Rapid, species-specific detection of uropathogen 16S rDNA and rRNA at ambient temperature by dot-blot hybridization and an electrochemical sensor array

2005 ◽  
Vol 84 (1) ◽  
pp. 90-99 ◽  
Author(s):  
Chien-Pin Sun ◽  
Joseph C. Liao ◽  
Yao-Hua Zhang ◽  
Vincent Gau ◽  
Mitra Mastali ◽  
...  
Plant Disease ◽  
1999 ◽  
Vol 83 (4) ◽  
pp. 390-395 ◽  
Author(s):  
M. L. Xu ◽  
A. E. Melchinger ◽  
T. Lübberstedt

Head smut of maize, caused by Sporisorium reiliana, may substantially reduce grain yield. The objective of the present study was to develop a highly specific and sensitive DNA-based assay for detection of S. reiliana and its differentiation from Ustilago maydis, a maize fungus inducing the symptomatically similar common smut disease. Plasmid libraries of S. reiliana and U. maydis were constructed using a shotgun cloning procedure. Clones containing strongly hybridizing species-specific DNA were selected by screening libraries with their own labeled genomic DNA, followed by cross-hybridization with genomic DNA of maize and other maize-pathogenic fungi. The selected clones were used to generate subclones with short insert fragments to facilitate PCR amplification for labeling and primer design for a PCR assay. Using Dig-dUTP labeled inserts, detection of less than 0.16 ng of fungal DNA was possible by dot blot hybridization. Sequences of insert fragments were determined to design primer pairs for a PCR-based assay. Primer pairs SR1 and SR3 are species-specific for S. reiliana, and UM11 is species-specific for U. maydis. The PCR-based assays can detect fungal DNA of less than 1.6 pg using SR1 and SR3, and 8 pg using UM11, irrespective of the presence of maize DNA. Use of SR1 and SR3 allowed detection of S. reiliana in the extracts of pith, node, and shank from S. reiliana-infected plants, but not in leaves. Thus, both the dot blot hybridization and the PCR-based assays provide a highly sensitive and reliable tool for detection and differentiation of corn smut caused either by S. reiliana or by U. maydis.


Parasitology ◽  
1988 ◽  
Vol 97 (1) ◽  
pp. 63-73 ◽  
Author(s):  
W. C. Gibson ◽  
P. Dukes ◽  
J. K. Gashumba

SUMMARYWe have obtained 5 specific DNA probes for African trypanosomes of the subgenera Trypanozoon and Nannomonas. Each probe consists of one repeat unit of the major repetitive DNA (satellite DNA) of each species or intra-specific group. One probe hybridized with all members of subgenus Trypanozoon (except T. equiperdum which was not tested). In subgenus Nannomonas, one probe recognized T. simiae, but 3 probes were needed to identify all stocks of T. congolense available. Each of the 3 latter probes recognized trypanosomes from one of the 3 major groups of T. congolense previously defined by isoenzyme characterization, i.e. savannah, forest and Kenya coast types. As few as 100 trypanosomes could be unequivocally identified by dot blot hybridization and individual trypanosomes could be identified by in situ hybridization. We show how this simple methodology can be used in the field for the identification of immature and mature trypanosome infections in tsetse.


2004 ◽  
Vol 94 (5) ◽  
pp. 470-477 ◽  
Author(s):  
Jose A. Navarro ◽  
Francisco Botella ◽  
Antonio Maruhenda ◽  
Pedro Sastre ◽  
M. Amelia Sánchez-Pina ◽  
...  

Nonisotopic molecular dot blot hybridization technique and multiplex reverse transcription-polymerase chain reaction assay for the specific detection of Lettuce big-vein virus (LBVV) and Mirafiori lettuce virus (MiLV) in lettuce tissue were developed. Both procedures were suitable for the specific detection of both viruses in a range of naturally infected lettuce plants from various Spanish production areas and seven different cultivars. The study of the distribution of both viruses in the plant revealed that the highest concentration of LBVV and MiLV occurred in roots and old leaves, respectively. LBVV infection progress in a lettuce production area was faster than that observed for MiLV. In spite of different rates of virus infection progress, most lettuce plants became infected with both viruses about 100 days posttransplant. The appearance of both viruses in lettuce crops was preceded by a peak in the concentration of resting spores and zoosporangia of the fungus vector Olpidium brassicae in lettuce roots.


Parasitology ◽  
2005 ◽  
Vol 130 (6) ◽  
pp. 611-619 ◽  
Author(s):  
N. M. RODRIGUEZ ◽  
Z. DE GUGLIELMO ◽  
M. A. BARRIOS ◽  
R. M. BARRIOS ◽  
O. ZERPA ◽  
...  

Leishmania infantum has been described as a highly polymorphic group of parasites, responsible for visceral leishmaniasis and cutaneous leishmaniasis. In this paper we report the life-cycle of L. (L.) infantum in an endemic area of visceral leishmaniasis in Venezuela, by using molecular diagnosis and characterization of parasites isolated from dogs, humans with visceral leishmaniasis and sand flies. The molecular characterization was carried out by use of kDNA restriction analysis, dot-blot hybridization with species-specific probes and RFLP of the PCR products. The results demonstrated that L. (L.) infantum is the parasite responsible for VL in the island. The parasites were revealed to be genetically homogeneous with no intra-specific differences between isolates from different individuals. The highest homology of the isolates was with L. (L.) infantum from the Old World rather than with L. (L.) chagasi from the New World. Additionally, we report the geographical distribution of Lutzomyia longipalpis, and the relationship with the transmission of L. (L.) infantum in the studied area.


Sign in / Sign up

Export Citation Format

Share Document