INFEKSI OPORTUNISTIK TINEA CAPITIS PADA PENDERITA PEDICULOSIS CAPITIS

Pediculosis capitis merupakan penyakit infeksi pada kulit kepala manusia yang disebabkan oleh infestasi ektoparasit Pediculus humanus capitis yang dapat menular di kepala tanpa disadari karena kontak erat di lingkungan yang sama seperti asrama pesantren. Di kepala penderita pediculosis ditemukan banyak lesi pada kulit, rambut saling melekat, bintik-bintik hitam atau coklat pada pangkal rambut, radang pada kulit kepala serta eksudat nanah yang berasal dari luka gigitan Pediculus humanus capitis yang meradang. Infeksi sekunder berupa tinea capitis dapat menyerang penderita pediculosis. Infeksi ini disebabkan dermatofita genus Microsforum sp dan Trichophyton sp. Penelitian ini bertujuan untuk mengetahui jenis jamur penyebab tinea capitis pada kulit kepala santriwati pesantren di Makassar. Jenis penelitian yang digunakan adalah penelitian deskriptif dengan mengkultur spesimen pada media Sabouraud Dextrose Agar (SDA) dan dilanjutkan dengan identifikasi jamur. Hasil penelitian dari 10 sampel menunjukkan bahwa 1 sampel terinfeksi Microsporum audouinii.

Real-Time PCR Assay for the Detection of Dermatophytes: Comparison between an In-House Method and a Commercial Kit for the Diagnosis of Dermatophytoses in Patients from Dakar, Senegal

Background. PCR assays have been developed for the diagnosis of dermatophytes, yet data in African populations are scarce. Objective. This study aimed to compare two PCR assays for the diagnosis of dermatophytosis in outpatients at the Aristide Le Dantec University Hospital in Dakar, Senegal. Patients and methods. A total of 105 samples, including 24 skin, 19 nail and 62 hair samples collected from 99 patients were included in this study. Each sample was subjected to conventional diagnosis (CD), including direct microscopy and culture, and two real-time PCR assays: one in-house (IH)-PCR, used at the University Hospital of Marseille and the Eurobio Scientific commercial kit (CK): designed for the specific detection of six dermatophytes not including Microsporum audouinii. Results. Of the 105 specimens, 24.8%, 36.2% and 20% were positive by CD, IH-PCR and CK-PCR, respectively. The IH-PCR and CK-PCR exhibited 88.9% and 65.4% sensitivity, respectively. With a 36.6 diagnostic odd ratio and 1.41 needed to diagnose, the IH-PCR displayed better diagnostic indices than the CK-PCR. It is notable that, when considering the species that it claims to detect, when it came to skin and nail samples, CK-PCR sensitivity increased to 77%. Conclusions. The pan-dermatophyte IH-PCR performed better in the diagnosis of dermatophytosis in this African population than the CK-PCR, which is not designed to detect M. audouinii. Nevertheless, both assays exhibited similarly good diagnostic indices for tinea corporis and tinea unguium, both of which are localisations where M. audouinii is more rarely involved than in tinea capitis.

Molecular Characterisation and Phylogenetic Analysis of Dermatophytic Fungi Isolated from Tinea Capitis in Northwest Nigeria Using Sequence of the 28S rRNA

The detection and identification of fungal DNA from clinical samples is one of the fundamental approaches in biomedicine. The incidence, distribution, and control of dermatophytes has progress significantly and the use of phylogenetic species concepts based on rRNA regions have enhanced the taxonomy of dermatophyte species; however, the use of 28S rDNA genes has certain limitations. This gene has been used in dermatophyte taxonomy with limited enumeration; we appraised the sequence disparity within and among groups of the species, the gene ranking in identification, phylogenetic analysis, and taxonomy of 32 strains of eight dermatophyte species. In this study, a set of primers was adopted to amplify the target followed by a partial sequencing of the rDNA. The utilization of a pairwise nucleotide differentiation, an affinity was observed among eight dermatophyte species, with disparity among species ranging from 0 to 197 base pair (bp). Intra-species bp differences were found within strains of Trichophyton eriotrephon, Trichophyton bullosum, Trichophyton simii (Trichophyton genus), Microsporum audouinii, and Trichophyton tonsurans (Microsporum and Trichophyton genus, respectively); however, only some strains of Trichophyton eriotrephon were found to be invariant having three genotypes. Trichophyton tonsurans exhibited most intra-species variability. The characterization and construction of a phylogenetic tree of 28S rDNA gene on dermatophyte species provide a bedrock of an additional finding of connections between species. However, 28S rRNA capture provides a novel method of effective and sensitive detection of dermatophytes lodged in human skin scale. We report for the first time the emergence of T. eriotrephon, T. bullosum, T. simii, T. benhamiae, and Ctenomyces serratus dermatophytes from Tinea capitis in Nigeria.

Phytochemical analysis and antifungal property of Mallotus oppositifolius (Geiseler) Müll.Arg. (Euphorbiaceae)

The emergence of resistant fungi to available drugs highlights the need for new antifungal drugs. The present study aimed to evaluate the antifungal activity of the isolated compounds, fractions and crude extract from the leaf of Mallotus oppositifolius (Geiseler) Müll. Arg. Three pure compounds labelled 1-3 were isolated from the methylene chloride / methanol (1/1) extract of the leaf of this plant using chromatography techniques. These compounds were identified using analytical spectroscopic methods as betulinic acid (1), quercetine (2) and quercitin (3). The crude extract, fractions and compounds were tested against pathogenic yeasts (Candida albicans, Candida glabrata, Candida krusei) and dermatophytes (Trichophyton rubrum, Trichophyton soudanense, Microsporum audouinii, Microsporum langeronii) using agar well diffusion and dilution methods. The safety of the crude extract was studied on Wistar rats according to the WHO guidelines. The minimal inhibitory concentration (MIC) values ranged from 48 to 781 μg/ml against yeasts for crude extract and fractions, and 1.86 to 25000 μg/ml against dermatophytes for pure compounds, fractions and crude extract. The antifungal activity of pure compounds was not determined against yeasts. The crude extract of leaf was found to be safe in rat at up to 12 g/kg. The results achieved supported the traditional use of Mallotus oppositifolius leaf for the treatment of fungal infections.Keywords: Mallotus oppositifolius, antifungal activity, safety, phytochemical screening.

Kerion celsi due to Microsporum audouinii: a severe form in an immunocompetent girl

A 9-year-old girl presented a large inflammatory cup-shaped scalp lesion with alopecia surrounded by pustules, dander, and suppuration associated with an occipital inflammatory lymphadenopathy for 1 month. Wood’s light exam was positive as well as KOH mount showing ectothrix type hair involvement. Hair and pus culture on Sabouraud dextrose agar (SDA) added with chloramphenicol and supplemented with cycloheximide isolated a dermatophyte species identified as Microsporum audouinii according to the colonies features. Species identification was confirmed by matrix-assisted laser desorption-ionization–time of flight mass spectrometry (MALDI–TOF MS) and the patient was treated for kerion celsi with terbinafine tablets 125 mg per day associated with a ketoconazole-based shampoo. The evolution was favorable, with hair regrowth after 2 months.

Belgian National Survey on Tinea Capitis: Epidemiological Considerations and Highlight of Terbinafine-Resistant T. mentagrophytes with a Mutation on SQLE Gene

Background: In this last decade, a huge increase in African anthropophilic strains causing tinea capitis has been observed in Europe. The Belgian National Reference Center for Mycosis (NRC) conducted a surveillance study on tinea capitis in 2018 to learn the profile of circulating dermatophytes. Methods: Belgian laboratories were invited to send all dermatophyte strains isolated from the scalp with epidemiological information. Strain identification was confirmed by ITS (Internal Transcribed Spacer) sequencing. Mutation in the squalene epoxidase (SQLE) gene was screened by PCR. Results: The main population affected by tinea capitis was children from 5–9 years. Males were more affected than females. The majority of the strains were collected in the Brussels area followed by the Liege area. Among known ethnic origins, African people were more affected by tinea capitis than European people. The major aetiological agent was Microsporum audouinii, followed by Trichophyton soudanense. One strain of Trichophyton mentagrophytes has been characterized to have a mutation on the squalene epoxidase gene and to be resistant to terbinafine. Conclusions: African anthropophilic dermatophytes are mainly responsible for tinea capitis in Belgium. People of African origin are most affected by tinea capitis. The monitoring of terbinafine resistance among dermatophytes seems necessary as we have demonstrated the emergence of resistance in T. mentagrophytes.

A new molecular marker for species-specific identification of Microsporum canis

Species identification of dermatophytes by conventional mycological methods based on macro- and microscopy analysis is time-consuming and has a lot of limitations such as slow fungal growth or low specificity. Thus, there is a need for the development of molecular methods that would provide reliable and prompt identification of this group of medically important fungi. The are many reports in the literature concerning PCR identification of dermatophyte species, but still, there are not many PCR assays for the separate detection of members of the genera Microsporum, especially Microsporum canis (zoophilic species) and Microsporum audouinii (anthropophilic species). The correct distinction of these species is important to determine the source of infection to implement the appropriate action to eliminate the path of infection transmission. In this paper, we present such a PCR-based method targeting velB gene that uses a set of two primers—Mc-VelB-F (5′-CTTCCCCACCCGCAACATC-3′) and Mc-VelB-R (5′-TGTGGCTGCACCTGAGAGTGG-3′). The amplified fragment is specific due to the presence of (CAGCAC)8 microsatellite sequence only in the velB gene of M. canis. DNA from 153 fungal samples was used in PCR assay followed by electrophoretic analysis. The specificity of the designed set of primers was also confirmed using the online BLAST-Primer tool. The positive results were observed only in the case of M. canis isolates, and no positive results were obtained neither for other dermatophytes and non-dermatophyte fungi nor for other Eukaryotes, including the human genome sequence, as well as the representatives of bacterial and viral taxa. The developed PCR assay using the proposed Mc-VelB-F and Mc-velB-R primers can be included in the algorithm of M. canis detection in animals and humans.

A Comparative Study on Phenotypic versus ITS-Based Molecular Identification of Dermatophytes Isolated in Dakar, Senegal

Classically, dermatophytes are identified by phenotypic methods even if these methods, sometimes, remain difficult or uncertain. On the other hand, nucleotide sequence analysis of internal transcribed spacers (ITS) of rDNA has proved to be a useful method for identification of dermatophytes. The objective of this study was to compare the phenotypic method with DNA sequencing of the ITS regions for identification of dermatophyte species isolated in Dakar, Senegal. A collection of thirty-two strains of dermatophytes were isolated from patients suffering from dermatophytosis. Mycological identification revealed Trichophyton soudanense (n = 13), T. interdigitale (n = 10), Microsporum audouinii (n = 5), and one strain for each of the following species: T. rubrum, T. mentagrophytes, and M. canis and one unidentified strain. For comparison, ITS-based PCR and DNA sequencing were applied for identification of the isolated dermatophytes. ITS sequences showed, in BLAST search analysis, 99-100% of similarity. Identification of dermatophyte isolates by conventional methods was confirmed by DNA sequencing of the ITS regions in 84% of cases. Discrepancies concern mostly T. rubrum misidentified as T. interdigitale. PCR sequencing provided an excellent tool for identifying dermatophyte strains that do not present typical morphological characteristics. It was also able to give correct identification of an atypical strain of M. audouinii responsible of mycetoma of the scalp.