Explore the vast range of titles available.

To unravel the biological function of the widely used probiotic bacterium Lactobacillus rhamnosus GG, we compared its 3.0-Mbp genome sequence with the similarly sized genome of L. rhamnosus LC705, an adjunct starter culture exhibiting reduced binding to mucus. Both genomes demonstrated high sequence identity and synteny. However, for both strains, genomic islands, 5 in GG and 4 in LC705, punctuated the colinearity. A significant number of strain-specific genes were predicted in these islands (80 in GG and 72 in LC705). The GG-specific islands included genes coding for bacteriophage components, sugar metabolism and transport, and exopolysaccharide biosynthesis. One island only found in L. rhamnosus GG contained genes for 3 secreted LPXTG-like pilins ( spaCBA ) and a pilin-dedicated sortase. Using anti-SpaC antibodies, the physical presence of cell wall-bound pili was confirmed by immunoblotting. Immunogold electron microscopy showed that the SpaC pilin is located at the pilus tip but also sporadically throughout the structure. Moreover, the adherence of strain GG to human intestinal mucus was blocked by SpaC antiserum and abolished in a mutant carrying an inactivated spaC gene. Similarly, binding to mucus was demonstrated for the purified SpaC protein. We conclude that the presence of SpaC is essential for the mucus interaction of L. rhamnosus GG and likely explains its ability to persist in the human intestinal tract longer than LC705 during an intervention trial. The presence of mucus-binding pili on the surface of a nonpathogenic Gram-positive bacterial strain reveals a previously undescribed mechanism for the interaction of selected probiotic lactobacilli with host tissues.

The intestinal mucus layer provides a potential niche for colonization by vancomycin-resistant Enterococcus faecium (VREF). We therefore examined the ability of six VREF strains to adhere to human intestinal mucus and determined binding kinetics. Four of six (67%) VREF strains demonstrated significant adhesion to immobilized intestinal mucus compared with a Salmonella typhimurium-negative control strain, but the level of adherence was low compared with Lactobacillus rhamnosus GG. Binding kinetics studies demonstrated that the maximum number of these four VREF strains that could adhere to a unit surface area of immobilized mucus was similar to or higher than the maximum number of L. rhamnosus GG that could adhere; however, L. rhamnosus GG demonstrated 20- to 130-times higher affinity than the VREF strains. These results demonstrate that VREF strains may adhere to human intestinal mucus and suggest that L. rhamnosus GG might be able to displace VREF strains.

To unravel the biological function of the widely used probiotic bacterium Lactobacillus rhamnosus GG, we compared its 3.0-Mbp genome sequence with the similarly sized genome of L rhamnosus LC705, an adjunct starter culture exhibiting reduced binding to mucus. Both genomes demonstrated high sequence identity and synteny. However, for both strains, genomic islands, 5 in GG and 4 in LC705, punctuated the colinearity. A significant number of strain-specific genes were predicted in these islands (80 in GG and 72 in LC705). The GG-specific islands included genes coding for bacteriophage components, sugar metabolism and transport, and exopolysaccharide biosynthesis. One island only found in L rhamnosus GG contained genes for 3 secreted LPXTG-like pilins (spaCBA) and a pilin-dedicated sortase. Using anti-SpaC antibodies, the physical presence of cell wall-bound pili was confirmed by immunoblotting. Immunogold electron microscopy showed that the SpaC pilin is located at the pilus tip but also sporadically throughout the structure. Moreover, the adherence of strain GG to human intestinal mucus was blocked by SpaC antiserum and abolished in a mutant carrying an inactivated spaC gene. Similarly, binding to mucus was demonstrated for the purified SpaC protein. We conclude that the presence of SpaC is essential for the mucus interaction of L rhamnosus GG and likely explains its ability to persist in the human intestinal tract longer than LC705 during an intervention trial. The presence of mucus-binding pili on the surface of a nonpathogenic Gram-positive bacterial strain reveals a previously undescribed mechanism for the interaction of selected probiotic lactobacilli with host tissues.

Background Limited evidence suggests that preeclampsia (PE) is associated with reduced cancer risk later in life. We aimed to investigate this using large registry-based cohorts. We hypothesised that enhanced immune activation in PE women, suggested by autoimmune-type reactivity, lowers their subsequent cancer risk. Methods Utilising Medical Birth Registry data from Sweden and Finland, we identified 123,495 women with PE and 3,223,537 women without. Data were cross-linked to the national Cancer Registries. Incidence rate ratios with 95% CIs were calculated and adjusted for maternal birth year, age at first birth, and parity. Results Overall cancer risk was significantly lower in Swedish PE women (IRR 0.91) but not in Finnish. Lower IRRs in PE women were found in both cohorts for breast (IRR 0.90 and 0.91), cervical (IRR 0.79 and 0.55) and lung cancer (IRR 0.72 and 0.63), while endometrial cancer showed increased incidence (IRR 1.28 and 1.46). Foetal sex had no impact on cancer risk. Among Swedish siblings to PE women, a slight reduction in cancer risk, driven by lower lung cancer incidence (IRR 0.86), was noted. Conclusion Our data show a link between PE and subsequent cancer risk, suggesting that shared mechanisms may predispose to PE and influence cancer development.