Test Organisms Research Articles

New QSTR models to evaluation of imidazolium- and pyridinium-contained ionic liquids toxicity

We present machine learning studies devoted to the creation of predictive models for toxicity evaluation of imidazolium- and pyridinium-containing ionic liquids. New created predictive models were developed using the OCHEM. The predictive ability of the models was tested by cross-validation, giving a coefficient of determination q2 = 0.77–0.82. The models were applied to screen a virtual chemical library to the toxicity of ILs in Danio rerio and Daphnia magna bioassays. Models were used to predict toxicity for 25 ILs, which were then synthesized and tested in vivo. The in vivo toxicity studies found that D. magna is a more sensitive aquatic test organism than D. rerio – 67 % of the studied ILs are classified as extremely toxic with an LC50 range from 0.005 to 0.01 mg/l. At the same time, only one IL 1-dodecylpyridinium bromide with an LC50 of 0.08 mg/l is classified as extremely toxic, and 76 % are classified as slightly and moderately toxic compounds using D. rerio as a test organism. The most toxic ILs 5 and 19 were docked into the human AChE active center and demonstrated calculated binding energy values −9.5 and −9.3 kcal/mol that is comparable with the complexation of the human AChE inhibitor Donepezil, which provides insight into the potential molecular mechanisms of ILs toxicity. The created QSTR models are a successful tool for the toxicity analysis of new promising ILs. QSTR models demonstrated not only high predictive indicators but also a high percentage of correctly predicted toxicity values in vivo studies.

Antifouling activities of proteinase K and α-amylase enzymes: Laboratory bioassays and in silico analysis

The application of enzymes as antifoulants is one of the environment-friendly strategies in biofouling management. In this study, antifouling activities of commercially available proteinase K and α-amylase enzymes were evaluated using barnacle larva and biofilm-forming bacteria as test organisms. The enzymes were also tested against barnacle cement protein through in silico analysis. The results showed that both enzymes inhibited the attachment of bacteria and settlement of barnacle larvae on the test surface. The lowest minimum inhibitory concentration of 0.312 mg ml−1 was exhibited by proteinase K against biofilm-forming bacteria. The calculated LC50 values for proteinase K and α-amylase against the barnacle nauplii were 91.8 and 230.96 mg ml−1 respectively. While α-amylase showed higher antibiofilm activity, proteinase K exhibited higher anti-larval settlement activity. Similarly, in silico analysis of the enzymes revealed promising anti-settlement activity, as the enzymes showed good binding scores with barnacle cement protein. Overall, the results suggested that the enzymes proteinase K and α-amylase could be used in antifouling coatings to reduce the settlement of biofouling on artificial materials in the marine environment.

Continuous warming drives the colonization dynamics of periphytic ciliate fauna in marine environments.

In order to evaluate the influence of global warming on the ecosystem processes in marine environments, the changes in colonization dynamics of periphytic microbiota were studied using the periphytic ciliate communities as the test organism fauna under a continuous warming gradient of 22℃ (control), 25℃, 28℃, 31℃, and 34 ℃. The results demonstrated that (1) the test ciliate communities generally showed a similar temporal pattern in within the colonization process under the water temperatures from 22 up to 28℃; however, (2) the colonization dynamics were significantly changed, and the fitness of colonization curves to the MacArthur-Wilson model equation was failed under the temperature increased by 6 ℃, and (3) the loading or assimilative capacity of the test aquatic ecosystem was decreased with the increase of water temperature. Therefore, this study suggests that continuous warming may significantly drive the colonization dynamics of periphytic ciliates in marine ecosystems.

Enhancing the biodiesel production in the green alga Chlorella vulgaris by heavy metal stress and prediction of fuel properties from fatty acid profiles.

The green microalga Chlorella vulgaris was used as a test organism during this study for evaluation of the impact of different heavy metal stress, Mn2+, Co2+, and Zn2+, on enhancing the biodiesel production. The algal cultures were grown for 13 days under heavy metal stress after which were subjected to estimation of growth, some primary metabolites, lipid, and fatty acid profiles. The maximum lipid accumulation (283.30 mg/g CDW) was recorded in the algal culture treated with 3µM cobalt nitrate. Application of 2 mM manganese chloride; 1, 2, and 3 μM cobalt nitrate; and 0.2, 0.4, and 0.6 mM zinc sulfate caused highly significant increases in the lipid contents amounting to 183.8, 191.4, 230.6, 283.3, 176.3, 226.0, and 212.1 mg/g CDW, respectively, in comparison to control (153.4 mg/g CDW). The maximum proportion of saturated fatty acids (SFA) (64.44%) was noted in the culture treated with 6 mM MnCl2 due to the existence of palmitic acid (C16:0), stearic acid (C18:0), and pentadecylic acid (C15:0) which are represented by 53.59%, 5.96%, and 1.37%, respectively, of the total FAs. Relative increase in energy compound (REEC) showed that 1, 2, and 3 µM Co2+ lead to the highest stimulation in lipid and carbohydrate contents to 0.207, 0.352, and 0.329×103%, respectively. Empirical formulas were used for the assessment of biodiesel fuel properties based on FAME composition. The estimated properties met the prescribed international standard criteria.

Streptomyces phaeochromogenes BV-204, K-1115A Anthraquinone-Producing Strain: A New Protein Biosynthesis Inhibitor.

In the search for new antibiotics, it is a common occurrence that already known molecules are "rediscovered" while new promising ones remain unnoticed. A possible solution to this problem may be the so-called "target-oriented" search, using special reporter microorganisms that combine increased antibiotic sensitivity with the ability to identify a molecule's damaging effect. The use of such test organisms makes it possible to discover new promising properties even in known metabolites. In this study, we used a high-throughput screening method based on the pDualrep2 dual reporter system, which combines high sensitivity through the use of modified strains of test organisms and makes it possible to easily and accurately identify the interaction mechanisms of a substance and a bacterial cell at the initial stages of screening. This reporter system is unknown in Russia and is significantly superior to its global analogues. In the system, translation inhibition induces the expression of the fluorescent protein Katushka2s, while DNA damage is induced by TurboRFP. Using pDualrep2, we have isolated and described BV-204, an S. phaeochromogenes strain producing K-1115A, the biologically active substance that we have previously described. In our study, K-1115A for the first time has demonstrated antibiotic activity and an ability to inhibit bacterial translation, which was confirmed in vitro in a cell-free translation system for FLuc mRNA. K-1115A's antibacterial activity was tested and confirmed for S. aureus (MRSA) and B. subtilis, its cytotoxicity measured against that for the HEK293 cell line. Its therapeutic index amounted to 2 and 8, respectively. The obtained results open up prospects for further study of K-1115A; so, this can be regarded as the basis for the production of semi-synthetic derivatives with improved therapeutic properties to be manufactured in dosage forms.

Side of chute does not affect the sensitivity of Tritrichomonas foetus sample collection in bulls when using dominant hand for collection

Tritrichomonas foetus, a sexually transmitted disease in cattle, continues to plague the cattle industry despite years of control programs. One reason for this continued prevalence through­out the U.S. and the world is that accurate diagnosis is compli­cated in the fact that retrieval of organisms for diagnosis and subsequent testing may be compromised by multiple factors in­cluding, but not limited to, how samples are collected. A commonly used sampling technique for diagnosing T. foetus in bulls is scraping of the preputial and penile mucosa with ei­ther an artificial insemination pipette or specially designed T. foetus testing device such as the Pizzle Stick Trich Testing De­vice (Lane Manufacturing Denver, CO). Parker et al. noted that right-hand dominant practitioners were more commonly suc­cessful in retrieving T. foetus in known positive bulls when col­lecting from the right side of the bull compared to the left; how­ever, the opposite was not investigated for left-hand dominant practitioners and only cultures were used to declare whether a sample was positive or not. The objective of this study was to determine if using current RT-qPCR testing if there is a differ­ence in rate of positive tests pending side of chute and use of dominant hand for testing.

Particulate and water-mobilizable phosphorus from a watershed with a plain river network contributes equal amounts of algal available phosphorus to its downstream lake

This research was designed to estimate the contributions of phosphorus (P) in different factions from an upstream plain river network to algal growth in a downstream shallow eutrophic lake, Taihu Lake, in China. During three flow regimes, the P fractions in multiple phases (particulate, colloidal and dissolved phases) and their algal availabilities were assessed via bioassays with Dolichospermum flos-aquae as the test organism. The P partitioning patterns among multiple phases were strongly affected by the concentration of total suspended solids (TSS) that changed with the river flow regime, with stronger disturbance of sediments at lower water levels (low flow) and weaker disturbance of sediments at higher water levels (high flow) in the plain river network. The median TSS concentration across the river network decreased from 157.4 mg/L during low flow to 31.8 mg/L during high flow, and the median particulate P concentration decreased from 0.132 mg/L to 0.093 mg/L. The particulate P contributed equally to the amount of algal available P (AAP) as did the water-mobilizable P (colloidal plus dissolved phase) in the rivers flowing into Taihu Lake. The annual average concentrations of particulate algal available P (P-AAP), colloidal algal available P (C-AAP) and dissolved algal available P (D-AAP) were estimated to be 0.032 mg/L, 0.012 mg/L and 0.019 mg/L, respectively, during 2012–2018, accounting for 50.8 %, 19.0 % and 30.2 %, respectively, of the total AAP. At the watershed scale, controlling P drainage from downstream urbanized areas should be emphasized. Additionally, controlling sediment resuspension or reducing the TSS concentration in the inflowing rivers is important for decreasing the particulate P flux to downstream lakes.

EFFECT OF WASTE ENGINE OIL ON PROXIMATE, PHYTOCHEMICAL, AND ANTIBACTERIAL CONSTITUENTS OF Teffairia Occidentalis (PUMPKIN LEAF)

The improper disposal of waste engine oil effluent onto gutters, open lands, and cultivated farm lands is a common practice in Nigeria, especially among mechanics. These effluents contain substances derived from hydrocarbons that can diminish soil fertility and also influence the properties of plants. This study was consequently undertaken to examine the effects of waste engine oil on the nutritional, phytochemical, and antibacterial constituents of Telfairia occidentalis (Pumpkin leaf). Various levels (0ml, 100ml, 200ml, 300ml, and 400ml) of diesel oil contamination were mixed with 2 kilograms (kg) of soil, with each treatment replicated three times. Plants were watered daily for four months, and after 16 weeks, leaf samples were collected for laboratory analysis. The nutritional composition, phytochemical properties, and antibacterial components of the leaves were examined. The results indicated a significant reduction (P<0.05) in protein (12±0.02), fats (7±0.02), ash (15±0.25), fiber (10±0.03), and carbohydrate (10±0.25) content in the 400ml waste oil treatment compared to the control (0ml) values (protein: 38±0.01, crude fat: 25±0.13, total ash: 45±0.07, crude fiber: 36±0.15, carbohydrate: 42±0.04). Phytochemical analysis demonstrated a noteworthy decrease in alkaloids, saponins, flavonoids, and phenols as waste oil levels increased in the soil, compared to the control (0ml). The antibacterial activity screening revealed that among the various concentrations (80mg/ml, and 20mg/100 ml) of extracts studied, 80g/ 100 ml showed the highest degree of inhibition on all the test organisms. However, there was a notable reduction in inhibition as the level of waste oil pollution increased in the soil, compared to the control...

TOXICITY OF LITHIUM BATTERY WASTE ON SELECTED INVERTEBRATES

Electronic waste poses a major menace to ecosystems owing to the toxic properties of materials used for the manufacture of electronic goods. In this present study, the toxicity of lithium battery waste on invertebrates, snails (Archachatina marginata) and earthworms (Apporrectodeal longa) were evaluated using appropriate concentrations of toxicant. The physicochemical and heavy metal analysis of the toxicant was carried out according to the method of APHA (2008). The standard protocol obtained from the Organization for Economic Cooperation and Development (OECD) and the protocol obtained from the International Organization for Standardization (ISO) were adopted for the 14-day exposure to varying concentrations of the toxicant (0.3125, 0.625, 1.25, 2.5 and 5.0 mg/kg) for earthworm and (3.125,6.25, 12.5, 25 and 50 mg/kg) for snail respectively. The pH, Electrical conductivity. Total dissolved solids, Lithium, cadmium and mercury results of the toxicant were (2.6, 13500, 8640, 36.60, 2.03 and 10.48mg/L) respectively. The result also shows an increased in the mortality of test organisms with increase in toxicant concentration. LC50, LOEC, NOEC, TUc and TUa with exposure time for snails and earthworms were (1.05, 0.86,0.77,94.88, 129.87 mg/kg) and (0.68, 0.41,0.31, 147.06, 322.58.mg/kg), respectively. The study established that the toxicant (lithium battery) is considered a high risk to animals, plants and the environment as it adversely affects soil invertebrates which bring about soil fertility if not properly disposed of.

Assessing the impact of antiviral drugs commonly utilized during the COVID-19 pandemic on the embryonic development of Xenopus laevis

The antiviral drugs favipiravir and oseltamivir are widely used to treat viral infections, including coronavirus 2019 (COVID-19), and their levels are expected to increase in the aquatic environment. In this study, the potential toxic and teratogenic effects of these drugs were evaluated using the frog embryo teratogenesis assay Xenopus (FETAX). In addition, glutathione S-transferase (GST), glutathione reductase (GR), catalase, carboxylesterase (CaE), and acetylcholinesterase (AChE) enzyme activities and malondialdehyde levels were measured as biochemical markers in embryos and tadpoles for comparative assessment of the sublethal effects of the test compounds. Prior to embryo exposure, drug concentrations in the exposure medium were measured with high-performance liquid chromatography. The 96-h median lethal concentration (LC50) was 137.9 and 32.3 mg/L for favipiravir and oseltamivir, respectively. The teratogenic index for favipiravir was 4.67. Both favipiravir and oseltamivir inhibited GR, CaE, and AChE activities in embryos, while favipiravir increased the GST and CaE activities in tadpoles. In conclusion, favipiravir, for which teratogenicity data are available in mammalian test organisms and human teratogenicity is controversial, inhibited Xenopus laevis embryo development and was teratogenic. In addition, sublethal concentrations of both drugs altered the biochemical responses in embryos and tadpoles, with differences between the developmental stages.

Chemical profiling and antimicrobial potential of crude extract and essential oil from Conyza bonariensis leaves

Background and objectives: Microbial infections have made significant contributions to the global health burden, particularly in developing countries with lagging economies. Challenges arising from the evolution of antimicrobial resistant (AMR) bacteria have led to the search for novel antimicrobial agents, especially those derived from medicinal plants. Therefore, this study aimed to assess the antibacterial activity of ethyl acetate crude extracts and essential oils from C. bonariensis collected from the Mbeya region of Tanzania. Methods: Initial experimental activities involved preparation of crude extracts and essential oil, which were then, tested for antimicrobial activity against selected test organisms (Staphlococcus aureus (ATCC29213), Bacillus subtilis (ATCC6051), Escherichia coli (ATCC8736), Salmonella typhi (ATCC6539), and Candida albicans (DSM1665)) by using the disc diffusion method. On the other hand, the chemical composition profiling of ethyl acetate and essential oils was performed by gas chromatography mass spectrometry (GC-MS). Results: The crude extracts and essential oil of C. bonariensis leaves from Tanzania demonstrated to have antibacterial and antifungal activity. The minimum inhibition concentration (MIC) of leaves ethyl acetate crude extract was 25 mg/mL > MIC > 12.5 mg/mL for tested organisms, with the exception of C. albicans, where the MIC was 50 mg/mL > MIC > 25 mg/mL. Similary, for all tested organisms, the MIC of leaves essential oils was :1 > MIC > l:2, except S. typhi, where the MIC was 2:1 > MIC > 1:1. On the other hand, 2,4-di-tert-butyl phenol in leaves crude extracts had the highest percentage composition of peak area (41%); whereas, in essential of, 2,4-Di-tert-butyl phenol had the highest percentage composition (38.8%). Conclusions: The present findings have demonstrated antimicrobial potential of ethyl acetate crude extract and essential oil of C. bonariensis leaves from Tanzania, and validate the wide use of the plant by local communities, particularly the local community of Mbeya region in Tanzania.

Valorization of waste engine oil to mono- and di-rhamnolipid in a sustainable approach to circular bioeconomy.

This study aims to valorize waste engine oil (WEO) for synthesizing economically viable biosurfactants (rhamnolipids) to strengthen the circular bioeconomy concept. It specifically focuses on investigating the influence of key bioprocess parameters, viz. agitation and aeration rates, on enhancing rhamnolipid yield in a fed-batch fermentation mode. The methodology involves conducting experiments in a stirred tank bioreactor (3 L) using Pseudomonas aeruginosa gi |KP 163922| as the test organism. Central composite design and response surface methodology (CCD-RSM) are employed to design the experiments and analyze the effects of agitation and aeration rates on various parameters, including dry cell biomass (DCBM), surface tension, tensoactivity, and rhamnolipid yield. It is also essential to determine the mechanistic pathway of biosurfactant production followed by the strain using complex hydrophobic substrates such as WEO. The study reveals that optimal agitation and aeration rates of 200rpm and 1 Lpm result in the highest biosurfactant yield of 29.76g/L with minimal surface tension (28 mN/m). Biosurfactant characterization using FTIR, 1H NMR, and UPLC-MS/MS confirm the presence of dominant molecular ion peaks m/z 543.9 and 675.1. This suggests that the biosurfactant is a mixture of mono- and di-rhamnolipids (RhaC10C10, RhaRhaC10C12:1, RhaRhaC12:1C10). The findings present a sustainable approach for biosurfactant production in a fed-batch bioreactor. This research opens the possibility of exploring the use of pilot or large-scale bioreactors for biosurfactant production in future investigations.

Histopathological investigation of some facial cosmetic products mixture exposed to fingerlings of mud catfish <i>(Clarias gariepinus</i>)

Cosmetics are one of the major pollutants in the aquatic ecosystem due to the quantum of production to meet the astronomical demand of users that eventually becomes harmful to organisms. Changes in physic-chemical parameters such as potential of hydrogen (pH), Electrical conductivity (EC), Temperature (T oC) Dissolved oxygen (DO) were investigated at the beginning and after 96 hours of cosmetic exposure. This study also investigated the effects of four facial cosmetic products (Powder, foundation, concealer, and primer) histopathologically in fingerlings of Clarias gariepinus (gills) exposed to binary, trinary, and quaternary mixtures in o laboratory bioassays for 48 hours and 96 hours. The results of pH, T C, EC and DO ranged from 6.21 - 6.64, o 25.40 - 26.70 oC, 0.04 - 0.14 mS/cm, and 10.00 -12.00 mg/l respectively. The joint action toxicity evaluation of the binary, trinary, and quaternary mixtures of the cosmetics prepared based on an equitoxic ratio against the test organism was in concordance with the model of synergism. Results showed the prevalence of severe lamellar necrosis in the gills of C. gariepinus which was observed across all combinations except in the combinations of Powder + Primer as well as Powder + Foundation + Concealer + Primer. Moderate lamellar necrosis and hypertrophied epithelium were observed in fish exposed to a mixture of Powder + Foundation + Concealer. The results obtained in this study suggested that the presence of facial cosmetics in the aquatic ecosystem could be dangerous to fish and subsequently human health via biomagnification. Therefore, there is an urgent need for environmental regulators to enforce safety standards for the emission of these selected cosmetics wastes into the waterways to prevent damage to aquatic organisms and public health issues.

Effect of Probiotic on Copper Nanoparticle Accumulation in Dreissena polymorpha

Materials with dimensions between 0.1 and 100 nm are called nanoparticle (NP) materials. In recent years, the usage areas and quantities of NP materials have increased in parallel with the development of the industry. The need and usage areas of heavy metals such as Cu have also expanded in NP sizes. All these developments have led to problems on the ecosystem that are becoming more difficult to compensate. In this study, Zebra Mussel (Dreissena polymorpha) was chosen as a model to investigate the effect of probiotics on CuNP heavy metal accumulation. The model organism was exposed to three different concentrations of CuNP (5, 10, 50 mg/L) with probiotics and directly for 24 and 96 hours. CuNP accumulation amounts in D. polymorpha tissues treated directly and with probiotics were compared. The amount of accumulation in the test organism directly exposed to CuNP was higher compared to the groups administered with probiotics, but a statistically significant difference (p<0.05) was found only in the treatment group with the highest 24-hour concentration (50 mg/L). As a result, according to the findings obtained from the study, it has been determined that probiotics have positive developmental effects on aquatic organisms, as well as beneficial in the elimination of their accumulation in the organism.

Influence of dissolved oxygen in the environment on toxicity indices obtained by various bio-testing methods

RELEVANCE of the study comes from the understanding of the necessity of continuous development of toxicological analysis. Since The simplest organisms are used in toxicological analysis as bioindicators, the reactions of which to the presence of certain pollutants will always differ, the only way to assess the usefulness of a bioindicators as a tool is to study its behavior under specific tasks. Biondicators differ in their metabolic properties, in particular, in the ways of obtaining energy from the presence of molecular oxygen in the environment. However, it is assumed that the presence of different concentrations of oxygen in the environment affects the behavior of the simplest organisms, which, in its turn, can affect the results of toxicological analysis. Previously, this effect has not been studied. THE PURPOSE. The research of the effect of dissolved oxygen on toxicity indices obtained using of bacteria Escherichia coli (Migula) Castellani and Chalmers and ciliates Paramecium caudatum Ehrenberg, METHODS. Obtaining indices of toxicity is given with different concentrations of dissolved oxygen in the environment, which are distilled water and Bonaqua brand water, by the bioluminescent reaction of bacteria and chemotactic reaction of ciliates. RESULTS. With an increase in the concentration of dissolved oxygen in the environment, the bioluminescence of bacteria increases, therefore, the toxicity index decreases. No effect on ciliates is observed. CONCLUSION. It can be concluded that dissolved oxygen does not affect the biotest analysis using ciliates. When using bacteria as a test organism, an error occurs in the toxicity index.

Copper-zinc metal complex exhibiting bactericidal and antibiofilm activity by membrane damage and quorum sensing inhibition

A hetero di nuclear complex [Zn(o-phen)LCu(OAc)] (K3 compound), where, H3L = o-HOC6H4C(H)=N−NH−C(OH)=N−NC(H)−C6H4OH-o, o-phen = 1,10-phenanthroline, and OAc = CH3COO− was synthesized. The Schiff base ligand in its keto form used for synthesis was derived from the condensation of salicylaldehyde and carbohydrazide, however, the Schiff base was found to coordinate in its enol form (L3−) as it was confirmed from the reported crystal structure of K3 compound. The K3 compound displayed significant antibacterial activity in both planktonic and biofilms of the test organisms, Pseudomonas aeruginosa and Staphylococcus aureus. The anti-quorum sensing activity was investigated in P. aeruginosa to determine the effect of the K3 compound on bacterial chemo-signaling networks that collectively control bacterial virulence, including twitching motility, swarming motility, rhamnolipids, pyocyanin and, exopolysaccharide production. The synthesized novel hetero Zn(II)/Cu(II)-based di-nuclear complex [Zn(o-phen)LCu(OAc)], K3 compound exhibited potent antibacterial and antibiofilm properties against P. aeruginosa and S. aureus, with significant biofilm disruption, inhibition, and anti-quorum sensing effects, making it a promising candidate for further investigation as a potential antibacterial agent.

Polymeric Amorphous Solid Dispersions of Dasatinib: Formulation and Ecotoxicological Assessment.

Dasatinib (DAS), a potent anticancer drug, has been subjected to formulation enhancements due to challenges such as significant first-pass metabolism, poor absorption, and limited oral bioavailability. To improve its release profile, DAS was embedded in a matrix of the hydrophilic polymer polyvinylpyrrolidone (PVP). Drug amorphization was induced in a planetary ball mill by solvent-free co-grinding, facilitating mechanochemical activation. This process resulted in the formation of amorphous solid dispersions (ASDs). The ASD capsules exhibited a notable enhancement in the release rate of DAS compared to capsules containing the initial drug. Given that anticancer drugs often undergo limited metabolism in the body with unchanged excretion, the ecotoxicological effect of the native form of DAS was investigated as well, considering its potential accumulation in the environment. The highest ecotoxicological effect was observed on the bacteria Vibrio fischeri, while other test organisms (bacteria Pseudomonas putida, microalgae Chlorella sp., and duckweed Lemna minor) exhibited negligible effects. The enhanced drug release not only contributes to improved oral absorption but also has the potential to reduce the proportion of DAS that enters the environment through human excretion. This comprehensive approach highlights the significance of integrating advances in drug development while considering its environmental implications.

Phytochemical Profile and Antibacterial Effects of Zingiber Officinale Root Extract on Some Enteric Bacterial Pathogens

The majority of Africans today depend either totally or partially on medicinal plants for the treatment of various diseases. In some rural communities, ethno-medicine is sometimes the only form of healthcare. Therefore, this work aimed to determine the phytochemical constituents and antibacterial potentials of Z. officinale, which is one of the medicinal plants used by some people. The active ingredients of the plant were first extracted using water and ethanol as solvents. This was followed by the phytochemical analysis of the extracts. Furthermore, the antibacterial effects of aqueous and ethanolic extracts of Z. officinale on Escherichia coli, Salmonella typhi and Shigella dysenteriae isolated from faeces of gastroenteritis patients were evaluated using the agar diffusion technique (punch method). Additionally, a two-fold tube dilution method was used to determine the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of the extracts. The mean values of zones of inhibition obtained were statistically analyzed using ANOVA. The least significant difference was determined according to the LSD test at P<0.05. Phytochemical analysis revealed the presence of saponin, alkaloids, flavonoids, and tannins. The antibacterial results showed that both the aqueous and ethanolic extracts have antibacterial effects against all the test organisms but at varying degrees. At the 500mg/ml concentration, the ethanolic extract of Zingiber officinale produced a zone of inhibition of 21.00b against S. dysenteriae and 20.00b against E. coli and S. typhi. On the other hand, the 500mg/ml concentration of the aqueous extract had a zone of inhibition of 20.00b against S. dysenteriae, 16.00b against E. coli and 10.00b against S. typhi. The findings from this study lend credence to the claims that Z. officinale extracts possess antibacterial potentials. Also, the higher potency in ethanolic than in aqueous extract suggests that the potency might be dose and solvent dependent. Conclusively, owing to the findings from this study, the active ingredients of Z. officinale could be harnessed and employed in the development of novel antibacterial therapies.

Antimicrobial Properties of Cola Nitida

The antimicrobial evaluation of ethanol, methanol and aqueous extracts of Cola nitida on Staphylococcus aureus, Pseudomonas aeruginosa and Escherichia coli was experimented. The assay was carried out by agar disc diffusion method. Results showed that the ethanol, methanol and aqueous extracts of the seed were found to be of a relatively higher effect having a zone of inhibition of 5mm against the samples of S. aureus than the other bacteria at the concentration of 400mg/mm. None of the extract was active against P. aeruginosa. E. coli showed a zone of inhibition of 3mm with ethanolic extract but showed a lower zone of inhibition with both methanol and aqueous extract. When compared to standard antibiotics such as septrin, amoxicillin, tetracycline, ampiclox and doxycycline, all the extracts had a high zone of inhibition of 5mm on S. aureus except for doxycycline which showed a higher zone of inhibition on all the test organisms. This antimicrobial property showed by the seed extracts on some of the organisms is an evidence of the ethno-medicinal uses of the plants due to the presence of some phytochemicals such as saponins, tanins, and alkaloids among others. For effective utilization of these Cola seeds as well as other relevant parts of the Cola plant, further research has been recommended.

The Phytochemical Composition and Antibacterial Effects of Allium sativum Clove Extracts on Some Enteric Bacterial Pathogens

In this study, the phytochemicals present in the cloves of Allium sativum were determined, and their antibacterial activities against some enteric bacterial pathogens were assessed. The phytochemical constituents were determined after the extraction process was completed using water and ethanol as the solvents. Furthermore, the aqueous and ethanolic extracts of A. sativum were tested against Escherichia coli, Salmonella typhi and Shigella dysenteriae isolated from faeces of gastroenteritis patients. The agar diffusion technique (punch method) was used for this. Additionally, the extracts' minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) were determined. The mean values of the zones of inhibition obtained were statistically analyzed using ANOVA. The least significant difference was determined according to the LSD test at P<0.05. The results of the phytochemical analysis revealed the presence of saponin, alkaloids, flavonoids, and tannins. Furthermore, the antibacterial susceptibility test showed that the aqueous and ethanolic extracts possess antibacterial properties against all the test organisms. The ethanolic extract at the concentration of 500mg/ml had zones of inhibition of 29.00b against E. coli, 24.00b against S. dysenteriae and the lowest 20.00b against S. typhi. On the other hand, at that same concentration, the aqueous extract had zones of inhibition of 20.00b against E. coli and 18.00b against S. dysenteriae and S. typhi. This study suggests that A. sativum extracts possess antibacterial properties. Furthermore, since the ethanolic extract was more effective than the aqueous extract, it could be that the antibacterial potency of A. sativum is solvent-dependent. In conclusion, the findings from this study suggest that further purification of the constituents of the plant might lead to the development of novel antibiotics.