Clinical types and fungal pathogens of children′s tinea capitis analysis of 542 cases in a tertiary first-class hospital of Wuhan / 中国热带医学

@#Abstract: Objective To investigate the clinical types of children's tinea capitis and the distribution of fungal pathogens in Wuhan from 2011 to 2020, and to provide scientific basis for the prevention, diagnosis and treatment of children's tinea capitis. Methods Laboratory data of children with tinea capitis in outpatient and inpatient department of dermatology in Wuhan No.1 Hospital from January 2011 to December 2020 were collected. A total of 542 cases of pediatric tinea capitis were included, with 239 male cases and 303 female cases. Microscopic examination of fungi and culture identification were performed on the affected skin lesions of the children. Chi-square test was used to analyze the differences in pathogen spectrum of children with different age groups and clinical type. Results Among the pediatric tinea capitis patients, the age group with the highest prevalence was preschool children（3 to <7 years old), accounting for 48.52%（263/542). The top three pathogenic fungi were Trichophytes violaceum（49.26%, 267/542), Microsporum canis（31.55%, 171/542) and Trichophyton mentagrophytes （9.96%, 54/542). Trichophyton violaceum was the main pathogen in all ages, followed by Microsporum canis. The infection rate of Microsporum canis in children over 7 years old was lower than that in children under 7 years old, and the infection rate of Trichophyton rubrum in infants was higher than that in other ages. The distribution of Trichophytes violaceum, Trichophyton mentagrophytes, Nannizzia gypseum and Microsporum ferrugineum was uniform in all age groups. Trichophytes violaceum and Trichophyton tousurans mainly caused black-dot ringworm, Microsporum canis mainly caused tinea alba, Trichophyton mentagrophytes,Nannizzia gypseum and Trichophytonrubrum mainly caused kerion. Except for Microsporum ferrugineum, the composition ratios of other fungi species showed statistically significant differences among different clinical types of tinea capitis（P<0.05). Conclusions Preschool children are the most commonly affected age group by pediatric tinea capitis, and black-dot ringworm caused by Trichophytes violaceum is the main clinical type. Analysis of the high-riskage group, pathogenic fungi and clinical types of tinea capitis in children can enhance the understanding of its epidemiological characteristics, which is helpful for early diagnosis and targeted standardized treatment of pediatric tinea capitis.

Research on fungal culturomics based on different universal media / 中国热带医学

@#Abstract: Objective To screen out a more universally applicable culture medium for the isolation and culturing of pathogenic fungi through comparing the performance of various universal fungal culture media, to optimize the fungal culturomics technique, and to better apply it to the culturomics research of pathogenic fungi. Methods Multiple common fungal culture media Sabouraud dextrose agar (SDA), potato dextrose agar (PDA), modified Dixon (mDixon), modified LeemingNotman agar (MLNA), etc., and a new pan-fungal medium (PF) were used to culture 40 strains of common pathogenic fungi to determine the growth states of strains under different conditions. Based on that, PF, SDA, PDA, mDixon and MLNA, a total of 5 culture media, were used to isolate and culture a simulated sample (suspension of Candida albicans and Aspergillus fumigatus), 10 human samples (4 fecal samples and 6 vaginal secretion samples) and 3 environmental samples. Results The positive growth rates of 40 strains of pathogenic fungi in the 7 media were as follows: PDA 95.0% (38/40), SDA 95.0% (38/40), BHI 95.0% (38/40), YPD 90.0% (36/40), mDixon 95.0% (38/40), MLNA 87.5% (35/40), PF 100.0% (40/40). For the simulated samples, PF could effectively promote the self-limited growth of filamentous fungi, performing better in isolation and culture. For the human samples and environmental samples, PF showed the same versatility as SDA and PDA. Conclusions In the isolation and culturing of pathogenic fungi, PF medium can effectively isolate and culture most fungal species. Meanwhile, PF can make the fast-growing fungi show self-limited growth and clear edges, and not easy to cross-contamination, which indicates it is conducive to the isolation and identification of single colonies. PF medium outperforms other common media in isolating strains from unknown samples in culturomics, which illustrates PF medium can be effectively used for the study of fungal culturomics.

New Insights on Environmental Occurrence of Pathogenic Fungi Based on Metagenomic Data from Brazilian Cerrado Biome

Abstract: Cerrado is the second largest biome in Brazil and majorly contributes to the country's grain production. Previous studies on soil metagenomics from the Cerrado revealed an outstanding microbial diversity. In this study, the abundance of pathogenic fungi was analyzed using metagenomic sequences of the Cerrado soils under native vegetation, and under agriculture with no-tillage and conventional tillage. In total, 128,627 sequences of fungi were identified, with 43,439 representing pathogenic fungi and were distributed as follows: native 17,301 (40%), no-tillage 13,780 (32%), and conventional tillage 12,358 (28%). We identified 41 pathogenic fungal species associated with human and animal infections. The data analysis revealed that the native soils had a higher relative abundance of fungal sequences, similar to pathogenic species sequences, in relation to the total eukaryotic sequences, than the conventional tillage and no-tillage treatments, which observed a reduction in fungal abundance because of anthropogenic activities.

Isolation, identification, and pathogenicity research of brown rot pathogens from Gastrodia elata / 中国中药杂志

Brown rot is a common disease in the cultivation and production of Gastrodia elata, but its pathogens have not been fully revealed. In this study, the pathogenic fungi were isolated and purified from tubers of 77 G. elata samples with brown rot. Pathogens were identified by the pathogenicity test and morphological and molecular identification. The pathogenicity of each pathogen and its inhibitory effects on Armillaria gallica were compared. The results showed that 119 strains of fungi were isolated from tubers of G. elata infected with brown rot. Among them, the frequency of separation of Ilyonectria fungi was as high as 42.01%. The pathogenicity test showed that the pathogenicity characteristics of six strains of fungi were consistent with the natural symptoms of brown rot in G. elata. The morphological and molecular identification results showed that the six strains belonged to I. cyclaminicola and I. robusta in the Nectriaceae family of Sordariomycetes class, respectively. Both types of fungi could produce pigments, conidia, and chlamycospore, and the growth rate of I. cyclaminicola was significantly higher than that of I. robusta. The comparison of pathogenicity showed that the spots formed by I. cyclaminicola inoculation were significantly larger than those of I. robusta inoculation, suggesting I. cyclaminicola was superior to I. robusta in pathogenicity. The results of confrontation culture showed that I. cyclaminicola and I. robusta could signi-ficantly inhibit the germination and cordage growth of A. gallica. A. gallica also inhibited the growth of pathogens, and I. cyclaminicola was less inhibited as compared with I. robusta. The results of this study revealed for the first time that I. cyclaminicola and I. robusta were the pathogens responsible for G. elata brown rot.

Synthesis and antibacterial activity of C-7 haloacyl cephalosporins / 药学学报

Cephalosporins are widely used in the treatment of infectious diseases. The structural differences in cephalosporin drugs mainly lie in the C-7 amino side chain and the C-3 substituent. In this study, twenty-five haloacylated cephalosporins of five series were designed by using a strategy of introducing simple substituents at the C-7 amino group in four cephalosporin parent nucleus with different C-3 substituents and efficiently synthesized under optimized conditions. Their activities against human pathogenic bacteria, Pichia pastoris, citrus canker and citrus pathogenic fungi were evaluated. The results showed that most of the molecules had activity against human pathogenic bacteria, of which seven compounds including TM1f had stronger or equivalent inhibitory activities against eight human pathogens than the marketed drugs cefalotin, cefoxitin sodium and ceftizoxime sodium. The inhibitory activity of TM1s against Alternaria alternate Al.6 was stronger than that of cephalosporins and comparable to that of the positive control prochloraz. TM1f and TM1s are worthy of further study.

Zoochemical analyses and in vitro antimicrobial activity of crude methanolic extract of Perna viridis

@#<p style="text-align: justify;"><strong>Introduction:</strong> The rise of antibiotic resistance and superbugs drives the search for new antibiotics today. Meanwhile, the green mussel Perna viridis is a cultivated and marketed staple bivalve in the Philippines due to its fast repro-duction, high protein content, and tolerance to environmental variables. Although some studies have analyzed the antimicrobial activity of P. viridis, zoochemical analyses and further evaluation of its antimicrobial activity, such as determining the minimum inhibitory concentration (MIC), remains unexplored.</p><p style="text-align: justify;"><strong>Objectives:</strong> The study evaluated the zoochemicals present in crude methanolic extract of P. viridis by qualitative screening and thin-layer chromatography analysis. It further evaluated the crude extract for its antimicrobial activity against common pathogenic bacteria and plant pathogenic fungi.</p><p style="text-align: justify;"><strong>Materials and Methods:</strong> The zoochemicals in crude methanolic extract of P. viridis were screened using qualitative spotting methods and thin-layer chromatography (TLC). The antimicrobial activity of the extract was evaluated against the bacteria Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, and Bacillus subtilis, and the fungi Colletotrichum capsici, Lasiodiplodia theobromae, and Rhizopus sp. using disk diffusion assay and two-fold microdilution.</p><p style="text-align: justify;"><strong>Results:</strong> Qualitative screening and thin-layer chromatography analysis of the crude extract revealed detectable amounts of alkaloids, saponins, terpenoids, sterols, and polyphenols. All of the tested bacteria were susceptible to the extract with P. aeruginosa (19.00±0.82 mm) and S. aureus (19.33±0.47 mm) as the most inhibited with MICs of 2.60±0.63 and 3.65±1.69 mg/mL, respectively. However, for the three fungi tested, only the growth of the fungus L. theobromae (7.33±0.94 mm) was inhibited with a MIC of 33.33±11.79 mg/mL.</p><p style="text-align: justify;"><strong>Conclusion:</strong> It can be inferred that the zoochemicals detected in the crude extract of P. viridis contributed to its antimicrobial activity.</p><p style="text-align: justify;"><strong>Key Words:</strong> Antibacterial agent, Antifungal agent, Green mussel, Plant pathogenic fungi, Secondary metabolites</p>

Medicines for Malaria Venture COVID Box: a source for repurposing drugs with antifungal activity against human pathogenic fungi

BACKGROUND Treatment of mycoses is often ineffective, usually prolonged, and has some side effects. These facts highlight the importance of discovering new molecules to treat fungal infections. OBJECTIVES To search the Medicines for Malaria Venture COVID Box for drugs with antifungal activity. METHODS Fourteen human pathogenic fungi were tested against the 160 drugs of this collection at 1.0 µM concentration. We evaluated the ability of the drugs to impair fungal growth, their fungicidal nature, and morphological changes caused to cells. FINDINGS Thirty-four molecules (21.25%) presented antifungal activity. Seven are antifungal drugs and one is the agricultural fungicide cycloheximide. The other drugs with antifungal activity included antibiotics (n = 3), antimalarials (n = 4), antivirals (n = 2), antiparasitcs (n = 3), antitumor agents (n = 5), nervous system agents (n = 3), immunosuppressants (n = 3), antivomiting (n = 1), antiasthmatic (n = 1), and a genetic disorder agent (n = 1). Several of these drugs inhibited Histoplasma capsulatum and Paracoccidioides brasiliensis growth (15 and 20, respectively), while Fusarium solani was not affected by the drugs tested. Most drugs were fungistatic, but niclosamide presented fungicidal activity against the three dimorphic fungi tested. Cyclosporine affected morphology of Cryptococcus neoformans. MAIN CONCLUSIONS These drugs represent new alternatives to the development of more accessible and effective therapies to treat human fungal infections.

Esporotricosis: la micosis subcutánea más frecuente en México / Sporotrichosis: the most frequent subcutaneous mycosis in Mexico

Resumen La esporotricosis es una micosis causada por especies del complejo Sporothrix schenckii. Basado en estudios epidemiológicos y moleculares. Se reconocen seis especies de Sporothrix como causantes de la esporotricosis humana. Algunas especies de este complejo, tienen un potencial zoonótico relevante para la transmisión al humano, y muchas otras son exclusivamente fitopatógenas. Es considerada la micosis subcutánea más frecuente en México. El principal mecanismo de infección es el traumatismo con pérdida de continuidad de la piel seguido por la contaminación con el hongo Sporothrix spp. Las principales formas clínicas son la esporotricosis linfangítica, la forma cutánea fija y la forma diseminada. Los procedimientos de laboratorio más útiles para confirmar el diagnóstico, son el cultivo de especímenes como exudado y tejido, así como el estudio histopatológico. La forma parasitaria está representada por levaduras en el tejido o exudados. Los medicamentos más útiles en el tratamiento son el yoduro de potasio y el itraconazol. La prevención es difícil; sin embargo, el uso de equipo protector durante las actividades laborales puede contribuir a evitar este padecimiento.

Abstract Sporotrichosis is a mycosis caused by fungal species that are part of the Sporothrix schenckii complex. Epidemiological and molecular studies have found only six species of the Sporothrix schenckii complex that cause infections in humans. Some species of this complex have a relevant zoonotic potential for transmission to humans, and some others only have phytopathogenic properties. It is considered the most frequent form of subcutaneous mycosis in Mexico. The main mechanism of infection a wound with loss of continuity of the skin followed by contamination with the fungus Sporothrix spp. The main clinical manifestations are lymphangitic sporotrichosis, fixed skin manifestation and disseminated manifestation. The most useful laboratory procedures to confirm the diagnosis are the cultivation of specimens such as exudate and tissue, as well as the histopathological study. The parasitic manifestation is represented by yeasts in the tissue or exudates. The most useful medications for its treatment are potassium iodide and itraconazole. Prevention is difficult; however, the use of protective equipment during work activities can help prevent this condition.

Phytochemistry and fungitoxic potential of extract and fractions of pouteria ramiflora on fusarium solani f. sp. phaseoli / Fitoquímica e potencial fungitóxico de extrato e frações de Pouteria ramiflora SOBRE Fusarium solani f. sp. phaseoli

Among the fungus that attack the common bean crop there is Fusarium solani f.sp. phaseoli (Fsp), causing major losses. Taking into account its importance, the objective of this work was to determine the secondary metabolites class and the potential fungicide of the Pouteria ramiflora leaves on Fsp. The ethanol extract was dissolved in methanol/water and partitioned successively with hexane, dichloromethane, chloroform, ethyl acetate and butanol, subjected to the chemical profile. The solutions were prepared in concentrations of 800, 1200, 1600, 2000 and 2400 µ g/mL and poured into Petri dishes; then, 0.5 cm disc of diameter with spores and mycelia of Fsp was deposited. These dishes were incubated in temperature of 25 ± 2 °C and the evaluations, performed by measuring the colonies diameter (five replications) until reaching the dishes border (three days) with a completely randomized experimental design. Through the Mycelial Index Growth Speed (MIGS) data, analysis of variance was performed and when significant, applied the regression analysis. The results indicated that all fractions and the extract have the phenolic compounds and/or derivatives as one of the major constituents except the hydroethanolic fraction. The extract and its fractions decreased the Fsp MIGS, in the same proportion in which concentrations were increased; the greatest reduction occurred in the butanol fraction at the concentration of 2400 µg/mL, with growth close to zero, indicating its potential use for the Fsp control, probably due to the presence of anthraquinones.

Entre os fungos que acometem a cultura do feijão está Fusarium solani f.sp. phaseoli, causando perdas na produtividade. Levando-se em consideração sua importância, o objetivo deste trabalho foi determinar a classe de metabólitos secundários e o potencial fungicida das folhas de curriola (Pouteria ramiflora) sobre F. solani, em condições de laboratório. O extrato etanólico foi dissolvido em metanol/água e particionado sucessivamente com hexâno, diclorometano, clorofórmio, acetato de etila e butanol, submetidos ao perfil químico. As soluções foram preparadas nas concentrações de 800, 1200, 1600, 2000 e 2400 µ g/mL evertidas em placas de petri (10 mL); em seguida, foi depositado um disco de 0,5 cm de diâmetro com esporos e micélio de F. solani. As placas foram incubadas a temperatura de 25 ± 2 °C e as avaliações, realizadas por meio da medição do diâmetro das colônias (cinco repetições) até atingir a borda da placa (três dias), com delineamento experimental inteiramente casualizado. Através dos dados do Índice de Velocidade de Crescimento Micelial (IVCM), foi realizada a análise de variância e quando significativa, aplicada a análise de regressão. Os resultados indicaram que todos as frações e o extrato possuem os compostos fenólicos e/ou derivados como um dos constituintes majoritários, exceto a fração hidrometanólica. O extrato e suas frações diminuíram o IVCM de F. solani, à medida que se aumentava as concentrações; a maior redução ocorreu na fração butanolica para a concentração de 2400 µ g/mL, com crescimento próximo a zero, indicando seu potencial de uso para controle de F. solani, provavelmente devido a presença de antraquinonas em sua composição.

Entomopathogenic fungi and their potential for the management of Aedes aegypti (Diptera: Culicidae) in the Americas

Classical biological control has been used extensively for the management of exotic weeds and agricultural pests, but never for alien insect vectors of medical importance. This simple but elegant control strategy involves the introduction of coevolved natural enemies from the centre of origin of the target alien species. Aedes aegypti - the primary vector of the dengue, yellow fever and Zika flaviviruses - is just such an invasive alien in the Americas where it arrived accidentally from its West African home during the slave trade. Here, we introduce the concept of exploiting entomopathogenic fungi from Africa for the classical biological control of Ae. aegypti in the Americas. Fungal pathogens attacking arthropods are ubiquitous in tropical forests and are important components in the natural balance of arthropod populations. They can produce a range of specialised spore forms, as well as inducing a variety of bizarre behaviours in their hosts, in order to maximise infection. The fungal groups recorded as specialised pathogens of mosquito hosts worldwide are described and discussed. We opine that similar fungal pathogens will be found attacking and manipulating Ae. aegypti in African forests and that these could be employed for an economic, environmentally-safe and long-term solution to the flavivirus pandemics in the Americas.

Recent advances in understanding the fungal G-protein-coupled receptors

Abstract@#Transmission of extracellular signal across the plasma membrane into the cells of organisms is impossible without cell surface receptors. One of the most broadly studied receptor is the G-protein coupled receptor. This receptor is coupled with heterotrimeric G proteins with α, β and γ subunits that perceives external stimuli and transduces the signal into the cell for suitable physiological and biochemical responses. They have also been reported as potential receptors to sense light and fatty acids, but their exact mechanism remains unclear in fungi. Signalling and regulation via G proteins has been extensively studied in various models including pathogenic fungi. Fungal GPCRs are broadly required in fungal defence stimulation, vegetative growth, and pathogenicity mechanism. This review aims to highlight the research in fungal GPCRs including classification, physiological roles, mechanisms of action and signalling in GPCR function. Through fungal genome sequencing, mammalian GPCRs have been identified apart from fungal-specific GPCRs which adds another dimension to the classification. The deorphanisation of unclassified fungal GPCRs is necessary to further understand their role in fungi. While the mechanism of action has been well documented in mammals, the glucose and pheromone sensing are the only two well mapped systems in yeast. However, we are yet to ascertain if there are any additional mechanisms of signalling at work in fungi. Further we endeavour to compare and contrast between the eukaryotic GPCRs in various aspects of functionality. Through the information derived we hope to determine the gaps in knowledge and by so doing determine the future directions of GPCR research in fungi.

Antifungal potential of crude extracts of Trichoderma spp / Potencial antifúngico de extratos brutos de Trichoderma spp

Abstract Antibiosis is the mechanism by which certain microorganisms respond to the presence of others, secreting compounds or metabolites capable of inhibiting or impeding their development. The crude extract of Trichoderma contains a mixture of secondary compounds, which may show antibiotic effect, and has been used for the prospect of this fungus for biological control and other industrial purposes. Faced with the increasing demand of agriculture for ecologically compatible alternatives for the management of diseases, this work aimed to investigate the spectrum of action of Non-Volatile Metabolites (NVMs) of Trichoderma isolates against different plant pathogenic fungi. The antagonistic potential of NVMs was evaluated through the incorporation method of the filtered liquid extract in PDA medium. The assays showed that all the NVMs produced inhibited the fungus Sclerotinia sclerotiorum similarly. On the other hand, strains CEN1245 and CEN1274, both belonging to the species Trichoderma brevicompactum, showed broad spectrum against Sclerotium rolfsii, Colletotrichum gloesporioides, Verticillium dahliae, Fusarium oxysporum and Cylindrocladium sp. The present study describes isolates producing non-volatile metabolites with broad spectrum of antifungal action, as well as pathogen-specific. The Trichoderma spp. NVMs obtained from different soil samples cultivated with vegetables, cassava and maize were efficient in inhibiting plant pathogenic fungi belonging to other patossystems, such as forest or fruit, which could increase their potential application in biological control of plant diseases. In addition, these antagonistic fungi should be studied in greater depth for the identification of bioactive molecules of industrial interest or in commercial formulations of products for biological control of plant pathogens.

Resumo Antibiose é um mecanismo pelo qual certos microrganismos respondem à presença de outros, secretando compostos ou metabólitos capazes de inibir ou impedir o seu desenvolvimento. O extrato bruto de Trichoderma contém uma mistura de compostos secundários e tem sido utilizado na prospecção deste fungo para o controle biológico e demais fins industriais. Diante da crescente demanda da agricultura por alternativas ecologicamente compatíveis para o manejo de doenças, este trabalho teve como objetivo investigar o espectro de ação de Metabólitos Não Voláteis (MNVs), produzidos por isolados de Trichoderma, contra diferentes fungos fitopatogênicos. O potencial antagônico dos MNVs foi avaliado através do método de incorporação do extrato líquido filtrado em meio BDA. Os ensaios mostraram que todos os MNVs produzidos inibiram de forma semelhante o fungo Sclerotinia sclerotiorum. Por outro lado, os isolados CEN1245 e CEN1274, ambos Trichoderma brevicompactum, mostraram um amplo espectro de ação, atuando contra Sclerotium rolfsii, Colletotrichum gloesporioides, Verticillium dahliae, Fusarium oxysporum e Cylindrocladium sp. O presente estudo descreve isolados que produziram metabólitos não voláteis com amplo espectro de ação antifúngico, assim como patógeno-específico. Os MNVs de Trichoderma spp. obtidos de diferentes amostras de solo cultivadas com vegetais, mandioca e milho, foram eficientes na inibição de fungos fitopatogênicos pertencentes a outros patossistemas, como os de espécies florestais e frutíferas, o que poderia aumentar sua potencial aplicação no controle de doenças de plantas. Adicionalmente, estes fungos antagonistas devem ser mais bem estudados para identificação de moléculas bioativas de interesse industrial ou formulação de produtos para o controle biológico de patógenos de plantas.

Metabolism and antifungal activity of safrole, dillapiole, and derivatives against botryodiplodia theobromae and colletotrichum acutatum / Metabolismo y actividad antifúngica de safrol, dilapiol, y derivados contra botryodiplodia theobromae y colletotrichum acutatum

The direct in vitro fungitoxicity and metabolism of safrole and dillapiole (isolated from Piper auritum and Piper holtonii, respectively) by Botryodiplodia theobromae and Colletotrichum acutatum were investigated. Higher values of mycelial growth inhibition for both fungi were obtained for dillapiole, as compared with safrole. B. theobromae was able to metabolize both compounds to their respective vicinal diols, reaching 65 percent relative abundance during the biotransformation of dillapiole; while C. acutatum only transformed safrole to various metabolites with relative abundances under 5 percent. According to the low antifungal activity of the major metabolic products (< 5 percent for vicinal diols), a detoxification process was implied. Studies on the influence of some substituents in the aromatic ring of safrole and dillapiole on the antifungal activity against B. theobromae were also carried out. As result, the safrole nitrated derivative, 6-nitrosafrole, showed a fungitoxicity level similar to that displayed by the commercial fungicide Carbendazim® under the conditions used. In light of this, safrole and dillapiole could be suggested as feasible structural templates for developing new antifungal agents.

Se investigó la fungitoxicidad directa in vitro y el metabolismo de safrol y dilapiol (obtenidos desde Piper auritum and Piper holtonii, respectivamente) por Botryodiplodia theobromae y Colletotrichum acutatum. Los valores mayores de inhibición del crecimiento micelial de ambos hongos se obtuvieron para dilapiol, en comparación con safrol. B. theobromae metabolizó ambos compuestos a sus respectivos dioles vecinales, alcanzando abundancias relativas del 65 por ciento durante la biotransformación del dilapiol; mientras que C. acutatum solo transformó safrol en varios metabolitos con abundancias relativas menores al 5 por ciento. De acuerdo con la baja actividad antifúngica de los productos metabólicos mayoritarios (< 5 por ciento para los dioles vecinales), se sugiere un proceso de desintoxicación. Adicionalmente, se evaluó la influencia de algunos sustituyentes en el anillo aromático de safrol y dilapiol sobre la actividad antifúngica contra B. theobromae. Como resultado, el derivado nitrado del safrol, el 6–nitro safrol, presentó un nivel de fungitoxicidad similar al exhibido por el fungicida comercial Carbendazim® bajo las condiciones usadas. A la luz de lo anterior, safrol y dilapiol podrían ser sugeridos como plantillas estructurales adecuadas para el desarrollo de nuevos agentes antifúngicos.

Human Oral Lower Palate Isolates and their Antagonistic Effect on Phytopathogenic Fungi Pathogens.

Production of certain substances that inhibit other microorganisms in the microbial environment of the oral cavity could serve as aggressive by product that may eliminate competitors and pathogens. Hence, this study was carried out to isolate and identify microorganisms from the oral cavity (lower palate of the mouth) and challenge these organisms with some selected strains of pathogenic fungi. The samples were aseptically collected using sterile swab sticks and transported to the Microbiology laboratory, for morphological, biochemical, and antagonistic tests in vitro. Nutrient Agar (NA) and MacConkey Agar (MCA) were used for the isolation of bacteria, Potato Dextrose Agar (PDA) for fungi and Malt Extract Agar (MEA) for antagonistic test. The isolated oral bacteria were Bacillus sp., Lactobacillus sp., Staphylococcus aureus and Streptococcus salivarius. Antagonistic effect was measured by zone of inhibition between the fungal plug and bacterial streak. The inhibition varied with different fungi. Results revealed that there were considerable variations in inhibitory activity. The zone of inhibition was more apparent in Bacillus sp. against Fusarium oxysporum (57.2±0.1: P = .05). There was no inhibition/antagonistic activity with S. aureus and S. salivarius against all the selected fungi (0.0 - 0.1±0.1: P = .05). Antibiotics susceptibility test was carried out on the isolated oral microorganisms. The highest zone of inhibition was found in cotrimoxazole against Lactobacillus (23 mm), while the lowest zone of inhibition was found in ciprofloxacin against Lactobacillus sp. S. salivarius exhibited resistance to all antibiotics (0-12 mm). Bacillus sp., Lactobacillus sp. and S. aureus showed susceptibility to gentamycin. None of the bacterial isolates showed susceptibility to perfloxacin and streptomycin. Hence, gentamycin could be used to treat oral/dental infections caused by these bacterial isolates. Result from preliminary antagonistic studies showed that Bacillus sp. and Lactobacillus sp. could prove to be potent against all selected pathogenic fungi. Therefore, the metabolites produced by these isolates could be further studied for use as biocontrol agents of diseases caused by these fungi.

Influência de diferentes extratos aquosos de plantas medicinais no desenvolvimento de Colletotrichum gloeosporioides e de Fusarium moniliforme / Influence of different aqueous extracts of medicinal plants in the development of Colletotrichum gloeosporioides and Fusarium moniliforme

O objetivo deste trabalho foi avaliar a influência dos extratos aquosos das plantas medicinais alecrim, alho, cravo-da-índia, sálvia, capim-limão, orégano ou pimenta-do-reino no desenvolvimento in vitro de Colletotrichum gloeosporioides e de Fusarium moniliforme. Os extratos foram obtidos pela infusão de 60 g de cada planta medicinal em 200 mL de água fervente. Cada extrato aquoso foi fracionado em concentrações de 0, 5, 10 e 20% (p:v) e incorporado ao meio de cultivo BDA (batata-dextrose-ágar) antes da esterilização em autoclave. Posteriormente, um disco de 8 mm de diâmetro de micélio fúngico de cada patógeno foi transferido para o centro de placas de Petri. Após 24, 48 e 96 horas de incubação em câmara de crescimento a 22 ± 2 ºC e fotoperíodo de 12 horas avaliou-se o crescimento micelial de F. moniliforme e de C. gloesporioides. No último período de incubação, também se quantificou o número de conídios de cada fungo. Para o teste de germinação adicionou-se nas cavidades de placas de teste Elisa, uma alíquota de 40 µL de cada extrato nas concentrações de 0, 5, 10 e 20%, e outra alíquota, da suspensão de conídios de cada patógeno. Após 24 horas a 22 ± 2 ºC, no escuro, a germinação dos conídios foi paralisada com a adição de 20 µL de lactofenol; avaliou-se então a porcentagem de germinação de conídios. Os experimentos foram conduzidos no delineamento inteiramente casualizado em esquema fatorial 7 x 4 (extratos de plantas medicinais x concentrações) com quatro repetições. Para ambos os patógenos o extrato aquoso de alho e cravo-da-índia apresentaram maior ou total inibição do crescimento micelial, respectivamente, quando comparado com os demais extratos. Para C. gloeosporioides, o extrato de cravo-da-índia apresentou menor número de conídios em todas as concentrações testadas, e para o extrato de alho a 20%, também não foi observada a germinação de conídios. O extrato de alho foi eficiente em reduzir o número e a germinação dos conídios de F. moniliforme na concentração de 20%. Os extratos de alecrim, cravo-da-índia, orégano e pimenta-do-reino, nas maiores concentrações, tiveram efeito positivo na redução da produção de conídios deste mesmo fungo.

The objective of this study was to evaluate the influence of aqueous extracts of the medicinal plants rosemary, garlic, clove, sage, lemongrass, oregano and black pepper in the in vitro development of Colletotrichum gloeosporioides and Fusarium moniliforme. The extracts were obtained by infusing 60 g of each medicinal plant in 200 mL of boiling water. Each aqueous extract was fractionated in the concentrations of 0, 5, 10 and 20% (w:v) and incorporated into the PDA (potato dextrose agar) culture medium before sterilization by autoclaving. Later, an 8 mm diameter disc of each pathogen mycelium was transferred to the center of the Petri dishes. After 24, 48 and 96 hours of incubation in a growth chamber at 22 ± 2 ºC and a photoperiod of 12 hours, we evaluated the mycelial growth of F. moniliforme, and C. gloesporioides. In the last period of incubation, we quantified the production of conidia of each fungus. For the germination test, we added, into the wells of an ELISA test plates, a 40 µL aliquot of each extract at the concentrations of 0, 5, 10 and 20% and another aliquot of a suspension of conidia of each pathogen. After 24 hours at 22 ± 2 ºC in the dark, the germination of the fungi was stopped with the addition of 20 µL of lactophenol. Then, we evaluated the germination of conidia. The experiments followed a completely randomized 7 x 4 factorial design (medicinal plants x concentrations) with four replications. For both pathogens, the aqueous extract of garlic and clove showed a greater or total inhibition of the mycelial growth, when compared to the other extracts. For the C. gloeosporioides, the clove extract showed a lower number of conidia at all concentrations tested, and the garlic extract at 20% showed not conidial germination. The garlic extract was efficient to reduce the conidial number and germination of F. moniliforme at 20%. Extracts of rosemary, clove, oregano and black pepper, in the highest concentrations, had positive effect in reducing the production of spores of the same fungus.

A New Record of Pseudallescheria boydii Isolated from Crop Field Soil in Korea

Pseudallescheria boydii KNU13-2 was isolated from crop field soil and identified by analysis of internal transcribed spacer regions of rDNA and morphological characteristics. In the literature, P. boydii has been mentioned as a human pathogen. This is the first record of P. boydii isolated from crop field soil in Korea.

Identification of Fusarium solani as the prevalent strain in fungal keratitis / 中华微生物学和免疫学杂志

Objective To investigate the etiological and epidemiological characteristics of fungal keratitis in Jilin province of China and to establish a rapid and specific method for molecular identification of the prevalent fungal pathogens.Methods Corneal scrapings were collected from 225 patients with suspected fungal keratitis.Fungal strains were isolated and identified based on their morphology and physiological characteristics.The epidemiological characteristics of all isolated strains causing fungal keratitis were statistically analyzed.Species-specific primers of Fusarium solani (F.solani) were designed and used together with the universal fungal primers to establish a multiplex PCR assay for identification of F.solani in corneal scrapings.Results 156 out of 225 patients (69.3％) were diagnosed as fungal keratitis by fungal culture followed by the examination of morphological and physiological characteristics.A total of 168 pathogenic fungi strains were isolated,most of which were Fasarium spp.(49.4％),followed by Aspergillus spp.(17.9％) and Candida spp.(14.3％).F.solani was the predominant pathogen accounting for 34.5％ in all patients.Most of the patients (87.5％) were farmer and male patients (57.1％) accounted for the majority of 156 patients as well.Corneal trauma (38.5％) was considered as the main predisposing factor.The established multiplex PCR could specifically amplify a 300 bp nucleotide fragment of F.solani.It could be used for a rapid identification of F.solani in corneal scrapings.Conclusion Fusarium genus,particularly the species of F.solani,was the predominant pathogen for fungal keratitis in Jilin province of China.Corneal trauma was the most important predisposing factor.The established multiplex PCR could identify fungal infection from corneal scrapings rapidly and specifically.These findings are very important for the early diagnosis and treatment of fungal keratitis.

Conservación de cultivos de hongos de importancia médica en agua destilada / Preservation of fungal cultures of medical importance in distilled water

Introducción: en la colección de cultivos de hongos patógenos del Instituto de Medicina Tropical Pedro Kourí, como centro de referencia nacional, se conservan los agentes causales de las principales micosis humanas, con fines de diagnóstico, investigaciones y enseñanza de la microbiología médica. La conservación de cultivos fúngicos en agua destilada estéril o método de Castellani ha sido avalada como un método que garantiza porcentajes elevados de viabilidad, pureza y estabilidad de las cepas; esto unido a su bajo costo y sencillez, la convierte en una alternativa ventajosa para el mantenimiento de los microorganismos en muchos laboratorios. Objetivo: mostrar los resultados en la preservación en agua destilada estéril de las principales especies fúngicas que integran esta colección. Métodos: se evaluó la viabilidad, pureza y estabilidad de las principales características morfológicas y fisiológicas de 240 cepas de diferentes especies fúngicas pertenecientes a la colección, conservadas en agua destilada estéril. Resultados: de los cultivos, 80 por ciento se conservó en estado viable y sin contaminaciones. Los mejores resultados se obtuvieron en la preservación de los hongos productores de abundantes conidios (97 por ciento de recuperación) y las levaduras (83 por ciento), mientras que con los dermatofitos y hongos dimórficos fue de 69 y 68 por ciento, respectivamente. En 17 géneros, la recuperación de cepas viables fue superior a 60 por ciento, mientras que en 8 resultó de 100 por ciento. El tiempo de conservación fue de 15 a 20 años. Se implementó una base de datos en formato digital de la colección sobre plataforma web. Conclusiones: el método de Castellani es un método de elección para la conservación de cultivos fúngicos en laboratorios de recursos limitados

Introduction: causal agents of the main human myicoses have been preserved in the culture collection of pathogenic fungi at Pedro Kourí Tropical Medicine Institute, a national reference center, with the purpose of using them for medical microbiology diagnoses, research and teaching. Preservation of fungal cultures in sterile distilled water, or Castellani's method, has been endorsed as a method ensuring high rates of strain viability, purity and stability, low costs and great simplicity. It is therefore an advantageous alternative for the maintenance of microorganisms in many laboratories. Objective: present the results obtained from the preservation in sterile distilled water of the main fungal species included in the collection. Methods: an evaluation was conducted of the viability, purity and stability of the main morphological and physiological characteristics of 240 strains of different fungal species from the collection, which had been preserved in sterile distilled water. Results: 80 percent of the cultures had retained their viable status without any contamination. The best results corresponded to the preservation of fungi producing abundant conidia (97 percent recovery) and yeasts (83 percent), followed by dermatophytes (69 percent) and dimorphic fungi (68 percent). In 8 genera, recovery of viable strains was 100 percent, and in 17 it was above 60 percent. Preservation time was 15-20 years. A web-based digital database was created for the collection. Conclusions: Castellani's is the method of choice for the preservation of fungal cultures in resource-limited laboratories

Incidência e viabilidade de sementes crioulas de milho naturalmente infestadas com fungos em pré e pós-armazenamento / Incidence and viability of creole seeds of corn naturally infested with fungi in pre-and post-storage

Objetivou-se com este trabalho avaliar a qualidade sanitária e fisiológica de quatorze variedades de sementes de milho crioulas em pré e pós-armazenamento em embalagens de polietileno tereftalato (PET). Houve efeito das variedades e das épocas de avaliações sobre a incidência de fungos e germinação. Dentre a micobiota observada, Fusarium moniliforme (88%), Penicillium spp. (6,9%) e Aspergillus spp. (2,1%) tiveram a maior porcentagem de incidência. Após o armazenamento, houve decréscimo de F. moniliforme (69%) e aumento de Penicillium spp. (35%) e Aspergillus spp. (22%). A incidência desses fungos não comprometeu a qualidade fisiológica das sementes, que apresentaram elevadas porcentagens de vigor e germinação.

The objective of this study was to evaluate the sanitary and physiological quality of fourteen varieties of creole corn seeds in pre-and post-storage in packaging of polyethylene terephthalate (PET). Among the mycobiota observed Fusarium moniliforme (88%), Penicillium spp. (6,9%) and Aspergillus spp. (2,1%) had the highest incidence. After storage there was a slight decrease in the percentage of F. moniliforme (69%) and a increase of Penicillium spp. (35%) and Aspergillus spp. (22%). The incidence of these fungi did not compromise the physiological quality of seeds that showed high percentages of vigor and germination.

Anti-dermatophytic activity of some traditionally used medicinal plants of North Karnataka Region.

To find the potentiality of the following medicinal plants for their anti dermatophytic property. Agar and broth dilution methods, Leaf extracts of Cassia occidentalis, Cassia tora, Lawsonia inermis, Xanthium strumarium and Caesalpinia bonducella with various solvents viz., methanol, alcohol, acetone, acetone, petroleum ether, chloroform and ethyl acetate were evaluated for antidermatophytic activity against human pathogenic fungi. In agar and broth dilution methods, all extracts showed antifungal activity even at minimum inhibitory concentrations (MICs) and minimum fungicidal concentrations (MFCs). The most biologically active extract was found to be ethyl acetate leaf extract of C. bonducella, which inhibited all test fungi with time and dose dependent activity. This plant extract retarded the growth of all the organisms at 10000 μg/ml up to 30 days and beyond. It is further suggested for detail investigation of active constituents of the plants used in the present.