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White RT, Legione AR, Taylor-Brown A, Fernandez CM, Higgins DP, Timms P, Jelocnik M. Completing the Genome Sequence of Chlamydia pecorum Strains MC/MarsBar and DBDeUG: New Insights into This Enigmatic Koala ( Phascolarctos cinereus) Pathogen. Pathogens 2021; 10:1543. [PMID: 34959498 PMCID: PMC8703710 DOI: 10.3390/pathogens10121543] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2021] [Revised: 11/17/2021] [Accepted: 11/24/2021] [Indexed: 12/30/2022] Open
Abstract
Chlamydia pecorum, an obligate intracellular pathogen, causes significant morbidity and mortality in livestock and the koala (Phascolarctos cinereus). A variety of C. pecorum gene-centric molecular studies have revealed important observations about infection dynamics and genetic diversity in both koala and livestock hosts. In contrast to a variety of C. pecorum molecular studies, to date, only four complete and 16 draft genomes have been published. Of those, only five draft genomes are from koalas. Here, using whole-genome sequencing and a comparative genomics approach, we describe the first two complete C. pecorum genomes collected from diseased koalas. A de novo assembly of DBDeUG_2018 and MC/MarsBar_2018 resolved the chromosomes and chlamydial plasmids each as single, circular contigs. Robust phylogenomic analyses indicate biogeographical separation between strains from northern and southern koala populations, and between strains infecting koala and livestock hosts. Comparative genomics between koala strains identified new, unique, and shared loci that accumulate single-nucleotide polymorphisms and separate between northern and southern, and within northern koala strains. Furthermore, we predicted novel type III secretion system effectors. This investigation constitutes a comprehensive genome-wide comparison between C. pecorum from koalas and provides improvements to annotations of a C. pecorum reference genome. These findings lay the foundations for identifying and understanding host specificity and adaptation behind chlamydial infections affecting koalas.
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Affiliation(s)
- Rhys T. White
- Genecology Research Centre, University of the Sunshine Coast, Sippy Downs, Sunshine Coast, QLD 4557, Australia; (R.T.W.); (A.T.-B.); (P.T.)
| | - Alistair R. Legione
- Asia Pacific Centre for Animal Health, Melbourne Veterinary School, The University of Melbourne, Parkville, VIC 3010, Australia;
| | - Alyce Taylor-Brown
- Genecology Research Centre, University of the Sunshine Coast, Sippy Downs, Sunshine Coast, QLD 4557, Australia; (R.T.W.); (A.T.-B.); (P.T.)
- Parasites and Microbes Programme, Wellcome Sanger Institute, Hinxton, Cambridgeshire CB10 1SA, UK
| | - Cristina M. Fernandez
- Sydney School of Veterinary Science, The University of Sydney, Sydney, NSW 2006, Australia; (C.M.F.); (D.P.H.)
| | - Damien P. Higgins
- Sydney School of Veterinary Science, The University of Sydney, Sydney, NSW 2006, Australia; (C.M.F.); (D.P.H.)
| | - Peter Timms
- Genecology Research Centre, University of the Sunshine Coast, Sippy Downs, Sunshine Coast, QLD 4557, Australia; (R.T.W.); (A.T.-B.); (P.T.)
| | - Martina Jelocnik
- Genecology Research Centre, University of the Sunshine Coast, Sippy Downs, Sunshine Coast, QLD 4557, Australia; (R.T.W.); (A.T.-B.); (P.T.)
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2
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Manning C, O’Neill C, Clarke IN, Rebec M, Cliff PR, Marsh P. High-resolution genotyping of Lymphogranuloma Venereum (LGV) strains of Chlamydia trachomatis in London using multi-locus VNTR analysis-ompA genotyping (MLVA-ompA). PLoS One 2021; 16:e0254233. [PMID: 34237111 PMCID: PMC8266103 DOI: 10.1371/journal.pone.0254233] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2021] [Accepted: 06/22/2021] [Indexed: 12/02/2022] Open
Abstract
BACKGROUND Lymphogranuloma venereum (LGV) is caused by Chlamydia trachomatis strains with ompA genotypes L1 to L3. An LGV epidemic associated with the L2b genotype has emerged in the past few decades amongst men who have sex with men (MSM). C. trachomatis genotypes can be discriminated by outer membrane protein A gene (ompA) sequencing, however this method has limited resolution. This study employed a high-resolution genotyping method, namely, multi-locus tandem repeat (VNTR) analysis with ompA sequencing (MLVA-ompA), to assess the distribution of LGV MLVA-ompA genotypes amongst individuals attending genitourinary medicine (GUM) clinics in London. METHODS Clinical specimens were collected from individuals attending eight London-based GUM clinics. Specimens that tested positive for C. trachomatis by commercial nucleic acid amplification test (NAAT) were confirmed as LGV by pmpH real-time PCR. LGV-positive DNA extracts were subsequently genotyped using MLVA-ompA. RESULTS Two hundred and thirty DNA extracts were confirmed as LGV, and 162 (70%) yielded complete MLVA-ompA genotypes. Six LGV MLVA-ompA genotypes were identified: 1.9.2b-L2, 1.9.3b-L2b, 1.9.2b-L2b, 1.9.2b-L2b/D, 1.4a.2b-L2b, and 5.9.2b-L1. The following LGV ompA genotypes were identified (in descending order of abundance): L2, L2b, L2b/D, and L1. Eight ompA sequences with the hybrid L2b/D profile were detected. The hybrid sequence was identical to the ompA of a recombinant L2b/D strain detected in Portugal in 2017. CONCLUSIONS The L2 ompA genotype was found to predominate in the London study population. The study detected an unusual hybrid L2b/D ompA profile that was previously reported in Portugal. We recommend further monitoring and surveillance of LGV strains within the UK population.
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Affiliation(s)
- Chloe Manning
- Department of Molecular Microbiology, Division of Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, Southampton, United Kingdom
| | - Colette O’Neill
- Department of Molecular Microbiology, Division of Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, Southampton, United Kingdom
| | - Ian N. Clarke
- Department of Molecular Microbiology, Division of Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, Southampton, United Kingdom
| | - Monica Rebec
- Department of Microbiology, Imperial College Healthcare NHS Trust, Charing Cross Hospital, London, United Kingdom
| | - Penelope R. Cliff
- Department of Infection Sciences, St Thomas’ Hospital, London, United Kingdom
| | - Peter Marsh
- Public Health England, Porton Down, Salisbury, United Kingdom
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Borges V, Cordeiro D, Salas AI, Lodhia Z, Correia C, Isidro J, Fernandes C, Rodrigues AM, Azevedo J, Alves J, Roxo J, Rocha M, Côrte-Real R, Vieira L, Borrego MJ, Gomes JP. Chlamydia trachomatis: when the virulence-associated genome backbone imports a prevalence-associated major antigen signature. Microb Genom 2020; 5. [PMID: 31697227 PMCID: PMC6927300 DOI: 10.1099/mgen.0.000313] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Chlamydia trachomatis is the most prevalent sexually transmitted bacterium worldwide and the causative agent of trachoma. Its strains are classified according to their ompA genotypes, which are strongly linked to differential tissue tropism and disease outcomes [ocular disease, urogenital disease and lymphogranuloma venereum (LGV)]. While the genome-based species phylogenetic tree presents four main clades correlating with tropism/prevalence, namely ocular, LGV, urogenital T1 (more prevalent genotypes) and urogenital T2 (less prevalent genotypes), inter-clade exchange of ompA is considered a rare phenomenon probably mediating marked tropism alterations. An LGV epidemic, associated with the clonal expansion of the L2b genotype, has emerged in the last few decades, raising concerns particularly due to its atypical clinical presentation (ulcerative proctitis) and circulation among men who have sex with men (MSM). Here, we report an LGV outbreak, mostly affecting human immunodeficiency virus-positive MSM engaging in high-risk sexual practices, caused by an L2b strain with a rather unique non-LGV ompA signature that precluded the laboratory notification of this outbreak as LGV. C. trachomatis whole-genome capture and sequencing directly from clinical samples was applied to deeply characterize the genomic backbone of this novel LGV outbreak-causing clone. It revealed a chimeric genome structure due to the genetic transfer of ompA and four neighbouring genes from a serovar D/Da strain, likely possessing the genomic backbone associated with the more prevalent urogenital genotypes (T1 clade), to an LGV (L2b) strain. The hybrid L2b/D-Da strain presents the adhesin and immunodominant antigen MOMP (major outer membrane protein) (encoded by ompA) with an epitope repertoire typical of non-invasive genital strains, while keeping the genome-dispersed virulence fingerprint of a classical LGV strain. As previously reported for inter-clade ompA exchange among non-LGV clades, this novel C. trachomatis genomic mosaic involving a contemporary epidemiologically and clinically relevant LGV strain may have implications on its transmission, tissue tropism and pathogenic capabilities. The emergence of variants with epidemic and pathogenic potential highlights the need for more focused surveillance strategies to capture C. trachomatis evolution in action.
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Affiliation(s)
- Vítor Borges
- Bioinformatics Unit, Department of Infectious Diseases, National Institute of Health, Lisbon, Portugal
| | - Dora Cordeiro
- National Reference Laboratory (NRL) for Curable Sexually Transmitted Infections (STIs), National Institute of Health, Lisbon, Portugal
| | - Ana Isabel Salas
- National Reference Laboratory (NRL) for Curable Sexually Transmitted Infections (STIs), National Institute of Health, Lisbon, Portugal
| | - Zohra Lodhia
- National Reference Laboratory (NRL) for Curable Sexually Transmitted Infections (STIs), National Institute of Health, Lisbon, Portugal
| | - Cristina Correia
- National Reference Laboratory (NRL) for Curable Sexually Transmitted Infections (STIs), National Institute of Health, Lisbon, Portugal
| | - Joana Isidro
- Bioinformatics Unit, Department of Infectious Diseases, National Institute of Health, Lisbon, Portugal
| | - Cândida Fernandes
- Sexually Transmitted Diseases Clinic, Dermatovenereology Department, Central Lisbon University Hospital Centre (CHULC), Lisbon, Portugal
| | - Ana Maria Rodrigues
- Sexually Transmitted Diseases Clinic, Dermatovenereology Department, Central Lisbon University Hospital Centre (CHULC), Lisbon, Portugal
| | - Jacinta Azevedo
- Sexually Transmitted Diseases Clinic, Lapa Health Centre, Lisbon, Portugal
| | - João Alves
- Sexually Transmitted Diseases Clinic, Lapa Health Centre, Lisbon, Portugal
| | - João Roxo
- CheckpointLX, Grupo de Ativistas em Tratamentos, Lisboa, Portugal
| | - Miguel Rocha
- CheckpointLX, Grupo de Ativistas em Tratamentos, Lisboa, Portugal
| | - Rita Côrte-Real
- Sexually Transmitted Diseases Clinic, Dermatovenereology Department, Central Lisbon University Hospital Centre (CHULC), Lisbon, Portugal
| | - Luís Vieira
- Innovation and Technology Unit, Department of Human Genetics, National Institute of Health, Lisbon, Portugal
| | - Maria José Borrego
- National Reference Laboratory (NRL) for Curable Sexually Transmitted Infections (STIs), National Institute of Health, Lisbon, Portugal
| | - João Paulo Gomes
- Bioinformatics Unit, Department of Infectious Diseases, National Institute of Health, Lisbon, Portugal
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4
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Jones CA, Hadfield J, Thomson NR, Cleary DW, Marsh P, Clarke IN, O’Neill CE. The Nature and Extent of Plasmid Variation in Chlamydia trachomatis. Microorganisms 2020; 8:microorganisms8030373. [PMID: 32155798 PMCID: PMC7143637 DOI: 10.3390/microorganisms8030373] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2020] [Revised: 03/02/2020] [Accepted: 03/03/2020] [Indexed: 01/03/2023] Open
Abstract
Chlamydia trachomatis is an obligate intracellular pathogen of humans, causing both the sexually transmitted infection, chlamydia, and the most common cause of infectious blindness, trachoma. The majority of sequenced C. trachomatis clinical isolates carry a 7.5-Kb plasmid, and it is becoming increasingly evident that this is a key determinant of pathogenicity. The discovery of the Swedish New Variant and the more recent Finnish variant highlight the importance of understanding the natural extent of variation in the plasmid. In this study we analysed 524 plasmid sequences from publicly available whole-genome sequence data. Single nucleotide polymorphisms (SNP) in each of the eight coding sequences (CDS) were identified and analysed. There were 224 base positions out of a total 7550 bp that carried a SNP, which equates to a SNP rate of 2.97%, nearly three times what was previously calculated. After normalising for CDS size, CDS8 had the highest SNP rate at 3.97% (i.e., number of SNPs per total number of nucleotides), whilst CDS6 had the lowest at 1.94%. CDS5 had the highest total number of SNPs across the 524 sequences analysed (2267 SNPs), whereas CDS6 had the least SNPs with only 85 SNPs. Calculation of the genetic distances identified CDS6 as the least variable gene at the nucleotide level (d = 0.001), and CDS5 as the most variable (d = 0.007); however, at the amino acid level CDS2 was the least variable (d = 0.001), whilst CDS5 remained the most variable (d = 0.013). This study describes the largest in-depth analysis of the C. trachomatis plasmid to date, through the analysis of plasmid sequence data mined from whole genome sequences spanning 50 years and from a worldwide distribution, providing insights into the nature and extent of existing variation within the plasmid as well as guidance for the design of future diagnostic assays. This is crucial at a time when single-target diagnostic assays are failing to detect natural mutants, putting those infected at risk of a serious long-term and life-changing illness.
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Affiliation(s)
- Charlotte A. Jones
- Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, Southampton General Hospital, Southampton SO166YD, UK; (C.A.J.); (D.W.C.); (I.N.C.)
| | - James Hadfield
- Vaccine and Infectious Disease Division, Fred Hutchinson Cancer Research Center, Seattle, WA 98109-1024, USA;
| | - Nicholas R. Thomson
- Pathogen Genomics, The Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge CB10 1SA, UK;
| | - David W. Cleary
- Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, Southampton General Hospital, Southampton SO166YD, UK; (C.A.J.); (D.W.C.); (I.N.C.)
| | - Peter Marsh
- Public Health England, Porton Down, Wiltshire SP40JG, UK;
| | - Ian N. Clarke
- Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, Southampton General Hospital, Southampton SO166YD, UK; (C.A.J.); (D.W.C.); (I.N.C.)
| | - Colette E. O’Neill
- Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, Southampton General Hospital, Southampton SO166YD, UK; (C.A.J.); (D.W.C.); (I.N.C.)
- Correspondence:
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Patiño LH, Camargo M, Muñoz M, Ríos-Chaparro DI, Patarroyo MA, Ramírez JD. Unveiling the Multilocus Sequence Typing (MLST) Schemes and Core Genome Phylogenies for Genotyping Chlamydia trachomatis. Front Microbiol 2018; 9:1854. [PMID: 30186244 PMCID: PMC6113918 DOI: 10.3389/fmicb.2018.01854] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2017] [Accepted: 07/24/2018] [Indexed: 11/21/2022] Open
Abstract
Multilocus sequence typing (MLST) has become a useful tool for studying the genetic diversity of important public health pathogens, such as Chlamydia trachomatis (Ct). Four MLST schemes have been proposed for Ct (data available from Chlamydiales MLST databases). However, the lack of a sole standardized scheme represents the greatest limitation regarding typing this species. This study was thus aimed at evaluating the usefulness of the four MLST schemes available for Ct, describing each molecular marker's pattern and its contribution toward a description of intra-specific genetic diversity and population structure. The markers for each scheme, showed a variable power of dicrimination, exhibiting in some cases over estimation in the determination of Sequence Types (STs). However, individual analysis of each locus's typing efficiency and discrimination power led to identifying 8 markers as having a suitable pattern for intra-specific typing. analyzing the 8 candidate markers gave a combination of 3 of these loci as an optimal scheme for identifying a large amount of STs, maximizing discrimination power whilst maintaining suitable typing efficiency. One scheme was compared against core genome phylogenies, finding a higher typing resolution through the last approach. These results confirm once again that although complete genome data, in particular from core genome MLST (cgMLST) allow a high resolution clustering for Ct isolates. There are combinations of molecular markers that could generate equivalent results, with the advantage of representing an easy implementation strategy and lower costs leading to contribute to the monitoring and molecular epidemiology of Ct.
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Affiliation(s)
- Luz H. Patiño
- Grupo de Investigaciones Microbiológicas-UR (GIMUR), Programa de Biología, Facultad de Ciencias Naturales y Matemáticas, Universidad del Rosario, Bogotá, Colombia
- Ph.D. Programme in Biomedical and Biological Sciences, Universidad del Rosario, Bogotá, Colombia
| | - Milena Camargo
- Ph.D. Programme in Biomedical and Biological Sciences, Universidad del Rosario, Bogotá, Colombia
- Molecular Biology and Immunology Department, Fundación Instituto de Inmunología de Colombia (FIDIC), Bogotá, Colombia
| | - Marina Muñoz
- Grupo de Investigaciones Microbiológicas-UR (GIMUR), Programa de Biología, Facultad de Ciencias Naturales y Matemáticas, Universidad del Rosario, Bogotá, Colombia
| | - Dora I. Ríos-Chaparro
- Grupo de Investigaciones Microbiológicas-UR (GIMUR), Programa de Biología, Facultad de Ciencias Naturales y Matemáticas, Universidad del Rosario, Bogotá, Colombia
| | - Manuel A. Patarroyo
- Molecular Biology and Immunology Department, Fundación Instituto de Inmunología de Colombia (FIDIC), Bogotá, Colombia
- School of Medicine and Health Sciences, Universidad del Rosario, Bogotá, Colombia
| | - Juan D. Ramírez
- Grupo de Investigaciones Microbiológicas-UR (GIMUR), Programa de Biología, Facultad de Ciencias Naturales y Matemáticas, Universidad del Rosario, Bogotá, Colombia
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Last AR, Pickering H, Roberts CH, Coll F, Phelan J, Burr SE, Cassama E, Nabicassa M, Seth-Smith HMB, Hadfield J, Cutcliffe LT, Clarke IN, Mabey DCW, Bailey RL, Clark TG, Thomson NR, Holland MJ. Population-based analysis of ocular Chlamydia trachomatis in trachoma-endemic West African communities identifies genomic markers of disease severity. Genome Med 2018; 10:15. [PMID: 29482619 PMCID: PMC5828069 DOI: 10.1186/s13073-018-0521-x] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2017] [Accepted: 02/13/2018] [Indexed: 12/20/2022] Open
Abstract
BACKGROUND Chlamydia trachomatis (Ct) is the most common infectious cause of blindness and bacterial sexually transmitted infection worldwide. Ct strain-specific differences in clinical trachoma suggest that genetic polymorphisms in Ct may contribute to the observed variability in severity of clinical disease. METHODS Using Ct whole genome sequences obtained directly from conjunctival swabs, we studied Ct genomic diversity and associations between Ct genetic polymorphisms with ocular localization and disease severity in a treatment-naïve trachoma-endemic population in Guinea-Bissau, West Africa. RESULTS All Ct sequences fall within the T2 ocular clade phylogenetically. This is consistent with the presence of the characteristic deletion in trpA resulting in a truncated non-functional protein and the ocular tyrosine repeat regions present in tarP associated with ocular tissue localization. We have identified 21 Ct non-synonymous single nucleotide polymorphisms (SNPs) associated with ocular localization, including SNPs within pmpD (odds ratio, OR = 4.07, p* = 0.001) and tarP (OR = 0.34, p* = 0.009). Eight synonymous SNPs associated with disease severity were found in yjfH (rlmB) (OR = 0.13, p* = 0.037), CTA0273 (OR = 0.12, p* = 0.027), trmD (OR = 0.12, p* = 0.032), CTA0744 (OR = 0.12, p* = 0.041), glgA (OR = 0.10, p* = 0.026), alaS (OR = 0.10, p* = 0.032), pmpE (OR = 0.08, p* = 0.001) and the intergenic region CTA0744-CTA0745 (OR = 0.13, p* = 0.043). CONCLUSIONS This study demonstrates the extent of genomic diversity within a naturally circulating population of ocular Ct and is the first to describe novel genomic associations with disease severity. These findings direct investigation of host-pathogen interactions that may be important in ocular Ct pathogenesis and disease transmission.
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Affiliation(s)
- A. R. Last
- Clinical Research Department, London School of Hygiene and Tropical Medicine, Keppel Street, London, UK
| | - H. Pickering
- Clinical Research Department, London School of Hygiene and Tropical Medicine, Keppel Street, London, UK
| | - C. h. Roberts
- Clinical Research Department, London School of Hygiene and Tropical Medicine, Keppel Street, London, UK
| | - F. Coll
- Department of Pathogen Molecular Biology, London School of Hygiene and Tropical Medicine, Keppel Street, London, UK
| | - J. Phelan
- Department of Pathogen Molecular Biology, London School of Hygiene and Tropical Medicine, Keppel Street, London, UK
| | - S. E. Burr
- Clinical Research Department, London School of Hygiene and Tropical Medicine, Keppel Street, London, UK
- Disease Control and Elimination Theme, Medical Research Council Unit The Gambia, Fajara, Gambia
| | - E. Cassama
- Programa Nacional de Saúde de Visão, Ministério de Saúde Publica, Bissau, Guinea-Bissau
| | - M. Nabicassa
- Programa Nacional de Saúde de Visão, Ministério de Saúde Publica, Bissau, Guinea-Bissau
| | - H. M. B. Seth-Smith
- Pathogen Genomics, Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, UK
- Clinical Microbiology, Universitätsspital Basel, Basel, Switzerland
- Applied Microbiology Research, Department of Biomedicine, University of Basel, Basel, Switzerland
| | - J. Hadfield
- Pathogen Genomics, Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, UK
| | - L. T. Cutcliffe
- Molecular Microbiology Group, University of Southampton Medical School, Southampton, UK
| | - I. N. Clarke
- Molecular Microbiology Group, University of Southampton Medical School, Southampton, UK
| | - D. C. W. Mabey
- Clinical Research Department, London School of Hygiene and Tropical Medicine, Keppel Street, London, UK
| | - R. L. Bailey
- Clinical Research Department, London School of Hygiene and Tropical Medicine, Keppel Street, London, UK
| | - T. G. Clark
- Department of Pathogen Molecular Biology, London School of Hygiene and Tropical Medicine, Keppel Street, London, UK
- Department of Infectious Diseases Epidemiology, London School of Hygiene and Tropical Medicine, Keppel Street, London, UK
| | - N. R. Thomson
- Department of Pathogen Molecular Biology, London School of Hygiene and Tropical Medicine, Keppel Street, London, UK
- Pathogen Genomics, Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, UK
| | - M. J. Holland
- Clinical Research Department, London School of Hygiene and Tropical Medicine, Keppel Street, London, UK
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7
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Ferreira R, Borges V, Borrego MJ, Gomes JP. Global survey of mRNA levels and decay rates of Chlamydia trachomatis trachoma and lymphogranuloma venereum biovars. Heliyon 2017; 3:e00364. [PMID: 28795162 PMCID: PMC5541142 DOI: 10.1016/j.heliyon.2017.e00364] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2017] [Accepted: 07/18/2017] [Indexed: 12/15/2022] Open
Abstract
Interpreting the intricate bacterial transcriptomics implies understanding the dynamic relationship established between de novo transcription and the degradation of transcripts. Here, we performed a comparative overview of gene expression levels and mRNA decay rates for different-biovar (trachoma and lymphogranuloma venereum) strains of the obligate intracellular bacterium Chlamydia trachomatis. By using RNA-sequencing to measure gene expression levels at mid developmental stage and mRNA decay rates upon rifampicin-based transcription blockage, we observed that: i) 60-70% of the top-50 expressed genes encode proteins with unknown function and proteins involved in "Translation, ribosomal structure and biogenesis" for all strains; ii) the expression ranking by genes' functional categories was in general concordant among different-biovar strains; iii) the median of the half-life time (t1/2) values of transcripts were 15-17 min, indicating that the degree of transcripts' stability seems to correlate with the bacterial intracellular life-style, as these values are considerably higher than the ones observed in other studies for facultative intracellular and free-living bacteria; iv) transcript decay rates were highly heterogeneous within each C. trachomatis strain and did not correlate with steady-state expression levels; v) only at very few instances (essentially at gene functional category level) was possible to unveil dissimilarities potentially underlying phenotypic differences between biovars. In summary, the unveiled transcriptomic scenario, marked by a general lack of correlation between transcript production and degradation and a huge inter-transcript heterogeneity in decay rates, likely reflects the challenges underlying the unique biphasic developmental cycle of C. trachomatis and its intricate interactions with the human host, which probably exacerbate the complexity of the bacterial transcription regulation.
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Affiliation(s)
- Rita Ferreira
- Reference Laboratory of Bacterial Sexually Transmitted Infections, Department of Infectious Diseases, National Institute of Health, Lisbon, Portugal
| | - Vítor Borges
- Reference Laboratory of Bacterial Sexually Transmitted Infections, Department of Infectious Diseases, National Institute of Health, Lisbon, Portugal.,Bioinformatics Unit, Department of Infectious Diseases, National Institute of Health, Lisbon, Portugal
| | - Maria José Borrego
- Reference Laboratory of Bacterial Sexually Transmitted Infections, Department of Infectious Diseases, National Institute of Health, Lisbon, Portugal
| | - João Paulo Gomes
- Reference Laboratory of Bacterial Sexually Transmitted Infections, Department of Infectious Diseases, National Institute of Health, Lisbon, Portugal.,Bioinformatics Unit, Department of Infectious Diseases, National Institute of Health, Lisbon, Portugal
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Abstract
Etiology, transmission and protection: Chlamydia
trachomatis is the leading cause of bacterial sexually transmitted
infection (STI) globally. However, C. trachomatis also causes
trachoma in endemic areas, mostly Africa and the Middle East, and is a leading
cause of preventable blindness worldwide. Epidemiology, incidence and
prevalence: The World Health Organization estimates 131 million
new cases of C. trachomatis genital infection occur annually.
Globally, infection is most prevalent in young women and men (14-25 years),
likely driven by asymptomatic infection, inadequate partner treatment and
delayed development of protective immunity.
Pathology/Symptomatology: C.
trachomatis infects susceptible squamocolumnar or transitional
epithelial cells, leading to cervicitis in women and urethritis in men. Symptoms
are often mild or absent but ascending infection in some women may lead to
Pelvic Inflammatory Disease (PID), resulting in reproductive sequelae such as
ectopic pregnancy, infertility and chronic pelvic pain. Complications of
infection in men include epididymitis and reactive arthritis.
Molecular mechanisms of infection: Chlamydiae
manipulate an array of host processes to support their obligate intracellular
developmental cycle. This leads to activation of signaling pathways resulting in
disproportionate influx of innate cells and the release of tissue damaging
proteins and pro-inflammatory cytokines. Treatment and
curability: Uncomplicated urogenital infection is treated with
azithromycin (1 g, single dose) or doxycycline (100 mg twice daily x 7 days).
However, antimicrobial treatment does not ameliorate established disease. Drug
resistance is rare but treatment failures have been described. Development of an
effective vaccine that protects against upper tract disease or that limits
transmission remains an important goal.
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Affiliation(s)
- Catherine M O'Connell
- Department of Pediatrics, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| | - Morgan E Ferone
- Department of Pediatrics, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
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9
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Andersson P, Harris SR, Smith HMBS, Hadfield J, O'Neill C, Cutcliffe LT, Douglas FP, Asche LV, Mathews JD, Hutton SI, Sarovich DS, Tong SYC, Clarke IN, Thomson NR, Giffard PM. Chlamydia trachomatis from Australian Aboriginal people with trachoma are polyphyletic composed of multiple distinctive lineages. Nat Commun 2016; 7:10688. [PMID: 26912299 PMCID: PMC4773424 DOI: 10.1038/ncomms10688] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2015] [Accepted: 01/07/2016] [Indexed: 01/29/2023] Open
Abstract
Chlamydia trachomatis causes sexually transmitted infections and the blinding disease trachoma. Current data on C. trachomatis phylogeny show that there is only a single trachoma-causing clade, which is distinct from the lineages causing urogenital tract (UGT) and lymphogranuloma venerum diseases. Here we report the whole-genome sequences of ocular C. trachomatis isolates obtained from young children with clinical signs of trachoma in a trachoma endemic region of northern Australia. The isolates form two lineages that fall outside the classical trachoma lineage, instead being placed within UGT clades of the C. trachomatis phylogenetic tree. The Australian trachoma isolates appear to be recombinants with UGT C. trachomatis genome backbones, in which loci that encode immunodominant surface proteins (ompA and pmpEFGH) have been replaced by those characteristic of classical ocular isolates. This suggests that ocular tropism and association with trachoma are functionally associated with some sequence variants of ompA and pmpEFGH. Chlamydia trachomatis isolates causing a blinding disease (trachoma) form a single lineage that is different from the lineages causing urogenital infections. Here, Andersson et al. show however that trachoma isolates from Australia are more closely related to urogenital strains than to other trachoma isolates.
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Affiliation(s)
- Patiyan Andersson
- Global and Tropical Health Division, Menzies School of Health Research, Charles Darwin University, Darwin, Casuarina, Northern Territory 0811, Australia
| | - Simon R Harris
- Pathogen Variation Programme, The Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Cambridge CB10 1SA, UK
| | - Helena M B Seth Smith
- Pathogen Variation Programme, The Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Cambridge CB10 1SA, UK.,Functional Genomics Centre Zürich, University of Zurich, Zurich CH-8057, Switzerland.,Institute for Veterinary Pathology, Vetsuisse Faculty, University of Zurich, Zurich CH-8057, Switzerland
| | - James Hadfield
- Pathogen Variation Programme, The Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Cambridge CB10 1SA, UK
| | - Colette O'Neill
- Department of Clinical and Experimental Science, Molecular Microbiology Group, University Medical School, Southampton General Hospital, Southampton SO16 6YD, UK
| | - Lesley T Cutcliffe
- Department of Clinical and Experimental Science, Molecular Microbiology Group, University Medical School, Southampton General Hospital, Southampton SO16 6YD, UK
| | - Fiona P Douglas
- Global and Tropical Health Division, Menzies School of Health Research, Charles Darwin University, Darwin, Casuarina, Northern Territory 0811, Australia
| | - L Valerie Asche
- Global and Tropical Health Division, Menzies School of Health Research, Charles Darwin University, Darwin, Casuarina, Northern Territory 0811, Australia
| | - John D Mathews
- Global and Tropical Health Division, Menzies School of Health Research, Charles Darwin University, Darwin, Casuarina, Northern Territory 0811, Australia.,School of Population and Global Health, University of Melbourne, Melbourne, Victoria 3010, Australia
| | - Susan I Hutton
- Global and Tropical Health Division, Menzies School of Health Research, Charles Darwin University, Darwin, Casuarina, Northern Territory 0811, Australia
| | - Derek S Sarovich
- Global and Tropical Health Division, Menzies School of Health Research, Charles Darwin University, Darwin, Casuarina, Northern Territory 0811, Australia
| | - Steven Y C Tong
- Global and Tropical Health Division, Menzies School of Health Research, Charles Darwin University, Darwin, Casuarina, Northern Territory 0811, Australia
| | - Ian N Clarke
- Department of Clinical and Experimental Science, Molecular Microbiology Group, University Medical School, Southampton General Hospital, Southampton SO16 6YD, UK
| | - Nicholas R Thomson
- Pathogen Variation Programme, The Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Cambridge CB10 1SA, UK.,Department of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London WC1E 7HT, UK
| | - Philip M Giffard
- Global and Tropical Health Division, Menzies School of Health Research, Charles Darwin University, Darwin, Casuarina, Northern Territory 0811, Australia.,School of Psychological and Clinical Sciences, Charles Darwin University, Casuarina, Northern Territory 0811, Australia
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10
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Bohlin J. Genome expansion in bacteria: the curios case of Chlamydia trachomatis. BMC Res Notes 2015; 8:512. [PMID: 26423146 PMCID: PMC4589037 DOI: 10.1186/s13104-015-1464-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2015] [Accepted: 09/21/2015] [Indexed: 11/23/2022] Open
Abstract
Background Recent findings indicated that a correlation between genomic % AT and genome size within strains of microbial species was predominantly associated with the uptake of foreign DNA. One species however, Chlamydia trachomatis, defied any explanation. In the present study 79 fully sequenced C. trachomatis genomes, representing ocular- (nine strains), urogenital- (36 strains) and lymphogranuloma venereum strains (LGV, 22 strains), in three pathogroups, in addition to 12 laboratory isolates, were scrutinized with the intent of elucidating the positive correlation between genomic AT content and genome size. Results The average size difference between the strains of each pathogroup was largely explained by the incorporation of genetic fragments. These fragments were slightly more AT rich than their corresponding host genomes, but not enough to justify the difference in AT content between the strains of the smaller genomes lacking the fragments. In addition, a genetic region predominantly found in the ocular strains, which had the largest genomes, was on average more GC rich than the host genomes of the urogenital strains (58.64 % AT vs. 58.69 % AT), which had the second largest genomes, implying that the foreign genetic regions cannot alone explain the association between genome size and AT content in C. trachomatis. 23,492 SNPs were identified for all 79 genomes, and although the SNPs were on average slightly GC rich (~47 % AT), a significant association was found between genome-wide SNP AT content, for each pathogroup, and genome size (p < 0.001, R2 = 0.86) in the C. trachomatis strains. Conclusions The correlation between genome size and AT content, with respect to the C. trachomatis pathogroups, was explained by the incorporation of genetic fragments unique to the ocular and/or urogenital strains into the LGV- and urogential strains in addition to the genome-wide SNP AT content differences between the three pathogroups. Electronic supplementary material The online version of this article (doi:10.1186/s13104-015-1464-6) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Jon Bohlin
- Department of Bacteriology and Immunology, Norwegian Institute of Public Health, Lovisenberggata 6, P.O. Box 4404, 0403, Oslo, Norway.
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11
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Chlamydia trachomatis In Vivo to In Vitro Transition Reveals Mechanisms of Phase Variation and Down-Regulation of Virulence Factors. PLoS One 2015. [PMID: 26207372 PMCID: PMC4514472 DOI: 10.1371/journal.pone.0133420] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Research on the obligate intracellular bacterium Chlamydia trachomatis demands culture in cell-lines, but the adaptive process behind the in vivo to in vitro transition is not understood. We assessed the genomic and transcriptomic dynamics underlying C. trachomatis in vitro adaptation of strains representing the three disease groups (ocular, epithelial-genital and lymphogranuloma venereum) propagated in epithelial cells over multiple passages. We found genetic features potentially underlying phase variation mechanisms mediating the regulation of a lipid A biosynthesis enzyme (CT533/LpxC), and the functionality of the cytotoxin (CT166) through an ON/OFF mechanism. We detected inactivating mutations in CT713/porB, a scenario suggesting metabolic adaptation to the available carbon source. CT135 was inactivated in a tropism-specific manner, with CT135-negative clones emerging for all epithelial-genital populations (but not for LGV and ocular populations) and rapidly increasing in frequency (~23% mutants per 10 passages). RNA-sequencing analyses revealed that a deletion event involving CT135 impacted the expression of multiple virulence factors, namely effectors known to play a role in the C. trachomatis host-cell invasion or subversion (e.g., CT456/Tarp, CT694, CT875/TepP and CT868/ChlaDub1). This reflects a scenario of attenuation of C. trachomatis virulence in vitro, which may take place independently or in a cumulative fashion with the also observed down-regulation of plasmid-related virulence factors. This issue may be relevant on behalf of the recent advances in Chlamydia mutagenesis and transformation where culture propagation for selecting mutants/transformants is mandatory. Finally, there was an increase in the growth rate for all strains, reflecting gradual fitness enhancement over time. In general, these data shed light on the adaptive process underlying the C. trachomatis in vivo to in vitro transition, and indicates that it would be prudent to restrict culture propagation to minimal passages and check the status of the CT135 genotype in order to avoid the selection of CT135-negative mutants, likely originating less virulent strains.
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Nunes A, Gomes JP, Karunakaran KP, Brunham RC. Bioinformatic Analysis of Chlamydia trachomatis Polymorphic Membrane Proteins PmpE, PmpF, PmpG and PmpH as Potential Vaccine Antigens. PLoS One 2015; 10:e0131695. [PMID: 26131720 PMCID: PMC4488443 DOI: 10.1371/journal.pone.0131695] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2015] [Accepted: 06/05/2015] [Indexed: 12/31/2022] Open
Abstract
Chlamydia trachomatis is the most important infectious cause of infertility in women with important implications in public health and for which a vaccine is urgently needed. Recent immunoproteomic vaccine studies found that four polymorphic membrane proteins (PmpE, PmpF, PmpG and PmpH) are immunodominant, recognized by various MHC class II haplotypes and protective in mouse models. In the present study, we aimed to evaluate genetic and protein features of Pmps (focusing on the N-terminal 600 amino acids where MHC class II epitopes were mapped) in order to understand antigen variation that may emerge following vaccine induced immune selection. We used several bioinformatics platforms to study: i) Pmps' phylogeny and genetic polymorphism; ii) the location and distribution of protein features (GGA(I, L)/FxxN motifs and cysteine residues) that may impact pathogen-host interactions and protein conformation; and iii) the existence of phase variation mechanisms that may impact Pmps' expression. We used a well-characterized collection of 53 fully-sequenced strains that represent the C. trachomatis serovars associated with the three disease groups: ocular (N=8), epithelial-genital (N=25) and lymphogranuloma venereum (LGV) (N=20). We observed that PmpF and PmpE are highly polymorphic between LGV and epithelial-genital strains, and also within populations of the latter. We also found heterogeneous representation among strains for GGA(I, L)/FxxN motifs and cysteine residues, suggesting possible alterations in adhesion properties, tissue specificity and immunogenicity. PmpG and, to a lesser extent, PmpH revealed low polymorphism and high conservation of protein features among the genital strains (including the LGV group). Uniquely among the four Pmps, pmpG has regulatory sequences suggestive of phase variation. In aggregate, the results suggest that PmpG may be the lead vaccine candidate because of sequence conservation but may need to be paired with another protective antigen (like PmpH) in order to prevent immune selection of phase variants.
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Affiliation(s)
- Alexandra Nunes
- Bioinformatics Unit, Department of Infectious Diseases, National Institute of Health, Lisbon, Portugal
| | - João P. Gomes
- Bioinformatics Unit, Department of Infectious Diseases, National Institute of Health, Lisbon, Portugal
| | - Karuna P. Karunakaran
- Vaccine Research Laboratory, University of British Columbia Centre for Disease Control, Vancouver, Canada
| | - Robert C. Brunham
- Vaccine Research Laboratory, University of British Columbia Centre for Disease Control, Vancouver, Canada
- * E-mail:
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