Optimal treatment regimen for CAPD peritonitis caused by Rhodococcus species

Peritoneal Dialysis-Related Recurrent Rhodococcus corynebacterioides Peritonitis: A Case Report and Review of Literature

Rhodococcus corynebacterioides is a Gram-positive bacterium known to cause bacteremia and oligoarthritis. There have been only a few case reports in the literature that describe its association with peritoneal dialysis (PD)-related peritonitis. We report a case of recurrent peritonitis caused by R. corynebacterioides. The patient presented with abdominal pain, and PD fluid analysis was positive for infection, with cultures growing R. corynebacterioides. The patient was treated with multiple courses of intraperitoneal antibiotics due to recurrent episodes of PD-associated peritonitis from this bacterium, ultimately necessitating the removal of the PD catheter and the transition to hemodialysis.

A case of peritoneal dialysis-associated peritonitis caused by Rhodococcus kroppenstedtii

BACKGROUND

Rhodococcus kroppenstedtii is an aerobic, gram-positive bacterium firstly identified in the environment, which has not been reported in human-related infection. Herein, we reported the first case of peritoneal dialysis (PD)-associated peritonitis caused by R. kroppenstedtii which was identified by whole genome sequencing.

CASE PRESENTATION

A 69-year-old man was admitted to hospital with abdominal pain and fever. Over the last 2 years, he had been undergoing continuous ambulatory peritoneal dialysis (CAPD) due to end-stage renal disease. Clinical symptom and sign in combination with laboratory examinations supported the clinical diagnosis of PD-associated peritonitis. Thus, ceftizoxime and teicoplanin were empirically used after PD effluent was collected for bacterial culture. A gram-positive bacterium was found from the PD effluent culture, which could not be identified by either Vitek 2 Compact ANC card or matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. The strain was finally confirmed to be R. kroppenstedtii by whole genome sequencing (WGS) through the average nucleotide identity (ANI) analysis. With a continuous treatment with teicoplanin and imipenem for 15 days and intraperitoneal catheter removed, the infection symptom was improved evidenced by a normal body temperature, also with white blood cell count (WBC), procalcitonin (PCT) and C-reactive protein (CRP) dropped to normal levels. Peritoneal dialysis effluent culture showed a negative result. Then, hemodialysis and arteriovenous fistula angioplasty were performed, but the patient developed a progressive blood pressure loss, accompanied by multiple organ disorder, and died on Feb 25, 2020.

CONCLUSIONS

To the best of our knowledge, this is the first time to report a peritoneal dialysis-associated peritonitis caused by R. kroppenstedtii which was identified by average nucleotide identity analysis based on WGS.

Pets-related peritonitis in peritoneal dialysis: companion animals or trojan horses?

Infectious peritonitis is still a major concern in peritoneal dialysis (PD). Standard antibiotic regimens target common causative microorganisms such as Staphylococcus aureus and epidermidis or Pseudomonas aeruginosa. When the infection does not respond, unusual infective agents are to be considered including zoonoses-infections with an animal source. Companion animals or occupations involving animal contact favor the development of zoonoses, especially for immunocompromised patients such as those with end-stage renal disease. We reviewed the literature for all animals-related peritonitis in PD and analyzed data from our own PD unit and from the French-speaking registry for peritoneal dialyis (RDPLF) to assess both the frequency and the potential risk for PD patients in owning a pet or to working with animals. In a literature search, we identified 124 cases of PD peritonitis caused by 12 different zoonotic agents. Animals were involved in 24% of the cases. Overall mortality rate was 13.5% and Tenckhoff catheters had to be removed in 27% of the cases. The results from RDPLF analysis show that zoonotic microorganisms were responsible for 0.54% of the peritonitis episodes (51 out of a total of 9433 during a 9-year period). In our unit, zoonotic microorganisms were responsible for 0.03% of the peritonitis episodes (four out of a total of 128 during a 9-year period). Considering those results, some specific treatment recommendations can be made, but the major factor still remains prevention, by insisting on strict hygenic measures when a PD patient owns a pet.

Rhodococcus erythropolis septicaemia in a patient with acute lymphocytic leukaemia

Rhodococcus erythropolis rarely causes infection in humans. We report the second case of R. erythropolis septicaemia in a 7-year-old child. However, to our knowledge it is the first case in a patient with acute lymphocytic leukaemia who had been undergoing chemotherapy. The identification was performed using 16S rRNA gene sequencing. Even though R. erythropolis is rarely associated with human infections, it should be considered as a potential causative agent of bacteraemia, rather than overlooked as a contaminant.

Rhodococcus equi pneumonia in a patient with human immunodeficiency virus: case report and review

Rhodococcus equi is a facultative, intracellular, gram-positive coccobacillus increasingly reported as an opportunistic pathogen in patients positive for human immunodeficiency virus (HIV). An HIV-positive man developed R. equi pneumonia and sepsis. He failed to improve despite surgical drainage of localized infection and many empiric antibiotics. Time-kill studies of R. equi isolated from the patient were performed against various antimicrobial agents to optimize therapy. Levofloxacin seemed to offer excellent in vitro bactericidal activity. Antagonism was observed with certain antibiotic combinations. Our anecdotal case report suggests that fluoroquinolones such as levofloxacin may offer superior efficacy to standard therapy in rhodococcal infections; their clinical utility deserves further investigation. In view of potential antagonism, prospective susceptibility testing for various drugs and drug combinations should be considered when clinically indicated.