Can bacterial translocation be a beneficial event?
© BioMed Central Ltd 2005
Published: 9 June 2005
Bacterial migration to extraintestinal sites has been attributed as the central component of the gut hypothesis of sepsis. However, some studies have pointed out the beneficial effect of bacterial translocation (BT) on the host's acquired immune system. In this study we evaluated the role of previous BT on the subsequent BT challenge, examining the BT index to organs, changes in WBC count at the mesenteric lymph and blood, and clinical outcome.
Wistar rats (n = 60) were distributed into: BT group (n = 20), inoculation of 10 ml of 1010 CFU/ml Escherichia coli R-6 confined to the small intestine; BT1-14 group (n = 20), submitted to the BT procedure on days 1 and 14; S1-BT14 group (n = 20), received 10 ml saline on day 1 and the BT procedure on day 14. One-half of animals were killed 2 hours following the BT procedure. Samples from different compartments were collected for culture, mesenteric lymph and peripheral blood for WBC count. The other half were subjected to the clinical outcome evaluation concerning weight gain and mortality.
Animals submitted to double BT presented a significantly lower index of bacterial recovery (liver, spleen and blood) as compared with animals submitted to a single BT (P < 0.05). The WBC count of mesenteric lymph cells post double BT was similar to naïve animals, and it was significantly lower when compared with single BT (P < 0.05). The clinical outcome was unchanged in double BT as compared with other groups.
A previous BT challenge was efficient in generating a host defense mechanism against a second episode of BT induced by intestinal overgrowth with the same bacterial strain.