scholarly journals Effect of Amoxicillin-Clavulanic Acid on Human Fecal Flora in a Gnotobiotic Mouse Model Assessed with Fluorescence Hybridization Using Group-Specific 16S rRNA Probes in Combination with Flow Cytometry

2004 ◽  
Vol 48 (4) ◽  
pp. 1365-1368 ◽  
Author(s):  
Marie Claude Barc ◽  
François Bourlioux ◽  
Lionel Rigottier-Gois ◽  
Céline Charrin-Sarnel ◽  
Claire Janoir ◽  
...  

ABSTRACT Predominant groups of bacteria from a human fecal flora-associated mouse model challenged with amoxicillin-clavulanic acid were quantified with fluorescence in situ hybridization combined with flow cytometry using specific 16S rRNA targeted oligonucleotide probes. This approach provides a useful tool with high throughput to evaluate fecal microflora under antibiotic treatment.

1998 ◽  
Vol 64 (9) ◽  
pp. 3336-3345 ◽  
Author(s):  
Alison H. Franks ◽  
Hermie J. M. Harmsen ◽  
Gerwin C. Raangs ◽  
Gijsbert J. Jansen ◽  
Frits Schut ◽  
...  

ABSTRACT Six 16S rRNA-targeted oligonucleotide probes were designed, validated, and used to quantify predominant groups of anaerobic bacteria in human fecal samples. A set of two probes was specific for species of the Bacteroides fragilis group and the speciesBacteroides distasonis. Two others were designed to detect species of the Clostridium histolyticum and theClostridium lituseburense groups. Another probe was designed for the genera Streptococcus andLactococcus, and the final probe was designed for the species of the Clostridium coccoides-Eubacterium rectalegroup. The temperature of dissociation of each of the probes was determined. The specificities of the probes for a collection of target and reference organisms were tested by dot blot hybridization and fluorescent in situ hybridization (FISH). The new probes were used in initial FISH experiments to enumerate human fecal bacteria. The combination of the two Bacteroides-specific probes detected a mean of 5.4 × 1010 cells per g (dry weight) of feces; the Clostridium coccoides-Eubacterium rectalegroup-specific probe detected a mean of 7.2 × 1010cells per g (dry weight) of feces. The Clostridium histolyticum, Clostridium lituseburense, andStreptococcus-Lactococcus group-specific probes detected only numbers of cells ranging from 1 × 107 to 7 × 108 per g (dry weight) of feces. Three of the newly designed probes and three additional probes were used in further FISH experiments to study the fecal flora composition of nine volunteers over a period of 8 months. The combination of probes was able to detect at least two-thirds of the fecal flora. The normal biological variations within the fecal populations of the volunteers were determined and indicated that these variations should be considered when evaluating the effects of agents modulating the flora.


2008 ◽  
Vol 74 (16) ◽  
pp. 5068-5077 ◽  
Author(s):  
Tatsuhiko Hoshino ◽  
L. Safak Yilmaz ◽  
Daniel R. Noguera ◽  
Holger Daims ◽  
Michael Wagner

ABSTRACT Fluorescence in situ hybridization (FISH) with rRNA-targeted oligonucleotide probes is a method that is widely used to detect and quantify microorganisms in environmental samples and medical specimens by fluorescence microscopy. Difficulties with FISH arise if the rRNA content of the probe target organisms is low, causing dim fluorescence signals that are not detectable against the background fluorescence. This limitation is ameliorated by technical modifications such as catalyzed reporter deposition (CARD)-FISH, but the minimal numbers of rRNA copies needed to obtain a visible signal of a microbial cell after FISH or CARD-FISH have not been determined previously. In this study, a novel competitive FISH approach was developed and used to determine, based on a thermodynamic model of probe competition, the numbers of 16S rRNA copies per cell required to detect bacteria by FISH and CARD-FISH with oligonucleotide probes in mixed pure cultures and in activated sludge. The detection limits of conventional FISH with Cy3-labeled probe EUB338-I were found to be 370 ± 45 16S rRNA molecules per cell for Escherichia coli hybridized on glass microscope slides and 1,400 ± 170 16S rRNA copies per E. coli cell in activated sludge. For CARD-FISH the values ranged from 8.9 ± 1.5 to 14 ± 2 and from 36 ± 6 to 54 ± 7 16S rRNA molecules per cell, respectively, indicating that the sensitivity of CARD-FISH was 26- to 41-fold higher than that of conventional FISH. These results suggest that optimized FISH protocols using oligonucleotide probes could be suitable for more recent applications of FISH (for example, to detect mRNA in situ in microbial cells).


1996 ◽  
Vol 42 (10) ◽  
pp. 1061-1071 ◽  
Author(s):  
Marc E. Frischer ◽  
Peter J. Floriani ◽  
Sandra A. Nierzwicki-Bauer

The use of 16S rRNA targeted gene probes for the direct analysis of microbial communities has revolutionized the field of microbial ecology, yet a comprehensive approach for the design of such probes does not exist. The development of 16S rRNA targeted oligonucleotide probes for use with fluorescence in situ hybridization (FISH) procedures has been especially difficult as a result of the complex nature of the rRNA target molecule. In this study a systematic comparison of 16S rRNA targeted oligonucleotide gene probes was conducted to determine if target location influences the hybridization efficiency of oligonucleotide probes when used with in situ hybridization protocols for the detection of whole microbial cells. Five unique universal 12-mer oligonucleotide sequences, located at different regions of the 16S rRNA molecule, were identified by a computer-aided sequence analysis of over 1000 partial and complete 16S rRNA sequences. The complements of these oligomeric sequences were chemically synthesized for use as probes and end labeled with either [γ-32P] ATP or the fluorescent molecule tetramethylrhodamine-5/-6. Hybridization sensitivity for each of the probes was determined by hybridization to heat-denatured RNA immobilized on blots or to formaldehyde fixed whole cells. All of the probes hybridized with equal efficiency to denatured RNA. However, the probes exhibited a wide range of sensitivity (from none to very strong) when hybridized with whole cells using a previously developed FISH procedure. Differential hybridization efficiencies against whole cells could not be attributed to cell wall type, since the relative probe efficiency was preserved when either Gram-negative or -positive cells were used. These studies represent one of the first attempts to systematically define criteria for 16S rRNA targeted probe design for use against whole cells and establish target site location as a critical parameter in probe design.Key words: 16S rRNA, oligonucleotide probes, in situ hybridization.


2001 ◽  
Vol 67 (10) ◽  
pp. 4850-4857 ◽  
Author(s):  
Svetlana N. Dedysh ◽  
Manigee Derakshani ◽  
Werner Liesack

ABSTRACT Two 16S rRNA-targeted oligonucleotide probes, Mcell-1026 and Mcell-181, were developed for specific detection of the acidophilic methanotroph Methylocella palustris using fluorescence in situ hybridization (FISH). The fluorescence signal of probe Mcell-181 was enhanced by its combined application with the oligonucleotide helper probe H158. Mcell-1026 and Mcell-181, as well as 16S rRNA oligonucleotide probes with reported group specificity for either type I methanotrophs (probes M-84 and M-705) or theMethylosinus/Methylocystis group of type II methanotrophs (probes MA-221 and M-450), were used in FISH to determine the abundance of distinct methanotroph groups in aSphagnum peat sample of pH 4.2. M. palustris was enumerated at greater than 106 cells per g of peat (wet weight), while the detectable population size of type I methanotrophs was three orders of magnitude below the population level of M. palustris. The cell counts with probe MA-221 suggested that only 104 type II methanotrophs per g of peat (wet weight) were present, while the use of probe M-450 revealed more than 106 type II methanotroph cells per g of the same samples. This discrepancy was due to the fact that probe M-450 targets almost all currently known strains of Methylosinus andMethylocystis, whereas probe MA-221, originally described as group specific, does not detect a large proportion ofMethylocystis strains. The total number of methanotrophic bacteria detected by FISH was 3.0 (±0.2) × 106 cells per g (wet weight) of peat. This was about 0.8% of the total bacterial cell number. Thus, our study clearly suggests that M. palustris and a defined population ofMethylocystis spp. were the predominant methanotrophs detectable by FISH in an acidic Sphagnum peat bog.


1998 ◽  
Vol 37 (4-5) ◽  
pp. 431-440 ◽  
Author(s):  
Jean-Jacques Pernelle ◽  
Eric Cotteux ◽  
Philippe Duchène

In situ hybridization (FISH) of two fluorescent oligonucleotide probes, TNI and 21N, directed against 16S rRNA fragments of Thiothrix nivea and type 021N filamentous bacteria, was used to study activated sludge samples of various origins. Comparison of the results obtained by this technique with morphological data enabled us to evaluate the sensitivity and specificity of the probes, as well as to propose practical classification criteria, in an effort to correlate the identification and ecology of these two microorganisms. We applied the two oligonucleotide probes to the study of Thiothrix sp. in pilot and laboratory batch reactors fed a substrate that was moderately deficient in rapidly available phosphorus. We monitored the growth dynamics of Thiothrix sp. in the pilot reactor, using various hydraulic configurations and after certain perturbations, such as transient substrate overloads. The results provided data which led us to question the importance of the length of time oxygen-deficient sludges spend in clarifier tanks and we discuss the effects of both moderate reductions in oxygen and of very intermittent feedings on the occurrence of Thiothrix sp. growth peaks. The identification and quantification of these filamentous bacteria by size class, made possible by in situ hybridization, are shown to be powerful tools for the early detection and evaluation of episodes of proliferation of filamentous bacteria, revealing them to be much more sensitive indicators than the sludge volume index (SVI).


2003 ◽  
Vol 69 (9) ◽  
pp. 5519-5529 ◽  
Author(s):  
Isabelle C. Biegala ◽  
Fabrice Not ◽  
Daniel Vaulot ◽  
Nathalie Simon

ABSTRACT Picoeukaryotes (cells of <3 μm in diameter) contribute significantly to marine plankton biomass and productivity, and recently molecular studies have brought to light their wide diversity. Among the methods that have been used so far to quantify aquatic microorganisms, fluorescence in situ hybridization of oligonucleotide probes combined with flow cytometry offers the advantages of both high resolution for taxonomic identification and automated cell counting. However, cell losses, cell clumps, and low signal-to-background ratio have often been mentioned as major problems for routine application of this combination of techniques. We developed a new protocol associating tyramide signal amplification-fluorescence in situ hybridization and flow cytometry, which allows the detection of picoeukaryotes in cultures during both the exponential and stationary phases. The use of surfactant and sonication proved to be essential for the detection and quantification of picoeukaryotes from the natural environment, with as little as a few tenths of a milliliter of 3-μm-pore-size prefiltered sea water. The routine application of the technique was tested along a coastal transect off Brittany (France), where the different groups of picoeukaryotes were investigated using already published specific probes and a newly designed probe that targets the order Mamiellales (Prasinophyceae, Chlorophyta). Among the picoeukaryotes, Mamiellales outnumbered by 1 order of magnitude both the cyanobacteria and the non-Chlorophyta, which were represented mainly by the Pelagophyceae class. Picoeukaryote abundance increased from open toward more estuarine water, probably following changes in water temperature and stability.


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