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Bacterial Community Profiles (bacterial + community_profile)

Distribution by Scientific Domains
Medical Sciences75%

Selected Abstracts

Bacterial community profiles of endodontic abscesses from Brazilian and USA subjects as compared by denaturing gradient gel electrophoresis analysis

MOLECULAR ORAL MICROBIOLOGY, Issue 1 2007
J. C. Machado de Oliveira
This study compared the bacterial community profiles of the microbiota associated with acute apical abscesses from Brazilian and USA patients using denaturing gradient gel electrophoresis (DGGE). DNA was extracted from purulent exudate aspirates and part of the 16S rRNA gene was amplified by polymerase chain reaction and separated by DGGE. The resulting banding patterns, which were representative of the bacterial community structures in samples from the two locations, were then compared. Distinct DGGE banding patterns were observed from different samples. Ninety-nine bands with distinct positions in the gels were detected, of which 27 were found only in the USA samples and 13 were exclusive to Brazilian samples. Four of the 59 shared bands showed very discrepant findings with regard to prevalence in the two locations. Cluster analysis of DGGE banding profiles showed a great variability in the bacterial populations associated with teeth with abscesses regardless of the geographical location. Two big clusters, one for each location, were observed. Other clusters contained a mixture of samples from the two locations. The results of the present study demonstrated a great variability in the bacterial community profiles among samples. This indicates that the bacterial communities of abscesses are unique for each individual in terms of diversity. The composition of the microbiota in some samples showed a geography-related pattern. Furthermore, several bands were exclusive for each location and others were shared by the two locations and showed great differences in prevalence. [source]

Spatial and temporal heterogeneity of the bacterial communities in stream epilithic biofilms

FEMS MICROBIOLOGY ECOLOGY, Issue 3 2008
Gavin Lear
Abstract The spatial and temporal variability in bacterial communities within freshwater systems is poorly understood. The bacterial composition of stream epilithic biofilms across a range of different spatial and temporal scales both within and between streams and across the profile of individual stream rocks was characterised using a community DNA-fingerprinting technique (Automated Ribosomal Intergenic Spacer Analysis, ARISA). The differences in bacterial community structure between two different streams were found to be greater than the spatial variability within each stream site, and were larger than the weekly temporal variation measured over a 10-week study period. Greater variations in bacterial community profiles were detected on different faces of individual stream rocks than between whole rocks sampled within a 9-m stream section. Stream temperature was found to be the most important determinant of bacterial community variability using distance-based redundancy analysis (dbRDA) of ARISA data, which may have broad implications for riparian zone management and ecological change as a consequence of global warming. The combination of ARISA with multivariate statistical methods and ordination, such as multidimensional scaling (MDS), permutational manova and RDA, provided rapid and effective methods for quantifying and visualising variation in bacterial community structure, and to identify potential drivers of ecological change. [source]

Bacterial community profiles of endodontic abscesses from Brazilian and USA subjects as compared by denaturing gradient gel electrophoresis analysis

MOLECULAR ORAL MICROBIOLOGY, Issue 1 2007
J. C. Machado de Oliveira
This study compared the bacterial community profiles of the microbiota associated with acute apical abscesses from Brazilian and USA patients using denaturing gradient gel electrophoresis (DGGE). DNA was extracted from purulent exudate aspirates and part of the 16S rRNA gene was amplified by polymerase chain reaction and separated by DGGE. The resulting banding patterns, which were representative of the bacterial community structures in samples from the two locations, were then compared. Distinct DGGE banding patterns were observed from different samples. Ninety-nine bands with distinct positions in the gels were detected, of which 27 were found only in the USA samples and 13 were exclusive to Brazilian samples. Four of the 59 shared bands showed very discrepant findings with regard to prevalence in the two locations. Cluster analysis of DGGE banding profiles showed a great variability in the bacterial populations associated with teeth with abscesses regardless of the geographical location. Two big clusters, one for each location, were observed. Other clusters contained a mixture of samples from the two locations. The results of the present study demonstrated a great variability in the bacterial community profiles among samples. This indicates that the bacterial communities of abscesses are unique for each individual in terms of diversity. The composition of the microbiota in some samples showed a geography-related pattern. Furthermore, several bands were exclusive for each location and others were shared by the two locations and showed great differences in prevalence. [source]

Fecal microbiota in sensitized wheezy and non-sensitized non-wheezy children: a nested case,control study

CLINICAL & EXPERIMENTAL ALLERGY, Issue 6 2005
C. S. Murray
Summary Background It has been suggested that intestinal microbiota of allergic and non-allergic children differs in composition, and that microbiota,immune system interactions may predispose children to develop sensitization. Previous studies have examined fecal microbiota of allergic children with atopic dermatitis, but little is known about that of atopic wheezy children. Objective To investigate the composition of the fecal microbiota of young sensitized wheezy and non-sensitized non-wheezy children, using molecular methods. Methods Within the context of a prospective birth cohort, we carried out a nested case,control study of sensitized wheezy children (cases) and non-sensitized non-wheezy controls. Cases and controls were matched for age, sex, parental atopy, allergen exposure, and pet ownership. We evaluated the composition of fecal microbiota by nucleic acid-based methods (PCR combined with denaturing gradient gel electrophoresis and quantification of bifidobacteria by fluorescent in situ hybridization). Results Thirty-three case,control pairs (mean age 4.4 years) provided stool samples. Comparison of total bacterial community profiles showed that each child had a unique fecal microbiota (mean Dice's similarity coefficient 22%, range 3.3,60.8%). There was no difference between the groups in prevalence of Lactic Acid bacteria (12/33 vs. 11/33, P=0.8) or bifidobacteria (30/33 vs. 31/33, P=1.00, cases vs. controls). The bifidobacterial species detected were similar in both groups. The percentage of bifidobacteria in total fecal microflora was no different between cases (median 1.7%, range 0,20.8%) and controls (1.9%, 0,18.2%, P=0.7). However, cases with eczema had significantly fewer bifidobacteria (median 1.6%, range 0,4.8%) than their controls (4.0%, 1.9,18.2%, P=0.05). Conclusion We found no differences in fecal microbiota composition between sensitized wheezy and non-sensitized, non-wheezy children aged 3,5 years using nucleic acid-based methods. Differences appear to be isolated to those allergic children with eczema. [source]