scholarly journals Mucosa-Associated Bacterial Diversity in Relation to Human Terminal Ileum and Colonic Biopsy Samples

2007 ◽  
Vol 73 (22) ◽  
pp. 7435-7442 ◽  
Author(s):  
Shakil Ahmed ◽  
George T. Macfarlane ◽  
Alemu Fite ◽  
Andrew J. McBain ◽  
Peter Gilbert ◽  
...  
Keyword(s):  
Gastrointestinal Tract ◽  
Real Time ◽  
Large Intestine ◽  
Terminal Ileum ◽  
Real Time Pcr ◽  
Large Bowel ◽  
Laser Scanning ◽  
Laser Scanning Microscopy ◽  
Confocal Laser ◽  
Descending Colon

ABSTRACT Little is known about bacterial communities that colonize mucosal surfaces in the human gastrointestinal tract, but they are believed to play an important role in host physiology. The objectives of this study were to investigate the compositions of these populations in the distal small bowel and colon. Healthy mucosal tissue from either the terminal ileum (n = 6) or ascending (n = 8), transverse (n = 8), or descending colon (n = 4) of 26 patients (age, 68.5 ± 1.2 years [mean ± standard deviation]) undergoing emergency resection of the large bowel was used to study these communities. Mucosa-associated eubacteria were characterized by using PCR-denaturing gradient gel electrophoresis (DGGE), while real-time PCR was employed for quantitative analysis. Mucosal communities were also visualized in situ using confocal laser scanning microscopy. DGGE banding profiles from all the gut regions exhibited at least 45% homology, with five descending colon profiles clustering at ca. 75% concordance. Real-time PCR showed that mucosal bacterial population densities were highest in the terminal ileum and that there were no significant differences in overall bacterial numbers in different parts of the colon. Bifidobacterial numbers were significantly higher in the large bowel than in the terminal ileum (P = 0.006), whereas lactobacilli were more prominent in the distal large intestine (P = 0.019). Eubacterium rectale (P = 0.0004) and Faecalibacterium prausnitzii (P = 0.001) were dominant in the ascending and descending colon. Site-specific colonization in the gastrointestinal tract may be contributory in the etiology of some diseases of the large intestine.

scholarly journals Kaurenoic Acid fromAralia continentalisInhibits Biofilm Formation ofStreptococcus mutans

2013 ◽  
Vol 2013 ◽  
pp. 1-9 ◽  
Author(s):  
Seung-Il Jeong ◽  
Beom-Su Kim ◽  
Ki-Suk Keum ◽  
Kwang-Hee Lee ◽  
Sun-Young Kang ◽  
...  
Keyword(s):  
Real Time ◽  
Real Time Pcr ◽  
Biofilm Formation ◽  
Acid Production ◽  
Laser Scanning ◽  
Laser Scanning Microscopy ◽  
Confocal Laser ◽  
Pcr Analysis ◽  
Dependent Manner ◽  
Kaurenoic Acid

We isolated a single chemical compound fromA. continentalisand identified it to be kaurenoic acid (KA) and investigated the influence of anticariogenic properties. Inhibitory effects of KA on cariogenic properties such as growth, acid production, biofilm formation, and the adherence ofS. mutanswere evaluated. Furthermore, real-time PCR analysis was performed to evaluate the influence of KA on the genetic expression of virulence factors. KA significantly inhibited the growth and acid production ofS. mutansat 2–4 μg/mL and 4 μg/mL of KA, respectively. Furthermore, the adherence onto S-HAs was inhibited at 3-4 μg/mL of KA and biofilm formation was significantly inhibited when treated with 3 μg/mL KA and completely inhibited at 4 μg/mL. Also, the inhibitory effect of KA on biofilm formation was confirmed by SEM. In confocal laser scanning microscopy, bacterial viability gradually decreased by KA in a dose dependent manner. Real-time PCR analysis showed that the expressions ofgtfB, gtfC, gbpB, spaP, brpA, relA, andvicRwere significantly decreased inS. mutanswhen it was treated with KA. These results suggest that KA fromA. continentalismay be a useful agent for inhibiting the cariogenic properties ofS. mutans.

scholarly journals Colonization of Pythium oligandrum in the Tomato Rhizosphere for Biological Control of Bacterial Wilt Disease Analyzed by Real-Time PCR and Confocal Laser-Scanning Microscopy

2008 ◽  
Vol 98 (2) ◽  
pp. 187-195 ◽  
Author(s):  
Shigehito Takenaka ◽  
Hiroyuki Sekiguchi ◽  
Kazuhiro Nakaho ◽  
Motoaki Tojo ◽  
Akira Masunaka ◽  
...  
Keyword(s):  
Real Time ◽  
Confocal Laser Scanning Microscopy ◽  
Bacterial Wilt ◽  
Real Time Pcr ◽  
Laser Scanning ◽  
Laser Scanning Microscopy ◽  
Confocal Laser Scanning ◽  
Confocal Laser ◽  
Pythium Oligandrum ◽  
Rhizosphere Population

It recently has been reported that the non-plant-pathogenic oomycete Pythium oligandrum suppresses bacterial wilt caused by Ralstonia solanacearum in tomato. As one approach to determine disease-suppressive mechanisms of action, we analyzed the colonization of P. oligandrum in rhizospheres of tomato using real-time polymerase chain reaction (PCR) and confocal laser-scanning microscopy. The real-time PCR specifically quantified P. oligandrum in the tomato rhizosphere that is reliable over a range of 0.1 pg to 1 ng of P. oligandrum DNA from 25 mg dry weight of soil. Rhizosphere populations of P. oligandrum from tomato grown for 3 weeks in both unsterilized and sterilized field soils similarly increased with the initial application of at least 5 × 105 oospores per plant. Confocal microscopic observation also showed that hyphal development was frequent on the root surface and some hyphae penetrated into root epidermis. However, rhizosphere population dynamics after transplanting into sterilized soil showed that the P. oligandrum population decreased with time after transplanting, particularly at the root tips, indicating that this biocontrol fungus is rhizosphere competent but does not actively spread along roots. Protection over the long term from root-infecting pathogens does not seem to involve direct competition. However, sparse rhizosphere colonization of P. oligandrum reduced the bacterial wilt as well as more extensive colonization, which did not reduce the rhizosphere population of R. solanacearum. These results suggest that competition for infection sites and nutrients in rhizosphere is not the primary biocontrol mechanism of bacterial wilt by P. oligandrum.

Fuzzy tissue detection for real-time focal control in corneal confocal microscopy

2019 ◽  
Vol 67 (10) ◽  
pp. 879-888
Author(s):  
Andreas Bartschat ◽  
Stephan Allgeier ◽  
Tim Scherr ◽  
Johannes Stegmaier ◽  
Sebastian Bohn ◽  
...  
Keyword(s):  
Real Time ◽  
Focal Plane ◽  
Laser Scanning ◽  
Nerve Fibers ◽  
Laser Scanning Microscopy ◽  
Confocal Laser ◽  
Loop Control ◽  
Visual Words ◽  
Corneal Confocal Microscopy

Abstract Corneal confocal laser scanning microscopy is a promising method for in vivo investigation of cellular structures, e. g., of nerve fibers in the sub-basal nerve plexus. During recording, even slight displacements of the focal plane lead to images of adjacent tissue layers. In this work, we propose a closed-loop control of the focal plane. To detect and evaluate the visible tissues, we utilize the Bag of Visual Words approach to implement a customizable image processing pipeline for real-time applications. Furthermore, we show that the proposed model can be trained with small classification datasets and can be applied as a segmentation method. The proposed control loop, including tissue detection, is implemented in a proof-of-concept setup and shows promising results in a first evaluation with a human subject.

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