1
|
Lim GS, Er JC, Bhaskaran K, Sin P, Shen P, Lee KM, Teo GS, Chua JMC, Chew PCF, Ang WM, Lee J, Wee S, Wu Y, Li A, Chan JSH, Aung KT. Singapore's Total Diet Study (2021-2023): Study Design, Methodology, and Relevance to Ensuring Food Safety. Foods 2024; 13:511. [PMID: 38397488 PMCID: PMC10887509 DOI: 10.3390/foods13040511] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2023] [Revised: 02/01/2024] [Accepted: 02/03/2024] [Indexed: 02/25/2024] Open
Abstract
A total diet study is often used to evaluate a population's baseline dietary exposure to chemical hazards from across the diet. In 2021-2023, Singapore carried out a TDS, and this article presents an overview of the study design and methodological selections in Singapore's TDS, as well as its relevance to ensuring food safety. A food consumption survey was conducted on Singapore citizens and permanent residents, where food consumption patterns of the Singapore population were identified. The selection of chemical hazards and foods for inclusion in Singapore's TDS, as well as principal considerations on sampling, food preparation, and analytical testing are discussed. Commonly consumed foods by the Singapore population in food categories such as grain and grain-based products, meat and meat products, fish and seafood, vegetables, fruits, milk and dairy products were included in this study, and mean concentrations of chemicals tested in each food category were reported, with food categories possessing higher levels identified. Future work will include dietary exposure assessments for the population and analysis of the contributions by food and cooking method.
Collapse
Affiliation(s)
- Geraldine Songlen Lim
- National Centre for Food Science, Singapore Food Agency, 7 International Business Park, Singapore 609919, Singapore (G.S.T.); (P.C.F.C.); (J.L.); (K.T.A.)
| | - Jun Cheng Er
- National Centre for Food Science, Singapore Food Agency, 7 International Business Park, Singapore 609919, Singapore (G.S.T.); (P.C.F.C.); (J.L.); (K.T.A.)
| | - Kalpana Bhaskaran
- School of Applied Science, Temasek Polytechnic, 21 Tampines Ave 1, Singapore 529757, Singapore (P.S.)
| | - Paul Sin
- School of Applied Science, Temasek Polytechnic, 21 Tampines Ave 1, Singapore 529757, Singapore (P.S.)
| | - Ping Shen
- National Centre for Food Science, Singapore Food Agency, 7 International Business Park, Singapore 609919, Singapore (G.S.T.); (P.C.F.C.); (J.L.); (K.T.A.)
| | - Kah Meng Lee
- National Centre for Food Science, Singapore Food Agency, 7 International Business Park, Singapore 609919, Singapore (G.S.T.); (P.C.F.C.); (J.L.); (K.T.A.)
| | - Guat Shing Teo
- National Centre for Food Science, Singapore Food Agency, 7 International Business Park, Singapore 609919, Singapore (G.S.T.); (P.C.F.C.); (J.L.); (K.T.A.)
| | - Joachim Mun Choy Chua
- National Centre for Food Science, Singapore Food Agency, 7 International Business Park, Singapore 609919, Singapore (G.S.T.); (P.C.F.C.); (J.L.); (K.T.A.)
| | - Peggy Chui Fong Chew
- National Centre for Food Science, Singapore Food Agency, 7 International Business Park, Singapore 609919, Singapore (G.S.T.); (P.C.F.C.); (J.L.); (K.T.A.)
| | - Wei Min Ang
- National Centre for Food Science, Singapore Food Agency, 7 International Business Park, Singapore 609919, Singapore (G.S.T.); (P.C.F.C.); (J.L.); (K.T.A.)
| | - Joanna Lee
- National Centre for Food Science, Singapore Food Agency, 7 International Business Park, Singapore 609919, Singapore (G.S.T.); (P.C.F.C.); (J.L.); (K.T.A.)
| | - Sheena Wee
- National Centre for Food Science, Singapore Food Agency, 7 International Business Park, Singapore 609919, Singapore (G.S.T.); (P.C.F.C.); (J.L.); (K.T.A.)
| | - Yuansheng Wu
- National Centre for Food Science, Singapore Food Agency, 7 International Business Park, Singapore 609919, Singapore (G.S.T.); (P.C.F.C.); (J.L.); (K.T.A.)
| | - Angela Li
- National Centre for Food Science, Singapore Food Agency, 7 International Business Park, Singapore 609919, Singapore (G.S.T.); (P.C.F.C.); (J.L.); (K.T.A.)
| | - Joanne Sheot Harn Chan
- National Centre for Food Science, Singapore Food Agency, 7 International Business Park, Singapore 609919, Singapore (G.S.T.); (P.C.F.C.); (J.L.); (K.T.A.)
- Department of Food Science & Technology, National University of Singapore, Science Drive 2, Singapore 117542, Singapore
| | - Kyaw Thu Aung
- National Centre for Food Science, Singapore Food Agency, 7 International Business Park, Singapore 609919, Singapore (G.S.T.); (P.C.F.C.); (J.L.); (K.T.A.)
- Department of Food Science & Technology, National University of Singapore, Science Drive 2, Singapore 117542, Singapore
- School of Biological Sciences, Nanyang Technological University, 60 Nanyang Dr, Singapore 637551, Singapore
| |
Collapse
|
2
|
Fua’di MT, Er B, Lee S, Chan PP, Khoo J, Tan D, Li H, Muhammad IR, Raj P, Kurupatham L, Lee V, Tan LK, Chan JSH, Li A, Aung KT. Characteristics of Gastroenteritis Outbreaks Investigated in Singapore: 2018-2021. Int J Environ Res Public Health 2024; 21:64. [PMID: 38248529 PMCID: PMC10815581 DOI: 10.3390/ijerph21010064] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/27/2023] [Revised: 12/30/2023] [Accepted: 01/04/2024] [Indexed: 01/23/2024]
Abstract
There is a need to study the characteristics of outbreaks via Singapore's outbreak surveillance system to understand and identify the gaps in food safety for targeted policy interventions due to the increasing trend in gastroenteritis outbreaks and consequential increase in foodborne-related deaths and economic burden on public health systems worldwide. A total of 171 gastroenteritis outbreaks were investigated in Singapore from January 2018 to December 2021. This study analyzed the annual trend of investigated gastroenteritis outbreaks, the proportion of outbreaks by implicated sources of food, and the proportion of the type of pathogens identified from human cases, food samples, and environmental swabs collected from outbreak investigations. Among the foodborne gastroenteritis outbreaks (n = 121) investigated in Singapore, approximately 42.1% of the outbreaks had food prepared by caterers, 14.9% by restaurants, and 12.4% had food prepared by in-house kitchens. Clostridium perfringens and Salmonella were the most common causative pathogens in foodborne outbreaks throughout the analysis period. The food samples and environmental swabs collected were mostly detected for Bacillus cereus. Norovirus was the most common causative pathogen in non-foodborne outbreaks and was mainly attributable to preschools. This highlights the importance of monitoring and educating the catering industry and preschools to prevent future outbreaks.
Collapse
Affiliation(s)
- Muhd Tarmidzi Fua’di
- National Centre for Food Science, Singapore Food Agency, 7 International Business Park, Techquest, Singapore 609919, Singapore; (M.T.F.); (B.E.); (J.K.); (D.T.); (H.L.); (L.K.T.); (J.S.H.C.); (A.L.)
| | - Benjamin Er
- National Centre for Food Science, Singapore Food Agency, 7 International Business Park, Techquest, Singapore 609919, Singapore; (M.T.F.); (B.E.); (J.K.); (D.T.); (H.L.); (L.K.T.); (J.S.H.C.); (A.L.)
| | - Sylvester Lee
- Communicable Disease Division, Ministry of Health, Singapore 169854, Singapore; (S.L.); (P.P.C.); (I.R.M.); (P.R.); (V.L.)
| | - Pei Pei Chan
- Communicable Disease Division, Ministry of Health, Singapore 169854, Singapore; (S.L.); (P.P.C.); (I.R.M.); (P.R.); (V.L.)
| | - Joanna Khoo
- National Centre for Food Science, Singapore Food Agency, 7 International Business Park, Techquest, Singapore 609919, Singapore; (M.T.F.); (B.E.); (J.K.); (D.T.); (H.L.); (L.K.T.); (J.S.H.C.); (A.L.)
| | - Desmond Tan
- National Centre for Food Science, Singapore Food Agency, 7 International Business Park, Techquest, Singapore 609919, Singapore; (M.T.F.); (B.E.); (J.K.); (D.T.); (H.L.); (L.K.T.); (J.S.H.C.); (A.L.)
| | - Huilin Li
- National Centre for Food Science, Singapore Food Agency, 7 International Business Park, Techquest, Singapore 609919, Singapore; (M.T.F.); (B.E.); (J.K.); (D.T.); (H.L.); (L.K.T.); (J.S.H.C.); (A.L.)
| | - Imran Roshan Muhammad
- Communicable Disease Division, Ministry of Health, Singapore 169854, Singapore; (S.L.); (P.P.C.); (I.R.M.); (P.R.); (V.L.)
| | - Pream Raj
- Communicable Disease Division, Ministry of Health, Singapore 169854, Singapore; (S.L.); (P.P.C.); (I.R.M.); (P.R.); (V.L.)
| | - Lalitha Kurupatham
- Communicable Disease Division, Ministry of Health, Singapore 169854, Singapore; (S.L.); (P.P.C.); (I.R.M.); (P.R.); (V.L.)
| | - Vernon Lee
- Communicable Disease Division, Ministry of Health, Singapore 169854, Singapore; (S.L.); (P.P.C.); (I.R.M.); (P.R.); (V.L.)
| | - Li Kiang Tan
- National Centre for Food Science, Singapore Food Agency, 7 International Business Park, Techquest, Singapore 609919, Singapore; (M.T.F.); (B.E.); (J.K.); (D.T.); (H.L.); (L.K.T.); (J.S.H.C.); (A.L.)
| | - Joanne Sheot Harn Chan
- National Centre for Food Science, Singapore Food Agency, 7 International Business Park, Techquest, Singapore 609919, Singapore; (M.T.F.); (B.E.); (J.K.); (D.T.); (H.L.); (L.K.T.); (J.S.H.C.); (A.L.)
- Department of Food Science and Technology, National University of Singapore, 2 Science Drive 2, Singapore 117543, Singapore
| | - Angela Li
- National Centre for Food Science, Singapore Food Agency, 7 International Business Park, Techquest, Singapore 609919, Singapore; (M.T.F.); (B.E.); (J.K.); (D.T.); (H.L.); (L.K.T.); (J.S.H.C.); (A.L.)
- Department of Food Science and Technology, National University of Singapore, 2 Science Drive 2, Singapore 117543, Singapore
| | - Kyaw Thu Aung
- National Centre for Food Science, Singapore Food Agency, 7 International Business Park, Techquest, Singapore 609919, Singapore; (M.T.F.); (B.E.); (J.K.); (D.T.); (H.L.); (L.K.T.); (J.S.H.C.); (A.L.)
- Department of Food Science and Technology, National University of Singapore, 2 Science Drive 2, Singapore 117543, Singapore
- School of Biological Sciences, Nanyang Technological University, 60 Nanyang Drive, Singapore 637551, Singapore
| |
Collapse
|
3
|
Shi RRS, Shen P, Yu WZ, Cai M, Tay AJ, Lim I, Chin YS, Ang WM, Er JC, Lim GS, Wu Y, Li A, Aung KT, Chan SH. Occurrence and Dietary Exposure of 3-MCPD Esters and Glycidyl Esters in Domestically and Commercially Prepared Food in Singapore. Foods 2023; 12:4331. [PMID: 38231853 DOI: 10.3390/foods12234331] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2023] [Revised: 11/28/2023] [Accepted: 11/29/2023] [Indexed: 01/19/2024] Open
Abstract
This study investigated the prevalence and occurrence of 3-monochloropropanediol esters (3-MCPDEs) and glycidyl esters (GEs) in domestically and commercially prepared food in Singapore and assessed the total dietary exposure for the Singaporean population. Minimal impact on the formation of 3-MCPDEs and GEs was observed from the domestic cooking methods commonly practiced in Singapore such as deep frying and stir frying. The estimated total dietary exposure to 3-MCPDEs for the Singaporean population (aged 15 to 92) was 0.982 µg/kg bw/day for general consumers and 2.212 µg/kg bw/day for high consumers (95th percentile), which accounted for 49.1% and 110.6% of the tolerable dietary intake (TDI) at 2 µg/kg bw/day by the European Food Safety Authority (EFSA). The calculated margins of exposure (MOE) for GEs based on the dietary exposure for general consumers at 0.882 µg/kg bw/day and 2.209 µg/kg bw/day for high consumers were below 10,000, indicating a potential health concern. Our study showed that the occurrence of 3-MCPDEs and GEs varied among vegetable oils, and domestic cooking methods did not significantly impact the levels of 3-MCPDEs and GEs in prepared food. The critical factor influencing the prevalence and occurrence of 3-MCPDEs and GEs was the choice of oil used for cooking, which absorbed into the cooked food. It is essential to encourage the food industry to continue its innovation on mitigation measures to control and reduce 3-MCPDEs and GEs in vegetable oil production. Consumers are advised to make informed choices on food consumption and cooking oil for food preparation to reduce their exposure to 3-MCPDEs and GEs.
Collapse
Affiliation(s)
- Raymond Rong Sheng Shi
- National Centre for Food Science, Singapore Food Agency, 7 International Business Park, Singapore 609919, Singapore
| | - Ping Shen
- National Centre for Food Science, Singapore Food Agency, 7 International Business Park, Singapore 609919, Singapore
| | - Wesley Zongrong Yu
- National Centre for Food Science, Singapore Food Agency, 7 International Business Park, Singapore 609919, Singapore
| | - Miaohua Cai
- National Centre for Food Science, Singapore Food Agency, 7 International Business Park, Singapore 609919, Singapore
| | - Ai Jin Tay
- National Centre for Food Science, Singapore Food Agency, 7 International Business Park, Singapore 609919, Singapore
| | - Ignatius Lim
- National Centre for Food Science, Singapore Food Agency, 7 International Business Park, Singapore 609919, Singapore
| | - Yee Soon Chin
- National Centre for Food Science, Singapore Food Agency, 7 International Business Park, Singapore 609919, Singapore
| | - Wei Min Ang
- National Centre for Food Science, Singapore Food Agency, 7 International Business Park, Singapore 609919, Singapore
| | - Jun Cheng Er
- National Centre for Food Science, Singapore Food Agency, 7 International Business Park, Singapore 609919, Singapore
| | - Geraldine Songlen Lim
- National Centre for Food Science, Singapore Food Agency, 7 International Business Park, Singapore 609919, Singapore
| | - Yuansheng Wu
- National Centre for Food Science, Singapore Food Agency, 7 International Business Park, Singapore 609919, Singapore
| | - Angela Li
- National Centre for Food Science, Singapore Food Agency, 7 International Business Park, Singapore 609919, Singapore
| | - Kyaw Thu Aung
- National Centre for Food Science, Singapore Food Agency, 7 International Business Park, Singapore 609919, Singapore
- School of Biological Sciences, Nanyang Technological University, 60 Nanyang Drive, Singapore 637551, Singapore
| | - Sheot Harn Chan
- National Centre for Food Science, Singapore Food Agency, 7 International Business Park, Singapore 609919, Singapore
- Department of Food Science and Technology, Faculty of Science, National University of Singapore, 2 Science Drive 2, Singapore 117543, Singapore
| |
Collapse
|
4
|
Selvaraj R, Cheng EJ, Gan P, Oh JQ, Aung KT. Microbiological Profiles of Disposable Gloves Used for Handling Ready-to-Eat Foods. J Food Prot 2023; 86:100146. [PMID: 37619692 DOI: 10.1016/j.jfp.2023.100146] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2023] [Revised: 08/15/2023] [Accepted: 08/17/2023] [Indexed: 08/26/2023]
Abstract
Hand hygiene is critical in the food service industry. Bacteria can easily be transferred between different surfaces to food during food preparation. Common hygiene practices include hand washing and usage of disposable gloves. Food handlers are often susceptible to transferring pathogenic bacteria to food, thus proper hand hygiene can limit such transmission. While gloves serve as a barrier between bare hands and food, their misuse, including reuse or lack of change, can potentially result in cross-contamination, compromising on food safety. In Singapore, strict regulations and consumer perceptions have encouraged the use of gloves in food handling. This study assessed the microbiological profile of gloves used by food handlers across fifty randomly chosen food establishments, by swabbing samples from the inner and outer surfaces of gloves. Glove samples were also subjected to a watertight test to detect significant physical damage. The results revealed that gloves with damage exhibited significantly higher mean Standard Plate Counts (SPCs), suggesting the likelihood that damaged gloves promoted the transfer of bacteria. Damaged gloves used to handle certain types of food, like noodles and rice dishes, also had significantly higher mean SPC than those used for beverages and snacks. However, gloves without visible damage showed no significant difference in mean SPC across different food types. The study highlighted that proper glove use can help in preventing bacterial transfer and consequently, maintaining food safety. Regular glove changes, particularly when damaged, are imperative. The findings underscore the importance of proper glove use in conjunction with other hand hygiene practices to uphold food hygiene and safety standards.
Collapse
Affiliation(s)
- Renuka Selvaraj
- National Centre for Food Science, Singapore Food Agency, 7 International Business Park, Singapore 609919, Singapore
| | - Er Jun Cheng
- National Centre for Food Science, Singapore Food Agency, 7 International Business Park, Singapore 609919, Singapore
| | - Patrick Gan
- National Centre for Food Science, Singapore Food Agency, 7 International Business Park, Singapore 609919, Singapore
| | - Jia Quan Oh
- National Centre for Food Science, Singapore Food Agency, 7 International Business Park, Singapore 609919, Singapore
| | - Kyaw Thu Aung
- National Centre for Food Science, Singapore Food Agency, 7 International Business Park, Singapore 609919, Singapore; School of Biological Sciences, Nanyang Technological University, 60 Nanyang Drive, Singapore 637551, Singapore.
| |
Collapse
|
5
|
Yu WZ, Shen P, Lim I, Shi RRS, Cai M, Chin YS, Tay AJ, Ang WM, Er JC, Lim GS, Wu Y, Li A, Aung KT, Chan SH. Occurrence and Dietary Exposure to Acrylamide from Foods Consumed within and outside Main Meals in Singapore. Foods 2023; 12:3022. [PMID: 37628020 PMCID: PMC10453405 DOI: 10.3390/foods12163022] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2023] [Revised: 08/03/2023] [Accepted: 08/08/2023] [Indexed: 08/27/2023] Open
Abstract
This study investigated the influence of 'snackification' in Singaporean diets, leading to increased dietary acrylamide exposure. Acrylamide concentrations in commonly consumed foods within and outside the main meals were measured using liquid chromatography with tandem mass spectrometry (LC-MS/MS). High acrylamide concentrations were detected in vegetables cooked at high temperatures (ranging from 0.5 to 478.4 µg/kg) and potato-based crackers and chips (ranging from 81.8 to 2095.8 µg/kg). The estimated total dietary exposure for the Singapore population was 0.165 µg/kg bw/day for general consumers and 0.392 µg/kg bw/day for high consumers (95th percentile). The acrylamide exposure from outside main meals was nearly equivalent to that from within the main meals. The calculated margins of exposure (MOE) were below 10,000, indicating potential human health concern. These findings highlight the need for industry practices and consumer advisories to reduce acrylamide exposure from foods consumed both within and outside main meals.
Collapse
Affiliation(s)
- Wesley Zongrong Yu
- National Centre for Food Science, Singapore Food Agency, 7 International Business Park, Singapore 609919, Singapore; (W.Z.Y.)
| | - Ping Shen
- National Centre for Food Science, Singapore Food Agency, 7 International Business Park, Singapore 609919, Singapore; (W.Z.Y.)
| | - Ignatius Lim
- National Centre for Food Science, Singapore Food Agency, 7 International Business Park, Singapore 609919, Singapore; (W.Z.Y.)
| | - Raymond Rong Sheng Shi
- National Centre for Food Science, Singapore Food Agency, 7 International Business Park, Singapore 609919, Singapore; (W.Z.Y.)
| | - Miaohua Cai
- National Centre for Food Science, Singapore Food Agency, 7 International Business Park, Singapore 609919, Singapore; (W.Z.Y.)
| | - Yee Soon Chin
- National Centre for Food Science, Singapore Food Agency, 7 International Business Park, Singapore 609919, Singapore; (W.Z.Y.)
| | - Ai Jin Tay
- National Centre for Food Science, Singapore Food Agency, 7 International Business Park, Singapore 609919, Singapore; (W.Z.Y.)
| | - Wei Min Ang
- National Centre for Food Science, Singapore Food Agency, 7 International Business Park, Singapore 609919, Singapore; (W.Z.Y.)
| | - Jun Cheng Er
- National Centre for Food Science, Singapore Food Agency, 7 International Business Park, Singapore 609919, Singapore; (W.Z.Y.)
| | - Geraldine Songlen Lim
- National Centre for Food Science, Singapore Food Agency, 7 International Business Park, Singapore 609919, Singapore; (W.Z.Y.)
| | - Yuansheng Wu
- National Centre for Food Science, Singapore Food Agency, 7 International Business Park, Singapore 609919, Singapore; (W.Z.Y.)
| | - Angela Li
- National Centre for Food Science, Singapore Food Agency, 7 International Business Park, Singapore 609919, Singapore; (W.Z.Y.)
| | - Kyaw Thu Aung
- National Centre for Food Science, Singapore Food Agency, 7 International Business Park, Singapore 609919, Singapore; (W.Z.Y.)
- School of Biological Sciences, Nanyang Technological University, 60 Nanyang Drive, Singapore 637551, Singapore
| | - Sheot Harn Chan
- National Centre for Food Science, Singapore Food Agency, 7 International Business Park, Singapore 609919, Singapore; (W.Z.Y.)
- Department of Food Science and Technology, 2 Science Drive 2, Faculty of Science, National University of Singapore, Singapore 117543, Singapore
| |
Collapse
|
6
|
Lim KL, Khor WC, Ong KH, Timothy L, Aung KT. Occurrence and Patterns of Enterotoxin Genes, spa Types and Antimicrobial Resistance Patterns in Staphylococcus aureus in Food and Food Contact Surfaces in Singapore. Microorganisms 2023; 11:1785. [PMID: 37512957 PMCID: PMC10386305 DOI: 10.3390/microorganisms11071785] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2023] [Revised: 06/12/2023] [Accepted: 07/08/2023] [Indexed: 07/30/2023] Open
Abstract
Staphylococcus aureus contamination of food and food contact surfaces is a public health concern given its virulent and antimicrobial-resistant properties worldwide. In this study, a total of 181 MSSA isolates were analyzed for SE genes, antimicrobial resistance patterns, and spa types. Overall, 24.9% of isolates were positive for SE gene detection, with sea being the most prevalent classical SE (18.8%). The most predominant sample sources for SE gene contamination were hand swabs for sea (6/48), meat dishes for seb (3/14) and seafood dishes for sec (2/24). Antimicrobial resistance was also observed at relatively high frequencies for the clinically important antibiotics penicillin G and ampicillin (both 54.7%), followed by tetracycline (14.9%) and azithromycin (8.8%). In addition, characterization of spa types revealed spa type t5078 to be the most predominant (40.3%), with significant associations between spa types t127 and t5521 and the sea gene. This study offers insights into the enterotoxin gene and antimicrobial resistance profiles of S. aureus in cooked or ready-to-eat food to inform future surveillance and epidemiological studies.
Collapse
Affiliation(s)
- Ker Li Lim
- National Centre for Food Science, Singapore Food Agency, 7 International Business Park, Techquest, Singapore 609919, Singapore
| | - Wei Ching Khor
- National Centre for Food Science, Singapore Food Agency, 7 International Business Park, Techquest, Singapore 609919, Singapore
| | - Kar Hui Ong
- National Centre for Food Science, Singapore Food Agency, 7 International Business Park, Techquest, Singapore 609919, Singapore
| | - Lois Timothy
- School of Biological Sciences, Nanyang Technological University, 60 Nanyang Dr, Singapore 637551, Singapore
| | - Kyaw Thu Aung
- National Centre for Food Science, Singapore Food Agency, 7 International Business Park, Techquest, Singapore 609919, Singapore
- School of Biological Sciences, Nanyang Technological University, 60 Nanyang Dr, Singapore 637551, Singapore
| |
Collapse
|
7
|
Hartantyo SHP, Selvaraj R, Ho J, Oh JQ, Er JC, Li A, Aung KT. Food Safety Controls during Bulk Food Preparation-An Observational Analysis. Foods 2023; 12:2376. [PMID: 37372586 DOI: 10.3390/foods12122376] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2023] [Revised: 06/08/2023] [Accepted: 06/13/2023] [Indexed: 06/29/2023] Open
Abstract
Seeing the palpable impact of food poisoning associated with catering operations, we surveyed caterers with and without past hygiene violations to examine staffing, food safety practices and correlations with microbial counts in food and the processing environment. Past infringements did not negatively impact the current execution of food safety measures nor the microbial quality of food. In preference to added stringencies for errant operators, we discuss alternative efforts to augment food safety, as well as the policy implications thereof.
Collapse
Affiliation(s)
- Sri Harminda Pahm Hartantyo
- National Centre for Food Science, Singapore Food Agency, 7 International Business Park, Singapore 609919, Singapore
| | - Renuka Selvaraj
- National Centre for Food Science, Singapore Food Agency, 7 International Business Park, Singapore 609919, Singapore
| | - Jiaying Ho
- National Centre for Food Science, Singapore Food Agency, 7 International Business Park, Singapore 609919, Singapore
| | - Jia Quan Oh
- National Centre for Food Science, Singapore Food Agency, 7 International Business Park, Singapore 609919, Singapore
| | - Jun Cheng Er
- National Centre for Food Science, Singapore Food Agency, 7 International Business Park, Singapore 609919, Singapore
| | - Angela Li
- National Centre for Food Science, Singapore Food Agency, 7 International Business Park, Singapore 609919, Singapore
| | - Kyaw Thu Aung
- National Centre for Food Science, Singapore Food Agency, 7 International Business Park, Singapore 609919, Singapore
- School of Biological Sciences, Nanyang Technological University, 60 Nanyang Drive, Singapore 637551, Singapore
| |
Collapse
|
8
|
Ong HMG, Zhong Y, Hu C, Ong KH, Khor WC, Schlundt J, Aung KT. Antimicrobial Resistance Risk Assessment of Vibrio parahaemolyticus Isolated from Farmed Green Mussels in Singapore. Microorganisms 2023; 11:1498. [PMID: 37375000 DOI: 10.3390/microorganisms11061498] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2023] [Revised: 05/23/2023] [Accepted: 05/31/2023] [Indexed: 06/29/2023] Open
Abstract
Vibrio parahaemolyticus, commonly found in seafood products, is responsible for gastroenteritis resulting from the consumption of undercooked seafood. Hence, there is a need to characterize and quantify the risk involved from this pathogen. However, there has been no study reporting the quantification of hemolytic antimicrobial-resistant (AMR) Vibrio parahaemolyticus in locally farmed shellfish in Singapore. In this study, ampicillin, penicillin G, tetracycline resistant, and non-AMR hemolytic V. parahaemolyticus were surveyed and quantified in green mussel samples from different premises in the food chain (farm and retail). The occurrence data showed that 31/45 (68.9%) of farmed green mussel samples, 6/6 (100%) farm water samples, and 41/45 (91.1%) retail shellfish samples detected the presence of hemolytic V. parahaemolyticus. V. parahaemolyticus counts ranged from 1.6-5.9 Log CFU/g in the retail shellfish samples and 1.0-2.9 Log CFU/g in the farm water samples. AMR risk assessments (ARRA), specifically for ampicillin, penicillin G, tetracycline, and hemolytic (non-AMR) scenarios were conducted for the full farm-to-home and partial retail-to-home chains. The hemolytic ARRA scenario estimated an average probability of illness of 5.7 × 10-3 and 1.2 × 10-2 per serving for the full and partial chains, respectively, translating to 165 and 355 annual cases per total population or 2.9 and 6.2 cases per 100,000 population, respectively. The average probability of illness per year ratios for the three ARRAs to the hemolytic ARRA were 0.82, 0.81, and 0.47 (ampicillin, penicillin G, and tetracycline, respectively) for the full chain and 0.54, 0.39, and 0.09 (ampicillin, penicillin G, and tetracycline, respectively) for the partial chain. The sensitivity analysis showed that the overall cooking effect, initial concentrations of pathogenic V. parahaemolyticus, and harvest duration and harvest temperature were key variables influencing the risk estimates in all of the modelled ARRAs. The study findings can be used by relevant stakeholders to make informed decisions for risk management that improve food safety.
Collapse
Affiliation(s)
- Hong Ming Glendon Ong
- School of Chemistry, Chemical Engineering and Biotechnology, Nanyang Technological University, Block N1.2, B3-15, 62 Nanyang Drive, Singapore 637459, Singapore
- National Centre for Food Science, Singapore Food Agency, 7 International Business Park, Techquest, Singapore 609919, Singapore
| | - Yang Zhong
- Department of Clinical Translational Research, Singapore General Hospital, Academia, 20 College Road, Singapore 169856, Singapore
| | - Chengcheng Hu
- Singapore Institute of Manufacturing Technology, 08-04, Innovis, 2 Fusionopolis Way, Singapore 138634, Singapore
| | - Kar Hui Ong
- National Centre for Food Science, Singapore Food Agency, 7 International Business Park, Techquest, Singapore 609919, Singapore
| | - Wei Ching Khor
- National Centre for Food Science, Singapore Food Agency, 7 International Business Park, Techquest, Singapore 609919, Singapore
| | | | - Kyaw Thu Aung
- National Centre for Food Science, Singapore Food Agency, 7 International Business Park, Techquest, Singapore 609919, Singapore
- School of Biological Sciences, Nanyang Technological University, Singapore 637551, Singapore
| |
Collapse
|
9
|
Akiyama K, Aung KT, Talamini L, Huck O, Kuboki T, Muller S. Therapeutic effects of peptide P140 in a mouse periodontitis model. Cell Mol Life Sci 2022; 79:518. [DOI: 10.1007/s00018-022-04537-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2022] [Revised: 08/26/2022] [Accepted: 08/27/2022] [Indexed: 11/25/2022]
|
10
|
Aung PL, Soe MT, Oo TL, Aung KT, Lin KK, Thi A, Menezes L, Parker DM, Cui L, Kyaw MP. Correction: Spatiotemporal dynamics of malaria in Banmauk Township, Sagaing region of Northern Myanmar: characteristics, trends, and risk factors. BMC Infect Dis 2022; 22:708. [PMID: 36008751 PMCID: PMC9414162 DOI: 10.1186/s12879-022-07676-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Affiliation(s)
| | - Myat Thu Soe
- Myanmar Health Network Organization, Yangon, Myanmar
| | - Thit Lwin Oo
- Myanmar Health Network Organization, Yangon, Myanmar
| | - Kyaw Thu Aung
- Township Health Department, Banmauk Township, Sagaing, Myanmar
| | - Kyaw Kyaw Lin
- Township Health Department, Banmauk Township, Sagaing, Myanmar
| | - Aung Thi
- Department of Public Health, Ministry of Health, NayPyiTaw, Myanmar
| | - Lynette Menezes
- Division of Infectious Diseases and International Medicine, Department of Internal Medicine, Morsani College of Medicine, University of South Florida, 3720 Spectrum Boulevard, Suite 304, Tampa, FL, 33612, USA
| | - Daniel M Parker
- Department of Population Health and Disease Prevention, University of California, Irvine, CA, USA.
| | - Liwang Cui
- Division of Infectious Diseases and International Medicine, Department of Internal Medicine, Morsani College of Medicine, University of South Florida, 3720 Spectrum Boulevard, Suite 304, Tampa, FL, 33612, USA.
| | | |
Collapse
|
11
|
Aung PL, Soe MT, Oo TL, Aung KT, Lin KK, Thi A, Menezes L, Parker DM, Cui L, Kyaw MP. Spatiotemporal dynamics of malaria in Banmauk Township, Sagaing region of Northern Myanmar: characteristics, trends, and risk factors. BMC Infect Dis 2022; 22:653. [PMID: 35902825 PMCID: PMC9331130 DOI: 10.1186/s12879-022-07634-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2021] [Accepted: 07/19/2022] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND While national malaria incidence has been declining in Myanmar, some subregions within the nation continue to have high burdens of malaria morbidity and mortality. This study assessed the malaria situation in one of these regions, Banmauk Township, located near the Myanmar-India border. Our goal was to provide a detailed description of the malaria epidemiology in this township and to provide some evidence-based recommendations to formulate a strategy for reaching the national malaria elimination plan. Banmauk consistently has one of the highest malaria burdens in Myanmar. METHODS With the implementation of strengthened malaria control and surveillance activities after the endorsement of a national malaria elimination plan in 2015, detailed incidence data were obtained for 2016-2018 for Banmauk Township. The data include patient demographics, parasite species, disease severity, and disease outcome. Data were analyzed to identify characteristics, trends, distribution, and risk factors. RESULTS During 2016-2018, 2,402 malaria cases were reported, with Plasmodium falciparum accounting for 83.4% of infections. Both P. falciparum and P. vivax were transmitted more frequently during the rainy season (May-October). Despite intensified control, the annual parasite incidence rate (API) in 2017 (11.0) almost doubled that in 2016 (6.5). In total, 2.5% (59/2042) of the cases, of which 54 P. falciparum and 5 P. vivax, were complicated cases, resulting in 5 deaths. Malaria morbidity was high in children < 15 years and accounted for 33.4% of all cases and about 47% of the complicated cases. Older age groups and males living with poor transportation conditions were more likely to test positive especially in rainy and cold seasons. Despite the clear seasonality of malaria, severe cases were found among young children even more common in the dry season, when malaria incidence was low. CONCLUSIONS Despite the declining trend, the malaria burden remained high in Banmauk Township. Our study also documented severe cases and deaths from both falciparum and vivax malaria. P. falciparum remained the predominant parasite species, demanding increased efforts to achieve the goal of elimination of P. falciparum by 2025. As P. falciparum cases decreased, the proportion of cases attributable to P. vivax increased. In order to eliminate malaria, it will likely be important to increasingly target this species as well.
Collapse
Affiliation(s)
| | - Myat Thu Soe
- Myanmar Health Network Organization, Yangon, Myanmar
| | - Thit Lwin Oo
- Myanmar Health Network Organization, Yangon, Myanmar
| | - Kyaw Thu Aung
- Township Health Department, Banmauk Township, Sagaing, Myanmar
| | - Kyaw Kyaw Lin
- Township Health Department, Banmauk Township, Sagaing, Myanmar
| | - Aung Thi
- Department of Public Health, Ministry of Health, NayPyiTaw, Myanmar
| | - Lynette Menezes
- Division of Infectious Diseases and International Medicine, Department of Internal Medicine, Morsani College of Medicine, University of South Florida, 3720 Spectrum Boulevard, Suite 304, Tampa, FL, 33612, USA
| | - Daniel M Parker
- Department of Population Health and Disease Prevention, University of California, Irvine, CA, USA.
| | - Liwang Cui
- Division of Infectious Diseases and International Medicine, Department of Internal Medicine, Morsani College of Medicine, University of South Florida, 3720 Spectrum Boulevard, Suite 304, Tampa, FL, 33612, USA.
| | | |
Collapse
|
12
|
Tanaka Y, Aung KT, Ono M, Mikai A, Dang AT, Hara ES, Tosa I, Ishibashi K, Ono-Kimura A, Nawachi K, Kuboki T, Oohashi T. Suppression of Bone Necrosis around Tooth Extraction Socket in a MRONJ-like Mouse Model by E-rhBMP-2 Containing Artificial Bone Graft Administration. Int J Mol Sci 2021; 22:ijms222312823. [PMID: 34884630 PMCID: PMC8657653 DOI: 10.3390/ijms222312823] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2021] [Revised: 11/23/2021] [Accepted: 11/23/2021] [Indexed: 11/30/2022] Open
Abstract
Medication-related osteonecrosis of the jaw (MRONJ) is related to impaired bone healing conditions in the maxillomandibular bone region as a complication of bisphosphonate intake. Although there are several hypotheses for the onset of MRONJ symptoms, one of the possible causes is the inhibition of bone turnover and blood supply leading to bone necrosis. The optimal treatment strategy for MRONJ has not been established either. BMP-2, a member of the TGF-β superfamily, is well known for regulating bone remodeling and homeostasis prenatally and postnatally. Therefore, the objectives of this study were to evaluate whether cyclophosphamide/zoledronate (CY/ZA) induces necrosis of the bone surrounding the tooth extraction socket, and to examine the therapeutic potential of BMP-2 in combination with the hard osteoinductive biomaterial, β-tricalcium phosphate (β-TCP), in the prevention and treatment of alveolar bone loss around the tooth extraction socket in MRONJ-like mice models. First, CY/ZA was intraperitoneally administered for three weeks, and alveolar bone necrosis was evaluated before and after tooth extraction. Next, the effect of BMP-2/β-TCP was investigated in both MRONJ-like prevention and treatment models. In the prevention model, CY/ZA was continuously administered for four weeks after BMP-2/β-TCP transplantation. In the treatment model, CY/ZA administration was suspended after transplantation of BMP-2/β-TCP. The results showed that CY/ZA induced a significant decrease in the number of empty lacunae, a sign of bone necrosis, in the alveolar bone around the tooth extraction socket after tooth extraction. Histological analysis showed a significant decrease in the necrotic alveolar bone around tooth extraction sockets in the BMP-2/β-TCP transplantation group compared to the non-transplanted control group in both MRONJ-like prevention and treatment models. However, bone mineral density, determined by micro-CT analysis, was significantly higher in the BMP-2/β-TCP transplanted group than in the control group in the prevention model only. These results clarified that alveolar bone necrosis around tooth extraction sockets can be induced after surgical intervention under CY/ZA administration. In addition, transplantation of BMP-2/β-TCP reduced the necrotic alveolar bone around the tooth extraction socket. Therefore, a combination of BMP-2/β-TCP could be an alternative approach for both prevention and treatment of MRONJ-like symptoms.
Collapse
Affiliation(s)
- Yukie Tanaka
- Department of Molecular Biology and Biochemistry, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama 700-8558, Japan; (Y.T.); (A.T.D.); (K.I.); (T.O.)
- Department of Oral Rehabilitation and Regenerative Medicine, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama 700-8558, Japan; (K.T.A.); (I.T.); (T.K.)
| | - Kyaw Thu Aung
- Department of Oral Rehabilitation and Regenerative Medicine, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama 700-8558, Japan; (K.T.A.); (I.T.); (T.K.)
| | - Mitsuaki Ono
- Department of Molecular Biology and Biochemistry, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama 700-8558, Japan; (Y.T.); (A.T.D.); (K.I.); (T.O.)
- Department of Oral Rehabilitation and Implantology, Okayama University Hospital, Okayama 700-8558, Japan; (A.M.); (A.O.-K.); (K.N.)
- Correspondence: ; Tel.: +81-86-235-7129; Fax: +81-86-222-7768
| | - Akihiro Mikai
- Department of Oral Rehabilitation and Implantology, Okayama University Hospital, Okayama 700-8558, Japan; (A.M.); (A.O.-K.); (K.N.)
| | - Anh Tuan Dang
- Department of Molecular Biology and Biochemistry, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama 700-8558, Japan; (Y.T.); (A.T.D.); (K.I.); (T.O.)
- Department of Oral Rehabilitation and Regenerative Medicine, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama 700-8558, Japan; (K.T.A.); (I.T.); (T.K.)
| | - Emilio Satoshi Hara
- Department of Biomaterials, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama 700-8558, Japan;
| | - Ikue Tosa
- Department of Oral Rehabilitation and Regenerative Medicine, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama 700-8558, Japan; (K.T.A.); (I.T.); (T.K.)
| | - Kei Ishibashi
- Department of Molecular Biology and Biochemistry, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama 700-8558, Japan; (Y.T.); (A.T.D.); (K.I.); (T.O.)
- Department of Oral Rehabilitation and Regenerative Medicine, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama 700-8558, Japan; (K.T.A.); (I.T.); (T.K.)
| | - Aya Ono-Kimura
- Department of Oral Rehabilitation and Implantology, Okayama University Hospital, Okayama 700-8558, Japan; (A.M.); (A.O.-K.); (K.N.)
- Center for Innovative Clinical Medicine, Okayama University Hospital, Okayama 700-8558, Japan
| | - Kumiko Nawachi
- Department of Oral Rehabilitation and Implantology, Okayama University Hospital, Okayama 700-8558, Japan; (A.M.); (A.O.-K.); (K.N.)
| | - Takuo Kuboki
- Department of Oral Rehabilitation and Regenerative Medicine, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama 700-8558, Japan; (K.T.A.); (I.T.); (T.K.)
- Department of Oral Rehabilitation and Implantology, Okayama University Hospital, Okayama 700-8558, Japan; (A.M.); (A.O.-K.); (K.N.)
| | - Toshitaka Oohashi
- Department of Molecular Biology and Biochemistry, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama 700-8558, Japan; (Y.T.); (A.T.D.); (K.I.); (T.O.)
| |
Collapse
|
13
|
Guo S, Aung KT, Leekitcharoenphon P, Tay MYF, Seow KLG, Zhong Y, Ng LC, Aarestrup FM, Schlundt J. Prevalence and genomic analysis of ESBL-producing Escherichia coli in retail raw meats in Singapore. J Antimicrob Chemother 2021; 76:601-605. [PMID: 33331642 DOI: 10.1093/jac/dkaa461] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2020] [Accepted: 10/05/2020] [Indexed: 01/19/2023] Open
Abstract
OBJECTIVES To determine the prevalence and genetic characteristics of ESBL-producing Escherichia coli in retail raw meats from Singapore markets. METHODS A total of 634 raw meat (chicken, pork and beef) samples were collected from markets in Singapore during June 2017-October 2018. The samples were enriched overnight and then incubated on Brilliance™ ESBL Agar. Presumptive ESBL isolates were confirmed using the double-disc synergy test. Confirmed ESBL-producing E. coli were sent for WGS and bioinformatic analysis was performed. RESULTS The prevalence of ESBL-producing E. coli in chicken, pork and beef meats was 51.2% (109/213), 26.9% (58/216) and 7.3% (15/205), respectively. A total of 225 ESBL-producing E. coli were isolated from 184 samples. β-Lactam resistance genes were detected in all isolates. After β-lactam resistance genes, the most common antimicrobial resistance genes detected were aminoglycoside resistance genes (92.4%). One hundred and seventy-two (76.4%), 102 (45.3%) and 52 (23.1%) isolates carried blaCTX-M genes, blaTEM genes and blaSHV genes, respectively. blaCTX-M-55 (57/225, 25.3%) and blaCTX-M-65 (40/225, 17.8%) were the most frequent ESBL genes. Colistin resistance genes (including mcr-1, mcr-3 and mcr-5) were found in 15.6% of all isolates. CONCLUSIONS This study indicates that ESBL-producing E. coli are widely found in retail raw meats, especially chicken, in Singapore. Occurrence of MDR (resistance to at least three classes of antimicrobial) and colistin resistance genes in retail raw meat suggests potential food safety and public health risks.
Collapse
Affiliation(s)
- Siyao Guo
- Nanyang Technological University Food Technology Centre (NAFTEC), 62 Nanyang Drive, 637459, Singapore.,School of Chemical and Biomedical Engineering, Nanyang Technological University, 62 Nanyang Drive, 637459, Singapore
| | - Kyaw Thu Aung
- Nanyang Technological University Food Technology Centre (NAFTEC), 62 Nanyang Drive, 637459, Singapore.,School of Chemical and Biomedical Engineering, Nanyang Technological University, 62 Nanyang Drive, 637459, Singapore.,School of Biological Science, Nanyang Technological University, 60 Nanyang Drive, 637551, Singapore.,Environmental Health Institute, National Environment Agency, 11 Biopolis Way, Helios Block #06-05/08, 138667, Singapore.,National Centre for Food Science, Singapore Food Agency, 52 Jurong Gateway Road, JEM Office Tower, #14-01, 608550, Singapore
| | - Pimlapas Leekitcharoenphon
- Research Group for Genomic Epidemiology, National Food Institute, Technical University of Denmark, Lyngby, 2800, Denmark
| | - Moon Y F Tay
- Nanyang Technological University Food Technology Centre (NAFTEC), 62 Nanyang Drive, 637459, Singapore.,School of Chemical and Biomedical Engineering, Nanyang Technological University, 62 Nanyang Drive, 637459, Singapore
| | - Kelyn L G Seow
- Nanyang Technological University Food Technology Centre (NAFTEC), 62 Nanyang Drive, 637459, Singapore.,School of Chemical and Biomedical Engineering, Nanyang Technological University, 62 Nanyang Drive, 637459, Singapore
| | - Yang Zhong
- Nanyang Technological University Food Technology Centre (NAFTEC), 62 Nanyang Drive, 637459, Singapore.,School of Chemical and Biomedical Engineering, Nanyang Technological University, 62 Nanyang Drive, 637459, Singapore
| | - Lee Ching Ng
- School of Biological Science, Nanyang Technological University, 60 Nanyang Drive, 637551, Singapore.,Environmental Health Institute, National Environment Agency, 11 Biopolis Way, Helios Block #06-05/08, 138667, Singapore
| | - Frank Møller Aarestrup
- Research Group for Genomic Epidemiology, National Food Institute, Technical University of Denmark, Lyngby, 2800, Denmark
| | - Joergen Schlundt
- Nanyang Technological University Food Technology Centre (NAFTEC), 62 Nanyang Drive, 637459, Singapore.,School of Chemical and Biomedical Engineering, Nanyang Technological University, 62 Nanyang Drive, 637459, Singapore
| |
Collapse
|
14
|
Aung KT, Akiyama K, Kunitomo M, Mun AY, Tosa I, Nguyen HTT, Zhang J, Kohno T, Ono M, Hara ES, Kuboki T. Aging-Affected MSC Functions and Severity of Periodontal Tissue Destruction in a Ligature-Induced Mouse Periodontitis Model. Int J Mol Sci 2020; 21:ijms21218103. [PMID: 33143068 PMCID: PMC7663404 DOI: 10.3390/ijms21218103] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2020] [Revised: 10/23/2020] [Accepted: 10/28/2020] [Indexed: 12/15/2022] Open
Abstract
Mesenchymal stem cells (MSCs) are known to play important roles in the repair of lost or damaged tissues and immunotolerance. On the other hand, aging is known to impair MSC function. However, little is currently known about how aged MSCs affect the host response to the local inflammatory condition and tissue deterioration in periodontitis, which is a progressive destructive disease of the periodontal tissue potentially leading to multiple tooth loss. In this study, we examined the relationship between aging-induced impairment of MSC function and the severity of periodontal tissue destruction associated with the decrease in host immunomodulatory response using a ligature-induced periodontitis model in young and aged mice. The results of micro computerized tomography (micro-CT) and histological analysis revealed a more severe bone loss associated with increased osteoclast activity in aged (50-week-old) mice compared to young (5-week-old) mice. Immunostaining analysis revealed that, in aged mice, the accumulation of inflammatory T and B cells was higher, whereas the percentage of platelet-derived growth factor receptor α (PDGFRα)+ MSCs, which are known to modulate the apoptosis of T cells, was significantly lower than in young mice. In vitro analysis of MSC function showed that the expression of surface antigen markers for MSCs (Sca-1, CD90, CD146), colony formation, migration, and osteogenic differentiation of aged MSCs were significantly declined compared to those of young MSCs. Moreover, a significantly higher proportion of aged MSCs were positive for the senescence-associated β galactosidase activity. Importantly, aged MSCs presented a decreased expression of FAS-L, which was associated with a lower immunomodulatory property of aged MSCs to induce T cell apoptosis in co-cultures compared with young MSCs. In summary, this is the first study showing that aging-induced impairment of MSC function, including immunomodulatory response, is potentially correlated with progressive periodontal tissue deterioration.
Collapse
Affiliation(s)
- Kyaw Thu Aung
- Department of Oral Rehabilitation and Regenerative Medicine, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama 700-8558, Japan; (K.T.A.); (M.K.); (A.Y.M.); (I.T.); (H.T.T.N.); (J.Z.); (T.K.); (T.K.)
| | - Kentaro Akiyama
- Department of Oral Rehabilitation and Regenerative Medicine, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama 700-8558, Japan; (K.T.A.); (M.K.); (A.Y.M.); (I.T.); (H.T.T.N.); (J.Z.); (T.K.); (T.K.)
- Correspondence: ; Tel.: +81-86-235-6682; Fax: +81-86-235-6684
| | - Masayoshi Kunitomo
- Department of Oral Rehabilitation and Regenerative Medicine, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama 700-8558, Japan; (K.T.A.); (M.K.); (A.Y.M.); (I.T.); (H.T.T.N.); (J.Z.); (T.K.); (T.K.)
| | - Aung Ye Mun
- Department of Oral Rehabilitation and Regenerative Medicine, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama 700-8558, Japan; (K.T.A.); (M.K.); (A.Y.M.); (I.T.); (H.T.T.N.); (J.Z.); (T.K.); (T.K.)
| | - Ikue Tosa
- Department of Oral Rehabilitation and Regenerative Medicine, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama 700-8558, Japan; (K.T.A.); (M.K.); (A.Y.M.); (I.T.); (H.T.T.N.); (J.Z.); (T.K.); (T.K.)
| | - Ha Thi Thu Nguyen
- Department of Oral Rehabilitation and Regenerative Medicine, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama 700-8558, Japan; (K.T.A.); (M.K.); (A.Y.M.); (I.T.); (H.T.T.N.); (J.Z.); (T.K.); (T.K.)
- Department of Molecular Biology and Biochemistry, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama 700-8558, Japan;
| | - Jiewen Zhang
- Department of Oral Rehabilitation and Regenerative Medicine, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama 700-8558, Japan; (K.T.A.); (M.K.); (A.Y.M.); (I.T.); (H.T.T.N.); (J.Z.); (T.K.); (T.K.)
| | - Teisaku Kohno
- Department of Oral Rehabilitation and Regenerative Medicine, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama 700-8558, Japan; (K.T.A.); (M.K.); (A.Y.M.); (I.T.); (H.T.T.N.); (J.Z.); (T.K.); (T.K.)
| | - Mitsuaki Ono
- Department of Molecular Biology and Biochemistry, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama 700-8558, Japan;
| | - Emilio Satoshi Hara
- Department of Biomaterials, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama 700-8558, Japan;
| | - Takuo Kuboki
- Department of Oral Rehabilitation and Regenerative Medicine, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama 700-8558, Japan; (K.T.A.); (M.K.); (A.Y.M.); (I.T.); (H.T.T.N.); (J.Z.); (T.K.); (T.K.)
| |
Collapse
|
15
|
Ong KH, Khor WC, Quek JY, Low ZX, Arivalan S, Humaidi M, Chua C, Seow KLG, Guo S, Tay MYF, Schlundt J, Ng LC, Aung KT. Occurrence and Antimicrobial Resistance Traits of Escherichia coli from Wild Birds and Rodents in Singapore. Int J Environ Res Public Health 2020; 17:ijerph17155606. [PMID: 32756497 PMCID: PMC7432465 DOI: 10.3390/ijerph17155606] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/05/2020] [Revised: 07/26/2020] [Accepted: 07/28/2020] [Indexed: 12/03/2022]
Abstract
Antimicrobial resistance (AMR) in Escherichia coli (E. coli) poses a public health concern worldwide. Wild birds and rodents, due to their mobility, are potential vehicles for transmission of AMR bacteria to humans. Ninety-six wild birds’ faecal samples and 135 rodents’ droppings samples were collected and analysed in 2017. Forty-six E. coli isolates from wild birds and rodents were subjected to AMR phenotypic and genotypic characterisation. The proportion of E. coli isolates resistant to at least one of the antimicrobials tested from wild birds (80.8%) was significantly higher than that of isolates from rodents (40.0%). The proportion of E. coli isolates resistant to each antimicrobial class for wild birds was 3.8% to 73.1% and that for rodents was 5.0% to 35.0%. Six out of 26 E. coli isolates from wild birds (23.1%) and two out of 20 (10.0%) isolates from rodents were multi-drug resistant (MDR) strains. These MDR E. coli isolates were detected with various antimicrobial resistance genes such as blaTEM-1B and qnrS1 and could be considered as part of the environmental resistome. Findings in this study suggested that wild birds and rodents could play a role in disseminating antimicrobial resistant E. coli, and this underscores the necessity of environment management and close monitoring on AMR bacteria in wild birds and rodents to prevent spreading of resistant organisms to other wildlife animals and humans.
Collapse
Affiliation(s)
- Kar Hui Ong
- Environmental Health Institute, National Environment Agency, Singapore 138667, Singapore; (K.H.O.); (J.Y.Q.); (Z.X.L.); (S.A.); (M.H.); (C.C.); (K.T.A.)
- National Centre for Food Science, Singapore Food Agency, Singapore 608550, Singapore;
| | - Wei Ching Khor
- National Centre for Food Science, Singapore Food Agency, Singapore 608550, Singapore;
| | - Jing Yi Quek
- Environmental Health Institute, National Environment Agency, Singapore 138667, Singapore; (K.H.O.); (J.Y.Q.); (Z.X.L.); (S.A.); (M.H.); (C.C.); (K.T.A.)
| | - Zi Xi Low
- Environmental Health Institute, National Environment Agency, Singapore 138667, Singapore; (K.H.O.); (J.Y.Q.); (Z.X.L.); (S.A.); (M.H.); (C.C.); (K.T.A.)
| | - Sathish Arivalan
- Environmental Health Institute, National Environment Agency, Singapore 138667, Singapore; (K.H.O.); (J.Y.Q.); (Z.X.L.); (S.A.); (M.H.); (C.C.); (K.T.A.)
| | - Mahathir Humaidi
- Environmental Health Institute, National Environment Agency, Singapore 138667, Singapore; (K.H.O.); (J.Y.Q.); (Z.X.L.); (S.A.); (M.H.); (C.C.); (K.T.A.)
| | - Cliff Chua
- Environmental Health Institute, National Environment Agency, Singapore 138667, Singapore; (K.H.O.); (J.Y.Q.); (Z.X.L.); (S.A.); (M.H.); (C.C.); (K.T.A.)
| | - Kelyn L. G. Seow
- School of Chemical and Biomedical Engineering, Nanyang Technological University, Singapore 637459, Singapore; (K.L.G.S.); (S.G.); (M.Y.F.T.); (J.S.)
- Nanyang Technological University Food Technology Centre (NAFTEC), Singapore 637459, Singapore
| | - Siyao Guo
- School of Chemical and Biomedical Engineering, Nanyang Technological University, Singapore 637459, Singapore; (K.L.G.S.); (S.G.); (M.Y.F.T.); (J.S.)
- Nanyang Technological University Food Technology Centre (NAFTEC), Singapore 637459, Singapore
| | - Moon Y. F. Tay
- School of Chemical and Biomedical Engineering, Nanyang Technological University, Singapore 637459, Singapore; (K.L.G.S.); (S.G.); (M.Y.F.T.); (J.S.)
- Nanyang Technological University Food Technology Centre (NAFTEC), Singapore 637459, Singapore
| | - Joergen Schlundt
- School of Chemical and Biomedical Engineering, Nanyang Technological University, Singapore 637459, Singapore; (K.L.G.S.); (S.G.); (M.Y.F.T.); (J.S.)
- Nanyang Technological University Food Technology Centre (NAFTEC), Singapore 637459, Singapore
| | - Lee Ching Ng
- Environmental Health Institute, National Environment Agency, Singapore 138667, Singapore; (K.H.O.); (J.Y.Q.); (Z.X.L.); (S.A.); (M.H.); (C.C.); (K.T.A.)
- School of Biological Sciences, Nanyang Technological University, Singapore 637551, Singapore
- Correspondence:
| | - Kyaw Thu Aung
- Environmental Health Institute, National Environment Agency, Singapore 138667, Singapore; (K.H.O.); (J.Y.Q.); (Z.X.L.); (S.A.); (M.H.); (C.C.); (K.T.A.)
- National Centre for Food Science, Singapore Food Agency, Singapore 608550, Singapore;
- School of Chemical and Biomedical Engineering, Nanyang Technological University, Singapore 637459, Singapore; (K.L.G.S.); (S.G.); (M.Y.F.T.); (J.S.)
- Nanyang Technological University Food Technology Centre (NAFTEC), Singapore 637459, Singapore
- School of Biological Sciences, Nanyang Technological University, Singapore 637551, Singapore
| |
Collapse
|
16
|
Zwe YH, Chin SF, Kohli GS, Aung KT, Yang L, Yuk HG. Whole genome sequencing (WGS) fails to detect antimicrobial resistance (AMR) from heteroresistant subpopulation of Salmonella enterica. Food Microbiol 2020; 91:103530. [PMID: 32539974 DOI: 10.1016/j.fm.2020.103530] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2019] [Revised: 03/28/2020] [Accepted: 04/22/2020] [Indexed: 10/24/2022]
Abstract
Due to rapidly falling costs, whole genome sequencing (WGS) is becoming an essential tool in the surveillance of antimicrobial resistance (AMR) in Salmonella enterica. Although there have been many recent works evaluating the accuracy of WGS in predicting AMR from a large number of Salmonella isolates, little attention has been devoted to deciphering the underlying causes of disagreement between the WGS genotype and experimentally determined AMR phenotype. This study analyzed the genomes of six S. enterica isolates previously obtained from raw chicken which exhibited disagreements between WGS genotype and AMR phenotype. A total of five WGS false negative predictions toward ampicillin, amoxicillin/clavulanate, colistin, and fosfomycin resistance were presented in conjunction with their corresponding empirical phenotypic and/or genetic evidence of heteroresistance. A further case study highlighting the inherent limitations of WGS to detect the underlying genetic mechanisms of colistin heteroresistance was presented. These findings implicate heteroresistance as an underlying cause for false negative WGS-based AMR predictions in S. enterica and suggest that widespread use of WGS in the surveillance of AMR in food isolates might severely underestimate true resistance rates.
Collapse
Affiliation(s)
- Ye Htut Zwe
- Department of Food Science and Technology, National University of Singapore, Singapore
| | - Seow Fong Chin
- Singapore Centre for Environmental Life Sciences Engineering, Nanyang Technological University, Singapore
| | - Gurjeet Singh Kohli
- Singapore Centre for Environmental Life Sciences Engineering, Nanyang Technological University, Singapore; Alfred Wegener-Institut Helmholtz-Zentrum für Polarund Meeresforschung, Bremerhaven, Germany
| | - Kyaw Thu Aung
- National Centre for Food Science, Singapore Food Agency, Singapore; School of Chemical and Biomedical Engineering, Nanyang Technological University, Singapore; School of Biological Sciences, Nanyang Technological University, Singapore
| | - Liang Yang
- Singapore Centre for Environmental Life Sciences Engineering, Nanyang Technological University, Singapore; School of Biological Sciences, Nanyang Technological University, Singapore; School of Medicine, Southern University of Science and Technology, Shenzhen, China
| | - Hyun-Gyun Yuk
- Department of Food Science and Technology, Korea National University of Transportation, Jeungpyeong-gun, Chungbuk, Republic of Korea.
| |
Collapse
|
17
|
Guo S, Aung KT, Tay MYF, Seow KLG, Ng LC, Schlundt J. Extended-spectrum β-lactamase-producing Proteus mirabilis with multidrug resistance isolated from raw chicken in Singapore: Genotypic and phenotypic analysis. J Glob Antimicrob Resist 2019; 19:252-254. [PMID: 31639544 DOI: 10.1016/j.jgar.2019.10.013] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2019] [Accepted: 10/14/2019] [Indexed: 11/26/2022] Open
Abstract
OBJECTIVES Proteus mirabilis is ubiquitous in soil and water. It is an important catheter-associated urinary tract pathogen and has reportedly been associated with antimicrobial-resistant infections. This study reports the draft genome of a multidrug-resistant P. mirabilis isolated from raw retail chicken meat in Singapore. METHODS The P. mirabilis strain was isolated on BrillianceTM ESBL Agar and was screened for antimicrobial susceptibility against 29 antimicrobial agents using a MicroScan® Neg MIC Panel Type 44. The double-disk synergy test (DDST) was used for confirmation of extended-spectrum β-lactamase (ESBL) production. Genomic DNA from the pure culture isolate was extracted and was sent for sequencing based on Illumina HiSeq 2500 technology. Further bioinformatics analysis was performed using online tools available at the Center for Genomic Epidemiology. RESULTS Species identification of the isolate was performed by KmerFinder. Antimicrobial susceptibility testing of the isolate showed multidrug resistance to broad-spectrum β-lactams, fluoroquinolones and aminoglycosides, among others. ESBL production was confirmed by the DDST. A total of 29 antimicrobial resistance genes were detected by ResFinder. CONCLUSION To the best of our knowledge, this is the first report of the whole-genome sequence of a multidrug-resistant P. mirabilis producing an ESBL from raw chicken meat in Singapore. This indicates that raw meat in Singapore can be a reservoir for drug-resistant pathogens.
Collapse
Affiliation(s)
- Siyao Guo
- Nanyang Technological University Food Technology Centre (NAFTEC), 62 Nanyang Drive, Singapore 637459, Singapore; School of Chemical and Biomedical Engineering, Nanyang Technological University, 62 Nanyang Drive, Singapore 637459, Singapore
| | - Kyaw Thu Aung
- Nanyang Technological University Food Technology Centre (NAFTEC), 62 Nanyang Drive, Singapore 637459, Singapore; School of Chemical and Biomedical Engineering, Nanyang Technological University, 62 Nanyang Drive, Singapore 637459, Singapore; Environmental Health Institute, National Environment Agency, 11 Biopolis Way, Helios Block #06-05/08, Singapore 138667, Singapore; National Centre for Food Science, Singapore Food Agency, 52 Jurong Gateway Road, JEM Office Tower, #14-01, Singapore 608550, Singapore
| | - Moon Y F Tay
- Nanyang Technological University Food Technology Centre (NAFTEC), 62 Nanyang Drive, Singapore 637459, Singapore; School of Chemical and Biomedical Engineering, Nanyang Technological University, 62 Nanyang Drive, Singapore 637459, Singapore
| | - Kelyn Lee Ghee Seow
- Nanyang Technological University Food Technology Centre (NAFTEC), 62 Nanyang Drive, Singapore 637459, Singapore; School of Chemical and Biomedical Engineering, Nanyang Technological University, 62 Nanyang Drive, Singapore 637459, Singapore
| | - Lee Ching Ng
- School of Biological Science, Nanyang Technological University, 60 Nanyang Drive, Singapore 637551, Singapore; Environmental Health Institute, National Environment Agency, 11 Biopolis Way, Helios Block #06-05/08, Singapore 138667, Singapore
| | - Joergen Schlundt
- Nanyang Technological University Food Technology Centre (NAFTEC), 62 Nanyang Drive, Singapore 637459, Singapore; School of Chemical and Biomedical Engineering, Nanyang Technological University, 62 Nanyang Drive, Singapore 637459, Singapore.
| |
Collapse
|
18
|
Guo S, Tay MY, Aung KT, Seow KL, Ng LC, Purbojati RW, Drautz-Moses DI, Schuster SC, Schlundt J. Phenotypic and genotypic characterization of antimicrobial resistant Escherichia coli isolated from ready-to-eat food in Singapore using disk diffusion, broth microdilution and whole genome sequencing methods. Food Control 2019. [DOI: 10.1016/j.foodcont.2018.12.043] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
|
19
|
Yap M, Chau ML, Hartantyo SHP, Oh JQ, Aung KT, Gutiérrez RA, Ng LC. Microbial Quality and Safety of Sushi Prepared with Gloved or Bare Hands: Food Handlers' Impact on Retail Food Hygiene and Safety. J Food Prot 2019; 82:615-622. [PMID: 30907665 DOI: 10.4315/0362-028x.jfp-18-349] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Food handlers play an important role in retail food hygiene and safety. This study was conducted to better understand the impact of food handlers on the microbiological quality and safety of sushi and ingredients handled by gloved and bare hands. At retail premises, food handlers were asked to prepare a batch of sushi with raw fish followed by a batch of sushi with cooked ingredients. Food (sushi and ready-to-eat ingredients), hand, and glove samples were collected for analysis of overall microorganisms (standard plate counts) and targeted foodborne bacteria: Staphylococcus aureus, Bacillus cereus, Escherichia coli, Salmonella, and Listeria monocytogenes. Results suggested that cross-contamination was more prevalent at premises where bare hands were used to prepare sushi. When bare hands were used, significantly higher standard plate counts were obtained from samples of cooked rice (2.3 to 4.9 log CFU/g) and sushi (2.8 to 6.9 log CFU/g) and the prevalence of S. aureus in samples was higher on food (21.7%, 28 of 129 samples) and hands (30%, 18 of 60 samples) ( P < 0.05). Glove changing in combination with hand washing minimized cross-contamination during sushi preparation as indicated by the lower prevalence of S. aureus (0%, 0 of 28 samples) and total targeted foodborne bacteria (3.6%, 1 of 28 samples) on the gloves of food handlers who changed gloves and washed their hands compared with those handlers who did not don new gloves. Repeated use of dishcloths could be a cause of cross-contamination, and the prevalence of total targeted foodborne bacteria was significantly higher on hands dried with dishcloths (64.7%, 11 of 17 samples) than on hands dried with paper towels (12.5%, 1 of 8 samples) ( P < 0.05). The prevalences of B. cereus, L. monocytogenes, and Salmonella in the 356 food samples were 5.1% (18 samples), 0.8% (3 samples), and 0%, respectively. Improvements to hand washing, hand drying, and glove changing practices are needed to lower the occurrence of cross-contamination during sushi preparation.
Collapse
Affiliation(s)
- Min Yap
- 1 Environmental Health Institute, National Environment Agency, 11 Biopolis Way, 04-03/04 Helios Block, Singapore 138667, Singapore
| | - Man Ling Chau
- 1 Environmental Health Institute, National Environment Agency, 11 Biopolis Way, 04-03/04 Helios Block, Singapore 138667, Singapore
| | - Sri Harminda Pahm Hartantyo
- 1 Environmental Health Institute, National Environment Agency, 11 Biopolis Way, 04-03/04 Helios Block, Singapore 138667, Singapore
| | - Jia Quan Oh
- 1 Environmental Health Institute, National Environment Agency, 11 Biopolis Way, 04-03/04 Helios Block, Singapore 138667, Singapore
| | - Kyaw Thu Aung
- 1 Environmental Health Institute, National Environment Agency, 11 Biopolis Way, 04-03/04 Helios Block, Singapore 138667, Singapore
| | - Ramona Alikiiteaga Gutiérrez
- 1 Environmental Health Institute, National Environment Agency, 11 Biopolis Way, 04-03/04 Helios Block, Singapore 138667, Singapore
| | - Lee Ching Ng
- 1 Environmental Health Institute, National Environment Agency, 11 Biopolis Way, 04-03/04 Helios Block, Singapore 138667, Singapore.,2 School of Biological Sciences, Nanyang Technological University, 60 Nanyang Drive, Singapore 637551, Singapore
| |
Collapse
|
20
|
Hazehara-Kunitomo Y, Hara ES, Ono M, Aung KT, Komi K, Pham HT, Akiyama K, Okada M, Oohashi T, Matsumoto T, Kuboki T. Acidic Pre-Conditioning Enhances the Stem Cell Phenotype of Human Bone Marrow Stem/Progenitor Cells. Int J Mol Sci 2019; 20:ijms20051097. [PMID: 30836626 PMCID: PMC6429188 DOI: 10.3390/ijms20051097] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2019] [Revised: 02/18/2019] [Accepted: 02/27/2019] [Indexed: 12/13/2022] Open
Abstract
A deeper understanding of the detailed mechanism of in vivo tissue healing is necessary for the development of novel regenerative therapies. Among several external factors, environmental pH is one of the crucial parameters that greatly affects enzyme activity and cellular biochemical reactions involving tissue repair and homeostasis. In this study, in order to analyze the microenvironmental conditions during bone healing, we first measured the pH in vivo at the bone healing site using a high-resolution fiber optic pH microsensor directly in femur defects and tooth extraction sockets. The pH was shown to decrease from physiological 7.4 to 6.8 during the initial two days of healing (inflammatory phase). In the same initial stages of the inflammatory phase of the bone healing process, mesenchymal stem cells (MSCs) are known to migrate to the healing site to contribute to tissue repair. Therefore, we investigated the effect of a short-term acidic (pH 6.8) pre-treatment on the stemness of bone marrow-derived MSCs (BMSCs). Interestingly, the results showed that pre-treatment of BMSCs with acidic pH enhances the expression of stem cell markers (OCT-4, NANOG, SSEA-4), as well as cell viability and proliferation. On the other hand, acidic pH decreased BMSC migration ability. These results indicate that acidic pH during the initial stages of bone healing is important to enhance the stem cell properties of BMSCs. These findings may enable the development of novel methods for optimization of stem cell function towards tissue engineering or regenerative medicine.
Collapse
Affiliation(s)
- Yuri Hazehara-Kunitomo
- Department of Oral Rehabilitation and Regenerative Medicine, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama 700-8525, Japan.
| | - Emilio Satoshi Hara
- Department of Biomaterials, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama 700-8525, Japan.
| | - Mitsuaki Ono
- Department of Molecular Biology and Biochemistry, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama 700-8558, Japan.
| | - Kyaw Thu Aung
- Department of Oral Rehabilitation and Regenerative Medicine, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama 700-8525, Japan.
| | - Keiko Komi
- Department of Oral Rehabilitation and Regenerative Medicine, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama 700-8525, Japan.
| | - Hai Thanh Pham
- Department of Oral Rehabilitation and Regenerative Medicine, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama 700-8525, Japan.
- Craniofacial and Skeletal Diseases Branch, NIDCR, NIH, Bethesda, MD 20892, USA.
- Department of Oral Surgery, Faculty of Dentistry, Haiphong University of Medicine and Pharmacy, Haiphong 04212, Vietnam.
| | - Kentaro Akiyama
- Department of Oral Rehabilitation and Regenerative Medicine, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama 700-8525, Japan.
| | - Masahiro Okada
- Department of Biomaterials, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama 700-8525, Japan.
| | - Toshitaka Oohashi
- Department of Molecular Biology and Biochemistry, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama 700-8558, Japan.
| | - Takuya Matsumoto
- Department of Biomaterials, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama 700-8525, Japan.
| | - Takuo Kuboki
- Department of Oral Rehabilitation and Regenerative Medicine, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama 700-8525, Japan.
| |
Collapse
|
21
|
Nguyen HT, Ono M, Oida Y, Hara ES, Komori T, Akiyama K, Nguyen HTT, Aung KT, Pham HT, Tosa I, Takarada T, Matsuo K, Mizoguchi T, Oohashi T, Kuboki T. Bone Marrow Cells Inhibit BMP-2-Induced Osteoblast Activity in the Marrow Environment. J Bone Miner Res 2019; 34:327-332. [PMID: 30352125 DOI: 10.1002/jbmr.3598] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/16/2018] [Revised: 08/24/2018] [Accepted: 09/10/2018] [Indexed: 01/04/2023]
Abstract
Bone morphogenetic protein 2 (BMP-2) is widely known as a potent growth factor that promotes bone formation. However, an increasing number of studies have demonstrated side effects of BMP-2 therapy. A deeper understanding of the effect of BMP-2 on cells other than those involved directly in bone remodeling is of fundamental importance to promote a more effective delivery of BMP-2 to patients. In this study, we aimed to investigate the effect of BMP-2 in the marrow environment. First, BMP-2 adsorbed onto titanium implants was delivered at the tooth extraction socket (marrow-absent site) or in the mandible marrow of beagle dogs. BMP-2 could induce marked bone formation around the implant at the tooth extraction socket. Surprisingly, however, no bone formation was observed in the BMP-2-coated titanium implants inserted in the mandible marrow. In C57BL/6 mice, BMP-2 adsorbed in freeze-dried collagen pellets could induce bone formation in marrow-absent calvarial bone. However, similar to the canine model, BMP-2 could not induce bone formation in the femur marrow. Analysis of osteoblast differentiation using Col1a1(2.3)-GFP transgenic mice revealed a scarce number of osteoblasts in BMP-2-treated femurs, whereas in the control group, osteoblasts were abundant. Ablation of femur marrow recovered the BMP-2 ability to induce bone formation. In vitro experiments analyzing luciferase activity of C2C12 cells with the BMP-responsive element and alkaline phosphatase activity of MC3T3-E1 osteoblasts further revealed that bone marrow cells inhibit the BMP-2 effect on osteoblasts by direct cell-cell contact. Collectively, these results showed that the effect of BMP-2 in inducing bone formation is remarkably repressed by marrow cells via direct cell-cell contact with osteoblasts; this opens new perspectives on the clarification of the side-effects associated with BMP-2 application. © 2018 American Society for Bone and Mineral Research.
Collapse
Affiliation(s)
- Ha Thi Nguyen
- Department of Oral Rehabilitation and Regenerative Medicine, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama, Japan.,Department of Molecular Biology and Biochemistry, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama, Japan
| | - Mitsuaki Ono
- Department of Molecular Biology and Biochemistry, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama, Japan
| | - Yasutaka Oida
- Department of Oral Rehabilitation and Regenerative Medicine, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama, Japan
| | - Emilio Satoshi Hara
- Department of Biomaterials, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama, Japan
| | - Taishi Komori
- Department of Oral Rehabilitation and Regenerative Medicine, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama, Japan
| | - Kentaro Akiyama
- Department of Oral Rehabilitation and Regenerative Medicine, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama, Japan
| | - Ha Thi Thu Nguyen
- Department of Oral Rehabilitation and Regenerative Medicine, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama, Japan
| | - Kyaw Thu Aung
- Department of Oral Rehabilitation and Regenerative Medicine, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama, Japan
| | - Hai Thanh Pham
- Department of Oral Rehabilitation and Regenerative Medicine, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama, Japan
| | - Ikue Tosa
- Department of Oral Rehabilitation and Regenerative Medicine, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama, Japan.,Department of Regenerative Science, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama, Japan
| | - Takeshi Takarada
- Department of Regenerative Science, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama, Japan
| | - Koichi Matsuo
- Laboratory of Cell and Tissue Biology, Keio University School of Medicine, Tokyo, Japan
| | | | - Toshitaka Oohashi
- Department of Molecular Biology and Biochemistry, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama, Japan
| | - Takuo Kuboki
- Department of Oral Rehabilitation and Regenerative Medicine, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama, Japan
| |
Collapse
|
22
|
Zwe YH, Goh ZHE, Chau ML, Aung KT, Yuk HG. Survival of an emerging foodborne pathogen: Group B Streptococcus (GBS) serotype III sequence type (ST) 283-under simulated partial cooking and gastric fluid conditions. Food Sci Biotechnol 2018; 28:939-944. [PMID: 31093453 DOI: 10.1007/s10068-018-0525-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2018] [Revised: 11/19/2018] [Accepted: 11/27/2018] [Indexed: 01/13/2023] Open
Abstract
Group B Streptococcus (GBS) was previously not known to be transmitted through food, but an outbreak investigation in Singapore in 2015 documented for the first time an association between GBS Type III Sequence Type 283 infection and consumption of raw fish dishes. As very little is known about the survival of GBS during heat treatment and the stomach transit, its survival under simulated conditions was studied, in comparison with that of Escherichia coli O157:H7 and Listeria monocytogenes. The mean D-values of four GBS strains ranging from 0.72 to 0.88 min in neutral pH tryptone soy broth at 56.4 °C and 0.44-1.43 min at pH 2.35 at 37 °C in simulated gastric fluid, were significantly lower (p < 0.05) than those of E. coli O157:H7 and L. monocytogenes. This study suggests possible factors other than acid or heat resistance of GBS to be instrumental to its pathogenicity.
Collapse
Affiliation(s)
- Ye Htut Zwe
- 1Food Science and Technology Programme, Department of Chemistry, National University of Singapore, Science Drive 2, Singapore, 117543 Singapore
| | - Zhu Hui Esther Goh
- 1Food Science and Technology Programme, Department of Chemistry, National University of Singapore, Science Drive 2, Singapore, 117543 Singapore
| | - Man Ling Chau
- 2Environmental Health Institute, National Environment Agency, 11 Biopolis Way, Singapore, 138667 Singapore
| | - Kyaw Thu Aung
- 2Environmental Health Institute, National Environment Agency, 11 Biopolis Way, Singapore, 138667 Singapore.,3School of Chemical and Biomedical Engineering, Nanyang Technological University, 62 Nanyang Drive, Singapore, 637459 Singapore
| | - Hyun-Gyun Yuk
- 4Department of Food Science and Technology, Korea National University of Transportation, 61 Daehak-ro, Jeungpyeong-gun, Cheongju, Chungbuk 27909 Republic of Korea
| |
Collapse
|
23
|
Hartantyo SHP, Chau ML, Fillon L, Ariff AZBM, Kang JSL, Aung KT, Gutiérrez RA. Sick pets as potential reservoirs of antibiotic-resistant bacteria in Singapore. Antimicrob Resist Infect Control 2018; 7:106. [PMID: 30186596 PMCID: PMC6117887 DOI: 10.1186/s13756-018-0399-9] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2018] [Accepted: 08/21/2018] [Indexed: 08/25/2023] Open
Abstract
An analysis of 186 diagnostic reports collected from a veterinary clinic in Singapore between 2014 to 2016 showed that sick companion animals can carry bacteria that are of significance to human health. Among the 186 specimens submitted, 82 showed polymicrobial growth (45%, 82/186) and in total, 359 bacteria were isolated. Of the 359 bacteria reported, 45% (162/359) were multi-drug resistant and 18% (66/359) were extended-spectrum-beta-lactamase species. Resistance to broad-spectrum antibiotics were also observed among individual species. Namely, methicillin-resistance among Staphylococcus pseudintermedius (63%, 32/51) and Staphylococcus aureus (50%, 4/8); fluoroquinolone-resistance among Escherichia coli (40%, 17/42) and carbapenem-resistance among Klebsiella pneumoniae (7%, 2/30) were noted. Our analysis suggests that sick pets may contribute to the pool of clinically relevant antibiotic-resistant bacteria and play a role in the spread of antibiotic resistance in Singapore. A more extensive study to better understand the extent of distribution and the factors affecting transmission of antibiotic-resistant bacteria to and from pets is necessary.
Collapse
Affiliation(s)
- Sri Harminda Pahm Hartantyo
- 1Environmental Health Institute, National Environment Agency, 11 Biopolis Way, #04-03/04/05, Helios Block, Singapore, 138667 Singapore
| | - Man Ling Chau
- 1Environmental Health Institute, National Environment Agency, 11 Biopolis Way, #04-03/04/05, Helios Block, Singapore, 138667 Singapore
| | - Laurent Fillon
- Veterinary Emergency and Specialty Hospital Pte Ltd, 2-14 Rochdale Road, Singapore, 535815 Singapore
| | - Ahmad Zhafir Bin Mohamad Ariff
- 1Environmental Health Institute, National Environment Agency, 11 Biopolis Way, #04-03/04/05, Helios Block, Singapore, 138667 Singapore
| | - Joanne Su Lin Kang
- 1Environmental Health Institute, National Environment Agency, 11 Biopolis Way, #04-03/04/05, Helios Block, Singapore, 138667 Singapore
| | - Kyaw Thu Aung
- 1Environmental Health Institute, National Environment Agency, 11 Biopolis Way, #04-03/04/05, Helios Block, Singapore, 138667 Singapore.,3School of Chemical and Biomedical Engineering, Nanyang Technological University, 62 Nanyang Drive, Singapore, 637459 Singapore
| | - Ramona Alikiiteaga Gutiérrez
- 1Environmental Health Institute, National Environment Agency, 11 Biopolis Way, #04-03/04/05, Helios Block, Singapore, 138667 Singapore
| |
Collapse
|
24
|
Zwe YH, Tang VCY, Aung KT, Gutiérrez RA, Ng LC, Yuk HG. Prevalence, sequence types, antibiotic resistance and, gyrA mutations of Salmonella isolated from retail fresh chicken meat in Singapore. Food Control 2018. [DOI: 10.1016/j.foodcont.2018.03.004] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
|
25
|
Chuang L, Aung KT, Kang JS, Lim M, Kang C, Gutiérrez RA, Yap JH. A Case Note on Legionnaires' Disease Caused by Serogroup 1, Sequence Type ST496 in Singapore. Ann Acad Med Singap 2018; 47:194-195. [PMID: 29911737] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Affiliation(s)
- Leyland Chuang
- Department of Medicine, Ng Teng Fong General Hospital, Singapore
| | | | | | | | | | | | | |
Collapse
|
26
|
Chau ML, Aung KT, Hapuarachchi HC, Lee PSV, Lim PY, Kang JSL, Ng Y, Yap HM, Yuk HG, Gutiérrez RA, Ng LC. Microbial survey of ready-to-eat salad ingredients sold at retail reveals the occurrence and the persistence of Listeria monocytogenes Sequence Types 2 and 87 in pre-packed smoked salmon. BMC Microbiol 2017; 17:46. [PMID: 28245788 PMCID: PMC5331722 DOI: 10.1186/s12866-017-0956-z] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2016] [Accepted: 02/14/2017] [Indexed: 02/07/2023] Open
Abstract
BACKGROUND As the preparation of salads involves extensive handling and the use of uncooked ingredients, they are particularly vulnerable to microbial contamination. This study aimed to determine the microbial safety and quality of pre-packed salads and salad bar ingredients sold in Singapore, so as to identify public health risks that could arise from consuming salads and to determine areas for improvement in the management of food safety. RESULTS The most frequently encountered organism in pre-packed salad samples was B. cereus, particularly in pasta salads (33.3%, 10/30). The most commonly detected organism in salad bar ingredients was L. monocytogenes, in particular seafood ingredients (44.1%, 15/34), largely due to contaminated smoked salmon. Further investigation showed that 21.6% (37/171) of the pre-packed smoked salmon sold in supermarkets contained L. monocytogenes. Significantly higher prevalence of L. monocytogenes and higher Standard Plate Count were detected in smoked salmon at salad bars compared to pre-packed smoked salmon in supermarkets, which suggested multiplication of the organism as the products move down the supply chain. Further molecular analysis revealed that L. monocytogenes Sequence Type (ST) 2 and ST87 were present in a particular brand of pre-packed salmon products over a 4-year period, implying a potential persistent contamination problem at the manufacturing level. CONCLUSIONS Our findings highlighted a need to improve manufacturing and retail hygiene processes as well as to educate vulnerable populations to avoid consuming food prone to L. monocytogenes contamination.
Collapse
Affiliation(s)
- Man Ling Chau
- Environmental Health Institute, National Environment Agency, 11 Biopolis Way, #04-03/04, Helios Block, Singapore, 138667 Singapore
| | - Kyaw Thu Aung
- Environmental Health Institute, National Environment Agency, 11 Biopolis Way, #04-03/04, Helios Block, Singapore, 138667 Singapore
| | | | - Pei Sze Valarie Lee
- Department of Chemistry, Food Science and Technology Programme, National University of Singapore, 3 Science Drive 3, Singapore, 117543 Singapore
| | - Pei Ying Lim
- School of Biological Sciences, Nanyang Technological University, 60 Nanyang Drive, Singapore, 637551 Singapore
| | - Joanne Su Lin Kang
- Environmental Health Institute, National Environment Agency, 11 Biopolis Way, #04-03/04, Helios Block, Singapore, 138667 Singapore
| | - Youming Ng
- Environmental Health Institute, National Environment Agency, 11 Biopolis Way, #04-03/04, Helios Block, Singapore, 138667 Singapore
| | - Hooi Ming Yap
- Environmental Health Institute, National Environment Agency, 11 Biopolis Way, #04-03/04, Helios Block, Singapore, 138667 Singapore
| | - Hyun-Gyun Yuk
- Department of Chemistry, Food Science and Technology Programme, National University of Singapore, 3 Science Drive 3, Singapore, 117543 Singapore
| | - Ramona Alikiiteaga Gutiérrez
- Environmental Health Institute, National Environment Agency, 11 Biopolis Way, #04-03/04, Helios Block, Singapore, 138667 Singapore
| | - Lee Ching Ng
- Environmental Health Institute, National Environment Agency, 11 Biopolis Way, #04-03/04, Helios Block, Singapore, 138667 Singapore
- School of Biological Sciences, Nanyang Technological University, 60 Nanyang Drive, Singapore, 637551 Singapore
| |
Collapse
|
27
|
Aung KT, Lo JACY, Chau ML, Kang JSL, Yap HM, Gutiérrez RA, Yuk HG, Ng LC. MICROBIOLOGICAL SAFETY ASSESSMENT AND RISK MITIGATION OF INDIAN ROJAK (DEEP FRIED READYTO-EAT FOOD) IN SINGAPORE. Southeast Asian J Trop Med Public Health 2016; 47:1231-1245. [PMID: 29634190] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
We conducted a microbiological assessment of Indian Rojak, a popular deep fried food in Singapore to evaluate its overall microbial quality, assess the effectiveness of reheating and identify key food items that could contribute to the microbial load of the dish. In 2009, an outbreak of foodborne illness associated with this food led to 154 reported cases of acute gastroenteritis, 48 were hospitalized and 2 died. Vibrio parahaemolyticus was isolated from the patients. We evaluated 455 Indian Rojak ingredients from 35 stalls; no Salmonella spp, Vibrio cholerae/parahaemolyticus or Escherichia coli O157:H7 were recovered from the studied samples. The reheating by the food handlers significantly reduced the overall median Standard Plate Count (SPC) of food from 4.5 to 2.7 log colony forming units (CFU)/g (p<0.05). The cooked ingredients with the highest microbial loads were tofu and fish cake, with those purchased from wet markets having significantly higher bacterial loads than those purchased from supermarkets (p<0.05). The Rojak gravy had the lowest median bacterial load (1.9 log CFU/g). Raw, ready-to-eat vegetables, namely green chillis, cucumbers and onions had higher levels ranging from 5.9 to 6.1 log CFU/g. Contamination with E. coli, Staphylococcus aureus, and Bacillus cereus was seen with some of the ready-to-eat raw vegetables. Repeated education of food handlers with emphasis on good hygiene practices should be conducted to reduce the risk of foodborne illnesses.
Collapse
|
28
|
Chau ML, Hartantyo SHP, Yap M, Kang JSL, Aung KT, Gutiérrez RA, Ng LC, Tam CC, Barkham T. Diarrheagenic pathogens in adults attending a hospital in Singapore. BMC Infect Dis 2016; 16:32. [PMID: 26822615 PMCID: PMC4730775 DOI: 10.1186/s12879-016-1354-0] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2015] [Accepted: 01/18/2016] [Indexed: 11/10/2022] Open
Abstract
Background Singapore’s diarrhoeal notification system is based on specific pathogens. Official data may thus be skewed towards notifiable diseases. Limited information is available on the profiles of aetiological agents responsible for acute gastroenteritis (AGE) cases, especially among the adult population. To understand the frequency and distribution of potential causative agents of diarrheal disease in Singapore, we screened adults’ stool samples collected from a large public hospital. Methods The stool samples were screened for 18 diarrheagenic pathogens using a combination of commercial multiplex polymerase chain reaction (PCR), in-house singleplex PCR and immunochromatographic assays. One hundred adult faecal samples that were collected from October 2013 to January 2014 for routine diagnostic purposes and submitted for culture at Tan Tock Seng Hospital, Singapore were used. Results Pathogens were detected in 32 % of the samples. The predominant organisms encountered were norovirus genogroup II (11 %), Aeromonas spp. (9 %) and Campylobacter spp. (5 %). One sample was positive for both verocytotoxigenic E. coli (VTEC) and E. coli O157:H7. Two other samples were positive for VTEC only, and one other sample was positive for E. coli O157:H7 only. Astrovirus, C. perfringens, Shigella spp. and toxigenic C. difficile were each detected in 2 % of the samples. Cryptosporidium parvum, Giardia lamblia, group A rotavirus, Salmonella spp. and Vibrio spp. were each detected in 1 % of the samples. No L. monocytogenes, Y. enterocolitica, enteric adenovirus, or norovirus genogroup I were detected. Conclusion Our preliminary findings suggest that pathogens causing non-notifiable diseases might have contributed considerably to the adult hospitalised AGE cases. However, as the samples were from an adult hospital, the data obtained may not be representative of the whole community. Thus, a larger study to collect clinical samples and risk exposure data from primary healthcare clinics and children hospital is planned for, to gain a more holistic perspective on the epidemiology of AGE in Singapore. A larger study may also offer valuable insights for improving the approach of microbiological surveillance of food, as well as strategizing inspection efforts along the food supply chain by public health authorities.
Collapse
Affiliation(s)
- Man Ling Chau
- Environmental Health Institute, National Environment Agency, 11 Biopolis Way, #04-03/04, Helios Block, Singapore, 138667, Singapore.
| | - Sri Harminda Pahm Hartantyo
- Environmental Health Institute, National Environment Agency, 11 Biopolis Way, #04-03/04, Helios Block, Singapore, 138667, Singapore.
| | - Min Yap
- Environmental Health Institute, National Environment Agency, 11 Biopolis Way, #04-03/04, Helios Block, Singapore, 138667, Singapore.
| | - Joanne Su Lin Kang
- Environmental Health Institute, National Environment Agency, 11 Biopolis Way, #04-03/04, Helios Block, Singapore, 138667, Singapore.
| | - Kyaw Thu Aung
- Environmental Health Institute, National Environment Agency, 11 Biopolis Way, #04-03/04, Helios Block, Singapore, 138667, Singapore.
| | - Ramona Alikiiteaga Gutiérrez
- Environmental Health Institute, National Environment Agency, 11 Biopolis Way, #04-03/04, Helios Block, Singapore, 138667, Singapore.
| | - Lee Ching Ng
- Environmental Health Institute, National Environment Agency, 11 Biopolis Way, #04-03/04, Helios Block, Singapore, 138667, Singapore.
| | - Clarence C Tam
- Saw Swee Hock School of Public Health, National University of Singapore, Tahir Foundation Building, 12 Science Drive 2, #10-01, Singapore, 117549, Singapore. .,London School of Hygiene & Tropical Medicine, Keppel Street, London, WC1E 7HT, UK.
| | - Timothy Barkham
- Department of Laboratory Medicine, Tan Tock Seng Hospital, 11 Jalan Tan Tock Seng, Singapore, 308433, Singapore.
| |
Collapse
|