Taxonomy of the Trichophyton mentagrophytes/T. interdigitale Species Complex Harboring the Highly Virulent, Multiresistant Genotype T. indotineae.

A severe outbreak of highly virulent and multi-resistant dermatophytosis by species in the Trichophyton mentagrophytes/T. interdigitale complex is ongoing in India. The correct identity of the etiologic agent is a much-debated issue. In order to define species limits, a taxonomic study was undertaken combining molecular, morphological, and physiological characteristics as evidence of classification. Molecular characteristics show that T. mentagrophytes s. str. and T. interdigitale s. str. can be distinguished with difficulty from each other, but are unambiguously different from the Indian genotype, T. indotineae by sequences of the HMG gene. The entities were confirmed by multilocus analysis using tanglegrams. Phenotypic characters of morphology and physiology are not diagnostic, but statistically significant differences are observed between the molecular siblings. These properties may be drivers of separate evolutionary trends. Trichophyton mentagrophytes represents the ancestral, homothallic cloud of genotypes with a probable geophilic lifestyle, while T. indotineae and T. interdigitale behave as anthropophilic, clonal offshoots. The origin of T. indotineae, which currently causes a significant public health problem, is zoonotic, and its emergence is likely due to widespread misuse of antifungals.

Early versus delayed antiretroviral therapy and cerebrospinal fluid fungal clearance in adults with HIV and cryptococcal meningitis.

BACKGROUND: The burden of Cryptococcus neoformans in cerebrospinal fluid (CSF) predicts clinical outcomes in human immunodeficiency virus (HIV)-associated cryptococcal meningitis (CM) and is lower in patients on antiretroviral therapy (ART). This study tested the hypothesis that initiation of ART during initial treatment of HIV/CM would improve CSF clearance of C. neoformans. METHODS: A randomized treatment-strategy trial was conducted in Botswana. HIV-infected, ART-naive adults aged≥21 years initiating amphotericin B treatment for CM were randomized to ART initiation within 7 (intervention) vs after 28 days (control) of randomization, and the primary outcome of the rate of CSF clearance of C. neoformans over the subsequent 4 weeks was compared. Adverse events, including CM immune reconstitution inflammatory syndrome (CM-IRIS), and immunologic and virologic responses were compared over 24 weeks. RESULTS: Among 27 subjects enrolled (13 intervention and 14 control), [corrected] the median times to ART initiation were 7 (interquartile range [IQR], 5­10) and 32days (IQR, 28­36), respectively. The estimated rate of CSF clearance did not differ significantly by treatment strategy (-0.32 log10 colony-forming units [CFU]/mL/day±0.20 intervention and -0.52 log10 CFUs/mL/day (±0.48) control, P=.4). Two of 13 (15%) and 5 of 14 (36%) subjects died in the intervention and control arms, respectively (P=0.39). Seven of 13 subjects (54%) in the intervention arm vs 0 of 14 in the control arm experienced CM-IRIS (P=.002). CONCLUSIONS: Early ART was not associated with improved CSF fungal clearance, but resulted in a high risk of CM-IRIS. Further research on optimal incorporation of ART into CM care is needed. CLINICAL TRIALS REGISTRATION: NCT00976040.

Tinea universalis due to Trichophyton indotineae in an adult male.

Tinea universalis is a condition when most of the anatomical sites of body are involved due to dermatophyte infection both in immunocompetent and immunocompromised individuals. Here we present a case of tinea universalis due to Trichophyton indotineae (T. indotineae) from India. This species has emerged recently. Earlier, it has been reported as Trichophyton mentagrophytes (T. mentagrophytes) and Trichophyton interdigitale (T. interdigitale). T. indotineae has been associated with outbreaks and epidemics of chronic, recalcitrant, and nonresponsive to terbinafine, in India and several other countries. The patient was prescribed Itraconazole (200 mg/day), Luliconazole cream topically and antihistamine at night, with marked improvement clinically. Easy availability and misuse of corticosteroids cream, as over-the-counter drug, should be discouraged.

Cutaneous cryptococcosis in an adult male of sub-saharan origin.

Cryptococcosis is caused by the inhalation of the desiccated encapsulated yeast or basidiospores, which are found in the environment. After the infectious particles reach the lungs, get disseminated hematogenously in various organs. Meningoencephalitis is one of the most common manifestations, especially in sub-Saharan Africa. The dermal lesions can be either primary due to the traumatic implantation of infectious propagule or secondary in patients with disseminated infection due to cryptococcus. The typical presentations of the cutaneous lesions are like umbilicated lesions of molluscum contagiosum. The dermal lesions can also be similar to Kaposi sarcoma or talaromycosis (formerly penicilliosis). Here, we present a 34-year-old male HIV-positive and antiretroviral therapy-naive. The patient had a very low CD4 cell count and a high viral load. The patient was referred to the dermatology clinic for multiple eruptions due to umbilicated skin colored lesions 3-5 mm in diameter on the nose.The patient was first treated for the opportunistic infection. The causes of the dermal umbilicated skin lesions are several. We must find out whether the dermal lesion is due to infection with a single organism or more than one. It can be colesional also. Punch biopsy, India ink, and culture on Sabouraud dextrose agar confirmed the diagnosis of Cryptococcus neoformans.

Detection of emerging genotypes in Trichophyton mentagrophytes species complex: A proposal for handling biodiversity in dermatophytes.

A resistant and hypervirulent dermatophyte from India has been described as a taxonomic novelty, Trichophyton indotineae, a species of the Trichophyton mentagrophytes complex. Rapid detection and correct identification of closely similar dermatophytes with different predilections are essential for efficient clinical management. We evaluated the efficacy of rapid diagnostic methods clinical and environmental strains in the T. mentagrophytes complex. The methods included Real-time-PCR, DermaGenius, LAMP, and MALDI-ToF MS, using rDNA ITS sequences as taxonomic standard. The results show that only MALDI-ToF MS can distinguish 96.97% T. indotineae from other closely related species. The complex comprises numerous clones which may differ in anonymous markers but with similar evolutionary behavior. Therefore, we recommend to distinguish species only when they show an appreciable degree of adaptation and thus are clinically significant. The distinction of remaining clonal diversity is an epidemiological query and can be solved by haplotype numbering.

In-hospital mortality of HIV-infected cryptococcal meningitis patients with C. gattii and C. neoformans infection in Gaborone, Botswana.

The clinical presentations and outcomes of cryptococcal meningitis (CM) may be associated with the cryptococcal species causing the infections. To evaluate clinical differences between CM caused by C. neoformans and Cryptococcus gattii, we examined outcomes in HIV-infected adults with CM admitted to Princess Marina Hospital in Gaborone, Botswana. Among HIV-infected adults with CM, we found that 29 of 96 (30%) patients were infected with C. gattii, but species type was not associated with in-hospital mortality [mortality for C. gattii: 5 of 29 (17%) vs C. neoformans: 13 of 67 (19%); OR = 0.87 (95% CI 0.28 to 2.70)]. The proportion of C. gattii infection among this HIV-infected cohort in Botswana is the highest reported to date, but we found no difference between C. gattii and C. neoformans in clinical presentation or in-hospital mortality.

Updates on Genital Dermatophytosis.

Dermatophytes are a group of keratinophilic fungi, which normally cause superficial infection of skin, hair and nails. Based on ecology, they are classified into three groups: anthropophilic, zoophilic and geophilic. Superficial dermatophytic infection of the genital region is called genital dermatophytosis, tinea genitalis or pubo-genital dermatophytosis. In this review, we would like to discuss briefly, the various clinical presentations of genital dermatophytosis, current changes in the taxonomy and nomenclature, introduction of new diagnostic techniques and briefly describe some common dermatophytes and their sources. Also, there are serious concerns associated with the recent development of antifungal resistance among the dermatophytes. We are also facing the scenario of hard-to-treat dermatophytosis.

Outbreaks And Epidemics Of Superficial Dermatophytosis Due To Trichophyton mentagrophytes Complex And Microsporum canis: Global And Indian Scenario.

Until recently, superficial dermatophytosis, also known as tinea, was considered as a minor skin infection, which was easy to treat. There used to be rare outbreaks and epidemics of superficial dermatophytosis. Lately, there is a sweeping change in the clinical presentation due to extensive, atypical and recalcitrant dermatophytosis. Treating such infections poses a great challenge to the clinicians. Dermatophytosis is a superficial fungal infection of keratinized tissue (skin, hairs and nails) by dermatophytes (fungus). It is caused by the three genera of dermatophytes: Trichophyton, Epidermophyton and Microsporum. The conventional methods of laboratory diagnosis have now been substantiated by molecular characterization. Earlier epidemics were usually due to anthropophilic dermatophytes. Now, zoophilic dermatophytes are also responsible for many outbreaks and epidemics. We need to be equipped with the tools to face the current scenario, because this depends upon the competence of the staff working in the state-of-the-art laboratories, which is needed for the study of the epidemiology and appropriate treatment.

Multilocus sequence typing reveals three genetic subpopulations of Cryptococcus neoformans var. grubii (serotype A), including a unique population in Botswana.

We applied multilocus sequence typing (MLST) to investigate the population structure and mode of reproduction of Cryptococcus neoformans var. grubii (serotype A). This MLST system utilizes 12 unlinked polymorphic loci, which are dispersed on nine different chromosomes, and allows the unambiguous identification of closely related strains of serotype A. We compared MLST analyses with the conventional genotyping method of detecting amplified fragment length polymorphisms (AFLPs), and there was excellent correlation between the MLST and AFLP results. However, MLST differentiated a larger number of strains. We analyzed a global collection of isolates of serotype A using both methods, and the results identified at least three genetically distinct subpopulations, designated groups VNI, VNII, and VNB. Groups VNI and VNII are widespread, dominated by isolates with the MATalpha mating type, and predominantly clonal. Conversely, isolates of group VNB are unique to Botswana, include a significant proportion of fertile strains with the MATa mating type, and manifest compelling evidence of recombination. We have AFLP genotyped >1000 strains of serotype A from different parts of the world, including isolates from several African countries, and, to date, haploid serotype A isolates of group VNB have been found only in Botswana.

Spectrum of dermatophyte infections in Botswana.

BACKGROUND: Dermatophyte infections are a common cause of superficial fungal infection in different geographical locations of the world. Usually, it involves superficial invasion of keratinized tissue, eg, skin, nails, and hair, but in immunosuppressed individuals, it may cause atypical, extensive and deep lesions, which may pose serious diagnostic and therapeutic challenges. AIM: To find out the causative dermatophyte species responsible for the various clinical types of dermatophyte infection. RESULTS: Trichophyton violaceum was found to be the predominant species, being the causative organism responsible for all the clinical types. CONCLUSION: T. violaceum was found to be the most common species responsible for most of the clinical forms of dermatophytosis (96; 80%). Tinea unguium was found to be the most frequent clinical type of dermatophytosis (33; 27.50%).

Tinea Capitis: Mixed or Consecutive Infection with White and Violet Strains of Trichophyton violaceum: A Diagnostic or Therapeutic Challenge.

Tinea capitis is a common dermatophyte infection affecting scalp and hair of pre-pubertal children. With introduction of Griseofulvin in 1958, there has been considerable improvement in the treatment of tinea capitis. A seven-year-old male child was brought to the dermatology clinic. He presented with diffuse white scaly patches of alopecia on scalp of one-year duration. The child was sent to the microbiology section of the National Health laboratory, Botswana for the collection of the samples. The samples consisted of scalp scrapings and few plucked hairs from the suspicious areas, which were collected by swab and scalpel blade methods. Potassium hydroxide (10% KOH) mounts were prepared for scales and hair samples. Scales were positive for fungal elements and endothrix type of perforation was seen in hair. Cultures on Sabouraud's dextrose agar (SDA) and Derm agar were incubated at 25°C, which yielded white variant of Trichophyton violaceum after two weeks of incubation. T. vioaceum (white variant) grew in all the plates. After six weeks of treatment with griseofulvin, the repeat culture grew only T. violaceum (violet strain). The child showed a definite clinical improvement.

Tinea capitis in Botswana.

BACKGROUND: Tinea capitis (TC) is a common dermatophyte infection of the scalp that can also involve the eyebrows and eyelashes. AIM: This study aimed to find the causative fungus responsible for TC in Botswana and determine its association with the clinical types of TC. METHODS: Samples for potassium hydroxide 10% mounts and fungal cultures were collected in a microbiology laboratory at the National Health Laboratory, Gaborone, Botswana. Dermasel agar and Sabouraud dextrose agar were inoculated with the samples. Lactophenol cotton blue mounts were prepared from the culture-positive samples to study the morphological characteristics. RESULTS: Trichophyton violaceum was found to be the predominant causative organism of TC. Trichophyton tonsurans was isolated from one patient. Both are anthropophilic species. CONCLUSION: TC was found to be most common in those aged 1-15 years (81%). Of 17 patients in this age group, 16 were younger than 10 years old and one was 14 years old. T. violaceum was the most common dermatophyte species isolated.

Epidemiologic cutoff values for triazole drugs in Cryptococcus gattii: correlation of molecular type and in vitro susceptibility.

Cryptococcus gattii causes infection in tropical and subtropical regions worldwide but has garnered increased attention since its 1999 emergence in North America. C. gattii can be divided into 4 molecular types that may represent cryptic species. Recent evidence has shown that azole antifungal MIC values differ among these molecular types. We tested a large collection of C. gattii isolates for susceptibility to 4 azole drugs. We found that isolates of molecular type VGII have the highest geometric mean (GM) fluconazole MIC values (8.6 µg/mL), while isolates of molecular type VGI have the lowest (1.7 µg/mL). For fluconazole, itraconazole, and voriconazole GM MIC values, VGI < VGIII < VGIV < VGII. The GM MIC values for posaconazole were similarly represented across molecular types, with the exception that VGII < VGIII and VGIV. We used the MIC values to establish preliminary epidemiologic cutoff values for each azole and molecular type of C. gattii.

Evidence that the human pathogenic fungus Cryptococcus neoformans var. grubii may have evolved in Africa.

Most of the species of fungi that cause disease in mammals, including Cryptococcus neoformans var. grubii (serotype A), are exogenous and non-contagious. Cryptococcus neoformans var. grubii is associated worldwide with avian and arboreal habitats. This airborne, opportunistic pathogen is profoundly neurotropic and the leading cause of fungal meningitis. Patients with HIV/AIDS have been ravaged by cryptococcosis--an estimated one million new cases occur each year, and mortality approaches 50%. Using phylogenetic and population genetic analyses, we present evidence that C. neoformans var. grubii may have evolved from a diverse population in southern Africa. Our ecological studies support the hypothesis that a few of these strains acquired a new environmental reservoir, the excreta of feral pigeons (Columba livia), and were globally dispersed by the migration of birds and humans. This investigation also discovered a novel arboreal reservoir for highly diverse strains of C. neoformans var. grubii that are restricted to southern Africa, the mopane tree (Colophospermum mopane). This finding may have significant public health implications because these primal strains have optimal potential for evolution and because mopane trees contribute to the local economy as a source of timber, folkloric remedies and the edible mopane worm.

The use of HAART is associated with decreased risk of death during initial treatment of cryptococcal meningitis in adults in Botswana.

OBJECTIVE: The objective of this study was to evaluate outcomes among adults with a first episode of cryptococcal meningitis (CM), comparing those on highly active antiretroviral therapy (HAART) with those not on HAART. METHODS: We conducted a prospective cohort study among HIV-infected adults (aged 18 years and older) with a first episode of CM at the Princess Marina Hospital, in Gaborone, Botswana. The proportions surviving to discharge were compared. Logistic regression was used to evaluate the relationship between HAART use and risk of death in the hospital, adjusting for potential confounders. RESULTS: Ninety-two patients [median CD4 41 cells/mm (interquartile range 22-85)] were included, 26 of whom were on HAART at the time that they developed CM. The in-hospital mortality was lower among those on HAART {2 of 26 (8%) vs 14 of 66 (21%); odds ratio = 0.36 [95% confidence interval (CI) 0.09 to 1.49]}, and this result was statistically significant after adjustment for male sex and tuberculosis [adjusted odds ratio = 0.19 (95% CI 0.04 to 1.00)]. CONCLUSIONS: HAART use at the time of a first admission with CM is associated with decreased risk of death during the acute phase of disease. Reasons for this association should be explored.

Prevalence of clinical isolates of Cryptococcus gattii serotype C among patients with AIDS in Sub-Saharan Africa.

Cryptococcus gattii is a group of exogenous, neurotropic yeasts that possess the capsular serotype B or C. Isolates of serotype C are extremely rare and, until recently, were known to infect only immunocompetent individuals. We genotyped 176 isolates of Cryptococcus from patients in sub-Saharan Africa who had AIDS; 22 (13.7%) of 161 isolates from Botswana and 2 (13.3%) of 15 isolates from Malawi were C. gattii serotype C strains. All of these serotype C strains belong to the rare VGIV genotype, possess the MAT alpha mating-type allele, and exhibit little genetic diversity.