The rhizomes of Alpinia pahangensis Ridley yielded a new bis-labdanic diterpene for which the name pahangensin A (1) was proposed along with a new labdane diterpene, pahangensin B (2). Their structures were elucidated by spectroscopic methods including, 1D and 2D NMR techniques and LCMS-IT-TOF analysis. Pahangensin A (1) was found to be an antibacterial agent against Staphylococcus aureus, Bacillus cereus and Bacillus subtilis with MIC values less than 100 μg/mL, respectively. Pahangensin B (2) exhibited antibacterial activity (MIC <100 μg/mL) against B. cereus.
The discovery of antibiotics had been one of the most significant events in the history of medicine. Antibiotics had saved countless number of lives and had contributed significantly to the health of mankind.The emergence of resistance is however a major threat to the continued usefulness of antibiotics. There are now strains of bacteria which are resistant to virtually all available antibiotics and these strains are increasingly being encountered in clinical practice. The development of new agents had not kept pace with resistance and it is unlikely that there will be major breakthroughs in the near future. The world needs to conserve and prolong the useful lives of the existing agents. This can only be achieved through good antibiotic stewardship programmes. As antibiotic resistance is a global threat all major stakeholders have to work together to meet this challenge.
A report is given of 60 cases of bronchopneumonia in infants treated with Aureomycin during a period of 4 months, Aureomycin was given orally in a mixture. Dosage depended on the severity of the infection, the age and weight of the patient. The results of this series are compared with a series of penicillin treated cases and showed a distinct improvement. The cure rate of Aureomycin treated cases is about 70%.
We aim at fabricating a ternary magnetic recyclable Bi2WO6/BiOI@Fe3O4 composite that could be applied for photodegradation of tetracycline (TC) from synthetic wastewater. To identify any changes with respect to the composite's morphology and crystal structure properties, ΧRD, FTIR, FESEM-EDS, PL and VSM analyses are carried out. The effects of Fe3O4 loading ratio on the Bi2WO6/BiOI for TC photodegradation are evaluated, while operational parameters such as pH, reaction time, TC concentration, and photocatalyst's dose are optimized. Removal mechanisms of the TC by the composite and its photodegradation pathways are elaborated. With respect to its performance, under the same optimized conditions (1 g/L of dose; 5 mg/L of TC; pH 7; 3 h of reaction time), the Bi2WO6/BiOI@5%Fe3O4 composite has the highest TC removal (97%), as compared to the Bi2WO6 (63%). After being saturated, the spent photocatalyst could be magnetically separated from solution for subsequent use. In spite of three consecutive cycles with 71% of efficiency, the spent composite still has reasonable photocatalytic activities for reuse. Overall, this suggests that the composite is a promising photocatalyst for TC removal from aqueous solutions.
In searching for symbionts derived from bioactive natural products, six sulfureous diketopiperazines designated as lasiodiplines A-F (1-6) were characterized from the culture of Lasiodiplodia pseudotheobromae F2, previously residing in the apparently normal flower of Illigera rhodantha (Hernandiaceae). Identification of structures was accomplished by a combination of spectroscopic and computational approaches, in conjunction with the low-temperature (100K) single-crystal X-ray diffraction with Cu Kα radiation. Lasiodipline E (5) was demonstrated to be antibacterial against the clinical strains Streptococcus sp., Bacteroides vulgates, Peptostreptococcus sp. and Veillonella parvula, respectively, with an minimum inhibitory concentration (MIC) range of 0.12-0.25 μg/mL. In addition, compounds 4 and 6 exemplify two unusual architectures of natural cyclodipeptides, signifying the unique biochemical characteristics of the producing fungus.
This study was undertaken to investigate the influence of culture conditions and medium components on production of antibacterial compounds by Serratia sp. WPRA3 (JX020764) which was isolated from marine water of Port Dickson, Malaysia. Biochemical, morphological, and molecular characteristics suggested that the isolate is a new candidate of the Serratia sp. The isolate showed strong antimicrobial activity against fungi, Gram-negative and Gram-positive bacteria. This bacterium exhibited optimum antibacterial compounds production at 28°C, pH 7 and 200 rev/min aeration during 72 h of incubation period. Highest antibacterial activity was obtained when sodium chloride (2%), yeast extract (0.5%), and glucose concentration (0.75%) were used as salt, nitrogen, and carbon sources respectively. Different active fractions were obtained by Thin-Layer Chromatography (TLC) and Flash Column Chromatography (FCC) from ethyl acetate crude extracts namely OCE and RCE in different culture conditions, OCE (pH 5, 200 rev/min) and RCE (pH 7/without aeration). In conclusion, the results suggested different culture conditions have a significant impact on the types of secondary metabolites produced by the bacterium.
The antibacterial efficiency of the methanolic extract of Phyllanthus niruri Linn. was investigated against pathogenic bacteria responsible for common infections of skin, and urinary and gastrointestinal tracts. The extract demonstrated antibacterial activities against all the Gram-positive and Gram-negative bacteria tested. The results obtained suggested that at higher concentrations the extract would eradicate the growth of bacterial cells. The bacterial cells, after exposure to the extract, showed complete alteration in their morphology, followed by collapse of the cells beyond repair. The study revealed that the methanolic extract of P. niruri may be an effective antibacterial agent to treat bacterial infections since the extract exhibited significant antimicrobial potency, comparable with that of the standard antibiotic chloramphenicol.
Many phytochemicals derived from edible medicinal plants have been investigated intensively for their various bioactivities. However, the detailed mechanism and their corresponding molecular targets frequently remain elusive. In this review, we present a summary of the research works done on phytochemical-mediated molecular targets, identified via proteomic approach. Concurrently, we also highlighted some pharmaceutical drugs which could be traced back to their origins in phytochemicals. For ease of presentation, these identified protein targets were categorized into two important healthcare-related fields, namely anti-bacterial and anti-cancer research. Through this review, we hope to highlight the usefulness of comparative proteomic as a powerful tool in phytochemical-mediated protein target identifications. Likewise, we wish to inspire further investigations on some of these protein targets identified over the last few years. With contributions from all researchers, the accumulative efforts could eventually lead to the discovery of some target-specific, low-toxicity therapeutic agents.
Nanoparticles (NPs) are nano-sized particles (generally 1⁻100 nm) that can be synthesized through various methods. The wide range of physicochemical characteristics of NPs permit them to have diverse biological functions. These particles are versatile and can be adopted into various applications, particularly in biomedical field. In the past five years, NPs’ roles in biomedical applications have drawn considerable attentions, and novel NPs with improved functions and reduced toxicity are continuously increasing. Extensive studies have been carried out in evaluating antibacterial potentials of NPs. The promising antibacterial effects exhibited by NPs highlight the potential of developing them into future generation of antimicrobial agents. There are various methods to synthesize NPs, and each of the method has significant implication on the biological action of NPs. Among all synthetic methods, green technology is the least toxic biological route, which is particularly suitable for biomedical applications. This mini-review provides current update on the antibacterial effects of NPs synthesized by green technology using plants. Underlying challenges in developing NPs into future antibacterials in clinics are also discussed at the present review.
The in vitro activities of 6 antimicrobial agents against clinical isolates of Streptococcus pneumoniae (pneumococci) were investigated and the erythromycin minimum inhibitory concentrations (MICs) were correlated with the two major macrolide resistance determinants, mef(A) and erm(B). MICs of commonly used antibiotics as well as the presence of macrolide resistance determinant genes in all isolates were tested. Seventy one pneumococcal isolates collected at Institute for Medical Research (IMR) were included in this study. Phenotypic characterization, MIC determination using E-test strips and polymerase chain reactions for antibiotic resistance determination were included. Among the isolates, 25 (35.2%) isolates were erythromycin susceptible, 3 (4.2%) were intermediate and 42 (60.6%) were resistant. Fifty three isolates (74.7%) were found with mef(A) alone, 15 (21.1%) isolates with erm(B) + mef(A) combination and 3 (4.2%) isolates with none of the two genes. The in vitro activity of penicillin, amoxicillin clavulanic acid, ceftriaxone and cefotaxime is superior to trimethoprim-sulfamethoxazole and erythromycin. In conclusion, pneumococcal isolates in this study were highly susceptible to penicillin with very low MICs. However, a very high prevalence rate of erythromycin resistance was observed. Erythromycin resistant S. pneumoniae isolates with both mef(A) and erm(B) showed very high MICs ≥256 μg/mL.
OBJECTIVE: The aim of this study was to assess the knowledge, attitude and practice of B.Sc. Pharmacy students about usage and resistance of antibiotics in Trinidad and Tobago.
METHODS: This was a cross-sectional questionnaire-based study involving B.Sc. Pharmacy students. The questionnaire was divided into five components including Demographics data, knowledge about antibiotic use, attitude toward antibiotic use and resistance, self-antibiotic usage and possible causes of antibiotic resistance. Data were analyzed by employing Mann-Whitney and Chi-square tests using SPSS version 20.
FINDINGS: The response rate was 83.07%. The results showed good knowledge of antibiotic use among students. The overall attitude of pharmacy students was poor. About 75% of participants rarely use antibiotics, whereas self-decision was the major reason of antibiotic use (40.7%) and main source of information was retail pharmacist (42.6%). Common cold and flu is a major problem for which antibiotics were mainly utilized by pharmacy students (35.2%).
CONCLUSION: The study showed good knowledge of pharmacy students regarding antibiotic usage. However, students' attitude towards antibiotic use was poor. The study recommends future studies to be conducted with interventional design to improve knowledge and attitude of pharmacy students about antibiotic use and resistance.
KEYWORDS: Antibiotics; Trinidad and Tobago; knowledge; pharmacy students; resistance