A monospecific polyclonal antiserum, prepared against Bacteroides fragilis common polysaccharide antigen purified by polyacrylamide gel immunoblot detected B. fragilis, B. thetaiotaomicron, B. ovatus and Prevotella melaninogenica in pus samples from various anatomical sites by immunofluorescence microscopy of the pus. With standard clinical laboratory culture methods, 36% of 147 samples were positive for one or more of the above bacteria. Of these, B. fragilis accounted for 33%. By immunofluorescent labelling of pus with the common antigen antiserum the detection of these bacteria in the samples increased to 50%. All nine of the blood cultures in which B. fragilis was detected by culture contained bacteria positive for the common antigen. Immunofluorescent labelling of pus samples with a selection of monoclonal antibodies specific for surface polysaccharides which are known to be antigenically variable in culture in vitro and in an animal model of infection showed that these polysaccharides are also variable in natural infection. The results indicate that the common polysaccharide antigen, in contrast to the variable surface polysaccharides, is a suitable target for the immunodetection of B. fragilis in clinical samples from a range of anatomical sites.
NamavarF.,
TheunissenE. B.,
Verweij-Van VughtA. M. J. J. Epidemiology of the Bacteroides fragilis group in the colonic flora of patients with colonic cancer. J Med Microbiol1989; 29:171–176
SlackM. P. E.,
GriffithsD. T.,
JohnstonH. H. The Fluoretec system for rapid diagnosis of bacteroides infections by direct immunofluorescence of clinical specimens. J Clin Pathol1981; 34:1381–1384
LabbéM.,
DelamareN.,
PepersackF.,
CrokaertF.,
YourassowskyE. Detection of Bacteroides fragilis and Bacteroides melaninogenicus by direct immunofluorescence. J Clin Pathol1980; 33:1189–1192
HolstE.,
OscarsonJ.,
MardhP.-A. Evaluation of two fluorescent test kits for detection of selected Bacteroides species in clinical specimens. Curr Microbiol1979; 3:133–136
FiksdalL.,
BergJ. D. Evaluation of a fluorescent antibody technique for the rapid enumeration of Bacteroides fragilis group of organisms in water. J Appl Bacteriol1987; 62:377–383
ViljanenM. K.,
LinkoL.,
LehtonenO.-P. Detection of Bacteroides fragilis. Bacteroides thetaiotaomicron and Bacteroides or at us in clinical specimens by immunofluorescence with a monoclonal antibody to B. fragilis lipopolysaccharide. J Clin Microbiol1988; 26:448–452
LuttonD. A.,
PatrickS.,
CrockardA. D. Flow cytometric analysis of within-strain variation in polysaccharide expression by Bacteroides fragilis by use of murine monoclonal antibodies. J Med Microbiol1991; 35:229–237
PoxtonI. R.,
BrownR. Immunochemistry of the surface carbohydrate antigens of Bacteroides fragilis and definition of a common antigen. J Gen Microbiol1986; 132:2475–2481
PatrickS.,
LarkinM. J. Attachment in disease. In
DenyerS. P.,
GormanS. P.,
SussmanM.
(eds) Microbial biofilms: formation and control Society for applied bacteriology technical series 30 Oxford: Blackwell Scientific Publications; 1993109–131
ReidJ. H.,
PatrickS.,
TabaqchaliS. Immunochemical characterization of a polysaccharide antigen of Bacteroides fragilis with an IgM monoclonal antibody. J Gen Microbiol1987; 133:171–179
ReidJ. H.,
PatrickS.,
DermottE. Investigation of antigenic expression of Bacteroides fragilis by immunogold labelling and immunoblotting with a monoclonal antibody. FEMS Microbiol Lett1985; 30:289–293
WilsonK. G. Investigation of the surface structures of Bacteroides fragilis using immunological methods. (MMedSc thesis) Queen’s University of Belfast; Belfast: 1992
NikolichM. P.,
HongG.,
ShoemakerN. B.,
SalyersA. A. Evidence for natural horizontal transfer of tetQ between bacteria that normally colonize humans and bacteria that normally colonize livestock. Appl Environ Microbiol1994; 60:3255–3260
KellyM. J. The quantitative and histological demonstration of pathogenic synergy between Escherichia coli and Bacteroides fragilis in guinea-pig wounds. J Med Microbiol1978; 11:513–523