Browsing by Author "Jayaratne, D.L."

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Antibacterial Activity of Euphobia antiquorum latex
(International Journal of Applied Pharmaceutical Science and Research, 2017) Pushpakumara, A.A.J.,; Jayaratne, D.L.; Samaranayake, G.V.P.
Eumorbia antrquorum is a shrub tree Monging to the largest and the rnost family in the plant kingdom. Euphorbiaceae. E emnquram latex was used as a classical binding agent the kshu-a sutra in the management of the anal fistula. In the present study, an attempt made to evaluate the antimicrobial properties of latex Of E. antiquorum on certain microbes. methanolic extract Of the latex prepared. The fractions of methanol extract were tested br their antibacterial activity against the Gram positi•.e bwteria, Streptococus agrlactiæ and aweus Gram negative bacteria Escherichia coli and P. aeruginosa. results revealed that the latex showed minimum inhibition only to E coli and S aureus_ Latex did not antibacterial activity against S agalactiae and P. aerugintßa_ results suggest that the E. anuquorum latex extract account for the antibacterial propcrtics and has a potential use as an antimicrobial agent.
Biocide testing programme for control of lichens on archeological monuments at World Heritage sites in Sri Lanka
(University of Kelaniya, 2008) Fernando, S.; Jayaratne, D.L.
Cultural monuments in the world heritage sites in Sri Lanka have suffered many disfigurements over the centuries due to a variety of threats. The main threats are the biological agents such as higher plants, bryophytes, algae, fungi and lichens. Lichen is a symbiotic association of a fungus with an alga that appears to be a single plant. These lichens attached firmly to the surfaces of monuments and as they grow and spread progressively weaken the surface making disfigurement of monuments. This study focused on finding the safe and best effective treatment which can remove and control all the different types of lichens growing on stone monuments at Sigiriya and Anuradapura. The two acceptable methods for the removal of lichens from the archeological monuments are the physical removal and the chemical treatment for eradication. The application of biocide chemicals for the complete eradication of lichens have been considered as the most effective method than physical removal which allows remaining microscopic propagules eventually colonize monument surface making more denser cover than the previous colonization. Therefore, seven commercially available biocides; "Captan, Mancozeb, F olicur, Hadonal D, Paraquat, Mergal S 89 and No More Mould" were tested on the stone monuments in three different locations at Sigiriya and one location at "Abayagiriya Monastry", Anuradapura. To begin treatments, the lichen inhabiting surface areas of 1 00cm2 quadrates were marked on the stone monuments. Then randomly selected five quadrates in each location were assigned to each of the biocide treatment. The manufacturers recommended concentrations of the biocides were spayed at the rate of 0.03ml/cm2 onto the lichens inhabiting surface area of the assigned quadrates using hand operated sprayers. The observations were recorded every three months intervals during the 18 months period. Data were analyzed statistically using two-way ANOVA. The treatments showed highly significant effects on lichen control (p< 0.001). Further the Tukey's multiple comparison tests concluded that the product "No more mould" has highly significant positive control effect on the eradication of lichens in the treated areas. This product is an effective biocide recommended for the eradication of both partners (the fungi and algae) of the symbiotic association of lichens. Also, the treatment showed some kind of sealer effect to retard recolonization of lichens and other growth forms for a minimum of one year period on the treated quadrates of the stone monuments.
Chemical composition of Ksharasutra (medicated seton) used in ayurvedic Parasurgical management for fistula-in-ano
(Faculty of Graduate Studies, University of Sri Jayewardenepura., 2015) Kumara, A.A.J.P.; Liyanage, J.A.; Jayaratne, D.L.
Determination of toxic heavy metals in selected Arishta used in Sri Lanka
(Gampaha Wickramarachchi Ayurveda Institute, 2009) Weerasooriya, W.M.B.; Liyanage, J.A.; Jayaratne, D.L.
Effective biocide options for eliminating Ceratocystis spp associated with coir products
(Sri Lanka Association for the Advancement of Science, 2011) Senavirathna, H.G.L.A.K.; Jayaratne, D.L.
This study describes the determination of suitable methods for eliminating the fungus Ceratocystis associated with coir products. Ceratocystis spp is a pathogen causing diseases in several plants including coconut. The occurrence of this organism in coconut cultivations in Sri Lanka has been reported since 1906. Sri Lanka has extensive coconut cultivation and many coir products are exported. It is a quarantine requirement that the coir products are free from this organism. Currently, methyl bromide is used as a fumigant to eliminate the organism, but the use of this chemical is restricted due to its high toxicity and because it affects the ozone layer. In this study the organism was isolated from the coir dust samples collected from the areas of Lunuwila and Kurunegala. The morphological characters of spores were similar in the isolates obtained from these two different locations. However, the color of the chlamydospores was darker in the isolates obtained from Kurunegala than in the samples collected from Lunuwila. The effectiveness of the fumigant formaldehyde (37% formaldehyde 120 ml with 60 g potassium permanganate for 2.83 m3 or 100 ft3 air space) was tested in fumigation chambers parallel with methyl bromide (48 g/m3) on a Potato Dextrose Agar culture and in inoculated coir dust. The formaldehyde was effective for inoculated coir dust but not for the fungus grown on culture plates, while methyl bromide was effective for both. As an alternative method, water vapor heat treatment was applied at different time temperature combinations on coir dust inoculated with fungal spores. At 55 °C for 5 min., the vapor heat treatment destroyed the viable spores in it. For the elimination of Ceratocystis associated with coir dust, formaldehyde can be used in place of the currently used methyl bromide. Formaldehyde is less effective when the organism is grown on culture media due to the different conditions prevalent in culture media and coir dust. Besides the chemical formaldehyde, heat treatment can be applied for eliminating the organism. A temperature of 55 °C generated from water vapor for 5 minutes is sufficient for eliminating the fungal spores.
Genetic Variation and Phytotoxin Production among Cylindrocladium. Quinqueseptatum Isolates of Hevea Brasiliensis and Eugenia Carryophyllata
(University of Kelaniya, 2012) Jayaratne, D.L.; de Silva, B.A.C.; Silva, W.P.K.
Cylindrocladium quinqueseptatum (Boedijn & Reitsma 1950) is one of the major plant pathogenic fungi that infects a wide range of plants in humid tropics. The prevailing strains in Sri Lanka cause the foliage and shoot blight diseases and severe defoliation of Hevea brasiliensis (rubber) and Eugenia carryophyllata (clove). The isolates obtained from rubber and clove plants growing in Rathnapura district, in Sabaragamuwa province and Kalutara district, in Western province were evaluated for their toxin activity on hosts and genetic characterization was done using random amplified polymorphic DNA Polymerase Chain Reaction (RAPD-PCR grouping). The analysis of the results using ‘Wilcoxon signed-rank test’ revealed no correlation among the isolates based on their host or geographical origins. But a relationship was observed between the toxin activity and the RAPD grouping of the isolates. The time course experiment reveled that the minimum toxin activity recorded after three days of inoculation and maximum toxin activity was recorded after nine days of inoculation in Modified Fries Medium (MFM) for all the isolates. Based on the toxin activity and genetic characterization data, the isolates were categorized into two groups. The close genetic relationship (similarity index = 0.731) and high toxin activity were shown by one group of isolates obtained from cloves grown in Rathnapura with other two groups of isolates obtained from rubber grown in Kalutara. This observation suggests that C. quinqueseptatum isolated from clove grown in Rathnapura can be a potential pathogen on rubber.
Histological and Microbiological Assessment of the Role of Micro Organisms in Chronic Anal Fistula
(University of Kelaniya, 2012) Kumara, A.A.J.P.; Jayaratne, D.L.; Anthony, D.J.
Fistula in ano is one of the commonest ailments pertaining to the ano-rectal area and said to arise from crypto glandular infection of the anal gland, which lies within the intersphincteric space. Infection would seem to be an integral part of the pathogenesis of fistula in ano. The microbiology of acute anorectal sepsis is well documented, but the studies on chronic anal fistula have continuously raised doubts about the relevance of infection in fistula persistence. The present histological study complements the earlier work, which used microbiological methods alone where important organisms might have been overlooked. Granulation tissue from twenty patients with non specific fistula in ano was processed within 4h of medicated seton (Kshara sutra) therapy. Three samples from the intersphincteric part of the fistula were obtained.Two samples were studied microbiologically. The pus smear was taken from the fistulous opening by sterile cotton swab and sent to the Department of Microbiology, in a sterile container, and pus culture was done. Pus swab was inoculated on nutrient agar medium. The plated media were incubated at 37 C and examined at 48, hours. Smears from colonies that grew on the nutrient agar media were stained with Gram-stain. Gram-positive organisms and Gram-negative organisms were identified by conventional biochemical techniques. The third sample was fixed in 10 per cent formal saline for histological processing. Multiple 4 μm paraffin sections were stained using haematoxylin and eosin, gram, cresyl fast violet, periodic acid – Schiff and Ziehl – Neelsen stains. The results show the incidence of fistula in ano and the origin of the predominant microorganism present in ano rectal fistula. These were investigated using 100 pus samples obtained from the 20 patients.Isolates of Staphyloccus aureus, streptococus Spp and Corynebactrium spp. were identified as skin derived organisms. Isolates of Enterococcus spp., Escherichia coli, Bacteriodes spp were considered gastro intestinal tract derived organisms. No mycobacterium species was grown from any of the eight specimens. Sections of tissue from all twenty specimens showed a similar pattern of intense active chronic inflammatory change characterized by a large number of plasma cells, scattered multinucleate foreign-body giant cells and prominent vascular proliferation. Acute inflammatory change (of variable degree) was superimposed. No granulomas were seen in any specimen. Vegetable matter was demonstrated on the granulation tissue surface in one specimen only and bacteria were seen on histological examination and subsequent Gram staining. Relatively large numbers of organisms were grown from specimen. Stains for Helicobacter species, mycobacterium tuberculosis and fungi were negative in all specimens. The present study has confirmed the relative paucity of organisms and demonstrates through micro biological study but the histological examination does not reveal many organisms. In fact, i9t is difficult to obtain a detailed picture through microbiological examinations. But details of the inflammatory changes can be witnessed through histological examination. In other circumstances, histological examination has been used to demonstrate important pathogens such as tuberculosis, Mycobacterium leprae and Helicobacter Pylori.
Identification and characterization of dieback syndrome in Camelliasinensis (TRI 2025)
(University of Kelaniya, 2005) Ranasinghe, C.P.; Balasuriya, A.; Jayaratne, D.L.
The disease has been reported in the tea cultivar TRI 2025, grown in the upcountry since 1989 (Nethaniel, 1999). Preliminary observations from different locations where the disease has already been reported showed pathological affiliations instead of a physiological disorder or agronomical reasons. During the eight months under investigation in the Nuwara Eliya Estate, the affected area expandedby 129.75 m2. A distinctive increase in the rate of spread was observed during dry seasons. Asignificant relationship between the spread of the disease and climatic stress was found. The rate ofspread of the disease was higher with low relative humidity and rainfall. The expansion of the patch followed the direction of the wind with an indication of an airborne disease. Phylloplane microflora of TRI 2025 between healthy and diseased plants, the soils, which they are grown, collected from diseased and healthy areas found to have no significant difference. However, Pantoea agglomerans (Beijerinck) (Gavini et al., 1989), a Gram negative rod was solely and repeatedly isolated on nutrient agar, from the xylem sap of diseased plants. The sap of visually healthy plants, of the same cultivar upon prolonged incubation developed few colonies of the same bacterium. The bacterium was also isolated from dew collected from leaves of the diseased plants. The isolate was confirmed by the International Mycological Institute (IMI) in the United Kingdom (Offord, 2003). Four experimental sets of plants used to demonstrate Koch’s postulates, using mature tea bushes (Nuwara Eliya and St. Coomb’s), young plants and tomato seedlings. None of the sets met with conclusive results. Stem section analysis of the cultivar showed a significant xylem blocking in diseased plants, which increased in numbers with the severity of symptoms. P. agglomerans (Beijerinck) (Gavini et al., 1989), produce high-molecular-weight extra-cellular polysaccharides (Balows et al., 1992) and some strains are ice-nucleae active causing frost damage (Pajand,2005). Under the evidences the dieback in TRI 2025 can be classified as a stress driven relationship between a stressed plant and an opportunist.
Microbiological investigations of Sigiriya Frescos
(2006) Fernando, S.; Jayaratne, D.L.
The archaeologically valued Frescoes at Sigiriya, a World Heritage Site in Sri Lanka,play a major role in remarkable historic interest. Microbial growth on fresco paintings has been identified worldwide as a significant factor which affects the quality of paintings. Microbiological investigation of fresco paintings therefore has become an important aspect of conservation strategy. The microbiological investigation of the Sigiriya frescoes was carried out in June 2005 by visual detection, microscopic investigations and using microbial culture techniques. The samples for microbial culture techniques were taken from each colour regions separately using sterile cotton swabs and cultured in Nutrient Agar (NA), Trypton Soy Agar (TSA) and Potato Dextrose Agar (PDA) media.The observations revealed that the fresco surface was free from any fungal, lichen or cyanobacterial growth but eleven bacterial cultures were isolated from a decayed patch,from non painted plaster and from a cavity. All the isolates belong to the Genus Bacillus having no conformity with any of the Bacillus spp either indicated in ?Bergy?s manual of systematic bacteriology vol I and II or included in the computer database developed by Trevor Bryant, University of Southampton, UK (2005). One isolate showed similar morphological characteristic features to the Bacillus decoloratiois sp. Nov. bacterium which has been proposed for the new isolate that was responsible for de-colorization of the fresco paintings in Spain and Austria. However, the biochemical characterization of the isolate showed that is a distinctive species having no conformity with Bacillus decoloratiois sp. Nov. Further characterizations using DNA based techniques are being carried out in order to determine whether the isolate is a new species or a similar strain of the Bacillus decoloratiois sp. Nov. In the process of conservation, periodic monitoring and further investigations are being carried out for the detection of microbial growth forms including the Bacillus species on the fresco paintings in order to protect them from any microbial de-colorization and degradation.
Microbiological investigations of Sigiriya Frescos
(University of Kelaniya, 2006) Fernando, S.; Jayaratne, D.L.
The archaeologically valued Frescoes at Sigiriya, a World Heritage Site in Sri Lanka, play a major role in remarkable historic interest. Microbial growth on fresco paintings has been identified worldwide as a significant factor which affects the quality of paintings. Microbiological investigation of fresco paintings therefore has become an important aspect of conservation strategy. The microbiological investigation of the Sigiriya frescoes was carried out in June 2005 by visual detection, microscopic investigations and using microbial culture techniques. The samples for microbial culture techniques were taken from each colour regions separately using sterile cotton swabs and cultured in Nutrient Agar (NA), Trypton Soy Agar (TSA) and Potato Dextrose Agar (PDA) media. The observations revealed that the fresco surface was free from any fungal, lichen or cyanobacterial growth but eleven bacterial cultures were isolated from a decayed patch, from non painted plaster and from a cavity. All the isolates belong to the Genus Bacillus having no conformity with any of the Bacillus spp either indicated in ‘Bergy’s manual of systematic bacteriology vol I and II or included in the computer database developed by Trevor Bryant, University of Southampton, UK (2005). One isolate showed similar morphological characteristic features to the Bacillus decoloratiois sp. Nov. bacterium which has been proposed for the new isolate that was responsible for de-colorization of the fresco paintings in Spain and Austria. However, the biochemical characterization of the isolate showed that is a distinctive species having no conformity with Bacillus decoloratiois sp. Nov. Further characterizations using DNA based techniques are being carried out in order to determine whether the isolate is a new species or a similar strain of the Bacillus decoloratiois sp. Nov. In the process of conservation, periodic monitoring and further investigations are being carried out for the detection of microbial growth forms including the Bacillus species on the fresco paintings in order to protect them from any microbial de-colorization and degradation.
Microbiological quality of Aravindasava used in Ayurveda
(Sri Lanka Association for the Advancement of Science, 2009) Weerasooriya, W.M.B.; Liyanage, J.A.; Jayaratne, D.L.
A Phage Indicator Model for In-Vitro Evaluation of Antiviral Drugs Used in Ayurvedic and Traditional Medicine
(19th Conference on Postgraduate Research, International Postgraduate Research Conference 2018, Faculty of Graduate Studies,University of Kelaniya, Sri Lanka, 2018) Dayarathna, M.T.A.; Jayaratne, D.L.
Finding new antiviral drugs for the emerging new viruses have become an outstanding scope of study. The analysis of anti-phage activity evaluation model based on plaque reduction assay has been performed by numerous researchers in evaluating antiviral properties of Western and Ayurvedic medicines. This has been performed by using phages with their corresponding hosts. This study was carried out to validate the antiviral sensitivity of a phage-indicator model to evaluate antiviral drugs used in Ayurvedic and traditional medical treatments in Sri Lanka The host bacterium Escherichia coli was isolated with its corresponding coliphage from sewage effluents. Prior to the antiviral assay, the antibacterial effect of standard antiviral drugs, Acyclovir, Lamuvidine, Ribavarin and Oseltamivir on E. coli was determined. According to the results up to 80mg/ml for Acyclovir, Lamuvidine and Ribavarin did not show any antibacterial effect while Oseltamivir showed only up to 20mg/ml. The antiviral assay was performed in two approaches where the corresponding test drug was applied to a young culture of host bacterium and incubated overnight prior to the inoculation of the bacterium by phage suspensions. As the second approach, the test drug was applied to a phage suspension and incubated overnight prior to the inoculation of phage into the bacterium. According to the reduction of plaques on agar plates after performing the two approaches the mode of antiviral activity was determined. There was a significant reduction of plaque formation observed when the host bacterium was treated with the western antiviral drugs, suggesting that their antiviral effects occur during the viral replication stages in the host cell and this complies with the available literature which describes the mode of action of these Western antiviral drugs. The model was also used to evaluate traditional herbal extracts to determine the presence of antiviral properties. Accordingly, the second approach revealed that the aqueous black tea extract showed an antiviral effect during the adsorption stages while crude papaya leaf extract in the replication stages of the virus life cycle. However, the Ayurvedic product ‘Sudarshana Churnaya’ showed no effects in either the two stages of the virus life cycle. With these results it is concluded that this model is feasible, and efficient against laborious cell culture techniques in screening antiviral drugs
Potential Biocide Options and Biological Control Agent For Ceratocystis paradoxa Isolated From Coconut Growing Areas of Sri Lanka
(2016) Jayaratne, D.L.; Dayarathna, M.T.A.
A preliminary study on application of phage-indicator model in evaluation of antiviral drugs
(Sri Lanka Association for the Advancement of Science, 2015) Malalasekara, A.M.A.L.R.; Jayaratne, D.L.
Ratoon stunting disease of sugarcane in Sri Lanka
(Natural Resources, Energy and Science Authority of Sri Lanka, 1987) Jayaratne, D.L.; Widanapathirana, S.
Species of fungi and bacteria transmitted by the workers of two household ant species, Anoplolepis gracilipes Jerdon and Monomorium pharaonis Linne
(Research Symposium 2010 - Faculty of Graduate Studies, University of Kelaniya, 2010) Kosgamage, K.R.K.A.; Dias, R.K.S.; Jayaratne, D.L.
Workers of several ant species are considered as nuisance insects and household pests. Anoplolepis gracilipes and Monomorium pharaonis are two such species that attend food and this study was carried out to investigate if the workers of the two species contaminate food by transmitting any species of fungi or bacteria. Worker ants of A. gracilipes and M. pharaonis were collected in to sterilized Petridishes from a cafeteria of University of Kelaniya using a pair of sterilized forceps around 10 a.m. on the 24th of March, 2009. Five workers of each ant species were introduced to each of the five petridishes containing two culture media; Potato Dextrose Agar (PDA) for isolation of fungi and Nutrient Agar (NA) for isolation of bacteria under aseptic conditions. Both introductions were done within ten minutes after the collection of ants. Ants were allowed to crawl for five minutes in each petridish. Five petridishes containing PDA and five petridishes of NA but without introduction of ants were also maintained in each experiment. The PDA plates contaminated by ants and the control PDA plates were incubated at room temperature (28 °C) for a week. The NA plates contaminated by ants and the control NA plates were incubated at room temperature overnight. Microorganisms observed in each plate were identified according to the standard procedures. Five microorganisms transmitted by A. gracilipes included three fungi species; Aspergillus niger, Curvularia sp., Helminthesporium sp. and two bacteria species; Salmonella sp. and Micrococcus sp. In addition, four microbes, transmitted by M. pharaonis were identified as three species of fungi; Aspergillus niger, Aspergillus sp., Mucor sp. and a species of bacteria; Micrococcus sp. The identification of bacteria was done at Medical Research Institute in Colombo. The results indicated the possibility of food contamination by the workers of the two ant species.
Use of molecular features for identification of isolated fungal pathogens of big onion damping off disease and Trichoderma spp. isolated from soil
(Faculty of Graduate Studies, University of Kelaniya, 2015) Gunaratna, L.N.R.; Deshappriya, N.; Jayaratne, D.L.
Big onion (Allium cepa L.) is one of the economically important spices grown in Sri Lanka. Damping off disease caused by Fusarium sp. during nursery stage of growth poses a major factor that affect the yield significantly. Application of fungicides decrease incidence of damping off disease considerably, but this is neither economical nor environmental friendly. Thus, disease management practices have to be directed towards biological control strategies. Trichoderma spp. have been extensively studied as biological control agents for controlling numerous soil-borne fungal pathogens. In the present study, isolation and identification of fungal pathogens associated with damping off disease of onion and Trichoderma spp. present in soil of the same onion fields was carried out with a view to using the Trichoderma spp. in the management of damping off pathogens. Pathogens associated with damping off were isolated from diseased and healthy seedlings (7-30 days old) collected from the fields in the Matale and Anuradhapura districts. Seedlings were surface sterilized and plated in Potato Dextrose Agar (PDA) supplemented with tetracycline. Soil samples collected from the same fields were used for the isolation of Trichoderma spp. using the Warcup method. Based on morphological characteristics and using identification keys, the fungal pathogens isolated from seedlings were identified as Fusarium, Curvularia, Alternaria and Sclerotium spp. and 14 fungal species isolated from soil samples were identified as Trichoderma spp. Although fungi can be identified using morphological features, the use of molecular biological methods tend to be more accurate. Therefore, the identity of isolated fungal species was confirmed by molecular biological methods. Genomic DNA of Fusarium spp., Alternaria spp., Trichoderma spp. were extracted. Molecular characterization of these DNA was carried out using Polymerase Chain Reaction (PCR) where the Internal Transcribed Spacer (ITS) region of rDNA gene was amplified using ITS-1 and ITS-4 primer pairs. The products were subjected to agarose gel electrophoresis. The procedures were repeated 3 times. Results showed 550 bp size bands characteristic of Fusarium spp. and 570 bp products specific to Alternaria spp. confirming the previous identity using culture based methods. Fungal species isolated from soil showed products of 600 bp which corresponds to Trichoderma sp. Molecular characterization of the potential biocontrol agents i.e. Trichoderma spp. and A.cepa L. pathogens using PCR amplification of ITS region confirmed the preliminary identities carried out using culture based methods.