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1.
Microbiol Spectr ; 10(1): e0116921, 2022 02 23.
Article in English | MEDLINE | ID: mdl-35019692

ABSTRACT

Seborrheic dermatitis (SD) is a common, chronic, and relapsing skin disease. The roles of Malassezia spp. in the pathogenesis of SD are still not clear due to the lack of direct evidence for the existence of hyphae within affected skin tissues. We set out to elucidate if Malassezia mycelium contributes to the onset and development of SD and if Malassezia mycelium is correlated with the clinical severity of SD patients. We detected Malassezia hyphae in patients with SD using potassium hydroxide (KOH) and calcofluor white (CFW) staining. Fluorescent microscopy was performed for the analysis of fungal cell wall and morphological characteristics of Malassezia under CFW staining. Culture growth in modified Dixon agar was used for DNA extraction and sequencing, and Malassezia species were confirmed by a sequencing data BLAST search against the NCBI database. We demonstrated that Malassezia hyphae were positively correlated with the clinical severity of SD patients (P = 3.1738 × 10-11). All the patients responded well to antifungal treatment. There is no significant difference for species dominance across the variant groups. However, the exact molecular mechanisms of how Malassezia spp. affect SD need to be further explored. The results show that Malassezia spp. in the hyphal stage are restricted to SD patients compared with healthy controls, suggesting that the presence of Malassezia hyphae contributes to the pathogenesis of SD. The results highlight the importance of the antifungal therapy for the future treatment of SD patients. IMPORTANCE Our results support the proposal that the hyphal form of Malassezia could be one of the pathogenic factors that contribute to SD, which has been previously less well studied. This clinical observation paves the way for further investigations of the molecular mechanisms of Malassezia hyphal pathogenicity in SD.


Subject(s)
Dermatitis, Seborrheic/microbiology , Dermatomycoses/microbiology , Hyphae/growth & development , Malassezia/isolation & purification , Adult , Antifungal Agents/therapeutic use , Dermatitis, Seborrheic/drug therapy , Dermatomycoses/drug therapy , Female , Humans , Hyphae/drug effects , Hyphae/genetics , Hyphae/isolation & purification , Malassezia/drug effects , Malassezia/genetics , Malassezia/growth & development , Male , Middle Aged , Skin/microbiology
2.
Molecules ; 26(15)2021 Jul 29.
Article in English | MEDLINE | ID: mdl-34361746

ABSTRACT

New agricultural strategies aim to reduce the use of pesticides due to their damage to the environment and humans, and the caused resistance to pathogens. Therefore, alternative sources of antifungal compounds from plants are under investigation lately. Extracts from plants have a wide composition of chemical compounds which may complicate the development of pathogen resistance. Botrytis cinerea, causing grey mould, is an important horticultural and ornamental pathogen, responsible for the relevant yield and quality losses. B. cinerea isolated from a different plant host may differ in the sensitivity to antifungal substances from plants. Assessing the importance of research covering a wide range of pathogens for the rapid development of biopesticides, this study aims to determine the sensitivity of the B. cinerea isolate complex (10 strains) to plant extracts, describe morphological changes caused by the extract treatment, and detect differences between the sensitivity of different plant host isolates. The results showed the highest sensitivity of the B. cinerea isolates complex to cinnamon extract, and the lowest to laurel extract. In contrast, laurel extract caused the most changes of morphological attributes in the isolates. Five B. cinerea isolates from plant hosts of raspberry, cabbage, apple, bell pepper, and rose were grouped statistically according to their sensitivity to laurel extract. Meanwhile, the bell pepper isolate separated from the isolate complex based on its sensitivity to clove extract, and the strawberry and apple isolates based on their sensitivity to cinnamon extract.


Subject(s)
Antifungal Agents/pharmacology , Biological Control Agents/pharmacology , Botrytis/drug effects , Cinnamomum zeylanicum/chemistry , Hyphae/drug effects , Plant Diseases/prevention & control , Antifungal Agents/isolation & purification , Biological Control Agents/isolation & purification , Botrytis/growth & development , Botrytis/isolation & purification , Brassica/microbiology , Capsicum/microbiology , Cinnamomum camphora/chemistry , Fragaria/microbiology , Humans , Hyphae/growth & development , Hyphae/isolation & purification , Malus/microbiology , Microbial Sensitivity Tests , Plant Diseases/microbiology , Plant Extracts/chemistry , Syzygium/chemistry , Vitis/microbiology
3.
Mycoses ; 64(6): 583-602, 2021 Jun.
Article in English | MEDLINE | ID: mdl-33529414

ABSTRACT

Approximately 70-75% of women will have vulvovaginal candidosis (VVC) at least once in their lifetime. In premenopausal, pregnant, asymptomatic and healthy women and women with acute VVC, Candida albicans is the predominant species. The diagnosis of VVC should be based on clinical symptoms and microscopic detection of pseudohyphae. Symptoms alone do not allow reliable differentiation of the causes of vaginitis. In recurrent or complicated cases, diagnostics should involve fungal culture with species identification. Serological determination of antibody titres has no role in VVC. Before the induction of therapy, VVC should always be medically confirmed. Acute VVC can be treated with local imidazoles, polyenes or ciclopirox olamine, using vaginal tablets, ovules or creams. Triazoles can also be prescribed orally, together with antifungal creams, for the treatment of the vulva. Commonly available antimycotics are generally well tolerated, and the different regimens show similarly good results. Antiseptics are potentially effective but act against the physiological vaginal flora. Neither a woman with asymptomatic colonisation nor an asymptomatic sexual partner should be treated. Women with chronic recurrent Candida albicans vulvovaginitis should undergo dose-reducing maintenance therapy with oral triazoles. Unnecessary antimycotic therapies should always be avoided, and non-albicans vaginitis should be treated with alternative antifungal agents. In the last 6 weeks of pregnancy, women should receive antifungal treatment to reduce the risk of vertical transmission, oral thrush and diaper dermatitis of the newborn. Local treatment is preferred during pregnancy.


Subject(s)
Candidiasis, Vulvovaginal , Anti-Bacterial Agents/adverse effects , Antifungal Agents/therapeutic use , Candida albicans/drug effects , Candida albicans/isolation & purification , Candida glabrata/drug effects , Candida glabrata/isolation & purification , Candidiasis, Vulvovaginal/diagnosis , Candidiasis, Vulvovaginal/microbiology , Candidiasis, Vulvovaginal/therapy , Causality , Ciclopirox/administration & dosage , Ciclopirox/therapeutic use , Contraceptive Agents/administration & dosage , Contraceptive Agents/adverse effects , Diabetes Mellitus , Female , Hormones/adverse effects , Humans , Hyphae/isolation & purification , Imidazoles/administration & dosage , Imidazoles/therapeutic use , Infant, Newborn , Polyenes/administration & dosage , Polyenes/therapeutic use , Pregnancy , Vaginitis/diagnosis
4.
Methods Appl Fluoresc ; 9(2): 025004, 2021 Mar 02.
Article in English | MEDLINE | ID: mdl-33601341

ABSTRACT

Rapid and direct observation of fungal spores or hyphae in clinical liquid specimens poses a challenge for the diagnosis of invasive fungal infection. To allow rapid detection of fungal pathogens, we designed a new method of fungal cell detection involving double fluorescence staining with calcium fluorescent white (CFW) and SYTOX green combined with single-cell real-time imaging flow cytometry (IFC). IFC allowed quick detection and analysis of detailed morphology of the spores and pseudohyphae of Candida albicans, and small hyphae and typical truncated large mycelia of Aspergillus fumigatus. Further, cell sorting based on fluorescence, the width-to-height ratio and bright-field parameters preferentially identified spores or hyphae with a typical cell wall. The specificity and overall coincidence rate of IFC for fungi detection in common clinical samples were 100% and 98.18%, respectively. Moreover, the detection rate by IFC (102/105, 97.14%) was significantly higher (P = 0.002) than that by wet mount method (89/105, 84.5%). Therefore, IFC is a reliable diagnostic method with a high potential for application for rapid diagnosis of fungal infection in the clinic.


Subject(s)
Aspergillus fumigatus/isolation & purification , Body Fluids/microbiology , Candida albicans/isolation & purification , Flow Cytometry/methods , Fluorescent Dyes/chemistry , Humans , Hyphae/isolation & purification , Microscopy, Fluorescence , Mycelium/isolation & purification , Organic Chemicals/chemistry
5.
Am J Dermatopathol ; 43(7): 489-492, 2021 Jul 01.
Article in English | MEDLINE | ID: mdl-33481375

ABSTRACT

ABSTRACT: Epidermal barrier disruption caused by atypical squamous proliferations of the lip (SOL) creates an ideal environment for fungal growth. Histologic features of SOL include parakeratosis overlying partial- or full-thickness keratinocyte atypia with or without invasion of the dermis, dermal solar elastosis, and scattered inflammatory cells which are predominantly lymphocytes. Histologic features of SOL with fungal superinfections overlap those seen in primary fungal cheilitis with reactive atypia, creating a diagnostic challenge. One-hundred seventy SOL cases were examined for the presence of fungal elements, and the histological features associated with superinfection were identified. Cases diagnosed as actinic cheilitis with fungal superinfection were carefully examined to rule out the possibility of misdiagnosed primary fungal cheilitis with reactive atypia. Histopathological characteristics commonly present with fungal hyphae included intraepidermal or intradermal neutrophils, bacterial colonies, and erosion or ulceration. Medical record review of those patients treated conservatively with topical antifungals revealed persistent clinical neoplasm and histological evidence of residual SOL on repeat biopsy. Thus, when biopsies exhibit histological overlap between these 2 entities, clinicians should keep a high index of suspicion for underlying SOL and carefully follow these patients if conservative antifungal therapy is initially trialed.


Subject(s)
Cell Proliferation , Cheilitis/pathology , Fungi/pathogenicity , Hyphae/pathogenicity , Lip Neoplasms/pathology , Mycoses/pathology , Precancerous Conditions/pathology , Adult , Aged , Aged, 80 and over , Antifungal Agents/therapeutic use , Biopsy , Cheilitis/drug therapy , Cheilitis/microbiology , Diagnosis, Differential , Female , Fungi/isolation & purification , Host-Pathogen Interactions , Humans , Hyphae/isolation & purification , Lip Neoplasms/drug therapy , Lip Neoplasms/microbiology , Male , Middle Aged , Mycoses/drug therapy , Mycoses/microbiology , Precancerous Conditions/drug therapy , Precancerous Conditions/microbiology , Predictive Value of Tests , Treatment Outcome
6.
BMJ Case Rep ; 14(1)2021 Jan 11.
Article in English | MEDLINE | ID: mdl-33431445

ABSTRACT

A 42-year-old woman presented with fever, left ear pain, restricted mouth opening, difficulty in swallowing and inability to open her left eyelid for a period of 10 days. She was treated with antibiotics for the same at a local medical facility; however, a sudden decrease in her left eye vision prompted her to visit our tertiary centre. Her history was insignificant except for having multiple left ear syringing for an insect removal 10 days before onset of her current symptoms. On examination, she had ptosis of the left eye with chemosis, dilated pupil with only perception of light and restricted ocular mobility. Oral examination revealed trismus and bulge in the left peritonsillar region. Left ear examination revealed a large central perforation with mucopurulent discharge. CT of the neck with contrast demonstrated a collection in the left peritonsillar space with left internal carotid artery thrombosis. MRI of the brain with gadolinium revealed left cavernous sinus thrombosis with acute infarcts in the left frontal lobe. An emergency incision and drainage of the left peritonsillar abscess was performed. Culture grew broad aseptate fungal hyphae. Despite starting on antifungal therapy, she succumbed to her illness.


Subject(s)
Cavernous Sinus Thrombosis/diagnosis , Eye Foreign Bodies/complications , Mucormycosis/diagnosis , Osteomyelitis/diagnosis , Skull Base/microbiology , Adult , Amphotericin B/therapeutic use , Animals , Cavernous Sinus/diagnostic imaging , Cavernous Sinus Thrombosis/drug therapy , Cavernous Sinus Thrombosis/etiology , Coleoptera/microbiology , Drainage , Drug Therapy, Combination , Enoxaparin/therapeutic use , Eye Foreign Bodies/diagnosis , Eye Foreign Bodies/microbiology , Eye Foreign Bodies/therapy , Fatal Outcome , Female , Humans , Hyphae/isolation & purification , Magnetic Resonance Imaging , Meropenem/therapeutic use , Mucorales/isolation & purification , Mucormycosis/microbiology , Mucormycosis/therapy , Osteomyelitis/microbiology , Osteomyelitis/therapy , Skull Base/diagnostic imaging , Skull Base/pathology , Skull Base/surgery , Vancomycin/therapeutic use
7.
BMJ Case Rep ; 13(9)2020 Sep 13.
Article in English | MEDLINE | ID: mdl-32928823

ABSTRACT

We describe an elderly diabetic patient presenting with sudden onset right-sided proptosis and vision loss secondary to rhino-orbital mucormycosis and central retinal vascular occlusion. He underwent orbital exenteration that was complicated by intraoperative cerebrospinal fluid (CSF) leak from lateral orbital wall. The leak was surgically repaired and the patient recovered well. We postulate the cause of the CSF leak to be twofold: necrotic periorbital tissue due to mucormycosis rendering the thin bones susceptible to damage and second, intraoperative manipulation and dissection at the orbital apex with monopolar cautery and instruments. We describe measures taken to successfully repair the CSF leak and the possible precautions that can be taken to avoid it.


Subject(s)
Cerebrospinal Fluid Leak/etiology , Intraoperative Complications/etiology , Mucormycosis/therapy , Orbit Evisceration/adverse effects , Orbital Diseases/therapy , Sinusitis/therapy , Administration, Intravenous , Amphotericin B/administration & dosage , Antifungal Agents/administration & dosage , Blepharoptosis/microbiology , Blindness/microbiology , Cerebrospinal Fluid Leak/diagnosis , Cerebrospinal Fluid Leak/surgery , Debridement , Diabetes Mellitus, Type 2/immunology , Endoscopy , Humans , Hyphae/isolation & purification , Intraoperative Complications/diagnosis , Intraoperative Complications/surgery , Magnetic Resonance Angiography , Male , Middle Aged , Mucormycosis/complications , Mucormycosis/immunology , Mucormycosis/microbiology , Orbit/diagnostic imaging , Orbit/microbiology , Orbit/surgery , Orbital Diseases/complications , Orbital Diseases/diagnosis , Orbital Diseases/microbiology , Paranasal Sinuses/diagnostic imaging , Paranasal Sinuses/microbiology , Paranasal Sinuses/surgery , Retinal Artery Occlusion/diagnosis , Retinal Artery Occlusion/microbiology , Sinusitis/complications , Sinusitis/immunology , Sinusitis/microbiology , Treatment Outcome
8.
BMC Infect Dis ; 20(1): 527, 2020 Jul 22.
Article in English | MEDLINE | ID: mdl-32698804

ABSTRACT

BACKGROUND: Conidiobolus spp. (mainly C. coronatus) are the causal agents of rhino-facial conidiobolomycosis, a limited soft tissue infection, which is essentially observed in immunocompetent individuals from tropical areas. Rare cases of invasive conidiobolomycosis due to C. coronatus or other species (C.incongruus, C.lamprauges) have been reported in immunocompromised patients. We report here the first case of invasive pulmonary fungal infection due to Conidiobolus pachyzygosporus in a Swiss patient with onco-haematologic malignancy. CASE PRESENTATION: A 71 year-old female was admitted in a Swiss hospital for induction chemotherapy of acute myeloid leukemia. A chest CT performed during the neutropenic phase identified three well-circumscribed lung lesions consistent with invasive fungal infection, along with a positive 1,3-beta-d-glucan assay in serum. A transbronchial biopsy of the lung lesions revealed large occasionally septate hyphae. A Conidiobolus spp. was detected by direct 18S rDNA in the tissue biopsy and subsequently identified at species level as C. pachyzygosporus by 28S rDNA sequencing. The infection was cured after isavuconazole therapy, recovery of the immune system and surgical resection of lung lesions. CONCLUSIONS: This is the first description of C. pachyzygosporus as human pathogen and second case report of invasive conidiobolomycosis from a European country.


Subject(s)
Conidiobolus/genetics , Leukemia, Myeloid, Acute/complications , Lung Diseases, Fungal/complications , Lung Diseases, Fungal/diagnosis , Zygomycosis/complications , Zygomycosis/diagnosis , Aged , Antifungal Agents/therapeutic use , Biopsy , Conidiobolus/isolation & purification , DNA, Fungal/genetics , DNA, Ribosomal/genetics , Female , Humans , Hyphae/isolation & purification , Immunocompromised Host , Lung Diseases, Fungal/drug therapy , Lung Diseases, Fungal/pathology , Nitriles/therapeutic use , Pyridines/therapeutic use , Switzerland , Tomography, X-Ray Computed , Treatment Outcome , Triazoles/therapeutic use , Zygomycosis/drug therapy , Zygomycosis/pathology
9.
J Int Med Res ; 48(5): 300060520918469, 2020 May.
Article in English | MEDLINE | ID: mdl-32431185

ABSTRACT

Acute mediastinitis (AM) is a rare but life-threatening disease. Here, we report a case of AM secondary to endobronchial tuberculosis (EBTB) and pseudomembranous Aspergillus tracheobronchitis (PMATB) co-infection. EBTB was confirmed by tissue culture for Mycobacterium tuberculosis and GeneXpert MTB/RIF (Cepheid, Sunnyvale, CA, USA) detection (simultaneous detection of M. tuberculosis and resistance to rifampin) using endobronchial biopsies; PMATB was confirmed by histopathology. Even with antibiotic treatment and systemic support treatment, the patient died of massive hemoptysis on day 10 after admission. When immunocompromised hosts have AM, especially with central airway involvement, EBTB and aspergillosis should be considered potential causes. Bronchoscopy is helpful for rapid diagnosis and administering precise treatment.


Subject(s)
Aspergillosis/complications , Coinfection/complications , Diabetes Complications/complications , Mediastinitis/microbiology , Tuberculosis, Pulmonary/complications , Anti-Bacterial Agents/therapeutic use , Antifungal Agents/therapeutic use , Antitubercular Agents/therapeutic use , Aspergillosis/diagnosis , Aspergillosis/immunology , Aspergillosis/microbiology , Aspergillus/immunology , Aspergillus/isolation & purification , Bronchi/diagnostic imaging , Bronchi/microbiology , Bronchi/pathology , Bronchoscopy , Coinfection/diagnosis , Coinfection/immunology , Coinfection/microbiology , Diabetes Complications/diagnosis , Diabetes Complications/immunology , Diabetes Complications/microbiology , Fatal Outcome , Female , Humans , Hyphae/isolation & purification , Immunocompromised Host , Mediastinitis/diagnosis , Mediastinitis/drug therapy , Mediastinitis/etiology , Mediastinum/diagnostic imaging , Middle Aged , Mycobacterium tuberculosis/immunology , Mycobacterium tuberculosis/isolation & purification , Sputum/microbiology , Tomography, X-Ray Computed , Tuberculosis, Pulmonary/diagnosis , Tuberculosis, Pulmonary/immunology , Tuberculosis, Pulmonary/microbiology
10.
Methods Mol Biol ; 2146: 53-59, 2020.
Article in English | MEDLINE | ID: mdl-32415595

ABSTRACT

The colonization of a host plant root by arbuscular mycorrhizal (AM) fungi is a progressive process, characterized by asynchronous hyphal growth in intercellular and intracellular spaces, leading to the coexistence of diverse intraradical structures, such as hyphae, coils, arbuscules, and vesicles. In addition, the relative abundance of intercellular and intracellular fungal structures is highly dependent on root anatomy and the combination of plant and fungal species. Lastly, more than one fungal species may colonize the same root, adding a further level of complexity. For all these reasons, detailed imaging of a large number of samples is often necessary to fully assess the developmental processes and functionality of AM symbiosis. To this aim, the use of rapid and efficient staining methods that can be used routinely is crucial.We herein present a simple protocol to obtain high detail images of both overall intraradical fungal colonization pattern and fine morphology, in AM root sections of Lotus japonicus. The procedure is based on tissue clearing, fluorescent staining of fungal cell walls with fluorescein isothiocyanate-conjugated wheat germ agglutinin (FITC-WGA), and the combined counterstaining of plant cell walls with propidium iodide (PI). The resulting images can be acquired using traditional or confocal fluorescence microscopes and used for qualitative and quantitative analyses of fungal colonization, of particular interest for the comparison of mycorrhizal phenotypes between different experimental conditions or genetic backgrounds.


Subject(s)
Mycorrhizae/isolation & purification , Propidium/pharmacology , Staining and Labeling/methods , Wheat Germ Agglutinins/pharmacology , Fluorescence , Gene Expression Regulation, Plant/drug effects , Hyphae/genetics , Hyphae/isolation & purification , Lotus/microbiology , Lotus/ultrastructure , Mycorrhizae/ultrastructure , Plant Roots/microbiology , Plant Roots/ultrastructure , Symbiosis
12.
J Am Acad Dermatol ; 83(2): 455-462, 2020 Aug.
Article in English | MEDLINE | ID: mdl-31931081

ABSTRACT

BACKGROUND: Deep cutaneous fungal infections (DCFIs) are varied in immunosuppressed patients, with few data for such infections in solid-organ transplant recipients (s-OTRs). OBJECTIVE: To determine DCFI diagnostic characteristics and outcome with treatments in s-OTRs. METHODS: A 20-year retrospective observational study in France was conducted in 8 primary dermatology-dedicated centers for s-OTRs diagnosed with DCFIs. Relevant clinical data on transplants, fungal species, treatments, and outcomes were analyzed. RESULTS: Overall, 46 s-OTRs developed DCFIs (median delay, 13 months after transplant) with predominant phaeohyphomycoses (46%). Distribution of nodular lesions on limbs and granulomatous findings on histopathology were helpful diagnostic clues. Treatments received were systemic antifungal therapies (48%), systemic antifungal therapies combined with surgery (28%), surgery alone (15%), and modulation of immunosuppression (61%), leading to complete response in 63% of s-OTRs. LIMITATIONS: Due to the retrospective observational design of the study. CONCLUSIONS: Phaeohyphomycoses are the most common DCFIs in s-OTRs. Multidisciplinary teams are helpful for optimal diagnosis and management.


Subject(s)
Dermatomycoses/epidemiology , Immunocompromised Host , Organ Transplantation/adverse effects , Phaeohyphomycosis/epidemiology , Transplant Recipients/statistics & numerical data , Adolescent , Adult , Aged , Antifungal Agents/therapeutic use , Dermatologic Surgical Procedures , Dermatomycoses/immunology , Dermatomycoses/microbiology , Dermatomycoses/therapy , Female , Graft Rejection/immunology , Graft Rejection/prevention & control , Humans , Hyphae/isolation & purification , Immunosuppressive Agents/adverse effects , Male , Middle Aged , Phaeohyphomycosis/immunology , Phaeohyphomycosis/microbiology , Phaeohyphomycosis/therapy , Prevalence , Retrospective Studies , Skin/immunology , Skin/microbiology , Young Adult
13.
Mycopathologia ; 185(2): 389-394, 2020 Apr.
Article in English | MEDLINE | ID: mdl-31915988

ABSTRACT

A case of fungal keratitis due to Coprinellus radians is reported. To our knowledge, fungal keratitis caused by this species was rare. Fungal hyphae were detected in corneal scrapings, and isolates were identified by morphology and by sequencing the internal transcribed spacer region of ribosomal DNA. The patient was treated with systemic and local antifungal therapy for 5 days, and lamellar keratoplasty was performed after no obvious improvement in symptoms. The in vitro antifungal susceptibilities of the case strain were tested for six antifungal agents. The results showed that 5-fluorouracil was resistant, fluconazole was moderately sensitive, and the other drugs assayed (amphotericin B, posaconazole, itraconazole and voriconazole) were highly effective against this fungus.


Subject(s)
Agaricales , Antifungal Agents/therapeutic use , Keratitis , Agaricales/cytology , Agaricales/genetics , Agaricales/isolation & purification , Amphotericin B/therapeutic use , Corneal Transplantation , Corneal Ulcer/drug therapy , Corneal Ulcer/surgery , DNA, Fungal , DNA, Ribosomal Spacer , Eye Infections, Fungal/pathology , Female , Humans , Hyphae/isolation & purification , Keratitis/drug therapy , Keratitis/microbiology , Keratitis/pathology , Microbial Sensitivity Tests , Middle Aged , Triazoles/therapeutic use
15.
Sci Rep ; 9(1): 18013, 2019 11 29.
Article in English | MEDLINE | ID: mdl-31784693

ABSTRACT

Saprolegniosis is a worldwide fungal-like infection affecting freshwater fishes and their eggs. Reports show high mortalities and subsequent economic losses annually from Saprolegnia infections. Most therapeutants against Saprolegnia spp. infections are inefficient and some have negative impact on the environment. In this study, we have investigated the ability of boric acid (BA) to prevent Saprolegnia infection in Nile tilapia (Oreochromis niloticus). BA inhibited radial growth of Saprolegnia hyphae in vitro. Complete in vitro growth inhibition was found at a concentration of ≥0.6 g/L. Inhibitory effects were also observed in vivo when Nile tilapia were experimentally challenged with Saprolegnia spores and followed over 10 days post challenge and under continuous exposure to different BA concentrations. No signs of saprolegniosis were observed in fish treated with BA at concentrations of 0.4 g/L and above. Comet assay revealed that BA has low toxicity in tilapia continuously exposed to concentrations of 0.2-0.6 g/L for 96 h. Additionally, no significant histomorphological changes were observed in BA-treated fish compared to non-treated controls. Alanine Aminotransferase (ALT) and Aspartate Aminotransferase (AST) enzyme levels indicated reduction in systemic tissue damage associated with Saprolegnia infection. This study demonstrates the potential of BA as a prophylactic measure against Saprolegnia infection in tilapia, and we recommend additional studies on environmental impact.


Subject(s)
Boric Acids/administration & dosage , Cichlids/microbiology , Fish Diseases/prevention & control , Saprolegnia/drug effects , Animals , Boric Acids/adverse effects , Fish Diseases/microbiology , Fisheries , Fresh Water , Hyphae/drug effects , Hyphae/isolation & purification , Saprolegnia/isolation & purification
16.
J Basic Microbiol ; 59(11): 1092-1104, 2019 Nov.
Article in English | MEDLINE | ID: mdl-31613011

ABSTRACT

Melanins are one of the great natural pigments produced by a wide variety of fungal species that promote fitness and cell survival in diverse hostile environments, including during mammalian infection. In this study, we sought to demonstrate the production of melanin in the conidia and hyphae of saprophytic fungi, including dematiaceous and hyaline fungi. We showed that a melanin-specific monoclonal antibody (MAb) avidly labeled the cell walls of hyphae and conidia, consistent with the presence of melanin in these structures, in 14 diverse fungal species. The conidia of saprophytic fungi were treated with proteolytic enzymes, denaturant, and concentrated hot acid to yield dark particles, which were shown to be stable free radicals, consistent with their identification as melanins. Samples obtained from patients with fungal keratitis due to Fusarium falciforme, Aspergillus fumigatus, Aspergillus flavus, Curvularia lunata, Exserohilum rostratum, or Fonsecaea pedrosoi were found to be intensely labeled by the melanin-specific MAb at the fungal hyphal cell walls. These results support the hypothesis that melanin is a common component that promotes survival under harsh conditions and facilitates fungal virulence. Increased understanding of the processes of melanization and the development of methods to interfere with pigment formation may lead to novel approaches to combat these complex pathogens that are associated with high rates of morbidity and mortality.


Subject(s)
Fungi/metabolism , Melanins/biosynthesis , Mycoses/microbiology , Antibodies, Monoclonal/immunology , Cell Wall/metabolism , Fungi/isolation & purification , Humans , Hyphae/isolation & purification , Hyphae/metabolism , Keratitis/microbiology , Melanins/immunology , Spores, Fungal/isolation & purification , Spores, Fungal/metabolism
18.
Virol Sin ; 34(6): 688-700, 2019 Dec.
Article in English | MEDLINE | ID: mdl-31376081

ABSTRACT

Mycoviruses have been found to infect more than 12 species of Penicillium, but have not been isolated from Penicillium italicum (P. italicum). In this study, we isolated and characterized a new double-stranded RNA (dsRNA) virus, designated Penicillium italicum chrysovirus 1 (PiCV1), from the citrus pathogen P. italicum HSPi-YN1. Viral genome sequencing and molecular characterization indicated that PiCV1 was highly homologous to the previously described Penicillium chrysogenum virus. We further constructed the mutant HSPi-YN1ΔpksP defective in the polyketide synthase gene (pksP), which is involved in pigment biosynthesis, and these mutants formed albino (white) colonies. Then we applied hyphal anastomosis method to horizontally transmit PiCV1 from the white virus-donors (i.e., HSPi-YN1 mutants) to wild-type recipients (i.e., P. italicum strains HSPi-CQ54, HSPi-HB4, and HSPi-HN1), and the desirable PiCV1-infected isogenic recipients, a certain part of blue wild-type strains, can be eventually selected and confirmed by viral genomic dsRNA profile analysis. This blue-white colony screening would be an easier method to select virus-infected P. italicum recipients, according to distinguishable color phenotypes between blue virus-recipients and white virus-donors. In summary, the current work newly isolated and characterized PiCV1, verified its horizontal transmission among dually cultured P. italicum isolates, and based on these, established an effective and simplified approach to screen PiCV1-infected isogenic recipients.


Subject(s)
Fungal Viruses/physiology , Penicillium/isolation & purification , Penicillium/virology , Citrus/microbiology , Fungal Proteins/genetics , Fungal Viruses/classification , Fungal Viruses/genetics , Fungal Viruses/ultrastructure , Genome, Viral/genetics , Genotype , Hyphae/classification , Hyphae/genetics , Hyphae/isolation & purification , Hyphae/virology , Mutation , Penicillium/classification , Penicillium/genetics , Phenotype , Phylogeny , Pigmentation , Plant Diseases/microbiology , Polyketide Synthases/genetics , RNA, Double-Stranded , Viral Proteins/genetics
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