Multifocal osteoarthritis due to Candida albicans in a neonate: serum level monitoring of liposomal amphotericin B and literature 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.

Osteoarticular Mycoses

Osteoarticular mycoses are chronic debilitating infections that require extended courses of antifungal therapy and may warrant expert surgical intervention. As there has been no comprehensive review of these diseases, the International Consortium for Osteoarticular Mycoses prepared a definitive treatise for this important class of infections. Among the etiologies of osteoarticular mycoses are Candida spp., Aspergillus spp., Mucorales, dematiaceous fungi, non-Aspergillus hyaline molds, and endemic mycoses, including those caused by Histoplasma capsulatum, Blastomyces dermatitidis, and Coccidioides species. This review analyzes the history, epidemiology, pathogenesis, clinical manifestations, diagnostic approaches, inflammatory biomarkers, diagnostic imaging modalities, treatments, and outcomes of osteomyelitis and septic arthritis caused by these organisms. Candida osteomyelitis and Candida arthritis are associated with greater events of hematogenous dissemination than those of most other osteoarticular mycoses. Traumatic inoculation is more commonly associated with osteoarticular mycoses caused by Aspergillus and non-Aspergillus molds. Synovial fluid cultures are highly sensitive in the detection of Candida and Aspergillus arthritis. Relapsed infection, particularly in Candida arthritis, may develop in relation to an inadequate duration of therapy. Overall mortality reflects survival from disseminated infection and underlying host factors.

Invasive fungal infections in neonates: a review

Invasive fungal infections remain the leading causes of morbidity and mortality in neonates, especially preterm and very low birth weight infants. Most invasive fungal infections are due to Candida or Aspergillus species, and other fungi are increasingly reported and described. Appropriate identification and treatment are required to augment activity and reduce the toxicity of antifungal drugs. Successful use of antifungals in the vulnerable neonatal population is important for both prevention and treatment of infection. Strategies for prevention, including prophylactic antifungal therapy as well as reducing exposure to modifiable risk factors, like limiting antibiotic exposure, discontinuation of central catheters, and hand hygiene are key techniques to prevent and decrease rates of invasive fungal infections. In conclusion, this is a review of the most common causes, prevention strategies, prophylaxis, and treatment of invasive fungal infections in neonates.

Recognition and Clinical Presentation of Invasive Fungal Disease in Neonates and Children

Invasive fungal diseases (IFDs) are devastating opportunistic infections that result in significant morbidity and death in a broad range of pediatric patients, particularly those with a compromised immune system. Recognizing them can be difficult, because nonspecific clinical signs and symptoms or isolated fever are frequently the only presenting features. Therefore, a high index of clinical suspicion is necessary in patients at increased risk of IFD, which requires knowledge of the pediatric patient population at risk, additional predisposing factors within this population, and the clinical signs and symptoms of IFD. With this review, we aim to summarize current knowledge regarding the recognition and clinical presentation of IFD in neonates and children.

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.

Tissue penetration of antifungal agents

Understanding the tissue penetration of systemically administered antifungal agents is critical for a proper appreciation of their antifungal efficacy in animals and humans. Both the time course of an antifungal drug and its absolute concentrations within tissues may differ significantly from those observed in the bloodstream. In addition, tissue concentrations must also be interpreted within the context of the pathogenesis of the various invasive fungal infections, which differ significantly. There are major technical obstacles to the estimation of concentrations of antifungal agents in various tissue subcompartments, yet these agents, even those within the same class, may exhibit markedly different tissue distributions. This review explores these issues and provides a summary of tissue concentrations of 11 currently licensed systemic antifungal agents. It also explores the therapeutic implications of their distribution at various sites of infection.

Treatment and prophylaxis of invasive candidiasis

Invasive candidiasis (IC) is a leading cause of morbidity and mortality in preterm infants. Even if successfully treated, IC can cause significant neurodevelopmental impairment. Preterm infants are at increased risk for hematogenous Candida meningoencephalitis owing to increased permeability of the blood-brain barrier, so antifungal treatment should have adequate central nervous system penetration. Amphotericin B deoxycholate, lipid preparations of amphotericin B, fluconazole, and micafungin are first-line treatments of IC. Fluconazole prophylaxis reduces the incidence of IC in extremely premature infants, but its safety has not been established for this indication, and as yet, the product has not been shown to reduce mortality in neonates. Targeted prophylaxis may have a role in reducing the burden of disease in this vulnerable population.

Candida osteomyelitis: analysis of 207 pediatric and adult cases (1970-2011)

BACKGROUND

The epidemiology, pathogenesis, clinical manifestations, management, and outcome of Candida osteomyelitis are not well understood.

METHODS

Cases of Candida osteomyelitis from 1970 through 2011 were reviewed. Underlying conditions, microbiology, mechanisms of infection, clinical manifestations, antifungal therapy, and outcome were studied in 207 evaluable cases.

RESULTS

Median age was 30 years (range, ≤ 1 month to 88 years) with a >2:1 male:female ratio. Most patients (90%) were not neutropenic. Localizing pain, tenderness, and/or edema were present in 90% of patients. Mechanisms of bone infection followed a pattern of hematogenous dissemination (67%), direct inoculation (25%), and contiguous infection (9%). Coinciding with hematogenous infection, most patients had ≥2 infected bones. When analyzed by age, the most common distribution of infected sites for adults was vertebra (odds ratio [OR], 0.09; 95% confidence interval [CI], .04-.25), rib, and sternum; for pediatric patients (≤18 years) the pattern was femur (OR, 20.6; 95% CI, 8.4-48.1), humerus, then vertebra/ribs. Non-albicans Candida species caused 35% of cases. Bacteria were recovered concomitantly from 12% of cases, underscoring the need for biopsy and/or culture. Candida septic arthritis occurred concomitantly in 21%. Combined surgery and antifungal therapy were used in 48% of cases. The overall complete response rate of Candida osteomyelitis of 32% reflects the difficulty in treating this infection. Relapsed infection, possibly related to inadequate duration of therapy, occurred among 32% who ultimately achieved complete response.

CONCLUSIONS

Candida osteomyelitis is being reported with increasing frequency. Localizing symptoms are usually present. Vertebrae are the most common sites in adults vs femora in children. Timely diagnosis of Candida osteomyelitis with extended courses of 6-12 months of antifungal therapy, and surgical intervention, when indicated, may improve outcome.

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.

Les spondylodiscites à Candida; à propos de deux cas

In recent years, the incidence of systemic infections due to Candida increased, but the incidence of spondylodiscitis remained low, and epidural involvement during such infection was seldom reported. The purpose of this study was to report the cases of 2 young male heroin addicts who developed spondylodiscitis due to Candida sp., with epidural involvement. In one case, a microbiological diagnosis was obtained after biopsy. In the other case, the diagnosis was based on serological data and Candida antigenemia. In both cases, an oral fluconazole based therapy was administered at first (because of a poor peripheral venous system), but proved to be inefficient. A secondary therapy by liposomal amphotericin B proved efficient allowing a favourable evolution. This pathology raised a number of problems concerning diagnosis and treatment. The clinical data was non-specific the paraclinical diagnosis required MRI, and biopsy. When microbiological assessment is negative, serology and the antigenemia can be useful. The treatment pattern suggested for the management of bone and joint infections is: intravenous amphotericine B for 2-3 weeks, followed by oral administration of fluconazole or voriconazole for 6-12 month. Surgical treatment is recommended only to patients ay risk of neurological disorders or severe epidural abscess.

Antifungals in systemic neonatal candidiasis

Fungal infections are common in the newborn period, especially among premature neonates, and are responsible for considerable morbidity and mortality. Currently, three classes of antifungals are commonly used in the treatment of systemic fungal infections in neonates: the polyene macrolides (e.g. amphotericin B [deoxycholate and lipid preparations]); the azoles (e.g. fluconazole); and the fluorinated pyrimidines (e.g. flucytosine). The echinocandins (e.g. caspofungin and micafungin) are a newer class of antifungals which shows promise in this population.The available kinetic data on amphotericin B deoxycholate in neonates are derived from very small studies and exhibit considerable variability. There are no kinetic data available for the use of lipid preparations in this population and, again, much has been inferred from adult studies. The information available for flucytosine is also limited but appears similar to what is observed in adults. Fluconazole has the most neonatal pharmacokinetic data, which show slightly less variability than the other antifungals. Genomic factors which affect the metabolism of amphotericin B and fluconazole may explain some of the observed variability. Most of the data for the efficacy of antifungal drugs in neonates are derived from retrospective studies and case reports. The data for amphotericin B deoxycholate and flucytosine are limited. There are more data for the liposomal and lipid complex preparations of amphotericin B and for fluconazole in this population. These support the use of these drugs in neonates, but because of their largely noncomparative nature they can not define the optimal dosage or duration of therapy. Amphotericin B deoxycholate is primarily nephrotoxic. It also induces electrolyte abnormalities and is to a lesser degree cardiotoxic. This toxicity in neonates appears similar to published data in older children and adults. While the lipid preparations of amphotericin B owe their existence to a presumed decrease in toxicity, the observed toxicity in neonates appears to be equal to that seen with the deoxycholate, although it should be noted that the lipid preparations are usually given at much higher dosages. Fluconazole toxicity appears to be milder and less frequent in this population than is seen with amphotericin B. In the final analysis, we do not have sufficient data to define the pharmacokinetic profiles, optimal dose or duration of therapy, or toxicity for any of these compounds in neonates. Further studies are necessary if the optimisation of antifungal therapy in this population is to continue.

[Septic arthritis in neonates and infants]

INTRODUCTION

Septic arthritis represents an intra-articular infection caused by pyogenic bacteria. During the earliest childhood it is considered to be a systemic septic condition and demands early diagnosis and prompt surgical treatment.

MATERIAL AND METHODS

This is a retrospective analysis of patients with septic arthritis treated at the Department of Orthopedics of the Pediatric Surgery Clinic in Novi Sad, over a 10-year period. We are also presenting a case of a 12-day-old newborn baby, with clear radiological signs of osteoarthritis of the right knee.

RESULTS

A retrospective study included the period 1991-2000, and showed that 15 patients, aged 10 days--12 months were treated for osteoarthritis. The most common localization was the hip, in 60% of cases. In 11 patients the causative agent was Staphylococcus aureus, while in the 4 remaining patients the bacteriologic finding was negative. One patient died of generalized sepsis.

DISCUSSION

In neonates and infants septic arthritis is characterized by atypical clinical picture, often causing delayed diagnosis. In the initial phases of the disease ultrasonographic findings were of greater use compared to radiological imaging, due to relatively late appearance of radiological signs of disease.

CONCLUSIONS

Due to possible development of serious and irreversible damage, even lethal outcome, septic arthritis requires early diagnosis, prompt administration of antibiotics and early surgical treatment. It is a quite unique area in Pediatric Orthopedics where missed or delayed diagnosis may have serious consequences.

Antifungal pharmacotherapy for neonatal candidiasis

Candida is a leading cause of late onset infection (> 3 days of age) in the premature infant. Therefore, decisions about the diagnosis and management of infections caused by Candida are commonplace in the neonatal intensive care unit. Despite this fact, there are few comparative trials about treatment of neonatal Candida infections to guide the practitioner. New antifungals have been developed in the past decade and some clinical experience has been reported that can be used to guide the treatment of infants with serious Candida infections. This article reviews recent pertinent data with regard to dosing guidelines, efficacy, and toxicities of available systemic antifungal agents in the newborn.

Eradication of severe neonatal systemic candidiasis with amphotericin B lipid complex

OBJECTIVE

To report the successful use of amphotericin B lipid complex in treating severe systemic candidiasis in a very-low-birth-weight infant.

CASE SUMMARY

A preterm female infant, born at 25 weeks' gestational age with a birth weight of 870 g, had received full supportive care in the neonatal intensive care unit (NICU), including mechanical ventilation, total parenteral nutrition, and placement of central venous catheters. At seven weeks of age, she developed severe disseminated candidiasis, which failed to respond to conventional amphotericin B and fluconazole therapy. Her progressive deterioration was reversed only after amphotericin B lipid complex (A-complex) was substituted for conventional amphotericin B. The improvement in her condition was impressive, and she made a full recovery without any adverse effect.

DISCUSSION

With increased reliance on invasive technologies for life support, systemic candida infections have become increasingly common among premature infants in the NICU. Such infections are potentially fatal for the high-risk neonate. A literature review shows limited documentation of the use of lipid-based formulations of amphotericin B, especially A-complex, in preterm infants. However, the collective experience with these products appears to show that they are effective and cause fewer adverse effects than conventional amphotericin B. The infant reported here had shown progressive deterioration from disseminated candidiasis until conventional amphotericin B therapy was replaced with A-complex. Her recovery corresponded to the clearance of the candidemia.

CONCLUSIONS

With favorable results and increasing experience with lipid-based formulations of amphotericin B, it is reasonable to consider these new formulations as therapy for candidemia in preterm infants who are at a high risk of nephrotoxicity or who have failed conventional therapy.

Liposomal amphotericin B treatment for neonatal fungal infections

BACKGROUND

Disseminated fungal infections are a major problem in high risk neonates. Conventional antifungal agents are often unsatisfactory and have a high incidence of severe adverse effects.

METHODS

We administered liposomal encapsulated amphotericin B (AmBisome), which is an alternative to conventional amphotericin B, to 40 preterm (mean birth weight, 1090 +/- 313.6 g; mean gestational age, 28.35 +/- 2.13 weeks) and 4 full term (mean birth weight, 3080 +/- 118 g; mean gestational age, 39 +/- 0.7 weeks) newborn infants with a severe fungal infection.

RESULTS

Candida albicans was the most frequent fungus isolated (70%). The duration of intravenous AmBisome therapy ranged from 7 to 49 days; the cumulative dose ranged from 7 to 138.8 mg/kg (median, 45.2 mg/kg). Administration of AmBisome was effective in 72.7% of patients; 5 of 6 cases of meningitis also recovered; 63.6% of 33 very low birth weight infants survived. No side effects were observed.

CONCLUSIONS

To our knowledge this is the largest study of the treatment of neonates with liposomal amphotericin B, and the results confirm its effectiveness and safety. However, randomized clinical trials are required to establish the most effective administration protocol for AmBisome, i.e. the starting dosage, the maximum effective dosage and the cumulative dosage, and to verify whether the preparation should be associated with another antifungal agent.