1
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Barkham T, Tang WY, Wang YC, Sithithaworn P, Kopolrat KY, Worasith C. Human Fecal Carriage of Streptococcus agalactiae Sequence Type 283, Thailand. Emerg Infect Dis 2023; 29:1627-1629. [PMID: 37486205 PMCID: PMC10370859 DOI: 10.3201/eid2908.230098] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/25/2023] Open
Abstract
Streptococcus agalactiae (group B Streptococcus) sequence type 283 bacteremia, found almost exclusively in Southeast Asia, is associated with consuming raw freshwater fish, but some patients deny consumption. We detected fecal carriage in 5/184 (2.7%) persons in northeast Thailand. Human carriers might contribute to transmission or be the original source of this sequence type.
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2
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Zohari Z, Barkham T, Mohamad Maswan N, Chen SL, Muthanna A, Lee KW, Mohd Desa MN, Azmai MNA, Sither Joseph NM, Amin-Nordin S. Fish-associated Streptococcus agalactiae ST283: first human cases reported from Malaysia. J Med Microbiol 2023; 72. [PMID: 37389575 DOI: 10.1099/jmm.0.001729] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/01/2023] Open
Abstract
In South East Asia, Streptococcus agalactiae ST283 causes sepsis in healthy adults. Raw freshwater fish consumption is the only known risk factor. These two case reports are the first from Malaysia. Although they cluster with Singapore ST283, the epidemiology is complicated by the flow of people and fish across borders.
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Affiliation(s)
- Zahira Zohari
- Department of Medicine, Faculty of Medicine and Health Sciences, Universiti Putra Malaysia, 43400, Serdang, Selangor, Malaysia
| | - Timothy Barkham
- Department of Laboratory Medicine, Tan Tock Seng Hospital, 308433, Singapore
| | | | - Swaine Lin Chen
- Infectious Diseases Translational Research Programme, Department of Medicine, Division of Infectious Diseases, Yong Loo Lin School of Medicine, National University of Singapore, 1E Kent Ridge Road, NUHS Tower Block, 119228, Singapore
- Laboratory of Bacterial Genomics, Genome Institute of Singapore, 60 Biopolis Street, 138672, Singapore
| | - AbdulRahman Muthanna
- Department of Biomedical Sciences, Faculty of Medicine and Health Sciences, Universiti Putra Malaysia, 43400, Serdang, Selangor, Malaysia
| | - Kai Wei Lee
- Department of Medical Microbiology, Faculty of Medicine and Health Sciences, Universiti Putra Malaysia, 43400, Serdang, Selangor, Malaysia
| | - Mohd Nasir Mohd Desa
- Department of Biomedical Sciences, Faculty of Medicine and Health Sciences, Universiti Putra Malaysia, 43400, Serdang, Selangor, Malaysia
| | - Mohammad Noor Amal Azmai
- Aquatic Animal Health and Therapeutics Laboratory, Institute of Bioscience, Universiti Putra Malaysia, 43400, Serdang, Selangor, Malaysia
- Department of Biology, Faculty of Science, Universiti Putra Malaysia, 43400,Serdang, Selangor, Malaysia
| | - Narcisse Mary Sither Joseph
- Department of Medical Microbiology, Faculty of Medicine and Health Sciences, Universiti Putra Malaysia, 43400, Serdang, Selangor, Malaysia
| | - Syafinaz Amin-Nordin
- Hospital Sultan Abdul Aziz Shah,Universiti Putra Malaysia, Persiaran MARDI-UPM, 43400, Serdang, Selangor, Malaysia
- Department of Medical Microbiology, Faculty of Medicine and Health Sciences, Universiti Putra Malaysia, 43400, Serdang, Selangor, Malaysia
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3
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Chen YYC, Tang WY, Barkham T. Molecular characterisation of a meropenem-resistant Haemophilus influenzae. Pathology 2023. [DOI: 10.1016/j.pathol.2022.12.332] [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] [Indexed: 01/28/2023]
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4
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Luangraj M, Hiestand J, Rasphone O, Chen SL, Davong V, Barkham T, Simpson AJ, Dance DA, Keoluangkhot V. Invasive Streptococcus agalactiae ST283 infection after fish consumption in two sisters, Lao PDR. Wellcome Open Res 2022; 7:148. [PMID: 36324702 PMCID: PMC9607938 DOI: 10.12688/wellcomeopenres.17804.1] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/22/2022] [Indexed: 07/25/2023] Open
Abstract
Background: Streptococcus agalactiae is a normal commensal of the human gastro-intestinal and female genital tracts. It causes serious disease in neonates and pregnant women, as well as non-pregnant adults. Food-borne outbreaks have also been described. A link between invasive Group B streptococcus (GBS) infection in humans caused by S. agalactiae serotype III-4, sequence type 283 (ST283) and the consumption of raw fresh-water fish was first described in Singapore in 2015. Case presentation: We report the simultaneous occurrence of acute fever and myalgia in two sisters who were visiting Laos. Both were found to have invasive GBS ST283 infection, confirmed by blood culture. Infection was temporally linked to fish consumption. They responded well to intravenous antibiotics within 48 hours. Conclusions: Food-borne transmission of Streptococcus agalactiae is an important and under-recognised source of serious human disease throughout Southeast Asia and possibly beyond.
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Affiliation(s)
- Manophab Luangraj
- Lao-Oxford-Mahosot hospital-Wellcome Trust Research Unit, Microbiology department, Mahosot hospital, Vientiane, 0100, Lao People's Democratic Republic
| | - Jasmin Hiestand
- Epidemiology, Biostatistics and Prevention Institute, University of Zurich, Zurich, 8091, Swaziland
| | - Othila Rasphone
- Infectious Diseases Centre, Mahosot Hospital, Vientiane, 0100, Lao People's Democratic Republic
| | - Swaine L. Chen
- NUHS Infectious Diseases Translational Research Programme, Department of Medicine, Division of Infectious diseases, Yong Loo Lin School of Medicine, National University of Singapore, 1E Kent Ridge Road, NUHS Tower Block, 119228, Singapore
- Laboratory of Bacterial Genomics, Genome Institute of Singapore, 60 Biopolis street, 138672, Singapore
| | - Viengmon Davong
- Lao-Oxford-Mahosot hospital-Wellcome Trust Research Unit, Microbiology department, Mahosot hospital, Vientiane, 0100, Lao People's Democratic Republic
| | - Timothy Barkham
- Department of Laboratory Medicine, Tan Tock Seng Hospital, 11 Jalan Tan Tock Seng, 308433, Singapore
| | - Andrew J.H. Simpson
- Lao-Oxford-Mahosot hospital-Wellcome Trust Research Unit, Microbiology department, Mahosot hospital, Vientiane, 0100, Lao People's Democratic Republic
- Centre for Tropical Medicine and Global Health, Old Road Campus, Roosevelt Drive, University of Oxford, Oxford, OX3 7LG, UK
| | - David A.B. Dance
- Lao-Oxford-Mahosot hospital-Wellcome Trust Research Unit, Microbiology department, Mahosot hospital, Vientiane, 0100, Lao People's Democratic Republic
- Centre for Tropical Medicine and Global Health, Old Road Campus, Roosevelt Drive, University of Oxford, Oxford, OX3 7LG, UK
- Faculty of Infectious and Tropical Diseases, London School of Hygiene & Tropical Medicine, Keppel Street, London, WC1E 7HT, UK
| | - Valy Keoluangkhot
- Infectious Diseases Centre, Mahosot Hospital, Vientiane, 0100, Lao People's Democratic Republic
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5
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Mohid SA, Biswas K, Won T, Mallela LS, Gucchait A, Butzke L, Sarkar R, Barkham T, Reif B, Leipold E, Roy S, Misra AK, Lakshminarayanan R, Lee D, Bhunia A. Structural insights into the interaction of antifungal peptides and ergosterol containing fungal membrane. Biochim Biophys Acta Biomembr 2022; 1864:183996. [PMID: 35753394 DOI: 10.1016/j.bbamem.2022.183996] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [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: 01/24/2022] [Revised: 06/09/2022] [Accepted: 06/13/2022] [Indexed: 06/15/2023]
Abstract
The treatment of invasive drug-resistant and potentially life-threatening fungal infections is limited to few therapeutic options that are usually associated with severe side effects. The development of new effective antimycotics with a more tolerable side effect profile is therefore of utmost clinical importance. Here, we used a combination of complementary in vitro assays and structural analytical methods to analyze the interaction of the de novo antimicrobial peptide VG16KRKP with the sterol moieties of biological cell membranes. We demonstrate that VG16KRKP disturbs the structural integrity of fungal membranes both invitro and in model membrane system containing ergosterol along with phosphatidylethanolamine lipid and exhibits broad-spectrum antifungal activity. As revealed by systematic structure-function analysis of mutated VG16KRKP analogs, a specific pattern of basic and hydrophobic amino acid side chains in the primary peptide sequence determines the selectivity of VG16KRKP for fungal specific membranes.
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Affiliation(s)
- Sk Abdul Mohid
- Department of Biophysics, Bose Institute, Unified Academic Campus, Salt Lake, EN 80, Sector V, Kolkata 700091, India
| | - Karishma Biswas
- Department of Biophysics, Bose Institute, Unified Academic Campus, Salt Lake, EN 80, Sector V, Kolkata 700091, India
| | - TaeJun Won
- Department of Fine Chemistry, Seoul National University of Science and Technology, Seoul 01811, Republic of Korea
| | - Lakshmi S Mallela
- Prof. Brien Holden Eye Research Centre, LV Prasad Eye Institute, Hyderabad 500034, India
| | - Arin Gucchait
- Division of Molecular Medicine, Bose Institute, Unified Academic Campus, Salt Lake, EN 80, Sector V, Kolkata 700091, India
| | - Lena Butzke
- Department of Anesthesiology and Intensive Care & Center of Brain, Behavior and Metabolism, University of Lübeck, Ratzeburger Allee 160, 23562 Lübeck, Germany
| | | | - Timothy Barkham
- Department of Laboratory Medicine, Tan Tock Seng Hospital, 11 Jalan Tan Tock Seng, Singapore
| | - Bernd Reif
- Technical University of Munich, 85748 Garching, Germany
| | - Enrico Leipold
- Department of Anesthesiology and Intensive Care & Center of Brain, Behavior and Metabolism, University of Lübeck, Ratzeburger Allee 160, 23562 Lübeck, Germany
| | - Sanhita Roy
- Prof. Brien Holden Eye Research Centre, LV Prasad Eye Institute, Hyderabad 500034, India
| | - Anup K Misra
- Division of Molecular Medicine, Bose Institute, Unified Academic Campus, Salt Lake, EN 80, Sector V, Kolkata 700091, India
| | | | - DongKuk Lee
- Department of Fine Chemistry, Seoul National University of Science and Technology, Seoul 01811, Republic of Korea.
| | - Anirban Bhunia
- Department of Biophysics, Bose Institute, Unified Academic Campus, Salt Lake, EN 80, Sector V, Kolkata 700091, India.
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6
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Wong JJ, Ho FK, Choo PY, Chong KKL, Ho CMB, Neelakandan R, Keogh D, Barkham T, Chen J, Liu CF, Kline KA. Escherichia coli BarA-UvrY regulates the pks island and kills Staphylococci via the genotoxin colibactin during interspecies competition. PLoS Pathog 2022; 18:e1010766. [PMID: 36067266 PMCID: PMC9481169 DOI: 10.1371/journal.ppat.1010766] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2022] [Revised: 09/16/2022] [Accepted: 07/25/2022] [Indexed: 11/19/2022] Open
Abstract
Wound infections are often polymicrobial in nature, biofilm associated and therefore tolerant to antibiotic therapy, and associated with delayed healing. Escherichia coli and Staphylococcus aureus are among the most frequently cultured pathogens from wound infections. However, little is known about the frequency or consequence of E. coli and S. aureus polymicrobial interactions during wound infections. Here we show that E. coli kills Staphylococci, including S. aureus, both in vitro and in a mouse excisional wound model via the genotoxin, colibactin. Colibactin biosynthesis is encoded by the pks locus, which we identified in nearly 30% of human E. coli wound infection isolates. While it is not clear how colibactin is released from E. coli or how it penetrates target cells, we found that the colibactin intermediate N-myristoyl-D-Asn (NMDA) disrupts the S. aureus membrane. We also show that the BarA-UvrY two component system (TCS) senses the environment created during E. coli and S. aureus mixed species interaction, leading to upregulation of pks island genes. Further, we show that BarA-UvrY acts via the carbon storage global regulatory (Csr) system to control pks expression. Together, our data demonstrate the role of colibactin in interspecies competition and show that it is regulated by BarA-UvrY TCS during interspecies competition. Wound infections are often polymicrobial in nature and are associated with poor disease prognoses. Escherichia coli and Staphylococcus aureus are among the top five most cultured pathogens from wound infections. However, little is known about the polymicrobial interactions between E. coli and S. aureus during wound infections. In this study, we show that E. coli kills S. aureus both in vitro and in a mouse excisional wound model via the genotoxin, colibactin. We also show that the BarA-UvrY two component system (TCS) regulates the pks island during this mixed species interaction, acting through the carbon storage global regulatory (Csr) system to control colibactin production. Together, our data demonstrate the role of colibactin in interspecies competition and show that it is regulated by BarA-UvrY TCS during interspecies competition.
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Affiliation(s)
- Jun Jie Wong
- Singapore Centre for Environmental Life Sciences Engineering, Nanyang Technological University, Singapore, Singapore
- Singapore Centre for Environmental Life Sciences Engineering, Interdisciplinary Graduate Programme, Nanyang Technological University, Singapore, Singapore
| | - Foo Kiong Ho
- Singapore Centre for Environmental Life Sciences Engineering, Nanyang Technological University, Singapore, Singapore
| | - Pei Yi Choo
- Singapore Centre for Environmental Life Sciences Engineering, Nanyang Technological University, Singapore, Singapore
| | - Kelvin K. L. Chong
- Singapore Centre for Environmental Life Sciences Engineering, Nanyang Technological University, Singapore, Singapore
- Nanyang Technological University Institute for Health Technologies, Interdisciplinary Graduate School, Nanyang Technological University, Singapore, Singapore
| | - Chee Meng Benjamin Ho
- School of Mechanical and Aerospace Engineering, Nanyang Technological University, Singapore, Singapore
| | - Ramesh Neelakandan
- School of Biological Sciences, Nanyang Technological University, Singapore, Singapore
| | - Damien Keogh
- Singapore Centre for Environmental Life Sciences Engineering, Nanyang Technological University, Singapore, Singapore
| | - Timothy Barkham
- Department of Microbiology and Immunology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
- Department of Laboratory Medicine, Tan Tock Seng Hospital, Singapore, Singapore
| | - John Chen
- Department of Microbiology and Immunology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
| | - Chuan Fa Liu
- School of Biological Sciences, Nanyang Technological University, Singapore, Singapore
| | - Kimberly A. Kline
- Singapore Centre for Environmental Life Sciences Engineering, Nanyang Technological University, Singapore, Singapore
- School of Biological Sciences, Nanyang Technological University, Singapore, Singapore
- Department of Microbiology and Molecular Medicine, University of Geneva, Geneva, Switzerland
- * E-mail:
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7
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Ch'ng JH, Muthu M, Chong KKL, Wong JJ, Tan CAZ, Koh ZJS, Lopez D, Matysik A, Nair ZJ, Barkham T, Wang Y, Kline KA. Heme cross-feeding can augment Staphylococcus aureus and Enterococcus faecalis dual species biofilms. ISME J 2022; 16:2015-2026. [PMID: 35589966 PMCID: PMC9296619 DOI: 10.1038/s41396-022-01248-1] [Citation(s) in RCA: 25] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/12/2021] [Revised: 04/18/2022] [Accepted: 04/29/2022] [Indexed: 12/17/2022]
Abstract
The contribution of biofilms to virulence and as a barrier to treatment is well-established for Staphylococcus aureus and Enterococcus faecalis, both nosocomial pathogens frequently isolated from biofilm-associated infections. Despite frequent co-isolation, their interactions in biofilms have not been well-characterized. We report that in combination, these two species can give rise to augmented biofilms biomass that is dependent on the activation of E. faecalis aerobic respiration. In E. faecalis, respiration requires both exogenous heme to activate the cydAB-encoded heme-dependent cytochrome bd, and the availability of O2. We determined that the ABC transporter encoded by cydDC contributes to heme import. In dual species biofilms, S. aureus provides the heme to activate E. faecalis respiration. S. aureus mutants deficient in heme biosynthesis were unable to augment biofilms whereas heme alone is sufficient to augment E. faecalis mono-species biofilms. Our results demonstrate that S. aureus-derived heme, likely in the form of released hemoproteins, promotes E. faecalis biofilm formation, and that E. faecalis gelatinase activity facilitates heme extraction from hemoproteins. This interspecies interaction and metabolic cross-feeding may explain the frequent co-occurrence of these microbes in biofilm-associated infections.
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Affiliation(s)
- Jun-Hong Ch'ng
- Department of Microbiology and Immunology, National University of Singapore, Singapore, Singapore. .,Department of Surgery Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore. .,Infectious Disease Translational Research Program, National University Health System, Singapore, Singapore. .,Singapore Centre for Environmental Life Sciences Engineering, National University of Singapore, Singapore, Singapore.
| | - Mugil Muthu
- Department of Microbiology and Immunology, National University of Singapore, Singapore, Singapore.,Singapore Centre for Environmental Life Sciences Engineering, Nanyang Technological University, Singapore, Singapore
| | - Kelvin K L Chong
- Singapore Centre for Environmental Life Sciences Engineering, Nanyang Technological University, Singapore, Singapore.,Nanyang Technological University Institute for Health Technologies, Interdisciplinary Graduate School, Nanyang Technological University, Singapore, Singapore
| | - Jun Jie Wong
- Singapore Centre for Environmental Life Sciences Engineering, Nanyang Technological University, Singapore, Singapore.,Singapore Centre for Environmental Life Sciences Engineering, Interdisciplinary Graduate Program, Nanyang Technological University, Singapore, Singapore
| | - Casandra A Z Tan
- Singapore Centre for Environmental Life Sciences Engineering, Nanyang Technological University, Singapore, Singapore.,Singapore Centre for Environmental Life Sciences Engineering, Interdisciplinary Graduate Program, Nanyang Technological University, Singapore, Singapore
| | - Zachary J S Koh
- Department of Microbiology and Immunology, National University of Singapore, Singapore, Singapore
| | - Daniel Lopez
- Singapore Centre for Environmental Life Sciences Engineering, Nanyang Technological University, Singapore, Singapore
| | - Artur Matysik
- Singapore Centre for Environmental Life Sciences Engineering, Nanyang Technological University, Singapore, Singapore
| | - Zeus J Nair
- Singapore Centre for Environmental Life Sciences Engineering, Nanyang Technological University, Singapore, Singapore
| | - Timothy Barkham
- Department of Microbiology and Immunology, National University of Singapore, Singapore, Singapore.,Department of Laboratory Medicine, Tan Tock Seng Hospital, Singapore, Singapore
| | - Yulan Wang
- Singapore Phenome Center, Lee Kong Chian School of Medicine, Nanyang Technological University, Nanyang, Singapore
| | - Kimberly A Kline
- Singapore Centre for Environmental Life Sciences Engineering, Nanyang Technological University, Singapore, Singapore. .,School of Biological Sciences, Nanyang Technological University, Singapore, Singapore.
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8
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Luangraj M, Hiestand J, Rasphone O, Chen SL, Davong V, Barkham T, Simpson AJ, Dance DA, Keoluangkhot V. Invasive Streptococcus agalactiae ST283 infection after fish consumption in two sisters, Lao PDR. Wellcome Open Res 2022; 7:148. [PMID: 36324702 PMCID: PMC9607938 DOI: 10.12688/wellcomeopenres.17804.2] [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] [Accepted: 11/22/2022] [Indexed: 11/27/2022] Open
Abstract
Background: Streptococcus agalactiae is a normal commensal of the human gastro-intestinal and female genital tracts. It causes serious disease in neonates and pregnant women, as well as non-pregnant adults. Food-borne outbreaks have also been described. A link between invasive Group B streptococcus (GBS) infection in humans caused by S. agalactiae serotype III-4, sequence type 283 (ST283) and the consumption of raw fresh-water fish was first described in Singapore in 2015. Case presentation: We report the simultaneous occurrence of acute fever and myalgia in two sisters who were visiting Laos. Both were found to have invasive GBS ST283 infection, confirmed by blood culture. Infection was temporally linked to fish consumption. They responded well to intravenous antibiotics within 48 hours. Conclusions: Food-borne transmission of Streptococcus agalactiae is an important and under-recognised source of serious human disease throughout Southeast Asia and possibly beyond.
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Affiliation(s)
- Manophab Luangraj
- Lao-Oxford-Mahosot hospital-Wellcome Trust Research Unit, Microbiology department, Mahosot hospital, Vientiane, 0100, Lao People's Democratic Republic,
| | - Jasmin Hiestand
- Epidemiology, Biostatistics and Prevention Institute, University of Zurich, Zurich, 8091, Swaziland
| | - Othila Rasphone
- Infectious Diseases Centre, Mahosot Hospital, Vientiane, 0100, Lao People's Democratic Republic
| | - Swaine L. Chen
- NUHS Infectious Diseases Translational Research Programme, Department of Medicine, Division of Infectious diseases, Yong Loo Lin School of Medicine, National University of Singapore, 1E Kent Ridge Road, NUHS Tower Block, 119228, Singapore,Laboratory of Bacterial Genomics, Genome Institute of Singapore, 60 Biopolis street, 138672, Singapore
| | - Viengmon Davong
- Lao-Oxford-Mahosot hospital-Wellcome Trust Research Unit, Microbiology department, Mahosot hospital, Vientiane, 0100, Lao People's Democratic Republic
| | - Timothy Barkham
- Department of Laboratory Medicine, Tan Tock Seng Hospital, 11 Jalan Tan Tock Seng, 308433, Singapore
| | - Andrew J.H. Simpson
- Lao-Oxford-Mahosot hospital-Wellcome Trust Research Unit, Microbiology department, Mahosot hospital, Vientiane, 0100, Lao People's Democratic Republic,Centre for Tropical Medicine and Global Health, Old Road Campus, Roosevelt Drive, University of Oxford, Oxford, OX3 7LG, UK
| | - David A.B. Dance
- Centre for Tropical Medicine and Global Health, Old Road Campus, Roosevelt Drive, University of Oxford, Oxford, OX3 7LG, UK,Faculty of Infectious and Tropical Diseases, London School of Hygiene & Tropical Medicine, Keppel Street, London, WC1E 7HT, UK
| | - Valy Keoluangkhot
- Infectious Diseases Centre, Mahosot Hospital, Vientiane, 0100, Lao People's Democratic Republic
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9
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Lim VW, Wee HL, Lee P, Lin Y, Tan YR, Tan MX, Lin LW, Yap P, Chee CB, Barkham T, Lee V, Chen M, Ong RTH. Cross-sectional study of prevalence and risk factors, and a cost-effectiveness evaluation of screening and preventive treatment strategies for latent tuberculosis among migrants in Singapore. BMJ Open 2021; 11:e050629. [PMID: 34266845 PMCID: PMC8286773 DOI: 10.1136/bmjopen-2021-050629] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [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] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/03/2022] Open
Abstract
OBJECTIVES WHO recommends that low burden countries consider systematic screening and treatment of latent tuberculosis infection (LTBI) in migrants from high incidence countries. We aimed to determine LTBI prevalence and risk factors and evaluate cost-effectiveness of screening and treating LTBI in migrants to Singapore from a government payer perspective. DESIGN Cross-sectional study and cost-effectiveness analysis. SETTING Migrants in Singapore. PARTICIPANTS 3618 migrants who were between 20 and 50 years old, have not worked in Singapore previously and stayed in Singapore for less than a year were recruited. PRIMARY AND SECONDARY OUTCOME MEASURES Costs, quality-adjusted life-years (QALYs), threshold length of stay, incremental cost-effectiveness ratios (ICERs), cost per active TB case averted. RESULTS Of 3584 migrants surveyed, 20.4% had positive interferon-gamma release assay (IGRA) results, with the highest positivity in Filipinos (33.2%). Higher LTBI prevalence was significantly associated with age, marital status and past TB exposure. The cost-effectiveness model projected an ICER of S$57 116 per QALY and S$12 422 per active TB case averted for screening and treating LTBI with 3 months once weekly isoniazid and rifapentine combination regimen treatment compared with no screening over a 50-year time horizon. ICER was most sensitive to the cohort's length of stay in Singapore, yearly disease progression rates from LTBI to active TB, followed by the cost of IGRA testing. CONCLUSIONS For LTBI screening and treatment of migrants to be cost-effective, migrants from high burden countries would have to stay in Singapore for ~50 years. Risk-stratified approaches based on projected length of stay and country of origin and/or age group can be considered.
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Affiliation(s)
- Vanessa W Lim
- Infectious Disease Research and Training Office, National Centre for Infectious Diseases, Singapore
| | - Hwee Lin Wee
- Saw Swee Hock School of Public Health, National University of Singapore and National University Health System, Singapore
| | - Phoebe Lee
- Saw Swee Hock School of Public Health, National University of Singapore and National University Health System, Singapore
- Communicable Diseases Division, Ministry of Health Singapore, Singapore
| | - Yijun Lin
- Saw Swee Hock School of Public Health, National University of Singapore and National University Health System, Singapore
- Communicable Diseases Division, Ministry of Health Singapore, Singapore
| | - Yi Roe Tan
- Infectious Disease Research and Training Office, National Centre for Infectious Diseases, Singapore
| | - Mei Xuan Tan
- Infectious Disease Research and Training Office, National Centre for Infectious Diseases, Singapore
| | - Lydia Wenxin Lin
- Saw Swee Hock School of Public Health, National University of Singapore and National University Health System, Singapore
| | - Peiling Yap
- Infectious Disease Research and Training Office, National Centre for Infectious Diseases, Singapore
| | - Cynthia Be Chee
- Tuberculosis Control Unit, Singapore TB Elimination Programme, Singapore
| | - Timothy Barkham
- Department of Laboratory Medicine, Tan Tock Seng Hospital, Singapore
| | - Vernon Lee
- Saw Swee Hock School of Public Health, National University of Singapore and National University Health System, Singapore
- Communicable Diseases Division, Ministry of Health Singapore, Singapore
| | - Mark Chen
- Infectious Disease Research and Training Office, National Centre for Infectious Diseases, Singapore
| | - Rick Twee-Hee Ong
- Saw Swee Hock School of Public Health, National University of Singapore and National University Health System, Singapore
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10
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Marimuthu K, Mo Y, Ling ML, Hernandez-Koutoucheva A, Fenlon SN, Bertrand D, Lye DC, Ang BSP, Perencevich E, Ng OT, Cooper BS, Nagarajan N, Chen SL, Barkham T. Household transmission of carbapenemase-producing Enterobacteriaceae: a prospective cohort study. J Antimicrob Chemother 2021; 76:1299-1302. [PMID: 33417711 DOI: 10.1093/jac/dkaa561] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2020] [Accepted: 12/18/2020] [Indexed: 11/14/2022] Open
Abstract
OBJECTIVES To estimate the transmission rate of carbapenemase-producing Enterobacteriaceae (CPE) in households with recently hospitalized CPE carriers. METHODS We conducted a prospective case-ascertained cohort study. We identified the presence of CPE in stool samples from index subjects, household contacts and companion animals and environmental samples at regular intervals. Linked transmissions were identified by WGS. A Markov model was constructed to estimate the household transmission potential of CPE. RESULTS Ten recently hospitalized index patients and 14 household contacts were included. There were seven households with one contact, two households with two contacts, and one household with three contacts. Index patients were colonized with blaOXA-48-like (n = 4), blaKPC-2 (n = 3), blaIMP (n = 2), and blaNDM-1 (n = 1), distributed among divergent species of Enterobacteriaceae. After a cumulative follow-up time of 9.0 years, three family members (21.4%, 3/14) acquired four different types of CPE in the community (hazard rate of 0.22/year). The probability of CPE transmission from an index patient to a household contact was 10% (95% CI 4%-26%). CONCLUSIONS We observed limited transmission of CPE from an index patient to household contacts. Larger studies are needed to understand the factors associated with household transmission of CPE and identify preventive strategies.
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Affiliation(s)
- Kalisvar Marimuthu
- National Centre for Infectious Diseases, Singapore.,Department of Infectious Diseases, Tan Tock Seng Hospital, Singapore.,Yong Loo Lin School of Medicine, National University of Singapore, Singapore
| | - Yin Mo
- Yong Loo Lin School of Medicine, National University of Singapore, Singapore.,Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Salaya, Thailand.,Division of Infectious Diseases, National University Hospital, Singapore
| | - Moi Lin Ling
- Department of Infection Prevention and Epidemiology, Singapore General Hospital, Singapore
| | | | - Shannon N Fenlon
- Laboratory of Bacterial Genomics, Genome Institute of Singapore, Singapore
| | - Denis Bertrand
- Computational and Systems Biology, Genome Institute of Singapore, Singapore
| | - David Chien Lye
- National Centre for Infectious Diseases, Singapore.,Department of Infectious Diseases, Tan Tock Seng Hospital, Singapore.,Yong Loo Lin School of Medicine, National University of Singapore, Singapore.,Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore
| | - Brenda Sze Peng Ang
- National Centre for Infectious Diseases, Singapore.,Department of Infectious Diseases, Tan Tock Seng Hospital, Singapore.,Department of Infection Prevention and Control, Tan Tock Seng Hospital, Singapore
| | - Eli Perencevich
- Carver College of Medicine, University of Iowa, Iowa City, IA, USA
| | - Oon Tek Ng
- National Centre for Infectious Diseases, Singapore.,Department of Infectious Diseases, Tan Tock Seng Hospital, Singapore.,Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore
| | - Ben S Cooper
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Salaya, Thailand.,Centre for Tropical Medicine, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - Niranjan Nagarajan
- Yong Loo Lin School of Medicine, National University of Singapore, Singapore.,Computational and Systems Biology, Genome Institute of Singapore, Singapore
| | - Swaine L Chen
- Yong Loo Lin School of Medicine, National University of Singapore, Singapore.,Laboratory of Bacterial Genomics, Genome Institute of Singapore, Singapore
| | - Timothy Barkham
- Department of Laboratory Medicine, Tan Tock Seng Hospital, Singapore
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11
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Lee TH, Junhao Lin R, Lin RTP, Barkham T, Rao P, Leo YS, Chien Lye D, Young B. Testing for SARS-CoV-2: Can We Stop at 2? Clin Infect Dis 2020; 71:2246-2248. [PMID: 32306042 PMCID: PMC7188180 DOI: 10.1093/cid/ciaa459] [Citation(s) in RCA: 47] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2020] [Accepted: 04/17/2020] [Indexed: 01/19/2023] Open
Abstract
The COVID-19 epidemic requires accurate identification and isolation of confirmed cases for effective control. This report describes the effectiveness of our testing strategy and highlights the importance of repeat testing in suspect cases in our cohort.
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Affiliation(s)
- Tau Hong Lee
- National Centre for Infectious Diseases, Singapore.,Tan Tock Seng Hospital, Singapore.,Lee Kong Chian School of Medicine, Singapore.,Yong Loo Lin School of Medicine, Singapore
| | - Ray Junhao Lin
- National Centre for Infectious Diseases, Singapore.,Tan Tock Seng Hospital, Singapore
| | | | - Timothy Barkham
- Tan Tock Seng Hospital, Singapore.,Yong Loo Lin School of Medicine, Singapore
| | - Pooja Rao
- Tan Tock Seng Hospital, Singapore.,Lee Kong Chian School of Medicine, Singapore
| | - Yee-Sin Leo
- National Centre for Infectious Diseases, Singapore.,Tan Tock Seng Hospital, Singapore.,Lee Kong Chian School of Medicine, Singapore.,Yong Loo Lin School of Medicine, Singapore.,Saw Swee Hock School of Public Health, Singapore
| | - David Chien Lye
- National Centre for Infectious Diseases, Singapore.,Tan Tock Seng Hospital, Singapore.,Lee Kong Chian School of Medicine, Singapore.,Yong Loo Lin School of Medicine, Singapore
| | - Barnaby Young
- National Centre for Infectious Diseases, Singapore.,Tan Tock Seng Hospital, Singapore.,Lee Kong Chian School of Medicine, Singapore
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12
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Basri L, Nor RM, Salleh A, Md. Yasin IS, Saad MZ, Abd. Rahaman NY, Barkham T, Amal MNA. Co-Infections of Tilapia Lake Virus, Aeromonas hydrophila and Streptococcus agalactiae in Farmed Red Hybrid Tilapia. Animals (Basel) 2020; 10:E2141. [PMID: 33217902 PMCID: PMC7698767 DOI: 10.3390/ani10112141] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2020] [Revised: 11/03/2020] [Accepted: 11/06/2020] [Indexed: 02/02/2023] Open
Abstract
A high death rate among red hybrid tilapias was observed in a farm in Selangor, Malaysia, in January 2020. The affected fish appeared lethargic, isolated from schooling group, showed loss of appetite, red and haemorrhagic skin, exophthalmia and enlarged gall bladders. Histopathological assessment revealed deformation of kidney tubules, and severe congestion with infiltrations of inflammatory cells in the brains and kidneys. Syncytial cells and intracytoplasmic inclusion bodies were occasionally observed in the liver and brain sections. Tilapia Lake Virus (TiLV), Aeromonas hydrophila and Streptococcus agalactiae were identified in the affected fish, either through isolation or through PCR and sequencing analysis. The phylogenetic tree analysis revealed that the TiLV strain in this study was closely related to the previously reported Malaysian strain that was isolated in 2019. On the other hand, A. hydrophila and S. agalactiae were closer to Algerian and Brazilian strains, respectively. The multiple antibiotic resistance index for A. hydrophila and S. agalactiae was 0.50 and 0.25, respectively. Co-infections of virus and bacteria in cultured tilapia is a new threat for the tilapia industry.
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Affiliation(s)
- Lukman Basri
- Aquatic Animal Health and Therapeutics Laboratory, Institute of Bioscience, Universiti Putra Malaysia, UPM Serdang 43400, Selangor, Malaysia; (L.B.); (A.S.); (I.S.M.Y.); (M.Z.S.)
| | - Roslindawani Md. Nor
- Department of Veterinary Laboratory Diagnosis, Faculty of Veterinary Medicine, Universiti Putra Malaysia, UPM Serdang 43400, Selangor, Malaysia; (R.M.N.); (N.Y.A.R.)
| | - Annas Salleh
- Aquatic Animal Health and Therapeutics Laboratory, Institute of Bioscience, Universiti Putra Malaysia, UPM Serdang 43400, Selangor, Malaysia; (L.B.); (A.S.); (I.S.M.Y.); (M.Z.S.)
- Department of Veterinary Laboratory Diagnosis, Faculty of Veterinary Medicine, Universiti Putra Malaysia, UPM Serdang 43400, Selangor, Malaysia; (R.M.N.); (N.Y.A.R.)
| | - Ina Salwany Md. Yasin
- Aquatic Animal Health and Therapeutics Laboratory, Institute of Bioscience, Universiti Putra Malaysia, UPM Serdang 43400, Selangor, Malaysia; (L.B.); (A.S.); (I.S.M.Y.); (M.Z.S.)
- Department of Aquaculture, Faculty of Agriculture, Universiti Putra Malaysia, UPM Serdang 43400, Selangor, Malaysia
| | - Mohd Zamri Saad
- Aquatic Animal Health and Therapeutics Laboratory, Institute of Bioscience, Universiti Putra Malaysia, UPM Serdang 43400, Selangor, Malaysia; (L.B.); (A.S.); (I.S.M.Y.); (M.Z.S.)
- Department of Veterinary Laboratory Diagnosis, Faculty of Veterinary Medicine, Universiti Putra Malaysia, UPM Serdang 43400, Selangor, Malaysia; (R.M.N.); (N.Y.A.R.)
| | - Nor Yasmin Abd. Rahaman
- Department of Veterinary Laboratory Diagnosis, Faculty of Veterinary Medicine, Universiti Putra Malaysia, UPM Serdang 43400, Selangor, Malaysia; (R.M.N.); (N.Y.A.R.)
| | - Timothy Barkham
- Department of Laboratory Medicine, Tan Tock Seng Hospital, Singapore 308433, Singapore;
| | - Mohammad Noor Azmai Amal
- Aquatic Animal Health and Therapeutics Laboratory, Institute of Bioscience, Universiti Putra Malaysia, UPM Serdang 43400, Selangor, Malaysia; (L.B.); (A.S.); (I.S.M.Y.); (M.Z.S.)
- Department of Biology, Faculty of Science, Universiti Putra Malaysia, UPM Serdang 43400, Selangor, Malaysia
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13
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Mo Y, Hernandez-Koutoucheva A, Musicha P, Bertrand D, Lye D, Ng OT, Fenlon SN, Chen SL, Ling ML, Tang WY, Barkham T, Nagarajan N, Cooper BS, Marimuthu K. Duration of Carbapenemase-Producing Enterobacteriaceae Carriage in Hospital Patients. Emerg Infect Dis 2020; 26:2182-2185. [PMID: 32818397 PMCID: PMC7454053 DOI: 10.3201/eid2609.190592] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
To determine the duration of carbapenemase-producing Enterobacteriaceae (CPE) carriage, we studied 21 CPE carriers for »1 year. Mean carriage duration was 86 days; probability of decolonization in 1 year was 98.5%, suggesting that CPE-carriers' status can be reviewed yearly. Prolonged carriage was associated with use of antimicrobial drugs.
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14
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Young BE, Fong SW, Chan YH, Mak TM, Ang LW, Anderson DE, Lee CYP, Amrun SN, Lee B, Goh YS, Su YCF, Wei WE, Kalimuddin S, Chai LYA, Pada S, Tan SY, Sun L, Parthasarathy P, Chen YYC, Barkham T, Lin RTP, Maurer-Stroh S, Leo YS, Wang LF, Renia L, Lee VJ, Smith GJD, Lye DC, Ng LFP. Effects of a major deletion in the SARS-CoV-2 genome on the severity of infection and the inflammatory response: an observational cohort study. Lancet 2020; 396:603-611. [PMID: 32822564 PMCID: PMC7434477 DOI: 10.1016/s0140-6736(20)31757-8] [Citation(s) in RCA: 308] [Impact Index Per Article: 77.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/25/2020] [Revised: 07/30/2020] [Accepted: 07/30/2020] [Indexed: 12/19/2022]
Abstract
BACKGROUND Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants with a 382-nucleotide deletion (∆382) in the open reading frame 8 (ORF8) region of the genome have been detected in Singapore and other countries. We investigated the effect of this deletion on the clinical features of infection. METHODS We retrospectively identified patients who had been screened for the ∆382 variant and recruited to the PROTECT study-a prospective observational cohort study conducted at seven public hospitals in Singapore. We collected clinical, laboratory, and radiological data from patients' electronic medical records and serial blood and respiratory samples taken during hospitalisation and after discharge. Individuals infected with the ∆382 variant were compared with those infected with wild-type SARS-CoV-2. Exact logistic regression was used to examine the association between the infection groups and the development of hypoxia requiring supplemental oxygen (an indicator of severe COVID-19, the primary endpoint). Follow-up for the study's primary endpoint is completed. FINDINGS Between Jan 22 and March 21, 2020, 278 patients with PCR-confirmed SARS-CoV-2 infection were screened for the ∆382 deletion and 131 were enrolled onto the study, of whom 92 (70%) were infected with the wild-type virus, ten (8%) had a mix of wild-type and ∆382-variant viruses, and 29 (22%) had only the ∆382 variant. Development of hypoxia requiring supplemental oxygen was less frequent in the ∆382 variant group (0 [0%] of 29 patients) than in the wild-type only group (26 [28%] of 92; absolute difference 28% [95% CI 14-28]). After adjusting for age and presence of comorbidities, infection with the ∆382 variant only was associated with lower odds of developing hypoxia requiring supplemental oxygen (adjusted odds ratio 0·07 [95% CI 0·00-0·48]) compared with infection with wild-type virus only. INTERPRETATION The ∆382 variant of SARS-CoV-2 seems to be associated with a milder infection. The observed clinical effects of deletions in ORF8 could have implications for the development of treatments and vaccines. FUNDING National Medical Research Council Singapore.
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Affiliation(s)
- Barnaby E Young
- National Centre for Infectious Diseases, Singapore; Department of Infectious Diseases, Tan Tock Seng Hospital, Singapore; Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore
| | - Siew-Wai Fong
- Infectious Diseases Horizontal Technology Centre, Agency for Science, Technology, and Research, Singapore; Singapore Immunology Network, Agency for Science, Technology, and Research, Singapore; Department of Biological Sciences, National University of Singapore, Singapore
| | - Yi-Hao Chan
- Infectious Diseases Horizontal Technology Centre, Agency for Science, Technology, and Research, Singapore; Singapore Immunology Network, Agency for Science, Technology, and Research, Singapore
| | | | - Li Wei Ang
- National Public Health and Epidemiology Unit, National Centre for Infectious Diseases, Singapore
| | | | - Cheryl Yi-Pin Lee
- Infectious Diseases Horizontal Technology Centre, Agency for Science, Technology, and Research, Singapore; Singapore Immunology Network, Agency for Science, Technology, and Research, Singapore
| | - Siti Naqiah Amrun
- Infectious Diseases Horizontal Technology Centre, Agency for Science, Technology, and Research, Singapore; Singapore Immunology Network, Agency for Science, Technology, and Research, Singapore
| | - Bernett Lee
- Singapore Immunology Network, Agency for Science, Technology, and Research, Singapore
| | - Yun Shan Goh
- Infectious Diseases Horizontal Technology Centre, Agency for Science, Technology, and Research, Singapore; Singapore Immunology Network, Agency for Science, Technology, and Research, Singapore
| | - Yvonne C F Su
- Duke-NUS Medical School, National University of Singapore, Singapore
| | - Wycliffe E Wei
- National Public Health and Epidemiology Unit, National Centre for Infectious Diseases, Singapore
| | - Shirin Kalimuddin
- Duke-NUS Medical School, National University of Singapore, Singapore; Department of Infectious Diseases, Singapore General Hospital, Singapore
| | - Louis Yi Ann Chai
- Yong Loo Lin School of Medicine, National University of Singapore, Singapore; Department of Medicine, National University Health System, Singapore
| | - Surinder Pada
- Department of Medicine, Infectious Diseases Service, Ng Teng Fong General Hospital, Singapore
| | - Seow Yen Tan
- Department of Infectious Diseases, Changi General Hospital, Singapore
| | | | | | | | - Timothy Barkham
- Department of Laboratory Medicine, Tan Tock Seng Hospital, Singapore; Yong Loo Lin School of Medicine, National University of Singapore, Singapore
| | | | - Sebastian Maurer-Stroh
- National Centre for Infectious Diseases, Singapore; Bioinformatics Institute, Agency for Science, Technology, and Research, Singapore; Department of Biological Sciences, National University of Singapore, Singapore; Global Initiative on Sharing All Influenza Data, Munich, Germany
| | - Yee-Sin Leo
- National Centre for Infectious Diseases, Singapore; Department of Infectious Diseases, Tan Tock Seng Hospital, Singapore; Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore; Yong Loo Lin School of Medicine, National University of Singapore, Singapore; Saw Swee Hock School of Public Health, National University of Singapore, Singapore
| | - Lin-Fa Wang
- Duke-NUS Medical School, National University of Singapore, Singapore
| | - Laurent Renia
- Infectious Diseases Horizontal Technology Centre, Agency for Science, Technology, and Research, Singapore; Singapore Immunology Network, Agency for Science, Technology, and Research, Singapore
| | - Vernon J Lee
- Saw Swee Hock School of Public Health, National University of Singapore, Singapore; Ministry of Health, Singapore
| | - Gavin J D Smith
- Duke-NUS Medical School, National University of Singapore, Singapore.
| | - David Chien Lye
- National Centre for Infectious Diseases, Singapore; Department of Infectious Diseases, Tan Tock Seng Hospital, Singapore; Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore; Yong Loo Lin School of Medicine, National University of Singapore, Singapore
| | - Lisa F P Ng
- Infectious Diseases Horizontal Technology Centre, Agency for Science, Technology, and Research, Singapore; Singapore Immunology Network, Agency for Science, Technology, and Research, Singapore.
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15
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Young BE, Ong SWX, Ng LFP, Anderson DE, Chia WN, Chia PY, Ang LW, Mak TM, Kalimuddin S, Chai LYA, Pada S, Tan SY, Sun L, Parthasarathy P, Fong SW, Chan YH, Tan CW, Lee B, Rötzschke O, Ding Y, Tambyah P, Low JGH, Cui L, Barkham T, Lin RTP, Leo YS, Renia L, Wang LF, Lye DC. Viral dynamics and immune correlates of COVID-19 disease severity. Clin Infect Dis 2020; 73:e2932-e2942. [PMID: 32856707 PMCID: PMC7499509 DOI: 10.1093/cid/ciaa1280] [Citation(s) in RCA: 122] [Impact Index Per Article: 30.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2020] [Accepted: 08/26/2020] [Indexed: 12/13/2022] Open
Abstract
Background Key knowledge gaps remain in the understanding of viral dynamics and immune response of SARS-CoV-2 infection. Methods We evaluated these characteristics and established their association with clinical severity in a prospective observational cohort study of 100 patients with PCR-confirmed SARS-CoV-2 infection (mean age 46 years, 56% male, 38% with comorbidities). Respiratory samples (n=74) were collected for viral culture, serum samples for measurement of IgM/IgG levels (n=30), and plasma samples for levels of inflammatory cytokines and chemokines (n=81). Disease severity was correlated with results from viral culture, serologic testing, and immune markers. Results 57 (57%) patients developed viral pneumonia, of whom 20 (20%) required supplemental oxygen including 12 (12%) invasive mechanical ventilation. Viral culture from respiratory samples was positive for 19 of 74 patients (26%). No virus was isolated when the PCR cycle threshold (Ct) value was >30 or >14 days after symptom onset. Seroconversion occurred at a median of 12.5 days (IQR 9-18) for IgM and 15.0 days (IQR 12-20) for IgG; 54/62 patients (87.1%) sampled at day 14 or later seroconverted. Severe infections were associated with earlier seroconversion and higher peak IgM and IgG levels. Levels of IP-10, HGF, IL-6, MCP-1, MIP-1α, IL-12p70, IL-18, VEGF-A, PDGF-BB and IL-1RA significantly correlated with disease severity. Conclusion We found virus viability was associated with lower PCR Ct value in early illness. A stronger antibody response was associated with disease severity. The overactive proinflammatory immune signatures offers targets for host-directed immunotherapy which should be evaluated in randomised controlled trials.
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Affiliation(s)
- Barnaby E Young
- National Centre for Infectious Diseases, Singapore.,Tan Tock Seng Hospital, Singapore.,Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore
| | - Sean W X Ong
- National Centre for Infectious Diseases, Singapore.,Tan Tock Seng Hospital, Singapore
| | - Lisa F P Ng
- Infection Diseases Horizontal Technology Centre (ID HTC), Agency for Science, Technology and Research, Singapore.,Singapore Immunology Network, Agency for Science, Technology and Research, Singapore
| | | | | | - Po Ying Chia
- National Centre for Infectious Diseases, Singapore.,Tan Tock Seng Hospital, Singapore.,Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore
| | - Li Wei Ang
- National Centre for Infectious Diseases, Singapore
| | - Tze-Minn Mak
- National Centre for Infectious Diseases, Singapore
| | - Shirin Kalimuddin
- Duke-NUS Medical School, Singapore.,Singapore General Hospital, Singapore
| | - Louis Yi Ann Chai
- National University Health System, Singapore.,Yong Loo Lin School of Medicine, National University of Singapore, Singapore
| | | | | | | | | | - Siew-Wai Fong
- Infection Diseases Horizontal Technology Centre (ID HTC), Agency for Science, Technology and Research, Singapore.,Singapore Immunology Network, Agency for Science, Technology and Research, Singapore.,Department of Biological Science, National University of Singapore, Singapore
| | - Yi-Hao Chan
- Infection Diseases Horizontal Technology Centre (ID HTC), Agency for Science, Technology and Research, Singapore.,Singapore Immunology Network, Agency for Science, Technology and Research, Singapore
| | - Chee Wah Tan
- Singapore Immunology Network, Agency for Science, Technology and Research, Singapore
| | - Bernett Lee
- Singapore Immunology Network, Agency for Science, Technology and Research, Singapore
| | - Olaf Rötzschke
- Singapore Immunology Network, Agency for Science, Technology and Research, Singapore
| | - Ying Ding
- National Centre for Infectious Diseases, Singapore
| | - Paul Tambyah
- National University Health System, Singapore.,Yong Loo Lin School of Medicine, National University of Singapore, Singapore
| | - Jenny G H Low
- Duke-NUS Medical School, Singapore.,Singapore General Hospital, Singapore
| | - Lin Cui
- National Centre for Infectious Diseases, Singapore
| | - Timothy Barkham
- Tan Tock Seng Hospital, Singapore.,Yong Loo Lin School of Medicine, National University of Singapore, Singapore
| | | | - Yee-Sin Leo
- National Centre for Infectious Diseases, Singapore.,Tan Tock Seng Hospital, Singapore.,Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore.,Yong Loo Lin School of Medicine, National University of Singapore, Singapore.,Saw Swee Hock School of Public Health, National University of Singapore, Singapore
| | - Laurent Renia
- Infection Diseases Horizontal Technology Centre (ID HTC), Agency for Science, Technology and Research, Singapore.,Singapore Immunology Network, Agency for Science, Technology and Research, Singapore
| | | | - David Chien Lye
- National Centre for Infectious Diseases, Singapore.,Tan Tock Seng Hospital, Singapore.,Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore.,Yong Loo Lin School of Medicine, National University of Singapore, Singapore
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16
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Sutjipto S, Lee PH, Tay JY, Mendis SM, Abdad MY, Marimuthu K, Ng OT, Cui L, Chan M, Soon M, Lin RTP, Leo YS, De PP, Barkham T, Vasoo S. The Effect of Sample Site, Illness Duration, and the Presence of Pneumonia on the Detection of SARS-CoV-2 by Real-time Reverse Transcription PCR. Open Forum Infect Dis 2020; 7:ofaa335. [PMID: 32964061 PMCID: PMC7454916 DOI: 10.1093/ofid/ofaa335] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [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: 05/24/2020] [Accepted: 07/31/2020] [Indexed: 12/28/2022] Open
Abstract
Background The performance of real-time reverse transcription polymerase chain reaction (rRT-PCR) for SARS-CoV-2 varies with sampling site(s), illness stage, and infection site. Methods Unilateral nasopharyngeal, nasal midturbinate, throat swabs, and saliva were simultaneously sampled for SARS-CoV-2 rRT-PCR from suspected or confirmed cases of COVID-19. True positives were defined as patients with at least 1 SARS-CoV-2 detected by rRT-PCR from any site on the evaluation day or at any time point thereafter, until discharge. Diagnostic performance was assessed and extrapolated for site combinations. Results We evaluated 105 patients; 73 had active SARS-CoV-2 infection. Overall, nasopharyngeal specimens had the highest clinical sensitivity at 85%, followed by throat, 80%, midturbinate, 62%, and saliva, 38%–52%. Clinical sensitivity for nasopharyngeal, throat, midturbinate, and saliva was 95%, 88%, 72%, and 44%–56%, respectively, if taken ≤7 days from onset of illness, and 70%, 67%, 47%, 28%–44% if >7 days of illness. Comparing patients with upper respiratory tract infection (URTI) vs pneumonia, clinical sensitivity for nasopharyngeal, throat, midturbinate, and saliva was 92% vs 70%, 88% vs 61%, 70% vs 44%, 43%–54% vs 26%–45%, respectively. A combination of nasopharyngeal plus throat or midturbinate plus throat specimen afforded overall clinical sensitivities of 89%–92%; this rose to 96% for persons with URTI and 98% for persons ≤7 days from illness onset. Conclusions Nasopharyngeal specimens, followed by throat specimens, offer the highest clinical sensitivity for COVID-19 diagnosis in early illness. Clinical sensitivity improves and is similar when either midturbinate or nasopharyngeal specimens are combined with throat specimens. Upper respiratory specimens perform poorly if taken after the first week of illness or if there is pneumonia.
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Affiliation(s)
- Stephanie Sutjipto
- Department of Infectious Diseases, Tan Tock Seng Hospital, Singapore.,National Centre for Infectious Diseases, Singapore
| | - Pei Hua Lee
- Department of Infectious Diseases, Tan Tock Seng Hospital, Singapore.,National Centre for Infectious Diseases, Singapore
| | - Jun Yang Tay
- Department of Infectious Diseases, Tan Tock Seng Hospital, Singapore.,National Centre for Infectious Diseases, Singapore
| | - Shehara M Mendis
- Department of Laboratory Medicine, Tan Tock Seng Hospital, Singapore
| | - Mohammad Yazid Abdad
- Infectious Disease Research Laboratory, National Centre for Infectious Diseases, Singapore
| | - Kalisvar Marimuthu
- Department of Infectious Diseases, Tan Tock Seng Hospital, Singapore.,National Centre for Infectious Diseases, Singapore.,Yong Loo Lin School of Medicine, National University of Singapore, Singapore
| | - Oon Tek Ng
- Department of Infectious Diseases, Tan Tock Seng Hospital, Singapore.,National Centre for Infectious Diseases, Singapore.,Lee Kong Chian School of Medicine, Singapore.,Yong Loo Lin School of Medicine, National University of Singapore, Singapore
| | - Lin Cui
- National Public Health Laboratory, National Centre for Infectious Diseases, Singapore
| | - Monica Chan
- Department of Infectious Diseases, Tan Tock Seng Hospital, Singapore.,National Centre for Infectious Diseases, Singapore.,Lee Kong Chian School of Medicine, Singapore.,Yong Loo Lin School of Medicine, National University of Singapore, Singapore
| | | | - Raymond T P Lin
- National Public Health Laboratory, National Centre for Infectious Diseases, Singapore.,Yong Loo Lin School of Medicine, National University of Singapore, Singapore
| | - Yee-Sin Leo
- Department of Infectious Diseases, Tan Tock Seng Hospital, Singapore.,National Centre for Infectious Diseases, Singapore.,Lee Kong Chian School of Medicine, Singapore.,Yong Loo Lin School of Medicine, National University of Singapore, Singapore.,Saw Swee Hock School of Public Health, National Centre for Infectious Diseases, Singapore
| | - Partha P De
- Department of Laboratory Medicine, Tan Tock Seng Hospital, Singapore
| | - Timothy Barkham
- Department of Laboratory Medicine, Tan Tock Seng Hospital, Singapore.,Yong Loo Lin School of Medicine, National University of Singapore, Singapore
| | - Shawn Vasoo
- Department of Infectious Diseases, Tan Tock Seng Hospital, Singapore.,National Centre for Infectious Diseases, Singapore.,Infectious Disease Research Laboratory, National Centre for Infectious Diseases, Singapore.,Lee Kong Chian School of Medicine, Singapore.,Yong Loo Lin School of Medicine, National University of Singapore, Singapore
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17
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Sun Y, Koh V, Marimuthu K, Ng OT, Young B, Vasoo S, Chan M, Lee VJM, De PP, Barkham T, Lin RTP, Cook AR, Leo YS. Epidemiological and Clinical Predictors of COVID-19. Clin Infect Dis 2020; 71:786-792. [PMID: 32211755 PMCID: PMC7542554 DOI: 10.1093/cid/ciaa322] [Citation(s) in RCA: 150] [Impact Index Per Article: 37.5] [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: 03/16/2020] [Accepted: 03/21/2020] [Indexed: 12/23/2022] Open
Abstract
BACKGROUND Rapid identification of COVID-19 cases, which is crucial to outbreak containment efforts, is challenging due to the lack of pathognomonic symptoms and in settings with limited capacity for specialized nucleic acid-based reverse transcription polymerase chain reaction (PCR) testing. METHODS This retrospective case-control study involves subjects (7-98 years) presenting at the designated national outbreak screening center and tertiary care hospital in Singapore for SARS-CoV-2 testing from 26 January to 16 February 2020. COVID-19 status was confirmed by PCR testing of sputum, nasopharyngeal swabs, or throat swabs. Demographic, clinical, laboratory, and exposure-risk variables ascertainable at presentation were analyzed to develop an algorithm for estimating the risk of COVID-19. Model development used Akaike's information criterion in a stepwise fashion to build logistic regression models, which were then translated into prediction scores. Performance was measured using receiver operating characteristic curves, adjusting for overconfidence using leave-one-out cross-validation. RESULTS The study population included 788 subjects, of whom 54 (6.9%) were SARS-CoV-2 positive and 734 (93.1%) were SARS-CoV-2 negative. The median age was 34 years, and 407 (51.7%) were female. Using leave-one-out cross-validation, all the models incorporating clinical tests (models 1, 2, and 3) performed well with areas under the receiver operating characteristic curve (AUCs) of 0.91, 0.88, and 0.88, respectively. In comparison, model 4 had an AUC of 0.65. CONCLUSIONS Rapidly ascertainable clinical and laboratory data could identify individuals at high risk of COVID-19 and enable prioritization of PCR testing and containment efforts. Basic laboratory test results were crucial to prediction models.
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Affiliation(s)
- Yinxiaohe Sun
- Saw Swee Hock School of Public Health, National University of Singapore and National University Health System, Singapore
| | - Vanessa Koh
- Department of Infectious Diseases, National Centre for Infectious Diseases, Singapore
- Department of Infectious Diseases, Tan Tock Seng Hospital, Singapore
| | - Kalisvar Marimuthu
- Department of Infectious Diseases, National Centre for Infectious Diseases, Singapore
- Department of Infectious Diseases, Tan Tock Seng Hospital, Singapore
- Yong Loo Lin School of Medicine, National University of Singapore and National University Health System, Singapore
| | - Oon Tek Ng
- Department of Infectious Diseases, National Centre for Infectious Diseases, Singapore
- Department of Infectious Diseases, Tan Tock Seng Hospital, Singapore
- Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore
| | - Barnaby Young
- Department of Infectious Diseases, National Centre for Infectious Diseases, Singapore
- Department of Infectious Diseases, Tan Tock Seng Hospital, Singapore
- Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore
| | - Shawn Vasoo
- Department of Infectious Diseases, National Centre for Infectious Diseases, Singapore
- Department of Infectious Diseases, Tan Tock Seng Hospital, Singapore
| | - Monica Chan
- Department of Infectious Diseases, National Centre for Infectious Diseases, Singapore
- Department of Infectious Diseases, Tan Tock Seng Hospital, Singapore
| | - Vernon J M Lee
- Saw Swee Hock School of Public Health, National University of Singapore and National University Health System, Singapore
- Communicable Disease Division, Ministry of Health, Singapore
| | - Partha P De
- Department of Laboratory Medicine, Tan Tock Seng Hospital, Singapore
| | - Timothy Barkham
- Yong Loo Lin School of Medicine, National University of Singapore and National University Health System, Singapore
- Department of Laboratory Medicine, Tan Tock Seng Hospital, Singapore
| | - Raymond T P Lin
- Yong Loo Lin School of Medicine, National University of Singapore and National University Health System, Singapore
- National Public Health Laboratory, National Centre for Infectious Diseases, Singapore
| | - Alex R Cook
- Saw Swee Hock School of Public Health, National University of Singapore and National University Health System, Singapore
| | - Yee Sin Leo
- Saw Swee Hock School of Public Health, National University of Singapore and National University Health System, Singapore
- Department of Infectious Diseases, National Centre for Infectious Diseases, Singapore
- Department of Infectious Diseases, Tan Tock Seng Hospital, Singapore
- Yong Loo Lin School of Medicine, National University of Singapore and National University Health System, Singapore
- Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore
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Chia PY, Coleman KK, Tan YK, Ong SWX, Gum M, Lau SK, Lim XF, Lim AS, Sutjipto S, Lee PH, Son TT, Young BE, Milton DK, Gray GC, Schuster S, Barkham T, De PP, Vasoo S, Chan M, Ang BSP, Tan BH, Leo YS, Ng OT, Wong MSY, Marimuthu K. Detection of air and surface contamination by SARS-CoV-2 in hospital rooms of infected patients. Nat Commun 2020; 11:2800. [PMID: 32472043 DOI: 10.1101/2020.03.29.20046557] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2020] [Accepted: 05/18/2020] [Indexed: 05/20/2023] Open
Abstract
Understanding the particle size distribution in the air and patterns of environmental contamination of SARS-CoV-2 is essential for infection prevention policies. Here we screen surface and air samples from hospital rooms of COVID-19 patients for SARS-CoV-2 RNA. Environmental sampling is conducted in three airborne infection isolation rooms (AIIRs) in the ICU and 27 AIIRs in the general ward. 245 surface samples are collected. 56.7% of rooms have at least one environmental surface contaminated. High touch surface contamination is shown in ten (66.7%) out of 15 patients in the first week of illness, and three (20%) beyond the first week of illness (p = 0.01, χ2 test). Air sampling is performed in three of the 27 AIIRs in the general ward, and detects SARS-CoV-2 PCR-positive particles of sizes >4 µm and 1-4 µm in two rooms, despite these rooms having 12 air changes per hour. This warrants further study of the airborne transmission potential of SARS-CoV-2.
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Affiliation(s)
- Po Ying Chia
- National Centre for Infectious Diseases, Singapore, Singapore
- Tan Tock Seng Hospital, Singapore, Singapore
- Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore, Singapore
| | | | | | - Sean Wei Xiang Ong
- National Centre for Infectious Diseases, Singapore, Singapore
- Tan Tock Seng Hospital, Singapore, Singapore
| | - Marcus Gum
- DSO National Laboratories, Singapore, Singapore
| | | | | | - Ai Sim Lim
- DSO National Laboratories, Singapore, Singapore
| | - Stephanie Sutjipto
- National Centre for Infectious Diseases, Singapore, Singapore
- Tan Tock Seng Hospital, Singapore, Singapore
| | - Pei Hua Lee
- National Centre for Infectious Diseases, Singapore, Singapore
- Tan Tock Seng Hospital, Singapore, Singapore
| | - Than The Son
- Duke-NUS Medical School, National University of Singapore, Singapore, Singapore
| | - Barnaby Edward Young
- National Centre for Infectious Diseases, Singapore, Singapore
- Tan Tock Seng Hospital, Singapore, Singapore
- Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore, Singapore
| | - Donald K Milton
- Maryland Institute for Applied Environmental Health, University of Maryland School of Public Health, College Park, MD, USA
| | - Gregory C Gray
- Duke-NUS Medical School, National University of Singapore, Singapore, Singapore
- School of Medicine and Global Health Institute, Duke University, Durham, NC, USA
- Global Health Research Center, Duke Kunshan University, Kunshan, China
| | - Stephan Schuster
- Singapore Centre for Environmental Life Sciences Engineering, Nanyang Technological University, Singapore, Singapore
| | - Timothy Barkham
- Tan Tock Seng Hospital, Singapore, Singapore
- Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
| | - Partha Pratim De
- Tan Tock Seng Hospital, Singapore, Singapore
- Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore, Singapore
| | - Shawn Vasoo
- National Centre for Infectious Diseases, Singapore, Singapore
- Tan Tock Seng Hospital, Singapore, Singapore
- Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore, Singapore
| | - Monica Chan
- National Centre for Infectious Diseases, Singapore, Singapore
- Tan Tock Seng Hospital, Singapore, Singapore
| | - Brenda Sze Peng Ang
- National Centre for Infectious Diseases, Singapore, Singapore
- Tan Tock Seng Hospital, Singapore, Singapore
- Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore, Singapore
- Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
| | | | - Yee-Sin Leo
- National Centre for Infectious Diseases, Singapore, Singapore
- Tan Tock Seng Hospital, Singapore, Singapore
- Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore, Singapore
- Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
| | - Oon-Tek Ng
- National Centre for Infectious Diseases, Singapore, Singapore.
- Tan Tock Seng Hospital, Singapore, Singapore.
- Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore, Singapore.
| | | | - Kalisvar Marimuthu
- National Centre for Infectious Diseases, Singapore, Singapore.
- Tan Tock Seng Hospital, Singapore, Singapore.
- Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore.
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19
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Hart T, Tang WY, Mansoor SAB, Chio MTW, Barkham T. Mycoplasma genitalium in Singapore is associated with Chlamydia trachomatis infection and displays high macrolide and Fluoroquinolone resistance rates. BMC Infect Dis 2020; 20:314. [PMID: 32345231 PMCID: PMC7189604 DOI: 10.1186/s12879-020-05019-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2019] [Accepted: 04/07/2020] [Indexed: 02/04/2023] Open
Abstract
BACKGROUND Mycoplasma genitalium is an emerging sexually transmitted infection, with increasing rates of resistance to fluroquinolones and macrolides, the recommended treatments. Despite this, M. genitalium is not part of routine screening for Sexually Transmitted Infections (STIs) in many countries and the prevalence of infection and patterns of disease remain to be determined in many populations. Such data is of particular importance in light of the reported rise in antibiotic resistance in M. genitalium isolates. METHODS Urine and urethral swab samples were collected from the primary public sexual health clinic in Singapore and tested for C. trachomatis (CT) or N. gonorrhoeae (NG) infection and for the presence of M. genitalium. Antibiotic resistance in M. genitalium strains detected was determined by screening for genomic mutations associated with macrolide and fluroquinolone resistance. RESULTS We report the results of a study into M. genitalium prevalence at the national sexual health clinic in Singapore. M. genitalium was heavily associated with CT infection (8.1% of cases), but present in only of 2.4% in CT negative cases and not independently linked to NG infection. Furthermore, we found high rates of resistance mutations to both macrolides (25%) and fluoroquinolones (37.5%) with a majority of resistant strains being dual-resistant. Resistance mutations were only found in strains from patients with CT co-infection. CONCLUSIONS Our results support targeted screening of CT positive patients for M. genitalium as a cost-effective strategy to reduce the incidence of M. genitalium in the absence of comprehensive routine screening. The high rate of dual resistance also highlights the need to ensure the availability of alternative antibiotics for the treatment of multi-drug resistant M. genitalium isolates.
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MESH Headings
- Ambulatory Care Facilities
- Anti-Bacterial Agents/pharmacology
- Anti-Bacterial Agents/therapeutic use
- Chlamydia Infections/complications
- Chlamydia Infections/diagnosis
- Chlamydia Infections/drug therapy
- Chlamydia trachomatis/drug effects
- Chlamydia trachomatis/genetics
- Chlamydia trachomatis/isolation & purification
- DNA, Bacterial/genetics
- DNA, Bacterial/metabolism
- Drug Resistance, Multiple, Bacterial/genetics
- Fluoroquinolones/pharmacology
- Fluoroquinolones/therapeutic use
- Humans
- Macrolides/pharmacology
- Macrolides/therapeutic use
- Mycoplasma Infections/complications
- Mycoplasma Infections/diagnosis
- Mycoplasma Infections/drug therapy
- Mycoplasma Infections/epidemiology
- Mycoplasma genitalium/drug effects
- Mycoplasma genitalium/genetics
- Mycoplasma genitalium/isolation & purification
- Prevalence
- RNA, Ribosomal, 23S/chemistry
- RNA, Ribosomal, 23S/genetics
- RNA, Ribosomal, 23S/metabolism
- Sequence Analysis, DNA
- Singapore/epidemiology
- Urethra/microbiology
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Affiliation(s)
- Tim Hart
- Tan Tock Seng Hospital, 11 Jalan Tan Tock Seng, Singapore, 308433, Singapore.
| | - Wen Ying Tang
- Tan Tock Seng Hospital, 11 Jalan Tan Tock Seng, Singapore, 308433, Singapore
| | - Siti Aminah Bte Mansoor
- Department of Sexually Transmitted Infections Control Clinic, 31 Kelantan Ln, Singapore, 200031, Singapore
| | - Martin T W Chio
- Department of Sexually Transmitted Infections Control Clinic, 31 Kelantan Ln, Singapore, 200031, Singapore
| | - Timothy Barkham
- Tan Tock Seng Hospital, 11 Jalan Tan Tock Seng, Singapore, 308433, Singapore
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20
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Dance D, Zadoks RN, Luangraj M, Simpson A, Chen SL, Barkham T. Community-acquired Group B streptococcal meningitis in adults. J Infect 2020; 81:147-178. [PMID: 32171868 DOI: 10.1016/j.jinf.2020.03.009] [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] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2020] [Revised: 03/09/2020] [Accepted: 03/09/2020] [Indexed: 10/24/2022]
Affiliation(s)
- Dab Dance
- Lao-Oxford-Mahosot Hospital-Wellcome Trust Research Unit, Mahosot Hospital, Vientiane, Lao Democratic People's Republic; Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom; Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, United Kingdom.
| | | | - M Luangraj
- Lao-Oxford-Mahosot Hospital-Wellcome Trust Research Unit, Mahosot Hospital, Vientiane, Lao Democratic People's Republic
| | - A Simpson
- Lao-Oxford-Mahosot Hospital-Wellcome Trust Research Unit, Mahosot Hospital, Vientiane, Lao Democratic People's Republic; Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
| | - S L Chen
- Department of Medicine, Yong Loo Lin School of Medicine, National University of Singapore, Singapore; Infectious Diseases Group, Genome Institute of Singapore, Singapore
| | - T Barkham
- Department of Laboratory Medicine, Tan Tock Seng Hospital, Singapore
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21
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Barkham T, Zadoks RN, Azmai MNA, Baker S, Bich VTN, Chalker V, Chau ML, Dance D, Deepak RN, van Doorn HR, Gutierrez RA, Holmes MA, Huong LNP, Koh TH, Martins E, Mehershahi K, Newton P, Ng LC, Phuoc NN, Sangwichian O, Sawatwong P, Surin U, Tan TY, Tang WY, Thuy NV, Turner P, Vongsouvath M, Zhang D, Whistler T, Chen SL. One hypervirulent clone, sequence type 283, accounts for a large proportion of invasive Streptococcus agalactiae isolated from humans and diseased tilapia in Southeast Asia. PLoS Negl Trop Dis 2019; 13:e0007421. [PMID: 31246981 PMCID: PMC6597049 DOI: 10.1371/journal.pntd.0007421] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2019] [Accepted: 04/29/2019] [Indexed: 12/11/2022] Open
Abstract
Background In 2015, Singapore had the first and only reported foodborne outbreak of invasive disease caused by the group B Streptococcus (GBS; Streptococcus agalactiae). Disease, predominantly septic arthritis and meningitis, was associated with sequence type (ST)283, acquired from eating raw farmed freshwater fish. Although GBS sepsis is well-described in neonates and older adults with co-morbidities, this outbreak affected non-pregnant and younger adults with fewer co-morbidities, suggesting greater virulence. Before 2015 ST283 had only been reported from twenty humans in Hong Kong and two in France, and from one fish in Thailand. We hypothesised that ST283 was causing region-wide infection in Southeast Asia. Methodology/Principal findings We performed a literature review, whole genome sequencing on 145 GBS isolates collected from six Southeast Asian countries, and phylogenetic analysis on 7,468 GBS sequences including 227 variants of ST283 from humans and animals. Although almost absent outside Asia, ST283 was found in all invasive Asian collections analysed, from 1995 to 2017. It accounted for 29/38 (76%) human isolates in Lao PDR, 102/139 (73%) in Thailand, 4/13 (31%) in Vietnam, and 167/739 (23%) in Singapore. ST283 and its variants were found in 62/62 (100%) tilapia from 14 outbreak sites in Malaysia and Vietnam, in seven fish species in Singapore markets, and a diseased frog in China. Conclusions GBS ST283 is widespread in Southeast Asia, where it accounts for a large proportion of bacteraemic GBS, and causes disease and economic loss in aquaculture. If human ST283 is fishborne, as in the Singapore outbreak, then GBS sepsis in Thailand and Lao PDR is predominantly a foodborne disease. However, whether transmission is from aquaculture to humans, or vice versa, or involves an unidentified reservoir remains unknown. Creation of cross-border collaborations in human and animal health are needed to complete the epidemiological picture. An outbreak due to a bacterium called Streptococccus agalactiae in Singapore in 2015 was caused by a clone called ST283, and was associated with consumption of raw freshwater-fish. It was considered unique as it was the only reported foodborne outbreak of this bacterium. Our new data show that invasive ST283 disease is far from unique. ST283 has been causing disease in humans and farmed fish in SE Asian countries for decades. Reports of ST283 are almost absent outside Asia. We suspect that human ST283 is fishborne in other Asian countries, as it was in Singapore, but we haven’t looked at this yet. We don’t know where ST283 originally came from; it may have been transmitted from humans to fish, or come from another animal. More studies are needed to determine ST283’s geographical extent and burden of disease, as well as its origin, how it is transmitted, and what enables it to be so aggressive. We may then be able to interrupt transmission, to the benefit of fish, farmers, and the general public.
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Affiliation(s)
- Timothy Barkham
- Department of Laboratory Medicine, Tan Tock Seng Hospital, Singapore
- * E-mail: (TB); (SLC)
| | - Ruth N. Zadoks
- Institute of Biodiversity Animal Health and Comparative Medicine, College of Medical Veterinary and Life Sciences, University of Glasgow, Glasgow, United Kingdom
| | - Mohammad Noor Amal Azmai
- Department of Biology, Faculty of Science, and Laboratory of Marine Biotechnology, Institute of Bioscience, Universiti Putra Malaysia, Selangor, Malaysia
| | - Stephen Baker
- Oxford University Clinical Research Unit, Ho Chi Minh City, Vietnam
| | - Vu Thi Ngoc Bich
- Centre for Tropical Medicine, Oxford University Clinical Research Unit, Hanoi, Vietnam
| | | | - Man Ling Chau
- Environmental Health Institute, National Environment Agency, Singapore
- National Centre for Food Science, Singapore Food Agency, Singapore
| | - David Dance
- Lao-Oxford-Mahosot Hospital-Wellcome Trust Research Unit, Mahosot Hospital, Vientiane, Lao People’s Democratic Republic
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
- Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | | | - H. Rogier van Doorn
- Oxford University Clinical Research Unit, Hanoi, Vietnam
- Nuffield Department of Clinical Medicine, Centre for Tropical Medicine and Global Health, University of Oxford, United Kingdom
| | - Ramona A. Gutierrez
- Environmental Health Institute, National Environment Agency, Singapore
- National Centre for Infectious Diseases, Singapore
| | - Mark A. Holmes
- Department of Veterinary Medicine, University of Cambridge, Cambridge, United Kingdom
| | | | - Tse Hsien Koh
- Department of Microbiology, Singapore General Hospital, Singapore
| | - Elisabete Martins
- Instituto de Microbiologia, Instituto de Medicina Molecular, Faculdade de Medicina, Universidade de Lisboa, Lisboa, Portugal
| | - Kurosh Mehershahi
- Department of Medicine, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
| | - Paul Newton
- Lao-Oxford-Mahosot Hospital-Wellcome Trust Research Unit, Mahosot Hospital, Vientiane, Lao People’s Democratic Republic
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
- Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Lee Ching Ng
- Environmental Health Institute, National Environment Agency, Singapore
| | - Nguyen Ngoc Phuoc
- Faculty of Fisheries, University of Agriculture and Forestry, Hue University, Hue City, Vietnam
| | - Ornuma Sangwichian
- Thailand Ministry of Public Health (MOPH)-US Centers for Disease Control and Prevention Collaboration (TUC), Nonthaburi, Thailand
| | - Pongpun Sawatwong
- Thailand Ministry of Public Health (MOPH)-US Centers for Disease Control and Prevention Collaboration (TUC), Nonthaburi, Thailand
| | - Uraiwan Surin
- Nakhon Phanom General Hospital, Nakhon Phanom Provincial Health Office, Nakhon Phanom, Thailand
| | - Thean Yen Tan
- Department of Laboratory Medicine, Changi General Hospital, Singapore
| | - Wen Ying Tang
- Molecular Biology Laboratory, Tan Tock Seng Hospital, Singapore
| | - Nguyen Vu Thuy
- National Hospital for Obstetrics & Gynaecology, Hanoi, Vietnam
| | - Paul Turner
- Nuffield Department of Clinical Medicine, Centre for Tropical Medicine and Global Health, University of Oxford, United Kingdom
- Cambodia-Oxford Medical Research Unit, Angkor Hospital for Children, Siem Reap, Cambodia
| | - Manivanh Vongsouvath
- Lao-Oxford-Mahosot Hospital-Wellcome Trust Research Unit, Mahosot Hospital, Vientiane, Lao People’s Democratic Republic
| | - Defeng Zhang
- Key Laboratory of Tropical & Subtropical Fishery Resource Application & Cultivation, Ministry of Agriculture and Rural Affairs, Pearl River Fisheries Research Institute, Chinese Academy of Fishery Sciences, Guangzhou, People’s Republic of China
| | - Toni Whistler
- Thailand Ministry of Public Health (MOPH)-US Centers for Disease Control and Prevention Collaboration (TUC), Nonthaburi, Thailand
- Division of Global Health Protection, Centers for Disease Control and Prevention, Atlanta, Georgia, United States of America
| | - Swaine L. Chen
- Department of Medicine, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
- Infectious Diseases Group, Genome Institute of Singapore, Singapore
- * E-mail: (TB); (SLC)
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22
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Barkham T, Dance D, Vongsouvath M, Newton P, Chen S. Streptococcus agalactiae ST283 has been present in Laos for over 18 years. Int J Infect Dis 2018. [DOI: 10.1016/j.ijid.2018.04.3843] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022] Open
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23
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Chau ML, Chen SL, Yap M, Hartantyo SHP, Chiew PKT, Fernandez CJ, Wong WK, Fong RK, Tan WL, Tan BZY, Ng Y, Aung KT, Mehershahi KS, Goh C, Kang JSL, Barkham T, Leong AOK, Gutiérrez RA, Ng LC. Group B Streptococcus Infections Caused by Improper Sourcing and Handling of Fish for Raw Consumption, Singapore, 2015-2016. Emerg Infect Dis 2018; 23. [PMID: 29148967 PMCID: PMC5708258 DOI: 10.3201/eid2312.170596] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
Policies and guidelines regarding sale of ready-to-eat raw fish dishes have been updated. We assessed microbial safety and quality of raw fish sold in Singapore during 2015–2016 to complement epidemiologic findings for an outbreak of infection with group B Streptococcus serotype III sequence type (ST) 283 associated with raw fish consumption. Fish-associated group B Streptococcus ST283 strains included strains nearly identical (0–2 single-nucleotide polymorphisms) with the human outbreak strain, as well as strains in another distinct ST283 clade (57–71 single-nucleotide polymorphisms). Our investigations highlight the risk for contamination of freshwater fish (which are handled and distributed separately from saltwater fish sold as sashimi) and the need for improved hygienic handling of all fish for raw consumption. These results have led to updated policy and guidelines regarding the sale of ready-to-eat raw fish dishes in Singapore.
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24
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Ong SW, Barkham T, Kyaw WM, Ho HJ, Chan M. Characterisation of bone and joint infections due to Group B Streptococcus serotype III sequence type 283. Eur J Clin Microbiol Infect Dis 2018; 37:1313-1317. [PMID: 29671175 DOI: 10.1007/s10096-018-3252-4] [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: 02/13/2018] [Accepted: 04/05/2018] [Indexed: 01/02/2023]
Abstract
In 2015, an epidemic of Group B Streptococcus (GBS) serotype III sequence type 283 (ST283) disease was reported in Singapore, associated with consumption of raw freshwater fish. In this study, we further characterise the characteristics of bone and joint infections associated with ST283 GBS in adults and the differences between ST283 and non-ST283 manifestations. A retrospective study of 54 inpatients with invasive GBS disease involving bones and/or joints from 2010 to 2015 was performed. Archived isolates were identified as GBS serotype III and ST283 positive using PCR methods. Clinical data were collected from a review of clinical charts. Twenty-three cases were ST283 and 31 were non-ST283. ST283 GBS patients were more likely to be of Chinese ethnicity, have lower Charlson comorbidity scores, and have fewer overall comorbidities, including diabetes mellitus with end-organ damage, peripheral vascular disease, and previous stroke, compared to non-ST283 GBS patients. ST283 patients had more oligoarthritis, with greater involvement of the knee, shoulder, and vertebrae, compared to monoarticular joint involvement in non-ST283 patients. Six patients had a unique combination of knee and shoulder joint involvement. All ST283 cases were mono-microbial, compared to a significant proportion of polymicrobial cultures in non-ST283 patients. Non-ST283 patients had a significantly longer length of stay and were more likely to undergo amputation or wound debridement. This study adds to growing evidence of a distinct clinical presentation associated with ST283 GBS, involving predominantly healthier patients without significant comorbidities, and with distinct clinical manifestations with regard to bone and joint disease.
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Affiliation(s)
- Sean W Ong
- Department of Infectious Diseases, Tan Tock Seng Hospital, 11 Jalan Tan Tock Seng, Singapore, 308433, Republic of Singapore.
| | - Timothy Barkham
- Department of Laboratory Medicine, Tan Tock Seng Hospital, 11 Jalan Tan Tock Seng, Singapore, 308433, Republic of Singapore
| | - Win Mar Kyaw
- Department of Clinical Epidemiology, Tan Tock Seng Hospital, 11 Jalan Tan Tock Seng, Singapore, 308433, Republic of Singapore
| | - Hanley J Ho
- Department of Clinical Epidemiology, Tan Tock Seng Hospital, 11 Jalan Tan Tock Seng, Singapore, 308433, Republic of Singapore
| | - Monica Chan
- Department of Infectious Diseases, Tan Tock Seng Hospital, 11 Jalan Tan Tock Seng, Singapore, 308433, Republic of Singapore
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25
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Barkham T, Sheppard A, Jones N, Chen SL. Streptococcus agalactiae that caused meningitis in healthy adults in 1998 are ST283, the same type that caused a food-borne outbreak of invasive sepsis in 2015: an observational molecular epidemiology study. Clin Microbiol Infect 2018; 24:923-925. [PMID: 29655956 DOI: 10.1016/j.cmi.2018.04.006] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2018] [Revised: 03/30/2018] [Accepted: 04/03/2018] [Indexed: 10/17/2022]
Affiliation(s)
- T Barkham
- Department of Laboratory Medicine, Tan Tock Seng Hospital, Singapore.
| | - A Sheppard
- Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - N Jones
- Department of Infectious Diseases, Oxford University Hospitals NHS Foundation Trust, Oxford, UK
| | - S L Chen
- Department of Medicine, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
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26
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Ng SMS, Yap JM, Lau QY, Ng FM, Ong EHQ, Barkham T, Teo JWP, Alfatah M, Kong KW, Hoon S, Arumugam P, Hill J, Brian Chia CS. Structure-activity relationship studies of ultra-short peptides with potent activities against fluconazole-resistant Candida albicans. Eur J Med Chem 2018; 150:479-490. [PMID: 29549835 DOI: 10.1016/j.ejmech.2018.03.027] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [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: 10/10/2017] [Revised: 03/02/2018] [Accepted: 03/08/2018] [Indexed: 11/30/2022]
Abstract
Vulvovaginal candidiasis (VVC) is a genital fungal infection afflicting approximately 75% of women globally and is primarily caused by the yeast Candida albicans. The extensive use of fluconazole, the first-line antifungal drug of choice, has led to the emergence of fluconazole-resistant C. albicans, creating a global clinical concern. This, coupled to the lack of new antifungal drugs entering the market over the past decade, has made it imperative for the introduction of new antifungal drug classes. Peptides with antifungal properties are deemed potential drug candidates due to their rapid membrane-disrupting mechanism of action. By specifically targeting and rapidly disrupting fungal membranes, they reduce the chances of resistance development and treatment duration. In a previous screening campaign involving an antimicrobial peptide library, we identified an octapeptide (IKIKIKIK-NH2) with potent activity against C. albicans. Herein, we report a structure-activity relationship study on this peptide with the aim of designing a more potent peptide for further development. The lead peptide was then tested against a panel of fluconazole-resistant C. albicans, subjected to a fungicidal/static determination assay, a human dermal fibroblast viability assay and a homozygous profiling assay to gain insights into its mechanism of action and potential for further development as a topical antifungal agent.
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Affiliation(s)
- Siew Mei Samantha Ng
- Experimental Therapeutics Centre, Agency for Science, Technology and Research (A*STAR), 31 Biopolis Way, Nanos #03-01, Singapore, 138669, Singapore
| | - Jia Mao Yap
- Experimental Therapeutics Centre, Agency for Science, Technology and Research (A*STAR), 31 Biopolis Way, Nanos #03-01, Singapore, 138669, Singapore
| | - Qiu Ying Lau
- Experimental Therapeutics Centre, Agency for Science, Technology and Research (A*STAR), 31 Biopolis Way, Nanos #03-01, Singapore, 138669, Singapore
| | - Fui Mee Ng
- Experimental Therapeutics Centre, Agency for Science, Technology and Research (A*STAR), 31 Biopolis Way, Nanos #03-01, Singapore, 138669, Singapore
| | - Esther Hong Qian Ong
- Experimental Therapeutics Centre, Agency for Science, Technology and Research (A*STAR), 31 Biopolis Way, Nanos #03-01, Singapore, 138669, Singapore
| | - Timothy Barkham
- Department of Laboratory Medicine, Tan Tock Seng Hospital, 11 Jalan Tan Tock Seng, 308433, Singapore
| | - Jeanette Woon Pei Teo
- Department of Laboratory Medicine, National University Hospital, 5 Lower Kent Ridge Road, Singapore, 119074, Singapore
| | - Mohammad Alfatah
- Bioinformatics Institute, 30 Biopolis Street, #07-01, Matrix, 138671, Singapore
| | - Kiat Whye Kong
- Molecular Engineering Lab, 61 Biopolis Drive, #03-12, Proteos, 138673, Singapore
| | - Shawn Hoon
- Molecular Engineering Lab, 61 Biopolis Drive, #03-12, Proteos, 138673, Singapore
| | - Prakash Arumugam
- Bioinformatics Institute, 30 Biopolis Street, #07-01, Matrix, 138671, Singapore
| | - Jeffrey Hill
- Experimental Therapeutics Centre, Agency for Science, Technology and Research (A*STAR), 31 Biopolis Way, Nanos #03-01, Singapore, 138669, Singapore
| | - Cheng San Brian Chia
- Experimental Therapeutics Centre, Agency for Science, Technology and Research (A*STAR), 31 Biopolis Way, Nanos #03-01, Singapore, 138669, Singapore.
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Haller L, Chen H, Ng C, Le TH, Koh TH, Barkham T, Sobsey M, Gin KYH. Occurrence and characteristics of extended-spectrum β-lactamase- and carbapenemase- producing bacteria from hospital effluents in Singapore. Sci Total Environ 2018; 615:1119-1125. [PMID: 29751417 DOI: 10.1016/j.scitotenv.2017.09.217] [Citation(s) in RCA: 61] [Impact Index Per Article: 10.2] [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: 07/27/2017] [Revised: 09/17/2017] [Accepted: 09/20/2017] [Indexed: 05/09/2023]
Abstract
One of the most important resistance mechanisms in Gram-negative bacteria today is the production of enzymes causing resistance to cephalosporin and carbapenem antibiotics. The spread of extended-spectrum β-lactamases (ESBL)- and carbapenemase- producing Gram-negative bacteria is an emerging global public health problem. The aim of the present study was to (i) assess the prevalence of carbapenem-resistant bacteria (CRB) and ESBL-producing strains in sewage effluents from two major hospitals in Singapore, (ii) characterize the isolated strains and (iii) identify some of the ESBL and carbapenemase genes responsible for the resistance. CHROMagar ESBL and KPC plates were used to rapidly screen for ESBL-producing bacteria and those expressing reduced susceptibility to carbapenems, respectively. The abundance of ESBL-producers and CRB in hospital wastewater ranged between 103 and 106CFU/mL. Out of the 66 isolates picked from ESBL and KPC plates, 95%, 82%, 82% and 76% were resistant to ceftriaxone, ceftazidime (3rd generation cephalosporin family), ertapenem and meropenem (carbapenem family), respectively. Among the resistant isolates, the most predominant taxa identified were Pseudomonas spp. (28.2%), Klebsiella spp. (28.2%), Enterobacter spp. (18.3%) and Citrobacter spp. (11.3%). PCR and sequencing analysis showed that the predominant β-lactamase genes were blaSHV (41.1%) followed by blaNDM-1 (35.6%), blaCTX (35.6%) and blaKPC (28.8%). The results of this study show a high prevalence of bacteria resistant to modern extended-spectrum cephalosporins and carbapenems and the presence of ESBL- and carbapenemase producers in hospital effluents. These findings support the need to improve management of hospital wastewater in order to minimize the spread of antimicrobial resistant microorganisms from this source.
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Affiliation(s)
- Laurence Haller
- Department of Civil & Environmental Engineering, National University of Singapore, E1A-07-03, 1 Engineering Drive 2, 117576, Singapore
| | - Hongjie Chen
- Department of Civil & Environmental Engineering, National University of Singapore, E1A-07-03, 1 Engineering Drive 2, 117576, Singapore
| | - Charmaine Ng
- Department of Civil & Environmental Engineering, National University of Singapore, E1A-07-03, 1 Engineering Drive 2, 117576, Singapore
| | - Thai Hoang Le
- Department of Civil & Environmental Engineering, National University of Singapore, E1A-07-03, 1 Engineering Drive 2, 117576, Singapore
| | - Tse Hsien Koh
- Department of Pathology, Singapore, General Hospital, Outram Road, Singapore 169608
| | - Timothy Barkham
- Department of Laboratory Medicine, Tan Tock Seng Hospital, 11 Jalan Tan Tock Seng, Singapore 308433
| | - Mark Sobsey
- Department of Environmental Sciences and Engineering, School of Public Health, University of North Carolina CB# 7431, Chapel Hill, N.C. 27599, USA
| | - Karina Yew-Hoong Gin
- Department of Civil & Environmental Engineering, National University of Singapore, E1A-07-03, 1 Engineering Drive 2, 117576, Singapore; NUS Environmental Research Institute (NERI), National University of Singapore, T-Lab Building (#02-01), 5A Engineering Drive 1, 117411, Singapore.
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Kalimuddin S, Chen SL, Lim CTK, Koh TH, Tan TY, Kam M, Wong CW, Mehershahi KS, Chau ML, Ng LC, Tang WY, Badaruddin H, Teo J, Apisarnthanarak A, Suwantarat N, Ip M, Holden MTG, Hsu LY, Barkham T. 2015 Epidemic of Severe Streptococcus agalactiae Sequence Type 283 Infections in Singapore Associated With the Consumption of Raw Freshwater Fish: A Detailed Analysis of Clinical, Epidemiological, and Bacterial Sequencing Data. Clin Infect Dis 2018; 64:S145-S152. [PMID: 28475781 DOI: 10.1093/cid/cix021] [Citation(s) in RCA: 57] [Impact Index Per Article: 9.5] [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: 12/26/2022] Open
Abstract
Background Streptococcus agalactiae (group B Streptococcus [GBS]) has not been described as a foodborne pathogen. However, in 2015, a large outbreak of severe invasive sequence type (ST) 283 GBS infections in adults epidemiologically linked to the consumption of raw freshwater fish occurred in Singapore. We attempted to determine the scale of the outbreak, define the clinical spectrum of disease, and link the outbreak to contaminated fish. Methods Time-series analysis was performed on microbiology laboratory data. Food handlers and fishmongers were screened for enteric carriage of GBS. A retrospective cohort study was conducted to assess differences in demographic and clinical characteristics of patients with invasive ST283 and non-ST283 infections. Whole-genome sequencing was performed on human and fish ST283 isolates from Singapore, Thailand, and Hong Kong. Results The outbreak was estimated to have started in late January 2015. Within the study cohort of 408 patients, ST283 accounted for 35.8% of cases. Patients with ST283 infection were younger and had fewer comorbidities but were more likely to develop meningoencephalitis, septic arthritis, and spinal infection. Of 82 food handlers and fishmongers screened, none carried ST283. Culture of 43 fish samples yielded 13 ST283-positive samples. Phylogenomic analysis of 161 ST283 isolates from humans and fish revealed they formed a tight clade distinguished by 93 single-nucleotide polymorphisms. Conclusions ST283 is a zoonotic GBS clone associated with farmed freshwater fish, capable of causing severe disease in humans. It caused a large foodborne outbreak in Singapore and poses both a regional and potentially more widespread threat.
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Affiliation(s)
| | - Swaine L Chen
- Department of Medicine, Yong Loo Lin School of Medicine, National University of Singapore.,Genome Institute of Singapore
| | - Cindy T K Lim
- Saw Swee Hock School of Public Health, National University Singapore
| | | | - Thean Yen Tan
- Department of Laboratory Medicine, Changi General Hospital, Singapore
| | - Michelle Kam
- Department of Internal Medicine, Singapore General Hospital
| | | | - Kurosh S Mehershahi
- Department of Medicine, Yong Loo Lin School of Medicine, National University of Singapore
| | - Man Ling Chau
- Environmental Health Institute, National Environment Agency
| | - Lee Ching Ng
- Environmental Health Institute, National Environment Agency
| | - Wen Ying Tang
- Department of Laboratory Medicine, Tan Tock Seng Hospital
| | | | - Jeanette Teo
- Department of Laboratory Medicine, Microbiology Unit, National University Hospital, Singapore
| | | | - Nuntra Suwantarat
- Infectious Disease Division, Thammasat University Hospital, and.,Chulabhorn International College of Medicine, Thammasat University, Pathumthani, Thailand
| | - Margaret Ip
- Department of Microbiology, Chinese University of Hong Kong, Shatin; and
| | | | - Li Yang Hsu
- Department of Medicine, Yong Loo Lin School of Medicine, National University of Singapore.,Saw Swee Hock School of Public Health, National University Singapore
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Rajendram P, Mar Kyaw W, Leo YS, Ho H, Chen WK, Lin R, Pratim DP, Badaruddin H, Ang B, Barkham T, Chow A. Group B Streptococcus Sequence Type 283 Disease Linked to Consumption of Raw Fish, Singapore. Emerg Infect Dis 2018; 22:1974-1977. [PMID: 27767905 PMCID: PMC5088009 DOI: 10.3201/eid2211.160252] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
An outbreak of invasive group B Streptococcus (GBS) disease occurred in Singapore in mid-2015. We conducted a case–control study of 22 adults with invasive GBS infections during June 21–November 21, 2015. Consumption of raw fish was strongly associated with invasive sequence type 283 infections, but not with non–sequence type 283 infections.
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Abstract
Background Mycoplasma genitalium was first reported as a cause of non-gonococcal urethritis in 1980. It has progressed from being an ‘emerging’ sexually transmitted infection (STI) to an accepted STI. Prevalence of infection has been reported as the Netherlands 4.5%, Sweden 6.3%, UK 1.2% and France 4%. M. genitalium has the smallest known bacterial genome and was the second bacterial genome fully sequenced. It has minimal requirements and is said to approach the minimum possible for a living cell. It is extremely fastidious; only a few strains have been cultured worldwide. Diagnosis relies on direct detection. It does not have a cell wall so it is not susceptible to antibiotics such as penicillins and cephalosporins. Therapy depends on fluoroquinolones and macrolides but resistance to macrolides has been widely reported: 13% France, 18% Sweden, 40% UK, Australia and Denmark, 100% Greenland, 30% Japan. Methods Ethics approval was granted. DNA extracts left over after routine clinical diagnostics at the Department of STI Control (DSC) Clinic, Kelantan Lane, Singapore were harvested. DNA had been extracted on a Cobas 4800 instrument (Roche) from urine and urethral swabs collected for testing for Chlamydia trachomatis (CT) and Neisseria gonorrhoeae (NG). A 2-plex real-time PCR assay targeting the pdhD and mgpB genes was used to screen for M. genitalium. Samples were deemed positive if both targets were detected. If only one target was detected, the sample was retested; if reactive in either target upon retest, the sample was considered positive for M. genitalium. Positive DNA preps were then screened for macrolide resistance mutations after Sanger sequencing of the 23S rRNA gene. Results 368 anonymised DNA elutes from 254 urines and 114 urethral swabs were collected between May and July 2016. One hundred eighty-four were CT/NG positive and 184 were CT/NG negative. Sixteen (4.3%) were positive for M. genitalium. Four (25%) of these 16 samples contained macrolide resistance associated mutations; A2058T (x2), A2058G (x1), and A2059G (x1). Conclusion M. genitalium was detected in 4.3% of samples. Macrolide resistance mutations were detected in 25%, similar to international rates. Some guidelines recommend testing for resistance to guide therapy and to perform a test of cure. Disclosures All authors: No reported disclosures.
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Ng SMS, Yap YYA, Cheong JWD, Ng FM, Lau QY, Barkham T, Teo JWP, Hill J, Chia CSB. Antifungal peptides: a potential new class of antifungals for treating vulvovaginal candidiasis caused by fluconazole-resistant Candida albicans. J Pept Sci 2017; 23:215-221. [PMID: 28105725 DOI: 10.1002/psc.2970] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [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: 11/19/2016] [Revised: 12/14/2016] [Accepted: 12/23/2016] [Indexed: 11/06/2022]
Abstract
Vulvovaginal candidiasis/candidosis is a common fungal infection afflicting approximately 75% of women globally caused primarily by the yeast Candida albicans. Fluconazole is widely regarded as the antifungal drug of choice since its introduction in 1990 due to its high oral bioavailability, convenient dosing regimen and favourable safety profile. However, its widespread use has led to the emergence of fluconazole-resistant C. albicans, posing a universal clinical concern. Coupled to the dearth of new antifungal drugs entering the market, it is imperative to introduce new drug classes to counter this threat. Antimicrobial peptides (AMPs) are potential candidates due to their membrane-disrupting mechanism of action. By specifically targeting fungal membranes and being rapidly fungicidal, they can reduce the chances of resistance development and treatment duration. Towards this goal, we conducted a head-to-head comparison of 61 short linear AMPs from the literature to identify the peptide with the most potent activity against fluconazole-resistant C. albicans. The 11-residue peptide, P11-6, was identified and assayed against a panel of clinical C. albicans isolates followed by fungicidal/static determination and a time-kill assay to gauge its potential for further drug development. Copyright © 2017 European Peptide Society and John Wiley & Sons, Ltd.
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Affiliation(s)
- Siew Mei Samantha Ng
- Experimental Therapeutics Centre, Agency for Science, Technology and Research (A*STAR), 31 Biopolis Way, Nanos #03-01, 138669, Singapore
| | - Yi Yong Alvin Yap
- Experimental Therapeutics Centre, Agency for Science, Technology and Research (A*STAR), 31 Biopolis Way, Nanos #03-01, 138669, Singapore
| | - Jin Wei Darryl Cheong
- Experimental Therapeutics Centre, Agency for Science, Technology and Research (A*STAR), 31 Biopolis Way, Nanos #03-01, 138669, Singapore
| | - Fui Mee Ng
- Experimental Therapeutics Centre, Agency for Science, Technology and Research (A*STAR), 31 Biopolis Way, Nanos #03-01, 138669, Singapore
| | - Qiu Ying Lau
- Experimental Therapeutics Centre, Agency for Science, Technology and Research (A*STAR), 31 Biopolis Way, Nanos #03-01, 138669, Singapore
| | - Timothy Barkham
- Department of Laboratory Medicine, Tan Tock Seng Hospital, 11 Jalan Tan Tock Seng, 308433, Singapore
| | - Jeanette Woon Pei Teo
- Department of Laboratory Medicine, National University Hospital, 5 Lower Kent Ridge Road, 119074, Singapore
| | - Jeffrey Hill
- Experimental Therapeutics Centre, Agency for Science, Technology and Research (A*STAR), 31 Biopolis Way, Nanos #03-01, 138669, Singapore
| | - Cheng San Brian Chia
- Experimental Therapeutics Centre, Agency for Science, Technology and Research (A*STAR), 31 Biopolis Way, Nanos #03-01, 138669, Singapore
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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.
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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.
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Ho SWL, Ang CL, Ding CSL, Barkham T, Teoh LC. Necrotizing Fasciitis Caused by Cryptococcus gattii. Am J Orthop (Belle Mead NJ) 2015; 44:E517-E522. [PMID: 26665255] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Necrotizing fasciitis (NF) is a severe soft-tissue infection that can lead to high morbidity and mortality. The etiology of NF is often polymicrobial. Although rare, fungal organisms have been known to cause NF. Cryptococcus is a fungal infection that may lead to NF. Here we report the case of a 73-year-old man who had diabetes and presented with pain and swelling in the left hand after being bitten by an insect over the dorsum of the hand. Operative débridement revealed NF caused by Cryptococcus gattii. Antifungal medication was started, and the patient underwent multiple débridements of the hand with subsequent skin grafting. Four months later, the hand wound was completely healed. Authors have reported several cases of NF secondary to Cryptococcus neoformans in immunocompromised patients. The emerging C gattii pathogen affects immunocompetent patients. Although the transmission route is mainly respiratory, direct inoculation has been described as well. Ours is the first reported case of NF secondary to C gattii. It is important to consider fungal elements as a source of NF. Appropriate treatment includes aggressive surgical débridement and antifungal therapy.
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Affiliation(s)
- Sean Wei Loong Ho
- Department of Orthopaedic Surgery, Tan Tock Seng Hospital, Singapore.
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Shin Y, Perera AP, Tang WY, Fu DL, Liu Q, Sheng JK, Gu Z, Lee TY, Barkham T, Kyoung Park M. A rapid amplification/detection assay for analysis of Mycobacterium tuberculosis using an isothermal and silicon bio-photonic sensor complex. Biosens Bioelectron 2015; 68:390-396. [DOI: 10.1016/j.bios.2015.01.030] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2014] [Revised: 01/12/2015] [Accepted: 01/13/2015] [Indexed: 02/04/2023]
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Leow MKS, Dalan R, Chee CBE, Earnest A, Chew DEK, Tan AWK, Kon WYC, Jong M, Barkham T, Wang YT. Latent tuberculosis in patients with diabetes mellitus: prevalence, progression and public health implications. Exp Clin Endocrinol Diabetes 2014; 122:528-32. [PMID: 25003362 DOI: 10.1055/s-0034-1377044] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
BACKGROUND Diabetes mellitus (DM) confers a higher risk for tuberculosis (TB). Yet, TB screening and chemoprophylaxis for latent TB infection (LTBI) in DM remains controversial. We conducted a cross-sectional study to elucidate LTBI prevalence and longitudinal follow-up to ascertain LTBI to active TB progression rate in DM. METHODS 220 DM patients without previous TB from the outpatient diabetes clinic of the hospital were enrolled. T-Spot TB, tuberculin-skin-test (TST) and chest radiography (CXR) were performed. LTBI was defined by negative CXR with reactive T-Spot TB. Progression to active TB was confirmed by cross-checking against the TB registry. RESULTS The prevalence of LTBI was 28.2% (62/220) by reactive T-Spot. None progressed to active TB from 2007-2013. Multivariate analysis revealed that any co-morbidity (p=0.016) was positively associated while metformin (p=0.008) was negatively associated with LTBI. CONCLUSIONS Over a quarter of DM patients harbor LTBI. While the lack of demonstrable progression to active TB within the follow-up time frame up to this point does not unequivocally support a routine TB screening policy or anti-TB chemoprophylaxis for LTBI in a diabetic population for now, this preliminary evidence needs re-evaluation with longer follow-up of this enrolled cohort over the next decade.
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Affiliation(s)
- M K S Leow
- Senior Consultant, Department of Endocrinology, Tan Tock Seng Hospital
| | - R Dalan
- Consultant, Department of Endocrinology, Tan Tock Seng Hospital
| | - C B E Chee
- Senior Consultant, Tuberculosis Control Unit, Tan Tock Seng Hospital
| | - A Earnest
- Associate Professor, Centre for Quantitative Medicine, Duke-NUS Graduate Medical School
| | - D E K Chew
- Consultant, Department of Endocrinology, Tan Tock Seng Hospital
| | - A W K Tan
- Consultant, Department of Endocrinology, Tan Tock Seng Hospital
| | - W Y C Kon
- Senior Consultant, Department of Endocrinology, Tan Tock Seng Hospital
| | - M Jong
- Senior Consultant, Department of Endocrinology, Tan Tock Seng Hospital
| | - T Barkham
- Senior Consultant, Clinical Microbiology, Laboratory Medicine, Tan Tock Seng Hospital
| | - Y T Wang
- Senior Consultant, Tuberculosis Control Unit, Tan Tock Seng Hospital
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Pok K, Lee L, Lye D, lee V, Leo Y, Barkham T, Ng L. Cytokine changes in adult dengue hemorrhagic fever. Int J Infect Dis 2012. [DOI: 10.1016/j.ijid.2012.05.216] [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] [Indexed: 11/17/2022] Open
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Chow A, Her Z, Ong EKS, Chen JM, Dimatatac F, Kwek DJC, Barkham T, Yang H, Rénia L, Leo YS, Ng LFP. Persistent arthralgia induced by Chikungunya virus infection is associated with interleukin-6 and granulocyte macrophage colony-stimulating factor. J Infect Dis 2011; 203:149-57. [PMID: 21288813 PMCID: PMC3071069 DOI: 10.1093/infdis/jiq042] [Citation(s) in RCA: 264] [Impact Index Per Article: 20.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
Background. Chikungunya virus (CHIKV) infection induces arthralgia. The involvement of inflammatory cytokines and chemokines has been suggested, but very little is known about their secretion profile in CHIKV-infected patients. Methods. A case-control longitudinal study was performed that involved 30 adult patients with laboratory-confirmed Chikungunya fever. Their profiles of clinical disease, viral load, and immune mediators were investigated. Results. When patients were segregated into high viral load and low viral load groups during the acute phase, those with high viremia had lymphopenia, lower levels of monocytes, neutrophilia, and signs of inflammation. The high viral load group was also characterized by a higher production of pro-inflammatory cytokines, such as interferon-α and interleukin (IL)–6, during the acute phase. As the disease progressed to the chronic phase, IL-17 became detectable. However, persistent arthralgia was associated with higher levels of IL-6 and granulocyte macrophage colony-stimulating factor, whereas patients who recovered fully had high levels of Eotaxin and hepatocyte growth factor. Conclusions. The level of CHIKV viremia during the acute phase determined specific patterns of pro-inflammatory cytokines, which were associated with disease severity. At the chronic phase, levels of IL-6, and granulocyte macrophage colony-stimulating factor found to be associated with persistent arthralgia provide a possible explanation for the etiology of arthralgia that plagues numerous CHIKV-infected patients.
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Inoue M, Barkham T, Leo YS, Chan KP, Chow A, Wong CW, Tze Chuen Lee R, Maurer-Stroh S, Lin R, Lin C. Emergence of oseltamivir-resistant pandemic (H1N1) 2009 virus within 48 hours. Emerg Infect Dis 2011; 16:1633-6. [PMID: 20875299 PMCID: PMC3294403 DOI: 10.3201/eid1610.100688] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
An oseltamivir-resistant influenza A pandemic (H1N1) 2009 virus evolved and emerged from zero to 52% of detectable virus within 48 hours of a patient’s exposure to oseltamivir. Phylogenetic analysis and data gathered by pyrosequencing and cloning directly on clinical samples suggest that the mutant emerged de novo.
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Inoue M, Tang WY, Wee SY, Barkham T. Audit and improve! Evaluation of a real-time probe-based PCR assay with internal control for the direct detection of Mycobacterium tuberculosis complex. Eur J Clin Microbiol Infect Dis 2010; 30:131-5. [DOI: 10.1007/s10096-010-1059-z] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2010] [Accepted: 08/28/2010] [Indexed: 11/28/2022]
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Chen MI, Barr IG, Koh GCH, Lee VJ, Lee CPS, Shaw R, Lin C, Yap J, Cook AR, Tan BH, Loh JP, Barkham T, Chow VTK, Lin RTP, Leo YS. Serological response in RT-PCR confirmed H1N1-2009 influenza a by hemagglutination inhibition and virus neutralization assays: an observational study. PLoS One 2010; 5:e12474. [PMID: 20814575 PMCID: PMC2930007 DOI: 10.1371/journal.pone.0012474] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2010] [Accepted: 08/04/2010] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND We describe the serological response following H1N1-2009 influenza A infections confirmed by reverse-transcriptase polymerase chain reaction (RT-PCR). METHODOLOGY AND PRINCIPAL FINDINGS The study included patients admitted to hospital, subjects of a seroepidemiologic cohort study, and participants identified from outbreak studies in Singapore. Baseline (first available blood sample) and follow-up blood samples were analyzed for antibody titers to H1N1-2009 and recently circulating seasonal influenza A virus strains by hemagglutination inhibition (HI) and virus micro-neutralization (VM) assays. 267 samples from 118 cases of H1N1-2009 were analyzed. Geometric mean titers by HI peaked at 123 (95% confidence interval, CI 43-356) between days 30 to 39. The chance of observing seroconversion (four-fold or greater increase of antibodies) was maximized when restricting analysis to 45 participants with baseline sera collected within 5 days of onset and follow-up sera collected 15 or more days after onset; for these participants, 82% and 89% seroconverted to A/California/7/2009 H1N1 by HI and VM respectively. A four-fold or greater increase in cross-reactive antibody titers to seasonal A/Brisbane/59/2007 H1N1, A/Brisbane/10/2007 H3N2 and A/Wisconsin/15/2009 H3N2 occurred in 20%, 18% and 16% of participants respectively. CONCLUSIONS AND SIGNIFICANCE Appropriately timed paired serology detects 80-90% RT-PCR confirmed H1N1-2009; Antibodies from infection with H1N1-2009 cross-reacted with seasonal influenza viruses.
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Affiliation(s)
- Mark I Chen
- Clinical Epidemiology, Tan Tock Seng Hospital, Singapore, Singapore.
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Lee KS, Lai YL, Lo S, Barkham T, Aw P, Ooi PL, Tai JC, Hibberd M, Johansson P, Khoo SP, Ng LC. Dengue virus surveillance for early warning, Singapore. Emerg Infect Dis 2010; 16:847-9. [PMID: 20409381 PMCID: PMC2953985 DOI: 10.3201/eid1605.091006] [Citation(s) in RCA: 94] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
In Singapore, after a major outbreak of dengue in 2005, another outbreak occurred in 2007. Laboratory-based surveillance detected a switch from dengue virus serotype 1 (DENV-1) to DENV-2. Phylogenetic analysis showed a clade replacement within DENV-2 cosmopolitan genotype, which accompanied the predominant serotype switch, and cocirculation of multiple genotypes of DENV-3.
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Sandar S, Chow A, Lye D, Barkham T, Leo YS. PP-077 Risk factors associated with severe influenza in tropical Singapore. Int J Infect Dis 2010. [DOI: 10.1016/s1201-9712(10)60145-2] [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] [Indexed: 10/19/2022] Open
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Kalimuddin S, Seow CJ, Barkham T, Deepak RN, Li L, Tan TT. Hidden health risks of the Hajj--a report of two cases of brucellosis contracted by pilgrims during the Hajj. ACTA ACUST UNITED AC 2010; 42:228-30. [PMID: 20085421 DOI: 10.3109/00365540903402971] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Commonly occurring health hazards associated with the Hajj have been well described in the literature. However, there remain other serious but less well known health risks. We present here 2 cases of brucellosis contracted from drinking unpasteurised camel's milk during the Hajj.
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Affiliation(s)
- Shirin Kalimuddin
- Department of Respiratory and Critical Care Medicine, Singapore General Hospital, Singapore
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Donaldson A, Barkham T. De-escalation for amoxicillin-susceptible Escherichia coli: easier said than done. J Hosp Infect 2010; 74:304-5. [DOI: 10.1016/j.jhin.2009.07.013] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2009] [Accepted: 07/21/2009] [Indexed: 10/20/2022]
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Abstract
On April 25, 2009, Singapore implemented strict containment measures for pandemic (H1N1) 2009 with enhanced surveillance and hospital isolation. In the first month, seasonal influenza, predominantly virus subtype H3N2, was diagnosed for 32% of patients with acute febrile respiratory illness. Our findings underscore the high prevalence of seasonal influenza in Singapore.
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Affiliation(s)
- Yee Sin Leo
- Tan Tock Seng Hospital, 11 Jalan Tan Tock Seng, Singapore 308433.
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Mukherjee P, Lim PL, Chow A, Barkham T, Seow E, Win MK, Chua A, Leo YS, Cheng Chen MI. Epidemiology of travel-associated pandemic (H1N1) 2009 infection in 116 patients, Singapore. Emerg Infect Dis 2010; 16:21-6. [PMID: 20031038 PMCID: PMC2874386 DOI: 10.3201/eid1601.091376] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
In June 2009, during Singapore's pandemic influenza plan containment phase, pandemic (H1N1) 2009 was introduced into the country through imported cases. To understand how travel patterns affected the initial outbreak, we examined epidemiologic and travel data for the first 116 case-patients admitted to Tan Tock Seng Hospital, Singapore, with travel-associated infection. Sixty-one percent and 54% of patients, respectively, met US Centers for Disease Control and Prevention and World Health Organization temperature criteria for influenza-like illness. One fourth of the case-patients traveled after illness onset, and 15% became ill while traveling. Regions of exposure for imported infections changed rapidly; case-patients initially arrived from North America, followed by Australasia and Southeast Asia. Case-patients on longer flights were more likely to become ill before arrival; those with shorter flights tended to become ill after arrival. Thermal scanners detected fevers in 12% of the arriving case-patients, resulting in a shorter time to isolation.
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Mukherjee P, Lim PL, Chow A, Barkham T, Seow E, Win MK, Chua A, Leo YS, Chen MIC. Epidemiology of Travel-associated Pandemic (H1N1) 2009 Infection in 116 Patients, Singapore. Emerg Infect Dis 2010. [DOI: 10.3201/eid1512.091376] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
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48
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Donaldson AD, Tang WY, Tan AL, Barkham T. Neisseria meningitidis with reduced susceptibility to quinolones in Singapore. J Antimicrob Chemother 2009; 65:362-4. [PMID: 20007332 DOI: 10.1093/jac/dkp437] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Affiliation(s)
- Annabelle D Donaldson
- Department of Laboratory Medicine, Tan Tock Seng Hospital, 11 Jalan Tan Tock Seng, Singapore 308433.
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Jimmy LWK, Barkham T, Ming CQ, Lim L, Lin J, Hong GL, Jin HW. Reduction in length of hospitalisation for microbial keratitis patients: a prospective study. Int J Health Care Qual Assur 2009; 22:701-8. [PMID: 19957824 DOI: 10.1108/09526860910995038] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
PURPOSE Prolonged hospital stay in the course of management of microbial keratitis patients has been a burden to the resources of a multi-disciplinary tertiary hospital. The paper aims to evaluate the impact of streamlining the workflow and increased cross-disciplinary interactions on the average length of hospitalisation. It also seeks to study secondary outcomes including the average time for initiation of therapy, microbial culture positive rate, patients' satisfaction and resource savings. DESIGN/METHODOLOGY/APPROACH The authors employed the model of clinical practice improvement (CPI) (New South Wales Health Department) methodology for a systematic approach to improve processes of care and service delivery. A team consisting of ophthalmologist, microbiologist, pharmacist and nursing staff was formed to brainstorm and highlight the problems. A new workflow was formulated and data were prospectively collected to evaluate and to identify areas where improvements could be made. FINDINGS The average length of hospitalisation stay was reduced from 7.43 to 5.93 days with a mean difference of 1.50 +/- 0.63 days (p < 0.05). The microbial keratitis culture positive rate increased from 54.6 to 73.0 per cent (p > 0.05). The average time taken to initiate antibiotic eye drops after first contact with the doctor was 26.1 minutes (n = 28), and 74.4 per cent of the patients surveyed were satisfied with their length of stay. RESEARCH LIMITATIONS/IMPLICATIONS Intervention was carried out on the top 20 per cent of areas for improvement after voting by the team members. PRACTICAL IMPLICATIONS The reduction in average length of hospitalisation can be improved by strict adherence to a formulated workflow and coordinated cross-disciplinary interactions. ORIGINALITY/VALUE The management protocol discussed in the paper for microbial keratitis enables more effective and efficient treatment for the inpatients. Increased cross-discipline and nursing coordination decreases length of hospitalisation of microbial keratitis patients and achieve better care for these patients.
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Seow CJ, Barkham T, Wong PM, Lin L, Pada SK, Tan SH. Brucellosis in a Singaporean with prolonged fever. Singapore Med J 2009; 50:e312-e314. [PMID: 19787157] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Brucellosis, a zoonotic disease of worldwide distribution, is common in many developing countries as well as in countries of the Mediterranean basin. We report brucellosis in a 52-year-old man, who had a recent travel history to Saudi Arabia, and who presented with prolonged fever and deranged liver enzymes. In view of the rarity of brucellosis and its potential life-threatening complications, patients returning from an endemic country need to be questioned for possible Brucella exposure, to ensure that diagnostic tests and treatment are carried out in a timely fashion. In addition to notifying the authorities, the clinician should also warn the laboratory early as cultures of brucellosis are highly transmissible and are one of the most common laboratory-acquired infections.
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Affiliation(s)
- C J Seow
- Department of General Medicine, Tan Tock Seng Hospital, 11 Jalan Tan Tock Seng, Singapore 308433.
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