1
|
Sangal V, Marrs ECL, Nelson A, Perry JD. Phylogenomic analyses of multidrug resistant Corynebacterium striatum strains isolated from patients in a tertiary care hospital in the UK. Eur J Clin Microbiol Infect Dis 2024; 43:1495-1501. [PMID: 38801486 PMCID: PMC11271431 DOI: 10.1007/s10096-024-04857-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2024] [Accepted: 05/17/2024] [Indexed: 05/29/2024]
Abstract
Corynebacterium striatum is an emerging nosocomial pathogen. This is the first report showing the presence of three distinct multidrug resistant lineages of C. striatum among patients in a UK hospital. The presence of ErmX, Tet(W), Bla and AmpC proteins, and mutations in gyrA gene are associated with the resistance to clindamycin, doxycycline, penicillin and moxifloxacin, respectively. These strains are equipped with several corynebacterial virulence genes including two SpaDEF-type and a novel pilus gene cluster, which needs further molecular characterisation. This study highlights a need of developing an active surveillance strategy for routine monitoring and preventing potential cross-transmission among susceptible patients.
Collapse
Affiliation(s)
- Vartul Sangal
- Faculty of Health and Life Sciences, Northumbria University, Newcastle upon Tyne, UK.
| | - Emma C L Marrs
- Microbiology Research Department, Freeman Hospital, Newcastle upon Tyne, UK
| | - Andrew Nelson
- Faculty of Health and Life Sciences, Northumbria University, Newcastle upon Tyne, UK
| | - John D Perry
- Microbiology Research Department, Freeman Hospital, Newcastle upon Tyne, UK
| |
Collapse
|
2
|
Ramos JN, Araújo MRB, Sant'Anna LO, Bokermann S, Camargo CH, Prates FD, Sacchi CT, Vieira VV, Campos KR, Santos MBN, Viana MVC, Azevedo V, Aburjaile FF, de Mattos-Guaraldi AL, Dos Santos LS. Molecular characterization and whole-genome sequencing of Corynebacterium diphtheriae causing skin lesion. Eur J Clin Microbiol Infect Dis 2024; 43:203-208. [PMID: 37985550 DOI: 10.1007/s10096-023-04706-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2023] [Accepted: 11/08/2023] [Indexed: 11/22/2023]
Abstract
We present a case of skin lesion caused by nontoxigenic Corynebacterium diphtheriae. Genomic taxonomy analyses corroborated the preliminary identification provided by mass spectrometry. The strain showed a susceptible phenotype with increased exposure to penicillin, the first drug of choice for the treatment. An empty type 1 class integron carrying only the sul1 gene, which encodes sulfonamide resistance, was found flanked by transposases. Virulence factors involved in adherence and iron uptake, as well as the CRISPR-Cas system, were predicted. MLST analysis revealed the ST-681, previously reported in French Guiana, a European territory.
Collapse
Affiliation(s)
- Juliana Nunes Ramos
- Laboratory of Diphtheria and Corynebacteria of Clinical Relevance, Department of Microbiology, Immunology and Parasitology, Rio de Janeiro State University, Rio de Janeiro, Brazil
| | - Max Roberto Batista Araújo
- Operational Technical Nucleus, Microbiology, Hermes Pardini Institute, Belo Horizonte, Minas Gerais, Brazil
| | - Lincoln Oliveira Sant'Anna
- Laboratory of Diphtheria and Corynebacteria of Clinical Relevance, Department of Microbiology, Immunology and Parasitology, Rio de Janeiro State University, Rio de Janeiro, Brazil
| | - Sérgio Bokermann
- Center of Bacteriology, Adolfo Lutz Institute, Secretary of Health of the State of São Paulo, São Paulo, Brazil
| | - Carlos Henrique Camargo
- Center of Bacteriology, Adolfo Lutz Institute, Secretary of Health of the State of São Paulo, São Paulo, Brazil
| | - Fernanda Diniz Prates
- Operational Technical Nucleus, Microbiology, Hermes Pardini Institute, Belo Horizonte, Minas Gerais, Brazil
| | - Cláudio Tavares Sacchi
- Strategic Laboratory, Adolfo Lutz Institute, Secretary of Health of the State of São Paulo, São Paulo, Brazil
| | - Verônica Viana Vieira
- Interdisciplinary Laboratory of Medical Research, Oswaldo Cruz Institute, Oswaldo Cruz Foundation, Rio de Janeiro, Brazil
| | - Karoline Rodrigues Campos
- Strategic Laboratory, Adolfo Lutz Institute, Secretary of Health of the State of São Paulo, São Paulo, Brazil
| | | | | | - Vasco Azevedo
- Institute of Biological Sciences, Federal University of Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
| | - Flávia Figueira Aburjaile
- Department of Preventive Veterinary Medicine, Veterinary School, Federal University of Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
| | - Ana Luiza de Mattos-Guaraldi
- Laboratory of Diphtheria and Corynebacteria of Clinical Relevance, Department of Microbiology, Immunology and Parasitology, Rio de Janeiro State University, Rio de Janeiro, Brazil
| | - Louisy Sanches Dos Santos
- Laboratory of Diphtheria and Corynebacteria of Clinical Relevance, Department of Microbiology, Immunology and Parasitology, Rio de Janeiro State University, Rio de Janeiro, Brazil.
| |
Collapse
|
3
|
Araújo MRB, Ramos JN, de Oliveira Sant'Anna L, Bokermann S, Santos MBN, Mattos-Guaraldi AL, Azevedo V, Prates FD, Rodrigues DLN, Aburjaile FF, Sacchi CT, Campos KR, Alvim LB, Vieira VV, Camargo CH, Dos Santos LS. Phenotypic and molecular characterization and complete genome sequence of a Corynebacterium diphtheriae strain isolated from cutaneous infection in an immunized individual. Braz J Microbiol 2023; 54:1325-1334. [PMID: 37597133 PMCID: PMC10485220 DOI: 10.1007/s42770-023-01086-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2023] [Accepted: 07/24/2023] [Indexed: 08/21/2023] Open
Abstract
Diphtheria is an infectious disease potentially fatal that constitutes a threat to global health security, with possible local and systemic manifestations that result mainly from the production of diphtheria toxin (DT). In the present work, we report a case of infection by Corynebacterium diphtheriae in a cutaneous lesion of a fully immunized individual and provided an analysis of the complete genome of the isolate. The clinical isolate was first identified by MALDI-TOF Mass Spectrometry. The commercial strip system and mPCR performed phenotypic and genotypic characterization, respectively. The antimicrobial susceptibility profile was determined by the disk diffusion method. Additionally, genomic DNA was sequenced and analyzed for species confirmation and sequence type (ST) determination. Detection of resistance and virulence genes was performed by comparisons against ResFinder and VFDB databases. The isolate was identified as a nontoxigenic C. diphtheriae biovar Gravis strain. Its genome presented a size of 2.46 Mbp and a G + C content of 53.5%. Ribosomal Multilocus Sequence Typing (rMLST) allowed the confirmation of species as C. diphtheriae with 100% identity. DDH in silico corroborated this identification. Moreover, MLST analyses revealed that the isolate belongs to ST-536. No resistance genes were predicted or mutations detected in antimicrobial-related genes. On the other hand, virulence genes, mostly involved in iron uptake and adherence, were found. Presently, we provided sufficient clinical data regarding the C. diphtheriae cutaneous infection in addition to the phenotypic and genomic data of the isolate. Our results indicate a possible circulation of ST-536 in Brazil, causing cutaneous infection. Considering that cases of C. diphtheriae infections, as well as diphtheria outbreaks, have still been reported in several regions of the world, studies focusing on taxonomic analyzes and predictions of resistance genes may help to improve the diagnosis and to monitor the propagation of resistant clones. In addition, they can contribute to understanding the association between variation in genetic factors and resistance to antimicrobials.
Collapse
Affiliation(s)
- Max Roberto Batista Araújo
- Operational Technical Nucleus (Microbiology), Hermes Pardini Institute, Vespasiano, Minas Gerais, Brazil
| | - Juliana Nunes Ramos
- Department of Microbiology, Immunology and Parasitology, Rio de Janeiro State University, Rio de Janeiro, Rio de Janeiro, Brazil
| | - Lincoln de Oliveira Sant'Anna
- Department of Microbiology, Immunology and Parasitology, Rio de Janeiro State University, Rio de Janeiro, Rio de Janeiro, Brazil
| | - Sérgio Bokermann
- Center of Bacteriology, Adolfo Lutz Institute, São Paulo, São Paulo, Brazil
| | | | - Ana Luiza Mattos-Guaraldi
- Department of Microbiology, Immunology and Parasitology, Rio de Janeiro State University, Rio de Janeiro, Rio de Janeiro, Brazil
| | - Vasco Azevedo
- Institute of Biological Sciences, Federal University of Minas Gerais, Minas Gerais, Belo Horizonte, Brazil
| | - Fernanda Diniz Prates
- Operational Technical Nucleus (Microbiology), Hermes Pardini Institute, Vespasiano, Minas Gerais, Brazil
| | - Diego Lucas Neres Rodrigues
- Department of Preventive Veterinary Medicine, Federal University of Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
| | - Flávia Figueira Aburjaile
- Department of Preventive Veterinary Medicine, Federal University of Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
| | | | | | - Luige Biciati Alvim
- Operational Technical Nucleus (Research and Development), Hermes Pardini Institute, Vespasiano, Minas Gerais, Brazil
| | - Verônica Viana Vieira
- Interdisciplinary Medical Research Laboratory, Oswaldo Cruz Foundation, Rio de Janeiro, Rio de Janeiro, Brazil
| | | | - Louisy Sanches Dos Santos
- Department of Microbiology, Immunology and Parasitology, Rio de Janeiro State University, Rio de Janeiro, Rio de Janeiro, Brazil.
| |
Collapse
|
4
|
Griffin ME, Klupt S, Espinosa J, Hang HC. Peptidoglycan NlpC/P60 peptidases in bacterial physiology and host interactions. Cell Chem Biol 2023; 30:436-456. [PMID: 36417916 PMCID: PMC10192474 DOI: 10.1016/j.chembiol.2022.11.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2022] [Revised: 09/15/2022] [Accepted: 10/31/2022] [Indexed: 11/23/2022]
Abstract
The bacterial cell wall is composed of a highly crosslinked matrix of glycopeptide polymers known as peptidoglycan that dictates bacterial cell morphology and protects against environmental stresses. Regulation of peptidoglycan turnover is therefore crucial for bacterial survival and growth and is mediated by key protein complexes and enzyme families. Here, we review the prevalence, structure, and activity of NlpC/P60 peptidases, a family of peptidoglycan hydrolases that are crucial for cell wall turnover and division as well as interactions with antibiotics and different hosts. Understanding the molecular functions of NlpC/P60 peptidases should provide important insight into bacterial physiology, their interactions with different kingdoms of life, and the development of new therapeutic approaches.
Collapse
Affiliation(s)
- Matthew E Griffin
- Department of Immunology and Microbiology, Scripps Research, La Jolla, CA 92037, USA
| | - Steven Klupt
- Department of Immunology and Microbiology, Scripps Research, La Jolla, CA 92037, USA
| | - Juliel Espinosa
- Laboratory of Chemical Biology and Microbial Pathogenesis, The Rockefeller University, New York, NY 10065, USA
| | - Howard C Hang
- Department of Immunology and Microbiology, Scripps Research, La Jolla, CA 92037, USA; Department of Chemistry, Scripps Research, La Jolla, CA 92037, USA.
| |
Collapse
|
5
|
Wołkowicz T, Zacharczuk K, Zasada AA. Genomic Analysis of Corynebacterium diphtheriae Strains Isolated in the Years 2007-2022 with a Report on the Identification of the First Non-Toxigenic tox Gene-Bearing Strain in Poland. Int J Mol Sci 2023; 24:ijms24054612. [PMID: 36902043 PMCID: PMC10003741 DOI: 10.3390/ijms24054612] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2022] [Revised: 02/17/2023] [Accepted: 02/21/2023] [Indexed: 03/03/2023] Open
Abstract
Infections caused by non-toxigenic Corynebacterium diphtheriae have been reported every year in Poland since 2004, with the ST8 biovar gravis strains being most commonly isolated. This study analyzed thirty strains isolated between 2017 and 2022 and six previously isolated strains. All the strains were characterized using classic methods in terms of species, biovar level, and diphtheria toxin production, as well as by means of whole genome sequencing. The phylogenetic relationship based on SNP analysis was determined. The number of C. diphtheriae infections has been rising in Poland every year with a maximum of 22 cases in the year 2019. Since 2022, only the non-toxigenic gravis ST8 (most common) and mitis ST439 (less common) strains have been isolated. An analysis of the genomes of the ST8 strains showed that they had many potential virulence factors, such as adhesins and iron-uptake systems. The situation rapidly changed in 2022 and strains from different STs were isolated (ST32, 40, and 819). The ST40 biovar mitis strain was found to be non-toxigenic tox gene-bearing (NTTB), with the tox gene inactivated due to a single nucleotide deletion. Such strains were previously isolated in Belarus. The sudden appearance of new C. diphtheriae strains with different STs and the isolation of the first NTTB strain in Poland indicate that C. diphtheriae should be classified as a pathogen of special public health concern.
Collapse
Affiliation(s)
- Tomasz Wołkowicz
- Department of Bacteriology and Biocontamination Control, National Institute of Public Health NIH—National Research Institute, 24 Chocimska Str., 00-791 Warsaw, Poland
- Correspondence:
| | - Katarzyna Zacharczuk
- Department of Bacteriology and Biocontamination Control, National Institute of Public Health NIH—National Research Institute, 24 Chocimska Str., 00-791 Warsaw, Poland
| | - Aleksandra Anna Zasada
- Department of Sera and Vaccines Evaluation, National Institute of Public Health NIH—National Research Institute, 24 Chocimska Str., 00-791 Warsaw, Poland
| |
Collapse
|
6
|
Ott L, Möller J, Burkovski A. Interactions between the Re-Emerging Pathogen Corynebacterium diphtheriae and Host Cells. Int J Mol Sci 2022; 23:ijms23063298. [PMID: 35328715 PMCID: PMC8952647 DOI: 10.3390/ijms23063298] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2022] [Revised: 03/16/2022] [Accepted: 03/17/2022] [Indexed: 02/07/2023] Open
Abstract
Corynebacterium diphtheriae, the etiological agent of diphtheria, is a re-emerging pathogen, responsible for several thousand deaths per year. In addition to diphtheria, systemic infections, often by non-toxigenic strains, are increasingly observed. This indicates that besides the well-studied and highly potent diphtheria toxin, various other virulence factors may influence the progression of the infection. This review focuses on the known components of C. diphtheriae responsible for adhesion, invasion, inflammation, and cell death, as well as on the cellular signaling pathways activated upon infection.
Collapse
Affiliation(s)
- Lisa Ott
- Department of Biology, Friedrich-Alexander-Universität Erlangen-Nürnberg, Staudtstr. 5, 91058 Erlangen, Germany;
| | - Jens Möller
- Microbiology Division, Friedrich-Alexander-Universität Erlangen-Nürnberg, Staudtstr. 5, 91058 Erlangen, Germany;
| | - Andreas Burkovski
- Microbiology Division, Friedrich-Alexander-Universität Erlangen-Nürnberg, Staudtstr. 5, 91058 Erlangen, Germany;
- Correspondence: ; Tel.: +49-9131-852-8086
| |
Collapse
|
7
|
Phylogenomic Characterization of a Novel Corynebacterium Species Associated with Fatal Diphtheritic Stomatitis in Endangered Yellow-Eyed Penguins. mSystems 2021; 6:e0032021. [PMID: 34100641 PMCID: PMC8269222 DOI: 10.1128/msystems.00320-21] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Yellow-eyed penguins, Megadyptes antipodes, are an endangered species that are endemic to New Zealand. Outbreaks of diphtheritic stomatitis have caused significant mortality for this species, especially among young chicks. In this study, we isolated 16 Corynebacterium sp. isolates from the oral cavities of 2- to 14-day-old chicks at a range of infection stages and sequenced the genomes to understand their virulence mechanisms. Phylogenomic and matrix-assisted laser desorption ionization–time of flight (MALDI-TOF) characterization indicate that these strains belong to a novel Corynebacterium species. A simple multiplex PCR-based diagnostic assay has been developed to identify these strains rapidly and reliably. Similar to other corynebacteria, genomic islands and prophages introduced significant diversity among these strains that has potentially led to minor functional variations between the two lineages. Despite the presence of multiple corynebacterial virulence genes and a spaDEF-type pilus gene cluster among these strains, the survival rate was much higher in Galleria mellonella larvae than in those inoculated with Corynebacterium ulcerans NZRM 818 and Corynebacterium pseudotuberculosis NZRM 3004. Therefore, these strains are opportunistic pathogens causing high mortality among young penguin chicks due to a less-developed immune system. IMPORTANCE Yellow-eyed penguins, Megadyptes antipodes, are endangered species with a sharp decline in the numbers of breeding pairs over the last 2 decades. Diphtheritic stomatitis, characterized by a thick fibrinopurulent exudate in the oral cavities and symptoms, including inanition and significant weight loss, is responsible for significant mortality among the young chicks. These chicks are treated with antibiotics, amoxicillin-clavulanic acid or enrofloxacin, but do not always recover from the infection. The pathogen causing these infections and the mechanism of pathogenesis are unclear. This study has identified a novel Corynebacterium species to be associated with diphtheritic stomatitis in yellow-eyed penguins with potential virulence genes that are likely involved in pathogenesis. Importantly, a gene encoding an exotoxin, phospholipase D, is present among these strains. The inactivated form of this enzyme could potentially be used as an effective vaccine to protect these penguins from infection.
Collapse
|
8
|
Möller J, Nosratabadi F, Musella L, Hofmann J, Burkovski A. Corynebacterium diphtheriae Proteome Adaptation to Cell Culture Medium and Serum. Proteomes 2021; 9:proteomes9010014. [PMID: 33805816 PMCID: PMC8005964 DOI: 10.3390/proteomes9010014] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2021] [Revised: 03/09/2021] [Accepted: 03/10/2021] [Indexed: 12/03/2022] Open
Abstract
Host-pathogen interactions are often studied in vitro using primary or immortal cell lines. This set-up avoids ethical problems of animal testing and has the additional advantage of lower costs. However, the influence of cell culture media on bacterial growth and metabolism is not considered or investigated in most cases. To address this question growth and proteome adaptation of Corynebacterium diphtheriae strain ISS3319 were investigated in this study. Bacteria were cultured in standard growth medium, cell culture medium, and fetal calf serum. Mass spectrometric analyses and label-free protein quantification hint at an increased bacterial pathogenicity when grown in cell culture medium as well as an influence of the growth medium on the cell envelope.
Collapse
Affiliation(s)
- Jens Möller
- Microbiology Division, Department of Biology, Friedrich-Alexander-Universität Erlangen-Nürnberg, 91058 Erlangen, Germany; (F.N.); (L.M.); (A.B.)
- Correspondence: ; Tel.: +49-9131-85-28802
| | - Fatemeh Nosratabadi
- Microbiology Division, Department of Biology, Friedrich-Alexander-Universität Erlangen-Nürnberg, 91058 Erlangen, Germany; (F.N.); (L.M.); (A.B.)
| | - Luca Musella
- Microbiology Division, Department of Biology, Friedrich-Alexander-Universität Erlangen-Nürnberg, 91058 Erlangen, Germany; (F.N.); (L.M.); (A.B.)
| | - Jörg Hofmann
- Biochemistry Division, Department of Biology, Friedrich-Alexander-Universität Erlangen-Nürnberg, 91058 Erlangen, Germany;
| | - Andreas Burkovski
- Microbiology Division, Department of Biology, Friedrich-Alexander-Universität Erlangen-Nürnberg, 91058 Erlangen, Germany; (F.N.); (L.M.); (A.B.)
| |
Collapse
|
9
|
Sharma NC, Efstratiou A, Mokrousov I, Mutreja A, Das B, Ramamurthy T. Diphtheria. Nat Rev Dis Primers 2019; 5:81. [PMID: 31804499 DOI: 10.1038/s41572-019-0131-y] [Citation(s) in RCA: 87] [Impact Index Per Article: 17.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 10/25/2019] [Indexed: 01/09/2023]
Abstract
Diphtheria is a potentially fatal infection mostly caused by toxigenic Corynebacterium diphtheriae strains and occasionally by toxigenic C. ulcerans and C. pseudotuberculosis strains. Diphtheria is generally an acute respiratory infection, characterized by the formation of a pseudomembrane in the throat, but cutaneous infections are possible. Systemic effects, such as myocarditis and neuropathy, which are associated with increased fatality risk, are due to diphtheria toxin, an exotoxin produced by the pathogen that inhibits protein synthesis and causes cell death. Clinical diagnosis is confirmed by the isolation and identification of the causative Corynebacterium spp., usually by bacterial culture followed by enzymatic and toxin detection tests. Diphtheria can be treated with the timely administration of diphtheria antitoxin and antimicrobial therapy. Although effective vaccines are available, this disease has the potential to re-emerge in countries where the recommended vaccination programmes are not sustained, and increasing proportions of adults are becoming susceptible to diphtheria. Thousands of diphtheria cases are still reported annually from several countries in Asia and Africa, along with many outbreaks. Changes in the epidemiology of diphtheria have been reported worldwide. The prevalence of toxigenic Corynebacterium spp. highlights the need for proper clinical and epidemiological investigations to quickly identify and treat affected individuals, along with public health measures to prevent and contain the spread of this disease.
Collapse
Affiliation(s)
- Naresh Chand Sharma
- Laboratory Department, Maharishi Valmiki Infectious Diseases Hospital, Delhi, India
| | - Androulla Efstratiou
- WHO Collaborating Centre for Diphtheria and Streptococcal Infections, Reference Microbiology Division, Public Health England, London, UK
| | - Igor Mokrousov
- Laboratory of Molecular Epidemiology and Evolutionary Genetics, St. Petersburg Pasteur Institute, St. Petersburg, Russia
| | - Ankur Mutreja
- Global Health-Infectious Diseases, Department of Medicine, University of Cambridge, Cambridge, UK
| | - Bhabatosh Das
- Infection and Immunology Division, Translational Health Science and Technology Institute, Faridabad, India
| | - Thandavarayan Ramamurthy
- Infection and Immunology Division, Translational Health Science and Technology Institute, Faridabad, India.
| |
Collapse
|
10
|
Kittl S, Brodard I, Rychener L, Jores J, Roosje P, Gobeli Brawand S. Otitis in a cat associated with Corynebacterium provencense. BMC Vet Res 2018; 14:200. [PMID: 29940943 PMCID: PMC6019829 DOI: 10.1186/s12917-018-1526-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2018] [Accepted: 06/18/2018] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND The role of corynebacteria in canine and feline otitis has not been investigated in detail; however, members of this genus are increasingly recognized as pathogens of otitis in both human and veterinary medicine. CASE PRESENTATION Here we report the first case of feline otitis associated with the recently described species Corynebacterium provencense. A seven-month old cat presented with a head tilt and ataxia was diagnosed with peripheral vestibular syndrome associated with an otitis media/interna. This took place 6 weeks after resection of a polyp, having initially shown a full recovery with topical ofloxacin and glucocorticoid treatment. Bacteriology of an ear swab yielded a pure culture of corynebacteria, which could not be identified at the species level using routine methods. However, the 16S rRNA gene sequence was 100% identical to the recently published novel corynebacterium species, Corynebacterium provencense. Whole genome sequencing of the cat isolate and calculation of average nucleotide identity (99.1%) confirmed this finding. The cat isolate was found to contain additional presumptive iron acquisition genes that are likely to encode virulence factors. Furthermore, the strain tested resistant to clindamycin, penicillin and ciprofloxacin. The cat was subsequently treated with chloramphenicol, which lead to clinical improvement. CONCLUSION Corynebacteria from otitis cases are not routinely identified at the species level and not tested for antimicrobial susceptibility in veterinary laboratories, as they are not considered major pathogens. This may lead to underreporting of this genus or animals being treated with inappropriate antimicrobials since corynebacteria are often resistant to multiple drugs.
Collapse
Affiliation(s)
- Sonja Kittl
- Institute of Veterinary Bacteriology, Vetsuisse Faculty, University of Bern, Laenggassstrasse 122, CH-3001 Bern, Switzerland
| | - Isabelle Brodard
- Institute of Veterinary Bacteriology, Vetsuisse Faculty, University of Bern, Laenggassstrasse 122, CH-3001 Bern, Switzerland
| | - Lorenz Rychener
- Institute of Veterinary Bacteriology, Vetsuisse Faculty, University of Bern, Laenggassstrasse 122, CH-3001 Bern, Switzerland
| | - Jörg Jores
- Institute of Veterinary Bacteriology, Vetsuisse Faculty, University of Bern, Laenggassstrasse 122, CH-3001 Bern, Switzerland
| | - Petra Roosje
- Division of Clinical Dermatology, Department of Clinical Veterinary Medicine, Vetsuisse Faculty, University of Bern, Bremgartenstrasse 109a, CH-3001 Bern, Switzerland
- DermFocus, Vetsuisse Faculty, University of Bern, Bern, Switzerland
| | - Stefanie Gobeli Brawand
- Institute of Veterinary Bacteriology, Vetsuisse Faculty, University of Bern, Laenggassstrasse 122, CH-3001 Bern, Switzerland
| |
Collapse
|
11
|
Abstract
Corynebacterium diphtheriae, Corynebacterium pseudotuberculosis and Corynebacterium ulcerans share one distinctive feature: they are all putative carriers of the diphtheria toxin (DT), encoded by a β-corynephage integrated into the genome. Due to its medical relevance, C. diphtheriae may be the most highly investigated species of the genus Corynebacterium. Nevertheless, systemic infections caused by C. ulcerans are increasingly being reported indicating that this species is an emerging pathogen today. C. diphtheriae, C. pseudotuberculosis and C. ulcerans are able to colonize different types of epithelial cells in a strain-specific manner, independent of the presence of the tox gene. However, the molecular mechanisms contributing to host colonization are barely understood. This review gives a comprehensive update of recent data concerning the adhesion properties of toxigenic corynebacteria, demonstrating that adhesion is a multi-factorial process.
Collapse
Affiliation(s)
- Lisa Ott
- Friedrich-Alexander-Universität Erlangen-Nürnberg, Professur für Mikrobiologie, Staudtstr. 5, 91058 Erlangen, Germany
| |
Collapse
|
12
|
Hacker E, Antunes CA, Mattos-Guaraldi AL, Burkovski A, Tauch A. Corynebacterium ulcerans, an emerging human pathogen. Future Microbiol 2016; 11:1191-208. [PMID: 27545005 DOI: 10.2217/fmb-2016-0085] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
While formerly known infections of Corynebacterium ulcerans are rare and mainly associated with contact to infected cattle, C. ulcerans has become an emerging pathogen today. In Western Europe, cases of respiratory diphtheria caused by C. ulcerans have been reported more often than infections by Corynebacterium diphtheria, while systemic infections are also increasingly reported. Little is known about factors that contribute to host colonization and virulence of this zoonotic pathogen. Research in this field has received new impetus by the publication of several C. ulcerans genome sequences in the past years. This review gives a comprehensive overview of the basic knowledge of C. ulcerans, as well as the recent advances made in the analysis of putative virulence factors.
Collapse
Affiliation(s)
- Elena Hacker
- Professur für Mikrobiologie, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany
| | - Camila A Antunes
- Professur für Mikrobiologie, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany.,Laboratory of Diphtheria and Clinically Important Corynebacteria (LDCIC), Rio de Janeiro State University, Rio de Janeiro, Brazil
| | - Ana L Mattos-Guaraldi
- Laboratory of Diphtheria and Clinically Important Corynebacteria (LDCIC), Rio de Janeiro State University, Rio de Janeiro, Brazil
| | - Andreas Burkovski
- Professur für Mikrobiologie, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany
| | - Andreas Tauch
- Centrum für Biotechnologie, Universität Bielefeld, Bielefeld, Germany
| |
Collapse
|
13
|
Sangal V, Blom J, Sutcliffe IC, von Hunolstein C, Burkovski A, Hoskisson PA. Adherence and invasive properties of Corynebacterium diphtheriae strains correlates with the predicted membrane-associated and secreted proteome. BMC Genomics 2015; 16:765. [PMID: 26452736 PMCID: PMC4600297 DOI: 10.1186/s12864-015-1980-8] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2015] [Accepted: 10/02/2015] [Indexed: 11/25/2022] Open
Abstract
BACKGROUND Non-toxigenic Corynebacterium diphtheriae strains are emerging as a major cause of severe pharyngitis and tonsillitis as well as invasive diseases such as endocarditis, septic arthritis, splenic abscesses and osteomyelitis. C. diphtheriae strains have been reported to vary in their ability to adhere and invade different cell lines. To identify the genetic basis of variation in the degrees of pathogenicity, we sequenced the genomes of four strains of C. diphtheriae (ISS 3319, ISS 4060, ISS 4746 and ISS 4749) that are well characterised in terms of their ability to adhere and invade mammalian cells. RESULTS Comparative analyses of 20 C. diphtheriae genome sequences, including 16 publicly available genomes, revealed a pan-genome comprising 3,989 protein coding sequences that include 1,625 core genes and 2,364 accessory genes. Most of the genomic variation between these strains relates to uncharacterised genes encoding hypothetical proteins or transposases. Further analyses of protein sequences using an array of bioinformatic tools predicted most of the accessory proteome to be located in the cytoplasm. The membrane-associated and secreted proteins are generally involved in adhesion and virulence characteristics. The genes encoding membrane-associated proteins, especially the number and organisation of the pilus gene clusters (spa) including the number of genes encoding surface proteins with LPXTG motifs differed between different strains. Other variations were among the genes encoding extracellular proteins, especially substrate binding proteins of different functional classes of ABC transport systems and 'non-classical' secreted proteins. CONCLUSIONS The structure and organisation of the spa gene clusters correlates with differences in the ability of C. diphtheriae strains to adhere and invade the host cells. Furthermore, differences in the number of genes encoding membrane-associated proteins, e.g., additional proteins with LPXTG motifs could also result in variation in the adhesive properties between different strains. The variation in the secreted proteome may be associated with the degree of pathogenesis. While the role of the 'non-classical' secretome in virulence remains unclear, differences in the substrate binding proteins of various ABC transport systems and cytoplasmic proteins potentially suggest strain variation in nutritional requirements or a differential ability to utilize various carbon sources.
Collapse
Affiliation(s)
- Vartul Sangal
- Faculty of Health and Life Sciences, Northumbria University, Newcastle upon Tyne, NE1 8ST, UK.
| | - Jochen Blom
- Heinrich-Buff-Ring 58, Justus-Liebig-Universität, 35392, Gießen, Germany.
| | - Iain C Sutcliffe
- Faculty of Health and Life Sciences, Northumbria University, Newcastle upon Tyne, NE1 8ST, UK.
| | | | - Andreas Burkovski
- Professur für Mikrobiologie, Friedrich-Alexander-Universität Erlangen-Nürnberg, Staudtstr. 5, 91058, Erlangen, Germany.
| | - Paul A Hoskisson
- Strathclyde Institute of Pharmacy and Biomedical Sciences, University of Strathclyde, 161 Cathedral Street, Glasgow, G4 0RE, UK.
| |
Collapse
|
14
|
Virulence Factor Genes Detected in the Complete Genome Sequence of Corynebacterium uterequi DSM 45634, Isolated from the Uterus of a Maiden Mare. GENOME ANNOUNCEMENTS 2015; 3:3/4/e00783-15. [PMID: 26227590 PMCID: PMC4520889 DOI: 10.1128/genomea.00783-15] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
ABSTRACT
The complete genome sequence of the type strain
Corynebacterium uterequi
DSM 45634 from an equine urogenital tract specimen comprises 2,419,437 bp and 2,163 protein-coding genes. Candidate virulence factors are homologs of DIP0733, DIP1281, and DIP1621 from
Corynebacterium diphtheriae
and of sialidase precursors from
Trueperella pyogenes
and
Chlamydia trachomatis
.
Collapse
|
15
|
Barh D, Gupta K, Jain N, Khatri G, León-Sicairos N, Canizalez-Roman A, Tiwari S, Verma A, Rahangdale S, Shah Hassan S, Rodrigues dos Santos A, Ali A, Carlos Guimarães L, Thiago Jucá Ramos R, Devarapalli P, Barve N, Bakhtiar M, Kumavath R, Ghosh P, Miyoshi A, Silva A, Kumar A, Narayan Misra A, Blum K, Baumbach J, Azevedo V. Conserved host–pathogen PPIs Globally conserved inter-species bacterial PPIs based conserved host-pathogen interactome derived novel target inC. pseudotuberculosis,C. diphtheriae,M. tuberculosis,C. ulcerans,Y. pestis, andE. colitargeted byPiper betelcompounds. Integr Biol (Camb) 2013; 5:495-509. [DOI: 10.1039/c2ib20206a] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Affiliation(s)
- Debmalya Barh
- Centre for Genomics and Applied Gene Technology, Institute of Integrative Omics and Applied Biotechnology (IIOAB), Nonakuri, Purba Medinipur, West Bengal-721172, India. Fax: +91-944 955 0032; Tel: +91-944 955 0032
- Department of Biosciences and Biotechnology, School of Biotechnology, Fakir Mohan University, Jnan Bigyan Vihar, Balasore, Orissa, India
| | - Krishnakant Gupta
- Centre for Genomics and Applied Gene Technology, Institute of Integrative Omics and Applied Biotechnology (IIOAB), Nonakuri, Purba Medinipur, West Bengal-721172, India. Fax: +91-944 955 0032; Tel: +91-944 955 0032
- School of Biotechnology, Devi Ahilya University, Khandwa Road Campus, Indore, MP, India
| | - Neha Jain
- Centre for Genomics and Applied Gene Technology, Institute of Integrative Omics and Applied Biotechnology (IIOAB), Nonakuri, Purba Medinipur, West Bengal-721172, India. Fax: +91-944 955 0032; Tel: +91-944 955 0032
| | - Gourav Khatri
- Centre for Genomics and Applied Gene Technology, Institute of Integrative Omics and Applied Biotechnology (IIOAB), Nonakuri, Purba Medinipur, West Bengal-721172, India. Fax: +91-944 955 0032; Tel: +91-944 955 0032
- School of Biotechnology, Devi Ahilya University, Khandwa Road Campus, Indore, MP, India
| | - Nidia León-Sicairos
- Unidad de investigacion, Facultad de Medicina, Universidad Autónoma de Sinaloa. Cedros y Sauces, Fraccionamiento Fresnos, Culiacán Sinaloa 80246, México
| | - Adrian Canizalez-Roman
- Unidad de investigacion, Facultad de Medicina, Universidad Autónoma de Sinaloa. Cedros y Sauces, Fraccionamiento Fresnos, Culiacán Sinaloa 80246, México
| | - Sandeep Tiwari
- Centre for Genomics and Applied Gene Technology, Institute of Integrative Omics and Applied Biotechnology (IIOAB), Nonakuri, Purba Medinipur, West Bengal-721172, India. Fax: +91-944 955 0032; Tel: +91-944 955 0032
| | - Ankit Verma
- Centre for Genomics and Applied Gene Technology, Institute of Integrative Omics and Applied Biotechnology (IIOAB), Nonakuri, Purba Medinipur, West Bengal-721172, India. Fax: +91-944 955 0032; Tel: +91-944 955 0032
- School of Biotechnology, Devi Ahilya University, Khandwa Road Campus, Indore, MP, India
| | - Sachin Rahangdale
- Centre for Genomics and Applied Gene Technology, Institute of Integrative Omics and Applied Biotechnology (IIOAB), Nonakuri, Purba Medinipur, West Bengal-721172, India. Fax: +91-944 955 0032; Tel: +91-944 955 0032
- School of Biotechnology, Devi Ahilya University, Khandwa Road Campus, Indore, MP, India
| | - Syed Shah Hassan
- Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brazil
| | | | - Amjad Ali
- Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brazil
| | - Luis Carlos Guimarães
- Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brazil
| | | | - Pratap Devarapalli
- Department of Genomic Science, School of Biological Sciences, Riverside Transit Campus, Central University of Kerala, Kasaragod, India
| | - Neha Barve
- Centre for Genomics and Applied Gene Technology, Institute of Integrative Omics and Applied Biotechnology (IIOAB), Nonakuri, Purba Medinipur, West Bengal-721172, India. Fax: +91-944 955 0032; Tel: +91-944 955 0032
- School of Biotechnology, Devi Ahilya University, Khandwa Road Campus, Indore, MP, India
| | - Marriam Bakhtiar
- Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brazil
| | - Ranjith Kumavath
- Department of Genomic Science, School of Biological Sciences, Riverside Transit Campus, Central University of Kerala, Kasaragod, India
| | - Preetam Ghosh
- Centre for Genomics and Applied Gene Technology, Institute of Integrative Omics and Applied Biotechnology (IIOAB), Nonakuri, Purba Medinipur, West Bengal-721172, India. Fax: +91-944 955 0032; Tel: +91-944 955 0032
- Department of Computer Science and Center for the Study of Biological Complexity, Virginia Commonwealth University, 401 West Main Street, Room E4234, P.O. Box 843019, Richmond, Virginia 23284-3019, USA
| | - Anderson Miyoshi
- Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brazil
| | - Artur Silva
- Instituto de Ciências Biológicas, Universidade Federal do Pará, Belém, PA, Brazil
| | - Anil Kumar
- School of Biotechnology, Devi Ahilya University, Khandwa Road Campus, Indore, MP, India
| | - Amarendra Narayan Misra
- Department of Biosciences and Biotechnology, School of Biotechnology, Fakir Mohan University, Jnan Bigyan Vihar, Balasore, Orissa, India
- Center for Life Sciences, School of Natural Sciences, Central University of Jharkhand, Ranchi, Jharkhand State, India
| | - Kenneth Blum
- Centre for Genomics and Applied Gene Technology, Institute of Integrative Omics and Applied Biotechnology (IIOAB), Nonakuri, Purba Medinipur, West Bengal-721172, India. Fax: +91-944 955 0032; Tel: +91-944 955 0032
- University of Florida, College of Medicine, Gainesville, Florida, USA
- Global Integrated Services Unit University of Vermont Center for Clinical & Translational Science, College of Medicine, Burlington, VT, USA
- Dominion Diagnostics LLC, North Kingstown, Rhode Island, USA
| | - Jan Baumbach
- Computational Biology Group Department of Mathematics and Computer Science, University of Southern Denmark, Campusvej 55, DK-5230 Odense, Denmark
| | - Vasco Azevedo
- Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brazil
| |
Collapse
|
16
|
Schröder J, Maus I, Meyer K, Wördemann S, Blom J, Jaenicke S, Schneider J, Trost E, Tauch A. Complete genome sequence, lifestyle, and multi-drug resistance of the human pathogen Corynebacterium resistens DSM 45100 isolated from blood samples of a leukemia patient. BMC Genomics 2012; 13:141. [PMID: 22524407 PMCID: PMC3350403 DOI: 10.1186/1471-2164-13-141] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2011] [Accepted: 04/23/2012] [Indexed: 12/12/2022] Open
Abstract
BACKGROUND Corynebacterium resistens was initially recovered from human infections and recognized as a new coryneform species that is highly resistant to antimicrobial agents. Bacteremia associated with this organism in immunocompromised patients was rapidly fatal as standard minocycline therapies failed. C. resistens DSM 45100 was isolated from a blood culture of samples taken from a patient with acute myelocytic leukemia. The complete genome sequence of C. resistens DSM 45100 was determined by pyrosequencing to identify genes contributing to multi-drug resistance, virulence, and the lipophilic lifestyle of this newly described human pathogen. RESULTS The genome of C. resistens DSM 45100 consists of a circular chromosome of 2,601,311 bp in size and the 28,312-bp plasmid pJA144188. Metabolic analysis showed that the genome of C. resistens DSM 45100 lacks genes for typical sugar uptake systems, anaplerotic functions, and a fatty acid synthase, explaining the strict lipophilic lifestyle of this species. The genome encodes a broad spectrum of enzymes ensuring the availability of exogenous fatty acids for growth, including predicted virulence factors that probably contribute to fatty acid metabolism by damaging host tissue. C. resistens DSM 45100 is able to use external L-histidine as a combined carbon and nitrogen source, presumably as a result of adaptation to the hitherto unknown habitat on the human skin. Plasmid pJA144188 harbors several genes contributing to antibiotic resistance of C. resistens DSM 45100, including a tetracycline resistance region of the Tet W type known from Lactobacillus reuteri and Streptococcus suis. The tet(W) gene of pJA144188 was cloned in Corynebacterium glutamicum and was shown to confer high levels of resistance to tetracycline, doxycycline, and minocycline in vitro. CONCLUSIONS The detected gene repertoire of C. resistens DSM 45100 provides insights into the lipophilic lifestyle and virulence functions of this newly recognized pathogen. Plasmid pJA144188 revealed a modular architecture of gene regions that contribute to the multi-drug resistance of C. resistens DSM 45100. The tet(W) gene encoding a ribosomal protection protein is reported here for the first time in corynebacteria. Cloning of the tet(W) gene mediated resistance to second generation tetracyclines in C. glutamicum, indicating that it might be responsible for the failure of minocycline therapies in patients with C. resistens bacteremia.
Collapse
Affiliation(s)
- Jasmin Schröder
- Institut für Genomforschung und Systembiologie, Centrum für Biotechnologie, Universität Bielefeld, Germany
| | | | | | | | | | | | | | | | | |
Collapse
|
17
|
Pangenomic study of Corynebacterium diphtheriae that provides insights into the genomic diversity of pathogenic isolates from cases of classical diphtheria, endocarditis, and pneumonia. J Bacteriol 2012; 194:3199-215. [PMID: 22505676 DOI: 10.1128/jb.00183-12] [Citation(s) in RCA: 93] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Corynebacterium diphtheriae is one of the most prominent human pathogens and the causative agent of the communicable disease diphtheria. The genomes of 12 strains isolated from patients with classical diphtheria, endocarditis, and pneumonia were completely sequenced and annotated. Including the genome of C. diphtheriae NCTC 13129, we herewith present a comprehensive comparative analysis of 13 strains and the first characterization of the pangenome of the species C. diphtheriae. Comparative genomics showed extensive synteny and revealed a core genome consisting of 1,632 conserved genes. The pangenome currently comprises 4,786 protein-coding regions and increases at an average of 65 unique genes per newly sequenced strain. Analysis of prophages carrying the diphtheria toxin gene tox revealed that the toxoid vaccine producer C. diphtheriae Park-Williams no. 8 has been lysogenized by two copies of the ω(tox)(+) phage, whereas C. diphtheriae 31A harbors a hitherto-unknown tox(+) corynephage. DNA binding sites of the tox-controlling regulator DtxR were detected by genome-wide motif searches. Comparative content analysis showed that the DtxR regulons exhibit marked differences due to gene gain, gene loss, partial gene deletion, and DtxR binding site depletion. Most predicted pathogenicity islands of C. diphtheriae revealed characteristics of horizontal gene transfer. The majority of these islands encode subunits of adhesive pili, which can play important roles in adhesion of C. diphtheriae to different host tissues. All sequenced isolates contain at least two pilus gene clusters. It appears that variation in the distributed genome is a common strategy of C. diphtheriae to establish differences in host-pathogen interactions.
Collapse
|
18
|
Comparative analysis of two complete Corynebacterium ulcerans genomes and detection of candidate virulence factors. BMC Genomics 2011; 12:383. [PMID: 21801446 PMCID: PMC3164646 DOI: 10.1186/1471-2164-12-383] [Citation(s) in RCA: 71] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2011] [Accepted: 07/30/2011] [Indexed: 11/10/2022] Open
Abstract
Background Corynebacterium ulcerans has been detected as a commensal in domestic and wild animals that may serve as reservoirs for zoonotic infections. During the last decade, the frequency and severity of human infections associated with C. ulcerans appear to be increasing in various countries. As the knowledge of genes contributing to the virulence of this bacterium was very limited, the complete genome sequences of two C. ulcerans strains detected in the metropolitan area of Rio de Janeiro were determined and characterized by comparative genomics: C. ulcerans 809 was initially isolated from an elderly woman with fatal pulmonary infection and C. ulcerans BR-AD22 was recovered from a nasal sample of an asymptomatic dog. Results The circular chromosome of C. ulcerans 809 has a total size of 2,502,095 bp and encodes 2,182 predicted proteins, whereas the genome of C. ulcerans BR-AD22 is 104,279 bp larger and comprises 2,338 protein-coding regions. The minor difference in size of the two genomes is mainly caused by additional prophage-like elements in the C. ulcerans BR-AD22 chromosome. Both genomes show a highly similar order of orthologous coding regions; and both strains share a common set of 2,076 genes, demonstrating their very close relationship. A screening for prominent virulence factors revealed the presence of phospholipase D (Pld), neuraminidase H (NanH), endoglycosidase E (EndoE), and subunits of adhesive pili of the SpaDEF type that are encoded in both C. ulcerans genomes. The rbp gene coding for a putative ribosome-binding protein with striking structural similarity to Shiga-like toxins was additionally detected in the genome of the human isolate C. ulcerans 809. Conclusions The molecular data deduced from the complete genome sequences provides considerable knowledge of virulence factors in C. ulcerans that is increasingly recognized as an emerging pathogen. This bacterium is apparently equipped with a broad and varying set of virulence factors, including a novel type of a ribosome-binding protein. Whether the respective protein contributes to the severity of human infections (and a fatal outcome) remains to be elucidated by genetic experiments with defined bacterial mutants and host model systems.
Collapse
|