Navarro-Pérez D, García-Oreja S, Tardáguila-García A, León-Herce D, Álvaro-Afonso FJ, Lázaro-Martínez JL. Microbiological culture combined with PCR for the diagnosis of onychomycosis: Descriptive analysis of 121 patients.
Mycoses 2023;
66:1045-1049. [PMID:
37574461 DOI:
10.1111/myc.13648]
[Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2023] [Revised: 07/28/2023] [Accepted: 08/04/2023] [Indexed: 08/15/2023]
Abstract
BACKGROUND
Onychomycosis is the most common nail pathology, involving various pathogens such as dermatophytes, moulds and yeasts.
OBJECTIVE
The objective of this study was to observe the prevalence of onychomycosis, analyse the most appropriate diagnostic test, and assess the distribution of pathogens based on age, sex, quarter of the year, duration of symptoms and previous treatment.
METHODS
Retrospectively, mycological culture and PCR data and results were collected from 121 patients.
RESULTS
Of the 121 samples, 57% (69/121) tested positive when both microbiological study techniques were combined. The prevalence of onychomycosis was higher when PCR was performed (52.1%) compared to microbiological culture (33.1%). Among the 81 samples negative by microbiological culture, 31 were positive by PCR. Similarly, of the 58 samples negative by PCR, eight were positive by microbiological culture. Diagnostic accuracy data (with 95% confidence intervals) for PCR, using microbiological culture as the gold standard, were as follows: sensitivity of 0.8, specificity of 0.62, positive predictive value of 0.51 and negative predictive value of 0.86. The most frequently identified pathogen was Trichophyton rubrum, and the hallux nail plate was the most commonly affected location. However, no statistically significant associations were found between sex, age, quarter of the year and affected area with culture and PCR results.
CONCLUSION
Combining microbiological culture and PCR can increase the detection rate of onychomycosis and help avoid false-negative results.
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