Browsing by Author "Perera, P. D. V. M."

Now showing 1 - 2 of 2

Antimicrobial activity of poly-herbal formula “Dasapanguwa” against several Gram positive bacteria and Gram negative bacteria
(Faculty of Science, University of Kelaniya Sri Lanka, 2023) Samaraweera, G. A.; Gunathilaka, V. H. N. M.; Perera, M. A. S. N.; Perera, P. D. V. M.; Wageesha, N. D. A.; Kadigamuwa, C. C.
The resistance of bacteria against available antibiotics has become a rising problem worldwide. Therefore, the discovery of alternatives using medicinal plants is widely studied. Although medicinal plants have been studied individually, the impact of herbal formulas was studied rarely. “Dasapanguwa” is a poly-herbal formula prepared as a decoction of 10 different plant parts to use in Ayurvedic medicine in Sri Lanka for colds, fever, and infectious diseases. Although the formula is used as a treatment for infectious diseases in Ayurvedic medicine in Sri Lanka, the antimicrobial action of this preparation was not scientifically assessed. The objective of the research was the determination of the antibacterial activity of the Dasapanguwa formula against Gram positive and Gram negative bacteria. Plant parts of Mollugo cerviana (L.) Ser., Solanum virginianum L., Solanum melongena L., Justicia adhatoda L., Rotheca serrata (L.) Steane & Mabb., Glycyrrhiza glabra L., Zingiber Officinale, Coscinium fenestratum (Gaertn.) Colebr., Piper nigrum L., and Coriandrum sativum L. were collected in dried form. Water extracts of decoction 1 (D1) (plant part: 5.0 g) and Decoction 2 (D2) (plants parts: 5.0 g ground into fine powder) were prepared by refluxing in 500.0 ml of water for two hours at 100 °C followed by freeze-drying. The antibacterial susceptibility test was performed by the Kirby-Bauer disc diffusion method against Gram positive bacteria (Staphylococcus aureus, Bacillus subtilis, and Enterococcus faecalis), and Gram negative bacteria (Pseudomonas aeruginosa, Escherichia coli, and Klebsiella pneumoniae). Antibiotic discs were prepared for each concentration of two decoctions (1.0 to 15.0 mg ml-1). Commercially available tetracycline (30 μg) and ceftriaxone (30 μg) were used as positive controls against Gram’s positive and Gram’s negative bacteria respectively according to the CLSI guideline. The diameter of the clear zones was measured. There were no inhibition zones against all the bacteria for tested concentrations of both decoctions compared to positive controls. Previous studies showed that the antibacterial activity of an herbal extract could depend on the plant, solvent, test pathogens, and concentrations. Furthermore, the activity could depend on the plant itself or the formula of poly-herbal. Therefore, it is recommended to further study the antibacterial activity of both decoctions for higher concentrations from 15 mg ml-1 against selected bacteria. Furthermore, the antibacterial activity could be studied for extracts prepared by different solvents including methanol and ethanol.
Determination of Staphylococcus spp. present as contaminants on public door handles of an institute and analysis of their antibiogram
(Faculty of Science, University of Kelaniya Sri Lanka, 2023) Pathirana, M. P. P. M.; Danushka, W. A. S.; Athukorala, N. N.; Niroshan, D. M. M. P.; Kaluaddaraarachchi, A.; Nayanathara, R. K. A. B.; Perera, P. D. V. M.
positive, Antibiotic resistanceStaphylococcus are potential pathogens that cause a range of infections, ranging from mild abscesses to severe septicemia. The objective of this study was to identify Staphylococcus present as surface contaminants and to analyze their antibiogram. KAATSU International University’s door knobs were sampled using cotton swabs that had been dipped in peptone water and incubated it for 18-24 hours at 37C0 . Incubated samples were inoculated on mannitol salt agar plates and incubated for 24 hours at 37°C. Gram staining and biochemical tests such as catalase, coagulase were carried out for further identification of the isolates. The disc diffusion method was used for antibiotic sensitivity testing (ABST) following the guidelines of the Clinical and Laboratory Standards Institute (CLSI). For coagulase-positive isolates, cefoxitin (30 g), erythromycin (10 g), gentamicin (10 g), vancomycin (30 g), and oxacillin (1 µg) were used. Novobiocin (5 mg), erythromycin (10 mg), gentamicin (10 mg), and vancomycin (30 mg) were utilized for coagulase-negative isolates. All 37 door handle samples were collected; 91.89% (n =31) were pure growth samples. Out of those samples, 64.86% (n = 24) were identified as Coagulase positive Staphylococcus aureus and 18.91% (n = 7) were identified as coagulase negative Staphylococcus. Out of 24 samples, 24.16% (n = 7) isolates were found to be Methicillin resistant Staphylococcus aureus (MRSA) strains. Rates of MRSA isolates showed resistance to erythromycin 100% (n = 7) and Oxacillin 14.28%. In (CoNS) coagulase negative Staphylococcus 71.42% (n = 5) were identified as Staphylococcus epidermidis, and 28.57% (n = 2) were Staphylococcus saprophyticus. Coagulase negative Staphylococcus showed 100% sensitivity to vancomycin, gentamycin (10 ug), and oxacillin, and 42.86% (n = 4) of the isolates showed resistance to erythromycin. Staphylococcus aureus with a considerable rate of MRSA was discovered in this investigation. [Contaminated door handles can be a source of transmission of MRSA.] This research can be used to find effective disinfectants and proper cleaning techniques to minimize the spread of Staphylococcus through door handles