Academy of Science of South Africa (ASSAf): Open Journal Systems
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Antibacterial activity of two actinomycetes species isolated from black sand in North Egypt
No full textIncreasingly high levels of multidrug-resistant (MDR) pathogens have necessitated the discovery of novel bioactive compounds. For this reason, two actinomycetes strains, Streptomyces griseorubens and Streptomyces rochei, were isolated for the first time from the black sand shores of Kafr El Sheikh in Egypt, which is home to several large fish farms. Isolates were identified via phenotypic, biochemical and 16S rRNA sequence protocols. Both strains exhibited powerful antimicrobial activity against three serious MDR pathogens: Bacillus subtilis, Salmonella enteritidis and Pseudomonas aeruginosa. The bioactive compounds of isolates’ filtrates were identified using gas chromatography–mass spectroscopy (GC-MS). For S. griseorubens, the detectable antibacterial compounds were hexanoic acid, 2-ethyl-, 2-ethylhexyl ester, n-Decane, hexadecanoic acid methyl ester, benzene acetic acid, ricinolic acid, and ethylparaben, while S. rochei secretes heptadecane, 2,6-dimethyl-, benzene acetic acid, dibutyl phthalate, octacosane, hexacosane, and vitamin A aldehyde. These results strongly encourage the use of these eco-friendly isolates as a biocontrol against MDR pathogens that attack fish farms.
Significance:
Streptomyces spp. act as strong weapons for fighting multidrug resistance in pathogenic bacteria – one of the most important current threats to public health. They are additionally regarded as eco-friendly organisms that can be used as a biocontrol agent against infections that endanger fish farms
Herbicide resistance cases in South Africa: A review of the current state of knowledge
No full textHerbicides play a major role in weed management worldwide. However, herbicide resistance is a global challenge that threatens weed management and sustainable agriculture. In South Africa, over 36 years, ten weed species have evolved resistance to five modes of action. In this review, cases of herbicide resistance that were published in scientific journals, proceedings of congresses, theses or dissertations, and in the international survey of herbicide-resistant weeds, were included to give national and international scientists’ perspectives on the current status of herbicide resistance in South Africa. Since the last review was published in 2010, there have been new insights and novel techniques to document the molecular mechanism of herbicide-resistant weeds. Most cases of herbicide resistance in South Africa involved monocot and dicot weeds which are problematic in various cropping systems such as Lolium spp. (annual ryegrass), Phalaris spp. (canary grass), Avena spp. (wild oats), and Raphanus raphanistrum L. (wild radish). Understanding the extent of herbicide resistance and the molecular mechanism involved in herbicide resistance is paramount to developing novel techniques to manage herbicide-resistant weeds.
Significance:
Data presented in this review help raise awareness of the threat of herbicide resistance in South Africa.
Herbicide resistance in South Africa continues to evolve steadily through a wide range of weed species and modes of action
Microstructure and chemical composition of deposited particulate matter from gasoline and diesel vehicle exhaust emissions
No full textA comprehensive physicochemical characterization of transport-emitted aerosols containing in vehicle exhaust emissions derived from the combustion of fuels such as diesel, premium gasoline, and unleaded gasoline was performed in this study by employing a range of analytical techniques (Laser granulometry, X-ray Fluorescence (XRF), Fourier Transform Infrared (FTIR), X-ray diffraction (DRX), Scanning Electron Microscopy (SEM), and Thermogravimetry). The X-ray diffractogram of diesel (D) derived aerosols showed an amorphous structure while those of unleaded gasoline (UG) and premium gasoline (PG), showed amorphous crystalline phases. The chemical composition of D, PG and UG derived particles was dominated by aliphatic C-H groups of alkanes with relatively low C=O groups of carboxylic acids, ketones, aldehydes, esters, lactones, and sulphate (SO4 2-) inorganic salts. The nitrogen-containing functionality (NO3-) was specific to particles of PG and UG. Laser particle size analysis showed fine particle sizes (Range) generated from diesel exhausts, thus making them dangerous when inhaled, as they can penetrate deeply into the human airways and become incorporated into the blood stream damaging other viscera
Building Smiles and Loyalty: The Power of Customer Loyalty Programs in Dental Practices
Get PDFIn the highly competitive world of dental practices, winning the loyalty of your patients is a critical factor for success. Happy, loyal patients not only return for their regular check ups but also become your brand advocates, referring friends and family to your practice. One effective way to nurture this loyalty is by implementing a customer loyalty programme. In this blog, we’ll explore how loyalty programmes can benefit your dental practice and offer some insights into creating on
Inaccessible specialised oral health services in South Africa – rationing policy uncertainty: Inaccessible specialised oral health services in South Africa – rationing policy uncertainty
No full textRationing by waiting lists is associated with patient costs such as pain, anxiety and poor health outcomes. Rationing is indicative of a mismatch between the demands and resources to service patients’ needs. Long waiting times for specialised oral health services are concerning and unjustifiable. The majority of oral health care services are devoid of an explicit policy and mechanism to address this problem. This paper attempts to provide the ethical basis for waiting times. That is, whether the mechanisms used in the allocation of services (or placing patients on waiting lists) is consistent with ethical principles
What’s new for the clinician – summaries of recently published papers (October 2023)
Get PDFAccording to the World Health Organization (WHO), tobacco kills more than 8 million people each year, including 1.3 million non-smokers who are exposed to second-hand smoke. Around 80% of the world’s 1.3 billion tobacco users live in low- and middle-income countries. In 2020, 22.3% of the world’s population used tobacco: 36.7% of men and 7.8% of women
Chrysomya chloropyga (copper-tailed blowfly) larvae reared on abattoir waste as a protein source for broiler production: carcass traits, meat quality and sensory attributes
No full textThe larvae of the copper-tailed blowfly (Chrysomya chloropyga) have the potential to break down high-risk waste such as abattoir waste and ameliorate the nutrients to be reintroduced into the food chain by including them in broiler feeds. Chrysomya chloropyga larvae were grown on abattoir waste, harvested, processed, and included in broiler diets at inclusion rates of either 5, 10 or 15%. Thereafter the carcass traits, meat quality characteristics and descriptive sensory attributes were determined. Further to this the mineral content of the tibia, as well as the tibia bone strength were determined. The highest inclusion rate of 15% resulted in broiler carcass and meat characteristics that were on par with a formulated soya-based control diet. The chemical composition of the meat was predominantly not significantly affected by the dietary larval meal inclusion (p > 0.05). In terms of its sensory attributes, meat from broilers fed C. chloropyga meal showed some significant differences for chicken aroma and initial juiciness (p ≤ 0.05). However, no significant differences were observed for any of five other sensory attributes of importance. Interestingly, the dietary inclusion of C. chloropyga meal was significantly related to increased tibia potassium and iron content, which could be linked to the insects’ accumulating these minerals present in the abattoir waste. The results indicate that C. chloropyga larval meal could be included in broiler diets at up to 15% without any negative effects on the aforementioned characteristics and could even influence them positively