is associated with the formation of intra-abdominal abscesses, whereas other species are rarely involved. Since bacterial clumping may contribute to the survival of bacteria in the face of host defence mechanisms, the hypothesis has been put forward that differences in aggregation between fragilis and non-fragilis strains of may account for their differences in survival All seven strains tested formed aggregates within 4 h, but strains not associated with intra-abdominal sepsis— and —did not form aggregates Aggregation occurred at 37°C, but not at 4°C or 2°C. Treatment with pronase partially inhibited aggregation. Periodate treatment killed the cells and caused them to form clumps which were distinguishable from the control aggregates. Heat-killed cells formed similar distinct clumps, but cells killed by glutaraldehyde and formaldehyde did so to a lesser degree. No inhibition was found upon addition of carbohydrates, ethylenediaminetetraacetic acid or after treatment with trypsin. These results demonstrate that aggregate formation occurs with strains alone, and that surface proteins probably mediate this interaction.


Article metrics loading...

Loading full text...

Full text loading...


Most cited this month Most Cited RSS feed

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