Paecilomyces/Purpureocillium keratitis: A consecutive study with a case series and literature review

Purpureocillium jiangxiense sp. nov.: Entomopathogenic Effects on Ostrinia furnacalis and Galleria mellonella

The genus Purpureocillium is renowned for its role in biocontrol and biotechnological applications. The identification of new species within this genus is crucial for broadening our understanding of its ecological roles and potential utility in sustainable agriculture. This study aimed to characterize a new species of Purpureocillium, isolated from soil in eastern China, and to evaluate its bioactivity against Ostrinia furnacalis (corn moth) and Galleria mellonella (greater wax moth). We utilized morphological characterization; molecular phylogenetic analysis employing ITS, nrLSU, and tef1 genes; and bioactivity assays to identify and characterize the new species. The newly identified species, Purpureocillium jiangxiense sp. nov., displays unique morphological and genetic profiles compared to known species. Bioactivity tests showed that this species exhibits inhibitory effects against O. furnacalis and G. mellonella, highlighting its potential in biocontrol applications. By the ninth day at a spore concentration of 1 × 108 spores/mL, the mortality rate of the corn moth and greater wax moth reached 30% to 50% respectively. The discovery of P. jiangxiense sp. nov. adds to the genetic diversity known within this genus and offers a promising candidate for the development of natural biocontrol agents. It underscores the importance of continued biodiversity exploration and the potential for natural solutions in pest and disease management.

Treatment of resistant Paecilomyces lilacinus keratitis with topical voriconazole and oral itraconazole: a rare case report from Somalia

Introduction and importance

Paecilomyces species are rare fungi that are resistant to standard treatment and have increasing clinical relevance. The Purpureocillium lilacinum, formerly known as Paecilomyces lilacinus, has a unique sensitivity for the corneal surface. However, only a few cases have been documented globally. This case report presents the successful management of a patient with Paecilomyces lilacinus keratitis with topical voriconazole and oral itraconazole.

Case presentation

A 40-year-old woman came to our ophthalmology clinic complaining of right eye pain due to a severe corneal infection in her right eye. Corneal scraping and identification of the cultured pathogen were performed, which revealed Paecilomyces lilacinus. The corneal infection improved after being treated with hourly topical voriconazole (10 mg/ml) and oral traconozole.

Clinical discussion

Paecilomyces/Purpureocillium keratitis, which accounts for 5% of keratomycosis cases in tropical and subtropical areas, is extremely rare. It does not respond well to conventional antifungal treatment and frequently requires therapeutic surgery. Risk factors include wearing contact lenses, ocular trauma, ocular surgery, corticosteroids, and intraocular lens implantation.

Conclusion

For the treatment of Paecilomyces lilacinus keratitis that is unresponsive to conventional antifungal medications, voriconazole may be helpful. Early organism detection and the appropriate therapy are necessary for the management of keratitis.

Three cases of recalcitrant Paecilomyces keratitis in Southern California within a short period

BACKGROUND

The aim of this report is to describe the risk factors, clinical course, and characteristics of three cases of Paecilomyces keratitis presenting concurrently within three months in the same location. We used in vivo confocal microscopy and histopathology to corroborate our clinical findings.

OBSERVATIONS

Three eyes of three elderly patients with culture-proven Paecilomyces keratitis were included in this series. These patients resided within a 15-mile radius and presented to a tertiary care eye institute in Southern California between February and April 2022. All three eyes experienced a prolonged, recalcitrant course with recurrence of keratitis in donor corneal tissue despite antifungal therapy and multiple therapeutic penetrating keratoplasties. In vivo confocal microscopy, histopathology, and microbiologic findings corroborated the diagnosis of fungal keratitis with Paecilomyces. With surgical intervention and extensive medical therapy, all three cases resolved after the addition of oral Posaconazole.

CONCLUSIONS

Paecilomyces is a rare cause of infectious keratitis. Herein we report three similar cases in elderly patients. All had prolonged, recalcitrant infections that required multiple treatment modalities. Our cases, which were supported by in vivo confocal microscopy and histopathology, highlight the importance of timely and aggressive therapy to prevent recurrence.

Metarhizium carneum Formulations: A Promising New Biological Control to Be Incorporated in the Integrated Management of Meloidogyne enterolobii on Tomato Plants

The increase in the populations of root-knot nematode Meloidogyne enterolobii in various vegetables such as tomatoes grown under greenhouse conditions as well as increasing restrictions on the use of certain chemical nematicides have led to the search for new, effective management strategies, preferably ones that are sustainable biological alternatives. In this work, two formulations of the nematophagous fungus Metarhizium carneum, one concentrated suspension and one wettable powder, were evaluated under greenhouse conditions to reduce the M. enterolobii infestation in tomato plants. In addition, the effectiveness of the liquid formulation of M. carneum was compared with two biological and three chemical commercial nematicides. The results show that the two M. carneum formulations reduced the M. enterolobii population density by 78 and 66% in relation to the control treatment. In comparison, the liquid formulation of M. carneum and Purpureocillium lilacinum treatments reduced nematode population density by 72 and 43%, respectively, while for metam sodium preplanting applications followed by M. carneum applications during the tomato growth stage, the reduction was 96%. The alternate use of some chemical compounds plus the application of M. carneum as a biocontrol is a good starting strategy for managing M. enterolobii populations. These results confirm that M. carneum is a serious candidate for the short-term commercialization of an environmentally friendly biological nematicide.

Challenges in the diagnosis and management of atypical fungal keratitis during the COVID-19 pandemic: a case series

Fungal keratitis is a time-sensitive ocular infection that often requires a high index of suspicion followed by intensive medical/surgical interventions to achieve a successful clinical outcome. COVID-19 pandemic-related restrictions, necessitated the modification of conventional protocols and guidelines associated with the treatment of keratomycosis. We report four cases of atypical fungal keratitis with poorly differentiated clinical characteristics. The challenges faced during their management were (1) the dilemma of clinically differentiating fungal (Scedosporium and Purpureocillium lilacinum) and bacterial keratitis; (2) treatment of Scedosporium and Trichosporon keratitis with natamycin monotherapy; (3) mixed infection of Candida albicans and Aureobasidium pullulans and continuing medications before rescraping the corneal ulcer against the recommended treatment guidelines; (4) phenotypic identification and differentiation among morphologically resembling fungi; and (5) decision making arising out of disparities between KOH and fungal culture results. Three patients responded well to conservative treatments. The fourth patient underwent therapeutic keratoplasty but was lost to follow-up due to travel-related pandemic restrictions. This case series seeks to broaden the clinician's knowledge of rare and emerging moulds as presumptive aetiologies of keratomycosis. It also intends to emphasize the significance of early microbiological investigations, (direct microscopy and culture), in resource-limited settings, for initiating empirical treatment for a better visual prognosis.

Oral voriconazole monotherapy for fungal keratitis: efficacy, safety, and factors associated with outcomes

Purpose

To provide preliminary data on the efficacy and safety of oral voriconazole (VCZ) as a primary treatment for fungal keratitis (FK).

Method

We performed a retrospective histopathological analysis of data on 90 patients with FK at The First Affiliated Hospital of Guangxi Medical University between September 2018 and February 2022. We recorded three outcomes: corneal epithelial healing, visual acuity (VA) improvement, and corneal perforation. Independent predictors were identified using univariate analysis, and multivariate logistic regression analysis was used to identify independent predictive factors associated with the three outcomes. The area under the curve was used to evaluate the predictive value of these factors.

Results

Ninety patients were treated with VCZ tablets as the only antifungal drug. Overall, 71.1% (n = 64) of the patients had extreme corneal epithelial healing, 56.7% (n = 51) showed an improvement in VA, and 14.4% (n = 13) developed perforation during treatment. Non-cured patients were more likely to have large ulcers (≥5 × 5 mm²) and hypopyon.

Conclusion

The results indicated that oral VCZ monotherapy was successful in the patients with FK in our study. Patients with ulcers larger than 5 × 5 mm² and hypopyon were less likely to respond to this treatment.

Paecilomyces/Purpureocillium Infection in Children, Case Report, and Review of the Literature

Paecilomyces/Purpureocillium has recently been recognized as an emerging human pathogen, causing serious infection in immunocompromised and immunocompetent patients. Several predisposing factors have been reported, including foreign body implants, previous surgery, or trauma. Treatment with antifungal drugs often fails as species-specific differences in antifungal susceptibilities are one of the management challenges. Surgical debridement with or without antifungal therapy was sufficient to cure the infection in a few reported cases. Nonetheless, the surgical approach has been found to decrease the chance of dissemination and recurrence. Here, we report the first pediatric patient with chronic osteomyelitis of the femur secondary to Paecilomyces species, with no predisposing risk factors. Our case was successfully treated with a combination of antifungal therapy and surgical debridement. Additionally, we describe the first extensive literature review of previously reported Paecilomyces/Purpureocillium species infections in pediatric age groups.

Species Identification and In Vitro Antifungal Susceptibility of Paecilomyces/Purpureocillium Species Isolated from Clinical Respiratory Samples: A Multicenter Study

Paecilomyces spp. are emerging fungal pathogens, where Paecilomyces lilacinus and Paecilomyces variotii are the most reported species. Taxonomic and phylogenetic revisions in this genus have shown that P. variotii represents a species complex, whereas P. lilacinus is related to another genus called Purpureocillium. The aims of this study were to identify clinical isolates of Paecilomyces spp. at the species level, and to determine their antifungal susceptibility profiles. 70 clinical Paecilomyces spp. isolates were identified by MALDI-TOF Mass Spectrometry (MS) and by multilocus rDNA genes sequencing including ITS and the D1/D2 genes. Among the 70 Paecilomyces spp. isolates, 28 were identified as P. lilacinum, 26 as P. variotii stricto sensu, and 16 as P. maximus. For antifungal susceptibility testing, Minimal Inhibitory Concentrations (MICs) or Minimal Effective Concentrations (MECs) were determined for 8 antifungals. All P. lilacinum isolates had high MICs and MECs of amphotericin B and echinocandins, respectively, unlike P. variotii and P. maximus. For azole drugs, MICs were molecule- and species- dependent. The differences in in vitro susceptibility to antifungals underline the importance of accurate species identification. The MALDI–TOF MS can be a good alternative in routine laboratory to ensure fast identification of Paecilomyces spp. and P. lilacinum.

First Report of a Case of Ocular Infection Caused by Purpureocillium lilacinum in Poland

This report describes the first case of an ocular infection induced by Purpureocillium lilacinum in Poland. The patient was a 51-year-old immunocompetent contact lens user who suffered from subacute keratitis and progressive granulomatous uveitis. He underwent penetrating keratoplasty for corneal perforation, followed by cataract surgery due to rapid uveitic cataract. A few weeks later, intraocular lens removal and pars plana vitrectomy were necessary due to endophthalmitis. The patient was treated with topical, systemic, and intravitreal voriconazole with improvement; however, the visual outcome was poor. The pathogen was identified by MALDI-TOF MS.

Eye Infections Caused by Filamentous Fungi: Spectrum and Antifungal Susceptibility of the Prevailing Agents in Germany

Fungal eye infections can lead to loss of vision and blindness. The disease is most prevalent in the tropics, although case numbers in moderate climates are increasing as well. This study aimed to determine the dominating filamentous fungi causing eye infections in Germany and their antifungal susceptibility profiles in order to improve treatment, including cases with unidentified pathogenic fungi. As such, we studied all filamentous fungi isolated from the eye or associated materials that were sent to the NRZMyk between 2014 and 2020. All strains were molecularly identified and antifungal susceptibility testing according to the EUCAST protocol was performed for common species. In total, 242 strains of 66 species were received. Fusarium was the dominating genus, followed by Aspergillus, Purpureocillium, Alternaria, and Scedosporium. The most prevalent species in eye samples were Fusarium petroliphilum, F. keratoplasticum, and F. solani of the Fusarium solani species complex. The spectrum of species comprises less susceptible taxa for amphotericin B, natamycin, and azoles, including voriconazole. Natamycin is effective for most species but not for Aspergillus flavus or Purpureocillium spp. Some strains of F. solani show MICs higher than 16 mg/L. Our data underline the importance of species identification for correct treatment.

Recent developments in less known and multi-resistant fungal opportunists

Fungal infections have increased in recent years due to host factors, such as oncohaematological and transplant-related disorders, immunosuppressive therapy, and AIDS. Additionally, molecular and proteomic facilities have become available to identify previously unrecognizable opportunists. For these reasons, reports on less-known and recalcitrant mycoses, such as those caused by black fungi, hyaline filamentous fungi, coelomycetes, Mucorales, and non-Candida yeasts have emerged. In this review, novel taxonomy in these groups, which often are multi-resistant to one or several classes of antifungals, is discussed. Clinical presentations, diagnosis and current treatment of some major groups are summarised.

Invasive infections with Purpureocillium lilacinum: clinical characteristics and outcome of 101 cases from FungiScope® and the literature

OBJECTIVES

To provide a basis for clinical management decisions in Purpureocillium lilacinum infection.

METHODS

Unpublished cases of invasive P. lilacinum infection from the FungiScope® registry and all cases reported in the literature were analysed.

RESULTS

We identified 101 cases with invasive P. lilacinum infection. Main predisposing factors were haematological and oncological diseases in 31 cases (30.7%), steroid treatment in 27 cases (26.7%), solid organ transplant in 26 cases (25.7%), and diabetes mellitus in 19 cases (18.8%). The most prevalent infection sites were skin (n = 37/101, 36.6%) and lungs (n = 26/101, 25.7%). Dissemination occurred in 22 cases (21.8%). Pain and fever were the most frequent symptoms (n = 40/101, 39.6% and n = 34/101, 33.7%, respectively). Diagnosis was established by culture in 98 cases (97.0%). P. lilacinum caused breakthrough infection in 10 patients (9.9%). Clinical isolates were frequently resistant to amphotericin B, whereas posaconazole and voriconazole showed good in vitro activity. Susceptibility to echinocandins varied considerably. Systemic antifungal treatment was administered in 90 patients (89.1%). Frequently employed antifungals were voriconazole in 51 (56.7%) and itraconazole in 26 patients (28.9%). Amphotericin B treatment was significantly associated with high mortality rates (n = 13/33, 39.4%, P = <0.001). Overall mortality was 21.8% (n = 22/101) and death was attributed to P. lilacinum infection in 45.5% (n = 10/22).

CONCLUSIONS

P. lilacinum mainly presents as soft-tissue, pulmonary or disseminated infection in immunocompromised patients. Owing to intrinsic resistance, accurate species identification and susceptibility testing are vital. Outcome is better in patients treated with triazoles compared with amphotericin B formulations.

Filamentous Fungal Keratitis in Taiwan: Based on Molecular Diagnosis

Purpose

To analyze the epidemiological pattern, demographics, risk factors, and treatment outcomes of filamentous fungal keratitis at a tertiary hospital in Taiwan.

Methods

We recruited 65 patients (65 eyes) with culture-proven filamentous fungal keratitis who received diagnosis and treatment at Chang Gung Memorial Hospital between 2015 and 2018. All isolates were examined through conventional morphological identification and subjected to molecular identification with internal transcribed spacer sequencing. Data on patient demographics, predisposing factors, and treatment outcomes were collected.

Results

In total, filamentous fungi belonged to 16 genera were identified. Fusarium spp. (29 cases [44.6%]) was the most commonly isolated organism overall, followed by Colletotrichum spp. and Purpureocillium linacinum (seven cases [10.8% for each]), and Aspergillus spp. (six cases [9.2%]). Some fungi that have not been regarded as human pathogens were also identified, such as Paracremonium and Phellinum. Among 52 (80%) patients with predisposing factors, 30 (46.2%) had trauma. The ulcers of 33 (50.8%) patients resolved with medical treatment only. Additionally, six patients (9.2%) had corneal perforation, and nine patients (13.9%) required therapeutic/destructive surgical interventions including therapeutic penetrating keratoplasty (seven patients) or evisceration (two patients). Only 16 patients (24.6%) had final visual acuity of 20/40 or better.

Conclusions

Through molecular diagnosis, a high diversity of fungal pathogens was revealed along with an increasing incidence of Colletotrichumspp. and Purpureocilliumspp. in Taiwan. The most common risk factor for filamentous fungal keratitis was trauma. The visual outcomes were guarded.

Translational Relevance

The molecular diagnosis provides insight into accurate identification, which affects the epidemiology and diversity of pathogens of filamentous fungal keratitis.