Saumya Wickramasinghe

University of California, Davis

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David A. Mills

University of California, Davis

Ruwini Rupasinghe

University of California, Davis

Rohana Chandrajith

University of Peradeniya

Juan F. Medrano

University of California, Davis

Woutrina Smith

University of California, Davis

Wendi Jackson

University of California, Davis

Jake M. Pry

University of California, Davis

Gonzalo Rincón

Zoetis (United States)

Zied Badurdeen

University of Peradeniya

Tilak Abeysekara

University of Peradeniya

Cooperative Institutions

University of California, Davis

University of Peradeniya

King's College London

University of California System

University of Ruhuna

St Thomas' Hospital

Guy's and St Thomas' NHS Foundation Trust

Guy's Hospital

University of Alberta

Institute for Family Health

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Microbial diversity and ecology of geothermal springs in the high-grade metamorphic terrain of Sri Lanka

Environmental Advances (2022)

Ruwini Rupasinghe Sathya Amarasena Sudeera Wickramarathna Patrick J. Biggs Rohana Chandrajith

The current study evaluated the bacterial diversity of six hot water spring clusters in Sri Lanka by Illumina MiSeq sequencing of the V3–V4 region of the 16S rRNA gene. Bacterial abundance measures and diversity statistics were assessed using QIIME2 metagenomics workflow, and the results were compared according to the region, the water temperature at the surface (36–59 °C), and pH (6.25–8.35). The predominant phyla observed were Proteobacteria, Actinobacteria, Firmicutes, [Thermi], and Cyanobacteria. A low abundance of Bacteroidetes, Chloroflexi, Acidobacteria, TM7, and Spirochaetes was detected in most of the springs. Several important bacterial species such as Deinococcus geothermalis that can tolerate Martian-like conditions, genera such as Legionella and Campylobacter that contain pathogenic species, sulfur metabolizing Desulfovibrio, Desulfatirhabdium, Desulforhabdus, Desulfacinum, Thermodesulfovibrio, Desulfovirga, and Thiobacter species, and several other species with the potential practical industrial application were detected. Several opportunistic human pathogens were detected in the water samples and raised a public health concern about the management of post-bathing water. Based on the Bray Curtis beta diversity metric, the microbial distribution correlated with temperature rather than the geographic distance. This study provides valuable new insights into the bacterial diversity of the hot springs in Sri Lanka. Future research needs to be conducted on industrially important thermophiles identified in this study.

Chloroflexi (class)

Acidobacteria

Hot spring

Phylogenetic diversity

10.1016/j.envadv.2022.100166

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Prevalence and identification of Cryptosporidium species in paediatric patients with diarrhoea

Ceylon Medical Journal (2014)

UM Sirisena WMDR Iddawela F Noorden Saumya Wickramasinghe

To determine the prevalence of Cryptosporidium infection in children with diarrhoea, identify associated factors and identify the parasite using Polymerase Chain Reaction (PCR).A total of 138 diarrhoeic faecal samples were collected between August 2011 and February 2013, from children under 12 years of age, admitted to paediatric units of Teaching Hospitals, Kandy and Peradeniya, Sirimawo Bandaranayake Childrens' Hospital, Peradeniya and District General Hospital, Matale. One hundred faecal samples collected from healthy children were used as controls. All control and test samples were screened for the presence of Cryptosporidium oocysts with Modified Ziehl-Neelsen (MZN) method and PCR.Prevalence of Cryptosporidium infection among children with diarrhoea was 5.7%. All the cases positive for Cryptosporidium were below 3 years of age. The majority (7 out of 8) of the positive cases had watery diarrhoea while none of the healthy children excreted Cryptosporidium oocysts in the faeces. Of the 8 positive cases, 6 had a history of animal contact. A large proportion of positive cases used pipe borne municipal water. The majority (66.6%) of positive cases did not consume boiled cooled water. We were able to identify C. parvum from one of the eight cases that had diarrhoea.The current study shows that Cryptosporidium is one of the aetiological agents responsible for childhood watery diarrhoea in Sri Lanka, thus stressing the importance of routine stool examination for Cryptosporidium oocysts. This study recommends boiling water as an important measure to prevent the transmission of Cryptosporidium oocysts. Further molecular studies are needed to determine the other species of Cryptosporidium responsible for cryptosporidiosis in children in Sri Lanka.

Sri lanka

Etiology

10.4038/cmj.v59i3.7467

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Additional file 1: of Bifidobacteria grown on human milk oligosaccharides downregulate the expression of inflammation-related genes in Caco-2 cells

Figshare (2015)

Saumya Wickramasinghe Alline R. Pacheco Danielle G. Lemay David A. Mills

A Microsoft Excel file that contains spreadsheets of Caco-2 genes differentially expressed in response to B. infantis grown on GLU, LAC, or HMO. (XLSX 86 kb)

Caco-2

10.6084/m9.figshare.c.3643475_d2

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An automated method for the measurement of a range of tyrosine kinase inhibitors in human plasma or serum using turbulent flow liquid chromatography–tandem mass spectrometry

Analytical and Bioanalytical Chemistry (2012)

Lewis Couchman M. Eileen Birch Robin Ireland A. L. Corrigan Saumya Wickramasinghe

Protein precipitation

Therapeutic Drug Monitoring

Lapatinib

10.1007/s00216-012-5970-2

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Iron Fortification and Inulin Supplementation in Early Infancy: Evaluating the Impact on Iron Metabolism and Trace Mineral Status in a Piglet Model

Current Developments in Nutrition (2024)

Jungjae Park Saumya Wickramasinghe David A. Mills Bo Lönnerdal Peng Ji

BackgroundInfant formula in the U.S. contains abundant iron, raising health concerns about excess iron intake in early infancy.ObjectivesUsing a piglet model, we explored the impact of high iron fortification and pre- or synbiotic supplementation on iron homeostasis and trace mineral bioavailability.MethodsTwenty-four piglets were stratified and randomly assigned to treatments on postnatal day (PD) 2. Piglets were individually housed and received an iron-adequate milk (AI), a high-iron milk (HI), the HI milk supplemented with 5% inulin (HIP), or the HIP milk with an oral gavage of Ligilactobacillus agilis YZ050, an inulin-fermenting strain, every third day (HIS). Milk was provided in 14 meals daily, mimicking formula feeding in infants. Fecal consistency score and body weight were recorded daily or every other day. Blood and feces were sampled weekly, and tissues collected on PD 29. Data were analyzed using mixed model ANOVA with repeated measures whenever necessary.ResultsDiet did not affect growth. High-iron milk increased hemoglobin, hematocrit and serum iron compared to AI. Despite marginal adequacy, AI milk upregulated iron transporter genes and maintained satisfactory iron status in most pigs. High-iron milk upregulated hepcidin gene in liver, caused pronounced tissue iron deposition, and markedly increased colonic and fecal iron. Inulin supplementation, regardless of L. agilis YZ050, not only attenuated hepatic iron overload but also decreased colonic and fecal iron without altering pH or iron regulatory genes. The HI milk lowered zinc (Zn) and copper (Cu) in duodenum and liver compared to AI, while HIP and HIS further decreased Zn and Cu in liver and diminished the increase of colonic and fecal trace minerals caused by HI.ConclusionEarly-infancy excessive iron fortification causes iron overload and compromises Zn and Cu absorption. Inulin decreases trace mineral absorption likely through enhancing gut peristalsis and stool frequency.

Trace Minerals

TRACE (psycholinguistics)

Trace Minerals

Iron supplementation

10.1016/j.cdnut.2024.102147

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P079 Bien nourrir son probiotique: le probiotique Bifidobacterium infantis consommé avec des oligosaccharides de lait de vache mais pas de l’inuline restaure l’homéostasie intestinale de souris obèses

Cahiers de Nutrition et de Diététique (2013)

Gaëlle Boudry M. Kristina Hamilton K.M. Kalenetra Saumya Wickramasinghe A.R. Pacheco

10.1016/s0007-9960(13)70437-1

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Genetic Variants of β-casein Gene in Indigenous and Exotic Dairy Cattle Breeds in Sri Lanka

Asian Journal of Dairy and Food Research (2020)

Saumya Wickramasinghe Ruwini Rupasinghe N. Shanjayan L. G. S. Lokugalappatti

Background: Bovine milk contains two types of β-casein (CSN2); A1 and A2, in which A1 type has shown associations with certain health issues. This study was conducted to identify the abundance of CSN2 A1/A2 variants in European and indigenous dairy breeds in Sri Lanka. Methods: The study included 123 Ayrshire, 101 Holstein Friesian and 92 indigenous White cattle (Bos indicus) populations. Genotyping was performed by PCR-RFLP method using Dde1. Allele and genotype frequencies and population genetic indices were calculated. Result: Results showed A1A2 to be predominant in both Holstein Friesian (0.63) and Ayrshire (0.68) populations while A2A2 (0.82) was predominant in the White cattle population. A1 and A2 allele frequencies were 0.52 and 0.48 in Ayrshire; 0.39 and 0.61 in Holstein Friesian and 0.09 and 0.91 in White cattle populations. Ayrshire and Holstein Friesian populations showed significant deviation from the Hardy-Weinberg equilibrium (p£0.05). When compared to the imported breeds, the White cattle population showed inbreeding and less genetic diversity.

Genotype frequency

White (mutation)

10.18805/ajdfr.dr-180

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Bifidobacteria grown on human milk oligosaccharides downregulate the expression of inflammation-related genes in Caco-2 cells

BMC Microbiology (2015)

Saumya Wickramasinghe Alline R. Pacheco Danielle G. Lemay David A. Mills

Breastfed human infants are predominantly colonized by bifidobacteria that thrive on human milk oligosaccharides (HMO). Two predominant species of bifidobacteria in infant feces are Bifidobacterium breve (B. breve) and Bifidobacterium longum subsp. infantis (B. infantis), both of which include avid HMO-consumer strains. Our laboratory has previously shown that B. infantis, when grown on HMO, increases adhesion to intestinal cells and increases the expression of the anti-inflammatory cytokine interleukin-10. The purpose of the current study was to investigate the effects of carbon source—glucose, lactose, or HMO—on the ability of B. breve and B. infantis to adhere to and affect the transcription of intestinal epithelial cells on a genome-wide basis. HMO-grown B. infantis had higher percent binding to Caco-2 cell monolayers compared to B. infantis grown on glucose or lactose. B. breve had low adhesive ability regardless of carbon source. Despite differential binding ability, both HMO-grown strains significantly differentially affected the Caco-2 transcriptome compared to their glucose or lactose grown controls. HMO-grown B. breve and B. infantis both downregulated genes in Caco-2 cells associated with chemokine activity. The choice of carbon source affects the interaction of bifidobacteria with intestinal epithelial cells. HMO-grown bifidobacteria reduce markers of inflammation, compared to glucose or lactose-grown bifidobacteria. In the future, the design of preventative or therapeutic probiotic supplements may need to include appropriately chosen prebiotics.

Bifidobacterium breve

Bifidobacterium longum

Caco-2

10.1186/s12866-015-0508-3

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Synergy between the prebiotic bovine milk oligosaccharides and the probiotic B. infantis improves gut barrier function in vivo

HAL (Le Centre pour la Communication Scientifique Directe) (2013)

Mary Kristina Hamilton Gaëlle Boudry Maciej Chichlowski Saumya Wickramasinghe David A. Mills

Prebiotic

Bovine milk

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Transcriptome Profiling of Bovine Milk Oligosaccharide Metabolism Genes Using RNA-Sequencing

PLoS ONE (2011)

Saumya Wickramasinghe Serenus Hua Gonzalo Rincón Alma Islas‐Trejo J. Bruce German

This study examines the genes coding for enzymes involved in bovine milk oligosaccharide metabolism by comparing the oligosaccharide profiles with the expressions of glycosylation-related genes. Fresh milk samples (n = 32) were collected from four Holstein and Jersey cows at days 1, 15, 90 and 250 of lactation and free milk oligosaccharide profiles were analyzed. RNA was extracted from milk somatic cells at days 15 and 250 of lactation (n = 12) and gene expression analysis was conducted by RNA-Sequencing. A list was created of 121 glycosylation-related genes involved in oligosaccharide metabolism pathways in bovine by analyzing the oligosaccharide profiles and performing an extensive literature search. No significant differences were observed in either oligosaccharide profiles or expressions of glycosylation-related genes between Holstein and Jersey cows. The highest concentrations of free oligosaccharides were observed in the colostrum samples and a sharp decrease was observed in the concentration of free oligosaccharides on day 15, followed by progressive decrease on days 90 and 250. Ninety-two glycosylation-related genes were expressed in milk somatic cells. Most of these genes exhibited higher expression in day 250 samples indicating increases in net glycosylation-related metabolism in spite of decreases in free milk oligosaccharides in late lactation milk. Even though fucosylated free oligosaccharides were not identified, gene expression indicated the likely presence of fucosylated oligosaccharides in bovine milk. Fucosidase genes were expressed in milk and a possible explanation for not detecting fucosylated free oligosaccharides is the degradation of large fucosylated free oligosaccharides by the fucosidases. Detailed characterization of enzymes encoded by the 92 glycosylation-related genes identified in this study will provide the basic knowledge for metabolic network analysis of oligosaccharides in mammalian milk. These candidate genes will guide the design of a targeted breeding strategy to optimize the content of beneficial oligosaccharides in bovine milk.

Oligosaccharide

Fucosyltransferase

10.1371/journal.pone.0018895

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Citations (72)