Open Access Short Research Article
Cultures of the blue green algae (cyanobacteria) Anabaena circinalis were identified and isolated from freshwater and their antimicrobial effect was studied. The extract of A. circinalis was tested to investigate its efficiency against four bacterial strains (Achromobacter xylosoxidans, Staphylococcus aureus, Escherichia coli, Shigella dysenteriae. Antimicrobial test was determined by disk diffusion method. Different concentrations of algal extracts (25, 50, 75 and 100%) were tested. Results showed that the highest level of antimicrobial activity was recorded against S. dysenteriae at 100% concentration followed by 25% extract concentration against the same bacteria. In comparison with two antibiotics Ampicillin (AMP), oxacilina (OXA), AMP was the most effective on S. dysenteriae followed by OXA. S. aureus and E. coli were resistant to both antibiotics while they were sensitive to A. circinalis extracts at even at low concentrations (25% and 50%). Thus the present study revealed that extracts of A. circinalis extract is would be a promising natural source, for novel antibiotics, hence worthy for more investigations.
Open Access Original Research Article
Tomato leaf curl virus (ToLCV) has frequently emerged as a severe problem for tomato in the recent past, in the tropical and subtropical region of the world. We have cloned and sequenced two isolates of ToLCV responsible for the leaf curl disease of tomato in Bangladesh. Two betasatellite DNAs were associated with ToLCV, and complete nucleotide sequences were determined. The complete genome sequences of ToLCV-[BD:Mym:11] and ToLCV-[BD:Mym2:11] shared the highest nucleotide sequence identities at 95.04 and 92.38%, respectively, with Indian isolate of Tomato leaf curl virus - [India:Ranchi:2007] (ToLCV-[IN:Ran:07]) and Tomato leaf curl Patna virus - [India:Lucknow:2009] (ToLCPatV-[IN:PLuc:09]). Complete nucleotide sequence analysis of the two betasatellite clones, tomato leaf curl betasatellite – [BD:Mym:11] and tomato leaf curl betasatellite – [BD:Mym2:11] associated with (ToLCV-[BD:Mym:11] and (ToLCV-[BD:Mym2:11], when used in BLAST searches respectively revealed 95.51 and 86.43% identity with Tomato leaf curl Bangladesh betasatellite (ToLCBDB-[BD-Gaz-01]) and Tomato leaf curl Patna betasatellite (ToLCPaB-[IN-Pat-07]).
Open Access Original Research Article
Introduction: The therapeutic actions of plants may be due to the presence of some phytochemical components. Due to the increasing emergence of multi antibiotics resistance, wound pathogens are causing huge public health concerns. There is need for exploring some necessary alternatives for treatment of wound infections.
Aim: This study investigated the phytochemical and antimicrobial activities of Vernonia amygdalina and Bryophyllum pinnatum leaves extracts on Pseudomonas aeruginosa, Escherichia coli and Staphylococcus aureus isolates from wound infection.
Methodology: The fresh leaves of both plants were extracted using Sofowora method and the phytochemicals were screened. Different concentrations of the extract, antibiotic and ethanol were tested against the isolates using disc diffusion technique.
Results: Alkaloids, flavonoids, tannins, anthraquinone and fixed oils were present in the both plant extracts but saponins were only found in V. amygdalina and cardenolide were only in B. pinnatum. Quantitatively, all the phytochemicals investigated in the study were present with V. amygdalina having the highest level of saponins than Bryophyllum pinnatum (P<0.05) and low steroids with P=0.2879 (P>0.05).The crude extract of V. amygdalina had the highest zone of inhibition compared to aqueous and ethanol extracts at 75 mg/ml concentration (P<0.05) but generally, the ethanol extracts of both plants had more inhibitions at varying concentrations. Thus comparing the antimicrobial activity of various extracts of both plants on the wound isolates and the controls (antibiotics and ethanol), there was significant variation in their zones of inhibition produce (P<0.05).
Conclusion: The results show that the zone of inhibition increases with the concentrations of the extracts. Therefore, the antimicrobial effect of these plants may depend on the concentration of the extract and the solvent used for extraction. This study showed that B. pinnatum and V. amygdalina could be used as an alternative therapy to antibiotics to treat wound infection caused by P. aeruginosa, E. coli and S. aureus.
Open Access Original Research Article
Nosocomial infection is a rising problem in developing countries. Microorganisms Isolated from three private and public hospital environmental surfaces in Akure Metropolis, Ondo State, Nigeria were investigated in this study. Bacterial and fungal organisms were isolated and compared among the three hospitals. The study revealed that bacteria were the most predominant microorganisms found in the hospital environmental surfaces than fungi. Staphylococcus aureus, Streptococcus pyogenes, Escherichia coli, Pseudomonas aeruginosa, Klebsiella pneumoniae and Bacillus cereus were the bacterial isolates while fungi include Aspergillus fumigatus, Aspergillus niger and Candida albicans. Staphylococcus aureus was found to be predominant bacteria but Aspergillus funmigatus was the predominant fungi. The result showed that the microbial loads of the public hospitals were higher than that of the private hospitals. The bacteria load of the male ward was found to be higher than that of the female ward while the fungal loads of each of the hospital environmental surfaces of female were higher than that of the male. The study revealed that bacteria were the most predominant microorganisms found in the hospital environment than fungi. Staphylococcus aureus, Streptococcus pyogenes, Escherichia coli, Pseudomonas aeruginosa, Klebsiella pneumoniae and Bacillus cereus were the bacterial isolates while fungi include Aspergillus fumigatus, Aspergillus niger and Candida albicans. Staphylococcus aureus was found to be predominant bacteria. All the hospital environmental surfaces were contaminated with one or more microorganisms in the course of the research.
Open Access Review Article
Infection of subcutaneous tissue with Mycobacterium ulcerans can lead to chronic skin ulceration known as Buruli ulcer. It has been reported in over 33 countries around the world, the greatest burden of disease is in the tropical regions of West and Central Africa, Australia, and Japan. It primarily affects children aged 5-15 years. Buruli ulcers generally begin as a painless dermal papule or subcutaneous edematous nodule, which over a period of weeks to months, breaks down to form an extensive necrotic ulcer with undermined edges. The pathogenesis of this neglected tropical disease is dependent on a lipidlike toxin, mycolactone, which diffuses through tissue away from the infecting organisms and elucidate its cytotoxic and immunosuppressive properties. The underlying molecular targets for mycolactone are: First, it can target scaffolding proteins (such as Wiskott Aldrich Syndrome Protein), which control actin dynamics in adherent cells and therefore lead to detachment and cell death. Second, it prevents the co-translational translocation (and therefore production) of many proteins that pass through the endoplasmic reticulum for secretion or placement in cell membranes. Treatment includes a prolonged course of antibiotics and surgical debridement. Early identification and treatment are key, as lesions heal with scarring that can be a significant source of morbidity.