Evaluation of bactericidal activity of antiseptics and disinfectants commonly used in healthcare settings in Colombo District

Background: Increasing risk of healthcare associated infections especially polymicrobial wound infections is a major problem in healthcare settings in Sri Lanka. Proper use of antiseptics and disinfectants may be useful in reducing the magnitude of such infections.Objectives: To determine the efficacy of bactericidal activity in recommended concentrations and lower concentrations of selected antiseptics and disinfectants.Methods: Bactericidal activity of 40%, 50% and 60% isopropyl alcohol, 1%, 5% and 10% povidone iodine, 1%, 2% and 4% chlorhexidine gluconate, 1.22%, 1.42% and 1.62% peracetic acid, 1.9% and 2.9% hypertonic saline and 1.5%, 2% and 2.5% of the mixture of 2-aminoethanol, didecyldimethylammonium chloride, potassium carbonate and bis (3-Aminopropyl) dodecylamine was evaluated with 9 standard strains of American Type Culture Collection (ATCC) and 13 clinical isolates of bacteria. Reduction of growth of methicillin sensitive Staphylococcus aureus (MSSA), methicillin resistant Staphylococcus aureus (MRSA), Streptococcus pyogenes, Enterococcus faecalis, Acinetobacter baumannii, Escherichia coli, Klebsiellapneumoniae (ESBL and carbapenem resistant), Pseudomonas aeruginosa was assessed with contact times of 1 minute, 15 minutes and 24 hours by counting colonies comparing with test control which contains same volume of distilled water instead of antiseptic or disinfectant solution.Results: All chemicals except hypertonic saline showed 100% bactericidal activity in all concentrations against all tested bacteria in stated contact times. Hypertonic saline in 1.9% and 2.9% showed significant reduction of Gram positive bacteria and Acinetobacter baumannii only after 24 hours. Acinetobacter baumannii was inhibited by1.9% and 2.9% of hypertonic saline in 67.48% and 68.20% of respectively; however, other Gram negative bacteria were not inhibited.Conclusion: Recommended concentrations of antiseptics and disinfectants have an accepted bactericidal activity against tested standard strains and clinical isolates. Hypertonic saline is only effective to inhibit Gram positive bacteria after 24 hours of contact time.Acknowledgement: Staff of Department of Microbiology, the University of Sri Jayewardenepura, Sri Jayewardenepura General Hospital and Colombo South Teaching Hospital

VASE LIFE STUDIES ON Dracaena reflexa CUT DECORATIVE SHOOTS

Wilting and color change of Dracaena leaves are major post harvestproblems in exportation. This study is an attempt to overcome these problemsand to improve vase life of Dracaena cut stems. Experiments were done atGreen Farms Ltd. Marawila to investigate post harvest handling of Dracaenareflexa to maintain export quality and freshness. Series of experiments wereconducted to investigate management practices; effect of glycerol solution(pure glycerol in 1,3 & 5hrs); effect of immersing one hour (using KMn04 2,5 & 10pmm); effect of sucrose solution (2, 5 & 10%); effect of KMn04 (2, 5& lOppm) for cultivars of Dracaena reflexa "Reflex a Green", "Song ofJamaica" and "Song of India". Treatments were arranged in completerandomized design with 4 replicates each. Data were analyzed using SASstatistical programme with analysis of variances. Mean separation was doneusing LSD on parametric procedures.The results revealed that wilting, color change and rotting, of Dracaenareflexa cultivars were not significantly affected by post harvest solutions ofKMn04 and sucrose compared to the control (tap water). However, pureglycerol (dipped for 1hr) and tap water maintained vase life of "Song ofJamaica" for 21days. Damaged cuttings showed Erwinia infection after 10-12days during vase period (CV = 05.628813). Results in general show avoidinginjury to specimens, and this helps to maintain the quality of the products.Many infections can be avoided by keeping the specimens dry. Experimentsproved that maximum vase life of Dracaena cuttings could be achieved bymaintaining proper management practices and sanitation conditions in a coldroom.

INVESTIGATION OF VASE LIFE PACKAGE ON Codiaeum Variegatum CUT DECORATIVE SHOOTS

Croton is one of the exportable type foliage species in Sri Lanka. However,wilting of the leaves is a major problem raised in the export of these foliagespecies. In order to full fill the demand in world market, it is essential toovercome such problems.In this study, seven experiments were conducted at Green Farms (Pvt) Ltd.Marawila, to maintain the vase life of Codiaeum varigatum cv. 'Batik','Pictum', and 'gold star' cut decorative shoots and to retain their exportquality characters. Sugar (0, 1, 2, 4 & 5%), NiCh (250, 500, 750 &1000ppm), combination of sugar (2%) + KMn04 2ppm and glycerol (1, 5 and10%) were tested as treatments (vase solutions) in separate experiments.Treatments were arranged in complete randomized design with 3 replicateseach. Data were analyzed using SAS statistical method with analysis ofvariances. Mean separation was done using LSD on parametric procedures.Croton had ability to maintain vase life up to 3 weeks in preliminary studies.To comparison of different packing methods for vase life of croton, wetpaper packing showed higher vase life and higher leaf freshness for croton.Sugar treatments applied to "Pictum" and "Gold star" were maintained 21days of vase life. "Batik" showed only 17 days vase life (C.V. =7.750323).NiCh gave 18 days of vase life for "Batik" (CV = 11.04419) however it isharmful to human. According to the re-cutting & water changes, 4 dayscutting interval and 2 days water change was the best. Combination ofsucrose & KMn04 was maintained vase life vase life up to 14 days.Combination of Sucrose 2% + KMn04 2 ppm & Cotton plug was bestamong all sugar concentrations (C.V. = 10.90617). For this could maintainexport quality up to 19 days. "Pictum" & "Gold Star" were tolerant cultivars.Pure glycerol gave negative effects. All dilute glycerol concentrations (1, 5and 10%) were good post harvest treatments. Among those, 5% couldmaintain export quality of "Batik" cuttings up to 20 days. Combination ofwax + KMn04 + sucrose treatment gave negative effect. Pure wax withcommercial preservatives did not enhance the quality.

Open and Distance Learner Engagement with Online Mediation Tools: An Activity Theory Analysis

This paper presents the results of a study conducted to ascertain the extent to which participants studying in an open and distance learning context utilized the mediation tools provided in an Advanced Writing Skills course, conducted in a blended-learning mode in Sri Lanka. Sixty-four participants engaged in the online component of the writing course using the Process Approach. The course consisted of seven sessions; four addressing the stages of the Process Approach to writing an essay, and three practice sessions. Data were gathered from log-files of the Learning Management System, questionnaires, and interviews related to five mediation tools provided to learners. The data were analyzed utilizing Engeström’s activity theory framework (1987); with focus on the contradictions that emerged in the use of each tool. First, the contradictions that emerged in participants’ engagement with the tools is presented, secondly, the factors that need to be taken into account to ensure greater engagement.</p

Group B streptococcal infective endocarditis in a young non-pregnant female with rheumatic heart disease - A Case Report

Group B Streptococcus (GBS) is a rare cause of infective endocarditis in adults associated with a high mortality rate due to the frequent occurrence of local and systemic complications. Here we report a case of infective endocarditis (IE) in a young non-pregnant female with a history of rheumatic heart disease (RHD) who presented with a short history of fever, shortness of breath and constitutional symptoms. GBS was isolated from a single blood culture along with echocardiographic findings of a cardiac vegetation and ophthalmologic findings of a Roth spot. Based on the Modified Duke Criteria, a definitive diagnosis of infective endocarditis was made. She was treated with a prolonged course of intravenous (IV) ceftriaxone, with gentamicin being added to the regimen, following which she made a complete recovery.</p

Measurement of the B+ --> p pbar K+ Branching Fraction and Study of the Decay Dynamics

With a sample of 232x10^6 Upsilon(4S) --> BBbar events collected with the BaBar detector, we study the decay B+ --> p pbar K+ excluding charmonium decays to ppbar. We measure a branching fraction Br(B+ --> p pbar K+)=(6.7+/-0.5+/-0.4)x10^{-6}. An enhancement at low ppbar mass is observed and the Dalitz plot asymmetry suggests dominance of the penguin amplitude in this B decay. We search for a pentaquark candidate Theta*++ decaying into pK+ in the mass range 1.43 to 2.00 GeV/c2 and set limits on Br(B+ --> Theta*++pbar)xBr(Theta*++ --> pK+) at the 10^{-7} level.Comment: 8 pages, 7 postscript figures, submitted to Phys. Rev. D (Rapid Communications

Measurement of the Branching Fraction for B- --> D0 K*-

We present a measurement of the branching fraction for the decay B- --> D0 K*- using a sample of approximately 86 million BBbar pairs collected by the BaBar detector from e+e- collisions near the Y(4S) resonance. The D0 is detected through its decays to K- pi+, K- pi+ pi0 and K- pi+ pi- pi+, and the K*- through its decay to K0S pi-. We measure the branching fraction to be B.F.(B- --> D0 K*-)= (6.3 +/- 0.7(stat.) +/- 0.5(syst.)) x 10^{-4}.Comment: 7 pages, 1 postscript figure, submitted to Phys. Rev. D (Rapid Communications

Measurement of Branching Fraction and Dalitz Distribution for B0->D(*)+/- K0 pi-/+ Decays

We present measurements of the branching fractions for the three-body decays B0 -> D(*)-/+ K0 pi^+/-$and their resonant submodes$B0 -> D(*)-/+ K*+/- using a sample of approximately 88 million BBbar pairs collected by the BABAR detector at the PEP-II asymmetric energy storage ring. We measure: B(B0->D-/+ K0 pi+/-)=(4.9 +/- 0.7(stat) +/- 0.5 (syst)) 10^{-4} B(B0->D*-/+ K0 pi+/-)=(3.0 +/- 0.7(stat) +/- 0.3 (syst)) 10^{-4} B(B0->D-/+ K*+/-)=(4.6 +/- 0.6(stat) +/- 0.5 (syst)) 10^{-4} B(B0->D*-/+ K*+/-)=(3.2 +/- 0.6(stat) +/- 0.3 (syst)) 10^{-4} From these measurements we determine the fractions of resonant events to be : f(B0-> D-/+ K*+/-) = 0.63 +/- 0.08(stat) +/- 0.04(syst) f(B0-> D*-/+ K*+/-) = 0.72 +/- 0.14(stat) +/- 0.05(syst)Comment: 7 pages, 3 figures submitted to Phys. Rev. Let

Evidence for the Rare Decay B -> K*ll and Measurement of the B -> Kll Branching Fraction

We present evidence for the flavor-changing neutral current decay $B\to K^*\ell^+\ell^-$ and a measurement of the branching fraction for the related process $B\to K\ell^+\ell^-$, where $\ell^+\ell^-$ is either an $e^+e^-$ or $\mu^+\mu^-$ pair. These decays are highly suppressed in the Standard Model, and they are sensitive to contributions from new particles in the intermediate state. The data sample comprises $123\times 10^6$ $\Upsilon(4S)\to B\bar{B}$ decays collected with the Babar detector at the PEP-II $e^+e^-$ storage ring. Averaging over $K^{(*)}$ isospin and lepton flavor, we obtain the branching fractions ${\mathcal B}(B\to K\ell^+\ell^-)=(0.65^{+0.14}_{-0.13}\pm 0.04)\times 10^{-6}$ and ${\mathcal B}(B\to K^*\ell^+\ell^-)=(0.88^{+0.33}_{-0.29}\pm 0.10)\times 10^{-6}$, where the uncertainties are statistical and systematic, respectively. The significance of the $B\to K\ell^+\ell^-$ signal is over $8\sigma$, while for $B\to K^*\ell^+\ell^-$ it is $3.3\sigma$.Comment: 7 pages, 2 postscript figues, submitted to Phys. Rev. Let