Mating behaviour of Microsporum equinum with Nannizzia otae

Twelve isolates of Microsporum equinum and nine monoascospore cultures of Nannizzia otae were studied on Sabouraud dextrose agar, polished rice grain, and on Pablum cereal agar for their gross morphology and micromorphology. The urease activity of each isolate was determined on Christensen's urea broth, and the in vitro hair perforation test was performed according to Ajello and Georg's technique. The 12 M. equinum isolates were paired with nine tester strains of N. otae (108 crosses) and with five M. canis isolates that were nonfertile with N. otae (60 crosses). The M. equinum isolates were also paired with each other in all possible combinations (78 crosses) on soil-hair medium, Pablum cereal agar, and oatmeal salts agar.Whereas most of the macroconidia produced by the M. equinum isolates were smaller than those of N. otae, some were in the size range of the latter species. Both species hydrolyzed urea within 8 to 14 days. Although N. otae isolates perforated hair consistently, none of the M. equinum isolates perforated hair in vitro. The crosses between N. otae and M. equinum cultures, between isolates of M. canis (that were incompatible with N. otae) and the isolates of M. equinum, and between M. equinum isolates among themselves were nonreactive. These differences strongly support the view that M. equinum is a distinct species and should not be treated as a synonym of M. canis (N. otae).     

Decreasing Prevalence of <Emphasis Type="Italic">Microsporum canis</Emphasis> Infection in Korea: Through Analysis of 944 Cases (1993–2009) and Review of Our Previous Data (1975–1992)

Since 1957, Microsporum (M.) canis has been one of the common causative agents of dermatophytosis in Korea. We analyzed 944 patients infected with M. canis who attended outpatient clinic over a 17-year period (1993–2009). M. canis infections were diagnosed by mycological examinations, including direct microscopic examinations with 15% KOH and cultures on potato dextrose agar complemented with 0.5% chloramphenicol. Mycological examinations confirmed 164,903 cases of dermatophytosis, 944 (0.6%) of which were M. canis infections. The annual prevalence of patients with M. canis infection was the highest in 2002 (91 cases). Then, the prevalence of patients with M. canis infection markedly decreased until 2008 (15 cases). The ratio of male to female patients was 0.65:1, but the ratio in children under the age of 15 was 1.14:1 and was 0.20:1 in adults. Seasonally, 274 cases occurred in winter, showing higher incidence than in other seasons. There was a difference in the clinical forms of M. canis infections between children and adults; tinea (T.) capitis was the most common form in children, but T. corporis was the most common in adults. We demonstrate that the decreasing prevalence of M. canis infections over the study period has been noted in Korea.     

Candida albicans stress mannoproteins expression in superficial and systemic candidiasis

The presence of heat shock mannoproteins (HSMPs) reactive with sIgA was demonstrated in several C. albicans strains. The subculture of the C. albicans isolated from mucosal surfaces on Sabouraud's dextrose agar at 25 °C switched off the HSMP expression. A re-expression of the HSMPs was obtained in the same medium by shifting the temperature of incubation to 37 °C. However, expression of HSMPs in two strains isolated from deep infections was maintained during several subcultures on Sabouraud's dextrose agar at 25 °C. A glycoprotein of 200 kDa seemed to be the main HSMP reacting with vaginal sIgA. The data presented in this study suggest that factors other than temperature can influence the expression of C. albicans HSMPs and therefore these antigens should be referred as stress mannoproteins.Abbreviations HSMPs heat shock mannoproteins - MAb monoclonal antibody - sIgA secretory IgA     

Nosocomial Invasive Infection Caused by Cunninghamella bertholletiae: Case Report

Human infection by Cunninghamella bertholletiae occurs almost exclusively in immunocompromised patients. Infections due to this microorganism have been most frequently diagnosed in patients with hematological malignancies, with neutropenia and in diabetes mellitus patients. This work reports a case of fungal infection by Cunninghamella bertholletiae isolated from blood in a man with a complex clinical picture, involving diabetes and pharmacological immunosupression. Blood culture at room temperature and at 37 °C on Sabouraud agar grew a single mold with characteristic properties of Cunninghamella. In the microscopic morphology, were found wide, non-septate, branching hyphae with erect sporangiophores terminated in swollen vesicles and sporangioles borne off the vesicles. C. bertholetiae was identified after subculture on Sabouraud dextrose agar at 45 °C. The patient died 15 days after the beginning of amphotericin B therapy.     

An evaluation of straw-extract agar media for the growth and sporulation of Madurella mycetomatis

Four new media, namely Wheat straw extract agar, Bajra straw extract agar, Jowar straw extract agar and Paddy straw extract agar, were evaluated for their potential to stimulate the growth and sporulation of Madurella mycetomatis in comparison with the conventional Sabouraud dextrose agar and Soil extract agar. Vegetative growth of M. mycetomatis on the four types of Straw extract agars was superior to that obtained on Sabouraud dextrose agar. Isolates of M. mycetomatis sporulated better and faster on the Straw extract agars than on the Sabouraud dextrose agar and Soil extract agar. Straw extract agar is recommended as a sporulation medium for M. mycetomatis. It may prove useful especially for studies of the conidium ontogeny of the fungus for elucidating its taxonomic status.     

Dermatophytosis due to <Emphasis Type="Italic">Trichophyton verrucosum</Emphasis> in a chamois (<Emphasis Type="Italic">Rupicapra rupicapra)</Emphasis>

A 3-year-old male chamois (Rupicapra rupicapra) shot during a harvest plan in Piedmont (Italy) presented periocular alopecic and thickened crusty lesions, some of which slightly red in colour. Hair still present was broken and easily removed. Direct microscopic examination of the pathological material collected by skin scraping led to the diagnosis of dermatophytosis, as the hair shafts appeared invaded by unstained spherical spores (arthroconidia). Fungal growth was obtained by culturing hair and crusts on thiamine/inositol enriched Sabouraud’s medium at 37°C. The macro- and microscopic characteristics of the organism were typical of the dermatophyte Trichophyton verrucosum. Wild ruminants are rarely affected by dermatophytosis, whereas in cattle, sheep and goats, infection because of this dermatophyte is quite common. This seems to be the first case of infection by T. verrucosum in chamois.     

Use of cereals as basal medium for the formulation of alternative culture media for fungi

Summary The feasibility of developing alternative media to different culture media particularly potato dextrose agar was assessed using local cereal species as the basal media. Three cereal meal extracts – corn, sorghum and millet – were prepared, using them as substitute for the potato in potato dextrose agar. Potato dextrose agar (PDA) was the standard set up with which the performances of the formulated media were compared. Eight genera of fungi (Aspergillus niger, Fusarium moniliforme, Penicillium sp., Cercospora sp., Curvularia palescens, Botryodiplopodia sp., Rhizopus sp. and Rhodotorula rubra) were isolated and pure cultures of each species aseptically inoculated onto the three different formulated media including PDA and allowed to grow. Their growths were measured at 24, 48, 72, and 96 h after inoculation, using diameter of growth as an index. The set up was repeated thrice for each species on the three formulated media and the control (PDA). Growth of all the fungal species were observed to be about the same or sometimes better in the formulated media relative to those on the standard set up, except for Rhodotorula rubra. The radius of growth of F. moniliformehad an average of 15 + 0.58 mm on corn-dextrose agar relative to 12 mm on PDA at 96 h while Cercospora sp. measured 30 + 0.58 mm on millet-meal dextrose agar relative to 37 + 1.16 mm at 48 h. Botryodiplopodia sp. grew through the whole diameter of the plate (covering the total length of the radius of 45 mm) in both sorghum-meal and PDA at 96 h.     

Nutritional requirements of keratinophilic fungi and dermatophytes for conidial germination

Germination of spores of Chrysosporium crassitunicatum, Nannizzia fulva (+), Nannizzia fulva (–) and Trichophyton equinum was studied in the presence of various carbon and nitrogen sources. Effect of different temperatures on spore germination was also determined. Maximum spore germination within 24 hours was recorded when glucose was used as a carbon source for all the test fungi. Except sodium nitrate all the inorganic nitrogen sources enhanced the spore germination at 0.05% concentration. Most of the organic nitrogen sources used were found to be stimulatory for the spore germination of test fungi. Optimum temperature i.e. 28 °C supported maximum spore germination of all the test fungi within 24 hours. C. Crassitunicatum, N. fulva(+), N. fulva(–) could germinate upto 35 °C but beyond that no spore germination was noticed in these fungi. T. equinum could germinate at a higher temperature of 40 °C but the percentage of germination was very low.     

<Emphasis Type="Italic">Microsporum praecox</Emphasis>: Molecular Identification of a New Case and Review of the Literature

We report a rare case of dermatophytosis due to Microsporum praecox in a 28-year-old female horse rider. The skin lesion was located on the right external malleolus. Microscopic examination of skin scrapings revealed a dermatophyte which was also isolated in culture. The identification of M. praecox was confirmed by molecular biology (sequence analysis of PCR products amplified from internal transcribed spacer regions with universal primers). Combined antifungal therapy with oral terbinafine and topical cyclopiroxolamide resulted in complete remission of the fungal lesion within 1 month. Since 1944, only 29 cases of human M. praecox infection have been reported in the literature. The clinical features and treatment of these cases are reviewed. The prevalence of M. praecox infection is probably underestimated, and systematic molecular identification could improve our understanding of the epidemiology of this fungal dermatosis.     

First Case of Microsporum ferrugineum from Iran

This is a first case of Microsporum ferrugineum from Iranian patient. A 42 year old man was examined for tinea faciei infection. Direct KOH preparations from skin scrapping revealed hyaline septate branching mycelium. Cultures of skin scrapings yielded M. ferrugineum after three weeks. Isolate was identified based on colony morphology on Sabouraud’s dextrose agar medium (S), microscopic morphology of slide culture, and biochemical reactions.     

Lack of Involvement of Nutrients in the Latency of Colletotrichum gloeosporioides in Unripe Avocado Fruits

Hypobaric pressures prevented the ripening of avocado fruit discs and the development of Colletotrichum gloeosporioides infection on them. The same condition did not prevent the growth of C. gloeosporioides on potato dextrose agar. Using this system it was shown that the resistance of unripe avocado fruit discs does not originate in the lack of subsrate for fungal growth.     

Bioassay of Mildiomycin and a Rapid, Cost-Effective Agar Plug Method for Screening High-yielding Mutants of Mildiomycin

Summary A simple, reliable and low-cost agar diffusion bioassay for quantitative determination of mildiomycin was developed using a strain of Rhodotorula rubra AS 2.166 as the indicator organism and potato dextrose agar at pH 7.0 as the test medium. With equivalent precision and accuracy to HPLC analysis, this method was applied to analyse mildiomycin in complex culture broth during the fermentation process. A modified agar plug method based on the bioassay was constructed for rapid and efficient screening of high-yielding mutants of mildiomycin. Within four weeks, a high production strain, the mildiomycin productivity of which was 75.5% higher than the parent strain, was obtained from 15,000 mutants.     

Growth and mycotoxin production by <Emphasis Type="Italic">Chaetomium globosum</Emphasis>

Chaetomium globosum, the most common species within this genus, produces chaetoglobosins A and C when cultured on building material. Relatively low levels of these compounds have been shown to be lethal to various tissue culture cell lines. This study had two major objectives: (1) to determine the frequency at which Chaetomium species are isolated in water-damaged buildings and (2) to examine the production of chaetoglobosins A and C in isolates of C. globosum obtained from different buildings. Out of 794 water-damaged buildings, Chaetomium species were isolated in 49% of these structures. C. globosum ATCC 16021 was grown on four different media: oatmeal agar (OA), potato dextrose agar (PDA), corn meal agar (CMA), and malt extract agar (MEA). After 4 weeks, fungal growth was evaluated based on colony diameter and the quantity of spores produced on agar plates. In addition, production of chaetoglobosin A and C was monitored using high performance liquid chromatography. Colony diameter, spore production, and mycotoxin production by C. globosum were the highest on OA. Out of 30 C. globosum isolates cultured on OA for 4 weeks, 16 produced detectable amounts of chaetoglobosin A and every isolate produced chaetoglobosin C.     

Antifungal activity of tea tree oil from Melaleuca alternifolia against Trichophyton equinum: An in vivo assay

Dermatophytes are a group of keratinophilic and keratinolytic molds, some of which are responsible for ringworm. Among them Trichophyton equinum, which mostly infects equids, can cause extensive outbreaks in stud farms. The conventional treatment of equine trichophytosis is topic, based upon medicated shampoos to reduce the spread of infection among the animals. Nevertheless the popularity of phytotherapy is at an all-time peak, and the interest for natural alternatives or complements to conventional drug therapy is challenging both in human and veterinary field. Among herbal remedia Tea Tree Oil (TTO) shows a wide range of antimicrobial activities. A randomized open clinical trial was carried out on 60 thoroughbred breeding horses affected by equine ringworm. The animals were randomly divided into 2 groups of 30 subjects. Diagnostic criteria were the presence of clinical signs and positive T. equinum culture. Specificity control using TTO mixture in 5 not dermatophyte affected animals was achieved also. The antimycotic activity against T. equinum of a mixture containing 25% TTO in sweet almond oil, was evaluated in vivo treating 30 subjects, the others were administered enilconazole 2% solution. The animals of both groups were topically treated twice a day for 15 days with a 25% mixture of TTO diluted in sweet almond oil and every 3 days, four times with enilconazole rinses, respectively. The clinical and mycological outcome were evaluated at day 30 from the start of the treatments. Data analysis was performed by chi square test. All the treated animals showed complete clinical and aetiological healing. Part of control subjects also, showed an improvement and none of them exacerbate the lesions. This therapeutic protocol appears to be effective and versatile, being applicable immediately after physical examination, prior to have the laboratory response. It could be an alternative for practitioners interested in herbal medicines, contributing to fulfill the gap existing between in vitro and clinical studies.     

Comparison of coal solubilization by bacteria and fungi

Coal-solubilizing agents produced byTrametes versicolor, Phanerochaete chrysosporium, Aspergillus sp., a bacterial consortium, and a bacterial isolate,Arthrobacter sp., from that consortium were compared in terms of pH dependence, thermostability, molecular mass, mechanism of action, and product diversity. The thermostability and low molecular weights exhibited by the coal-solubilizing agents indicated a non-enzymatic mechanism of action. Competition studies using cupric copper indicated that coal solubilization by these agents involved metal chelation. Results demonstrated that oxalate could account for some but not all of the coal solubilization observed forT.versicolor andP.chrysosporium. The very low levels of oxalate detected inAspergillus sp. and the bacterial cultures indicated that oxalate is not an important factor in coal solubilization by these microbes. When subjected to gel permeation chromatography, the soluble coal products generated by each microbial coal-solubilizing agent yielded unique molecular mass profiles suggesting substantial product diversity. Such diversity increases the possibility of identifying potentially valuable compounds and extending the commercial utilization of coal.Abbreviations A₄₅₀, A₂₆₀ absorbances respectively at 450 nm and 260 nm - CSA coal-solubilizing agent - CSU coal-solubilizing unit - GPC gel permeation chromatography - MEA malt extract agar - PDA potato dextrose agar - SDA Sabouraud dextrose agar - SDB Sabouraud dextrose broth - SEM standard error of the mean - Tris tris(hydroxymethyl)aminomethane - TSA trypticase soy agar - TSB trypticase soy broth     

Susceptibility of <Emphasis Type="Italic">Sclerotinia sclerotiorum</Emphasis> strains different in oxalate production to infection by the mycoparasite <Emphasis Type="Italic">Coniothyrium minitans</Emphasis>

Three strains of Sclerotinia sclerotiorum, namely Ep-1PB (PB), Ep-1PK (PK) and Ep-1PNA5 (A5), were compared for the production of oxalic acid (OA) on potato dextrose agar (PDA) and Maxwell agar medium (MAM) and for mycelial susceptibility to infection by the mycoparasite Coniothyrium minitans on PDA. Results showed that strain PB produced negligible oxalate, whereas strain PK was detected to produce oxalate, but much less than that produced by strain A5. The three investigated strains differed slightly in mycelial growth rates and mycelial biomass on PDA. However, colonies of strains PB and PK formed on PDA were more susceptible to invasion by C. minitans than colonies of strain A5. Meanwhile, amendment of synthetic oxalate in PDA at 0.25–2.00 mg g⁻¹ medium suppressed aggressiveness of C. minitans in invasion of colonies of S. sclerotiorum strain PB developed on this medium. These results suggest that infection of hyphae of S. sclerotiorum is negatively affected by the presence of oxalate. The importance of oxalate degradation by C. minitans in its mycoparasitism on hyphae of S. sclerotiorum provides a clue for improvement of the biocontrol efficacy of C. minitans in the future.     

Ethanol-sensitive mutants of Saccharomyces cerevisiae

Saccharomyces cerevisiae mutants unable to grow at ethanol concentrations at which the wild type strain S288C does grow, have been isolated. Some of them show additional phenotypic alterations in colony size, temperature sensitivity and viability in ethanol, which cosegregate with the growth sensitivity in ethanol. 21 selected monogenic ethanol-sensitive mutants define 20 complementation groups, denominated ETA1 to ETA20, which indicates that there is a high number of genes involved in the ethanol tolerance/sensitivity mechanism.Out of 21 selected monogenic mutants, 20 are not altered in the glycolytic pathway since, when maintained in glucosesupplemented medium, they can produce as much ethanol as the wild type and at about the same velocity. Nor do any of the mutants seem to be altered in the lipid biosynthetic pathway since, whether grown in the absence or in the presence of ethanol, their concentration of fatty acids and ergosterol is similar to that of the wild type under the same conditions. Therefore growth sensitivity to ethanol does not seem necessarily to be related to carbohydrate or lipid metabolism.Non-common abbreviations YP yeast extract peptone medium - YPD yeast extract peptone dextrose agar or medium - YPG yeast extract peptone glycerol agar - YPDE yeast extract peptone dextrose ethanol agar or medium - SD yeast nitrogen base dextrose agar - SPO yeast extract potassium acetate glucose agar - PD parental ditype - NPD non-parental ditype - TT tetratype     

Studies on production and food consumption by the larval simuliidae (Diptera) of a chalk stream

Summary Large populations of S. ornatum and S. equinum inhabit Ranunculus plants in the Bere Stream at Bere Heath. A weekly sampling programme obtained both larvae and pupae. The results of weekly sampling indicated four annual generations of S. ornatum and three of S. equinum. Quantitative samples of larvae, obtained at least three times in each generation gave estimates of production ranging from 0.26 g to 2.75 g dry weight m-² per generation of larvae of S. equinum and 0.15 g to 1.19 g dry weight m-² per generation of larvae of S. ornatum.Retention times of food by larvae, under field conditions were in the order of twenty to thirty minutes. Following determination of the weight of the gut contents for each size class of larvae, the activity of feeding larvae was calculated to achieve complete theoretical clearance of suspended material in a distance of 0.6 km, at peak population densities in the summer months.Dept. of Applied Biology, Bath University of Technology     

Identification of bacterial species on Lippia multiflora herbal tea leaves and the influence of steam pasteurization

The consumption of herbal teas is an increasing phenomenon among tea consumers globally. Some of these herbal teas are not pre-treated to reduce their microbial load before consumption, and thus constitute a health risk to consumers. In this study, the effect of steam pasteurization, at >99 °C for 2.5 min, on the microbial load of Lippia multiflora herbal tea leaves was evaluated. Microbial enumeration was conducted on potato dextrose agar, plate count agar, violet red bile agar, yeast peptone dextrose agar, and DeMan-Rogosa-Sharpe agar. Morphologically distinct colonies were isolated, sub-cultured and their Gram reaction recorded. These bacteria were identified to the species level using 16S ribosomal DNA sequence data. Most of the bacteria identified belonged to the genus Bacillus. One species each from the genera Pantoea and Kocuria was also identified, but only the Bacillus species survived the steam pasteurization treatment. Coliform bacteria detected prior to pasteurization were not detected after the steam treatment. Steam pasteurization reduced the microbial load from 10⁴ to 10² c.f.u.g⁻¹and it is potentially an effective method to treat L. multiflora herbal teas prior to consumption. It is important to note that the steam treatment should complement good agricultural and hygienic practices rather than replace them, as some bacteria can survive this treatment.     

First report of anthracnose caused by Colletotrichum gloeosporioides on Boehravia diffusa in India

Leaf spot symptoms were observed on the leaves of Boehravia diffusa L. plants from different regions of Bilaspur, Himachal Pradesh, India. The symptoms initially appeared as a small light-pale coloured, circular spots enlarge gradually and ultimately leading to drying of the leaves. The disease was found to be caused by a fungus. The fungus was cultured on potato dextrose agar medium and identified as Colletotrichum gloeosporioides. According to the literature, this is thefirst report of anthracnose disease of B. diffusa caused by C. gloeosporioides in India.