Examination of Strains of Lactobacilli for Properties that May Influence Bacterial Interference in the Urinary Tract

Abstract

Lactobacilli strains vary in their ability to interfere with colonization of uroepithelial cells by pathogenic organisms. Bacterial size, adherence capability, competitive exclusion and inhibition of pathogenic growth were examined in selected strains of lactobacilli to assess their relative importance. We tested adherence to uroepithelial cells of 34 lactobacillus isolates originating from the urogenital tract, dairy sources and chickens, and 1 lactobacillus strain isolated from a commercially available preparation. The ability to adhere differed greatly among the 34 strains, with a range of 8 to 74 bacteria per cell, and the commercial strain attached poorly with a mean of 15 bacteria per cell. Eleven strains of lactobacilli were selected and found to differ in length and width dimensions. These strains were found to exclude competitively with varying efficiency 6 strains of uropathogens from adhering to uroepithelial cells. The effective ability of Lactobacillus casei GR-1 to exclude the uropathogens confirmed previous findings and other strains (GR-2, GR-3 and A-60) gave a similar range of exclusion. The lactobacillus isolates varied greatly in their ability to inhibit the growth of 11 uropathogens under the conditions of an agar overlay inhibition assay. A combination score was allocated to each of the 11 lactobacillus strains based on size, adherence, exclusion and inhibition. Lactobacillus casei GR-1 attained the highest score while the commercial strain attained the lowest score. The results of this study identified 4 properties that should be examined to select lactobacillus strains before embarking upon bacterial interference studies to prevent urinary tract and other infections in humans.

CCL20/Macrophage Inflammatory Protein 3α and Tumor Necrosis Factor Alpha Production by Primary Uterine Epithelial Cells in Response to Treatment with Lipopolysaccharide or Pam3Cys

“…In contrast, TGF-␤ release was inhibited by live E. coli. Unexpectedly, we found that live and heat-killed Lactobacillus rhamnosus, a known commensal found in the female reproductive tract (44), had no effect on epithelial cell signaling.…”

Potential Uses of Probiotics in Clinical Practice

“…Extensive research since then has shown that certain Lactobacillus strains are able to colonize the vagina following vaginal suppository use (18) and reduce the risk of urinary tract infection, yeast vaginitis (108), and bacterial vaginosis (112). Strain selection at that time, and even recently, has been based upon in vitro tests and source of the strains (17,111,116,144), but human studies provide the definitive answer to whether or not strains can function as probiotics.…”

Lactobacillus reuteri -produced cyclic dipeptides quench agr -mediated expression of toxic shock syndrome toxin-1 in staphylococci

“…In this work, we report that Lactobacillus reuteri RC-14, a human vaginal isolate (15), is capable of inhibiting the staphylococcal quorum-sensing system agr, repressing the expression of TSST-1 in S. aureus MN8, a prototype of menstrual TSS S. aureus strains (16). Two active compounds involved in this interspecies communication were isolated and identified as the cyclic dipeptides cyclo(L-Tyr-LPro) and cyclo(L-Phe-L-Pro).…”