Epidemiology of Dermatophytes in Belgium: A 5 Years’ Survey

Dermatophytes are among the most common fungal agents causing superficial skin infections worldwide. Epidemiology of these infections is evolving and variable in every country. This report presents the Belgian epidemiological data regarding the distribution of dermatophytes species isolated by the two national reference centers for mycosis during a period of 5 years (2012–2016). Trichophyton rubrum was the most frequently isolated species, considering all sampling sites (60.3% on average between 2012 and 2016). More precisely, this dermatophyte was the major agent of Tinea unguium and Tinea corporis during this period, followed by species of the Trichophyton mentagrophytes complex. Moreover, Microsporum audouinii was the main etiological agent of Tinea capitis (TC) with a frequency of 52.5% on average between 2012 and 2016. Other African dermatophytes species such as Trichophyton soudanense and Trichophyton violaceum were also agents of TC with a respective prevalence of 11.6% and 11.5% on average. This study highlights a different dermatophyte distribution in Belgium in comparison with other European countries.

     

Molecular Identification and Antifungal Susceptibility of Clinical Isolates of Sporothrix schenckii Complex in Medellin,Colombia

Background

Sporotrichosis is a subcutaneous mycosis that affects humans and other animals. Infection prevails in tropical and subtropical countries. Until a few years ago, it was considered that two varieties of Sporothrix schenckii caused this mycosis, but by applying molecular taxonomic markers, it has been demonstrated that there are several cryptic species within S. schenckii complex which varies in susceptibility, virulence, and geographic distribution.

Objective

This study aimed to identify the clinical isolates of Sporothrix spp. from patients with sporotrichosis in Medellin, Colombia, using two markers and to evaluate the in vitro susceptibility to itraconazole.

Methods

Thirty-four clinical isolates of Sporothrix spp. from Colombia, three from Mexico, and one from Guatemala were identified through sequencing of the noncoding region ITS-1?+?5.8SDNAr?+?ITS-2 and of the fragment containing exons 3 and 4 of the β-tubulin gene. Clinical isolate sequences were compared with GenBank reference sequences using the BLASTN tool, and then, phylogenetic analysis was performed. Besides, the in vitro susceptibility to itraconazole was evaluated by determining the minimum inhibitory concentrations according to the CLSI M38-A2 method.

Results

Clinical isolates were identified by morphology as Sporothrix spp. Using the molecular markers, ITS and β-tubulin, isolates were identified as S. schenckii sensu stricto (25) and Sporothrix globosa (13). Susceptibility to itraconazole was variable among clinical isolates.

Conclusion

This is the first scientific publication that identifies species that cause sporotrichosis in Colombia, along with the antifungal susceptibility to itraconazole.

     

Onychomycosis in Tehran,Iran: Prevailing fungi and treatment with itraconazole

A total of 187 Patients with suspected onychomycosis were examined for causative fungal agents between 1996 and 1997. Laboratory examination confirmed onychomycosis in 115 patients, of which 97 cases were presented with positive microscopic and cultural examinations, and they were selected for itraconazole pulse therapy. From an etiological point of view, 48.4% of the nail infections, mainly toenail infections, were caused by dermatophytes, 43.3% were infected with Candida spp, specially infected fingernails, and 8.2% by non-dermatophytic molds. Trichophyton mentagrophytes var. interdigital and T. violaceum were the most prevalent species. Candida albicans and C. parapsilosis were the predominant species of the Genus Candida. Scopolariopsis brevicaulis was the most common non-dermatophyte molds observed. Female affected more frequently than male and in both sexes, those who were 30–49 years old, more infected. Toenails were affected more frequently than fingernails. In this study, itraconazole pulse therapy (400 mg daily) gave during the first week of per month for 3 months. The study included 51 patients with toenail onychomychosis (group 1) and 46 patients with fingernail infections (group 2). Patients were followed up for 9 months after the last treatment. Clinical response rates were 83% in the group 1, 95% in the group 2 at month 12; the corresponding mycological cure rates were 71 and 87%, respectively. This revised version was published online in June 2006 with corrections to the Cover Date.     

Rapid Identification of Four Fusarium spp. Complex by High-Resolution Melting Curve Analysis and their Antifungal Susceptibility Profiles

Fusarium species are globally distributed filamentous ascomycete fungi that are frequently reported as plant pathogens and opportunistic human pathogens, leading to yield loss of crops, mycotoxin contamination of food and feed products as well as damage to human and livestock. Human infections of Fusarium spp. are difficult to treat due to broad antifungal resistance by members of this genus. Their role as disease-causing agents in crops and humans suggests a need for antifungal resistance profiles as well as a simple, rapid, and cost effective identification method. Fusarium strains were isolated from food and clinical samples. High-resolution melting curve (HRM) analysis was performed using specific primers targeting internal transcribed spacer (ITS) region, followed with evaluation of specificity and sensitivity. The antifungal susceptibility of four Fusarium species was studied using the Sensititre YeastOne method. HRM analysis revealed reproducible, unimodal melting profiles specific to each of the four Fusarium strains, while no amplification of the negative controls. The minimum detection limits were 100–120 copies based on a 2 µl volume of template. Clear susceptibility differences were observed against antifungal agents by different Fusarium isolates, with amphotericin B and voriconazole displayed strongest antifungal effects to all the tested strains. We developed a simple, rapid, and low-cost qPCR-HRM method for identification of four Fusarium spp. (F. oxysporum, F. lateritium, F. fujikuroi, and F. solani). The antifungal susceptibility profiles supplied antifungal information of foodborne and clinical Fusarium spp. and provided guidance for clinical treatment of human infections.

     

Aquatic environments: A potential source of antimicrobial-resistant Vibrio spp.

Vibrio spp. are associated with water and seafood-related outbreaks worldwide. They are naturally present in aquatic environments such as seawater, brackish water and freshwater environments. These aquatic environments serve as the main reservoirs of antimicrobial-resistant genes and promote the transfer of antimicrobial-resistant bacterial species to aquatic animals and humans through the aquatic food chain. Vibrio spp. are known as etiological agents of cholera and non-cholera Vibrio infections in humans and animals. Antimicrobial-resistant Vibrio species have become a huge threat in regard to treating Vibrio infections in aquaculture and public health. Most of the Vibrio spp. possess resistance towards the commonly used antimicrobials, including β-lactams, aminoglycosides, tetracyclines, sulphonamides, quinolones and macrolides. The aim of this review is to summarize the antimicrobial resistance properties of Vibrio spp. isolated from aquatic environments to provide awareness about potential health risks related to Vibrio infections in aquaculture and public health.     

Fusarium Nail and Skin Infection: A Report of Eight Cases from Natal, Brazil

Fusarium spp. are non-dermatophytic hyaline moulds distributed worldwide and recovered from the nature as soil saprophytes and plant pathogens. Human infections are usually precipitated by local or systemic predisposing factors and disseminated infection is associated with impaired immune responses. We report eight cases of cutaneous lesions caused by Fusarium spp. All patients were immunocompetent. Seven cases with presented onychomycosis and one patient with interdigital intertrigo. It is important to alert the medical community about the relevance of the opportunistic fungi, such as Fusarium spp., which have emerged as human infectious agents, emphasizing the importance of correct etiological identification, allowing for appropriate treatment.     

Anaerobes Isolated from Infectious Skin Diseases

Anaerobic bacteria isolated from clinical specimens at our clinic from January 1994 to June 1998 were analysed. Anaerobes were usually isolated from secondary infections due to eczema/dermatitis. The majority of anaerobes identified were Peptostreptococcus spp., followed by Propion-ibacterium spp. and Prevotella spp. Among the Peptostreptococcus spp., P. magnus was the species most frequently isolated, followed by P. assaccharolyticus and P. prevotii. Pure or predominant growth of anaerobes was seen for each of the two P. prevotti and two Prevotella spp., strains, and for each of the single P. magnus andPropionibacterium spp. strains isolated. The presence of aerobic as well as anaerobic bacteria is important for choosing the antimicrobial agents to be used. Furthermore, Peptostreptococcus spp. showed high susceptibility to benzylpenicillin, ampicillin, piperacillin and minocycline, Propionibacterium spp. showed high susceptibility to all six antimicrobial agents tested, while Prevotella spp. and Bacteroides spp. showed low susceptibilities to all tested antimicrobial agents, except minocycline. Prevotella spp. was also susceptible to piperacillin.     

Onychomycosis in Malaysia

The common etiological agents of onychomycosis are dermatophytes, molds and yeasts. A mycological nail investigation of onychomycosis using direct microscopy and culture was conducted by the Mycology Unit, Department of Medical Microbiology, University of Malaya from March 1996 to November 1998. The study involved 878 nail clippings or subungal scrapings from subjects with onychomycosis. On direct microcopy examination, 50% of the specimens were negative for fungal elements. On culture, 373 specimens had no growth; bacteria were isolated from 15 nail specimens. Among the 490 specimens with positive fungal cultures, 177 (36.1%) were dermatophytes, 173 (35.5%) were molds and 130 (26.5%) were Candida. There were 2% (10/490) mixed infections of molds, yeasts and dermatophytes. Trichophyton rubrum (115/177) and Trichophyton mentagrophytes (59/177) were the main dermatophytes isolated. The molds isolated were predominantly Aspergillus niger (61/173), Aspergillus nidulans (30/173), Hendersonula toruloidea (26/173) and Fusarium species (16/173). 96.9% of the Candida species identified were Candida albicans.This revised version was published online in October 2005 with corrections to the Cover Date.     

Interference of Cranberry Constituents in Cell–Cell Signaling System of <Emphasis Type="Italic">Vibrio harveyi</Emphasis>

Cranberry juice has long been recognized in folk medicine as a therapeutic agent, mainly in urinary track infections. It acts as an antibiofilm agent against various pathogens. Quorum sensing is process where bacteria communicate with each other via signal molecules known as autoinducers. This process is strongly involved in various bacterial pathological and physiological pathways. Various strains of Vibrio harveyi bacteria were incubated with different concentrations of nondialyzable material of cranberry (NDM) with or without addition of exogenous autoinducer. Bioluminescence regulated by the autoinducers was measured in GENios reader. Effect of NDM alone or NDM supplemented with autoinducer on quorum sensing was determined as change in bioluminescence in each treated sample compared to appropriate control in every strain. Using model of V. harveyi, we found an inhibitory effect of cranberry constituents on bacterial signaling system. This effect was reversible, since exogenous autoinducer was able to recover bioluminescence which was decreased by NDM. We hypothesized that cranberry NDM interacts with V. harveyi quorum sensing by competition with autoinducer for binding to autoinducer sensor.     

Antifungal Therapy for Invasive Fungal Diseases in Allogeneic Stem Cell Transplant Recipients: An Update

Invasive fungal diseases (IFDs) remain a major cause of morbidity and mortality in allogeneic stem cell transplant (SCT) recipients. While the most common pathogens are Candida spp. and Aspergillus spp., the incidence of infections caused by non-albicans Candida species as well as molds such as Zygomycetes has increased. For many years, amphotericin B deoxycholate (AMB-D) was the only available antifungal for the treatment of IFDs. Within the past decade, there has been a surge of new antifungal agents developed and added to the therapeutic armamentarium. Lipid-based formulations of amphotericin B provide an effective and less nephrotoxic alternative to AMB-D. Voriconazole has now replaced AMB-D as first choice for primary therapy of invasive aspergillosis (IA). Another extended-spectrum triazole, posaconazole, also appears to be a promising agent in the management of zygomycosis, refractory aspergillosis, and for prophylaxis. Members of the newest antifungal class, the echinocandins, are attractive agents in select infections due to their safety profile, and are a more attractive option compared to AMB-D as initial treatment for invasive candidiasis and (based on one study) challenge fluconazole for superiority in management with this mycoses. However, challenges do exist among these newer agents in very high-risk individuals like allogeneic SCT recipients, which may include adverse drug events, drug–drug interactions, variability in oral absorption, and availability of alternative formulations. The addition of newer agents has also stimulated interest in the potential application of combination therapy in serious, life-threatening infections. However, adequate studies are not available for most IFDs; thus, the clinical use of combination therapy is not evidenced based on most cases and preciseness in its use is uncertain. Finally, therapeutic drug monitoring of select antifungals (notably posaconazole and voriconazole) may play an increasing role due to significant interpatient variability in serum concentrations after standard doses.     

Etiology and clinical characteristics of mycotic leukonychia

The purpose of the present paper is to add to our understanding of the prevalence of mycotic leukonychia. Twenty patients with mycotic leukonychia were studied. Leukonychia with atypical characteristics not previously described or with discordant characteristics relative to the ones that were responsible of this infection were found. Direct microscopic examination and cultures showed that Fusarium spp. were the responsible agents in 10% of the cases and that dermatophytes were implicated in the other 90%, where Trichophyton rubrum was the predominant etiologic agent.In this report we describe the clinical characteristics of the nail infections, the probable predisposing causes of the disease and the evolution of the cases.     

Profile of Dermatophytic and Other Fungal Infections in Jaipur

The common cause of skin infections are dermatophytes and opportunistic fungi. Aim of present study is to find predominant etiological agent of dermatophytoses and to isolate various fungal agents from clinical samples of patients with different mycoses and Clinical samples from 260 patients were subjected to potassium hydroxide (KOH) examination and culture isolation; causative agents were identified macroscopically and microscopically. One hundred sixty three (62.7%) were found to be positive by KOH examination while 132 (50.8%) were culture positive. Dermatophytes were isolated in 90/140 (64.3%) specimens. Trichophyton rubrum (75.5%) was the commonest isolate among the patients suffering from dermatophytoses. Candida spp. and Malassezia furfur were isolated from patient suffering from candidiasis and pityriasis versicolor.     

Clinical significance of infection pathogen resistance in a urological clinic for selection of antibacterial therapy regimes for the treatment of complicated urinary infections]

Data on changes of etiological structure of the complicated urinary tract infections treated at the Research Institute of Urology and Hospital No. 47 at the 5-year period (1996-2000) are given. It was shown that the most important microorganisms were the following: Enterobacter spp., E. coli, Proteus spp., Staphylococcus spp., Enterococcus faecalis. The correlation between frequency of the microorganisms isolation and their susceptibility to antimicrobial agents at different periods was analysed. The results of analysis allowed to elaborate algorithm of etiotropic therapy. Choice of the drug depends on pathogen susceptibility to antibiotics, bacteriuria level and clinical symptoms severity.     

Onychomycosis in Rome,Italy

This report presents the results of a study conducted between 1985 and 1994 on onychomycosis observed in the city of Rome. Six thousand six hundred and eighty eight patients were examined during this period. Among them 1,762 (26.3%) were affected by fungal nail infections. Because the etiologic agents could not be isolated in 105 cases (6%), the results refer to 1,657 subjects (24.8% of the total), presenting with positive microscopic and cultural examinations. Thirty eight patients (2.3%) had onychomycosis of both their hands and feet.From an etiological point of view, 59.1% of the nail infections were caused by yeasts, 23.2% were infected with dermatophytes and 17.6% by non-dermatophytic fungi. The etiology of onychomycosis of the hands differed from that of the feet. Yeasts were primarily responsible for onychomycosis of the hands (86.2%), while dermatophytes caused tinea unguium peduum (48%). Fungal fingernail infections by Candida spp. were the most common (50.3%), followed by those of the feet by dermatophytes (20%). Candida albicans was responsible for 70.6% of the hand infections but for only 15.9% of those of the feet. Trichophyton rubrum and T mentagrophytes were the most common dermatophytes, mainly causing toenail infections (23.4% and 21%, respectively), while Aspergillus spp., Scopulariopsis brevicaulis, Acremonium spp. and Aspergillus niger were the most common non-dermatophytes observed.With regard to sex, the fungal nail infections were more widespread in women (72.1%) and in subjects of both sexes over the age of 50.     

Non-dermatophytic Molds as Agents of Onychomycosis in Izmir,Turkey – A Prospective Study

The purpose of this study was to determine the prevalence of causative non-dermatophytic filamentous fungi in onychomycosis. Totally 1,222 (1,222 × 3 = 3,666) samples of nail scrapings from 1,146 patients (from 76 patients two specimens: both from finger- and toe-nails) with prediagnosis of onychomycosis sent to the Mycology Laboratory from the Clinic of Dermatology, Ege University Hospital, Izmir, Turkey, July 2001–December 2003, were prospectively studied with conventional mycological procedures. The set criteria for the diagnosis of onychomycosis due to non-dermatophytic molds were: (1) Observation of fungal elements in 15% KOH-preparations made from nail scrapings, (2) growth of the same mold in all three consecutive cultures of the specimens taken three times from the same patient with one-week intervals, (3) no growth of a dermatophyte or yeast in three consecutive cultures. As agents of onychomycosis molds were detected in 33 (9%), dermatophytes in 175 (48%), yeasts in 150 (41%), and mixed (two different fungi) in 8 (2%) patients. In cases of mold onychomycosis, 11 (33%) had finger-nail and 22 (67%) toe-nail infection; 25 (76%) were female and 8 (24%) male; and 27 (82%) were above 40 years of age. The agents of mold onychomycosis, in order of frequency, were Aspergillus niger (7), Acremonium spp. (6), Fusarium spp. (6), Ulocladium spp. (4), sterile mycelia (2), Alternaria sp. (1), Aspergillus flavus (1), Aspergillus fumigatus (1), Aspergillus terreus (1), Cladosporium sp. (1), Paecilomyces spp. (1), Scopulariopsis sp. (1) and Trichoderma sp. (1). In conclusion, this study showed that non-dermatophytic molds were responsible for nearly 10% of onychomycoses cases attending the dermatology outpatient clinic of a university hospital in Izmir, Turkey. Since molds are common contaminants in the laboratory, cultures from consecutively taken nail scrapings should be made and carefully evaluated in order to diagnose a “mold onychomycosis”.     

New developments in the antifungal susceptibility testing of Candida

Antifungal susceptibility testing of Candida spp has been standardized and refined and now may play an important role in managing Candida infections. Important new developments include standardizing methods for testing echinocandins, fluconazole, and voriconazole and establishing interpretive breakpoints for these agents. Refinements in broth microdilution technology include the ability to read results after 24-hour incubation for several agents, addition of new azoles and echinocandins to commercially available microdilution trays, and automation of the entire testing process. Cross-resistance studies have identified important relationships among the triazole antifungals, and international collaboration offers the promise of harmonization and the development of an international standard for the testing of yeasts.     

Advances in the Non-culture Based Laboratory Diagnosis of <Emphasis Type="Italic">Cryptococcus</Emphasis> and the Endemic Molds

Given the widespread availability of non-culture based diagnostic techniques, the approach to diagnosis of Cryptococcus spp. and the endemic molds has become increasingly complex. These techniques include: histopathology, cytopathology, fungal serology, antigen detection, and molecular methods such as polymerase chain reaction (PCR). This paper reviews the approach to diagnosis of Cryptococcus spp. and the endemic molds focusing on non-culture based diagnostic techniques.     

Functional,genetic and bioinformatic characterization of a calcium/calmodulin kinase gene in <Emphasis Type="Italic">Sporothrix schenckii</Emphasis>

Background  

Sporothrix schenckiiis a pathogenic, dimorphic fungus, the etiological agent of sporotrichosis, a subcutaneous lymphatic mycosis. Dimorphism inS. schenckiiresponds to second messengers such as cAMP and calcium, suggesting the possible involvement of a calcium/calmodulin kinase in its regulation. In this study we describe a novel calcium/calmodulin-dependent protein kinase gene inS. schenckii, sscmk1, and the effects of inhibitors of calmodulin and calcium/calmodulin kinases on the yeast to mycelium transition and the yeast cell cycle.