scholarly journals Real-Time PCR Quantitation of Clostridia in Feces of Autistic Children

2004 ◽  
Vol 70 (11) ◽  
pp. 6459-6465 ◽  
Author(s):  
Yuli Song ◽  
Chengxu Liu ◽  
Sydney M. Finegold

ABSTRACT Based on the hypothesis that intestinal clostridia play a role in late-onset autism, we have been characterizing clostridia from stools of autistic and control children. We applied the TaqMan real-time PCR procedure to detect and quantitate three Clostridium clusters and one Clostridium species, C. bolteae, in stool specimens. Group- and species-specific primers targeting the 16S rRNA genes were designed, and specificity of the primers was confirmed with DNA from related bacterial strains. In this procedure, a linear relationship exists between the threshold cycle (CT ) fluorescence value and the number of bacterial cells (CFU). The assay showed high sensitivity: as few as 2 cells of members of cluster I, 6 cells of cluster XI, 4 cells of cluster XIVab, and 0.6 cell of C. bolteae could be detected per PCR. Analysis of the real-time PCR data indicated that the cell count differences between autistic and control children for C. bolteae and the following Clostridium groups were statistically significant: mean counts of C. bolteae and clusters I and XI in autistic children were 46-fold (P = 0.01), 9.0-fold (P = 0.014), and 3.5-fold (P = 0.004) greater than those in control children, respectively, but not for cluster XIVab (2.6 � 108 CFU/g in autistic children and 4.8 � 108 CFU/g in controls; respectively). More subjects need to be studied. The assay is a rapid and reliable method, and it should have great potential for quantitation of other bacteria in the intestinal tract.

2016 ◽  
Vol 6 (1) ◽  
Author(s):  
Naeime Karamipour ◽  
Yaghoub Fathipour ◽  
Mohammad Mehrabadi

Abstract Many members of suborder Heteroptra harbor heritable symbiotic bacteria. Here we characterize the gut symbiotic bacterium in Graphosoma lineatum (Hemiptera: Pentatomidae) by using molecular phylogeny, real-time PCR analysis as well as light and electron microscopy observations. The microscopy observations revealed the presence of a large number of rod-shaped bacterial cells in the crypts. A very high prevalence (98 to 100%) of the symbiont infection was found in the insect populations that strongly supports an intimate association between these two organisms. Real-time PCR analysis also showed that the Gammaproteobacteria dominated the crypts. The sequences of 16sr RNA and groEL genes of symbiont showed high levels of similarity (93 to 95%) to Pantoea agglomeranse and Erwinia herbicola Gammaproteobacteria. Phylogenetic analyses placed G. lineatum symbiont in a well-defined branch, divergent from other stink bug bacterial symbionts. Co-evolutionary analysis showed lack of host-symbiont phylogenetic congruence. Surface sterilization of eggs resulted in increased pre-adult stage in the offspring (aposymbionts) in comparison to the normal. Also, fecundity, longevity, and adult stage were significantly decreased in the aposymbionts. Therefore, it seems that the symbiont might play a vital function in the host biology, in which host optimal development depends on the symbiont.


2007 ◽  
Vol 20-21 ◽  
pp. 539-542 ◽  
Author(s):  
Francisco Remonsellez ◽  
F. Galleguillos ◽  
Sonestie Janse van Rensburg ◽  
G.F. Rautenbach ◽  
Pedro A. Galleguillos ◽  
...  

Microbial heap bioleaching is being used as an industrial process to recover copper from low grade ores. It is known that a consortium of different microorganisms participates in this process. Therefore identification and quantification of communities inhabiting heap bioleaching operations is a key step for understanding the dynamics and role of these microorganisms in the process. A quantitative real-time PCR approach was used to investigate the microbial dynamics in this process. To study the microbial population inhabiting a low-grade copper sulphide ore bioleaching industrial heap process at Escondida Mine in Chile, 16S rRNA genetic libraries were constructed using bacterial and archaeal universal primers. Phylogenetic analyses of sequences retrieved from genetic libraries showed that the community is mainly composed by microoganisms related to Acidithiobacillus ferrooxidans (2 strains), Acidithiobacillus thiooxidans, Leptospirillum ferrooxidans, Leptospirillum ferriphilum and the archaea Ferroplasma. Specific primers for real-time PCR determination were designed and tested to amplify each of the sequences obtained by cloning. Standard curves for real time PCR were performed using plasmid DNA from selected clones. This methodology is actually being used to monitor relevant microorganisms inhabiting this low-grade copper sulphide ore bioleaching industrial heap.


2007 ◽  
Vol 53 (10) ◽  
pp. 1741-1748 ◽  
Author(s):  
Qiuying Huang ◽  
Qinghua Hu ◽  
Qingge Li

Abstract Background: Real-time PCR assays have been widely used for detecting foodborne pathogens but have been much less frequently applied in species identification, mainly because of the low number of species they can distinguish in 1 reaction. The present study used a new probe coding/labeling strategy, termed multicolor combinational probe coding (MCPC), to increase the number of targets that can be distinguished in a single real-time PCR for rapid and reliable species identification. Methods: With MCPC, 8 pairs of species-specific tagged primers, 1 pair of universal primers, and 8 unilabeled or mix-labeled molecular beacon probes were included in a single reaction tube. Real-time PCR was performed, and the identity of each of the 8 pathogens was determined by amplification profile comparison. The method was validated via blind assessment of 118 bacterial strains, including clinical isolates and isolates from food products. Results: The blind test with 118 samples gave no false-positive or -negative results for the target genes. The template DNA suitable for MCPC analysis was simply prepared by heating lysis, and the total PCR analysis was finished within 2.5 h, excluding template preparation. Conclusions: MCPC is suitable for rapid and reliable identification of foodborne pathogens at the species level.


2006 ◽  
Vol 54 (1) ◽  
pp. 91-99 ◽  
Author(s):  
T. Limpiyakorn ◽  
F. Kurisu ◽  
O. Yagi

This study carried out quantification of ammonia-oxidizing bacteria (AOB) populations in 12 full-scale sewage activated sludge systems that were different in ammonia removals and treatment processes during three different seasons. Experiment was divided into 3 parts: 1) analysis of AOB communities by PCR-DGGE-cloning-sequencing of 16S rRNA genes; 2) development of four real-time PCR primer sets for quantification of the particular AOB of interest; and 3) quantification of AOB populations by using the newly developed real-time PCR primer sets. The results suggested that all the primer sets gave good reproducibility and specificity for PCR amplification with the detection limits of 102 copies/PCR reaction. Although the 12 systems were different in several aspects, one of the identified sequence types of Nitrosomonas oligotropha cluster was the dominant AOB in every system and every season studied. However, the other sequence type of this cluster was not significantly involved in ammonia removals in the systems. The occurrence of N. communis cluster in the systems seemed to depend on the remaining oxygen concentrations in the sludge floc and thus the activity of aerobic heterotrophs in the aeration tanks. N. europaea–Nitrosococcus. mobilis solely existed in one A2O system of which the influent contained twice the chloride concentrations than those of other systems.


2005 ◽  
Vol 49 (8) ◽  
pp. 3166-3170 ◽  
Author(s):  
Erik Glocker ◽  
Marco Berning ◽  
Monique M. Gerrits ◽  
Johannes G. Kusters ◽  
Manfred Kist

ABSTRACT The effectiveness of recommended first-line therapies for Helicobacter pylori infections is decreasing due to the occurrence of resistance to metronidazole and/or clarithromycin. Quadruple therapies, which include tetracycline and a bismuth salt, are useful alternative regimens. However, resistance to tetracycline, mainly caused by mutations in the 16S rRNA genes (rrnA and rrnB) affecting nucleotides 926 to 928, are already emerging and can impair the efficacies of such second-line regimens. Here, we describe a novel real-time PCR for the detection of 16S rRNA gene mutations associated with tetracycline resistance. Our PCR method was able to distinguish between wild-type strains and resistant strains exhibiting single-, double, or triple-base-pair mutations. The method was applicable both to DNA extracted from pure cultures and to DNA extracted from fresh or frozen H. pylori-infected gastric biopsy samples. We therefore conclude that this real-time PCR is an excellent method for determination of H. pylori tetracycline resistance even when live bacteria are no longer available.


2011 ◽  
Vol 49 (10) ◽  
pp. 3691-3693 ◽  
Author(s):  
M. Kramski ◽  
A. J. Gaeguta ◽  
G. F. Lichtfuss ◽  
R. Rajasuriar ◽  
S. M. Crowe ◽  
...  

2005 ◽  
Vol 71 (8) ◽  
pp. 4214-4219 ◽  
Author(s):  
Abu Sadeque Md Selim ◽  
Piyanuch Boonkumklao ◽  
Teruo Sone ◽  
Apinya Assavanig ◽  
Masaru Wada ◽  
...  

ABSTRACT A new real-time PCR assay was successfully developed using a TaqMan fluorescence probe for specific detection and enumeration of a novel bacterium, Lactobacillus thermotolerans, in chicken feces. The specific primers and probe were designed based on the L. thermotolerans 16S rRNA gene sequences, and these sequences were compared to those of all available 16S rRNA genes in the GenBank database. The assay, targeting 16S rRNA gene, was evaluated using DNA from a pure culture of L. thermotolerans, DNA from the closely related bacteria Lactobacillus mucosae DSM 13345T and Lactobacillus fermentum JCM 1173T, and DNA from other lactic acid bacteria in quantitative experiments. Serial dilutions of L. thermotolerans DNA were used as external standards for calibration. The minimum detection limit of this technique was 1.84 × 103 cells/ml of an L. thermotolerans pure culture. The assay was then applied to chicken feces in two different trials. In the first trial, the cell population was 104 cells/g feces on day 4 and 105 cells/g feces on days 11 to 18. However, cell populations of 106 to 107 cells/g feces were detected in the second trial. The total bacterial count, measured by 4′,6-diamidino-2-phenylindole (DAPI) staining, was approximately 1011 cells/g feces. These results suggest that in general, L. thermotolerans is a normal member of the chicken gut microbiota, although it is present at relatively low levels in the feces.


2021 ◽  
Vol 19 ◽  
Author(s):  
Mina Ahmadi ◽  
Pegah Shakib ◽  
Mohammad Reza Zolfaghari

Background: Identification of non-tuberculosis mycobacteria by culture and phenotypic description is commonly used; however, it takes 4 to 6 weeks or even a longer time for slow growing species as well as for identification of some species that may be missed by biochemical characteristics methods. This study aimed to evaluate Real Time PCR for Detection of NTM by Amplification of Internal Transcribed Spacer (ITS) and 16S rRNA. Methods: In our investigation, using Real Time PCR and two pairs of unique primers targeted to ITS and 16S rRNA genes as well as Beta- actin as an internal control, Non tuberculosis mycobacteria species were detected. Results: Real time PCR was performed on the prepared dilutions. In addition, the threshold of sensitivity in this study was 10pg. To test the specificity, the genome of several bacteria responsible for respiratory infections was used, in which only the test response related to the non-tuberculosis mycobacterium genome and internal control was positive. Conclusion: In this research, an effective and up-to-date Real Time PCR method was used to design a diagnostic kit from all aspects. To avoid any error or mistake and to minimize the false results, internal control was used. The ability to design diagnostic kits allows us to increase efficiency, minimize mistakes, and save a considerable amount of time and cost.


Sign in / Sign up

Export Citation Format

Share Document