Browsing by Author "Jayarathne, J.A.J.C."

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Dengue Encephalitis with Concurrent Infections by Multiple Dengue Virus Serotypes
(International Postgraduate Research Conference 2019, Faculty of Graduate Studies, University of Kelaniya, Sri Lanka, 2019) Jayarathne, J.A.J.C.; Wijesinghe, W.A.T.A.; Mendis, S.; Waidyasekara, J.; Gunathilaka, P.A.D.H.N.; Gunasekara, D.
Dengue is a serious public health problem caused by an arbovirus. Abnormal-neurological presentations associated with dengue infection is rare. Herewith, we report a case of a patient with dengue encephalitis who was concurrently infected with multiple serotypes. A 36-year-old, male resident from Poogoda presented to North Colombo Teaching Hospital with a history of generalized tonic-clonic seizures (GTCS) and unconsciousness. On admission, he displayed only a persisting headache. He had no significant illnesses in the past. Detailed history revealed that he has had a fever and left the hospital against the medical advice on the same day. On clinical examination, he was afebrile and blood pressure was 110/80 mmHg. He was well oriented with a Glasgow Coma Scale (GCS) of 15/15 and there was no focal neurological deficit. The funduscopic examination was normal. His initial full blood count revealed a rise in white blood cells with a predominant elevation of neutrophils of 12.44 x 103/uL. His platelet count was reported to be 306 x103/uL and, he was treated for a bacterial infection. On the following day, the patient started developing a fever and GTCS. Aggressive behavior, confusion, and delirium were also demonstrated. Neck stiffness was not observed. Non-contrast computed tomography (NCCT) scan, contrast-enhanced computed tomography (CECT) scan, chest X-ray scan and magnetic resonance image (MRI) of the brain were normal. Electroencephalography (EEG) revealed encephalopathy with non-epileptic discharge. Lumbar puncture was performed on the third day of admission and analysis of cerebrospinal fluid (CSF) was unremarkable. IgM antibody for the dengue virus (DENV) was detected in CSF. All the other viral and parasitological studies were normal. The patient was treated with anti-epileptic, anti-psychotic, antibacterial and antiviral drugs. High fever spikes and seizures were continued. GCS started to deteriorate from 9/15 to 3/15. Urine out-put started to decline. Ultra-sound scanning revealed mild ascites. Blood picture analysis showed evidence of having a severe bacterial infection. On day 9, both CSF and serum specimens were referred to Molecular Diagnostic Laboratory, Faculty of Medicine, Ragama for dengue viral investigations. The presence of NS-1 antigen, IgM/IgG antibodies, and the occurrence of concurrent infections with serotype 2 and 3 in the serum sample confirmed that the patient was infected with DENV. The presence of IgM/IgG antibodies were observed in the CSF sample. On day 10, the patient was transferred to the medical intensive care unit and monitored thoroughly. As the condition was deteriorated, he was ventilated and incubated for 11 days in the intensive care unit. He started to recover gradually after the 31st day. On day 36, the patient was discharged without any residual neurological symptoms. The patient is currently being followed up at the neurological clinic. Dengue encephalitis is a rare and deleterious manifestation of dengue infection. It is believed that concurrent infections with multiple serotypes and serotype replacement may cause disease severity. Therefore, reporting uncommon cases will provide insights for the physicians in early diagnosis and effective management
Detection of Dengue Co Infections Using a Novel Single Tube Multiplex Reverse Transcription Polymerase Chain Reaction.
(In: Proceedings of the International Postgraduate Research Conference 2017 (IPRC – 2017), Faculty of Graduate Studies, University of Kelaniya, Sri Lanka., 2017) Jayathilake, E.K.S.; Jayarathne, J.A.J.C.; Muhandiramlage, T.P.; Fujii, Y.; Gunasekara, K.A.D.C.
Co-infection in individuals by more than one Dengue Virus (DENV) serotype has been reported in regions where multiple serotypes co-circulate. Co-infections can be detected using Polymerase Chain Reaction (PCR). Semi-nested multiplex PCR with Lanciotti’s primers is a widely used PCR method for serotyping DENV and it has also been used for detecting coinfections. Despite of being widely used, Lanciotti’s method may be sub-optimal in detecting co-infections as overlapping primer targets will create a bias in the amplification of the serotype with a low viral load. This could lead to underreporting of co-infections. Nine new non- overlapping primers were designed to independently amplify each serotype with minimal competition between primers to their target.In mixed infections, novel PCR assay exhibited higher sensitivity in detecting the minor serotype compared to Lanciotti’s method. The new method can also detect all four serotypes in viral RNA isolated from viral cultures and patient samples in a single tube multiplex PCR. This enables rapid and cost-effective serotyping with improved sensitivity indetection ofco-infections in clinical samples.
Production, Optimization and Characterization of Thermostable, Halotolerant, Detergent Compatible Cellulase from a Bacillus sp using Agricultural Residues
(International Postgraduate Research Conference 2019, Faculty of Graduate Studies, University of Kelaniya, Sri Lanka, 2019) Jayarathne, J.A.J.C.; Kawan, A.; Prakash, P.
Lignocellulose biomass is considered to be the most copious and renewable organic material on the planet. Agricultural residues are a great source of lignocellulose biomass which is inexpensive, renewable and environmentally friendly. Cellulose is the predominant constitute, while hemicellulose, pectin, and lignin are present as minor components. Cellulase is the key to achieve economically valuable high-energy molecules via effective enzymatic hydrolysis. Cellulases are adaptive enzymes which are synthesized by microorganisms during their growth in the media when cellulosic substrates are present. The current study was focused on optimizing the production conditions of cellulase-producing bacteria isolated from garden soil using inexpensive agro wastes as the sole carbon source. Furthermore, the cellulase enzyme was partially purified and characterized under different parameters. Bacterial strain, Bacillus clausii was manifested to produce extracellular thermostable, halotolerant and detergent stable cellulase. The culture conditions for the growth of the enzyme producer were optimized with respect to incubation time, pH, temperature, carbon sources and nitrogen sources. Cellulase production was instigated at 12 hours as soon as the bacterium entered the exponential phase and reached its maximum at 48 hours. The production of cellulase was active in a significant range of pH from pH 7 to 11. Optimal pH was recorded to be pH 11. The maximal cellulase activity was obtained between 30⁰C to 40⁰C. The yield of cellulase was enhanced nearly by 45% in the presence of agricultural residues including 1% of corn husks and jack fruit peel powder. Cellulase was partially purified by 60% of ammonium sulfate precipitation method followed by the dialysis. Partially purified cellulase was subjected to characterization. Maximum enzyme activity was recorded at pH 5 and 50⁰C. The enzyme was thermostable perpetuating 100% original activity at 60⁰C for 1 hour. The enzyme was active over a broad spectrum of sodium chloride of 2 % to 14% and the enzyme activity was induced by 8% of Sodium Chloride (NaCl). Cellulase activity was significantly inhibited by the presence of mercury (ii) ion. Detergent compatibility was varied with different types of commercially available laundry detergents. Cellulase depicted its apex of stability with respect to Surf Excel. In addition, cellulase rendered its stability in the presence of 1% Sodium Dodecyl Sulphate (SDS) and it might give an indication to be used as a potential additive in the detergent industry. We believe that the utilization of garden soil bacteria upon cellulosic waste is an inexpensive approach to reduce the enzyme production cost. And also, indirectly it helps to reduce environmental pollution. Besides, the production of cellulases that can actively participate in harsh environmental conditions is considered to be an important application from the industrial perspective.