Rapid identification of Escherichia coli microcin J25 producing strains using polymerase chain reaction and colony blot hybridization

2001 ◽  
Vol 47 (9) ◽  
pp. 877-882 ◽  
Author(s):  
Mariela Duarte ◽  
Gilles Cottenceau ◽  
Véronique Portrait ◽  
Anne-Marie Pons
Keyword(s):  
Escherichia Coli ◽  
Polymerase Chain Reaction ◽  
Blot Hybridization ◽  
Rapid Identification ◽  
Molecular Techniques ◽  
Chain Reaction ◽  
Gene Encoding ◽  
Bacterial Populations ◽  
Polymerase Chain ◽  
Microcin J25

To screen, isolate, and characterize bacterial populations producing microcin J25, we report here two rapid, reliable, and sensitive methods, using polymerase chain reaction and colony blot hybridization with a digoxigenin-labelled probe. A sample of 26 Escherichia coli strains isolated from poultry intestinal contents was evaluated to detect the sequence of mcjA, the gene encoding the MccJ25 precursor. The two molecular techniques were compared with the commonly used cross-immunity tests. They generate accurate data with no obvious cross-reactions with other microcins. The results display that the producers of MccJ25 were widely distributed in the poultry intestinal habitat. The applications of these molecular methods will be useful in future studies of microcinogenic populations, and thus contribute to understand the relationships within the complex intestinal microbial ecosystem.Key words: microcin J25, microcinogenic strains detection, digoxigenin-labelled probe, colony hybridization, polymerase chain reaction.

Rapid Identification of Enterovirulent Escherichia coli Strains using Polymerase Chain Reaction from Shrimp Farms

2013 ◽  
Vol 16 (21) ◽  
pp. 1260-1269 ◽  
Author(s):  
Debashis Roy ◽  
Bhabananda Biswas ◽  
H.M. Rakibul Islam ◽  
Md. Shamim Ahmed ◽  
Md. Rasheduzza ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Polymerase Chain Reaction ◽  
Rapid Identification ◽  
Chain Reaction ◽  
Polymerase Chain ◽  
Shrimp Farms

scholarly journals Occurrence of F42 colonization factor in Escherichia coli strains isolated from piglets with diarrhea

2005 ◽  
Vol 25 (1) ◽  
pp. 31-33
Author(s):  
Mário Paulo A. Penatti ◽  
Alex S. Silva ◽  
Geórgio F. Valadares ◽  
Domingos S. Leite
Keyword(s):  
Escherichia Coli ◽  
Polymerase Chain Reaction ◽  
Strong Association ◽  
Agglutination Test ◽  
Chain Reaction ◽  
Gene Encoding ◽  
Newborn Piglets ◽  
Colonization Factor ◽  
Heat Stable ◽  
Polymerase Chain

The objective of this study was to determine the presence of the colonization factor F42 in 168 strains of Escherichia coli isolated from diarrheic stools of newborn piglets. The presence of F42 in 12 (7.1%) strains was detected with the agglutination test. Through the Polymerase Chain Reaction (PCR) of F42 positive strains, gene encoding enterotoxins (ST-I, ST-II, LT-I and LT-II) were detected. The finding of ST-I/ST-II genes in 50% of the strains, ST-I (16%) and ST-II (25%) indicates a strong association of FC F42 with heat-stable enterotoxins (91%). In contrast, the thermolabile enterotoxin (LT-I and LT-II) genes were not detected. Serogroups of F42 positive strains were determined, serogroup O8 being the most prevalent (41,7%). Other serogroups, as there are O9, O11, O18, O32, O35, O98 and O101, were also identified. Thus, FC F42 was confirmed as an additional factor of virulence in the pathogenesis of porcine colibacillosis.

Modification of reagents in the EnviroAmp™ kit to increase recovery of Legionella organisms in water

1994 ◽  
Vol 40 (6) ◽  
pp. 495-499 ◽  
Author(s):  
Robin K. Oshiro ◽  
Teresa Picone ◽  
Betty H. Olson
Keyword(s):  
Polymerase Chain Reaction ◽  
Sample Preparation ◽  
Legionella Pneumophila ◽  
Polymerase Chain Reaction Amplification ◽  
Blot Hybridization ◽  
Molecular Techniques ◽  
Chain Reaction ◽  
Colony Forming Units ◽  
Reaction Amplification ◽  
Polymerase Chain

Organisms of the bacterial genus Legionella, commonly found in aqueous reservoirs, have been associated with Legionnaires' disease (legionella pneumonia, caused by Legionella pneumophila) and Pontiac fever (nonpneumonic legionellosis). EnviroAmp™ Legionella sample preparation, polymerase chain reaction amplification, and detection kits (Perkin-Elmer Corp.) were developed for rapid detection of DNA from organisms of the genus Legionella and the species L. pneumophila from environmental water samples. The kits are based on molecular techniques incorporating polymerase chain reaction amplification and detection by reverse dot blot hybridization to particular genus and species probes. The manufacturer states that the EnviroAmp™ Legionella sample preparation, polymerase chain reaction amplification, and detection kits can detect approximately 100 Legionella organisms/mL (10 000 organisms/100 mL) in the original water sample. The sensitivity of the kits was increased to 0.1 colony-forming units/mL (10 colony-forming units/100 mL), at least for cultured organisms, by modifying the EnviroAmp™ Legionella sample preparation kit protocol. Data obtained in this study indicated that sample volume could be increased from 100 to 1000 mL (in the absence of interfering substances such as humic acid) and DNA extraction volume could be decreased from 2 to 0.5 mL to increase the ability of the kit to detect lower numbers of Legionella spp. or L. pneumophila per volume.Key words: Legionella, environment, water, EnviroAmp™ kit.

scholarly journals Prevalence of the genes for shigella enterotoxins 1 and 2 among clinical isolates of shigella in Israel

2002 ◽  
Vol 128 (3) ◽  
pp. 533-535 ◽  
Author(s):  
M. YAVZORI ◽  
D. COHEN ◽  
N. ORR
Keyword(s):  
Escherichia Coli ◽  
Polymerase Chain Reaction ◽  
Vaccine Strain ◽  
Clinical Manifestation ◽  
Large Deletion ◽  
Virulence Plasmid ◽  
Chain Reaction ◽  
Gene Encoding ◽  
Non Invasive ◽  
Polymerase Chain

Two enterotoxins, shigella enterotoxin 1 (SHET1) and shigella enterotoxin 2 (SHET2) have been recently characterized and are believed to play a role in the clinical manifestation of shigellosis. One hundred and twenty-one isolates of Shigella spp. of 13 different serotypes and variants and 10 isolates of enteroinvasive Escherichia coli (EIEC) isolated in Israel, were examined by polymerase chain reaction for the presence of SHET1 and SHET2 genes. SHET1 was only prevalent among isolates of S. flexneri 2a while SHET2 was found in all the serotypes that were tested except for several isolates of S. flexneri 1b that lost their virulence plasmid during storage. In addition, we found that the S. flexneri 2a vaccine strain T-32 Istrati contains the gene encoding for SHET1 but not that encoding for SHET2, suggesting that the latter is located within a large deletion occurring in the 140 Mda plasmid of this S. flexneri 2a non-invasive vaccine strain.

Molecular Analysis of Uropathogenic E.coli Isolates from Urinary Tract Infections

2019 ◽  
Vol 19 (3) ◽  
pp. 322-326 ◽  
Author(s):  
Hassan Valadbeigi ◽  
Elham Esmaeeli ◽  
Sobhan Ghafourian ◽  
Abbas Maleki ◽  
Nourkhoda Sadeghifard
Keyword(s):  
Escherichia Coli ◽  
Polymerase Chain Reaction ◽  
Urinary Tract ◽  
Urinary Tract Infections ◽  
Multiplex Polymerase Chain Reaction ◽  
Virulence Genes ◽  
Uropathogenic Escherichia Coli ◽  
Chain Reaction ◽  
Polymerase Chain ◽  
Tract Infections

Introduction: The aim of the current study was to investigate the prevalence of virulence genes in uropathogenic Escherichia coli (UPEC) isolates in Ilam. Materials and Methods: For this purpose, a total of 80 UPEC isolates were collected for patients with UTIs during a 6 months period. The multiplex polymerase chain reaction (multiplex PCR) was used to detect the papEF, fimH, iucD, hlyA, fyuA, and ompT genes. Results: The prevalence of fimH, papEF, iucD, fyuA, hlyA, hlyA, and ompT genes were 87.5%, 47.5%, 60%, 67.5%, 27.5%, 47.5% and 71.2%, respectively. Among all of the isolates, 27 profiles were obtained. Conclusion: Our findings demonstrated that the most prevalence was found for fimH, and different distribution of virulence genes suggested different ability of pathogenicity.

Diagnostic Accuracy of a Direct Panfungal Polymerase Chain Reaction Assay Performed on Stained Cytology Slides

2021 ◽  
pp. 030098582199156
Author(s):  
Alexandra N. Myers ◽  
Unity Jeffery ◽  
Zachary G. Seyler ◽  
Sara D. Lawhon ◽  
Aline Rodrigues Hoffmann
Keyword(s):  
Polymerase Chain Reaction ◽  
Diagnostic Accuracy ◽  
Molecular Techniques ◽  
Fungal Culture ◽  
Chain Reaction ◽  
Identification Of Fungi ◽  
Fungal Dna ◽  
Polymerase Chain ◽  
Panfungal Pcr ◽  
Pcr Targeting

Molecular techniques are increasingly being applied to stained cytology slides for the diagnosis of neoplastic and infectious diseases. Such techniques for the identification of fungi from stained cytology slides have not yet been evaluated. This study aimed to assess the diagnostic accuracy of direct (without nucleic acid isolation) panfungal polymerase chain reaction (PCR) followed by sequencing for identification of fungi and oomycetes on stained cytology slides from dogs, cats, horses, and other species. Thirty-six cases were identified with cytologically identifiable fungi/oomycetes and concurrent identification via fungal culture or immunoassay. Twenty-nine controls were identified with no cytologically or histologically visible organisms and a concurrent negative fungal culture. Direct PCR targeting the internal transcribed spacer region followed by sequencing was performed on one cytology slide from each case and control, and the sensitivity and specificity of the assay were calculated. The sensitivity of the panfungal PCR assay performed on stained cytology slides was 67% overall, 73% excluding cases with oomycetes, and 86% when considering only slides with abundant fungi. The specificity was 62%, which was attributed to amplification of fungal DNA from control slides with no visible fungus and negative culture results. Direct panfungal PCR is capable of providing genus- or species-level identification of fungi from stained cytology slides. Given the potential of panfungal PCR to amplify contaminant fungal DNA, this assay should be performed on slides with visible fungi and interpreted in conjunction with morphologic assessment by a clinical pathologist.

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