Molecular Strain Typing Using Repetitive Sequence–Based PCR

Abstract Objective The aim of this study was to identify and isolate Trichosporon asahii (T. asahii) from clinical samples and to assess the genetic relatedness of the most frequently isolated strains of T. asahii using random amplification of polymorphic DNA (RAPD) primers GAC-1 and M13. Methods All the clinical samples that grew Trichosporon species, identified and confirmed by polymerase chain reaction (PCR) using Trichosporon genus-specific primers, were considered for the study. Confirmation of the species T. asahii was carried out by T. asahii-specific PCR. Fingerprinting of the most frequently isolated T. asahii isolates was carried out by RAPD using random primers GAC-1 and M13. Results Among the 72 clinical isolates of Trichosporon sp. confirmed by Trichosporon-specific PCR, 65 were found to be T. asahii as identified by T. asahii-specific PCR. Fingerprinting of the 65 isolates confirmed as T. asahii using GAC-1 RAPD primer yielded 11 different patterns, whereas that of M13 primer produced only 5 patterns. The pattern I was found to be the most predominant type (29.2%) followed by pattern III (16.9%) by GAC-1 primer. Conclusions This study being the first of its kind in India on strain typing of T. asahii isolates by adopting RAPD analysis throws light on genetic diversity among the T. asahii isolates from clinical samples. Fingerprinting by RAPD primer GAC-1 identified more heterogeneity among the T. asahii isolates than M13.

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Techniques in bacterial strain typing

Current Opinion in Infectious Diseases ◽

10.1097/qco.0000000000000743 ◽

2021 ◽

Vol Publish Ahead of Print ◽

Author(s):

Shelby R. Simar ◽

Blake M. Hanson ◽

Cesar A. Arias

Keyword(s):

Bacterial Strain ◽

Strain Typing

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Comparison of Whole Genome Sequencing and Repetitive Element PCR for Multidrug- Resistant Pseudomonas aeruginosa Strain Typing

Journal of Molecular Diagnostics ◽

10.1016/j.jmoldx.2021.10.004 ◽

2021 ◽

Author(s):

Jennifer K. Spinler ◽

Sabeen Raza ◽

Santosh Thapa ◽

Alamelu Venkatachalam ◽

Tiana Scott ◽

...

Keyword(s):

Pseudomonas Aeruginosa ◽

Whole Genome Sequencing ◽

Genome Sequencing ◽

Repetitive Element ◽

Multidrug Resistant ◽

Whole Genome ◽

Strain Typing

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Analysis of repetitive transient response of lobster motor axons

American Journal of Physiology-Legacy Content ◽

10.1152/ajplegacy.1960.199.2.367 ◽

1960 ◽

Vol 199 (2) ◽

pp. 367-372

Author(s):

W. J. Adelman ◽

E. Pautler ◽

S. Epstein

Keyword(s):

Repetitive Sequence ◽

Spike Timing ◽

Constant Current ◽

Intensity Increase ◽

Transient Phase ◽

Intensity Data ◽

Probability Level ◽

Excitation Process ◽

Excitatory State ◽

Repetitive Discharge

An analysis was made to determine the relation between spike timing and the intensity of a constant current evoking a repetitive discharge in the single lobster motor axon. Accurate measurements of repetition intervals during the transient phase showed that an intensity increase of about 10–3 rheobase units produces a significantly different change in spike interval timing at the 0.005 probability level. Applications of excitation theory to the latency-intensity data have produced an equation which predicts the latency to the nth spike in a repetitive sequence as a function of stimulus intensity. The equation implies that the excitation process producing the nth spike is similar to the process producing the first spike in the repetitive sequence. Influences of supernormality and refractoriness were incorporated into the analysis. Also repeated stimulation at a fixed intensity indicated an inherent variability in the timing of the repetitive response which was shown to be a function of the magnitude of the latency. To explain this result a fixed uncertainty in the level of the initiating excitatory state was postulated.

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