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1.
Invest Ophthalmol Vis Sci ; 65(6): 13, 2024 Jun 03.
Artigo em Inglês | MEDLINE | ID: mdl-38848078

RESUMO

Purpose: Fungal keratitis (FK) is an invasive corneal infection associated with significant risk to vision. Although the cyclic GMP-AMP synthase (cGAS)/stimulator of interferon genes (STING) signaling pathway has been recognized for its role in defending against viral infections, its involvement in FK still remains largely unclear. This study sought to elucidate the contribution of the cGAS/STING signaling pathway to the pathogenesis of FK. Methods: The expression of cGAS/STING signaling components was assessed in a murine model of Candida albicans keratitis through RNA sequencing, western blot analysis, immunofluorescence staining, and real-time PCR. Both genetic (utilizing Sting1gt/gt mice) and pharmacological (using C176) interventions were employed to inhibit STING activity, allowing for the evaluation of resultant pathogenic alterations in FK using slit-lamp examination, clinical scoring, hematoxylin and eosin (H&E) staining, fungal culture, and RNA sequencing. Subconjunctival administration of the NOD-like receptor protein 3 (NLRP3) inflammasome inhibitor MCC950 was performed to evaluate FK manifestations following STING activity blockade. Furthermore, the impact of the STING agonist diABZI on FK progression was investigated. Results: Compared to uninfected corneas, those infected with C. albicans exhibited increased expression of cGAS/STING signaling components, as well as its elevated activity. Inhibiting cGAS/STING signaling exacerbated the advancement of FK, as evidenced by elevated clinical scores, augmented fungal load, and heightened inflammatory response, including NLRP3 inflammasome activation and pyroptosis. Pharmacological inhibition of the NLRP3 inflammasome effectively mitigated the exacerbated FK by suppressing STING activity. Conversely, pre-activation of STING exacerbated FK progression compared to the PBS control, characterized by increased fungal burden and reinforced inflammatory infiltration. Conclusions: This study demonstrates the essential role of the cGAS/STING signaling pathway in FK pathogenesis and highlights the necessity of its proper activation for the host against FK.


Assuntos
Candida albicans , Candidíase , Modelos Animais de Doenças , Infecções Oculares Fúngicas , Proteínas de Membrana , Nucleotidiltransferases , Transdução de Sinais , Animais , Proteínas de Membrana/metabolismo , Proteínas de Membrana/genética , Nucleotidiltransferases/metabolismo , Nucleotidiltransferases/genética , Infecções Oculares Fúngicas/microbiologia , Infecções Oculares Fúngicas/metabolismo , Camundongos , Candida albicans/fisiologia , Candidíase/microbiologia , Candidíase/metabolismo , Camundongos Endogâmicos C57BL , Reação em Cadeia da Polimerase em Tempo Real , Ceratite/microbiologia , Ceratite/metabolismo , Western Blotting , Proteína 3 que Contém Domínio de Pirina da Família NLR/metabolismo , Proteína 3 que Contém Domínio de Pirina da Família NLR/genética , Feminino , Úlcera da Córnea/microbiologia , Úlcera da Córnea/metabolismo , Inflamassomos/metabolismo
3.
Int Ophthalmol ; 44(1): 230, 2024 May 28.
Artigo em Inglês | MEDLINE | ID: mdl-38805103

RESUMO

PURPOSE: The present study aimed to epidemiologically evaluate patients with infectious keratitis following corneal transplantation. METHODS: This retrospective study analyzed medical records of patients who underwent keratoplasty from March 2014 to March 2022 at a tertiary center. A total of seventy-five patients were evaluated. The data were classified based on culture results, the type of microorganisms involved, treatment requirements, and the type of primary keratoplasty performed. RESULTS: Seventy-five patients were evaluated in this study, with a mean age of 45.9 years (22-95 years). The mean duration between the first surgery and the incidence of infectious keratitis was 1.43 years, and most cases occurred in the first year (56.2%). Bacterial and fungal keratitis in 2.17%, 1.39%, and 1.26% of cases undergoing penetrating keratoplasty (PK), endothelial keratoplasty (EK), and anterior lamellar keratoplasty (ALK) occurred, respectively. Streptococcus viridans (9.3%) and Staphylococcus aureus (6.6%) had the highest prevalence. Across various smear and culture results (gram-positive, gram-negative, fungal, and negative culture), no significant differences were found in endophthalmitis rates (P = 0.797) and the necessity for tectonic grafts (P = 0.790). Similarly, the choice of surgical method (PK, ALK, EK) showed no significant impact on the need for tectonic grafts (P = 0.45) or the rate of endophthalmitis (P = 0.55). CONCLUSIONS: The incidence of keratitis after a corneal graft was 1.7%, with Streptococcus viridans and Staphylococcus aureus the most common microorganisms. The rate of endophthalmitis associated with post-keratoplasty keratitis was 0.053%. There was no correlation between the necessity for a tectonic graft or the incidence of endophthalmitis and the type of microorganisms involved.


Assuntos
Transplante de Córnea , Infecções Oculares Bacterianas , Infecções Oculares Fúngicas , Ceratite , Centros de Atenção Terciária , Humanos , Estudos Retrospectivos , Pessoa de Meia-Idade , Feminino , Masculino , Adulto , Idoso , Infecções Oculares Bacterianas/epidemiologia , Infecções Oculares Bacterianas/microbiologia , Infecções Oculares Bacterianas/etiologia , Infecções Oculares Bacterianas/diagnóstico , Centros de Atenção Terciária/estatística & dados numéricos , Adulto Jovem , Idoso de 80 Anos ou mais , Incidência , Ceratite/epidemiologia , Ceratite/microbiologia , Ceratite/diagnóstico , Ceratite/etiologia , Transplante de Córnea/efeitos adversos , Infecções Oculares Fúngicas/epidemiologia , Infecções Oculares Fúngicas/microbiologia , Infecções Oculares Fúngicas/diagnóstico , Infecções Oculares Fúngicas/etiologia , Bactérias/isolamento & purificação , Complicações Pós-Operatórias/epidemiologia
4.
Mycoses ; 67(5): e13728, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38695201

RESUMO

BACKGROUND: Fungal keratitis is a severe eye infection that can result in blindness and visual impairment, particularly in developing countries. Fusarium spp. are the primary causative agents of this condition. Diagnosis of Fusarium keratitis (FK) is challenging, and delayed treatment can lead to serious complications. However, there is limited epidemiological data on FK, especially in tropical areas. OBJECTIVES: This study aimed to describe the clinical, laboratorial and epidemiological characteristics of FK in a tropical semi-arid region of Brazil. PATIENTS/METHODS: Adult patients with laboratory-confirmed FK diagnosed between October 2019 and March 2022 were evaluated. Fusarium isolates were characterized at molecular level and evaluated regarding antifungal susceptibility. RESULTS: A total of 226 clinical samples from patients suspected of keratitis were evaluated; fungal growth was detected in 50 samples (22.12%); out of which 42 were suggestive of Fusarium spp. (84%). Molecular analysis of a randomly selected set of 27 isolates identified F. solani species complex (n = 14); F. fujikuroi sensu lato (n = 6) and F. dimerum sensu lato (n = 7); a total of 10 haplotypes were identified among the strains. All but one Fusarium strains were inhibited by amphotericin B, natamycin and fluconazole. Most patients were male (71.42%; 30 out of 42), aged from 27 to 73 years old. Trauma was the most important risk factor for FK (40.47%; 17 out of 42). Patients were treated with antifungals, corticoids and antibiotics; keratoplasty and eye enucleation were also performed. CONCLUSIONS: The study provided insights into the characteristics of FK in tropical regions and emphasized the importance of enhanced surveillance and management strategies.


Assuntos
Antifúngicos , Infecções Oculares Fúngicas , Fusariose , Fusarium , Ceratite , Testes de Sensibilidade Microbiana , Humanos , Brasil/epidemiologia , Fusarium/genética , Fusarium/efeitos dos fármacos , Fusarium/isolamento & purificação , Fusarium/classificação , Masculino , Feminino , Antifúngicos/farmacologia , Antifúngicos/uso terapêutico , Adulto , Ceratite/microbiologia , Ceratite/epidemiologia , Ceratite/tratamento farmacológico , Pessoa de Meia-Idade , Fusariose/microbiologia , Fusariose/epidemiologia , Fusariose/tratamento farmacológico , Infecções Oculares Fúngicas/microbiologia , Infecções Oculares Fúngicas/epidemiologia , Infecções Oculares Fúngicas/tratamento farmacológico , Idoso , Adulto Jovem , Adolescente , Clima Tropical , Idoso de 80 Anos ou mais , Anfotericina B/farmacologia , Anfotericina B/uso terapêutico
5.
BMJ Case Rep ; 17(5)2024 May 06.
Artigo em Inglês | MEDLINE | ID: mdl-38719269

RESUMO

A middle-aged male patient presented with a central corneal perforation in a deep stromal infiltrate in his left eye. An emergency therapeutic penetrating keratoplasty was performed. Microbiological evaluation of the corneal scraping specimen revealed septate fungal filaments on stains. However, culture reports after 24 hours from the scraping sample and the excised half corneal button showed growth of gram-negative bacilli. This pathogen was identified as an aerobic, non-fermentative, gram-negative, bacillus by conventional microbiology and confirmed as Myroides species by the VITEK 2 Compact system (bioMérieux, Marcy l'Etoile, France). Susceptibility to chloramphenicol was noted based on which the patient was treated with topical chloramphenicol 0.5%. No recurrence of the infection was noted. This is the first reported case of corneal infection with the Myroides species of bacteria which, heretofore, have been known to cause endocarditis and urinary tract infections.


Assuntos
Infecções Oculares Fúngicas , Ceratite , Humanos , Masculino , Pessoa de Meia-Idade , Ceratite/microbiologia , Ceratite/diagnóstico , Ceratite/tratamento farmacológico , Infecções Oculares Fúngicas/microbiologia , Infecções Oculares Fúngicas/diagnóstico , Infecções Oculares Fúngicas/tratamento farmacológico , Antibacterianos/uso terapêutico , Ceratoplastia Penetrante , Cloranfenicol/uso terapêutico , Cloranfenicol/administração & dosagem , Infecções Oculares Bacterianas/microbiologia , Infecções Oculares Bacterianas/diagnóstico , Infecções Oculares Bacterianas/tratamento farmacológico , Perfuração da Córnea/microbiologia , Perfuração da Córnea/diagnóstico
6.
Redox Biol ; 73: 103206, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38796864

RESUMO

Fungal keratitis is a severely vision-threatening corneal infection, where the prognosis depends on both fungal virulence and host immune defense. Inappropriate host responses can induce substantial inflammatory damage to the cornea. Therefore, in the treatment of fungal keratitis, it is important to concurrently regulate the immune response while efforts are made to eliminate the pathogen. Ebselen is a widely studied organo-selenium compound and has been demonstrated to have antifungal, antibacterial, anti-inflammatory, and oxidative stress-regulatory properties. The effectiveness of ebselen for the treatment of fungal keratitis remains unknown. In this study, ebselen was demonstrated to produce a marked inhibitory effect on Aspergillus fumigatus (A. fumigatus), including spore germination inhibition, mycelial growth reduction, and fungal biofilm disruption. The antifungal activity of ebselen was related to the cell membrane damage caused by thioredoxin (Trx) system inhibition-mediated oxidative stress. On the contrary, ebselen enhanced the antioxidation of Trx system in mammalian cells. Further, ebselen was proven to suppress the expressions of inflammatory mediators (IL-1ß, IL-6, TNF-α, COX-2, iNOS, and CCL2) and reduce the production of oxidative stress-associated indicators (ROS, NO, and MDA) in fungi-stimulated RAW264.7 cells. In addition, ebselen regulated PI3K/Akt/Nrf2 and p38 MAPK signaling pathways, which contributed to the improvement of inflammation and oxidative stress. Finally, we verified the therapeutic effect of ebselen on mouse fungal keratitis. Ebselen improved the prognosis and reduced the fungal burden in mouse corneas. Expressions of inflammatory mediators, as well as the infiltration of macrophages and neutrophils in the cornea were also obviously decreased by ebselen. In summary, ebselen exerted therapeutic effects by reducing fungal load and protecting host tissues in fungal keratitis, making it a promising treatment for fungal infections.


Assuntos
Anti-Inflamatórios , Antifúngicos , Azóis , Isoindóis , Ceratite , Compostos Organosselênicos , Estresse Oxidativo , Compostos Organosselênicos/farmacologia , Compostos Organosselênicos/uso terapêutico , Animais , Ceratite/tratamento farmacológico , Ceratite/microbiologia , Camundongos , Estresse Oxidativo/efeitos dos fármacos , Azóis/farmacologia , Azóis/uso terapêutico , Antifúngicos/farmacologia , Antifúngicos/uso terapêutico , Anti-Inflamatórios/farmacologia , Anti-Inflamatórios/uso terapêutico , Células RAW 264.7 , Antioxidantes/farmacologia , Aspergillus fumigatus/efeitos dos fármacos , Aspergilose/tratamento farmacológico , Aspergilose/microbiologia , Infecções Oculares Fúngicas/tratamento farmacológico , Infecções Oculares Fúngicas/microbiologia , Infecções Oculares Fúngicas/metabolismo , Modelos Animais de Doenças
7.
ACS Appl Mater Interfaces ; 16(20): 25637-25651, 2024 May 22.
Artigo em Inglês | MEDLINE | ID: mdl-38728098

RESUMO

Fluconazole (FNL) is one of the first-line treatments for fungal keratitis as it is an effective broad-spectrum antimicrobial commonly administered orally or topically. However, FNL has a very low water solubility, limiting its drug formulation, therapeutic application, and bioavailability through tissues. To overcome these limitations, this study aimed to develop FNL inclusion complexes (FNL-IC) with cyclodextrin (α-cyclodextrin, sulfobutylether-ß-cyclodextrin, and hydroxypropyl-γ cyclodextrin) and incorporate it into a dissolvable microneedle (DMN) system to improve solubility and drug penetration. FNL-IC was evaluated for saturation solubility, Fourier transform infrared spectroscopy, differential scanning calorimetry, in vitro release, minimum inhibitory concentration, minimum fungicidal concentration, and time-killing assay. DMN-FNL-IC was evaluated for mechanical and insertion properties, surface pH, moisture absorption ability, water vapor transmission, and drug content recovery. Moreover, ocular kinetic, ex vivo antimicrobial, in vivo antifungal, and chorioallantoic membrane (HET-CAM) assays were conducted to assess the overall performance of the formulation. Mechanical strength and insertion properties revealed that DMN-FNL-IC has great mechanical and insertion properties. The in vitro release of FNL-IC was significantly improved, exhibiting a 9-fold increase compared to pure FNL. The ex vivo antifungal activity showed significant inhibition of Candida albicans from 6.54 to 0.73 log cfu/mL or 100-0.94%. In vivo numbers of colonies of 0.87 ± 0.13 log cfu/mL (F2), 4.76 ± 0.26 log cfu/mL (FNL eye drops), 3.89 ± 0.24 log cfu/mL (FNL ointments), and 8.04 ± 0.58 log cfu/mL (control) showed the effectiveness of DMN preparations against other standard commercial preparations. The HET-CAM assay showed that DMN-FNL-IC (F2) did not show any vascular damage. Finally, a combination of FNL-IC and DMN was developed appropriately for ocular delivery of FNL, which was safe and increased the effectiveness of treatments for fungal keratitis.


Assuntos
Antifúngicos , Candida albicans , Fluconazol , Ceratite , Fluconazol/farmacologia , Fluconazol/química , Fluconazol/farmacocinética , Animais , Antifúngicos/farmacologia , Antifúngicos/química , Antifúngicos/farmacocinética , Ceratite/tratamento farmacológico , Ceratite/microbiologia , Candida albicans/efeitos dos fármacos , Testes de Sensibilidade Microbiana , Coelhos , Agulhas , Solubilidade , Infecções Oculares Fúngicas/tratamento farmacológico , Infecções Oculares Fúngicas/microbiologia
8.
J Int Med Res ; 52(5): 3000605241239857, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38757522

RESUMO

Fungal orbital cellulitis is usually seen in immunocompromised individuals, and opportunistic pathogens are the main etiology. We herein report a case of fungal orbital cellulitis due to Aspergillus in a patient with no history of trauma. A 48-year-old man presented to the emergency room of our hospital with a 2-week history of periorbital swelling, conjunctival hyperemia, and chemosis of his right eye. The visual acuity of his right eye was 6/20, and the intraocular pressure was 44 mmHg. The main clinical findings were proptosis of the right ocular globe with conjunctival hyperemia and a palpable infratemporal orbital mass. Laboratory testing failed to detect the presence of a pathogenic infection, and the lesions on computed tomography images resembled those of a malignant tumor of the orbit. The diagnosis was finally confirmed by postoperative pathological examination, and the patient responded favorably to debridement combined with antifungal therapy. Histopathological examination may help to reveal the nature of this disease. Surgical removal of inflammatory lesions can serve as an important diagnostic and treatment method for fungal orbital cellulitis.


Assuntos
Antifúngicos , Aspergilose , Hospedeiro Imunocomprometido , Tomografia Computadorizada por Raios X , Humanos , Masculino , Pessoa de Meia-Idade , Aspergilose/diagnóstico , Aspergilose/complicações , Aspergilose/microbiologia , Aspergilose/imunologia , Antifúngicos/uso terapêutico , Celulite Orbitária/microbiologia , Celulite Orbitária/diagnóstico , Desbridamento , Infecções Oculares Fúngicas/diagnóstico , Infecções Oculares Fúngicas/microbiologia
9.
Int Ophthalmol ; 44(1): 205, 2024 Apr 27.
Artigo em Inglês | MEDLINE | ID: mdl-38676784

RESUMO

PURPOSE: Microbial keratitis is a sight-threatening condition with a higher incidence in agrarian populations. In countries with a high indigent population, due to financial and other constraints, patients prefer to seek therapy locally rather than travel to advanced centres. The aim of this study is to describe the epidemiology, clinical characteristics, and outcomes of 60 consecutive patients with microbial keratitis managed at a rural centre. METHODS: Descriptive case series. All patients clinically diagnosed with infectious keratitis were included. Corneal scrapings were obtained and microbiological identification was done by Gram stain. Anti-microbial therapy was commenced based on smear findings and the patients were followed up till disease resolution. RESULTS: Sixty eyes of 60 patients were diagnosed with microbial keratitis in the study period. The mean age was 47.43 ± 18.69 years. Male:female ratio was 47:53. Risk factors included ocular trauma in the majority of patients (46/60; 76.7%). Microorganisms were identified on 75.6% of smears, with fungal filaments (65.4%) being the most common. Ulcers were central in over half (32/60; 53.3%), and > 3 mm in diameter in over three-fourths (81.6%) of patients. Forty-four patients (73.3%) achieved treatment success whereas 16/60 (26.6%) required referral to our tertiary-eye care facility for management. The median time to resolution was 14 days (IQR 10-26 days). CONCLUSION: Our series demonstrates the feasibility of microbiology-guided therapy in microbial keratitis by ophthalmologists at the secondary rural eye-care level. Two-thirds of the patients could be successfully managed at the rural centre and only severe cases needed a referral to tertiary centres.


Assuntos
Infecções Oculares Bacterianas , População Rural , Humanos , Masculino , Feminino , Pessoa de Meia-Idade , Adulto , Infecções Oculares Bacterianas/epidemiologia , Infecções Oculares Bacterianas/microbiologia , Infecções Oculares Bacterianas/diagnóstico , Infecções Oculares Bacterianas/terapia , Idoso , Índia/epidemiologia , População Rural/estatística & dados numéricos , Ceratite/epidemiologia , Ceratite/microbiologia , Ceratite/diagnóstico , Adulto Jovem , Antibacterianos/uso terapêutico , Adolescente , Úlcera da Córnea/microbiologia , Úlcera da Córnea/epidemiologia , Úlcera da Córnea/diagnóstico , Úlcera da Córnea/tratamento farmacológico , Úlcera da Córnea/terapia , Incidência , Infecções Oculares Fúngicas/epidemiologia , Infecções Oculares Fúngicas/microbiologia , Infecções Oculares Fúngicas/diagnóstico , Infecções Oculares Fúngicas/terapia , Infecções Oculares Fúngicas/tratamento farmacológico , Fatores de Risco , Bactérias/isolamento & purificação
11.
Int J Pharm ; 656: 124118, 2024 May 10.
Artigo em Inglês | MEDLINE | ID: mdl-38615806

RESUMO

Fungal infections of cornea are important causes of blindness especially in developing nations with tropical climate. However, the challenges associated with current treatments are responsible for poor outcome. Natamycin is the only FDA-approved antifungal drug to treat fungal keratitis, but unfortunately due to its poor water solubility, it is available as suspension. The marketed suspension (5% Natamycin) has rapid precorneal clearance, poor corneal permeability, a higher frequency of administration, and corneal irritation due to undissolved suspended drug particles. In our study, we developed clear and stable natamycin-loaded nanomicelles (1% Natcel) to overcome the above challenges. We demonstrated that 1% Natcel could permeate the cornea better than 5% suspension. The developed 1% Natcel was able to provide sustained release for up to 24 h. Further, it was found to be biocompatible and also improved the mean residence time (MRT) than 5% suspension in tears. Therefore, the developed 1% Natcel could be a potential alternative treatment for fungal keratitis.


Assuntos
Antifúngicos , Córnea , Liberação Controlada de Fármacos , Infecções Oculares Fúngicas , Ceratite , Micelas , Nanopartículas , Natamicina , Natamicina/administração & dosagem , Antifúngicos/administração & dosagem , Antifúngicos/química , Antifúngicos/farmacologia , Ceratite/tratamento farmacológico , Ceratite/microbiologia , Animais , Córnea/microbiologia , Córnea/metabolismo , Córnea/efeitos dos fármacos , Infecções Oculares Fúngicas/tratamento farmacológico , Infecções Oculares Fúngicas/microbiologia , Coelhos , Solubilidade , Preparações de Ação Retardada , Lágrimas/metabolismo
12.
Jpn J Ophthalmol ; 68(3): 233-242, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38658453

RESUMO

PURPOSE: To evaluate and compare the results of the conjunctival flap (CF) and cryopreserved amniotic membrane graft (AMG) in the management of fungal corneal ulcers either with complications or non-responsive to medical treatment. STUDY DESIGN: A retrospective observational study. METHODS: Medical records of 30 patients with culture-positive fungal corneal ulcer treated with either CF or AMG (15 eyes in each group) in real world settings were retrieved for analysis. After the surgical procedure, patients were followed up on days 1, 7, 14, 21, 30, 60, 90, 120, and 180 to explore the outcomes of the operations along with complications. RESULTS: Infecting fungi were of genus Fusarium (n = 11), Aspergillus (n = 10), Mucor (n = 4) and Penicillium (n = 10). The most common indication was resistant ulcer with perforation. After the procedure, epithelization was completed in 11(73.33%) patients in the CF, and 13 patients in the (86.67%) AMG group. Visual acuity improvement was significantly better in the latter group (CF: 1 [6.67%] vs. AMG: 7 [46.67%], p = 0.023). Flap failure occurred in 4 patients (26.67%) from the CF and 2 (13.33%) from the AMG group. No significant differences were found between the two groups regarding success rate (p = 0.651), epithelialization time (p = 0.691), healing of corneal ulcer (p = 0.651), and postoperative stability (p = 0.651) of the flaps. CONCLUSIONS: CF and AMG are both effective for the management of refractory fungal corneal ulcers. However, AMG appears to improve visual acuity better than CF.


Assuntos
Âmnio , Túnica Conjuntiva , Úlcera da Córnea , Infecções Oculares Fúngicas , Retalhos Cirúrgicos , Acuidade Visual , Humanos , Úlcera da Córnea/cirurgia , Úlcera da Córnea/microbiologia , Úlcera da Córnea/diagnóstico , Estudos Retrospectivos , Masculino , Âmnio/transplante , Feminino , Infecções Oculares Fúngicas/microbiologia , Infecções Oculares Fúngicas/cirurgia , Infecções Oculares Fúngicas/diagnóstico , Pessoa de Meia-Idade , Túnica Conjuntiva/microbiologia , Túnica Conjuntiva/cirurgia , Adulto , Idoso , Resultado do Tratamento , Seguimentos , Fungos/isolamento & purificação
13.
Eye Contact Lens ; 50(6): 265-269, 2024 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-38687618

RESUMO

PURPOSE: To examine the microbiological profile of cases of culture-positive fungal keratitis presenting to a tertiary eye care center in eastern India. METHODS: Microbiology records of all culture-positive microbial keratitis patients presenting to L V Prasad Eye Institute, Bhubaneswar, between January 2020 and December 2021, were retrospectively reviewed. Collected data included smear results of culture-positive fungal or mixed infections, the species isolated, and the time taken for organisms to grow in each media. RESULTS: Fungal keratitis formed 36% of all culture-positive microbial keratitis, whereas mixed infections (fungi and other organisms) formed 8.5%. The most common fungal species isolated was Fusarium spp. (25.8%). The most common bacteria involved in mixed infection with fungi was Staphylococcus spp. (54.8%). The positivity of potassium hydroxide+calcofluor white stain in detecting fungal filaments was 89.0% and that of Gram stain was 76.1%. Culture-positive cases of fungal keratitis showed most frequent growth on potato-dextrose agar (77.6%). A similar pattern was observed in culture-positive mixed infections (Sabouraud dextrose agar [SDA]: 84%). Most frequent growth of bacteria in mixed infections was seen in thioglycolate broth (54.7%). The shortest time to achieve significant fungal growth was observed in blood agar (BA) and chocolate agar (CA) (2.2/2.3 days, and 1.8/2 days for fungal keratitis and mixed infections, respectively). Filamentous hyaline fungi took the shortest time to achieve significant growth (2.8 days), whereas yeast forms took the longest (5 days). CONCLUSION: This study highlights the importance of combined use of both solid and liquid culture media, especially potato dextrose agar (PDA)/SDA and CA, to arrive at a definitive diagnosis of fungal keratitis and possible bacterial co-infection, which forms a significant proportion of cases with fungal keratitis. In resource-poor laboratories, two culture media, either SDA or PDA, along with BA, may be plated to detect mixed infections. Examination of stained smears of corneal samples provides an inexpensive method of rapid diagnosis of fungal keratitis when culture media is not available.


Assuntos
Infecções Oculares Fúngicas , Fungos , Ceratite , Humanos , Infecções Oculares Fúngicas/microbiologia , Infecções Oculares Fúngicas/diagnóstico , Estudos Retrospectivos , Fungos/isolamento & purificação , Ceratite/microbiologia , Ceratite/diagnóstico , Masculino , Feminino , Pessoa de Meia-Idade , Adulto , Índia , Bactérias/isolamento & purificação , Idoso
14.
Invest Ophthalmol Vis Sci ; 65(4): 44, 2024 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-38687493

RESUMO

Purpose: Fungal endophthalmitis is characterized by chronic inflammation leading to the partial or complete vision loss. Herein, we analyzed the transcriptomic landscape of Aspergillus flavus (A. flavus) endophthalmitis in C57BL/6 mice to understand the host-pathogen interactions. Methods: Endophthalmitis was induced by intravitreal injection of A. flavus spores in C57BL/6 mice and monitored for disease progression up to 72 hours. The enucleated eyeballs were subjected to histopathological analysis and mRNA sequencing using the Illumina Nextseq 2000. Pathway enrichment analysis was performed to further annotate the functions of differentially expressed genes (DEGs) and validation of cytokines was performed in vitreous of patients with fungal endophthalmitis using multiplex ELISA. Results: Transcriptomic landscape of A. flavus endophthalmitis revealed upregulated T-cell receptor signaling, PI3K-AKT, MAPK, NF-κB, JAK-STAT, and NOD like receptor signaling pathways. We observed significant increase in the T-cells during infection especially at 72 hours infection along with elevated expression levels of IL-6, IL-10, IL-12, IL-18, IL-19, IL-23, CCR3, and CCR7. Furthermore, host-immune response associated genes, such as T-cell interacting activating receptor, TNF receptor-associated factor 1, TLR1, TLR9, and bradykinin receptor beta 1, were enriched. Histopathological assessment validated the significant increase in inflammatory cells, especially T-cells at 72 hours post-infection along with increased disruption in the retinal architecture. Additionally, IL-6, IL-8, IL-17, TNF-α, and IL-1ß were also significantly elevated, whereas IL-10 was downregulated in vitreous of patients with Aspergillus endophthalmitis. Conclusions: Regulating T-cell influx could be a potential strategy to modulate the excessive inflammation in the retina and potentially aid in better vision recovery in fungal endophthalmitis.


Assuntos
Imunidade Adaptativa , Aspergilose , Aspergillus flavus , Citocinas , Modelos Animais de Doenças , Endoftalmite , Infecções Oculares Fúngicas , Perfilação da Expressão Gênica , Imunidade Inata , Camundongos Endogâmicos C57BL , Animais , Aspergillus flavus/genética , Camundongos , Infecções Oculares Fúngicas/microbiologia , Infecções Oculares Fúngicas/genética , Infecções Oculares Fúngicas/imunologia , Endoftalmite/microbiologia , Endoftalmite/imunologia , Endoftalmite/genética , Aspergilose/microbiologia , Aspergilose/genética , Aspergilose/imunologia , Imunidade Adaptativa/genética , Imunidade Inata/genética , Citocinas/metabolismo , Citocinas/genética , Transcriptoma , Ensaio de Imunoadsorção Enzimática , Corpo Vítreo/microbiologia
15.
Nano Lett ; 24(13): 4044-4053, 2024 Apr 03.
Artigo em Inglês | MEDLINE | ID: mdl-38517749

RESUMO

Fungal keratitis (FK) is an infectious eye disease that poses a significant risk of blindness. However, the effectiveness of conventional antifungal drugs is limited due to the intrinsic ocular barrier that impedes drug absorption. There is an urgent need to develop new therapeutic strategies to effectively combat FK. Herein, we synthesized an ultrasmall positively charged carbon dot using a simple stage-melting method. The carbon dot can penetrate the corneal barrier by opening the tight junctions, allowing them to reach the lesion site and effectively kill the fungi. The results both in vitro and in vivo demonstrated that it exhibited good biocompatibility and antifungal activity, significantly improving the therapeutic effect in a mouse model of FK. Therefore, this biophilic ultrasmall size and positive carbon dot, characterized by its ability to penetrate the corneal barrier and its antifungal properties, may offer valuable insights into the design of effective ocular nanomedicines.


Assuntos
Úlcera da Córnea , Infecções Oculares Fúngicas , Ceratite , Animais , Camundongos , Antifúngicos/farmacologia , Antifúngicos/uso terapêutico , Ceratite/tratamento farmacológico , Ceratite/microbiologia , Úlcera da Córnea/tratamento farmacológico , Úlcera da Córnea/microbiologia , Infecções Oculares Fúngicas/tratamento farmacológico , Infecções Oculares Fúngicas/microbiologia , Córnea/microbiologia
16.
J Control Release ; 368: 483-497, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38458571

RESUMO

Fungal keratitis is a refractory eye disease that is prone to causing blindness. Fungal virulence and inflammatory responses are two major factors that accelerate the course of fungal keratitis. However, the current antifungal drugs used for treatment usually possess transient residence time on the ocular surface and low bioavailability deficiencies, which limit their therapeutic efficacy. In this work, natamycin (NATA)-loaded mesoporous zinc oxide (Meso-ZnO) was synthesized for treating Aspergillus fumigatus keratitis with excellent drug-loading and sustained drug release capacities. In addition to being a carrier for drug delivery, Meso-ZnO could restrict fungal growth in a concentration-dependent manner, and the transcriptome analysis of fungal hyphae indicated that it inhibited the mycotoxin biosynthesis, oxidoreductase activity and fungal cell wall formation. Meso-ZnO also promoted cell migration and exhibited anti-inflammatory role during fungal infection by promoting the activation of autophagy. In mouse models of fungal keratitis, Meso-ZnO/NATA greatly reduced corneal fungal survival, alleviated tissue inflammatory damage, and reduced neutrophils accumulation and cytokines expression. This study suggests that Meso-ZnO/NATA can be a novel and effective treatment strategy for fungal keratitis.


Assuntos
Aspergilose , Infecções Oculares Fúngicas , Ceratite , Óxido de Zinco , Animais , Camundongos , Antifúngicos/uso terapêutico , Antifúngicos/farmacologia , Óxido de Zinco/uso terapêutico , Aspergilose/tratamento farmacológico , Aspergilose/microbiologia , Ceratite/tratamento farmacológico , Ceratite/metabolismo , Ceratite/microbiologia , Natamicina/uso terapêutico , Infecções Oculares Fúngicas/tratamento farmacológico , Infecções Oculares Fúngicas/metabolismo , Infecções Oculares Fúngicas/microbiologia , Sistemas de Liberação de Medicamentos , Camundongos Endogâmicos C57BL
17.
Korean J Ophthalmol ; 38(2): 98-104, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38351488

RESUMO

PURPOSE: To compare the efficacy and rapidity of direct microscopic detection of fungal elements from corneal ulcers between 10% potassium hydroxide (KOH) and 1% Chicago Sky Blue 6B (CSB) in 10% KOH (CSB-KOH). METHODS: Thirty patients with clinically suspected fungal keratitis were recruited. Participants with impending corneal perforation were excluded. Two slides were smeared with corneal ulcer scrapings from the ulcer's edge and base for comparison of fungal staining solutions. One slide was infused with KOH, and the other slide was filled with CSB-KOH. Additional scraping was collected for inoculation on Sabouraud dextrose agar for fungal culture. The sensitivity, specificity and rapidity of both stainings were analyzed. RESULTS: The sensitivity of fungal culture, KOH, and CSB-KOH were 43.75% (95% confidence interval [CI], 19.75%-70.12%), 62.50% (95% CI, 35.43%-84.80%), and 87.50% (95% CI, 61.65%-98.45%), respectively. The specificity were 100% (95% CI, 69.15%-100%) of both stainings and fungal culture which analyzed from 16 fungal keratitis cases by laboratory and clinical diagnosis. Mean CSB-KOH examination time was quicker than KOH with the mean time difference of 5.6 minutes (95% CI, 3.22-7.98 minutes) and p-value < 0.001. CONCLUSIONS: CSB-KOH was more effective and faster than KOH in detecting fungal elements from corneal ulcers. Therefore, CSB-KOH may be beneficial in diagnosing fungal keratitis and preventing blindness. Moreover, to the best of our knowledge, this is the first use of CSB stain in fungal keratitis detection.


Assuntos
Úlcera da Córnea , Infecções Oculares Fúngicas , Hidróxidos , Compostos de Potássio , Azul Tripano , Humanos , Úlcera da Córnea/diagnóstico , Úlcera da Córnea/tratamento farmacológico , Úlcera da Córnea/microbiologia , Corantes , Úlcera , Córnea , Infecções Oculares Fúngicas/diagnóstico , Infecções Oculares Fúngicas/microbiologia
19.
J Ocul Pharmacol Ther ; 40(3): 160-172, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38394222

RESUMO

Fungal keratitis (FK) is a dangerous corneal infection that is common in tropical and subtropical areas. Its incidence is extremely high, and ocular trauma and contact lenses can lead to FK, but its common treatment such as using topical antifungal eye drop instillation is often less effective because of several drawbacks of the drugs typically used, including limited ocular penetration, high frequency of dosing, poor biocompatibility, and the potential for severe drug reactions. Therefore, the development of novel drug delivery devices for the treatment of FK is urgent. The urgent need for novel drug delivery devices to treat FK has led to the development of several techniques, including nanoparticles (NPs), in situ forming hydrogels, contact lenses, and microneedles (MNs). However, it is important to note that the main mechanisms differ between these techniques. NPs can transport large amounts of drugs and be taken up by cells owing to their large surface area and small size. In situ forming hydrogels can significantly extend the residence time of drugs because of their strong adhesive properties. Contact lenses, with their comfortable shape and drug-carrying capacity, can also act as drug delivery devices. MNs can create channels in the cornea, bypassing its barrier and enhancing drug bioavailability. This article will go over novel medication delivery techniques for treating FK and make a conclusion about their advantages and limitations in anticipation to serve the best option for the individual therapy of FK.


Assuntos
Úlcera da Córnea , Infecções Oculares Fúngicas , Ceratite , Humanos , Úlcera da Córnea/tratamento farmacológico , Sistemas de Liberação de Medicamentos/métodos , Ceratite/tratamento farmacológico , Ceratite/microbiologia , Infecções Oculares Fúngicas/tratamento farmacológico , Infecções Oculares Fúngicas/microbiologia , Hidrogéis
20.
J Biol Chem ; 300(3): 105701, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38301897

RESUMO

Fungal keratitis is the foremost cause of corneal infections worldwide, of which Fusariumspp. is the common etiological agent that causes loss of vision and warrants surgical intervention. An increase in resistance to the available drugs along with severe side effects of the existing antifungals demands for new effective antimycotics. Here, we demonstrate that antimicrobial peptide S100A12 directly binds to the phospholipids of the fungal membrane, disrupts the structural integrity, and induces generation of reactive oxygen species in fungus. In addition, it inhibits biofilm formation by Fusariumspp. and exhibits antifungal property against Fusariumspp. both in vitro and in vivo. Taken together, our results delve into specific effect of S100A12 against Fusariumspp. with an aim to investigate new antifungal compounds to combat fungal keratitis.


Assuntos
Antifúngicos , Biofilmes , Membrana Celular , Fusarium , Proteína S100A12 , Antifúngicos/metabolismo , Antifúngicos/farmacologia , Biofilmes/efeitos dos fármacos , Infecções Oculares Fúngicas/microbiologia , Fusarium/efeitos dos fármacos , Ceratite/microbiologia , Proteína S100A12/metabolismo , Proteína S100A12/farmacologia , Humanos , Membrana Celular/efeitos dos fármacos , Fosfolipídeos/metabolismo , Espécies Reativas de Oxigênio/metabolismo
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