Infectious keratitis in Vietnam: etiology, organisms, and management at Vietnam National Eye Hospital

AIM: To report the etiologies, risk factors, treatments, and outcomes of infectious keratitis (IK) at a major Vietnamese eye hospital. METHODS: This is a retrospective review of all cases of IK at Vietnam National Eye Hospital (VNEH) in Hanoi, Vietnam. Medical histories, demographics, clinical features, microbiological results, and treatment outcomes were reviewed. RESULTS: IK was diagnosed in 1974 eyes of 1952 patients, with ocular trauma being the greatest risk factor for IK (34.2%), frequently resulting from an agriculture-related injury (53.3%). The mean duration between symptom onset and presentation to VNEH was 19.3±14.4d, and 98.7% of patients had been treated with topical antibiotic and/or antifungal agents prior to evaluation at VNEH. Based on smear results of 1706 samples, the most common organisms identified were bacteria (n=1107, 64.9%) and fungi (n=1092, 64.0%), with identification of both bacteria and fungi in 614 (36.0%) eyes. Fifty-five of 374 bacterial cultures (14.7%) and 426 of 838 fungal cultures (50.8%) were positive, with the most commonly cultured pathogens being Pseudomonas aeruginosa, Streptococcus pneumonia, Fusarium spp., and Aspergillus spp. Corneal perforation and descemetocele developed in 391 (19.8%) and 93 (4.7%) eyes, respectively. Medical treatment was successful in resolving IK in 50.4% eyes, while 337 (17.1%) eyes underwent penetrating or anterior lamellar keratoplasty. Evisceration was performed in 7.1% of eyes, most commonly in the setting of fungal keratitis. CONCLUSION: Ocular trauma is a major risk factor for IK in Vietnam, which is diagnosed in almost 400 patients each year at VNEH. Given this, and as approximately one quarter of the eyes that develop IK require corneal transplantation or evisceration, greater emphasis should be placed on the development of prevention and treatment programs for IK in Vietnam.

Microwave assisted extraction, phytochemical and antimicrobial evaluation of ethyl acetate extracts of stem bark of Ficus exasperata (Vahl)

Stem bark of Ficus exasperata was extracted using ethyl acetate by microwave-assisted solvent extraction. Phytochemical screening and antimicrobial evaluation were carried out on the extract. Phytochemical screening revealed the presence of cardiac glycosides, tannins, flavonoids, triterpenes and steroids. Antimicrobial evaluation revealed that the extract is active against Methicillin – resistant Staphylococcus aureus (MRSA), Staphylococcus aureus, Streptococcus pneumoniae, Salmonella typhi, Proteus mirabilis, Shigella dysenteriae, Candida stellatoidea and Candida tropicalis. The zones of inhibition (mm) for the test organisms were (24 - 31) mm. Minimum inhibition concentrations (mg/L) of extract against MRSA, Staphylococcus aureus, Streptococcus pneumonia, Salmonella typhi, Proteus mirabilis, Shigella dysenteriae, Candida stellatoidea and Candida tropicalis were 2.5, 1.25,1.25, 2.5, 1.25, 1.25, 1.25 and 2.5 respectively. Minimum bactericidal concentrations (mg/L) of extract against Methicillin – resistant Staphylococcus aureus (MRSA), Staphylococcus aureus, Streptococcus pneumonia, Salmonella typhi, Proteus mirabilis Shigella dysenteriae Candida stellatoidea and Candida tropicalis were 5, 2.5, 2.5, 5, 5, 2.5,2.5 and 5 respectively. The extract showed high inhibition against MRSA and Candida tropicalis.

Screening of antimicrobial, anti-quorum sensing activity and cytotoxicity of origanumoil against Gram-positive and Gram-negative bacteria

Introduction and Aim: Essential oils have been used from ancient times to treat different gram-positive and gram-negative bacterial-related infections. The study aims to screen the antibacterial, anti-quorum sensing activity of origanum oil against the common infection causing gram-negative and gram-positive bacteria. Material andMethods: The MIC (minimum inhibitory concentration) and antibacterial activity of origanum oil against the eight bacterial species, namely, Pseudomonas aeruginosa, Shigella flexneri, Salmonella enterica, Klebsiella pneumoniae, Streptococcus pneumonia, Streptococcus pyogenes, Staphylococcus aureus, and Enterococcus faecalis, was assessed by broth-dilution method and well diffusion method. The anti-quorum sensing activity was analyzed using bioreporter strain CV026 at sub-MIC concentrations, while the cytotoxicity of the origanum oil was analyzed using the SW480 cell line. Results: The oil's antibacterial activity was analyzed by measuring the clear inhibitory zone diameter, and maximum inhibitory zone of 36.66 mm zone against Staphylococcus aureus (Gram-positive) and 33.33 mm against Salmonella enterica (Gram-negative) of origanum oil was measured. And the minimum inhibitory zone of 16.66 mm zone of Enterococcus faecalis (Gram-positive) and 19.66 mm against Klebsiella pneumoniae (Gram-negative) of oil was noted. And the lowest MIC (0.1 mg/ml) of oilwas found against Streptococcus pneumonia. The oil significantly inhibited the violacein pigment production (30.29 %) at 0.02 mg/ml concentration (this oil concentration did not significantly affect the growth curve). The in vitro cytotoxicity assay shows that the oil inhibited the SW480 cells growth with increasing concentration. Conclusion: The origanum oil possesses antibacterial and anti-quorum sensing activity and can be used as an alternative for treating tested bacterial infection.

A TLR5 mono-agonist restores inhibited immune responses to Streptococcus pneumoniae during influenza virus infection in human monocytes

Influenza A virus (IAV) predisposes individuals to often more severe secondary bacterial infections with Streptococcus pneumonia (S. pneumoniae). The outcomes of these infections may be made worse with the increase in antimicrobial resistance and a lack of new treatments to combat this. Th17 responses are crucial in clearing S. pneumoniae from the lung. We previously demonstrated that early IAV infection of human monocytes significantly reduced levels of S. pneumoniae-driven cytokines involved in the Th17 response. Here, we have further identified that IAV targets specific TLRs (TLR2, TLR4, TLR9) involved in sensing S. pneumoniae infection resulting, in a reduction in TLR agonist-induced IL-23 and TGF-β. The effect of IAV is more profound on the TLR2 and TLR9 pathways. We have established that IAV-mediated inhibition of TLR9-induction is related to a downregulation of RORC, a Th17 specific transcription factor. Other studies using mouse models demonstrated that TLR5 agonism improved the efficacy of antibiotics in the treatment of IAV/S. pneumoniae co-infections. Therefore, we investigated if TLR5 agonism could restore inhibited Th17 responses in human monocytes. Levels of pneumococcus-driven cytokines, which had previously been inhibited by IAV were not reduced in the presence of the TLR5 mono-agonist, suggesting that such treatment may overcome IAV inhibition of Th17 responses. The importance of our research is in demonstrating the IAV directly targets S. pneumoniae-associated TLR pathways. Additionally, the IAV-inhibition of Th17 responses can be restored by TLR5 agonism, which indicates that there may be a different Th17 signalling pathway which is not affected by IAV infection.

Marie: Validation of the Artificial Intelligence Model for Covid-19 Detection

Lung X-ray images, if processed using statistical and computational methods, can distinguish pneumonia from COVID-19. The present work shows that it is possible to extract lung X-ray characteristics to improve the methods of examining and diagnosing patients with suspected COVID-19, distinguishing them from malaria, tuberculosis, and Streptococcus pneumonia. More precisely, an intelligent computational model was developed to process lung X-ray images and classify whether the image is of a patient with COVID-19. In partnership with the municipality of Itapeva, Minas Gerais, we carried out patient analysis and, at the same time, we evolved the algorithms to meet the needs of health professionals and also expand support in tracking COVID-19 in the municipality. In this project we will describe cases and even signs and symptoms that were similar to the clinical performed by the doctor. The average recognition accuracy of COVID-19 was 0.97,4 ± 0.043.

Synthesis and biological activity of aldehyde derivatives of isopimaric acid

: Four series of acylhydrazone derivatives, including halogenated aryl modified acylhydrazone, thiophene, pyrrole and quinoline, were synthesized and characterized. The minimum inhibitory concentrations of the compounds against five bacteria were determined and most of the compounds displayed some degree of antibacterial activity. Isopimaric acid (pyrrole-3-carboxaldehyde) acylhydrazone (3j) exhibited the most potent activity against Streptococcus pneumonia and Klebsiella Pneumonia, with the minimum inhibitory concentration being 3.91 μg/mL. The antimicrobial activity against S. pneumoniae was improved when the pyrrole structure was introduced into isopimaric acid. All heterocyclic acylhydrazone derivatives of isopimaric acid exhibited a good in vitro antitumorial activity at 100 μM. It is concluded that the inhibitory effect of isopimaric acid (2-fluoro-6-methoxybenzaldehyde) acylhydrazone (3d) on Hep G2 and isopimaric acid (3-bromothiophene-2-carbaldehyde) acylhydrazone (3g) on Hep G2 and MDAMB 231 is better than that of the positive control 5-fluorouracil (5-FU) (76.51%), which is a widely used clinical anticancer agent, at 100 μM.

Synergistic broad-spectrum antibacterial activity of Hypoxis hemerocallidea-derived silver nanoparticles and streptomycin against respiratory pathobionts

Respiratory tract infections arise due to the introduction of microbes into the airway, disrupting the normal, healthy, complex interdependent microbiome. The selective disruption of this community can be either beneficial or dangerous. Nanoparticles are a potential tool for modifying this population. Coated silver nanoparticles (AgNPs) were synthesized using ethanolic extracts of Hypoxis hemerocallidea (EEHH), a Southern African plant used extensively in traditional medicine and the source of many bioactive secondary metabolites. The room temperature reaction between silver nitrate and EEHH forms largely spherical AgNPs with an average diameter of 6–20 nm. These nanoparticles show similar levels of antibacterial activity as the broad-spectrum antibiotic streptomycin against Bacillus cereus, Streptococcus pneumonia, Escherichia coli, Pseudomonas aeuroginosa, and Moraxella catarrhalis. However, the AgNPs synergistically increase the antibacterial activity of streptomycin when they are applied in combination (30–52%). AgNPs are reiterated to be promising dual-function antibiotics, synergistically enhancing activity while also acting as delivery agents for small molecules.

Determination of the Chemical Composition and Antimicrobial Activity of Lavatera thuringiaca L. Medicinal Herb Material Extracted under Subcritical Conditions by the Liquid Carbon Dioxide Method

This article presents the composition of the components of Lavatera thuringiaca L. (Malvaceae Juss. family), which has a certain antibacterial effect. The plant collection was carried out in the Shamalgan gorge of Mountain Range of the Trans-Ili Alatau in the territory of the Karasay district of the Almaty region, in the flowering phase. A CO2 extract of the aboveground part of the medicinal plant Lavatera thuringiaca L. was obtained under subcritical conditions and, for the first time, studied for its component composition and antimicrobial activity. Determination of the chemical composition of the extract was carried out by gas chromatography/mass spectrometry (GC/MS). To identify the obtained mass spectra, we used the Wiley 7th edition and the NIST’02 data library. To determine the antimicrobial and antifungal activity, standard test strains of microorganisms were used: Staphylococcus aureus ATCC 6538-P, Escherichia coli ATCC 8739, Pseudomonas aeruginosa ATCC 9027, Candida albicans ATCC 10231, Streptococcus pneumonia ATCC 660, Klebsiella pneumoniae ATCC 700603, Staphylococcus haemolyticus, and Staphylococcus saprophyticus. In the composition of thick CO2Lavatera thuringiaca L. extract, the content of 31 components was proven: spathulenol 6.97%, pulegone 5 08%, cis-β-farnesene 7.63%, verbenone 1.93%, α-bisabolol oxide B 9.65%, bisabolol oxide A 8.26%, α-bisabolol 1.36%, linolenic acid, ethyl ether 3.15%, phytol 2.49%, herniarin 5.61%, linolenic acid 9.38%, linoleic acid 6.95%, myristic acid 2.33%, and elaidic acid 2.57%. Antimicrobial activity studies have shown that the CO2 extract of Lavatera thuringiaca L. has a pronounced effect against clinically significant microorganisms: Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, Candida albicans, Streptococcus pneumonia, Klebsiella pneumoniae, Staphylococcus haemolyticus, and Staphylococcus saprophyticus. During testing, the method of serial dilutions proved that the extract of Lavatera thuringiaca L. has a bactericidal effect on Staphylococcus aureus at a concentration of 0.83 μg/μl, on Escherichia coli at a concentration of 3.33 μg/μl, on Pseudomonas aeruginosa at a concentration of 0.83 μg/μl, on Streptococcus pneumoniae at a concentration of 1.67 μg/μl, on a clinical isolate of Staphylococcus haemolyticus at a concentration of 26.65 μg/μl, on Staphylococcus saprophyticus at a concentration of 6.67 μg/μl, and against Klebsiella pneumoniae at a concentration of 13.36 μg/μl. The test result showed that the extract also has fungicidal activity against the test culture of Candida albicans at a concentration of 0.21 μg/μl. At tests, the disc diffusion method proved that the extract has antimicrobial activity with high values of the growth suppression zone exceeding 15 mm. The zones of growth retardation of the test strains were 19.33 ± 1.15 for Staphylococcus aureus; 17.33 ± 3.21 for Escherichia coli; 15.67 ± 0.57 for Pseudomonas aeruginosa; 20.0 ± 1.0 for Streptococcus pneumoniae; 16.0 ± 2.64 for Klebsiella pneumoniae; 15.0 ± 1.0 for Staphylococcus saprophyticus, and 22.0 ± 1.73 for Candida albicans. In relation to the clinical isolate of Staphylococcus haemolyticus, the extract has a bacteriostatic effect.

Microbiological profile of infective keratitis in a tertiary care hospital in north Karnataka

Corneal blindness is seen worldwide with 1.5 to 2 million new cases reported every year and approximately there are 6.8 million cases of corneal blindness in India. The study constituted 109 clinically diagnosed infective keratitis cases. Aseptically collected corneal scrapings are subjected to Gram stain, KOH wet mount & Culture. Further identification done by study of Colony morphology, staining & biochemical tests. Antibiotic sensitivity was found using Kirby buer’s disc diffusion method following CLSI guidelines. Males affected more common than females. Common age group being 21-40 yrs. Infective keratitis is usually Bacterial(61.4%) in origin than fungal(22%). Trauma found to be the most common predisposing factor followed by diabetes, other ocular diseases, surgery & corticosteroid therapy. Trauma with vegetative material is most common. Streptococcus pneumonia & pseudomonas are most common bacterial cause while Fusarium & Aspergillus cause most fungal cases. Infective keratitis both bacterial & fungal are more common in working males, mainly agriculturists who are exposed to vegetative trauma. Early detection and treatment with proper antibacterial & antifungals is important to prevent ocular problems and scarring of cornea.