Applied and environmental microbiology
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Appl. Environ. Microbiol. · Oct 2011
Comparative StudyComparison of the gut microbiotas of healthy adult twins living in South Korea and the United States.
We compared the composition of the fecal microbiotas of Korean and U. S. adult twins. Our data indicated that the gut microbiota shows some signature of biogeography, potentially mediated by differences in diet and/or other environmental factors; however, these regional differences may be masked by other phenotypic variations, such as obesity.
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Appl. Environ. Microbiol. · Oct 2011
Inhibition of Escherichia coli CFT073 fliC expression and motility by cranberry materials.
In humans, uropathogenic Escherichia coli (UPEC) is the most common etiological agent of uncomplicated urinary tract infections (UTIs). Cranberry extracts have been linked to the prevention of UTIs for over a century; however, a mechanistic understanding of the way in which cranberry derivatives prevent bacterial infection is still lacking. In this study, we used a fliC-lux reporter as well as quantitative reverse transcription-PCR to demonstrate that when UPEC strain CFT073 was grown or exposed to dehydrated, crushed cranberries or to purified cranberry-derived proanthocyanidins (cPACs), expression of the flagellin gene (fliC) was inhibited. ⋯ Because flagellum-mediated motility has been suggested to enable UPEC to disseminate to the upper urinary tract, we propose that inhibition of flagellum-mediated motility might be a key mechanism by which cPACs prevent UTIs. This is the first report to show that cranberry compounds inhibit UPEC motility via downregulation of the fliC gene. Further studies are required to establish whether these inhibitors play a role in vivo.
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Appl. Environ. Microbiol. · Aug 2011
Population genetic structure of clinical and environmental isolates of Blastomyces dermatitidis, based on 27 polymorphic microsatellite markers.
Blastomyces dermatitidis, a thermally dimorphic fungus, is the etiologic agent of North American blastomycosis. Clinical presentation is varied, ranging from silent infections to fulminant respiratory disease and dissemination to skin and other sites. Exploration of the population genetic structure of B. dermatitidis would improve our knowledge regarding variation in virulence phenotypes, geographic distribution, and difference in host specificity. ⋯ The mating type of individual isolates was determined by PCR. Both mating type-specific genes, the HMG and α-box domains, were represented in each of the genetic groups, with slightly more isolates having the HMG allele. One interpretation of this study is that the species currently designated B. dermatitidis includes a cryptic subspecies or perhaps a separate species.
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Appl. Environ. Microbiol. · May 2011
Bacteriophages LIMElight and LIMEzero of Pantoea agglomerans, belonging to the "phiKMV-like viruses".
Pantoea agglomerans is a common soil bacterium used in the biocontrol of fungi and bacteria but is also an opportunistic human pathogen. It has been described extensively in this context, but knowledge of bacteriophages infecting this species is limited. ⋯ Based on the presence of an RNA polymerase in their genomes and their overall genome architecture, these phages should be classified in the subfamily of the Autographivirinae, within the genus of the "phiKMV-like viruses." Phylogenetic analysis of all the sequenced members of the Autographivirinae supports the classification of phages LIMElight and LIMEzero as members of the "phiKMV-like viruses" and corroborates the subdivision into the different genera. These data expand the knowledge of Pantoea phages and illustrate the wide host diversity of phages within the "phiKMV-like viruses."