Corynebacterium ssp. are opportunist pathogens that are common colonizers of the skin and mucosae in asymptomatic individuals that are frequently considered contaminants when isolated in blood cultures.1 We report a case of septic arthritis due to Corynebacterium striatum (C. striatum), a pathogen whose implication in infection of native joints is exceptional.

The patient was an 84-year-old man who was allergic to penicillin. He had a history of chronic obstructive pulmonary disease (COPD), chronic atrial fibrillation and left nephrectomy. He had been admitted 5 months earlier for acute monoarthritis of left knee with microcrystalline disease (calcium pyrophosphate), and required arthrocentesis and anti-inflammatory agents. Since then, he had had an indolent course, with slight intermittent fever and impaired function, reasons for which he was reevaluated. On admission he had inflammatory signs in left knee, C-reactive protein 72mg/L and arthrocentesis yielded a fluid containing blood and pus, the glucose level was 3mg/dL and proteins 4.4g/dL; cell count could not be performed. Given the suspicion of the presence of infectious arthritis, we decided to perform surgical joint lavage. In cultures of the fluid from arthrocentesis and in intraoperative specimens, we isolated C. striatum, which is resistant to penicillins, clindamycin and quinolones, whereas it is sensitive to vancomycin, linezolid and rifampicin. It was decided to treat him with intravenous linezolid (600mg/12h) as the patient had only 1 kidney. After a week, the patient developed gastrointestinal toxicity, and the arthritis persisted. Thus, we replaced linezolid with teicoplanin (600–800mg/24h) and he underwent a second surgical lavage. After a number of determinations, therapeutic levels were not being achieved. Therefore, we decided to treat him with dalbavancin in a single dose of 1500mg after confirming sensitivity by means of an E-test® (minimum inhibitory concentration <0.125μg/mL). After that treatment, the patient began to show clinical and analytical improvement, and we decided to discharge him 7 days later. The patient was followed in the outpatient clinic for 6 months, with no signs of reactivation.

Corynebacterium is a genus of facultative anaerobic Gram-positive bacilli. With the exception of C. diphtheriae, the rest of the species are saprophytes of the skin and mucosae, and are considered common contaminants.1 Their repeated isolation in relation to medical devices and in patients in whom infection is suspected signifies that they are considered a pathogen. C. striatum has been implicated in endocarditis, pneumonias and osteoarticular infections. They are usually resistant to diverse groups of antibiotics but, basically, continue to be sensitive to glycopeptides, linezolid and imipenem.2

In a review of the literature, we found 4 cases of infection in native joints by C. striatum and only 2 cases with genicular involvement. Westblade et al.3 described a patient with acute arthritis of the knee produced by C. striatum with a positive outcome after 4 weeks of treatment with intravenous vancomycin. Scholle4 reported another case of arthritis of the knee treated for 2 weeks with intravenous vancomycin. Both of these cases developed after a previous traumatic injury affecting the joint. Cone et al.5 described the case of a patient with arthritis of the elbow secondary to an accidental injury with a scalpel during an intervention, that was treated with vancomycin for 10 days, followed by ciprofloxacin for 7 days. Finally, Feced Olmos et al.6 published a case of arthritis of the shoulder that developed after corticosteroid injection, and improved after 15 days of treatment with ceftriaxone. In the case we report here, aside from factors known to have a role in immunosuppression, such as advanced age and COPD, we suspect, as a probable additional risk factor, the fact that the patient had undergone arthrocentesis, as well as arthritis due to calcium pyrophosphate deposition, which could, in turn, contribute to the development of septic arthritis.

Dalbavancin is a semisynthetic lipoglycopeptide, derived from teicoplanin. It is a bactericide and time-dependent, and acts by inhibiting the formation of the bacterial wall, with a spectrum of activity against methicillin-susceptible and methicillin-resistant Gram-positive pathogens, as well as intermediate susceptibility to vancomycin. It is also effective against certain Gram-positive anaerobic pathogens. It is not active against enterococci expressing the VanA gene. Dosage is convenient as its long half-life enables a single dose every 2 weeks (1500mg) or 2 doses at an interval of 1 week (1000mg followed by 500mg). The dose does not need to be adjusted in patients with renal insufficiency, except with a glomerular filtration rate <30mL/min. The safety profile is acceptable, although medium-to-long-term studies have yet to be done. Dalbavancin was approved by the Spanish Agency of Medicines and Medical Devices in June 2015. Its main indications are infections of the skin and soft tissue. The clinical trials conducted have demonstrated noninferiority of dalbavancin and a comparator (vancomycin+linezolid).7

Authors Rolston et al.8 and Jones and Stilwell9 studied the in vitro activity of dalbavancin against different Gram-positive strains, and showed it to have more potent activity than vancomycin and daptomycin against Bacillus spp., Corynebacterium ssp., Micrococcus spp. and several species of streptococci, as well as bactericide activity against methicillin-resistant Staphylococcus aureus, including those with a minimum inhibitory concentration >1μg/mL of vancomycin.

In summary, we must keep in mind the pathogenic role of Corynebacterium ssp. in certain clinical circumstances and the option of novel antibiotics like dalbavancin that can be just as effective, and reduce the nosocomial infections derived from a prolonged hospital stay.

The authors declare they have no conflicts of interest.