Comparison of primers for RAPD-PCR from environmental isolates of Cryptococcus neoformans, Cryptococcus albidus and Cryptococcus laurentii complex

Various organisms have been characterized by molecular methods, including fungi of the genus Cryptococcus. The purposes of this study were: to determine the discriminatory potential of the RAPD (Random Amplified Polymorphic DNA) primers, the pattern of similarity of the Cryptococcus species, and discuss their useful application in epidemiological studies. We analyzed 10 isolates of each specie/group: C. albidus, C. laurentii complex, C. neoformans var. grubii, all from environmental source, and two ATCC strains, C. neoformans var. grubii ATCC 90112, and C. neoformans var. neoformans ATCC 28957 by RAPD-PCR using the primers CAV1, CAV2, ZAP19, ZAP20, OPB11 and SEQ6. The primers showed a good discriminatory power, revealing important differences between them and between species; the SEQ6 primer discriminated a larger number of isolates of three species. Isolates of C. laurentii showed greater genetic diversity than other species revealed by all six primers. Isolates of C. neoformans were more homogeneous. Only the primer CAV2 showed no amplification of DNA bands for C. albidus. It was concluded that the use of limited number of carefully selected primers allowed the discrimination of different isolates, and some primers (e.g., CAV2 for C. albidus) may not to be applied to some species.

Metodologia científica na formação do médico veterinário: experiênciateórico-prática na análise de fontes urbanas de Cryptococcus spp – Jaboticabal, SP – Brasil / Scientific methodology in veterinary medical training: a theoretical andpractical experience in the analysis of urban sources of Cryptococcus spp in Jaboticabal, SP – Brazil / Metodología científica en la formación médica veterinaria: la experienciateórica y práctica en el análisis de fuentes urbanas de Cryptococcus spp de Jaboticabal, SP – Brasil

O artigo apresenta resultados de um projeto de ensino de Metodologia Científica em Curso de Graduação deMedicina Veterinária. Pautou-se por uma reflexão crítica da necessidade de interação entre as dimensões teórica eprática na formação do profissional e realizou-se análise de fontes urbanas de Cryptococcus spp em fezes de pombos(Columbia livia), evidenciando a importância de orientação à população sobre os riscos de contágio, caracterizando a patogenicidade dos agentes identificados em dez ambientes públicos.

This article presents the results of an educational project for the Scientific Methodology degree course for veterinary medicine. The project was guided by the critical reflection on the necessity for the interaction between the theoretical and practical dimensions of professional training. An analysis was performed of urban sources of Cryptococcus spp in excrements of pigeons (Columbia livia), indicating the need for education of the population about the risks factors of transmission and characterizing the pathogenicity of the identified agents in ten public places.

El artículo presenta los resultados de un proyecto de enseñanza de Metodología Científica en el Curso de Graduaciónde Medicina Veterinaria. Se marcó por una reflexión crítica da la necesidad de la interacción entre las dimensionesteóricas y prácticas en la formación del profesional y se realizó un análisis de fuentes urbanas de Cryptococcus sppen excremento de palomas (Columbia livia), mostrando la importancia de la orientación a la población sobre losriesgos del contagio, caracterizando la patogenicidad de los agentes identificados en diez ambientes públicos.

In vitro evaluation of nematophagous fungi patogenicity against nematode of domestic animals / Avaliação in vitro da patogenicidade de fungos predadores de nematóides parasitos de animais domésticos

Biological control is a promising alternative for the control of pre-parasitic stages through the action of nematophagous fungis. The present study evaluated in vitro the patogenicity of both Arthrobotrys musiformis and A. conoides fungi on infective larvae (or L3 state larvae) of Haemonchus contortus, L3 larvae of Ancylostoma spp. And larvated eggs of the nematode Ascaridia galli. Nine groups were formed: six treated groups (G1A and G2A: L3 of H. contortus; G1B and G2B: L3 of Ancylostoma spp.; G1C and G2C: larvated eggs of A. galli, being that G1 with A. musiformis and G2 with A. conoides) and three untreated groups (G3A, G3B and G3C: larvae of H. contortus, Ancylostoma spp. And eggs of A. galli, respectively, without fungi). Each treatment had ten repetitions (ten Petri dishes with an average of 120 larvae of H. contortus and 200 larvae of Ancylostoma spp. and, approximately, 100 larvated A. galli eggs). The results showed A. musiformis plundered 66% and 94% of Ancylostoma spp. L3 larvae and H. contortus L3 larvae, respectively. While that A. conoides plundered 51,7% and 89,4% at the same larvae. The nematophagous fungi evaluated have not presented any predation type on A. galli larvated eggs. Afterwards, both are promising fungi as to their use for biological control of parasitic helminths of animal hosts.

O controle biológico é uma alternativa promissora no controle dos estágios pré-parasitários de helmintos, por meio da ação de fungos nematófagos. Com este propósito, o presente estudo avaliou in vitro a patogenicidade dos fungos Arthrobotrys musiformis e A. conoides sobre larvas infectantes de Haemonchus contortus, Ancylostoma spp. e ovos larvados de Ascaridia galli. Foram utilizados nove grupos: seis tratamentos (G1A e G2A: L3 de H. contortus; G1B e G2B: L3 de Ancylostoma spp.; G1C e G2C: ovos larvados de A. galli, com A. musiformis (G1) e A. conoides (G2), respectivamente) e três testemunhos (G3A, G3B e G3C: larvas de H. contortus, Ancylostoma spp. e ovos de A. galli, respectivamente, na ausência do fungo). Cada tratamento constou de dez repetições (placas de Petri, de 90mm de diâmetro, com média de 120 larvas de H. contortus, 200 larvas de Ancylostoma spp. e média de 100 ovos de A. galli). Os resultados demostraram que A. musiformis predou 66,33% e 94,44% das larvas infectantes de Ancylostoma spp. e H. contortus, respectivamente. Enquanto que A. conoides predou 51,76% e 89,39% das mesmas larvas. Os fungos nematófagos avaliados não apresentaram predação sobre ovos larvados de A. galli. Portanto, ambos os fungos mostraram-se promissores quanto a sua utilização no biocontrole desses helmintos parasitos de animais domésticos.