Browsing by Author "Perera, J."

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Analysis of data of urine culture isolates of 2013 sent from four laboratories of National Laboratory Based Surveillance of Sri Lanka College of Microbiologists
(Sri Lanka College of Microbiologists, 2014) Jayatilleke, S.K.; Karunaratne, G.K.D.; Perera, J.; Perera, R.R.D.P.; Wijesooriya, W.R.P.L.I.; Sunil-Chandra, N.P.
OBJECTVES: To determine the aetioiogical agents of midstream urine cultures with a colony count of > 10 5CFU/ml. To analyse the antimicrobial susceptibility of those isolates. METHOD: The National Laboratory Based Surveillance on Antimicrobial Resistance is a collaborative project of the Ministry of Health and the Sri Lanka College of Microbiologists. At the initial phase decided to analyse midstream urine cultures with a colony count of >105 CFU/ml. The specimens were processed according to the standard protocol specified in the laboratory manual in microbiology. Antibiotic susceptibility tests were performed according to the method established in the centre which is either by CLSI method or by Stake's comparative disk diffusion method. Data of 2013 sent by the participating laboratories were analysed using WHONET software. RESULTS: The data was received from four centres. They were Sri Jayewardenapura General Hospital, Lady Ridgeway those isolates. ATotal of 1175 significant isolates were analysed. The majority were Gram negative enteric organisms, com¬monly known as coiforms, with 922 (78.5%) isolates. The others were Enterococcus species 83 (7%), Candida species 60 (5.1%), Pseudomonas species 38 (3.2%), Acinetobacter species 21 (1.8%), Group B beta-haemolytic Streptococcus 20 (1.7%), coagulase negative Staphylococcus species 10 (0.85%), Streptococcus species 9 (0.8%), Staphylococcus aureus 7 (0.6%), and Staphylococcus saprophyticus 5 (0.4%). The susceptibility of coliforms were 11.6% (92/795) to ampicillin, 71.1% (621/873) to nitrofurantoin, 25.9% (223/ 862) to cephalexin, 46% (392/853) to cefuroxime, 29.4% (255/866) to nalidixic acid, 47.8% (422/883) to cefo-taxime, 92.6% (665/718) to meropenem, 70.3% (601/ 855) to gentamicin, 41.6% (341/819) to amoxicillin-clavulanic acid and 38.4% (318/829) to ciprofloxacin. None of the 13 isolates of Acinetobacter species tested were sensitive to meropenem while only 55% (16/29) of Pseudomonas sp. were sensitive to meropenem. 74% (60/81) of Enterococcus species were sensitive to ampicillin. CONCLUSION: Coliforms constitute the commonest organism causing urinary tract infections (UTI). A high resistance rate was noted in coliforms for broad spectrum antibiotics like cefotaxime and ciprofloxacin. Acinetobacter sp. shows a very high resistance rate even for carbapenems. Ampicillin can be recommended as empirical therapy to treat UTI due to enterococcus species.
Analysis of data of urine culture isolates of 2014 sent from seven laboratories of National Laboratory Based Surveillance of Sri Lanka College of Microbiologists
(Sri Lanka College of Microbiologists, 2015) Jayatilleke, S.K.; Patabendige, G.; Karunaratne, G.K.D.; Perera, J.; Perera, R.R.D.P.; Wijesooriya, W.R.P.L.I.; Sunil-Chandra, N.P.; Kottahachchi, J.; Athukorala, D.; Dissanayake, P.; Dasanayake, M.
OBJECTIVES: To determine the aetiological agents of midstream urine cultures with a colony count of >105 CFU/ml. To analyse the antimicrobial susceptibility patterns of urine culture isolates of 2014. METHOD: The National Laboratory Based surveillance on antimicrobial resistance is a collaborative project of the Ministry of Health and the Sri Lanka College of Microbiologists. In this project midstream urine cultures with a colony count of >105 CFU/ml were analysed. The specimens were processed according to the standard protocol specified in the laboratory manual in microbiology. Antibiotic susceptibility tests were performed according to the method established in the centre which is either by CLSI method or by Stake's comparative disk diffusion method. Data of 2014 sent by the participating laboratories were analysed using WHONET 5.6 software. RESULTS: The data was received from seven centres. They were The National Hospital of Sri Lanka, Sri Jayewardenapura General Hospital, Lady Ridgeway Childrens' Hospital, Faculty of Medicine, Colombo, Faculty of Medicine, Ragama, Faculty of Medicine, Sri Jayewardenapura and North Colombo Teaching Hospital, Ragama. A total of 4441 significant isolates were analysed. The majority were Gram negative enteric organisms, commonly known as conforms, with 3975/4979 (79.8%) isolates. The others were Candida species 408, Enterococcus species 254, Pseudomonas species 194, coagulase negative Staphylococcus species 59, Staphylococcus aureus 36, Acinetobacter species 35 and Group B beta-haemolytic Streptococcus 18. The coliforms from adults who were attending outpatient clinics had 55.2% (112/203) susceptibility to cephalexin andcephradine, 54% (161/298) to amoxycillin/clavulanic acid, 65.1% (278/427) to nitrofurantoin, 48.3% (144/298) to norfloxacin, 63.4% (189/298) to cefotaxime, 97.4% (113/116) to imipenem and 100% (90/90) to meropenem. The adult inward patients had 39.5% (519/1313) susceptibility to cefotaxime, 87.9% (445/506) to meropenem, 62.6% (812/1298) togentamicin and 31.9% (405/1281) to ciprofloxacin. The coliforms from paediatric outpatients had 58.5% (69/118) susceptibility to cephalexin and cephradine, 58.5% (76/130) to amoxycillin/clavulanic acid, 80% (16/20) to nitrofurantoin, 85% (17/20) to cefotaxime and 89.7% (26/29) to meropenem. The paediatric inward patients had 64.6% (53/82) susceptibility to cefotaxime, 90.5% (19/ 21) to meropenem and 80.2% (65/81)togentamicin. CONCLUSION: Coliforms, the commonest organism causing urinary tract infections (UTI), had high resistance rate in in-wardpatients but the resistance was less in outpatients, especially in the paediatric age group.
Analysis of Mycoplasma pneumoniae IgG response in patients with respiratory tract infections
(Research Symposium 2010 - Faculty of Graduate Studies, University of Kelaniya, 2010) Wijesooriya, W.R.P.L.I.; Kok, T.W.; Perera, J.; Thilakarathna, Y.
Introduction M. pneumoniae is the causative agent of primary atypical pneumonia. Patients mount IgM and IgG antibody responses against this infection. However, IgM antibodies are not always produced in adults upon reinfection. Therefore, diagnosis of M. pneumoniae infection in adults relies on specific IgG response which increases slowly during the course of illness. Most clinicians receive a single serum sample for serology tests, as paired sera testing will not be useful for management due to time delay or patients may not provide a convalescent-phase sample. Aim Analysis of the M. pneumoniae specific IgG response in paired-sera of patients with respiratory tract infections. Methodology A prospective clinical study was carried out involving 418 adult patients in Colombo North Teaching Hospital, Ragama and chest hospital, Welisara (Pneumonia-97, acute bronchitis-183, pharyngitis-138). M. pneumoniae specific IgG was tested and analyzed in paired sera using ELISA kits (IBLHamburg-Germany). Results 27 patients showed positive IgG antibody titer in acute, convalescent or both serum samples. In these 27 samples, seven were positive in acute-serum samples and negative in convalescent-samples. Thirteen were positive at convalescent-sampling but negative at acute-sampling. Seven were positive in both acute and convalescent samples. Discussion Only 25.9% (7/27) of the cases would be diagnosed correctly using paired sera. 48.2% (13/27) would be negatively misdiagnosed 25.9% (7/27) would be positively misdiagnosed by testing acute sample alone. Paired-serum samples were essential to confirm the diagnosis of 74.1% (20/27) of patients with suspected M. pneumoniae infection. Conclusion Paired-serum samples are mandatory in the diagnosis M. pneumoniae infection based on IgG response.
Analysis of urine culture isolates from seven laboratories of Sri Lanka: National Laboratory Based Surveillance of Sri Lanka College of Microbiologists in 2014
(Sri Lankan Society for Microbiology, 2016) Jayatilleke, S.K.; Patabendige, G.; Dassanayake, M.; Karunaratne, G.K.D.; Perera, J.; Perera, R.R.D.P; Wijesooriya, W.R.P.L.I.; Sunil-Chandra, N.P.; Kottahachchi, J.; Athukorala, D.; Dissanayake, T.
INTRODUCTION: National Laboratory Based Surveillance of Antimicrobial Resistance in urinary isolates conducted by the Sri Lanka College of Microbiologists was started in 2011 in collaboration with the Ministry of Health of Sri Lanka. METHODS: Pooled susceptibility data of urine culture isolates with a colony count of ≥105 CFU/ml from samples of non-catheterised patients received in 2014 were analysed using WHONET 5.6 software. RESULTS: The majority of the isolates (3975/4979:79.8%) were Gram negative enteric organisms, commonly known as coliforms. The other bacterial isolates identified were Enterococcus spp. (254), Pseudomonas spp. (194), coagulase negative staphylococci (59), Staphylococcus aureus (36), Acinetobacter spp. (35) and Group B β-haemolytic streptococci (18). The coliforms isolated from adults attending outpatient clinics (n=277) had 55.2% susceptibility to cephalexin and cephradine, 54% to amoxycillin/clavulanic acid, 65.1% to nitrofurantoin, 48.3% to norfloxacin, 63.4 % to cefotaxime, 86.4% to gentamicin, 97.4% to imipenem and 100% to meropenem. The isolates from adult hospitalized patients (n=1297) had 39.5% susceptibility to cefotaxime, 87.9% to meropenem, 62.6% to gentamicin and 31.9% to ciprofloxacin. Coliforms isolated from paediatric outpatients (n=182) had 58.5% susceptibility to cephalexin and cephradine, 58.5% to amoxycillin/clavulanic acid, 80% to nitrofurantoin, 85% to cefotaxime, 86.5% to gentamicin and 89.7% to meropenem. Those from paediatric hospitalized patients (n= 663) had 64.6% susceptibility to cefotaxime, 90.5% to meropenem and 80.2% to gentamicin. CONCLUSION: Coliforms, the commonest category of organisms isolated had high resistance rate in hospitalized patients whereas the resistance was less in outpatients, especially in the paediatric age group.
Behaviour of Cytokines IL10, IL6 and IFy during late febrile and immediate defervercent phases of Dengue
(Sri Lanka Medical Association, 2014) Weerasinghe, O.M.S.; Premaratna, R.; Gomes, L.; Perera, J.; Silva, S.; Abeyratna, C.; Kasturiratne, A.; Malavige, N.; de Silva, H.J.
INTRODUCTION AND OBJECTIVES: Cytokines have been implicated in dengue (DF) pathogenesis. Behaviour of cytokines during the late febrile phase (LFP) and immediate defeversence have not been studied, but may be useful to understand the pathophysiology of disease progression and effect of interventions. METHODS: A preliminary prospective study was performed to investigate 1L-10, IL6 and IFy (pg/ml) responses during the late febrile phase (around fifth day) and immediate defervestence in confirmed (NSlAg positive} dengue patients. Demographic, clinical and laboratory data were collected. Two samples of 1 m! serum were obtained during the above stages of the illness and stored at -80°C to assess cytokine levels. Cytokine levels were compared between phases (LFP and afebrile) and stages (DF, precritical and critical dengue shock syndrome (DSS)). LFP cytokine levels were compared for disease stages using one-way Anova test. RESULTS: 18 patients (11 males, mean age 26 years (SD 10.6)) were studied. There were 3 DF, 9 precritical and 6 criticaj DSS based on national guidelines. Mean temperature during LFP and defervescent phases were 102.07°F (SD 0.98) and 98.53°F (SD 0.26). Median (interquartile range) of IL10, IL6 and IFy in LFP were 164.3 (90.8 - 259.5), 26 (12.7-54.6), 246.5 (117.5-511.8) and during defervescent phase were 17.4 (6A-112.2), 11.9 (4.9-28.2), 2.58 (0.0-58.4) respectively. LFP IL10 significantly correlated with disease stages (F-3.99, P-0.041), IL6 and IFy had no correlation. CONCLUSIONS: All three cytokines rapidly declined with defervecence. IL10 in febrile phase showed significant correlation with disease severity.
Bordete//a pertussis specific Immunoglobulin G antibody levels among asymptomatic individuals aged 4-24 years admitted to two selected hospitals in Sri Lanka
(Sri Lanka College of Microbiologists, 2015) Sigera, L.S.M.; Perera, J.; Samaranayake, D.; Ediriweera, E.P.D.S.
INTRODUCTION: Pertussis continues to circulate in the community and cases among adolescents and adults have been increasing. Waning of pertussis-specific immunity following natural infection or immunisation may contribute to the persistent circulation. Even though it is not included in the extended programme of immunization in Sri Lanka, the booster doses including the adolescent booster dose of dTap, (acellular pertussis) are included into the list of recommended immunizations in several countries. Even though the protective titre yet not established, information on immunity to pertussis in this age group is needed before any vaccination policy can be considered. OBJECTIVES: To determine the antibody levels against pertussis toxin to determine the need and the optimal age for booster immunization. METHODS: The quantitative determination of specific IgG antibodies to Bordetella pertussis toxin was done by the ELISA using sera of 385 asymptomatic individuals aged 4-24 years admitted to surgical units of Lady Ridgeway Hospital, Colombo and Colombo South Teaching Hospital, Kalubowila. Mann-Whitney U test and Kruskal-Wallis test were used in analysis and p<0.05 was taken as significant. RESULTS: Median age was 12 years (IQR 8-19) with 212 (55.1 %) females. The median (IQR) anti PT antibody level was 3.31 lU/ml (0.73-15.12) and 352 (91%) had anti PT level <55 ID/ml. Median {IQR) anti PT levels were 3.18 ILJ/ml (0.591 -8.00) for 4-7 years, 1.43 Ill/ml (0.336-6.27) for 8-11 years, 4.28 lU/ml (0.978-13.39) for 12-15 years, 6.14 lU/ml (1.44-63.25) for 16-19 years and 4.89 lU/ml {1.11 -16.78) for 20-24 years and all of these difference were statistically significant (Spearman Correlation Coefficient P=0.0121). Females (p<0.003) and those having a sibling above 12 years (p=0.017) had significantly higher anti PT lev els. CONCLUSION: The majority of the study population, especially 8 to 11 years age group had very low anti PT IgG levels. The infection may occur in early adolescents, A booster dose of acellular pertussis vaccine could be considered.
Bordetella pertussis serological profile among asymptomatic individuals aged 4-24 years.
(Sri Lanka Medical Association, 2014) Sigera, L.S.M.; Perera, J.; Samaranayake, D.; Ediriweera, E.P.D.S.
INTRODUCTION AND OBJECTIVES: To determine the antibody levels against pertussis toxin to determine the need and the optimal age for booster immunization. METHODS: The quantitative determination of specific IgG antibodies to Bordetellajiertussistox'm was done by the ELISA using sera of 385 asymptomatic individuals aged 4 -24 years admitted to surgical units of Lady Ridgeway Hospital, Colombo and Colombo South Teaching Hospital, Kalubowila. Mann-Whitney U test and Kruskal-Waliis test were used in analysis and p<0.05 was taken as significant. RESULTS: Median age was 12 years {IQR 8-19) with 212 (55.1%) females. The median (1QR) anti PT antibody level was 3.31 lu/ml (0.73-15.12) and 352 (91%) had anti PT level <55 lU/ml. Median {IQR) anti PT levels were 3.18 ILJ/ml (0.591-8.00) for 4-7 years, 1.43 lU/ml (0.336-6.27) for 8-11 years, 4.28 lU/ml (0.978-13.39) for 12-15 years,6.14 lU/ml (1.44-63.25) for 16-19 years and 4.89 lU/ml (1.11-16.78) for 20-24 years and this difference was statistically significant (p=0.000). Females (p<0.003) and those having a sibling above 12 years (p=0.017) had significantly higher anti PT levels. CONCLUSIONS: The majority of the study population, especially 8 to 11 years age group had very low anti PT IgG levels. The infection may occur in early adolescents. A booster dose of acellular pertussis vaccine could be considered.
Cutaneous leishmaniasis in Sri Lanka. an imported disease linked to the Middle East and African employment boom
(Foundation Tropical and Geographical Medicine, 1990) Naotunne, T. de S.; Rajakulendran, S.; Abeyewickreme, W.; Kulasiri, C.D.; Perera, J.; Premaratne, U.N.; Attygalle, D.; Mendis, K.N.; Wanniarachchi, P.
Cutaneous leishmaniasis acquired by two Sri Lankan nationals while they were employed in Iraq and Northern Nigeria respectively constitutes examples of an imported disease related to the 'Middle East and African employment boom'. In both cases the diagnoses were confirmed by demonstrating the parasites in smears from the lesions and in tissue sections, and by culturing the parasites in vitro. Since leishmaniasis, neither visceral nor cutaneous is prevalent in Sri Lanka the risks of 'introduced' diseases is discussed here in the context of these two cases.
Detection of M. pneumoniae DNA and specific antibodies in relation to duration of illness
(Sri Lanka College of Microbiologists, 2009) Wijesooriya, W.R.P.L.I.; Kok, T.W.; Perera, J.; Thilakarathna, Y.; Sunil-Chandra, N.P.
INTRODUCTION: M. pneumoniae is the causative agent of primary atypical pneumonia. Patients mount IgM and IgG antibody responses, which provide useful diagnostic markers. Tests for specific antibodies-and DMA amplification by poiymerase chain reaction (PCR) in respiratory samples are now widely used for this infection. The timing of specimen collection is the one most important component to influence test sensitivity, amongst other test parameters. AIM: To determine optimum sampling time for detection of M. pneumoniae specific IgG/IgM antibodies and DNA by PCR. DESIGN, SETTING AND METHOD: A prospective clinical study was carried out involving 418 adult patients in Colombo North Teaching Hospital, Ragama and Chest Hospital, Welisara. (Pneumonia -97, acute bronchitis - 183, pharyngitis - 138). M. pneumoniae specific IgG and IgM were tested in paired sera using ELISA kits (IBL-Hamburg-Germany). PCRfor M. pneumoniae DNA was done for serologically positive and serologically negative patients. Each positive result was analysed in relation to duration of illness. RESULTS: IgM was detected in 37.5% (3/8) of patients on days 1-10 , 37.5% (3/8) on, days 11-20 , 12.5% (1/8) days 21 -30 and 12.5% (1/8) days 31 -40 post onset of illness (poi). IgG was detected in 48% (11/23) of patients on days 11-20, 22% (5/23) days 21-30 poi. M. pneumoniae DNA was detected in 94% (16/17) during the first 15 days of illness. Three seronegative patients (3/4, 75%) were negative for M. pneumoniae DNA >15 days poi. CONCLUSION: IgM response, higher during the first 20 days of illness than IgG which was detected during days 11-20, post onset of illness. M. pneumoniae DNA was detected within the first two weeks of illness.
Herbal treatments for non-alcoholic fatty liver disease: A systematic review and meta-analysis of randomized controlled trials
(Elsevier Ltd, 2024) Rathnayake, D.W.; Sooriyaarachchi, P.; Niriella, M.A.; Ediriweera, D.; Perera, J.
BACKGROUND With the rising prevalence of non-alcoholic fatty liver disease (NAFLD), there is a growing need to explore alternative therapeutic interventions. This study aimed to comprehensively evaluate the available evidence from randomized controlled trials (RCTs) for the use of herbal medications in NAFLD.METHODS A literature search was conducted in PubMed, Web of Science and Scopus databases using appropriate keywords for studies published before the 6th of July 2023. RCTs involving humans, with confirmed NAFLD, the intervention group (IG) receiving herbal treatment, the control group (CG) given a placebo, participants aged ≥18 years, published in English, and a Jadad score ≥6 were included. Coffee and green tea as interventions were excluded. A meta-analysis of studies examining the effects of herbal supplementation on clinical and biochemical parameters in patients with NAFLD was performed. Analysis was done with the “meta” package in R programming language version 4.3.RESULTS In this analysis encompassing 48 articles, study durations varied from 6 weeks to 12 months, with sample sizes ranging between 36 and 226 patients. The study included a total of 3741 patients, (IG=2013, CG=1728). Predominant single herbal medicines identified were Phyllanthus niruri, Beta vulgaris, Allium sativum L., Silymarin (Silybum marianum), Portulaca oleracea L., Nigella sativa, and Cynara cardunculus L. Meanwhile, Cynara cardunculus and curcumin were the most common ingredients in polyherbal compounds. Meta-analysis outcomes revealed a higher reduction in alanine aminotransferase (ALT), aspartate aminotransferase (AST), liver stiffness, waist circumference (WC), weight, body mass index (BMI), triglycerides (TG), and fasting blood glucose (FBG) in the IG compared to the CG. Notably, the reductions in ALT and weight were more pronounced in single herb compounds compared to polyherbal compounds. No differences were observed between the two groups regarding HbA1c levels.CONCLUSION These findings highlight the potential benefits of herbal interventions with regard to improvements in anthropometry, metabolic profiles, and liver enzymes in study participants.
Mycoplasma pneumoniae DNA detection and specific antibody class response in patients from two tertiary care hospitals in tropical Sri Lanka
(Microbiology Society, 2018) Wijesooriya, L.I.; Kok, T.; Perera, J.; Tilakarathne, Y.; Sunil-Chandra, N.P.
PURPOSE: Respiratory tract infections are a major cause of global morbidity and mortality. Pneumonia is the ninth leading cause of mortality in Sri Lanka. Atypical pathogens cause about one-fifth of community-acquired pneumonia, while Mycoplasma pneumoniae accounts for about 50 %. This study aimed to determine the seroprevalence of M. pneumoniae respiratory tract infections in Sri Lanka while attempting to understand the relationships between the serology and PCR. METHODOLOGY: Paired sera from 418 adult patients (pneumonia, n=97; bronchitis, n=183; pharyngitis, n=138) and 87 healthy controls were studied. IgM, IgG and IgA antibodies were tested by M. pneumoniae enzyme-linked immunosorbent assay (ELISA). Positive IgM and or IgG seroconversion was considered to be seropositive. M. pneumoniae DNA were tested by PCR in age and gender-matched seropositives and seronegatives. RESULTS: M. pneumoniae IgG was in 14.4 % (14/97), 6.0 % (11/183) and 1.5 % (2/138) of pneumonia, bronchitis and pharyngitis patients, respectively, whilst IgM was in 6.2 % (6/97), 1.1 % (2/183) and 0 % (0/138), respectively. Amongst the pneumonia seropositives, 64.7 % (11/17) showed IgG alone, 17.5 % (3/17) showed IgM alone and 17.5 % (3/17) showed IgM and IgG. Amongst the bronchitis seropositives, 84.6 % (11/13) had IgG alone and 15.4 % (2/13) had IgM alone. In the pharyngitis seropositives, only IgG was detected 100 % (2/2). M. pneumoniae DNA was in 52.2 % (12/23) of seropositives and 15.4 % (4/26) of seronegatives. In pneumonia or bronchitis patients, specific DNA was in 77.8 % (7/10) and 50 % (6/12) of patients, respectively. M. pneumoniae DNA was not found in pharyngitis patients. Of the seropositive PCR-negative pneumonia patients, 66.7 % (2/3) showed IgG alone and 33.3 % (1/3)showed IgM alone. In bronchitis patients, 83.3 % (5/6) showed IgG alone and 16.7 % (1/6) showed IgM alone. Of the seronegative PCR-positive patients, 16.7 % (2/12) had pneumonia and 18.2 % (2/11) had bronchitis. CONCLUSION: The serological evidence for M. pneumoniae infection in Sri Lanka comprised the following prevalences: 17.5 % (17/97), 7.1 % (13/183) and 1.4 % (2/138) in adults with pneumonia, bronchitis or pharyngitis, respectively. M. pneumoniae DNA was in 52.2 % (12/23) of seropositives and 15.4 % (4/26) of seronegatives. IgG was predominant in PCR positives and negatives.
Novel PCR for Mycoplasma pneumoniae detection in specimens from patients with various types of respiratory infections
(Sri Lanka College of Microbiologists, 2010) Wijesooriya, W.R.P.L.I.; Kok, T.W.; Perera, J.
INTRODUCTION: M. pneumoniae is the causative agent of primary atypical pneumonia and causes 20-40% of community acquired pneumonia. Patients mount IgM and IgG antibody responses, which provide useful diagnostic markers. IgM antibodies are not always produced in adults upon reinfection. Specific IgG antibodies increase slowly during the course of illness. Hence, test interpretation needs paired-serum which is not user friendly. Use of molecular diagnostic methods will overcome these. OBJECTIVE: To develop novel PCR primers to detect M. pneumoniae. METHODOLOGY: New forward and reverse primers which exclusively amplify M. pneumoniae-DWk encoding P1 adherent protein were developed. Master mix consisted of distilled water, 25mM-Mgcl2, 10X-PCR-Buffer, 10mM-dNTPS, two primers (10-p.M-Mpn-S (0.50p.M), 10-y.M-Mpn-RS (0.50|iM)) and Taq-Gold (5U/pJ). Purified M. pneumoniae- DNA (M129-B7-ATCC-29342) (20pg/ I) was used to determine PCR sensitivity. Detection limit was expressed as M. pneumoniae-DNA copy number. Each test had positive and negative controls. Specificity of PCR was evaluated using blast search. In addition, specificity was checked in the laboratory by doing the M. pneumoniae PCR with S. pneumoniae, H. influenzae and S. aureus (common respiratory pathogens causing pneumonia) and no positive reactions were observed among them. RESULTS: Limit of detection of M.pneumoniae-PCR was 400 fg of DNA which is equivalent to 10 copies per45pl of reaction mix. Specificity of the designed primer sequences was 100% with GenBank blast search and no cross reactions were observed with other respiratory-pathogens. M.pneumoniae-DNfltwas detected in 52% (13/25) of sero¬logy confirmed (positive IgM +/ IgG seroconversion) cases. CONCLUSION: Novel M. pneumoniae PCR has a sensitivity of 52% when tested with serology confirmed cases and a specificity of 100% when tested against other common respiratory pathogens. Detection limit was 10 copies / 45 pi of reaction mix.
Paired sera IgG test detects more Mycoplasma pneumonias infections than the single IgM test
(Sri Lanka College of Microbiologists, 2009) Wijesooriya, W.R.P.L.I.; Kok, T.W.; Perera, J.; Thilakarathna, Y.; Sunil-Chandra, N.P.
INTRODUCTION: M. pneumoniae is the causative agent of primary atypical pneumonia. Patients mount an IgM and IgG antibody response, which are useful diagnostic markers. The single serum test for IgM specific antibodies may be attractive for rapid laboratory diagnosis, due to delays or non-provision of the convalescent phase serum sample by patients. IgM antibodies are not always produced in adults upon reinfection. AIMS: To evaluate the diagnostic value of paired serum IgG testing compared to single serum IgM for diagnosis of M. pneumoniae infection. DESIGN, SETTING AND METHOD: A prospective clinical study was done involving 418 adult patients in Colombo North Teaching Hospital, Ragama and Chest Hospital, Welisara. {Pneumonia-97, acute bronchitis-183, pharyngitis-138). Control group-87 adults with no acute respiratory infections. M. pneumoniae specific IgG and IgM were tested in paired sera (taken 2-3 weeks apart) using an ELISA kit (IBL-Hamburg-Germany). RESULTS: Patients with >12 U/ml IgM response or IgG sero-conversion were considered positive for this infection. IgM response was detected in 27% (6/22) (4 - pneumonia, 2 - acute bronchitis) of the study population. IgG sero-conversion was detected in 64% (14/22) (9 - pneumonia, 10 - acute bronchitis, 2 - pharyngitis) and 9% (2/22) (2 -pneumonia) by both antibody types. In this study population, IgM specific antibodies were detected in 36% (8/22).There were no IgG responders in the control group but 2% (2/87) showed positive IgM response. CONCLUSION: Specific IgG testing with paired serum samples detect more cases of M. pneumoniae infection than the use of a single serum IgM test.
Predisposing factors associated with Mycoplasma pneumoniae respiratory tract infections
(Research Symposium 2010 - Faculty of Graduate Studies, University of Kelaniya, 2010) Wijesooriya, W.R.P.L.I.; Kok, T.W.; Perera, J.; Thilakarathna, Y.
Introduction Lower respiratory tract infections account for ~10% of worldwide burden of morbidity and mortality. Pneumonia is the 9th leading cause of hospital mortality in Sri Lanka and atypical pathogens account for 1/5th of the cases. M. pneumoniae is the predominant (50%) atypical pathogen. Knowing predisposing factors strengthen the modes of prevention. Objective Determination of predisposing-factors associated with M. pneumoniae respiratory infections in Sri Lanka. Methodology A prospective clinical study was done involving 416 adult-patients in Colombo-North Teaching-Hospital, Ragama and chest-hospital, Welisara (Pneumonia-97, acute-bronchitis-182, pharyngitis-137). M. pneumoniae specific IgG and IgM were tested in paired-sera using commercial-ELISA. Patient-interviewed-questionnaire was used to obtain data on predisposing factors and evaluated in serologically-positive and serologically-negative groups. The level of significance was considered as p < 0.05. Results There was no significant difference observed in relation to age (p-value-0.28, 0.76 and 0.2in pneumonia, bronchitis, pharyngitis respectively), gender, number of individuals/room (sleeping area) (p=0.82), having respiratory tract infections in close contacts (p=0.15), malignancies or past history of asthma (p>0.05 in both groups) with M. pneumoniae infection. However, there was significant association between M. pneumoniae pneumonia and diabetes mellitus (p<0.05). Discussion There was no specific age group detected to have M. pneumoniae infections which predominantly occur in childhood or significant gender predominance seen as with previous studies. The present study was not carried out in a setting with closed population to have significant infection amongst closed contacts. The significant association between M.pneumoniae infection and having diabetes mellitus would need further studies. Conclusion There were no identifiable strong factors predisposing to M. pneumoniae infection except diabetes mellitus.
Reliability of cold agglutinin test (CAT) for the detection of patients with Mycoplasma pneumoniae pneumonia in hospitalized patients.
(Sri Lankan Society for Microbiology, 2016) Wijesooriya, W.R.P.L.I.; Suni-Chandra, N.P.; Perera, J.
INTRODUCTION: M. pneumoniae is one of the causative agents of primary atypical pneumonia. This infection causes 20-40% of community acquired pneumonia and is associated with an array of extra-pulmonary manifestations. There is a need for a rapid diagnostic test in order to prescribe prompt and appropriate antibiotic therapy. Even though isotype specific antibody testing provides definitive diagnosis, paired sera testing does not help in real time diagnosis. Cold agglutinins detectable by the Cold Agglutination Test (CAT) appear and disappear early in infection compared to long lasting specific antibodies that are detectable by specific immunoassays. Although there are some reports suggesting CAT is unreliable, it is being often used to diagnose M. pneumoniae pneumonia in Sri Lankan clinical settings. The aim of the current study was to evaluate the use of CAT as a bed-side screening test for early diagnosis of M. pneumoniae pneumonia compared to ELISA for detection of specific antibodies in the Sri Lankan context. METHODS: Ninety seven clinically and radiologically confirmed patients with pneumonia were enrolled in the study. CAT was performed on acute stage sera. A CAT titer ≥1/32 was considered as positive. Isotype specific M. pneumoniae ELISA with paired sera was compared with CAT results. RESULTS: Mycoplasma pneumonia was confirmed in 15 of the 97 patients in the study using Mycoplasma specific IgM and 4 fold rise in titre. Of these, 3 were positive by the CAT. The sensitivity and specificity of the CAT compared to IgM/4fold rise in IgG detection were 20% (3/15) and 81.7% (67/82) respectively. Negative and positive predictive values of the CAT compared to ELISA were 84.8% (67/79) and 16.7% (3/18) respectively. CONCLUSION: CAT is not a reliable screening test compared to specific antibody detection by isotype ELISA for the detection of M. pneumoniae pneumonia due to its low sensitivity and positive predictive values.
Role models and teachers: medical students perception of teaching-learning methods in clinical settings, a qualitative study from Sri Lanka
(Biomed Central, 2016) Jayasuriya-Illesinghe, V.; Nazeer, I.; Athauda, L.; Perera, J.
BACKGROUND: Medical education research in general, and those focusing on clinical settings in particular, have been a low priority in South Asia. This explorative study from 3 medical schools in Sri Lanka, a South Asian country, describes undergraduate medical students’ experiences during their final year clinical training with the aim of understanding the teaching-learning experiences. METHODS: Using qualitative methods we conducted an exploratory study. Twenty eight graduates from 3 medical schools participated in individual interviews. Interview recordings were transcribed verbatim and analyzed using qualitative content analysis method. RESULTS: Emergent themes revealed 2 types of teaching-learning experiences, role modeling, and purposive teaching. In role modelling, students were expected to observe teachers while they conduct their clinical work, however, this method failed to create positive learning experiences. The clinical teachers who predominantly used this method appeared to be ‘figurative’ role models and were not perceived as modelling professional behaviors. In contrast, purposeful teaching allowed dedicated time for teacher-student interactions and teachers who created these learning experiences were more likely to be seen as ‘true’ role models. Students’ responses and reciprocations to these interactions were influenced by their perception of teachers’ behaviors, attitudes, and the type of teaching-learning situations created for them. CONCLUSIONS: Making a distinction between role modeling and purposeful teaching is important for students in clinical training settings. Clinical teachers’ awareness of their own manifest professional characterizes, attitudes, and behaviors, could help create better teaching-learning experiences. Moreover, broader systemic reforms are needed to address the prevailing culture of teaching by humiliation and subordination.
Seroprevalence of Bordetella pertussis specific Immunoglobulin G antibody levels among asymptomatic individuals aged 4 to 24 years: a descriptive cross sectional study from Sri Lanka
(BioMed Central, 2016) Sigera, S.; Perera, J.; Rasarathinam, J.; Samaranayake, D.; Ediriweera, D.
Seroprevalence of rubella antibodies among pregnant females in Sri Lanka
(SEAMEO Regional Tropical Medicine and Public Health Project, 2003) Palihawadana, P.; Wickremasinghe, A.R.; Perera, J.
The purpose of this study was to determine the seroprevalence of rubella antibodies among pregnant females in the Kalutara District of Sri Lanka, and to identify factors associated with susceptibility to rubella infection among pregnant females. A cross-sectional clinic-based study was conducted among 620 pregnant women attending antenatal clinics and residing in the district for more than one month. Data on the pregnant females and the socio-economic characteristics of the families were obtained using an interviewer-administered structured questionnaire. Three milliliters of blood was obtained to measure rubella-specific IgG antibody levels by ELISA (enzyme linked immunosorbent assay) tests. Overall, 76 percent of pregnant females were seropositive for rubella antibodies. Seropositivity in pregnant females increased with age. Susceptibility to rubella was significantly associated with rubella immunization status. Given the high susceptibility rate to rubella infection among pregnant females, it is imperative that any vaccination strategy in the short-term should focus on reducing the number of susceptible women of child-bearing age.
Strategies for immunisation against rubella:evidence from a study in the Kalutara district
(Sri Lanka Medical Association, 2002) Palihawadana, P.; Wickremasinghe, A.R.; Perera, J.
OBJECTIVE: To simulate different immunisation programs against rubella and estimate the proportion of the population susceptible to rubella infection of each. METHODS: The impact of 3 immunisation schedules on the susceptibility of women of childbearing age and the community to rubella infection was simulated using a probabilistic approach. The first schedule involved selective immunisation of 12-year old girls, the second immunisation of all children at 3 years of age for different immunisation coverages, and the third comprised a combination of the first two. The proportion of different segments of the population currently susceptible to rubella was obtained from a field study conducted in the Kalutara District in 1999. RESULTS: An immunisation program of 12-year old girls will reduce the susceptibility to rubella in 5 years in only the 15 to 19 year age group. In 10 years, the susceptibility in both the 15 to 19 and 20 to 24 year age groups will be reduced. Immunisation only of children at 3 years will take 20 years for a reduction in the susceptibility to rubella infection in the 15 to 19 year and the 20 to 24 year age groups, and the proportion of the population susceptible to rubella can be reduced to less than 10 percent in 20 years if 90 percent coverage is attained. If a combination of the two strategies i.e. selective immunisation of girls at 12 years for 10 years and immunisation of all children at 3 years is adopted, the proportion of the community susceptible to rubella will be less than 14 percent in 10 years. CONCLUSIONS: The combination of immunising girls at 12 years of age for 10 years and all children at 3 years of age against rubella is recommended for Sri Lanka to reduce the risk of congenital rubella syndrome in the short term and the proportion susceptible to rubella in the community in the long term.
A study on the efficacy of a herbal mouthwash in the management of Sheethada and Upakusha
(Gampaha Wickramarachchi Ayurveda Institute, 2012) Perera, B.P.R.; Amarasena, P.A.D.R.; Gunarathne, U.M.P.M.; Perera, J.