title: On the evolution of the sexually transmitted bacteria Haemophilus ducreyi and Klebsiella granulomatis.
abstract: Haemophilus ducreyi and Klebsiella (Calymmatobacterium) granulomatis are sexually transmitted bacteria that cause characteristic, persisting ulceration on external genitals called chancroid and granuloma inguinale, respectively. Those ulcers are endemic in developing countries or exist, as does granuloma inguinale, only in some geographic "hot spots."H. ducreyi is placed in the genus Haemophilus (family Pasteurellacae); however, this phylogenetic position is not obvious. The multiple ways in which the bacterium may be adapted to its econiche through specialized nutrient acquisitions; defenses against the immune system; and virulence factors that increase attachment, fitness, and persistence within genital tissue are discussed below. The analysis of K. granulomatis phylogeny demonstrated a high degree of identity with other Klebsiella species, and the name K. granulomatis comb. nov. was proposed. Because of the difficulty in growing this bacterium on artificial media, its characteristics have not been sufficiently defined. More studies are needed to understand bacterial genetics related to the pathogenesis and evolution of K. granulomatis.
authors.affiliation: Department of Microbiology and Immunology, Institute of Biomedicine, University of Gothenburg, Gothenburg, Sweden. teresa.lagergard@microbio.gu.se
authors.forename: Teresa
authors.initials: T
authors.lastname: Lagergård
authors.forename: Ingrid
authors.initials: I
authors.lastname: Bölin
authors.forename: Leif
authors.initials: L
authors.lastname: Lindholm
mesh_terms: D000818:Animals; D002602:Chancroid / Q000235:genetics / Q000382:microbiology / Q000635:transmission; D019143:Evolution, Molecular; D014644:Genetic Variation; D006191:Haemophilus ducreyi / Q000235:genetics* / Q000472:pathogenicity / Q000502:physiology; D006801:Humans; D007709:Klebsiella / Q000235:genetics* / Q000472:pathogenicity / Q000502:physiology; D007710:Klebsiella Infections / Q000235:genetics / Q000382:microbiology / Q000635:transmission; D010802:Phylogeny; D015231:Sexually Transmitted Diseases, Bacterial / Q000382:microbiology*; D037521:Virulence Factors / Q000235:genetics / Q000502:physiology
chemical_list: D037521:Virulence Factors