We monitored bacterioplankton communities from Chesapeake Bay over 2 years (2002–2004) by use of denaturing gradient gel electrophoresis (DGGE) of PCR-amplified 16S rRNA gene. Chesapeake Bay bacterioplankton exhibited a repeatable annual pattern and strong seasonal shifts. In winter, the bacterial communities were dominated by Alphaproteobacteria and Actinobacteria, whereas in summer, the predo...

Healthy children, aged between 5 and 9 years who had not taken antibiotics in the preceding three months were recruited. Plaque was sampled from the gingival crevice of either the lower left or lower right first permanent molar to estimate the prevalence of Porphyromonas gingivalis, Actinobacillus actinomycetemcomitans and Tannerella forsythensis which have been implicated as main etiological a...

OBJECTIVE This study aimed to investigate the possible topical effect of a broad-spectrum antibiotic on dental biofilm formed in situ in the absence or presence of sucrose. METHODS A crossover study was conducted in three phases of 14 days each, during which 11 volunteers wore palatal devices containing 6 enamel blocks covered with meshes to allow biofilm formation. Dental blocks were extraor...

Cyanophages (viruses that infect cyanobacteria) are abundant in the marine environment and are thought to be a significant factor in determining the population dynamics of members of the unicellular phycoerythrin-containing cyanobacteria of the genus Synechococcus. In an effort to use molecular techniques to characterise cyanophage populations, a conserved region from the cyanophage genome was ...

The microbial spoilage of beef was monitored during storage at 5 degrees C under three different conditions of modified-atmosphere packaging (MAP): (i) air (MAP1), (ii) 60% O2 and 40% CO2 (MAP2), and (iii) 20% O2 and 40% CO2 (MAP3). Pseudomonas, Enterobacteriaceae, Brochothrix thermosphacta, and lactic acid bacteria were monitored by viable counts and PCR-denaturing gradient gel electrophoresis...

BACKGROUND Bacterial vaginosis (BV) is a polymicrobial syndrome characterized by a change in vaginal flora away from predominantly Lactobacillus species. The cause of BV is unknown, but the condition has been implicated in diverse medical outcomes. The bacterium Atopobium vaginae has been recognized only recently. It is not readily identified by commercial diagnostic kits. Its clinical signific...

BACKGROUND Ventilator-associated pneumonia is the most prevalent acquired infection of patients on intensive care units and is associated with considerable morbidity and mortality. Evidence suggests that an improved understanding of the composition of the biofilm communities that form on endotracheal tubes may result in the development of improved preventative strategies for ventilator-associat...

Agricultural soils are typically fumigated to provide effective control of nematodes, soilborne pathogens, and weeds in preparation for planting of high-value cash crops. The ability of soil microbial communities to recover after treatment with fumigants was examined using culture-dependent (Biolog) and culture-independent (phospholipid fatty acid [PLFA] analysis and denaturing gradient gel ele...

In this study microbial species diversity was assessed across a landscape in Yellowstone National Park, where an abrupt increase in soil temperature had occurred due to recent geothermal activity. Soil temperatures were measured, and samples were taken across a temperature gradient (35 to 65 degrees C at a 15-cm depth) that spanned geothermally disturbed and unimpacted soils; thermally perturbe...