Bifunctional solid catalysts facilitate the esterification of free fatty acids (FFA) into alkyl esters alongside the transesterification reaction, which allows for the use of waste vegetable oils with high water and FFA contents for biodiesel production. This makes the process economically viable and greener, as the waste fats and oils are readily available. The concurrent esterification and transesterification of waste palm oil (WPO) and waste sunflower oil (WSO) with methanol was investigated in the presence of calcium oxide on alumina catalyst in a conventional batch process. The catalyst characterization showed the existence of calcium oxide aluminates (calcined at 750 °C), which exhibited crystalline phases with porous/spongy-like particles. The high concentration of CaO in CaO/Al₂O₃ was a favorable support material in the heterogeneously-catalyzed transesterification reactions. The optimum catalyst parameters for the production of fatty acid methyl esters (FAMEs) were observed at 65 °C for 4 h with a methanol-to-oil ratio of 9:1, 60% (waste palm oil, or WPO) and 80% (waste sunflower oil, or WSO), CaO/Al₂O₃ (% wt/wt) catalyst ratio as well as 4% CaO/Al₂O₃ concentration (% wt.) for WSO and WPO. The simultaneous esterification/transesterification reactions at optimum conditions on WPO and WSO led to high yield of FAMEs of 89, 61 and 55% for WPO and 54, 75 and 98% for WSO at catalyst ratios (wt %) of 60, 70 and 80% respectively. The use of bifunctional heterogeneous catalyst (CaO/Al₂O₃) with waste vegetable oil can result in high performance and the upscaling of biodiesel production.

Helicobacter pylori prevalence in dyspeptic patients in the Eastern Cape province - race and disease status

Helicobacter pylori is a major risk factor for gastritis, ulcers and gastric cancer. This study was aimed to determine the antimicrobial activity of the stem bark of Bridelia. micrantha on H. pylori isolated in South Africa. Extracts and clarithromycin were tested against 31 clinical strains, including a standard strain (NCTC 11638) of H. pylori, by measuring the diameters of the corresponding inhibition zones, followed by determination of the Minimum Inhibitory Concentration (MIC) (using metronidazole, and amoxicillin as control antibiotics) and the rate of kill. Preliminary phytochemical screening was also done. Inhibition zone diameters which ranged from 0–23 mm were observed for all five of the extracts and 0–35 mm for clarithromycin. Marked susceptibility of strains (100%) was noted for the acetone extract (P < 0.05), followed by ethyl acetate extract (93.5%). The MIC₅₀ values ranged from 0.0048 to 0.156 mg/mL for the ethyl acetate extract and 0.0048 to 0.313 mg/mL for the acetone extract. The MIC₉₀ values ranged from 0.0048 to 2.5 mg/mL for the ethyl acetate extract and 0.078 to >0.625 mg/mL for the acetone extract, respectively. Insignificant statistical difference in potency was observed when comparing the crude ethyl acetate extract to metronidazole and amoxicillin (P > 0.05). Complete killing of strain PE430C by the ethyl acetate extract was observed at 0.1 mg/mL (2 × MIC) and 0.2 mg/mL (4 × MIC) at 66 and 72 h. For strain PE369C, 100% killing was observed at 0.1 mg/mL (2 × MIC) in 66 and 72 h. The ethyl acetate extract could thus be a potential source of lead molecules for the design of new anti-Helicobacter pylori therapies as this study further confirmed the presence of phytochemicals including alkaloids, flavonoids, steroids, tannins and saponins.

We assessed the in vitro antimicrobial activity of Peltophorum africanum by means of the agar well and macrodilution methods. The toxicity on a normal human liver cell (Chang liver cell) was determined using the CellTiter‐Blue cell viability assay, and the compounds contained in the fractions were identified using GC‐MS. Zone diameter of inhibition of the extract ranged from 12.5 ± 0.7 to 32 ± 2.8 mm for bacteria and from 7.5 ± 0.7 to 26.4 ± 3.4 mm for yeast. Marked activity of the extract was observed against Plesiomonas shigelloides ATCC 51903, with MIC and MLC values of 0.15625 and 0.3125 mg/mL, respectively. The extract was both bactericidal (MIC_index ≤ 2) and bacteriostatic/fungistatic (MIC_index > 2) in activity. Lethal dose at 50 (LD₅₀) showed 82.64 ± 1.40 degree of toxicity at 24 hrs, and 95 percentile of cell death dose activity ranged from log 3.12 ± 0.01 to 4.59 ± 0.03. The activity of the eight fractions tested ranged from 1.0 ± 0.5 to 3.7 ± 1.6 mg/mL (IC₅₀) and from 2.1 ± 0.8 to 6.25 ± 0 mg/mL (IC₉₀). The extract was toxic to human Chang liver cell lines.

Candida species are the leading cause of invasive fungal infections, and over the past decade there has been an increased isolation of drug resistant Candida species. This study aimed to identify the species distribution of Candida isolates and to determine their unique antifungal susceptibility and resistance patterns. During a cross-sectional study, 209 Candida isolates (recovered from 206 clinical samples) were collected and their species distribution was determined using ChromAgar Candida. The Vitek-2 system (Biomerieux, South Africa) was used to determine minimum inhibitory concentrations (MICs) to azoles (fluconazole, voriconazole), echinocandins (caspofungin, micafungin), polyenes (amphotericin B) and flucytosine. Four species of Candida were isolated, of which C. albicans was the most frequent, isolated in 45.4% (95/209) of the isolates, followed by C. glabrata: 31.1% (65/209). The MICs of the different antifungal drugs varied amongst the species of Candida. From the 130 isolates tested for MICs, 90.77% (112/130) were susceptible to all antifungal drugs and 6.9% (9/130) of the isolates were multi-drug resistant. C. dubliniensis (n=2) isolates were susceptible to all the above mentioned antifungal drugs. There was no significant difference in species distribution amongst clinical specimens and between patients' genders (P>0.05). An increase in MIC values for fluconazole and flucytosine towards the resistance range was observed. To our knowledge, this is the first report on surveillance of Candida species distribution and antifungal susceptibility at a public tertiary teaching hospital in Eastern Cape, South Africa.

Dyslipidaemia, an irregular aggregate of lipids in the blood is common in diabetes and cardiovascular disease sufferers. A cross-sectional study on the prevalence of dyslipidaemia was performed among type 2 diabetes mellitus (T2DM) patients in the Western Cape, South Africa. Patients (n = 100) that participated in the study were within the age range of 19–68 years, of whom 89% were observed to have serum lipid abnormalities. Out of the 100 patients, 56%, 64%, 61%, and 65% were recorded to have high total cholesterol (TC), hypertriglycemia, increased low-density lipoproteins cholesterol (LDL-C), and reduced high-density lipoproteins cholesterol (HDL-C), respectively. In male diabetic patients, a marked prevalence of (94%) dyslipidemia was noted, of which 52% were affected by high TC (5.3–7.9 mmol/L), with 70% having a high level of triglyceride (TG) [1.72–7.34 mmol/L], while 60% had a high LDL-C (3.1–5.5 mmol/L), including 78% with low HDL-C (0.7–1.1 mmol/L). In comparison, 84% of diabetic females had dyslipidemia, with high TC (5.1–8.1 mmol/L), hypertriglycemia (1.73–8.63 mmol/L), high LDL-C (3.1–5.6 mmol/L), and low levels of HDL-C (0.8–1.1 mmol/L) affecting 60%, 58%, 62%, and 52% of the patients, respectively. This study showed the importance of screening and the regular surveillance of dyslipidaemia in T2DM patients as there is a paucity of data on it in Africa.