Browsing by Author "Sunil-Chandra, N.P."

Now showing 1 - 20 of 53

2'-Deoxy-5-ethyl-beta-4'-thiouridine inhibits replication of murine gammaherpesvirus and delays the onset of virus latency
(International Medical Press, 1999) Barnes, A.; Dyson, H.; Sunil-Chandra, N.P.; Collins, P.; Nash, A. A.
The antiviral thionucleoside analogue 2'-deoxy-5-ethyl-beta-4'-thiouridine (4'-S-EtdU) was shown to be a more potent inhibitor of gammaherpesvirus infection than acyclovir. This compound inhibits replication of murine herpesvirus (MHV)-68 in the lungs of mice when given 3 days post-infection. However, as with other nucleoside analogues, it was unable to prevent the establishment of latency, despite delaying the onset of latent infection in the spleen. In contrast, virus persistence in the lung was inhibited following drug treatment, although persistence was re-established in mice when treatment was suspended after 12 days. These data suggest that 4'-S-EtdU is a highly effective inhibitor of murine gamma herpesvirus replication and as such provides a powerful tool to study the pathogenesis of this virus in vivo.
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 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.
Application of Elisa in the diagnosis of rotavirus infections in buffalo calves
(An International Journal Of Buffalo Science., 1994) Sunil-Chandra, N.P.; Mahalingam, S.
The conditions for diagnosis of group A rotavirus infection in buffalo calves by enzyme linked immunosorbent assay (ELISA) were optimised in terms of type of microtitre plates, all reagents and the cut off points for positivity. Irradiated polystyrene plates were the plates of choice. The optimal dilution for the clinical samples (faecal extracts), capture and detector antibodies and the enzyme conjugate were I : 10, I : 5,000, I : 10,000 and I : 300, respectively. Further, we found that the cut off point for positivity by the screening ELISA was an optical density (OD) of ≥ 0.170 at 450 nm wave length, and for confirmation when blocking activity was ≥ 30%. 'The positivity of a faecal sample was graded as strongly positive if the PIN value was ≥2.7 by screening ELISA and ≥ 50% blocking activity in the confirmatory blocking ELISA. Samples having PIN value < 2.7 but ≥ 2. I and < 50% but ≥ 30% blocking activity were regarded as weakly positive. in addition, pre and post colostral buffalo sel'd as negative and positive control sera respectively, were selected and used for detection of antirotavlral antibodies by the blocking ELISA. 'This study establishes that the ELISA technique can be profitably used (once required parameters are defined), in the diagnosis of rotavirus infection in buffalo calves.
Association of Hantavirus infections and Leptospirosis with the occurrence of Chronic Kidney Disease of Uncertain Etiology in the North Central Province of Sri Lanka: A prospective study with patients and healthy persons
(Frontiers Media SA, 2020) Sunil-Chandra, N.P.; Jayaweera, J.A.A.S.; Kumbukgolla, W.; Jayasundara, M.V.M.L.
ABSTRACT: Chronic Kidney disease of uncertain etiology (CKDu) has become a significant disease burden, affecting farming community of Sri Lanka and the exact etiology, which could be multifactorial, is not hitherto established. This study is aimed to determine the association of past hantavirus infection and leptospirosis with the occurrence of CKDu. A cohort (n = 179) of known CKDu patients living in high-CKDu prevalent areas of Anuradhapura district of Sri Lanka was compared with a group of 49 healthy, sex-matched younger blood relatives of CKDu patients (control-1) and another 48 healthy, age, and sex-matched individuals living in low-CKDu prevalent area (control-2) of the same district where same life style and climate conditions prevail. Fifty out of 179 (27.9%) CKDu patients, 16/49 (32.7%) of control-1 and 7/48 (14.6%) of control-2 were found positive for IgG antibodies to Puumala, Hantaan or both strains of hantaviruses. Hantaan strain specificity was found to be predominant in all study groups. Hantavirus IgG sero-prevalence of healthy individuals living in low-CKDu prevalent area was significantly lower compared to CKDu patients and healthy younger blood relatives living in high-CKDu prevalent areas (p = 0.03). Past hantavirus infection possesses a significant risk for the occurrence of CKDu (OR = 4.5; 95% CI-3.1-5.4, p = 0.02). In contrast, IgG seroprevalence to hantaviruses was not significantly different in CKDu patients and healthy younger blood relatives living in high-CKDu prevalent areas indicating past hantavirus infection has no association with the occurrence of CKDu or possibly, younger relatives may develop CKDu in subsequent years. Seroprevalence to leptospirosis showed no significant difference between CKDu patients and healthy controls. KEYWORDS: CKDu; chronic kidney disease; hantaviruses; leptospira; sero-prevalence. Erratum in: Front Cell Infect Microbiol. 2020;10:631515
Canine Rabies and its implications for human health in Sri Lanka
(Veterinary Research Institute, 2018) Ubeyratne, J.K.H.; Srikitjakarn, L.; Pfeiffer, D.U.; Kohnle, L.; Sunil-Chandra, N.P.; Chaisowwong, W.; Hemwan, P.
Rabies is an endemic viral zoonotic disease in Sri Lanka. Dogs are the main reservoir and transmitter, making surveillance of canine rabies crucial for disease elimination. Sri Lanka is one of the Asian countries where human deaths from rabies have been reduced markedly, but it still remains a significant public health problem. Ninety-five percent of human cases in the country are attributed to dog bites. Human settlement patterns allow the existence of dogs. The size of the dog populations is dependent on the habitat, especially the availability of resources such as food, water, and shelter. Although most dogs are owned, many ownerless dogs are allowed to roam freely resulting in vaccination coverage in dogs is heterogeneous. Other terms for ownerless dogs, i.e., dogs which do not have an acknowledged owner include community dogs and stray dogs. Such type of ownerless dogs are more common in rural as compared to urban areas. The frequency of vaccination in ownerless dogs is below the required level. Human attitudes towards dogs, especially ideas of responsible ownership, dog-keeping practices, and other aspects of human behavior influence rabies transmission risk. Research is required to reduce existing gaps in understanding of the knowledge, attitudes, and practices of the general population regarding the need for both dog population control and for rabies vaccination. Additionally, an improved understanding of dog demography and the ecological context of dog populations is essential for increasing dog vaccination coverage, achieving more effective vaccination campaign planning, and better determining the needs of dog population management programs. In order to achieve control of and finally eliminate rabies in Sri Lanka, the epidemiology of canine rabies in the country should be studied in relation to dog ecology and social aspects of pet ownership. A well-executed rabies control program needs to be based on integrated information regarding dog populations including an understanding of relevant differences in environmental habitats, in human cultures and social strata, and in different epidemiological situations. This article examines the rabies situation in Sri Lanka with respect to trends in human and canine rabies and identifies challenges ahead for rabies elimination.
Characterization of murine gammaherpesvirus 68 glycoprotein B (gB) homolog: similarity to Epstein-Barr virus gB (gp110)
(American Society for Microbiology, 1994) Stewart, J.P.; Janjua, N.J.; Sunil-Chandra, N.P.; Nash, A.A.; Arrand, J.R.
Murine gammaherpesvirus 68 (MHV-68) is a natural pathogen of murid rodents and displays similar pathobiological characteristics to those of the human gammaherpesvirus Epstein-Barr virus (EBV). However, in contrast to EBV, MHV-68 will replicate in epithelial cells in vitro. It has therefore been proposed that MHV-68 may be of use as a model for the study of gammaherpesviruses, EBV in particular, both in vitro and in vivo. The EBV homolog of herpes simplex virus glycoprotein B (gB), termed gp110, is somewhat unusual compared with those of many other herpesviruses. We therefore decided to characterize the homolog of gB encoded by MHV-68 (termed MHV gB) to observe the properties of a gammaherpesvirus gB produced in epithelial cells and also to test the relatedness of MHV-68 and EBV. The MHV gB-coding sequence was determined from cloned DNA. The predicted amino acid sequence shared closest homology with gammaherpesvirus gB homologs. Biochemical analysis showed that MHV gB was a glycoprotein with a molecular weight of 105,000. However, the glycans were of the N-linked, high-mannose type, indicating retention in the endoplasmic reticulum. In line with this, MHV gB was localized to the cytoplasm and nuclear margins of infected cells but was not detected on the cell surface or in virions. Additionally, anti-MHV gB antisera were nonneutralizing. Thus, the MHV gB was unlike many other herpesvirus gBs but was extremely similar to the EBV gB. This highlights the close relationship between MHV-68 and EBV and underlines the potential of MHV-68 as a model for EBV in epithelial cells both in vitro and in vivo.
A comparison of serological diagnostic techniques in Dengue fever
(Sri Lanka College of Microbiologists, 2005) Gunasekera, H.A.K.M.; Senanayake, C.P.; Sunil-Chandra, N.P.; Mendis, L.
INTRODUCTION: The Dengue Duo IgM and IgG Rapid Strip test (PanBio Pvt. Ltd., Brisbane, Australia) is a commercially available immunochromatographic test. The Armed Forces Research Institute of Medical Sciences (AFRIMS), Bangkok Thailand, has developed an in-house anti-dengue/anti-JE IgM and IgG reference enzyme-linked immunosorbent assay (ELISA). OBJECTIVE: To compare the usefulness of the AFRIMS ELISA and PanBio Dengue Duo IgM and IgG Rapid Strip test (PanBio Strip test) in the diagnosis of dengue infections. MATERIALS AND METHOD: 93 non-bacterial undifferentiated fever cases and 50 suspected dengue fever cases were screened for dengue and JE virus infections by the AFRIMS ELISA and also by the PanBio Strip test for dengue. All cases positive for dengue antibodies by either test were also tested by the Haemagglutination Inhibition test. RESULTS: Results were considered conclusive when at least 2 or all 3 of the above tests agreed. The AFRIMS ELISA had a sensitivity of 91.7% and specificity of 100% while the PanBio Strip test has a sensitivity of 93.8% and specificity of 96.8% in diagnosing dengue infections. 91.7% primary and 91.4% secondary infections were correctly classified by the AFRIMS ELISA. The PanBio Strip test identified 100% primary infections and 65.7% of secondary infections. CONCLUSIONS: The PanBio Strip test has a sensitivity and specificity comparable to the AFRIMS ELISA in diagnosing dengue infections although it tends to underestimate the number of secondary infections.
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.
Concomitant leptospirosis-hantavirus co-infection in acute patients hospitalized in Sri Lanka: implications for a potentially worldwide underestimated problem
(Cambridge University Press, 2015) Sunil-Chandra, N.P.; Clement, J.; Maes, P.; de Silva, H.J.; Van Esbroeck, M.; Van Ranst, M.
Two global (re-)emerging zoonoses, leptospirosis and hantavirus infections, are clinically indistinguishable. Thirty-one patients, hospitalized in Sri Lanka for acute severe leptospirosis, were after exclusion of other potentially involved pathogens, prospectively screened with IgM ELISA for both pathogens. Of these, nine (29·0%) were positive for leptospirosis only, one (3·2%) for hantavirus only, seven (22·5%) for both pathogens concomitantly, whereas 13 (41·9%) remained negative for both. Moreover, in a retrospective study of 23 former patients, serologically confirmed for past leptospirosis, six (26·0%) were also positive in two different IgG ELISA hantavirus formats. Surprisingly, European Puumala hantavirus (PUUV) results were constantly higher, although statistically not significantly different, than Asian Hantaan virus (HTNV), suggesting an unexplained cross-reaction, since PUUV is considered absent throughout Asia. Moreover, RT-PCR on all hantavirus IgM ELISA positives was negative. Concomitant leptospirosis-hantavirus infections are probably heavily underestimated worldwide, compromising epidemiological data, therapeutical decisions, and clinical outcome.
Corrigendum: Association of Hantavirus infections and Leptospirosis with the occurrence of Chronic Kidney Disease of Uncertain Etiology in the North Central Province of Sri Lanka: A Prospective study with patients and healthy persons
(Frontiers Media SA, 2020) Sunil-Chandra, N.P.; Jayaweera, J.A.A.S.; Kumbukgolla, W.; Jayasundara, M.V.M.L.
[This corrects the article doi: 10.3389/fcimb.2020.556737]. Erratum for : Association of Hantavirus infections and Leptospirosis with the occurrence of Chronic Kidney Disease of uncertain etiology in the North Central Province of Sri Lanka: A Prospective study with patients and healthy persons [Frontiers in Cellular and Infection Microbiology. 2020;10:556737].
A Descriptive Study on Antibiotic Resistant, Clinically Significant Coliform Species Isolated from the Patients at Colombo North Teaching Hospital (CNTH), Ragama, Sri Lanka
(19th Conference on Postgraduate Research, International Postgraduate Research Conference 2018, Faculty of Graduate Studies,University of Kelaniya, Sri Lanka, 2018) Wijesooriya, L.I.; Namalie, K.D.; Sunil-Chandra, N.P.
Introduction: Antibiotic resistance (AR) is a great therapeutic challenge globally and locally today. The rate of development of AR is far ahead compared to the discovery of a new class of antibiotics, which has not been successful in last three decades. Of the antibiotic resistant coliforms, extended spectrum beta-lactamase producers (ESBLP) play a key role in life threatening infections. Moreover, emergence of carbapenem-resistant Enterobacteriaceae (CRE) has further limited the effective therapeutic options. Objective: To investigate the AR of clinically significant Enterobacteriaceae isolated from patients in a tertiary healthcare setting. Method: A descriptive, cross-sectional study was conducted involving patients with coliform infections at CNTH from 01/03/2018 to 31/08/2018. Demographic details, clinical data & antibiotic sensitivity test (ABST) patterns were analyzed. ABST was performed according to John-Stokes method & ESBLPwere identified by the keyhole method. Resistance to either meropenem or imipenem is used to identify CRE. Statistical analysis was done via R programming language (level of significance P<0.05). Results: Of the 200 coliforms, 85.5% (171/200) were from inpatients & the rest were from outpatients. Of the studied patients, 53.5% (107/200) were females & 46.5% (93/200) were males. Of the Enterobacteriaceae spp isolated, 48.5% (97/200) were from urine, 34.5% (69/200) from pus / wound swabs, 9.5% (19/200) respiratory samples, 3% (6/200) sterile fluids & stents, & 3% (6/200) from blood & CVP tips. As per ABST, about 90% were resistant to ampicillin. Resistance was 61-70% against cefuroxime (oral), ciprofloxacin & nalidixic acid, 60% for amoxiclav, 41-50% for cefotaxime, cefuroxime (intravenous), co-trimoxazole, levofloxacin, norfloxacin & ofloxacin, 31-40% for cefepime, ceftazidime, ceftriaxone & nitrofurantoin, 21-30% for gentamicin & piperacillin tazobactam & 0-10% for amikacin & meropenem. Of the coliforms, 29% (58/200) were ESBLP & 8% (16/200) were CRE. None of the ESBLP was CRE. Of CRE, 37% (10/16) were resistant to amikacin. However, 93.8% (15/16) of CRE were colistin sensitive. Conclusion: Majority of the isolates represented infections of the inward patients & there was no statistically significant difference between male & female proportions. Coliforms were detectedmostly from urine. Majority (>50%) of clinically significant Enterobacteriaceae were resistant to most of the oral antibiotics namely cefuroxime, ciprofloxacin, nalidixic acid & amoxiclav. Of the oral antibiotics, nitrofurantoin has the lowest resistance against Enterobacteriaceae. None of the antibiotics had 100% sensitivity against Enterobacteriaceae. Results indicate that ESBLP can be safely treated with carbapenems. Colistin will be an effective empiric antibiotic for CRE.
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.
The Effect of acyclovir on the acute and latent murine gammaherpesvirus-68 infection of mice
(Sage Publishing, 1994) Sunil-Chandra, N.P.; Efstathiou, S.; Nash, A.A.
Mice inoculated intranasally with murine gammaherpesvirus-68 were used to evaluate the efficacy of acyclovir (ACV) in the treatment of acute and latent infections. Effectiveness was measured by infectious virus assay of the lung (site of active replication) and infectious centre assay of spleen cells (site of latency). Intraperitoneal administration of ACV at 6-h intervals starting soon after inoculation was more effective in reducing infectious virus in the lung than was treatment with 12-hourly injections commencing 3 days post-infection.
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
An epidemiological study on a varicella outbreak among initial entry trainees of the Sri Lankan Army and the cost-effectiveness of vaccinating susceptible individuals
(Sri Lanka College of Microbiologists, 2003) Dias, K.P.K.; Sunil-Chandra, N.P.
INTRODUCTION: Varicella which is a disease burden to the Sri Lankan Army. VZV immunization of susceptible recruits is limited due to its high cost and therefore, recommendation of vaccination should be evaluated from a cost effectiveness perspective. OBJECTIVE: To study : 1. Spread of a varicella outbreak among initial entry trainees. 2. Usefulness of taking the past history of varicella for screening of susceptible individuals. 3. Cost effectiveness of VZV vaccination of initial entry trainees of the Sri Lankan Army. DESIGN: A hospital based descriptive study conducted prospectively over a period of three months during an outbreak. SETTING: 682 initial entry trainees aged 18-24 years who entered the Volunteer Force Training School of the Sri Lankan Army, Diyatalawa on 21!d July 2002 from various parts of the country were enrolled in this study. They were either hospitalized for varicella at the Army Base Hospital or billeted in the Camp. METHODS: Details of the index, secondary and tertiary cases, and preventive and management measures carried out for varicella patients were recorded. The rate of contracting varicella amongst immune and non-immune recruits based on past history were analyzed. A sample of blood was collected from some patients for the serological confirmation of varicella and rubelSa. Cost effectiveness of VZV vaccination at the Sri Lankan Army Hospital was analyzed. RESULTS: 263 (38.6 %) of all new recruits had a past history of chicken pox and only 9 (3.4%) of them re-infected. A total of 271 recruits were hospitalized for chicken pox during the outbreak and 262 (96.7%) of them did not have a past history. In addition to the varicella, there was also clinical and serological evidence of an outbreak of rubella Vaccination of recruits was found to be cheaper (Rs. 4293.00 or US$ 43.00) compared to the cost of 14 days of hospital stay (Rs. 7265.00 or US$ 72.00). CONCLUSIONS: Hospitalization and treatment of patients with varicella in the Army Hospital found to be more costly compared to the vaccination of susceptible recruits against VZV. Past history of varicella will be useful to identify susceptible new recruits for VZV immunization. Proper isolation of the patients and segregation of susceptible individuals at the index and secondary case levels will minimise the spread.
Epidemiology of multidrug-resistant Enterobacteriaceae in Sri Lanka: First evidence of bla KPC harboring Klebsiella pneumoniae.
(Elsevier., 2020) Kumudunie, W.G.M.; Wijesooriya, L.I.; Namalie, K.D.; Sunil-Chandra, N.P.; Wijayasinghe, Y.S.
BACKGROUND: Extended-spectrum β-lactamase producing Enterobacteriaceae (ESBL-PE) and carbapenem-resistant Enterobacteriaceae (CRE) are disseminated worldwide posing a serious public health concern. Although, the presence of ESBL-PE and CRE in Sri Lanka has been reported, the prevalence is unknown. This study aimed to provide up-to-date epidemiological data on multidrug-resistant Enterobacteriaceae and to characterize the molecular determinants of carbapenemase-producing Enterobacteriaceae (CPE) in Sri Lanka.METHODS: A prospective cross-sectional study was conducted at a tertiary care hospital in Sri Lanka between December 2017 and February 2018. ESBL-PE and CRE were identified by disc diffusion method. Carbapenemase production was determined by carbapenem inactivation method and the presence of selected carbapenemase genes were detected by PCR. RESULTS: Five hundred and ninety-three Enterobacteriaceae were isolated from variety of clinical samples. Overall prevalence of ESBL-PE and CRE were 26.0% (n = 154) and 9.6% (n = 57), respectively. The highest rate of ESBL-PE (30.8%) was found in urine samples, while the highest occurrence of CRE (20.8%) was seen in respiratory specimens. The most common CRE species identified was K. pneumoniae (n = 46, 80.7%), followed by C. freundii (n = 4, 7.0%), E. coli (n = 3, 5.3%), P. rettgeri (n = 2, 3.5%), E. cloacae (n = 1, 1.7%), and K. aerogenes (n = 1, 1.7%). Carbapenemase production was observed in 54 (94.7%) of CRE isolates. Fifty eight carbapenemase encoding genes were identified in 54 CPE. The most prevalent carbapenemase gene was blaOXA-48-like (n = 48, 88.9%), followed by blaNDM (n = 8, 14.8%), and blaKPC (n = 2, 3.7%). CONCLUSIONS: This study reports an alarming rate of CRE and the emergence of blaKPC harboring K. pneumoniae in Sri Lanka. The need for preventive measures is highlighted to limit the spread of these difficult-to-treat bacteria in the country. KEYWORDS: Carbapenem resistance; Carbapenemase; ESBL; Enterobacteriaceae; KPC; Sri Lanka.
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.