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Selway CA, May JP, Goonetilleke SMA, Hocking H, Turra M, Leong LEX. Complete genome of a rare Salmonella enterica subsp. enterica serovar Hessarek from human stool. Microbiol Resour Announc 2024; 13:e0000924. [PMID: 39162441 PMCID: PMC11385726 DOI: 10.1128/mra.00009-24] [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: 02/04/2024] [Accepted: 07/16/2024] [Indexed: 08/21/2024] Open
Abstract
We present a complete genome of Salmonella enterica subsp. enterica serovar Hessarek isolated from a human stool from an outbreak linked to egg consumption in South Australia. Orientation of the rrn operon and characteristics of the Salmonella virulence plasmid indicates that this serovar is virulent toward humans and birds.
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Affiliation(s)
- Caitlin A Selway
- Microbiology and Infectious Diseases, Public Health Laboratory, SA Pathology, Adelaide, South Australia, Australia
| | - Jacob P May
- Microbiology and Infectious Diseases, Public Health Laboratory, SA Pathology, Adelaide, South Australia, Australia
| | - Shenoi M A Goonetilleke
- Microbiology and Infectious Diseases, Public Health Laboratory, SA Pathology, Adelaide, South Australia, Australia
| | - Helen Hocking
- Salmonella Reference Laboratory, SA Pathology, Adelaide, South Australia, Australia
| | - Mark Turra
- Microbiology and Infectious Diseases, Public Health Laboratory, SA Pathology, Adelaide, South Australia, Australia
| | - Lex E X Leong
- Microbiology and Infectious Diseases, Public Health Laboratory, SA Pathology, Adelaide, South Australia, Australia
- UniSA Clinical & Health Sciences, University of South Australia, Adelaide, South Australia, Australia
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2
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Salmonella enterica Serovar Typhi on an Island: No H58, No Multidrug Resistance, but for How Long? mBio 2022; 13:e0242622. [PMID: 36468871 PMCID: PMC9765464 DOI: 10.1128/mbio.02426-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Little genomic data is available for typhoid fever from island nations, though the disease has a moderately high burden there. Sikorski et al. (M. J. Sikorski, T. H. Hazen, S. N. Desai, S. Nimarota-Brown, et al., mBio 13:e01920-22, 2022, https://doi.org/10.1128/mbio.01920-22) studied 306 Salmonella enterica serovar Typhi genomes from the Samoan Islands collected during 1983 to 2020 and reported dominance of a rare genotype, 2.5.4, and no H58 (genotype 4.3.1). They found pansusceptibility of all isolates to three first lines of antimicrobial agents (ampicillin, chloramphenicol, and cotrimoxazole). This commentary evaluates the importance of these findings for the Samoan Islands and how they can help the global typhoid community. The microbial community in the environment and human gut could have played a role in the lack of antimicrobial resistance (AMR). However, drug-resistant strains may arrive soon at the island, as their international spread is common. Further investigation would help the global typhoid community to better understand the evolution of an isolated pathogen community and the effect of vaccination there.
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Waters EV, Tucker LA, Ahmed JK, Wain J, Langridge GC. Impact of Salmonella genome rearrangement on gene expression. Evol Lett 2022; 6:426-437. [PMID: 36579163 PMCID: PMC9783417 DOI: 10.1002/evl3.305] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2022] [Revised: 10/03/2022] [Accepted: 11/07/2022] [Indexed: 11/20/2022] Open
Abstract
In addition to nucleotide variation, many bacteria also undergo changes at a much larger scale via rearrangement of their genome structure (GS) around long repeat sequences. These rearrangements result in genome fragments shifting position and/or orientation in the genome without necessarily affecting the underlying nucleotide sequence. To date, scalable techniques have not been applied to GS identification, so it remains unclear how extensive this variation is and the extent of its impact upon gene expression. However, the emergence of multiplexed, long-read sequencing overcomes the scale problem, as reads of several thousand bases are routinely produced that can span long repeat sequences to identify the flanking chromosomal DNA, allowing GS identification. Genome rearrangements were generated in Salmonella enterica serovar Typhi through long-term culture at ambient temperature. Colonies with rearrangements were identified via long-range PCR and subjected to long-read nanopore sequencing to confirm genome variation. Four rearrangements were investigated for differential gene expression using transcriptomics. All isolates with changes in genome arrangement relative to the parent strain were accompanied by changes in gene expression. Rearrangements with similar fragment movements demonstrated similar changes in gene expression. The most extreme rearrangement caused a large imbalance between the origin and terminus of replication and was associated with differential gene expression as a factor of distance moved toward or away from the origin of replication. Genome structure variation may provide a mechanism through which bacteria can quickly adapt to new environments and warrants routine assessment alongside traditional nucleotide-level measures of variation.
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Affiliation(s)
- Emma V. Waters
- Microbes in the Food ChainQuadram Institute BioscienceNorwichNR4 7UQUnited Kingdom
| | - Liam A. Tucker
- Microbes in the Food ChainQuadram Institute BioscienceNorwichNR4 7UQUnited Kingdom
| | - Jana K. Ahmed
- The Wellcome Trust Sanger InstituteCambridgeCB10 1SAUnited Kingdom
| | - John Wain
- Microbes in the Food ChainQuadram Institute BioscienceNorwichNR4 7UQUnited Kingdom
- Norwich Medical SchoolUniversity of East AngliaNorwichNR4 7TJUnited Kingdom
| | - Gemma C. Langridge
- Microbes in the Food ChainQuadram Institute BioscienceNorwichNR4 7UQUnited Kingdom
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Bloomfield S, Duong VT, Tuyen HT, Campbell JI, Thomson NR, Parkhill J, Le Phuc H, Chau TTH, Maskell DJ, Perron GG, Ngoc NM, Vi LL, Adriaenssens EM, Baker S, Mather AE. Mobility of antimicrobial resistance across serovars and disease presentations in non-typhoidal Salmonella from animals and humans in Vietnam. Microb Genom 2022; 8. [PMID: 35511231 PMCID: PMC9465066 DOI: 10.1099/mgen.0.000798] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Non-typhoidal Salmonella (NTS) is a major cause of bacterial enterocolitis globally but also causes invasive bloodstream infections. Antimicrobial resistance (AMR) hampers the treatment of these infections and understanding how AMR spreads between NTS may help in developing effective strategies. We investigated NTS isolates associated with invasive disease, diarrhoeal disease and asymptomatic carriage in animals and humans from Vietnam. Isolates included multiple serovars and both common and rare phenotypic AMR profiles; long- and short-read sequencing was used to investigate the genetic mechanisms and genomic backgrounds associated with phenotypic AMR profiles. We demonstrate concordance between most AMR genotypes and phenotypes but identified large genotypic diversity in clinically relevant phenotypes and the high mobility potential of AMR genes (ARGs) in this setting. We found that 84 % of ARGs identified were located on plasmids, most commonly those containing IncHI1A_1 and IncHI1B(R27)_1_R27 replicons (33%), and those containing IncHI2_1 and IncHI2A_1 replicons (31%). The vast majority (95%) of ARGS were found within 10 kbp of IS6/IS26 elements, which provide plasmids with a mechanism to exchange ARGs between plasmids and other parts of the genome. Whole genome sequencing with targeted long-read sequencing applied in a One Health context identified a comparatively limited number of insertion sequences and plasmid replicons associated with AMR. Therefore, in the context of NTS from Vietnam and likely for other settings as well, the mechanisms by which ARGs move contribute to a more successful AMR profile than the specific ARGs, facilitating the adaptation of bacteria to different environments or selection pressures.
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Affiliation(s)
| | | | - Ha Thanh Tuyen
- The Hospital for Tropical Diseases, Wellcome Trust Major Overseas Programme, Oxford University Clinical Research Unit, Ho Chi Minh City, Vietnam
| | - James I Campbell
- The Hospital for Tropical Diseases, Wellcome Trust Major Overseas Programme, Oxford University Clinical Research Unit, Ho Chi Minh City, Vietnam
| | | | - Julian Parkhill
- Department of Veterinary Medicine, University of Cambridge, Cambridge, UK
| | | | - Tran Thi Hong Chau
- The Hospital for Tropical Diseases, Wellcome Trust Major Overseas Programme, Oxford University Clinical Research Unit, Ho Chi Minh City, Vietnam
| | | | - Gabriel G Perron
- Department of Biology, Bard College, Annandale-on-Hudson, New York, USA
| | | | - Lu Lan Vi
- The Hospital for Tropical Diseases, Wellcome Trust Major Overseas Programme, Oxford University Clinical Research Unit, Ho Chi Minh City, Vietnam
| | | | - Stephen Baker
- Department of Medicine, University of Cambridge School of Clinical Medicine, Cambridge Biomedical Campus, Cambridge, UK
| | - Alison E Mather
- Quadram Institute Bioscience, Norwich Research Park, Norwich, UK.,University of East Anglia, Norwich, UK
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5
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Cao S, Brandis G, Huseby DL, Hughes D. Positive selection during niche adaptation results in large-scale and irreversible rearrangement of chromosomal gene order in bacteria. Mol Biol Evol 2022; 39:6554941. [PMID: 35348727 PMCID: PMC9016547 DOI: 10.1093/molbev/msac069] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Analysis of bacterial genomes shows that, whereas diverse species share many genes in common, their linear order on the chromosome is often not conserved. Whereas rearrangements in gene order could occur by genetic drift, an alternative hypothesis is rearrangement driven by positive selection during niche adaptation (SNAP). Here, we provide the first experimental support for the SNAP hypothesis. We evolved Salmonella to adapt to growth on malate as the sole carbon source and followed the evolutionary trajectories. The initial adaptation to growth in the new environment involved the duplication of 1.66 Mb, corresponding to one-third of the Salmonella chromosome. This duplication is selected to increase the copy number of a single gene, dctA, involved in the uptake of malate. Continuing selection led to the rapid loss or mutation of duplicate genes from either copy of the duplicated region. After 2000 generations, only 31% of the originally duplicated genes remained intact and the gene order within the Salmonella chromosome has been significantly and irreversibly altered. These results experientially validate predictions made by the SNAP hypothesis and show that SNAP can be a strong driving force for rearrangements in chromosomal gene order.
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Affiliation(s)
- Sha Cao
- Department of Medical Biochemistry and Microbiology, Uppsala University, Uppsala, Sweden.,These authors contributed equally: Sha Cao, Gerrit Brandis
| | - Gerrit Brandis
- Department of Cell and Molecular Biology, Uppsala University, Uppsala, Sweden.,These authors contributed equally: Sha Cao, Gerrit Brandis
| | - Douglas L Huseby
- Department of Medical Biochemistry and Microbiology, Uppsala University, Uppsala, Sweden
| | - Diarmaid Hughes
- Department of Medical Biochemistry and Microbiology, Uppsala University, Uppsala, Sweden
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Dyson ZA, Malau E, Horwood PF, Ford R, Siba V, Yoannes M, Pomat W, Passey M, Judd LM, Ingle DJ, Williamson DA, Dougan G, Greenhill AR, Holt KE. Whole genome sequence analysis of Salmonella Typhi in Papua New Guinea reveals an established population of genotype 2.1.7 sensitive to antimicrobials. PLoS Negl Trop Dis 2022; 16:e0010306. [PMID: 35344544 PMCID: PMC8989336 DOI: 10.1371/journal.pntd.0010306] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2021] [Revised: 04/07/2022] [Accepted: 03/05/2022] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND Typhoid fever, a systemic infection caused by Salmonella enterica serovar Typhi, remains a considerable public health threat in impoverished regions within many low- and middle-income settings. However, we still lack a detailed understanding of the emergence, population structure, molecular mechanisms of antimicrobial resistance (AMR), and transmission dynamics of S. Typhi across many settings, particularly throughout the Asia-Pacific islands. Here we present a comprehensive whole genome sequence (WGS) based overview of S. Typhi populations circulating in Papua New Guinea (PNG) over 30 years. PRINCIPLE FINDINGS Bioinformatic analysis of 86 S. Typhi isolates collected between 1980-2010 demonstrated that the population structure of PNG is dominated by a single genotype (2.1.7) that appears to have emerged in the Indonesian archipelago in the mid-twentieth century with minimal evidence of inter-country transmission. Genotypic and phenotypic data demonstrated that the PNG S. Typhi population appears to be susceptible to former first line drugs for treating typhoid fever (chloramphenicol, ampicillin and co-trimoxazole), as well as fluoroquinolones, third generation cephalosporins, and macrolides. PNG genotype 2.1.7 was genetically conserved, with very few deletions, and no evidence of plasmid or prophage acquisition. Genetic variation among this population was attributed to either single point mutations, or homologous recombination adjacent to repetitive ribosomal RNA operons. SIGNIFICANCE Antimicrobials remain an effective option for the treatment of typhoid fever in PNG, along with other intervention strategies including improvements to water, sanitation and hygiene (WaSH) related infrastructure and potentially the introduction of Vi-conjugate vaccines. However, continued genomic surveillance is warranted to monitor for the emergence of AMR within local populations, or the introduction of AMR associated genotypes of S. Typhi in this setting.
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Affiliation(s)
- Zoe Anne Dyson
- London School of Hygiene & Tropical Medicine, London, United Kingdom
- Department of Infectious Diseases, Central Clinical School, Monash University, Melbourne, Australia
- Cambridge Institute of Therapeutic Immunology & Infectious Disease (CITIID), Department of Medicine, University of Cambridge, Cambridge, United Kingdom
- Wellcome Sanger Institute, Wellcome Genome Campus, Hinxton, United Kingdom
| | - Elisheba Malau
- School of Science, Psychology and Sport, Federation University, Churchill, Australia
| | - Paul F. Horwood
- College of Public Health, Medical and Veterinary Sciences, James Cook University, Townsville, Australia
| | - Rebecca Ford
- Papua New Guinea Institute of Medical Research, Goroka, Papua New Guinea
| | - Valentine Siba
- Papua New Guinea Institute of Medical Research, Goroka, Papua New Guinea
| | - Mition Yoannes
- Papua New Guinea Institute of Medical Research, Goroka, Papua New Guinea
| | - William Pomat
- Papua New Guinea Institute of Medical Research, Goroka, Papua New Guinea
| | - Megan Passey
- University Centre for Rural Health, Faculty of Medicine and Health, University of Sydney, Lismore, Australia
| | - Louise M. Judd
- Department of Infectious Diseases, Central Clinical School, Monash University, Melbourne, Australia
| | - Danielle J. Ingle
- Department of Microbiology and Immunology, The University of Melbourne at The Peter Doherty Institute for Infection and Immunity, Melbourne, Australia
| | - Deborah A. Williamson
- Department of Microbiology and Immunology, The University of Melbourne at The Peter Doherty Institute for Infection and Immunity, Melbourne, Australia
- Microbiological Diagnostic Unit Public Health Laboratory, Department of Microbiology and Immunology, The University of Melbourne at The Peter Doherty Institute for Infection and Immunity, Melbourne, Australia
| | - Gordon Dougan
- Cambridge Institute of Therapeutic Immunology & Infectious Disease (CITIID), Department of Medicine, University of Cambridge, Cambridge, United Kingdom
| | - Andrew R. Greenhill
- School of Science, Psychology and Sport, Federation University, Churchill, Australia
| | - Kathryn E. Holt
- London School of Hygiene & Tropical Medicine, London, United Kingdom
- Department of Infectious Diseases, Central Clinical School, Monash University, Melbourne, Australia
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7
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Foster N, Tang Y, Berchieri A, Geng S, Jiao X, Barrow P. Revisiting Persistent Salmonella Infection and the Carrier State: What Do We Know? Pathogens 2021; 10:1299. [PMID: 34684248 PMCID: PMC8537056 DOI: 10.3390/pathogens10101299] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2021] [Revised: 09/28/2021] [Accepted: 09/29/2021] [Indexed: 11/17/2022] Open
Abstract
One characteristic of the few Salmonella enterica serovars that produce typhoid-like infections is that disease-free persistent infection can occur for months or years in a small number of individuals post-convalescence. The bacteria continue to be shed intermittently which is a key component of the epidemiology of these infections. Persistent chronic infection occurs despite high levels of circulating specific IgG. We have reviewed the information on the basis for persistence in S. Typhi, S. Dublin, S. Gallinarum, S. Pullorum, S. Abortusovis and also S. Typhimurium in mice as a model of persistence. Persistence appears to occur in macrophages in the spleen and liver with shedding either from the gall bladder and gut or the reproductive tract. The involvement of host genetic background in defining persistence is clear from studies with the mouse but less so with human and poultry infections. There is increasing evidence that the organisms (i) modulate the host response away from the typical Th1-type response normally associated with immune clearance of an acute infection to Th2-type or an anti-inflammatory response, and that (ii) the bacteria modulate transformation of macrophage from M1 to M2 type. The bacterial factors involved in this are not yet fully understood. There are early indications that it might be possible to remodulate the response back towards a Th1 response by using cytokine therapy.
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Affiliation(s)
- Neil Foster
- SRUC Aberdeen Campus, Craibstone Estate, Ferguson Building, Aberdeen AB21 9YA, UK
| | - Ying Tang
- Institute of Molecular Physiology, Shenzhen Bay Laboratory, Shenzhen 518055, China;
| | - Angelo Berchieri
- Departamento de Patologia Veterinária, Faculdade de Ciências Agrárias e Veterinárias, Univ Estadual Paulista, Via de Acesso Paulo Donato Castellane, s/n, 14884-900 Jaboticabal, SP, Brazil;
| | - Shizhong Geng
- Jiangsu Key Laboratory of Zoonosis, Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou University, Yangzhou 225009, China; (S.G.); (X.J.)
| | - Xinan Jiao
- Jiangsu Key Laboratory of Zoonosis, Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou University, Yangzhou 225009, China; (S.G.); (X.J.)
| | - Paul Barrow
- School of Veterinary Medicine, University of Surrey, Daphne Jackson Road, Guildford GU2 7AL, UK;
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Genomic and phenotypic comparison of two Salmonella Typhimurium strains responsible for consecutive salmonellosis outbreaks in New Zealand. Int J Med Microbiol 2021; 311:151534. [PMID: 34564018 DOI: 10.1016/j.ijmm.2021.151534] [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: 03/13/2018] [Revised: 03/20/2021] [Accepted: 08/16/2021] [Indexed: 11/20/2022] Open
Abstract
Salmonella enterica serovar Typhimurium DT160 was the predominant cause of notified human salmonellosis cases in New Zealand from 2000 to 2010, before it was superseded by another S. Typhimurium strain, DT56 variant (DT56v). Whole genome sequencing and phenotypic testing were used to compare 109 DT160 isolates with eight DT56v isolates from New Zealand animal and human sources. Phylogenetic analysis provided evidence that DT160 and DT56v strains were distantly related with an estimated date of common ancestor between 1769 and 1821. The strains replicated at different rates but had similar antimicrobial susceptibility profiles. Both strains were resistant to the phage expressed from the chromosome of the other strain, which may have contributed to the emergence of DT56v. DT160 contained the pSLT virulence plasmid, and the sseJ and sseK2 genes that may have contributed to the higher reported prevalence compared to DT56v. A linear pBSSB1-family plasmid was also found in one of the DT56v isolates, but there was no evidence that this plasmid affected bacterial replication or antimicrobial susceptibility. One of the DT56v isolates was also sequenced using long-read technology and found to contain an uncommon chromosome arrangement for a Typhimurium isolate. This study demonstrates how comparative genomics and phenotypic testing can help identify strain-specific elements and factors that may have influenced the emergence and supersession of bacterial strains of public health importance.
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9
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Devaraj A, González JF, Eichar B, Thilliez G, Kingsley RA, Baker S, Allard MW, Bakaletz LO, Gunn JS, Goodman SD. Enhanced biofilm and extracellular matrix production by chronic carriage versus acute isolates of Salmonella Typhi. PLoS Pathog 2021; 17:e1009209. [PMID: 33465146 PMCID: PMC7815147 DOI: 10.1371/journal.ppat.1009209] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2020] [Accepted: 12/02/2020] [Indexed: 01/01/2023] Open
Abstract
Salmonella Typhi is the primary causative agent of typhoid fever; an acute systemic infection that leads to chronic carriage in 3–5% of individuals. Chronic carriers are asymptomatic, difficult to treat and serve as reservoirs for typhoid outbreaks. Understanding the factors that contribute to chronic carriage is key to development of novel therapies to effectively resolve typhoid fever. Herein, although we observed no distinct clustering of chronic carriage isolates via phylogenetic analysis, we demonstrated that chronic isolates were phenotypically distinct from acute infection isolates. Chronic carriage isolates formed significantly thicker biofilms with greater biomass that correlated with significantly higher relative levels of extracellular DNA (eDNA) and DNABII proteins than biofilms formed by acute infection isolates. Importantly, extracellular DNABII proteins include integration host factor (IHF) and histone-like protein (HU) that are critical to the structural integrity of bacterial biofilms. In this study, we demonstrated that the biofilm formed by a chronic carriage isolate in vitro, was susceptible to disruption by a specific antibody against DNABII proteins, a successful first step in the development of a therapeutic to resolve chronic carriage. Salmonella Typhi, a human restricted pathogen is the primary etiologic agent of typhoid fever, an acute systemic infection that has a global incidence of 21 million cases annually. Although the acute infection is resolved by antibiotics, 3–5% of individuals develop chronic carriage that is difficult to resolve with antibiotics. A majority of these indivuals serve as reservoirs for further spread of the disease. Understanding the differences between acute and chronic carrier strains is key to design novel targeted approaches to undermine carriage. Here, we demonstrated that chronic carrier strains although not genotypically distinct from acute strains, formed thicker biofilms with greater relative levels of extracellular eDNA and DNABII proteins than those formed by acute infection isolates. We also demonstrated that an antibody against DNABII proteins significantly disrupted biofilms formed by a chronic carrier strain and therefore supported development of therapeutic use of this antibody to attenuate chronic carriage.
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Affiliation(s)
- Aishwarya Devaraj
- Center for Microbial Pathogenesis, Research Institute at Nationwide Children's Hospital, Columbus, Ohio, United States of America
| | - Juan F. González
- Center for Microbial Pathogenesis, Research Institute at Nationwide Children's Hospital, Columbus, Ohio, United States of America
- Department of Microbial Infection and Immunity, The Ohio State University, Columbus, Ohio, United States of America
- Department of Pediatrics, College of Medicine, The Ohio State University, Columbus, Ohio, United States of America
| | - Bradley Eichar
- Center for Microbial Pathogenesis, Research Institute at Nationwide Children's Hospital, Columbus, Ohio, United States of America
- Department of Microbial Infection and Immunity, The Ohio State University, Columbus, Ohio, United States of America
| | | | - Robert A. Kingsley
- Quadram Institute Bioscience, Norwich, United Kingdom
- University of East Anglia, Norwich, United Kingdom
| | - Stephen Baker
- Cambridge Institute of Therapeutic Immunology and Infectious Disease, University of Cambridge School of Clinical Medicine, Cambridge Biomedical Campus, Cambridge, United Kingdom
- Department of Medicine, University of Cambridge School of Clinical Medicine, Cambridge Biomedical Campus, Cambridge, United Kingdom
| | - Marc W. Allard
- Food and Drug Administration-FDA, College Park, Maryland, United States of America
| | - Lauren O. Bakaletz
- Center for Microbial Pathogenesis, Research Institute at Nationwide Children's Hospital, Columbus, Ohio, United States of America
- Department of Pediatrics, College of Medicine, The Ohio State University, Columbus, Ohio, United States of America
- Infectious Diseases Institute, The Ohio State University, Columbus, Ohio, United States of America
| | - John S. Gunn
- Center for Microbial Pathogenesis, Research Institute at Nationwide Children's Hospital, Columbus, Ohio, United States of America
- Department of Microbial Infection and Immunity, The Ohio State University, Columbus, Ohio, United States of America
- Department of Pediatrics, College of Medicine, The Ohio State University, Columbus, Ohio, United States of America
- Infectious Diseases Institute, The Ohio State University, Columbus, Ohio, United States of America
- Oral and GI Microbiology Research Affinity Group, Nationwide Children’s Hospital, Columbus, Ohio, United States of America
- * E-mail: (JSG); (SDG)
| | - Steven D. Goodman
- Center for Microbial Pathogenesis, Research Institute at Nationwide Children's Hospital, Columbus, Ohio, United States of America
- Department of Pediatrics, College of Medicine, The Ohio State University, Columbus, Ohio, United States of America
- Infectious Diseases Institute, The Ohio State University, Columbus, Ohio, United States of America
- Oral and GI Microbiology Research Affinity Group, Nationwide Children’s Hospital, Columbus, Ohio, United States of America
- * E-mail: (JSG); (SDG)
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10
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Kim S, Lee KS, Pak GD, Excler JL, Sahastrabuddhe S, Marks F, Kim JH, Mogasale V. Spatial and Temporal Patterns of Typhoid and Paratyphoid Fever Outbreaks: A Worldwide Review, 1990-2018. Clin Infect Dis 2020; 69:S499-S509. [PMID: 31665782 PMCID: PMC6821269 DOI: 10.1093/cid/ciz705] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
BACKGROUND Analyses of the global spatial and temporal distribution of enteric fever outbreaks worldwide are important factors to consider in estimating the disease burden of enteric fever disease burden. METHODS We conducted a global literature review of enteric fever outbreak data by systematically using multiple databases from 1 January 1990 to 31 December 2018 and classified them by time, place, diagnostic methods, and drug susceptibility, to illustrate outbreak characteristics including spatial and temporal patterns. RESULTS There were 180 940 cases in 303 identified outbreaks caused by infection with Salmonella enterica serovar Typhi (S. Typhi) and Salmonella enterica serovar Paratyphi A or B (S. Paratyphi). The size of outbreak ranged from 1 to 42 564. Fifty-one percent of outbreaks occurred in Asia, 15% in Africa, 14% in Oceania, and the rest in other regions. Forty-six percent of outbreaks specified confirmation by blood culture, and 82 outbreaks reported drug susceptibility, of which 54% had multidrug-resistant pathogens. Paratyphoid outbreaks were less common compared to typhoid (22 vs 281) and more prevalent in Asia than Africa. Risk factors were multifactorial, with contaminated water being the main factor. CONCLUSIONS Enteric fever outbreak burden remains high in endemic low- and middle-income countries and, despite its limitations, outbreak data provide valuable contemporary evidence in prioritizing resources, public health policies, and actions. This review highlights geographical locations where urgent attention is needed for enteric fever control and calls for global action to prevent and contain outbreaks.
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Affiliation(s)
- Samuel Kim
- International Vaccine Institute, Seoul, Republic of Korea.,Imperial College London, United Kingdom
| | - Kang Sung Lee
- International Vaccine Institute, Seoul, Republic of Korea
| | - Gi Deok Pak
- International Vaccine Institute, Seoul, Republic of Korea
| | | | | | - Florian Marks
- International Vaccine Institute, Seoul, Republic of Korea.,Department of Medicine, University of Cambridge, Cambridge, United Kingdom
| | - Jerome H Kim
- International Vaccine Institute, Seoul, Republic of Korea
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11
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Page AJ, Ainsworth EV, Langridge GC. socru: typing of genome-level order and orientation around ribosomal operons in bacteria. Microb Genom 2020; 6. [PMID: 32584752 PMCID: PMC7478630 DOI: 10.1099/mgen.0.000396] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Rearrangements of large genome fragments occur in bacteria between repeat sequences and can impact on growth and gene expression. Homologous recombination resulting in inversion between indirect repeats and excision/translocation between direct repeats enables these structural changes. One form of rearrangement occurs around ribosomal operons, found in multiple copies across many bacteria, but identification of these rearrangements by sequencing requires reads of several thousand bases to span the ribosomal operons. With long-read sequencing aiding the routine generation of complete bacterial assemblies, we have developed socru, a typing method for the order and orientation of genome fragments between ribosomal operons. It allows for a single identifier to convey the order and orientation of genome-level structure and we have successfully applied this typing to 433 of the most common bacterial species. In a focused analysis, we observed the presence of multiple structural genotypes in nine bacterial pathogens, underscoring the importance of routinely assessing this form of variation alongside traditional single-nucleotide polymorphism (SNP) typing.
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Affiliation(s)
- Andrew J Page
- Microbes in the Food Chain, Quadram Institute Bioscience, Norwich Research Park, Norwich, NR4 7UQ, UK
| | - Emma V Ainsworth
- Microbes in the Food Chain, Quadram Institute Bioscience, Norwich Research Park, Norwich, NR4 7UQ, UK
| | - Gemma C Langridge
- Microbes in the Food Chain, Quadram Institute Bioscience, Norwich Research Park, Norwich, NR4 7UQ, UK
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12
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Gal-Mor O. Persistent Infection and Long-Term Carriage of Typhoidal and Nontyphoidal Salmonellae. Clin Microbiol Rev 2019; 32:e00088-18. [PMID: 30487167 PMCID: PMC6302356 DOI: 10.1128/cmr.00088-18] [Citation(s) in RCA: 74] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
The ability of pathogenic bacteria to affect higher organisms and cause disease is one of the most dramatic properties of microorganisms. Some pathogens can establish transient colonization only, but others are capable of infecting their host for many years or even for a lifetime. Long-term infection is called persistence, and this phenotype is fundamental for the biology of important human pathogens, including Helicobacter pylori, Mycobacterium tuberculosis, and Salmonella enterica Both typhoidal and nontyphoidal serovars of the species Salmonella enterica can cause persistent infection in humans; however, as these two Salmonella groups cause clinically distinct diseases, the characteristics of their persistent infections in humans differ significantly. Here, following a general summary of Salmonella pathogenicity, host specificity, epidemiology, and laboratory diagnosis, I review the current knowledge about Salmonella persistence and discuss the relevant epidemiology of persistence (including carrier rate, duration of shedding, and host and pathogen risk factors), the host response to Salmonella persistence, Salmonella genes involved in this lifestyle, as well as genetic and phenotypic changes acquired during prolonged infection within the host. Additionally, I highlight differences between the persistence of typhoidal and nontyphoidal Salmonella strains in humans and summarize the current gaps and limitations in our understanding, diagnosis, and curing of persistent Salmonella infections.
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Affiliation(s)
- Ohad Gal-Mor
- Infectious Diseases Research Laboratory, Sheba Medical Center, Tel-Hashomer, Israel
- Department of Clinical Microbiology and Immunology, Sackler Faculty of Medicine, Tel-Aviv University, Tel-Aviv, Israel
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13
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Tanner JR, Kingsley RA. Evolution of Salmonella within Hosts. Trends Microbiol 2018; 26:986-998. [PMID: 29954653 PMCID: PMC6249985 DOI: 10.1016/j.tim.2018.06.001] [Citation(s) in RCA: 63] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2018] [Revised: 05/22/2018] [Accepted: 06/01/2018] [Indexed: 11/18/2022]
Abstract
Within-host evolution has resulted in thousands of variants of Salmonella that exhibit remarkable diversity in host range and disease outcome, from broad host range to exquisite host restriction, causing gastroenteritis to disseminated disease such as typhoid fever. Within-host evolution is a continuing process driven by genomic variation that occurs during each infection, potentiating adaptation to a new niche resulting from changes in animal husbandry, the use of antimicrobials, and emergence of immune compromised populations. We discuss key advances in our understanding of the evolution of Salmonella within the host, inferred from (i) the process of host adaptation of Salmonella pathovars in the past, and (ii) direct observation of the generation of variation and selection of beneficial traits during single infections. Salmonella is a bacterial pathogen with remarkable diversity in its host range and pathogenicity due to past within-host evolution in vertebrate species that modified ancestral mechanisms of pathogenesis. Variation arising during infection includes point mutations, new genes acquired through horizontal gene transfer (HGT), deletions, and genomic rearrangements. Beneficial mutations increase in frequency within the host and, if they retain the ability to be transmitted to subsequent hosts, may become fixed in the population. Whole-genome sequencing of sequential isolates from clinical infections reveals within-host HGT and point mutations that impact therapy and clinical management. HGT is the primary mechanism for evolution in prokaryotes and is synergised by complex networks of transfer involving the microbiome. Within-host evolution of Salmonella, resulting in new pathovars, can proceed in the absence of HGT.
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Affiliation(s)
- Jennifer R Tanner
- Quadram Institute Bioscience, Norwich Research Park, Colney, Norwich, UK
| | - Robert A Kingsley
- Quadram Institute Bioscience, Norwich Research Park, Colney, Norwich, UK.
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14
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Hiyoshi H, Tiffany CR, Bronner DN, Bäumler AJ. Typhoidal Salmonella serovars: ecological opportunity and the evolution of a new pathovar. FEMS Microbiol Rev 2018; 42:527-541. [DOI: 10.1093/femsre/fuy024] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2018] [Accepted: 05/19/2018] [Indexed: 12/20/2022] Open
Affiliation(s)
- Hirotaka Hiyoshi
- Department of Medial Microbiology and Immunology, School of Medicine, University of California Davis, Davis, CA 95616, USA
| | - Connor R Tiffany
- Department of Medial Microbiology and Immunology, School of Medicine, University of California Davis, Davis, CA 95616, USA
| | - Denise N Bronner
- Department of Medial Microbiology and Immunology, School of Medicine, University of California Davis, Davis, CA 95616, USA
| | - Andreas J Bäumler
- Department of Medial Microbiology and Immunology, School of Medicine, University of California Davis, Davis, CA 95616, USA
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15
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Tau NP, Smith AM, Wain JR, Tarupiwa A, Coulibaly KJ, Keddy KH, Germs-Sa. Development and evaluation of a multiple-locus variable-number tandem-repeats analysis assay for subtyping Salmonella Typhi strains from sub-Saharan Africa. J Med Microbiol 2017; 66:937-945. [PMID: 28721851 DOI: 10.1099/jmm.0.000526] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
PURPOSE Molecular epidemiological investigations of the highly clonal Salmonella enterica subspecies enterica serovar Typhi (S. Typhi) are important in outbreak detection and in tracking disease transmission. In this study, we developed and evaluated a multiple-locus variable-number tandem-repeats (VNTR) analysis (MLVA) assay for characterization of S. Typhi isolates from sub-Saharan Africa. METHODOLOGY Twelve previously reported VNTR loci were evaluated and an MLVA assay consisting of five polymorphic loci was adopted. The MLVA assay was developed for use on capillary electrophoresis systems by testing a collection of 50 S. Typhi isolates. This S. Typhi strain panel consisted of six outbreak related isolates and 44 epidemiologically unlinked isolates. Amongst these were nine S.Typhi haplotype H58 isolates. RESULTS The MLVA assay characterized the 50 isolates into 47 MLVA profiles while PFGE analysis of the same isolates revealed 34 pulsotypes. MLVA displayed higher discriminatory power (Simpson's index of diversity (DI) 0.998 [95 % confidence interval (CI) 0.995-1.000)] as compared to pulsed-field gel electrophoresis [Simpson's DI 0.984 (95 % CI 0.974-0.994)]. CONCLUSION The MLVA assay presented in this study is a simple, rapid and more accessible tool that serves as a good alternative to other molecular subtyping methods for S. Typhi.
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Affiliation(s)
- Nomsa P Tau
- Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa.,Centre for Enteric Diseases, National Institute for Communicable Diseases, a division of the National Health Laboratory Service, Johannesburg, South Africa
| | - Anthony M Smith
- Centre for Enteric Diseases, National Institute for Communicable Diseases, a division of the National Health Laboratory Service, Johannesburg, South Africa.,Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
| | | | - Andrew Tarupiwa
- National Microbiology Reference Laboratory, Harare, Zimbabwe
| | - Kalpy J Coulibaly
- Unit of Chemistry and Environmental Microbiology, Pasteur Institute, Ivory Coast
| | - Karen H Keddy
- Centre for Enteric Diseases, National Institute for Communicable Diseases, a division of the National Health Laboratory Service, Johannesburg, South Africa.,Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
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16
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Matthews TD, Schmieder R, Silva GGZ, Busch J, Cassman N, Dutilh BE, Green D, Matlock B, Heffernan B, Olsen GJ, Farris Hanna L, Schifferli DM, Maloy S, Dinsdale EA, Edwards RA. Genomic Comparison of the Closely-Related Salmonella enterica Serovars Enteritidis, Dublin and Gallinarum. PLoS One 2015; 10:e0126883. [PMID: 26039056 PMCID: PMC4454671 DOI: 10.1371/journal.pone.0126883] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2014] [Accepted: 04/08/2015] [Indexed: 11/18/2022] Open
Abstract
The Salmonella enterica serovars Enteritidis, Dublin, and Gallinarum are closely related but differ in virulence and host range. To identify the genetic elements responsible for these differences and to better understand how these serovars are evolving, we sequenced the genomes of Enteritidis strain LK5 and Dublin strain SARB12 and compared these genomes to the publicly available Enteritidis P125109, Dublin CT 02021853 and Dublin SD3246 genome sequences. We also compared the publicly available Gallinarum genome sequences from biotype Gallinarum 287/91 and Pullorum RKS5078. Using bioinformatic approaches, we identified single nucleotide polymorphisms, insertions, deletions, and differences in prophage and pseudogene content between strains belonging to the same serovar. Through our analysis we also identified several prophage cargo genes and pseudogenes that affect virulence and may contribute to a host-specific, systemic lifestyle. These results strongly argue that the Enteritidis, Dublin and Gallinarum serovars of Salmonella enterica evolve by acquiring new genes through horizontal gene transfer, followed by the formation of pseudogenes. The loss of genes necessary for a gastrointestinal lifestyle ultimately leads to a systemic lifestyle and niche exclusion in the host-specific serovars.
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Affiliation(s)
- T. David Matthews
- Department of Biology, San Diego State University, San Diego, California, 92182, United States of America
| | - Robert Schmieder
- Department of Computer Science, San Diego State University, San Diego, California, 92182, United States of America
| | - Genivaldo G. Z. Silva
- Computational Science Research Center, San Diego State University, San Diego, California, 92182, United States of America
| | - Julia Busch
- Department of Biology, San Diego State University, San Diego, California, 92182, United States of America
| | - Noriko Cassman
- Department of Biology, San Diego State University, San Diego, California, 92182, United States of America
| | - Bas E. Dutilh
- Theoretical Biology and Bioinformatics, Utrecht University, Utrecht, The Netherlands
- Centre for Molecular and Biomolecular Informatics, Radboud Institute for Molecular Life Sciences, Radboud University Medical Centre, Nijmegen, The Netherlands
| | - Dawn Green
- Department of Microbiology, University of Illinois at Urbana-Champaign, Urbana, Illinois, United States of America
| | - Brian Matlock
- Department of Microbiology, University of Illinois at Urbana-Champaign, Urbana, Illinois, United States of America
| | - Brian Heffernan
- Department of Microbiology, University of Illinois at Urbana-Champaign, Urbana, Illinois, United States of America
| | - Gary J. Olsen
- Department of Microbiology, University of Illinois at Urbana-Champaign, Urbana, Illinois, United States of America
| | - Leigh Farris Hanna
- Molecular Sciences Department, University of Tennessee Health Sciences Center, 858 Madison Ave, Memphis, Tennessee, United States of America
| | - Dieter M. Schifferli
- University of Pennsylvania School of Veterinary Medicine, 3800 Spruce St, Philadelphia, Pennsylvania, 19104, United States of America
| | - Stanley Maloy
- Department of Biology, San Diego State University, San Diego, California, 92182, United States of America
| | - Elizabeth A. Dinsdale
- Department of Biology, San Diego State University, San Diego, California, 92182, United States of America
| | - Robert A. Edwards
- Department of Biology, San Diego State University, San Diego, California, 92182, United States of America
- Department of Computer Science, San Diego State University, San Diego, California, 92182, United States of America
- Department of Marine Biology, Institute of Biology, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
- Argonne National Laboratory, 9700 S. Cass Ave, Argonne, Illinois, 60349, United States of America
- * E-mail:
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17
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Ravindran A, Jalan N, Yuan JS, Wang N, Gross DC. Comparative genomics of Pseudomonas syringae pv. syringae strains B301D and HS191 and insights into intrapathovar traits associated with plant pathogenesis. Microbiologyopen 2015; 4:553-73. [PMID: 25940918 PMCID: PMC4554452 DOI: 10.1002/mbo3.261] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2015] [Revised: 03/17/2015] [Accepted: 03/27/2015] [Indexed: 01/09/2023] Open
Abstract
Pseudomonas syringae pv. syringae is a common plant-associated bacterium that causes diseases of both monocot and dicot plants worldwide. To help delineate traits critical to adaptation and survival in the plant environment, we generated complete genome sequences of P. syringae pv. syringae strains B301D and HS191, which represent dicot and monocot strains with distinct host specificities. Intrapathovar comparisons of the B301D (6.09 Mb) and HS191 (5.95 Mb plus a 52 kb pCG131 plasmid) genomes to the previously sequenced B728a genome demonstrated that the shared genes encompass about 83% of each genome, and include genes for siderophore biosynthesis, osmotolerance, and extracellular polysaccharide production. Between 7% and 12% of the genes are unique among the genomes, and most of the unique gene regions carry transposons, phage elements, or IS elements associated with horizontal gene transfer. Differences are observed in the type III effector composition for the three strains that likely influences host range. The HS191 genome had the largest number at 25 of effector genes, and seven effector genes are specific to this monocot strain. Toxin production is another major trait associated with virulence of P. syringae pv. syringae, and HS191 is distinguished by genes for production of syringopeptin SP25 and mangotoxin.
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Affiliation(s)
- Aravind Ravindran
- Department of Plant Pathology and Microbiology, Texas A&M University, College Station, Texas, 77843-2132
| | - Neha Jalan
- Department of Microbiology and Cell Sciences, Citrus Research and Education Center, University of Florida, 700 Experiment Station Road, Lake Alfred, Florida, 33850
| | - Joshua S Yuan
- Department of Plant Pathology and Microbiology, Texas A&M University, College Station, Texas, 77843-2132
| | - Nian Wang
- Department of Microbiology and Cell Sciences, Citrus Research and Education Center, University of Florida, 700 Experiment Station Road, Lake Alfred, Florida, 33850
| | - Dennis C Gross
- Department of Plant Pathology and Microbiology, Texas A&M University, College Station, Texas, 77843-2132
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Martelli F, Gosling R, Kennedy E, Rabie A, Reeves H, Clifton-Hadley F, Davies R, La Ragione R. Characterization of the invasiveness of monophasic and aphasicSalmonellaTyphimurium strains in 1-day-old and point-of-lay chickens. Avian Pathol 2014; 43:269-75. [DOI: 10.1080/03079457.2014.917759] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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Delgado G, Souza V, Morales R, Cerritos R, González-González A, Méndez JL, Vázquez V, Cravioto A. Genetic characterization of atypical Citrobacter freundii. PLoS One 2013; 8:e74120. [PMID: 24069274 PMCID: PMC3771896 DOI: 10.1371/journal.pone.0074120] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2013] [Accepted: 07/29/2013] [Indexed: 11/24/2022] Open
Abstract
The ability of a bacterial population to survive in different niches, as well as in stressful and rapidly changing environmental conditions, depends greatly on its genetic content. To survive such fluctuating conditions, bacteria have evolved different mechanisms to modulate phenotypic variations and related strategies to produce high levels of genetic diversity. Laboratories working in microbiological diagnosis have shown that Citrobacter freundii is very versatile in its colony morphology, as well as in its biochemical, antigenic and pathogenic behaviours. This phenotypic versatility has made C. freundii difficult to identify and it is frequently confused with both Salmonella enterica and Escherichia coli. In order to determine the genomic events and to explain the mechanisms involved in this plasticity, six C. freundii isolates were selected from a phenotypic variation study. An I-CeuI genomic cleavage map was created and eight housekeeping genes, including 16S rRNA, were sequenced. In general, the results showed a range of both phenotypes and genotypes among the isolates with some revealing a greater similarity to C. freundii and some to S. enterica, while others were identified as phenotypic and genotypic intermediary states between the two species. The occurrence of these events in natural populations may have important implications for genomic diversification in bacterial evolution, especially when considering bacterial species boundaries. In addition, such events may have a profound impact on medical science in terms of treatment, course and outcomes of infectious diseases, evading the immune response, and understanding host-pathogen interactions.
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Affiliation(s)
- Gabriela Delgado
- Departmento de Microbiología y Parasitología, Facultad de Medicina, Universidad Nacional Autónoma de México (UNAM), México City, México
| | - Valeria Souza
- Departamento de Ecología Evolutiva, Instituto de Ecología, Universidad Nacional Autónoma de México (UNAM), México City, México
| | - Rosario Morales
- Departmento de Microbiología y Parasitología, Facultad de Medicina, Universidad Nacional Autónoma de México (UNAM), México City, México
| | - René Cerritos
- Departamento de Cirugía Experimental, Facultad de Medicina, Universidad Nacional Autónoma de México (UNAM), México City, México
| | - Andrea González-González
- Departamento de Ecología Evolutiva, Instituto de Ecología, Universidad Nacional Autónoma de México (UNAM), México City, México
| | - José Luis Méndez
- Departmento de Microbiología y Parasitología, Facultad de Medicina, Universidad Nacional Autónoma de México (UNAM), México City, México
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20
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Maharjan RP, Gaffé J, Plucain J, Schliep M, Wang L, Feng L, Tenaillon O, Ferenci T, Schneider D. A case of adaptation through a mutation in a tandem duplication during experimental evolution in Escherichia coli. BMC Genomics 2013; 14:441. [PMID: 23822838 PMCID: PMC3708739 DOI: 10.1186/1471-2164-14-441] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2012] [Accepted: 03/08/2013] [Indexed: 11/21/2022] Open
Abstract
Background DNA duplications constitute important precursors for genome variation. Here we analyzed an unequal duplication harboring a beneficial mutation that may provide alternative evolutionary outcomes. Results We characterized this evolutionary event during experimental evolution for only 100 generations of an Escherichia coli strain under glucose limitation within chemostats. By combining Insertion Sequence based Restriction Length Polymorphism experiments, pulsed field gel electrophoresis and two independent genome re-sequencing experiments, we identified an evolved lineage carrying a 180 kb duplication of the 46’ region of the E. coli chromosome. This evolved duplication revealed a heterozygous state, with one copy harboring a 2668 bp deletion that included part of the ogrK gene and both the yegR and yegS genes. By genetically manipulating ancestral and evolved strains, we showed that the single yegS inactivation was sufficient to confer a frequency dependent fitness increase under the chemostat selective conditions in both the ancestor and evolved genetic contexts, implying that the duplication itself was not a direct fitness contributor. Nonetheless, the heterozygous duplicated state was relatively stable in the conditions prevailing during evolution in chemostats, in striking contrast to non selective conditions in which the duplication resolved at high frequency into either its ancestral or deleted copy. Conclusions Our results suggest that the duplication state may constitute a second order selection process providing higher evolutionary potential. Moreover, its heterozygous nature may provide differential evolutionary opportunities in alternating environments. Our results also highlighted how careful analyses of whole genome data are needed to identify such complex rearrangements.
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Affiliation(s)
- Ram P Maharjan
- School of Molecular Bioscience, University of Sydney, Sydney, NSW 2006, Australia
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21
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Abstract
Long-term typhoid carriers can simultaneously excrete Salmonella enterica serovar Typhi variants with considerable genetic differences, a situation that complicates the interpretation of the subtyping data used in outbreak investigations and disease surveillance.
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Insights from the genome sequence of a Salmonella enterica serovar Typhi strain associated with a sporadic case of typhoid fever in Malaysia. J Bacteriol 2012; 194:5124-5. [PMID: 22933756 DOI: 10.1128/jb.01062-12] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Salmonella enterica serovar Typhi is the causative agent of typhoid fever, which causes nearly 21.7 million illnesses and 217,000 deaths globally. Herein, we describe the whole-genome sequence of the Salmonella Typhi strain ST0208, isolated from a sporadic case of typhoid fever in Kuala Lumpur, Malaysia. The whole-genome sequence and comparative genomics allow an in-depth understanding of the genetic diversity, and its link to pathogenicity and evolutionary dynamics, of this highly clonal pathogen that is endemic to Malaysia.
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