Fungal arthritis. A review

Deciphering the antifungal mechanism and functional components of cinnamomum cassia essential oil against Candida albicans through integration of network-based metabolomics and pharmacology, the greedy algorithm, and molecular docking

ETHNOPHARMACOLOGICAL RELEVANCE

Fungal pathogens can cause deadly invasive infections and have become a major global public health challenge. There is an urgent need to find new treatment options beyond established antifungal agents, as well as new drug targets that can be used to develop novel antifungal agents. Cinnamomum cassia is a tropical aromatic plant that has a wide range of applications in traditional Chinese medicine, especially in the treatment of bacterial and fungal infections.

AIM OF THE STUDY

The present study aimed to explore the mechanism of action and functional components of Cinnamomum cassia essential oil (CEO) against Candida albicans using an integrated strategy combining network-based metabolomics and pharmacology, the greedy algorithm and molecular docking.

MATERIALS AND METHODS

CEO was extracted using hydrodistillation and its chemical composition was identified by GC-MS. Cluster analysis was performed on the compositions of 19 other CEOs from the published literature, as well as the sample obtained in this study. The damages of C. albicans cells upon treatment with CEO was observed using a scanning electron microscope. The mechanisms of its antifungal effect at a subinhibitory concentration of 0.1 × MIC were determined using microbial metabolomics and network analysis. The functional components were studied using the greedy algorithm and molecular docking.

RESULTS

A total of 69 compounds were identified in the chemical analysis of CEO, which accounted for 90% of the sample. The major compounds were terpenoids (34.04%), aromatic compounds (4.52%), aliphatic compounds (0.9%), and others. Hierarchical cluster analysis of the compositions of 20 essential oils extracted from Cinnamomum cassia grown in different geographical locations showed a wide diversity of chemical composition with four major chemotypes. CEO showed strong antifungal activity and caused destruction of cell membranes in a concentration-dependent way. Metabolic fingerprint analysis identified 29 metabolites associated with lipid metabolism, which were mapped to 23 core targets mainly involved in fatty acid biosynthesis and metabolism. Six antifungal functional components of CEO were identified through network construction, greedy algorithm and molecular docking, including trans-cinnamaldehyde, δ-cadinol, ethylcinnamate, safrole, trans-anethole, and trans-cinnamyl acetate, which showed excellent binding with specific targets of AKR1B1, PPARG, BCHE, CYP19A1, CYP2C19, QPCT, and CYP51A1.

CONCLUSIONS

This study provides a systematic understanding of the antifungal activity of CEO and offers an integrated strategy for deciphering the potential metabolism and material foundation of complex component drugs.

[Strategies for antifungal treatment failure in intensive care units]

Recent epidemiologic studies reveal both an increasing incidence and an escalation in resistance of invasive fungal infections in intensive care units. Primary therapy fails in 70 % of cases, depending on the underlying pathogens and diseases. The purpose of this review is to raise awareness for the topic of antifungal therapy failure, describe the clinical conditions in which it occurs, and suggest a possible algorithm for handling the situation of suspected primary therapy failure.

Candida Arthritis: Analysis of 112 Pediatric and Adult Cases

Background. Candida arthritis is a debilitating form of deeply invasive candidiasis. However, its epidemiology, clinical manifestations, management, and outcome are not well understood.

Methods. Cases of Candida arthritis were reviewed from 1967 through 2014. Variables included Candida spp in joint and/or adjacent bone, underlying conditions, clinical manifestations, inflammatory biomarkers, diagnostic imaging, management, and outcome.

Results. Among 112 evaluable cases, 62% were males and 36% were pediatric. Median age was 40 years (range, <1–84 years). Most patients (65%) were not pharmacologically immunosuppressed. Polyarticular infection (≥3 joints) occurred in 31% of cases. Clinical manifestations included pain (82%), edema (71%), limited function (39%), and erythema (22%) with knees (75%) and hips (15%) most commonly infected. Median erythrocyte sedimentation rate was 62 mm/hr (10–141) and C reactive protein 26 mg/dL (0.5–95). Synovial fluid median white blood cell count was 27 500/µL (range, 100–220 000/µL) with 90% polymorphonuclear neutrophils (range, 24–98). Adjacent osteomyelitis was present in 30% of cases. Candida albicans constituted 63%, Candida tropicalis 14%, and Candida parapsilosis 11%. Most cases (66%) arose de novo, whereas 34% emerged during antifungal therapy. Osteolysis occurred in 42%, joint-effusion in 31%, and soft tissue extension in 21%. Amphotericin and fluconazole were the most commonly used agents. Surgical interventions included debridement in 25%, irrigation 10%, and drainage 12%. Complete or partial response was achieved in 96% and relapse in 16%.

Conclusion. Candida arthritis mainly emerges as a de novo infection in usually non-immunosuppressed patients with hips and knees being most commonly infected. Localizing symptoms are frequent, and the most common etiologic agents are C albicans, C tropicalis, and C parapsilosis. Management of Candida arthritis remains challenging with a clear risk of relapse, despite antifungal therapy.

ESCMID* guideline for the diagnosis and management of Candida diseases 2012: non-neutropenic adult patients

This part of the EFISG guidelines focuses on non-neutropenic adult patients. Only a few of the numerous recommendations can be summarized in the abstract. Prophylactic usage of fluconazole is supported in patients with recent abdominal surgery and recurrent gastrointestinal perforations or anastomotic leakages. Candida isolation from respiratory secretions alone should never prompt treatment. For the targeted initial treatment of candidaemia, echinocandins are strongly recommended while liposomal amphotericin B and voriconazole are supported with moderate, and fluconazole with marginal strength. Treatment duration for candidaemia should be a minimum of 14 days after the end of candidaemia, which can be determined by one blood culture per day until negativity. Switching to oral treatment after 10 days of intravenous therapy has been safe in stable patients with susceptible Candida species. In candidaemia, removal of indwelling catheters is strongly recommended. If catheters cannot be removed, lipid-based amphotericin B or echinocandins should be preferred over azoles. Transoesophageal echocardiography and fundoscopy should be performed to detect organ involvement. Native valve endocarditis requires surgery within a week, while in prosthetic valve endocarditis, earlier surgery may be beneficial. The antifungal regimen of choice is liposomal amphotericin B +/- flucytosine. In ocular candidiasis, liposomal amphotericin B +/- flucytosine is recommended when the susceptibility of the isolate is unknown, and in susceptible isolates, fluconazole and voriconazole are alternatives. Amphotericin B deoxycholate is not recommended for any indication due to severe side effects.

Micro-CT analysis of experimental Candida osteoarthritis in rats

Experimental osteoarthritis induced by Candida albicans in rats was studied using micro-computed tomography (micro-CT). When C. albicans cells at a nonlethal dose were intravenously injected into 40 rats, joint swelling was induced in 24 rats. Two or more joints were affected in 10 of the 24 rats. Tarsal regions of the hind paw were affected most frequently, followed by elbows of the fore paw. Micro-CT analysis in vivo showed that erosions of the affected tarsal joint bones were apparent several days after the onset of swelling. Thereafter, severe surface roughness and disintegration in the joint bones progressed during the development of arthritis. Three-dimensional (3D) trabecular microstructures and changes in 3D bone parameters were characterized ex vivo with calcanei from affected hind paws. Three-dimensional morphology showed coarsening of the trabecular distribution and weakening of the trabecular connectivity in arthritic bones. These morphological changes were quantitatively confirmed by changes in 3D bone parameters measured from consecutively scanned bone slices. Micro-CT has been shown to be useful for quantifying morphological changes occurring in Candida arthritic bones.

Microbiology and management of joint and bone infections due to anaerobic bacteria

PURPOSE

To describes the microbiology, diagnosis, and management of septic arthritis and osteomyelitis due to anaerobic bacteria.

RESULTS

The predominant anaerobes in arthritis are anaerobic Gram-negative bacilli (AGNB) including the Bacteroides fragilis group, Fusobacterium spp., Peptostreptococcus spp., and Propionibacterium acnes. Infection with P. acnes is associated with a prosthetic joint, previous surgery, and trauma. B. fragilis group is associated with distant infection, Clostridium spp. with trauma, and Fusobacterium spp. with oropharyngeal infection. Most cases of anaerobic arthritis, in contrast to anaerobic osteomyelitis, involved a single isolate, and most cases are secondary to hematogenous spread. The predominant anaerobes in osteomyelitis are Bacteroides, Peptostreptococcus, Fusobacterium, and Clostridium spp. as well as P. acnes. Conditions predisposing to bone infections are vascular disease, bites, contiguous infection, peripheral neuropathy, hematogenous spread, and trauma. Pigmented Prevotella and Porphyromonas spp. are mostly isolated in skull and bite infections, members of the B. fragilis group in hand and feet infections, and Fusobacterium spp. in skull, bite, and hematogenous long bone infections. Many patients with osteomyelitis due to anaerobic bacteria have evidence of an anaerobic infection elsewhere in the body that is the source of the organisms involved in the osteomyelitis. Treatment of arthritis and osteomyelitis involving anaerobic bacteria includes symptomatic therapy, immobilization in some cases, adequate drainage of purulent material, and antibiotic therapy effective against these organisms.

CONCLUSIONS

Anaerobic bacteria can cause septic arthritis and osteomyelitis. Correct diagnosis and appropriate therapy are important contributor to successful outcome.

Fungal arthritis of the knee caused by Candida parapsilosis in a kidney transplant recipient

Fungal arthritis is a rare infection usually caused by Candida species. Candida parapsilosis has emerged as a new pathogen and has been implicated in several cases of fungal arthritis, mostly associated with a joint prosthesis or after arthrocentesis. We report an unusual case of fungal arthritis of the knee caused by this organism in a 38-year-old female kidney transplant recipient, who had no previous invasive procedures on her knee. Systemic and intraarticular antifungal therapy combined with surgical debridement proved to be an effective treatment of this clinically difficult condition. To our knowledge, this case is the first report of fungal arthritis caused by C. parapsilosis in a transplant recipient. The multimodality approach used in the treatment of this patient should be considered in similar forms of fungal arthritis in immunocompromised patients.

Deeply invasive candidiasis

The incidence of invasive candidiasis is on the rise because of increasing numbers of immunocompromised hosts and more invasive medical technology. Recovery of Candida spp from several body sites in a critically ill or immunocompromised patient should raise the question of disseminated disease. Although identification to the species level and antifungal susceptibility testing should guide therapy, at this time amphotericin B preparations are the usual initial therapy for severe life-threatening disease. Azole therapy has an expanding body of evidence that proves it is as effective as and safer than amphotericin B therapy. Some forms of candidiasis (e.g., those with ocular, bone, or heart involvement) require a combined medical and surgical approach.

[Fungal arthritis--a rare complication of systemic candidiasis or orthopedic intervention. Review of therapeutic experience with fluconazole]

The higher number of implanted artificial joints, the broader use of aggressive treatment regimen, e.g. high-dose chemotherapy and total parenteral nutrition, the increasing use of central venous catheters and a broader use of immunosuppressive drugs are likely to result in a higher incidence of fungal arthritis, especially caused by Candida spp. Therefore, a careful evaluation of the available therapeutic options is necessary. The published clinical data on the therapeutic use of fluconazole in the treatment of fungal arthritis were reviewed. A total of 24 publications report the use of fluconazole in fungal arthritis in 32 patients. The mean duration of therapy was 6 months (maximum duration: 2 years) with an average dosage of 200-400 mg/d (maximum dosage: 800 mg/d). Native arthritis was diagnosed in 27 patients, prosthetic arthritis in 5 patients. In all patients an isolated joint was infected, most frequently the knee joint. Fluconazole was effective and safe in acute therapy alone or in combination with surgery as well as in long term suppression therapy.