Laboratory-based epidemiological study of superficial fungal infections

Species distribution and antifungal susceptibility profiles of yeasts isolated from onychomycosis: a cross-sectional study with insights into emerging species

Candida onychomycosis is a common fungal infection affecting the nails, primarily caused by Candida (C.) species. Regarding the increasing trend of Candida onychomycosis and the antifungal resistant phenomenon in recent years, this study aims to evaluate the epidemiological characteristics of Candida onychomycosis, the distribution of emerging species, and the antifungal susceptibility profiles of isolates. Onychomycosis caused by yeast species was confirmed through direct examination and culture of nail scraping among all individuals suspected to have onychomycosis and referred to a medical mycology laboratory between June 2019 and March 2022. Species of yeast isolates were identified using the multiplex PCR and PCR-RFLP methods. The antifungal susceptibility of isolates to common antifungal agents and imidazole drugs was evaluated according to the M-27-A3 CLSI protocol. Among 101 yeast strains isolated from onychomycosis, Candida parapsilosis complex (50.49%) was the most common species, followed by C. albicans (20.79%) and C. tropicalis (10.89%). Rare species of yeasts such as C. guilliermondii and Saccharomyces cerevisiae were also identified by molecular methods. Results obtained from antifungal susceptibility testing showed significant differences in MIC values of isoconazole, fenticonazole, and sertaconazole among different species. Overall, a fluconazole-resistant rate of 3% was found among Candida species. Moreover, there was a statistically significant difference in MICs of fenticonazole and clotrimazole between the two most prevalent causative species, C. parapsilosis complex and C. albicans. Correct identification of the causative agents of onychomycosis and performing susceptibility testing could be helpful in choosing the most appropriate antifungal therapy.

A retrospective study on drug utilization pattern and cost utility analysis of antifungal drugs

Objectives

Fungal infections in humans are superficial or systemic and are found to be life threatening. They are common among the middle age group and particularly in females and immunocompromised patients.

Methods

This study was conducted to evaluate the prescription pattern of antifungal drugs and their economic burden on patients. The study was designed as a single centered, cross-sectional retrospective pharmacy database study of utilization of antifungal drug therapy and their cost analysis. Data for the period from 1 January 2019 to 31 December 2019 were retrieved from the inpatients and outpatient electronic pharmacy records along with the unit dose prices of antifungal drug in the study hospital.

Key findings

Antifungals use was more among females (67.05%) compared with males (34.91%). The use was predominant among middle age group (31–45) with Clotrimazole being the most utilized lower cost topical drug and fluconazole the next preferred systemic drug with least toxicity. Variconazole is a novel drug utilized the least among all age groups due to its adverse effects and higher cost. Clotrimazole is the drug of choice topically due to low cost and lesser absorption orally. Fluconazole is the next preferred drug that can be given systemically and its use remain unchanged due to lower cost and least toxicity in immunocompromised patients.

Conclusions

Variconazole although have adverse effects and used rarely it is the drug preferred in invasive treatments when benefit outweighs the risk. Variconazole is highly expensive drug used in invasive treatments and its adverse drug reactions, and cost need to be monitored.

Relationship between helicobacter pylori infection and pityriasis versicolor: can helicobacter pylori infection be a new etiologic factor for pityriasis versicolor?

Background/aim

H. pylori has been found to be related to certain dermatological diseases. However, there is no data as yet to propose an association between H. pylori and pityriasis versicolor. In this study, we aimed to evaluate the association between H. pylori and pityriasis versicolor.

Materials and methods

This was a prospective study performed in the Gastroenterology and Dermatology and Venereology departments of the Health Sciences University, Ankara Training and Research Centre. A total of 57 consecutive patients (27 pityriasis versicolor, 30 telogen effluvium) were enrolled from the Department of Dermatology and Venereology. All patients were screened for H. pylori IgG and CagA. In addition, urea breath test was carried out to detect the existence of H. pylori infection.

Results

There were significantly higher rates of H. pylori positivity, H. pylori IgG in serum in the pityriasis versicolor group compared to the telogen effluvium group (P < 0.05). In addition, the number of patients with dyspeptic complaints was higher in the pityriasis versicolor group than in the telogen effluvium group. The odds ratio for dyspepsia, H. pylori positivity, and H. pylori IgG were 2.48, 1.67, and 1.78, respectively.

Conclusion

In this study, we found a statistically significant relationship between H. pylori infection and pityriasis versicolor. Therefore, H. pylori eradication could be considered in recurrent pityriasis versicolor patients with dyspepsia. New studies are required to clarify the effect of eradication treatment on the clinical course of pityriasis versicolor.

Comparison of modified Chicago sky blue stain and potassium hydroxide mount for the diagnosis of dermatomycoses and onychomycoses

The diagnostic value of modified Chicago sky blue (CSB) stain and potassium hydroxide (KOH) mount for superficial mycoses was compared using fungal culture as gold standard. The sensitivity and screening time of the CSB stain were superior to the KOH mount. The CBS stain is simple, quick and reliable for diagnosing superficial mycoses.

Isolation of dermatophytes (and other fungi) from human nail and skin dust produced by podiatric medical treatments in Australia

BACKGROUND

Podiatric physicians routinely use electric drills for the treatment of nail and skin conditions. The grinding process produces human nail and skin dust that is generally vacuumed into bags in the grinding unit. Many of the nails are thought to be mycotic, particularly because they are obtained from patients with symptoms of dermatophyte infections. Currently, there is limited information available on the detection of fungi from nail dust samples. Herein, we attempt to address this situation and outline some of the difficulties that pathology laboratories face in isolating and identifying dermatophytes from nail samples.

METHODS

Fifty nail dust bags from podiatric medical clinics across all of the states and territories of Australia were collected and analyzed. Samples from the bags were inoculated onto primary isolation media. Fungal colonies that grew were then inoculated onto potato dextrose agar for identification using standard morphological (macroscopic and microscopic) features.

RESULTS

One hundred fifty-one colonies of dermatophytes were identified from 43 of the 50 samples. In addition 471 nondermatophyte molds were isolated, along with some yeasts and bacteria.

CONCLUSIONS

The most common dermatophytes isolated were from the Trichophyton mentagrophytes/interdigitale complexes. Trichophyton rubrum, Trichophyton tonsurans, Trichophyton soudanense, and Epidermophyton floccosum were also isolated. An unidentified group of dermatophytes was also present. The three most common genera of nondermatophyte molds were Aspergillus, Penicillium, and Scopulariopsis, all of which have been implicated in onychomycosis and more general disease. The presence of viable fungal pathogens in the dust could potentially pose a health problem to podiatric physicians.

Candida parapsilosis and Candida guillermondii: emerging pathogens in nail candidiasis

Background:

Onychomycosis of the fingernails and toenails is generally caused by dermatophytes and yeasts. Toenail mycoses involve mainly dermatophytes but when Candida is also involved, the strain most commonly isolated worldwide is C. albicans.

Aims:

To determine Candida strains prevailing in onychomycosis.

Materials and Methods:

A retrospective, observational and descriptive study of fungal cultures retrieved from the registry of the microbiology laboratory of the Pontificia Universidad Católica was performed. Specimens obtained from patients attending the healthcare network between December 2007 and December 2010 was analyzed.

Statistical Analysis:

A descriptive statistical analysis was performed.

Results:

Candida was retrieved from 467 of 8443 specimens (52% fingernails and 48% toenails). Cultures were negative in 5320 specimens (63.6%). Among Candida-positive cultures, parapsilosis was the most commonly isolated strain with 202 cases (43.3%). While isolates of Candida guillermondii were 113 (24.2%), those of Candida albicans were 110 (23.6%), those of spp. were 20 (4.3%) and there were 22 cases of other isolates (4.71%). Among the 467 patients with positive cultures for Candida, 136 (29,1%) were men and 331 (70,9%) were women. All patients were older than 18 years old. Clinical files were available for only 169 of the 467 patients with positive cultures for Candida. For those, age, gender, underlying illnesses and use of immunossupresive agents during the trial was reviewed.

Conclusions:

The present study shows that both C. parapsilosis as well as C. guillermondii appear as emerging pathogens that would be in fact taking the place of C. albicans as the most commonly isolated pathogen in patients with Candida onychomycosis. The relative percentage of C parapsilosis increases every year. Identification of Candida strains as etiological agents of nail candidiasis becomes relevant to the management both nail as well as systemic candidiasis, in view of the resistance to conventional treatments readily reported in the literature.

Molecular epidemiology, phylogeny and evolution of dermatophytes

Dermatophytes are fungi that invade and propagate in the keratinized skin of mammals, including humans, often causing contagious infections. The species of medical concern belong to the genera Microsporum, Trichophyton, Epidermophyton (in their anamorphic state) and Arthroderma (in their telomorphic state), which were traditionally identified based on their morphology and biochemical characters. Nonetheless, limitations linked to the differentiation of closely related agents at species and strains level have been recently overcome by molecular studies. Indeed, an accurate identification of dermatophytes is pivotal for the establishment of effective control and prevention programs as well as for determining the most appropriate and effective antifungal therapies to be applied. This article reviews the DNA techniques and the molecular markers used to identify and to characterize dermatophyte species, as well as aspects of their phylogeny and evolution. The applications of typing molecular strain to both basic and applied research (e.g., taxonomy, ecology, typing of infection, antifungal susceptibility) have also been discussed.

A study to evaluate the price control of antifungal medicines and its practical applicability

Background:

Superficial fungal infections are common and treatment imposes economic burden on the patients. Government of India had introduced price control over griseofulvin and tolnaftate in 1995; however, this measure can only benefit the needy if the policy is harmonized with the health-care service provider, that is, dermatologists. The aim of this study was to evaluate the existing Government mechanisms over price control of antifungal medications and its reach to the people-in-need.

Materials and Methods:

A questionnaire-based, cross-sectional study was carried out over a period of 6 months. Questionnaire was mailed to members of a state branch of Indian Association of Dermatologists, Venereologists, and Leprologists. Responses reaching investigators within 2 months from the date of mailing were finally analyzed.

Results:

Among 93 (41.33%) respondents, only 6 (6.5%) were aware of existing price control over griseofulvin but none about tolnaftate. Thirty-nine (41.9%) respondents were in favor of introducing price control on terbinafine and 42 (45.2%) for itraconazole. The topically preferred antifungals were primarily azoles and terbinafine, while among systemic antifungals, dermatologists mostly preferred fluconazole and terbinafine. The choice of antifungals by the dermatologists matched with the evidence-based dermatology data.

Conclusion:

Currently, price-controlled antifungal drugs are less commonly used by practitioners. Although the dermatologists favor price control, the initiative undertaken by the Government has not reached them. This shows the need to bridge the gap between policy makers and health-care service providers to help the ailing population.

Clinical and mycological features of onychomycosis in central Tunisia: a 22 years retrospective study (1986-2007)

Onychomycosis is the most frequently encountered nail disease and may be difficult to diagnose and treat. The objective of this study was to determine the prevalence, the clinical and mycological characteristics of onychomycosis in central Tunisia. It is a retrospective study performed over a 22-year period (1986-2007). It included 7151 patients (4709 women and 2442 men) with suspected fingernails and/or toenails onychomycosis. The patients were referred to the Mycology-Parasitology Laboratory of Farhat Hached hospital in Sousse for mycological examination. Both direct microscopy and culture of the nail material were performed to diagnose and identify the causative fungal species. Onychomycosis was confirmed in 78.6% of investigated patients (5624/7151). The positivity rate was higher in women as compared with men. In both men and women, fingernails were most frequently involved than toenails. No significant relation was found between gender and toenails onychomycosis, whereas fingernails were frequently involved in women. As far as aetiological agents are considered, dermatophytes, yeast and moulds were responsible for 49.9%, 47.4% and 2.7% of onyxis cases respectively. In fingernail infections, yeast were the most frequent fungi (83.6%), Candida albicans being the leading species (51.6%). In contrast, in toenail infections, dermatophytes were more frequent (74.1%). Trichophyton rubrum was by far the dominant species (88.1%). Yeast were observed more frequently in women whereas dermatophytes were more common in men. Moulds were involved in 4.2% of cases. The most frequent species were Aspergillus sp. and Chrysosporium sp. Onychomycosis is a frequent disease in central Tunisia. T. rubrum is the predominant agent in toenails infection and yeast, mainly C. albicans, in fingernails onychomycosis.

In vitro antifungal activity of epigallocatechin 3-O-gallate against clinical isolates of dermatophytes

Previously, we reported that epigallocatechin 3-O-gallate (EGCg) has growth-inhibitory effect on clinical isolates of Candida species. In this study, we investigated the antifungal activity of EGCg and antifungal agents against thirty-five of dermatophytes clinically isolated by the international guidelines (M38-A2). All isolates exhibited good susceptibility to EGCg (MIC₅₀, 2-4 μg/mL, MIC₉₀, 4-8 μg/mL, and geometric mean (GM) MICs, 3.36-4 μg/mL) than those of fluconazole (MIC₅₀, 2-16 μg/mL, MIC₉₀, 4-32 μg/mL, and GM MICs, 3.45-25.8 μg/mL) and flucytosin (MIC₅₀, MIC₉₀, and GM MICs, >64 μg/mL), although they were less susceptible to other antifungal agents, such as amphotericin B, itraconazole, and miconazole. These activities of EGCg were approximately 4-fold higher than those of fluconazole, and were 4 to 16-fold higher than flucytosin. This result indicates that EGCg can inhibit pathogenic dermatophyte species. Therefore, we suggest that EGCg may be effectively used solely as a possible agent or combined with other antifungal agents for antifungal therapy in dermatophytosis.

A comparative study of dermatophyte infections in Bursa, Turkey

A total of 555 specimens from 372 patients with symptoms compatible with superficial mycosis were included in this study. Those from patients clinically diagnosed as having dermatomycosis were thoroughly investigated by mycological examinations in the laboratory, including microscopic studies of KOH mounts and cultivation of the samples in culture. The results of this study and a previous study in our hospital conducted in 1980 were compared with respect to clinical presentation and etiological agents. Onychomycosis was the most common clinical form of dermatomycoses, and Trichophyton rubrum was the most common pathogen in this study.

Cutaneous fungal infections in the United States: Analysis of the National Ambulatory Medical Care Survey (NAMCS) and National Hospital Ambulatory Medical Care Survey (NHAMCS), 1995-2004

BACKGROUND

Dermatophyte infections lead to high costs and differentially affect certain groups. Previous population studies have been limited in size, duration, and representativeness.

METHODS

Using the National Ambulatory Medical Care Survey (NAMCS) and National Hospital Ambulatory Medical Care Survey (NHAMCS) (1995-2004), a cross-sectional analysis of ambulatory visits in the USA was performed. Outpatients presenting with International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM)-coded diagnoses of tinea unguium, tinea corporis/manuum, tinea pedis, tinea capitis, and tinea cruris were identified. Trends, descriptive epidemiology, and point prevalence estimates for these conditions were determined using stratification and standardization.

RESULTS

There was an estimated average of 4,124,038 +/- 202,977 annual visits for dermatophytoses during the study period. Tinea unguium, tinea corporis, tinea pedis, tinea capitis, and tinea cruris represented 23.2%, 20.4%, 18.8%, 15.0%, and 8.4%, respectively, of such infections; 71.6% of tinea unguium visits occurred among those older than 45 years. Tinea capitis was significantly more common among the black than the white population (prevalence odds ratio = 12.4; 95% confidence interval, 9.9-15.7). Ineffective treatment of tinea pedis, tinea corporis, and tinea cruris with polyenes, such as nystatin, commonly occurred.

CONCLUSIONS

Improved healthcare provider education is needed to ensure judicious antidermatophyte drug management. Further studies, including proven diagnoses via fungal microscopy and culture, are needed to explain the prevalence discrepancy of tinea capitis among black children and tinea unguium in older adults, focusing on preventable risk factors.

Candidal onychomycosis: a mini-review

Onychomycosis is a common fungal infection affecting nails. The primary cause for onychomycosis is dermatophytes, while Candida species have emerged as second-line pathogens. Onychomycosis due to Candida (candidal onychomycosis) is increasingly found in individuals having defective immunity consequential to aging, diabetes mellitus, vascular diseases, HIV infection and drug therapies such as immunosuppressives and broad-spectrum antibiotics. Breached local immunity at the nail complex due to trauma, chronic exposure to moisture and chemicals including smoke, detergents, soap, etc., also contribute to candidal onychomycosis. Adhesion, filamentation, secretion of extracellular enzymes and the development of antifungal resistance are some of the virulence mechanisms of Candida species associated with onychomycosis. Diagnosis of onychomycosis depends on history and clinical examination, direct microscopic investigation, mycological culture and histopathology. Restoration of immune defenses, elimination of fungi using appropriate drug therapy and improvement of nail hygiene with the removal of predisposing factors are key aspects in the management of candidal onychomycosis.

Tinea capitis among primary school children in Anambra state of Nigeria

Tinea capitis continues to be a common problem of infancy and childhood, particularly among those living in unhygienic crowded conditions. The prevalence and aetiology of tinea capitis have not been well defined in Anambra state of Nigeria - hence the need to undertake this study. A total of 47,723 primary school children residing in different regions of the State was screened for tinea capitis between 2002 and 2005. Of this number, 4498 (9.4%) had tinea capitis. The highest prevalence of the disease occurred in the Southern region of the state (12.6%). Schools in urban areas recorded lower prevalence of the disease. Male : female prevalence ratio of 1.6 : 1 was recorded. Tinea capitis occurred significantly more in children below 10 years of age than in those above this age (chi(2 )= 3.178; P < 0.10). Of 502 isolates recovered in culture, Microsporum audouinii was the most prevalent (42%), followed by M. ferrugineum (17%) and Trichophyton mentagrophytes (16%). Four of the samples revealed spore head of Aspergillus spp. in direct sample microscopy. A total of 29 (6%) isolates was atypical forms. The majority (91%) of children with the lesion came from families of three or more children, living in crowded apartments. Results showed that tinea capitis remains an important public health problem in Anambra state of Nigeria.