Papers by JAMS Jayatilake
Sri Lankan Journal of Infectious Diseases
Introduction: Amidst a rapid outbreak of COVID-19, ChAdOx1 nCoV-19 vaccine was initially administ... more Introduction: Amidst a rapid outbreak of COVID-19, ChAdOx1 nCoV-19 vaccine was initially administered to health care workers in Sri Lanka.Objective: The aim of this study was to investigate adverse events following immunization (AEFI) after the first dose of ChAdOx1 nCoV-19 vaccine in a group of Sri Lankan medical officers from 5th February to 7th March 2021.Methods: A retrospective survey was conducted using a pretested Google form questionnaire designed to gather demographic data, medical history, AEFI and their management. The questionnaire was shared among a convenience sample of medical officers through online apps (Facebook, Imo, Viber, WhatsApp). Responses to the questionnaire were collected and the quantitative and categorical data and their associations were analyzed statistically.Results: Of 836 participants (male/female ratio = 0.92; mean age = 39.6±7.9 years), the majority, 738 (88.3%) experienced AEFI. Commonest AEFI were body ache (80.7%), lethargy (76.1%), local site ...
Sri Lanka Journal of Medicine
Background: Onychomycosis is increasingly found in tropical populations. Objectives: To investiga... more Background: Onychomycosis is increasingly found in tropical populations. Objectives: To investigate the incidence and etiology of onychomycosis in a group of patients presented to the Teaching Hospital, Kurunegala, Sri Lanka. Methods: A total of 47 patients (8 males, 39 females clinically diagnosed with onychomycosis were randomly selected as study participants. After obtaining written informed consent from the participants, demographics and onychomycosis-associated factors were recorded using an interviewer-administered questionnaire. Nail specimens were subjected to direct microscopy (DM) after 20% KOH digestion and were cultured on Sabourauds Dextrose Agar (SDA) containing chloramphenicol alone and SDA with chloramphenicol and cycloheximide. Fungi were identified macroscopically and microscopically. Results: Out of 47 patients clinically diagnosed with onychomycosis, only 30 (63.8%) were confirmed as onychomycosis mycologically. Overall, 93.4% of confirmed onychomycosis patients...
Oral manifestations of COVID-19 in a group of Sri Lankans infected with SARS-CoV-2
Journal of Global Oral Health
Objectives: COVID-19 due to SARS-CoV-2 is primarily a respiratory disease despite occasional syst... more Objectives: COVID-19 due to SARS-CoV-2 is primarily a respiratory disease despite occasional systemic involvements. This study investigated orofacial manifestations of COVID-19 in a group of Sri Lankans. Materials and Methods: A descriptive study was undertaken using 1112 COVID-19 patients managed at an intermediate care center in Penideniya, Peradeniya, Sri Lanka during January–May 2021. Demographic data, systemic, and orofacial manifestations of COVID-19 were recorded using a structured questionnaire administered over the telephone on participants’ verbal informed consent. Results: Study population (mean age = 34.1 ± 19 years) included 90 (8%) males and 1022 (92%) females, belonging to Sinhala (936; 84.2%), Tamil (105; 9.4%), and Muslim (71; 6.4%) communities. There were 712 (64%) married, 395 (35.5%) unmarried, and 05 (0.4%) divorced individuals. There were 16 (1.4%) participants who practiced betel chewing. All participants had been subjected to RAT or PCR for symptoms (249, 22....
Sri Lankan Journal of Infectious Diseases
A 56-year-old man with multiple comorbidities presented with diarrhea (CDAD) following prolonged ... more A 56-year-old man with multiple comorbidities presented with diarrhea (CDAD) following prolonged antibiotic therapy. Clostridium difficile associated diarrhea (CDAD) was confirmed by detecting C. difficile toxin A and B in stools with Rapid Immunoassay. The patient was managed successfully with custom prepared oral vancomycin.
Effect of gut microbiota on immune checkpoint inhibitor (ICI) based cancer immunotherapy
Ceylon Journal of Science, 2021
Modulation of the host immunity is one of the important functions rendered by the human gut micro... more Modulation of the host immunity is one of the important functions rendered by the human gut microbiota. Tumor cells are able to exploit the host immune system for their survival and spread within the host. Cancer immunotherapy is one of the therapeutic strategies that are used to stimulate the host anti-tumor immune response against cancer cells. Immune checkpoint inhibitor (ICI) based immunotherapy is a novel treatment approach in cancer immunotherapy that targets the immune checkpoints, namely, programmed cell death-1 (PD-1) and cytotoxic T-lymphocyte–associated protein 4 (CTLA-4). However, patients showing both primary and acquired resistance to ICI based immunotherapy significantly limit its clinical application. Remarkably, the gut microbiota affects the ICI therapy by effectively modulating both PD-1 and CTLA-4 immune checkpoints. Hence, improvement of the gut microbial composition in favor of ICI based immunotherapy has gained promising therapeutic outcomes for cancer patients worldwide.
Identification, genotyping and invasive enzyme production of oral Candida species from denture induced stomatitis patients and healthy careers
Journal of Oral and Maxillofacial Surgery, Medicine, and Pathology, 2021
Abstract Objective Denture induced stomatitis (DIS) is often associated withCandida infection. Th... more Abstract Objective Denture induced stomatitis (DIS) is often associated withCandida infection. This study aimed to identify oral Candida species from DIS patients and healthy careers and to evaluate their invasive enzyme production. Methods Candida from DIS patients (n = 38) and healthy careers (n = 23) were identified using chromogenic agar and molecular techniques. Phospholipase, esterase and hemolysin activities of C. albicans were evaluated using in vitro assays. Results Chromogenic agar revealed 29 C. albicans and 09 non-C. albicans Candida among pathogenic isolates. Commensal isolates consisted of 18 C. albicans and 05 non-C. albicans Candida. PCR-RFLP analysis identified C. albicans (76.3 %) as the commonest pathogenic species followed by C. glabrata (13.2 %), C. parapsilosis (5.3 %) and C. tropicalis (5.3 %). Within commensal isolates, C. albicans (78.3 %) was leading followed by C. parapsilosis (13 %), C. glabrata (4.3 %) and C. guilliermondii (4.3 %). Furthermore, ABC genotyping revealed that pathogenic C. albicans genotype A (69 %) was predominant followed by genotypes C (20.7 %) and B (10.3 %). Commensal C. albicans had only the genotype A. Phospholipase, esterase and hemolysin activities of pathogenic C. albicans were significantly higher (P Conclusions C. albicans is the leading Candida species isolated from DIS patients and healthy careers. C. albicans genotype A remains predominant in both pathogenic and commensal isolates while prevalence of genotype C is more than the genotype B among the pathogenic isolates. C. albicans from DIS patients has significantly higher phospholipase, esterase and haemolysin activities compared to commensals which may contribute in pathogenesis.
Phospholipase Enzyme (caPLB1) Expression and Candidal Virulence in HIV Infection
No: 69 (Poster) Health and Hygiene 238 POST ANTIFUNGAL EFFECT, PHOSPHOLIPASE AND ASPARTYL PROTEIN... more No: 69 (Poster) Health and Hygiene 238 POST ANTIFUNGAL EFFECT, PHOSPHOLIPASE AND ASPARTYL PROTEINASE PRODUCTION OF CANDIDA ALBICANS ORAL ISOLATES FOLLOWING EXPOSURE TO CHLORHEXIDINE A.N.B. Ellepola*, B.K. Joseph, Z.U. Khan and J.A.M.S. Jayatilake Health Sciences Centre, Kuwait University, Kuwait Faculty of Dental Sciences, University of Peradeniya, Sri Lanka *arjuna@hsc.edu.kw An important virulent factor of Candida albicans, the major aetiological agent of oral candidosis is its ability to produce extracellular enzymes such as phospholipases and aspartyl proteinases. Post-antifungal effect (PAFE) is the suppression of fungal growth following brief exposure to antifungal agents. Chlorhexidine gluconate (CG) is an antimicrobial mouth wash with antifungal properties used in dentistry. Its concentration in the mouth reaches subtherapeutic levels during dosage intervals due to the diluent effect of saliva and the cleansing effect of the oral musculature. Therefore, Candida undergo only ...
Isolation, identification and characterization of Lactobacillus species diversity from Meekiri: traditional fermented buffalo milk gels in Sri Lanka
Heliyon, 2021
Traditional fermented buffalo milk gel; Meekiri, is a popular buffalo milk-derived product in Sri... more Traditional fermented buffalo milk gel; Meekiri, is a popular buffalo milk-derived product in Sri Lanka. Predominantly, it is produced using the back-slopping (adding a small amount of the previous fermentate) technique, following the life-long traditions available at the cottage level. Hence, diverse and unclassified starter cultures are likely to be established across the varying geographical regions of Meekiri production. In the present study, we aimed to elucidate the diversity of lactic acid bacteria (LAB) and their characteristics including probiotic properties from major Meekeri production areas (n = 22) in Sri Lanka. Lactic acid bacteria was isolated from locally produced Meekiri samples (n = 23) and characterized based on morphological, biochemical, physiological profiles and potential of probiotic properties. The isolates revealed five different colony and cell morphologies and were classified as heterofermenters, homofermenters and facultative heterofermenters based on CO2 production using glucose. None of the isolates showed the ability to grow either at 5 °C or 0 °C, while 71 % and 100 % survival of the isolates were observed at 15 °C and 45 °C, respectively. Amplified ribosomal DNA restriction analysis (ARDRA) primarily grouped the isolates into three distinct clusters based on their DNA banding patterns. Subsequently, 16S rRNA sequencing of isolates revealed the presence of four species namely, Limosilactobacillus fermentum (n = 18), Latilactobacillus curvatus (n = 2), Lactobacillus acidophilus (n = 2) and Lactiplantibacillus plantarum (n = 1) and in the phylogenetic analysis, it was represented by four distinctive clades. All the isolated species demonstrated promising probiotic potential with antibiotic sensitivity, antimicrobial properties, bile acid tolerance and acid tolerance. In conclusion, traditional back-slopping Meekiri in Sri Lanka contains diverse LAB, with a negligible geographical variation at species-level. Our work provides a strong foundation and insights into future applications in starter culture development for the fermentation of buffalo's milk.
Sri Lankan Journal of Infectious Diseases, 2019
This an open-access article distributed under the terms of the Creative Commons Attribution Licen... more This an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Disability, CBR & Inclusive Development, 2015
Purpose: Assessment of physical disability at the community level is essential for rehabilitation... more Purpose: Assessment of physical disability at the community level is essential for rehabilitation and supply of services. This study aimed to assess the prevalence of physical disability among adults in an urban community in Sri Lanka.Methods: A descriptive cross-sectional study was conducted among 2460 adults (18-59 years of age) who were selected using cluster sampling. Physical disability was measured using a Physical Impairment Examination Tool (PIET) and World Health Organisation Disability Assessment Schedule II (WHODAS II). Results: Prevalence of physical disability was 4.2% (95% CI= 3.5-5.1). Physical disability was higher among people in the age group of 40-59 years (6.5%, n=64) than among those in the age group of 18-39 years (2.6%, n=39) (P<0.05). Physical disability was more prevalent among females (4.4%, 95% CI= 4.2-4.6) than males (2.6%, 95% CI: 2.4-2.8), and among Tamils (7.8%, 95% CI=5.1%- 10.5%) than Sinhalese (3.3%, 95% CI=2.4%- 4.1%). It was higher among those ...
Microbiology Spectrum
ABSTRACTCandidaspecies are the most common infectious fungal species in humans; out of the approx... more ABSTRACTCandidaspecies are the most common infectious fungal species in humans; out of the approximately 150 known species,Candida albicansis the leading pathogenic species, largely affecting immunocompromised individuals. Apart from its role as the primary etiology for various types of candidiasis,C. albicansis known to contribute to polymicrobial infections. Polymicrobial interactions, particularly betweenC. albicansand bacterial species, have gained recent interest in which polymicrobial biofilm virulence mechanisms have been studied including adhesion, invasion, quorum sensing, and development of antimicrobial resistance. These trans-kingdom interactions, either synergistic or antagonistic, may help modulate the virulence and pathogenicity of bothCandidaand bacteria while uniquely impacting the pathogen–host immune response. As antibiotic and antifungal resistance increases, there is a great need to explore the intermicrobial cross-talk with a focus on the treatment ofCandida-as...
Disability, CBR & Inclusive Development, 2015
Purpose: Rehabilitation with assistive devices is of great benefit to people with limb disabiliti... more Purpose: Rehabilitation with assistive devices is of great benefit to people with limb disabilities, enabling them to lead independent and productive lives. While assistive devices improve the quality of life of persons with lower limb disabilities by facilitating activities of daily living, there are also many barriers to their use. This study aims to describe these barriers among community-dwelling persons with lower limb disabilitiesin central Sri Lanka. Methods: A community survey was conducted among adults between 18 and 59 years of age, to find persons with lower limb disabilities in Kandy Municipal Council area, in the central province of Sri Lanka. This was followed by purposive sampling to select a sub-sample of 12 individuals with unilateral lower limb disabilities for a qualitative study using in-depth interviews. Unilateral lower limb disabilities were identified using a clinical examination and World Health Organisation Disability Assessment Schedule 2.0 (WHODAS 2.0). A qualitative thematic content analysis was used to evaluate the interview text. Results: Participants described several barriers in using assistive devices, such as unaffordable assistive technology like wheelchairs and artificial limbs, unavailability of appropriate assistive technology, difficulties associated with repair and maintenance, and problems in accessibility. Limited knowledge of
Ultrastructural, histochemical and molecular features of the invasive phase of candida species
ABSTRACT Thesis (Ph. D.)--University of Hong Kong, 2006.
IL‐1α, IL‐1ra and IL‐8 are differentially induced by Candida in experimental oral candidiasis
Oral Diseases, 2007
Objective: To investigate the expression of interleukin‐1α (IL‐1α), IL‐1ra and IL‐8 by the oral ... more Objective: To investigate the expression of interleukin‐1α (IL‐1α), IL‐1ra and IL‐8 by the oral epithelium challenged by various Candida species.Materials and methods: In vitro candidiasis was induced by C. albicans wild type SC5314, its EFG1, CPH1 and secretory aspartyl proteinase (SAP) mutants and, ATCC isolates of C. albicans, C. tropicalis and C. dubliniensis using a reconstituted human oral epithelium (RHOE) model. IL‐1α, IL‐1ra and IL‐8 levels in culture media were quantified by an enzyme‐linked immunosorbent assay at 12, 24 and 48 h. Fungal invasion and IL‐1ra expression in RHOE were detected by periodic acid‐Schiff staining and immunohistochemistry.Results: Overall, the invasive Candida induced relatively higher levels of IL‐1α, IL‐1ra and IL‐8 in the culture media than the noninvasive isolates. IL‐1α and IL‐1ra levels induced by Candida with hyphal invasion were significantly higher (P < 0.05) than those induced by the isolates without hyphal invasion at 12, 24 and 48...
Experimental superficial candidiasis on tissue models
Mycoses, 2010
Candida species are common pathogens causing superficial mycoses primarily affecting the mucosa a... more Candida species are common pathogens causing superficial mycoses primarily affecting the mucosa and the skin in humans. Crucial steps during pathogenesis of superficial candidiasis comprise fungal adhesion, colonisation and subsequent penetration of the respective tissues. Exploring these pathological events and perhaps fungal and tissue responses towards drug treatment is imperative in the management of this infection. Unfortunately, pathological biopsies of superficial candidiasis do not exhibit the early changes in the host-pathogen interaction as the tissues are already invaded by the fungi. In vivo experimental assessments of pathological processes of superficial candidiasis are also limited because of the difficulties in providing reproducible and comparable conditions in the host environment. Conversely, in vitro models have helped studying fungal-host interactions under more defined and controlled conditions. Some common in vitro models used to simulate superficial candidiasis are chick chorioallantoic membrane, mucosal explants and single layer or multiple layer cell cultures. Interestingly, these experimental approaches share advantages as well as disadvantages when compared with in vivo conditions. Hence, this review intends to discuss about the experimental superficial candidiasis produced in various tissue models and their advantages as well as disadvantages with a particular reference to further improvement of validity and reliability of such experiments.
A Comparative Study of Candidal Invasion in Rabbit Tongue Mucosal Explants and Reconstituted Human Oral Epithelium
Mycopathologia, 2008
The purpose of this study is to compare the light and scanning electron microscopic (SEM) feature... more The purpose of this study is to compare the light and scanning electron microscopic (SEM) features of tissue invasion by three Candida species (C. albicans, C. tropicalis, and C. dubliniensis) in two different tissue culture models: rabbit tongue mucosal explants (RTME) and reconstituted human oral epithelium (RHOE). Tongue mucosal biopsies of healthy New Zealand rabbits were maintained in explant culture using a transwell system. RHOE was obtained from Skinethic Laboratory (Nice, France). RTME and RHOE were inoculated with C. albicans, C. tropicalis, and C. dubliniensis separately and incubated at 37 degrees C, 5% CO(2), and 100% humidity up to 48 h. Light microscopic and SEM examinations of uninfected (controls) and infected tissues were performed at 24 and 48 h. C. albicans produced characteristic hallmarks of pathological tissue invasion in both tissue models over a period of 48 h. Hyphae penetrated through epithelial cells and intercellular gaps latter resembling thigmotropism. SEM showed cavitations on the epithelial cell surfaces particularly pronounced at sites of hyphal invasion. Some hyphae on RTME showed several clusters of blastospores attached in regular arrangements resembling &quot;appareil sporifere&quot;. C. tropicalis and C. dubliniensis produced few hyphae mainly on RTME but they did not penetrate either model. Our findings indicate that multiple host-fungal interactions such as cavitations, thigmotropism, and morphogenesis take place during candidal tissue invasion. RTME described here appears to be useful in investigations of such pathogenic processes of Candida active at the epithelial front.
Mycopathologia, 2009
Onychomycosis is a common fungal infection affecting nails. The primary cause for onychomycosis i... more Onychomycosis is a common fungal infection affecting nails. The primary cause for onychomycosis is dermatophytes, while Candida species have emerged as second-line pathogens. Onychomycosis due to Candida (candidal onychomycosis) is increasingly found in individuals having defective immunity consequential to aging, diabetes mellitus, vascular diseases, HIV infection and drug therapies such as immunosuppressives and broad-spectrum antibiotics. Breached local immunity at the nail complex due to trauma, chronic exposure to moisture and chemicals including smoke, detergents, soap, etc., also contribute to candidal onychomycosis. Adhesion, filamentation, secretion of extracellular enzymes and the development of antifungal resistance are some of the virulence mechanisms of Candida species associated with onychomycosis. Diagnosis of onychomycosis depends on history and clinical examination, direct microscopic investigation, mycological culture and histopathology. Restoration of immune defenses, elimination of fungi using appropriate drug therapy and improvement of nail hygiene with the removal of predisposing factors are key aspects in the management of candidal onychomycosis.
A Review of the Ultrastructural Features of Superficial Candidiasis
Mycopathologia, 2010
Commensal yeast Candida causes opportunistic infections ranging from superficial lesions to disse... more Commensal yeast Candida causes opportunistic infections ranging from superficial lesions to disseminated mycoses in compromised patients. Superficial candidiasis, the commonest form of candidal infections, primarily affects the mucosa and the skin where Candida lives as a commensal. Conversion of candidal commensalism into opportunism at the fungal-epithelial interface is still ill-defined. Nevertheless, fungal virulence mechanisms such as adhesion to epithelia, morphogenesis, production of secretory hydrolytic enzymes, and phenotypic switching are thought to contribute in the process of pathogenesis. On the other hand, host responses in terms of immunity and local epithelial responses are actively involved in resisting the fungal challenge at the advancing front of the infection. Ultrastructural investigations using electron microscopy along with immunohistochemistry, cytochemistry, etc. have helped better viewing of Candida-host interactions. Thus, studies on the ultrastructure of superficial candidiasis have revealed a number of fungal behaviors and associated host responses such as adhesion, morphogenesis (hyphae and appresoria formation), thigmotropism, production and distribution of extracellular enzymes, phagocytosis, and epithelial changes. The purpose of this review is to sum up most of the ultrastructural findings of Candida-host interactions and to delineate the important pathological processes underlying superficial candidiasis.
Medical Mycology, 2010
The post-antifungal effect (PAFE) has been shown to affect Candida pathogenicity, but there is li... more The post-antifungal effect (PAFE) has been shown to affect Candida pathogenicity, but there is little information on either PAFE or its association with the colonization traits of Candida glabrata. The objective of this study was to determine, in vitro , the PAFE on 14 C. glabrata isolates following exposure to amphotericin B (AMB), nystatin (NYS), ketoconazole (KETO) and 5-fl uorocytosine (5FC). In addition, we evaluated the impact of PAFE on yeast adherence to buccal epithelial cells (BEC), cell-surfacehydrophobicity (CSH) and biofi lm growth (BG) on denture acrylic surfaces. PAFE was induced following a 1-h exposure of yeasts to (ϫ1-ϫ4MIC) of AMB, NYS, KETO and 5FC in RPMI medium and, measured using automated turbidometry. The BEC adhesion, CSH and BG assays were performed by the methods of Kimura & Pearsall, Sweet et al ., and Jin et al ., respectively. Signifi cant differences in PAFE (P Ͻ 0.001) were observed after exposure to AMB and NYS, but not KETO and 5FC. Following exposure to AMB, NYS, KETO and 5FC, signifi cant inter-strain differences (P Ͻ 0.001) were observed in percentage terms in adhesion (39.0%, 43.48%, 38.28%, 35.07%) and biofi lm growth (42.86%, 39.86%, 42.81%, 36.38%), respectively. Short exposure of C. glabrata to sub-cidal concentrations of antifungals modulates yeast growth and also affects some of their colonization traits.
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Papers by JAMS Jayatilake