In vitro susceptibility of Propionibacterium acnes to simulated intrawound vancomycin concentrations

Vancomycin Soaking to Reduce Intraoperative Contamination by Cutibacterium acnes During the Latarjet Procedure

BACKGROUND

Postoperative infection after the Latarjet procedure, ranging from 1% to 6%, can compromise the functional outcome of young athletes. Cutibacterium acnes is a main pathogen as a consequence of an intraoperative contamination.

PURPOSE

To evaluate intraoperative contamination with C. acnes and the effectiveness of the local application of vancomycin during the Latarjet procedure.

STUDY DESIGN

Cohort study; Level of evidence, 2.

METHODS

This was a single-center study including 75 patients (mean age, 26 years; range, 15-55 years) operated on for anterior shoulder instability with the primary open Latarjet procedure; they underwent the same protocol of skin preparation and preoperative prophylactic antibiotics. Three groups of 25 patients were created and divided sequentially, without the results of each group being known before the end of the study: group A (5 mg/mL of vancomycin), group B (20 mg/mL of vancomycin), and group C (control group with no vancomycin). Swab samples of the coracoid were taken before sectioning the coracoid process (time 1) and after its preparation (time 2). The coracoid was then wrapped in gauze impregnated with different concentrations of vancomycin, except for group C. A final sample (time 3) was taken before screwing the bone block onto the glenoid. All samples were cultured for 21 days, and patients underwent clinical and radiological follow-up for 6 months.

RESULTS

The C. acnes contamination rates at times 1, 2, and 3 were 25%, 44%, and 45%, respectively, without significant difference. There was no significant difference between groups A and B with respect to the number of positive cultures at each time point. Of 9 positive cultures at time 1, all were still positive at time 3 in group A, whereas 3 of 5 were negative in group B (P = .027). The rate of C. acnes at time 3 in the control group was higher than that in the 2 other groups (68% vs 44% for group A and 20% for group B; P = .003). Body mass index was the only prognostic factor for a C. acnes-positive culture (26.05 ± 3.39 vs 23.34 ± 2.33; P = .018). No clinical infection was reported at the 6-month postoperative follow-up.

CONCLUSION

The rate of C. acnes contamination ranged from 25% to 68% during the open Latarjet procedure in young athletes. Vancomycin reduced the bacterial contamination when it was used at high concentrations in a gauze wrap on the coracoid. The type of C. acnes detected and its clinical implications remain to be studied.

Is there value in the routine practice of discarding the incision scalpel from the surgical field to prevent deep wound contamination with Cutibacterium acnes? An update

BACKGROUND

Cutibacterium acnes is the most common microbe implicated in periprosthetic infection in shoulder arthroplasty. We present an update of a previous pilot study in which we demonstrated the persistence of C acnes on the skin and contamination of the scalpel used for the initial skin incision despite a robust presurgical skin preparation protocol.

METHODS

We collected a consecutive case series of patients undergoing primary or revision anatomic or reverse total shoulder arthroplasty performed by a single fellowship-trained surgeon at a tertiary referral hospital from November 2019 to December 2022. The scalpel blade used for the initial skin incision in each patient was swabbed, with cultures being held for 21 days according to a C acnes-specific protocol. Demographic data, medical comorbidities, surgical information, culture results, and infections were documented.

RESULTS

We identified 100 patients (51 men and 49 women) who met the inclusion criteria (mean age, 66.91 years; age range, 44-93 years). Cultures returned positive findings for C acnes in 12 patients (12%), 11 of whom were men (odds ratio, 13.2; 95% confidence interval, 1.73-194.87). No association was found between positive culture findings and age, body mass index, medical comorbidities, or procedure type. No postoperative infections occurred in this patient cohort, and the patients will continue to be monitored for the development of infection.

CONCLUSION

Despite stringent presurgical preparation and scrub protocols, a significant portion of patients undergoing shoulder arthroplasty have C acnes in culturable quantities on their skin at the time of incision. C acnes contamination is much more common in male patients. These findings should be taken into consideration regarding preventive measures such as discarding the initial scalpel and avoiding unnecessary dermal contact during the procedure.

Vancomycin powder embedded in collagen sponge decreases the rate of prosthetic shoulder infection

BACKGROUND

Shoulder arthroplasty is a successful procedure to treat degenerative and traumatic diseases of the glenohumeral joint. Periprosthetic infection represents an infrequent but dreaded complication (2%-4%). Application of intrawound vancomycin powder seems to reduce periprosthetic infections, but limited information is available on its efficiency in shoulder arthroplasty. The purpose of this study was to evaluate if the vancomycin powder embedded in a collagen sponge could decrease the rate of prosthetic shoulder infection.

METHODS

A retrospective analysis of 827 patients undergoing total shoulder arthroplasty was performed. The study involved a control group of 405 patients and a group of 422 with the intraoperative insertion of intrawound vancomycin powder. Incidence of periprosthetic infection was evaluated comparing the 2 groups at a minimum follow-up of 12 months. Patient demographics, comorbidities, and perioperative information were compared between the 2 groups.

RESULTS

No infection was observed in the group treated with intrawound vancomycin, and 13 cases of infection were observed in the control group (3.2%) (P value <.001) without subacromial vancomycin application. No wound complications requiring revision were observed as a result of intrawound vancomycin application.

DISCUSSION AND CONCLUSION

Intrawound vancomycin powder significantly reduces the rate of periprosthetic shoulder infections without any increase in local and systemic aseptic complications at a minimum follow-up of 12 months. Our results support the use of intrawound local vancomycin for prophylaxis of shoulder periprosthetic infections.

Cutibacterium (Formerly Propionibacterium ) acnes Keratitis: A Review

ABSTRACT

Infectious keratitis is a devastating cause of vision loss worldwide. Cutibacterium acnes ( C. acnes ), a commensal bacterium of the skin and ocular surface, is an underrecognized but important cause of bacterial keratitis. This review presents the most comprehensive and up-to-date information for clinicians regarding the risk factors, incidence, diagnosis, management, and prognosis of C. acnes keratitis (CAK). Risk factors are similar to those of general bacterial keratitis and include contact lens use, past ocular surgery, and trauma. The incidence of CAK may be approximately 10%, ranging from 5% to 25% in growth-positive cultures. Accurate diagnosis requires anaerobic blood agar and a long incubation period (≥7 days). Typical clinical presentation includes small (<2 mm) ulcerations with deep stromal infiltrate causing an anterior chamber cell reaction. Small, peripheral lesions are usually resolved, and patients recover a high visual acuity. Severe infections causing VA of 20/200 or worse are common and often do not significantly improve even after treatment. Vancomycin is considered the most potent antibiotic against CAK, although other antibiotics such as moxifloxacin and ceftazidime are more commonly used as first-line treatment.

Techniques for Decreasing Bacterial Load for Open Shoulder Surgery

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Benzoyl peroxide (BPO) 5% has been shown to reduce Cutibacterium acnes load on the skin. BPO 5% with miconazole nitrate (MN) 2% may be beneficial, whereas BPO 5% with clindamycin cream 1% to 1.2% does not seem to have additive effects when compared with BPO 5% alone. Chlorhexidine gluconate solutions reduce the total bacterial load on the skin, but do not seem to have a significant effect on C. acnes.

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ChloraPrep seems to be the best surgical skin preparation to decrease overall positive skin cultures. Preincisional hydrogen peroxide 3% application has been shown to be a cost-effective practice to inhibit growth of C. acnes. Vancomycin powder before deltopectoral interval closure has antimicrobial effects against C. acnes and is a cost-effective practice. Finally, Bactisure surgical lavage is protective against the formation of biofilms.

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IV cefazolin has been shown to be more effective for shoulder arthroplasty infection prophylaxis than antibiotic alternatives such as vancomycin. Thus, patients with a questionable history of penicillin allergy should undergo additional testing.

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For shoulder surgery infection prophylaxis, we recommend the use of BPO 5% cream for 5 days preoperatively with chlorhexidine wipes the night before and the morning of surgery. IV cefazolin should be administered perioperatively, and patients with a questionable history of penicillin allergy should be tested. Surgeons should consider preincisional application of hydrogen peroxide 3% for 5 minutes, followed by standard ChloraPrep preparation. Normal saline should be used for preclosure lavage. Finally, application of vancomycin powder deep to the deltopectoral interval closure should be considered.

Vancomycin is effective in preventing Cutibacterium acnes growth in a mimetic shoulder arthroplasty

BACKGROUND

Intra-incisional deposition of vancomycin powder is a strategy to limit Cutibacterium acnes infection after shoulder surgery. Unfortunately, limited research exists examining the effectiveness of vancomycin in a clinically relevant joint infection model. This basic science study investigated the efficacy of vancomycin administration as prophylaxis for C acnes growth in vitro using a mimetic shoulder arthroplasty.

METHODS

A new bioartificial shoulder joint mimetic implant (S-JIM) was used to investigate the effect of vancomycin powder on C acnes growth within the first 48 hours after surgery. The impact of vancomycin was assessed on a skin-derived (ATCC 11827) C acnes strain and a periprosthetic joint infection-derived strain. C acnes strains were applied to titanium alloy foil and embedded beneath multiple layers of collagen-impregnated cellulose scaffold strips containing human shoulder joint capsular fibroblasts, facilitating the development of an oxygen gradient with an anaerobic environment around the foil and inner layers. Ten milligrams of vancomycin powder was applied between the C acnes layer and the human cell-containing scaffold strips to model direct antibiotic application, and intravenous vancomycin prophylaxis was modeled by adding vancomycin in media at 5 or 20 μg/mL. After 48 hours, the C acnes inoculum layer was subcultured from each S-JIM onto agar plates to assess the formation of viable C acnes colonies. Primary human shoulder capsule cells were assessed microscopically to detect any detrimental effects of vancomycin on cellular integrity.

RESULTS

Agar plates inoculated with extracts from untreated S-JIMs consistently resulted in the growth of large numbers of C acnes colonies, whereas treatments with vancomycin powder or vancomycin in media at 20-μg/mL dilution effectively prevented the recovery of any C acnes colonies. The lowest vancomycin dilution tested (5 μg/mL) was insufficient to prevent the recovery of C acnes colonies. Vancomycin powder had no discernible short-term impact on shoulder capsule cell morphology, and the presence of these cells had no discernible impact on vancomycin degradation over time.

CONCLUSIONS

Vancomycin administration effectively prevented C acnes growth in a bioartificial S-JIM. These results support the hypothesis that intra-incisional vancomycin application may limit C acnes prosthetic joint infections.

Is there value in the routine practice of discarding the incision scalpel from the surgical field to prevent deep wound contamination with Cutibacterium acnes?

BACKGROUND

Cutibacterium acnes is found in skin flora of the shoulder and is the most common microbe identified in periprosthetic shoulder infections. The purpose of this study is to determine if there is C acnes present on the incision scalpel in patients undergoing shoulder arthroplasty despite extensive skin preparation techniques to prevent wound contamination.

METHODS

The authors collected a consecutive case series of patients meeting inclusion criteria. Patients were included if they underwent either primary or revision shoulder arthroplasty at the tertiary care hospital with the senior author during the study period. Culture swab samples, testing for presence of C acnes, were collected from 17 consecutive patients who underwent shoulder arthroplasty with a single fellowship-trained surgeon between November 2019 and March 2020. Culture reports were recorded as "positive" or "negative" after 21 days. Institutional review board approval of the study protocol was obtained. The null hypothesis was that there would be no cases with knife blades "culture positive" for C acnes.

RESULTS

17 patients were identified and fit inclusion criteria. There were 12 men (mean age 64.3 years, range 48-79 years) and 5 women (mean age 69.8 years, range 59-79 years). Two patients (11.8%) were found to have C acnes growth on the skin knife. Both patients were male and older than 70 years undergoing primary reverse shoulder arthroplasty with no history of previous shoulder infections.

CONCLUSION

The presence of C acnes on the skin blade in 2 patients validates concerns that there is C acnes present in dermal tissue despite extensive attention to eradication of these microbes. There was a high rate of C acnes contamination on scalpel blades used for initial skin incisions and the authors conclude that there is value in discarding these blades from the surgical field.