Lakshman Perera Samaranayake

Lakshman Perera Samaranayake
The University of Hong Kong | HKU

DSc, DDS (Glas), FRCPath, FDSRCS(Edin), FRACDS, FDS RCPS (Glas), FHKCPath, FCDSHK

About

636
Publications
92,904
Reads
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21,083
Citations
Introduction
Professor Lakshman Perera Samaranayake ( h-index 80, Citations >22,000) is an Emeritus Professor and Dean at The Faculty of Dentistry, University of Hong Kong. He is currently a Professor, and Vice-Dean at the Sharjah College of Dental Medicine, University of Sharjah, UAE. Lakshman does research in oral Infectious Diseases and Dentistry. His main interest is in 'Candida biofilm biology' and oral microbiomics, and dental education.
Additional affiliations
January 2014 - present
The University of Queensland
Position
  • Professor of Oral Microbiomics and Infection, and Head of School
Description
  • Leading a research team working on biofilm biology and microbiomics
January 2014 - July 2016
The University of Queensland
Position
  • Head of School and Professor of Oral Microbiomics and Infection,
Description
  • Head of School, Oral Health Center, 288 Herston Road, Herston , Queensland 4006, Australia
January 1994 - December 2013
The University of Hong Kong
Position
  • Dean, Faculty of Dentistry and Chair Professor of Oral Microbiology; Director, Prince Philip Dental Hospital

Publications

Publications (636)
Article
Candida auris is a recently emerged multidrug-resistant fungal pathogen that causes life-threatening infections to the human population worldwide. Recent rampant outbreaks of C. auris in coronavirus disease 2019 (COVID-19) patients, together with outbreaks in over 45 countries, highlight its threat to patients and healthcare economies. Unlike other...
Article
Full-text available
Background: There is a debate as to whether some types of oral leucoplakias (OL) are caused by Candida species, and whether they contribute to the malignant transformation, associated with a minority of such lesions. As no detailed population analysis of yeast isolates from OL is available, we evaluated the virulence attributes, and genotypes of 3...
Article
Full-text available
Microorganisms employ quorum sensing (QS) mechanisms to communicate with each other within microbial ecosystems. Emerging evidence suggests that intraspecies and interspecies QS plays an important role in antimicrobial resistance in microbial communities. However, the relationship between interkingdom QS and antimicrobial resistance is largely unkn...
Article
Aims: Oral candidiasis is a major oral manifestation of uncontrolled diabetes mellitus, and a number of cofactors are associated with the pathogenesis of this infection. Here, we describe the prevalence of oral Candida in a Sri Lankan cohort of type 2 diabetes mellitus and risk factors that predispose them to this common fungal infection. Methods:...
Article
Full-text available
Objective: Pseudomonas aeruginosa and Staphylococcus aureus dual species biofilm infections are notoriously difficult to manage. This study was aimed at investigating the influence of four different culture media on the planktonic growth, adhesion and biofilm formation of Pseudomonas aeruginosa and Staphylococcus aureus. Materials and methods: W...
Article
Recent advances in the field of molecular microbiology provide an unprecedented opportunity to decipher the vast diversity of the oral microbiome in health and disease. Here, we provide a contemporary overview of the oral microbiome and the microbiota of Early Childhood Caries (ECC) with particular reference to newer analytical techniques. A MEDLIN...
Article
Objective The aim of this cross‐sectional study was to compare oral Candida carriage among cigarette‐ and waterpipe‐smokers, electronic‐cigarette (E‐Cig) users and never‐smokers. Methods Demographic data and information regarding smoking and vaping were collected using a questionnaire. Number of missing teeth and unstimulated whole salivary flow r...
Article
Full-text available
The organisms that colonize the human body over a lifetime are diverse, extensive and gargantuan. A fair proportion of the microbiota that constitutes this human microbiome live within our oral cavities mostly as harmonious associates causing only sporadic disease. An important core constituent of the microbiome is the mycobiome, representing vario...
Article
Full-text available
Candida albicans is a clinically important human fungal pathogen. We previously identified the presence of cell-associated phytase activity in C. albicans. Here, we reveal for the first time, that orf19.3727 contributes to phytase activity in C. albicans and ultimately to its virulence potency. Compared with its wild type counterpart, disruption of...
Article
Full-text available
Objective: To determine the effect of glucose, sucrose, and saccharin on growth, adhesion and biofilm formation of Candida albicans and C.tropicalis. Materials and methods: The growth rates of mono-cultures of planktonic C. albicans and C. tropicalis and co-cultures (1:1), were determined in yeast nitrogen broth supplemented with 5% (30 mM) and...
Article
Purpose: We assessed the effects of four different types of tea extracts (green, oolong, black and pu-erh tea) on cellular surface properties (hydrophobicity and auto-aggregation) and the colonization attributes (attachment and biofilm formation) of four strains of Candida albicans and three strains of Candida krusei. Methodology: The cellular s...
Article
Full-text available
Candida dubliniensis shares a wide range of phenotypic characteristics with Candida albicans including a common trait called germ tube positivity. Hence, laboratory differentiation of these two species is cumbersome. Duplex PCR analyses for C. albicans and C. dubliniensis was performed directly on DNA extracted from a total of 122 germ tube positiv...
Article
Pathobiology of dental caries is complex. Data from recent molecular microbiologic studies have further redefined the role of the oral microbiome in the etiology of dental caries. This new information challenges the conventional view on the hegemony of classic cariogenic prokaryotes such as Streptococcus mutans in caries aetiology, and raises the i...
Article
The oral ecosystem comprises the oral flora, so-called oral microbiome, the different anatomic microniches of the oral cavity, and its bathing fluid, saliva. The oral microbiome comprises a group of organisms and includes bacteria, archaea, fungi, protozoa, and viruses. The oral microbiome exists suspended in saliva as planktonic phase organisms or...
Article
The perceived threat to public health from dental unit water line (DUWL) contamination comes from opportunistic and respiratory pathogens such as Legionella spp, Nontuberculous Mycobacteria (NTM) and pseudomonads. These organisms can grow and multiply in the DUWL biofilm to reach infective concentrations, with the potential for inhalation leading t...
Article
Full-text available
Background: Over the next 20 years, oropharyngeal cancers (OPC) will represent the majority of head and neck cancers (HNCs) in the United States. It is estimated that human papillomavirus (HPV) may account for as much as 70% to 80% of OPCs in North America and in certain parts of Europe. It is hence crucial to understand the disease risk factors a...
Article
Introduction: Candida species are common human commensals and cause either superficial or invasive opportunistic infections. The biofilm form of Candida as opposed to its suspended, planktonic form, is predominantly associated with these infections. Alternative or adjunctive therapies are urgently needed to manage Candida infections as the currentl...
Article
Full-text available
As there are sparse data on the impact of growth media on the phenomenon of biofilm development for Candida we evaluated the efficacy of three culture media on growth, adhesion and biofilm formation of two pathogenic yeasts, Candida albicans and Candida tropicalis. The planktonic phase yeast growth, either as monocultures or mixed cultures, in sabo...
Article
Full-text available
Enterococci are considered as transient constituent components of the oral microbiome that may cause a variety of oral and systemic infections. As there is sparse data on the oral enterococcal prevalence, we evaluated the Enterococcus spp. and their virulence attributes including antimicrobial resistance in a healthy Brazilian cohort. A total of 24...
Article
Background and objective: Chronic periodontitis causes damage to tooth-supporting tissues, resulting in tooth loss in adults. Recently, cell-sheet-based approaches have been studied to overcome the limitations of conventional cytotherapeutic procedures for periodontal regeneration. The purpose of the present study was to investigate the regenerati...
Article
Full-text available
We evaluated the inhibitory effects of the probiotic Lactobacillus species on different phases of Candida albicans biofilm development. Quantification of biofilm growth and ultrastructural analyses were performed on C. albicans biofilms treated with Lactobacillus rhamnosus, Lactobacillus casei, and Lactobacillus acidophilus planktonic cell suspen-...
Article
Full-text available
Objective: Candida albicans is the primary causative agent of oral candidosis, and one of its key virulent attributes is considered to be its ability to produce extracellular phospholipases that facilitate cellular invasion. Oral candidosis can be treated with polyenes, and azoles, and the more recently introduced echinocandins. However, once admi...
Article
Saliva plays a key role in maintaining oral homeostasis, function, and health. The prevalence of xerostomia and its consequences are rising due to the increasing aging population, the effects of some systemic diseases, medical management, and commonly-prescribed medications that reduce saliva production. When salivary function is diminished, patien...
Article
Introduction: The frequent recolonization of treated sites by periodontopathogens and the emergence of antibiotic resistance have led to a call for new therapeutic approaches for managing periodontal diseases. As probiotics are considered a new tool for combating infectious diseases, we systematically reviewed the evidences for their effectiveness...
Article
Full-text available
Candida bloodstream infections (CBI) are one of the most common nosocomial infections globally, and they account for a high mortality rate. The increasing global prevalence of drug-resistant Candida strains has also been posing a challenge to clinicians. In this study, we comprehensively evaluated the biofilm formation and production of hemolysin a...
Article
Adhesion to buccal epithelial cells (BEC) and denture acrylic surfaces (DAS), germ tube (GT) formation and cell surface hydrophobicity (CSH) are all virulence traits involved in pathogenicity of Candida. Post-antifungal effect (PAFE) also have a bearing on pathogenicity and virulence of Candida. Candida dubliniensis is associated with oral and syst...
Article
Candida is an opportunistic pathogen that causes mucosal and deep systemic candidiasis. The emergence of drug resistance, and the side effects of currently available antifungals have restricted their use as long-term prophylactic agents for candidal infections. Given this scenario, probiotics have been suggested as a useful alternative for the mana...
Article
Recent culture-independent studies have enabled detailed mapping of human microbiome that has not been hitherto achievable by culture-based methods. DNA extraction is a key element of bacterial culture-independent studies that critically impacts on the outcome of the detected microbial profile. Despite the variations in DNA extraction methods descr...
Article
Dietary carbohydrates and polyols affect the microbial colonization of oral surfaces by modulating adhesion and biofilm formation. The aim of this study was to evaluate the influence of a select group of l-carbohydrates and polyols on either Streptococcus mutans or Candida albicans adhesion and biofilm formation in vitro. S. mutans or C. albicans s...
Article
Full-text available
Objective Therefore, the PAFE and hemolysin production of oral C. albicans isolates following brief exposure to sublethal concentrations of the foregoing antifungals were evaluated. Material and Methods A total of 50 C. albicans oral isolates obtained from smokers, diabetics, asthmatics using steroid inhalers, partial denture wearers and healthy i...
Article
AimNo oral niche can be considered to be segregated from the subjacent milieu because of the complex community behavior and nature of the oral biofilms. The aim of this study was to address the paucity of information on how these species are clonally related to the subjacent gingival crevice bacteria.Methods We utilized a metagenomic approach of am...
Article
Most viral infections encountered in resource-rich countries are relatively trivial and transient with perhaps fever, malaise, myalgia, rash (exanthema), and sometimes mucosal manifestations (enanthema), including oral in some. However, the apparent benignity may be illusory since some viral infections have unexpected consequences - such as the onc...
Article
Full-text available
Clinical isolates of the fungal human pathogen Candida albicans are invariably diploid and heterozygous, impeding genetic study. Recent isolation of C. albicans haploids opens opportunities to apply technologies unfeasible in diploids. However, doubts remain on whether the haploids, derived from chromosome loss, can represent the diploids. Here, we...
Article
Full-text available
The presentation of alternative treatment plans and the discussion of these options with the adolescent patient is a routine part of both general dental and specialist orthodontic practice. This article will cover the issues involved in obtaining consent for treatment from the adolescent patient and suggests a practical means, if appropriate, to en...
Conference Paper
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Article
Full-text available
The role of the BDJ is to inform its readers of ideas, opinions, developments and key issues in dentistry - clinical, practical and scientific - stimulating interest, debate and discussion amongst dentists of all disciplines.
Article
Full-text available
Candida albicans is a major agent of fungaemias and frequently causes systemic disease through seeded, blood stream dissemination. These infections, particularly common in hospitalized patients with central venous catheters (CVCs), appear to persevere due to biofilm reservoirs of the yeast that tend to develop on the device. Although it is known th...
Conference Paper
Introduction/Aim: Recent studies have demonstrated the correlation between intestinal microbiota and human diseases such as obesity, inflammatory bowel disease and gastrointestinal cancers to name a few. Next generation sequencing (NGS) has revolutionized human bacterial identification and taxonomy. However, NGS is timeconsuming, costly and require...
Poster
Full-text available
Introduction/Aim: Recent studies have demonstrated the correlation between intestinal microbiota and human diseases such as obesity, inflammatory bowel disease and gastrointestinal cancers to name a few. Next generation sequencing (NGS) has revolutionized human bacterial identification and taxonomy. However, NGS is timeconsuming, costly and require...
Article
Full-text available
Objectives: We aimed to investigate the effect of brief exposure to sub-cidal concentrations of nystatin, amphotericin B, ketoconazole, fluconazole and chlorhexidine gluconate on the adhesion of oral Candida dubliniensis isolates to the surface of acrylic dentures. Methods: After determining the minimum inhibitory concentration of each drug, 20...
Article
AimCandida adherence is implicated in the pathogenesis of oral candidosis. Adhesion to buccal epithelial cells (BEC), germ tube (GT) formation, and relative cell surface hydrophobicity (CSH) are colonization attributes of candidal pathogenicity. Candida dubliniensis (C. dubliniensis) is allied with recurrent oral candidosis, which can be treated wi...
Article
Ebola Virus (EBOV) Disease (EVD) is a lethal viral haemorrhagic fever (VHF) that has been smouldering in Sub-Saharan Africa at least since the 1970s and possibly longer. The current epidemic that has spread mainly in West Africa, and sporadic appearances in geographic locales such as USA, Europe and the Antipodes, primarily via infected travellers,...
Article
Securing an adequate blood supply for the survival of cell transplants is critical for a successful outcome in tissue engineering. Interactions between endothelial and progenitor/stem cells are important for the vascularization of regenerating tissue. Recently, self-assembling peptide nanofibers were described as a promising environment for pulp re...
Article
Full-text available
Orofacial viral infections may be less common but appear in different clinical forms. Often these infections initially get treated with antibiotics which will have no effect on the course of the primary infection. The authors review the current concepts of orofacial viral infections, causative agents, their classification and clinical manifestation...
Article
Saliva plays a key role in maintaining oral homeostasis, function, and health. The prevalence of xerostomia and its consequences are rising due to the increasing aging population, the effects of some systemic diseases, medical management, and commonly-prescribed medications that reduce saliva production. When salivary function is diminished, patien...
Article
Full-text available
Secretion of hydrolytic enzymes such as hemolysin is considered an important virulence attribute of the opportunistic pathogenic fungus Candida. It is known that Candida spp. isolated from HIV-infected patients produce copious hemolysins. As common antifungal agents may perturb the production of extracellular enzymes, we evaluated the effect of thr...
Article
Various features of endodontic microbiology have been investigated using various methods. The aim of the present study was to review the existing literature on endodontic microbiology in dentinal tubules, and to present the features of two cases with endodontic pathology. An electronic search was performed with a search string created ad hoc. Ex vi...
Conference Paper
Objective: Candida infections are major problem in immunocompromised populations. The limited number of antifungals and emergence of drug-resistant strains have posed a huge clinical challenge and highlighted the dire need for novel antifungal agents with new mechanism of action. Recently, a high-throughput screening of a library with 50,240 small...
Conference Paper
Corrected and Republished Objective: To assess the regenerative capacity of 3D periodontal ligament stem cell (PDLSC) sheet in vivo. Method: Single culture and co-culture cell sheets were prepared by using PDLSCs and Human umbilical vein endothelial cells (HUVECs) in thermo-responsive culture dishes. Scanning electron microscopy (SEM) was used t...
Article
Candida infections have created a great burden on the public healthcare sector. The situation is worsened by recent epidemiological changes. Furthermore, the current arsenal of antifungal agents is limited and associated with undesirable drawbacks. Therefore, new antifungal agents that surpass the existing ones are urgently needed. High-throughput...
Article
Full-text available
Objective: To evaluate the impact of brief and sequential exposure to nystatin on the germ tube formation and cell surface hydrophobicity of oral isolates of Candida albicans obtained from patients infected with human immunodeficiency virus (HIV). Materials and methods: After determining the minimum inhibitory concentration of nystatin, 10 oral...
Article
The aim was to review the efficacy of antimicrobial photodynamic therapy (PDT) in the treatment of oral fungal infections. To address the focused question “Should PDT be considered a possible treatment regimen for oral fungal infections?” PubMed/Medline and Google-Scholar databases were searched from 1997 up to March 2014 using various combinations...
Article
Chronic periodontitis is a serious infectious and inflammatory oral disease of humans worldwide. Conventional treatment modalities are effective for controlling periodontal disease. However, the regeneration of damaged periodontal tissues remains a major challenge in clinical practice due to the complex structure of the periodontium. Stem cell-base...
Article
Oral Candida colonisation is higher in tobacco smokers as compared to non-smokers; however, it remains unknown whether or not smokeless tobacco chewers are susceptible to increased oral Candida colonisation. The aim was to determine the oral Candida carriage and species prevalence amongst habitual gutka-chewers and non-chewers in a cohort from Kara...