Gianfranco Grompone

Danone Research · Life Science

Here, we report three genome sequences of bacteria isolated from murine proximal colonic tissue and identified as Acinetobacter parvus CM11, Acinetobacter radioresistens CM38, and Stenotrophomonas maltophilia BR12.

The present invention relates to a method using Caenorhabditis elegans for screening of food grade bacteria which have a protective effect against oxidative stress.

Numerous studies have shown that resistance to oxidative stress is crucial to stay healthy and to reduce the adverse effects of aging. Accordingly, nutritional interventions using antioxidant food-grade compounds or food products are currently an interesting option to help improve health and quality of life in the elderly. Live lactic acid bacteria...

C. elegans BA17 can be fed with Bifidobacteria, Lactobacilli and Streptococci strains. Survival of C. elegans BA 17 strain fed for 3 days with Bifidobacteria, Lactobacilli and Streptococci strains in liquid medium was followed, after larvae 1st stage synchronization with E. coli OP 50 and without any oxidative stress. Protection by E. coli OP50 is...

DAF-16, DAF-2 and SKN-1 play an essential role in C. elegans longevity resulting from feeding with Lactobacillus rhamnosus CNCM I-3690. See corresponding data in Figure 2. *NS: No significant differences between control conditions (NGM+E. coli OP50) and treatment conditions (NGM + CNCM I-3690). Statistical analysis was performed with GraphPad prism...

List of the 1278 differentially expressed genes in C. elegans fed with L. rhamnosus CNCM I-3690 versus E. coli OP50. C. elegans N2 wild-type strain was fed with L. rhamnosus strain CNCM I-3690 and E. coli strain OP50 during 3 days. Transcriptome profiling was performed comparing worms fed with the two bacterial strains. RNA samples were hybridized...

List of the 18 genes differentially expressed in C. elegans fed with L. rhamnosus CNCM I-3690 versus L. rhamnosus CNCM I-4317 and in C. elegans fed with L. rhamnosus CNCM I-3690 versus E. coli OP50. C. elegans N2 wild-type strain was fed with the three strains L. rhamnosus CNCM I-3690, L. rhamnosus CNCM I-4317 and E. coli OP50 during 3 days. Transc...

Genera and species specifications for all the bacterial strains used in this work. Genera, species and subspecies are specified for each bacterial strain used in this study, with their corresponding code names. (DOCX)

LAB and bifidobacteria growth curves. Growth curves of representative strains for each genus, Streptococcus CNCM I-2778, Lactobacillus CNCM I-3064 and Bifidobacterium Bal7, and detailed protocols are presented. (DOCX)

List of the 133 differentially expressed genes C. elegans fed for 10 days with L. rhamnosus CNCM I-3690 versus E. coli OP50. C. elegans N2 wild-type strain was fed with L. rhamnosus CNCM I-3690 and E. coli OP50 strains during 10 days. Transcriptome profiling was performed comparing worms fed with the two bacterial strains. RNA samples were hybridiz...

List of the 196 differentially expressed genes C. elegans fed for 10 days with L.rhamnosus CNCM I-4317 versus E. coli OP50. C. elegans N2 wild-type strain was fed with L. rhamnosus CNCM I-4317 and E. coli OP50 strains during 10 days. Transcriptome profiling was performed comparing worms fed with the two bacterial strains. RNA samples were hybridize...

Confirmation of microarray data by RT-qPCR for arf-1.1 and gst-22 genes. Expression ratios for arf-1.1 and gst-22 genes were obtained by RT-qPCR. All experiments were repeated at least three times (biological replicates) and were internally controlled (technical replicate). Expression changes were obtained by calculating the relative expression lev...

List of the 7 differentially expressed genes not shared between C. elegans fed with L. rhamnosus CNCM I-3690 versus L. rhamnosus CNCM I-4317 and in C. elegans fed with L. rhamnosus CNCM I-3690 versus E. coli OP50. C. elegans N2 wild-type strain was fed with the three strains L. rhamnosus CNCM I-3690, L. rhamnosus CNCM I-4317 and E. coli OP50 during...

List of the 4 differentially expressed genes C. elegans fed for 10 days with L.rhamnosus CNCM I-3690 versus L. rhamnosus CNCM I-4317. C. elegans N2 wild-type strain was fed with both L. rhamnosus strains CNCM I-3690 and CNCM I-4317 during 10 days. Transcriptome profiling was performed comparing worms fed with the two bacterial strains. RNA samples...

(A) FISH using the “no-bacteria” probe on different sections of the intestine of C57BL/6 mice. (B) FISH with the pan-bacterial probe Eub338 at the proximal colon and the lumen of germfree C3H/HeN mice. Download Figure S1, PDF file, 1.5 MB.

Relative contributions of OTUs at 97% similarity in the different samples resulting from bar-coded pyrosequencing.

qRT-PCR experiments with DNA extracted from the autoclaved chow using phylum- and family-specific primers. Download Figure S3, PDF file, 0.1 MB.

Number of reads after multiplex pyrosequencing of murine crypt and luminal samples.

Pie chart showing the percentages of phylotypes (genus level) observed in three murine colonic crypt samples (pilot experiment). Download Figure S2, PDF file, 0.1 MB.

Sequences of primers and probes used in this study.

Unlabelled: In an attempt to explore the microbial content of functionally critical niches of the mouse gastrointestinal tract, we targeted molecular microbial diagnostics of the crypts that contain the intestinal stem cells, which account for epithelial regeneration. As current evidence indicates, the gut microbiota affects epithelial regeneratio...

Numerous studies have shown that resistance to oxidative stress is crucial to stay healthy and to reduce the adverse effects of aging. Accordingly, nutritional interventions using antioxidant food-grade compounds or food products are currently an interesting option to help improve health and quality of life in the elderly. Live lactic acid bacteria...

Shigella, the causative agent of bacillary dysentery in humans, invades epithelial cells, using a type III secretory system (T3SS) to inject bacterial effectors into host cells and remodel the actin cytoskeleton. ATP released through connexin hemichanels on the epithelial membrane stimulates Shigella invasion and dissemination in epithelial cells....

The structure and function of the intestinal epithelium is briefly described, with the principal mechanisms involved in diarrhea. Human enteric viruses and probiotics are presented. We then review how probiotic bacteria could interfere with virus-induced pathology, we present our own view and describe specific interactions that would be valuable ta...

Upon epithelial cell contact, Shigella type III effectors activate complex signaling pathways that induce localized membrane ruffling, resulting in Shigella invasion. Bacterial induced membrane ruffles require a timely coordination of cytoskeletal processes, including actin polymerization, filament reorganization and depolymerization, orchestrated...

Impairment of replication fork progression is a serious threat to living organisms and a potential source of genome instability. Studies in prokaryotes have provided evidence that inactivated replication forks can restart by the reassembly of the replication machinery. Several strategies for the processing of inactivated replication forks before re...

We have studied the fate of blocked replication forks with the use of the Escherichia coli priA mutant, in which spontaneously arrested replication forks persist owing to the lack of the major replication restart pathway. Such blocked forks undergo a specific reaction named replication fork reversal, in which newly synthesized strands anneal to for...

Restart of arrested replication forks is an important process and PriA, the main Escherichia coli replication restart protein, is essential for viability under any condition that increases the frequency of fork arrest. In priA mutant, replication forks are arrested by spontaneously occurring roadblocks and blocked replication forks persist as a res...

The ability of a pathogenic microorganism to cause a disease is conditioned by its ability to colonise a given niche and implicates the expression of specific determinants, i.e. virulence factors, that allow the pathogen to adhere to or to invade epithelial cells. Diseases may be induced by bacteria that replicate extracellularly and alter the epit...

The parE10(Ts) mutation, which renders Escherichia coli thermosensitive for growth by inactivation of the essential E. coli topoisomerase topo IV, is lethal at all temperatures when PriA, the main replication restart protein, is absent. This lethality is suppressed by the activation of a PriA-independent replication restart pathway (dnaC809 mutatio...

Gyrase is an essential topoisomerase in bacteria that introduces negative supercoils in DNA and relaxes the positive supercoils that form downstream of proteins tracking on DNA, such as DNA or RNA polymerases. Two gyrase mutants that suffer partial loss of function were used here to study the need for replication restart in conditions in which gyra...

Certain replication mutations lead in Escherichia coli to a specific reaction named replication fork reversal: at blocked forks, annealing of the nascent strands and pairing of the template strands form a four-way junction. RuvABC-catalysed resolution of this Holliday junction causes chromosome double-strand breaks (DSBs) in a recBC context and the...

DNA synthesis is an accurate and very processive phenomenon; nevertheless, replication fork progression on chromosomes can be impeded by DNA lesions, DNA secondary structures, or DNA-bound proteins. Elements interfering with the progression of replication forks have been reported to induce rearrangements and/or render homologous recombination essen...

DNA synthesis is an accurate and very processive phenomenon; nevertheless, replication fork progression on chromosomes can be impeded by DNA lesions, DNA secondary structures, or DNA-bound proteins. Elements interfering with the progression of replication forks have been reported to induce rearrangements andyor render homologous recombination essen...