BackgroundAntibiotic resistance is rising in important bacterial pathogens. Phage therapy (PT), the use of bacterial viruses infecting the pathogen in a species-specific way, is a potential alternative.MethodT4-like coliphages or a commercial Russian coliphage product or placebo was orally given over 4 days to Bangladeshi children hospitalized with acute bacterial diarrhea. Safety of oral phage was assessed clinically and by functional tests; coliphage and Escherichia coli titers and enteropathogens were determined in stool and quantitative diarrhea parameters (stool output, stool frequency) were measured. Stool microbiota was studied by 16S rRNA gene sequencing; the genomes of four fecal Streptococcus isolates were sequenced.FindingsNo adverse events attributable to oral phage application were observed (primary safety outcome). Fecal coliphage was increased in treated over control children, but the titers did not show substantial intestinal phage replication (secondary microbiology outcome). 60% of the children suffered from a microbiologically proven E. coli diarrhea; the most frequent diagnosis was ETEC infections. Bacterial co-pathogens were also detected. Half of the patients contained phage-susceptible E. coli colonies in the stool. E. coli represented less than 5% of fecal bacteria. Stool ETEC titers showed only a short-lived peak and were otherwise close to the replication threshold determined for T4 phage in vitro. An interim analysis after the enrollment of 120 patients showed no amelioration in quantitative diarrhea parameter by PT over standard care (tertiary clinical outcome). Stool microbiota was characterized by an overgrowth with Streptococcus belonging to the Streptococcus gallolyticus and Streptococcus salivarius species groups, their abundance correlated with quantitative diarrhea outcome, but genome sequencing did not identify virulence genes.InterpretationOral coliphages showed a safe gut transit in children, but failed to achieve intestinal amplification and to improve diarrhea outcome, possibly due to insufficient phage coverage and too low E. coli pathogen titers requiring higher oral phage doses. More knowledge is needed on in vivo phage–bacterium interaction and the role of E. coli in childhood diarrhea for successful PT.FundingThe study was supported by a grant from . The trial was registered with Identifier NCT00937274 at ClinicalTrials.gov.
By decreasing the tube voltage, the amount of contrast material can be reduced without image quality degradation. In scans obtained with a low tube voltage, the radiation dose can be reduced as much as 56.8%, and higher contrast material enhancement can be achieved.
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. No Escherichia coli was present in initial stool samples, and no amplification of phage was observed. One percent of the administered oral phage was recovered from the feces. No adverse events were observed by self-report, clinical examination, or from laboratory tests for liver, kidney, and hematology function. No impact of oral phage was seen on the fecal microbiota composition with respect to bacterial 16S rRNA from stool.
Phage therapy has a long tradition in Eastern Europe, where preparations are comprised of complex phage cocktails whose compositions have not been described. We investigated the composition of a phage cocktail from the Russian pharmaceutical company Microgen targeting Escherichia coli/Proteus infections. Electron microscopy identified six phage types, with numerically T7-like phages dominating over T4-like phages. A metagenomic approach using taxonomical classification, reference mapping and de novo assembly identified 18 distinct phage types, including 7 genera of Podoviridae, 2 established and 2 proposed genera of Myoviridae, and 2 genera of Siphoviridae. De novo assembly yielded 7 contigs greater than 30 kb, including a 147-kb Myovirus genome and a 42-kb genome of a potentially new phage. Bioinformatic analysis did not reveal undesired genes and a small human volunteer trial did not associate adverse effects with oral phage exposure.
A reduction from 120 kV to 90 kV led to as much as a 35% reduction in the radiation dose, without sacrifice of low-contrast detectability, at CT.
ABSTRACT. Background. Previous studies have shown that selected strains of lactobacilli that are administered orally result in a modest reduction of diarrhea duration. However, duration alone is not considered optimal for therapeutic evaluation of any agent in diarrhea.Objective. To examine the effect of a new probiotic, Lactobacillus paracasei strain ST11 (ST11), in acute childhood diarrhea by using evaluation criteria recommended by the World Health Organization.Methods. In a randomized, double-blind, placebocontrolled clinical trial, 230 male infants and young children, 4 to 24 months of age, presenting with diarrhea of <2 days' duration were admitted to the metabolic research ward of the International Centre for Diarrheal Disease Research, Bangladesh, and fed 10 10 colony-forming units of lyophilized ST11 or placebo daily for 5 days. Stool output and frequency, oral rehydration solution intake, and excretion of rotavirus were monitored daily.Results. No effect of ST11 treatment on severe rotavirus diarrhea was observed. However, the probiotic treatment did significantly reduce cumulative stool output (225 ؎ 218 vs 381 ؎ 240 mL/kg), stool frequency (27.9 ؎ 17 vs 42.5 ؎ 26), and oral rehydration solution intake (180 ؎ 207 vs 331 ؎ 236 mL/kg) in children with lesssevere nonrotavirus diarrhea compared with those receiving placebo treatment. A significantly higher proportion of nonrotavirus children receiving ST11 had their diarrhea resolve within 6 days of therapy (ST11 versus placebo: 76% vs 49%).Conclusions. ST11 has a clinically significant benefit in the management of children with nonrotavirus-induced diarrhea, but it is ineffective in those with rotavirus diarrhea. Pediatrics 2005;116:e221-e228. URL: www. pediatrics.org/cgi
Bacteriophage therapy is a commonly used treatment for Staphylococcus aureus infections in countries of the former Soviet Union, using both single phages and phage cocktails. The scarce data available on Eastern phage cocktails prompted an investigation into commercially-available Pyophage cocktails from two different manufacturers used to treat skin and wound infections. Comparison of the metagenomic composition of two Pyophage products from Georgia and Russia revealed substantial differences in phage-types targeting Escherichia, Enterococcus, Salmonella, Pseudomonas aeruginosa and Proteus, therefore indicating multiple strategies for composing phage cocktails against these bacterial pathogens. Closely-related Kayvirus-like Myoviruses were, however, a shared component against S. aureus within all products, except for the inclusion of a secondary S. aureus Podovirus in one Microgen cocktail. Metagenomic analysis also revealed the presence of several probable prophage sequences but detected no genetic safety risks in terms of virulence factors or antibiotic resistance genes. The safety of broad-spectrum cocktails was tested by comparing the effects of nasal and oral exposure to Eliava Pyophage, a monospecies counterpart and placebo in healthy human carriers of S. aureus. The lack of adverse effects in any treatment groups supports the clinical safety of S. aureus phages administered as a single phage or as phage cocktail.
A T4-like coliphage cocktail was given with different oral doses to healthy Bangladeshi children in a placebo-controlled randomized phase I safety trial. Fecal phage detection was oral dose dependent suggesting passive gut transit of coliphages through the gut. No adverse effects of phage application were seen clinically and by clinical chemistry. Similar results were obtained for a commercial phage preparation (Coliproteus from Microgen/Russia). By 16S rRNA gene sequencing, only a low degree of fecal microbiota conservation was seen in healthy children from Bangladesh who were sampled over a time interval of 7 days suggesting a substantial temporal fluctuation of the fecal microbiota composition. Microbiota variability was not associated with the age of the children or the presence of phage in the stool. Stool microbiota composition of Bangladeshi children resembled that found in children of other regions of the world. Marked variability in fecal microbiota composition was also seen in 71 pediatric diarrhea patients receiving only oral rehydration therapy and in 38 patients receiving coliphage preparations or placebo when sampled 1.2 or 4 days apart respectively. Temporal stability of the gut microbiota should be assessed in case-control studies involving children before associating fecal microbiota composition with health or disease phenotypes.
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