Cladophialophora bantiana as an Emerging Pathogen in Animals: Case Report of Equine Endometritis and Review of the Literature

Reappraising Cladophialophora bantiana phaeohyphomycosis in France: retrospective nation-based study

BACKGROUND

Cladophialophora bantiana is one of the most virulent phaeohyphomycetes, typically causes non-angiogenic single (or sometimes multiple) cystic brain lesions, and has resulted in a mortality rate of up to 70%. Most C bantiana cases are described either in a series of isolated reports or in very small cohorts. The aim of this retrospective nation-based study was to share the data on C bantiana phaeohyphomycosis cases reported in France and French overseas territories over the past two decades to improve understanding of this disease.

METHODS

Patients with C bantiana infection were processed through the active surveillance programme of invasive fungal infections launched by the National Reference Center for Mycoses and Antifungals, Institut Pasteur (Paris, France), and the French Surveillance Network of Invasive Fungal Infections, which involved 29 hospitals from mainland France and overseas French territories. Only proven and probable cases of infection, according to the revised and updated consensus definitions from the European Organization for Research and Treatment of Cancer and Mycoses Study Group, were included in the study. Patients were diagnosed or confirmed, or both, using a polyphasic approach at the Institut Pasteur between 2002 and 2022. Patients were separated into two groups: those with CNS involvement and those with no CNS involvement. The primary outcome was the survival rate.

FINDINGS

A total of 23 patients with a C bantiana invasive infection were included during the study period (Jan 1, 2002, to Dec 31, 2022). The median age was 56 years in the CNS involvement group and 65 years in the non-CNS involvement group. Until 2021, the annual number of cases varied between zero and two, with six cases observed in 2022, the warmest year recorded in France since 1900. CNS involvement was observed in 15 (65%) patients, including three disseminated cases; skin and soft tissue involvement in seven (30%) patients and an isolated lung infection in one case. Diabetes was observed in five patients, and any immunodepression factor was observed in 14 (61%) of 23 patients. When considering only patients with CNS involvement, 9-month survival appeared higher in patients who underwent exeresis or large drainage (three [75%] of four patients vs three [27%] of 11 patients; p=0·24) and significantly higher in those treated for 2 or more weeks with triple antifungal therapy (liposomal amphotericin B plus posaconazole and flucytosine; seven [78%] of nine patients vs one [17%] of six patients; p=0·040). Two patients were treated with excision surgery alone (one patient with success, and the other patient lost to follow-up).

INTERPRETATION

This study shows that the clinical presentations and underlying medical conditions of C bantiana infections are more diverse than previously described. It also emphasises a significant difference in mortality rate between those with and without CNS involvement. The prognosis improved when surgery was performed and triple antifungal therapy was administered. Such rare and devastating invasive fungal infections should be managed by a multidisciplinary team.

FUNDING

Santé Publique France.

Case report: Disseminated Cladophialophora bantiana phaeohyphomycosis in a dog with hepatic dysfunction, and concurrent ehrlichiosis

A 1-year-old mixed breed dog initially presented with marked ascites due to a low-protein transudate resulting from portal hypertension. Laboratory evaluation revealed non-regenerative anemia, lymphopenia, thrombocytopenia, evidence of hepatic insufficiency [hypoalbuminemia, decreased urea, increased post-prandial bile acids, prolonged activated partial thromboplastin time (aPTT)] and Ehrlichia canis infection. Approximately a week later, the dog was declining and was euthanized. On autopsy, multifocal hepatic granulomas and acquired portosystemic shunts (APSS) were seen. Imprint cytology revealed fungal hyphae and pyogranulomatous inflammation in the liver and brain. Disseminated Cladophialophora bantiana phaeohyphomycosis was diagnosed by histologic examination, culture and PCR. Immunosuppression due to ehrlichiosis is suspected to have predisposed this animal to fungal infection. To the authors' knowledge, this is the first report of C. bantiana in the West Indies.

Endometrial and vaginal microbiome in donkeys with and without clinical endometritis

Endometrial and vaginal microbiomes are critical in the study of endometritis, which is an important cause of infertility in donkeys. Our objective was to investigate the difference of the endometrial and vaginal microbiomes between healthy donkey jennies (group C) and jennies with endometritis (group E). Endometrial and vaginal swab samples were collected, and the 16 s rRNA gene amplicon high-throughput sequencing technique was applied to identify the microbial composition in the samples. A similar microbial composition pattern was found between endometrial and vaginal samples, which indicated the impact of the vaginal microbiome on the endometrial microbial environment and health. There was a significant difference of endometrial and vaginal swab samples between the two groups. Ruminococcaceae and Lachnospiraceae were significantly more abundant in endometrial and vaginal microbiomes of group E than in group C. Their dominance was consistent with increased anaerobic bacterial taxa in the functional analysis, which might be associated with the pathogenesis of endometritis in donkeys. Sphingomonadaceae, a bacterial family reported in bovine semen, was statistically more abundant in endometrial microbiome of group E than in group C, which might suggest an association between high abundance of Sphingomonadaceae possibly due to uncleared semen and donkey endometritis. Our study revealed the composition of the vaginal and endometrial microbiomes in healthy and endometritis donkeys. These findings will provide more insights into the pathogenesis of donkey endometritis.

Cerebral phaeohyphomycosis due to Cladophialophora bantiana in an immunocompetent individual: A case report and brief review of literature

Background and Purpose

Fungal infections of the central nervous system (CNS) are life-threatening conditions that are frequently misdiagnosed with bacterial and viral CNS infections. Cerebral phaeohyphomycosis is a cerebral infection caused by dematiaceous fungi, especially Cladophialophora bantiana. Very few cases of fungal CNS infection have been reported across the world. High clinical suspicion should be cast for the patients with brain abscess that do not respond to conventional antibiotic therapy.

Case report

We report a case of a 21-year-old male presenting with headache, seizures and weakness in the limbs. Radiological examination revealed multiple brain abscesses. After surgical excision and laboratory evaluation, it was found to be caused by C. bantiana. The patient's outcome was good with surgical excision and voriconazole therapy.

Conclusion

Brain abscess caused by C. bantiana is on rise, especially in immunocompromised groups. Thus, high clinical suspicion, accurate diagnosis and management are the fundamentals for good prognosis.

Cladophialophora encephalitis in an alpaca

A 4-year-old Huacaya hembra was evaluated for acute neurologic signs including recumbency and a left head tilt. Cranial nerve examination revealed a left ear droop, muzzle deviation to the right, mydriasis of the left eye, an absent menace response, bilateral absent pupillary light reflex when light was directed into the left eye, and bilateral horizontal nystagmus with fast phase to the right. Multifocal intracranial lesions were suspected. Computed tomography revealed an intracranial mass. Postmortem examination, histopathology, and sequencing of a polymerase chain reaction product confirmed a diagnosis of phaeohyphomycotic meningoencephalitis caused by Cladophialophora bantiana. Key clinical message: Advanced diagnostic imaging (computed tomography) was useful in achieving a diagnosis of an intracranial mass in an alpaca with acute neurological signs, later confirmed to be central nervous system (CNS) phaeohyphomycosis. Although uncommon, intracranial fungal infection should be considered as a differential diagnosis in camelid patients exhibiting CNS signs, particularly if they do not respond to initial antimicrobial and anthelmintic therapy.

Disseminated melanized fungal infection due to Cladosporium halotolerans in a dog coinfected with canine adenovirus-1 and canine parvovirus-2

This report presents the pathologic findings associated with disseminated infection due to Cladosporium halotolerans in a dog that was simultaneously infected with canine adenovirus-1 (CAdV-1) and canine parvovirus-2 (CPV-2). A 12-year-old, mixed breed dog, with a clinical history of neurological manifestations was submitted for routine autopsy due to poor prognosis. The principal pathologic findings were mycotic necrotizing nephritis, hepatitis, and splenitis with embolic dissemination to the brain resulting in mycotic necrotizing meningoencephalitis, ventriculitis, choroid plexitis, and obstructive hydrocephalus associated with intralesional and intravascular septate pigmented fungi. PCR and sequencing of the ITS region of fungi revealed that the intralesional fungal organisms had 82% nucleotide identity with members of the Cladosporium sphaerospermum complex of organisms. However, a PCR assay and sequencing of the beta tubulin gene confirmed that the organism identified in this dog had 100% nucleotide sequence identity with C. halotolerans. Using immunohistochemistry, intralesional antigens of CAdV-1 were identified within the epithelial cells of the liver and lungs; there was positive immunolabeling for CPV-2 antigens in degenerated cardiomyocytes. These findings confirmed the active participation of C. halotolerans in the development of disseminated cladosporiosis in this dog and represent a rare occurrence of concomitant infection with CAdV-1 and CPV-2.

Mycotic Rhinitis and Sinusitis in Florida Horses

Rhinitis and sinusitis caused by fungal pathogens were studied in biopsy samples submitted from 52 horses distributed throughout subtropical and tropical regions of Florida. Methods included routine histopathology as well as polymerase chain reaction (PCR) with panfungal/panoomycete primers and DNA sequencing on extracted DNA (DNA barcoding). Granulomatous, pyogranulomatous, and fibrinopurulent lesions in nasal and sinus mucosa were associated with signs of upper airway obstruction and noise as well as nasal discharge. Morphologic and histochemical assessment of cases identified 31 cases of zygomycosis/pythiosis plus 1 mixed infection case, 16 cases of phaeohyphomycosis with 2 additional mixed infection cases, and 3 cases caused by other fungi. Morphologic evidence of Aspergillus sp. infection as a superficial copathogen was found in 2 of the mixed fungal infection cases. PCR and DNA sequencing facilitated identification of fungal pathogens in 11 of 52 cases (21%). No evidence of oomycete infection was found. Histomorphologic features of previously unrecognized forms of equine rhinitis/sinusitis were described, including those caused by Flavodon flavus, Curvularia lunata, Exserohilum rostrata, Alternaria alternata, Alternaria sp., Cladophialophora bantiana, Fusarium solani, and Toxicocladosporium irritans. PCR and DNA sequencing using panfungal and oomycete primers with DNA from formalin-fixed and paraffin-embedded specimens successfully identified the pathogen in phaeohyphomycosis (7/18 cases, 39%), zygomycosis/pythiosis (1/32 cases, 3%), and other nonpigmented fungal infections (3/3 cases, 100%). Zygomycosis and phaeohyphomycosis were the most common forms of fungal rhinitis found in Florida horses.

An updated comprehensive systematic review of Cladophialophora bantiana and analysis of epidemiology, clinical characteristics, and outcome of cerebral cases

Cladophialophora bantiana is a phaeoid fungus that only rarely has been isolated from sources other than the human brain. It has a particular tropism for the central nervous system (CNS). We have integrated and updated large-scale data related to several aspects of C. Bantiana and reviewed all the available reports on its cerebral infections, focusing on their geographical distribution, infection routes, immune status of infected individuals, type and location of infections, clinical manifestations and treatment and outcome, briefly looking over the spectrum of other disease entities associated with C. bantiana, that is, extra-cerebral and animal infections and on the environmental sources of this fungus. Among the agents of phaeohyphomycosis, a term used to describe an infection caused by a dark pigmented fungus, C. bantiana has some significant specific features. A total of 120 case reports were identified with a significantly higher percentage of healthy subjects than immune-debilitated patients (58.3% vs. 41.7%). Infections due to C. bantiana occur worldwide. The main clinical manifestations are brain abscess (97.5%), coinfection of brain tissue and meninges (14.2%) and meningitis alone (2.5%). Among immunocompetent patients, cerebral infection occurred in the absence of pulmonary lesions. The mortality rate is 65.0% regardless of the patient's immune status. The therapeutic options used include surgery or antifungals alone, and the combination of both, in most cases the fatal outcome being rapid after admission. Since the fungus is a true pathogen, laboratory workers should be made aware that BioSafety Level-3 precautions might be necessary.

A case of central nervous system infection due to Cladophialophora bantiana

BACKGROUND

Cladophialophora bantiana is a melanised mold with a pronounced tropism for the central nervous system, almost exclusively causing human brain abscesses.

CASE REPORT

We describe a case of cerebral infection by this fungus in an otherwise healthy 28-year-old coal-miner. Environmental occurrence, route of entry, and incubation period of this fungus are unknown, but our case is informative in that the first symptoms occurred about eight weeks after known traumatic inoculation. Lesions were compatible with tuberculous granulomas, and the patient initially received antitubercular treatment. Melanised fungal cells were seen in a brain biopsy and abscess materials. Therapy was switched from empirical antitubercular treatment to amphotericin B (0.5mg/kg/d), but was changed to voriconazole 200mg/d, i.v. on the basis of antifungal susceptibility test results. The patient responded clinically, and gradually improved. The isolate was identified by sequencing of the Internal Transcribed Spacer domain of rDNA.

CONCLUSIONS

Given the non-specific clinical manifestations of C. bantiana cerebral abscesses, clinicians and laboratory workers should suspect infections caused by C. bantiana, particularly in immunocompromised patients with a trauma history.