomerulosclerosis. The organism cultured from the peritoneal dialysis fluid was Mycobacterium wolinskyi. Peritonitis caused by M. wolinskyi in a chronic peritoneal dialysis patient has never been reported before.

Peritoneal dialysis-associated nontuberculous mycobacterium peritonitis: a systematic review of reported cases

BACKGROUND

Peritonitis caused by nontuberculous mycobacterium (NTM) is an important complication in peritoneal dialysis (PD) patients.

METHODS

Cases of PD complicated by NTM peritonitis reported in the English language literature were identified in the PubMed database. The characteristics of these cases were reviewed.

RESULTS

In 41 articles, we identified 57 cases of PD-associated NTM peritonitis in patients ranging from 5 to 82 years. The prevalent clinical findings of these cases were fever, abdominal pain, cloudy fluid and an elevated leukocyte count in peritoneal fluid. These findings were non-specific and could not be differentiated from symptoms caused by Mycobacterium tuberculosis or other bacteria. The majority of these cases received empirical antibacterial therapy before diagnosis of NTM peritonitis. Isolates in more than half of the peritonitis cases were the rapidly growing Mycobacterium, Mycobacterium fortuitum (38.6%) and Mycobacterium chelonae (14.0%). In most cases, PD catheters were removed and experience with non-removal was limited.

CONCLUSION

Diagnosis of NTM infection should be considered in PD patients with peritonitis that are culture negative or refractory to empirical antibiotic therapy.

Mycobacterium porcinum peritonitis in a patient on continuous ambulatory peritoneal dialysis

Mycobacterium porcinum has been reported to cause a variety of illnesses including wound infections, respiratory tract infections, osteomyelitis and catheter-related bacteremias. We report the first case of M. porcinum peritonitis in a patient on continuous ambulatory peritoneal dialysis (CAPD). A 67-year-old woman on CAPD presented with three weeks of constitutional symptoms and abdominal pain. Peritoneal fluid cultures on day three grew acid-fast rods. Nocardiosis was suspected and the patient was empirically treated with amikacin and trimethoprim-sulfamethoxazole. The dialysis catheter was removed. Two weeks later final culture results revealed M. porcinum. Ciprofloxacin and trimethoprim-sulfamethoxazole were initiated with good clinical response.