Effect of Interaction of Methanol Leaf Extract of Spondias mombin (Linn) and Amoxicillin on Some Diarrheagenic Escherichia coli

Purpose: To study the effect of interaction between methanol leaf extract of Spondias mombin and amoxicillin on diarrheagenic Escherichia coli (DEC).Methods: Cold methanol extraction of Spondias mombin leaf and its phytochemical screening were carried out. Isolated, characterized and identified strains of enterotoxigenic E. coli (ETEC), enteroinvasive E. coli (EIEC), and enterohemorrhagic E. coli (EHEC) from watery stool, mucoid bloody stool and watery bloody stool of diarrheal patients, respectively, were confirmed and typed by conventional and molecular methods. The minimum inhibitory concentration (MIC) and ½ MIC at which the extract and amoxicillin interacted were determined.Results: Spondias mombin extract showed remarkable antibacterial activity at extract concentration of 50 - 200 mg/mL with a mean zone of inhibition (MZ) ≥ 11.1 and activity index (AI) of 0.8 - 1.1. MIC of 12.5 mg/mL was observed for both ETEC and EIEC while it was 6.25 mg/mL for EHEC. The extract showed synergistic interaction at various concentrations (50 – 200, 12.5 and 6.25 mg/mL, respectively) with amoxycillin against ETEC, EHEC and EIEC. Synergy across a wide range of concentrations compared favourably with the ½ MIC and MIC of both extract and amoxycillin for ETEC. The extract contained moderate levels of alkaloids, flavonoids and tannins, as well as a lot of saponins, and low levels of phenol. The activity of the extract of Spondias mombin compares well with that of amoxicillin with AI ≥ 1 in some cases.Conclusion: A synergistic interaction between the leaf extract of S. mombin and amoxicillin confirms the extract as potential antibacterial agent but further studies are required to ascertain this.Keywords: Diarrheagenic E. coli, Drug interaction, Spondias mombin, Amoxicillin, Time-kill, Activity inde

The analysis of physicochemical characteristics of pig farm seepage and its possible impact on the receiving natural environment

Pig farm seepage poses an environmental risk, considering that seepage can be generally applied on land without appropriate agronomic criteria or may accidentally spill on the natural environment. These environmental risks include increasing oxygen demand, nutrient loading of water-bodies, promoting toxic and algal blooms eutrophication, thus, leading to a destabilized environment. This research was conducted to determine the impact that the pig farm seepage may have the receiving environment based on the analyses of the physicochemical parameters of the adjacent environments. Wastewater and soil samples were collected between the periods of March 2013 to August 2013 and wastewater was analyzed for pH, temperature, Biological Oxygen Demand (BOD), Chemical Oxygen Demand (COD), Total Dissolved Solids (TDS), salinity, turbidity, Dissolved Oxygen (DO), NO3, NO2, and PO4 3−. The results for wastewater samples for BOD (163 mg/L to 3350 mg/L), TDS (0.77 g/L to 6.48 mg/L), COD (210 mg/L to 9400 mg/L), and NO3 (55 mg/L to 1680 mg/L), were higher than the maximum permissible limits. Results of soil samples for TDS (0.01g/L to 0.88 g/L), COD (40 mg/L to 304 mg/L), NO3 (32.5 mg/L to 475 mg/L), and NO2 (7.35 mg/L to 255 mg/L) were also higher than recommended limits. The results revealed that the seepage from pig farm degraded the natural environment by causing eutrophication, promote toxic and algal blooms, increase oxygen demand and thus destabilize the homeostatic balance of the receiving environment.Keywords: Physicochemical parameters, pollution, soil, wastewater, seepage, pig farm, environmen

Isolation, identification and screening of potential probiotic bacteria in milk from South African Saanen goats

This study aimed to evaluate lactic acid bacteria isolates from Saanen goats’ milk for probiotic attributes, thereby determining their potential as direct-fed microbials for goats. Isolates were identified using API 50CH system, 16S rDNA sequencing and matrix-assisted laser desorption ionization-time of flight mass spectrometry. All 17 isolates obtained were identified as Lactobacillus plantarum except one identified as Pediococcus acidilactici. Four isolates identified as L. plantarum (Accession numbers KJ026587.1, KM207826.1, KC83663.1 and KJ958428.1) by at least two of the techniques used and isolate 17 differently identified by all the methods used were selected as representatives and then screened for probiotic properties. These isolates displayed phenotypic probiotic attributes including tolerance to acid and bile salts, ability to adhere to intestines and possession of antagonistic activities against Proteus vulgaris, Staphylococcus aureus, Salmonella typhimurium, Pseudomonas aeruginosa and Escherichia coli. The lactic acid bacteria isolated from Saanen goats’ milk showed potential to be used as sustainable probiotics in goats’ industry. Successful use of probiotics in animals depends upon availability of appropriate isolates originating from the specific host animal. This study is a positive contribution towards identification of isolates with potential for formulation as direct-fed microbials for South African Saanen goats.The Agricultural Research Council, Irene, South Africahttp://link.springer.com/journal/126022018-09-01hb2017Microbiology and Plant Patholog

Anti-staphylococcal, anti-HIV and cytotoxicity studies of four South African medicinal plants and isolation of bioactive compounds from Cassine transvaalensis (Burtt. Davy) codd

Background: Medicinal plants represent an important opportunity to rural communities in Africa, as a source of affordable medicine and as a source of income. Increased patient awareness about safe usage is important as well as more training with regards to traditional medicine. The aim of this study was to evaluate the ethnomedicinal prowess of some indigenous South African plants commonly used in Eastern Cape Province of South Africa for the treatment of skin and respiratory tract infections, HIV and their toxicity potential. Methods: Cassine transvaalensis, Vangueria infausta, Croton gratissimus and Vitex ferruginea were tested for antibacterial activities against Staphylococcus aureus and Staphylococcus epidermidis using Kirby-Bauer disk diffusion and minimum inhibition concentration (MIC). Cytotoxic and anti-HIV-1 activities of plants were tested using MTT Assay (3- (Dimethylthiozole-2-yl-2,5-diphenyltetrazolium bromide)) and anti- HIV-1iib assay. In search of bioactive lead compounds, Cassine transvaalensis which was found to be the most active plant extract against the two Staphylocoous bacteria was subjected to various chromatographic. Thin layer chromatography, Column chromatography and Nuclear Magnetic Resonance (NMR), (1H-1H, 13C-13C, in DMSO_d6, Bruker 600 MHz) were used to isolate and characterize 3-Oxo-28-hydroxylbetuli-20(29)-ene and 3,28-dihydroxylbetuli-20(29)-ene bioactive compounds from C. transvaalensis. Results: The four plants studied exhibited bioactive properties against the test isolates. The zones of inhibition rangedbetween 16 mm to 31 mm for multi-drug resistant staphylococci species. MIC values varied between 0.6 and 0.02 μg/ml. C. gratissimus and C. transvaalensis exhibited the abilities to inhibit HIV-1iib. Two bioactive compounds were isolated from C. transvaalensis. Conclusion: Data from this study reveals the use of these plant by traditional healers in the Eastern Cape. Furthermore, C. transvaalensis and C. gratissimus were found to be more active as against HIV-1iib. While C. transvaalensis was most active against the two Staphylococcus bacteria

Evaluation of Antibacterial and Antifungal Properties of Alchornea laxiflora

Alchornea laxiflora leaf extract was tested against a range of microorganisms using standard microbiological methods for antimicrobial activities. The extract inhibited the growth of all the bacterial and 15 fungal isolates tested. The zones of inhibition exhibited against the test bacteria ranged between 12 mm and 24 mm and between 11 mm and 24 mm for the extract and the antibiotic streptomycin, respectively. The zones of inhibition observed against the fungal isolates by the extract ranged between 12 mm and 23 mm. The minimum inhibitory concentrations (MICs) and the minimum bactericidal concentrations (MBCs) exhibited by the extract against test bacteria ranged between 0.78 mg/mL–25 mg/mL and 1.56 mg/mL–25 mg/mL, respectively, while the MICs and minimum fungicidal concentrations (MFCs) values for the test fungi ranged between 8.75 mg/mL–35.00 mg/mL and 8.75 mg/mL–35.00 mg/L, respectively. The preliminary phytochemical screening of the extract revealed the presence of alkaloids, tannins, flavonoids, saponins, and reducing sugars as major phytoconstituents in the extract. A. laxiflora leaf extract is a potent source of antibacterial and antifungal compounds; further studies on the extract are ongoing in our laboratories to elucidate the probable mechanism(s) of action on bacteria and fungi found to be susceptible to the extract

Preliminary phytochemical screening and In vitro antioxidant activities of the aqueous extract of Helichrysum longifolium DC

<p>Abstract</p> <p>Background</p> <p>Many oxidative stress related diseases are as a result of accumulation of free radicals in the body. A lot of researches are going on worldwide directed towards finding natural antioxidants of plants origins. The aims of this study were to evaluate <it>in vitro </it>antioxidant activities and to screen for phytochemical constituents of <it>Helichrysum longifolium </it>DC. [Family Asteraceae] aqueous crude extract.</p> <p>Methods</p> <p>We assessed the antioxidant potential and phytochemical constituents of crude aqueous extract of <it>Helichrysum longifolium </it>using tests involving inhibition of superoxide anions, DPPH, H₂O₂, NO and ABTS. The flavonoid, proanthocyanidin and phenolic contents of the extract were also determined using standard phytochemical reaction methods.</p> <p>Results</p> <p>Phytochemical analyses revealed the presence of tannins, flavonoids, steroids and saponins. The total phenolic content of the aqueous leaf extract was 0.499 mg gallic acid equivalent/g of extract powder. The total flavonoid and proanthocyanidin contents of the plant were 0.705 and 0.005 mg gallic acid equivalent/g of extract powder respectively. The percentage inhibition of lipid peroxide at the initial stage of oxidation showed antioxidant activity of 87% compared to those of BHT (84.6%) and gallic acid (96%). Also, the percentage inhibition of malondialdehyde by the extract showed percentage inhibition of 78% comparable to those of BHT (72.24%) and Gallic (94.82%).</p> <p>Conclusions</p> <p>Our findings provide evidence that the crude aqueous extract of <it>H. longifolium </it>is a potential source of natural antioxidants, and this justified its uses in folkloric medicines.</p

Synergistic interaction of Helichrysum pedunculatum leaf extracts with antibiotics against wound infection associated bacteria

The effect of combinations of the crude methanolic extract of the leaves of Helichrysum pedunculatum and eight first-line antibiotics were investigated by time kill assays against a panel of bacterial strains that have been implicated in wound infections. The plant extract showed appreciable antibacterial activities against the test bacteria with zones of inhibition ranging between 18 and 27 mm, and minimum inhibitory concentrations (MICs) varying between 0.1 and 5.0 mg/ml. The MICs of the test antibiotics range between 0.001 and 0.412 mg/ml, and combination of the plant extract and the antibiotics resulted in reduction of bacterial counts by between 0 and 6.63 Log10 cfu/ml. At V2 MIC, 56.81% synergy; 43.19% indifference and no antagonism were observed, and at MIC levels, 55.68% synergy; 44.32% indifference and no antagonism were observed when the extracts were combined with eight different antibiotics. In all, 60% of the interactions were synergistic. All combination regimes on Staphylococcus aureus ATCC 6538 yielded no synergy, neither was antagonism detected in any of the assays. We propose that extracts of the leaves of Helichrysum pedunculatum could be of relevance in combination therapy and as a source of resistance modifying principies that could be useful as treatment options for persistent wound infections