Browsing by Author "Wijesooriya, W.R.P.L.I."

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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.
Antibiotic sensitivity pattern for non-beta lactam antibiotics and carbapenems in extended-spectrum beta-lactamase (ESBL) producing uropathogens versus non-ESBL producing uropathogens
(Sri Lankan Society for Microbiology, 2017) Wijesooriya, W.R.P.L.I.; Herath, Y.B.; Sugandhi, R.A.I.; Weerawardhana, A.; Ediriweera, D.S.
INTRODUCTION AND OBJECTIVES: Urinary tract infections (UTIs) are frequent and predominantly caused by coliforms. ESBL producers are increasing in number limiting therapeutic options. It is therefore vital to institute precise, empiric antibiotic guidelines in order to prevent life-threatening urosepsis. The objective of this study was to compare antibiotic sensitivity (ABST) pattern of ESBL producers and non-ESBL producers against selected non-beta lactams and carbapenem antibiotics. METHODOLOGY: Retrospective analysis of ABST of significant urinary coliform isolates was done. STUDY SETTING: Department of Medical Microbiology, Faculty of Medicine, University of Kelaniya and Base Hospital, Wathupitiwala, Sri Lanka. STUDY PERIOD: 01.01.2012 - 01.01.2016. STUDY GROUPS: ESBL producers and non-ESBL producers, 63 in each group. Sensitivity profiles of amikacin, gentamicin, netilmicin, nitrofurantoin, nalidixic acid, norfloxacin, ciprofloxacin, imipenem and meropenem were analyzed. Statistical analysis: R programming language. Level of significance P<0.05. RESULTS: ESBL producers were present in 63 patients, 36 (57.1%) of whom were females and 39 were inpatients (61.9%). Non-ESBL producers were isolated from urine of 63 patients, of whom 49 (77.8%) were females and 17 (26.9%) inpatients. Antibiotic sensitivity of ESBL producers ranged from 82.2% to 100% for netilmicin, amikacin, meropenem and imipenem, 65% for nitrofurantoin and from 14.8% to 32.1% for nalidixic acid, ciprofloxacin, norfloxacin and gentamicin. Antibiotic sensitivity of the non-ESBL producers ranged from 56.7% for nalidixic acid and from 76.8% to 85.1% for ciprofloxacin, nitrofurantoin, norfloxacin and gentamicin. CONCLUSION: A female predominance was noted in both non ESBL and ESBL producers but there was a significant dominance of ESBL producers in male patients. ESBL producers were significantly common amongst inpatients than outpatients. ESBL-producers had significantly high resistance against nalidixic acid, ciprofloxacin, norfloxacin and gentamicin compared to non-ESBL producers. However, more than 2/3rd of isolates in both groups were sensitive to nitrofurantoin.
Antimicrobials in Gynaecological practice
(Sri Lanka college of Obstetricians & Gynaecologists, 2017) Patabendige, M.; Herath, R.P.; Wijesooriya, W.R.P.L.I.
Surgical site infections are a common complication of Gynaecological surgeries. Up to 8-10% of Gynaecological patients undergoing an operative procedure will develop a surgical site infection. In surgeries with high rates of post-operative infection, antibiotic prophylaxis can play a major role in improving outcomes. In addition there are many indications where antimicrobial treatment is necessary in day-to-day Gynaecological practice. This review summarizes the available medical literature to assess the indications and appropriate antimicrobials for common circumstances in Gynaecological practice.
Comparison of Three Carbapenemase Producing Enterobacteria (CPE) Detection Methods
(19th Conference on Postgraduate Research, International Postgraduate Research Conference 2018, Faculty of Graduate Studies,University of Kelaniya, Sri Lanka, 2018) Kumudunie, W.G.M.; Wijayasinghe, Y.S.; Wijesooriya, W.R.P.L.I.; Sunil-Chandra, N.P.; Namalie, K.D.
Introduction: The emergence of carbapenem resistant enterobacteria (CRE) is a critical and growing health threat, causing a failure of almost all the available antibiotics and limiting the effective therapeutic options. CRE has been reported all over the world including Sri Lanka. The carbapenem resistance in enterobacteria is mainly occurred due to the production of carbapenemases, the carbapenem inactivating enzymes. Therefore, accurate and timely detection of CPE is an important aspect to streamline the empiric antibiotic therapy. In this study, three CPE detection methods namely, Carba NP-rapid biochemical test, modified carbapenem inhibition method (MCIM) and modified Hodge test (MHT) were compared for the detection of CPE. Carba NP test is a rapid biochemical test that requires 2 hours or less. However, both MCIM and MHT require incubation of 18 – 24 hours. Objective: To compare theCarba NP-rapid biochemical test with the MCIM and MHT for the detection of CPE. Methodology: Fifty-eight clinically significant CRE isolates were recovered from clinical specimens from patients attended to North Colombo Teaching Hospital (NCTH)during December 2017 – February 2018. Antibiotic sensitivity testing for the screening of CRE was performed according to Clinical and Laboratory Standards Institute (CLSI) guidelines. Enterobacteria, resistant to at least one carbapenem antibiotic were considered as CRE. Carba NP test, MCIM and MHT were carried out for CRE isolates according to the CLSI guidelines. Statistical analysis was done using R programming language (level of significance P<0.05). Results: Of 58 CRE, 94.82% (55/58) were confirmed as CPE via both MCIM and MHT while 77.58% (45/58) were revealed as CPE by Carba NP test. There was a significant reduction of CPE detection by Carba NP method compared to MCIM and MHT(P=0.007). Conclusion: Of the three CPE detection methods, sensitivity was higher in MCIM and MHT compared to Carba NP – rapid biochemical test. Acknowledgement: Financial assistance by National Research Council, Sri Lanka (NRC 17-055) is acknowledged.
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.
Detection, identification, and antimicrobial susceptibility of Campylobacter spp. and Salmonella spp. fromfree-ranging Nonhuman Primates in Sri Lanka
(Wildlife Disease Association, 2019) Tegner, C.; Sunil-Chandra, N.P.; Wijesooriya, W.R.P.L.I.; Perera, B.V.; Hansson, I.; Fahlman, A.
ABSTRACT: Infections with Campylobacter spp. and Salmonella spp. are the most frequently reported causes of human bacterial enteritis. Warm-blooded animals, including livestock, pets, and wildlife, can be carriers of the bacteria and may contaminate the environment and food products. The present study investigated the occurrence of Campylobacter spp. and Salmonella spp. in fecal pat samples from free-ranging toque macaques (Macaca sinica) and tufted gray langurs (Semnopithecus priam) collected in March-May 2015 in Sri Lanka. In 58 samples from toque macaques, Campylobacter jejuni was isolated in 10 (17%), Campylobacter coli in four (7%), and Salmonella enterica subsp. enterica serovar Virchow in two (3%). None of the bacteria were isolated in the 40 samples from tufted gray langurs. Pulse-field gel electrophoresis and multilocus sequence typing identified six profiles and four clonal complexes of C. jejuni. The isolated Campylobacter spp. showed varying susceptibility to antimicrobial substances. All Campylobacter spp. isolates were susceptible to chloramphenicol, erythromycin, florfenicol, gentamicin, and streptomycin. Four of the C. jejuni were resistant to at least one of the following: ampicillin, ciprofloxacin, nalidixic acid, and tetracycline, and one of the isolates was multidrug resistant. All four C. coli were resistant to ampicillin, whereas the two Salmonella Virchow strains were susceptible to all antibiotics tested. The presence of Campylobacter spp. and Salmonella spp. in toque macaques may have an impact on the conservation of endangered primates and public health in Sri Lanka. KEYWORDS: Campylobacter spp .; Antimicrobial resistance; PFGE; Salmonella spp; conservation; nonhuman primates.
Down the drain:carbapenem-resistant bacteria in intensive care unit patients and handwashing sinks
(Australasian Medical Publishing Co., 2013) Kotsanas, D.; Wijesooriya, W.R.P.L.I.; Korman, T.M.; Gillespie, E.E.; Wright, L.; Snook, K.; Williams, N.; Bell, J.M.; Li, H.Y.; Stuart, R.L.
OBJECTIVES: Clinical utility of carbapenem antibiotics is under threat because of the emergence of acquired metallo-β-lactamase (MBL) genes. We describe an outbreak in an intensive care unit (ICU) possibly associated with contaminated sinks. DESIGN, SETTING AND PARTICIPANTS: Four clusters of gram-negative bacteria harbouring the MBL gene blaIMP-4 were detected in the ICU at Dandenong Hospital between November 2009 and July 2012. Epidemiological investigations were undertaken in order to identify a common point source. During September 2012, screening using rectal swabs for all ICU patients, and environmental swabs targeting all ICU hand washing sinks and taps were collected. Samples were cultured onto selective carbapenem-resistant Enterobacteriaceae (CRE) agar. Suspected CRE isolates were further characterised using the modified Hodge test and VITEK 2 and confirmed by polymerase chain reaction and sequencing of MBL genes. Clinical and environmental CRE isolates were typed by pulsed-field gel electrophoresis. RESULTS: Ten clinical isolates and one screening isolate of CRE (consisting of Klebsiella pneumoniae [5], Serratia marcescens [4], Enterobacter cloacae [1] and Escherichia coli [1]) were detected with the blaIMP-4 gene over the 30-03 period. S. marcescens was isolated persistently from the grating and drain of eight central sinks. Molecular typing confirmed that clinical and environmental isolates were related. Tap water cultures were negative. Several attempts to clean and decontaminate the sinks using detergents and steam cleaning proved unsuccessful. CONCLUSION: This report highlights the importance of identification of potential environmental reservoirs, such as sinks, for control of outbreaks of environmentally hardy multi-resistant organisms.
Empirical antibiotic therapy for community acquired pneumonia: where are we?
(University of Kelaniya, 2008) Wijesooriya, W.R.P.L.I.; Fonseka, M.N.D.; Dewaraje, D.M.D.T.
Community acquired pneumonia is a leading cause of death in the world and it is the ninth in Sri Lanka. In the management of pneumonia, prompt initiation of empirical antibiotic therapy is critical. Compliance with an appropriate guideline is important in empirical antibiotic therapy in order to optimize the tentative coverage of po'ssible pathogens and to prevent emergence of drug resistance. There are different guidelines published locally (Ministry of Healthcare and Nutrition- Sri Lanka) and internationally (British Thoracic Society, Infectious Disease Society of America) to guide the empirical antibiotic therapy. General objective To determine compliance of empirical antibiotic therapy in the treatment of patients with community acquired pneumonia, of with all three above mentioned guidelines for the hospitalised patients in general medical wards in Sri Lankan setting. Method Setting: Colombo North Teaching Hospital Ragama and Chest hospital Welisara Study period- October 2003 -August 2004 Study population: Hundred and eight patients with community acquired pneumonia (diagnosed clinically and radiologically) were studied with regard to received empirical antibiotic therapy. Results Of the 108 patients, only 57 .4%, 41.6%, 62.2% were managed in accordance with national guidelines of Sri Lanka, guidelines published by Infectious Disease Society of America and British T horacic Society respectively. In the study population, 37.8% of patients were not managed according to any of the above guidelines. Conclusion In a large proportion of cases of community acquired pneumonia admitted to Colombo North Teaching Hospital, Ragama and Chest hospital, Welisara, empirical antibiotic therapy did not comply with currently available guidelines.
Enteric pathogens of zoonotic concern in non-human primates in Sri Lanka
(European Wildlife Disease Association (EWDA, 2016) Tegner, C.; Sunil-Chandra, N.P.; Ingrid, H.; Perera, V.; Wijesooriya, W.R.P.L.I.; Fahlman, A.
Zoonotic disease is a two-way street where humans and other animals are interchanging pathogens. We investigated the occurrence of the potentially zoonotic Campylobacter spp., Salmonella spp. and group A rotaviruses in faecal samples from free-ranging toque macaques and tufted gray langurs in Sri Lanka. Samples were opportunistically collected from primate troops with close human contact at five sites. Standardized culturing was used to detect the bacteria and an ELISA-based dipstick test was used for detection of group A rotaviruses antigens. Genotyping was performed using pulse field gel electrophoresis (PFGE) and multi-locus sequence typing (MLST) and the isolates' sensitivity to selected antibiotics was tested with VetMIC TM (National Veterinary Institute, Uppsala, Sweden) panels Camp EU, CLIN GN and GN-mo (version 4). All 98 samples tested negative for rotavirus. The 40 samples from gray langurs were also all negative for Campylobacter spp. and Salmonella spp. Of the 58 samples collected from toque macaques, C. jejuni was isolated from ten, C. coli from four and Salmonella enterica enterica subsp. Virchow from two of the samples. The fact that neither of the bacteria were isolated from tufted gray langur samples could reflect a true difference between the primate species. However, this should be interpreted in the light of a relatively small sample size. Resistance to ampicillin, ciprofloxacin, nalidixic acid and tetracycline was identified in four C. jejuni isolates, of which three were multidrug resistant. In addition, all C. jejuni showed undetectable MIC-values to colistin, while all C. coli were sensitive to the substance. All C. coli were resistant to ampicillin. The S. Virchow isolates were sensitive to all antibiotics tested for. Six strains of C. jejuni were identified using PFGE and MLST clonal complexes were assigned to all isolates. Sequence types were assigned to seven out of ten C. jejuni. The detection of antibiotic resistant zoonotic bacteria in free-ranging toque macaques with close human contact may have implications for both non-human primate conservation and public health in Sri Lanka and beyond
Evaluation of a rapid whole blood assay for testing dengue patients at point of care
(Sri Lanka College of Microbiologists, 2004) Sunil-Chandra, N.P.; Karunasekera, E.W.S.; Somasiri, D.A.D.H.; Samarakoon, S.M.R.M.; Jayawardena, K.A.T.M.; Fernando, W.M.D.; Wijesooriya, W.R.P.L.I.; Garcia, M.
INTRODUCTION: Dengue is the most significant mosquito borne viral disease affecting nations from Asia to the Americas. Symptoms associated with dengue infection range in severity. . The presentation of disease is impacted by age, prior exposure to the virus and the infecting strain of virus. The more severe form of the disease (haemorrhagic fever) can lead to mortality are generally associated with Secondary infections. Clinically, the measurement of dengue-specific IgM and elevated IgG, allows for the detection and differentiation of Primary and Secondary dengue infection. This discrimination is particularly important in situations such as outbreaks where the allocation of resources needs to be directed to those at greatest risk. In cities and major regional centers worldwide clinicians have access to traditional serological techniques such as ELISA and HAI that measure IgM and IgG levels. Unfortunately, clinicians in rural and remote areas generally do not have the resources available for this technology. Hence there is high clinical utility in a field diagnostic device which has the ability to rapidly and accurately detect and differentiate dengue infections. OBJECTIVES: To evaluate a novel dengue whole blood assay (PanBio) having the capacity for qualitative detection of both dengue-specific IgM and IgG, and differentiate between primary and secondary dengue with regard to sensitivity and specificity. To meet the demand for testing at the point of care or in the near patient environment, the test was required to have the capacity to detect antibodies in whole blood. DESIGN, SETTING AND METHODS: This assay device was used at the bed site of patients to evaluate its performance. The test is simply performed by adding the specimen to the sample well followed by running buffer to the buffer well, wait 15 minutes and visually reading the results. No additional materials required. 231 hospital inpatients in the Gampaha district of Sri Lanka, using a finger prick drop of blood as the analyte were assessed against PanBio Dengue Capture IgM and IgG ELISA for the period of 6 weeks starting from 10Ih November 2003. The capacity to detect and differentiate presumptive primary and secondary dengue was evaluated. RESULTS: The whole blood dengue cassette was able to detect 151 positive and 80 negative samples where as the ELISA could detect 126 positive samples and 105 negative patients. The detection of IgM and IgG positive samples by the cassette gave a relative sensitivity of 94.5%, specificity of 86% and 87.1% agreement between the assays. The cassette was able to identify 71% of positive samples as primary infections (IgM positive) and 96.7% as secondary infections (IgG positive with or without IgM) compared to ELISA. CONCLUSION: These data indicate that the Whole Blood Dengue Cassette has good utility in the detection of primary and secondary dengue with a very high accuracy in discriminating patients at greatest risk and represents a valuable field based assay to support the clinical evaluation of patients presenting with symptoms suggestive of dengue fever. ACKNOWLEDGEMENTS: PanBio Ltd, Australia for the financial assistance and Directors of Teaching hospital Ragama and Base hospitals of Negombo, Gampaha and Wathupitiwala.
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.
Prevalence of antibodies to herpes simplex virus types 1 and 2 (hsv-1 and hsv-2) Amongst non-high risk and High risk populations in Sri Lanka
(Sri Lanka College of Microbiologists, 2001) Sunil-Chandra, N.P.; Kumarage, J.; Wijesooriya, W.R.P.L.I.; Jayasinghe, S.M.A.S.
INTRODUCTION: HSV-1 and HSV-2 infects both the ora cavity and the genital tract whilst the HSV-i generally causes genital infection. Both c these human herpesviruses cause botl primary and recurrent infections leading ft a lifelong persistence of antibodies. Mol infections of either type are asymptomatic Detection of type specific antibodies hai important implications in the diagnosis of HS' infection in sexually active adults ar> prevention of mother to child transmissiof Recently, problems associated with commo epitopes which elicit cross reactiv antibodies in infected individuals have bee overcome by new HSV type specif! serological assays using the gG1 protein < HSV-1 and gG-2 of HSV-2 as antigens. Th study determine the burden and the epidemiology of type specific HSV infection amongst Sri Lankan populations. OBJECTIVE: To estimate and compare age and gender specific seroprevalences of HSV-1 and HSV-2 amongst non-high risk and high risk populations from Sri Lanka. DESIGN: A prospective study among selected target groups. Setting: Children (aged 1-12 years) and non-high risk adults (aged 13-89 years) and blood donors (aged 15-54 years) reported to Teaching Hospital, Ragama, expectant mothers (aged 14-44 years) of Kelaniya Medical Officer of Health (MOH) division, and the patients attended Central STD Clinic Colombo (aged 4-79 years) during the years 2000 and 2001 were included in this study. METHODS: Single sample of blood was obtained from each of 433 children, 757 ante-natal women, 1374 non-high risk adults, 929 blood donors, and 676 STD clinic attendees. Samples were tested for IgG class antibody responses to HSV infections using FDA approved type specific ELISA assay (MRL) at the Dept . of Microbiology, Faculty of Medicine , University of Kelaniya. RESULTS: Overall seroprevalence of HSV-1 among children, ante-natal women, blood donors, adult patients and STD attendees was 51.3%, 75.2%, 79.3%, 75.9% and 78.7% respectively whilst the seroprevalence of HSV-2 was 4.6%, 8.3%, 10.9%, 19.8% and 39.6% respectively. Age and gender specific differences in seroprevalence were observed within study groups.
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.
The silver lining of disposable sporicidal privacy curtains in an intensive care unit
(Elsevier, 2014) Kotsanas, D.; Wijesooriya, W.R.P.L.I.; Sloane, T.; Stuart, R. L.; Gillespie, E. E.
BACKGROUND: The environment is a well-known source of health care-acquired infection. Because of the known risk of contamination, patient privacy curtains require frequent changes to decrease the risk of spread from patients to curtain and visa versa. METHODS: Fourteen disposable sporicidal privacy curtains were tested from December 2012 to June 2013 while hanging in a busy intensive care unit. Significant bacterial pathogens were identified and total bacteria enumerated as colony-forming units. Antimicrobial activity of curtain swatches was also tested against a range of bacteria in the laboratory. Measurements were recorded as zone of inhibition and contact inhibition. A cost analysis to replace standard curtains with disposable sporicidal curtains was also undertaken. RESULTS: Cultures grew low numbers of skin and environmental microorganisms with no methicillin-resistant Staphylococcus aureus, carbapenem-resistant Enterobacteriaceae, or Clostridium difficile detected. Vancomycin-resistant enterococci were recovered in very low numbers from 2 curtains where vancomycin-resistant enterococci-infected patients had been located. Privacy curtains demonstrated antimicrobial activity against C difficile and 13 additional bacterial pathogens. CONCLUSION:We conclude that disposable sporicidal privacy curtains are cost-effective and best replaced at 6 months in a high-risk area such as an intensive care unit.
Teicoplanin non-susceptible coagulase-negative staphylococci in a large Australian healthcare network: Implications for treatment with vancomycin
(Sri Lankan Society for Microbiology, 2017) Wijesooriya, W.R.P.L.I.; Kotsanas, D.N.; Korman, T.M.; Graham, M.
INTRODUCTION AND OBJECTIVES: Coagulase-negative staphylococci (CoNS) are relatively low in virulence but some are increasingly recognized as agents of clinically important infections. Glycopeptides are the drugs of choice for treatment of methicillin-resistant CoNS infections. Our aim was to analyse the susceptibility profile of CoNS in our healthcare network from 2010-2012. METHODS: All CoNS with susceptibility results were analysed as two groups; teicoplanin-susceptible (Teico-S) and non–susceptible (Teico-NS). Analysis included results of other antistaphylococcal antibiotic susceptibilities, sample type (sterile, non-sterile), species and patient location (intensive care unit (ICU) vs non-ICU). RESULTS: Of the 1510 CoNS isolates with susceptibility results, 109 (7.2%) were non-susceptible to teicoplanin. Teicoplanin non-susceptibility was associated with non-susceptibility to ≥ 3 antistaphylococcal-antibiotics, detected more frequently from sterile samples compared to non-sterile samples and from ICU compared to ward patients. Staphylococcus epidermidis was the most common species recovered and was more likely to be Teico-NS. CONCLUSIONS: Teicoplanin non-susceptibility is associated with multi-resistance to ≥3 antistaphylococcal antibiotics. Clinicians should be aware that vancomycin resistance may be selected from Teico-NS strains.