Bacillus subtilis induces morphological changes in Fonsecaea pedrosoi in vitro resulting in more resistant fungal forms in vivo

Interactions among microorganisms may be the cause of morphological modifications, particularly in fungal cells. The aim of this work was to examine the changes that occur in cells of the fungus Fonsecaea pedrosoi after in vitro co-culturing with Bacillus subtilis and to explore the results of this interaction in vivo in an experimental murine infection. B. subtilis strain was inoculated into a 15-day pure culture of F. pedrosoi. In vitro, after 48 hours of co-culturing, the fungal cells were roundish. The secretion of fungal dark pigments and production of terminal chlamydoconidia were observed in hyphae after one week. In the in vivo study, two animal groups of 30 BALB/c mice each were employed. One group was inoculated intraperitoneally with hyphal fragments from the co-culture of bacteria and fungi; the other group was infected only with F. pedrosoi hyphae. After seven days of infection, both animal groups developed neutrophilic abscesses. Phagocytosis of bacilli by macrophages occurred at three days. At later periods, generally after 25 days, only roundish cells similar to sclerotic bodies remained in the tissues while hyphae were eliminated by 15 to 20 days. These fungal forms originated mainly from terminal chlamydoconidia. The co-culturing between bacteria and fungi may constitute a mechanism to rapidly obtain resistant fungal forms for host defenses, especially for chromoblastomycosis (CBM) experimental infections.Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)FAPEMATFederal University of Mato Grosso Department of Basic Health SciencesFederal University of São Paulo Department of Microbiology, Immunology and ParasitologyUNIFESP, Department of Microbiology, Immunology and ParasitologyFAPEMAT: 002.138/2007SciEL

Ocorrência de microsporum gypseum no tegumento de bovino São (São Jose do rio preto, São Paulo, Brasil)

Se describe por primera vez, en Brasil, la presencia de Microsporum gypseum en piel de bovino sano. Se llama la atención sobre la importancia de esos animales como reservório de M. gypseum

Efeito tópico de iodo-povidona 0,5% comparado com natamicina 5% em ceratites fúngicas causadas por Fusarium solani em um modelo animal de coelhos: estudo piloto

PURPOSE: To evaluate the efficacy of topical administration of 0.5% povidone-iodine in experimental Fusarium solani keratitis in rabbits. METHODS: Fungal keratitis caused by Fusarium solani was induced in the right eye of 24 New Zealand rabbits. The rabbits were randomly divided into 3 different treatment groups: Group I (povidone-iodine) - treated with topical 0.5% povidone-iodine; Group II (natamycin) - treated with topical 5% natamycin; and Group III (control) - treated with topical saline solution. In all groups the rabbits were treated for three days and then sacrificed. The corneas were excised, macerated and immersed in 10 mL BHI. Culture samples were plated daily on Sabouraud's agar for 7 days, and the number of colony-forming units (CFU) was counted. The rabbits were clinically evaluated during the treatment period. RESULTS: The povidone-iodine and natamycin groups demonstrated better efficacy than the control group based on the number of rabbits with no colonies growing. However, there were no statistically significant differences between the three groups when the number of CFU was analyzed (p>0.05). CONCLUSIONS: Our study demonstrates important methodological considerations in the use of in vivo animal models for the testing of antifungal agents. Using this sample size and methodology of counting CFU, topical 0.5% povidone-iodine demonstrated no benefit in the treatment of experimental Fusarium solani when compared with topical 5% natamycin.OBJETIVO: Avaliar a eficácia do uso tópico de iodo-povidona 0,5% em ceratite experimental por Fusarium solani em coelhos. MÉTODOS: Ceratite fúngica por Fusarium solani foi induzida no olho direito de 24 coelhos da raça New Zealand. Os coelhos foram divididos aleatoriamente em 3 diferentes grupos de tratamento: Grupo I (iodo-povidona) - tratados com iodo-povidona 0,5%; Grupo II (natamicina) - tratados com natamicina 5%; Grupo III (controle) - tratados com solução salina. Os coelhos dos 3 grupos foram tratados por 3 dias e sacrificados em seguida. As córneas foram removidas cirurgicamente, maceradas e incubadas em meio BHI. Semeou-se culturas em placas de ágar Sabouraud, diariamente, durante 7 dias, e contou-se o número de unidades formadoras de colônias (UFC). Os coelhos foram avaliados clinicamente durante o período de tratamento. RESULTADOS: Os grupos iodo-povidona e natamicina demonstraram melhor eficácia do que o grupo controle considerando-se o número de coelhos nos quais não houve crescimento de colônias. Entretanto, não houve diferença estatística significante entre os 3 grupos quando se analizou o número de UFC (p>0,05). CONCLUSÃO: Este estudo demonstrou considerações metodológicas importantes na utilização de modelos animais para o teste de agentes antifúngicos. Usando a metodologia de contar UFC e com este tamanho amostral, administração tópica de iodo-povidona 0,5% não demonstrou benefício do tratamento de ceratite fúngica experimental causada por Fusarium solani quando comparado com a administração tópica de natamicina 5%.Universidade Federal de São Paulo (UNIFESP)University of CaliforniaUNIFESPSciEL

Prototheca stagnora, an encapsulated organism

ESCOLA PAULISTA MED,DEPT MICROBIOL IMUNOL & PARASITOL,SAO PAULO 04023,SP,BRAZILESCOLA PAULISTA MED,DEPT MICROBIOL IMUNOL & PARASITOL,SAO PAULO 04023,SP,BRAZILWeb of Scienc

Use of morpho-physiological characteristics for differentiation of the species of Prototheca

ESCOLA PAULISTA MED,DEPT MICROBIOL IMUNOL & PARASITOL,SAO PAULO 04023,SP,BRAZILESCOLA PAULISTA MED,DEPT MICROBIOL IMUNOL & PARASITOL,SAO PAULO 04023,SP,BRAZILWeb of Scienc

Microsporum Gypseum Infection in a Gray Wolf (Canis Lupus) and a Camel (Camelus Bactrianus) in a Zoological Garden

CONSELHO NACL PESQUISAS,BR-22290 RIO DE JANEIRO,RJ,BRAZILINST ZOOTECN,NOVA ODESSA,SP,BRAZILWeb of Scienc