Bacterial spot disease of lamb's lettuce [ (L.) Laterr.] was first observed in fields in 1991. This new bacterial disease is localized in western France in high-technology field production of lamb's lettuce for the preparation of ready-to-use salad. Nineteen strains isolated in 1992 and 1993 from typical black leaf spots of naturally infected lamb's lettuce were characterized and compared with reference strains of and . The pathogenicity of the 19 strains was confirmed by artificial inoculation. Biochemical and physiological tests, fatty acid profiles, DNA–DNA hybridization and other nucleic acid-based tests were performed. A numerical taxonomic analysis of the 19 lamb's lettuce strains showed a single homogeneous phenon closely related to previously described phytopathogenic taxa of the genus . DNA–DNA hybridization studies showed that the lamb's lettuce strains were 91–100 % related to a representative strain, strain CFBP 4730, and constituted a discrete DNA hybridization group, indicating that they belong to the same novel species. Results from DNA–rRNA hybridization, 16S rRNA sequence analysis and fatty acid analysis studies confirmed that this novel species belongs to the -subclass of the and, more specifically, to the family and the genus . The name sp. nov. is proposed for this novel taxon of phytopathogenic bacteria. The type strain is strain CFBP 4730 (=NCPPB 4283).


Article metrics loading...

Loading full text...

Full text loading...



  1. De Ley, J. ( 1978; ). Modern molecular methods in bacterial taxonomy: evaluation, application, prospects. In Proceedings of the International Conference on Plant Pathogenic Bacteria, vol. 1, pp. 347–357. Tours: Gilbert.
  2. De Ley, J. & De Smedt, J. ( 1975; ). Improvements of the membrane filter method for DNA : rRNA hybridization. Antonie van Leeuwenhoek 41, 287–307.[CrossRef]
    [Google Scholar]
  3. Gardan, L., Dauga, C., Prior, P., Gillis, M. & Saddler, G. S. ( 2000; ). Acidovorax anthurii sp. nov., a new phytopathogenic bacterium which causes bacterial leaf-spot of anthurium. Int J Syst Evol Microbiol 50, 235–246.[CrossRef]
    [Google Scholar]
  4. Oyaizu, H. & Komagata, K. ( 1983; ). Grouping of Pseudomonas species on the basis of cellular fatty acid composition and the quinone system with special reference to the existence of 3-hydroxy fatty acids. J Gen Appl Microbiol 29, 17–40.[CrossRef]
    [Google Scholar]
  5. Péron, J. Y. & Rees, D. C. ( 1998; ). High-tech production of corn salad (Valerianella locusta (L.) Laterr.), a local, French vegetable crop. Acta Hortic 467, 259–268.
    [Google Scholar]
  6. Rat, B. & Gardan, L. ( 1993; ). La tache bactérienne due à un Pseudomonas sp. Fruits Légumes 11, 42–43.
    [Google Scholar]
  7. Rat, B., Gardan, L. & Bollet, C. ( 1994; ). Black spot of lamb lettuce: a new bacterial disease. In Plant Pathogenic Bacteria, p. 183. Edited by M. Lemattre, S. Freigoun, K. Rudolph & J. G. Swing. Paris: INRA.
  8. Rossello-Mora, R. & Amann, R. ( 2001; ). The species concept for prokaryotes. FEMS Microbiol Rev 25, 39–67.[CrossRef]
    [Google Scholar]
  9. Sneath, P. H. A. & Sokal, R. R. ( 1973; ). Numerical Taxonomy: Principles and Practice of Numerical Classification. San Francisco: W. H. Freeman.
  10. Stackebrandt, E., Murray, R. G. E. & Trüper, H. G. ( 1988; ). Proteobacteria classis nov., a name for the phylogenetic taxon that includes the “purple bacteria and their relatives”. Int J Syst Bacteriol 38, 321–325.[CrossRef]
    [Google Scholar]
  11. Stead, D. E. ( 1992a; ). Grouping of plant-pathogenic and some other Pseudomonas spp. by using cellular fatty acid profiles. Int J Syst Bacteriol 42, 281–295.[CrossRef]
    [Google Scholar]
  12. Stead, D. E. ( 1992b; ). Techniques for detecting and identifying plant pathogenic bacteria. In Techniques for Rapid Diagnosis of Plant Pathogens, pp. 76–111. Edited by J. Duncan & L. Torrance. Oxford: Blackwell Science.
  13. Stead, D. E., Sellwood, J. E., Wilson, J. & Viney, I. ( 1992; ). Evaluation of a commercial microbial identification system based on fatty acid profiles for rapid, accurate identification of plant pathogenic bacteria. J Appl Bacteriol 72, 315–321.[CrossRef]
    [Google Scholar]
  14. Wen, A., Fegan, M., Hayward, C., Chakraborty, S. & Sly, L. I. ( 1999; ). Phylogenetic relationships among members of the Comamonadaceae, and description of Delftia acidovorans (den Dooren de Jong 1926 and Tamaoka et al. 1987) gen. nov., comb. nov. Int J Syst Bacteriol 49, 567–576.[CrossRef]
    [Google Scholar]
  15. Willems, A., Falsen, E., Pot, B., Jantzen, E., Hoste, B., Vandamme, P., Gillis, M., Kersters, K. & De Ley, J. ( 1990; ). Acidovorax, a new genus for Pseudomonas facilis, Pseudomonas delafieldii, E. Falsen (EF) group 13, EF group 16, and several clinical isolates, with the species Acidovorax facilis comb. nov., Acidovorax delafieldii comb. nov., and Acidovorax temperans sp. nov. Int J Syst Bacteriol 40, 384–398.[CrossRef]
    [Google Scholar]

Data & Media loading...


vol. , part 3, pp. 795 - 800

Neighbour-joining tree obtained from 16S rRNA gene sequences. The scale bar represents 1 estimated base substitution per 100 nucleotide positions. Percentages refer to bootstrap values of calculated 100 trees. EMBL or GenBank accession numbers are given in parentheses. Abbreviations: ATCC, American Type Culture Collection, Manassas, VA, USA; CCUG, Culture Collection of the University of Göteborg, Department of Clinical Bacteriology, University of Göteborg, Sweden; CFBP, Collection Française de Bactéries Phytopathogènes, Angers, France; DSM, Deutsche Sammlung Von Mikroorganismen und Zellkulturen, Germany; IAM, Institute of Applied Microbiology, University of Tokyo, Japan; LMG, Laboratorium voor Microbiologie, Ghent, Belgium; NCIMB, National Collections of Industrial, Food and Marine Bacteria, Aberdeen, UK; NCPPB, National Collection of Plant-Pathogenic Bacteria, Harpenden, UK. [PDF](31 KB)


Most cited this month

This is a required field
Please enter a valid email address
Approval was a Success
Invalid data
An Error Occurred
Approval was partially successful, following selected items could not be processed due to error