Polybacterial community analysis in human conjunctiva through 16S rRNA gene libraries.

The conjunctival sac of healthy human harbours a variety of microorganisms. When the eye is compromised, an occasional inadvertent spread happens to the adjacent tissue, resulting in bacterial ocular infections. Microbiological investigation of the conjunctival swab is one of the broadly used modality to study the aetiological agent of conjunctiva. However, most of the time such methods yield unsatisfactory results. Hence, the present study intends to identify the bacterial community in human conjunctiva of pre-operative subjects through 16S rRNA gene libraries. Out of 45 samples collected from preoperative patients undergoing cataract surgery, 36 libraries were constructed with bacterial nested-PCR-positive samples. The representative clones with unique restriction pattern were generated through Amplified Ribosomal DNA Restriction Analysis (ARDRA) which were sequenced for phylogenetic affiliation. A total of 211 representative clones were obtained which were distributed in phyla Actinobacteria, Firmicutes, α-Proteobacteria, ß-Proteobacteria, γ-Proteobacteria, Bacteroidetes, and Deinococcus-Thermus. Findings revealed the presence of polybacterial community, especially in some cases even though no bacterium or a single bacterium alone was identified through cultivable method. Remarkably, we identified 17 species which have never been reported in any ocular infections. The sequencing data reported 6 unidentified bacteria suggesting the possibility of novel organisms in the sample. Since, polybacterial community has been identified consisting of both gram positive and gram negative bacteria, a broad spectrum antibiotic therapy is advisable to the patients who are undergoing cataract surgery. Consolidated effort would significantly improve a clear understanding of the nature of microbial community in the human conjunctiva which will promote administration of appropriate antibiotic regimen and also help in the development of oligonucleotide probes to screen the predominant pathogens for early predisposition.

Exophiala dermatitidis Endophthalmitis: Case Report and Literature Review.

We report a case of a 59-year-old male patient with a postoperative fungal infection of the left eye. A dark-pigmented yeast, Exophiala dermatitidis (previously known as Wangiella dermatitidis), was identified from the culture of the biopsy taken from the posterior capsule. The infection was successfully eradicated by a combination of surgical and medical (i.e., voriconazole and fluconazole) treatment. This is the first report of successfully treated E. dermatitidis endophthalmitis, which demonstrates that a prompt and aggressive antifungal therapy combined with surgical intervention is necessary to prevent vision loss in cases of endophthalmitis due to Exophiala species. Beside the case description, we also aim to provide a literature review of previously reported eye infections caused by Exophiala species in order to help the future diagnosis and management of the disease.

Combined genotyping strategy reveals structural differences between Aspergillus flavus lineages from different habitats impacting human health.

Aspergillus flavus is a filamentous fungus which is widespread on agricultural products and also able to cause various human diseases. This species is frequently isolated from indoor air as well, furthermore, it is known as a common causal agent of keratomycosis, particularly in subtropical and tropical areas. It is also able to produce aflatoxins, one of the most carcinogenic mycotoxins which are harmful to animals and humans. In this study, 59 A. flavus isolates from four different habitats and 1 A. minisclerotigenes isolate were investigated. The isolates were identified and confirmed at the species level by the sequence analysis of a part of their calmodulin gene. Applying a combined analysis of UP-PCR, microsatellite, and calmodulin sequence data, the four group of isolates formed separate clusters on the phylogenetic tree. Examining the distribution of mating type genes MAT1-1 and MAT1-2, a ratio of approximately 3:1 was determined, and no correlation was found between the carried mating type gene and the aflatoxin production capability. HPLC analysis revealed that none of the examined isolates collected from indoor air or maize in Central Europe were able to produce aflatoxins, while about half of the isolates from India produced these mycotoxins under the test conditions.

Antifungal Susceptibility and Phylogeny of Opportunistic Members of the Genus Fusarium Causing Human Keratomycosis in South India.

Fusarium species are reported frequently as the most common causative agents of fungal keratitis in tropical countries such as India. Sixty-five fusaria isolated from patients were subjected to multilocus DNA sequencing to characterize the spectrum of the species associated with keratitis infections in India. Susceptibilities of these fusaria to ten antifungals were determined in vitro by the broth microdilution method. An impressive phylogenetic diversity of fusaria was reflected in susceptibilities differing at species level. Typing results revealed that the isolates were distributed among species in the species complexes (SCs) of F. solani (FSSC; n = 54), F. oxysporum (FOSC; n = 1), F. fujikuroi (FFSC; n = 3), and F. dimerum (FDSC; n = 7). Amphotericin B, voriconazole, and clotrimazole proved to be the most effective drugs, followed by econazole.

Antifungal Effect of Essential Oils against Fusarium Keratitis Isolates.

The present study was carried out to investigate the antifungal effects of Cinnamomum zeylanicum, Citrus limon, Juniperus communis, Eucalyptus citriodora, Gaultheria procumbens, Melaleuca alternifolia, Origanum majorana, Salvia sclarea, and Thymus vulgaris essential oils against Fusarium species, the most common etiologic agents of filamentous fungal keratitis in South India. C. zeylanicum essential oil showed strong anti-Fusarium activity, whereas all the other tested essential oils proved to be less effective. The main component of C. zeylanicum essential oil, trans-cinnamaldehyde, was also tested and showed a similar effect as the oil. The in vitro interaction between trans-cinnamaldehyde and natamycin, the first-line therapeutic agent of Fusarium keratitis, was also investigated; an enhanced fungal growth inhibition was observed when these agents were applied in combination. Light and fluorescent microscopic observations revealed that C. zeylanicum essential oil/trans-cinnamaldehyde reduces the cellular metabolism and inhibits the conidia germination. Furthermore, necrotic events were significantly more frequent in the presence of these two compounds. According to our results, C. zeylanicum essential oil/trans-cinnamaldehyde provides a promising basis to develop a novel strategy for the treatment of Fusarium keratitis.

Filamentous fungal infections of the cornea: a global overview of epidemiology and drug sensitivity.

Fungal keratitis is a serious suppurative, usually ulcerative corneal infection which may result in blindness or reduced vision. Epidemiological studies indicate that the occurrence of fungal keratitis is higher in warm, humid regions with agricultural economy. The most frequent filamentous fungal genera among the causal agents are Fusarium, Aspergillus and Curvularia. A more successful therapy of fungal keratitis relies on precise identification of the pathogen to the species level using molecular tools. As the sequence analysis of the internal transcribed spacer (ITS) region of the ribosomal RNA gene cluster (rDNA) is not discriminative enough to reveal a species-level diagnosis for several filamentous fungal species highly relevant in keratitis infections, analysis of other loci is also required for an exact diagnosis. Molecular identifications may also reveal the involvement of fungal species which were not previously reported from corneal infections. The routinely applied chemotherapy of fungal keratitis is based on the topical and systemic administration of polyenes and azole compounds. Antifungal susceptibility testing of the causal agents is of special importance due to the emergence and spread of resistance. Testing the applicability of further available antifungals and screening for new, potential compounds for the therapy of fungal keratitis are of highlighted interest.

Molecular identification and antifungal susceptibility of Curvularia australiensis, C. hawaiiensis and C. spicifera isolated from human eye infections.

A reliable identification method was developed for three closely related Curvularia species, which are frequently isolated from human keratomycoses. Since the traditionally used morphological method and the increasingly used internal transcribed spacer (ITS)-based molecular method proved to be insufficient to discern C. australiensis, C. hawaiiensis and C. spicifera, other molecular targets, such as ß-tubulin, translation elongation factor 1-α and the nuclear ribosomal intergenic spacer (IGS), were tested. Among them, the use of the highly divergent IGS sequence is suggested and the species-specific discriminating characters were determined in appropriate reference strains. It was also concluded that C. hawaiiensis and C. spicifera can be predominantly isolated from eye infections among the three species. The in vitro antifungal susceptibility of 10 currently used antifungal agents against 32 Curvularia isolates was also investigated. MICs were determined in each case. Isolates of C. spicifera proved to be less susceptible to the tested antifungals than those of C. hawaiiensis, which underline the importance of the correct identification of these species.

Identification of polybacterial communities in patients with postoperative, posttraumatic, and endogenous endophthalmitis through 16S rRNA gene libraries.

Endophthalmitis is a potential vision-threatening complication following surgical procedures (postoperative endophthalmitis [POE]), trauma (posttraumatic endophthalmitis [PTE]), and bacteremic seeding of the eye from a distant infection site (endogenous endophthalmitis [EE]). Several studies have revealed the polybacterial characteristics of endophthalmitis, which make the administration of antibiotics to treat the disease challenging. However, until now, the polybacterial communities of POE, PTE, and EE have not been precisely studied. Hence, the present study was designed to identify the bacterial community of endophthalmitis through 16S rRNA gene libraries. Of the 40 intraocular samples tested, 30 libraries were constructed with bacterial nested-PCR-positive samples. The obtained recombinant clones were screened through amplified rRNA gene restriction analysis (ARDRA) to identify unique clones. The multiple types of ARDRA patterns (P=0.345) and diverse bacterial sequences (P=0.277) within the libraries revealed the polybacterial nature of infection in POE, PTE, and EE. Moreover, to the best of our knowledge, this is the first report on polybacterial infection in EE. Gram-positive bacteria, including Bacillus spp. (n=19), Streptococcus spp. (n=18), Staphylococcus spp. (n=6), Exiguobacterium spp. (n=3), Gemella spp. (n=2), Enterococcus spp. (n=2), a Lysinibacillus sp. (n=1), a Clostridium sp. (n=1), and a Nocardia sp. (n=1), and Gram-negative bacteria, including Serratia spp. (n=18), Pseudomonas spp. (n=10), Enterobacter spp. (n=8), Acinetobacter spp. (n=3), Pantoea spp. (n=3), a Haemophilus sp. (n=1), and a Massilia sp. (n=1), were identified. Interestingly, among them, 10 bacterial species were not previously reported to be associated with endophthalmitis or other ocular infections. Besides, the presence of 4 unidentifiable clones suggests the possibility of novel organisms that might cause eye infections. Therefore, it is recommended that, in addition to the polybacterial nature of POE, PTE, and EE infections, the spectrum of the pathogenic bacterial community identified in this work should be considered while administering antibiotic therapy in suspected endophthalmitis cases.

Fusarium keratitis in South India: causative agents, their antifungal susceptibilities and a rapid identification method for the Fusarium solani species complex.

Seventy Fusarium isolates derived from human keratomycosis were identified based on partial sequences of the ß-tubulin (ß-TUB) and translation elongation factor 1α (EF-1α) genes. Most of the isolates were confirmed as members of the F. solani species complex (75.71%), followed by the F. dimerum species complex (8.57%), the F. fujikuroi species complex (8.57%), the F. oxysporum species complex (4.29%) and the F. incarnatum-equiseti species complex (2.86%). A combined phylogenetic tree was estimated including all the 70 isolates. Isolates belonging to different species complexes formed separate clades. In this study, we also report the first isolation of F. napiforme from human keratomycosis. A new method based on a specific EcoRI restriction site in the EF-1α gene was developed for the rapid identification of F. solani. In vitro antifungal susceptibilities of the isolates to seven antifungals were determined by broth microdilution method. Terbinafine, natamycin and amphotericin B proved to be the most effective drugs, followed by voriconazole. The minimal inhibitory concentrations of clotrimazole, econazole and itraconazole were generally high (≥64 µg ml(-1) ). The interactions between the two most effective antifungals (natamycin and terbinafine) were determined by checkerboard microdilution method. Synergism (71.8%) or no interaction (28.2%) was revealed between the two compounds.

Epidemiology of Aspergillus keratitis at a tertiary care eye hospital in South India and antifungal susceptibilities of the causative agents.

In recent years, Aspergillus species are reported frequently as aetiological agents of fungal keratitis in tropical countries such as India. Our aim was to evaluate the epidemiological features of Aspergillus keratitis cases over a 3-year period in a tertiary eye care hospital and to determine the antifungal susceptibilities of the causative agents. This study included culture proven Aspergillus keratitis cases diagnosed between September 2005 and August 2008. Data including prevalence, predisposing factors and demography were recorded, the isolates were identified by morphological and molecular methods and the minimum inhibitory concentration values of antifungal agents towards the isolates were determined by the microdilution method. Two hundred Aspergillus isolates were identified among 1737 culture proven cases. Most of the aspergilli (75%) proved to be A. flavus, followed by A. fumigatus (11.5%). Sixteen (8%) isolates belonged to species that are recently identified causative agents of mycotic keratitis. Most of the infected patients (88%) were adults ranging from 21 to 70 years of age. Co-existing ocular disease was confirmed in 16.5% of the patients. Econazole, clotrimazole and ketoconazole were notably active against A. flavus. Aspergillus keratitis is a significant problem in patients with ocular lesions in South-Indian States, warranting early diagnosis and initiation of specific antifungal therapy to improve outcome.

Prevalence of Multidrug-Resistant Bacteria in Healthcare-Associated Bloodstream Infections at Hospitals in Riyadh, Saudi Arabia.

Bloodstream infection (BSI) prevalence in hospitalized patients has increased owing to the spread of antibiotic-resistant pathogens; moreover, antimicrobial resistance in bacteria is a global problem. Here, BSIs are investigated in several patients at a hospital in Saudi Arabia, and the resistance of bacterial isolates to widely used drugs is determined. Throughout 2020, bacteria isolated from patients were identified and subjected to antibiotic susceptibility testing. In total, 1125 bacterial isolates were obtained from 1039 patients; among them, gram-positive bacteria were significantly more abundant than gram-negative bacteria. The most prevalent bacteria were Staphylococcus epidermidis and Klebsiella pneumoniae. Notably, gram-negative bacteria were mainly isolated from adult patients, and 20.63% of the gram-positive isolates were from pediatric patients, which was significantly higher than the corresponding percentages in elders and adults. The gram-positive isolates were mainly resistant to cephalothin, oxacillin, amoxicillin-clavulanate, and erythromycin and susceptible to penicillin, gentamicin, ciprofloxacin, and vancomycin. Additionally, the gram-negative isolates were mainly resistant to ampicillin, cephalothin, and amoxicillin-clavulanate and susceptible to amikacin, ertapenem, aztreonam, colistin, and trimethoprim-sulfamethoxazole. Consequently, the high prevalence of infective multidrug-resistant bacteria may account as a significant health issue; it is considered a hazard in Riyadh hospitals and must be prevented at all costs.

The Prevalence of Transfusion-Transmitted Diseases Among Blood Donors in the Central Blood Bank in Makkah, Saudi Arabia.

Background This study aimed to analyze the health and demographic characteristics of blood donors in Makkah, Saudi Arabia, and assess the prevalence and correlation of two markers related to hepatitis B infection: hepatitis B virus surface antigen (HBsAg) and anti-hepatitis B virus surface antibody (HBsAb). Materials and methods The study used a retrospective design and collected data from the Central Blood Bank in Makkah, Saudi Arabia, in 2022. The sample size was 7,875 blood donors. The study used various methods, such as serological testing, nucleic acid testing (NAT), and statistical analysis. The data were analyzed using Pearson correlation to examine the relationships between different variables. Results The predominant age group was 29-39 years, accounting for 46.9% of the total donors. In terms of blood types, O+ve was the most common, representing 40.3% of the donors. The investigation into infectious markers revealed overall low levels of reactivity among donors. For HBsAg, a marker of active hepatitis B infection, only 0.36% of the units were reactive. Conversely, the anti-HBsAb, which indicates immunity to hepatitis B, was reactive in 6.83% of the units. The correlation analysis illuminated some critical relationships. The total number of units tested had a statistically significant, albeit weak, positive relationship with HBsAg reactivity, shown by a Pearson correlation coefficient of 0.030 and a p-value of 0.008. Conversely, the total number of units tested and anti-HBsAb reactivity showed a moderate negative correlation, with a Pearson correlation coefficient of -0.437 and a p-value of less than 0.001. However, no significant correlation was identified between HBsAg and anti-HBsAb reactivity, indicating that active infection and immunity status might not be directly linked. Conclusion This extensive study provides in-depth insights into the sociodemographic characteristics of blood donors and the prevalence of key infectious markers within this population. It underlines the imperative of rigorous screening of blood units, particularly given the low immunity levels to hepatitis B identified. Also, the study showed the importance of screening blood units and vaccinating people against hepatitis B. It also suggested the need for more research on blood safety and infection-immunity relationships.

Molecular identification, phylogeny and antifungal susceptibilities of dematiaceous fungi isolated from human keratomycosis.

PURPOSE: To investigate the dematiaceous fungal profile of patients with ocular mycoses attending a tertiary eye care hospital in Coimbatore, India METHODS: The identification of dematiaceous fungus based on their morphology, their genotypes, and the measurement of the minimum inhibitory concentrations (MICs) using microdilution method of routinely used antifungal drugs were all compared. RESULTS: A total of 148 dematiaceous fungi were isolated during a study period of 27 months. Isolates were confirmed as Curvularia spp. (n = 98), Exserohilum spp. (n = 32), Alternaria spp. (n = 14), Exophiala spp. (n = 2), Cladosporium sp. (n = 1) and Aureobasidium sp. (n = 1). Out of 50 well grown isolates characterized genotypically based on the amplification and sequencing of the ITS region of the ribosomal RNA gene cluster and subsequent BLAST analysis, Curvularia lunata (n = 24), C. aeria (n = 1), C. spicifera (n = 8), C. hawaiiensis (n = 1), C. maydis (n = 2), C. papendorfii (n = 2), C. geniculata (n = 3), C. tetramera (n = 2) and Exs. rostratum (n = 7) were identified. In vitro antifungal susceptibilities of the most tested dematiaceous isolates showed that voriconazole had a MIC50 of 0.25 µg ml-1, while amphotericin B had a MIC50 of 0.25 µg ml-1 for Curvularia spp. and Alternaria spp. CONCLUSION: Voriconazole proved to be the most effective drug against the pigmented filamentous fungi, followed by amphotericin B, itraconazole and econazole.

Exploring the biological behavior of Heat shock protein (HSPs) for understanding the Anti-ischemic stroke in humans.

BACKGROUND: An ischemic stroke can be caused by thrombosis and ischemia, which is a major public health problem around the world, resulting in severe disability and a high death rate. The goal of this work is to examine and target various heat shock proteins (HSPs) via their interacting partners, which may have an anti-ischemic stroke impact. METHODS: Various heat shock proteins are identified and used for construction of PPI network through STRING webserver. Networks are analysed and visualized using the cytoscape for checking the protein-protein interactions. Along with this, multiple cytoscape based modules are integrated for the analysis of results, and Gene Ontology results are analysed using GOView. RESULTS: The core PPI network was revealed with 129 nodes and 1174 edges. Through Gene ontology (GO) and KEGG enrichment analysis the promising function of HSPs in two important signaling pathways were mainly recorded, representing the HSPs are necessary for repair and activations of brain cells during ischemic stroke. In addition, the study is revelation for targeting multiple HSPs via their interacting partners, which can provide anti-ischemic stroke effect. CONCLUSION: Overall, this finding provides a network-based framework for future research on HSP as therapeutic molecules for anti-ischemic stroke related applications.

Evaluating the structural and immune mechanism of Interleukin-6 for the investigation of goat milk peptides as potential treatments for COVID-19.

The function of Immune control, haematopoiesis, and inflammation all depend on the cytokine Interleukin 6 (IL-6), and higher expression of IL-6 is seen in COVID-19 and other diseases. The immune protein IL-6 activation is dependent on binding interactions with IL-6Rα, mIL-6R, and sIL-6R for its cellular function. Termination of these reaction could benefit for controlling the over-expression in COVID-19 patients and that may arise as inhibitors for controlling COVID-19. Traditionally, the goat milk has been prescribed as medicine in ayurvedic practice and through this work, we have explored the benefits of peptides from goat milk as IL-6 inhibitors, and it have the potential of inhibiting the over expression of IL-6 and control the COVID-19 disease. Computational experiments have shown that goat peptides had strong interactions with IL-6, with higher scoring profiles and energy efficiency ranging from -6.00 kcal/mol to -9.00 kcal/mol in docking score and -39.00 kcal/mol in binding energy. Especially the YLGYLEQLLR, VLVLDTDYK and AMKPWIQPK peptides from goat milk holds better scoring and shows strong interactions were identified as the most potential IL-6 inhibitor candidates in this study. Peptides from Goat proteins, which are capable of binding to the IL-6 receptor with strong binding conformations, have no negative effects on other immune system proteins.

Therapeutic potential of nitric oxide synthase inhibitor from natural sources for the treatment of ischemic stroke.

Nitric oxide (NO) is one of the major signalling molecules in the mammalian body playing critical role in regulation of blood pressure, cardiovascular disease including stroke, immune activation, neuronal and cell communication. Moreover, hyper production of NO by the activity of nitric oxide synthase (NOS) involved in neuropathic pain, neurodegenerative disorders and stroke. Hence, the search on small molecules from the natural sources for the inhibition of NOS is desirable in therapeutic point of view. The elevated level of NO caused by NOS enzyme become a novel target in finding new inhibitors from natural sources as antistroke agents. The present study focuses on the molecular docking of quercetin and its analogues against NOS. The active site of the enzyme was docked with the ligand and pharmacological properties were analysed. From this result, we suggest the therapeutic property of quercetin and its analogues against NOS.

In Vitro Antibacterial, Antifungal, Nematocidal and Growth Promoting Activities of Trichoderma hamatum FB10 and Its Secondary Metabolites.

Microbial natural biocides have attracted much more attention in recent years in order to avoid the unrestricted use of chemical biocides in the environment. The aim of this study is to analyze the antibacterial and antifungal activities of secondary metabolites and growth promoting, nematicidal, and soil enzyme activity mediated by Trichoderma hamatum FB10. The bactericidal and fungicidal activities were performed using cell-free extract. Results revealed that the selected strain exert antibacterial activity against Acidovorax avenae, Erutimacarafavora, and Xanthomonas campestris. The selected fungal strain FB10 showed antagonistic activity against fungal pathogens such as, S. sclerotiorum, Rhizoctonia solani, Alternaria radicina, Alternaria citri, and Alternaria dauci. Among the bacterial pathogens, A. avenae showed least MIC (30 ± 2.5 µg/mL) and MBC (70 ± 1.25 µg/mL) values. T. hamatum FB10 strain synthesized bioactive volatile secondary metabolite, which effectively inhibited the growth of bacteria and fungi and indicated the presence of 6-pentyl-alpha-pyrone as the major compound (67.05%). The secondary metabolite synthesized by T. hamatum FB10 showed nematicidal activity against M. incognita eggs. Egg hatch inhibition was 78 ± 2.6% and juvenile stage mortality rate was 89 ± 2.5% when the strain FB10 was treated with nematode. The cell free extract of T. hamatum FB10 showed protease, amylase, cellulase, chitinase, glucanase activities. T. hamatum FB10 inoculated with green gram increased 11% plant height, compared to the control. The fresh weight of the experimental group inoculated with T. hamatum FB10 increased 33.6% more compared to the control group. The green gram seedlings inoculated with T. hamatum FB10 increased 18% more dry weight than control group. Soil enzymes such as, urease, phosphatase, catalase and saccharase were improved in the soil inoculated with T. hamatum FB10. These biochemical components play potent role in soil fertility, energy conversion, and in soil organic matter conversion.

Paecilomyces formosus MD12, a Biocontrol Agent to Treat Meloidogyne incognita on Brinjal in Green House.

The present study was carried out to analyze the potential of fungi isolated from the rhizosphere of soybean, brinjal, tomato, and potato plants. The density of fungi varied in the pot soil and rhizosphere after Paecilomyces formosus MD12 treatment. The P. formosus MD12 population was 6.3 ± 0.13 × 104 CFU g-1 in the pot planted with brinjal, and the population increased in the rhizosphere (6.72 ± 0.41 × 104 CFU g-1). P. formosus MD12 was cultured in the production medium, and the supernatant was used for egg inhibition studies on a root-knot nematode parasite, Meloidogyne incognita. It was revealed that maximum egg inhibition (94.7 ± 6.2%) was obtained at 100% concentration of extract. The culture supernatant from P. formosus MD12 affected the development of M. incognita juvenile, and the mortality rate was maximum after 96 h (95 ± 6%). Mortality was reduced when treated with 25%, 50%, and 75% supernatant. At 1 × 107 mL-1 of spore suspension, we found reductions of 71.6 ± 3.3% nematode populations in the soil, 60.7 ± 2.2% from the root, and 63.6 ± 2.4% egg mass compared with the control in the pot experiment. The culture supernatant applied at the 10% level showed a maximum mean reduction of the nematode population in roots (72.4 ± 2.2%), soil (77.9 ± 2.5%), and egg masses (73.2 ± 1.5%), respectively. The presence of P. formosus MD12 in a soil environment could antagonize nematode parasites and improve soil amendment. The P. formosus MD12 strain showed good biocontrol ability against the root-knot nematode, M. incognita, under in vitro and green house experimental condition.

Evaluation of in vitro activities of extracellular enzymes from Aspergillus species isolated from corneal ulcer/keratitis.

Mycotic/fungal keratitis is a suppurative, generally ulcerative infection of the cornea. The filamentous fungi, Aspergillus spp. are the second leading cause of mycotic keratitis, particularly in India. Aspergillus spp. produce a range of extracellular enzymes that are used to break down complex molecules and used for growth and reproduction, also for survival on/in host organism. The current study was designed with an objective to screen in vitro extracellular enzyme activity of Fusarium and Aspergillus isolates from mycotic keratitis patients and to correlate the same as a putative virulence factor. Extracellular enzymes viz., deoxyribonuclease (DNase), protease, lipase, elastase, keratinase, etc., produced by Aspergillus have key role in keratomycosis and hence their (n = 85) in vitro activities were investigated. It was found that, the majority of the Aspergillus isolates produced protease (n = 75; 88% of 85) followed by lipase (n = 59; 69% of 85), DNase (n = 35; 41% of 85), elastase (n = 26; 31% of 85) and keratinase (n = 13; 15% of 85). The enzyme activity indices (EAI) for DNase, elastase, protease and lipase ranged between 1.01 and 1.98, whereas elastase EAI varied between 1.26 and 1.92. DNase, protease and lipase showed a maximum EAI of 1.98 and lowest EAI value of 1.01, respectively. Extracellular enzymes of Aspergillus spp. may have potential role in the onset and progression of keratitis.

In-vitro assessment of first-line antifungal drugs against Aspergillus spp. caused human keratomycoses.

BACKGROUND AND OBJECTIVES: Aspergillus keratitis are in the increasing trend and reported as the second most common cause of mycotic keratitis in developing countries. The present study was designed to isolate, identify Aspergillus spp. from the keratits/corneal ulcer patients attending a tertiary care eye hospital, Coimbatore, South India and to assess the minimum inhibitory concentrations (MICs) against ten clinically used first-line antifungal drugs. METHODS: A total of seventy-three Aspergillus strains isolated from corneal scrapings were included and assessed for a period of one year. All isolates were identified up to the species level by morphological observations. Antifungal drug susceptibilities were determined against a standard panel of antifungal agents. CONCLUSIONS: Five different species of aspergilli, A. flavus (n=53), A. fumigatus (n=14), A. terreus (n=9), A. tamarii (n=6) and A. niger (n=3) were identified based on morphological features. Minimum inhibitory concentration analyses indicated that, voriconazole, natamycin, itraconazole, clotrimazole, econazole followed by ketoconazole shall be the order of choices for the effective treatment for Aspergillus keratitis.