Emergence infection is a fairly frequent complication, but one that needs to be diagnosed early in order to initiate the appropriate treatment or risk catheter removal and transfer to hemodialysis.

Definitive exit-site infection is defined in the ISPD recommendations on catheter-related infections as the presence of purulent discharge, with or without erythema of the skin at the catheter-epidermal interface; in the absence of purulent discharge, other signs of inflammation at the exit site (e.g., erythema, tenderness, swelling, granuloma, or crust formation) are insufficient to definitively diagnose exit-site infection [1].

According to the source of the French-language peritoneal dialysis register (RDPLF), in France, the frequency is approximately 0.16 episode per year [2].

We report a case of Staphylococcus carnosus emergence infection that occurred in our PD center

Mr. P, aged 81, has been under nephrology care since June 2019 for the management of renal failure. The patient’s history is marked by chronic renal failure complicating heart failure refractory to drug treatment, thus creating a cardio-renal syndrome. He also had liver damage of common origin.

The patient had been hospitalized on several occasions for congestive global cardiac decompensation with preserved ejection fraction refractory to optimized medical treatment including sacubitril-valsartan, propranolol, spironolactone, and dapagliflozin. PD was decided, and the Tenckhoff catheter was inserted on July 17, 2019, for cardiac, renal, and hepatic PD.

Beforehand, we visited the patient’s home to check on the home’s hygiene and ask questions about the patient’s lifestyle. The presence of pets in the home was checked: there was no pet at home.

On August 12, 2019, the patient was hospitalized for dialysis start-up; he did not wish to handle the dialysis himself. PD was performed with the help of private nurses. The PD protocol included a 4.25% hypertonic bag during the day, 4 hours of stasis, and an empty stomach in the afternoon, 7 days a week.

The first emergence infection occurred at home on June 22, 2020. This infection showed Staphylococcus aureus. The second emergence infection occurred on July 15, 2020, positive for Staphylococcus epidermidis. The third emergence infection occurred on July 24, 2020, with Corynebacterium accolens and Staphylococcus warneri. As the patient was still on antibiotic ointment (mupirocin) from the previous infection, we did not change treatment. The control swab taken on August 13, 2020, came back sterile. One year after the last emergence infection, the patient reported a new emergence infection with S. aureus, treated with topical mupirocin. A new infection occurred on July 22, 2024, with a positive swab for S. carnosus. The sample (superficial smear) was taken by the nurse at home following redness and pain at the emergence site, with no discharge. The dressing was well in place (not detached). The patient was stable and apyretic and had no other complaints. According to the protocol, the dressing was reapplied every day, along with antibiotic ointment. After 8 days of treatment, a new sterile swab was taken, and the emergence was no longer inflammatory or painful. Emergence infections are treated with an application of mupirocin (Bactroban®) for a period of 8 to 10 days, with a control swab taken 8 days after the start of topical treatment.

S. carnosus is a gram-positive, catalase-positive, immobile, non-spore-forming coc-cus [3]. They occur as single cells, in pairs, or in tetrads. S. carnosus, long assimilated to Staphylococcus simulans, has been confirmed as a new species. Nevertheless, S. carnosus belongs to the S. simulans group, which is formed by these two species (Kloos & Schleifer, 1986 [4]; Schleifer & Fischer, 1982 [5]). S. carnosus has been isolated from dry sausages, salami, and raw ham (Götz, 1990 [6]; Wagner et al., 1998 [7]). Its ecological niche is not well known, although it is related to the animals and meat products from which it has been isolated. No isolations linked to human or animal infections with S. carnosus have ever been reported, and this species produces neither enterotoxin, coagulase, hemolysin, nor clumping factor (Euzéby, 2006).

This clinical case reports the first human case of S. carnosus infection in a PD catheter emergence.

A dog was present once a week. It is therefore possible that this germ was transmitted by the presence of the animal in the patient’s home. This could be verified by taking a sample from the animal to ensure the presence of the germ in the dog in question. Unfortunately, the patient did not give his consent for this to be carried out, and multilocus sequence typing was not performed.

We also know that the germ is ubiquitous in dry food such as sausages, salami, and raw ham, which constitutes another etiological possibility [8] However, the dressing was applied every 48 hours by home care nurses, making it unlikely that sausages were responsible for the emergence infection. In this case, it is therefore impossible to confirm the origin of our patient’s emergence infection, or to rule out transmission by the nurses’ hands. All the more so as this is not the patient’s first emergence infection, and never before with S. carnosus.

None

MG, JS, and RA wrote the article together, with identical roles for each.