Abstract. Scott S, Daniel R, Kalicharran L. 2023. Effectiveness of Passiflora foetida (Baby Semitoo) and Ocimum campechianum extracts (Married Man Pork) against Pseudomonas aeruginosa and Klebsiella pneumoniae. Asian J Nat Prod Biochem 21: 79-87. Medicinal plants have long been used to treat illnesses. They contain many secondary metabolites, which have antibiotic properties, and can treat antimicrobial resistance in bacteria. The aim of this study was to investigate the phytochemicals in Passiflora foetida L. (Baby Semitoo) and Ocimum campechianum Mill. (Married Man Pork) and to analyze the antimicrobial potential against Klebsiella pneumoniae and Pseudomonas aeruginosa. Plant extracts were prepared using hexane, methanol, and water, with a rotary evaporator. The extracts were tested using zone of inhibition, Minimum Inhibitory Concentration (MIC), and Minimum Bacterial Concentration (MBC) methods. The extract of O. campechianum produced the highest percent yield for each solvent, while methanol produced the highest yield of all solvents. The results of the phytochemical test showed that, O. campechianum contained flavonoids, tannins, saponins, glycosides, and phenols; while flavonoids, tannins, glycosides, and saponins were found in P. foetida extract. Similarly, O. campechianum also showed higher antimicrobial potential than P. foetida. The P. aeruginosa proved more susceptible than K. pneumoniae to both plants.

This review analyzed literature from online journals and peer-reviewed articles dating back to the year 2020 covering the emergence, transmission, mutation, and strategic responses of coronavirus diseases. Most of the studies related to those areas found that early responses would effectively limit and control the transmission of the novel coronavirus. Currently, the use of masks, the use of detergents, social distancing and limiting overcrowding are measures in place, even though daily cases and deaths continue to increase worldwide. Previous responses in 2019 included border closures and lockdowns, which were more stringent. The public should be aware of transmission routes (e.g., mouth, nose) and modes of transmission (e.g., sneezing, both permeable and impermeable inanimate objects) that put their health at risk, whether they are inside their homes or other environments such as the workplace or public spaces, as discussed in this document. The findings indicate that the implementation time of the strategies is significant, the increase in transmission will result in mutations that will affect many people, and in turn the development of new drugs in search of triggering a response in the cell, which results in the activation (stimulation) or deactivation (inhibition) of a symptom-improving effect and to counteract the inherent complications, as well as vaccines to increase the immune response in the body. The mutation is related to the spike protein which allows binding to the angiotensin-converting enzyme 2 receptor on human host cells. Additional research can be done on the evolution of new coronavirus strains to determine factors that can be disrupted to prevent resurgence or new occurrences.

This study compared the antibacterial activity of honey-garlic and honey-ginger mixtures against two clinically important bacteria frequently implicated in acute wound infections; Pseudomonas aeruginosa and Klebsiella pneumoniae. Individual extracts of honey, ginger, garlic and erythromycin antibiotics (positive control), were also tested. Concentrations of 100%, 75%, 50%, and 25% of the natural extracts and mixtures were prepared by the use of sterilized distilled water as the solvent. The antibacterial activity of each natural extract and the antibiotic was tested against the aforementioned bacterial species at different concentrations using the disc diffusion method. Further, MIC and MBC tests were conducted on each natural mixture using the broth dilution method and spread plate method, respectively. Our results showed garlic exhibited the highest antibacterial activity against both bacteria at 100% concentration, whereas honey and ginger showed the lowest antibacterial activity against Klebsiella pneumoniae and Pseudomonas aeruginosa, respectively at 25% concentrations. Honey-garlic mixture was the most effective against Klebsiella pneumoniae, whereas honey-ginger mixture was the most effective against Pseudomonas aeruginosa. The antibiotic was more effective than the natural mixtures against Pseudomonas aeruginosa, but not so effective against Klebsiella pneumoniae. The MIC of both mixtures against Pseudomonas aeruginosa ranged from 25%-50%, while it ranged from 6%-50% for Klebsiella pneumoniae. Honey-garlic was the only mixture against Klebsiella pneumoniae that exhibited bactericidal effects at 50% (MBC).

Water is an important asset to life, but, sometimes it can contain dangerous pathogens that can be located with coliform bacteria. Bleach is an effective substance that has been considered by many to reduce pathogen appearances in water. Studies done indicated that an increase in concentration and volume of bleach can reduce some, if not all, traces of coliform. This research used a five-fold serial dilution and incorporated techniques like addition of bleach and Gram staining to obtain its findings. Only 50% of the samples (Village Two) showcased a presence of coliform bacteria. There were signs of Klebsiella pneumoniaee, Pseudomonas aeruginosa, Coagulase Positive Staphylococci and Escherichia coli with the first two mentioned being the most occurring. All three volumes of bleach showed 100% effectiveness in removing active coliform traces. It is important to note that reduction of coliform is a topic that should be addressed immediately, because of its dire consequence on the health of the population.

Fruits and vegetables are important to human health because they provide nutritional benefits, they are a good source of vitamins and minerals and help to improve the immune system of individuals. It was advised by the Food and Agriculture Organization of Guyana that individuals should consume more fruits and vegetables to boost their immune systems during the Coronavirus pandemic. Due to the increase in consumption of fruits and vegetables, there can also be an increase in cases of food-borne diseases, as evident from studies done in countries such as, the United States, Malaysia, and India. The objectives of this research was to identify the presence of microorganisms on leafy vegetables, Lactuca sativa (lettuce), Brassica oleracea (cabbage), and Amaranthus viridis (callaloo), that were purchased from local markets and to determine if washing with tap water only, will significantly decrease the concentration of microorganisms on the vegetables by performing microbial assessments. It was found that the most common microorganisms present on the leafy vegetables were pathogenic bacteria such as Neisseria spp., Pseudomonas aeruginosa, Paracoccus marcusii, Pseudomonas fluorescens, Bordetella pertussis, and Klebsiella pneumonia. The results of a Wilcoxon signed-rank test (p value = 1) revealed that washing with tap water alone did not significantly decrease the quantity of microorganisms present on the leafy vegetables (avg: 3.305x10-2 CFU/ml). Therefore, it is recommended that other hygienic methods such as washing with salt, lemon juice, or vinegar should be utilized in order to significantly reduce the concentration of the microorganisms present on the leafy vegetables.

The hexane extracts of ginger root (Zingiber officinale) of the Zingiberaceae family and Coconut; Cocos nucifera a member of the Arecaceae family, from two locations in Guyana were used for the investigation of their antibacterial properties. To evaluate the scientific basis for the use of the plant and plant product, the antimicrobial activities of the extracts were evaluated against three common bacteria found on wound infections; Staphylococcus aureus a gram-positive bacteria, Klebsiella pneumoniae a Gram-negative, and Pseudomonas aeruginosa a common encapsulated, facultative aerobic and Gram-negative. The disc diffusion method was used to test the antimicrobial activity of the extracts which were evaluated in 20%, 25%, 50%, 75%, and 100% concentrations against each organism in triplicates, and the diameter of the zone of inhibition was measured. There was no significant difference among the plant extracts from the different locations. The results showed that coconut oil in 50% was most effective against Staphylococcus aureus forming zones measuring 19-20mm, the 100% ginger concentration was most effective against Staphylococcus aureus also and the zones measured 23-15mm, the mixture of ginger and coconut oil was equally effective against Staphylococcus aureus and Pseudomonas aeruginosa with zones measured 12-15mm. The study also investigated the phytochemical constituents of the plant hexane extracts to test the presence or absence of secondary metabolites. Results of the phytochemical studies revealed the presence of tannins, saponins, alkaloids, flavonoids, glycoside, phenol, and steroids in the extracts were active against the bacteria.

A comparative assessment of the antimicrobial activity of two well-known and tropically distributed plants was conducted. Scientists and other researchers have been continuously investigating plants distributed all across the globe for medicinal properties so as to replace the chemically developed cures and treatment that are being used today. However, these plants and their extracts have not been developed for use in the medical field since adequate knowledge of the chemical makeup of these plants as well as clinical trials is still lacking. This study aimed to seek out the most antimicrobially active of the plants for testing and eventual use in medicine. The plant Artocarpus altilis and Syzygium cumini were investigated against a gram positive and a gram negative bacterium: Staphylococcus aureus and Escherichia coli respectively. Selective solvent extraction was used to extract the active compounds present in leaves. The solvents used were hexane, methanol and ethanol. The disc diffusion method was used to test antimicrobial activity of the plant extracts. The plant extracts were compared against a control and a reference, which were the solvents and Ampicillin respectively. Methanol and ethanol extracts of both plants showed zone of inhibition against the investigated microorganisms. However, the hexane extracts were unable to produce results. The results of this study noted that the ethanol extracts were more effective than the methanol extracts. According to this study, the most antimicrobially active plant is Syzygium cumini and the most inhibited bacteria is the gram positive bacteria: Staphylococcus aureus.

Abstract. Prashad L, Daniel R, Ram M. 2020. Survey of the bacterial diversity at two coastal beaches in Guyana. Biofarmasi J Nat Prod Biochem 18: 1-8. The #63 Beach, Berbice and Marriott Beach, Kingston Seawall, Guyana were surveyed for halophilic bacteria present in its waters. NaCl tolerance, temperature tolerance and antimicrobial activity of isolates against Staphylococcus aureus and Bacillus sp. were tested. Samples of 100 mL were taken from the Shore, 5.0 m, and 10.0 m depth from both locations. The samples were plated and examined for the growth of bacteria of different pigmentation. A total of 4 halophilic isolates were found; 3 from Marriott Beach (Isolates A, B, and G) and 1 (Isolate M) from the #63 Beach. Isolates were of yellow, light orange and pink pigmentation, the 3 isolates from Marriott Beach were, Gram-negative and cocci while the one isolates from #63 Beach were Gram-positive and cocci. The optimum salinity tolerance for the Isolate G from Marriott Beach was 1.5M NaCl, Isolate M from #63 Beach 1.0M NaCl, Isolate B from Marriott Beach 1.0M NaCl and Isolate A from, Marriott Beach 0.5M NaCl. The optimum temperature for the growth of the isolates was 37°C. The isolates had no antimicrobial activity against S. aureus and Bacillus sp.

The aim of this study was to compare the antibiotic potency of Cyanthillium cinereum and Moringa oleifera (natural antibiotics) against Ampicillin and Erythromycin (synthetic antibiotics) using zone of inhibition and both the natural and synthetic antibiotic was treated against Staphylococcus aureus, Klebsiella. pneumoniae and Pseudomonas aeruginosa. The extracts from the natural agents were obtained by the use of methanol (polar) and hexane (non-polar). The bacteria were treated with six different conc. (100%, 75%, 50%, 25%, 10% and 5%) of the extracts, where the largest zone of inhibition was observed with C. cinereum extract at 5% concentration against S. aureus with mean and standard deviation of 22.1±2.1. S. aureus followed by P. aeruginosa was most susceptible towards the treatments. The correlation (Pearson) indicated that the conc. of the extract was indirectly proportional to the zone of inhibition. The phytochemical analysis revealed that C. cinereum contained alkaloids, catecholic tannins, saponins, flavones, volatile oils phenols and steroids and M. oleifera only contained Alkaloid, tannins and steroids.

The present study was conducted to investigate the antibacterial activity of ethanol extracts of turmeric (Curcuma longa L.) locally grown in Guyana against the different strains of bacteria, namely Escherichia coli, Proteus vulgaris, Pseudomonas aeruginosa and Staphylococcus aureus. Different concentrations of the turmeric extract were prepared ranging from 100%, 75%, 50% and 25% using the solvent 95% ethanol. The antibacterial activity was tested against the aforementioned bacterial strains at the different concentrations of the extract using the disc diffusion method. According to the results, the ethanolic turmeric extract exhibited considerable antibacterial activity against all the tested bacteria. Maximum antibacterial activity was seen at 25% concentration against three of the tested bacteria, namely E. coli, P. aeruginosa and S. aureus. Overall, the effect of the ethanolic turmeric extract varied with the concentrations against the four tested bacteria whereby Pseudomonas aeruginosa was the most susceptible to the extracts while Proteus vulgaris was the most resistant. The use of ethanolic turmeric extract as an antibacterial agent in treatment of infections caused by bacteria has been suggested by many researchers.

Abstract. Philander M, Ragobeer P, Daniel R. 2019. Short communication: A comparison of the rate of polyethylene decomposition among Bacillus spp., Pseudomonas spp., and Escherichia coli bacteria. Nusantara Bioscience 11: 97-100. This study did a comparative analysis of the rate of polythene plastic decomposition among three species of bacteria namely, Bacillus spp., Pseudomonas spp., and Escherichia coli. The three bacterial species were cultured and grown in 2-liter polyethylene terephthalate bottles with nutrient broth separately in triplicates along with a control that did not include any bacteria. These bottles were left undisturbed at room temperature for three months (92 days) after which the containers were subjected to sterilization. Plastic weights were taken using an electronic scale and compared with original values. From the results, it showed that in the three months there was a relatively large amount of degradation that occurred. Bacillus spp. and E.coli bacteria yielded similar results and moved at a rate faster than the Pseudomonas spp., A daily rate for each bacterial species was calculated and a predictive figure based on rates was made. If the rates remained constant there would be total degradation of the polyethylene plastics by the Bacillus spp., E. coli and Pseudomonas spp., in 11.45, 11.45 and 12.35 years respectively. This is a significant finding since in nature plastics can take hundreds of years to decompose.

Abstract. David D, Daniel R, Seecharran D, 2019. Antimicrobial properties of Chlorocardium rodiei on Pseudomonas aeruginosa, Bacillus spp. and Candida albicans. Nusantara Bioscience 11: 128-132. This research seeks to investigate the antimicrobial properties of Chlorocardium rodiei leaves and seeds on Pseudomonas aeruginosa, Bacillus spp. and Candida albicans. It also seeks to extract and identify the phytochemical compounds presented in leaves and seeds. The crude plant extract was obtained using the maceration method of extraction (ethanol and acetone as solvent) followed by rotary evaporation. Phytochemicals were analyzed from the crude extract using standard phytochemical procedures. 1%, 50% and 100% concentrations of each extract were prepared and used in the disk diffusion assay against C. albicans, P. aeruginosa, and Bacillus spp. and compared against Ciprofloxacin and Erythromycin for the bacteria and Fluconazole for the fungus. The results showed that the extract from the leaves possesses weak (≤12 mm) to moderate (>12 ≤15mm) inhibitory effect, while the extract from the seeds had weak (<12mm) inhibitory effect on the microorganisms. The phytochemical compounds tannins, essential oils, saponins, and phenols were tested positive from the crude extract. For the first time, the antimicrobial properties of C. rodiei’s leaves and seeds were evaluated and showed to possessed antimicrobial properties.

In recent years, biological activities, potential health benefits, and nutritional value of marine algae have been intensively investigated. Marine algae represent about 9% of biomedical compounds obtained from the sea. Infectious diseases caused by bacteria have a large impact on public health. The resistance of pathogenic bacteria to existing antibiotics has become a global epidemic. Marine algae derivatives have shown promise as candidates in novel, antibacterial drug discovery. The antibacterial activity of the marine diatom Skeletonema costatum (Greville) Cleve collected from South East Coast of India was examined against the selected Human Pathogenic bacteria. The active compounds extracted using water, ethanol and methanol partly purified from the algal extract were tested against the pathogens: Pseudomonas aeruginosa, Proteus vulgaris, Proteus mirabilis, Salomonella typhi, Salmonella paratyphi B, Vibrio cholerae and Staphylococcus aureus. The organic extract B (Methonol) appeared to be the most active. The extract B exhibited weak activity against Proteus mirabilis, Proteus vulgaris,Pseudomonas aeroginosa, Salmonella paratyphi B and Vibrio cholerae. Extract B exhibited it maximum activity against Staphylococcus aureus. It exhibited no activity against Salmonella typhi, the fraction C (Ethanol) appeared to inhibit Proteus mirabilis, Samolnella typhi and Staphylococcus aureues weakly, whereas Vibrio cholerae was inhibited effectively by this fraction. The growth of the Human pathogenic bacteria appeared to be inhibited by the organic extract of the diatom. However, there was no activity in distilled water extracts against all pathogens tested. Hence from the observed results The Extract B extract was found to be potent against mentioned human pathogens. They could be used by the pharmaceutical industry in drug development to treat diseases like cancer, acquired immune-deficiency syndrome (AIDS), infection from virus, bacteria and fungus, inflammation, pain, arthritis etc.

The Book of Abstracts – Student Research 2023 features a collection of abstracts from the University of Guyana, Department of Biology’s BIO4200 Capstone Research Project for the academic year 2022/2023. This is JARE’s fourth volume of the Book of Abstracts – Student Research series. Volume 4 comprises student research on topics such as microplastic pollution, the nutritional content of fruits, agricultural microbiology, and microbes and human health studies in Guyana.