An Analysis of Drivers of International Investment Decisions in South Africa

The study investigated the drivers of international investment decisions in South Africa. As part of its investment drive, the government has embarked on a series of activities to lure investors. That been the case it appears that most of the empirical studies focused mainly on the relationship between investment and economic growth, hence very little seems to be known about the empirical evidence of other drivers of international investment decisions and their impact on the South African economy. The findings are envisaged to provide information and to add policy formulation to attract the much needed foreign investment. The autoregressive distribution lag approach was chosen to analyse the long and the short run relationships amongst the variables of interest and Granger Causality analysis was also employed to determine causal relationships between dependent variable and its regressors. The results indicated that a stronger statistical and economic basis for empirical error correction model was established by the presence of cointegration amongst the variables and all the regressors were found to have a positive effect in the stock of foreign direct investment. Empirical findings suggest that government should ensure stable macroeconomic policies and labour disputes that result into prolonged strike actions must be minimised

Biofilm reduction, in-vitro cytotoxicity and computational drug-likeness of selected phytochemicals to combat multidrug-resistant bacteria

Multidrug-resistant (MDR) bacteria in biofilms are frequently linked with persistent infections across healthcare settings, due to their virulence factors. Since the post-antibiotic era coerces the quest for novel therapeutics, the use of medicinal plants and their phytochemicals emerges as prospective alternatives for the failing antibiotics. Preliminary screening of untargeted drugs for their drug-likeness and biosafety properties is a necessary step in the advancement of the drug discovery process. Thus, the study aimed to assess the noteworthy phytochemicals with antibacterial potential to reduce the biofilm formation of selected MDR bacteria, evaluate their safe use and drug-likeness properties thereby providing advanced knowledge to contribute to the search for safe, antipathogenic drugs. Three phytochemicals of 1,2,3-benzenetriol, guanosine and phytol revealed significant minimum inhibitory concentrations (MIC) between 0.250 – 0.040 mg/mL against Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, Staphylococcus aureus and Streptococcus pyogenes. Guanosine and phytol, both revealed noteworthy MIC values of 0.016 and 0.031 mg/mL for S. pyogenes and S. aureus, respectively. Five MDR bacterial pathogens treated with 1,2,3-benzenetriol, guanosine and phytol at a concentration of 0.250 mg/mL reduced anti-adhesion and biofilm development up to 78.88% and 31.82%, respectively. In situ visualisation by scanning electron microscope (SEM) displayed guanosine to significantly disrupt the biofilm structures of S. aureus, S. pyogenes and P. aeruginosa. Atomic force microscope (AFM) detected differences between the topographies of S. aureus, S. pyogenes and P. aeruginosa biofilms treated with guanosine and phytol. Guanosine and phytol showed approximately 100% of cell viability in a dose-dependent manner (0.25 – 0.001 mg/mL) while causing no cell damage on African monkey kidney Vero (epithelial) cells and showed a cytostatic rather than a cytotoxic effect. Drug-likeness in-silico screening revealed that the compounds obeyed Lipinski's rules and have bioavailable scores of 0.55F. Guanosine and phytol showed antivirulent, biosafety and drug-likeness properties with significant pharmacokinetic predictions. This study highlights the significance of phytotherapeutics for the development of novel antipathogenic agents

In Silico and In Vitro Screening of Antipathogenic Properties of Melianthus comosus (Vahl) against Pseudomonas aeruginosa

Bacterial quorum sensing (QS) system regulates pathogenesis, virulence, and biofilm formation, and together they contribute to nosocomial infections. Opportunistic pathogens, such as Pseudomonas aeruginosa, rely on QS for regulating virulence factors. Therefore, blocking the QS system may aid management of various infectious diseases caused by human pathogens. Plant secondary metabolites can thwart bacterial colonization and virulence. As such, this study was undertaken to evaluate three extracts from the medicinal plant, Melianthus comosus, from which phytochemical compounds were identified with potential to inhibit QS-dependent virulence factors in P. aeruginosa. Chemical profiling of the three extracts identified 1,2-benzene dicarboxylic acid, diethyl ester, neophytadiene and hexadecanoic acid as the common compounds. Validation of antibacterial activity confirmed the same MIC values of 0.78 mg/mL for aqueous, methanol and dichloromethane extracts while selected guanosine showed MIC 0.031 mg/mL. Molecular docking analysis showed anti-quorum sensing (AQS) potential of guanosine binding to CviR’ and 2UV0 proteins with varying docking scores of −5.969 and −8.376 kcal/mol, respectively. Guanosine inhibited biofilm cell attachment and biofilm development at 78.88% and 34.85%, respectively. Significant swimming and swarming motility restriction of P. aeruginosa were observed at the highest concentration of plant extracts and guanosine. Overall, guanosine revealed the best swarming motility restrictions. M. comosus extracts and guanosine have shown clear antibacterial effects and subsequent reduction of QS-dependent virulence activities against P.aeruginosa. Therefore, they could be ideal candidates in the search for antipathogenic drugs to combat P.aeruginosa infections