Discussion Group 1: Where pathogenesis and commensalism meet

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1 Discussion Group 1: Where pathogenesis and commensalism meet Pathogen Probiotic Shared Challenges: Survive gastric juice Survive bile Virulence factors Competition Survival and growth Attachment Evasion Housekeeping Probiotic factors Compete with microbiota Attachment/invasion Interact with immune system Commensal Impact health (+/-) 1

2 Unique G + Pili Island in L.rhamnosus GG SpaC SpaB SpaA Sortase SpaC SpaB SpaA sortase Single Anti-SpaC Immunogold Labeling L.rhamnosus GG Contains Pili Kankainen et al PNAS 2009 Satokari LGG and E. faecium pili compared L. rhamnosus GG spacba pilin gene cluster ISL2 srtc1 spaa spab spac E. faecium 1165 pilin gene cluster Similarities: Order & sequence in genetic locus PilB-ab SpaC-ab Shared protein sequences in Von Willebrand factor domain in the tip pilin proteins SpaC & 2571 Cross-reactivity of the SpaC-antiserum with E. faecium pili Possibilities to combat E. faecium with LGG? 2

3 LGG Displaces Pathogens from Mucus via SpaC Pilus Reetta Satokari & Ingemar von Ossowski Adhesion % 1,80 1,60 1,40 1,20 1,00 0,80 0,60 0,40 0,20 0,00 Displacement of E. faecium from human intestinal mucus by LGG or its SpaC protein * * E. faecium E. faecium + LGG E. faecium + SpaC Shared adhesion underpins probiotic effect? Lb. johnsonii La1 Serine-Rich Surface Proteins L. johnsonii Serine-rich surface protein fap1 Serine-rich surface protein nss asp1 gspb gtf1 secy2 asp2 seca2 gtf2 asp1 asp3 39 gap1 gap3 secy2 gap2 seca2 gtf1 gtf LJ0384 LJ0391 LJ0394 Serine-rich gtf surface protein S. parasanguinis S. gordonii 1kb nss nss LJ1708 LJ0394 LJ0391 and LJ1711 identified as large sortase-anchored proteins containing extensive semi-conserved SLSNSVSMSErepeats. These genes and the surrounding operonshow a strong similarity to the glycosylated fimbriae operons of Streptococcus parasanguis and Streptococcus gordonii. Includes an auxiliary, dedicated SecA2, SecY2 secretion system, glycosyl-transferases and serine-rich fimbriae genes. Pridmore 3

4 9/5/2010 Lb. johnsonii La1 Serine-Rich Surface Proteins LJ LJ1711 not expressed during growth in MRS medium. 8 Log10 CFU / g feces NCC 533 CmR NCC Animal experiments with the deletion mutant implies a role in persistence. GIT regulation? Time in days Communication across a barrier Peterson Peterson, Frank, Pace Gordon. Cell Host & Microbe 3(6):417 (2008) 4

5 Broadly Reactive Antibodies Pathogenic Index B. longum B. thetaiotaomicron ToxigenicB. fragilis V. cholera

6 Lactobacillus reuteri RC-14 signaling molecules TCS? P Pssl11 Ptst ssl11 tst RNAIII P3 P2 AgrA P AgrC AIP hld agrb agrd agrc agra AgrB Staphylococcus aureus MN8 McCormick Prebiotic oligosaccharides: Beyond bifidogenicity GOS human intervention analyzed by pyrosequencing showed a significant increase in Bifidobacterium sp. other effects were minor. Only a small % of HMO s are fermented another role? Adhesin receptors for pathogens are carbohydrate ligands located at the surface of epithelial cells Oligosaccharides currently used as prebiotics mimic the cognate ligands and thereby may inhibit adherence and infection Hutkins 6

7 Sharon, 2006 Hutkins control Human Milk Oligosaccharides EPEC Salmonella From Coppa et al., Human milk oligosaccharides inhibit the adhesion to caco-2 cells of diarrheal pathogens: Pediatr. Res. 59:

8 Enterococcus-at the interface of pathogenesis and commensalism Enterococciare commensals, probiotics, food starters and pathogens Found in tissues, GI tract and food ~30% of culturablelab in babies (0-12 months) were enterococci 77% of enterococciscreened produced one or more bacteriocins(an important factor for colonisation?) Nes UCC118 and bacterocinalters the composition of the gut microbiota in diet-induced obesity. DIO + UCC118Bac - 2.1% 2.5% 0.4% 0.7% 0.1% 11.4% 55.9% 21.1% 0.2% 0.1% 0.4% 5.1% = DIO + UCC118 Bac+ 58.2% 4.4% 0.7% 2.3% 1.4% 0.8% 16.9% 15.0% 0.1% 0.2% Acinetobacter Desulfovibrio Sutterella Bacteroides Odoribacter Spirochaeta Leuconostoc Weissella Lactococcus Aerococcus Lactobacillus Clostridium Eubacterium Oscillospira Bifidobacterium Anaeroplasma Enterococcus Olsenella Pseudoalteromonas others Bacteroides Bifidobacteria Daly, Murphy 8

9 Pathobiotechnology Sleator Bile (Bifidobacterium) Transferred gene(s) to Bifidobacterium breve. Improved bile tolerance in vitro by 5 logs. Mice fed Bifidobacterium breve BilE + were more resistant to infection (Listeria) and had more mucoid faecal pellets ** 9 ** P< ** cfu/g faeces 8 7 * ** ** ** BilE days 2 Large Small 9

10 Pathogen Probiotic Shared Challenges: Survive gastric juice Survive bile Virulence factors Competition Survival and growth Attachment Evasion Housekeeping Probiotic factors Compete with microbiota Attachment/invasion Interact with immune system Commensal Impact health (+/-) Shared Strategies Communication is very important Pathogens and commensalsdo meet, in the gut. As expected, bacteria that share an ecological niche share strategies for colonisation, survival and evasion. Because these strategies and factors were discovered first in pathogens they are often termed virulence factors, a more accurate description might be survival factor, or GI factor? With more sequencing and HT technologies, more similarities are likely to emerge. 10

11 Group 1 participants Todd Klaenhammer, Chair Colin Hill, Co-chair Martin Antonsson Duane Charbonneau Jeffrey Christensen Charles Daly Robert Hutkins Maryse Lamoureux John K. McCormick Ingolf Nes Daniel Peterson Gabriela Perdigon David Pridmore Tomoyuki Sako Reetta Satokari Roy Sleator 11