Sandalwood Oils of Different Origins Are Active In Vitro against Madurella mycetomatis, the Major Fungal Pathogen Responsible for Eumycetoma.

In the search for new bioactive agents against the infectious pathogen responsible for the neglected tropical disease (NTD) mycetoma, we tested a collection of 27 essential oils (EOs) in vitro against Madurella mycetomatis, the primary pathogen responsible for the fungal form of mycetoma, termed eumycetoma. Among this series, the EO of Santalum album (Santalaceae), i.e., East Indian sandalwood oil, stood out prominently with the most potent inhibition in vitro. We, therefore, directed our research toward 15 EOs of Santalum species of different geographical origins, along with two samples of EOs from other plant species often commercialized as "sandalwood oils". Most of these EOs displayed similar strong activity against M. mycetomatis in vitro. All tested oils were thoroughly analyzed by GC-QTOF MS and most of their constituents were identified. Separation of the sandalwood oil into the fractions of sesquiterpene hydrocarbons and alcohols showed that its activity is associated with the sesquiterpene alcohols. The major constituents, the sesquiterpene alcohols (Z)-α- and (Z)-ß-santalol were isolated from the S. album oil by column chromatography on AgNO3-coated silica. They were tested as isolated compounds against the fungus, and (Z)-α-santalol was about two times more active than the ß-isomer.

Naphthylisoquinoline alkaloids: novel agents against the causative pathogens of eumycetoma and actinomycetoma-en route to broad-spectrum antimycetomal drugs.

Mycetoma is a devastating neglected tropical infection of the subcutaneous tissues. It is caused by fungal and bacterial pathogens recognized as eumycetoma and actinomycetoma, respectively. Mycetoma treatment involves diagnosing the causative microorganism as a prerequisite to prescribing a proper medication. Current therapy of fungal eumycetoma causative agents, such as Madurella mycetomatis, consists of long-term antifungal medication with itraconazole followed by surgery, yet with usually unsatisfactory clinical outcomes. Actinomycetoma, on the contrary, usually responds to treatment with co-trimoxazole and amikacin. Therefore, there is a pressing need to discover novel broad-spectrum antimicrobial agents to circumvent the time-consuming and costly diagnosis. Using the resazurin assay, a series of 23 naphthylisoquinoline (NIQ) alkaloids and related naphthoquinones were subjected to in vitro screening against two fungal strains of M. mycetomatis and three bacterial strains of Actinomadura madurae and A. syzygii. Seven NIQs, mostly dimers, showed promising in vitro activities against at least one strain of the mycetoma-causative pathogens, while the naphthoquinones did not show any activity. A synthetic NIQ dimer, 8,8'''-O,O-dimethylmichellamine A (18), inhibited all tested fungal and bacterial strains (IC50 = 2.81-12.07 µg/mL). One of the dimeric NIQs, michellamine B (14), inhibited a strain of M. mycetomatis and significantly enhanced the survival rate of Galleria mellonella larvae infected with M. mycetomatis at concentrations of 1 and 4 µg/mL, without being toxic to the uninfected larvae. As a result, broad-spectrum dimeric NIQs like 14 and 18 with antimicrobial activity are considered hit compounds that could be worth further optimization to develop novel lead antimycetomal agents.

Actinomycetoma in a patient with pre-existing sensorineural hearing loss: a linezolid-based treatment paradigm.

Mycetoma is a chronic granulomatous infectious disease with a triad of subcutaneous swelling, discharging sinuses and the presence of granules. The infection may occur following minor trauma or penetrating thorn injury. We report a case of a man in his 40s with a history of thorn prick 9 years ago, followed by the formation of painless discharging sinuses on the right foot for the past 2 years. Clinical, local epidemiological, histopathological examination and Gram stain confirmed the diagnosis of actinomycetoma. Prior to initiating the Welsh regimen, a pretreatment assessment of the patient's auditory function was conducted through pure tone audiometry, indicating the existence of pre-existing high-frequency bilateral sensorineural hearing loss. The patient was treated with linezolid as an alternative to amikacin, at a dosage of 600 mg two times per day, leading to complete resolution within 3 weeks. This underscores linezolid's efficacy as a safe and cost-effective alternative for actinomycetoma, without causing ototoxic side effects.

Fusarium falciforme eumycetoma: a diagnostic challenge of a neglected tropical disease.

Eumycetoma, a subcutaneous infection caused by various fungi with pathognomonic discharging grain, is rarely reported in Malaysia. This case concerns a eumycetoma infection in an immunocompetent man who presented with progressive left foot swelling complicated with pustules, sinuses and pale grain discharge for the past year after recurrent thorn pricks. Histological findings of the grain and tissue showed foci of septate fungal hyphae. Tissue culture yielded no growth. Amplification and sequencing of the rDNA internal transcribed spacer 1 (ITS1), ITS4 and large subunit regions of the tissue identified the causative agent as Fusarium falciforme, highlighting the role of molecular diagnostic method in identifying fungal species in eumycetoma. The patient was treated with surgical excision and oral itraconazole with excellent improvement. However, he presented again with recurrence after defaulting therapy. F. falciforme has been implicated in causing diseases in crops and sea turtles. Therefore, the One Health approach should be adopted to manage this emerging species.

Complete Genome Sequence of the Itraconazole Decreased Susceptible Madurella fahalii Type-Strain CBS 129176.

Madurella fahalii is a causative agent of the implantation mycosis mycetoma with decreased susceptibility to itraconazole, the preferred therapeutic drug to combat mycetoma. Here, we report the M. fahalii type-strain CBS 129176 genome assembly and annotation to identify a glutamic acid insert near the azole-binding pocket in the Cyp51A protein.

Mycetoma in Ecuador.

BACKGROUND: Previous studies on the distribution of mycetoma globally have failed to identify Ecuador as an endemic country. METHODS: We present data on 35 cases of mycetoma in Ecuador between 1955 and 2021: 5 cases from our experience and 30 cases from the literature. RESULTS: Eight cases of eumycetoma (23%) and 27 cases of actinomycetoma (77%) were diagnosed. Most cases originated from the coastal region of Ecuador. CONCLUSIONS: For the first time in an English-language publication, this communication confirms the presence of mycetoma in Ecuador, securing Ecuador's position on the global mycetoma map.

The nutritional status of mycetoma affected patients seen at the Mycetoma Research Center, Sudan.

Nutrition plays a critical and crucial role in addressing neglected tropical diseases (NTDs) and their complications, as they often contribute to malnutrition, which can worsen the impact of these conditions. Therefore, it is necessary to investigate the nutritional status of mycetoma patients, which has not been explored previously. This descriptive cross-sectional hospital-based study was conducted at the Mycetoma Research Center (MRC), University of Khartoum, Sudan. The study included 179 confirmed mycetoma patients and an equal number of age- and sex-matched normal controls. The nutritional status of the mycetoma patients was assessed and compared with that of the control group. The majority of the patients were young adults with varying educational levels, predominantly from Central Sudan. The foot was the most commonly affected part; most patients had lesions more than 10 cm in diameter. The Body Mass Index (BMI) was calculated for both study groups, revealing that 43.5% of the patients and 53.6% of controls had a normal BMI. Furthermore, 36% of patients were underweight, contrasting with only 11% in the control group. Correlation analyses indicated no significant associations between BMI and age groups, educational levels, daily meals, food quantity, and appetite in the study population (p > 0.05). Similarly, no significant differences were observed in BMI concerning disease duration and affected sites (p = 0.0577). The Kruskal-Wallis test did not reveal significant differences in BMI means among the groups. The study revealed that most participants consumed three meals daily, and the control group showed a more robust appetite and consumed more food than the patient group (p = 0.005). Nevertheless, there were no significant differences in the consumption of different food types between the patient and control groups and among different BMI categories (p = 0.025 and 0.040, respectively).

Evaluation of a computational model for mycetoma-causative agents identification.

BACKGROUND: The therapeutic strategy for mycetoma relies heavily on the identification of the causative agents, which are either fungal or bacterial. While histopathological examination of surgical biopsies is currently the most used diagnostic tool, it requires well-trained pathologists, who are lacking in most rural areas where mycetoma is endemic. In this work we propose and evaluate a machine learning approach that semi-automatically analyses histopathological microscopic images of grains and provides a classification of the disease as eumycetoma or actinomycetoma. METHODS: The computational model is based on radiomics and partial least squares. It is assessed on a dataset that includes 890 individual grains collected from 168 patients originating from the Mycetoma Research Centre in Sudan. The dataset contained 94 eumycetoma cases and 74 actinomycetoma cases, with a distribution of the species among the two causative agents that is representative of the Sudanese distribution. RESULTS: The proposed model achieved identification of causative agents with an accuracy of 91.89%, which is comparable to the accuracy of experts from the domain. The method was found to be robust to a small error in the segmentation of the grain and to changes in the acquisition protocol. Among the radiomics features, the homogeneity of mycetoma grain textures was found to be the most discriminative feature for causative agent identification. CONCLUSION: The results presented in this study support that this computational approach could greatly benefit rural areas with limited access to specialized clinical centres and also provide a second opinion for expert pathologists to implement the appropriate therapeutic strategy.

Actinomycetoma by Cellulosimicrobium cellulans in a Young Man from Guinea-Bissau: Short Literature Review Regarding a Case Report.

Mycetoma is caused by the subcutaneous inoculation of filamentous fungi or aerobic filamentous bacteria. Cellulosimicrobium cellulans is a gram-positive bacterium from the order Actinomycetales that rarely causes human disease. The diagnosis is based on the clinical presentation and identification of the causative microorganism. We present a short literature review regarding the case report of a young man diagnosed with actinomycetoma due to Cellulosimicrobium cellulans and who received treatment with an association of amikacin and sulfamethoxazole/ trimethoprim (Welsh regimen).

Mycetoma case series in Somalia.

Mycetoma is a suppurative chronic bacterial or fungal disease inoculated into the body by minor trauma which may penetrate from subcutaneous tissue to bone. Although the lower extremities are most commonly affected, rare forms can also be seen from time to time. The diagnostic triad of swelling in the affected area, multiple sinus formation, and purulent discharge with grains are typical. Definitive diagnosis is made by isolation of the causative pathogen, radiologic imaging, and histopathologic examination. Antifungal and antibacterial options are applied together with surgery. Our aim in this case series is to report and analyze 10 rare cases of mycetoma.

Using (1,3)-ß-D-glucan concentrations in serum to monitor the response of azole therapy in patients with eumycetoma caused by Madurella mycetomatis.

INTRODUCTION: (1,3)-ß-D-glucan is a panfungal biomarker secreted by many fungi, including Madurella mycetomatis, the main causative agent of eumycetoma. Previously we demonstrated that (1,3)-ß-D-glucan was present in serum of patients with eumycetoma. However, the use of (1,3)-ß-D-glucan to monitor treatment responses in patients with eumycetoma has not been evaluated. MATERIALS AND METHODS: In this study, we measured (1,3)-ß-D-glucan concentrations in serum with the WAKO (1,3)-ß-D-glucan assay in 104 patients with eumycetoma treated with either 400 mg itraconazole daily, or 200 mg or 300 mg fosravuconazole weekly. Serial serum (1,3)-ß-D-glucan concentrations were measured at seven different timepoints. Any correlation between initial and final (1,3)-ß-D-glucan concentrations and clinical outcome was evaluated. RESULTS: The concentration of (1,3)-ß-D-glucan was obtained in a total of 654 serum samples. Before treatment, the average (1,3)-ß-D-glucan concentration was 22.86 pg/mL. During the first 6 months of treatment, this concentration remained stable. (1,3)-ß-D-glucan concentrations significantly dropped after surgery to 8.56 pg/mL. After treatment was stopped, there was clinical evidence of recurrence in 18 patients. Seven of these 18 patients had a (1,3)-ß-D-glucan concentration above the 5.5 pg/mL cut-off value for positivity, while in the remaining 11 patients, (1,3)-ß-D-glucan concentrations were below the cut-off value. This resulted in a sensitivity of 38.9% and specificity of 75.0%. A correlation between lesion size and (1,3)-ß-D-glucan concentration was noted. CONCLUSION: Although in general (1,3)-ß-D-glucan concentrations can be measured in the serum of patients with eumycetoma during treatment, a sharp decrease in ß-glucan concentration was only noted after surgery and not during or after antimicrobial treatment. (1,3)-ß-D-glucan concentrations were not predictive for recurrence and seem to have no value in determining treatment response to azoles in patients with eumycetoma.

Invasive Eumycotic mycetoma of the nasal septum in a post-dialysis patient: A case report.

BACKGROUND: Mycetoma is a slowly progressive chronic granulomatous disease of the skin, subcutaneous tissue, and underlying or adjacent cartilage or bone. Most commonly involves the foot region. Other parts such as the knee, arm, leg, head, neck, thigh, perineum, chest, abdominal walls, facial bones, mandible, paranasal sinuses, eyelid, vulva, orbit, and scrotum are seldom affected. METHODS: This is a rare presentation of Eumycotic mycetoma involving the nasal septum. Surgical debridement is done under local anesthesia. Histopathological examination of debrided specimen guided in the diagnosis and treatment. RESULTS: Histopathological examination is the one that confirms the diagnosis and rules out the other granulomatous conditions and fungal rhinitis causing septal perforation. CONCLUSIONS: In an immunocompromised state, we know that mucormycosis and zygomycosis are known to cause aggressive complications like orbital invasion and palatal perforation by vascular route. However, other fungal infections also can lead to septal perforations whenever there is lessened resistance by the mucosal barrier due to trauma (nasal intubations).

A Novel Report of mycetoma with Spinal Spread due to Madurella fahalli from India.

Eumycetoma caused by Madurella fahalii, a drug-resistant fungus, has never been reported in India. Here, we describe a fatal case of eumycetoma with spinal involvement due to M. fahalii for the first time in India.

Fungal mycetoma and pregnancy: An association with costly and difficult management, about a case.

Mycetomas are endemic diseases in tropical and sub-tropical countries of Africa, Asia and America, mainly affecting rural populations living below the poverty line. We report a particular case of a mycetoma associated with pregnancy whose evolution was good, but at the cost of significant financial expenses. This was a 39-year-old woman who developed a fungal mycetoma due to Madurella mycetomatis from the ingunocrural region. The patient had to develop several previous pregnancies on this site of mycetoma, the outcome of which was favorable. The last pregnancy was accompanied by an aggravation of the mycetoma in the form of polyfistulized inflammatory swelling of the right inguino-crural region emitting black grains. Magnetic Resonance Imaging (MRI) of the region showed invasion of the adductor muscles at the level of the root of the thigh on its antero-internal side with no sign of pelvic extension or underlying bone lesion. The patient was treated by surgery associated with antifungal treatment. The evolution was favorable for pregnancy and mycetoma.

The combination of manogepix and itraconazole is synergistic and inhibits the growth of Madurella mycetomatis in vitro but not in vivo.

Mycetoma is a neglected tropical disease commonly caused by the fungus Madurella mycetomatis. Standard treatment consists of extensive treatment with itraconazole in combination with surgical excision of the infected tissue, but has a low success rate. To improve treatment outcomes, novel treatment strategies are needed. Here, we determined the potential of manogepix, a novel antifungal agent that targets the GPI-anchor biosynthesis pathway by inhibition of the GWT1 enzyme. Manogepix was evaluated by determining the minimal inhibitory concentrations (MICs) according to the CLSI-based in vitro susceptibility assay for 22 M. mycetomatis strains and by in silico protein comparison of the target protein. The synergy between manogepix and itraconazole was determined using a checkerboard assay. The efficacy of clinically relevant dosages was assessed in an in vivo grain model in Galleria mellonella larvae. MICs for manogepix ranged from <0.008 to >8 mg/l and 16/22 M. mycetomatis strains had an MIC ≥4 mg/ml. Differences in MICs were not related to differences observed in the GWT1 protein sequence. For 70% of the tested isolates, synergism was found between manogepix and itraconazole in vitro. In vivo, enhanced survival was not observed upon admission of 8.6 mg/kg manogepix, nor in combination treatment with 5.7 mg/kg itraconazole. MICs of manogepix were high, but the in vitro antifungal activity of itraconazole was enhanced in combination therapy. However, no efficacy of manogepix was found in an in vivo grain model using clinically relevant dosages. Therefore, the therapeutic potential of manogepix in mycetoma caused by M. mycetomatis seems limited.

Treatment of Madurella mycetomatis-caused mycetoma consists of extensive exposure to antifungals and surgery. To improve therapy, we evaluated manogepix, a novel antifungal agent, as a therapeutic option against M. mycetomatis. Our findings suggest limited therapeutic potential for manogepix.