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Monecke S, Burgold-Voigt S, Braun SD, Diezel C, Liebler-Tenorio EM, Müller E, Nassar R, Reinicke M, Reissig A, Senok A, Ehricht R. Characterisation of PVL-Positive Staphylococcus argenteus from the United Arab Emirates. Antibiotics (Basel) 2024; 13:401. [PMID: 38786130 PMCID: PMC11117363 DOI: 10.3390/antibiotics13050401] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2024] [Revised: 04/23/2024] [Accepted: 04/24/2024] [Indexed: 05/25/2024] Open
Abstract
Staphylococcus argenteus is a recently described staphylococcal species that is related to Staphylococcus aureus but lacks the staphyloxanthin operon. It is able to acquire both resistance markers such as the SCCmec elements and mobile genetic elements carrying virulence-associated genes from S. aureus. This includes those encoding the Panton-Valentine leukocidin (PVL), which is associated mainly with severe and/or recurrent staphylococcal skin and soft tissue infections. Here, we describe the genome sequences of two PVL-positive, mecA-negative S. argenteus sequence type (ST) 2250 isolates from the United Arab Emirates in detail. The isolates were found in a dental clinic in the United Arab Emirates (UAE). Both were sequenced using Oxford Nanopore Technology (ONT). This demonstrated the presence of temperate bacteriophages in the staphylococcal genomes, including a PVL prophage. It was essentially identical to the published sequence of phiSa2wa_st78 (GenBank NC_055048), a PVL phage from an Australian S. aureus clonal complex (CC) 88 isolate. Besides the PVL prophage, one isolate carried another prophage and the second isolate carried two additional prophages, whereby the region between these two prophages was inverted. This "flipped" region comprised about 1,083,000 bp, or more than a third of the strain's genome, and it included the PVL prophage. Prophages were induced by Mitomycin C treatment and subjected to transmission electron microscopy (TEM). This yielded, in accordance to the sequencing results, one or, respectively, two distinct populations of icosahedral phages. It also showed prolate phages which presumptively might be identified as the PVL phage. This observation highlights the significance bacteriophages have as agents of horizontal gene transfer as well as the need for monitoring emerging staphylococcal strains, especially in cosmopolitan settings such as the UAE.
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Affiliation(s)
- Stefan Monecke
- Leibniz Institute of Photonic Technology (IPHT), Leibniz Center for Photonics in Infection Research (LPI), 07745 Jena, Germany (A.R.); (R.E.)
- InfectoGnostics Research Campus, 07743 Jena, Germany
| | - Sindy Burgold-Voigt
- Leibniz Institute of Photonic Technology (IPHT), Leibniz Center for Photonics in Infection Research (LPI), 07745 Jena, Germany (A.R.); (R.E.)
- InfectoGnostics Research Campus, 07743 Jena, Germany
| | - Sascha D. Braun
- Leibniz Institute of Photonic Technology (IPHT), Leibniz Center for Photonics in Infection Research (LPI), 07745 Jena, Germany (A.R.); (R.E.)
- InfectoGnostics Research Campus, 07743 Jena, Germany
| | - Celia Diezel
- Leibniz Institute of Photonic Technology (IPHT), Leibniz Center for Photonics in Infection Research (LPI), 07745 Jena, Germany (A.R.); (R.E.)
- InfectoGnostics Research Campus, 07743 Jena, Germany
| | | | - Elke Müller
- Leibniz Institute of Photonic Technology (IPHT), Leibniz Center for Photonics in Infection Research (LPI), 07745 Jena, Germany (A.R.); (R.E.)
- InfectoGnostics Research Campus, 07743 Jena, Germany
| | - Rania Nassar
- College of Medicine, Mohammed Bin Rashid University of Medicine and Health Sciences, Dubai P.O. Box 505055, United Arab Emirates (A.S.)
| | - Martin Reinicke
- Leibniz Institute of Photonic Technology (IPHT), Leibniz Center for Photonics in Infection Research (LPI), 07745 Jena, Germany (A.R.); (R.E.)
- InfectoGnostics Research Campus, 07743 Jena, Germany
| | - Annett Reissig
- Leibniz Institute of Photonic Technology (IPHT), Leibniz Center for Photonics in Infection Research (LPI), 07745 Jena, Germany (A.R.); (R.E.)
- InfectoGnostics Research Campus, 07743 Jena, Germany
| | - Abiola Senok
- College of Medicine, Mohammed Bin Rashid University of Medicine and Health Sciences, Dubai P.O. Box 505055, United Arab Emirates (A.S.)
- School of Dentistry, Cardiff University, Cardiff CF14 4XY, UK
| | - Ralf Ehricht
- Leibniz Institute of Photonic Technology (IPHT), Leibniz Center for Photonics in Infection Research (LPI), 07745 Jena, Germany (A.R.); (R.E.)
- InfectoGnostics Research Campus, 07743 Jena, Germany
- Institute of Physical Chemistry, Friedrich-Schiller University, 07743 Jena, Germany
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Chen JHK, Leung HY, Wong CMC, Yuen KY, Cheng VCC. Prevalence and Characteristics of Invasive Staphylococcus argenteus among Patients with Bacteremia in Hong Kong. Microorganisms 2023; 11:2435. [PMID: 37894094 PMCID: PMC10609611 DOI: 10.3390/microorganisms11102435] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2023] [Revised: 09/25/2023] [Accepted: 09/25/2023] [Indexed: 10/29/2023] Open
Abstract
Staphylococcus argenteus is a novel Staphylococcus species derived from Staphylococcus aureus. Information on the prevalence and genetic characteristics of invasive S. argenteus in Asia is limited. In this study, 275 invasive S. aureus complex strains were retrieved from blood culture specimens in Hong Kong and re-analyzed using MALDI-TOF mass spectrometry and an in-house multiplex real-time PCR for S. argenteus. The prevalence of invasive S. argenteus in Hong Kong was found to be 4.0% (11/275). These strains were primarily susceptible to commonly used antibiotics, except penicillin. Whole-genome sequencing revealed the circulation of three S. argenteus genotypes (ST-2250, ST-1223, and ST-2854) in Hong Kong, with ST-2250 and ST-1223 being the predominant genotypes. The local ST-2250 and ST-1223 strains showed close phylogenetic relationships with isolates from mainland China. Antimicrobial-resistant genes (fosB, tet-38, mepA, blaI, blaZ) could be found in nearly all local S. argenteus strains. The ST-1223 and ST-2250 genotypes carried multiple staphylococcal enterotoxin genes that could cause food poisoning and toxic shock syndrome. The CRISPR/Cas locus was observed only in the ST-2250 strains. This study provides the first report on the molecular epidemiology of invasive S. argenteus in Hong Kong, and further analysis is needed to understand its transmission reservoir.
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Affiliation(s)
- Jonathan H. K. Chen
- Department of Microbiology, Queen Mary Hospital, Hong Kong SAR, China; (H.-Y.L.); (V.C.C.C.)
- Department of Microbiology, School of Clinical Medicine, The University of Hong Kong, Hong Kong SAR, China; (C.M.C.W.); (K.-Y.Y.)
| | - Hoi-Yi Leung
- Department of Microbiology, Queen Mary Hospital, Hong Kong SAR, China; (H.-Y.L.); (V.C.C.C.)
| | - Charles M. C. Wong
- Department of Microbiology, School of Clinical Medicine, The University of Hong Kong, Hong Kong SAR, China; (C.M.C.W.); (K.-Y.Y.)
| | - Kwok-Yung Yuen
- Department of Microbiology, School of Clinical Medicine, The University of Hong Kong, Hong Kong SAR, China; (C.M.C.W.); (K.-Y.Y.)
| | - Vincent C. C. Cheng
- Department of Microbiology, Queen Mary Hospital, Hong Kong SAR, China; (H.-Y.L.); (V.C.C.C.)
- Infection Control Team, Queen Mary Hospital, Hong Kong West Cluster, Hong Kong SAR, China
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Chang CH, Lee SH, Lin YC, Hsu CY, Cheng CC, Teng SH, Chen MF, Hsieh PH, Chang Y, Chiang-Ni C. Characterization of the phenotypes of methicillin- and vancomycin-susceptible Staphylococcus argenteus after vancomycin passages. J Glob Antimicrob Resist 2022; 31:63-71. [PMID: 35964863 DOI: 10.1016/j.jgar.2022.08.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2022] [Revised: 08/02/2022] [Accepted: 08/08/2022] [Indexed: 12/30/2022] Open
Abstract
OBJECTIVES Staphylococcus argenteus is generally more susceptible to antibiotic treatments than Staphylococcus aureus; however, the study showed that the daptomycin/vancomycin-resistant S. argenteus was isolated from a patient with repeated antibiotic treatments. In this study, the methicillin- and vancomycin-susceptible S. argenteus isolates were used to characterize the phenotypes of S. argenteus after vancomycin passages in vitro. METHODS Eleven S. argenteus isolates were used for passaging under different concentrations of vancomycin. The minimal inhibitory concentration (MIC) of vancomycin was determined by the agar dilution assay, and the biofilm mass of the passaged variants was quantified by the crystal violet staining assay and observed under the confocal microscope. RESULTS The MIC of vancomycin for eight of 11 S. argenteus isolates was increased from ≤2 µg/mL to ≤4-8 µg/mL after vancomycin passages. Two variants with the high-level vancomycin-intermediate (vancomycin MIC ≤8 µg/mL) phenotype were identified, and the parental strains of these variants did not have the heterogeneous vancomycin-intermediate population determined by the population profile analysis. Further, three S. argenteus isolates showed an increase in biofilm production and icaA transcription after the low-dose (2 µg/mL) vancomycin passages. CONCLUSIONS S. argenteus is capable of acquiring a vancomycin-tolerant phenotype and/or converting to a strong biofilm producer after vancomycin passages, which could contribute to the decrease of their antibiotic susceptibility.
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Affiliation(s)
- Chih-Hsiang Chang
- Department of Orthopedic Surgery, Chang Gung Memorial Hospital at Linkou, Taoyuan, Taiwan; Bone and Joint Research Center, Chang Gung Memorial Hospital at Linkou, Taoyuan, Taiwan; College of Medicine, Chang Gung University, Taoyuan, Taiwan; Graduate Institute of Clinical Medical Sciences, College of Medicine, Chang Gung University, Taoyuan, Taiwan
| | - Sheng-Hsun Lee
- Department of Orthopedic Surgery, Chang Gung Memorial Hospital at Linkou, Taoyuan, Taiwan; Bone and Joint Research Center, Chang Gung Memorial Hospital at Linkou, Taoyuan, Taiwan; College of Medicine, Chang Gung University, Taoyuan, Taiwan
| | - Yu-Chih Lin
- Department of Orthopedic Surgery, Chang Gung Memorial Hospital at Linkou, Taoyuan, Taiwan; Bone and Joint Research Center, Chang Gung Memorial Hospital at Linkou, Taoyuan, Taiwan; College of Medicine, Chang Gung University, Taoyuan, Taiwan
| | - Chih-Yun Hsu
- Department of Microbiology and Immunology, College of Medicine, Chang Gung University, Taoyuan, Taiwan
| | - Chih-Chieh Cheng
- Graduate Institute of Biomedical Sciences, College of Medicine, Chang Gung University, Taoyuan, Taiwan
| | - Shih-Hua Teng
- Department of Microbiology and Immunology, College of Medicine, Chang Gung University, Taoyuan, Taiwan
| | - Mei-Feng Chen
- Department of Orthopedic Surgery, Chang Gung Memorial Hospital at Linkou, Taoyuan, Taiwan; Bone and Joint Research Center, Chang Gung Memorial Hospital at Linkou, Taoyuan, Taiwan
| | - Pang-Hsin Hsieh
- Department of Orthopedic Surgery, Chang Gung Memorial Hospital at Linkou, Taoyuan, Taiwan; Bone and Joint Research Center, Chang Gung Memorial Hospital at Linkou, Taoyuan, Taiwan; College of Medicine, Chang Gung University, Taoyuan, Taiwan
| | - Yuhan Chang
- Department of Orthopedic Surgery, Chang Gung Memorial Hospital at Linkou, Taoyuan, Taiwan; Bone and Joint Research Center, Chang Gung Memorial Hospital at Linkou, Taoyuan, Taiwan
| | - Chuan Chiang-Ni
- Department of Orthopedic Surgery, Chang Gung Memorial Hospital at Linkou, Taoyuan, Taiwan; Molecular Infectious Disease Research Center, Chang Gung Memorial Hospital at Linkou, Taoyuan, Taiwan; Graduate Institute of Biomedical Sciences, College of Medicine, Chang Gung University, Taoyuan, Taiwan; Department of Microbiology and Immunology, College of Medicine, Chang Gung University, Taoyuan, Taiwan.
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Monecke S, Schaumburg F, Shittu AO, Schwarz S, Mühldorfer K, Brandt C, Braun SD, Collatz M, Diezel C, Gawlik D, Hanke D, Hotzel H, Müller E, Reinicke M, Feßler AT, Ehricht R. Description of Staphylococcal Strains from Straw-Coloured Fruit Bat (Eidolon helvum) and Diamond Firetail (Stagonopleura guttata) and a Review of their Phylogenetic Relationships to Other Staphylococci. Front Cell Infect Microbiol 2022; 12:878137. [PMID: 35646742 PMCID: PMC9132046 DOI: 10.3389/fcimb.2022.878137] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2022] [Accepted: 03/16/2022] [Indexed: 12/30/2022] Open
Abstract
The phylogenetic tree of the Staphylococcus aureus complex consists of several distinct clades and the majority of human and veterinary S. aureus isolates form one large clade. In addition, two divergent clades have recently been described as separate species. One was named Staphylococcus argenteus, due to the lack of the “golden” pigment staphyloxanthin. The second one is S. schweitzeri, found in humans and animals from Central and West Africa. In late 2021, two additional species, S. roterodami and S. singaporensis, have been described from clinical samples from Southeast Asia. In the present study, isolates and their genome sequences from wild Straw-coloured fruit bats (Eidolon helvum) and a Diamond firetail (Stagonopleura guttata, an estrildid finch) kept in a German aviary are described. The isolates possessed staphyloxanthin genes and were closer related to S. argenteus and S. schweitzeri than to S. aureus. Phylogenetic analysis revealed that they were nearly identical to both, S. roterodami and S. singaporensis. We propose considering the study isolates, the recently described S. roterodami and S. singaporensis as well as some Chinese strains with MLST profiles stored in the PubMLST database as different clonal complexes within one new species. According to the principle of priority we propose it should be named S. roterodami. This species is more widespread than previously believed, being observed in West Africa, Southeast Asia and Southern China. It has a zoonotic connection to bats and has been shown to be capable of causing skin and soft tissue infections in humans. It is positive for staphyloxanthin, and it could be mis-identified as S. aureus (or S. argenteus) using routine procedures. However, it can be identified based on distinct MLST alleles, and “S. aureus” sequence types ST2470, ST3135, ST3952, ST3960, ST3961, ST3963, ST3965, ST3980, ST4014, ST4075, ST4076, ST4185, ST4326, ST4569, ST6105, ST6106, ST6107, ST6108, ST6109, ST6999 and ST7342 belong to this species.
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Affiliation(s)
- Stefan Monecke
- Leibniz Institute of Photonic Technology (IPHT), Jena, Germany
- InfectoGnostics Research Campus, Jena, Germany
- *Correspondence: Stefan Monecke,
| | - Frieder Schaumburg
- Institute of Medical Microbiology, University Hospital Münster, Münster, Germany
| | - Adebayo O. Shittu
- Institute of Medical Microbiology, University Hospital Münster, Münster, Germany
- Department of Microbiology, Obafemi Awolowo University, Ile-Ife, Nigeria
| | - Stefan Schwarz
- Institute of Microbiology and Epizootics, Freie Universität Berlin, Berlin, Germany
- Veterinary Centre for Resistance Research (TZR), Freie Universität Berlin, Berlin, Germany
| | - Kristin Mühldorfer
- Department of Wildlife Diseases, Leibniz Institute for Zoo and Wildlife Research, Berlin, Germany
| | - Christian Brandt
- Institute for Infectious Diseases and Infection Control, Jena University Hospital, Jena, Germany
| | - Sascha D. Braun
- Leibniz Institute of Photonic Technology (IPHT), Jena, Germany
- InfectoGnostics Research Campus, Jena, Germany
| | - Maximilian Collatz
- Leibniz Institute of Photonic Technology (IPHT), Jena, Germany
- InfectoGnostics Research Campus, Jena, Germany
| | - Celia Diezel
- Leibniz Institute of Photonic Technology (IPHT), Jena, Germany
- InfectoGnostics Research Campus, Jena, Germany
| | | | - Dennis Hanke
- Institute of Microbiology and Epizootics, Freie Universität Berlin, Berlin, Germany
- Veterinary Centre for Resistance Research (TZR), Freie Universität Berlin, Berlin, Germany
| | - Helmut Hotzel
- Friedrich-Loeffler-Institut (Federal Research Institute for Animal Health), Institute of Bacterial Infections and Zoonoses, Jena, Germany
| | - Elke Müller
- Leibniz Institute of Photonic Technology (IPHT), Jena, Germany
- InfectoGnostics Research Campus, Jena, Germany
| | - Martin Reinicke
- Leibniz Institute of Photonic Technology (IPHT), Jena, Germany
- InfectoGnostics Research Campus, Jena, Germany
| | - Andrea T. Feßler
- Institute of Microbiology and Epizootics, Freie Universität Berlin, Berlin, Germany
- Veterinary Centre for Resistance Research (TZR), Freie Universität Berlin, Berlin, Germany
| | - Ralf Ehricht
- Leibniz Institute of Photonic Technology (IPHT), Jena, Germany
- InfectoGnostics Research Campus, Jena, Germany
- Institute of Physical Chemistry, Friedrich-Schiller-University, Jena, Germany
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Abstract
Clustered regularly interspaced short palindromic repeats (CRISPRs) and CRISPR-associated (Cas) genes (CRISPR-Cas) are present in many bacterial genomes with functions beyond adaptive immunity. We aimed to characterize the CRISPR-Cas system in the pathogenic Gram-positive bacterium Staphylococcus lugdunensis and determine its association with sequence types (STs) determined by multilocus sequence typing (MLST) and oxacillin susceptibility. Primers were designed to detect and sequence types IIIA and IIC CRISPR-Cas in 199 S. lugdunensis isolates. MLST and oxacillin susceptibility tests were also performed on the isolates. We found that 84 S. lugdunensis isolates had type IIIA CRISPR-Cas, while 46 had type IIC. The results showed a strong association between STs and CRISPR-Cas types. The ST1, ST6, ST12, and ST15 isolates had type IIIA CRISPR-Cas systems, and the ST4, ST27, and ST29 isolates had type IIC CRISPR-Cas. Interestingly, of 83 isolates containing type IIIA CRISPR-Cas, 17 (20.5%) were oxacillin-resistant S. lugdunensis (ORSL), and all of these ORSL isolates belonged to ST6 cluster 1. Moreover, spacers 23 and 21 were found in 16 and 17 ORSL isolates, respectively. In contrast, all 46 isolates with type IIC CRISPR-Cas were susceptible to oxacillin. Our results showed that 41.3% of CRISPR-Cas IIIA spacers were homologous to plasmids and 20.2% were homologous to phages. However, in type IIC CRISPR-Cas, 11.8% and 39.9% of spacers showed sequence homology with plasmids and phages, respectively. In conclusion, we found that the distribution and composition of the CRISPR-Cas system in S. lugdunensis was associated with STs and oxacillin susceptibility. IMPORTANCE CRISPR-Cas systems have been characterized as playing several biological roles in many bacterial genomes. Moreover, CRISPR-Cas systems are useful for epidemiological, diagnostic, and evolutionary studies of pathogenic bacteria. However, the characteristics of CRISPR-Cas systems in Staphylococcus lugdunensis have been rarely reported. In this study, we revealed that type IIIA CRISPR-Cas was dominant in S. lugdunensis isolates, followed by type IIC CRISPR-Cas. Moreover, the composition of CRISPR-Cas spacers was strongly associated with multilocus sequence typing and oxacillin susceptibility of S. lugdunensis. These results advance our understanding of the evolution of CRISPR-Cas systems; however, the biological functions of CRISPR-Cas systems in S. lugdunensis remain to be further characterized.
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Aung MS, Urushibara N, Kawaguchiya M, Hirose M, Ike M, Ito M, Kobayashi N. Distribution of Virulence Factors and Resistance Determinants in Three Genotypes of Staphylococcus argenteus Clinical Isolates in Japan. Pathogens 2021; 10:pathogens10020163. [PMID: 33546443 PMCID: PMC7913748 DOI: 10.3390/pathogens10020163] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2020] [Revised: 01/29/2021] [Accepted: 02/01/2021] [Indexed: 11/16/2022] Open
Abstract
Staphylococcus argenteus, a novel staphylococcal species independent of S. aureus, causes a wide spectrum of infectious diseases. As detection of this species from humans and animals has been increasingly reported worldwide, its growing virulence and drug resistance via external genetic determinants has become concerning. In this study, the prevalence and genetic characteristics of virulence factors and drug resistance determinants were investigated for 82 S. argenteus clinical isolates in Hokkaido, Japan, for a one-year period starting in August 2019. These S. argenteus isolates corresponded to 0.66% of the total number of S. aureus isolates collected in the same period. The most prevalent genotype was sequence type (ST) 2250 and staphylocoagulase (coa) genotype XId (45.1%, n = 37), followed by ST1223-coa XV (30.5%, n = 25) and ST2198-coa XIV (24.4%, n = 20). Panton-Valentine leukocidin genes (lukS-PV-lukF-PV) were identified in a single ST2250 isolate. Only ST1223 isolates had the enterotoxin gene cluster (egc-2), seb, and selw (detection rate; 100%, 60%, and 84%, respectively), while sec, sey, sel26-sel27, tst-1 were only detected in ST2250 isolates (detection rate; 10.8%, 100%, 67.6%, and 10.8%, respectively). ST2198 isolates harbored selx at a significantly higher rate (60%) than isolates of other STs. Although most of S. argenteus isolates were susceptible to antimicrobials examined, ST2198 showed higher resistance rates to penicillin, macrolides, and aminoglycosides than other STs, and it harbored various resistance genes such as blaZ, erm(C), msr(A), lnuA, and aac(6′)-Ie-aph(2″)-Ia. Only one ST2250 isolate possessed SCCmec-IVc, showing resistance to oxacillin. blaZ was the most prevalent determinant of resistance in the three STs and belonged to two plasmid groups and a chromosomal group, suggesting its diverse origin. lnu(A) in ST2198 isolates was assigned to a major cluster with various staphylococcal species. The present study indicates that the prevalence of virulence factors and drug resistance profile/determinants differ depending on the lineage (ST) of S. argenteus.
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Affiliation(s)
- Meiji Soe Aung
- Department of Hygiene, Sapporo Medical University School of Medicine, Hokkaido, Sapporo 060-8556, Japan; (N.U.); (M.K.); (N.K.)
- Correspondence: ; Tel.: +81-11-611-2111
| | - Noriko Urushibara
- Department of Hygiene, Sapporo Medical University School of Medicine, Hokkaido, Sapporo 060-8556, Japan; (N.U.); (M.K.); (N.K.)
| | - Mitsuyo Kawaguchiya
- Department of Hygiene, Sapporo Medical University School of Medicine, Hokkaido, Sapporo 060-8556, Japan; (N.U.); (M.K.); (N.K.)
| | - Mina Hirose
- Division of Pediatric Dentistry, Department of Oral Growth and Development, School of Dentistry, Health Sciences University of Hokkaido, Ishikari-Tobetsu 061-0293, Japan;
| | - Miyo Ike
- Sapporo Clinical Laboratory, Incorporated, Hokkaido, Sapporo 060-0005, Japan; (M.I.); (M.I.)
| | - Masahiko Ito
- Sapporo Clinical Laboratory, Incorporated, Hokkaido, Sapporo 060-0005, Japan; (M.I.); (M.I.)
| | - Nobumichi Kobayashi
- Department of Hygiene, Sapporo Medical University School of Medicine, Hokkaido, Sapporo 060-8556, Japan; (N.U.); (M.K.); (N.K.)
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