Septic arthritis due to Staphylococcus lugdunensis in a native joint

Protracted Course of Staphylococcus lugdunensis Septic Arthritis in Native Knee Joint

Staphylococcus lugdunensis is a coagulase-negative bacteria of the Staphylococcus family. It is a highly invasive organism with similar virulence to Staphylococcus aureus. It is commonly associated with bacteremia and infections of the skin, soft tissues, joints, and bones. Those with indwelling medical devices are at the highest risk of infection due to biofilm formation. Instances of native joint infections are exceedingly rare. We describe a case of a 72-year-old female with multiple comorbidities presenting with native right knee joint septic arthritis from S. lugdunensis. Due to treatment noncompliance secondary to latent social determinants of health, she faced a complicated and protracted clinical course that was treated with inpatient intravenous antibiotics and outpatient oral doxycycline. Few cases of native joint infections with S. lugdunensis have been documented, and to our knowledge, the impact of treatment noncompliance on the sequelae of septic arthritis with this organism has not been reported. Socioeconomic factors and comorbidities have been shown to increase a patient's risk for an extended joint infection with S. lugdunensis.

Bacterial contamination of irrigation fluid and suture material during ACL reconstruction and meniscus surgery : Low infection rate despite increasing contamination over surgery time

PURPOSE

During knee arthroscopy, irrigation fluid from the surgical site accumulates in the sterile reservoir. Whether these fluid collections and also suture material used during the arthroscopic surgical processes show bacterial contamination over time during surgery remains unclear. The purpose of this study was to determine this contamination rate and to analyze its possible influence on postoperative infection.

MATERIALS AND METHODS

In this study, 155 patients were included. Fifty-eight underwent reconstruction of the anterior cruciate ligament (ACL), 63 meniscal surgery and 34 patients combined ACL reconstruction and meniscus repair. We collected pooled samples of irrigation fluid from the reservoir on the sterile drape every 15 min during the surgery. In addition, we evaluated suture material of ACL graft and meniscus repair for bacterial contamination. Samples were sent for microbiological analysis, incubation time was 14 days. All patients were seen in the outpatient department 6, 12 weeks and 12 months postoperatively and examined for clinical signs of infection.

RESULTS

A strong statistical correlation (R² = 0.81, p = 0.015) was found between an advanced duration of surgery and the number of positive microbiological findings in the accumulated fluid. Suture and fixation material showed a contamination rate of 28.4% (29 cases). Despite the high contamination rate, only one infection was found in the follow-up examinations, caused by Staphylococcus lugdunensis.

CONCLUSION

Since bacterial contamination of accumulated fluid increases over time the contact with the fluid reservoirs should be avoided.

LEVEL OF EVIDENCE

IV.

Polyarticular septic arthritis caused by Staphylococcus lugdunensis in a patient with systemic lupus erythematosus

Septic arthritis in patients with systemic lupus erythematosus (SLE) is rare and is reported in only 3% of patients. Contrary to lupus arthritis, which tends to be polyarticular in nature, primarily involving the small joints of the hands, septic arthritis is commonly monoarticular. Here, we present an unusual case of a patient with SLE, who developed oligoarticular inflammatory arthritis caused by a rare native joint pathogen Staphylococcus lugdunensis. The infection resulted in extensive early damage to the joints involved, highlighting the need for early diagnosis and treatment.

S. lugdunensisNative-Joint Septic Arthritis: Case Report and Review of the Literature

Staphylococcus lugdunensisis a skin commensal classified as a coagulase-negativeStaphylococcus(CoNS). Though CoNS is typically associated with less aggressive clinical disease thanStaphylococcus aureus, there is growing awareness thatS. lugdunensismay be as virulent asS. aureus. The association betweenS. lugdunensisand infective endocarditis is well known, but few reports of native-joint disease with this organism exist. We report a case a 28-year-old male with no prior medical problems presenting with native-joint septic arthritis. Cultures grewS. lugdunensis. To our knowledge, this is the fifth case reported in the literature.

Coagulase-negative staphylococci

The definition of the heterogeneous group of coagulase-negative staphylococci (CoNS) is still based on diagnostic procedures that fulfill the clinical need to differentiate between Staphylococcus aureus and those staphylococci classified historically as being less or nonpathogenic. Due to patient- and procedure-related changes, CoNS now represent one of the major nosocomial pathogens, with S. epidermidis and S. haemolyticus being the most significant species. They account substantially for foreign body-related infections and infections in preterm newborns. While S. saprophyticus has been associated with acute urethritis, S. lugdunensis has a unique status, in some aspects resembling S. aureus in causing infectious endocarditis. In addition to CoNS found as food-associated saprophytes, many other CoNS species colonize the skin and mucous membranes of humans and animals and are less frequently involved in clinically manifested infections. This blurred gradation in terms of pathogenicity is reflected by species- and strain-specific virulence factors and the development of different host-defending strategies. Clearly, CoNS possess fewer virulence properties than S. aureus, with a respectively different disease spectrum. In this regard, host susceptibility is much more important. Therapeutically, CoNS are challenging due to the large proportion of methicillin-resistant strains and increasing numbers of isolates with less susceptibility to glycopeptides.

Clinical and microbiological characterization of Staphylococcus lugdunensis isolates obtained from clinical specimens in a hospital in China

Background

Several reports have associated Staphylococcus lugdunensis with the incidence of severe infection in humans; however, the frequency and prevalence of this microorganism and thus the propensity of its antimicrobial drug resistance is unknown in China. The objective of the current study was to determine the prevalence of Staphylococcus lugdunensis among six hundred and seventy non-replicate coagulase negative Staphylococcus (CoNS) isolates collected in a 12-month period from clinical specimens in the General Hospital of the People’s Liberation Army in Beijing, China.

Results

Five (0.7%) of the 670 isolates of CoNS were identified as S. lugdunensis. Whereas three isolates were resistant to erythromycin, clindamycin, and penicillin and carried the ermC gene and a fourth one was resistant to cefoxitin and penicillin and carried the mecA gene, one isolate was not resistant to any of the tested antimicrobials. Pulse field gel electrophoretic analysis did not reveal widespread epidemiological diversity of the different isolates.

Conclusion

Hence, even though S. lugdunensis may be yet unrecognized and undefined in China, it still might be the infrequent cause of infection and profound multi-drug resistance in the same population.

[A man with pain following a knee operation]

BACKGROUND

Infection after arthroscopy is a rare, but feared complication. Aggressive infection with atypical microbiological agents severely complicates the clinical evaluation.

CASE PRESENTATION

A man in his thirties, previously healthy man had undergone elective knee arthroscopy with synovectomy. Eight days after surgery he was admitted to hospital with swelling and pain in the operated knee. Re-arthroscopy revealed bleeding in the affected joint, but no obvious signs of infection. The patient developed severe pain, fever and elevated infection parameters. Staphylococcus lugdunensis was detected in the joint fluid taken during re-arthroscopy. He was treated with a combination of antibiotics, including cloxacillin, gentamicin and linezolid, and made a full recovery after treatment.

INTERPRETATION

S lugdunensis is a highly virulent, coagulase-negative staphylococcus, capable of causing significant infections. It should never be dismissed as a contaminant without careful review.