Malaria infection modulates effects of genotoxic chemicals in the mouse bone-marrow micronucleus test.

Malaria has been reported to modulate the activity of cytochrome-P450 enzymes (CYP). Since CYPs are involved both in the activation and detoxication of xenobiotics, we investigated whether malaria would modify the effects of chemical carcinogens in the bone-marrow micronucleus assay. Female C57BL6 mice were infected with Plasmodium berghei (ANKA) and treated (ip route) with cyclophosphamide (CPA, 25 mg/kg body weight), 7,12-dimethylbenz[a]anthracene (DMBA, 50mg/kg body weight) or ethyl methanesulfonate (EMS, 150 mg/kg body weight), on post-infection days 9-12 when parasitemia was > or =9% of RBC. Controls were age-paired non-infected mice. Bone marrows were sampled at 24 and 48 h (CPA), 24 h (EMS) or 48 h (DMBA) after treatment. The background incidence of polychromatic erythrocytes with micronuclei (MN-PCE) in malaria-infected mice was approximately twofold the background incidence in non-infected controls. Effects of indirect clastogens (CPA and DMBA) in the micronucleus assay were attenuated while the effect of EMS, a direct clastogen, was enhanced by infection. In a separate experiment, malaria was shown to decrease activities of ethoxy-(EROD, a marker for CYP1A) and benzyloxy-(BROD, CYP2B) resorufin-O-dealkylases in liver microsomes. The foregoing findings are consistent with the hypothesis that malaria-caused attenuation of genotoxicity arose from a down modulation of CYP isoforms that convert CPA (CYP2B) and DMBA (CYP1A) into their active metabolites.

Sexual reproduction in subcultures of Absidia blakesleeana after years of preservation under mineral oil.

Two subcultures of Absidia blakesleeana IOC No. 2425 (-) mating type strain preserved in 1959 and 1981 on a thick layer of potato dextrose agar (PDA) medium under sterile mineral oil and maintained at room temperature in the Fungal Cultural Collection of Institute Oswaldo Cruz--IOC--were paired with the defined Absidia blakesleeana URM-UFP No. 2076 (+) mating type strain. Portions of the line where mycelia of the two strains met were observed under light microscopy. Zygospores belonging to Subgenus Mycocladus were observed. The results demonstrated conservation and re-establishment of the physiological and genetic metabolic processes of two subcultures preserved under mineral oil.

Morphological observations on Absidia corymbifera and Absidia blakesleeana strains preserved under mineral oil.

Macro- and micromorphology of 30 living subcultures of Absidia corymbifera (10 strains plus three strains of Absidia ramosa) and Absidia blakesleeana (two strains) preserved under mineral oil at room temperature for periods ranging from 3 to 44 years in The Fungal Culture Collection of Instituto Oswaldo Cruz (IOC) were observed and described by permanent mycological preparations mounted in a glycerol 10% and/or Amann lactophenol solution. Vegetative and asexual reproductive structures are illustrated by drawings made with the aid of a camera-lucida. The study showed that the period of maintenance under mineral oil and the stress which took place during the period of storage did not affect the vegetative and asexual reproductive morphology of the Absidia strains and species studied here.

[What is the source of mycelial fungi in expressed human milk?]. / Qual seria a fonte de fungos miceliais encontrados em leite humano ordenhado?

The authors characterized the genera of mycelial fungi found in samples of expressed human milk received through home collection by the Human Milk Bank of the Instituto Fernandes Figueira in Rio de Janeiro. A total of 821 samples of expressed human milk were taken randomly from bottles collected at home by the milk donors themselves and were investigated for molds, yeasts, and mesophilic microorganisms. The analyses showed the occurrence of molds and yeasts in 43 (5.2%) of the samples, with counts reaching 103CFU/ml. Some 48 strains of mycelial fungi were identified by standard laboratory techniques, including: Aspergillus Niger group (6.3%), Aspergillus sp. (4.2%), Paecilomyces sp. (12.6%), Penicillium sp. (60.4%), Rhizopus sp. (2.0%), and Syncephalastrum sp. (14.5%). The authors discuss the importance of donor hands' asepsis prior to collecting human milk.

Qual seria a fonte de fungos miceliais encontrados em leite humano ordenhado? / What is the source of mycelial fungi in expressed human milk?

The authors characterized the genera of mycelial fungi found in samples of expressed human milk received through home collection by the Human Milk Bank of the Instituto Fernandes Figueira in Rio de Janeiro. A total of 821 samples of expressed human milk were taken randomly from bottles collected at home by the milk donors themselves and were investigated for molds, yeasts, and mesophilic microorganisms. The analyses showed the occurrence of molds and yeasts in 43 (5.2) of the samples, with counts reaching 103CFU/ml. Some 48 strains of mycelial fungi were identified by standard laboratory techniques, including: Aspergillus Niger group (6.3), Aspergillus sp. (4.2), Paecilomyces sp. (12.6), Penicillium sp. (60.4), Rhizopus sp. (2.0), and Syncephalastrum sp. (14.5). The authors discuss the importance of donor hands' asepsis prior to collecting human milk.

Contaminação do leite humano ordenhado por fungos miceliais / Contamination of expressed human milk by mycelial fungi

Objetivo: caracterizar os gêneros de fungos miceliais encontra- dos em amostras de leite humano ordenhado, recebidas a partir de coleta domiciliar, pelo Banco de Leite Humano do Instituto Fernandes Figueira. Métodos: foram estudadas 821 amostras de leite humano ordenhado, obtidas ao acaso, a partir de frascos coletados nos domicílios pelas próprias doadoras. Foram realizadas pesquisas de bolores e leveduras e de microorganismos mesófilos. A partir das amostras de leite humano ordenhado, foram isoladas 48 cepas de fungos miceliais, que foram identificadas por técnicas-padrão de laboratório. Resultados: as análises microbiológicas revelaram a ocorrência de bolores e leveduras em 43 (5,2por cento ) das amostras, com contagens atingindo a ordem de 103 UFC/ml, e foram identificados os microor- ganismos Aspergillus Grupo Niger (6,3por cento), Aspergillus sp. (4,2por cento), Paecilomyces sp. (12,6por cento), Penicillium sp. (60,4por cento), Rhizopus sp. (2,0por cento) e Syncephalastrum sp. (14,5por cento). Quatro amostras apresentavam mais de um tipo de fungo micelial. Conclusão: a presença de bolores e leveduras no leite humano ordenhado nos domicílios sugere que as condições higiênicas do local de coleta podem contaminar o leite. Portanto, quando se trata do repasse do produto cru para bebês prematuros hospitalizados, é fundamental observar as condições de coleta, estocagem e transporte para evitar a presença e as conseqüências da multiplicação de contaminantes

[Contamination of expressed human milk by mycelial fungi]. / Contaminação do leite humano ordenhado por fungos miceliais.

OBJECTIVE: To characterize the genera of mycelial fungi detected in expressed human milk received at the human milk bank of Instituto Fernandes Figueira after home collection. METHODS: We studied 821 expressed human milk samples randomly obtained from flasks filled by the donors at home. The possible presence of molds, yeasts and mesophilic microorganisms was investigated. A total of 48 strains of mycelial fungi were isolated from the human milk bank samples and identified through standard laboratory techniques. RESULTS: Microbiological analysis revealed the occurrence of molds and yeasts in 43 samples (5.2%), with counts reaching 10(3) CFU/ml. The following microorganisms were identified: Aspergillus niger group (6.3%), Aspergillus sp. (4.2%), Paecilomyces sp. (12.6%), Penicillium sp. (60.4%), Rhizopus sp. (2.0%), and Syncephalastrum sp. (14.5%). Four samples showed the presence of more than one mycelial fungus type. CONCLUSIONS: The presence of molds and yeasts in human milk manually expressed at home suggests that the hygiene conditions of the collection site may contaminate milk. Thus, when hospitalized premature babies receive the raw product, it is very important to observe the collection, storage and transport conditions in order to avoid the presence and consequences of contaminants increase.