Detection Methods for Microsporum canis and Trichophyton

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Questions and Answers

Which method is used for the phylogenetic classification of dermatophytes based on DNA sequences?

Loop-mediated isothermal amplification

Quantitative real-time PCR

Chitin synthase gene analysis

Internal transcribed spacer sequencing (correct)

What is a critical application of polymerase chain reaction (PCR) in mycology?

Epidemiological studies of fungal infections

Antifungal susceptibility testing

Identification of dermatophyte species (correct)

Clinical specimen culture

Which technique is NOT typically used for detecting dermatophytes?

Microbial fermentation (correct)

Real-time quantitative PCR

Classical culture methods

Loop-mediated isothermal amplification

Which of the following is a focus of molecular epidemiology in dermatophytes?

Phylogenetic relationships Signup and view all the answers

What does the comparative evaluation of inoculum preparation methods aim to improve?

Accuracy of antifungal susceptibility results Signup and view all the answers

Which of the following is a primary benefit of using quantitative PCR in the detection of fungi?

Sensitivity and specificity Signup and view all the answers

Which gene analysis is specifically associated with dermatophytes?

Chitin synthase gene Signup and view all the answers

What advantage do loop-mediated isothermal amplification (LAMP) methods provide in clinical diagnostics?

Rapid diagnosis without thermal cycling Signup and view all the answers

What is one significant disadvantage of classical mycological culturing?

It depends on well-trained personnel. Signup and view all the answers

Which molecular method is NOT mentioned for rapid detection of dermatophytes?

Reverse transcription PCR Signup and view all the answers

Which of the following fungal species was present in the validation studies?

Candida albicans Signup and view all the answers

How long does classical mycological culturing typically take to yield results?

10-14 days Signup and view all the answers

What type of DNA extraction kit was used for fungal strain extraction?

Quick-DNA Fungal/Bacterial Miniprep kit Signup and view all the answers

What is one function of molecular methods in fungal diagnosis?

Detecting virulence and antifungal resistance genes. Signup and view all the answers

What is one possible result of misdiagnosis during fungal evaluation?

Misleading treatment decisions. Signup and view all the answers

Which advantage does molecular diagnosis have over classical mycological culturing?

It reduces reliance on subjective evaluation. Signup and view all the answers

Which method is suggested as an alternative for laboratory detection of dermatophyte fungi?

LAMP method Signup and view all the answers

What does PCR stand for in the context of fungal identification?

Polymerase Chain Reaction Signup and view all the answers

What type of diagnostic feature is emphasized for canine and feline dermatophytosis in the study?

Epidemiological and diagnostic features Signup and view all the answers

Which of the following techniques is NOT mentioned in the detection or identification of dermatophyte fungi?

Ultrasonic imaging Signup and view all the answers

Which application is mentioned as a method to distinguish common species of dermatophytes?

Simple genomic DNA extraction Signup and view all the answers

What aspect of fungal strains is addressed with quantitative real-time PCR?

Antifungal resistance detection Signup and view all the answers

What is the primary advantage of using multiplex qPCR for dermatophyte diagnosis?

It can identify multiple species simultaneously. Signup and view all the answers

Which method is known for colorimetric detection of loop-mediated isothermal amplification?

Hydroxy naphthol blue Signup and view all the answers

Study Notes

Detection of Microsporum canis and Trichophyton mentagrophytes

Background: Dermatophytes are infectious zoonotic fungal agents common in animals. LAMP (Loop-mediated isothermal amplification) and qPCR (quantitative PCR) are new methods for identifying these fungi. They are highly specific and sensitive, and quick.
Hypothesis/Objectives: To create a LAMP and qPCR method to detect the common fungal species Microsporum canis and Trichophyton mentagrophytes in cats and dogs.
Material and Methods: Both methods targeted the CHS-1 gene. Specificity and sensitivity were tested using 64 M. canis and 44 T. mentagrophytes field strains. Validation was performed using 250 clinical fungal-positive hair samples.
Results:
- Specificity was 100% for both methods.
- LAMP sensitivity: 96.9% for M. canis and 93.2% for T. mentagrophytes.
- qPCR sensitivity: 98.4% for M. canis and 97.7% for T. mentagrophytes.
- Similar specificity and sensitivity results were obtained with the validation study.
- LAMP and multiplex qPCR took 30 and 45 minutes, respectively.
- Limit of detection (LOD): 10 and 1 spores/mL for LAMP and multiplex qPCR, respectively.
Conclusion: Developed LAMP and multiplex qPCR methods, targeting the CHS-1 gene, can be used for rapid point-of-care testing and laboratory detection of M. canis and T. mentagrophytes. The methods have high specificity and sensitivity, with an internal control.

Introduction

Dermatophytes are a fungal group infecting skin, hair, hooves, nails, horns, etc.
The genera are Microsporum, Trichophyton, and Epidermophyton.
Common species include M. canis, N. gypsea, T. verrucosum, M. equinum, T. mentagrophytes,.
M. canis and T. mentagrophytes are frequent in cats and dogs, having zoonotic importance (transfer to humans).

Additional notes (from the body of the article)

Clinical diagnosis of T. mentagrophytes and M. canis uses direct microscopic hair examination and mycological culture.
Classical mycological culturing has limitations: slow, subjective, and requires skilled personnel. Molecular methods are better alternatives.
Many gene regions varying in specificity and sensitivity can be used for molecular diagnosis of dermatophytes. The CHS-1 gene is highly conserved for T. mentagrophytes and M. canis.

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Description

This quiz explores the detection methods for the dermatophytes Microsporum canis and Trichophyton mentagrophytes using LAMP and qPCR techniques. It covers the background, objectives, methodologies, and results of sensitivity and specificity in identifying these fungal species in cats and dogs.