What Are Cutibacterium (Propionibacterium) Infections?
Cutibacterium infections are a rare but severe complication of shoulder arthroplasty. The most common cause of patient infections is Cutibacterium acnes (Propionibacterium acnes), a communal skin bacterial species. Its production is always non-specific and can appear long after shoulder arthroplasty, resulting in a delay in diagnosis. This bacterium is hard to culture, generally taking 14 to 17 days for a positive culture, and frequently does not express abnormal findings on a standard laboratory workup for infection (for example, C-reactive protein, erythrocyte sedimentation rate, and synovial white blood cell count).
Male patients are exceptionally at high risk as they possess a larger number of sebaceous follicles than females. While it is tough to diagnose, early diagnosis can lead to reduced morbidity, proper treatment, and enhanced clinical outcomes. Existing possibilities for treatment include one-stage implant exchange, two-implant exchange, and antibiotics, although the success rates of each are not presently well defined. A sufficient understanding of the prevention, diagnosis and treatment of C. acnes infection can result in better patient results from shoulder arthroplasty.
What May Cause Cutibacterium (Propionibacterium) Infections?
-
C. acnes is a Gram-positive bacteria of the natural flora of the skin, oral cavity, conjunctiva, large intestine, and external ear canal. Although primarily understood for its role in acne, C. acnes may moreover result in a range of postoperative and medical device-related infections such as cerebrospinal fluid (CSF) shunt infection and bone and prosthesis infections (BPI).
-
This communal bacteria can evolve into an opportunistic pathogen, but the underlying procedures are unclear. C. acnes infections are always delayed (occurring 3 to 24 months or more after the medical device setting).
-
Moreover, the diagnosis of C. acnes infections is lengthy and risky due to the challenges of C. acnes culturing and low-grade clinical symptoms, portraying an additional issue for the patients.
-
This wait in pathogen identification can lead to severe long-term outcomes as the infection advances during the time of diagnosis.
-
In CSF shunt infections, C. acnes infections are correlated with severe neurologic morbidity for patients.
-
In implantable device-related infections, removal of any foreign material, a second surgery, and prolonged antibiotic treatment are required to treat C. acnes infection. Such therapeutic approaches may have stunning consequences, the emergence of antibiotic resistance, and irreversible sequelae.
What Are the Symptoms of Cutibacterium (Propionibacterium) Infections?
-
C. acnes infections do not generally elicit particular host inflammatory responses. Classic signs of swelling, drainage, erythema, tenderness, and sinus tract are less common.
-
Common symptoms include - stiffness, unexplained pain, and component loosening after an originally good result and the normal period for acute postoperative infection has passed.
-
C. acnes may not have symptoms for a year or two postoperatively.
-
Good healing of function and pain control followed by a rise in pain and stiffness indicates C. acnes, especially in males.
-
C. acnes may infiltrate the surgical field through a surgical incision into the pilosebaceous glands in the deeper layers of the skin.
-
Risk factors for C. acnes infection include male gender and surgery encompassing a prosthesis or for treatment of trauma.
-
Other factors in the growth of C. acnes infections include the appropriateness of the joint for infection, the patient's immune response to the bacterium, the size of the bacterial inoculum, and the relative proportion of pathogenic strains.
How Are Cutibacterium (Propionibacterium) Infections Diagnosed?
-
Serological Testing - Serological testing can be less helpful in laboratory examination for C. acnes infection because the inflammatory markers, such as CRP and ESR, are likely to be low or borderline while white blood cell count may be within normal limits.
-
Tissue Culture - C. acnes are cultured with a tissue swab under anaerobic conditions for up to seven days. It is important to note that this method is inadequate to rule out C. acnes infection. However, signs of inflammation are not typically seen. In some cases, cloudy fluid, osteolysis, a periprosthetic membrane, and component loosening may be present and are associated with an increased chance of positive cultures, but absence does not prevent infection.
-
Polymerized Chain Reaction (PCR) Technique - A more sensitive technique for the diagnosis is by using PCR. This method uses restriction fragment length polymorphisms to build a clinically relevant assay that can detect C. acnes effortlessly. This new method barely requires 24 hours and can be carried out in a regular pathology laboratory. A PCR-based assay can detect as few as ten C. acnes cells when it is tested in an artificial tissue system.
How Are Cutibacterium (Propionibacterium) Infections Treated?
-
The treatment involves a combination of both surgical intervention and antibiotic therapy, effective antibiotic regimens, and specific preventive methods against C. acnes infections. Biomarkers such as IL-6 (interleukin-6) should be examined for the diagnosis of C. acnes implant-associated infections.
-
The practice of 16S rRNA (ribosomal ribonucleic acid) gene sequencing and other molecular techniques need to be explored in this setting.
-
Longer incubation periods should be followed every time a C. acnes infection is suspected. If the clinical indication is high, sonication of the excised implant should be encouraged.
-
Research should concentrate on developing effective anti-biofilm agents.
-
Ultimately, preventive methods such as hair removal prior to surgery should be further analyzed. A number of methods have been formulated as potential techniques to minimize infection and manage these infections.
-
It has been indicated that the second change of gloves for the surgeon and re-draping, use of a skin barrier, along with hair removal by electric clippers or depilatories, could reduce C. acnes infection.
-
Another preventive method used is the application of Vancomycin powder during shoulder arthroplasty to prevent C. acnes infection.
-
A technique under advancement is the disruption of the C. acnes biofilm by using calcium sulfate cement beads loaded with Tobramycin, Vancomycin, or a combination of the two to deliver increased local concentrations of antibiotics.
Conclusion
Cutibacterium acnes is a Gram-positive biofilm-forming rod involved in acne vulgaris and is increasingly known for its role in implant-associated infections. The diagnosis of C. acnes implant-associated infections continues to be challenging. The treatment implied is a combination of both surgical intervention and antibiotic therapy. The cause of the infection is the different types of implant-associated infections caused by C. acnes. The clinical manifestations pertaining to the various sites of infection include signs that are not typical of inflammation.
