THE COMBINATORIAL EFFECTS OF Azadirachta indica LEAF EXTRACTS WITH AMIKACIN AND TETRACYCLINE AGAINST CLINICALLY IMPORTANT BACTERIA

Antibiotic-resistance is a major threat in the treatment of diseases caused by resistant bacteria. Combination of plant extracts with antibiotics can serve as an alternative to antibiotics. Azadirachta indica (neem plant) has many antimicrobial properties due to the presence of secondary metabolites such as alkaloids and flavonoids. In this study, the combinatorial effects of neem leaf extracts with amikacin and tetracycline against eight clinically important gram-positive and gram-negative pathogens were investigated using the agar well diffusion assay. Synergistic effect of neem leaf extract and tetracycline was observed against Propionibacterium acnes, Bacillus subtilis, and S. pneumoniae  with a significant enlargement (p<0.05) in the diameter of the zone of inhibition. However, the same combination showed insignificant inhibition against S. faecalis, Staphylococcus epidermidis, Enterococcus faecalis, and Staphylococcus aureus. The neem leaf extract-amikacin combination showed insignificant antibacterial activity against Staphylococcus aureus, S. epidermidis, S. pneumoniae, and Pseudomonas aeruginosa. An antagonistic effect was observed when Bacillus subtilis was exposed to the same combination as there was a significant reduction (p<0.05) in the zone of inhibition.  This study suggests the potential development of the neem leaf extract-tetracycline combination as an antibacterial agent against P. acnes, B. subtilis, and S. pneumoniae. However, this preliminary data requires further investigation and test on a wider range of clinical isolates to make a more decisive conclusion. The antagonistic effect of the neem leaf extract and amikacin suggests that the individual agents are potent as antibacterial agents than the combination

Effects of Different Substrates on the Growth and Nutritional Composition of Pleurotus ostreatus: A Review

Mushrooms are a popular food source as they are highly nutritious and flavorful with a high content of proteins, vitamins, and minerals. Mushrooms could be an alternative solution to the world’s food crisis as they are inexpensive to grow on different types of substrates including waste materials. Pleurotus ostreatus, frequently known as oyster mushrooms, are the second most cultivated mushroom in the world. This species is known for its high protein content and easy cultivation. Oyster mushrooms have the potential to produce protein-rich biomass when grown on various substrates. There is a need to identify substrates that are cost-effective for the commercial production of nutritious oyster mushrooms as the substrates used currently are either costly or inadequate to produce oyster mushrooms in the required quantity or quality. Thus, the effects of 6 different lignocellulosic substrates on the growth and nutritional composition of P. ostreatus were reviewed and analyzed in this article. The substrates included in this review were wheat straw, sugarcane bagasse, corncob, softwood sawdust, hardwood sawdust, and general sawdust. Based on the analyzed data, sugarcane bagasse was concluded as the most suitable substrate to grow P. ostreatus. These substrates contain a high amount of nutrients and are also likely to produce a significantly high yield of oyster mushrooms in addition to enhancing the nutritional quality of the mushroom. However, these findings must be evaluated and confirmed through further research in this field

Antimicrobial and anti-biofilm activities of plant extracts against Pseudomonas aeruginosa – a review

Antimicrobial resistance among bacterial pathogens, including Pseudomonas aeruginosa, is a global problem that has led to research on naturally occurring compounds as an alternative source of antibacterial and anti-biofilm agents. This review focuses on determining plant extracts' antimicrobial and anti-biofilm activities against P. aeruginosa, an opportunistic pathogen contributing to microbial and biofilm-associated infections in humans. Medicinal plants are being widely researched as they are rich sources of phytochemicals, including flavonoids, alkaloids, tannins and terpenoids. These phytochemicals have been well known for their antibacterial activity, which contributes to the effectiveness of certain plants, including Punica granatum and Triumfetta welwitschia, against P. aeruginosa. Hypericum perforatum and Berginia ciliata contains phytochemicals that directly inhibit the quorum sensing mechanism, inhibiting the direct cell-to-cell communication, thereby preventing or reducing biofilm formation by P. aeruginosa. Plant extracts also inhibit bacterial growth and should be considered an alternative to antibiotics. Furthermore, plant extracts can be used with antibiotics for better efficacy against P. aeruginosa. However, more research must be carried out to select plants with a broad spectrum of activity against not only P. aeruginosa infections but other gram-negative bacteria in general. It would be economically viable to develop as a therapeutic drug. This would align with the third United Nations sustainable development goals on good health and well-being and is a significant step forward in the battle against antibiotic resistance