In vitro activity of commercial probiotic Lactobacillus strains against uropathogenic Escherichia coli.

Urinary tract infection (UTI) is one of the most prevalent infections in humans. In ≥80% of cases, the etiologic agents are strains of uropathogenic Escherichia coli (UPEC), which commonly reside in the gastrointestinal tract. Lactobacilli have been shown to prevent UTI reoccurrence by restoring the urogenital microbiota when administered vaginally or orally.

Nasopharyngeal microbiota in healthy children and pneumonia patients.

Our study is the first to compare the nasopharyngeal microbiota of pediatric pneumonia patients and control children by 454 pyrosequencing. A distinct microbiota was associated with different pneumonia etiologies. Viral pneumonia was associated with a high abundance of the operational taxonomic unit (OTU) corresponding to Moraxella lacunata.

Oral T4-like phage cocktail application to healthy adult volunteers from Bangladesh.

The genomic diversity of 99 T4-like coliphages was investigated by sequencing an equimolar mixture with Illumina technology and screening them against different databases for horizontal gene transfer and undesired genes. A 9-phage cocktail was given to 15 healthy adults from Bangladesh at a dose of 3×10(9) and 3×10(7) plaque-forming units and placebo respectively. Phages were detected in 64% of the stool samples when subjects were treated with higher titer phage, compared to 30% and 28% with lower-titer phage and placebo, respectively.

Infant gut microbiota is protective against cow's milk allergy in mice despite immature ileal T-cell response.

Faecal microbiota of healthy infant displays a large abundance of Bifidobacterium spp. and Bacteroides spp. Although some studies have reported an association between these two genera and allergy, these findings remain a subject of debate.

Colonization-induced host-gut microbial metabolic interaction.

Unlabelled: The gut microbiota enhances the host's metabolic capacity for processing nutrients and drugs and modulate the activities of multiple pathways in a variety of organ systems. We have probed the systemic metabolic adaptation to gut colonization for 20 days following exposure of axenic mice (n = 35) to a typical environmental microbial background using high-resolution (1)H nuclear magnetic resonance (NMR) spectroscopy to analyze urine, plasma, liver, kidney, and colon (5 time points) metabolic profiles. Acquisition of the gut microbiota was associated with rapid increase in body weight (4%) over the first 5 days of colonization with parallel changes in multiple pathways in all compartments analyzed.

In vivo replication of T4 and T7 bacteriophages in germ-free mice colonized with Escherichia coli.

The gut transit of T4 phages was studied in axenic mice mono-colonized with the non-pathogenic Escherichia coli strain K-12. Thirty minutes, 1 and 2 h after phage feeding, T4 phage had reached the jejunum, ileum and cecum, respectively. Phage was found in the lumen and was also associated with the mucosa.

T4 phages against Escherichia coli diarrhea: potential and problems.

A combination of in vitro and in vivo experiments with comparative phage genomics was used for the rational design of a phage cocktail against E. coli diarrhea. Orally applied T4 coliphages representing three different subgroups (T4-, RB49- and JS98-like phages) had no negative impact on the murine gut microbiota.

Genome analysis of phage JS98 defines a fourth major subgroup of T4-like phages in Escherichia coli.

Numerous T4-like Escherichia coli phages were isolated from human stool and environmental wastewater samples in Bangladesh and Switzerland. The sequences of the major head gene (g23) revealed that these coliphages could be placed into four subgroups, represented by the phages T4, RB69, RB49, and JS98. Thus, JS98 defines a new major subgroup of E.

Human volunteers receiving Escherichia coli phage T4 orally: a safety test of phage therapy.

Fifteen healthy adult volunteers received in their drinking water a lower Escherichia coli phage T4 dose (10(3) PFU/ml), a higher phage dose (10(5) PFU/ml), and placebo. Fecal coliphage was detected in a dose-dependent way in volunteers orally exposed to phage. All volunteers receiving the higher phage dose showed fecal phage 1 day after exposure; this prevalence was only 50% in subjects receiving the lower phage dose.

Isolation of Escherichia coli bacteriophages from the stool of pediatric diarrhea patients in Bangladesh.

A 3-week coliphage survey was conducted in stool samples from 140 Bangladeshi children hospitalized with severe diarrhea. On the Escherichia coli indicator strain K803, all but one phage isolate had 170-kb genomes and the morphology of T4 phage. In spot tests, the individual T4-like phages infected up to 27 out of 40 diarrhea-associated E.

Comparative genomics of the T4-Like Escherichia coli phage JS98: implications for the evolution of T4 phages.

About 130 kb of sequence information was obtained from the coliphage JS98 isolated from the stool of a pediatric diarrhea patient in Bangladesh. The DNA shared up to 81% base pair identity with phage T4. The most conserved regions between JS98 and T4 were the structural genes, but their degree of conservation was not uniform.

In vitro and in vivo bacteriolytic activities of Escherichia coli phages: implications for phage therapy.

Four T4-like coliphages with broad host ranges for diarrhea-associated Escherichia coli serotypes were isolated from stool specimens from pediatric diarrhea patients and from environmental water samples. All four phages showed a highly efficient gastrointestinal passage in adult mice when added to drinking water. Viable phages were recovered from the feces in a dose-dependent way.

Prophage genomics.

The majority of the bacterial genome sequences deposited in the National Center for Biotechnology Information database contain prophage sequences. Analysis of the prophages suggested that after being integrated into bacterial genomes, they undergo a complex decay process consisting of inactivating point mutations, genome rearrangements, modular exchanges, invasion by further mobile DNA elements, and massive DNA deletion. We review the technical difficulties in defining such altered prophage sequences in bacterial genomes and discuss theoretical frameworks for the phage-bacterium interaction at the genomic level.

DNA-binding activity of the Streptococcus thermophilus phage Sfi21 repressor.

The cloned Streptococcus thermophilus phage Sfi21 repressor open reading frame (orf) 127 gp protects a cell against superinfection with the homologous temperate, but not against virulent phages. As demonstrated by DNase protection assay and gel shift experiments, the repressor binds to a 25-bp operator site located upstream of the repressor gene. A second sequence-related operator was identified 265 bp apart at the 3'-end of orf 75, the topological equivalent of a cro repressor gene.

Transcription analysis of Streptococcus thermophilus phages in the lysogenic state.

The transcription of prophage genes was studied in two lysogenic Streptococcus thermophilus cells by Northern blot and primer-extension experiments. In the lysogen containing the cos-site phage Sfi21 only two gene regions of the prophage were transcribed. Within the lysogeny module an 1.

Transcription mapping as a tool in phage genomics: the case of the temperate Streptococcus thermophilus phage Sfi21.

For the lytic growth cycle of the temperate cos-site Streptococcus thermophilus phage Sfi21 a transcription map was developed on the basis of systematic Northern blot hybridizations. All deduced 5' ends were confirmed by primer extension analysis. Three time classes of transcripts were observed.