Assessment of antibiotic production by some marine Streptomyces isolated from the Nahoon Beach

Rapidly emerging strains of bacteria resistant to most advanced antibiotics have become issues of very important public health concern. Research currently directed towards marine actinomycetes presents a vast potential for new compounds that could be able to safely and effectively target resistant species. In this regard, ten putative Streptomyces strains isolated from the Nahoon beach were selected and assessed for antibiotic production and activity against a wide range of bacteria including reference strains, environmental strain and clinical isolates. The ethyl acetate extracts of the putative Streptomyces isolates showed activities against at least 6 and up to 26 of the 32 test bacteria. Inhibition zones were found to range between 9-32 mm diameters at a concentration of 10 mg/ml. The minimum inhibitory concentrations (MICs) of the crude extracts ranged from 0.039 - 10 mg/ml and the least minimum bactericidal concentration (MBC) demonstrated was 0.625 mg/ml against a reference strain Staphylococcus aureus ATCC 6538. Time kill kinetics of all extracts revealed bacteristatic and bactericidal activities. Average Log reductions in viable cell counts for all the extracts ranged from 0.86 Log10 and 3.99 Log10 cfu/ml after 3 h interaction and 0.01 Log10 and 4.86 Log10 after 6 h interaction at MIC, 2 × MIC, 3 × MIC and 4 × MIC concentrations. Most of the extracts were speedily bactericidal at 3 × MIC and 4 × MIC resulting in over 50 % elimination of most of the test bacteria within 3 h and 6 h interaction. The partial characterization of the crude extracts by IR spectral analysis revealed possibility of terpenoid, long chain fatty acids and secondary amine derivatives compounds in the extracts. It is therefore recommended that further investigation should address the relationship between the structure of the active component of the extracts and the broad spectrum activity, as well as a rapid method for large scale production and purification and whether this group of antibiotics has any application in managing human infectious disease

The genetic and epigenetic contributions to the development of nutritional rickets

Nutritional rickets is an important disease in global health. Although nutritional rickets commonly manifests as bony deformities, there is an increased risk of life-threatening seizures secondary to hypocalcaemia. Dietary vitamin D deficiency is associated with the development of nutritional rickets among children and infants. This is especially true in populations of darker skinned individuals in high-latitude environments due to decreased ultraviolet light exposure, and in populations in tropical and subtropical climates due to cultural practices. A growing body of evidence has demonstrated that genetic factors might influence the likelihood of developing nutritional rickets by influencing an individual’s susceptibility to develop deficiencies in vitamin D and/or calcium. This evidence has been drawn from a variety of different techniques ranging from traditional twin studies to next generation sequencing techniques. Additionally, the role of the epigenome in the development of rickets, although poorly understood, may be related to the effects of DNA methylation and non-coding RNAs on genes involved in bone metabolism. This review aims to provide an overview of the current evidence that investigates the genetic and epigenetic determinants of nutritional rickets

Antibiotic Producing Potentials of Three Freshwater Actinomycetes Isolated from the Eastern Cape Province of South Africa

Crude extracts of three actinomycetes species belonging to Saccharopolyspora (TR 046 and TR 039) and Actinosynnema (TR 024) genera were screened for antibacterial activities against a panel of several bacterial strains. The extracts showed antibacterial activities against both gram-negative and gram-positive test bacteria with inhibition zones ranging from 8 to 28 mm (TR 046); 8 to15 mm (TR 039); and 10 to 13 mm (TR 024). The minimum inhibitory concentrations ranged from 0.078 to 10 mg/mL (TR 046); 5 to >10 mg/mL (TR 039); and 1.25 to 5 mg/mL (TR 024). Time-kill studies revealed that crude extract of TR 046 showed strong bactericidal activity against Bacillus pumilus (ATCC14884), reducing the bacterial load by 104 cfu/mL and 102 cfu/mL at 4× MIC and 2× MIC, respectively, after 6 h of exposure. Similarly, against Proteus vulgaris (CSIR 0030), crude extract of TR 046 achieved a 0.9log10 and 0.13log10 cfu/mL reduction at 5 mg/mL (4× MIC) and 1.25 mg/mL (2× MIC) after 12 h of exposure. The extract was however weakly bactericidal against two environmental bacterial strains (Klebsiella pneumoniae and Staphylococcus epidermidis); and against Pseudomonas aeruginosa (ATCC 19582): the extract showed bacteriostatic activities at all concentrations tested. These freshwater actinomycetes appear to have immense potential as a source of new antibacterial compound(s)

Barriers to implementing a health policy curriculum in medical schools

Raihan Mohammed, Jamil Shah Foridi, Innocent OgunmwonyiFaculty of Medicine, University of Cambridge, Cambridge, UKAs clinical medical students, we read with great interest the perspective by Malik et al.1 Although medical schools excel at educating students on the pathology and treatment of diseases, we agree on the severe deficiency in teaching health policy (HP) in the medical curriculum. However, the authors fail to include challenges facing this implementation, which is an important aspect of the analysis. Thus, here we outline 3 key barriers that must be considered when including HP teaching in the medical curricula.First, as the authors mention, the medical curriculum is already saturated and there is insufficient space to add obligatory HP learning in timetables. The UK curriculum is so packed that lecturers resort to teaching facts, which students then rote-learn and commit to memory. This leaves little time for students to develop a deep understanding of the pathophysiology of diseases and subsequent management, and they also fail to develop core lifelong skills, including problem solving and critical thinking.2 It is well acknowledged that the medical course is extremely rigorous, and up to 90% of students have admitted to suffering from stress and up to 75% have complained of burnout.3 With mental health issues among students reaching epidemic levels, adding HP lectures to the timetable would put undue strain on both the medical school curricula and the students.View the original article by Malik et al

Biodegradability study to develop longer life jute geotextiles for road applications

To enhance the life of jute geotextiles (JGTs) for road applications, new types of JGT fabrics were developed following two different routes, viz., (a) rot-proof treatment of 100% JGT fabric and (b) preparation of jute–polypropylene blended JGT fabrics. The biodegradability behavior of these fabrics along with grey JGTs was studied for different durations up to 12 months in three categories of saturated soils, namely, Guwahati Lateritic Red soil, Kolkata Alluvial Silty soil and Andhra Pradesh Black Cotton soil and water separately. Biodegradability assessment was done through residual tensile strength study and microscopic study. The experimentation reveals that rate of biodegradation of the JGTs is different in the three experimental saturated soils and water. Saturated Black Cotton soil was found to be the most detrimental medium. Studies were also carried out to understand this differential degradation behavior of JGTs in different soils. This indicates that the pH of soil media and microbial population growing capability of the respective soils both affect the level of degradation of the JGT fabrics. Jute–synthetic blended JGT is essential for Black Cotton soil road-subgrade, while grey JGT and treated JGT can be used in Lateritic soil and Silty soil, respectively.by Mahuya Ghosh, Guda Rao Venkatappa, Syamal Kanti Chakrabarti, Supriya Pal and Uma Sankar Sarm