Delineation of Campylobacter concisus genomospecies by amplified fragment length polymorphism analysis and correlation of results with clinical data

TY - JOUR

T1 - Delineation of Campylobacter concisus genomospecies by amplified fragment length polymorphism analysis and correlation of results with clinical data

AU - Aabenhus, Rune Munck

AU - On, Stephen L W

AU - Siemer, Berit L

AU - Permin, Henrik

AU - Andersen, Leif P

PY - 2005/10

Y1 - 2005/10

N2 - Campylobacter concisus has been as frequently isolated from human diarrhea as the important enteropathogen Campylobacter jejuni, but it also occurs in the feces of healthy individuals. The role of C. concisus in human disease has been difficult to determine, since the species comprises at least two phenotypically indistinguishable but genetically distinct taxa (i.e., genomospecies) that may vary in pathogenicity. We examined 62 C. concisus strains by amplified fragment length polymorphism (AFLP) profiling and correlated the results with clinical data. All C. concisus strains gave unique AFLP profiles, and numerical analysis of these data distributed the strains among four clusters. The clustering was of taxonomic significance: two clusters contained, respectively, the type strain (of oral origin) and a reference strain (from diarrhea) of each of the known genomospecies. Genomospecies 2 strains were more frequently isolated from immunocompetent patients and/or patients without concomitant infections that presented with fever, chronic diarrhea, and gut inflammation than was genomospecies 1, clustering with the type strain of oral origin. Bloody diarrhea was recorded only with C. concisus genomospecies 2 infections. We identified two additional C. concisus genomospecies: genomospecies 3 comprised a single strain from an immunocompetent patient, and genomospecies 4 contained five isolates from severely immunodeficient patients, i.e., organ transplantation recipients or those with hematological malignancies. All genomospecies 4 strains were of the same protein profile group and failed to react with a C. concisus species-specific PCR assay based on 23S rRNA gene sequences: the taxonomic position of this group requires closer investigation. Campylobacter concisus is genetically and taxonomically diverse and contains at least four distinct genomospecies that may exhibit differences in their spectra of virulence potential.

AB - Campylobacter concisus has been as frequently isolated from human diarrhea as the important enteropathogen Campylobacter jejuni, but it also occurs in the feces of healthy individuals. The role of C. concisus in human disease has been difficult to determine, since the species comprises at least two phenotypically indistinguishable but genetically distinct taxa (i.e., genomospecies) that may vary in pathogenicity. We examined 62 C. concisus strains by amplified fragment length polymorphism (AFLP) profiling and correlated the results with clinical data. All C. concisus strains gave unique AFLP profiles, and numerical analysis of these data distributed the strains among four clusters. The clustering was of taxonomic significance: two clusters contained, respectively, the type strain (of oral origin) and a reference strain (from diarrhea) of each of the known genomospecies. Genomospecies 2 strains were more frequently isolated from immunocompetent patients and/or patients without concomitant infections that presented with fever, chronic diarrhea, and gut inflammation than was genomospecies 1, clustering with the type strain of oral origin. Bloody diarrhea was recorded only with C. concisus genomospecies 2 infections. We identified two additional C. concisus genomospecies: genomospecies 3 comprised a single strain from an immunocompetent patient, and genomospecies 4 contained five isolates from severely immunodeficient patients, i.e., organ transplantation recipients or those with hematological malignancies. All genomospecies 4 strains were of the same protein profile group and failed to react with a C. concisus species-specific PCR assay based on 23S rRNA gene sequences: the taxonomic position of this group requires closer investigation. Campylobacter concisus is genetically and taxonomically diverse and contains at least four distinct genomospecies that may exhibit differences in their spectra of virulence potential.

KW - Adolescent

KW - Adult

KW - Aged

KW - Aged, 80 and over

KW - Bacterial Typing Techniques

KW - Campylobacter

KW - Campylobacter Infections

KW - Child

KW - Child, Preschool

KW - Diarrhea

KW - Female

KW - Humans

KW - Immunocompetence

KW - Immunocompromised Host

KW - Infant

KW - Male

KW - Middle Aged

KW - Polymorphism, Restriction Fragment Length

KW - Species Specificity

KW - Virulence

U2 - 10.1128/JCM.43.10.5091-5096.2005

DO - 10.1128/JCM.43.10.5091-5096.2005

M3 - Journal article

C2 - 16207968

SN - 0095-1137

VL - 43

SP - 5091

EP - 5096

JO - Journal of Clinical Microbiology

JF - Journal of Clinical Microbiology

IS - 10

ER -