Detection of Leptosphaeria korrae with the polymerase chain reaction and primers from the ribosomal internal transcribed spacers

1994 ◽  
Vol 72 (3) ◽  
pp. 342-346 ◽  
Author(s):  
D. O'Gorman ◽  
B. Xue ◽  
T. Hsiang ◽  
P. H. Goodwin

Leptosphaeria korrae, the causal agent of necrotic ring spot, is a destructive patch disease of Kentucky bluegrass. To develop a rapid molecular test for the detection of this pathogen, an assay based on the polymerase chain reaction (PCR) was developed utilizing the internal transcribed spacer region 1 (ITS 1) of L. korrae ribosomal DNA. DNA sequence comparison showed 94.8% similarity of the ITS 1 region among L. korrae isolates and only 45–50% similarity between L. korrae and other fungal species. Based on ITS 1 sequence differences, a pair of oligonucleotide primers, LK17S and 5.8SC, were selected. With PCR, the primers specifically amplified L. korrae DNA and did not amplify DNA isolated from 15 other fungal species or healthy Kentucky bluegrass. The assay could also specifically detect L. korrae in diseased turfgrass samples. Key words: detection, ITS 1, Leptosphaeria korrae, necrotic ring spot, polymerase chain reaction, ribosomal DNA.

Genome ◽  
1994 ◽  
Vol 37 (4) ◽  
pp. 664-671 ◽  
Author(s):  
Lang Zhuo ◽  
S. L. Sajdak ◽  
R. B. Phillips

Intraspecific variation in the sequence of the transcribed spacer regions of the ribosomal DNA (rDNA) in lake trout was examined by restriction mapping and sequencing of these regions amplified by the polymerase chain reaction. The length of the first internal transcribed spacer region (ITS-1) was 566 bases and the second internal transcribed spacer region (ITS-2) was 368 bases in lake trout. When the 1.4-kb region including the ITS-1, the 5.8S coding region, and the ITS-2 was amplified from 12 individuals from four populations and digested with eight different enzymes only one intraindividual polymorphism was found that occurred in each population. When the amplified ITS-1 region was sequenced from an additional 10 individuals from five populations, no interindividual variation was found in the sequence. A 6-kb portion of the rDNA repeat unit including 1.6 kb of the 18S coding region, the 5′ external spacer region (5′ ETS), and part of the adjacent intergenic spacer was cloned and a restriction map was prepared for these regions in lake trout. No intraspecific variation was found in the region adjacent to the 18S rDNA, which includes the 5′ ETS, although intraspecific and intraindividual length variation was found in the intergenic spacer region 3–6 kb from the 18S. Sequencing of a 609-b segment of the 5′ ETS adjacent to the 18S coding region revealed the presence of two 41-b repeats. The 198-b sequence between the repeats had some similarity to the 18S coding region of other fishes. Primers were designed for amplification of 559 b of the 5′ ETS using the polymerase chain reaction. No intraspecific variation in this region in lake trout was found when the DNA amplified from this region in 12 individuals from four populations was digested with eight restriction enzymes.Key words: ribosomal DNA, internal transcribed spacer regions, 5′ external spacer region, transcribed spacer, lake trout.


2019 ◽  
Vol 10 (04) ◽  
pp. 655-661
Author(s):  
Zainab H Abood AL-Asadi

Aspergillosis refers to fungi infections of the respiratory tract caused by Aspergillus species, especially Aspergillus fumigatus. Infection of A. fumigatus was increased in the last few years due to either resistances to antibiotics or the influence of other factors such as other fungal infections. The present study aimed to review the impact of Aspergillus fumigatus in Aspergillosis cases, and study the role of Singleplex PCR for amplification of ITS1, ITS4 of rRNA gene in the detection of fungal isolate. In this study, One hundred sputum samples were collected from patients admitted to the specialize chest and respiratory diseases center / Baghdad who were suffering from respiratory problems. During these studied, molds were isolation and identification based on Conventional method (Direct microscopy by using 10% KOH, and fungal culture was done on Sabouraud Dextrose agar supplemented with chloramphenicol and on Czapek-Dox agar incubated at 37°C and examined for 3-7 days then macroscopic, microscopic examination of the colony by(lactophenol cotton blue stain )and molecular methods by using Polymerase chain reaction (PCR)technique for identification. The 10% KOH examination was positive for 35 cases, while laboratory culturing was positive for 53 cases. Aspergillus sp were isolated from 44(83%) patients; A. fumigatus was isolated in 23 (42. 4%) patients while A. flavus, A. niger, and A. terreus were isolated from 11 (20. 08%), (13. 2%) and 3 (5. 7%) patients respectively, also isolated Penicillium spp. at percentage 1(1. 9%). In this study. The ages of participants ranged from 10-70years with a mean age of 34years, the males were more susceptible to fungal infection, were recorded 35/53 (66. 3), compared to females were 18/53 (33. 96). The infection of fungi was more prevalent in ages 30-40recorded 26(53. 06%) followed by ages 40-50, 13(26. 5), while the lowest infection recorded in the age group 10- 20 years was 2(2. 04%). DNA isolated from twenty-three A. fumigatus isolates was used as a template, and the specific of oligonucleotide primer sequences were used in conventional PCR to detect the presence of internal transcribed spacer region ( ITS) region of the rRNA gene for Aspergillus fumigates. The results of the PCR amplification of the rRNA gene showed that this gene was present in 19 samples out 23 positive samples which isolation with a PCR product size of approximated 385 bp, while 4 samples out 23 positive samples showed negative results for the presence of this gene as indicated by the absence of the PCR products in their relevant lanes. Statistical analysis revealed that the PCR to have a sensitivity of 95. 1% in the detection of Aspergillus fumigatus in Aspergillosis cases. Polymerase chain reaction (PCR) is a rapid, specific, and sensitive method to detect Aspergillus fumigatus in aspergillosis cases of humans.


2003 ◽  
Vol 15 (1) ◽  
pp. 57-59 ◽  
Author(s):  
J. C. Patterson-Kane ◽  
P. Caplazi ◽  
F. Rurangirwa ◽  
R. R. Tramontin ◽  
K. Wolfsdorf

Encephalitozoon cuniculi is a microsporidial parasite, which has rarely been reported to cause placentitis in animals. A late-term aborted fetus and placenta from a Quarterhorse were presented to the Livestock Disease Diagnostic Center, University of Kentucky, for diagnostic examination. There was a necrotizing placentitis, with distension of many chorionic epithelial cells by intracytoplasmic vacuoles containing 1–2-μm-diameter, elongated, gram-positive organisms. The organisms were identified as E. cuniculi by electron microscopy and by polymerase chain reaction using primers to microsporidial ribosomal DNA. Joints of the fetus were swollen, with gross and microscopic lesions of synovitis; however, E. cuniculi DNA was not detected.


2001 ◽  
Vol 91 (9) ◽  
pp. 900-904 ◽  
Author(s):  
Bruno Le Cam ◽  
Martine Devaux ◽  
Luciana Parisi

A technique based on the polymerase chain reaction (PCR) was developed for the identification of Venturia nashicola using nucleotide sequence information of the ribosomal DNA region. The complete internal transcribed spacer (ITS) region of V. nashicola strains and phylo-genetically related species was amplified with the two universal ITS1 and ITS4 primers, sequenced, and digested with five restriction enzymes. The alignment of nucleotide sequences and analyses of digestion patterns indicated constant polymorphisms between V. nashicola and related species at nucleotides 126 and 127, which overlapped a TaqI restriction site. An oligonucleotide primer named A126 was designed for identifying this variable region. A primer set (A126 and ITS4) that allowed the amplification of a 391-bp DNA fragment within the ITS region by PCR was specific to V. nashicola when it was checked against fungal genomic DNAs of related fungi. This primer set was a good candidate for a species-specific reagent in a procedure for identification of V. nashicola by PCR.


Sign in / Sign up

Export Citation Format

Share Document