Experimental white piedra: a robust approach to ultrastructural analysis, scanning electron microscopy and etiological discoveries

Inácio, Cícero Pinheiro; Rocha, Ana Paula Santiago; Barbosa, Renan do Nascimento; Oliveira, Neiva Tinti de; Silva, Josineide C.; Lima-Neto, Reginaldo Gonçalves de; Macêdo, Danielle Patrícia Cerqueira; Neves, Rejane Pereira

doi:10.1111/exd.12884

Cited by 11 publications

(5 citation statements)

References 16 publications

(21 reference statements)

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…In electron microscopy studies, a well-organized mass of microorganisms is observed, sometimes with a bacterial coating that probably helps to establish the nodule and that it is mainly constituted by Corynebacterium sp. and other constituent microorganisms of the microbiota [4, 13-15]. In our study, an association with S. aureus was verified in 2 cases.…”

Section: Discussionsupporting

confidence: 58%

White Piedra: Clinical, Mycological, and Therapeutic Experience of Fourteen Cases

Bonifáz¹,

Tirado‐Sánchez²,

Santibáñez³

et al. 2018

Skin Appendage Disord

View full text Add to dashboard Cite

Background: White piedra (WP) is an asymptomatic superficial mycosis that affects the hair stems, forming whitish nodules caused by various species of the genus Trichosporon. Objective: To present a case series of WP of the head, its epidemiological data, as well as clinical, mycological, and therapeutic experience. Methods: We conducted a 12-year retrospective and observational study of WP cases tested by dermoscopy, mycological study, and the identification of species through morphology, biochemistry, and proteomics (matrix-assisted laser desorption/ionization time-of-flight mass spectrometry). The treatment was based on ketoconazole shampoo as well as keratolytics. Results: We included 14 cases of WP, all located in the head and 1 case with both head and scrotum affected. Nine cases (64.3%) presented in children aged < 15 years. The majority of the cases (13/14, 92.8%) were women. Two cases were associated with hyperkeratosis and intertrigo. Most patients had long hair and excessive moisture. In all cases hair nodules were observed and Trichosporon inkin (11/14, 78.6%) was usually isolated. Eleven cases (78.6%) were cured by administering 2% ketoconazole shampoo. Conclusion: WP was observed in school-age girls. The diagnosis was based on the observation of hair nodules and its main etiologic agent was T. inkin, with good response to treatment in most cases.

show abstract

Section: Discussionsupporting

confidence: 58%

White Piedra: Clinical, Mycological, and Therapeutic Experience of Fourteen Cases

Bonifáz¹,

Tirado‐Sánchez²,

Santibáñez³

et al. 2018

Skin Appendage Disord

View full text Add to dashboard Cite

show abstract

“…Biochemical analysis of white piedra nodules has shown them to be composed of carbon, oxygen, sodium, and magnesium. The nodules of black piedra have sulphur in addition, which could be responsible for their hardness [7].…”

Section: Discussionmentioning

confidence: 99%

White Piedra: An Uncommon Superficial Fungal Infection of Hair

Gaurav

Grover

Das

et al. 2021

Skin Appendage Disord

View full text Add to dashboard Cite

White piedra is a superficial fungal infection of hair caused by Trichosporon species. It presents clinically as white nodules encasing the hair shafts and may lead to increased fragility. It can usually be differentiated easily from clinically similar conditions based on clinical and microbiologic features. We report a case of white piedra of scalp hair in a 32-year-old female caused by T. ovoides, diagnosed using clinical, trichoscopic, microbiologic and molecular methods. In this case, trichoscopy acted as an interface between clinical and microbiologic examination, obviating the need for hair shaft microscopy. The genus Trichosporon contains 6 species of clinical significance viz., T. asahii, T. asteroides, T. cutaneum, T. inkin, T. mucoides, and T. ovoides, which cannot be differentiated based on their morphologic characteristics. A genotypic identification using molecular methods helped determine the causative species. It was treated successfully with oral itraconazole and topical ketoconazole.

show abstract

“…The DNA was extracted according to Inácio et al, (2016), where the biological samples were transferred to extraction tubes containing a glass bead matrix and 500µL of the extraction buffer (CTAB 2%, NaCl 1.5 M, 100mM Tris-HCl , 20mM EDTA, 1% polyvinylpyrrolidone) previously heated to 65°C. After extraction, the DNA products were assembled in parafilm (5µL of the extraction product, 2µL GLB and 2 µL GelRed), using the Lambda DNA marker as standard.…”

Section: Species-specific Diagnosismentioning

confidence: 99%

Epidemiology and antifungal susceptibility patterns of Candida species in tertiary hospitals: Update on regional trends

Inácio

Beserra

Soares

et al. 2021

RSD

View full text Add to dashboard Cite

Trends in epidemiology and antifungal susceptibility of Candida species in Brazil between 2019–2020 are reported. A total of 22 isolates diagnosed from candidemia episodes were analyzed. Candida species were identified by specie specific primer and/or sequencing of 28S rDNA. Antifungal susceptibility was determined by CLSI method. C. tropicalis accounted for 11 (50%) cases followed by C. albicans (n=5, 22.73%), C. parapsilosis (n=4, 18.19%), Issatchenkia orientalis (n= 1, 4.54%), and Saccharomyces cerevisiae (n= 1, 4.54%). All Candida isolates were susceptible to amphotericin B and micafungin, and one was dose-dependent to anidulafungin. Eight of 20 Candida isolates were resistant to fluconazole and four sensitive doses dependent. Sixteen of 20 Candida isolates were resistant to voriconazole, and one resistant and one sensitive dose-dependent on caspofungin. Besides, the respective MIC50 and MIC90 values were calculated with fluconazole (MIC50 and MIC90 of 4 and 64µg/mL, respectively) and voriconazole (MIC50 and MIC90 of 16µg/mL) showing the lowest potencies. The spread of fluconazole-resistant in one of major concerns, especially to C. tropicalis. The high use of antifungal drug may be a possible cause related to this scenario. Thus, the susceptibility profile test may be used to know the best way to introduce appropriateness empirical antibiotics therapy. Changing trends in incidence and antifungal susceptibility patterns of six Candida species causing candidemia in Kuwait between 2006–2017 are reported. A total of 2075 isolates obtained from 1448 patients were analyzed. Identity of Candida species isolates was determined by phenotypic methods and confirmed by PCR amplification/PCR-sequencing of rDNA and/or MALDI-TOF MS. Antifungal susceptibility was determined by Etest. C. albicans accounted for 539 (37.22%) cases followed by C. parapsilosis (n = 502, 34.67%), C. tropicalis (n = 210, 14.5%), C. glabrata (n = 148, 10.22%), C. krusei (n = 27, 1.81%) and C. dubliniensis (n = 22, 1.5%). The comparative percent distribution of Candida species causing candidemia between 2006–2011 and 2012–2017 was as follows: C. albicans 41.8% and 33.1%, C. parapsilosis complex 32.01% and 37.04%, C. tropicalis 13.59% and 15.31%, and C. glabrata 8.77% and 11.51%, C. krusei 2.0% and 1.7%, and C. dubliniensis 1.75 and 1.3%, respectively. Three of 371 C. albicans isolates during 2006–2011 and five of 363 during 2012–2017 were resistant to fluconazole. Among C. parapsilosis isolates, one of 310 during 2006–2011 and 21 of 446 during 2012–2017 were resistant to this drug. Furthermore, at an epidemiologic cutoff value (ECV) of ≤0.5 μg/ml, 70.1% C. albicans isolates were wild-type for fluconazole during 2006–2011 as compared to 58.1% during 2012–2017. Likewise, at an ECV of ≤2 μg/ml, 98.0% of C. parapsilosis isolates were wild-type during 2006–2011 as compared to 93.4% during 2012–2017. Clonal spread of fluconazole-resistant C. parapsilosis in one major hospital was documented. An 8.8% shift in favor of non-albicans Candida species with concomitant increase in MICs between the two periods preludes emergence of fluconazole-resistant candidemia cases in Kuwait.Changing trends in incidence and antifungal susceptibility patterns of six Candida species causing candidemia in Kuwait between 2006–2017 are reported. A total of 2075 isolates obtained from 1448 patients were analyzed. Identity of Candida species isolates was determined by phenotypic methods and confirmed by PCR amplification/PCR-sequencing of rDNA and/or MALDI-TOF MS. Antifungal susceptibility was determined by Etest. C. albicans accounted for 539 (37.22%) cases followed by C. parapsilosis (n = 502, 34.67%), C. tropicalis (n = 210, 14.5%), C. glabrata (n = 148, 10.22%), C. krusei (n = 27, 1.81%) and C. dubliniensis (n = 22, 1.5%). The comparative percent distribution of Candida species causing candidemia between 2006–2011 and 2012–2017 was as follows: C. albicans 41.8% and 33.1%, C. parapsilosis complex 32.01% and 37.04%, C. tropicalis 13.59% and 15.31%, and C. glabrata 8.77% and 11.51%, C. krusei 2.0% and 1.7%, and C. dubliniensis 1.75 and 1.3%, respectively. Three of 371 C. albicans isolates during 2006–2011 and five of 363 during 2012–2017 were resistant to fluconazole. Among C. parapsilosis isolates, one of 310 during 2006–2011 and 21 of 446 during 2012–2017 were resistant to this drug. Furthermore, at an epidemiologic cutoff value (ECV) of ≤0.5 μg/ml, 70.1% C. albicans isolates were wild-type for fluconazole during 2006–2011 as compared to 58.1% during 2012–2017. Likewise, at an ECV of ≤2 μg/ml, 98.0% of C. parapsilosis isolates were wild-type during 2006–2011 as compared to 93.4% during 2012–2017. Clonal spread of fluconazole-resistant C. parapsilosis in one major hospital was documented. An 8.8% shift in favor of non-albicans Candida species with concomitant increase in MICs between the two periods preludes emergence of fluconazole-resistant candidemia cases in Kuwait.

show abstract

Experimental white piedra: a robust approach to ultrastructural analysis, scanning electron microscopy and etiological discoveries

Cited by 11 publications

References 16 publications

White Piedra: Clinical, Mycological, and Therapeutic Experience of Fourteen Cases

White Piedra: Clinical, Mycological, and Therapeutic Experience of Fourteen Cases

White Piedra: An Uncommon Superficial Fungal Infection of Hair

Epidemiology and antifungal susceptibility patterns of Candida species in tertiary hospitals: Update on regional trends

Contact Info

Product

Resources

About